126175Sfenner/* 275107Sfenner * pcap-linux.c: Packet capture interface to the Linux kernel 326175Sfenner * 475107Sfenner * Copyright (c) 2000 Torsten Landschoff <torsten@debian.org> 575107Sfenner * Sebastian Krahmer <krahmer@cs.uni-potsdam.de> 6127664Sbms * 775107Sfenner * License: BSD 8127664Sbms * 975107Sfenner * Redistribution and use in source and binary forms, with or without 1075107Sfenner * modification, are permitted provided that the following conditions 1175107Sfenner * are met: 12127664Sbms * 1375107Sfenner * 1. Redistributions of source code must retain the above copyright 1475107Sfenner * notice, this list of conditions and the following disclaimer. 1575107Sfenner * 2. Redistributions in binary form must reproduce the above copyright 1675107Sfenner * notice, this list of conditions and the following disclaimer in 1775107Sfenner * the documentation and/or other materials provided with the 1875107Sfenner * distribution. 1975107Sfenner * 3. The names of the authors may not be used to endorse or promote 2075107Sfenner * products derived from this software without specific prior 2175107Sfenner * written permission. 22127664Sbms * 2375107Sfenner * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 2475107Sfenner * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 2575107Sfenner * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 26190225Srpaulo * 27190225Srpaulo * Modifications: Added PACKET_MMAP support 28190225Srpaulo * Paolo Abeni <paolo.abeni@email.it> 29190225Srpaulo * 30190225Srpaulo * based on previous works of: 31190225Srpaulo * Simon Patarin <patarin@cs.unibo.it> 32190225Srpaulo * Phil Wood <cpw@lanl.gov> 33214518Srpaulo * 34214518Srpaulo * Monitor-mode support for mac80211 includes code taken from the iw 35214518Srpaulo * command; the copyright notice for that code is 36214518Srpaulo * 37214518Srpaulo * Copyright (c) 2007, 2008 Johannes Berg 38214518Srpaulo * Copyright (c) 2007 Andy Lutomirski 39214518Srpaulo * Copyright (c) 2007 Mike Kershaw 40214518Srpaulo * Copyright (c) 2008 G��bor Stefanik 41214518Srpaulo * 42214518Srpaulo * All rights reserved. 43214518Srpaulo * 44214518Srpaulo * Redistribution and use in source and binary forms, with or without 45214518Srpaulo * modification, are permitted provided that the following conditions 46214518Srpaulo * are met: 47214518Srpaulo * 1. Redistributions of source code must retain the above copyright 48214518Srpaulo * notice, this list of conditions and the following disclaimer. 49214518Srpaulo * 2. Redistributions in binary form must reproduce the above copyright 50214518Srpaulo * notice, this list of conditions and the following disclaimer in the 51214518Srpaulo * documentation and/or other materials provided with the distribution. 52214518Srpaulo * 3. The name of the author may not be used to endorse or promote products 53214518Srpaulo * derived from this software without specific prior written permission. 54214518Srpaulo * 55214518Srpaulo * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 56214518Srpaulo * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 57214518Srpaulo * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 58214518Srpaulo * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 59214518Srpaulo * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 60214518Srpaulo * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 61214518Srpaulo * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 62214518Srpaulo * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 63214518Srpaulo * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 64214518Srpaulo * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 65214518Srpaulo * SUCH DAMAGE. 6626175Sfenner */ 67127664Sbms 6826175Sfenner#ifndef lint 69127664Sbmsstatic const char rcsid[] _U_ = 70214518Srpaulo "@(#) $Header: /tcpdump/master/libpcap/pcap-linux.c,v 1.164 2008-12-14 22:00:57 guy Exp $ (LBL)"; 7126175Sfenner#endif 7226175Sfenner 7375107Sfenner/* 7475107Sfenner * Known problems with 2.0[.x] kernels: 7575107Sfenner * 7675107Sfenner * - The loopback device gives every packet twice; on 2.2[.x] kernels, 7775107Sfenner * if we use PF_PACKET, we can filter out the transmitted version 7875107Sfenner * of the packet by using data in the "sockaddr_ll" returned by 7975107Sfenner * "recvfrom()", but, on 2.0[.x] kernels, we have to use 8075107Sfenner * PF_INET/SOCK_PACKET, which means "recvfrom()" supplies a 8175107Sfenner * "sockaddr_pkt" which doesn't give us enough information to let 8275107Sfenner * us do that. 8375107Sfenner * 8475107Sfenner * - We have to set the interface's IFF_PROMISC flag ourselves, if 8575107Sfenner * we're to run in promiscuous mode, which means we have to turn 8675107Sfenner * it off ourselves when we're done; the kernel doesn't keep track 8775107Sfenner * of how many sockets are listening promiscuously, which means 8875107Sfenner * it won't get turned off automatically when no sockets are 8975107Sfenner * listening promiscuously. We catch "pcap_close()" and, for 9075107Sfenner * interfaces we put into promiscuous mode, take them out of 9175107Sfenner * promiscuous mode - which isn't necessarily the right thing to 9275107Sfenner * do, if another socket also requested promiscuous mode between 9375107Sfenner * the time when we opened the socket and the time when we close 9475107Sfenner * the socket. 9598530Sfenner * 9698530Sfenner * - MSG_TRUNC isn't supported, so you can't specify that "recvfrom()" 9798530Sfenner * return the amount of data that you could have read, rather than 9898530Sfenner * the amount that was returned, so we can't just allocate a buffer 9998530Sfenner * whose size is the snapshot length and pass the snapshot length 10098530Sfenner * as the byte count, and also pass MSG_TRUNC, so that the return 10198530Sfenner * value tells us how long the packet was on the wire. 10298530Sfenner * 10398530Sfenner * This means that, if we want to get the actual size of the packet, 10498530Sfenner * so we can return it in the "len" field of the packet header, 10598530Sfenner * we have to read the entire packet, not just the part that fits 10698530Sfenner * within the snapshot length, and thus waste CPU time copying data 10798530Sfenner * from the kernel that our caller won't see. 10898530Sfenner * 10998530Sfenner * We have to get the actual size, and supply it in "len", because 11098530Sfenner * otherwise, the IP dissector in tcpdump, for example, will complain 11198530Sfenner * about "truncated-ip", as the packet will appear to have been 11298530Sfenner * shorter, on the wire, than the IP header said it should have been. 11375107Sfenner */ 11426175Sfenner 11575107Sfenner 116214518Srpaulo#define _GNU_SOURCE 117214518Srpaulo 11875107Sfenner#ifdef HAVE_CONFIG_H 11975107Sfenner#include "config.h" 12039291Sfenner#endif 12126175Sfenner 12226175Sfenner#include <errno.h> 123214518Srpaulo#include <stdio.h> 12426175Sfenner#include <stdlib.h> 125214518Srpaulo#include <ctype.h> 12675107Sfenner#include <unistd.h> 12775107Sfenner#include <fcntl.h> 12826175Sfenner#include <string.h> 129214518Srpaulo#include <limits.h> 130251129Sdelphij#include <sys/stat.h> 13175107Sfenner#include <sys/socket.h> 13275107Sfenner#include <sys/ioctl.h> 13375107Sfenner#include <sys/utsname.h> 134190225Srpaulo#include <sys/mman.h> 135214518Srpaulo#include <linux/if.h> 136251129Sdelphij#include <linux/if_packet.h> 13775107Sfenner#include <netinet/in.h> 13875107Sfenner#include <linux/if_ether.h> 13975107Sfenner#include <net/if_arp.h> 140190225Srpaulo#include <poll.h> 141214518Srpaulo#include <dirent.h> 14226175Sfenner 143190225Srpaulo#include "pcap-int.h" 144190225Srpaulo#include "pcap/sll.h" 145190225Srpaulo#include "pcap/vlan.h" 146190225Srpaulo 147190225Srpaulo/* 14898530Sfenner * If PF_PACKET is defined, we can use {SOCK_RAW,SOCK_DGRAM}/PF_PACKET 14998530Sfenner * sockets rather than SOCK_PACKET sockets. 15098530Sfenner * 15198530Sfenner * To use them, we include <linux/if_packet.h> rather than 15298530Sfenner * <netpacket/packet.h>; we do so because 15398530Sfenner * 15498530Sfenner * some Linux distributions (e.g., Slackware 4.0) have 2.2 or 15598530Sfenner * later kernels and libc5, and don't provide a <netpacket/packet.h> 15698530Sfenner * file; 15798530Sfenner * 15898530Sfenner * not all versions of glibc2 have a <netpacket/packet.h> file 15998530Sfenner * that defines stuff needed for some of the 2.4-or-later-kernel 16098530Sfenner * features, so if the system has a 2.4 or later kernel, we 16198530Sfenner * still can't use those features. 16298530Sfenner * 16398530Sfenner * We're already including a number of other <linux/XXX.h> headers, and 16498530Sfenner * this code is Linux-specific (no other OS has PF_PACKET sockets as 16598530Sfenner * a raw packet capture mechanism), so it's not as if you gain any 16698530Sfenner * useful portability by using <netpacket/packet.h> 16798530Sfenner * 16898530Sfenner * XXX - should we just include <linux/if_packet.h> even if PF_PACKET 16998530Sfenner * isn't defined? It only defines one data structure in 2.0.x, so 17098530Sfenner * it shouldn't cause any problems. 17198530Sfenner */ 172127664Sbms#ifdef PF_PACKET 17398530Sfenner# include <linux/if_packet.h> 17426175Sfenner 17575107Sfenner /* 17698530Sfenner * On at least some Linux distributions (for example, Red Hat 5.2), 17798530Sfenner * there's no <netpacket/packet.h> file, but PF_PACKET is defined if 17898530Sfenner * you include <sys/socket.h>, but <linux/if_packet.h> doesn't define 17975107Sfenner * any of the PF_PACKET stuff such as "struct sockaddr_ll" or any of 18075107Sfenner * the PACKET_xxx stuff. 18175107Sfenner * 18275107Sfenner * So we check whether PACKET_HOST is defined, and assume that we have 18375107Sfenner * PF_PACKET sockets only if it is defined. 18475107Sfenner */ 18575107Sfenner# ifdef PACKET_HOST 18675107Sfenner# define HAVE_PF_PACKET_SOCKETS 187190225Srpaulo# ifdef PACKET_AUXDATA 188190225Srpaulo# define HAVE_PACKET_AUXDATA 189190225Srpaulo# endif /* PACKET_AUXDATA */ 19075107Sfenner# endif /* PACKET_HOST */ 191190225Srpaulo 192190225Srpaulo 193190225Srpaulo /* check for memory mapped access avaibility. We assume every needed 194190225Srpaulo * struct is defined if the macro TPACKET_HDRLEN is defined, because it 195190225Srpaulo * uses many ring related structs and macros */ 196190225Srpaulo# ifdef TPACKET_HDRLEN 197190225Srpaulo# define HAVE_PACKET_RING 198190225Srpaulo# ifdef TPACKET2_HDRLEN 199190225Srpaulo# define HAVE_TPACKET2 200190225Srpaulo# else 201190225Srpaulo# define TPACKET_V1 0 202190225Srpaulo# endif /* TPACKET2_HDRLEN */ 203190225Srpaulo# endif /* TPACKET_HDRLEN */ 20498530Sfenner#endif /* PF_PACKET */ 20575107Sfenner 20675107Sfenner#ifdef SO_ATTACH_FILTER 20775107Sfenner#include <linux/types.h> 20875107Sfenner#include <linux/filter.h> 20926175Sfenner#endif 21026175Sfenner 211235426Sdelphij/* 212235426Sdelphij * We need linux/sockios.h if we have linux/net_tstamp.h (for time stamp 213235426Sdelphij * specification) or linux/ethtool.h (for ethtool ioctls to get offloading 214235426Sdelphij * information). 215235426Sdelphij */ 216235426Sdelphij#if defined(HAVE_LINUX_NET_TSTAMP_H) || defined(HAVE_LINUX_ETHTOOL_H) 217235426Sdelphij#include <linux/sockios.h> 218235426Sdelphij#endif 219235426Sdelphij 220235426Sdelphij#ifdef HAVE_LINUX_NET_TSTAMP_H 221235426Sdelphij#include <linux/net_tstamp.h> 222235426Sdelphij#endif 223235426Sdelphij 224235426Sdelphij/* 225235426Sdelphij * Got Wireless Extensions? 226235426Sdelphij */ 227235426Sdelphij#ifdef HAVE_LINUX_WIRELESS_H 228235426Sdelphij#include <linux/wireless.h> 229235426Sdelphij#endif /* HAVE_LINUX_WIRELESS_H */ 230235426Sdelphij 231235426Sdelphij/* 232235426Sdelphij * Got libnl? 233235426Sdelphij */ 234235426Sdelphij#ifdef HAVE_LIBNL 235235426Sdelphij#include <linux/nl80211.h> 236235426Sdelphij 237235426Sdelphij#include <netlink/genl/genl.h> 238235426Sdelphij#include <netlink/genl/family.h> 239235426Sdelphij#include <netlink/genl/ctrl.h> 240235426Sdelphij#include <netlink/msg.h> 241235426Sdelphij#include <netlink/attr.h> 242235426Sdelphij#endif /* HAVE_LIBNL */ 243235426Sdelphij 244235426Sdelphij/* 245235426Sdelphij * Got ethtool support? 246235426Sdelphij */ 247235426Sdelphij#ifdef HAVE_LINUX_ETHTOOL_H 248235426Sdelphij#include <linux/ethtool.h> 249235426Sdelphij#endif 250235426Sdelphij 251190225Srpaulo#ifndef HAVE_SOCKLEN_T 25275107Sfennertypedef int socklen_t; 25375107Sfenner#endif 25426175Sfenner 25575107Sfenner#ifndef MSG_TRUNC 25698530Sfenner/* 25798530Sfenner * This is being compiled on a system that lacks MSG_TRUNC; define it 25898530Sfenner * with the value it has in the 2.2 and later kernels, so that, on 25998530Sfenner * those kernels, when we pass it in the flags argument to "recvfrom()" 26098530Sfenner * we're passing the right value and thus get the MSG_TRUNC behavior 26198530Sfenner * we want. (We don't get that behavior on 2.0[.x] kernels, because 26298530Sfenner * they didn't support MSG_TRUNC.) 26398530Sfenner */ 26498530Sfenner#define MSG_TRUNC 0x20 26575107Sfenner#endif 26675107Sfenner 267127664Sbms#ifndef SOL_PACKET 268127664Sbms/* 269127664Sbms * This is being compiled on a system that lacks SOL_PACKET; define it 270127664Sbms * with the value it has in the 2.2 and later kernels, so that we can 271127664Sbms * set promiscuous mode in the good modern way rather than the old 272127664Sbms * 2.0-kernel crappy way. 273127664Sbms */ 274127664Sbms#define SOL_PACKET 263 275127664Sbms#endif 276127664Sbms 27775107Sfenner#define MAX_LINKHEADER_SIZE 256 27875107Sfenner 279127664Sbms/* 280127664Sbms * When capturing on all interfaces we use this as the buffer size. 28175107Sfenner * Should be bigger then all MTUs that occur in real life. 28275107Sfenner * 64kB should be enough for now. 28375107Sfenner */ 28475107Sfenner#define BIGGER_THAN_ALL_MTUS (64*1024) 28575107Sfenner 28675107Sfenner/* 287190225Srpaulo * Prototypes for internal functions and methods. 28875107Sfenner */ 289127664Sbmsstatic void map_arphrd_to_dlt(pcap_t *, int, int); 290190225Srpaulo#ifdef HAVE_PF_PACKET_SOCKETS 291190225Srpaulostatic short int map_packet_type_to_sll_type(short int); 292190225Srpaulo#endif 293190225Srpaulostatic int pcap_activate_linux(pcap_t *); 294190225Srpaulostatic int activate_old(pcap_t *); 295190225Srpaulostatic int activate_new(pcap_t *); 296235426Sdelphijstatic int activate_mmap(pcap_t *, int *); 297190225Srpaulostatic int pcap_can_set_rfmon_linux(pcap_t *); 298127664Sbmsstatic int pcap_read_linux(pcap_t *, int, pcap_handler, u_char *); 29975107Sfennerstatic int pcap_read_packet(pcap_t *, pcap_handler, u_char *); 300146768Ssamstatic int pcap_inject_linux(pcap_t *, const void *, size_t); 301127664Sbmsstatic int pcap_stats_linux(pcap_t *, struct pcap_stat *); 302127664Sbmsstatic int pcap_setfilter_linux(pcap_t *, struct bpf_program *); 303162012Ssamstatic int pcap_setdirection_linux(pcap_t *, pcap_direction_t); 304190225Srpaulostatic void pcap_cleanup_linux(pcap_t *); 30575107Sfenner 306190225Srpaulounion thdr { 307190225Srpaulo struct tpacket_hdr *h1; 308190225Srpaulo struct tpacket2_hdr *h2; 309190225Srpaulo void *raw; 310190225Srpaulo}; 311190225Srpaulo 312190225Srpaulo#ifdef HAVE_PACKET_RING 313190225Srpaulo#define RING_GET_FRAME(h) (((union thdr **)h->buffer)[h->offset]) 314190225Srpaulo 315190225Srpaulostatic void destroy_ring(pcap_t *handle); 316235426Sdelphijstatic int create_ring(pcap_t *handle, int *status); 317190225Srpaulostatic int prepare_tpacket_socket(pcap_t *handle); 318190225Srpaulostatic void pcap_cleanup_linux_mmap(pcap_t *); 319190225Srpaulostatic int pcap_read_linux_mmap(pcap_t *, int, pcap_handler , u_char *); 320190225Srpaulostatic int pcap_setfilter_linux_mmap(pcap_t *, struct bpf_program *); 321190225Srpaulostatic int pcap_setnonblock_mmap(pcap_t *p, int nonblock, char *errbuf); 322190225Srpaulostatic int pcap_getnonblock_mmap(pcap_t *p, char *errbuf); 323214518Srpaulostatic void pcap_oneshot_mmap(u_char *user, const struct pcap_pkthdr *h, 324214518Srpaulo const u_char *bytes); 325190225Srpaulo#endif 326190225Srpaulo 32775107Sfenner/* 32875107Sfenner * Wrap some ioctl calls 32975107Sfenner */ 33075107Sfenner#ifdef HAVE_PF_PACKET_SOCKETS 33175107Sfennerstatic int iface_get_id(int fd, const char *device, char *ebuf); 332235426Sdelphij#endif /* HAVE_PF_PACKET_SOCKETS */ 33375107Sfennerstatic int iface_get_mtu(int fd, const char *device, char *ebuf); 33475107Sfennerstatic int iface_get_arptype(int fd, const char *device, char *ebuf); 33575107Sfenner#ifdef HAVE_PF_PACKET_SOCKETS 33675107Sfennerstatic int iface_bind(int fd, int ifindex, char *ebuf); 337214518Srpaulo#ifdef IW_MODE_MONITOR 338190225Srpaulostatic int has_wext(int sock_fd, const char *device, char *ebuf); 339214518Srpaulo#endif /* IW_MODE_MONITOR */ 340214518Srpaulostatic int enter_rfmon_mode(pcap_t *handle, int sock_fd, 341190225Srpaulo const char *device); 342214518Srpaulo#endif /* HAVE_PF_PACKET_SOCKETS */ 343235426Sdelphijstatic int iface_get_offload(pcap_t *handle); 34475107Sfennerstatic int iface_bind_old(int fd, const char *device, char *ebuf); 34575107Sfenner 34675107Sfenner#ifdef SO_ATTACH_FILTER 347214518Srpaulostatic int fix_program(pcap_t *handle, struct sock_fprog *fcode, 348214518Srpaulo int is_mapped); 34975107Sfennerstatic int fix_offset(struct bpf_insn *p); 35098530Sfennerstatic int set_kernel_filter(pcap_t *handle, struct sock_fprog *fcode); 35198530Sfennerstatic int reset_kernel_filter(pcap_t *handle); 35298530Sfenner 35398530Sfennerstatic struct sock_filter total_insn 35498530Sfenner = BPF_STMT(BPF_RET | BPF_K, 0); 35598530Sfennerstatic struct sock_fprog total_fcode 35698530Sfenner = { 1, &total_insn }; 357235426Sdelphij#endif /* SO_ATTACH_FILTER */ 35875107Sfenner 35975107Sfennerpcap_t * 360251129Sdelphijpcap_create_interface(const char *device, char *ebuf) 36126175Sfenner{ 362190225Srpaulo pcap_t *handle; 36398530Sfenner 364190225Srpaulo handle = pcap_create_common(device, ebuf); 365190225Srpaulo if (handle == NULL) 36675107Sfenner return NULL; 367190225Srpaulo 368190225Srpaulo handle->activate_op = pcap_activate_linux; 369190225Srpaulo handle->can_set_rfmon_op = pcap_can_set_rfmon_linux; 370235426Sdelphij#if defined(HAVE_LINUX_NET_TSTAMP_H) && defined(PACKET_TIMESTAMP) 371235426Sdelphij /* 372235426Sdelphij * We claim that we support: 373235426Sdelphij * 374235426Sdelphij * software time stamps, with no details about their precision; 375235426Sdelphij * hardware time stamps, synced to the host time; 376235426Sdelphij * hardware time stamps, not synced to the host time. 377235426Sdelphij * 378235426Sdelphij * XXX - we can't ask a device whether it supports 379235426Sdelphij * hardware time stamps, so we just claim all devices do. 380235426Sdelphij */ 381235426Sdelphij handle->tstamp_type_count = 3; 382235426Sdelphij handle->tstamp_type_list = malloc(3 * sizeof(u_int)); 383235426Sdelphij if (handle->tstamp_type_list == NULL) { 384235426Sdelphij free(handle); 385235426Sdelphij return NULL; 386235426Sdelphij } 387235426Sdelphij handle->tstamp_type_list[0] = PCAP_TSTAMP_HOST; 388235426Sdelphij handle->tstamp_type_list[1] = PCAP_TSTAMP_ADAPTER; 389235426Sdelphij handle->tstamp_type_list[2] = PCAP_TSTAMP_ADAPTER_UNSYNCED; 390235426Sdelphij#endif 391235426Sdelphij 392190225Srpaulo return handle; 393190225Srpaulo} 394190225Srpaulo 395214518Srpaulo#ifdef HAVE_LIBNL 396214518Srpaulo/* 397235426Sdelphij * If interface {if} is a mac80211 driver, the file 398235426Sdelphij * /sys/class/net/{if}/phy80211 is a symlink to 399235426Sdelphij * /sys/class/ieee80211/{phydev}, for some {phydev}. 400235426Sdelphij * 401235426Sdelphij * On Fedora 9, with a 2.6.26.3-29 kernel, my Zydas stick, at 402235426Sdelphij * least, has a "wmaster0" device and a "wlan0" device; the 403235426Sdelphij * latter is the one with the IP address. Both show up in 404235426Sdelphij * "tcpdump -D" output. Capturing on the wmaster0 device 405235426Sdelphij * captures with 802.11 headers. 406235426Sdelphij * 407235426Sdelphij * airmon-ng searches through /sys/class/net for devices named 408235426Sdelphij * monN, starting with mon0; as soon as one *doesn't* exist, 409235426Sdelphij * it chooses that as the monitor device name. If the "iw" 410235426Sdelphij * command exists, it does "iw dev {if} interface add {monif} 411235426Sdelphij * type monitor", where {monif} is the monitor device. It 412235426Sdelphij * then (sigh) sleeps .1 second, and then configures the 413235426Sdelphij * device up. Otherwise, if /sys/class/ieee80211/{phydev}/add_iface 414235426Sdelphij * is a file, it writes {mondev}, without a newline, to that file, 415235426Sdelphij * and again (sigh) sleeps .1 second, and then iwconfig's that 416235426Sdelphij * device into monitor mode and configures it up. Otherwise, 417235426Sdelphij * you can't do monitor mode. 418235426Sdelphij * 419235426Sdelphij * All these devices are "glued" together by having the 420235426Sdelphij * /sys/class/net/{device}/phy80211 links pointing to the same 421235426Sdelphij * place, so, given a wmaster, wlan, or mon device, you can 422235426Sdelphij * find the other devices by looking for devices with 423235426Sdelphij * the same phy80211 link. 424235426Sdelphij * 425235426Sdelphij * To turn monitor mode off, delete the monitor interface, 426235426Sdelphij * either with "iw dev {monif} interface del" or by sending 427235426Sdelphij * {monif}, with no NL, down /sys/class/ieee80211/{phydev}/remove_iface 428235426Sdelphij * 429235426Sdelphij * Note: if you try to create a monitor device named "monN", and 430235426Sdelphij * there's already a "monN" device, it fails, as least with 431235426Sdelphij * the netlink interface (which is what iw uses), with a return 432235426Sdelphij * value of -ENFILE. (Return values are negative errnos.) We 433235426Sdelphij * could probably use that to find an unused device. 434235426Sdelphij * 435235426Sdelphij * Yes, you can have multiple monitor devices for a given 436235426Sdelphij * physical device. 437214518Srpaulo*/ 438214518Srpaulo 439214518Srpaulo/* 440214518Srpaulo * Is this a mac80211 device? If so, fill in the physical device path and 441214518Srpaulo * return 1; if not, return 0. On an error, fill in handle->errbuf and 442214518Srpaulo * return PCAP_ERROR. 443214518Srpaulo */ 444190225Srpaulostatic int 445214518Srpauloget_mac80211_phydev(pcap_t *handle, const char *device, char *phydev_path, 446214518Srpaulo size_t phydev_max_pathlen) 447190225Srpaulo{ 448214518Srpaulo char *pathstr; 449214518Srpaulo ssize_t bytes_read; 450214518Srpaulo 451214518Srpaulo /* 452214518Srpaulo * Generate the path string for the symlink to the physical device. 453214518Srpaulo */ 454214518Srpaulo if (asprintf(&pathstr, "/sys/class/net/%s/phy80211", device) == -1) { 455214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 456214518Srpaulo "%s: Can't generate path name string for /sys/class/net device", 457214518Srpaulo device); 458214518Srpaulo return PCAP_ERROR; 459214518Srpaulo } 460214518Srpaulo bytes_read = readlink(pathstr, phydev_path, phydev_max_pathlen); 461214518Srpaulo if (bytes_read == -1) { 462214518Srpaulo if (errno == ENOENT || errno == EINVAL) { 463214518Srpaulo /* 464214518Srpaulo * Doesn't exist, or not a symlink; assume that 465214518Srpaulo * means it's not a mac80211 device. 466214518Srpaulo */ 467214518Srpaulo free(pathstr); 468214518Srpaulo return 0; 469214518Srpaulo } 470214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 471214518Srpaulo "%s: Can't readlink %s: %s", device, pathstr, 472214518Srpaulo strerror(errno)); 473214518Srpaulo free(pathstr); 474214518Srpaulo return PCAP_ERROR; 475214518Srpaulo } 476214518Srpaulo free(pathstr); 477214518Srpaulo phydev_path[bytes_read] = '\0'; 478214518Srpaulo return 1; 479214518Srpaulo} 480214518Srpaulo 481251129Sdelphij#ifdef HAVE_LIBNL_SOCKETS 482235426Sdelphij#define get_nl_errmsg nl_geterror 483235426Sdelphij#else 484235426Sdelphij/* libnl 2.x compatibility code */ 485235426Sdelphij 486235426Sdelphij#define nl_sock nl_handle 487235426Sdelphij 488235426Sdelphijstatic inline struct nl_handle * 489235426Sdelphijnl_socket_alloc(void) 490235426Sdelphij{ 491235426Sdelphij return nl_handle_alloc(); 492235426Sdelphij} 493235426Sdelphij 494235426Sdelphijstatic inline void 495235426Sdelphijnl_socket_free(struct nl_handle *h) 496235426Sdelphij{ 497235426Sdelphij nl_handle_destroy(h); 498235426Sdelphij} 499235426Sdelphij 500235426Sdelphij#define get_nl_errmsg strerror 501235426Sdelphij 502235426Sdelphijstatic inline int 503235426Sdelphij__genl_ctrl_alloc_cache(struct nl_handle *h, struct nl_cache **cache) 504235426Sdelphij{ 505235426Sdelphij struct nl_cache *tmp = genl_ctrl_alloc_cache(h); 506235426Sdelphij if (!tmp) 507235426Sdelphij return -ENOMEM; 508235426Sdelphij *cache = tmp; 509235426Sdelphij return 0; 510235426Sdelphij} 511235426Sdelphij#define genl_ctrl_alloc_cache __genl_ctrl_alloc_cache 512251129Sdelphij#endif /* !HAVE_LIBNL_SOCKETS */ 513235426Sdelphij 514214518Srpaulostruct nl80211_state { 515235426Sdelphij struct nl_sock *nl_sock; 516214518Srpaulo struct nl_cache *nl_cache; 517214518Srpaulo struct genl_family *nl80211; 518214518Srpaulo}; 519214518Srpaulo 520214518Srpaulostatic int 521214518Srpaulonl80211_init(pcap_t *handle, struct nl80211_state *state, const char *device) 522214518Srpaulo{ 523235426Sdelphij int err; 524235426Sdelphij 525235426Sdelphij state->nl_sock = nl_socket_alloc(); 526235426Sdelphij if (!state->nl_sock) { 527214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 528214518Srpaulo "%s: failed to allocate netlink handle", device); 529214518Srpaulo return PCAP_ERROR; 530214518Srpaulo } 531214518Srpaulo 532235426Sdelphij if (genl_connect(state->nl_sock)) { 533214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 534214518Srpaulo "%s: failed to connect to generic netlink", device); 535214518Srpaulo goto out_handle_destroy; 536214518Srpaulo } 537214518Srpaulo 538235426Sdelphij err = genl_ctrl_alloc_cache(state->nl_sock, &state->nl_cache); 539235426Sdelphij if (err < 0) { 540214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 541235426Sdelphij "%s: failed to allocate generic netlink cache: %s", 542235426Sdelphij device, get_nl_errmsg(-err)); 543214518Srpaulo goto out_handle_destroy; 544214518Srpaulo } 545214518Srpaulo 546214518Srpaulo state->nl80211 = genl_ctrl_search_by_name(state->nl_cache, "nl80211"); 547214518Srpaulo if (!state->nl80211) { 548214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 549214518Srpaulo "%s: nl80211 not found", device); 550214518Srpaulo goto out_cache_free; 551214518Srpaulo } 552214518Srpaulo 553214518Srpaulo return 0; 554214518Srpaulo 555214518Srpauloout_cache_free: 556214518Srpaulo nl_cache_free(state->nl_cache); 557214518Srpauloout_handle_destroy: 558235426Sdelphij nl_socket_free(state->nl_sock); 559214518Srpaulo return PCAP_ERROR; 560214518Srpaulo} 561214518Srpaulo 562214518Srpaulostatic void 563214518Srpaulonl80211_cleanup(struct nl80211_state *state) 564214518Srpaulo{ 565214518Srpaulo genl_family_put(state->nl80211); 566214518Srpaulo nl_cache_free(state->nl_cache); 567235426Sdelphij nl_socket_free(state->nl_sock); 568214518Srpaulo} 569214518Srpaulo 570214518Srpaulostatic int 571214518Srpauloadd_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, 572214518Srpaulo const char *device, const char *mondevice) 573214518Srpaulo{ 574214518Srpaulo int ifindex; 575214518Srpaulo struct nl_msg *msg; 576214518Srpaulo int err; 577214518Srpaulo 578214518Srpaulo ifindex = iface_get_id(sock_fd, device, handle->errbuf); 579214518Srpaulo if (ifindex == -1) 580214518Srpaulo return PCAP_ERROR; 581214518Srpaulo 582214518Srpaulo msg = nlmsg_alloc(); 583214518Srpaulo if (!msg) { 584214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 585214518Srpaulo "%s: failed to allocate netlink msg", device); 586214518Srpaulo return PCAP_ERROR; 587214518Srpaulo } 588214518Srpaulo 589214518Srpaulo genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0, 590214518Srpaulo 0, NL80211_CMD_NEW_INTERFACE, 0); 591214518Srpaulo NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex); 592214518Srpaulo NLA_PUT_STRING(msg, NL80211_ATTR_IFNAME, mondevice); 593214518Srpaulo NLA_PUT_U32(msg, NL80211_ATTR_IFTYPE, NL80211_IFTYPE_MONITOR); 594214518Srpaulo 595235426Sdelphij err = nl_send_auto_complete(state->nl_sock, msg); 596214518Srpaulo if (err < 0) { 597251129Sdelphij#if defined HAVE_LIBNL_NLE 598235426Sdelphij if (err == -NLE_FAILURE) { 599235426Sdelphij#else 600214518Srpaulo if (err == -ENFILE) { 601235426Sdelphij#endif 602214518Srpaulo /* 603214518Srpaulo * Device not available; our caller should just 604235426Sdelphij * keep trying. (libnl 2.x maps ENFILE to 605235426Sdelphij * NLE_FAILURE; it can also map other errors 606235426Sdelphij * to that, but there's not much we can do 607235426Sdelphij * about that.) 608214518Srpaulo */ 609214518Srpaulo nlmsg_free(msg); 610214518Srpaulo return 0; 611214518Srpaulo } else { 612214518Srpaulo /* 613214518Srpaulo * Real failure, not just "that device is not 614214518Srpaulo * available. 615214518Srpaulo */ 616214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 617214518Srpaulo "%s: nl_send_auto_complete failed adding %s interface: %s", 618235426Sdelphij device, mondevice, get_nl_errmsg(-err)); 619214518Srpaulo nlmsg_free(msg); 620214518Srpaulo return PCAP_ERROR; 621214518Srpaulo } 622214518Srpaulo } 623235426Sdelphij err = nl_wait_for_ack(state->nl_sock); 624214518Srpaulo if (err < 0) { 625251129Sdelphij#if defined HAVE_LIBNL_NLE 626235426Sdelphij if (err == -NLE_FAILURE) { 627235426Sdelphij#else 628214518Srpaulo if (err == -ENFILE) { 629235426Sdelphij#endif 630214518Srpaulo /* 631214518Srpaulo * Device not available; our caller should just 632235426Sdelphij * keep trying. (libnl 2.x maps ENFILE to 633235426Sdelphij * NLE_FAILURE; it can also map other errors 634235426Sdelphij * to that, but there's not much we can do 635235426Sdelphij * about that.) 636214518Srpaulo */ 637214518Srpaulo nlmsg_free(msg); 638214518Srpaulo return 0; 639214518Srpaulo } else { 640214518Srpaulo /* 641214518Srpaulo * Real failure, not just "that device is not 642214518Srpaulo * available. 643214518Srpaulo */ 644214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 645214518Srpaulo "%s: nl_wait_for_ack failed adding %s interface: %s", 646235426Sdelphij device, mondevice, get_nl_errmsg(-err)); 647214518Srpaulo nlmsg_free(msg); 648214518Srpaulo return PCAP_ERROR; 649214518Srpaulo } 650214518Srpaulo } 651214518Srpaulo 652214518Srpaulo /* 653214518Srpaulo * Success. 654214518Srpaulo */ 655214518Srpaulo nlmsg_free(msg); 656214518Srpaulo return 1; 657214518Srpaulo 658214518Srpaulonla_put_failure: 659214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 660214518Srpaulo "%s: nl_put failed adding %s interface", 661214518Srpaulo device, mondevice); 662214518Srpaulo nlmsg_free(msg); 663214518Srpaulo return PCAP_ERROR; 664214518Srpaulo} 665214518Srpaulo 666214518Srpaulostatic int 667214518Srpaulodel_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state, 668214518Srpaulo const char *device, const char *mondevice) 669214518Srpaulo{ 670214518Srpaulo int ifindex; 671214518Srpaulo struct nl_msg *msg; 672214518Srpaulo int err; 673214518Srpaulo 674214518Srpaulo ifindex = iface_get_id(sock_fd, mondevice, handle->errbuf); 675214518Srpaulo if (ifindex == -1) 676214518Srpaulo return PCAP_ERROR; 677214518Srpaulo 678214518Srpaulo msg = nlmsg_alloc(); 679214518Srpaulo if (!msg) { 680214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 681214518Srpaulo "%s: failed to allocate netlink msg", device); 682214518Srpaulo return PCAP_ERROR; 683214518Srpaulo } 684214518Srpaulo 685214518Srpaulo genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0, 686214518Srpaulo 0, NL80211_CMD_DEL_INTERFACE, 0); 687214518Srpaulo NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex); 688214518Srpaulo 689235426Sdelphij err = nl_send_auto_complete(state->nl_sock, msg); 690214518Srpaulo if (err < 0) { 691235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 692235426Sdelphij "%s: nl_send_auto_complete failed deleting %s interface: %s", 693235426Sdelphij device, mondevice, get_nl_errmsg(-err)); 694235426Sdelphij nlmsg_free(msg); 695235426Sdelphij return PCAP_ERROR; 696214518Srpaulo } 697235426Sdelphij err = nl_wait_for_ack(state->nl_sock); 698214518Srpaulo if (err < 0) { 699235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 700235426Sdelphij "%s: nl_wait_for_ack failed adding %s interface: %s", 701235426Sdelphij device, mondevice, get_nl_errmsg(-err)); 702235426Sdelphij nlmsg_free(msg); 703235426Sdelphij return PCAP_ERROR; 704214518Srpaulo } 705214518Srpaulo 706214518Srpaulo /* 707214518Srpaulo * Success. 708214518Srpaulo */ 709214518Srpaulo nlmsg_free(msg); 710214518Srpaulo return 1; 711214518Srpaulo 712214518Srpaulonla_put_failure: 713214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 714214518Srpaulo "%s: nl_put failed deleting %s interface", 715214518Srpaulo device, mondevice); 716214518Srpaulo nlmsg_free(msg); 717214518Srpaulo return PCAP_ERROR; 718214518Srpaulo} 719214518Srpaulo 720214518Srpaulostatic int 721214518Srpauloenter_rfmon_mode_mac80211(pcap_t *handle, int sock_fd, const char *device) 722214518Srpaulo{ 723214518Srpaulo int ret; 724214518Srpaulo char phydev_path[PATH_MAX+1]; 725214518Srpaulo struct nl80211_state nlstate; 726214518Srpaulo struct ifreq ifr; 727214518Srpaulo u_int n; 728214518Srpaulo 729214518Srpaulo /* 730214518Srpaulo * Is this a mac80211 device? 731214518Srpaulo */ 732214518Srpaulo ret = get_mac80211_phydev(handle, device, phydev_path, PATH_MAX); 733214518Srpaulo if (ret < 0) 734214518Srpaulo return ret; /* error */ 735214518Srpaulo if (ret == 0) 736214518Srpaulo return 0; /* no error, but not mac80211 device */ 737214518Srpaulo 738214518Srpaulo /* 739214518Srpaulo * XXX - is this already a monN device? 740214518Srpaulo * If so, we're done. 741214518Srpaulo * Is that determined by old Wireless Extensions ioctls? 742214518Srpaulo */ 743214518Srpaulo 744214518Srpaulo /* 745214518Srpaulo * OK, it's apparently a mac80211 device. 746214518Srpaulo * Try to find an unused monN device for it. 747214518Srpaulo */ 748214518Srpaulo ret = nl80211_init(handle, &nlstate, device); 749214518Srpaulo if (ret != 0) 750214518Srpaulo return ret; 751214518Srpaulo for (n = 0; n < UINT_MAX; n++) { 752214518Srpaulo /* 753214518Srpaulo * Try mon{n}. 754214518Srpaulo */ 755214518Srpaulo char mondevice[3+10+1]; /* mon{UINT_MAX}\0 */ 756214518Srpaulo 757214518Srpaulo snprintf(mondevice, sizeof mondevice, "mon%u", n); 758214518Srpaulo ret = add_mon_if(handle, sock_fd, &nlstate, device, mondevice); 759214518Srpaulo if (ret == 1) { 760214518Srpaulo handle->md.mondevice = strdup(mondevice); 761214518Srpaulo goto added; 762214518Srpaulo } 763214518Srpaulo if (ret < 0) { 764214518Srpaulo /* 765214518Srpaulo * Hard failure. Just return ret; handle->errbuf 766214518Srpaulo * has already been set. 767214518Srpaulo */ 768214518Srpaulo nl80211_cleanup(&nlstate); 769214518Srpaulo return ret; 770214518Srpaulo } 771214518Srpaulo } 772214518Srpaulo 773214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 774214518Srpaulo "%s: No free monN interfaces", device); 775214518Srpaulo nl80211_cleanup(&nlstate); 776214518Srpaulo return PCAP_ERROR; 777214518Srpaulo 778214518Srpauloadded: 779214518Srpaulo 780214518Srpaulo#if 0 781214518Srpaulo /* 782214518Srpaulo * Sleep for .1 seconds. 783214518Srpaulo */ 784214518Srpaulo delay.tv_sec = 0; 785214518Srpaulo delay.tv_nsec = 500000000; 786214518Srpaulo nanosleep(&delay, NULL); 787214518Srpaulo#endif 788214518Srpaulo 789214518Srpaulo /* 790235426Sdelphij * If we haven't already done so, arrange to have 791235426Sdelphij * "pcap_close_all()" called when we exit. 792235426Sdelphij */ 793235426Sdelphij if (!pcap_do_addexit(handle)) { 794235426Sdelphij /* 795235426Sdelphij * "atexit()" failed; don't put the interface 796235426Sdelphij * in rfmon mode, just give up. 797235426Sdelphij */ 798235426Sdelphij return PCAP_ERROR_RFMON_NOTSUP; 799235426Sdelphij } 800235426Sdelphij 801235426Sdelphij /* 802214518Srpaulo * Now configure the monitor interface up. 803214518Srpaulo */ 804214518Srpaulo memset(&ifr, 0, sizeof(ifr)); 805214518Srpaulo strncpy(ifr.ifr_name, handle->md.mondevice, sizeof(ifr.ifr_name)); 806214518Srpaulo if (ioctl(sock_fd, SIOCGIFFLAGS, &ifr) == -1) { 807214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 808214518Srpaulo "%s: Can't get flags for %s: %s", device, 809214518Srpaulo handle->md.mondevice, strerror(errno)); 810214518Srpaulo del_mon_if(handle, sock_fd, &nlstate, device, 811214518Srpaulo handle->md.mondevice); 812214518Srpaulo nl80211_cleanup(&nlstate); 813214518Srpaulo return PCAP_ERROR; 814214518Srpaulo } 815214518Srpaulo ifr.ifr_flags |= IFF_UP|IFF_RUNNING; 816214518Srpaulo if (ioctl(sock_fd, SIOCSIFFLAGS, &ifr) == -1) { 817214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 818214518Srpaulo "%s: Can't set flags for %s: %s", device, 819214518Srpaulo handle->md.mondevice, strerror(errno)); 820214518Srpaulo del_mon_if(handle, sock_fd, &nlstate, device, 821214518Srpaulo handle->md.mondevice); 822214518Srpaulo nl80211_cleanup(&nlstate); 823214518Srpaulo return PCAP_ERROR; 824214518Srpaulo } 825214518Srpaulo 826214518Srpaulo /* 827214518Srpaulo * Success. Clean up the libnl state. 828214518Srpaulo */ 829214518Srpaulo nl80211_cleanup(&nlstate); 830214518Srpaulo 831214518Srpaulo /* 832214518Srpaulo * Note that we have to delete the monitor device when we close 833214518Srpaulo * the handle. 834214518Srpaulo */ 835214518Srpaulo handle->md.must_do_on_close |= MUST_DELETE_MONIF; 836214518Srpaulo 837214518Srpaulo /* 838214518Srpaulo * Add this to the list of pcaps to close when we exit. 839214518Srpaulo */ 840214518Srpaulo pcap_add_to_pcaps_to_close(handle); 841214518Srpaulo 842214518Srpaulo return 1; 843214518Srpaulo} 844214518Srpaulo#endif /* HAVE_LIBNL */ 845214518Srpaulo 846214518Srpaulostatic int 847214518Srpaulopcap_can_set_rfmon_linux(pcap_t *handle) 848214518Srpaulo{ 849214518Srpaulo#ifdef HAVE_LIBNL 850214518Srpaulo char phydev_path[PATH_MAX+1]; 851214518Srpaulo int ret; 852214518Srpaulo#endif 853190225Srpaulo#ifdef IW_MODE_MONITOR 854190225Srpaulo int sock_fd; 855190225Srpaulo struct iwreq ireq; 856190225Srpaulo#endif 857190225Srpaulo 858214518Srpaulo if (strcmp(handle->opt.source, "any") == 0) { 859190225Srpaulo /* 860214518Srpaulo * Monitor mode makes no sense on the "any" device. 861190225Srpaulo */ 862190225Srpaulo return 0; 86375107Sfenner } 86475107Sfenner 865214518Srpaulo#ifdef HAVE_LIBNL 866214518Srpaulo /* 867214518Srpaulo * Bleah. There doesn't seem to be a way to ask a mac80211 868214518Srpaulo * device, through libnl, whether it supports monitor mode; 869214518Srpaulo * we'll just check whether the device appears to be a 870214518Srpaulo * mac80211 device and, if so, assume the device supports 871214518Srpaulo * monitor mode. 872214518Srpaulo * 873214518Srpaulo * wmaster devices don't appear to support the Wireless 874214518Srpaulo * Extensions, but we can create a mon device for a 875214518Srpaulo * wmaster device, so we don't bother checking whether 876214518Srpaulo * a mac80211 device supports the Wireless Extensions. 877214518Srpaulo */ 878214518Srpaulo ret = get_mac80211_phydev(handle, handle->opt.source, phydev_path, 879214518Srpaulo PATH_MAX); 880214518Srpaulo if (ret < 0) 881214518Srpaulo return ret; /* error */ 882214518Srpaulo if (ret == 1) 883214518Srpaulo return 1; /* mac80211 device */ 884214518Srpaulo#endif 885214518Srpaulo 886190225Srpaulo#ifdef IW_MODE_MONITOR 887190225Srpaulo /* 888190225Srpaulo * Bleah. There doesn't appear to be an ioctl to use to ask 889190225Srpaulo * whether a device supports monitor mode; we'll just do 890190225Srpaulo * SIOCGIWMODE and, if it succeeds, assume the device supports 891190225Srpaulo * monitor mode. 892190225Srpaulo * 893190225Srpaulo * Open a socket on which to attempt to get the mode. 894190225Srpaulo * (We assume that if we have Wireless Extensions support 895190225Srpaulo * we also have PF_PACKET support.) 896190225Srpaulo */ 897190225Srpaulo sock_fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); 898190225Srpaulo if (sock_fd == -1) { 899214518Srpaulo (void)snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 900190225Srpaulo "socket: %s", pcap_strerror(errno)); 901190225Srpaulo return PCAP_ERROR; 902190225Srpaulo } 90375107Sfenner 904190225Srpaulo /* 905190225Srpaulo * Attempt to get the current mode. 906190225Srpaulo */ 907214518Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, handle->opt.source, 908190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 909190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 910190225Srpaulo if (ioctl(sock_fd, SIOCGIWMODE, &ireq) != -1) { 911190225Srpaulo /* 912190225Srpaulo * Well, we got the mode; assume we can set it. 913190225Srpaulo */ 914190225Srpaulo close(sock_fd); 915190225Srpaulo return 1; 916190225Srpaulo } 917190225Srpaulo if (errno == ENODEV) { 918190225Srpaulo /* The device doesn't even exist. */ 919214518Srpaulo (void)snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 920214518Srpaulo "SIOCGIWMODE failed: %s", pcap_strerror(errno)); 921190225Srpaulo close(sock_fd); 922190225Srpaulo return PCAP_ERROR_NO_SUCH_DEVICE; 923190225Srpaulo } 924190225Srpaulo close(sock_fd); 925190225Srpaulo#endif 926190225Srpaulo return 0; 927190225Srpaulo} 92875107Sfenner 929190225Srpaulo/* 930214518Srpaulo * Grabs the number of dropped packets by the interface from /proc/net/dev. 931214518Srpaulo * 932214518Srpaulo * XXX - what about /sys/class/net/{interface name}/rx_*? There are 933214518Srpaulo * individual devices giving, in ASCII, various rx_ and tx_ statistics. 934214518Srpaulo * 935214518Srpaulo * Or can we get them in binary form from netlink? 936214518Srpaulo */ 937214518Srpaulostatic long int 938214518Srpaulolinux_if_drops(const char * if_name) 939214518Srpaulo{ 940214518Srpaulo char buffer[512]; 941214518Srpaulo char * bufptr; 942214518Srpaulo FILE * file; 943214518Srpaulo int field_to_convert = 3, if_name_sz = strlen(if_name); 944214518Srpaulo long int dropped_pkts = 0; 945214518Srpaulo 946214518Srpaulo file = fopen("/proc/net/dev", "r"); 947214518Srpaulo if (!file) 948214518Srpaulo return 0; 949214518Srpaulo 950214518Srpaulo while (!dropped_pkts && fgets( buffer, sizeof(buffer), file )) 951214518Srpaulo { 952214518Srpaulo /* search for 'bytes' -- if its in there, then 953214518Srpaulo that means we need to grab the fourth field. otherwise 954214518Srpaulo grab the third field. */ 955214518Srpaulo if (field_to_convert != 4 && strstr(buffer, "bytes")) 956214518Srpaulo { 957214518Srpaulo field_to_convert = 4; 958214518Srpaulo continue; 959214518Srpaulo } 960214518Srpaulo 961214518Srpaulo /* find iface and make sure it actually matches -- space before the name and : after it */ 962214518Srpaulo if ((bufptr = strstr(buffer, if_name)) && 963214518Srpaulo (bufptr == buffer || *(bufptr-1) == ' ') && 964214518Srpaulo *(bufptr + if_name_sz) == ':') 965214518Srpaulo { 966214518Srpaulo bufptr = bufptr + if_name_sz + 1; 967214518Srpaulo 968214518Srpaulo /* grab the nth field from it */ 969214518Srpaulo while( --field_to_convert && *bufptr != '\0') 970214518Srpaulo { 971214518Srpaulo while (*bufptr != '\0' && *(bufptr++) == ' '); 972214518Srpaulo while (*bufptr != '\0' && *(bufptr++) != ' '); 973214518Srpaulo } 974214518Srpaulo 975214518Srpaulo /* get rid of any final spaces */ 976214518Srpaulo while (*bufptr != '\0' && *bufptr == ' ') bufptr++; 977214518Srpaulo 978214518Srpaulo if (*bufptr != '\0') 979214518Srpaulo dropped_pkts = strtol(bufptr, NULL, 10); 980214518Srpaulo 981214518Srpaulo break; 982214518Srpaulo } 983214518Srpaulo } 984214518Srpaulo 985214518Srpaulo fclose(file); 986214518Srpaulo return dropped_pkts; 987214518Srpaulo} 988214518Srpaulo 989214518Srpaulo 990214518Srpaulo/* 991190225Srpaulo * With older kernels promiscuous mode is kind of interesting because we 992190225Srpaulo * have to reset the interface before exiting. The problem can't really 993190225Srpaulo * be solved without some daemon taking care of managing usage counts. 994190225Srpaulo * If we put the interface into promiscuous mode, we set a flag indicating 995190225Srpaulo * that we must take it out of that mode when the interface is closed, 996190225Srpaulo * and, when closing the interface, if that flag is set we take it out 997190225Srpaulo * of promiscuous mode. 998190225Srpaulo * 999190225Srpaulo * Even with newer kernels, we have the same issue with rfmon mode. 1000190225Srpaulo */ 1001190225Srpaulo 1002190225Srpaulostatic void pcap_cleanup_linux( pcap_t *handle ) 1003190225Srpaulo{ 1004190225Srpaulo struct ifreq ifr; 1005214518Srpaulo#ifdef HAVE_LIBNL 1006214518Srpaulo struct nl80211_state nlstate; 1007214518Srpaulo int ret; 1008214518Srpaulo#endif /* HAVE_LIBNL */ 1009190225Srpaulo#ifdef IW_MODE_MONITOR 1010235426Sdelphij int oldflags; 1011190225Srpaulo struct iwreq ireq; 1012214518Srpaulo#endif /* IW_MODE_MONITOR */ 1013190225Srpaulo 1014214518Srpaulo if (handle->md.must_do_on_close != 0) { 1015190225Srpaulo /* 1016190225Srpaulo * There's something we have to do when closing this 1017190225Srpaulo * pcap_t. 1018190225Srpaulo */ 1019214518Srpaulo if (handle->md.must_do_on_close & MUST_CLEAR_PROMISC) { 1020190225Srpaulo /* 1021190225Srpaulo * We put the interface into promiscuous mode; 1022190225Srpaulo * take it out of promiscuous mode. 1023190225Srpaulo * 1024190225Srpaulo * XXX - if somebody else wants it in promiscuous 1025190225Srpaulo * mode, this code cannot know that, so it'll take 1026190225Srpaulo * it out of promiscuous mode. That's not fixable 1027190225Srpaulo * in 2.0[.x] kernels. 1028190225Srpaulo */ 1029190225Srpaulo memset(&ifr, 0, sizeof(ifr)); 1030190225Srpaulo strncpy(ifr.ifr_name, handle->md.device, 1031190225Srpaulo sizeof(ifr.ifr_name)); 1032190225Srpaulo if (ioctl(handle->fd, SIOCGIFFLAGS, &ifr) == -1) { 1033190225Srpaulo fprintf(stderr, 1034235426Sdelphij "Can't restore interface %s flags (SIOCGIFFLAGS failed: %s).\n" 1035190225Srpaulo "Please adjust manually.\n" 1036190225Srpaulo "Hint: This can't happen with Linux >= 2.2.0.\n", 1037235426Sdelphij handle->md.device, strerror(errno)); 1038190225Srpaulo } else { 1039190225Srpaulo if (ifr.ifr_flags & IFF_PROMISC) { 1040190225Srpaulo /* 1041190225Srpaulo * Promiscuous mode is currently on; 1042190225Srpaulo * turn it off. 1043190225Srpaulo */ 1044190225Srpaulo ifr.ifr_flags &= ~IFF_PROMISC; 1045190225Srpaulo if (ioctl(handle->fd, SIOCSIFFLAGS, 1046190225Srpaulo &ifr) == -1) { 1047190225Srpaulo fprintf(stderr, 1048235426Sdelphij "Can't restore interface %s flags (SIOCSIFFLAGS failed: %s).\n" 1049190225Srpaulo "Please adjust manually.\n" 1050190225Srpaulo "Hint: This can't happen with Linux >= 2.2.0.\n", 1051235426Sdelphij handle->md.device, 1052190225Srpaulo strerror(errno)); 1053190225Srpaulo } 1054190225Srpaulo } 1055190225Srpaulo } 1056190225Srpaulo } 1057190225Srpaulo 1058214518Srpaulo#ifdef HAVE_LIBNL 1059214518Srpaulo if (handle->md.must_do_on_close & MUST_DELETE_MONIF) { 1060214518Srpaulo ret = nl80211_init(handle, &nlstate, handle->md.device); 1061214518Srpaulo if (ret >= 0) { 1062214518Srpaulo ret = del_mon_if(handle, handle->fd, &nlstate, 1063214518Srpaulo handle->md.device, handle->md.mondevice); 1064214518Srpaulo nl80211_cleanup(&nlstate); 1065214518Srpaulo } 1066214518Srpaulo if (ret < 0) { 1067214518Srpaulo fprintf(stderr, 1068214518Srpaulo "Can't delete monitor interface %s (%s).\n" 1069214518Srpaulo "Please delete manually.\n", 1070214518Srpaulo handle->md.mondevice, handle->errbuf); 1071214518Srpaulo } 1072214518Srpaulo } 1073214518Srpaulo#endif /* HAVE_LIBNL */ 1074214518Srpaulo 1075190225Srpaulo#ifdef IW_MODE_MONITOR 1076214518Srpaulo if (handle->md.must_do_on_close & MUST_CLEAR_RFMON) { 1077190225Srpaulo /* 1078190225Srpaulo * We put the interface into rfmon mode; 1079190225Srpaulo * take it out of rfmon mode. 1080190225Srpaulo * 1081190225Srpaulo * XXX - if somebody else wants it in rfmon 1082190225Srpaulo * mode, this code cannot know that, so it'll take 1083190225Srpaulo * it out of rfmon mode. 1084190225Srpaulo */ 1085235426Sdelphij 1086235426Sdelphij /* 1087235426Sdelphij * First, take the interface down if it's up; 1088235426Sdelphij * otherwise, we might get EBUSY. 1089235426Sdelphij * If we get errors, just drive on and print 1090235426Sdelphij * a warning if we can't restore the mode. 1091235426Sdelphij */ 1092235426Sdelphij oldflags = 0; 1093235426Sdelphij memset(&ifr, 0, sizeof(ifr)); 1094235426Sdelphij strncpy(ifr.ifr_name, handle->md.device, 1095235426Sdelphij sizeof(ifr.ifr_name)); 1096235426Sdelphij if (ioctl(handle->fd, SIOCGIFFLAGS, &ifr) != -1) { 1097235426Sdelphij if (ifr.ifr_flags & IFF_UP) { 1098235426Sdelphij oldflags = ifr.ifr_flags; 1099235426Sdelphij ifr.ifr_flags &= ~IFF_UP; 1100235426Sdelphij if (ioctl(handle->fd, SIOCSIFFLAGS, &ifr) == -1) 1101235426Sdelphij oldflags = 0; /* didn't set, don't restore */ 1102235426Sdelphij } 1103235426Sdelphij } 1104235426Sdelphij 1105235426Sdelphij /* 1106235426Sdelphij * Now restore the mode. 1107235426Sdelphij */ 1108190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, handle->md.device, 1109190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 1110190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] 1111190225Srpaulo = 0; 1112190225Srpaulo ireq.u.mode = handle->md.oldmode; 1113190225Srpaulo if (ioctl(handle->fd, SIOCSIWMODE, &ireq) == -1) { 1114190225Srpaulo /* 1115190225Srpaulo * Scientist, you've failed. 1116190225Srpaulo */ 1117190225Srpaulo fprintf(stderr, 1118235426Sdelphij "Can't restore interface %s wireless mode (SIOCSIWMODE failed: %s).\n" 1119190225Srpaulo "Please adjust manually.\n", 1120235426Sdelphij handle->md.device, strerror(errno)); 1121190225Srpaulo } 1122235426Sdelphij 1123235426Sdelphij /* 1124235426Sdelphij * Now bring the interface back up if we brought 1125235426Sdelphij * it down. 1126235426Sdelphij */ 1127235426Sdelphij if (oldflags != 0) { 1128235426Sdelphij ifr.ifr_flags = oldflags; 1129235426Sdelphij if (ioctl(handle->fd, SIOCSIFFLAGS, &ifr) == -1) { 1130235426Sdelphij fprintf(stderr, 1131235426Sdelphij "Can't bring interface %s back up (SIOCSIFFLAGS failed: %s).\n" 1132235426Sdelphij "Please adjust manually.\n", 1133235426Sdelphij handle->md.device, strerror(errno)); 1134235426Sdelphij } 1135235426Sdelphij } 1136190225Srpaulo } 1137214518Srpaulo#endif /* IW_MODE_MONITOR */ 1138190225Srpaulo 1139190225Srpaulo /* 1140190225Srpaulo * Take this pcap out of the list of pcaps for which we 1141190225Srpaulo * have to take the interface out of some mode. 1142190225Srpaulo */ 1143190225Srpaulo pcap_remove_from_pcaps_to_close(handle); 1144190225Srpaulo } 1145190225Srpaulo 1146214518Srpaulo if (handle->md.mondevice != NULL) { 1147214518Srpaulo free(handle->md.mondevice); 1148214518Srpaulo handle->md.mondevice = NULL; 1149214518Srpaulo } 1150190225Srpaulo if (handle->md.device != NULL) { 1151190225Srpaulo free(handle->md.device); 1152190225Srpaulo handle->md.device = NULL; 1153190225Srpaulo } 1154190225Srpaulo pcap_cleanup_live_common(handle); 1155190225Srpaulo} 1156190225Srpaulo 1157190225Srpaulo/* 1158190225Srpaulo * Get a handle for a live capture from the given device. You can 1159190225Srpaulo * pass NULL as device to get all packages (without link level 1160190225Srpaulo * information of course). If you pass 1 as promisc the interface 1161190225Srpaulo * will be set to promiscous mode (XXX: I think this usage should 1162190225Srpaulo * be deprecated and functions be added to select that later allow 1163190225Srpaulo * modification of that values -- Torsten). 1164190225Srpaulo */ 1165190225Srpaulostatic int 1166190225Srpaulopcap_activate_linux(pcap_t *handle) 1167190225Srpaulo{ 1168190225Srpaulo const char *device; 1169190225Srpaulo int status = 0; 1170190225Srpaulo 1171190225Srpaulo device = handle->opt.source; 1172190225Srpaulo 1173190225Srpaulo handle->inject_op = pcap_inject_linux; 1174190225Srpaulo handle->setfilter_op = pcap_setfilter_linux; 1175190225Srpaulo handle->setdirection_op = pcap_setdirection_linux; 1176190225Srpaulo handle->set_datalink_op = NULL; /* can't change data link type */ 1177190225Srpaulo handle->getnonblock_op = pcap_getnonblock_fd; 1178190225Srpaulo handle->setnonblock_op = pcap_setnonblock_fd; 1179190225Srpaulo handle->cleanup_op = pcap_cleanup_linux; 1180190225Srpaulo handle->read_op = pcap_read_linux; 1181190225Srpaulo handle->stats_op = pcap_stats_linux; 1182190225Srpaulo 118375107Sfenner /* 1184214518Srpaulo * The "any" device is a special device which causes us not 1185214518Srpaulo * to bind to a particular device and thus to look at all 1186214518Srpaulo * devices. 118775107Sfenner */ 1188214518Srpaulo if (strcmp(device, "any") == 0) { 1189190225Srpaulo if (handle->opt.promisc) { 1190190225Srpaulo handle->opt.promisc = 0; 119198530Sfenner /* Just a warning. */ 1192190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 119398530Sfenner "Promiscuous mode not supported on the \"any\" device"); 1194190225Srpaulo status = PCAP_WARNING_PROMISC_NOTSUP; 119598530Sfenner } 1196214518Srpaulo } 1197127664Sbms 1198214518Srpaulo handle->md.device = strdup(device); 119975107Sfenner if (handle->md.device == NULL) { 1200190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s", 120175107Sfenner pcap_strerror(errno) ); 1202190225Srpaulo return PCAP_ERROR; 120375107Sfenner } 1204214518Srpaulo 1205214518Srpaulo /* 1206214518Srpaulo * If we're in promiscuous mode, then we probably want 1207214518Srpaulo * to see when the interface drops packets too, so get an 1208214518Srpaulo * initial count from /proc/net/dev 1209214518Srpaulo */ 1210214518Srpaulo if (handle->opt.promisc) 1211214518Srpaulo handle->md.proc_dropped = linux_if_drops(handle->md.device); 121275107Sfenner 1213127664Sbms /* 1214127664Sbms * Current Linux kernels use the protocol family PF_PACKET to 1215127664Sbms * allow direct access to all packets on the network while 1216127664Sbms * older kernels had a special socket type SOCK_PACKET to 121775107Sfenner * implement this feature. 121875107Sfenner * While this old implementation is kind of obsolete we need 1219127664Sbms * to be compatible with older kernels for a while so we are 122075107Sfenner * trying both methods with the newer method preferred. 122175107Sfenner */ 1222235426Sdelphij status = activate_new(handle); 1223235426Sdelphij if (status < 0) { 1224190225Srpaulo /* 1225235426Sdelphij * Fatal error with the new way; just fail. 1226235426Sdelphij * status has the error return; if it's PCAP_ERROR, 1227235426Sdelphij * handle->errbuf has been set appropriately. 1228235426Sdelphij */ 1229235426Sdelphij goto fail; 1230235426Sdelphij } 1231235426Sdelphij if (status == 1) { 1232235426Sdelphij /* 1233214518Srpaulo * Success. 1234190225Srpaulo * Try to use memory-mapped access. 1235190225Srpaulo */ 1236235426Sdelphij switch (activate_mmap(handle, &status)) { 1237214518Srpaulo 1238214518Srpaulo case 1: 1239235426Sdelphij /* 1240235426Sdelphij * We succeeded. status has been 1241235426Sdelphij * set to the status to return, 1242235426Sdelphij * which might be 0, or might be 1243235426Sdelphij * a PCAP_WARNING_ value. 1244235426Sdelphij */ 1245235426Sdelphij return status; 1246214518Srpaulo 1247214518Srpaulo case 0: 1248214518Srpaulo /* 1249214518Srpaulo * Kernel doesn't support it - just continue 1250214518Srpaulo * with non-memory-mapped access. 1251214518Srpaulo */ 1252214518Srpaulo break; 1253214518Srpaulo 1254214518Srpaulo case -1: 1255214518Srpaulo /* 1256235426Sdelphij * We failed to set up to use it, or the kernel 1257235426Sdelphij * supports it, but we failed to enable it. 1258235426Sdelphij * status has been set to the error status to 1259235426Sdelphij * return and, if it's PCAP_ERROR, handle->errbuf 1260235426Sdelphij * contains the error message. 1261214518Srpaulo */ 1262214518Srpaulo goto fail; 1263214518Srpaulo } 1264190225Srpaulo } 1265190225Srpaulo else if (status == 0) { 1266127664Sbms /* Non-fatal error; try old way */ 1267214518Srpaulo if ((status = activate_old(handle)) != 1) { 1268214518Srpaulo /* 1269214518Srpaulo * Both methods to open the packet socket failed. 1270214518Srpaulo * Tidy up and report our failure (handle->errbuf 1271214518Srpaulo * is expected to be set by the functions above). 1272214518Srpaulo */ 1273214518Srpaulo goto fail; 1274214518Srpaulo } 127575107Sfenner } 127675107Sfenner 1277214518Srpaulo /* 1278214518Srpaulo * We set up the socket, but not with memory-mapped access. 1279214518Srpaulo */ 1280235426Sdelphij status = 0; 1281190225Srpaulo if (handle->opt.buffer_size != 0) { 128298530Sfenner /* 1283190225Srpaulo * Set the socket buffer size to the specified value. 128498530Sfenner */ 1285190225Srpaulo if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, 1286190225Srpaulo &handle->opt.buffer_size, 1287190225Srpaulo sizeof(handle->opt.buffer_size)) == -1) { 1288190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 1289190225Srpaulo "SO_RCVBUF: %s", pcap_strerror(errno)); 1290190225Srpaulo status = PCAP_ERROR; 1291190225Srpaulo goto fail; 129298530Sfenner } 129398530Sfenner } 129498530Sfenner 129598530Sfenner /* Allocate the buffer */ 129698530Sfenner 129798530Sfenner handle->buffer = malloc(handle->bufsize + handle->offset); 129898530Sfenner if (!handle->buffer) { 1299190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 130098530Sfenner "malloc: %s", pcap_strerror(errno)); 1301190225Srpaulo status = PCAP_ERROR; 1302190225Srpaulo goto fail; 130398530Sfenner } 130498530Sfenner 1305127664Sbms /* 1306127664Sbms * "handle->fd" is a socket, so "select()" and "poll()" 1307127664Sbms * should work on it. 1308127664Sbms */ 1309127664Sbms handle->selectable_fd = handle->fd; 1310127664Sbms 1311190225Srpaulo return status; 1312127664Sbms 1313190225Srpaulofail: 1314190225Srpaulo pcap_cleanup_linux(handle); 1315190225Srpaulo return status; 131626175Sfenner} 131726175Sfenner 131875107Sfenner/* 131975107Sfenner * Read at most max_packets from the capture stream and call the callback 132075107Sfenner * for each of them. Returns the number of packets handled or -1 if an 1321127664Sbms * error occured. 132275107Sfenner */ 1323127664Sbmsstatic int 1324127664Sbmspcap_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 132526175Sfenner{ 132675107Sfenner /* 132775107Sfenner * Currently, on Linux only one packet is delivered per read, 132875107Sfenner * so we don't loop. 132975107Sfenner */ 133075107Sfenner return pcap_read_packet(handle, callback, user); 133175107Sfenner} 133226175Sfenner 133375107Sfenner/* 1334127664Sbms * Read a packet from the socket calling the handler provided by 133575107Sfenner * the user. Returns the number of packets received or -1 if an 133675107Sfenner * error occured. 133775107Sfenner */ 133875107Sfennerstatic int 133975107Sfennerpcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata) 134075107Sfenner{ 134198530Sfenner u_char *bp; 134275107Sfenner int offset; 134375107Sfenner#ifdef HAVE_PF_PACKET_SOCKETS 134475107Sfenner struct sockaddr_ll from; 134575107Sfenner struct sll_header *hdrp; 134675107Sfenner#else 134775107Sfenner struct sockaddr from; 134875107Sfenner#endif 1349190225Srpaulo#if defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) 1350190225Srpaulo struct iovec iov; 1351190225Srpaulo struct msghdr msg; 1352190225Srpaulo struct cmsghdr *cmsg; 1353190225Srpaulo union { 1354190225Srpaulo struct cmsghdr cmsg; 1355190225Srpaulo char buf[CMSG_SPACE(sizeof(struct tpacket_auxdata))]; 1356190225Srpaulo } cmsg_buf; 1357190225Srpaulo#else /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ 135875107Sfenner socklen_t fromlen; 1359190225Srpaulo#endif /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ 136075107Sfenner int packet_len, caplen; 136175107Sfenner struct pcap_pkthdr pcap_header; 136226175Sfenner 136375107Sfenner#ifdef HAVE_PF_PACKET_SOCKETS 136475107Sfenner /* 136575107Sfenner * If this is a cooked device, leave extra room for a 136675107Sfenner * fake packet header. 136775107Sfenner */ 136875107Sfenner if (handle->md.cooked) 136975107Sfenner offset = SLL_HDR_LEN; 137075107Sfenner else 137175107Sfenner offset = 0; 137275107Sfenner#else 137375107Sfenner /* 137475107Sfenner * This system doesn't have PF_PACKET sockets, so it doesn't 137575107Sfenner * support cooked devices. 137675107Sfenner */ 137775107Sfenner offset = 0; 137875107Sfenner#endif 137975107Sfenner 1380190225Srpaulo /* 1381190225Srpaulo * Receive a single packet from the kernel. 1382190225Srpaulo * We ignore EINTR, as that might just be due to a signal 1383190225Srpaulo * being delivered - if the signal should interrupt the 1384190225Srpaulo * loop, the signal handler should call pcap_breakloop() 1385190225Srpaulo * to set handle->break_loop (we ignore it on other 1386190225Srpaulo * platforms as well). 1387190225Srpaulo * We also ignore ENETDOWN, so that we can continue to 1388190225Srpaulo * capture traffic if the interface goes down and comes 1389190225Srpaulo * back up again; comments in the kernel indicate that 1390190225Srpaulo * we'll just block waiting for packets if we try to 1391190225Srpaulo * receive from a socket that delivered ENETDOWN, and, 1392190225Srpaulo * if we're using a memory-mapped buffer, we won't even 1393190225Srpaulo * get notified of "network down" events. 1394190225Srpaulo */ 1395190225Srpaulo bp = handle->buffer + handle->offset; 139675107Sfenner 1397190225Srpaulo#if defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) 1398190225Srpaulo msg.msg_name = &from; 1399190225Srpaulo msg.msg_namelen = sizeof(from); 1400190225Srpaulo msg.msg_iov = &iov; 1401190225Srpaulo msg.msg_iovlen = 1; 1402190225Srpaulo msg.msg_control = &cmsg_buf; 1403190225Srpaulo msg.msg_controllen = sizeof(cmsg_buf); 1404190225Srpaulo msg.msg_flags = 0; 1405190225Srpaulo 1406190225Srpaulo iov.iov_len = handle->bufsize - offset; 1407190225Srpaulo iov.iov_base = bp + offset; 1408190225Srpaulo#endif /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ 1409190225Srpaulo 141026175Sfenner do { 1411127664Sbms /* 1412127664Sbms * Has "pcap_breakloop()" been called? 1413127664Sbms */ 1414127664Sbms if (handle->break_loop) { 1415127664Sbms /* 1416214518Srpaulo * Yes - clear the flag that indicates that it has, 1417214518Srpaulo * and return PCAP_ERROR_BREAK as an indication that 1418214518Srpaulo * we were told to break out of the loop. 1419127664Sbms */ 1420127664Sbms handle->break_loop = 0; 1421214518Srpaulo return PCAP_ERROR_BREAK; 1422127664Sbms } 1423190225Srpaulo 1424190225Srpaulo#if defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) 1425190225Srpaulo packet_len = recvmsg(handle->fd, &msg, MSG_TRUNC); 1426190225Srpaulo#else /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ 142726175Sfenner fromlen = sizeof(from); 1428127664Sbms packet_len = recvfrom( 142998530Sfenner handle->fd, bp + offset, 1430127664Sbms handle->bufsize - offset, MSG_TRUNC, 143175107Sfenner (struct sockaddr *) &from, &fromlen); 1432190225Srpaulo#endif /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ 1433214518Srpaulo } while (packet_len == -1 && errno == EINTR); 143426175Sfenner 143575107Sfenner /* Check if an error occured */ 143626175Sfenner 143775107Sfenner if (packet_len == -1) { 1438214518Srpaulo switch (errno) { 1439214518Srpaulo 1440214518Srpaulo case EAGAIN: 144175107Sfenner return 0; /* no packet there */ 1442214518Srpaulo 1443214518Srpaulo case ENETDOWN: 1444214518Srpaulo /* 1445214518Srpaulo * The device on which we're capturing went away. 1446214518Srpaulo * 1447214518Srpaulo * XXX - we should really return 1448214518Srpaulo * PCAP_ERROR_IFACE_NOT_UP, but pcap_dispatch() 1449214518Srpaulo * etc. aren't defined to return that. 1450214518Srpaulo */ 1451190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 1452214518Srpaulo "The interface went down"); 1453214518Srpaulo return PCAP_ERROR; 1454214518Srpaulo 1455214518Srpaulo default: 1456214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 145775107Sfenner "recvfrom: %s", pcap_strerror(errno)); 1458214518Srpaulo return PCAP_ERROR; 145926175Sfenner } 146075107Sfenner } 146126175Sfenner 146275107Sfenner#ifdef HAVE_PF_PACKET_SOCKETS 1463147894Ssam if (!handle->md.sock_packet) { 1464147894Ssam /* 1465172677Smlaier * Unfortunately, there is a window between socket() and 1466172677Smlaier * bind() where the kernel may queue packets from any 1467172677Smlaier * interface. If we're bound to a particular interface, 1468172677Smlaier * discard packets not from that interface. 1469172677Smlaier * 1470172677Smlaier * (If socket filters are supported, we could do the 1471172677Smlaier * same thing we do when changing the filter; however, 1472172677Smlaier * that won't handle packet sockets without socket 1473172677Smlaier * filter support, and it's a bit more complicated. 1474172677Smlaier * It would save some instructions per packet, however.) 1475172677Smlaier */ 1476172677Smlaier if (handle->md.ifindex != -1 && 1477172677Smlaier from.sll_ifindex != handle->md.ifindex) 1478172677Smlaier return 0; 1479172677Smlaier 1480172677Smlaier /* 1481147894Ssam * Do checks based on packet direction. 1482147894Ssam * We can only do this if we're using PF_PACKET; the 1483147894Ssam * address returned for SOCK_PACKET is a "sockaddr_pkt" 1484147894Ssam * which lacks the relevant packet type information. 1485147894Ssam */ 1486147894Ssam if (from.sll_pkttype == PACKET_OUTGOING) { 1487147894Ssam /* 1488147894Ssam * Outgoing packet. 1489147894Ssam * If this is from the loopback device, reject it; 1490147894Ssam * we'll see the packet as an incoming packet as well, 1491147894Ssam * and we don't want to see it twice. 1492147894Ssam */ 1493147894Ssam if (from.sll_ifindex == handle->md.lo_ifindex) 1494147894Ssam return 0; 1495147894Ssam 1496147894Ssam /* 1497147894Ssam * If the user only wants incoming packets, reject it. 1498147894Ssam */ 1499162012Ssam if (handle->direction == PCAP_D_IN) 1500147894Ssam return 0; 1501147894Ssam } else { 1502147894Ssam /* 1503147894Ssam * Incoming packet. 1504147894Ssam * If the user only wants outgoing packets, reject it. 1505147894Ssam */ 1506162012Ssam if (handle->direction == PCAP_D_OUT) 1507147894Ssam return 0; 1508147894Ssam } 1509147894Ssam } 151075107Sfenner#endif 151126175Sfenner 151275107Sfenner#ifdef HAVE_PF_PACKET_SOCKETS 151375107Sfenner /* 151475107Sfenner * If this is a cooked device, fill in the fake packet header. 151575107Sfenner */ 151675107Sfenner if (handle->md.cooked) { 151775107Sfenner /* 151875107Sfenner * Add the length of the fake header to the length 151975107Sfenner * of packet data we read. 152075107Sfenner */ 152175107Sfenner packet_len += SLL_HDR_LEN; 152226175Sfenner 152398530Sfenner hdrp = (struct sll_header *)bp; 1524190225Srpaulo hdrp->sll_pkttype = map_packet_type_to_sll_type(from.sll_pkttype); 1525190225Srpaulo hdrp->sll_hatype = htons(from.sll_hatype); 1526190225Srpaulo hdrp->sll_halen = htons(from.sll_halen); 1527190225Srpaulo memcpy(hdrp->sll_addr, from.sll_addr, 1528190225Srpaulo (from.sll_halen > SLL_ADDRLEN) ? 1529190225Srpaulo SLL_ADDRLEN : 1530190225Srpaulo from.sll_halen); 1531190225Srpaulo hdrp->sll_protocol = from.sll_protocol; 1532190225Srpaulo } 153326175Sfenner 1534190225Srpaulo#if defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) 1535251129Sdelphij if (handle->md.vlan_offset != -1) { 1536251129Sdelphij for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { 1537251129Sdelphij struct tpacket_auxdata *aux; 1538251129Sdelphij unsigned int len; 1539251129Sdelphij struct vlan_tag *tag; 154026175Sfenner 1541251129Sdelphij if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct tpacket_auxdata)) || 1542251129Sdelphij cmsg->cmsg_level != SOL_PACKET || 1543251129Sdelphij cmsg->cmsg_type != PACKET_AUXDATA) 1544251129Sdelphij continue; 154526175Sfenner 1546251129Sdelphij aux = (struct tpacket_auxdata *)CMSG_DATA(cmsg); 1547251129Sdelphij#if defined(TP_STATUS_VLAN_VALID) 1548251129Sdelphij if ((aux->tp_vlan_tci == 0) && !(aux->tp_status & TP_STATUS_VLAN_VALID)) 1549251129Sdelphij#else 1550251129Sdelphij if (aux->tp_vlan_tci == 0) /* this is ambigious but without the 1551251129Sdelphij TP_STATUS_VLAN_VALID flag, there is 1552251129Sdelphij nothing that we can do */ 1553251129Sdelphij#endif 1554251129Sdelphij continue; 155575107Sfenner 1556251129Sdelphij len = packet_len > iov.iov_len ? iov.iov_len : packet_len; 1557251129Sdelphij if (len < (unsigned int) handle->md.vlan_offset) 1558251129Sdelphij break; 155975107Sfenner 1560251129Sdelphij bp -= VLAN_TAG_LEN; 1561251129Sdelphij memmove(bp, bp + VLAN_TAG_LEN, handle->md.vlan_offset); 156275107Sfenner 1563251129Sdelphij tag = (struct vlan_tag *)(bp + handle->md.vlan_offset); 1564251129Sdelphij tag->vlan_tpid = htons(ETH_P_8021Q); 1565251129Sdelphij tag->vlan_tci = htons(aux->tp_vlan_tci); 156675107Sfenner 1567251129Sdelphij packet_len += VLAN_TAG_LEN; 1568251129Sdelphij } 156926175Sfenner } 1570190225Srpaulo#endif /* defined(HAVE_PACKET_AUXDATA) && defined(HAVE_LINUX_TPACKET_AUXDATA_TP_VLAN_TCI) */ 1571190225Srpaulo#endif /* HAVE_PF_PACKET_SOCKETS */ 157275107Sfenner 157375107Sfenner /* 1574127664Sbms * XXX: According to the kernel source we should get the real 1575127664Sbms * packet len if calling recvfrom with MSG_TRUNC set. It does 157675107Sfenner * not seem to work here :(, but it is supported by this code 1577127664Sbms * anyway. 157875107Sfenner * To be honest the code RELIES on that feature so this is really 157975107Sfenner * broken with 2.2.x kernels. 158075107Sfenner * I spend a day to figure out what's going on and I found out 1581127664Sbms * that the following is happening: 158275107Sfenner * 1583127664Sbms * The packet comes from a random interface and the packet_rcv 158475107Sfenner * hook is called with a clone of the packet. That code inserts 158575107Sfenner * the packet into the receive queue of the packet socket. 158675107Sfenner * If a filter is attached to that socket that filter is run 158775107Sfenner * first - and there lies the problem. The default filter always 158875107Sfenner * cuts the packet at the snaplen: 158975107Sfenner * 159075107Sfenner * # tcpdump -d 159175107Sfenner * (000) ret #68 159275107Sfenner * 1593127664Sbms * So the packet filter cuts down the packet. The recvfrom call 159475107Sfenner * says "hey, it's only 68 bytes, it fits into the buffer" with 1595127664Sbms * the result that we don't get the real packet length. This 1596127664Sbms * is valid at least until kernel 2.2.17pre6. 159775107Sfenner * 159875107Sfenner * We currently handle this by making a copy of the filter 159975107Sfenner * program, fixing all "ret" instructions with non-zero 160075107Sfenner * operands to have an operand of 65535 so that the filter 160175107Sfenner * doesn't truncate the packet, and supplying that modified 160275107Sfenner * filter to the kernel. 160375107Sfenner */ 160475107Sfenner 160575107Sfenner caplen = packet_len; 160675107Sfenner if (caplen > handle->snapshot) 160775107Sfenner caplen = handle->snapshot; 160875107Sfenner 160975107Sfenner /* Run the packet filter if not using kernel filter */ 161075107Sfenner if (!handle->md.use_bpf && handle->fcode.bf_insns) { 161198530Sfenner if (bpf_filter(handle->fcode.bf_insns, bp, 161275107Sfenner packet_len, caplen) == 0) 161375107Sfenner { 161475107Sfenner /* rejected by filter */ 161575107Sfenner return 0; 161675107Sfenner } 161775107Sfenner } 161875107Sfenner 161975107Sfenner /* Fill in our own header data */ 162075107Sfenner 162175107Sfenner if (ioctl(handle->fd, SIOCGSTAMP, &pcap_header.ts) == -1) { 1622190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 1623172677Smlaier "SIOCGSTAMP: %s", pcap_strerror(errno)); 1624214518Srpaulo return PCAP_ERROR; 162575107Sfenner } 162675107Sfenner pcap_header.caplen = caplen; 162775107Sfenner pcap_header.len = packet_len; 162875107Sfenner 162998530Sfenner /* 163098530Sfenner * Count the packet. 163198530Sfenner * 163298530Sfenner * Arguably, we should count them before we check the filter, 163398530Sfenner * as on many other platforms "ps_recv" counts packets 163498530Sfenner * handed to the filter rather than packets that passed 163598530Sfenner * the filter, but if filtering is done in the kernel, we 163698530Sfenner * can't get a count of packets that passed the filter, 163798530Sfenner * and that would mean the meaning of "ps_recv" wouldn't 163898530Sfenner * be the same on all Linux systems. 163998530Sfenner * 164098530Sfenner * XXX - it's not the same on all systems in any case; 164198530Sfenner * ideally, we should have a "get the statistics" call 164298530Sfenner * that supplies more counts and indicates which of them 164398530Sfenner * it supplies, so that we supply a count of packets 164498530Sfenner * handed to the filter only on platforms where that 164598530Sfenner * information is available. 164698530Sfenner * 164798530Sfenner * We count them here even if we can get the packet count 164898530Sfenner * from the kernel, as we can only determine at run time 164998530Sfenner * whether we'll be able to get it from the kernel (if 165098530Sfenner * HAVE_TPACKET_STATS isn't defined, we can't get it from 165198530Sfenner * the kernel, but if it is defined, the library might 165298530Sfenner * have been built with a 2.4 or later kernel, but we 165398530Sfenner * might be running on a 2.2[.x] kernel without Alexey 165498530Sfenner * Kuznetzov's turbopacket patches, and thus the kernel 165598530Sfenner * might not be able to supply those statistics). We 165698530Sfenner * could, I guess, try, when opening the socket, to get 165798530Sfenner * the statistics, and if we can not increment the count 165898530Sfenner * here, but it's not clear that always incrementing 165998530Sfenner * the count is more expensive than always testing a flag 166098530Sfenner * in memory. 1661172677Smlaier * 1662172677Smlaier * We keep the count in "md.packets_read", and use that for 1663172677Smlaier * "ps_recv" if we can't get the statistics from the kernel. 1664172677Smlaier * We do that because, if we *can* get the statistics from 1665172677Smlaier * the kernel, we use "md.stat.ps_recv" and "md.stat.ps_drop" 1666172677Smlaier * as running counts, as reading the statistics from the 1667172677Smlaier * kernel resets the kernel statistics, and if we directly 1668172677Smlaier * increment "md.stat.ps_recv" here, that means it will 1669172677Smlaier * count packets *twice* on systems where we can get kernel 1670172677Smlaier * statistics - once here, and once in pcap_stats_linux(). 167198530Sfenner */ 1672172677Smlaier handle->md.packets_read++; 167375107Sfenner 167498530Sfenner /* Call the user supplied callback function */ 167598530Sfenner callback(userdata, &pcap_header, bp); 167698530Sfenner 167775107Sfenner return 1; 167826175Sfenner} 167926175Sfenner 1680146768Ssamstatic int 1681146768Ssampcap_inject_linux(pcap_t *handle, const void *buf, size_t size) 1682146768Ssam{ 1683146768Ssam int ret; 1684146768Ssam 1685146768Ssam#ifdef HAVE_PF_PACKET_SOCKETS 1686146768Ssam if (!handle->md.sock_packet) { 1687146768Ssam /* PF_PACKET socket */ 1688146768Ssam if (handle->md.ifindex == -1) { 1689146768Ssam /* 1690146768Ssam * We don't support sending on the "any" device. 1691146768Ssam */ 1692146768Ssam strlcpy(handle->errbuf, 1693146768Ssam "Sending packets isn't supported on the \"any\" device", 1694146768Ssam PCAP_ERRBUF_SIZE); 1695146768Ssam return (-1); 1696146768Ssam } 1697146768Ssam 1698146768Ssam if (handle->md.cooked) { 1699146768Ssam /* 1700146768Ssam * We don't support sending on the "any" device. 1701146768Ssam * 1702146768Ssam * XXX - how do you send on a bound cooked-mode 1703146768Ssam * socket? 1704146768Ssam * Is a "sendto()" required there? 1705146768Ssam */ 1706146768Ssam strlcpy(handle->errbuf, 1707146768Ssam "Sending packets isn't supported in cooked mode", 1708146768Ssam PCAP_ERRBUF_SIZE); 1709146768Ssam return (-1); 1710146768Ssam } 1711146768Ssam } 1712146768Ssam#endif 1713146768Ssam 1714146768Ssam ret = send(handle->fd, buf, size, 0); 1715146768Ssam if (ret == -1) { 1716146768Ssam snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "send: %s", 1717146768Ssam pcap_strerror(errno)); 1718146768Ssam return (-1); 1719146768Ssam } 1720146768Ssam return (ret); 1721146768Ssam} 1722146768Ssam 172375107Sfenner/* 172475107Sfenner * Get the statistics for the given packet capture handle. 172598530Sfenner * Reports the number of dropped packets iff the kernel supports 172698530Sfenner * the PACKET_STATISTICS "getsockopt()" argument (2.4 and later 172798530Sfenner * kernels, and 2.2[.x] kernels with Alexey Kuznetzov's turbopacket 172898530Sfenner * patches); otherwise, that information isn't available, and we lie 172998530Sfenner * and report 0 as the count of dropped packets. 173075107Sfenner */ 1731127664Sbmsstatic int 1732127664Sbmspcap_stats_linux(pcap_t *handle, struct pcap_stat *stats) 173326175Sfenner{ 173498530Sfenner#ifdef HAVE_TPACKET_STATS 173598530Sfenner struct tpacket_stats kstats; 173698530Sfenner socklen_t len = sizeof (struct tpacket_stats); 1737127664Sbms#endif 173898530Sfenner 1739214518Srpaulo long if_dropped = 0; 1740214518Srpaulo 1741214518Srpaulo /* 1742214518Srpaulo * To fill in ps_ifdrop, we parse /proc/net/dev for the number 1743214518Srpaulo */ 1744214518Srpaulo if (handle->opt.promisc) 1745214518Srpaulo { 1746214518Srpaulo if_dropped = handle->md.proc_dropped; 1747214518Srpaulo handle->md.proc_dropped = linux_if_drops(handle->md.device); 1748214518Srpaulo handle->md.stat.ps_ifdrop += (handle->md.proc_dropped - if_dropped); 1749214518Srpaulo } 1750214518Srpaulo 1751127664Sbms#ifdef HAVE_TPACKET_STATS 175298530Sfenner /* 175398530Sfenner * Try to get the packet counts from the kernel. 175498530Sfenner */ 175598530Sfenner if (getsockopt(handle->fd, SOL_PACKET, PACKET_STATISTICS, 175698530Sfenner &kstats, &len) > -1) { 175798530Sfenner /* 1758172677Smlaier * On systems where the PACKET_STATISTICS "getsockopt()" 1759172677Smlaier * argument is supported on PF_PACKET sockets: 1760172677Smlaier * 1761172677Smlaier * "ps_recv" counts only packets that *passed* the 1762172677Smlaier * filter, not packets that didn't pass the filter. 1763172677Smlaier * This includes packets later dropped because we 1764172677Smlaier * ran out of buffer space. 1765172677Smlaier * 1766172677Smlaier * "ps_drop" counts packets dropped because we ran 1767172677Smlaier * out of buffer space. It doesn't count packets 1768172677Smlaier * dropped by the interface driver. It counts only 1769172677Smlaier * packets that passed the filter. 1770172677Smlaier * 1771214518Srpaulo * See above for ps_ifdrop. 1772214518Srpaulo * 1773172677Smlaier * Both statistics include packets not yet read from 1774172677Smlaier * the kernel by libpcap, and thus not yet seen by 1775172677Smlaier * the application. 1776172677Smlaier * 177798530Sfenner * In "linux/net/packet/af_packet.c", at least in the 177898530Sfenner * 2.4.9 kernel, "tp_packets" is incremented for every 177998530Sfenner * packet that passes the packet filter *and* is 178098530Sfenner * successfully queued on the socket; "tp_drops" is 178198530Sfenner * incremented for every packet dropped because there's 178298530Sfenner * not enough free space in the socket buffer. 178398530Sfenner * 178498530Sfenner * When the statistics are returned for a PACKET_STATISTICS 178598530Sfenner * "getsockopt()" call, "tp_drops" is added to "tp_packets", 178698530Sfenner * so that "tp_packets" counts all packets handed to 178798530Sfenner * the PF_PACKET socket, including packets dropped because 178898530Sfenner * there wasn't room on the socket buffer - but not 178998530Sfenner * including packets that didn't pass the filter. 179098530Sfenner * 179198530Sfenner * In the BSD BPF, the count of received packets is 179298530Sfenner * incremented for every packet handed to BPF, regardless 179398530Sfenner * of whether it passed the filter. 179498530Sfenner * 179598530Sfenner * We can't make "pcap_stats()" work the same on both 179698530Sfenner * platforms, but the best approximation is to return 179798530Sfenner * "tp_packets" as the count of packets and "tp_drops" 179898530Sfenner * as the count of drops. 1799146768Ssam * 1800146768Ssam * Keep a running total because each call to 1801146768Ssam * getsockopt(handle->fd, SOL_PACKET, PACKET_STATISTICS, .... 1802146768Ssam * resets the counters to zero. 180398530Sfenner */ 1804146768Ssam handle->md.stat.ps_recv += kstats.tp_packets; 1805146768Ssam handle->md.stat.ps_drop += kstats.tp_drops; 1806172677Smlaier *stats = handle->md.stat; 1807172677Smlaier return 0; 180898530Sfenner } 180998530Sfenner else 181098530Sfenner { 181198530Sfenner /* 181298530Sfenner * If the error was EOPNOTSUPP, fall through, so that 181398530Sfenner * if you build the library on a system with 181498530Sfenner * "struct tpacket_stats" and run it on a system 181598530Sfenner * that doesn't, it works as it does if the library 181698530Sfenner * is built on a system without "struct tpacket_stats". 181798530Sfenner */ 181898530Sfenner if (errno != EOPNOTSUPP) { 181998530Sfenner snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 182098530Sfenner "pcap_stats: %s", pcap_strerror(errno)); 182198530Sfenner return -1; 182298530Sfenner } 182398530Sfenner } 182498530Sfenner#endif 182598530Sfenner /* 182698530Sfenner * On systems where the PACKET_STATISTICS "getsockopt()" argument 182798530Sfenner * is not supported on PF_PACKET sockets: 182898530Sfenner * 182998530Sfenner * "ps_recv" counts only packets that *passed* the filter, 183098530Sfenner * not packets that didn't pass the filter. It does not 183198530Sfenner * count packets dropped because we ran out of buffer 183298530Sfenner * space. 183398530Sfenner * 183498530Sfenner * "ps_drop" is not supported. 183598530Sfenner * 1836214518Srpaulo * "ps_ifdrop" is supported. It will return the number 1837214518Srpaulo * of drops the interface reports in /proc/net/dev, 1838214518Srpaulo * if that is available. 1839214518Srpaulo * 184098530Sfenner * "ps_recv" doesn't include packets not yet read from 184198530Sfenner * the kernel by libpcap. 1842172677Smlaier * 1843172677Smlaier * We maintain the count of packets processed by libpcap in 1844172677Smlaier * "md.packets_read", for reasons described in the comment 1845172677Smlaier * at the end of pcap_read_packet(). We have no idea how many 1846214518Srpaulo * packets were dropped by the kernel buffers -- but we know 1847214518Srpaulo * how many the interface dropped, so we can return that. 184898530Sfenner */ 1849214518Srpaulo 1850172677Smlaier stats->ps_recv = handle->md.packets_read; 1851172677Smlaier stats->ps_drop = 0; 1852214518Srpaulo stats->ps_ifdrop = handle->md.stat.ps_ifdrop; 185375107Sfenner return 0; 185475107Sfenner} 185526175Sfenner 185675107Sfenner/* 1857214518Srpaulo * Get from "/sys/class/net" all interfaces listed there; if they're 1858214518Srpaulo * already in the list of interfaces we have, that won't add another 1859214518Srpaulo * instance, but if they're not, that'll add them. 1860214518Srpaulo * 1861214518Srpaulo * We don't bother getting any addresses for them; it appears you can't 1862214518Srpaulo * use SIOCGIFADDR on Linux to get IPv6 addresses for interfaces, and, 1863214518Srpaulo * although some other types of addresses can be fetched with SIOCGIFADDR, 1864214518Srpaulo * we don't bother with them for now. 1865214518Srpaulo * 1866214518Srpaulo * We also don't fail if we couldn't open "/sys/class/net"; we just leave 1867214518Srpaulo * the list of interfaces as is, and return 0, so that we can try 1868214518Srpaulo * scanning /proc/net/dev. 1869214518Srpaulo */ 1870214518Srpaulostatic int 1871214518Srpauloscan_sys_class_net(pcap_if_t **devlistp, char *errbuf) 1872214518Srpaulo{ 1873214518Srpaulo DIR *sys_class_net_d; 1874214518Srpaulo int fd; 1875214518Srpaulo struct dirent *ent; 1876251129Sdelphij char subsystem_path[PATH_MAX+1]; 1877251129Sdelphij struct stat statb; 1878214518Srpaulo char *p; 1879214518Srpaulo char name[512]; /* XXX - pick a size */ 1880214518Srpaulo char *q, *saveq; 1881214518Srpaulo struct ifreq ifrflags; 1882214518Srpaulo int ret = 1; 1883214518Srpaulo 1884214518Srpaulo sys_class_net_d = opendir("/sys/class/net"); 1885235426Sdelphij if (sys_class_net_d == NULL) { 1886235426Sdelphij /* 1887235426Sdelphij * Don't fail if it doesn't exist at all. 1888235426Sdelphij */ 1889235426Sdelphij if (errno == ENOENT) 1890235426Sdelphij return (0); 1891214518Srpaulo 1892235426Sdelphij /* 1893235426Sdelphij * Fail if we got some other error. 1894235426Sdelphij */ 1895235426Sdelphij (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 1896235426Sdelphij "Can't open /sys/class/net: %s", pcap_strerror(errno)); 1897235426Sdelphij return (-1); 1898235426Sdelphij } 1899235426Sdelphij 1900214518Srpaulo /* 1901214518Srpaulo * Create a socket from which to fetch interface information. 1902214518Srpaulo */ 1903214518Srpaulo fd = socket(AF_INET, SOCK_DGRAM, 0); 1904214518Srpaulo if (fd < 0) { 1905214518Srpaulo (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 1906214518Srpaulo "socket: %s", pcap_strerror(errno)); 1907235426Sdelphij (void)closedir(sys_class_net_d); 1908214518Srpaulo return (-1); 1909214518Srpaulo } 1910214518Srpaulo 1911214518Srpaulo for (;;) { 1912214518Srpaulo errno = 0; 1913214518Srpaulo ent = readdir(sys_class_net_d); 1914214518Srpaulo if (ent == NULL) { 1915214518Srpaulo /* 1916214518Srpaulo * Error or EOF; if errno != 0, it's an error. 1917214518Srpaulo */ 1918214518Srpaulo break; 1919214518Srpaulo } 1920214518Srpaulo 1921214518Srpaulo /* 1922251129Sdelphij * Ignore "." and "..". 1923214518Srpaulo */ 1924251129Sdelphij if (strcmp(ent->d_name, ".") == 0 || 1925251129Sdelphij strcmp(ent->d_name, "..") == 0) 1926214518Srpaulo continue; 1927214518Srpaulo 1928214518Srpaulo /* 1929251129Sdelphij * Ignore plain files; they do not have subdirectories 1930251129Sdelphij * and thus have no attributes. 1931251129Sdelphij */ 1932251129Sdelphij if (ent->d_type == DT_REG) 1933251129Sdelphij continue; 1934251129Sdelphij 1935251129Sdelphij /* 1936251129Sdelphij * Is there an "ifindex" file under that name? 1937251129Sdelphij * (We don't care whether it's a directory or 1938251129Sdelphij * a symlink; older kernels have directories 1939251129Sdelphij * for devices, newer kernels have symlinks to 1940251129Sdelphij * directories.) 1941251129Sdelphij */ 1942251129Sdelphij snprintf(subsystem_path, sizeof subsystem_path, 1943251129Sdelphij "/sys/class/net/%s/ifindex", ent->d_name); 1944251129Sdelphij if (lstat(subsystem_path, &statb) != 0) { 1945251129Sdelphij /* 1946251129Sdelphij * Stat failed. Either there was an error 1947251129Sdelphij * other than ENOENT, and we don't know if 1948251129Sdelphij * this is an interface, or it's ENOENT, 1949251129Sdelphij * and either some part of "/sys/class/net/{if}" 1950251129Sdelphij * disappeared, in which case it probably means 1951251129Sdelphij * the interface disappeared, or there's no 1952251129Sdelphij * "ifindex" file, which means it's not a 1953251129Sdelphij * network interface. 1954251129Sdelphij */ 1955251129Sdelphij continue; 1956251129Sdelphij } 1957251129Sdelphij 1958251129Sdelphij /* 1959214518Srpaulo * Get the interface name. 1960214518Srpaulo */ 1961214518Srpaulo p = &ent->d_name[0]; 1962214518Srpaulo q = &name[0]; 1963214518Srpaulo while (*p != '\0' && isascii(*p) && !isspace(*p)) { 1964214518Srpaulo if (*p == ':') { 1965214518Srpaulo /* 1966214518Srpaulo * This could be the separator between a 1967214518Srpaulo * name and an alias number, or it could be 1968214518Srpaulo * the separator between a name with no 1969214518Srpaulo * alias number and the next field. 1970214518Srpaulo * 1971214518Srpaulo * If there's a colon after digits, it 1972214518Srpaulo * separates the name and the alias number, 1973214518Srpaulo * otherwise it separates the name and the 1974214518Srpaulo * next field. 1975214518Srpaulo */ 1976214518Srpaulo saveq = q; 1977214518Srpaulo while (isascii(*p) && isdigit(*p)) 1978214518Srpaulo *q++ = *p++; 1979214518Srpaulo if (*p != ':') { 1980214518Srpaulo /* 1981214518Srpaulo * That was the next field, 1982214518Srpaulo * not the alias number. 1983214518Srpaulo */ 1984214518Srpaulo q = saveq; 1985214518Srpaulo } 1986214518Srpaulo break; 1987214518Srpaulo } else 1988214518Srpaulo *q++ = *p++; 1989214518Srpaulo } 1990214518Srpaulo *q = '\0'; 1991214518Srpaulo 1992214518Srpaulo /* 1993214518Srpaulo * Get the flags for this interface, and skip it if 1994214518Srpaulo * it's not up. 1995214518Srpaulo */ 1996214518Srpaulo strncpy(ifrflags.ifr_name, name, sizeof(ifrflags.ifr_name)); 1997214518Srpaulo if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) { 1998235426Sdelphij if (errno == ENXIO || errno == ENODEV) 1999214518Srpaulo continue; 2000214518Srpaulo (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 2001214518Srpaulo "SIOCGIFFLAGS: %.*s: %s", 2002214518Srpaulo (int)sizeof(ifrflags.ifr_name), 2003214518Srpaulo ifrflags.ifr_name, 2004214518Srpaulo pcap_strerror(errno)); 2005214518Srpaulo ret = -1; 2006214518Srpaulo break; 2007214518Srpaulo } 2008214518Srpaulo if (!(ifrflags.ifr_flags & IFF_UP)) 2009214518Srpaulo continue; 2010214518Srpaulo 2011214518Srpaulo /* 2012214518Srpaulo * Add an entry for this interface, with no addresses. 2013214518Srpaulo */ 2014214518Srpaulo if (pcap_add_if(devlistp, name, ifrflags.ifr_flags, NULL, 2015214518Srpaulo errbuf) == -1) { 2016214518Srpaulo /* 2017214518Srpaulo * Failure. 2018214518Srpaulo */ 2019214518Srpaulo ret = -1; 2020214518Srpaulo break; 2021214518Srpaulo } 2022214518Srpaulo } 2023214518Srpaulo if (ret != -1) { 2024214518Srpaulo /* 2025214518Srpaulo * Well, we didn't fail for any other reason; did we 2026214518Srpaulo * fail due to an error reading the directory? 2027214518Srpaulo */ 2028214518Srpaulo if (errno != 0) { 2029214518Srpaulo (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 2030214518Srpaulo "Error reading /sys/class/net: %s", 2031214518Srpaulo pcap_strerror(errno)); 2032214518Srpaulo ret = -1; 2033214518Srpaulo } 2034214518Srpaulo } 2035214518Srpaulo 2036214518Srpaulo (void)close(fd); 2037214518Srpaulo (void)closedir(sys_class_net_d); 2038214518Srpaulo return (ret); 2039214518Srpaulo} 2040214518Srpaulo 2041214518Srpaulo/* 2042214518Srpaulo * Get from "/proc/net/dev" all interfaces listed there; if they're 2043214518Srpaulo * already in the list of interfaces we have, that won't add another 2044214518Srpaulo * instance, but if they're not, that'll add them. 2045214518Srpaulo * 2046214518Srpaulo * See comments from scan_sys_class_net(). 2047214518Srpaulo */ 2048214518Srpaulostatic int 2049214518Srpauloscan_proc_net_dev(pcap_if_t **devlistp, char *errbuf) 2050214518Srpaulo{ 2051214518Srpaulo FILE *proc_net_f; 2052214518Srpaulo int fd; 2053214518Srpaulo char linebuf[512]; 2054214518Srpaulo int linenum; 2055214518Srpaulo char *p; 2056214518Srpaulo char name[512]; /* XXX - pick a size */ 2057214518Srpaulo char *q, *saveq; 2058214518Srpaulo struct ifreq ifrflags; 2059214518Srpaulo int ret = 0; 2060214518Srpaulo 2061214518Srpaulo proc_net_f = fopen("/proc/net/dev", "r"); 2062235426Sdelphij if (proc_net_f == NULL) { 2063235426Sdelphij /* 2064235426Sdelphij * Don't fail if it doesn't exist at all. 2065235426Sdelphij */ 2066235426Sdelphij if (errno == ENOENT) 2067235426Sdelphij return (0); 2068214518Srpaulo 2069235426Sdelphij /* 2070235426Sdelphij * Fail if we got some other error. 2071235426Sdelphij */ 2072235426Sdelphij (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 2073235426Sdelphij "Can't open /proc/net/dev: %s", pcap_strerror(errno)); 2074235426Sdelphij return (-1); 2075235426Sdelphij } 2076235426Sdelphij 2077214518Srpaulo /* 2078214518Srpaulo * Create a socket from which to fetch interface information. 2079214518Srpaulo */ 2080214518Srpaulo fd = socket(AF_INET, SOCK_DGRAM, 0); 2081214518Srpaulo if (fd < 0) { 2082214518Srpaulo (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 2083214518Srpaulo "socket: %s", pcap_strerror(errno)); 2084235426Sdelphij (void)fclose(proc_net_f); 2085214518Srpaulo return (-1); 2086214518Srpaulo } 2087214518Srpaulo 2088214518Srpaulo for (linenum = 1; 2089214518Srpaulo fgets(linebuf, sizeof linebuf, proc_net_f) != NULL; linenum++) { 2090214518Srpaulo /* 2091214518Srpaulo * Skip the first two lines - they're headers. 2092214518Srpaulo */ 2093214518Srpaulo if (linenum <= 2) 2094214518Srpaulo continue; 2095214518Srpaulo 2096214518Srpaulo p = &linebuf[0]; 2097214518Srpaulo 2098214518Srpaulo /* 2099214518Srpaulo * Skip leading white space. 2100214518Srpaulo */ 2101214518Srpaulo while (*p != '\0' && isascii(*p) && isspace(*p)) 2102214518Srpaulo p++; 2103214518Srpaulo if (*p == '\0' || *p == '\n') 2104214518Srpaulo continue; /* blank line */ 2105214518Srpaulo 2106214518Srpaulo /* 2107214518Srpaulo * Get the interface name. 2108214518Srpaulo */ 2109214518Srpaulo q = &name[0]; 2110214518Srpaulo while (*p != '\0' && isascii(*p) && !isspace(*p)) { 2111214518Srpaulo if (*p == ':') { 2112214518Srpaulo /* 2113214518Srpaulo * This could be the separator between a 2114214518Srpaulo * name and an alias number, or it could be 2115214518Srpaulo * the separator between a name with no 2116214518Srpaulo * alias number and the next field. 2117214518Srpaulo * 2118214518Srpaulo * If there's a colon after digits, it 2119214518Srpaulo * separates the name and the alias number, 2120214518Srpaulo * otherwise it separates the name and the 2121214518Srpaulo * next field. 2122214518Srpaulo */ 2123214518Srpaulo saveq = q; 2124214518Srpaulo while (isascii(*p) && isdigit(*p)) 2125214518Srpaulo *q++ = *p++; 2126214518Srpaulo if (*p != ':') { 2127214518Srpaulo /* 2128214518Srpaulo * That was the next field, 2129214518Srpaulo * not the alias number. 2130214518Srpaulo */ 2131214518Srpaulo q = saveq; 2132214518Srpaulo } 2133214518Srpaulo break; 2134214518Srpaulo } else 2135214518Srpaulo *q++ = *p++; 2136214518Srpaulo } 2137214518Srpaulo *q = '\0'; 2138214518Srpaulo 2139214518Srpaulo /* 2140214518Srpaulo * Get the flags for this interface, and skip it if 2141214518Srpaulo * it's not up. 2142214518Srpaulo */ 2143214518Srpaulo strncpy(ifrflags.ifr_name, name, sizeof(ifrflags.ifr_name)); 2144214518Srpaulo if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) { 2145214518Srpaulo if (errno == ENXIO) 2146214518Srpaulo continue; 2147214518Srpaulo (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 2148214518Srpaulo "SIOCGIFFLAGS: %.*s: %s", 2149214518Srpaulo (int)sizeof(ifrflags.ifr_name), 2150214518Srpaulo ifrflags.ifr_name, 2151214518Srpaulo pcap_strerror(errno)); 2152214518Srpaulo ret = -1; 2153214518Srpaulo break; 2154214518Srpaulo } 2155214518Srpaulo if (!(ifrflags.ifr_flags & IFF_UP)) 2156214518Srpaulo continue; 2157214518Srpaulo 2158214518Srpaulo /* 2159214518Srpaulo * Add an entry for this interface, with no addresses. 2160214518Srpaulo */ 2161214518Srpaulo if (pcap_add_if(devlistp, name, ifrflags.ifr_flags, NULL, 2162214518Srpaulo errbuf) == -1) { 2163214518Srpaulo /* 2164214518Srpaulo * Failure. 2165214518Srpaulo */ 2166214518Srpaulo ret = -1; 2167214518Srpaulo break; 2168214518Srpaulo } 2169214518Srpaulo } 2170214518Srpaulo if (ret != -1) { 2171214518Srpaulo /* 2172214518Srpaulo * Well, we didn't fail for any other reason; did we 2173214518Srpaulo * fail due to an error reading the file? 2174214518Srpaulo */ 2175214518Srpaulo if (ferror(proc_net_f)) { 2176214518Srpaulo (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, 2177214518Srpaulo "Error reading /proc/net/dev: %s", 2178214518Srpaulo pcap_strerror(errno)); 2179214518Srpaulo ret = -1; 2180214518Srpaulo } 2181214518Srpaulo } 2182214518Srpaulo 2183214518Srpaulo (void)close(fd); 2184214518Srpaulo (void)fclose(proc_net_f); 2185214518Srpaulo return (ret); 2186214518Srpaulo} 2187214518Srpaulo 2188214518Srpaulo/* 2189127664Sbms * Description string for the "any" device. 219075107Sfenner */ 2191127664Sbmsstatic const char any_descr[] = "Pseudo-device that captures on all interfaces"; 2192127664Sbms 219375107Sfennerint 2194127664Sbmspcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) 219575107Sfenner{ 2196214518Srpaulo int ret; 2197214518Srpaulo 2198214518Srpaulo /* 2199214518Srpaulo * Read "/sys/class/net", and add to the list of interfaces all 2200214518Srpaulo * interfaces listed there that we don't already have, because, 2201214518Srpaulo * on Linux, SIOCGIFCONF reports only interfaces with IPv4 addresses, 2202214518Srpaulo * and even getifaddrs() won't return information about 2203214518Srpaulo * interfaces with no addresses, so you need to read "/sys/class/net" 2204214518Srpaulo * to get the names of the rest of the interfaces. 2205214518Srpaulo */ 2206214518Srpaulo ret = scan_sys_class_net(alldevsp, errbuf); 2207214518Srpaulo if (ret == -1) 2208214518Srpaulo return (-1); /* failed */ 2209214518Srpaulo if (ret == 0) { 2210214518Srpaulo /* 2211214518Srpaulo * No /sys/class/net; try reading /proc/net/dev instead. 2212214518Srpaulo */ 2213214518Srpaulo if (scan_proc_net_dev(alldevsp, errbuf) == -1) 2214214518Srpaulo return (-1); 2215214518Srpaulo } 2216214518Srpaulo 2217214518Srpaulo /* 2218214518Srpaulo * Add the "any" device. 2219214518Srpaulo */ 2220127664Sbms if (pcap_add_if(alldevsp, "any", 0, any_descr, errbuf) < 0) 2221127664Sbms return (-1); 2222127664Sbms 2223127664Sbms return (0); 2224127664Sbms} 2225127664Sbms 2226127664Sbms/* 2227127664Sbms * Attach the given BPF code to the packet capture device. 2228127664Sbms */ 2229127664Sbmsstatic int 2230214518Srpaulopcap_setfilter_linux_common(pcap_t *handle, struct bpf_program *filter, 2231214518Srpaulo int is_mmapped) 2232127664Sbms{ 223375107Sfenner#ifdef SO_ATTACH_FILTER 223475107Sfenner struct sock_fprog fcode; 223575107Sfenner int can_filter_in_kernel; 2236127664Sbms int err = 0; 223775107Sfenner#endif 223875107Sfenner 223975107Sfenner if (!handle) 224075107Sfenner return -1; 224175107Sfenner if (!filter) { 224275107Sfenner strncpy(handle->errbuf, "setfilter: No filter specified", 2243190225Srpaulo PCAP_ERRBUF_SIZE); 224475107Sfenner return -1; 224526175Sfenner } 224626175Sfenner 224775107Sfenner /* Make our private copy of the filter */ 224875107Sfenner 2249127664Sbms if (install_bpf_program(handle, filter) < 0) 2250127664Sbms /* install_bpf_program() filled in errbuf */ 225175107Sfenner return -1; 225239291Sfenner 2253127664Sbms /* 2254127664Sbms * Run user level packet filter by default. Will be overriden if 2255127664Sbms * installing a kernel filter succeeds. 225675107Sfenner */ 225775107Sfenner handle->md.use_bpf = 0; 225875107Sfenner 225975107Sfenner /* Install kernel level filter if possible */ 226075107Sfenner 226175107Sfenner#ifdef SO_ATTACH_FILTER 226275107Sfenner#ifdef USHRT_MAX 226375107Sfenner if (handle->fcode.bf_len > USHRT_MAX) { 226475107Sfenner /* 2265127664Sbms * fcode.len is an unsigned short for current kernel. 226675107Sfenner * I have yet to see BPF-Code with that much 226775107Sfenner * instructions but still it is possible. So for the 226875107Sfenner * sake of correctness I added this check. 226975107Sfenner */ 227075107Sfenner fprintf(stderr, "Warning: Filter too complex for kernel\n"); 2271172677Smlaier fcode.len = 0; 227275107Sfenner fcode.filter = NULL; 227375107Sfenner can_filter_in_kernel = 0; 227475107Sfenner } else 227575107Sfenner#endif /* USHRT_MAX */ 227675107Sfenner { 227775107Sfenner /* 227875107Sfenner * Oh joy, the Linux kernel uses struct sock_fprog instead 227975107Sfenner * of struct bpf_program and of course the length field is 228075107Sfenner * of different size. Pointed out by Sebastian 228175107Sfenner * 228275107Sfenner * Oh, and we also need to fix it up so that all "ret" 228375107Sfenner * instructions with non-zero operands have 65535 as the 2284214518Srpaulo * operand if we're not capturing in memory-mapped modee, 2285214518Srpaulo * and so that, if we're in cooked mode, all memory-reference 2286214518Srpaulo * instructions use special magic offsets in references to 2287214518Srpaulo * the link-layer header and assume that the link-layer 2288214518Srpaulo * payload begins at 0; "fix_program()" will do that. 228975107Sfenner */ 2290214518Srpaulo switch (fix_program(handle, &fcode, is_mmapped)) { 229175107Sfenner 229275107Sfenner case -1: 229375107Sfenner default: 229475107Sfenner /* 229575107Sfenner * Fatal error; just quit. 229675107Sfenner * (The "default" case shouldn't happen; we 229775107Sfenner * return -1 for that reason.) 229875107Sfenner */ 229975107Sfenner return -1; 230075107Sfenner 230175107Sfenner case 0: 230275107Sfenner /* 230375107Sfenner * The program performed checks that we can't make 230475107Sfenner * work in the kernel. 230575107Sfenner */ 230675107Sfenner can_filter_in_kernel = 0; 230775107Sfenner break; 230875107Sfenner 230975107Sfenner case 1: 231075107Sfenner /* 231175107Sfenner * We have a filter that'll work in the kernel. 231275107Sfenner */ 231375107Sfenner can_filter_in_kernel = 1; 231475107Sfenner break; 231575107Sfenner } 231639291Sfenner } 231739291Sfenner 2318235426Sdelphij /* 2319235426Sdelphij * NOTE: at this point, we've set both the "len" and "filter" 2320235426Sdelphij * fields of "fcode". As of the 2.6.32.4 kernel, at least, 2321235426Sdelphij * those are the only members of the "sock_fprog" structure, 2322235426Sdelphij * so we initialize every member of that structure. 2323235426Sdelphij * 2324235426Sdelphij * If there is anything in "fcode" that is not initialized, 2325235426Sdelphij * it is either a field added in a later kernel, or it's 2326235426Sdelphij * padding. 2327235426Sdelphij * 2328235426Sdelphij * If a new field is added, this code needs to be updated 2329235426Sdelphij * to set it correctly. 2330235426Sdelphij * 2331235426Sdelphij * If there are no other fields, then: 2332235426Sdelphij * 2333235426Sdelphij * if the Linux kernel looks at the padding, it's 2334235426Sdelphij * buggy; 2335235426Sdelphij * 2336235426Sdelphij * if the Linux kernel doesn't look at the padding, 2337235426Sdelphij * then if some tool complains that we're passing 2338235426Sdelphij * uninitialized data to the kernel, then the tool 2339235426Sdelphij * is buggy and needs to understand that it's just 2340235426Sdelphij * padding. 2341235426Sdelphij */ 234275107Sfenner if (can_filter_in_kernel) { 2343127664Sbms if ((err = set_kernel_filter(handle, &fcode)) == 0) 234475107Sfenner { 234575107Sfenner /* Installation succeded - using kernel filter. */ 234675107Sfenner handle->md.use_bpf = 1; 234775107Sfenner } 2348127664Sbms else if (err == -1) /* Non-fatal error */ 234975107Sfenner { 2350127664Sbms /* 235175107Sfenner * Print a warning if we weren't able to install 235275107Sfenner * the filter for a reason other than "this kernel 235375107Sfenner * isn't configured to support socket filters. 235475107Sfenner */ 235575107Sfenner if (errno != ENOPROTOOPT && errno != EOPNOTSUPP) { 235675107Sfenner fprintf(stderr, 2357127664Sbms "Warning: Kernel filter failed: %s\n", 235875107Sfenner pcap_strerror(errno)); 235975107Sfenner } 236075107Sfenner } 236139291Sfenner } 236239291Sfenner 236375107Sfenner /* 236498530Sfenner * If we're not using the kernel filter, get rid of any kernel 236598530Sfenner * filter that might've been there before, e.g. because the 236698530Sfenner * previous filter could work in the kernel, or because some other 236798530Sfenner * code attached a filter to the socket by some means other than 236898530Sfenner * calling "pcap_setfilter()". Otherwise, the kernel filter may 236998530Sfenner * filter out packets that would pass the new userland filter. 237098530Sfenner */ 237198530Sfenner if (!handle->md.use_bpf) 237298530Sfenner reset_kernel_filter(handle); 237398530Sfenner 237498530Sfenner /* 237575107Sfenner * Free up the copy of the filter that was made by "fix_program()". 237675107Sfenner */ 237775107Sfenner if (fcode.filter != NULL) 237875107Sfenner free(fcode.filter); 2379127664Sbms 2380127664Sbms if (err == -2) 2381127664Sbms /* Fatal error */ 2382127664Sbms return -1; 238375107Sfenner#endif /* SO_ATTACH_FILTER */ 238475107Sfenner 238575107Sfenner return 0; 238675107Sfenner} 238775107Sfenner 2388214518Srpaulostatic int 2389214518Srpaulopcap_setfilter_linux(pcap_t *handle, struct bpf_program *filter) 2390214518Srpaulo{ 2391214518Srpaulo return pcap_setfilter_linux_common(handle, filter, 0); 2392214518Srpaulo} 2393214518Srpaulo 2394214518Srpaulo 239575107Sfenner/* 2396147894Ssam * Set direction flag: Which packets do we accept on a forwarding 2397147894Ssam * single device? IN, OUT or both? 2398147894Ssam */ 2399147894Ssamstatic int 2400162012Ssampcap_setdirection_linux(pcap_t *handle, pcap_direction_t d) 2401147894Ssam{ 2402147894Ssam#ifdef HAVE_PF_PACKET_SOCKETS 2403147894Ssam if (!handle->md.sock_packet) { 2404147894Ssam handle->direction = d; 2405147894Ssam return 0; 2406147894Ssam } 2407147894Ssam#endif 2408147894Ssam /* 2409147894Ssam * We're not using PF_PACKET sockets, so we can't determine 2410147894Ssam * the direction of the packet. 2411147894Ssam */ 2412190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 2413147894Ssam "Setting direction is not supported on SOCK_PACKET sockets"); 2414147894Ssam return -1; 2415147894Ssam} 2416147894Ssam 2417190225Srpaulo#ifdef HAVE_PF_PACKET_SOCKETS 2418147894Ssam/* 2419190225Srpaulo * Map the PACKET_ value to a LINUX_SLL_ value; we 2420190225Srpaulo * want the same numerical value to be used in 2421190225Srpaulo * the link-layer header even if the numerical values 2422190225Srpaulo * for the PACKET_ #defines change, so that programs 2423190225Srpaulo * that look at the packet type field will always be 2424190225Srpaulo * able to handle DLT_LINUX_SLL captures. 2425190225Srpaulo */ 2426190225Srpaulostatic short int 2427190225Srpaulomap_packet_type_to_sll_type(short int sll_pkttype) 2428190225Srpaulo{ 2429190225Srpaulo switch (sll_pkttype) { 2430190225Srpaulo 2431190225Srpaulo case PACKET_HOST: 2432190225Srpaulo return htons(LINUX_SLL_HOST); 2433190225Srpaulo 2434190225Srpaulo case PACKET_BROADCAST: 2435190225Srpaulo return htons(LINUX_SLL_BROADCAST); 2436190225Srpaulo 2437190225Srpaulo case PACKET_MULTICAST: 2438190225Srpaulo return htons(LINUX_SLL_MULTICAST); 2439190225Srpaulo 2440190225Srpaulo case PACKET_OTHERHOST: 2441190225Srpaulo return htons(LINUX_SLL_OTHERHOST); 2442190225Srpaulo 2443190225Srpaulo case PACKET_OUTGOING: 2444190225Srpaulo return htons(LINUX_SLL_OUTGOING); 2445190225Srpaulo 2446190225Srpaulo default: 2447190225Srpaulo return -1; 2448190225Srpaulo } 2449190225Srpaulo} 2450190225Srpaulo#endif 2451190225Srpaulo 2452190225Srpaulo/* 2453127664Sbms * Linux uses the ARP hardware type to identify the type of an 2454127664Sbms * interface. pcap uses the DLT_xxx constants for this. This 245598530Sfenner * function takes a pointer to a "pcap_t", and an ARPHRD_xxx 245698530Sfenner * constant, as arguments, and sets "handle->linktype" to the 245798530Sfenner * appropriate DLT_XXX constant and sets "handle->offset" to 245898530Sfenner * the appropriate value (to make "handle->offset" plus link-layer 245998530Sfenner * header length be a multiple of 4, so that the link-layer payload 246098530Sfenner * will be aligned on a 4-byte boundary when capturing packets). 246198530Sfenner * (If the offset isn't set here, it'll be 0; add code as appropriate 246298530Sfenner * for cases where it shouldn't be 0.) 2463127664Sbms * 2464127664Sbms * If "cooked_ok" is non-zero, we can use DLT_LINUX_SLL and capture 2465127664Sbms * in cooked mode; otherwise, we can't use cooked mode, so we have 2466127664Sbms * to pick some type that works in raw mode, or fail. 2467127664Sbms * 246898530Sfenner * Sets the link type to -1 if unable to map the type. 246975107Sfenner */ 2470127664Sbmsstatic void map_arphrd_to_dlt(pcap_t *handle, int arptype, int cooked_ok) 247175107Sfenner{ 247275107Sfenner switch (arptype) { 247398530Sfenner 247439291Sfenner case ARPHRD_ETHER: 2475146768Ssam /* 2476146768Ssam * This is (presumably) a real Ethernet capture; give it a 2477146768Ssam * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 2478146768Ssam * that an application can let you choose it, in case you're 2479146768Ssam * capturing DOCSIS traffic that a Cisco Cable Modem 2480146768Ssam * Termination System is putting out onto an Ethernet (it 2481146768Ssam * doesn't put an Ethernet header onto the wire, it puts raw 2482146768Ssam * DOCSIS frames out on the wire inside the low-level 2483146768Ssam * Ethernet framing). 2484146768Ssam * 2485146768Ssam * XXX - are there any sorts of "fake Ethernet" that have 2486146768Ssam * ARPHRD_ETHER but that *shouldn't offer DLT_DOCSIS as 2487146768Ssam * a Cisco CMTS won't put traffic onto it or get traffic 2488190225Srpaulo * bridged onto it? ISDN is handled in "activate_new()", 2489146768Ssam * as we fall back on cooked mode there; are there any 2490146768Ssam * others? 2491146768Ssam */ 2492146768Ssam handle->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 2493146768Ssam /* 2494146768Ssam * If that fails, just leave the list empty. 2495146768Ssam */ 2496146768Ssam if (handle->dlt_list != NULL) { 2497146768Ssam handle->dlt_list[0] = DLT_EN10MB; 2498146768Ssam handle->dlt_list[1] = DLT_DOCSIS; 2499146768Ssam handle->dlt_count = 2; 2500146768Ssam } 2501146768Ssam /* FALLTHROUGH */ 2502146768Ssam 250339291Sfenner case ARPHRD_METRICOM: 250498530Sfenner case ARPHRD_LOOPBACK: 250598530Sfenner handle->linktype = DLT_EN10MB; 250698530Sfenner handle->offset = 2; 250798530Sfenner break; 250898530Sfenner 250998530Sfenner case ARPHRD_EETHER: 251098530Sfenner handle->linktype = DLT_EN3MB; 251198530Sfenner break; 251298530Sfenner 251398530Sfenner case ARPHRD_AX25: 2514190225Srpaulo handle->linktype = DLT_AX25_KISS; 251598530Sfenner break; 251698530Sfenner 251798530Sfenner case ARPHRD_PRONET: 251898530Sfenner handle->linktype = DLT_PRONET; 251998530Sfenner break; 252098530Sfenner 252198530Sfenner case ARPHRD_CHAOS: 252298530Sfenner handle->linktype = DLT_CHAOS; 252398530Sfenner break; 2524214518Srpaulo#ifndef ARPHRD_CAN 2525214518Srpaulo#define ARPHRD_CAN 280 2526214518Srpaulo#endif 2527214518Srpaulo case ARPHRD_CAN: 2528214518Srpaulo handle->linktype = DLT_CAN_SOCKETCAN; 2529214518Srpaulo break; 253098530Sfenner 253175107Sfenner#ifndef ARPHRD_IEEE802_TR 253275107Sfenner#define ARPHRD_IEEE802_TR 800 /* From Linux 2.4 */ 253375107Sfenner#endif 253475107Sfenner case ARPHRD_IEEE802_TR: 253598530Sfenner case ARPHRD_IEEE802: 253698530Sfenner handle->linktype = DLT_IEEE802; 253798530Sfenner handle->offset = 2; 253898530Sfenner break; 253939291Sfenner 254098530Sfenner case ARPHRD_ARCNET: 2541127664Sbms handle->linktype = DLT_ARCNET_LINUX; 254298530Sfenner break; 254398530Sfenner 2544127664Sbms#ifndef ARPHRD_FDDI /* From Linux 2.2.13 */ 2545127664Sbms#define ARPHRD_FDDI 774 2546127664Sbms#endif 254798530Sfenner case ARPHRD_FDDI: 254898530Sfenner handle->linktype = DLT_FDDI; 254998530Sfenner handle->offset = 3; 255098530Sfenner break; 255198530Sfenner 255275107Sfenner#ifndef ARPHRD_ATM /* FIXME: How to #include this? */ 255375107Sfenner#define ARPHRD_ATM 19 255475107Sfenner#endif 255598530Sfenner case ARPHRD_ATM: 255698530Sfenner /* 255798530Sfenner * The Classical IP implementation in ATM for Linux 255898530Sfenner * supports both what RFC 1483 calls "LLC Encapsulation", 255998530Sfenner * in which each packet has an LLC header, possibly 256098530Sfenner * with a SNAP header as well, prepended to it, and 256198530Sfenner * what RFC 1483 calls "VC Based Multiplexing", in which 256298530Sfenner * different virtual circuits carry different network 256398530Sfenner * layer protocols, and no header is prepended to packets. 256498530Sfenner * 256598530Sfenner * They both have an ARPHRD_ type of ARPHRD_ATM, so 256698530Sfenner * you can't use the ARPHRD_ type to find out whether 256798530Sfenner * captured packets will have an LLC header, and, 256898530Sfenner * while there's a socket ioctl to *set* the encapsulation 256998530Sfenner * type, there's no ioctl to *get* the encapsulation type. 257098530Sfenner * 257198530Sfenner * This means that 257298530Sfenner * 257398530Sfenner * programs that dissect Linux Classical IP frames 257498530Sfenner * would have to check for an LLC header and, 257598530Sfenner * depending on whether they see one or not, dissect 257698530Sfenner * the frame as LLC-encapsulated or as raw IP (I 257798530Sfenner * don't know whether there's any traffic other than 257898530Sfenner * IP that would show up on the socket, or whether 257998530Sfenner * there's any support for IPv6 in the Linux 258098530Sfenner * Classical IP code); 258198530Sfenner * 258298530Sfenner * filter expressions would have to compile into 258398530Sfenner * code that checks for an LLC header and does 258498530Sfenner * the right thing. 258598530Sfenner * 258698530Sfenner * Both of those are a nuisance - and, at least on systems 258798530Sfenner * that support PF_PACKET sockets, we don't have to put 258898530Sfenner * up with those nuisances; instead, we can just capture 2589127664Sbms * in cooked mode. That's what we'll do, if we can. 2590127664Sbms * Otherwise, we'll just fail. 259198530Sfenner */ 2592127664Sbms if (cooked_ok) 2593127664Sbms handle->linktype = DLT_LINUX_SLL; 2594127664Sbms else 2595127664Sbms handle->linktype = -1; 259698530Sfenner break; 259739291Sfenner 259898530Sfenner#ifndef ARPHRD_IEEE80211 /* From Linux 2.4.6 */ 259998530Sfenner#define ARPHRD_IEEE80211 801 260098530Sfenner#endif 260198530Sfenner case ARPHRD_IEEE80211: 260298530Sfenner handle->linktype = DLT_IEEE802_11; 260398530Sfenner break; 260498530Sfenner 2605127664Sbms#ifndef ARPHRD_IEEE80211_PRISM /* From Linux 2.4.18 */ 2606127664Sbms#define ARPHRD_IEEE80211_PRISM 802 2607127664Sbms#endif 2608127664Sbms case ARPHRD_IEEE80211_PRISM: 2609127664Sbms handle->linktype = DLT_PRISM_HEADER; 2610127664Sbms break; 2611127664Sbms 2612162012Ssam#ifndef ARPHRD_IEEE80211_RADIOTAP /* new */ 2613162012Ssam#define ARPHRD_IEEE80211_RADIOTAP 803 2614162012Ssam#endif 2615162012Ssam case ARPHRD_IEEE80211_RADIOTAP: 2616162012Ssam handle->linktype = DLT_IEEE802_11_RADIO; 2617162012Ssam break; 2618162012Ssam 261975107Sfenner case ARPHRD_PPP: 262098530Sfenner /* 262198530Sfenner * Some PPP code in the kernel supplies no link-layer 262298530Sfenner * header whatsoever to PF_PACKET sockets; other PPP 262398530Sfenner * code supplies PPP link-layer headers ("syncppp.c"); 262498530Sfenner * some PPP code might supply random link-layer 262598530Sfenner * headers (PPP over ISDN - there's code in Ethereal, 262698530Sfenner * for example, to cope with PPP-over-ISDN captures 262798530Sfenner * with which the Ethereal developers have had to cope, 262898530Sfenner * heuristically trying to determine which of the 262998530Sfenner * oddball link-layer headers particular packets have). 263098530Sfenner * 263198530Sfenner * As such, we just punt, and run all PPP interfaces 2632127664Sbms * in cooked mode, if we can; otherwise, we just treat 2633127664Sbms * it as DLT_RAW, for now - if somebody needs to capture, 2634127664Sbms * on a 2.0[.x] kernel, on PPP devices that supply a 2635127664Sbms * link-layer header, they'll have to add code here to 2636127664Sbms * map to the appropriate DLT_ type (possibly adding a 2637127664Sbms * new DLT_ type, if necessary). 263898530Sfenner */ 2639127664Sbms if (cooked_ok) 2640127664Sbms handle->linktype = DLT_LINUX_SLL; 2641127664Sbms else { 2642127664Sbms /* 2643127664Sbms * XXX - handle ISDN types here? We can't fall 2644127664Sbms * back on cooked sockets, so we'd have to 2645127664Sbms * figure out from the device name what type of 2646127664Sbms * link-layer encapsulation it's using, and map 2647127664Sbms * that to an appropriate DLT_ value, meaning 2648127664Sbms * we'd map "isdnN" devices to DLT_RAW (they 2649127664Sbms * supply raw IP packets with no link-layer 2650127664Sbms * header) and "isdY" devices to a new DLT_I4L_IP 2651127664Sbms * type that has only an Ethernet packet type as 2652127664Sbms * a link-layer header. 2653127664Sbms * 2654127664Sbms * But sometimes we seem to get random crap 2655127664Sbms * in the link-layer header when capturing on 2656127664Sbms * ISDN devices.... 2657127664Sbms */ 2658127664Sbms handle->linktype = DLT_RAW; 2659127664Sbms } 266098530Sfenner break; 266198530Sfenner 2662127664Sbms#ifndef ARPHRD_CISCO 2663127664Sbms#define ARPHRD_CISCO 513 /* previously ARPHRD_HDLC */ 2664127664Sbms#endif 2665127664Sbms case ARPHRD_CISCO: 266698530Sfenner handle->linktype = DLT_C_HDLC; 266798530Sfenner break; 266898530Sfenner 266975107Sfenner /* Not sure if this is correct for all tunnels, but it 267075107Sfenner * works for CIPE */ 267175107Sfenner case ARPHRD_TUNNEL: 267275107Sfenner#ifndef ARPHRD_SIT 2673127664Sbms#define ARPHRD_SIT 776 /* From Linux 2.2.13 */ 267475107Sfenner#endif 267575107Sfenner case ARPHRD_SIT: 267675107Sfenner case ARPHRD_CSLIP: 267775107Sfenner case ARPHRD_SLIP6: 267875107Sfenner case ARPHRD_CSLIP6: 267998530Sfenner case ARPHRD_ADAPT: 268098530Sfenner case ARPHRD_SLIP: 2681127664Sbms#ifndef ARPHRD_RAWHDLC 2682127664Sbms#define ARPHRD_RAWHDLC 518 2683127664Sbms#endif 2684127664Sbms case ARPHRD_RAWHDLC: 2685127664Sbms#ifndef ARPHRD_DLCI 2686127664Sbms#define ARPHRD_DLCI 15 2687127664Sbms#endif 2688127664Sbms case ARPHRD_DLCI: 268998530Sfenner /* 269098530Sfenner * XXX - should some of those be mapped to DLT_LINUX_SLL 269198530Sfenner * instead? Should we just map all of them to DLT_LINUX_SLL? 269298530Sfenner */ 269398530Sfenner handle->linktype = DLT_RAW; 269498530Sfenner break; 269598530Sfenner 2696127664Sbms#ifndef ARPHRD_FRAD 2697127664Sbms#define ARPHRD_FRAD 770 2698127664Sbms#endif 2699127664Sbms case ARPHRD_FRAD: 2700127664Sbms handle->linktype = DLT_FRELAY; 2701127664Sbms break; 2702127664Sbms 270398530Sfenner case ARPHRD_LOCALTLK: 270498530Sfenner handle->linktype = DLT_LTALK; 270598530Sfenner break; 270698530Sfenner 2707127664Sbms#ifndef ARPHRD_FCPP 2708127664Sbms#define ARPHRD_FCPP 784 2709127664Sbms#endif 2710127664Sbms case ARPHRD_FCPP: 2711127664Sbms#ifndef ARPHRD_FCAL 2712127664Sbms#define ARPHRD_FCAL 785 2713127664Sbms#endif 2714127664Sbms case ARPHRD_FCAL: 2715127664Sbms#ifndef ARPHRD_FCPL 2716127664Sbms#define ARPHRD_FCPL 786 2717127664Sbms#endif 2718127664Sbms case ARPHRD_FCPL: 2719127664Sbms#ifndef ARPHRD_FCFABRIC 2720127664Sbms#define ARPHRD_FCFABRIC 787 2721127664Sbms#endif 2722127664Sbms case ARPHRD_FCFABRIC: 2723127664Sbms /* 2724127664Sbms * We assume that those all mean RFC 2625 IP-over- 2725127664Sbms * Fibre Channel, with the RFC 2625 header at 2726127664Sbms * the beginning of the packet. 2727127664Sbms */ 2728127664Sbms handle->linktype = DLT_IP_OVER_FC; 2729127664Sbms break; 2730127664Sbms 2731146768Ssam#ifndef ARPHRD_IRDA 2732146768Ssam#define ARPHRD_IRDA 783 2733146768Ssam#endif 2734127664Sbms case ARPHRD_IRDA: 2735127664Sbms /* Don't expect IP packet out of this interfaces... */ 2736127664Sbms handle->linktype = DLT_LINUX_IRDA; 2737127664Sbms /* We need to save packet direction for IrDA decoding, 2738127664Sbms * so let's use "Linux-cooked" mode. Jean II */ 2739127664Sbms //handle->md.cooked = 1; 2740127664Sbms break; 2741127664Sbms 2742172677Smlaier /* ARPHRD_LAPD is unofficial and randomly allocated, if reallocation 2743172677Smlaier * is needed, please report it to <daniele@orlandi.com> */ 2744172677Smlaier#ifndef ARPHRD_LAPD 2745172677Smlaier#define ARPHRD_LAPD 8445 2746172677Smlaier#endif 2747172677Smlaier case ARPHRD_LAPD: 2748172677Smlaier /* Don't expect IP packet out of this interfaces... */ 2749172677Smlaier handle->linktype = DLT_LINUX_LAPD; 2750172677Smlaier break; 2751172677Smlaier 2752190225Srpaulo#ifndef ARPHRD_NONE 2753190225Srpaulo#define ARPHRD_NONE 0xFFFE 2754190225Srpaulo#endif 2755190225Srpaulo case ARPHRD_NONE: 2756190225Srpaulo /* 2757190225Srpaulo * No link-layer header; packets are just IP 2758190225Srpaulo * packets, so use DLT_RAW. 2759190225Srpaulo */ 2760190225Srpaulo handle->linktype = DLT_RAW; 2761190225Srpaulo break; 2762190225Srpaulo 2763235426Sdelphij#ifndef ARPHRD_IEEE802154 2764235426Sdelphij#define ARPHRD_IEEE802154 804 2765235426Sdelphij#endif 2766235426Sdelphij case ARPHRD_IEEE802154: 2767235426Sdelphij handle->linktype = DLT_IEEE802_15_4_NOFCS; 2768235426Sdelphij break; 2769235426Sdelphij 277098530Sfenner default: 277198530Sfenner handle->linktype = -1; 277298530Sfenner break; 277375107Sfenner } 277475107Sfenner} 277539291Sfenner 277675107Sfenner/* ===== Functions to interface to the newer kernels ================== */ 277739291Sfenner 277875107Sfenner/* 2779190225Srpaulo * Try to open a packet socket using the new kernel PF_PACKET interface. 2780190225Srpaulo * Returns 1 on success, 0 on an error that means the new interface isn't 2781190225Srpaulo * present (so the old SOCK_PACKET interface should be tried), and a 2782190225Srpaulo * PCAP_ERROR_ value on an error that means that the old mechanism won't 2783190225Srpaulo * work either (so it shouldn't be tried). 278475107Sfenner */ 278575107Sfennerstatic int 2786190225Srpauloactivate_new(pcap_t *handle) 278775107Sfenner{ 278875107Sfenner#ifdef HAVE_PF_PACKET_SOCKETS 2789214518Srpaulo const char *device = handle->opt.source; 2790214518Srpaulo int is_any_device = (strcmp(device, "any") == 0); 2791214518Srpaulo int sock_fd = -1, arptype; 2792214518Srpaulo#ifdef HAVE_PACKET_AUXDATA 2793214518Srpaulo int val; 2794214518Srpaulo#endif 2795190225Srpaulo int err = 0; 279675107Sfenner struct packet_mreq mr; 279739291Sfenner 2798190225Srpaulo /* 2799214518Srpaulo * Open a socket with protocol family packet. If the 2800214518Srpaulo * "any" device was specified, we open a SOCK_DGRAM 2801214518Srpaulo * socket for the cooked interface, otherwise we first 2802214518Srpaulo * try a SOCK_RAW socket for the raw interface. 2803190225Srpaulo */ 2804214518Srpaulo sock_fd = is_any_device ? 2805214518Srpaulo socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL)) : 2806214518Srpaulo socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); 280739291Sfenner 2808190225Srpaulo if (sock_fd == -1) { 2809235426Sdelphij if (errno == EINVAL || errno == EAFNOSUPPORT) { 2810235426Sdelphij /* 2811235426Sdelphij * We don't support PF_PACKET/SOCK_whatever 2812235426Sdelphij * sockets; try the old mechanism. 2813235426Sdelphij */ 2814235426Sdelphij return 0; 2815235426Sdelphij } 2816235426Sdelphij 2817190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "socket: %s", 2818190225Srpaulo pcap_strerror(errno) ); 2819235426Sdelphij if (errno == EPERM || errno == EACCES) { 2820235426Sdelphij /* 2821235426Sdelphij * You don't have permission to open the 2822235426Sdelphij * socket. 2823235426Sdelphij */ 2824235426Sdelphij return PCAP_ERROR_PERM_DENIED; 2825235426Sdelphij } else { 2826235426Sdelphij /* 2827235426Sdelphij * Other error. 2828235426Sdelphij */ 2829235426Sdelphij return PCAP_ERROR; 2830235426Sdelphij } 2831190225Srpaulo } 283239291Sfenner 2833190225Srpaulo /* It seems the kernel supports the new interface. */ 2834190225Srpaulo handle->md.sock_packet = 0; 283539291Sfenner 2836190225Srpaulo /* 2837190225Srpaulo * Get the interface index of the loopback device. 2838190225Srpaulo * If the attempt fails, don't fail, just set the 2839190225Srpaulo * "md.lo_ifindex" to -1. 2840190225Srpaulo * 2841190225Srpaulo * XXX - can there be more than one device that loops 2842190225Srpaulo * packets back, i.e. devices other than "lo"? If so, 2843190225Srpaulo * we'd need to find them all, and have an array of 2844190225Srpaulo * indices for them, and check all of them in 2845190225Srpaulo * "pcap_read_packet()". 2846190225Srpaulo */ 2847190225Srpaulo handle->md.lo_ifindex = iface_get_id(sock_fd, "lo", handle->errbuf); 284875107Sfenner 2849190225Srpaulo /* 2850190225Srpaulo * Default value for offset to align link-layer payload 2851190225Srpaulo * on a 4-byte boundary. 2852190225Srpaulo */ 2853190225Srpaulo handle->offset = 0; 285475107Sfenner 2855190225Srpaulo /* 2856190225Srpaulo * What kind of frames do we have to deal with? Fall back 2857190225Srpaulo * to cooked mode if we have an unknown interface type 2858190225Srpaulo * or a type we know doesn't work well in raw mode. 2859190225Srpaulo */ 2860214518Srpaulo if (!is_any_device) { 2861190225Srpaulo /* Assume for now we don't need cooked mode. */ 2862190225Srpaulo handle->md.cooked = 0; 286398530Sfenner 2864190225Srpaulo if (handle->opt.rfmon) { 2865190225Srpaulo /* 2866190225Srpaulo * We were asked to turn on monitor mode. 2867190225Srpaulo * Do so before we get the link-layer type, 2868190225Srpaulo * because entering monitor mode could change 2869190225Srpaulo * the link-layer type. 2870190225Srpaulo */ 2871214518Srpaulo err = enter_rfmon_mode(handle, sock_fd, device); 2872190225Srpaulo if (err < 0) { 2873190225Srpaulo /* Hard failure */ 2874190225Srpaulo close(sock_fd); 2875190225Srpaulo return err; 2876127664Sbms } 2877190225Srpaulo if (err == 0) { 287875107Sfenner /* 2879190225Srpaulo * Nothing worked for turning monitor mode 2880190225Srpaulo * on. 288175107Sfenner */ 2882190225Srpaulo close(sock_fd); 2883190225Srpaulo return PCAP_ERROR_RFMON_NOTSUP; 2884190225Srpaulo } 2885214518Srpaulo 2886214518Srpaulo /* 2887214518Srpaulo * Either monitor mode has been turned on for 2888214518Srpaulo * the device, or we've been given a different 2889214518Srpaulo * device to open for monitor mode. If we've 2890214518Srpaulo * been given a different device, use it. 2891214518Srpaulo */ 2892214518Srpaulo if (handle->md.mondevice != NULL) 2893214518Srpaulo device = handle->md.mondevice; 2894190225Srpaulo } 2895190225Srpaulo arptype = iface_get_arptype(sock_fd, device, handle->errbuf); 2896190225Srpaulo if (arptype < 0) { 2897190225Srpaulo close(sock_fd); 2898190225Srpaulo return arptype; 2899190225Srpaulo } 2900190225Srpaulo map_arphrd_to_dlt(handle, arptype, 1); 2901190225Srpaulo if (handle->linktype == -1 || 2902190225Srpaulo handle->linktype == DLT_LINUX_SLL || 2903190225Srpaulo handle->linktype == DLT_LINUX_IRDA || 2904190225Srpaulo handle->linktype == DLT_LINUX_LAPD || 2905190225Srpaulo (handle->linktype == DLT_EN10MB && 2906190225Srpaulo (strncmp("isdn", device, 4) == 0 || 2907190225Srpaulo strncmp("isdY", device, 4) == 0))) { 2908190225Srpaulo /* 2909190225Srpaulo * Unknown interface type (-1), or a 2910190225Srpaulo * device we explicitly chose to run 2911190225Srpaulo * in cooked mode (e.g., PPP devices), 2912190225Srpaulo * or an ISDN device (whose link-layer 2913190225Srpaulo * type we can only determine by using 2914190225Srpaulo * APIs that may be different on different 2915190225Srpaulo * kernels) - reopen in cooked mode. 2916190225Srpaulo */ 2917190225Srpaulo if (close(sock_fd) == -1) { 2918190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 2919190225Srpaulo "close: %s", pcap_strerror(errno)); 2920190225Srpaulo return PCAP_ERROR; 2921190225Srpaulo } 2922190225Srpaulo sock_fd = socket(PF_PACKET, SOCK_DGRAM, 2923190225Srpaulo htons(ETH_P_ALL)); 2924190225Srpaulo if (sock_fd == -1) { 2925190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 2926190225Srpaulo "socket: %s", pcap_strerror(errno)); 2927235426Sdelphij if (errno == EPERM || errno == EACCES) { 2928235426Sdelphij /* 2929235426Sdelphij * You don't have permission to 2930235426Sdelphij * open the socket. 2931235426Sdelphij */ 2932235426Sdelphij return PCAP_ERROR_PERM_DENIED; 2933235426Sdelphij } else { 2934235426Sdelphij /* 2935235426Sdelphij * Other error. 2936235426Sdelphij */ 2937235426Sdelphij return PCAP_ERROR; 2938235426Sdelphij } 2939190225Srpaulo } 2940190225Srpaulo handle->md.cooked = 1; 294175107Sfenner 2942190225Srpaulo /* 2943190225Srpaulo * Get rid of any link-layer type list 2944190225Srpaulo * we allocated - this only supports cooked 2945190225Srpaulo * capture. 2946190225Srpaulo */ 2947190225Srpaulo if (handle->dlt_list != NULL) { 2948190225Srpaulo free(handle->dlt_list); 2949190225Srpaulo handle->dlt_list = NULL; 2950190225Srpaulo handle->dlt_count = 0; 2951190225Srpaulo } 2952190225Srpaulo 2953190225Srpaulo if (handle->linktype == -1) { 2954146768Ssam /* 2955190225Srpaulo * Warn that we're falling back on 2956190225Srpaulo * cooked mode; we may want to 2957190225Srpaulo * update "map_arphrd_to_dlt()" 2958190225Srpaulo * to handle the new type. 2959146768Ssam */ 2960190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 2961190225Srpaulo "arptype %d not " 2962190225Srpaulo "supported by libpcap - " 2963190225Srpaulo "falling back to cooked " 2964190225Srpaulo "socket", 2965190225Srpaulo arptype); 296675107Sfenner } 296775107Sfenner 296875107Sfenner /* 2969190225Srpaulo * IrDA capture is not a real "cooked" capture, 2970190225Srpaulo * it's IrLAP frames, not IP packets. The 2971190225Srpaulo * same applies to LAPD capture. 297275107Sfenner */ 2973190225Srpaulo if (handle->linktype != DLT_LINUX_IRDA && 2974190225Srpaulo handle->linktype != DLT_LINUX_LAPD) 2975190225Srpaulo handle->linktype = DLT_LINUX_SLL; 2976190225Srpaulo } 297775107Sfenner 2978190225Srpaulo handle->md.ifindex = iface_get_id(sock_fd, device, 2979190225Srpaulo handle->errbuf); 2980190225Srpaulo if (handle->md.ifindex == -1) { 2981190225Srpaulo close(sock_fd); 2982190225Srpaulo return PCAP_ERROR; 298375107Sfenner } 298475107Sfenner 2985190225Srpaulo if ((err = iface_bind(sock_fd, handle->md.ifindex, 2986190225Srpaulo handle->errbuf)) != 1) { 2987190225Srpaulo close(sock_fd); 2988190225Srpaulo if (err < 0) 2989190225Srpaulo return err; 2990190225Srpaulo else 2991190225Srpaulo return 0; /* try old mechanism */ 2992190225Srpaulo } 2993190225Srpaulo } else { 2994127664Sbms /* 2995214518Srpaulo * The "any" device. 2996127664Sbms */ 2997214518Srpaulo if (handle->opt.rfmon) { 2998214518Srpaulo /* 2999214518Srpaulo * It doesn't support monitor mode. 3000214518Srpaulo */ 3001214518Srpaulo return PCAP_ERROR_RFMON_NOTSUP; 3002214518Srpaulo } 3003214518Srpaulo 3004214518Srpaulo /* 3005214518Srpaulo * It uses cooked mode. 3006214518Srpaulo */ 3007190225Srpaulo handle->md.cooked = 1; 3008190225Srpaulo handle->linktype = DLT_LINUX_SLL; 300975107Sfenner 3010127664Sbms /* 3011190225Srpaulo * We're not bound to a device. 3012190225Srpaulo * For now, we're using this as an indication 3013190225Srpaulo * that we can't transmit; stop doing that only 3014190225Srpaulo * if we figure out how to transmit in cooked 3015190225Srpaulo * mode. 301675107Sfenner */ 3017190225Srpaulo handle->md.ifindex = -1; 3018190225Srpaulo } 301975107Sfenner 3020190225Srpaulo /* 3021190225Srpaulo * Select promiscuous mode on if "promisc" is set. 3022190225Srpaulo * 3023190225Srpaulo * Do not turn allmulti mode on if we don't select 3024190225Srpaulo * promiscuous mode - on some devices (e.g., Orinoco 3025190225Srpaulo * wireless interfaces), allmulti mode isn't supported 3026190225Srpaulo * and the driver implements it by turning promiscuous 3027190225Srpaulo * mode on, and that screws up the operation of the 3028190225Srpaulo * card as a normal networking interface, and on no 3029190225Srpaulo * other platform I know of does starting a non- 3030190225Srpaulo * promiscuous capture affect which multicast packets 3031190225Srpaulo * are received by the interface. 3032190225Srpaulo */ 303339291Sfenner 3034190225Srpaulo /* 3035190225Srpaulo * Hmm, how can we set promiscuous mode on all interfaces? 3036214518Srpaulo * I am not sure if that is possible at all. For now, we 3037214518Srpaulo * silently ignore attempts to turn promiscuous mode on 3038214518Srpaulo * for the "any" device (so you don't have to explicitly 3039214518Srpaulo * disable it in programs such as tcpdump). 3040190225Srpaulo */ 304175107Sfenner 3042214518Srpaulo if (!is_any_device && handle->opt.promisc) { 3043190225Srpaulo memset(&mr, 0, sizeof(mr)); 3044190225Srpaulo mr.mr_ifindex = handle->md.ifindex; 3045190225Srpaulo mr.mr_type = PACKET_MR_PROMISC; 3046190225Srpaulo if (setsockopt(sock_fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, 3047190225Srpaulo &mr, sizeof(mr)) == -1) { 3048190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3049190225Srpaulo "setsockopt: %s", pcap_strerror(errno)); 3050190225Srpaulo close(sock_fd); 3051190225Srpaulo return PCAP_ERROR; 3052190225Srpaulo } 3053190225Srpaulo } 305475107Sfenner 3055190225Srpaulo /* Enable auxillary data if supported and reserve room for 3056190225Srpaulo * reconstructing VLAN headers. */ 3057190225Srpaulo#ifdef HAVE_PACKET_AUXDATA 3058190225Srpaulo val = 1; 3059190225Srpaulo if (setsockopt(sock_fd, SOL_PACKET, PACKET_AUXDATA, &val, 3060190225Srpaulo sizeof(val)) == -1 && errno != ENOPROTOOPT) { 3061190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3062190225Srpaulo "setsockopt: %s", pcap_strerror(errno)); 3063190225Srpaulo close(sock_fd); 3064190225Srpaulo return PCAP_ERROR; 3065190225Srpaulo } 3066190225Srpaulo handle->offset += VLAN_TAG_LEN; 3067190225Srpaulo#endif /* HAVE_PACKET_AUXDATA */ 306875107Sfenner 3069190225Srpaulo /* 3070190225Srpaulo * This is a 2.2[.x] or later kernel (we know that 3071190225Srpaulo * because we're not using a SOCK_PACKET socket - 3072190225Srpaulo * PF_PACKET is supported only in 2.2 and later 3073190225Srpaulo * kernels). 3074190225Srpaulo * 3075190225Srpaulo * We can safely pass "recvfrom()" a byte count 3076190225Srpaulo * based on the snapshot length. 3077190225Srpaulo * 3078190225Srpaulo * If we're in cooked mode, make the snapshot length 3079190225Srpaulo * large enough to hold a "cooked mode" header plus 3080190225Srpaulo * 1 byte of packet data (so we don't pass a byte 3081190225Srpaulo * count of 0 to "recvfrom()"). 3082190225Srpaulo */ 3083190225Srpaulo if (handle->md.cooked) { 3084190225Srpaulo if (handle->snapshot < SLL_HDR_LEN + 1) 3085190225Srpaulo handle->snapshot = SLL_HDR_LEN + 1; 3086190225Srpaulo } 3087190225Srpaulo handle->bufsize = handle->snapshot; 308875107Sfenner 3089251129Sdelphij /* 3090251129Sdelphij * Set the offset at which to insert VLAN tags. 3091251129Sdelphij */ 3092251129Sdelphij switch (handle->linktype) { 3093251129Sdelphij 3094251129Sdelphij case DLT_EN10MB: 3095251129Sdelphij handle->md.vlan_offset = 2 * ETH_ALEN; 3096251129Sdelphij break; 3097251129Sdelphij 3098251129Sdelphij case DLT_LINUX_SLL: 3099251129Sdelphij handle->md.vlan_offset = 14; 3100251129Sdelphij break; 3101251129Sdelphij 3102251129Sdelphij default: 3103251129Sdelphij handle->md.vlan_offset = -1; /* unknown */ 3104251129Sdelphij break; 3105251129Sdelphij } 3106251129Sdelphij 3107190225Srpaulo /* Save the socket FD in the pcap structure */ 3108190225Srpaulo handle->fd = sock_fd; 3109127664Sbms 3110190225Srpaulo return 1; 311175107Sfenner#else 3112127664Sbms strncpy(ebuf, 3113127664Sbms "New packet capturing interface not supported by build " 311475107Sfenner "environment", PCAP_ERRBUF_SIZE); 311575107Sfenner return 0; 311639291Sfenner#endif 311775107Sfenner} 311839291Sfenner 3119235426Sdelphij#ifdef HAVE_PACKET_RING 3120235426Sdelphij/* 3121235426Sdelphij * Attempt to activate with memory-mapped access. 3122235426Sdelphij * 3123235426Sdelphij * On success, returns 1, and sets *status to 0 if there are no warnings 3124235426Sdelphij * or to a PCAP_WARNING_ code if there is a warning. 3125235426Sdelphij * 3126235426Sdelphij * On failure due to lack of support for memory-mapped capture, returns 3127235426Sdelphij * 0. 3128235426Sdelphij * 3129235426Sdelphij * On error, returns -1, and sets *status to the appropriate error code; 3130235426Sdelphij * if that is PCAP_ERROR, sets handle->errbuf to the appropriate message. 3131235426Sdelphij */ 3132190225Srpaulostatic int 3133235426Sdelphijactivate_mmap(pcap_t *handle, int *status) 3134190225Srpaulo{ 3135190225Srpaulo int ret; 3136190225Srpaulo 3137214518Srpaulo /* 3138214518Srpaulo * Attempt to allocate a buffer to hold the contents of one 3139214518Srpaulo * packet, for use by the oneshot callback. 3140214518Srpaulo */ 3141214518Srpaulo handle->md.oneshot_buffer = malloc(handle->snapshot); 3142214518Srpaulo if (handle->md.oneshot_buffer == NULL) { 3143214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3144214518Srpaulo "can't allocate oneshot buffer: %s", 3145214518Srpaulo pcap_strerror(errno)); 3146235426Sdelphij *status = PCAP_ERROR; 3147235426Sdelphij return -1; 3148214518Srpaulo } 3149214518Srpaulo 3150190225Srpaulo if (handle->opt.buffer_size == 0) { 3151190225Srpaulo /* by default request 2M for the ring buffer */ 3152190225Srpaulo handle->opt.buffer_size = 2*1024*1024; 3153190225Srpaulo } 3154190225Srpaulo ret = prepare_tpacket_socket(handle); 3155235426Sdelphij if (ret == -1) { 3156214518Srpaulo free(handle->md.oneshot_buffer); 3157235426Sdelphij *status = PCAP_ERROR; 3158190225Srpaulo return ret; 3159214518Srpaulo } 3160235426Sdelphij ret = create_ring(handle, status); 3161235426Sdelphij if (ret == 0) { 3162235426Sdelphij /* 3163235426Sdelphij * We don't support memory-mapped capture; our caller 3164235426Sdelphij * will fall back on reading from the socket. 3165235426Sdelphij */ 3166214518Srpaulo free(handle->md.oneshot_buffer); 3167235426Sdelphij return 0; 3168214518Srpaulo } 3169235426Sdelphij if (ret == -1) { 3170235426Sdelphij /* 3171235426Sdelphij * Error attempting to enable memory-mapped capture; 3172235426Sdelphij * fail. create_ring() has set *status. 3173235426Sdelphij */ 3174235426Sdelphij free(handle->md.oneshot_buffer); 3175235426Sdelphij return -1; 3176235426Sdelphij } 3177190225Srpaulo 3178235426Sdelphij /* 3179235426Sdelphij * Success. *status has been set either to 0 if there are no 3180235426Sdelphij * warnings or to a PCAP_WARNING_ value if there is a warning. 3181235426Sdelphij * 3182235426Sdelphij * Override some defaults and inherit the other fields from 3183235426Sdelphij * activate_new. 3184235426Sdelphij * handle->offset is used to get the current position into the rx ring. 3185235426Sdelphij * handle->cc is used to store the ring size. 3186235426Sdelphij */ 3187190225Srpaulo handle->read_op = pcap_read_linux_mmap; 3188190225Srpaulo handle->cleanup_op = pcap_cleanup_linux_mmap; 3189190225Srpaulo handle->setfilter_op = pcap_setfilter_linux_mmap; 3190190225Srpaulo handle->setnonblock_op = pcap_setnonblock_mmap; 3191190225Srpaulo handle->getnonblock_op = pcap_getnonblock_mmap; 3192214518Srpaulo handle->oneshot_callback = pcap_oneshot_mmap; 3193190225Srpaulo handle->selectable_fd = handle->fd; 3194190225Srpaulo return 1; 3195235426Sdelphij} 3196190225Srpaulo#else /* HAVE_PACKET_RING */ 3197235426Sdelphijstatic int 3198235426Sdelphijactivate_mmap(pcap_t *handle _U_, int *status _U_) 3199235426Sdelphij{ 3200190225Srpaulo return 0; 3201235426Sdelphij} 3202190225Srpaulo#endif /* HAVE_PACKET_RING */ 3203190225Srpaulo 3204190225Srpaulo#ifdef HAVE_PACKET_RING 3205235426Sdelphij/* 3206235426Sdelphij * Attempt to set the socket to version 2 of the memory-mapped header. 3207235426Sdelphij * Return 1 if we succeed or if we fail because version 2 isn't 3208235426Sdelphij * supported; return -1 on any other error, and set handle->errbuf. 3209235426Sdelphij */ 3210190225Srpaulostatic int 3211190225Srpauloprepare_tpacket_socket(pcap_t *handle) 3212190225Srpaulo{ 3213190225Srpaulo#ifdef HAVE_TPACKET2 3214190225Srpaulo socklen_t len; 3215190225Srpaulo int val; 3216190225Srpaulo#endif 3217190225Srpaulo 3218190225Srpaulo handle->md.tp_version = TPACKET_V1; 3219190225Srpaulo handle->md.tp_hdrlen = sizeof(struct tpacket_hdr); 3220190225Srpaulo 3221190225Srpaulo#ifdef HAVE_TPACKET2 3222190225Srpaulo /* Probe whether kernel supports TPACKET_V2 */ 3223190225Srpaulo val = TPACKET_V2; 3224190225Srpaulo len = sizeof(val); 3225190225Srpaulo if (getsockopt(handle->fd, SOL_PACKET, PACKET_HDRLEN, &val, &len) < 0) { 3226190225Srpaulo if (errno == ENOPROTOOPT) 3227214518Srpaulo return 1; /* no - just drive on */ 3228214518Srpaulo 3229214518Srpaulo /* Yes - treat as a failure. */ 3230190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3231214518Srpaulo "can't get TPACKET_V2 header len on packet socket: %s", 3232214518Srpaulo pcap_strerror(errno)); 3233214518Srpaulo return -1; 3234190225Srpaulo } 3235190225Srpaulo handle->md.tp_hdrlen = val; 3236190225Srpaulo 3237190225Srpaulo val = TPACKET_V2; 3238190225Srpaulo if (setsockopt(handle->fd, SOL_PACKET, PACKET_VERSION, &val, 3239190225Srpaulo sizeof(val)) < 0) { 3240190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3241214518Srpaulo "can't activate TPACKET_V2 on packet socket: %s", 3242214518Srpaulo pcap_strerror(errno)); 3243214518Srpaulo return -1; 3244190225Srpaulo } 3245190225Srpaulo handle->md.tp_version = TPACKET_V2; 3246190225Srpaulo 3247190225Srpaulo /* Reserve space for VLAN tag reconstruction */ 3248190225Srpaulo val = VLAN_TAG_LEN; 3249190225Srpaulo if (setsockopt(handle->fd, SOL_PACKET, PACKET_RESERVE, &val, 3250190225Srpaulo sizeof(val)) < 0) { 3251190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3252214518Srpaulo "can't set up reserve on packet socket: %s", 3253214518Srpaulo pcap_strerror(errno)); 3254214518Srpaulo return -1; 3255190225Srpaulo } 3256190225Srpaulo 3257190225Srpaulo#endif /* HAVE_TPACKET2 */ 3258190225Srpaulo return 1; 3259190225Srpaulo} 3260190225Srpaulo 3261235426Sdelphij/* 3262235426Sdelphij * Attempt to set up memory-mapped access. 3263235426Sdelphij * 3264235426Sdelphij * On success, returns 1, and sets *status to 0 if there are no warnings 3265235426Sdelphij * or to a PCAP_WARNING_ code if there is a warning. 3266235426Sdelphij * 3267235426Sdelphij * On failure due to lack of support for memory-mapped capture, returns 3268235426Sdelphij * 0. 3269235426Sdelphij * 3270235426Sdelphij * On error, returns -1, and sets *status to the appropriate error code; 3271235426Sdelphij * if that is PCAP_ERROR, sets handle->errbuf to the appropriate message. 3272235426Sdelphij */ 3273190225Srpaulostatic int 3274235426Sdelphijcreate_ring(pcap_t *handle, int *status) 3275190225Srpaulo{ 3276214518Srpaulo unsigned i, j, frames_per_block; 3277190225Srpaulo struct tpacket_req req; 3278235426Sdelphij socklen_t len; 3279235426Sdelphij unsigned int sk_type, tp_reserve, maclen, tp_hdrlen, netoff, macoff; 3280235426Sdelphij unsigned int frame_size; 3281190225Srpaulo 3282235426Sdelphij /* 3283235426Sdelphij * Start out assuming no warnings or errors. 3284235426Sdelphij */ 3285235426Sdelphij *status = 0; 3286235426Sdelphij 3287235426Sdelphij /* Note that with large snapshot length (say 64K, which is the default 3288235426Sdelphij * for recent versions of tcpdump, the value that "-s 0" has given 3289235426Sdelphij * for a long time with tcpdump, and the default in Wireshark/TShark), 3290235426Sdelphij * if we use the snapshot length to calculate the frame length, 3291235426Sdelphij * only a few frames will be available in the ring even with pretty 3292235426Sdelphij * large ring size (and a lot of memory will be unused). 3293235426Sdelphij * 3294235426Sdelphij * Ideally, we should choose a frame length based on the 3295235426Sdelphij * minimum of the specified snapshot length and the maximum 3296235426Sdelphij * packet size. That's not as easy as it sounds; consider, for 3297235426Sdelphij * example, an 802.11 interface in monitor mode, where the 3298235426Sdelphij * frame would include a radiotap header, where the maximum 3299235426Sdelphij * radiotap header length is device-dependent. 3300235426Sdelphij * 3301235426Sdelphij * So, for now, we just do this for Ethernet devices, where 3302235426Sdelphij * there's no metadata header, and the link-layer header is 3303235426Sdelphij * fixed length. We can get the maximum packet size by 3304235426Sdelphij * adding 18, the Ethernet header length plus the CRC length 3305235426Sdelphij * (just in case we happen to get the CRC in the packet), to 3306235426Sdelphij * the MTU of the interface; we fetch the MTU in the hopes 3307235426Sdelphij * that it reflects support for jumbo frames. (Even if the 3308235426Sdelphij * interface is just being used for passive snooping, the driver 3309235426Sdelphij * might set the size of buffers in the receive ring based on 3310235426Sdelphij * the MTU, so that the MTU limits the maximum size of packets 3311235426Sdelphij * that we can receive.) 3312235426Sdelphij * 3313235426Sdelphij * We don't do that if segmentation/fragmentation or receive 3314235426Sdelphij * offload are enabled, so we don't get rudely surprised by 3315235426Sdelphij * "packets" bigger than the MTU. */ 3316235426Sdelphij frame_size = handle->snapshot; 3317235426Sdelphij if (handle->linktype == DLT_EN10MB) { 3318235426Sdelphij int mtu; 3319235426Sdelphij int offload; 3320235426Sdelphij 3321235426Sdelphij offload = iface_get_offload(handle); 3322235426Sdelphij if (offload == -1) { 3323235426Sdelphij *status = PCAP_ERROR; 3324235426Sdelphij return -1; 3325235426Sdelphij } 3326235426Sdelphij if (!offload) { 3327235426Sdelphij mtu = iface_get_mtu(handle->fd, handle->opt.source, 3328235426Sdelphij handle->errbuf); 3329235426Sdelphij if (mtu == -1) { 3330235426Sdelphij *status = PCAP_ERROR; 3331235426Sdelphij return -1; 3332235426Sdelphij } 3333235426Sdelphij if (frame_size > mtu + 18) 3334235426Sdelphij frame_size = mtu + 18; 3335235426Sdelphij } 3336235426Sdelphij } 3337235426Sdelphij 3338235426Sdelphij /* NOTE: calculus matching those in tpacket_rcv() 3339235426Sdelphij * in linux-2.6/net/packet/af_packet.c 3340235426Sdelphij */ 3341235426Sdelphij len = sizeof(sk_type); 3342235426Sdelphij if (getsockopt(handle->fd, SOL_SOCKET, SO_TYPE, &sk_type, &len) < 0) { 3343235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "getsockopt: %s", pcap_strerror(errno)); 3344235426Sdelphij *status = PCAP_ERROR; 3345235426Sdelphij return -1; 3346235426Sdelphij } 3347235426Sdelphij#ifdef PACKET_RESERVE 3348235426Sdelphij len = sizeof(tp_reserve); 3349235426Sdelphij if (getsockopt(handle->fd, SOL_PACKET, PACKET_RESERVE, &tp_reserve, &len) < 0) { 3350235426Sdelphij if (errno != ENOPROTOOPT) { 3351235426Sdelphij /* 3352235426Sdelphij * ENOPROTOOPT means "kernel doesn't support 3353235426Sdelphij * PACKET_RESERVE", in which case we fall back 3354235426Sdelphij * as best we can. 3355235426Sdelphij */ 3356235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "getsockopt: %s", pcap_strerror(errno)); 3357235426Sdelphij *status = PCAP_ERROR; 3358235426Sdelphij return -1; 3359235426Sdelphij } 3360235426Sdelphij tp_reserve = 0; /* older kernel, reserve not supported */ 3361235426Sdelphij } 3362235426Sdelphij#else 3363235426Sdelphij tp_reserve = 0; /* older kernel, reserve not supported */ 3364235426Sdelphij#endif 3365235426Sdelphij maclen = (sk_type == SOCK_DGRAM) ? 0 : MAX_LINKHEADER_SIZE; 3366235426Sdelphij /* XXX: in the kernel maclen is calculated from 3367235426Sdelphij * LL_ALLOCATED_SPACE(dev) and vnet_hdr.hdr_len 3368235426Sdelphij * in: packet_snd() in linux-2.6/net/packet/af_packet.c 3369235426Sdelphij * then packet_alloc_skb() in linux-2.6/net/packet/af_packet.c 3370235426Sdelphij * then sock_alloc_send_pskb() in linux-2.6/net/core/sock.c 3371235426Sdelphij * but I see no way to get those sizes in userspace, 3372235426Sdelphij * like for instance with an ifreq ioctl(); 3373235426Sdelphij * the best thing I've found so far is MAX_HEADER in the kernel 3374235426Sdelphij * part of linux-2.6/include/linux/netdevice.h 3375235426Sdelphij * which goes up to 128+48=176; since pcap-linux.c defines 3376235426Sdelphij * a MAX_LINKHEADER_SIZE of 256 which is greater than that, 3377235426Sdelphij * let's use it.. maybe is it even large enough to directly 3378235426Sdelphij * replace macoff.. 3379235426Sdelphij */ 3380235426Sdelphij tp_hdrlen = TPACKET_ALIGN(handle->md.tp_hdrlen) + sizeof(struct sockaddr_ll) ; 3381235426Sdelphij netoff = TPACKET_ALIGN(tp_hdrlen + (maclen < 16 ? 16 : maclen)) + tp_reserve; 3382235426Sdelphij /* NOTE: AFAICS tp_reserve may break the TPACKET_ALIGN of 3383235426Sdelphij * netoff, which contradicts 3384235426Sdelphij * linux-2.6/Documentation/networking/packet_mmap.txt 3385235426Sdelphij * documenting that: 3386235426Sdelphij * "- Gap, chosen so that packet data (Start+tp_net) 3387235426Sdelphij * aligns to TPACKET_ALIGNMENT=16" 3388235426Sdelphij */ 3389235426Sdelphij /* NOTE: in linux-2.6/include/linux/skbuff.h: 3390235426Sdelphij * "CPUs often take a performance hit 3391235426Sdelphij * when accessing unaligned memory locations" 3392235426Sdelphij */ 3393235426Sdelphij macoff = netoff - maclen; 3394235426Sdelphij req.tp_frame_size = TPACKET_ALIGN(macoff + frame_size); 3395190225Srpaulo req.tp_frame_nr = handle->opt.buffer_size/req.tp_frame_size; 3396214518Srpaulo 3397214518Srpaulo /* compute the minumum block size that will handle this frame. 3398214518Srpaulo * The block has to be page size aligned. 3399214518Srpaulo * The max block size allowed by the kernel is arch-dependent and 3400214518Srpaulo * it's not explicitly checked here. */ 3401214518Srpaulo req.tp_block_size = getpagesize(); 3402214518Srpaulo while (req.tp_block_size < req.tp_frame_size) 3403214518Srpaulo req.tp_block_size <<= 1; 3404214518Srpaulo 3405214518Srpaulo frames_per_block = req.tp_block_size/req.tp_frame_size; 3406214518Srpaulo 3407235426Sdelphij /* 3408235426Sdelphij * PACKET_TIMESTAMP was added after linux/net_tstamp.h was, 3409235426Sdelphij * so we check for PACKET_TIMESTAMP. We check for 3410235426Sdelphij * linux/net_tstamp.h just in case a system somehow has 3411235426Sdelphij * PACKET_TIMESTAMP but not linux/net_tstamp.h; that might 3412235426Sdelphij * be unnecessary. 3413235426Sdelphij * 3414235426Sdelphij * SIOCSHWTSTAMP was introduced in the patch that introduced 3415235426Sdelphij * linux/net_tstamp.h, so we don't bother checking whether 3416235426Sdelphij * SIOCSHWTSTAMP is defined (if your Linux system has 3417235426Sdelphij * linux/net_tstamp.h but doesn't define SIOCSHWTSTAMP, your 3418235426Sdelphij * Linux system is badly broken). 3419235426Sdelphij */ 3420235426Sdelphij#if defined(HAVE_LINUX_NET_TSTAMP_H) && defined(PACKET_TIMESTAMP) 3421235426Sdelphij /* 3422235426Sdelphij * If we were told to do so, ask the kernel and the driver 3423235426Sdelphij * to use hardware timestamps. 3424235426Sdelphij * 3425235426Sdelphij * Hardware timestamps are only supported with mmapped 3426235426Sdelphij * captures. 3427235426Sdelphij */ 3428235426Sdelphij if (handle->opt.tstamp_type == PCAP_TSTAMP_ADAPTER || 3429235426Sdelphij handle->opt.tstamp_type == PCAP_TSTAMP_ADAPTER_UNSYNCED) { 3430235426Sdelphij struct hwtstamp_config hwconfig; 3431235426Sdelphij struct ifreq ifr; 3432235426Sdelphij int timesource; 3433235426Sdelphij 3434235426Sdelphij /* 3435235426Sdelphij * Ask for hardware time stamps on all packets, 3436235426Sdelphij * including transmitted packets. 3437235426Sdelphij */ 3438235426Sdelphij memset(&hwconfig, 0, sizeof(hwconfig)); 3439235426Sdelphij hwconfig.tx_type = HWTSTAMP_TX_ON; 3440235426Sdelphij hwconfig.rx_filter = HWTSTAMP_FILTER_ALL; 3441235426Sdelphij 3442235426Sdelphij memset(&ifr, 0, sizeof(ifr)); 3443235426Sdelphij strcpy(ifr.ifr_name, handle->opt.source); 3444235426Sdelphij ifr.ifr_data = (void *)&hwconfig; 3445235426Sdelphij 3446235426Sdelphij if (ioctl(handle->fd, SIOCSHWTSTAMP, &ifr) < 0) { 3447235426Sdelphij switch (errno) { 3448235426Sdelphij 3449235426Sdelphij case EPERM: 3450235426Sdelphij /* 3451235426Sdelphij * Treat this as an error, as the 3452235426Sdelphij * user should try to run this 3453235426Sdelphij * with the appropriate privileges - 3454235426Sdelphij * and, if they can't, shouldn't 3455235426Sdelphij * try requesting hardware time stamps. 3456235426Sdelphij */ 3457235426Sdelphij *status = PCAP_ERROR_PERM_DENIED; 3458235426Sdelphij return -1; 3459235426Sdelphij 3460235426Sdelphij case EOPNOTSUPP: 3461235426Sdelphij /* 3462235426Sdelphij * Treat this as a warning, as the 3463235426Sdelphij * only way to fix the warning is to 3464235426Sdelphij * get an adapter that supports hardware 3465235426Sdelphij * time stamps. We'll just fall back 3466235426Sdelphij * on the standard host time stamps. 3467235426Sdelphij */ 3468235426Sdelphij *status = PCAP_WARNING_TSTAMP_TYPE_NOTSUP; 3469235426Sdelphij break; 3470235426Sdelphij 3471235426Sdelphij default: 3472235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3473235426Sdelphij "SIOCSHWTSTAMP failed: %s", 3474235426Sdelphij pcap_strerror(errno)); 3475235426Sdelphij *status = PCAP_ERROR; 3476235426Sdelphij return -1; 3477235426Sdelphij } 3478235426Sdelphij } else { 3479235426Sdelphij /* 3480235426Sdelphij * Well, that worked. Now specify the type of 3481235426Sdelphij * hardware time stamp we want for this 3482235426Sdelphij * socket. 3483235426Sdelphij */ 3484235426Sdelphij if (handle->opt.tstamp_type == PCAP_TSTAMP_ADAPTER) { 3485235426Sdelphij /* 3486235426Sdelphij * Hardware timestamp, synchronized 3487235426Sdelphij * with the system clock. 3488235426Sdelphij */ 3489235426Sdelphij timesource = SOF_TIMESTAMPING_SYS_HARDWARE; 3490235426Sdelphij } else { 3491235426Sdelphij /* 3492235426Sdelphij * PCAP_TSTAMP_ADAPTER_UNSYNCED - hardware 3493235426Sdelphij * timestamp, not synchronized with the 3494235426Sdelphij * system clock. 3495235426Sdelphij */ 3496235426Sdelphij timesource = SOF_TIMESTAMPING_RAW_HARDWARE; 3497235426Sdelphij } 3498235426Sdelphij if (setsockopt(handle->fd, SOL_PACKET, PACKET_TIMESTAMP, 3499235426Sdelphij (void *)×ource, sizeof(timesource))) { 3500235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3501235426Sdelphij "can't set PACKET_TIMESTAMP: %s", 3502235426Sdelphij pcap_strerror(errno)); 3503235426Sdelphij *status = PCAP_ERROR; 3504235426Sdelphij return -1; 3505235426Sdelphij } 3506235426Sdelphij } 3507235426Sdelphij } 3508235426Sdelphij#endif /* HAVE_LINUX_NET_TSTAMP_H && PACKET_TIMESTAMP */ 3509235426Sdelphij 3510214518Srpaulo /* ask the kernel to create the ring */ 3511214518Srpauloretry: 3512190225Srpaulo req.tp_block_nr = req.tp_frame_nr / frames_per_block; 3513190225Srpaulo 3514190225Srpaulo /* req.tp_frame_nr is requested to match frames_per_block*req.tp_block_nr */ 3515190225Srpaulo req.tp_frame_nr = req.tp_block_nr * frames_per_block; 3516214518Srpaulo 3517190225Srpaulo if (setsockopt(handle->fd, SOL_PACKET, PACKET_RX_RING, 3518190225Srpaulo (void *) &req, sizeof(req))) { 3519190225Srpaulo if ((errno == ENOMEM) && (req.tp_block_nr > 1)) { 3520214518Srpaulo /* 3521214518Srpaulo * Memory failure; try to reduce the requested ring 3522214518Srpaulo * size. 3523214518Srpaulo * 3524214518Srpaulo * We used to reduce this by half -- do 5% instead. 3525214518Srpaulo * That may result in more iterations and a longer 3526214518Srpaulo * startup, but the user will be much happier with 3527214518Srpaulo * the resulting buffer size. 3528214518Srpaulo */ 3529214518Srpaulo if (req.tp_frame_nr < 20) 3530214518Srpaulo req.tp_frame_nr -= 1; 3531214518Srpaulo else 3532214518Srpaulo req.tp_frame_nr -= req.tp_frame_nr/20; 3533190225Srpaulo goto retry; 3534190225Srpaulo } 3535214518Srpaulo if (errno == ENOPROTOOPT) { 3536214518Srpaulo /* 3537214518Srpaulo * We don't have ring buffer support in this kernel. 3538214518Srpaulo */ 3539214518Srpaulo return 0; 3540214518Srpaulo } 3541214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3542214518Srpaulo "can't create rx ring on packet socket: %s", 3543214518Srpaulo pcap_strerror(errno)); 3544235426Sdelphij *status = PCAP_ERROR; 3545214518Srpaulo return -1; 3546190225Srpaulo } 3547190225Srpaulo 3548190225Srpaulo /* memory map the rx ring */ 3549214518Srpaulo handle->md.mmapbuflen = req.tp_block_nr * req.tp_block_size; 3550214518Srpaulo handle->md.mmapbuf = mmap(0, handle->md.mmapbuflen, 3551214518Srpaulo PROT_READ|PROT_WRITE, MAP_SHARED, handle->fd, 0); 3552214518Srpaulo if (handle->md.mmapbuf == MAP_FAILED) { 3553214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3554214518Srpaulo "can't mmap rx ring: %s", pcap_strerror(errno)); 3555190225Srpaulo 3556190225Srpaulo /* clear the allocated ring on error*/ 3557190225Srpaulo destroy_ring(handle); 3558235426Sdelphij *status = PCAP_ERROR; 3559214518Srpaulo return -1; 3560190225Srpaulo } 3561190225Srpaulo 3562190225Srpaulo /* allocate a ring for each frame header pointer*/ 3563190225Srpaulo handle->cc = req.tp_frame_nr; 3564190225Srpaulo handle->buffer = malloc(handle->cc * sizeof(union thdr *)); 3565190225Srpaulo if (!handle->buffer) { 3566214518Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3567214518Srpaulo "can't allocate ring of frame headers: %s", 3568214518Srpaulo pcap_strerror(errno)); 3569214518Srpaulo 3570190225Srpaulo destroy_ring(handle); 3571235426Sdelphij *status = PCAP_ERROR; 3572214518Srpaulo return -1; 3573190225Srpaulo } 3574190225Srpaulo 3575190225Srpaulo /* fill the header ring with proper frame ptr*/ 3576190225Srpaulo handle->offset = 0; 3577190225Srpaulo for (i=0; i<req.tp_block_nr; ++i) { 3578214518Srpaulo void *base = &handle->md.mmapbuf[i*req.tp_block_size]; 3579190225Srpaulo for (j=0; j<frames_per_block; ++j, ++handle->offset) { 3580190225Srpaulo RING_GET_FRAME(handle) = base; 3581190225Srpaulo base += req.tp_frame_size; 3582190225Srpaulo } 3583190225Srpaulo } 3584190225Srpaulo 3585190225Srpaulo handle->bufsize = req.tp_frame_size; 3586190225Srpaulo handle->offset = 0; 3587190225Srpaulo return 1; 3588190225Srpaulo} 3589190225Srpaulo 3590190225Srpaulo/* free all ring related resources*/ 3591190225Srpaulostatic void 3592190225Srpaulodestroy_ring(pcap_t *handle) 3593190225Srpaulo{ 3594190225Srpaulo /* tell the kernel to destroy the ring*/ 3595190225Srpaulo struct tpacket_req req; 3596190225Srpaulo memset(&req, 0, sizeof(req)); 3597190225Srpaulo setsockopt(handle->fd, SOL_PACKET, PACKET_RX_RING, 3598190225Srpaulo (void *) &req, sizeof(req)); 3599190225Srpaulo 3600190225Srpaulo /* if ring is mapped, unmap it*/ 3601214518Srpaulo if (handle->md.mmapbuf) { 3602214518Srpaulo /* do not test for mmap failure, as we can't recover from any error */ 3603214518Srpaulo munmap(handle->md.mmapbuf, handle->md.mmapbuflen); 3604214518Srpaulo handle->md.mmapbuf = NULL; 3605190225Srpaulo } 3606190225Srpaulo} 3607190225Srpaulo 3608214518Srpaulo/* 3609214518Srpaulo * Special one-shot callback, used for pcap_next() and pcap_next_ex(), 3610214518Srpaulo * for Linux mmapped capture. 3611214518Srpaulo * 3612214518Srpaulo * The problem is that pcap_next() and pcap_next_ex() expect the packet 3613214518Srpaulo * data handed to the callback to be valid after the callback returns, 3614214518Srpaulo * but pcap_read_linux_mmap() has to release that packet as soon as 3615214518Srpaulo * the callback returns (otherwise, the kernel thinks there's still 3616214518Srpaulo * at least one unprocessed packet available in the ring, so a select() 3617214518Srpaulo * will immediately return indicating that there's data to process), so, 3618214518Srpaulo * in the callback, we have to make a copy of the packet. 3619214518Srpaulo * 3620214518Srpaulo * Yes, this means that, if the capture is using the ring buffer, using 3621214518Srpaulo * pcap_next() or pcap_next_ex() requires more copies than using 3622214518Srpaulo * pcap_loop() or pcap_dispatch(). If that bothers you, don't use 3623214518Srpaulo * pcap_next() or pcap_next_ex(). 3624214518Srpaulo */ 3625190225Srpaulostatic void 3626214518Srpaulopcap_oneshot_mmap(u_char *user, const struct pcap_pkthdr *h, 3627214518Srpaulo const u_char *bytes) 3628214518Srpaulo{ 3629214518Srpaulo struct oneshot_userdata *sp = (struct oneshot_userdata *)user; 3630214518Srpaulo 3631214518Srpaulo *sp->hdr = *h; 3632214518Srpaulo memcpy(sp->pd->md.oneshot_buffer, bytes, h->caplen); 3633214518Srpaulo *sp->pkt = sp->pd->md.oneshot_buffer; 3634214518Srpaulo} 3635214518Srpaulo 3636214518Srpaulostatic void 3637190225Srpaulopcap_cleanup_linux_mmap( pcap_t *handle ) 3638190225Srpaulo{ 3639190225Srpaulo destroy_ring(handle); 3640214518Srpaulo if (handle->md.oneshot_buffer != NULL) { 3641214518Srpaulo free(handle->md.oneshot_buffer); 3642214518Srpaulo handle->md.oneshot_buffer = NULL; 3643214518Srpaulo } 3644190225Srpaulo pcap_cleanup_linux(handle); 3645190225Srpaulo} 3646190225Srpaulo 3647190225Srpaulo 3648190225Srpaulostatic int 3649190225Srpaulopcap_getnonblock_mmap(pcap_t *p, char *errbuf) 3650190225Srpaulo{ 3651190225Srpaulo /* use negative value of timeout to indicate non blocking ops */ 3652190225Srpaulo return (p->md.timeout<0); 3653190225Srpaulo} 3654190225Srpaulo 3655190225Srpaulostatic int 3656190225Srpaulopcap_setnonblock_mmap(pcap_t *p, int nonblock, char *errbuf) 3657190225Srpaulo{ 3658251129Sdelphij /* 3659251129Sdelphij * Map each value to their corresponding negation to 3660251129Sdelphij * preserve the timeout value provided with pcap_set_timeout. 3661251129Sdelphij */ 3662190225Srpaulo if (nonblock) { 3663214518Srpaulo if (p->md.timeout >= 0) { 3664214518Srpaulo /* 3665251129Sdelphij * Indicate that we're switching to 3666251129Sdelphij * non-blocking mode. 3667214518Srpaulo */ 3668251129Sdelphij p->md.timeout = ~p->md.timeout; 3669214518Srpaulo } 3670214518Srpaulo } else { 3671214518Srpaulo if (p->md.timeout < 0) { 3672251129Sdelphij p->md.timeout = ~p->md.timeout; 3673214518Srpaulo } 3674214518Srpaulo } 3675190225Srpaulo return 0; 3676190225Srpaulo} 3677190225Srpaulo 3678190225Srpaulostatic inline union thdr * 3679190225Srpaulopcap_get_ring_frame(pcap_t *handle, int status) 3680190225Srpaulo{ 3681190225Srpaulo union thdr h; 3682190225Srpaulo 3683190225Srpaulo h.raw = RING_GET_FRAME(handle); 3684190225Srpaulo switch (handle->md.tp_version) { 3685190225Srpaulo case TPACKET_V1: 3686190225Srpaulo if (status != (h.h1->tp_status ? TP_STATUS_USER : 3687190225Srpaulo TP_STATUS_KERNEL)) 3688190225Srpaulo return NULL; 3689190225Srpaulo break; 3690190225Srpaulo#ifdef HAVE_TPACKET2 3691190225Srpaulo case TPACKET_V2: 3692190225Srpaulo if (status != (h.h2->tp_status ? TP_STATUS_USER : 3693190225Srpaulo TP_STATUS_KERNEL)) 3694190225Srpaulo return NULL; 3695190225Srpaulo break; 3696190225Srpaulo#endif 3697190225Srpaulo } 3698190225Srpaulo return h.raw; 3699190225Srpaulo} 3700190225Srpaulo 3701214518Srpaulo#ifndef POLLRDHUP 3702214518Srpaulo#define POLLRDHUP 0 3703214518Srpaulo#endif 3704214518Srpaulo 3705190225Srpaulostatic int 3706190225Srpaulopcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, 3707190225Srpaulo u_char *user) 3708190225Srpaulo{ 3709214518Srpaulo int timeout; 3710190225Srpaulo int pkts = 0; 3711214518Srpaulo char c; 3712190225Srpaulo 3713190225Srpaulo /* wait for frames availability.*/ 3714214518Srpaulo if (!pcap_get_ring_frame(handle, TP_STATUS_USER)) { 3715190225Srpaulo struct pollfd pollinfo; 3716190225Srpaulo int ret; 3717190225Srpaulo 3718190225Srpaulo pollinfo.fd = handle->fd; 3719190225Srpaulo pollinfo.events = POLLIN; 3720190225Srpaulo 3721214518Srpaulo if (handle->md.timeout == 0) 3722214518Srpaulo timeout = -1; /* block forever */ 3723214518Srpaulo else if (handle->md.timeout > 0) 3724214518Srpaulo timeout = handle->md.timeout; /* block for that amount of time */ 3725214518Srpaulo else 3726214518Srpaulo timeout = 0; /* non-blocking mode - poll to pick up errors */ 3727190225Srpaulo do { 3728214518Srpaulo ret = poll(&pollinfo, 1, timeout); 3729214518Srpaulo if (ret < 0 && errno != EINTR) { 3730190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3731214518Srpaulo "can't poll on packet socket: %s", 3732214518Srpaulo pcap_strerror(errno)); 3733214518Srpaulo return PCAP_ERROR; 3734214518Srpaulo } else if (ret > 0 && 3735214518Srpaulo (pollinfo.revents & (POLLHUP|POLLRDHUP|POLLERR|POLLNVAL))) { 3736214518Srpaulo /* 3737214518Srpaulo * There's some indication other than 3738214518Srpaulo * "you can read on this descriptor" on 3739214518Srpaulo * the descriptor. 3740214518Srpaulo */ 3741214518Srpaulo if (pollinfo.revents & (POLLHUP | POLLRDHUP)) { 3742214518Srpaulo snprintf(handle->errbuf, 3743214518Srpaulo PCAP_ERRBUF_SIZE, 3744214518Srpaulo "Hangup on packet socket"); 3745214518Srpaulo return PCAP_ERROR; 3746214518Srpaulo } 3747214518Srpaulo if (pollinfo.revents & POLLERR) { 3748214518Srpaulo /* 3749214518Srpaulo * A recv() will give us the 3750214518Srpaulo * actual error code. 3751214518Srpaulo * 3752214518Srpaulo * XXX - make the socket non-blocking? 3753214518Srpaulo */ 3754214518Srpaulo if (recv(handle->fd, &c, sizeof c, 3755214518Srpaulo MSG_PEEK) != -1) 3756214518Srpaulo continue; /* what, no error? */ 3757214518Srpaulo if (errno == ENETDOWN) { 3758214518Srpaulo /* 3759214518Srpaulo * The device on which we're 3760214518Srpaulo * capturing went away. 3761214518Srpaulo * 3762214518Srpaulo * XXX - we should really return 3763214518Srpaulo * PCAP_ERROR_IFACE_NOT_UP, 3764214518Srpaulo * but pcap_dispatch() etc. 3765214518Srpaulo * aren't defined to return 3766214518Srpaulo * that. 3767214518Srpaulo */ 3768214518Srpaulo snprintf(handle->errbuf, 3769214518Srpaulo PCAP_ERRBUF_SIZE, 3770214518Srpaulo "The interface went down"); 3771214518Srpaulo } else { 3772214518Srpaulo snprintf(handle->errbuf, 3773214518Srpaulo PCAP_ERRBUF_SIZE, 3774214518Srpaulo "Error condition on packet socket: %s", 3775214518Srpaulo strerror(errno)); 3776214518Srpaulo } 3777214518Srpaulo return PCAP_ERROR; 3778214518Srpaulo } 3779214518Srpaulo if (pollinfo.revents & POLLNVAL) { 3780214518Srpaulo snprintf(handle->errbuf, 3781214518Srpaulo PCAP_ERRBUF_SIZE, 3782214518Srpaulo "Invalid polling request on packet socket"); 3783214518Srpaulo return PCAP_ERROR; 3784214518Srpaulo } 3785214518Srpaulo } 3786190225Srpaulo /* check for break loop condition on interrupted syscall*/ 3787190225Srpaulo if (handle->break_loop) { 3788190225Srpaulo handle->break_loop = 0; 3789214518Srpaulo return PCAP_ERROR_BREAK; 3790190225Srpaulo } 3791190225Srpaulo } while (ret < 0); 3792190225Srpaulo } 3793190225Srpaulo 3794190225Srpaulo /* non-positive values of max_packets are used to require all 3795190225Srpaulo * packets currently available in the ring */ 3796190225Srpaulo while ((pkts < max_packets) || (max_packets <= 0)) { 3797190225Srpaulo int run_bpf; 3798190225Srpaulo struct sockaddr_ll *sll; 3799190225Srpaulo struct pcap_pkthdr pcaphdr; 3800190225Srpaulo unsigned char *bp; 3801190225Srpaulo union thdr h; 3802190225Srpaulo unsigned int tp_len; 3803190225Srpaulo unsigned int tp_mac; 3804190225Srpaulo unsigned int tp_snaplen; 3805190225Srpaulo unsigned int tp_sec; 3806190225Srpaulo unsigned int tp_usec; 3807190225Srpaulo 3808190225Srpaulo h.raw = pcap_get_ring_frame(handle, TP_STATUS_USER); 3809190225Srpaulo if (!h.raw) 3810190225Srpaulo break; 3811190225Srpaulo 3812190225Srpaulo switch (handle->md.tp_version) { 3813190225Srpaulo case TPACKET_V1: 3814190225Srpaulo tp_len = h.h1->tp_len; 3815190225Srpaulo tp_mac = h.h1->tp_mac; 3816190225Srpaulo tp_snaplen = h.h1->tp_snaplen; 3817190225Srpaulo tp_sec = h.h1->tp_sec; 3818190225Srpaulo tp_usec = h.h1->tp_usec; 3819190225Srpaulo break; 3820190225Srpaulo#ifdef HAVE_TPACKET2 3821190225Srpaulo case TPACKET_V2: 3822190225Srpaulo tp_len = h.h2->tp_len; 3823190225Srpaulo tp_mac = h.h2->tp_mac; 3824190225Srpaulo tp_snaplen = h.h2->tp_snaplen; 3825190225Srpaulo tp_sec = h.h2->tp_sec; 3826190225Srpaulo tp_usec = h.h2->tp_nsec / 1000; 3827190225Srpaulo break; 3828190225Srpaulo#endif 3829190225Srpaulo default: 3830190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3831190225Srpaulo "unsupported tpacket version %d", 3832190225Srpaulo handle->md.tp_version); 3833190225Srpaulo return -1; 3834190225Srpaulo } 3835190225Srpaulo /* perform sanity check on internal offset. */ 3836190225Srpaulo if (tp_mac + tp_snaplen > handle->bufsize) { 3837190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3838190225Srpaulo "corrupted frame on kernel ring mac " 3839190225Srpaulo "offset %d + caplen %d > frame len %d", 3840190225Srpaulo tp_mac, tp_snaplen, handle->bufsize); 3841190225Srpaulo return -1; 3842190225Srpaulo } 3843190225Srpaulo 3844190225Srpaulo /* run filter on received packet 3845190225Srpaulo * If the kernel filtering is enabled we need to run the 3846190225Srpaulo * filter until all the frames present into the ring 3847190225Srpaulo * at filter creation time are processed. 3848190225Srpaulo * In such case md.use_bpf is used as a counter for the 3849190225Srpaulo * packet we need to filter. 3850190225Srpaulo * Note: alternatively it could be possible to stop applying 3851190225Srpaulo * the filter when the ring became empty, but it can possibly 3852190225Srpaulo * happen a lot later... */ 3853190225Srpaulo bp = (unsigned char*)h.raw + tp_mac; 3854190225Srpaulo run_bpf = (!handle->md.use_bpf) || 3855190225Srpaulo ((handle->md.use_bpf>1) && handle->md.use_bpf--); 3856190225Srpaulo if (run_bpf && handle->fcode.bf_insns && 3857190225Srpaulo (bpf_filter(handle->fcode.bf_insns, bp, 3858190225Srpaulo tp_len, tp_snaplen) == 0)) 3859190225Srpaulo goto skip; 3860190225Srpaulo 3861214518Srpaulo /* 3862214518Srpaulo * Do checks based on packet direction. 3863214518Srpaulo */ 3864190225Srpaulo sll = (void *)h.raw + TPACKET_ALIGN(handle->md.tp_hdrlen); 3865214518Srpaulo if (sll->sll_pkttype == PACKET_OUTGOING) { 3866214518Srpaulo /* 3867214518Srpaulo * Outgoing packet. 3868214518Srpaulo * If this is from the loopback device, reject it; 3869214518Srpaulo * we'll see the packet as an incoming packet as well, 3870214518Srpaulo * and we don't want to see it twice. 3871214518Srpaulo */ 3872214518Srpaulo if (sll->sll_ifindex == handle->md.lo_ifindex) 3873214518Srpaulo goto skip; 3874190225Srpaulo 3875214518Srpaulo /* 3876214518Srpaulo * If the user only wants incoming packets, reject it. 3877214518Srpaulo */ 3878214518Srpaulo if (handle->direction == PCAP_D_IN) 3879214518Srpaulo goto skip; 3880214518Srpaulo } else { 3881214518Srpaulo /* 3882214518Srpaulo * Incoming packet. 3883214518Srpaulo * If the user only wants outgoing packets, reject it. 3884214518Srpaulo */ 3885214518Srpaulo if (handle->direction == PCAP_D_OUT) 3886214518Srpaulo goto skip; 3887214518Srpaulo } 3888214518Srpaulo 3889190225Srpaulo /* get required packet info from ring header */ 3890190225Srpaulo pcaphdr.ts.tv_sec = tp_sec; 3891190225Srpaulo pcaphdr.ts.tv_usec = tp_usec; 3892190225Srpaulo pcaphdr.caplen = tp_snaplen; 3893190225Srpaulo pcaphdr.len = tp_len; 3894190225Srpaulo 3895190225Srpaulo /* if required build in place the sll header*/ 3896190225Srpaulo if (handle->md.cooked) { 3897190225Srpaulo struct sll_header *hdrp; 3898190225Srpaulo 3899190225Srpaulo /* 3900190225Srpaulo * The kernel should have left us with enough 3901190225Srpaulo * space for an sll header; back up the packet 3902190225Srpaulo * data pointer into that space, as that'll be 3903190225Srpaulo * the beginning of the packet we pass to the 3904190225Srpaulo * callback. 3905190225Srpaulo */ 3906190225Srpaulo bp -= SLL_HDR_LEN; 3907190225Srpaulo 3908190225Srpaulo /* 3909190225Srpaulo * Let's make sure that's past the end of 3910190225Srpaulo * the tpacket header, i.e. >= 3911190225Srpaulo * ((u_char *)thdr + TPACKET_HDRLEN), so we 3912190225Srpaulo * don't step on the header when we construct 3913190225Srpaulo * the sll header. 3914190225Srpaulo */ 3915190225Srpaulo if (bp < (u_char *)h.raw + 3916190225Srpaulo TPACKET_ALIGN(handle->md.tp_hdrlen) + 3917190225Srpaulo sizeof(struct sockaddr_ll)) { 3918190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 3919190225Srpaulo "cooked-mode frame doesn't have room for sll header"); 3920190225Srpaulo return -1; 3921190225Srpaulo } 3922190225Srpaulo 3923190225Srpaulo /* 3924190225Srpaulo * OK, that worked; construct the sll header. 3925190225Srpaulo */ 3926190225Srpaulo hdrp = (struct sll_header *)bp; 3927190225Srpaulo hdrp->sll_pkttype = map_packet_type_to_sll_type( 3928190225Srpaulo sll->sll_pkttype); 3929190225Srpaulo hdrp->sll_hatype = htons(sll->sll_hatype); 3930190225Srpaulo hdrp->sll_halen = htons(sll->sll_halen); 3931190225Srpaulo memcpy(hdrp->sll_addr, sll->sll_addr, SLL_ADDRLEN); 3932190225Srpaulo hdrp->sll_protocol = sll->sll_protocol; 3933190225Srpaulo 3934190225Srpaulo /* update packet len */ 3935190225Srpaulo pcaphdr.caplen += SLL_HDR_LEN; 3936190225Srpaulo pcaphdr.len += SLL_HDR_LEN; 3937190225Srpaulo } 3938190225Srpaulo 3939190225Srpaulo#ifdef HAVE_TPACKET2 3940251129Sdelphij if ((handle->md.tp_version == TPACKET_V2) && 3941251129Sdelphij#if defined(TP_STATUS_VLAN_VALID) 3942251129Sdelphij (h.h2->tp_vlan_tci || (h.h2->tp_status & TP_STATUS_VLAN_VALID)) && 3943251129Sdelphij#else 3944251129Sdelphij h.h2->tp_vlan_tci && 3945251129Sdelphij#endif 3946251129Sdelphij handle->md.vlan_offset != -1 && 3947251129Sdelphij tp_snaplen >= (unsigned int) handle->md.vlan_offset) { 3948190225Srpaulo struct vlan_tag *tag; 3949190225Srpaulo 3950190225Srpaulo bp -= VLAN_TAG_LEN; 3951251129Sdelphij memmove(bp, bp + VLAN_TAG_LEN, handle->md.vlan_offset); 3952190225Srpaulo 3953251129Sdelphij tag = (struct vlan_tag *)(bp + handle->md.vlan_offset); 3954190225Srpaulo tag->vlan_tpid = htons(ETH_P_8021Q); 3955190225Srpaulo tag->vlan_tci = htons(h.h2->tp_vlan_tci); 3956190225Srpaulo 3957190225Srpaulo pcaphdr.caplen += VLAN_TAG_LEN; 3958190225Srpaulo pcaphdr.len += VLAN_TAG_LEN; 3959190225Srpaulo } 3960190225Srpaulo#endif 3961190225Srpaulo 3962214518Srpaulo /* 3963214518Srpaulo * The only way to tell the kernel to cut off the 3964214518Srpaulo * packet at a snapshot length is with a filter program; 3965214518Srpaulo * if there's no filter program, the kernel won't cut 3966214518Srpaulo * the packet off. 3967214518Srpaulo * 3968214518Srpaulo * Trim the snapshot length to be no longer than the 3969214518Srpaulo * specified snapshot length. 3970214518Srpaulo */ 3971214518Srpaulo if (pcaphdr.caplen > handle->snapshot) 3972214518Srpaulo pcaphdr.caplen = handle->snapshot; 3973214518Srpaulo 3974190225Srpaulo /* pass the packet to the user */ 3975190225Srpaulo pkts++; 3976190225Srpaulo callback(user, &pcaphdr, bp); 3977190225Srpaulo handle->md.packets_read++; 3978190225Srpaulo 3979190225Srpauloskip: 3980190225Srpaulo /* next packet */ 3981190225Srpaulo switch (handle->md.tp_version) { 3982190225Srpaulo case TPACKET_V1: 3983190225Srpaulo h.h1->tp_status = TP_STATUS_KERNEL; 3984190225Srpaulo break; 3985190225Srpaulo#ifdef HAVE_TPACKET2 3986190225Srpaulo case TPACKET_V2: 3987190225Srpaulo h.h2->tp_status = TP_STATUS_KERNEL; 3988190225Srpaulo break; 3989190225Srpaulo#endif 3990190225Srpaulo } 3991190225Srpaulo if (++handle->offset >= handle->cc) 3992190225Srpaulo handle->offset = 0; 3993190225Srpaulo 3994190225Srpaulo /* check for break loop condition*/ 3995190225Srpaulo if (handle->break_loop) { 3996190225Srpaulo handle->break_loop = 0; 3997214518Srpaulo return PCAP_ERROR_BREAK; 3998190225Srpaulo } 3999190225Srpaulo } 4000190225Srpaulo return pkts; 4001190225Srpaulo} 4002190225Srpaulo 4003190225Srpaulostatic int 4004190225Srpaulopcap_setfilter_linux_mmap(pcap_t *handle, struct bpf_program *filter) 4005190225Srpaulo{ 4006190225Srpaulo int n, offset; 4007214518Srpaulo int ret; 4008214518Srpaulo 4009214518Srpaulo /* 4010214518Srpaulo * Don't rewrite "ret" instructions; we don't need to, as 4011214518Srpaulo * we're not reading packets with recvmsg(), and we don't 4012214518Srpaulo * want to, as, by not rewriting them, the kernel can avoid 4013214518Srpaulo * copying extra data. 4014214518Srpaulo */ 4015214518Srpaulo ret = pcap_setfilter_linux_common(handle, filter, 1); 4016190225Srpaulo if (ret < 0) 4017190225Srpaulo return ret; 4018190225Srpaulo 4019190225Srpaulo /* if the kernel filter is enabled, we need to apply the filter on 4020190225Srpaulo * all packets present into the ring. Get an upper bound of their number 4021190225Srpaulo */ 4022190225Srpaulo if (!handle->md.use_bpf) 4023190225Srpaulo return ret; 4024190225Srpaulo 4025190225Srpaulo /* walk the ring backward and count the free slot */ 4026190225Srpaulo offset = handle->offset; 4027190225Srpaulo if (--handle->offset < 0) 4028190225Srpaulo handle->offset = handle->cc - 1; 4029190225Srpaulo for (n=0; n < handle->cc; ++n) { 4030190225Srpaulo if (--handle->offset < 0) 4031190225Srpaulo handle->offset = handle->cc - 1; 4032190225Srpaulo if (!pcap_get_ring_frame(handle, TP_STATUS_KERNEL)) 4033190225Srpaulo break; 4034190225Srpaulo } 4035190225Srpaulo 4036190225Srpaulo /* be careful to not change current ring position */ 4037190225Srpaulo handle->offset = offset; 4038190225Srpaulo 4039190225Srpaulo /* store the number of packets currently present in the ring */ 4040190225Srpaulo handle->md.use_bpf = 1 + (handle->cc - n); 4041190225Srpaulo return ret; 4042190225Srpaulo} 4043190225Srpaulo 4044190225Srpaulo#endif /* HAVE_PACKET_RING */ 4045190225Srpaulo 4046190225Srpaulo 404775107Sfenner#ifdef HAVE_PF_PACKET_SOCKETS 404875107Sfenner/* 4049127664Sbms * Return the index of the given device name. Fill ebuf and return 405075107Sfenner * -1 on failure. 405175107Sfenner */ 405275107Sfennerstatic int 405375107Sfenneriface_get_id(int fd, const char *device, char *ebuf) 405475107Sfenner{ 405575107Sfenner struct ifreq ifr; 405626175Sfenner 405739291Sfenner memset(&ifr, 0, sizeof(ifr)); 405839291Sfenner strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); 405975107Sfenner 406075107Sfenner if (ioctl(fd, SIOCGIFINDEX, &ifr) == -1) { 406175107Sfenner snprintf(ebuf, PCAP_ERRBUF_SIZE, 4062172677Smlaier "SIOCGIFINDEX: %s", pcap_strerror(errno)); 406375107Sfenner return -1; 406426175Sfenner } 406526175Sfenner 406675107Sfenner return ifr.ifr_ifindex; 406775107Sfenner} 406826175Sfenner 406975107Sfenner/* 4070127664Sbms * Bind the socket associated with FD to the given device. 4071190225Srpaulo * Return 1 on success, 0 if we should try a SOCK_PACKET socket, 4072190225Srpaulo * or a PCAP_ERROR_ value on a hard error. 407375107Sfenner */ 407475107Sfennerstatic int 407575107Sfenneriface_bind(int fd, int ifindex, char *ebuf) 407675107Sfenner{ 407775107Sfenner struct sockaddr_ll sll; 4078127664Sbms int err; 4079127664Sbms socklen_t errlen = sizeof(err); 408075107Sfenner 408175107Sfenner memset(&sll, 0, sizeof(sll)); 408275107Sfenner sll.sll_family = AF_PACKET; 408375107Sfenner sll.sll_ifindex = ifindex; 408475107Sfenner sll.sll_protocol = htons(ETH_P_ALL); 408575107Sfenner 408675107Sfenner if (bind(fd, (struct sockaddr *) &sll, sizeof(sll)) == -1) { 4087190225Srpaulo if (errno == ENETDOWN) { 4088190225Srpaulo /* 4089190225Srpaulo * Return a "network down" indication, so that 4090190225Srpaulo * the application can report that rather than 4091190225Srpaulo * saying we had a mysterious failure and 4092190225Srpaulo * suggest that they report a problem to the 4093190225Srpaulo * libpcap developers. 4094190225Srpaulo */ 4095190225Srpaulo return PCAP_ERROR_IFACE_NOT_UP; 4096190225Srpaulo } else { 4097190225Srpaulo snprintf(ebuf, PCAP_ERRBUF_SIZE, 4098190225Srpaulo "bind: %s", pcap_strerror(errno)); 4099190225Srpaulo return PCAP_ERROR; 4100190225Srpaulo } 410126175Sfenner } 410226175Sfenner 4103127664Sbms /* Any pending errors, e.g., network is down? */ 4104127664Sbms 4105127664Sbms if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &errlen) == -1) { 4106127664Sbms snprintf(ebuf, PCAP_ERRBUF_SIZE, 4107127664Sbms "getsockopt: %s", pcap_strerror(errno)); 4108190225Srpaulo return 0; 4109127664Sbms } 4110127664Sbms 4111190225Srpaulo if (err == ENETDOWN) { 4112190225Srpaulo /* 4113190225Srpaulo * Return a "network down" indication, so that 4114190225Srpaulo * the application can report that rather than 4115190225Srpaulo * saying we had a mysterious failure and 4116190225Srpaulo * suggest that they report a problem to the 4117190225Srpaulo * libpcap developers. 4118190225Srpaulo */ 4119190225Srpaulo return PCAP_ERROR_IFACE_NOT_UP; 4120190225Srpaulo } else if (err > 0) { 4121127664Sbms snprintf(ebuf, PCAP_ERRBUF_SIZE, 4122127664Sbms "bind: %s", pcap_strerror(err)); 4123190225Srpaulo return 0; 4124127664Sbms } 4125127664Sbms 4126190225Srpaulo return 1; 412775107Sfenner} 412875107Sfenner 4129214518Srpaulo#ifdef IW_MODE_MONITOR 413075107Sfenner/* 4131190225Srpaulo * Check whether the device supports the Wireless Extensions. 4132190225Srpaulo * Returns 1 if it does, 0 if it doesn't, PCAP_ERROR_NO_SUCH_DEVICE 4133190225Srpaulo * if the device doesn't even exist. 413475107Sfenner */ 4135190225Srpaulostatic int 4136190225Srpaulohas_wext(int sock_fd, const char *device, char *ebuf) 4137190225Srpaulo{ 4138190225Srpaulo struct iwreq ireq; 413975107Sfenner 4140190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4141190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4142190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4143190225Srpaulo if (ioctl(sock_fd, SIOCGIWNAME, &ireq) >= 0) 4144190225Srpaulo return 1; /* yes */ 4145190225Srpaulo snprintf(ebuf, PCAP_ERRBUF_SIZE, 4146190225Srpaulo "%s: SIOCGIWPRIV: %s", device, pcap_strerror(errno)); 4147190225Srpaulo if (errno == ENODEV) 4148190225Srpaulo return PCAP_ERROR_NO_SUCH_DEVICE; 4149190225Srpaulo return 0; 4150190225Srpaulo} 4151190225Srpaulo 415275107Sfenner/* 4153190225Srpaulo * Per me si va ne la citta dolente, 4154190225Srpaulo * Per me si va ne l'etterno dolore, 4155190225Srpaulo * ... 4156190225Srpaulo * Lasciate ogne speranza, voi ch'intrate. 4157190225Srpaulo * 4158190225Srpaulo * XXX - airmon-ng does special stuff with the Orinoco driver and the 4159190225Srpaulo * wlan-ng driver. 416075107Sfenner */ 4161190225Srpaulotypedef enum { 4162190225Srpaulo MONITOR_WEXT, 4163190225Srpaulo MONITOR_HOSTAP, 4164190225Srpaulo MONITOR_PRISM, 4165190225Srpaulo MONITOR_PRISM54, 4166190225Srpaulo MONITOR_ACX100, 4167190225Srpaulo MONITOR_RT2500, 4168190225Srpaulo MONITOR_RT2570, 4169190225Srpaulo MONITOR_RT73, 4170190225Srpaulo MONITOR_RTL8XXX 4171190225Srpaulo} monitor_type; 417275107Sfenner 417375107Sfenner/* 4174190225Srpaulo * Use the Wireless Extensions, if we have them, to try to turn monitor mode 4175190225Srpaulo * on if it's not already on. 4176190225Srpaulo * 4177190225Srpaulo * Returns 1 on success, 0 if we don't support the Wireless Extensions 4178190225Srpaulo * on this device, or a PCAP_ERROR_ value if we do support them but 4179190225Srpaulo * we weren't able to turn monitor mode on. 418075107Sfenner */ 4181190225Srpaulostatic int 4182190225Srpauloenter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device) 418375107Sfenner{ 4184190225Srpaulo /* 4185190225Srpaulo * XXX - at least some adapters require non-Wireless Extensions 4186190225Srpaulo * mechanisms to turn monitor mode on. 4187190225Srpaulo * 4188190225Srpaulo * Atheros cards might require that a separate "monitor virtual access 4189190225Srpaulo * point" be created, with later versions of the madwifi driver. 4190190225Srpaulo * airmon-ng does "wlanconfig ath create wlandev {if} wlanmode 4191190225Srpaulo * monitor -bssid", which apparently spits out a line "athN" 4192190225Srpaulo * where "athN" is the monitor mode device. To leave monitor 4193190225Srpaulo * mode, it destroys the monitor mode device. 4194190225Srpaulo * 4195190225Srpaulo * Some Intel Centrino adapters might require private ioctls to get 4196190225Srpaulo * radio headers; the ipw2200 and ipw3945 drivers allow you to 4197190225Srpaulo * configure a separate "rtapN" interface to capture in monitor 4198190225Srpaulo * mode without preventing the adapter from operating normally. 4199190225Srpaulo * (airmon-ng doesn't appear to use that, though.) 4200190225Srpaulo * 4201190225Srpaulo * It would be Truly Wonderful if mac80211 and nl80211 cleaned this 4202190225Srpaulo * up, and if all drivers were converted to mac80211 drivers. 4203190225Srpaulo * 4204190225Srpaulo * If interface {if} is a mac80211 driver, the file 4205190225Srpaulo * /sys/class/net/{if}/phy80211 is a symlink to 4206190225Srpaulo * /sys/class/ieee80211/{phydev}, for some {phydev}. 4207190225Srpaulo * 4208190225Srpaulo * On Fedora 9, with a 2.6.26.3-29 kernel, my Zydas stick, at 4209190225Srpaulo * least, has a "wmaster0" device and a "wlan0" device; the 4210190225Srpaulo * latter is the one with the IP address. Both show up in 4211190225Srpaulo * "tcpdump -D" output. Capturing on the wmaster0 device 4212190225Srpaulo * captures with 802.11 headers. 4213190225Srpaulo * 4214190225Srpaulo * airmon-ng searches through /sys/class/net for devices named 4215190225Srpaulo * monN, starting with mon0; as soon as one *doesn't* exist, 4216190225Srpaulo * it chooses that as the monitor device name. If the "iw" 4217190225Srpaulo * command exists, it does "iw dev {if} interface add {monif} 4218190225Srpaulo * type monitor", where {monif} is the monitor device. It 4219190225Srpaulo * then (sigh) sleeps .1 second, and then configures the 4220190225Srpaulo * device up. Otherwise, if /sys/class/ieee80211/{phydev}/add_iface 4221190225Srpaulo * is a file, it writes {mondev}, without a newline, to that file, 4222190225Srpaulo * and again (sigh) sleeps .1 second, and then iwconfig's that 4223190225Srpaulo * device into monitor mode and configures it up. Otherwise, 4224190225Srpaulo * you can't do monitor mode. 4225190225Srpaulo * 4226190225Srpaulo * All these devices are "glued" together by having the 4227190225Srpaulo * /sys/class/net/{device}/phy80211 links pointing to the same 4228190225Srpaulo * place, so, given a wmaster, wlan, or mon device, you can 4229190225Srpaulo * find the other devices by looking for devices with 4230190225Srpaulo * the same phy80211 link. 4231190225Srpaulo * 4232190225Srpaulo * To turn monitor mode off, delete the monitor interface, 4233190225Srpaulo * either with "iw dev {monif} interface del" or by sending 4234190225Srpaulo * {monif}, with no NL, down /sys/class/ieee80211/{phydev}/remove_iface 4235190225Srpaulo * 4236190225Srpaulo * Note: if you try to create a monitor device named "monN", and 4237190225Srpaulo * there's already a "monN" device, it fails, as least with 4238190225Srpaulo * the netlink interface (which is what iw uses), with a return 4239190225Srpaulo * value of -ENFILE. (Return values are negative errnos.) We 4240190225Srpaulo * could probably use that to find an unused device. 4241190225Srpaulo */ 4242190225Srpaulo int err; 4243190225Srpaulo struct iwreq ireq; 4244190225Srpaulo struct iw_priv_args *priv; 4245190225Srpaulo monitor_type montype; 4246190225Srpaulo int i; 4247190225Srpaulo __u32 cmd; 4248235426Sdelphij struct ifreq ifr; 4249235426Sdelphij int oldflags; 4250190225Srpaulo int args[2]; 4251190225Srpaulo int channel; 425275107Sfenner 4253190225Srpaulo /* 4254190225Srpaulo * Does this device *support* the Wireless Extensions? 4255190225Srpaulo */ 4256190225Srpaulo err = has_wext(sock_fd, device, handle->errbuf); 4257190225Srpaulo if (err <= 0) 4258190225Srpaulo return err; /* either it doesn't or the device doesn't even exist */ 4259190225Srpaulo /* 4260235426Sdelphij * Start out assuming we have no private extensions to control 4261235426Sdelphij * radio metadata. 4262235426Sdelphij */ 4263235426Sdelphij montype = MONITOR_WEXT; 4264235426Sdelphij cmd = 0; 4265235426Sdelphij 4266235426Sdelphij /* 4267190225Srpaulo * Try to get all the Wireless Extensions private ioctls 4268190225Srpaulo * supported by this device. 4269190225Srpaulo * 4270190225Srpaulo * First, get the size of the buffer we need, by supplying no 4271190225Srpaulo * buffer and a length of 0. If the device supports private 4272190225Srpaulo * ioctls, it should return E2BIG, with ireq.u.data.length set 4273190225Srpaulo * to the length we need. If it doesn't support them, it should 4274190225Srpaulo * return EOPNOTSUPP. 4275190225Srpaulo */ 4276190225Srpaulo memset(&ireq, 0, sizeof ireq); 4277190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4278190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4279190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4280214518Srpaulo ireq.u.data.pointer = (void *)args; 4281190225Srpaulo ireq.u.data.length = 0; 4282190225Srpaulo ireq.u.data.flags = 0; 4283190225Srpaulo if (ioctl(sock_fd, SIOCGIWPRIV, &ireq) != -1) { 4284190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4285190225Srpaulo "%s: SIOCGIWPRIV with a zero-length buffer didn't fail!", 4286190225Srpaulo device); 4287190225Srpaulo return PCAP_ERROR; 4288190225Srpaulo } 4289235426Sdelphij if (errno != EOPNOTSUPP) { 4290190225Srpaulo /* 4291235426Sdelphij * OK, it's not as if there are no private ioctls. 4292190225Srpaulo */ 4293235426Sdelphij if (errno != E2BIG) { 4294190225Srpaulo /* 4295235426Sdelphij * Failed. 4296190225Srpaulo */ 4297235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4298235426Sdelphij "%s: SIOCGIWPRIV: %s", device, 4299235426Sdelphij pcap_strerror(errno)); 4300235426Sdelphij return PCAP_ERROR; 4301190225Srpaulo } 4302235426Sdelphij 4303235426Sdelphij /* 4304235426Sdelphij * OK, try to get the list of private ioctls. 4305235426Sdelphij */ 4306235426Sdelphij priv = malloc(ireq.u.data.length * sizeof (struct iw_priv_args)); 4307235426Sdelphij if (priv == NULL) { 4308235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4309235426Sdelphij "malloc: %s", pcap_strerror(errno)); 4310235426Sdelphij return PCAP_ERROR; 4311190225Srpaulo } 4312235426Sdelphij ireq.u.data.pointer = (void *)priv; 4313235426Sdelphij if (ioctl(sock_fd, SIOCGIWPRIV, &ireq) == -1) { 4314235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4315235426Sdelphij "%s: SIOCGIWPRIV: %s", device, 4316235426Sdelphij pcap_strerror(errno)); 4317235426Sdelphij free(priv); 4318235426Sdelphij return PCAP_ERROR; 4319190225Srpaulo } 4320235426Sdelphij 4321235426Sdelphij /* 4322235426Sdelphij * Look for private ioctls to turn monitor mode on or, if 4323235426Sdelphij * monitor mode is on, to set the header type. 4324235426Sdelphij */ 4325235426Sdelphij for (i = 0; i < ireq.u.data.length; i++) { 4326235426Sdelphij if (strcmp(priv[i].name, "monitor_type") == 0) { 4327235426Sdelphij /* 4328235426Sdelphij * Hostap driver, use this one. 4329235426Sdelphij * Set monitor mode first. 4330235426Sdelphij * You can set it to 0 to get DLT_IEEE80211, 4331235426Sdelphij * 1 to get DLT_PRISM, 2 to get 4332235426Sdelphij * DLT_IEEE80211_RADIO_AVS, and, with more 4333235426Sdelphij * recent versions of the driver, 3 to get 4334235426Sdelphij * DLT_IEEE80211_RADIO. 4335235426Sdelphij */ 4336235426Sdelphij if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT) 4337235426Sdelphij break; 4338235426Sdelphij if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED)) 4339235426Sdelphij break; 4340235426Sdelphij if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 1) 4341235426Sdelphij break; 4342235426Sdelphij montype = MONITOR_HOSTAP; 4343235426Sdelphij cmd = priv[i].cmd; 4344190225Srpaulo break; 4345235426Sdelphij } 4346235426Sdelphij if (strcmp(priv[i].name, "set_prismhdr") == 0) { 4347235426Sdelphij /* 4348235426Sdelphij * Prism54 driver, use this one. 4349235426Sdelphij * Set monitor mode first. 4350235426Sdelphij * You can set it to 2 to get DLT_IEEE80211 4351235426Sdelphij * or 3 or get DLT_PRISM. 4352235426Sdelphij */ 4353235426Sdelphij if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT) 4354235426Sdelphij break; 4355235426Sdelphij if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED)) 4356235426Sdelphij break; 4357235426Sdelphij if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 1) 4358235426Sdelphij break; 4359235426Sdelphij montype = MONITOR_PRISM54; 4360235426Sdelphij cmd = priv[i].cmd; 4361190225Srpaulo break; 4362235426Sdelphij } 4363235426Sdelphij if (strcmp(priv[i].name, "forceprismheader") == 0) { 4364235426Sdelphij /* 4365235426Sdelphij * RT2570 driver, use this one. 4366235426Sdelphij * Do this after turning monitor mode on. 4367235426Sdelphij * You can set it to 1 to get DLT_PRISM or 2 4368235426Sdelphij * to get DLT_IEEE80211. 4369235426Sdelphij */ 4370235426Sdelphij if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT) 4371235426Sdelphij break; 4372235426Sdelphij if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED)) 4373235426Sdelphij break; 4374235426Sdelphij if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 1) 4375235426Sdelphij break; 4376235426Sdelphij montype = MONITOR_RT2570; 4377235426Sdelphij cmd = priv[i].cmd; 4378190225Srpaulo break; 4379235426Sdelphij } 4380235426Sdelphij if (strcmp(priv[i].name, "forceprism") == 0) { 4381235426Sdelphij /* 4382235426Sdelphij * RT73 driver, use this one. 4383235426Sdelphij * Do this after turning monitor mode on. 4384235426Sdelphij * Its argument is a *string*; you can 4385235426Sdelphij * set it to "1" to get DLT_PRISM or "2" 4386235426Sdelphij * to get DLT_IEEE80211. 4387235426Sdelphij */ 4388235426Sdelphij if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_CHAR) 4389235426Sdelphij break; 4390235426Sdelphij if (priv[i].set_args & IW_PRIV_SIZE_FIXED) 4391235426Sdelphij break; 4392235426Sdelphij montype = MONITOR_RT73; 4393235426Sdelphij cmd = priv[i].cmd; 4394190225Srpaulo break; 4395235426Sdelphij } 4396235426Sdelphij if (strcmp(priv[i].name, "prismhdr") == 0) { 4397235426Sdelphij /* 4398235426Sdelphij * One of the RTL8xxx drivers, use this one. 4399235426Sdelphij * It can only be done after monitor mode 4400235426Sdelphij * has been turned on. You can set it to 1 4401235426Sdelphij * to get DLT_PRISM or 0 to get DLT_IEEE80211. 4402235426Sdelphij */ 4403235426Sdelphij if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT) 4404235426Sdelphij break; 4405235426Sdelphij if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED)) 4406235426Sdelphij break; 4407235426Sdelphij if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 1) 4408235426Sdelphij break; 4409235426Sdelphij montype = MONITOR_RTL8XXX; 4410190225Srpaulo cmd = priv[i].cmd; 4411190225Srpaulo break; 4412235426Sdelphij } 4413235426Sdelphij if (strcmp(priv[i].name, "rfmontx") == 0) { 4414235426Sdelphij /* 4415235426Sdelphij * RT2500 or RT61 driver, use this one. 4416235426Sdelphij * It has one one-byte parameter; set 4417235426Sdelphij * u.data.length to 1 and u.data.pointer to 4418235426Sdelphij * point to the parameter. 4419235426Sdelphij * It doesn't itself turn monitor mode on. 4420235426Sdelphij * You can set it to 1 to allow transmitting 4421235426Sdelphij * in monitor mode(?) and get DLT_IEEE80211, 4422235426Sdelphij * or set it to 0 to disallow transmitting in 4423235426Sdelphij * monitor mode(?) and get DLT_PRISM. 4424235426Sdelphij */ 4425235426Sdelphij if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT) 4426235426Sdelphij break; 4427235426Sdelphij if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 2) 4428235426Sdelphij break; 4429235426Sdelphij montype = MONITOR_RT2500; 4430190225Srpaulo cmd = priv[i].cmd; 4431190225Srpaulo break; 4432235426Sdelphij } 4433235426Sdelphij if (strcmp(priv[i].name, "monitor") == 0) { 4434235426Sdelphij /* 4435235426Sdelphij * Either ACX100 or hostap, use this one. 4436235426Sdelphij * It turns monitor mode on. 4437235426Sdelphij * If it takes two arguments, it's ACX100; 4438235426Sdelphij * the first argument is 1 for DLT_PRISM 4439235426Sdelphij * or 2 for DLT_IEEE80211, and the second 4440235426Sdelphij * argument is the channel on which to 4441235426Sdelphij * run. If it takes one argument, it's 4442235426Sdelphij * HostAP, and the argument is 2 for 4443235426Sdelphij * DLT_IEEE80211 and 3 for DLT_PRISM. 4444235426Sdelphij * 4445235426Sdelphij * If we see this, we don't quit, as this 4446235426Sdelphij * might be a version of the hostap driver 4447235426Sdelphij * that also supports "monitor_type". 4448235426Sdelphij */ 4449235426Sdelphij if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT) 4450235426Sdelphij break; 4451235426Sdelphij if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED)) 4452235426Sdelphij break; 4453235426Sdelphij switch (priv[i].set_args & IW_PRIV_SIZE_MASK) { 4454190225Srpaulo 4455235426Sdelphij case 1: 4456235426Sdelphij montype = MONITOR_PRISM; 4457235426Sdelphij cmd = priv[i].cmd; 4458235426Sdelphij break; 4459235426Sdelphij 4460235426Sdelphij case 2: 4461235426Sdelphij montype = MONITOR_ACX100; 4462235426Sdelphij cmd = priv[i].cmd; 4463235426Sdelphij break; 4464235426Sdelphij 4465235426Sdelphij default: 4466235426Sdelphij break; 4467235426Sdelphij } 4468190225Srpaulo } 4469190225Srpaulo } 4470235426Sdelphij free(priv); 4471190225Srpaulo } 4472190225Srpaulo 4473190225Srpaulo /* 4474190225Srpaulo * XXX - ipw3945? islism? 4475190225Srpaulo */ 4476190225Srpaulo 4477190225Srpaulo /* 4478190225Srpaulo * Get the old mode. 4479190225Srpaulo */ 4480190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4481190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4482190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4483190225Srpaulo if (ioctl(sock_fd, SIOCGIWMODE, &ireq) == -1) { 448475107Sfenner /* 4485190225Srpaulo * We probably won't be able to set the mode, either. 4486190225Srpaulo */ 4487190225Srpaulo return PCAP_ERROR_RFMON_NOTSUP; 4488190225Srpaulo } 4489190225Srpaulo 4490190225Srpaulo /* 4491190225Srpaulo * Is it currently in monitor mode? 4492190225Srpaulo */ 4493190225Srpaulo if (ireq.u.mode == IW_MODE_MONITOR) { 4494190225Srpaulo /* 4495190225Srpaulo * Yes. Just leave things as they are. 4496190225Srpaulo * We don't offer multiple link-layer types, as 4497190225Srpaulo * changing the link-layer type out from under 4498190225Srpaulo * somebody else capturing in monitor mode would 4499190225Srpaulo * be considered rude. 4500190225Srpaulo */ 4501190225Srpaulo return 1; 4502190225Srpaulo } 4503190225Srpaulo /* 4504190225Srpaulo * No. We have to put the adapter into rfmon mode. 4505190225Srpaulo */ 4506190225Srpaulo 4507190225Srpaulo /* 4508190225Srpaulo * If we haven't already done so, arrange to have 4509190225Srpaulo * "pcap_close_all()" called when we exit. 4510190225Srpaulo */ 4511190225Srpaulo if (!pcap_do_addexit(handle)) { 4512190225Srpaulo /* 4513190225Srpaulo * "atexit()" failed; don't put the interface 4514190225Srpaulo * in rfmon mode, just give up. 4515190225Srpaulo */ 4516190225Srpaulo return PCAP_ERROR_RFMON_NOTSUP; 4517190225Srpaulo } 4518190225Srpaulo 4519190225Srpaulo /* 4520190225Srpaulo * Save the old mode. 4521190225Srpaulo */ 4522190225Srpaulo handle->md.oldmode = ireq.u.mode; 4523190225Srpaulo 4524190225Srpaulo /* 4525190225Srpaulo * Put the adapter in rfmon mode. How we do this depends 4526190225Srpaulo * on whether we have a special private ioctl or not. 4527190225Srpaulo */ 4528190225Srpaulo if (montype == MONITOR_PRISM) { 4529190225Srpaulo /* 4530190225Srpaulo * We have the "monitor" private ioctl, but none of 4531190225Srpaulo * the other private ioctls. Use this, and select 4532190225Srpaulo * the Prism header. 453375107Sfenner * 4534190225Srpaulo * If it fails, just fall back on SIOCSIWMODE. 453575107Sfenner */ 4536190225Srpaulo memset(&ireq, 0, sizeof ireq); 4537190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4538190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4539190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4540190225Srpaulo ireq.u.data.length = 1; /* 1 argument */ 4541190225Srpaulo args[0] = 3; /* request Prism header */ 4542190225Srpaulo memcpy(ireq.u.name, args, IFNAMSIZ); 4543190225Srpaulo if (ioctl(sock_fd, cmd, &ireq) != -1) { 4544190225Srpaulo /* 4545190225Srpaulo * Success. 4546190225Srpaulo * Note that we have to put the old mode back 4547190225Srpaulo * when we close the device. 4548190225Srpaulo */ 4549214518Srpaulo handle->md.must_do_on_close |= MUST_CLEAR_RFMON; 4550190225Srpaulo 4551190225Srpaulo /* 4552190225Srpaulo * Add this to the list of pcaps to close 4553190225Srpaulo * when we exit. 4554190225Srpaulo */ 4555190225Srpaulo pcap_add_to_pcaps_to_close(handle); 4556190225Srpaulo 4557190225Srpaulo return 1; 455826175Sfenner } 455975107Sfenner 456075107Sfenner /* 4561190225Srpaulo * Failure. Fall back on SIOCSIWMODE. 456275107Sfenner */ 4563190225Srpaulo } 4564190225Srpaulo 4565190225Srpaulo /* 4566235426Sdelphij * First, take the interface down if it's up; otherwise, we 4567235426Sdelphij * might get EBUSY. 4568190225Srpaulo */ 4569235426Sdelphij memset(&ifr, 0, sizeof(ifr)); 4570235426Sdelphij strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); 4571235426Sdelphij if (ioctl(sock_fd, SIOCGIFFLAGS, &ifr) == -1) { 4572235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4573235426Sdelphij "%s: Can't get flags: %s", device, strerror(errno)); 4574235426Sdelphij return PCAP_ERROR; 4575235426Sdelphij } 4576235426Sdelphij oldflags = 0; 4577235426Sdelphij if (ifr.ifr_flags & IFF_UP) { 4578235426Sdelphij oldflags = ifr.ifr_flags; 4579235426Sdelphij ifr.ifr_flags &= ~IFF_UP; 4580235426Sdelphij if (ioctl(sock_fd, SIOCSIFFLAGS, &ifr) == -1) { 4581235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4582235426Sdelphij "%s: Can't set flags: %s", device, strerror(errno)); 4583235426Sdelphij return PCAP_ERROR; 4584235426Sdelphij } 4585235426Sdelphij } 4586235426Sdelphij 4587235426Sdelphij /* 4588235426Sdelphij * Then turn monitor mode on. 4589235426Sdelphij */ 4590190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4591190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4592190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4593190225Srpaulo ireq.u.mode = IW_MODE_MONITOR; 4594190225Srpaulo if (ioctl(sock_fd, SIOCSIWMODE, &ireq) == -1) { 4595190225Srpaulo /* 4596190225Srpaulo * Scientist, you've failed. 4597235426Sdelphij * Bring the interface back up if we shut it down. 4598190225Srpaulo */ 4599235426Sdelphij ifr.ifr_flags = oldflags; 4600235426Sdelphij if (ioctl(sock_fd, SIOCSIFFLAGS, &ifr) == -1) { 4601235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4602235426Sdelphij "%s: Can't set flags: %s", device, strerror(errno)); 4603235426Sdelphij return PCAP_ERROR; 4604235426Sdelphij } 4605190225Srpaulo return PCAP_ERROR_RFMON_NOTSUP; 4606190225Srpaulo } 4607190225Srpaulo 4608190225Srpaulo /* 4609190225Srpaulo * XXX - airmon-ng does "iwconfig {if} key off" after setting 4610190225Srpaulo * monitor mode and setting the channel, and then does 4611190225Srpaulo * "iwconfig up". 4612190225Srpaulo */ 4613190225Srpaulo 4614190225Srpaulo /* 4615190225Srpaulo * Now select the appropriate radio header. 4616190225Srpaulo */ 4617190225Srpaulo switch (montype) { 4618190225Srpaulo 4619190225Srpaulo case MONITOR_WEXT: 4620190225Srpaulo /* 4621190225Srpaulo * We don't have any private ioctl to set the header. 4622190225Srpaulo */ 4623190225Srpaulo break; 4624190225Srpaulo 4625190225Srpaulo case MONITOR_HOSTAP: 4626190225Srpaulo /* 4627214518Srpaulo * Try to select the radiotap header. 4628190225Srpaulo */ 4629190225Srpaulo memset(&ireq, 0, sizeof ireq); 4630190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4631190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4632190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4633214518Srpaulo args[0] = 3; /* request radiotap header */ 4634214518Srpaulo memcpy(ireq.u.name, args, sizeof (int)); 4635214518Srpaulo if (ioctl(sock_fd, cmd, &ireq) != -1) 4636214518Srpaulo break; /* success */ 4637214518Srpaulo 4638214518Srpaulo /* 4639214518Srpaulo * That failed. Try to select the AVS header. 4640214518Srpaulo */ 4641214518Srpaulo memset(&ireq, 0, sizeof ireq); 4642214518Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4643214518Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4644214518Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4645190225Srpaulo args[0] = 2; /* request AVS header */ 4646190225Srpaulo memcpy(ireq.u.name, args, sizeof (int)); 4647214518Srpaulo if (ioctl(sock_fd, cmd, &ireq) != -1) 4648214518Srpaulo break; /* success */ 4649214518Srpaulo 4650214518Srpaulo /* 4651214518Srpaulo * That failed. Try to select the Prism header. 4652214518Srpaulo */ 4653214518Srpaulo memset(&ireq, 0, sizeof ireq); 4654214518Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4655214518Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4656214518Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4657214518Srpaulo args[0] = 1; /* request Prism header */ 4658214518Srpaulo memcpy(ireq.u.name, args, sizeof (int)); 4659214518Srpaulo ioctl(sock_fd, cmd, &ireq); 4660190225Srpaulo break; 4661190225Srpaulo 4662190225Srpaulo case MONITOR_PRISM: 4663190225Srpaulo /* 4664190225Srpaulo * The private ioctl failed. 4665190225Srpaulo */ 4666190225Srpaulo break; 4667190225Srpaulo 4668190225Srpaulo case MONITOR_PRISM54: 4669190225Srpaulo /* 4670190225Srpaulo * Select the Prism header. 4671190225Srpaulo */ 4672190225Srpaulo memset(&ireq, 0, sizeof ireq); 4673190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4674190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4675190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4676190225Srpaulo args[0] = 3; /* request Prism header */ 4677190225Srpaulo memcpy(ireq.u.name, args, sizeof (int)); 4678190225Srpaulo ioctl(sock_fd, cmd, &ireq); 4679190225Srpaulo break; 4680190225Srpaulo 4681190225Srpaulo case MONITOR_ACX100: 4682190225Srpaulo /* 4683190225Srpaulo * Get the current channel. 4684190225Srpaulo */ 4685190225Srpaulo memset(&ireq, 0, sizeof ireq); 4686190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4687190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4688190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4689190225Srpaulo if (ioctl(sock_fd, SIOCGIWFREQ, &ireq) == -1) { 4690190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4691190225Srpaulo "%s: SIOCGIWFREQ: %s", device, 4692190225Srpaulo pcap_strerror(errno)); 4693190225Srpaulo return PCAP_ERROR; 4694190225Srpaulo } 4695190225Srpaulo channel = ireq.u.freq.m; 4696190225Srpaulo 4697190225Srpaulo /* 4698190225Srpaulo * Select the Prism header, and set the channel to the 4699190225Srpaulo * current value. 4700190225Srpaulo */ 4701190225Srpaulo memset(&ireq, 0, sizeof ireq); 4702190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4703190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4704190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4705190225Srpaulo args[0] = 1; /* request Prism header */ 4706190225Srpaulo args[1] = channel; /* set channel */ 4707190225Srpaulo memcpy(ireq.u.name, args, 2*sizeof (int)); 4708190225Srpaulo ioctl(sock_fd, cmd, &ireq); 4709190225Srpaulo break; 4710190225Srpaulo 4711190225Srpaulo case MONITOR_RT2500: 4712190225Srpaulo /* 4713190225Srpaulo * Disallow transmission - that turns on the 4714190225Srpaulo * Prism header. 4715190225Srpaulo */ 4716190225Srpaulo memset(&ireq, 0, sizeof ireq); 4717190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4718190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4719190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4720190225Srpaulo args[0] = 0; /* disallow transmitting */ 4721190225Srpaulo memcpy(ireq.u.name, args, sizeof (int)); 4722190225Srpaulo ioctl(sock_fd, cmd, &ireq); 4723190225Srpaulo break; 4724190225Srpaulo 4725190225Srpaulo case MONITOR_RT2570: 4726190225Srpaulo /* 4727190225Srpaulo * Force the Prism header. 4728190225Srpaulo */ 4729190225Srpaulo memset(&ireq, 0, sizeof ireq); 4730190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4731190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4732190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4733190225Srpaulo args[0] = 1; /* request Prism header */ 4734190225Srpaulo memcpy(ireq.u.name, args, sizeof (int)); 4735190225Srpaulo ioctl(sock_fd, cmd, &ireq); 4736190225Srpaulo break; 4737190225Srpaulo 4738190225Srpaulo case MONITOR_RT73: 4739190225Srpaulo /* 4740190225Srpaulo * Force the Prism header. 4741190225Srpaulo */ 4742190225Srpaulo memset(&ireq, 0, sizeof ireq); 4743190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4744190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4745190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4746190225Srpaulo ireq.u.data.length = 1; /* 1 argument */ 4747190225Srpaulo ireq.u.data.pointer = "1"; 4748190225Srpaulo ireq.u.data.flags = 0; 4749190225Srpaulo ioctl(sock_fd, cmd, &ireq); 4750190225Srpaulo break; 4751190225Srpaulo 4752190225Srpaulo case MONITOR_RTL8XXX: 4753190225Srpaulo /* 4754190225Srpaulo * Force the Prism header. 4755190225Srpaulo */ 4756190225Srpaulo memset(&ireq, 0, sizeof ireq); 4757190225Srpaulo strncpy(ireq.ifr_ifrn.ifrn_name, device, 4758190225Srpaulo sizeof ireq.ifr_ifrn.ifrn_name); 4759190225Srpaulo ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0; 4760190225Srpaulo args[0] = 1; /* request Prism header */ 4761190225Srpaulo memcpy(ireq.u.name, args, sizeof (int)); 4762190225Srpaulo ioctl(sock_fd, cmd, &ireq); 4763190225Srpaulo break; 476426175Sfenner } 4765127664Sbms 4766190225Srpaulo /* 4767235426Sdelphij * Now bring the interface back up if we brought it down. 4768235426Sdelphij */ 4769235426Sdelphij if (oldflags != 0) { 4770235426Sdelphij ifr.ifr_flags = oldflags; 4771235426Sdelphij if (ioctl(sock_fd, SIOCSIFFLAGS, &ifr) == -1) { 4772235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4773235426Sdelphij "%s: Can't set flags: %s", device, strerror(errno)); 4774235426Sdelphij 4775235426Sdelphij /* 4776235426Sdelphij * At least try to restore the old mode on the 4777235426Sdelphij * interface. 4778235426Sdelphij */ 4779235426Sdelphij if (ioctl(handle->fd, SIOCSIWMODE, &ireq) == -1) { 4780235426Sdelphij /* 4781235426Sdelphij * Scientist, you've failed. 4782235426Sdelphij */ 4783235426Sdelphij fprintf(stderr, 4784235426Sdelphij "Can't restore interface wireless mode (SIOCSIWMODE failed: %s).\n" 4785235426Sdelphij "Please adjust manually.\n", 4786235426Sdelphij strerror(errno)); 4787235426Sdelphij } 4788235426Sdelphij return PCAP_ERROR; 4789235426Sdelphij } 4790235426Sdelphij } 4791235426Sdelphij 4792235426Sdelphij /* 4793190225Srpaulo * Note that we have to put the old mode back when we 4794190225Srpaulo * close the device. 4795190225Srpaulo */ 4796214518Srpaulo handle->md.must_do_on_close |= MUST_CLEAR_RFMON; 4797190225Srpaulo 4798190225Srpaulo /* 4799190225Srpaulo * Add this to the list of pcaps to close when we exit. 4800190225Srpaulo */ 4801190225Srpaulo pcap_add_to_pcaps_to_close(handle); 4802190225Srpaulo 4803190225Srpaulo return 1; 4804214518Srpaulo} 4805214518Srpaulo#endif /* IW_MODE_MONITOR */ 4806214518Srpaulo 4807214518Srpaulo/* 4808214518Srpaulo * Try various mechanisms to enter monitor mode. 4809214518Srpaulo */ 4810214518Srpaulostatic int 4811214518Srpauloenter_rfmon_mode(pcap_t *handle, int sock_fd, const char *device) 4812214518Srpaulo{ 4813214518Srpaulo#if defined(HAVE_LIBNL) || defined(IW_MODE_MONITOR) 4814214518Srpaulo int ret; 4815214518Srpaulo#endif 4816214518Srpaulo 4817214518Srpaulo#ifdef HAVE_LIBNL 4818214518Srpaulo ret = enter_rfmon_mode_mac80211(handle, sock_fd, device); 4819214518Srpaulo if (ret < 0) 4820214518Srpaulo return ret; /* error attempting to do so */ 4821214518Srpaulo if (ret == 1) 4822214518Srpaulo return 1; /* success */ 4823214518Srpaulo#endif /* HAVE_LIBNL */ 4824214518Srpaulo 4825214518Srpaulo#ifdef IW_MODE_MONITOR 4826214518Srpaulo ret = enter_rfmon_mode_wext(handle, sock_fd, device); 4827214518Srpaulo if (ret < 0) 4828214518Srpaulo return ret; /* error attempting to do so */ 4829214518Srpaulo if (ret == 1) 4830214518Srpaulo return 1; /* success */ 4831214518Srpaulo#endif /* IW_MODE_MONITOR */ 4832214518Srpaulo 4833190225Srpaulo /* 4834214518Srpaulo * Either none of the mechanisms we know about work or none 4835214518Srpaulo * of those mechanisms are available, so we can't do monitor 4836214518Srpaulo * mode. 4837190225Srpaulo */ 4838190225Srpaulo return 0; 483975107Sfenner} 484026175Sfenner 4841235426Sdelphij/* 4842235426Sdelphij * Find out if we have any form of fragmentation/reassembly offloading. 4843235426Sdelphij * 4844235426Sdelphij * We do so using SIOCETHTOOL checking for various types of offloading; 4845235426Sdelphij * if SIOCETHTOOL isn't defined, or we don't have any #defines for any 4846235426Sdelphij * of the types of offloading, there's nothing we can do to check, so 4847235426Sdelphij * we just say "no, we don't". 4848235426Sdelphij */ 4849235426Sdelphij#if defined(SIOCETHTOOL) && (defined(ETHTOOL_GTSO) || defined(ETHTOOL_GUFO) || defined(ETHTOOL_GGSO) || defined(ETHTOOL_GFLAGS) || defined(ETHTOOL_GGRO)) 4850235426Sdelphijstatic int 4851235426Sdelphijiface_ethtool_ioctl(pcap_t *handle, int cmd, const char *cmdname) 4852235426Sdelphij{ 4853235426Sdelphij struct ifreq ifr; 4854235426Sdelphij struct ethtool_value eval; 4855235426Sdelphij 4856235426Sdelphij memset(&ifr, 0, sizeof(ifr)); 4857235426Sdelphij strncpy(ifr.ifr_name, handle->opt.source, sizeof(ifr.ifr_name)); 4858235426Sdelphij eval.cmd = cmd; 4859235426Sdelphij ifr.ifr_data = (caddr_t)&eval; 4860235426Sdelphij if (ioctl(handle->fd, SIOCETHTOOL, &ifr) == -1) { 4861251129Sdelphij if (errno == EOPNOTSUPP || errno == EINVAL) { 4862235426Sdelphij /* 4863235426Sdelphij * OK, let's just return 0, which, in our 4864235426Sdelphij * case, either means "no, what we're asking 4865235426Sdelphij * about is not enabled" or "all the flags 4866235426Sdelphij * are clear (i.e., nothing is enabled)". 4867235426Sdelphij */ 4868235426Sdelphij return 0; 4869235426Sdelphij } 4870235426Sdelphij snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4871235426Sdelphij "%s: SIOETHTOOL(%s) ioctl failed: %s", handle->opt.source, 4872235426Sdelphij cmdname, strerror(errno)); 4873235426Sdelphij return -1; 4874235426Sdelphij } 4875235426Sdelphij return eval.data; 4876235426Sdelphij} 4877235426Sdelphij 4878235426Sdelphijstatic int 4879235426Sdelphijiface_get_offload(pcap_t *handle) 4880235426Sdelphij{ 4881235426Sdelphij int ret; 4882235426Sdelphij 4883235426Sdelphij#ifdef ETHTOOL_GTSO 4884235426Sdelphij ret = iface_ethtool_ioctl(handle, ETHTOOL_GTSO, "ETHTOOL_GTSO"); 4885235426Sdelphij if (ret == -1) 4886235426Sdelphij return -1; 4887235426Sdelphij if (ret) 4888235426Sdelphij return 1; /* TCP segmentation offloading on */ 4889235426Sdelphij#endif 4890235426Sdelphij 4891235426Sdelphij#ifdef ETHTOOL_GUFO 4892235426Sdelphij ret = iface_ethtool_ioctl(handle, ETHTOOL_GUFO, "ETHTOOL_GUFO"); 4893235426Sdelphij if (ret == -1) 4894235426Sdelphij return -1; 4895235426Sdelphij if (ret) 4896235426Sdelphij return 1; /* UDP fragmentation offloading on */ 4897235426Sdelphij#endif 4898235426Sdelphij 4899235426Sdelphij#ifdef ETHTOOL_GGSO 4900235426Sdelphij /* 4901235426Sdelphij * XXX - will this cause large unsegmented packets to be 4902235426Sdelphij * handed to PF_PACKET sockets on transmission? If not, 4903235426Sdelphij * this need not be checked. 4904235426Sdelphij */ 4905235426Sdelphij ret = iface_ethtool_ioctl(handle, ETHTOOL_GGSO, "ETHTOOL_GGSO"); 4906235426Sdelphij if (ret == -1) 4907235426Sdelphij return -1; 4908235426Sdelphij if (ret) 4909235426Sdelphij return 1; /* generic segmentation offloading on */ 4910235426Sdelphij#endif 4911235426Sdelphij 4912235426Sdelphij#ifdef ETHTOOL_GFLAGS 4913235426Sdelphij ret = iface_ethtool_ioctl(handle, ETHTOOL_GFLAGS, "ETHTOOL_GFLAGS"); 4914235426Sdelphij if (ret == -1) 4915235426Sdelphij return -1; 4916235426Sdelphij if (ret & ETH_FLAG_LRO) 4917235426Sdelphij return 1; /* large receive offloading on */ 4918235426Sdelphij#endif 4919235426Sdelphij 4920235426Sdelphij#ifdef ETHTOOL_GGRO 4921235426Sdelphij /* 4922235426Sdelphij * XXX - will this cause large reassembled packets to be 4923235426Sdelphij * handed to PF_PACKET sockets on receipt? If not, 4924235426Sdelphij * this need not be checked. 4925235426Sdelphij */ 4926235426Sdelphij ret = iface_ethtool_ioctl(handle, ETHTOOL_GGRO, "ETHTOOL_GGRO"); 4927235426Sdelphij if (ret == -1) 4928235426Sdelphij return -1; 4929235426Sdelphij if (ret) 4930235426Sdelphij return 1; /* generic (large) receive offloading on */ 4931235426Sdelphij#endif 4932235426Sdelphij 4933235426Sdelphij return 0; 4934235426Sdelphij} 4935235426Sdelphij#else /* SIOCETHTOOL */ 4936235426Sdelphijstatic int 4937235426Sdelphijiface_get_offload(pcap_t *handle _U_) 4938235426Sdelphij{ 4939235426Sdelphij /* 4940235426Sdelphij * XXX - do we need to get this information if we don't 4941235426Sdelphij * have the ethtool ioctls? If so, how do we do that? 4942235426Sdelphij */ 4943235426Sdelphij return 0; 4944235426Sdelphij} 4945235426Sdelphij#endif /* SIOCETHTOOL */ 4946235426Sdelphij 4947190225Srpaulo#endif /* HAVE_PF_PACKET_SOCKETS */ 4948190225Srpaulo 4949190225Srpaulo/* ===== Functions to interface to the older kernels ================== */ 4950190225Srpaulo 495175107Sfenner/* 4952190225Srpaulo * Try to open a packet socket using the old kernel interface. 4953190225Srpaulo * Returns 1 on success and a PCAP_ERROR_ value on an error. 495475107Sfenner */ 495575107Sfennerstatic int 4956190225Srpauloactivate_old(pcap_t *handle) 495775107Sfenner{ 4958127664Sbms int arptype; 495975107Sfenner struct ifreq ifr; 4960190225Srpaulo const char *device = handle->opt.source; 4961190225Srpaulo struct utsname utsname; 4962190225Srpaulo int mtu; 496375107Sfenner 4964190225Srpaulo /* Open the socket */ 496575107Sfenner 4966190225Srpaulo handle->fd = socket(PF_INET, SOCK_PACKET, htons(ETH_P_ALL)); 4967190225Srpaulo if (handle->fd == -1) { 4968190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 4969190225Srpaulo "socket: %s", pcap_strerror(errno)); 4970235426Sdelphij if (errno == EPERM || errno == EACCES) { 4971235426Sdelphij /* 4972235426Sdelphij * You don't have permission to open the 4973235426Sdelphij * socket. 4974235426Sdelphij */ 4975235426Sdelphij return PCAP_ERROR_PERM_DENIED; 4976235426Sdelphij } else { 4977235426Sdelphij /* 4978235426Sdelphij * Other error. 4979235426Sdelphij */ 4980235426Sdelphij return PCAP_ERROR; 4981235426Sdelphij } 4982190225Srpaulo } 498375107Sfenner 4984190225Srpaulo /* It worked - we are using the old interface */ 4985190225Srpaulo handle->md.sock_packet = 1; 498675107Sfenner 4987190225Srpaulo /* ...which means we get the link-layer header. */ 4988190225Srpaulo handle->md.cooked = 0; 498975107Sfenner 4990190225Srpaulo /* Bind to the given device */ 499175107Sfenner 4992214518Srpaulo if (strcmp(device, "any") == 0) { 4993190225Srpaulo strncpy(handle->errbuf, "pcap_activate: The \"any\" device isn't supported on 2.0[.x]-kernel systems", 4994190225Srpaulo PCAP_ERRBUF_SIZE); 4995190225Srpaulo return PCAP_ERROR; 4996190225Srpaulo } 4997190225Srpaulo if (iface_bind_old(handle->fd, device, handle->errbuf) == -1) 4998190225Srpaulo return PCAP_ERROR; 499975107Sfenner 5000190225Srpaulo /* 5001190225Srpaulo * Try to get the link-layer type. 5002190225Srpaulo */ 5003190225Srpaulo arptype = iface_get_arptype(handle->fd, device, handle->errbuf); 5004190225Srpaulo if (arptype < 0) 5005190225Srpaulo return PCAP_ERROR; 5006127664Sbms 5007190225Srpaulo /* 5008190225Srpaulo * Try to find the DLT_ type corresponding to that 5009190225Srpaulo * link-layer type. 5010190225Srpaulo */ 5011190225Srpaulo map_arphrd_to_dlt(handle, arptype, 0); 5012190225Srpaulo if (handle->linktype == -1) { 5013190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 5014190225Srpaulo "unknown arptype %d", arptype); 5015190225Srpaulo return PCAP_ERROR; 5016190225Srpaulo } 5017127664Sbms 5018190225Srpaulo /* Go to promisc mode if requested */ 5019127664Sbms 5020190225Srpaulo if (handle->opt.promisc) { 5021190225Srpaulo memset(&ifr, 0, sizeof(ifr)); 5022190225Srpaulo strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); 5023190225Srpaulo if (ioctl(handle->fd, SIOCGIFFLAGS, &ifr) == -1) { 5024190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 5025190225Srpaulo "SIOCGIFFLAGS: %s", pcap_strerror(errno)); 5026190225Srpaulo return PCAP_ERROR; 5027190225Srpaulo } 5028190225Srpaulo if ((ifr.ifr_flags & IFF_PROMISC) == 0) { 5029190225Srpaulo /* 5030190225Srpaulo * Promiscuous mode isn't currently on, 5031190225Srpaulo * so turn it on, and remember that 5032190225Srpaulo * we should turn it off when the 5033190225Srpaulo * pcap_t is closed. 5034190225Srpaulo */ 503575107Sfenner 5036190225Srpaulo /* 5037190225Srpaulo * If we haven't already done so, arrange 5038190225Srpaulo * to have "pcap_close_all()" called when 5039190225Srpaulo * we exit. 5040190225Srpaulo */ 5041190225Srpaulo if (!pcap_do_addexit(handle)) { 504275107Sfenner /* 5043190225Srpaulo * "atexit()" failed; don't put 5044190225Srpaulo * the interface in promiscuous 5045190225Srpaulo * mode, just give up. 504675107Sfenner */ 5047190225Srpaulo return PCAP_ERROR; 5048190225Srpaulo } 504975107Sfenner 5050190225Srpaulo ifr.ifr_flags |= IFF_PROMISC; 5051190225Srpaulo if (ioctl(handle->fd, SIOCSIFFLAGS, &ifr) == -1) { 5052190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 5053190225Srpaulo "SIOCSIFFLAGS: %s", 5054190225Srpaulo pcap_strerror(errno)); 5055190225Srpaulo return PCAP_ERROR; 5056190225Srpaulo } 5057214518Srpaulo handle->md.must_do_on_close |= MUST_CLEAR_PROMISC; 505875107Sfenner 5059190225Srpaulo /* 5060190225Srpaulo * Add this to the list of pcaps 5061190225Srpaulo * to close when we exit. 5062190225Srpaulo */ 5063190225Srpaulo pcap_add_to_pcaps_to_close(handle); 506475107Sfenner } 5065190225Srpaulo } 506675107Sfenner 5067190225Srpaulo /* 5068190225Srpaulo * Compute the buffer size. 5069190225Srpaulo * 5070190225Srpaulo * We're using SOCK_PACKET, so this might be a 2.0[.x] 5071190225Srpaulo * kernel, and might require special handling - check. 5072190225Srpaulo */ 5073190225Srpaulo if (uname(&utsname) < 0 || 5074190225Srpaulo strncmp(utsname.release, "2.0", 3) == 0) { 507598530Sfenner /* 5076190225Srpaulo * Either we couldn't find out what kernel release 5077190225Srpaulo * this is, or it's a 2.0[.x] kernel. 5078190225Srpaulo * 5079190225Srpaulo * In the 2.0[.x] kernel, a "recvfrom()" on 5080190225Srpaulo * a SOCK_PACKET socket, with MSG_TRUNC set, will 5081190225Srpaulo * return the number of bytes read, so if we pass 5082190225Srpaulo * a length based on the snapshot length, it'll 5083190225Srpaulo * return the number of bytes from the packet 5084190225Srpaulo * copied to userland, not the actual length 5085190225Srpaulo * of the packet. 5086190225Srpaulo * 5087190225Srpaulo * This means that, for example, the IP dissector 5088190225Srpaulo * in tcpdump will get handed a packet length less 5089190225Srpaulo * than the length in the IP header, and will 5090190225Srpaulo * complain about "truncated-ip". 5091190225Srpaulo * 5092190225Srpaulo * So we don't bother trying to copy from the 5093190225Srpaulo * kernel only the bytes in which we're interested, 5094190225Srpaulo * but instead copy them all, just as the older 5095190225Srpaulo * versions of libpcap for Linux did. 5096190225Srpaulo * 5097190225Srpaulo * The buffer therefore needs to be big enough to 5098190225Srpaulo * hold the largest packet we can get from this 5099190225Srpaulo * device. Unfortunately, we can't get the MRU 5100190225Srpaulo * of the network; we can only get the MTU. The 5101190225Srpaulo * MTU may be too small, in which case a packet larger 5102190225Srpaulo * than the buffer size will be truncated *and* we 5103190225Srpaulo * won't get the actual packet size. 5104190225Srpaulo * 5105190225Srpaulo * However, if the snapshot length is larger than 5106190225Srpaulo * the buffer size based on the MTU, we use the 5107190225Srpaulo * snapshot length as the buffer size, instead; 5108190225Srpaulo * this means that with a sufficiently large snapshot 5109190225Srpaulo * length we won't artificially truncate packets 5110190225Srpaulo * to the MTU-based size. 5111190225Srpaulo * 5112190225Srpaulo * This mess just one of many problems with packet 5113190225Srpaulo * capture on 2.0[.x] kernels; you really want a 5114190225Srpaulo * 2.2[.x] or later kernel if you want packet capture 5115190225Srpaulo * to work well. 511698530Sfenner */ 5117190225Srpaulo mtu = iface_get_mtu(handle->fd, device, handle->errbuf); 5118190225Srpaulo if (mtu == -1) 5119190225Srpaulo return PCAP_ERROR; 5120190225Srpaulo handle->bufsize = MAX_LINKHEADER_SIZE + mtu; 5121190225Srpaulo if (handle->bufsize < handle->snapshot) 5122190225Srpaulo handle->bufsize = handle->snapshot; 5123190225Srpaulo } else { 5124190225Srpaulo /* 5125190225Srpaulo * This is a 2.2[.x] or later kernel. 5126190225Srpaulo * 5127190225Srpaulo * We can safely pass "recvfrom()" a byte count 5128190225Srpaulo * based on the snapshot length. 5129190225Srpaulo */ 5130190225Srpaulo handle->bufsize = handle->snapshot; 5131190225Srpaulo } 513298530Sfenner 5133190225Srpaulo /* 5134190225Srpaulo * Default value for offset to align link-layer payload 5135190225Srpaulo * on a 4-byte boundary. 5136190225Srpaulo */ 5137190225Srpaulo handle->offset = 0; 513875107Sfenner 5139251129Sdelphij /* 5140251129Sdelphij * SOCK_PACKET sockets don't supply information from 5141251129Sdelphij * stripped VLAN tags. 5142251129Sdelphij */ 5143251129Sdelphij handle->md.vlan_offset = -1; /* unknown */ 5144251129Sdelphij 5145190225Srpaulo return 1; 514675107Sfenner} 514775107Sfenner 514875107Sfenner/* 5149127664Sbms * Bind the socket associated with FD to the given device using the 515075107Sfenner * interface of the old kernels. 515175107Sfenner */ 515275107Sfennerstatic int 515375107Sfenneriface_bind_old(int fd, const char *device, char *ebuf) 515475107Sfenner{ 515575107Sfenner struct sockaddr saddr; 5156127664Sbms int err; 5157127664Sbms socklen_t errlen = sizeof(err); 515875107Sfenner 515975107Sfenner memset(&saddr, 0, sizeof(saddr)); 516075107Sfenner strncpy(saddr.sa_data, device, sizeof(saddr.sa_data)); 516175107Sfenner if (bind(fd, &saddr, sizeof(saddr)) == -1) { 516275107Sfenner snprintf(ebuf, PCAP_ERRBUF_SIZE, 516375107Sfenner "bind: %s", pcap_strerror(errno)); 516475107Sfenner return -1; 516526175Sfenner } 516626175Sfenner 5167127664Sbms /* Any pending errors, e.g., network is down? */ 5168127664Sbms 5169127664Sbms if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &errlen) == -1) { 5170127664Sbms snprintf(ebuf, PCAP_ERRBUF_SIZE, 5171127664Sbms "getsockopt: %s", pcap_strerror(errno)); 5172127664Sbms return -1; 5173127664Sbms } 5174127664Sbms 5175127664Sbms if (err > 0) { 5176127664Sbms snprintf(ebuf, PCAP_ERRBUF_SIZE, 5177127664Sbms "bind: %s", pcap_strerror(err)); 5178127664Sbms return -1; 5179127664Sbms } 5180127664Sbms 518175107Sfenner return 0; 518226175Sfenner} 518326175Sfenner 518475107Sfenner 518575107Sfenner/* ===== System calls available on all supported kernels ============== */ 518675107Sfenner 518775107Sfenner/* 5188127664Sbms * Query the kernel for the MTU of the given interface. 518975107Sfenner */ 519075107Sfennerstatic int 519175107Sfenneriface_get_mtu(int fd, const char *device, char *ebuf) 519226175Sfenner{ 519375107Sfenner struct ifreq ifr; 519426175Sfenner 519575107Sfenner if (!device) 519675107Sfenner return BIGGER_THAN_ALL_MTUS; 519775107Sfenner 519875107Sfenner memset(&ifr, 0, sizeof(ifr)); 519975107Sfenner strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); 520075107Sfenner 520175107Sfenner if (ioctl(fd, SIOCGIFMTU, &ifr) == -1) { 520275107Sfenner snprintf(ebuf, PCAP_ERRBUF_SIZE, 5203172677Smlaier "SIOCGIFMTU: %s", pcap_strerror(errno)); 520475107Sfenner return -1; 520575107Sfenner } 520675107Sfenner 520775107Sfenner return ifr.ifr_mtu; 520826175Sfenner} 520926175Sfenner 521075107Sfenner/* 521175107Sfenner * Get the hardware type of the given interface as ARPHRD_xxx constant. 521275107Sfenner */ 521375107Sfennerstatic int 521475107Sfenneriface_get_arptype(int fd, const char *device, char *ebuf) 521526175Sfenner{ 521675107Sfenner struct ifreq ifr; 521726175Sfenner 521875107Sfenner memset(&ifr, 0, sizeof(ifr)); 521975107Sfenner strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); 522075107Sfenner 522175107Sfenner if (ioctl(fd, SIOCGIFHWADDR, &ifr) == -1) { 522275107Sfenner snprintf(ebuf, PCAP_ERRBUF_SIZE, 5223172677Smlaier "SIOCGIFHWADDR: %s", pcap_strerror(errno)); 5224190225Srpaulo if (errno == ENODEV) { 5225190225Srpaulo /* 5226190225Srpaulo * No such device. 5227190225Srpaulo */ 5228190225Srpaulo return PCAP_ERROR_NO_SUCH_DEVICE; 5229190225Srpaulo } 5230190225Srpaulo return PCAP_ERROR; 523175107Sfenner } 523275107Sfenner 523375107Sfenner return ifr.ifr_hwaddr.sa_family; 523426175Sfenner} 523575107Sfenner 523698530Sfenner#ifdef SO_ATTACH_FILTER 523775107Sfennerstatic int 5238214518Srpaulofix_program(pcap_t *handle, struct sock_fprog *fcode, int is_mmapped) 523975107Sfenner{ 524075107Sfenner size_t prog_size; 524175107Sfenner register int i; 524275107Sfenner register struct bpf_insn *p; 524375107Sfenner struct bpf_insn *f; 524475107Sfenner int len; 524575107Sfenner 524675107Sfenner /* 524775107Sfenner * Make a copy of the filter, and modify that copy if 524875107Sfenner * necessary. 524975107Sfenner */ 525075107Sfenner prog_size = sizeof(*handle->fcode.bf_insns) * handle->fcode.bf_len; 525175107Sfenner len = handle->fcode.bf_len; 525275107Sfenner f = (struct bpf_insn *)malloc(prog_size); 525375107Sfenner if (f == NULL) { 5254190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 525575107Sfenner "malloc: %s", pcap_strerror(errno)); 525675107Sfenner return -1; 525775107Sfenner } 525875107Sfenner memcpy(f, handle->fcode.bf_insns, prog_size); 525975107Sfenner fcode->len = len; 526075107Sfenner fcode->filter = (struct sock_filter *) f; 526175107Sfenner 526275107Sfenner for (i = 0; i < len; ++i) { 526375107Sfenner p = &f[i]; 526475107Sfenner /* 526575107Sfenner * What type of instruction is this? 526675107Sfenner */ 526775107Sfenner switch (BPF_CLASS(p->code)) { 526875107Sfenner 526975107Sfenner case BPF_RET: 527075107Sfenner /* 5271214518Srpaulo * It's a return instruction; are we capturing 5272214518Srpaulo * in memory-mapped mode? 527375107Sfenner */ 5274214518Srpaulo if (!is_mmapped) { 527575107Sfenner /* 5276214518Srpaulo * No; is the snapshot length a constant, 5277214518Srpaulo * rather than the contents of the 5278214518Srpaulo * accumulator? 527975107Sfenner */ 5280214518Srpaulo if (BPF_MODE(p->code) == BPF_K) { 5281214518Srpaulo /* 5282214518Srpaulo * Yes - if the value to be returned, 5283214518Srpaulo * i.e. the snapshot length, is 5284214518Srpaulo * anything other than 0, make it 5285214518Srpaulo * 65535, so that the packet is 5286214518Srpaulo * truncated by "recvfrom()", 5287214518Srpaulo * not by the filter. 5288214518Srpaulo * 5289214518Srpaulo * XXX - there's nothing we can 5290214518Srpaulo * easily do if it's getting the 5291214518Srpaulo * value from the accumulator; we'd 5292214518Srpaulo * have to insert code to force 5293214518Srpaulo * non-zero values to be 65535. 5294214518Srpaulo */ 5295214518Srpaulo if (p->k != 0) 5296214518Srpaulo p->k = 65535; 5297214518Srpaulo } 529875107Sfenner } 529975107Sfenner break; 530075107Sfenner 530175107Sfenner case BPF_LD: 530275107Sfenner case BPF_LDX: 530375107Sfenner /* 530475107Sfenner * It's a load instruction; is it loading 530575107Sfenner * from the packet? 530675107Sfenner */ 530775107Sfenner switch (BPF_MODE(p->code)) { 530875107Sfenner 530975107Sfenner case BPF_ABS: 531075107Sfenner case BPF_IND: 531175107Sfenner case BPF_MSH: 531275107Sfenner /* 531375107Sfenner * Yes; are we in cooked mode? 531475107Sfenner */ 531575107Sfenner if (handle->md.cooked) { 531675107Sfenner /* 531775107Sfenner * Yes, so we need to fix this 531875107Sfenner * instruction. 531975107Sfenner */ 532075107Sfenner if (fix_offset(p) < 0) { 532175107Sfenner /* 532275107Sfenner * We failed to do so. 532375107Sfenner * Return 0, so our caller 532475107Sfenner * knows to punt to userland. 532575107Sfenner */ 532675107Sfenner return 0; 532775107Sfenner } 532875107Sfenner } 532975107Sfenner break; 533075107Sfenner } 533175107Sfenner break; 533275107Sfenner } 533375107Sfenner } 533475107Sfenner return 1; /* we succeeded */ 533575107Sfenner} 533675107Sfenner 533775107Sfennerstatic int 533875107Sfennerfix_offset(struct bpf_insn *p) 533975107Sfenner{ 534075107Sfenner /* 534175107Sfenner * What's the offset? 534275107Sfenner */ 534375107Sfenner if (p->k >= SLL_HDR_LEN) { 534475107Sfenner /* 534575107Sfenner * It's within the link-layer payload; that starts at an 534675107Sfenner * offset of 0, as far as the kernel packet filter is 534775107Sfenner * concerned, so subtract the length of the link-layer 534875107Sfenner * header. 534975107Sfenner */ 535075107Sfenner p->k -= SLL_HDR_LEN; 5351241231Sdelphij } else if (p->k == 0) { 5352241231Sdelphij /* 5353241231Sdelphij * It's the packet type field; map it to the special magic 5354241231Sdelphij * kernel offset for that field. 5355241231Sdelphij */ 5356241231Sdelphij p->k = SKF_AD_OFF + SKF_AD_PKTTYPE; 535775107Sfenner } else if (p->k == 14) { 535875107Sfenner /* 535975107Sfenner * It's the protocol field; map it to the special magic 536075107Sfenner * kernel offset for that field. 536175107Sfenner */ 536275107Sfenner p->k = SKF_AD_OFF + SKF_AD_PROTOCOL; 5363241231Sdelphij } else if ((bpf_int32)(p->k) > 0) { 536475107Sfenner /* 536575107Sfenner * It's within the header, but it's not one of those 536675107Sfenner * fields; we can't do that in the kernel, so punt 536775107Sfenner * to userland. 536875107Sfenner */ 536975107Sfenner return -1; 537075107Sfenner } 537175107Sfenner return 0; 537275107Sfenner} 537398530Sfenner 537498530Sfennerstatic int 537598530Sfennerset_kernel_filter(pcap_t *handle, struct sock_fprog *fcode) 537698530Sfenner{ 537798530Sfenner int total_filter_on = 0; 537898530Sfenner int save_mode; 537998530Sfenner int ret; 538098530Sfenner int save_errno; 538198530Sfenner 538298530Sfenner /* 538398530Sfenner * The socket filter code doesn't discard all packets queued 538498530Sfenner * up on the socket when the filter is changed; this means 538598530Sfenner * that packets that don't match the new filter may show up 538698530Sfenner * after the new filter is put onto the socket, if those 538798530Sfenner * packets haven't yet been read. 538898530Sfenner * 538998530Sfenner * This means, for example, that if you do a tcpdump capture 539098530Sfenner * with a filter, the first few packets in the capture might 539198530Sfenner * be packets that wouldn't have passed the filter. 539298530Sfenner * 539398530Sfenner * We therefore discard all packets queued up on the socket 539498530Sfenner * when setting a kernel filter. (This isn't an issue for 539598530Sfenner * userland filters, as the userland filtering is done after 539698530Sfenner * packets are queued up.) 539798530Sfenner * 539898530Sfenner * To flush those packets, we put the socket in read-only mode, 539998530Sfenner * and read packets from the socket until there are no more to 540098530Sfenner * read. 540198530Sfenner * 540298530Sfenner * In order to keep that from being an infinite loop - i.e., 540398530Sfenner * to keep more packets from arriving while we're draining 540498530Sfenner * the queue - we put the "total filter", which is a filter 540598530Sfenner * that rejects all packets, onto the socket before draining 540698530Sfenner * the queue. 540798530Sfenner * 540898530Sfenner * This code deliberately ignores any errors, so that you may 540998530Sfenner * get bogus packets if an error occurs, rather than having 541098530Sfenner * the filtering done in userland even if it could have been 541198530Sfenner * done in the kernel. 541298530Sfenner */ 5413127664Sbms if (setsockopt(handle->fd, SOL_SOCKET, SO_ATTACH_FILTER, 541498530Sfenner &total_fcode, sizeof(total_fcode)) == 0) { 541598530Sfenner char drain[1]; 541698530Sfenner 541798530Sfenner /* 541898530Sfenner * Note that we've put the total filter onto the socket. 541998530Sfenner */ 542098530Sfenner total_filter_on = 1; 542198530Sfenner 542298530Sfenner /* 542398530Sfenner * Save the socket's current mode, and put it in 542498530Sfenner * non-blocking mode; we drain it by reading packets 5425127664Sbms * until we get an error (which is normally a 542698530Sfenner * "nothing more to be read" error). 542798530Sfenner */ 542898530Sfenner save_mode = fcntl(handle->fd, F_GETFL, 0); 542998530Sfenner if (save_mode != -1 && 543098530Sfenner fcntl(handle->fd, F_SETFL, save_mode | O_NONBLOCK) >= 0) { 543198530Sfenner while (recv(handle->fd, &drain, sizeof drain, 543298530Sfenner MSG_TRUNC) >= 0) 543398530Sfenner ; 5434127664Sbms save_errno = errno; 543598530Sfenner fcntl(handle->fd, F_SETFL, save_mode); 5436127664Sbms if (save_errno != EAGAIN) { 5437127664Sbms /* Fatal error */ 5438127664Sbms reset_kernel_filter(handle); 5439190225Srpaulo snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 5440127664Sbms "recv: %s", pcap_strerror(save_errno)); 5441127664Sbms return -2; 5442127664Sbms } 544398530Sfenner } 544498530Sfenner } 544598530Sfenner 544698530Sfenner /* 544798530Sfenner * Now attach the new filter. 544898530Sfenner */ 5449127664Sbms ret = setsockopt(handle->fd, SOL_SOCKET, SO_ATTACH_FILTER, 545098530Sfenner fcode, sizeof(*fcode)); 545198530Sfenner if (ret == -1 && total_filter_on) { 545298530Sfenner /* 545398530Sfenner * Well, we couldn't set that filter on the socket, 545498530Sfenner * but we could set the total filter on the socket. 545598530Sfenner * 545698530Sfenner * This could, for example, mean that the filter was 545798530Sfenner * too big to put into the kernel, so we'll have to 545898530Sfenner * filter in userland; in any case, we'll be doing 545998530Sfenner * filtering in userland, so we need to remove the 546098530Sfenner * total filter so we see packets. 546198530Sfenner */ 546298530Sfenner save_errno = errno; 546398530Sfenner 546498530Sfenner /* 546598530Sfenner * XXX - if this fails, we're really screwed; 546698530Sfenner * we have the total filter on the socket, 546798530Sfenner * and it won't come off. What do we do then? 546898530Sfenner */ 546998530Sfenner reset_kernel_filter(handle); 547098530Sfenner 547198530Sfenner errno = save_errno; 547298530Sfenner } 5473127664Sbms return ret; 547498530Sfenner} 547598530Sfenner 547698530Sfennerstatic int 547798530Sfennerreset_kernel_filter(pcap_t *handle) 547898530Sfenner{ 5479172677Smlaier /* 5480172677Smlaier * setsockopt() barfs unless it get a dummy parameter. 5481172677Smlaier * valgrind whines unless the value is initialized, 5482172677Smlaier * as it has no idea that setsockopt() ignores its 5483172677Smlaier * parameter. 5484172677Smlaier */ 5485172677Smlaier int dummy = 0; 548698530Sfenner 548798530Sfenner return setsockopt(handle->fd, SOL_SOCKET, SO_DETACH_FILTER, 548898530Sfenner &dummy, sizeof(dummy)); 548998530Sfenner} 549075107Sfenner#endif 5491