1335640Shselasky/* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */ 2335640Shselasky/* 3335640Shselasky * Copyright (c) 1994, 1995, 1996, 1997, 1998 4335640Shselasky * The Regents of the University of California. All rights reserved. 5335640Shselasky * 6335640Shselasky * Redistribution and use in source and binary forms, with or without 7335640Shselasky * modification, are permitted provided that the following conditions 8335640Shselasky * are met: 9335640Shselasky * 1. Redistributions of source code must retain the above copyright 10335640Shselasky * notice, this list of conditions and the following disclaimer. 11335640Shselasky * 2. Redistributions in binary form must reproduce the above copyright 12335640Shselasky * notice, this list of conditions and the following disclaimer in the 13335640Shselasky * documentation and/or other materials provided with the distribution. 14335640Shselasky * 3. All advertising materials mentioning features or use of this software 15335640Shselasky * must display the following acknowledgement: 16335640Shselasky * This product includes software developed by the Computer Systems 17335640Shselasky * Engineering Group at Lawrence Berkeley Laboratory. 18335640Shselasky * 4. Neither the name of the University nor of the Laboratory may be used 19335640Shselasky * to endorse or promote products derived from this software without 20335640Shselasky * specific prior written permission. 21335640Shselasky * 22335640Shselasky * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23335640Shselasky * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24335640Shselasky * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25335640Shselasky * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26335640Shselasky * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27335640Shselasky * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28335640Shselasky * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29335640Shselasky * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30335640Shselasky * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31335640Shselasky * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32335640Shselasky * SUCH DAMAGE. 33335640Shselasky */ 34335640Shselasky 35335640Shselasky#ifdef HAVE_CONFIG_H 36335640Shselasky#include <config.h> 37335640Shselasky#endif 38335640Shselasky 39335640Shselasky#include <sys/param.h> 40335640Shselasky#include <sys/ioctl.h> 41335640Shselasky#include <sys/socket.h> 42335640Shselasky#ifdef HAVE_SYS_SOCKIO_H 43335640Shselasky#include <sys/sockio.h> 44335640Shselasky#endif 45335640Shselasky#include <sys/time.h> /* concession to AIX */ 46335640Shselasky 47335640Shselaskystruct mbuf; /* Squelch compiler warnings on some platforms for */ 48335640Shselaskystruct rtentry; /* declarations in <net/if.h> */ 49335640Shselasky#include <net/if.h> 50335640Shselasky#include <netinet/in.h> 51335640Shselasky 52335640Shselasky#include <ctype.h> 53335640Shselasky#include <errno.h> 54335640Shselasky#include <memory.h> 55335640Shselasky#include <stdio.h> 56335640Shselasky#include <stdlib.h> 57335640Shselasky#include <string.h> 58335640Shselasky#include <unistd.h> 59335640Shselasky 60335640Shselasky#ifdef HAVE_LIMITS_H 61335640Shselasky#include <limits.h> 62335640Shselasky#else 63335640Shselasky#define INT_MAX 2147483647 64335640Shselasky#endif 65335640Shselasky 66335640Shselasky#include "pcap-int.h" 67335640Shselasky 68335640Shselasky#ifdef HAVE_OS_PROTO_H 69335640Shselasky#include "os-proto.h" 70335640Shselasky#endif 71335640Shselasky 72335640Shselasky/* 73335640Shselasky * This is fun. 74335640Shselasky * 75335640Shselasky * In older BSD systems, socket addresses were fixed-length, and 76335640Shselasky * "sizeof (struct sockaddr)" gave the size of the structure. 77335640Shselasky * All addresses fit within a "struct sockaddr". 78335640Shselasky * 79335640Shselasky * In newer BSD systems, the socket address is variable-length, and 80335640Shselasky * there's an "sa_len" field giving the length of the structure; 81335640Shselasky * this allows socket addresses to be longer than 2 bytes of family 82335640Shselasky * and 14 bytes of data. 83335640Shselasky * 84335640Shselasky * Some commercial UNIXes use the old BSD scheme, some use the RFC 2553 85335640Shselasky * variant of the old BSD scheme (with "struct sockaddr_storage" rather 86335640Shselasky * than "struct sockaddr"), and some use the new BSD scheme. 87335640Shselasky * 88335640Shselasky * Some versions of GNU libc use neither scheme, but has an "SA_LEN()" 89335640Shselasky * macro that determines the size based on the address family. Other 90335640Shselasky * versions don't have "SA_LEN()" (as it was in drafts of RFC 2553 91335640Shselasky * but not in the final version). 92335640Shselasky * 93335640Shselasky * We assume that a UNIX that doesn't have "getifaddrs()" and doesn't have 94335640Shselasky * SIOCGLIFCONF, but has SIOCGIFCONF, uses "struct sockaddr" for the 95335640Shselasky * address in an entry returned by SIOCGIFCONF. 96335640Shselasky */ 97335640Shselasky#ifndef SA_LEN 98335640Shselasky#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN 99335640Shselasky#define SA_LEN(addr) ((addr)->sa_len) 100335640Shselasky#else /* HAVE_STRUCT_SOCKADDR_SA_LEN */ 101335640Shselasky#define SA_LEN(addr) (sizeof (struct sockaddr)) 102335640Shselasky#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */ 103335640Shselasky#endif /* SA_LEN */ 104335640Shselasky 105335640Shselasky/* 106335640Shselasky * This is also fun. 107335640Shselasky * 108335640Shselasky * There is no ioctl that returns the amount of space required for all 109335640Shselasky * the data that SIOCGIFCONF could return, and if a buffer is supplied 110335640Shselasky * that's not large enough for all the data SIOCGIFCONF could return, 111335640Shselasky * on at least some platforms it just returns the data that'd fit with 112335640Shselasky * no indication that there wasn't enough room for all the data, much 113335640Shselasky * less an indication of how much more room is required. 114335640Shselasky * 115335640Shselasky * The only way to ensure that we got all the data is to pass a buffer 116335640Shselasky * large enough that the amount of space in the buffer *not* filled in 117335640Shselasky * is greater than the largest possible entry. 118335640Shselasky * 119335640Shselasky * We assume that's "sizeof(ifreq.ifr_name)" plus 255, under the assumption 120335640Shselasky * that no address is more than 255 bytes (on systems where the "sa_len" 121335640Shselasky * field in a "struct sockaddr" is 1 byte, e.g. newer BSDs, that's the 122335640Shselasky * case, and addresses are unlikely to be bigger than that in any case). 123335640Shselasky */ 124335640Shselasky#define MAX_SA_LEN 255 125335640Shselasky 126335640Shselasky/* 127335640Shselasky * Get a list of all interfaces that are up and that we can open. 128335640Shselasky * Returns -1 on error, 0 otherwise. 129335640Shselasky * The list, as returned through "alldevsp", may be null if no interfaces 130335640Shselasky * were up and could be opened. 131335640Shselasky * 132335640Shselasky * This is the implementation used on platforms that have SIOCGIFCONF but 133335640Shselasky * don't have any other mechanism for getting a list of interfaces. 134335640Shselasky * 135335640Shselasky * XXX - or platforms that have other, better mechanisms but for which 136335640Shselasky * we don't yet have code to use that mechanism; I think there's a better 137335640Shselasky * way on Linux, for example, but if that better way is "getifaddrs()", 138335640Shselasky * we already have that. 139335640Shselasky */ 140335640Shselaskyint 141335640Shselaskypcap_findalldevs_interfaces(pcap_if_list_t *devlistp, char *errbuf, 142335640Shselasky int (*check_usable)(const char *), get_if_flags_func get_flags_func) 143335640Shselasky{ 144335640Shselasky register int fd; 145335640Shselasky register struct ifreq *ifrp, *ifend, *ifnext; 146335640Shselasky size_t n; 147335640Shselasky struct ifconf ifc; 148335640Shselasky char *buf = NULL; 149335640Shselasky unsigned buf_size; 150335640Shselasky#if defined (HAVE_SOLARIS) || defined (HAVE_HPUX10_20_OR_LATER) 151335640Shselasky char *p, *q; 152335640Shselasky#endif 153335640Shselasky struct ifreq ifrflags, ifrnetmask, ifrbroadaddr, ifrdstaddr; 154335640Shselasky struct sockaddr *netmask, *broadaddr, *dstaddr; 155335640Shselasky size_t netmask_size, broadaddr_size, dstaddr_size; 156335640Shselasky int ret = 0; 157335640Shselasky 158335640Shselasky /* 159335640Shselasky * Create a socket from which to fetch the list of interfaces. 160335640Shselasky */ 161335640Shselasky fd = socket(AF_INET, SOCK_DGRAM, 0); 162335640Shselasky if (fd < 0) { 163335640Shselasky pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 164335640Shselasky errno, "socket"); 165335640Shselasky return (-1); 166335640Shselasky } 167335640Shselasky 168335640Shselasky /* 169335640Shselasky * Start with an 8K buffer, and keep growing the buffer until 170335640Shselasky * we have more than "sizeof(ifrp->ifr_name) + MAX_SA_LEN" 171335640Shselasky * bytes left over in the buffer or we fail to get the 172335640Shselasky * interface list for some reason other than EINVAL (which is 173335640Shselasky * presumed here to mean "buffer is too small"). 174335640Shselasky */ 175335640Shselasky buf_size = 8192; 176335640Shselasky for (;;) { 177335640Shselasky /* 178335640Shselasky * Don't let the buffer size get bigger than INT_MAX. 179335640Shselasky */ 180335640Shselasky if (buf_size > INT_MAX) { 181335640Shselasky (void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, 182335640Shselasky "interface information requires more than %u bytes", 183335640Shselasky INT_MAX); 184335640Shselasky (void)close(fd); 185335640Shselasky return (-1); 186335640Shselasky } 187335640Shselasky buf = malloc(buf_size); 188335640Shselasky if (buf == NULL) { 189335640Shselasky pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 190335640Shselasky errno, "malloc"); 191335640Shselasky (void)close(fd); 192335640Shselasky return (-1); 193335640Shselasky } 194335640Shselasky 195335640Shselasky ifc.ifc_len = buf_size; 196335640Shselasky ifc.ifc_buf = buf; 197335640Shselasky memset(buf, 0, buf_size); 198335640Shselasky if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 199335640Shselasky && errno != EINVAL) { 200335640Shselasky pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 201335640Shselasky errno, "SIOCGIFCONF"); 202335640Shselasky (void)close(fd); 203335640Shselasky free(buf); 204335640Shselasky return (-1); 205335640Shselasky } 206335640Shselasky if (ifc.ifc_len < (int)buf_size && 207335640Shselasky (buf_size - ifc.ifc_len) > sizeof(ifrp->ifr_name) + MAX_SA_LEN) 208335640Shselasky break; 209335640Shselasky free(buf); 210335640Shselasky buf_size *= 2; 211335640Shselasky } 212335640Shselasky 213335640Shselasky ifrp = (struct ifreq *)buf; 214335640Shselasky ifend = (struct ifreq *)(buf + ifc.ifc_len); 215335640Shselasky 216335640Shselasky for (; ifrp < ifend; ifrp = ifnext) { 217335640Shselasky /* 218335640Shselasky * XXX - what if this isn't an IPv4 address? Can 219335640Shselasky * we still get the netmask, etc. with ioctls on 220335640Shselasky * an IPv4 socket? 221335640Shselasky * 222335640Shselasky * The answer is probably platform-dependent, and 223335640Shselasky * if the answer is "no" on more than one platform, 224335640Shselasky * the way you work around it is probably platform- 225335640Shselasky * dependent as well. 226335640Shselasky */ 227335640Shselasky n = SA_LEN(&ifrp->ifr_addr) + sizeof(ifrp->ifr_name); 228335640Shselasky if (n < sizeof(*ifrp)) 229335640Shselasky ifnext = ifrp + 1; 230335640Shselasky else 231335640Shselasky ifnext = (struct ifreq *)((char *)ifrp + n); 232335640Shselasky 233335640Shselasky /* 234335640Shselasky * XXX - The 32-bit compatibility layer for Linux on IA-64 235335640Shselasky * is slightly broken. It correctly converts the structures 236335640Shselasky * to and from kernel land from 64 bit to 32 bit but 237335640Shselasky * doesn't update ifc.ifc_len, leaving it larger than the 238335640Shselasky * amount really used. This means we read off the end 239335640Shselasky * of the buffer and encounter an interface with an 240335640Shselasky * "empty" name. Since this is highly unlikely to ever 241335640Shselasky * occur in a valid case we can just finish looking for 242335640Shselasky * interfaces if we see an empty name. 243335640Shselasky */ 244335640Shselasky if (!(*ifrp->ifr_name)) 245335640Shselasky break; 246335640Shselasky 247335640Shselasky /* 248335640Shselasky * Skip entries that begin with "dummy". 249335640Shselasky * XXX - what are these? Is this Linux-specific? 250335640Shselasky * Are there platforms on which we shouldn't do this? 251335640Shselasky */ 252335640Shselasky if (strncmp(ifrp->ifr_name, "dummy", 5) == 0) 253335640Shselasky continue; 254335640Shselasky 255335640Shselasky /* 256335640Shselasky * Can we capture on this device? 257335640Shselasky */ 258335640Shselasky if (!(*check_usable)(ifrp->ifr_name)) { 259335640Shselasky /* 260335640Shselasky * No. 261335640Shselasky */ 262335640Shselasky continue; 263335640Shselasky } 264335640Shselasky 265335640Shselasky /* 266335640Shselasky * Get the flags for this interface. 267335640Shselasky */ 268335640Shselasky strncpy(ifrflags.ifr_name, ifrp->ifr_name, 269335640Shselasky sizeof(ifrflags.ifr_name)); 270335640Shselasky if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) { 271335640Shselasky if (errno == ENXIO) 272335640Shselasky continue; 273335640Shselasky pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, 274335640Shselasky errno, "SIOCGIFFLAGS: %.*s", 275335640Shselasky (int)sizeof(ifrflags.ifr_name), 276335640Shselasky ifrflags.ifr_name); 277335640Shselasky ret = -1; 278335640Shselasky break; 279335640Shselasky } 280335640Shselasky 281335640Shselasky /* 282335640Shselasky * Get the netmask for this address on this interface. 283335640Shselasky */ 284335640Shselasky strncpy(ifrnetmask.ifr_name, ifrp->ifr_name, 285335640Shselasky sizeof(ifrnetmask.ifr_name)); 286335640Shselasky memcpy(&ifrnetmask.ifr_addr, &ifrp->ifr_addr, 287335640Shselasky sizeof(ifrnetmask.ifr_addr)); 288335640Shselasky if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifrnetmask) < 0) { 289335640Shselasky if (errno == EADDRNOTAVAIL) { 290335640Shselasky /* 291335640Shselasky * Not available. 292335640Shselasky */ 293335640Shselasky netmask = NULL; 294335640Shselasky netmask_size = 0; 295335640Shselasky } else { 296335640Shselasky pcap_fmt_errmsg_for_errno(errbuf, 297335640Shselasky PCAP_ERRBUF_SIZE, errno, 298335640Shselasky "SIOCGIFNETMASK: %.*s", 299335640Shselasky (int)sizeof(ifrnetmask.ifr_name), 300335640Shselasky ifrnetmask.ifr_name); 301335640Shselasky ret = -1; 302335640Shselasky break; 303335640Shselasky } 304335640Shselasky } else { 305335640Shselasky netmask = &ifrnetmask.ifr_addr; 306335640Shselasky netmask_size = SA_LEN(netmask); 307335640Shselasky } 308335640Shselasky 309335640Shselasky /* 310335640Shselasky * Get the broadcast address for this address on this 311335640Shselasky * interface (if any). 312335640Shselasky */ 313335640Shselasky if (ifrflags.ifr_flags & IFF_BROADCAST) { 314335640Shselasky strncpy(ifrbroadaddr.ifr_name, ifrp->ifr_name, 315335640Shselasky sizeof(ifrbroadaddr.ifr_name)); 316335640Shselasky memcpy(&ifrbroadaddr.ifr_addr, &ifrp->ifr_addr, 317335640Shselasky sizeof(ifrbroadaddr.ifr_addr)); 318335640Shselasky if (ioctl(fd, SIOCGIFBRDADDR, 319335640Shselasky (char *)&ifrbroadaddr) < 0) { 320335640Shselasky if (errno == EADDRNOTAVAIL) { 321335640Shselasky /* 322335640Shselasky * Not available. 323335640Shselasky */ 324335640Shselasky broadaddr = NULL; 325335640Shselasky broadaddr_size = 0; 326335640Shselasky } else { 327335640Shselasky pcap_fmt_errmsg_for_errno(errbuf, 328335640Shselasky PCAP_ERRBUF_SIZE, errno, 329335640Shselasky "SIOCGIFBRDADDR: %.*s", 330335640Shselasky (int)sizeof(ifrbroadaddr.ifr_name), 331335640Shselasky ifrbroadaddr.ifr_name); 332335640Shselasky ret = -1; 333335640Shselasky break; 334335640Shselasky } 335335640Shselasky } else { 336335640Shselasky broadaddr = &ifrbroadaddr.ifr_broadaddr; 337335640Shselasky broadaddr_size = SA_LEN(broadaddr); 338335640Shselasky } 339335640Shselasky } else { 340335640Shselasky /* 341335640Shselasky * Not a broadcast interface, so no broadcast 342335640Shselasky * address. 343335640Shselasky */ 344335640Shselasky broadaddr = NULL; 345335640Shselasky broadaddr_size = 0; 346335640Shselasky } 347335640Shselasky 348335640Shselasky /* 349335640Shselasky * Get the destination address for this address on this 350335640Shselasky * interface (if any). 351335640Shselasky */ 352335640Shselasky if (ifrflags.ifr_flags & IFF_POINTOPOINT) { 353335640Shselasky strncpy(ifrdstaddr.ifr_name, ifrp->ifr_name, 354335640Shselasky sizeof(ifrdstaddr.ifr_name)); 355335640Shselasky memcpy(&ifrdstaddr.ifr_addr, &ifrp->ifr_addr, 356335640Shselasky sizeof(ifrdstaddr.ifr_addr)); 357335640Shselasky if (ioctl(fd, SIOCGIFDSTADDR, 358335640Shselasky (char *)&ifrdstaddr) < 0) { 359335640Shselasky if (errno == EADDRNOTAVAIL) { 360335640Shselasky /* 361335640Shselasky * Not available. 362335640Shselasky */ 363335640Shselasky dstaddr = NULL; 364335640Shselasky dstaddr_size = 0; 365335640Shselasky } else { 366335640Shselasky pcap_fmt_errmsg_for_errno(errbuf, 367335640Shselasky PCAP_ERRBUF_SIZE, errno, 368335640Shselasky "SIOCGIFDSTADDR: %.*s", 369335640Shselasky (int)sizeof(ifrdstaddr.ifr_name), 370335640Shselasky ifrdstaddr.ifr_name); 371335640Shselasky ret = -1; 372335640Shselasky break; 373335640Shselasky } 374335640Shselasky } else { 375335640Shselasky dstaddr = &ifrdstaddr.ifr_dstaddr; 376335640Shselasky dstaddr_size = SA_LEN(dstaddr); 377335640Shselasky } 378335640Shselasky } else { 379335640Shselasky /* 380335640Shselasky * Not a point-to-point interface, so no destination 381335640Shselasky * address. 382335640Shselasky */ 383335640Shselasky dstaddr = NULL; 384335640Shselasky dstaddr_size = 0; 385335640Shselasky } 386335640Shselasky 387335640Shselasky#if defined (HAVE_SOLARIS) || defined (HAVE_HPUX10_20_OR_LATER) 388335640Shselasky /* 389335640Shselasky * If this entry has a colon followed by a number at 390335640Shselasky * the end, it's a logical interface. Those are just 391335640Shselasky * the way you assign multiple IP addresses to a real 392335640Shselasky * interface, so an entry for a logical interface should 393335640Shselasky * be treated like the entry for the real interface; 394335640Shselasky * we do that by stripping off the ":" and the number. 395335640Shselasky */ 396335640Shselasky p = strchr(ifrp->ifr_name, ':'); 397335640Shselasky if (p != NULL) { 398335640Shselasky /* 399335640Shselasky * We have a ":"; is it followed by a number? 400335640Shselasky */ 401335640Shselasky q = p + 1; 402335640Shselasky while (isdigit((unsigned char)*q)) 403335640Shselasky q++; 404335640Shselasky if (*q == '\0') { 405335640Shselasky /* 406335640Shselasky * All digits after the ":" until the end. 407335640Shselasky * Strip off the ":" and everything after 408335640Shselasky * it. 409335640Shselasky */ 410335640Shselasky *p = '\0'; 411335640Shselasky } 412335640Shselasky } 413335640Shselasky#endif 414335640Shselasky 415335640Shselasky /* 416335640Shselasky * Add information for this address to the list. 417335640Shselasky */ 418335640Shselasky if (add_addr_to_if(devlistp, ifrp->ifr_name, 419335640Shselasky ifrflags.ifr_flags, get_flags_func, 420335640Shselasky &ifrp->ifr_addr, SA_LEN(&ifrp->ifr_addr), 421335640Shselasky netmask, netmask_size, broadaddr, broadaddr_size, 422335640Shselasky dstaddr, dstaddr_size, errbuf) < 0) { 423335640Shselasky ret = -1; 424335640Shselasky break; 425335640Shselasky } 426335640Shselasky } 427335640Shselasky free(buf); 428335640Shselasky (void)close(fd); 429335640Shselasky 430335640Shselasky return (ret); 431335640Shselasky} 432