l2_packet_freebsd.c revision 209139
1209139Srpaulo/* 2209139Srpaulo * WPA Supplicant - Layer2 packet handling with FreeBSD 3209139Srpaulo * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi> 4209139Srpaulo * Copyright (c) 2005, Sam Leffler <sam@errno.com> 5209139Srpaulo * 6209139Srpaulo * This program is free software; you can redistribute it and/or modify 7209139Srpaulo * it under the terms of the GNU General Public License version 2 as 8209139Srpaulo * published by the Free Software Foundation. 9209139Srpaulo * 10209139Srpaulo * Alternatively, this software may be distributed under the terms of BSD 11209139Srpaulo * license. 12209139Srpaulo * 13209139Srpaulo * See README and COPYING for more details. 14209139Srpaulo */ 15209139Srpaulo 16209139Srpaulo#include "includes.h" 17209139Srpaulo#ifdef __APPLE__ 18209139Srpaulo#include <net/bpf.h> 19209139Srpaulo#endif /* __APPLE__ */ 20209139Srpaulo#include <pcap.h> 21209139Srpaulo 22209139Srpaulo#include <sys/ioctl.h> 23209139Srpaulo#include <sys/sysctl.h> 24209139Srpaulo 25209139Srpaulo#include <net/if.h> 26209139Srpaulo#include <net/if_dl.h> 27209139Srpaulo#include <net/route.h> 28209139Srpaulo#include <netinet/in.h> 29209139Srpaulo 30209139Srpaulo#include "common.h" 31209139Srpaulo#include "eloop.h" 32209139Srpaulo#include "l2_packet.h" 33209139Srpaulo 34209139Srpaulo 35209139Srpaulostatic const u8 pae_group_addr[ETH_ALEN] = 36209139Srpaulo{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 }; 37209139Srpaulo 38209139Srpaulostruct l2_packet_data { 39209139Srpaulo pcap_t *pcap; 40209139Srpaulo char ifname[100]; 41209139Srpaulo u8 own_addr[ETH_ALEN]; 42209139Srpaulo void (*rx_callback)(void *ctx, const u8 *src_addr, 43209139Srpaulo const u8 *buf, size_t len); 44209139Srpaulo void *rx_callback_ctx; 45209139Srpaulo int l2_hdr; /* whether to include layer 2 (Ethernet) header data 46209139Srpaulo * buffers */ 47209139Srpaulo}; 48209139Srpaulo 49209139Srpaulo 50209139Srpauloint l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr) 51209139Srpaulo{ 52209139Srpaulo os_memcpy(addr, l2->own_addr, ETH_ALEN); 53209139Srpaulo return 0; 54209139Srpaulo} 55209139Srpaulo 56209139Srpaulo 57209139Srpauloint l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto, 58209139Srpaulo const u8 *buf, size_t len) 59209139Srpaulo{ 60209139Srpaulo if (!l2->l2_hdr) { 61209139Srpaulo int ret; 62209139Srpaulo struct l2_ethhdr *eth = os_malloc(sizeof(*eth) + len); 63209139Srpaulo if (eth == NULL) 64209139Srpaulo return -1; 65209139Srpaulo os_memcpy(eth->h_dest, dst_addr, ETH_ALEN); 66209139Srpaulo os_memcpy(eth->h_source, l2->own_addr, ETH_ALEN); 67209139Srpaulo eth->h_proto = htons(proto); 68209139Srpaulo os_memcpy(eth + 1, buf, len); 69209139Srpaulo ret = pcap_inject(l2->pcap, (u8 *) eth, len + sizeof(*eth)); 70209139Srpaulo os_free(eth); 71209139Srpaulo return ret; 72209139Srpaulo } else 73209139Srpaulo return pcap_inject(l2->pcap, buf, len); 74209139Srpaulo} 75209139Srpaulo 76209139Srpaulo 77209139Srpaulostatic void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx) 78209139Srpaulo{ 79209139Srpaulo struct l2_packet_data *l2 = eloop_ctx; 80209139Srpaulo pcap_t *pcap = sock_ctx; 81209139Srpaulo struct pcap_pkthdr hdr; 82209139Srpaulo const u_char *packet; 83209139Srpaulo struct l2_ethhdr *ethhdr; 84209139Srpaulo unsigned char *buf; 85209139Srpaulo size_t len; 86209139Srpaulo 87209139Srpaulo packet = pcap_next(pcap, &hdr); 88209139Srpaulo 89209139Srpaulo if (packet == NULL || hdr.caplen < sizeof(*ethhdr)) 90209139Srpaulo return; 91209139Srpaulo 92209139Srpaulo ethhdr = (struct l2_ethhdr *) packet; 93209139Srpaulo if (l2->l2_hdr) { 94209139Srpaulo buf = (unsigned char *) ethhdr; 95209139Srpaulo len = hdr.caplen; 96209139Srpaulo } else { 97209139Srpaulo buf = (unsigned char *) (ethhdr + 1); 98209139Srpaulo len = hdr.caplen - sizeof(*ethhdr); 99209139Srpaulo } 100209139Srpaulo l2->rx_callback(l2->rx_callback_ctx, ethhdr->h_source, buf, len); 101209139Srpaulo} 102209139Srpaulo 103209139Srpaulo 104209139Srpaulostatic int l2_packet_init_libpcap(struct l2_packet_data *l2, 105209139Srpaulo unsigned short protocol) 106209139Srpaulo{ 107209139Srpaulo bpf_u_int32 pcap_maskp, pcap_netp; 108209139Srpaulo char pcap_filter[200], pcap_err[PCAP_ERRBUF_SIZE]; 109209139Srpaulo struct bpf_program pcap_fp; 110209139Srpaulo 111209139Srpaulo pcap_lookupnet(l2->ifname, &pcap_netp, &pcap_maskp, pcap_err); 112209139Srpaulo l2->pcap = pcap_open_live(l2->ifname, 2500, 0, 10, pcap_err); 113209139Srpaulo if (l2->pcap == NULL) { 114209139Srpaulo fprintf(stderr, "pcap_open_live: %s\n", pcap_err); 115209139Srpaulo fprintf(stderr, "ifname='%s'\n", l2->ifname); 116209139Srpaulo return -1; 117209139Srpaulo } 118209139Srpaulo if (pcap_datalink(l2->pcap) != DLT_EN10MB && 119209139Srpaulo pcap_set_datalink(l2->pcap, DLT_EN10MB) < 0) { 120209139Srpaulo fprintf(stderr, "pcap_set_datalink(DLT_EN10MB): %s\n", 121209139Srpaulo pcap_geterr(l2->pcap)); 122209139Srpaulo return -1; 123209139Srpaulo } 124209139Srpaulo os_snprintf(pcap_filter, sizeof(pcap_filter), 125209139Srpaulo "not ether src " MACSTR " and " 126209139Srpaulo "( ether dst " MACSTR " or ether dst " MACSTR " ) and " 127209139Srpaulo "ether proto 0x%x", 128209139Srpaulo MAC2STR(l2->own_addr), /* do not receive own packets */ 129209139Srpaulo MAC2STR(l2->own_addr), MAC2STR(pae_group_addr), 130209139Srpaulo protocol); 131209139Srpaulo if (pcap_compile(l2->pcap, &pcap_fp, pcap_filter, 1, pcap_netp) < 0) { 132209139Srpaulo fprintf(stderr, "pcap_compile: %s\n", pcap_geterr(l2->pcap)); 133209139Srpaulo return -1; 134209139Srpaulo } 135209139Srpaulo 136209139Srpaulo if (pcap_setfilter(l2->pcap, &pcap_fp) < 0) { 137209139Srpaulo fprintf(stderr, "pcap_setfilter: %s\n", pcap_geterr(l2->pcap)); 138209139Srpaulo return -1; 139209139Srpaulo } 140209139Srpaulo 141209139Srpaulo pcap_freecode(&pcap_fp); 142209139Srpaulo /* 143209139Srpaulo * When libpcap uses BPF we must enable "immediate mode" to 144209139Srpaulo * receive frames right away; otherwise the system may 145209139Srpaulo * buffer them for us. 146209139Srpaulo */ 147209139Srpaulo { 148209139Srpaulo unsigned int on = 1; 149209139Srpaulo if (ioctl(pcap_fileno(l2->pcap), BIOCIMMEDIATE, &on) < 0) { 150209139Srpaulo fprintf(stderr, "%s: cannot enable immediate mode on " 151209139Srpaulo "interface %s: %s\n", 152209139Srpaulo __func__, l2->ifname, strerror(errno)); 153209139Srpaulo /* XXX should we fail? */ 154209139Srpaulo } 155209139Srpaulo } 156209139Srpaulo 157209139Srpaulo eloop_register_read_sock(pcap_get_selectable_fd(l2->pcap), 158209139Srpaulo l2_packet_receive, l2, l2->pcap); 159209139Srpaulo 160209139Srpaulo return 0; 161209139Srpaulo} 162209139Srpaulo 163209139Srpaulo 164209139Srpaulostatic int eth_get(const char *device, u8 ea[ETH_ALEN]) 165209139Srpaulo{ 166209139Srpaulo struct if_msghdr *ifm; 167209139Srpaulo struct sockaddr_dl *sdl; 168209139Srpaulo u_char *p, *buf; 169209139Srpaulo size_t len; 170209139Srpaulo int mib[] = { CTL_NET, AF_ROUTE, 0, AF_LINK, NET_RT_IFLIST, 0 }; 171209139Srpaulo 172209139Srpaulo if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 173209139Srpaulo return -1; 174209139Srpaulo if ((buf = os_malloc(len)) == NULL) 175209139Srpaulo return -1; 176209139Srpaulo if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) { 177209139Srpaulo os_free(buf); 178209139Srpaulo return -1; 179209139Srpaulo } 180209139Srpaulo for (p = buf; p < buf + len; p += ifm->ifm_msglen) { 181209139Srpaulo ifm = (struct if_msghdr *)p; 182209139Srpaulo sdl = (struct sockaddr_dl *)(ifm + 1); 183209139Srpaulo if (ifm->ifm_type != RTM_IFINFO || 184209139Srpaulo (ifm->ifm_addrs & RTA_IFP) == 0) 185209139Srpaulo continue; 186209139Srpaulo if (sdl->sdl_family != AF_LINK || sdl->sdl_nlen == 0 || 187209139Srpaulo os_memcmp(sdl->sdl_data, device, sdl->sdl_nlen) != 0) 188209139Srpaulo continue; 189209139Srpaulo os_memcpy(ea, LLADDR(sdl), sdl->sdl_alen); 190209139Srpaulo break; 191209139Srpaulo } 192209139Srpaulo os_free(buf); 193209139Srpaulo 194209139Srpaulo if (p >= buf + len) { 195209139Srpaulo errno = ESRCH; 196209139Srpaulo return -1; 197209139Srpaulo } 198209139Srpaulo return 0; 199209139Srpaulo} 200209139Srpaulo 201209139Srpaulo 202209139Srpaulostruct l2_packet_data * l2_packet_init( 203209139Srpaulo const char *ifname, const u8 *own_addr, unsigned short protocol, 204209139Srpaulo void (*rx_callback)(void *ctx, const u8 *src_addr, 205209139Srpaulo const u8 *buf, size_t len), 206209139Srpaulo void *rx_callback_ctx, int l2_hdr) 207209139Srpaulo{ 208209139Srpaulo struct l2_packet_data *l2; 209209139Srpaulo 210209139Srpaulo l2 = os_zalloc(sizeof(struct l2_packet_data)); 211209139Srpaulo if (l2 == NULL) 212209139Srpaulo return NULL; 213209139Srpaulo os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname)); 214209139Srpaulo l2->rx_callback = rx_callback; 215209139Srpaulo l2->rx_callback_ctx = rx_callback_ctx; 216209139Srpaulo l2->l2_hdr = l2_hdr; 217209139Srpaulo 218209139Srpaulo if (eth_get(l2->ifname, l2->own_addr) < 0) { 219209139Srpaulo fprintf(stderr, "Failed to get link-level address for " 220209139Srpaulo "interface '%s'.\n", l2->ifname); 221209139Srpaulo os_free(l2); 222209139Srpaulo return NULL; 223209139Srpaulo } 224209139Srpaulo 225209139Srpaulo if (l2_packet_init_libpcap(l2, protocol)) { 226209139Srpaulo os_free(l2); 227209139Srpaulo return NULL; 228209139Srpaulo } 229209139Srpaulo 230209139Srpaulo return l2; 231209139Srpaulo} 232209139Srpaulo 233209139Srpaulo 234209139Srpaulovoid l2_packet_deinit(struct l2_packet_data *l2) 235209139Srpaulo{ 236209139Srpaulo if (l2 != NULL) { 237209139Srpaulo if (l2->pcap) { 238209139Srpaulo eloop_unregister_read_sock( 239209139Srpaulo pcap_get_selectable_fd(l2->pcap)); 240209139Srpaulo pcap_close(l2->pcap); 241209139Srpaulo } 242209139Srpaulo os_free(l2); 243209139Srpaulo } 244209139Srpaulo} 245209139Srpaulo 246209139Srpaulo 247209139Srpauloint l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len) 248209139Srpaulo{ 249209139Srpaulo pcap_if_t *devs, *dev; 250209139Srpaulo struct pcap_addr *addr; 251209139Srpaulo struct sockaddr_in *saddr; 252209139Srpaulo int found = 0; 253209139Srpaulo char err[PCAP_ERRBUF_SIZE + 1]; 254209139Srpaulo 255209139Srpaulo if (pcap_findalldevs(&devs, err) < 0) { 256209139Srpaulo wpa_printf(MSG_DEBUG, "pcap_findalldevs: %s\n", err); 257209139Srpaulo return -1; 258209139Srpaulo } 259209139Srpaulo 260209139Srpaulo for (dev = devs; dev && !found; dev = dev->next) { 261209139Srpaulo if (os_strcmp(dev->name, l2->ifname) != 0) 262209139Srpaulo continue; 263209139Srpaulo 264209139Srpaulo addr = dev->addresses; 265209139Srpaulo while (addr) { 266209139Srpaulo saddr = (struct sockaddr_in *) addr->addr; 267209139Srpaulo if (saddr && saddr->sin_family == AF_INET) { 268209139Srpaulo os_strlcpy(buf, inet_ntoa(saddr->sin_addr), 269209139Srpaulo len); 270209139Srpaulo found = 1; 271209139Srpaulo break; 272209139Srpaulo } 273209139Srpaulo addr = addr->next; 274209139Srpaulo } 275209139Srpaulo } 276209139Srpaulo 277209139Srpaulo pcap_freealldevs(devs); 278209139Srpaulo 279209139Srpaulo return found ? 0 : -1; 280209139Srpaulo} 281209139Srpaulo 282209139Srpaulo 283209139Srpaulovoid l2_packet_notify_auth_start(struct l2_packet_data *l2) 284209139Srpaulo{ 285209139Srpaulo} 286