1 /* 2 * WPA Supplicant - Layer2 packet handling with FreeBSD 3 * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi> 4 * Copyright (c) 2005, Sam Leffler <sam@errno.com> 5 * 6 * This software may be distributed under the terms of the BSD license. 7 * See README for more details. 8 */ 9 10 #include "includes.h" 11 #include <sys/param.h> 12 #if defined(__APPLE__) || defined(__GLIBC__) || defined(__FreeBSD_version) 13 #include <net/bpf.h> 14 #endif /* __APPLE__ */ 15 #include <pcap.h> 16 17 #include <sys/ioctl.h> 18 #ifdef __sun__ 19 #include <libdlpi.h> 20 #else /* __sun__ */ 21 #include <sys/sysctl.h> 22 #endif /* __sun__ */ 23 24 #include <net/ethernet.h> 25 #include <net/if.h> 26 #include <net/if_dl.h> 27 #include <net/route.h> 28 #include <netinet/in.h> 29 30 #include "common.h" 31 #include "eloop.h" 32 #include "l2_packet.h" 33 34 35 static const u8 pae_group_addr[ETH_ALEN] = 36 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 }; 37 38 struct l2_packet_data { 39 pcap_t *pcap; 40 char ifname[100]; 41 u8 own_addr[ETH_ALEN]; 42 void (*rx_callback)(void *ctx, const u8 *src_addr, 43 const u8 *buf, size_t len); 44 void *rx_callback_ctx; 45 int l2_hdr; /* whether to include layer 2 (Ethernet) header data 46 * buffers */ 47 }; 48 49 50 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr) 51 { 52 os_memcpy(addr, l2->own_addr, ETH_ALEN); 53 return 0; 54 } 55 56 57 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto, 58 const u8 *buf, size_t len) 59 { 60 if (!l2->l2_hdr) { 61 int ret; 62 struct l2_ethhdr *eth = os_malloc(sizeof(*eth) + len); 63 if (eth == NULL) 64 return -1; 65 os_memcpy(eth->h_dest, dst_addr, ETH_ALEN); 66 os_memcpy(eth->h_source, l2->own_addr, ETH_ALEN); 67 eth->h_proto = htons(proto); 68 os_memcpy(eth + 1, buf, len); 69 ret = pcap_inject(l2->pcap, (u8 *) eth, len + sizeof(*eth)); 70 os_free(eth); 71 return ret; 72 } else 73 return pcap_inject(l2->pcap, buf, len); 74 } 75 76 77 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx) 78 { 79 struct l2_packet_data *l2 = eloop_ctx; 80 pcap_t *pcap = sock_ctx; 81 struct pcap_pkthdr *hdr; 82 const u_char *packet; 83 struct l2_ethhdr *ethhdr; 84 unsigned char *buf; 85 size_t len; 86 87 if (pcap_next_ex(pcap, &hdr, &packet) == -1) { 88 wpa_printf(MSG_ERROR, "Error reading packet, has device disappeared?"); 89 packet = NULL; 90 eloop_terminate(); 91 } 92 93 if (!l2->rx_callback || !packet || hdr->caplen < sizeof(*ethhdr)) 94 return; 95 96 ethhdr = (struct l2_ethhdr *) packet; 97 if (l2->l2_hdr) { 98 buf = (unsigned char *) ethhdr; 99 len = hdr->caplen; 100 } else { 101 buf = (unsigned char *) (ethhdr + 1); 102 len = hdr->caplen - sizeof(*ethhdr); 103 /* handle 8021Q encapsulated frames */ 104 if (ethhdr->h_proto == htons(ETH_P_8021Q)) { 105 buf += ETHER_VLAN_ENCAP_LEN; 106 len -= ETHER_VLAN_ENCAP_LEN; 107 } 108 } 109 l2->rx_callback(l2->rx_callback_ctx, ethhdr->h_source, buf, len); 110 } 111 112 113 static int l2_packet_init_libpcap(struct l2_packet_data *l2, 114 unsigned short protocol) 115 { 116 bpf_u_int32 pcap_maskp, pcap_netp; 117 char pcap_filter[200], pcap_err[PCAP_ERRBUF_SIZE]; 118 struct bpf_program pcap_fp; 119 120 pcap_lookupnet(l2->ifname, &pcap_netp, &pcap_maskp, pcap_err); 121 l2->pcap = pcap_open_live(l2->ifname, 2500, 0, 10, pcap_err); 122 if (l2->pcap == NULL) { 123 fprintf(stderr, "pcap_open_live: %s\n", pcap_err); 124 fprintf(stderr, "ifname='%s'\n", l2->ifname); 125 return -1; 126 } 127 if (pcap_datalink(l2->pcap) != DLT_EN10MB && 128 pcap_set_datalink(l2->pcap, DLT_EN10MB) < 0) { 129 fprintf(stderr, "pcap_set_datalink(DLT_EN10MB): %s\n", 130 pcap_geterr(l2->pcap)); 131 return -1; 132 } 133 os_snprintf(pcap_filter, sizeof(pcap_filter), 134 "not ether src " MACSTR " and " 135 "( ether dst " MACSTR " or ether dst " MACSTR " ) and " 136 "( ether proto 0x%x or ( vlan 0 and ether proto 0x%x ) )", 137 MAC2STR(l2->own_addr), /* do not receive own packets */ 138 MAC2STR(l2->own_addr), MAC2STR(pae_group_addr), 139 protocol, protocol); 140 if (pcap_compile(l2->pcap, &pcap_fp, pcap_filter, 1, pcap_netp) < 0) { 141 fprintf(stderr, "pcap_compile: %s\n", pcap_geterr(l2->pcap)); 142 return -1; 143 } 144 145 if (pcap_setfilter(l2->pcap, &pcap_fp) < 0) { 146 fprintf(stderr, "pcap_setfilter: %s\n", pcap_geterr(l2->pcap)); 147 return -1; 148 } 149 150 pcap_freecode(&pcap_fp); 151 #ifndef __sun__ 152 /* 153 * When libpcap uses BPF we must enable "immediate mode" to 154 * receive frames right away; otherwise the system may 155 * buffer them for us. 156 */ 157 { 158 unsigned int on = 1; 159 if (ioctl(pcap_fileno(l2->pcap), BIOCIMMEDIATE, &on) < 0) { 160 fprintf(stderr, "%s: cannot enable immediate mode on " 161 "interface %s: %s\n", 162 __func__, l2->ifname, strerror(errno)); 163 /* XXX should we fail? */ 164 } 165 } 166 #endif /* __sun__ */ 167 168 eloop_register_read_sock(pcap_get_selectable_fd(l2->pcap), 169 l2_packet_receive, l2, l2->pcap); 170 171 return 0; 172 } 173 174 175 static int eth_get(const char *device, u8 ea[ETH_ALEN]) 176 { 177 #ifdef __sun__ 178 dlpi_handle_t dh; 179 u32 physaddrlen = DLPI_PHYSADDR_MAX; 180 u8 physaddr[DLPI_PHYSADDR_MAX]; 181 int retval; 182 183 retval = dlpi_open(device, &dh, 0); 184 if (retval != DLPI_SUCCESS) { 185 wpa_printf(MSG_ERROR, "dlpi_open error: %s", 186 dlpi_strerror(retval)); 187 return -1; 188 } 189 190 retval = dlpi_get_physaddr(dh, DL_CURR_PHYS_ADDR, physaddr, 191 &physaddrlen); 192 if (retval != DLPI_SUCCESS) { 193 wpa_printf(MSG_ERROR, "dlpi_get_physaddr error: %s", 194 dlpi_strerror(retval)); 195 dlpi_close(dh); 196 return -1; 197 } 198 os_memcpy(ea, physaddr, ETH_ALEN); 199 dlpi_close(dh); 200 #else /* __sun__ */ 201 struct if_msghdr *ifm; 202 struct sockaddr_dl *sdl; 203 u_char *p, *buf; 204 size_t len; 205 int mib[] = { CTL_NET, AF_ROUTE, 0, AF_LINK, NET_RT_IFLIST, 0 }; 206 207 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 208 return -1; 209 if ((buf = os_malloc(len)) == NULL) 210 return -1; 211 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) { 212 os_free(buf); 213 return -1; 214 } 215 for (p = buf; p < buf + len; p += ifm->ifm_msglen) { 216 ifm = (struct if_msghdr *)p; 217 sdl = (struct sockaddr_dl *)(ifm + 1); 218 if (ifm->ifm_type != RTM_IFINFO || 219 (ifm->ifm_addrs & RTA_IFP) == 0) 220 continue; 221 if (sdl->sdl_family != AF_LINK || sdl->sdl_nlen == 0 || 222 os_memcmp(sdl->sdl_data, device, sdl->sdl_nlen) != 0) 223 continue; 224 os_memcpy(ea, LLADDR(sdl), sdl->sdl_alen); 225 break; 226 } 227 os_free(buf); 228 229 if (p >= buf + len) { 230 errno = ESRCH; 231 return -1; 232 } 233 #endif /* __sun__ */ 234 return 0; 235 } 236 237 238 struct l2_packet_data * l2_packet_init( 239 const char *ifname, const u8 *own_addr, unsigned short protocol, 240 void (*rx_callback)(void *ctx, const u8 *src_addr, 241 const u8 *buf, size_t len), 242 void *rx_callback_ctx, int l2_hdr) 243 { 244 struct l2_packet_data *l2; 245 246 l2 = os_zalloc(sizeof(struct l2_packet_data)); 247 if (l2 == NULL) 248 return NULL; 249 os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname)); 250 l2->rx_callback = rx_callback; 251 l2->rx_callback_ctx = rx_callback_ctx; 252 l2->l2_hdr = l2_hdr; 253 254 if (eth_get(l2->ifname, l2->own_addr) < 0) { 255 fprintf(stderr, "Failed to get link-level address for " 256 "interface '%s'.\n", l2->ifname); 257 os_free(l2); 258 return NULL; 259 } 260 261 if (l2_packet_init_libpcap(l2, protocol)) { 262 os_free(l2); 263 return NULL; 264 } 265 266 return l2; 267 } 268 269 270 struct l2_packet_data * l2_packet_init_bridge( 271 const char *br_ifname, const char *ifname, const u8 *own_addr, 272 unsigned short protocol, 273 void (*rx_callback)(void *ctx, const u8 *src_addr, 274 const u8 *buf, size_t len), 275 void *rx_callback_ctx, int l2_hdr) 276 { 277 return l2_packet_init(br_ifname, own_addr, protocol, rx_callback, 278 rx_callback_ctx, l2_hdr); 279 } 280 281 282 void l2_packet_deinit(struct l2_packet_data *l2) 283 { 284 if (l2 != NULL) { 285 if (l2->pcap) { 286 eloop_unregister_read_sock( 287 pcap_get_selectable_fd(l2->pcap)); 288 pcap_close(l2->pcap); 289 } 290 os_free(l2); 291 } 292 } 293 294 295 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len) 296 { 297 pcap_if_t *devs, *dev; 298 struct pcap_addr *addr; 299 struct sockaddr_in *saddr; 300 int found = 0; 301 char err[PCAP_ERRBUF_SIZE + 1]; 302 303 if (pcap_findalldevs(&devs, err) < 0) { 304 wpa_printf(MSG_DEBUG, "pcap_findalldevs: %s\n", err); 305 return -1; 306 } 307 308 for (dev = devs; dev && !found; dev = dev->next) { 309 if (os_strcmp(dev->name, l2->ifname) != 0) 310 continue; 311 312 addr = dev->addresses; 313 while (addr) { 314 saddr = (struct sockaddr_in *) addr->addr; 315 if (saddr && saddr->sin_family == AF_INET) { 316 os_strlcpy(buf, inet_ntoa(saddr->sin_addr), 317 len); 318 found = 1; 319 break; 320 } 321 addr = addr->next; 322 } 323 } 324 325 pcap_freealldevs(devs); 326 327 return found ? 0 : -1; 328 } 329 330 331 void l2_packet_notify_auth_start(struct l2_packet_data *l2) 332 { 333 } 334 335 336 int l2_packet_set_packet_filter(struct l2_packet_data *l2, 337 enum l2_packet_filter_type type) 338 { 339 return -1; 340 } 341