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 #ifndef ETHER_VLAN_ENCAP_LEN 35 #define ETHER_VLAN_ENCAP_LEN 4 36 #endif 37 38 static const u8 pae_group_addr[ETH_ALEN] = 39 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x03 }; 40 41 struct l2_packet_data { 42 pcap_t *pcap; 43 char ifname[100]; 44 u8 own_addr[ETH_ALEN]; 45 void (*rx_callback)(void *ctx, const u8 *src_addr, 46 const u8 *buf, size_t len); 47 void *rx_callback_ctx; 48 int l2_hdr; /* whether to include layer 2 (Ethernet) header data 49 * buffers */ 50 }; 51 52 53 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr) 54 { 55 os_memcpy(addr, l2->own_addr, ETH_ALEN); 56 return 0; 57 } 58 59 60 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto, 61 const u8 *buf, size_t len) 62 { 63 if (!l2->l2_hdr) { 64 int ret; 65 struct l2_ethhdr *eth = os_malloc(sizeof(*eth) + len); 66 if (eth == NULL) 67 return -1; 68 os_memcpy(eth->h_dest, dst_addr, ETH_ALEN); 69 os_memcpy(eth->h_source, l2->own_addr, ETH_ALEN); 70 eth->h_proto = htons(proto); 71 os_memcpy(eth + 1, buf, len); 72 ret = pcap_inject(l2->pcap, (u8 *) eth, len + sizeof(*eth)); 73 os_free(eth); 74 return ret; 75 } else 76 return pcap_inject(l2->pcap, buf, len); 77 } 78 79 80 static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx) 81 { 82 struct l2_packet_data *l2 = eloop_ctx; 83 pcap_t *pcap = sock_ctx; 84 struct pcap_pkthdr *hdr; 85 const u_char *packet; 86 struct l2_ethhdr *ethhdr; 87 unsigned char *buf; 88 size_t len; 89 90 if (pcap_next_ex(pcap, &hdr, &packet) == -1) { 91 wpa_printf(MSG_ERROR, "Error reading packet, has device disappeared?"); 92 packet = NULL; 93 eloop_terminate(); 94 } 95 96 if (!l2->rx_callback || !packet || hdr->caplen < sizeof(*ethhdr)) 97 return; 98 99 ethhdr = (struct l2_ethhdr *) packet; 100 if (l2->l2_hdr) { 101 buf = (unsigned char *) ethhdr; 102 len = hdr->caplen; 103 } else { 104 buf = (unsigned char *) (ethhdr + 1); 105 len = hdr->caplen - sizeof(*ethhdr); 106 107 /* Handle IEEE 802.1Q encapsulated frames */ 108 if (len >= ETHER_VLAN_ENCAP_LEN && 109 ethhdr->h_proto == htons(ETH_P_8021Q)) { 110 buf += ETHER_VLAN_ENCAP_LEN; 111 len -= ETHER_VLAN_ENCAP_LEN; 112 } 113 } 114 l2->rx_callback(l2->rx_callback_ctx, ethhdr->h_source, buf, len); 115 } 116 117 118 static int l2_packet_init_libpcap(struct l2_packet_data *l2, 119 unsigned short protocol) 120 { 121 bpf_u_int32 pcap_maskp, pcap_netp; 122 char pcap_filter[200], pcap_err[PCAP_ERRBUF_SIZE]; 123 struct bpf_program pcap_fp; 124 125 pcap_lookupnet(l2->ifname, &pcap_netp, &pcap_maskp, pcap_err); 126 l2->pcap = pcap_open_live(l2->ifname, 2500, 0, 10, pcap_err); 127 if (l2->pcap == NULL) { 128 fprintf(stderr, "pcap_open_live: %s\n", pcap_err); 129 fprintf(stderr, "ifname='%s'\n", l2->ifname); 130 return -1; 131 } 132 if (pcap_datalink(l2->pcap) != DLT_EN10MB && 133 pcap_set_datalink(l2->pcap, DLT_EN10MB) < 0) { 134 fprintf(stderr, "pcap_set_datalink(DLT_EN10MB): %s\n", 135 pcap_geterr(l2->pcap)); 136 return -1; 137 } 138 os_snprintf(pcap_filter, sizeof(pcap_filter), 139 "not ether src " MACSTR " and " 140 "( ether dst " MACSTR " or ether dst " MACSTR " ) and " 141 "( ether proto 0x%x or ( vlan 0 and ether proto 0x%x ) )", 142 MAC2STR(l2->own_addr), /* do not receive own packets */ 143 MAC2STR(l2->own_addr), MAC2STR(pae_group_addr), 144 protocol, protocol); 145 if (pcap_compile(l2->pcap, &pcap_fp, pcap_filter, 1, pcap_netp) < 0) { 146 fprintf(stderr, "pcap_compile: %s\n", pcap_geterr(l2->pcap)); 147 return -1; 148 } 149 150 if (pcap_setfilter(l2->pcap, &pcap_fp) < 0) { 151 fprintf(stderr, "pcap_setfilter: %s\n", pcap_geterr(l2->pcap)); 152 return -1; 153 } 154 155 pcap_freecode(&pcap_fp); 156 #ifndef __sun__ 157 /* 158 * When libpcap uses BPF we must enable "immediate mode" to 159 * receive frames right away; otherwise the system may 160 * buffer them for us. 161 */ 162 { 163 unsigned int on = 1; 164 if (ioctl(pcap_fileno(l2->pcap), BIOCIMMEDIATE, &on) < 0) { 165 fprintf(stderr, "%s: cannot enable immediate mode on " 166 "interface %s: %s\n", 167 __func__, l2->ifname, strerror(errno)); 168 /* XXX should we fail? */ 169 } 170 } 171 #endif /* __sun__ */ 172 173 eloop_register_read_sock(pcap_get_selectable_fd(l2->pcap), 174 l2_packet_receive, l2, l2->pcap); 175 176 return 0; 177 } 178 179 180 static int eth_get(const char *device, u8 ea[ETH_ALEN]) 181 { 182 #ifdef __sun__ 183 dlpi_handle_t dh; 184 u32 physaddrlen = DLPI_PHYSADDR_MAX; 185 u8 physaddr[DLPI_PHYSADDR_MAX]; 186 int retval; 187 188 retval = dlpi_open(device, &dh, 0); 189 if (retval != DLPI_SUCCESS) { 190 wpa_printf(MSG_ERROR, "dlpi_open error: %s", 191 dlpi_strerror(retval)); 192 return -1; 193 } 194 195 retval = dlpi_get_physaddr(dh, DL_CURR_PHYS_ADDR, physaddr, 196 &physaddrlen); 197 if (retval != DLPI_SUCCESS) { 198 wpa_printf(MSG_ERROR, "dlpi_get_physaddr error: %s", 199 dlpi_strerror(retval)); 200 dlpi_close(dh); 201 return -1; 202 } 203 os_memcpy(ea, physaddr, ETH_ALEN); 204 dlpi_close(dh); 205 #else /* __sun__ */ 206 struct if_msghdr *ifm; 207 struct sockaddr_dl *sdl; 208 u_char *p, *buf; 209 size_t len; 210 int mib[] = { CTL_NET, AF_ROUTE, 0, AF_LINK, NET_RT_IFLIST, 0 }; 211 212 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 213 return -1; 214 if ((buf = os_malloc(len)) == NULL) 215 return -1; 216 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) { 217 os_free(buf); 218 return -1; 219 } 220 for (p = buf; p < buf + len; p += ifm->ifm_msglen) { 221 ifm = (struct if_msghdr *)p; 222 sdl = (struct sockaddr_dl *)(ifm + 1); 223 if (ifm->ifm_type != RTM_IFINFO || 224 (ifm->ifm_addrs & RTA_IFP) == 0) 225 continue; 226 if (sdl->sdl_family != AF_LINK || sdl->sdl_nlen == 0 || 227 os_memcmp(sdl->sdl_data, device, sdl->sdl_nlen) != 0) 228 continue; 229 os_memcpy(ea, LLADDR(sdl), sdl->sdl_alen); 230 break; 231 } 232 os_free(buf); 233 234 if (p >= buf + len) { 235 errno = ESRCH; 236 return -1; 237 } 238 #endif /* __sun__ */ 239 return 0; 240 } 241 242 243 struct l2_packet_data * l2_packet_init( 244 const char *ifname, const u8 *own_addr, unsigned short protocol, 245 void (*rx_callback)(void *ctx, const u8 *src_addr, 246 const u8 *buf, size_t len), 247 void *rx_callback_ctx, int l2_hdr) 248 { 249 struct l2_packet_data *l2; 250 251 l2 = os_zalloc(sizeof(struct l2_packet_data)); 252 if (l2 == NULL) 253 return NULL; 254 os_strlcpy(l2->ifname, ifname, sizeof(l2->ifname)); 255 l2->rx_callback = rx_callback; 256 l2->rx_callback_ctx = rx_callback_ctx; 257 l2->l2_hdr = l2_hdr; 258 259 if (eth_get(l2->ifname, l2->own_addr) < 0) { 260 fprintf(stderr, "Failed to get link-level address for " 261 "interface '%s'.\n", l2->ifname); 262 os_free(l2); 263 return NULL; 264 } 265 266 if (l2_packet_init_libpcap(l2, protocol)) { 267 os_free(l2); 268 return NULL; 269 } 270 271 return l2; 272 } 273 274 275 struct l2_packet_data * l2_packet_init_bridge( 276 const char *br_ifname, const char *ifname, const u8 *own_addr, 277 unsigned short protocol, 278 void (*rx_callback)(void *ctx, const u8 *src_addr, 279 const u8 *buf, size_t len), 280 void *rx_callback_ctx, int l2_hdr) 281 { 282 return l2_packet_init(br_ifname, own_addr, protocol, rx_callback, 283 rx_callback_ctx, l2_hdr); 284 } 285 286 287 void l2_packet_deinit(struct l2_packet_data *l2) 288 { 289 if (l2 != NULL) { 290 if (l2->pcap) { 291 eloop_unregister_read_sock( 292 pcap_get_selectable_fd(l2->pcap)); 293 pcap_close(l2->pcap); 294 } 295 os_free(l2); 296 } 297 } 298 299 300 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len) 301 { 302 pcap_if_t *devs, *dev; 303 struct pcap_addr *addr; 304 struct sockaddr_in *saddr; 305 int found = 0; 306 char err[PCAP_ERRBUF_SIZE + 1]; 307 308 if (pcap_findalldevs(&devs, err) < 0) { 309 wpa_printf(MSG_DEBUG, "pcap_findalldevs: %s\n", err); 310 return -1; 311 } 312 313 for (dev = devs; dev && !found; dev = dev->next) { 314 if (os_strcmp(dev->name, l2->ifname) != 0) 315 continue; 316 317 addr = dev->addresses; 318 while (addr) { 319 saddr = (struct sockaddr_in *) addr->addr; 320 if (saddr && saddr->sin_family == AF_INET) { 321 os_strlcpy(buf, inet_ntoa(saddr->sin_addr), 322 len); 323 found = 1; 324 break; 325 } 326 addr = addr->next; 327 } 328 } 329 330 pcap_freealldevs(devs); 331 332 return found ? 0 : -1; 333 } 334 335 336 void l2_packet_notify_auth_start(struct l2_packet_data *l2) 337 { 338 } 339 340 341 int l2_packet_set_packet_filter(struct l2_packet_data *l2, 342 enum l2_packet_filter_type type) 343 { 344 return -1; 345 } 346