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