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