1 /* 2 * UPnP SSDP for WPS 3 * Copyright (c) 2000-2003 Intel Corporation 4 * Copyright (c) 2006-2007 Sony Corporation 5 * Copyright (c) 2008-2009 Atheros Communications 6 * Copyright (c) 2009, Jouni Malinen <j@w1.fi> 7 * 8 * See wps_upnp.c for more details on licensing and code history. 9 */ 10 11 #include "includes.h" 12 13 #include <fcntl.h> 14 #include <sys/ioctl.h> 15 #include <net/route.h> 16 17 #include "common.h" 18 #include "uuid.h" 19 #include "eloop.h" 20 #include "wps.h" 21 #include "wps_upnp.h" 22 #include "wps_upnp_i.h" 23 24 #define UPNP_CACHE_SEC (UPNP_CACHE_SEC_MIN + 1) /* cache time we use */ 25 #define UPNP_CACHE_SEC_MIN 1800 /* min cachable time per UPnP standard */ 26 #define UPNP_ADVERTISE_REPEAT 2 /* no more than 3 */ 27 #define MULTICAST_MAX_READ 1600 /* max bytes we'll read for UPD request */ 28 #define MAX_MSEARCH 20 /* max simultaneous M-SEARCH replies ongoing */ 29 #define SSDP_TARGET "239.0.0.0" 30 #define SSDP_NETMASK "255.0.0.0" 31 32 33 /* Check tokens for equality, where tokens consist of letters, digits, 34 * underscore and hyphen, and are matched case insensitive. 35 */ 36 static int token_eq(const char *s1, const char *s2) 37 { 38 int c1; 39 int c2; 40 int end1 = 0; 41 int end2 = 0; 42 for (;;) { 43 c1 = *s1++; 44 c2 = *s2++; 45 if (isalpha(c1) && isupper(c1)) 46 c1 = tolower(c1); 47 if (isalpha(c2) && isupper(c2)) 48 c2 = tolower(c2); 49 end1 = !(isalnum(c1) || c1 == '_' || c1 == '-'); 50 end2 = !(isalnum(c2) || c2 == '_' || c2 == '-'); 51 if (end1 || end2 || c1 != c2) 52 break; 53 } 54 return end1 && end2; /* reached end of both words? */ 55 } 56 57 58 /* Return length of token (see above for definition of token) */ 59 static int token_length(const char *s) 60 { 61 const char *begin = s; 62 for (;; s++) { 63 int c = *s; 64 int end = !(isalnum(c) || c == '_' || c == '-'); 65 if (end) 66 break; 67 } 68 return s - begin; 69 } 70 71 72 /* return length of interword separation. 73 * This accepts only spaces/tabs and thus will not traverse a line 74 * or buffer ending. 75 */ 76 static int word_separation_length(const char *s) 77 { 78 const char *begin = s; 79 for (;; s++) { 80 int c = *s; 81 if (c == ' ' || c == '\t') 82 continue; 83 break; 84 } 85 return s - begin; 86 } 87 88 89 /* No. of chars through (including) end of line */ 90 static int line_length(const char *l) 91 { 92 const char *lp = l; 93 while (*lp && *lp != '\n') 94 lp++; 95 if (*lp == '\n') 96 lp++; 97 return lp - l; 98 } 99 100 101 /* No. of chars excluding trailing whitespace */ 102 static int line_length_stripped(const char *l) 103 { 104 const char *lp = l + line_length(l); 105 while (lp > l && !isgraph(lp[-1])) 106 lp--; 107 return lp - l; 108 } 109 110 111 static int str_starts(const char *str, const char *start) 112 { 113 return os_strncmp(str, start, os_strlen(start)) == 0; 114 } 115 116 117 /*************************************************************************** 118 * Advertisements. 119 * These are multicast to the world to tell them we are here. 120 * The individual packets are spread out in time to limit loss, 121 * and then after a much longer period of time the whole sequence 122 * is repeated again (for NOTIFYs only). 123 **************************************************************************/ 124 125 /** 126 * next_advertisement - Build next message and advance the state machine 127 * @a: Advertisement state 128 * @islast: Buffer for indicating whether this is the last message (= 1) 129 * Returns: The new message (caller is responsible for freeing this) 130 * 131 * Note: next_advertisement is shared code with msearchreply_* functions 132 */ 133 static struct wpabuf * 134 next_advertisement(struct advertisement_state_machine *a, int *islast) 135 { 136 struct wpabuf *msg; 137 char *NTString = ""; 138 char uuid_string[80]; 139 140 *islast = 0; 141 uuid_bin2str(a->sm->wps->uuid, uuid_string, sizeof(uuid_string)); 142 msg = wpabuf_alloc(800); /* more than big enough */ 143 if (msg == NULL) 144 goto fail; 145 switch (a->type) { 146 case ADVERTISE_UP: 147 case ADVERTISE_DOWN: 148 NTString = "NT"; 149 wpabuf_put_str(msg, "NOTIFY * HTTP/1.1\r\n"); 150 wpabuf_printf(msg, "HOST: %s:%d\r\n", 151 UPNP_MULTICAST_ADDRESS, UPNP_MULTICAST_PORT); 152 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n", 153 UPNP_CACHE_SEC); 154 wpabuf_printf(msg, "NTS: %s\r\n", 155 (a->type == ADVERTISE_UP ? 156 "ssdp:alive" : "ssdp:byebye")); 157 break; 158 case MSEARCH_REPLY: 159 NTString = "ST"; 160 wpabuf_put_str(msg, "HTTP/1.1 200 OK\r\n"); 161 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n", 162 UPNP_CACHE_SEC); 163 164 wpabuf_put_str(msg, "DATE: "); 165 format_date(msg); 166 wpabuf_put_str(msg, "\r\n"); 167 168 wpabuf_put_str(msg, "EXT:\r\n"); 169 break; 170 } 171 172 if (a->type != ADVERTISE_DOWN) { 173 /* Where others may get our XML files from */ 174 wpabuf_printf(msg, "LOCATION: http://%s:%d/%s\r\n", 175 a->sm->ip_addr_text, a->sm->web_port, 176 UPNP_WPS_DEVICE_XML_FILE); 177 } 178 179 /* The SERVER line has three comma-separated fields: 180 * operating system / version 181 * upnp version 182 * software package / version 183 * However, only the UPnP version is really required, the 184 * others can be place holders... for security reasons 185 * it is better to NOT provide extra information. 186 */ 187 wpabuf_put_str(msg, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n"); 188 189 switch (a->state / UPNP_ADVERTISE_REPEAT) { 190 case 0: 191 wpabuf_printf(msg, "%s: upnp:rootdevice\r\n", NTString); 192 wpabuf_printf(msg, "USN: uuid:%s::upnp:rootdevice\r\n", 193 uuid_string); 194 break; 195 case 1: 196 wpabuf_printf(msg, "%s: uuid:%s\r\n", NTString, uuid_string); 197 wpabuf_printf(msg, "USN: uuid:%s\r\n", uuid_string); 198 break; 199 case 2: 200 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:device:" 201 "WFADevice:1\r\n", NTString); 202 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-" 203 "org:device:WFADevice:1\r\n", uuid_string); 204 break; 205 case 3: 206 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:service:" 207 "WFAWLANConfig:1\r\n", NTString); 208 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-" 209 "org:service:WFAWLANConfig:1\r\n", uuid_string); 210 break; 211 } 212 wpabuf_put_str(msg, "\r\n"); 213 214 if (a->state + 1 >= 4 * UPNP_ADVERTISE_REPEAT) 215 *islast = 1; 216 217 return msg; 218 219 fail: 220 wpabuf_free(msg); 221 return NULL; 222 } 223 224 225 static void advertisement_state_machine_handler(void *eloop_data, 226 void *user_ctx); 227 228 229 /** 230 * advertisement_state_machine_stop - Stop SSDP advertisements 231 * @sm: WPS UPnP state machine from upnp_wps_device_init() 232 */ 233 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm) 234 { 235 eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm); 236 } 237 238 239 static void advertisement_state_machine_handler(void *eloop_data, 240 void *user_ctx) 241 { 242 struct upnp_wps_device_sm *sm = user_ctx; 243 struct advertisement_state_machine *a = &sm->advertisement; 244 struct wpabuf *msg; 245 int next_timeout_msec = 100; 246 int next_timeout_sec = 0; 247 struct sockaddr_in dest; 248 int islast = 0; 249 250 /* 251 * Each is sent twice (in case lost) w/ 100 msec delay between; 252 * spec says no more than 3 times. 253 * One pair for rootdevice, one pair for uuid, and a pair each for 254 * each of the two urns. 255 * The entire sequence must be repeated before cache control timeout 256 * (which is min 1800 seconds), 257 * recommend random portion of half of the advertised cache control age 258 * to ensure against loss... perhaps 1800/4 + rand*1800/4 ? 259 * Delay random interval < 100 msec prior to initial sending. 260 * TTL of 4 261 */ 262 263 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state); 264 msg = next_advertisement(a, &islast); 265 if (msg == NULL) 266 return; 267 268 os_memset(&dest, 0, sizeof(dest)); 269 dest.sin_family = AF_INET; 270 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 271 dest.sin_port = htons(UPNP_MULTICAST_PORT); 272 273 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0, 274 (struct sockaddr *) &dest, sizeof(dest)) == -1) { 275 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:" 276 "%d (%s)", errno, strerror(errno)); 277 next_timeout_msec = 0; 278 next_timeout_sec = 10; /* ... later */ 279 } else if (islast) { 280 a->state = 0; /* wrap around */ 281 if (a->type == ADVERTISE_DOWN) { 282 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP"); 283 a->type = ADVERTISE_UP; 284 /* do it all over again right away */ 285 } else { 286 u16 r; 287 /* 288 * Start over again after a long timeout 289 * (see notes above) 290 */ 291 next_timeout_msec = 0; 292 os_get_random((void *) &r, sizeof(r)); 293 next_timeout_sec = UPNP_CACHE_SEC / 4 + 294 (((UPNP_CACHE_SEC / 4) * r) >> 16); 295 sm->advertise_count++; 296 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); " 297 "next in %d sec", 298 sm->advertise_count, next_timeout_sec); 299 } 300 } else { 301 a->state++; 302 } 303 304 wpabuf_free(msg); 305 306 eloop_register_timeout(next_timeout_sec, next_timeout_msec, 307 advertisement_state_machine_handler, NULL, sm); 308 } 309 310 311 /** 312 * advertisement_state_machine_start - Start SSDP advertisements 313 * @sm: WPS UPnP state machine from upnp_wps_device_init() 314 * Returns: 0 on success, -1 on failure 315 */ 316 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm) 317 { 318 struct advertisement_state_machine *a = &sm->advertisement; 319 int next_timeout_msec; 320 321 advertisement_state_machine_stop(sm); 322 323 /* 324 * Start out advertising down, this automatically switches 325 * to advertising up which signals our restart. 326 */ 327 a->type = ADVERTISE_DOWN; 328 a->state = 0; 329 a->sm = sm; 330 /* (other fields not used here) */ 331 332 /* First timeout should be random interval < 100 msec */ 333 next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8; 334 return eloop_register_timeout(0, next_timeout_msec, 335 advertisement_state_machine_handler, 336 NULL, sm); 337 } 338 339 340 /*************************************************************************** 341 * M-SEARCH replies 342 * These are very similar to the multicast advertisements, with some 343 * small changes in data content; and they are sent (UDP) to a specific 344 * unicast address instead of multicast. 345 * They are sent in response to a UDP M-SEARCH packet. 346 **************************************************************************/ 347 348 static void msearchreply_state_machine_handler(void *eloop_data, 349 void *user_ctx); 350 351 352 /** 353 * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine 354 * @a: Selected advertisement/reply state 355 */ 356 void msearchreply_state_machine_stop(struct advertisement_state_machine *a) 357 { 358 struct upnp_wps_device_sm *sm = a->sm; 359 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop"); 360 if (a->next == a) { 361 sm->msearch_replies = NULL; 362 } else { 363 if (sm->msearch_replies == a) 364 sm->msearch_replies = a->next; 365 a->next->prev = a->prev; 366 a->prev->next = a->next; 367 } 368 os_free(a); 369 sm->n_msearch_replies--; 370 } 371 372 373 static void msearchreply_state_machine_handler(void *eloop_data, 374 void *user_ctx) 375 { 376 struct advertisement_state_machine *a = user_ctx; 377 struct upnp_wps_device_sm *sm = a->sm; 378 struct wpabuf *msg; 379 int next_timeout_msec = 100; 380 int next_timeout_sec = 0; 381 int islast = 0; 382 383 /* 384 * Each response is sent twice (in case lost) w/ 100 msec delay 385 * between; spec says no more than 3 times. 386 * One pair for rootdevice, one pair for uuid, and a pair each for 387 * each of the two urns. 388 */ 389 390 /* TODO: should only send the requested response types */ 391 392 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)", 393 a->state, inet_ntoa(a->client.sin_addr), 394 ntohs(a->client.sin_port)); 395 msg = next_advertisement(a, &islast); 396 if (msg == NULL) 397 return; 398 399 /* 400 * Send it on the multicast socket to avoid having to set up another 401 * socket. 402 */ 403 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0, 404 (struct sockaddr *) &a->client, sizeof(a->client)) < 0) { 405 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto " 406 "errno %d (%s) for %s:%d", 407 errno, strerror(errno), 408 inet_ntoa(a->client.sin_addr), 409 ntohs(a->client.sin_port)); 410 /* Ignore error and hope for the best */ 411 } 412 wpabuf_free(msg); 413 if (islast) { 414 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done"); 415 msearchreply_state_machine_stop(a); 416 return; 417 } 418 a->state++; 419 420 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec", 421 next_timeout_sec, next_timeout_msec); 422 eloop_register_timeout(next_timeout_sec, next_timeout_msec, 423 msearchreply_state_machine_handler, sm, a); 424 } 425 426 427 /** 428 * msearchreply_state_machine_start - Reply to M-SEARCH discovery request 429 * @sm: WPS UPnP state machine from upnp_wps_device_init() 430 * @client: Client address 431 * @mx: Maximum delay in seconds 432 * 433 * Use TTL of 4 (this was done when socket set up). 434 * A response should be given in randomized portion of min(MX,120) seconds 435 * 436 * UPnP-arch-DeviceArchitecture, 1.2.3: 437 * To be found, a device must send a UDP response to the source IP address and 438 * port that sent the request to the multicast channel. Devices respond if the 439 * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:" 440 * followed by a UUID that exactly matches one advertised by the device. 441 */ 442 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm, 443 struct sockaddr_in *client, 444 int mx) 445 { 446 struct advertisement_state_machine *a; 447 int next_timeout_sec; 448 int next_timeout_msec; 449 450 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d " 451 "outstanding)", sm->n_msearch_replies); 452 if (sm->n_msearch_replies >= MAX_MSEARCH) { 453 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding " 454 "M-SEARCH replies"); 455 return; 456 } 457 458 a = os_zalloc(sizeof(*a)); 459 if (a == NULL) 460 return; 461 a->type = MSEARCH_REPLY; 462 a->state = 0; 463 a->sm = sm; 464 os_memcpy(&a->client, client, sizeof(client)); 465 /* Wait time depending on MX value */ 466 next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8; 467 next_timeout_sec = next_timeout_msec / 1000; 468 next_timeout_msec = next_timeout_msec % 1000; 469 if (eloop_register_timeout(next_timeout_sec, next_timeout_msec, 470 msearchreply_state_machine_handler, sm, 471 a)) { 472 /* No way to recover (from malloc failure) */ 473 goto fail; 474 } 475 /* Remember for future cleanup */ 476 if (sm->msearch_replies) { 477 a->next = sm->msearch_replies; 478 a->prev = a->next->prev; 479 a->prev->next = a; 480 a->next->prev = a; 481 } else { 482 sm->msearch_replies = a->next = a->prev = a; 483 } 484 sm->n_msearch_replies++; 485 return; 486 487 fail: 488 wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!"); 489 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a); 490 os_free(a); 491 } 492 493 494 /** 495 * ssdp_parse_msearch - Process a received M-SEARCH 496 * @sm: WPS UPnP state machine from upnp_wps_device_init() 497 * @client: Client address 498 * @data: NULL terminated M-SEARCH message 499 * 500 * Given that we have received a header w/ M-SEARCH, act upon it 501 * 502 * Format of M-SEARCH (case insensitive!): 503 * 504 * First line must be: 505 * M-SEARCH * HTTP/1.1 506 * Other lines in arbitrary order: 507 * HOST:239.255.255.250:1900 508 * ST:<varies -- must match> 509 * MAN:"ssdp:discover" 510 * MX:<varies> 511 * 512 * It should be noted that when Microsoft Vista is still learning its IP 513 * address, it sends out host lines like: HOST:[FF02::C]:1900 514 */ 515 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm, 516 struct sockaddr_in *client, const char *data) 517 { 518 const char *start = data; 519 const char *end; 520 int got_host = 0; 521 int got_st = 0, st_match = 0; 522 int got_man = 0; 523 int got_mx = 0; 524 int mx = 0; 525 526 /* 527 * Skip first line M-SEARCH * HTTP/1.1 528 * (perhaps we should check remainder of the line for syntax) 529 */ 530 data += line_length(data); 531 532 /* Parse remaining lines */ 533 for (; *data != '\0'; data += line_length(data)) { 534 end = data + line_length_stripped(data); 535 if (token_eq(data, "host")) { 536 /* The host line indicates who the packet 537 * is addressed to... but do we really care? 538 * Note that Microsoft sometimes does funny 539 * stuff with the HOST: line. 540 */ 541 #if 0 /* could be */ 542 data += token_length(data); 543 data += word_separation_length(data); 544 if (*data != ':') 545 goto bad; 546 data++; 547 data += word_separation_length(data); 548 /* UPNP_MULTICAST_ADDRESS */ 549 if (!str_starts(data, "239.255.255.250")) 550 goto bad; 551 data += os_strlen("239.255.255.250"); 552 if (*data == ':') { 553 if (!str_starts(data, ":1900")) 554 goto bad; 555 } 556 #endif /* could be */ 557 got_host = 1; 558 continue; 559 } else if (token_eq(data, "st")) { 560 /* There are a number of forms; we look 561 * for one that matches our case. 562 */ 563 got_st = 1; 564 data += token_length(data); 565 data += word_separation_length(data); 566 if (*data != ':') 567 continue; 568 data++; 569 data += word_separation_length(data); 570 if (str_starts(data, "ssdp:all")) { 571 st_match = 1; 572 continue; 573 } 574 if (str_starts(data, "upnp:rootdevice")) { 575 st_match = 1; 576 continue; 577 } 578 if (str_starts(data, "uuid:")) { 579 char uuid_string[80]; 580 data += os_strlen("uuid:"); 581 uuid_bin2str(sm->wps->uuid, uuid_string, 582 sizeof(uuid_string)); 583 if (str_starts(data, uuid_string)) 584 st_match = 1; 585 continue; 586 } 587 #if 0 588 /* FIX: should we really reply to IGD string? */ 589 if (str_starts(data, "urn:schemas-upnp-org:device:" 590 "InternetGatewayDevice:1")) { 591 st_match = 1; 592 continue; 593 } 594 #endif 595 if (str_starts(data, "urn:schemas-wifialliance-org:" 596 "service:WFAWLANConfig:1")) { 597 st_match = 1; 598 continue; 599 } 600 if (str_starts(data, "urn:schemas-wifialliance-org:" 601 "device:WFADevice:1")) { 602 st_match = 1; 603 continue; 604 } 605 continue; 606 } else if (token_eq(data, "man")) { 607 data += token_length(data); 608 data += word_separation_length(data); 609 if (*data != ':') 610 continue; 611 data++; 612 data += word_separation_length(data); 613 if (!str_starts(data, "\"ssdp:discover\"")) { 614 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected " 615 "M-SEARCH man-field"); 616 goto bad; 617 } 618 got_man = 1; 619 continue; 620 } else if (token_eq(data, "mx")) { 621 data += token_length(data); 622 data += word_separation_length(data); 623 if (*data != ':') 624 continue; 625 data++; 626 data += word_separation_length(data); 627 mx = atol(data); 628 got_mx = 1; 629 continue; 630 } 631 /* ignore anything else */ 632 } 633 if (!got_host || !got_st || !got_man || !got_mx || mx < 0) { 634 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d " 635 "%d mx=%d", got_host, got_st, got_man, got_mx, mx); 636 goto bad; 637 } 638 if (!st_match) { 639 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST " 640 "match)"); 641 return; 642 } 643 if (mx > 120) 644 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */ 645 msearchreply_state_machine_start(sm, client, mx); 646 return; 647 648 bad: 649 wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH"); 650 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start); 651 } 652 653 654 /* Listening for (UDP) discovery (M-SEARCH) packets */ 655 656 /** 657 * ssdp_listener_stop - Stop SSDP listered 658 * @sm: WPS UPnP state machine from upnp_wps_device_init() 659 * 660 * This function stops the SSDP listerner that was started by calling 661 * ssdp_listener_start(). 662 */ 663 void ssdp_listener_stop(struct upnp_wps_device_sm *sm) 664 { 665 if (sm->ssdp_sd_registered) { 666 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ); 667 sm->ssdp_sd_registered = 0; 668 } 669 670 if (sm->ssdp_sd != -1) { 671 close(sm->ssdp_sd); 672 sm->ssdp_sd = -1; 673 } 674 675 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, 676 ELOOP_ALL_CTX); 677 } 678 679 680 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx) 681 { 682 struct upnp_wps_device_sm *sm = sock_ctx; 683 struct sockaddr_in addr; /* client address */ 684 socklen_t addr_len; 685 int nread; 686 char buf[MULTICAST_MAX_READ], *pos; 687 688 addr_len = sizeof(addr); 689 nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0, 690 (struct sockaddr *) &addr, &addr_len); 691 if (nread <= 0) 692 return; 693 buf[nread] = '\0'; /* need null termination for algorithm */ 694 695 if (str_starts(buf, "NOTIFY ")) { 696 /* 697 * Silently ignore NOTIFYs to avoid filling debug log with 698 * unwanted messages. 699 */ 700 return; 701 } 702 703 pos = os_strchr(buf, '\n'); 704 if (pos) 705 *pos = '\0'; 706 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: " 707 "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf); 708 if (pos) 709 *pos = '\n'; 710 711 /* Parse first line */ 712 if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 && 713 !isgraph(buf[strlen("M-SEARCH")])) { 714 ssdp_parse_msearch(sm, &addr, buf); 715 return; 716 } 717 718 /* Ignore anything else */ 719 } 720 721 722 /** 723 * ssdp_listener_start - Set up for receiving discovery (UDP) packets 724 * @sm: WPS UPnP state machine from upnp_wps_device_init() 725 * Returns: 0 on success, -1 on failure 726 * 727 * The SSDP listerner is stopped by calling ssdp_listener_stop(). 728 */ 729 int ssdp_listener_start(struct upnp_wps_device_sm *sm) 730 { 731 int sd = -1; 732 struct sockaddr_in addr; 733 struct ip_mreq mcast_addr; 734 int on = 1; 735 /* per UPnP spec, keep IP packet time to live (TTL) small */ 736 unsigned char ttl = 4; 737 738 sm->ssdp_sd = sd = socket(AF_INET, SOCK_DGRAM, 0); 739 if (sd < 0) 740 goto fail; 741 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) 742 goto fail; 743 if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on))) 744 goto fail; 745 os_memset(&addr, 0, sizeof(addr)); 746 addr.sin_family = AF_INET; 747 addr.sin_addr.s_addr = htonl(INADDR_ANY); 748 addr.sin_port = htons(UPNP_MULTICAST_PORT); 749 if (bind(sd, (struct sockaddr *) &addr, sizeof(addr))) 750 goto fail; 751 os_memset(&mcast_addr, 0, sizeof(mcast_addr)); 752 mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY); 753 mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 754 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, 755 (char *) &mcast_addr, sizeof(mcast_addr))) 756 goto fail; 757 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, 758 &ttl, sizeof(ttl))) 759 goto fail; 760 if (eloop_register_sock(sd, EVENT_TYPE_READ, ssdp_listener_handler, 761 NULL, sm)) 762 goto fail; 763 sm->ssdp_sd_registered = 1; 764 return 0; 765 766 fail: 767 /* Error */ 768 wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed"); 769 ssdp_listener_stop(sm); 770 return -1; 771 } 772 773 774 /** 775 * add_ssdp_network - Add routing entry for SSDP 776 * @net_if: Selected network interface name 777 * Returns: 0 on success, -1 on failure 778 * 779 * This function assures that the multicast address will be properly 780 * handled by Linux networking code (by a modification to routing tables). 781 * This must be done per network interface. It really only needs to be done 782 * once after booting up, but it does not hurt to call this more frequently 783 * "to be safe". 784 */ 785 int add_ssdp_network(char *net_if) 786 { 787 int ret = -1; 788 int sock = -1; 789 struct rtentry rt; 790 struct sockaddr_in *sin; 791 792 if (!net_if) 793 goto fail; 794 795 os_memset(&rt, 0, sizeof(rt)); 796 sock = socket(AF_INET, SOCK_DGRAM, 0); 797 if (sock < 0) 798 goto fail; 799 800 rt.rt_dev = net_if; 801 sin = (struct sockaddr_in *) &rt.rt_dst; 802 sin->sin_family = AF_INET; 803 sin->sin_port = 0; 804 sin->sin_addr.s_addr = inet_addr(SSDP_TARGET); 805 sin = (struct sockaddr_in *) &rt.rt_genmask; 806 sin->sin_family = AF_INET; 807 sin->sin_port = 0; 808 sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK); 809 rt.rt_flags = RTF_UP; 810 if (ioctl(sock, SIOCADDRT, &rt) < 0) { 811 if (errno == EPERM) { 812 wpa_printf(MSG_DEBUG, "add_ssdp_network: No " 813 "permissions to add routing table entry"); 814 /* Continue to allow testing as non-root */ 815 } else if (errno != EEXIST) { 816 wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno " 817 "%d (%s)", errno, strerror(errno)); 818 goto fail; 819 } 820 } 821 822 ret = 0; 823 824 fail: 825 if (sock >= 0) 826 close(sock); 827 828 return ret; 829 } 830 831 832 /** 833 * ssdp_open_multicast - Open socket for sending multicast SSDP messages 834 * @sm: WPS UPnP state machine from upnp_wps_device_init() 835 * Returns: 0 on success, -1 on failure 836 */ 837 int ssdp_open_multicast(struct upnp_wps_device_sm *sm) 838 { 839 int sd = -1; 840 /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet 841 * time to live (TTL) small */ 842 unsigned char ttl = 4; 843 844 sm->multicast_sd = sd = socket(AF_INET, SOCK_DGRAM, 0); 845 if (sd < 0) 846 return -1; 847 848 #if 0 /* maybe ok if we sometimes block on writes */ 849 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) 850 return -1; 851 #endif 852 853 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF, 854 &sm->ip_addr, sizeof(sm->ip_addr))) 855 return -1; 856 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, 857 &ttl, sizeof(ttl))) 858 return -1; 859 860 #if 0 /* not needed, because we don't receive using multicast_sd */ 861 { 862 struct ip_mreq mreq; 863 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 864 mreq.imr_interface.s_addr = sm->ip_addr; 865 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr " 866 "0x%x", 867 mreq.imr_multiaddr.s_addr, 868 mreq.imr_interface.s_addr); 869 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, 870 sizeof(mreq))) { 871 wpa_printf(MSG_ERROR, 872 "WPS UPnP: setsockopt " 873 "IP_ADD_MEMBERSHIP errno %d (%s)", 874 errno, strerror(errno)); 875 return -1; 876 } 877 } 878 #endif /* not needed */ 879 880 /* 881 * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default? 882 * which aids debugging I suppose but isn't really necessary? 883 */ 884 885 return 0; 886 } 887