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 (at) 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 * @send_byebye: Send byebye advertisement messages immediately 233 */ 234 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm, 235 int send_byebye) 236 { 237 struct advertisement_state_machine *a = &sm->advertisement; 238 int islast = 0; 239 struct wpabuf *msg; 240 struct sockaddr_in dest; 241 242 eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm); 243 if (!send_byebye || sm->multicast_sd < 0) 244 return; 245 246 a->type = ADVERTISE_DOWN; 247 a->state = 0; 248 a->sm = sm; 249 250 os_memset(&dest, 0, sizeof(dest)); 251 dest.sin_family = AF_INET; 252 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 253 dest.sin_port = htons(UPNP_MULTICAST_PORT); 254 255 while (!islast) { 256 msg = next_advertisement(a, &islast); 257 if (msg == NULL) 258 break; 259 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 260 0, (struct sockaddr *) &dest, sizeof(dest)) < 0) { 261 wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto " 262 "failed: %d (%s)", errno, strerror(errno)); 263 } 264 wpabuf_free(msg); 265 a->state++; 266 } 267 } 268 269 270 static void advertisement_state_machine_handler(void *eloop_data, 271 void *user_ctx) 272 { 273 struct upnp_wps_device_sm *sm = user_ctx; 274 struct advertisement_state_machine *a = &sm->advertisement; 275 struct wpabuf *msg; 276 int next_timeout_msec = 100; 277 int next_timeout_sec = 0; 278 struct sockaddr_in dest; 279 int islast = 0; 280 281 /* 282 * Each is sent twice (in case lost) w/ 100 msec delay between; 283 * spec says no more than 3 times. 284 * One pair for rootdevice, one pair for uuid, and a pair each for 285 * each of the two urns. 286 * The entire sequence must be repeated before cache control timeout 287 * (which is min 1800 seconds), 288 * recommend random portion of half of the advertised cache control age 289 * to ensure against loss... perhaps 1800/4 + rand*1800/4 ? 290 * Delay random interval < 100 msec prior to initial sending. 291 * TTL of 4 292 */ 293 294 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state); 295 msg = next_advertisement(a, &islast); 296 if (msg == NULL) 297 return; 298 299 os_memset(&dest, 0, sizeof(dest)); 300 dest.sin_family = AF_INET; 301 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 302 dest.sin_port = htons(UPNP_MULTICAST_PORT); 303 304 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0, 305 (struct sockaddr *) &dest, sizeof(dest)) == -1) { 306 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:" 307 "%d (%s)", errno, strerror(errno)); 308 next_timeout_msec = 0; 309 next_timeout_sec = 10; /* ... later */ 310 } else if (islast) { 311 a->state = 0; /* wrap around */ 312 if (a->type == ADVERTISE_DOWN) { 313 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP"); 314 a->type = ADVERTISE_UP; 315 /* do it all over again right away */ 316 } else { 317 u16 r; 318 /* 319 * Start over again after a long timeout 320 * (see notes above) 321 */ 322 next_timeout_msec = 0; 323 os_get_random((void *) &r, sizeof(r)); 324 next_timeout_sec = UPNP_CACHE_SEC / 4 + 325 (((UPNP_CACHE_SEC / 4) * r) >> 16); 326 sm->advertise_count++; 327 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); " 328 "next in %d sec", 329 sm->advertise_count, next_timeout_sec); 330 } 331 } else { 332 a->state++; 333 } 334 335 wpabuf_free(msg); 336 337 eloop_register_timeout(next_timeout_sec, next_timeout_msec, 338 advertisement_state_machine_handler, NULL, sm); 339 } 340 341 342 /** 343 * advertisement_state_machine_start - Start SSDP advertisements 344 * @sm: WPS UPnP state machine from upnp_wps_device_init() 345 * Returns: 0 on success, -1 on failure 346 */ 347 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm) 348 { 349 struct advertisement_state_machine *a = &sm->advertisement; 350 int next_timeout_msec; 351 352 advertisement_state_machine_stop(sm, 0); 353 354 /* 355 * Start out advertising down, this automatically switches 356 * to advertising up which signals our restart. 357 */ 358 a->type = ADVERTISE_DOWN; 359 a->state = 0; 360 a->sm = sm; 361 /* (other fields not used here) */ 362 363 /* First timeout should be random interval < 100 msec */ 364 next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8; 365 return eloop_register_timeout(0, next_timeout_msec, 366 advertisement_state_machine_handler, 367 NULL, sm); 368 } 369 370 371 /*************************************************************************** 372 * M-SEARCH replies 373 * These are very similar to the multicast advertisements, with some 374 * small changes in data content; and they are sent (UDP) to a specific 375 * unicast address instead of multicast. 376 * They are sent in response to a UDP M-SEARCH packet. 377 **************************************************************************/ 378 379 static void msearchreply_state_machine_handler(void *eloop_data, 380 void *user_ctx); 381 382 383 /** 384 * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine 385 * @a: Selected advertisement/reply state 386 */ 387 void msearchreply_state_machine_stop(struct advertisement_state_machine *a) 388 { 389 struct upnp_wps_device_sm *sm = a->sm; 390 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop"); 391 if (a->next == a) { 392 sm->msearch_replies = NULL; 393 } else { 394 if (sm->msearch_replies == a) 395 sm->msearch_replies = a->next; 396 a->next->prev = a->prev; 397 a->prev->next = a->next; 398 } 399 os_free(a); 400 sm->n_msearch_replies--; 401 } 402 403 404 static void msearchreply_state_machine_handler(void *eloop_data, 405 void *user_ctx) 406 { 407 struct advertisement_state_machine *a = user_ctx; 408 struct upnp_wps_device_sm *sm = a->sm; 409 struct wpabuf *msg; 410 int next_timeout_msec = 100; 411 int next_timeout_sec = 0; 412 int islast = 0; 413 414 /* 415 * Each response is sent twice (in case lost) w/ 100 msec delay 416 * between; spec says no more than 3 times. 417 * One pair for rootdevice, one pair for uuid, and a pair each for 418 * each of the two urns. 419 */ 420 421 /* TODO: should only send the requested response types */ 422 423 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)", 424 a->state, inet_ntoa(a->client.sin_addr), 425 ntohs(a->client.sin_port)); 426 msg = next_advertisement(a, &islast); 427 if (msg == NULL) 428 return; 429 430 /* 431 * Send it on the multicast socket to avoid having to set up another 432 * socket. 433 */ 434 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0, 435 (struct sockaddr *) &a->client, sizeof(a->client)) < 0) { 436 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto " 437 "errno %d (%s) for %s:%d", 438 errno, strerror(errno), 439 inet_ntoa(a->client.sin_addr), 440 ntohs(a->client.sin_port)); 441 /* Ignore error and hope for the best */ 442 } 443 wpabuf_free(msg); 444 if (islast) { 445 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done"); 446 msearchreply_state_machine_stop(a); 447 return; 448 } 449 a->state++; 450 451 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec", 452 next_timeout_sec, next_timeout_msec); 453 eloop_register_timeout(next_timeout_sec, next_timeout_msec, 454 msearchreply_state_machine_handler, sm, a); 455 } 456 457 458 /** 459 * msearchreply_state_machine_start - Reply to M-SEARCH discovery request 460 * @sm: WPS UPnP state machine from upnp_wps_device_init() 461 * @client: Client address 462 * @mx: Maximum delay in seconds 463 * 464 * Use TTL of 4 (this was done when socket set up). 465 * A response should be given in randomized portion of min(MX,120) seconds 466 * 467 * UPnP-arch-DeviceArchitecture, 1.2.3: 468 * To be found, a device must send a UDP response to the source IP address and 469 * port that sent the request to the multicast channel. Devices respond if the 470 * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:" 471 * followed by a UUID that exactly matches one advertised by the device. 472 */ 473 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm, 474 struct sockaddr_in *client, 475 int mx) 476 { 477 struct advertisement_state_machine *a; 478 int next_timeout_sec; 479 int next_timeout_msec; 480 481 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d " 482 "outstanding)", sm->n_msearch_replies); 483 if (sm->n_msearch_replies >= MAX_MSEARCH) { 484 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding " 485 "M-SEARCH replies"); 486 return; 487 } 488 489 a = os_zalloc(sizeof(*a)); 490 if (a == NULL) 491 return; 492 a->type = MSEARCH_REPLY; 493 a->state = 0; 494 a->sm = sm; 495 os_memcpy(&a->client, client, sizeof(*client)); 496 /* Wait time depending on MX value */ 497 next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8; 498 next_timeout_sec = next_timeout_msec / 1000; 499 next_timeout_msec = next_timeout_msec % 1000; 500 if (eloop_register_timeout(next_timeout_sec, next_timeout_msec, 501 msearchreply_state_machine_handler, sm, 502 a)) { 503 /* No way to recover (from malloc failure) */ 504 goto fail; 505 } 506 /* Remember for future cleanup */ 507 if (sm->msearch_replies) { 508 a->next = sm->msearch_replies; 509 a->prev = a->next->prev; 510 a->prev->next = a; 511 a->next->prev = a; 512 } else { 513 sm->msearch_replies = a->next = a->prev = a; 514 } 515 sm->n_msearch_replies++; 516 return; 517 518 fail: 519 wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!"); 520 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a); 521 os_free(a); 522 } 523 524 525 /** 526 * ssdp_parse_msearch - Process a received M-SEARCH 527 * @sm: WPS UPnP state machine from upnp_wps_device_init() 528 * @client: Client address 529 * @data: NULL terminated M-SEARCH message 530 * 531 * Given that we have received a header w/ M-SEARCH, act upon it 532 * 533 * Format of M-SEARCH (case insensitive!): 534 * 535 * First line must be: 536 * M-SEARCH * HTTP/1.1 537 * Other lines in arbitrary order: 538 * HOST:239.255.255.250:1900 539 * ST:<varies -- must match> 540 * MAN:"ssdp:discover" 541 * MX:<varies> 542 * 543 * It should be noted that when Microsoft Vista is still learning its IP 544 * address, it sends out host lines like: HOST:[FF02::C]:1900 545 */ 546 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm, 547 struct sockaddr_in *client, const char *data) 548 { 549 const char *start = data; 550 const char *end; 551 int got_host = 0; 552 int got_st = 0, st_match = 0; 553 int got_man = 0; 554 int got_mx = 0; 555 int mx = 0; 556 557 /* 558 * Skip first line M-SEARCH * HTTP/1.1 559 * (perhaps we should check remainder of the line for syntax) 560 */ 561 data += line_length(data); 562 563 /* Parse remaining lines */ 564 for (; *data != '\0'; data += line_length(data)) { 565 end = data + line_length_stripped(data); 566 if (token_eq(data, "host")) { 567 /* The host line indicates who the packet 568 * is addressed to... but do we really care? 569 * Note that Microsoft sometimes does funny 570 * stuff with the HOST: line. 571 */ 572 #if 0 /* could be */ 573 data += token_length(data); 574 data += word_separation_length(data); 575 if (*data != ':') 576 goto bad; 577 data++; 578 data += word_separation_length(data); 579 /* UPNP_MULTICAST_ADDRESS */ 580 if (!str_starts(data, "239.255.255.250")) 581 goto bad; 582 data += os_strlen("239.255.255.250"); 583 if (*data == ':') { 584 if (!str_starts(data, ":1900")) 585 goto bad; 586 } 587 #endif /* could be */ 588 got_host = 1; 589 continue; 590 } else if (token_eq(data, "st")) { 591 /* There are a number of forms; we look 592 * for one that matches our case. 593 */ 594 got_st = 1; 595 data += token_length(data); 596 data += word_separation_length(data); 597 if (*data != ':') 598 continue; 599 data++; 600 data += word_separation_length(data); 601 if (str_starts(data, "ssdp:all")) { 602 st_match = 1; 603 continue; 604 } 605 if (str_starts(data, "upnp:rootdevice")) { 606 st_match = 1; 607 continue; 608 } 609 if (str_starts(data, "uuid:")) { 610 char uuid_string[80]; 611 data += os_strlen("uuid:"); 612 uuid_bin2str(sm->wps->uuid, uuid_string, 613 sizeof(uuid_string)); 614 if (str_starts(data, uuid_string)) 615 st_match = 1; 616 continue; 617 } 618 #if 0 619 /* FIX: should we really reply to IGD string? */ 620 if (str_starts(data, "urn:schemas-upnp-org:device:" 621 "InternetGatewayDevice:1")) { 622 st_match = 1; 623 continue; 624 } 625 #endif 626 if (str_starts(data, "urn:schemas-wifialliance-org:" 627 "service:WFAWLANConfig:1")) { 628 st_match = 1; 629 continue; 630 } 631 if (str_starts(data, "urn:schemas-wifialliance-org:" 632 "device:WFADevice:1")) { 633 st_match = 1; 634 continue; 635 } 636 continue; 637 } else if (token_eq(data, "man")) { 638 data += token_length(data); 639 data += word_separation_length(data); 640 if (*data != ':') 641 continue; 642 data++; 643 data += word_separation_length(data); 644 if (!str_starts(data, "\"ssdp:discover\"")) { 645 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected " 646 "M-SEARCH man-field"); 647 goto bad; 648 } 649 got_man = 1; 650 continue; 651 } else if (token_eq(data, "mx")) { 652 data += token_length(data); 653 data += word_separation_length(data); 654 if (*data != ':') 655 continue; 656 data++; 657 data += word_separation_length(data); 658 mx = atol(data); 659 got_mx = 1; 660 continue; 661 } 662 /* ignore anything else */ 663 } 664 if (!got_host || !got_st || !got_man || !got_mx || mx < 0) { 665 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d " 666 "%d mx=%d", got_host, got_st, got_man, got_mx, mx); 667 goto bad; 668 } 669 if (!st_match) { 670 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST " 671 "match)"); 672 return; 673 } 674 if (mx > 120) 675 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */ 676 msearchreply_state_machine_start(sm, client, mx); 677 return; 678 679 bad: 680 wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH"); 681 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start); 682 } 683 684 685 /* Listening for (UDP) discovery (M-SEARCH) packets */ 686 687 /** 688 * ssdp_listener_stop - Stop SSDP listered 689 * @sm: WPS UPnP state machine from upnp_wps_device_init() 690 * 691 * This function stops the SSDP listerner that was started by calling 692 * ssdp_listener_start(). 693 */ 694 void ssdp_listener_stop(struct upnp_wps_device_sm *sm) 695 { 696 if (sm->ssdp_sd_registered) { 697 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ); 698 sm->ssdp_sd_registered = 0; 699 } 700 701 if (sm->ssdp_sd != -1) { 702 close(sm->ssdp_sd); 703 sm->ssdp_sd = -1; 704 } 705 706 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, 707 ELOOP_ALL_CTX); 708 } 709 710 711 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx) 712 { 713 struct upnp_wps_device_sm *sm = sock_ctx; 714 struct sockaddr_in addr; /* client address */ 715 socklen_t addr_len; 716 int nread; 717 char buf[MULTICAST_MAX_READ], *pos; 718 719 addr_len = sizeof(addr); 720 nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0, 721 (struct sockaddr *) &addr, &addr_len); 722 if (nread <= 0) 723 return; 724 buf[nread] = '\0'; /* need null termination for algorithm */ 725 726 if (str_starts(buf, "NOTIFY ")) { 727 /* 728 * Silently ignore NOTIFYs to avoid filling debug log with 729 * unwanted messages. 730 */ 731 return; 732 } 733 734 pos = os_strchr(buf, '\n'); 735 if (pos) 736 *pos = '\0'; 737 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: " 738 "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf); 739 if (pos) 740 *pos = '\n'; 741 742 /* Parse first line */ 743 if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 && 744 !isgraph(buf[strlen("M-SEARCH")])) { 745 ssdp_parse_msearch(sm, &addr, buf); 746 return; 747 } 748 749 /* Ignore anything else */ 750 } 751 752 753 /** 754 * ssdp_listener_start - Set up for receiving discovery (UDP) packets 755 * @sm: WPS UPnP state machine from upnp_wps_device_init() 756 * Returns: 0 on success, -1 on failure 757 * 758 * The SSDP listerner is stopped by calling ssdp_listener_stop(). 759 */ 760 int ssdp_listener_start(struct upnp_wps_device_sm *sm) 761 { 762 int sd = -1; 763 struct sockaddr_in addr; 764 struct ip_mreq mcast_addr; 765 int on = 1; 766 /* per UPnP spec, keep IP packet time to live (TTL) small */ 767 unsigned char ttl = 4; 768 769 sm->ssdp_sd = sd = socket(AF_INET, SOCK_DGRAM, 0); 770 if (sd < 0) 771 goto fail; 772 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) 773 goto fail; 774 if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on))) 775 goto fail; 776 os_memset(&addr, 0, sizeof(addr)); 777 addr.sin_family = AF_INET; 778 addr.sin_addr.s_addr = htonl(INADDR_ANY); 779 addr.sin_port = htons(UPNP_MULTICAST_PORT); 780 if (bind(sd, (struct sockaddr *) &addr, sizeof(addr))) 781 goto fail; 782 os_memset(&mcast_addr, 0, sizeof(mcast_addr)); 783 mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY); 784 mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 785 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, 786 (char *) &mcast_addr, sizeof(mcast_addr))) 787 goto fail; 788 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, 789 &ttl, sizeof(ttl))) 790 goto fail; 791 if (eloop_register_sock(sd, EVENT_TYPE_READ, ssdp_listener_handler, 792 NULL, sm)) 793 goto fail; 794 sm->ssdp_sd_registered = 1; 795 return 0; 796 797 fail: 798 /* Error */ 799 wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed"); 800 ssdp_listener_stop(sm); 801 return -1; 802 } 803 804 805 /** 806 * add_ssdp_network - Add routing entry for SSDP 807 * @net_if: Selected network interface name 808 * Returns: 0 on success, -1 on failure 809 * 810 * This function assures that the multicast address will be properly 811 * handled by Linux networking code (by a modification to routing tables). 812 * This must be done per network interface. It really only needs to be done 813 * once after booting up, but it does not hurt to call this more frequently 814 * "to be safe". 815 */ 816 int add_ssdp_network(char *net_if) 817 { 818 #ifdef __linux__ 819 int ret = -1; 820 int sock = -1; 821 struct rtentry rt; 822 struct sockaddr_in *sin; 823 824 if (!net_if) 825 goto fail; 826 827 os_memset(&rt, 0, sizeof(rt)); 828 sock = socket(AF_INET, SOCK_DGRAM, 0); 829 if (sock < 0) 830 goto fail; 831 832 rt.rt_dev = net_if; 833 sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in); 834 sin->sin_family = AF_INET; 835 sin->sin_port = 0; 836 sin->sin_addr.s_addr = inet_addr(SSDP_TARGET); 837 sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in); 838 sin->sin_family = AF_INET; 839 sin->sin_port = 0; 840 sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK); 841 rt.rt_flags = RTF_UP; 842 if (ioctl(sock, SIOCADDRT, &rt) < 0) { 843 if (errno == EPERM) { 844 wpa_printf(MSG_DEBUG, "add_ssdp_network: No " 845 "permissions to add routing table entry"); 846 /* Continue to allow testing as non-root */ 847 } else if (errno != EEXIST) { 848 wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno " 849 "%d (%s)", errno, strerror(errno)); 850 goto fail; 851 } 852 } 853 854 ret = 0; 855 856 fail: 857 if (sock >= 0) 858 close(sock); 859 860 return ret; 861 #else /* __linux__ */ 862 return 0; 863 #endif /* __linux__ */ 864 } 865 866 867 /** 868 * ssdp_open_multicast - Open socket for sending multicast SSDP messages 869 * @sm: WPS UPnP state machine from upnp_wps_device_init() 870 * Returns: 0 on success, -1 on failure 871 */ 872 int ssdp_open_multicast(struct upnp_wps_device_sm *sm) 873 { 874 int sd = -1; 875 /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet 876 * time to live (TTL) small */ 877 unsigned char ttl = 4; 878 879 sm->multicast_sd = sd = socket(AF_INET, SOCK_DGRAM, 0); 880 if (sd < 0) 881 return -1; 882 883 #if 0 /* maybe ok if we sometimes block on writes */ 884 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) 885 return -1; 886 #endif 887 888 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF, 889 &sm->ip_addr, sizeof(sm->ip_addr))) 890 return -1; 891 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, 892 &ttl, sizeof(ttl))) 893 return -1; 894 895 #if 0 /* not needed, because we don't receive using multicast_sd */ 896 { 897 struct ip_mreq mreq; 898 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 899 mreq.imr_interface.s_addr = sm->ip_addr; 900 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr " 901 "0x%x", 902 mreq.imr_multiaddr.s_addr, 903 mreq.imr_interface.s_addr); 904 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, 905 sizeof(mreq))) { 906 wpa_printf(MSG_ERROR, 907 "WPS UPnP: setsockopt " 908 "IP_ADD_MEMBERSHIP errno %d (%s)", 909 errno, strerror(errno)); 910 return -1; 911 } 912 } 913 #endif /* not needed */ 914 915 /* 916 * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default? 917 * which aids debugging I suppose but isn't really necessary? 918 */ 919 920 return 0; 921 } 922
