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 MAX_MSEARCH 20 /* max simultaneous M-SEARCH replies ongoing */ 28 #define SSDP_TARGET "239.0.0.0" 29 #define SSDP_NETMASK "255.0.0.0" 30 31 32 /* Check tokens for equality, where tokens consist of letters, digits, 33 * underscore and hyphen, and are matched case insensitive. 34 */ 35 static int token_eq(const char *s1, const char *s2) 36 { 37 int c1; 38 int c2; 39 int end1 = 0; 40 int end2 = 0; 41 for (;;) { 42 c1 = *s1++; 43 c2 = *s2++; 44 if (isalpha(c1) && isupper(c1)) 45 c1 = tolower(c1); 46 if (isalpha(c2) && isupper(c2)) 47 c2 = tolower(c2); 48 end1 = !(isalnum(c1) || c1 == '_' || c1 == '-'); 49 end2 = !(isalnum(c2) || c2 == '_' || c2 == '-'); 50 if (end1 || end2 || c1 != c2) 51 break; 52 } 53 return end1 && end2; /* reached end of both words? */ 54 } 55 56 57 /* Return length of token (see above for definition of token) */ 58 static int token_length(const char *s) 59 { 60 const char *begin = s; 61 for (;; s++) { 62 int c = *s; 63 int end = !(isalnum(c) || c == '_' || c == '-'); 64 if (end) 65 break; 66 } 67 return s - begin; 68 } 69 70 71 /* return length of interword separation. 72 * This accepts only spaces/tabs and thus will not traverse a line 73 * or buffer ending. 74 */ 75 static int word_separation_length(const char *s) 76 { 77 const char *begin = s; 78 for (;; s++) { 79 int c = *s; 80 if (c == ' ' || c == '\t') 81 continue; 82 break; 83 } 84 return s - begin; 85 } 86 87 88 /* No. of chars through (including) end of line */ 89 static int line_length(const char *l) 90 { 91 const char *lp = l; 92 while (*lp && *lp != '\n') 93 lp++; 94 if (*lp == '\n') 95 lp++; 96 return lp - l; 97 } 98 99 100 /* No. of chars excluding trailing whitespace */ 101 static int line_length_stripped(const char *l) 102 { 103 const char *lp = l + line_length(l); 104 while (lp > l && !isgraph(lp[-1])) 105 lp--; 106 return lp - l; 107 } 108 109 110 static int str_starts(const char *str, const char *start) 111 { 112 return os_strncmp(str, start, os_strlen(start)) == 0; 113 } 114 115 116 /*************************************************************************** 117 * Advertisements. 118 * These are multicast to the world to tell them we are here. 119 * The individual packets are spread out in time to limit loss, 120 * and then after a much longer period of time the whole sequence 121 * is repeated again (for NOTIFYs only). 122 **************************************************************************/ 123 124 /** 125 * next_advertisement - Build next message and advance the state machine 126 * @a: Advertisement state 127 * @islast: Buffer for indicating whether this is the last message (= 1) 128 * Returns: The new message (caller is responsible for freeing this) 129 * 130 * Note: next_advertisement is shared code with msearchreply_* functions 131 */ 132 static struct wpabuf * 133 next_advertisement(struct upnp_wps_device_sm *sm, 134 struct advertisement_state_machine *a, int *islast) 135 { 136 struct wpabuf *msg; 137 char *NTString = ""; 138 char uuid_string[80]; 139 struct upnp_wps_device_interface *iface; 140 141 *islast = 0; 142 iface = dl_list_first(&sm->interfaces, 143 struct upnp_wps_device_interface, list); 144 uuid_bin2str(iface->wps->uuid, uuid_string, sizeof(uuid_string)); 145 msg = wpabuf_alloc(800); /* more than big enough */ 146 if (msg == NULL) 147 goto fail; 148 switch (a->type) { 149 case ADVERTISE_UP: 150 case ADVERTISE_DOWN: 151 NTString = "NT"; 152 wpabuf_put_str(msg, "NOTIFY * HTTP/1.1\r\n"); 153 wpabuf_printf(msg, "HOST: %s:%d\r\n", 154 UPNP_MULTICAST_ADDRESS, UPNP_MULTICAST_PORT); 155 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n", 156 UPNP_CACHE_SEC); 157 wpabuf_printf(msg, "NTS: %s\r\n", 158 (a->type == ADVERTISE_UP ? 159 "ssdp:alive" : "ssdp:byebye")); 160 break; 161 case MSEARCH_REPLY: 162 NTString = "ST"; 163 wpabuf_put_str(msg, "HTTP/1.1 200 OK\r\n"); 164 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n", 165 UPNP_CACHE_SEC); 166 167 wpabuf_put_str(msg, "DATE: "); 168 format_date(msg); 169 wpabuf_put_str(msg, "\r\n"); 170 171 wpabuf_put_str(msg, "EXT:\r\n"); 172 break; 173 } 174 175 if (a->type != ADVERTISE_DOWN) { 176 /* Where others may get our XML files from */ 177 wpabuf_printf(msg, "LOCATION: http://%s:%d/%s\r\n", 178 sm->ip_addr_text, sm->web_port, 179 UPNP_WPS_DEVICE_XML_FILE); 180 } 181 182 /* The SERVER line has three comma-separated fields: 183 * operating system / version 184 * upnp version 185 * software package / version 186 * However, only the UPnP version is really required, the 187 * others can be place holders... for security reasons 188 * it is better to NOT provide extra information. 189 */ 190 wpabuf_put_str(msg, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n"); 191 192 switch (a->state / UPNP_ADVERTISE_REPEAT) { 193 case 0: 194 wpabuf_printf(msg, "%s: upnp:rootdevice\r\n", NTString); 195 wpabuf_printf(msg, "USN: uuid:%s::upnp:rootdevice\r\n", 196 uuid_string); 197 break; 198 case 1: 199 wpabuf_printf(msg, "%s: uuid:%s\r\n", NTString, uuid_string); 200 wpabuf_printf(msg, "USN: uuid:%s\r\n", uuid_string); 201 break; 202 case 2: 203 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:device:" 204 "WFADevice:1\r\n", NTString); 205 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-" 206 "org:device:WFADevice:1\r\n", uuid_string); 207 break; 208 case 3: 209 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:service:" 210 "WFAWLANConfig:1\r\n", NTString); 211 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-" 212 "org:service:WFAWLANConfig:1\r\n", uuid_string); 213 break; 214 } 215 wpabuf_put_str(msg, "\r\n"); 216 217 if (a->state + 1 >= 4 * UPNP_ADVERTISE_REPEAT) 218 *islast = 1; 219 220 return msg; 221 222 fail: 223 wpabuf_free(msg); 224 return NULL; 225 } 226 227 228 static void advertisement_state_machine_handler(void *eloop_data, 229 void *user_ctx); 230 231 232 /** 233 * advertisement_state_machine_stop - Stop SSDP advertisements 234 * @sm: WPS UPnP state machine from upnp_wps_device_init() 235 * @send_byebye: Send byebye advertisement messages immediately 236 */ 237 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm, 238 int send_byebye) 239 { 240 struct advertisement_state_machine *a = &sm->advertisement; 241 int islast = 0; 242 struct wpabuf *msg; 243 struct sockaddr_in dest; 244 245 eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm); 246 if (!send_byebye || sm->multicast_sd < 0) 247 return; 248 249 a->type = ADVERTISE_DOWN; 250 a->state = 0; 251 252 os_memset(&dest, 0, sizeof(dest)); 253 dest.sin_family = AF_INET; 254 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 255 dest.sin_port = htons(UPNP_MULTICAST_PORT); 256 257 while (!islast) { 258 msg = next_advertisement(sm, a, &islast); 259 if (msg == NULL) 260 break; 261 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 262 0, (struct sockaddr *) &dest, sizeof(dest)) < 0) { 263 wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto " 264 "failed: %d (%s)", errno, strerror(errno)); 265 } 266 wpabuf_free(msg); 267 a->state++; 268 } 269 } 270 271 272 static void advertisement_state_machine_handler(void *eloop_data, 273 void *user_ctx) 274 { 275 struct upnp_wps_device_sm *sm = user_ctx; 276 struct advertisement_state_machine *a = &sm->advertisement; 277 struct wpabuf *msg; 278 int next_timeout_msec = 100; 279 int next_timeout_sec = 0; 280 struct sockaddr_in dest; 281 int islast = 0; 282 283 /* 284 * Each is sent twice (in case lost) w/ 100 msec delay between; 285 * spec says no more than 3 times. 286 * One pair for rootdevice, one pair for uuid, and a pair each for 287 * each of the two urns. 288 * The entire sequence must be repeated before cache control timeout 289 * (which is min 1800 seconds), 290 * recommend random portion of half of the advertised cache control age 291 * to ensure against loss... perhaps 1800/4 + rand*1800/4 ? 292 * Delay random interval < 100 msec prior to initial sending. 293 * TTL of 4 294 */ 295 296 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state); 297 msg = next_advertisement(sm, a, &islast); 298 if (msg == NULL) 299 return; 300 301 os_memset(&dest, 0, sizeof(dest)); 302 dest.sin_family = AF_INET; 303 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 304 dest.sin_port = htons(UPNP_MULTICAST_PORT); 305 306 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0, 307 (struct sockaddr *) &dest, sizeof(dest)) == -1) { 308 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:" 309 "%d (%s)", errno, strerror(errno)); 310 next_timeout_msec = 0; 311 next_timeout_sec = 10; /* ... later */ 312 } else if (islast) { 313 a->state = 0; /* wrap around */ 314 if (a->type == ADVERTISE_DOWN) { 315 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP"); 316 a->type = ADVERTISE_UP; 317 /* do it all over again right away */ 318 } else { 319 u16 r; 320 /* 321 * Start over again after a long timeout 322 * (see notes above) 323 */ 324 next_timeout_msec = 0; 325 os_get_random((void *) &r, sizeof(r)); 326 next_timeout_sec = UPNP_CACHE_SEC / 4 + 327 (((UPNP_CACHE_SEC / 4) * r) >> 16); 328 sm->advertise_count++; 329 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); " 330 "next in %d sec", 331 sm->advertise_count, next_timeout_sec); 332 } 333 } else { 334 a->state++; 335 } 336 337 wpabuf_free(msg); 338 339 eloop_register_timeout(next_timeout_sec, next_timeout_msec, 340 advertisement_state_machine_handler, NULL, sm); 341 } 342 343 344 /** 345 * advertisement_state_machine_start - Start SSDP advertisements 346 * @sm: WPS UPnP state machine from upnp_wps_device_init() 347 * Returns: 0 on success, -1 on failure 348 */ 349 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm) 350 { 351 struct advertisement_state_machine *a = &sm->advertisement; 352 int next_timeout_msec; 353 354 advertisement_state_machine_stop(sm, 0); 355 356 /* 357 * Start out advertising down, this automatically switches 358 * to advertising up which signals our restart. 359 */ 360 a->type = ADVERTISE_DOWN; 361 a->state = 0; 362 /* (other fields not used here) */ 363 364 /* First timeout should be random interval < 100 msec */ 365 next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8; 366 return eloop_register_timeout(0, next_timeout_msec, 367 advertisement_state_machine_handler, 368 NULL, sm); 369 } 370 371 372 /*************************************************************************** 373 * M-SEARCH replies 374 * These are very similar to the multicast advertisements, with some 375 * small changes in data content; and they are sent (UDP) to a specific 376 * unicast address instead of multicast. 377 * They are sent in response to a UDP M-SEARCH packet. 378 **************************************************************************/ 379 380 /** 381 * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine 382 * @a: Selected advertisement/reply state 383 */ 384 void msearchreply_state_machine_stop(struct advertisement_state_machine *a) 385 { 386 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop"); 387 dl_list_del(&a->list); 388 os_free(a); 389 } 390 391 392 static void msearchreply_state_machine_handler(void *eloop_data, 393 void *user_ctx) 394 { 395 struct advertisement_state_machine *a = user_ctx; 396 struct upnp_wps_device_sm *sm = eloop_data; 397 struct wpabuf *msg; 398 int next_timeout_msec = 100; 399 int next_timeout_sec = 0; 400 int islast = 0; 401 402 /* 403 * Each response is sent twice (in case lost) w/ 100 msec delay 404 * between; spec says no more than 3 times. 405 * One pair for rootdevice, one pair for uuid, and a pair each for 406 * each of the two urns. 407 */ 408 409 /* TODO: should only send the requested response types */ 410 411 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)", 412 a->state, inet_ntoa(a->client.sin_addr), 413 ntohs(a->client.sin_port)); 414 msg = next_advertisement(sm, a, &islast); 415 if (msg == NULL) 416 return; 417 418 /* 419 * Send it on the multicast socket to avoid having to set up another 420 * socket. 421 */ 422 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0, 423 (struct sockaddr *) &a->client, sizeof(a->client)) < 0) { 424 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto " 425 "errno %d (%s) for %s:%d", 426 errno, strerror(errno), 427 inet_ntoa(a->client.sin_addr), 428 ntohs(a->client.sin_port)); 429 /* Ignore error and hope for the best */ 430 } 431 wpabuf_free(msg); 432 if (islast) { 433 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done"); 434 msearchreply_state_machine_stop(a); 435 return; 436 } 437 a->state++; 438 439 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec", 440 next_timeout_sec, next_timeout_msec); 441 eloop_register_timeout(next_timeout_sec, next_timeout_msec, 442 msearchreply_state_machine_handler, sm, a); 443 } 444 445 446 /** 447 * msearchreply_state_machine_start - Reply to M-SEARCH discovery request 448 * @sm: WPS UPnP state machine from upnp_wps_device_init() 449 * @client: Client address 450 * @mx: Maximum delay in seconds 451 * 452 * Use TTL of 4 (this was done when socket set up). 453 * A response should be given in randomized portion of min(MX,120) seconds 454 * 455 * UPnP-arch-DeviceArchitecture, 1.2.3: 456 * To be found, a device must send a UDP response to the source IP address and 457 * port that sent the request to the multicast channel. Devices respond if the 458 * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:" 459 * followed by a UUID that exactly matches one advertised by the device. 460 */ 461 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm, 462 struct sockaddr_in *client, 463 int mx) 464 { 465 struct advertisement_state_machine *a; 466 int next_timeout_sec; 467 int next_timeout_msec; 468 int replies; 469 470 replies = dl_list_len(&sm->msearch_replies); 471 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d " 472 "outstanding)", replies); 473 if (replies >= MAX_MSEARCH) { 474 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding " 475 "M-SEARCH replies"); 476 return; 477 } 478 479 a = os_zalloc(sizeof(*a)); 480 if (a == NULL) 481 return; 482 a->type = MSEARCH_REPLY; 483 a->state = 0; 484 os_memcpy(&a->client, client, sizeof(*client)); 485 /* Wait time depending on MX value */ 486 next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8; 487 next_timeout_sec = next_timeout_msec / 1000; 488 next_timeout_msec = next_timeout_msec % 1000; 489 if (eloop_register_timeout(next_timeout_sec, next_timeout_msec, 490 msearchreply_state_machine_handler, sm, 491 a)) { 492 /* No way to recover (from malloc failure) */ 493 goto fail; 494 } 495 /* Remember for future cleanup */ 496 dl_list_add(&sm->msearch_replies, &a->list); 497 return; 498 499 fail: 500 wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!"); 501 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a); 502 os_free(a); 503 } 504 505 506 /** 507 * ssdp_parse_msearch - Process a received M-SEARCH 508 * @sm: WPS UPnP state machine from upnp_wps_device_init() 509 * @client: Client address 510 * @data: NULL terminated M-SEARCH message 511 * 512 * Given that we have received a header w/ M-SEARCH, act upon it 513 * 514 * Format of M-SEARCH (case insensitive!): 515 * 516 * First line must be: 517 * M-SEARCH * HTTP/1.1 518 * Other lines in arbitrary order: 519 * HOST:239.255.255.250:1900 520 * ST:<varies -- must match> 521 * MAN:"ssdp:discover" 522 * MX:<varies> 523 * 524 * It should be noted that when Microsoft Vista is still learning its IP 525 * address, it sends out host lines like: HOST:[FF02::C]:1900 526 */ 527 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm, 528 struct sockaddr_in *client, const char *data) 529 { 530 #ifndef CONFIG_NO_STDOUT_DEBUG 531 const char *start = data; 532 #endif /* CONFIG_NO_STDOUT_DEBUG */ 533 const char *end; 534 int got_host = 0; 535 int got_st = 0, st_match = 0; 536 int got_man = 0; 537 int got_mx = 0; 538 int mx = 0; 539 540 /* 541 * Skip first line M-SEARCH * HTTP/1.1 542 * (perhaps we should check remainder of the line for syntax) 543 */ 544 data += line_length(data); 545 546 /* Parse remaining lines */ 547 for (; *data != '\0'; data += line_length(data)) { 548 end = data + line_length_stripped(data); 549 if (token_eq(data, "host")) { 550 /* The host line indicates who the packet 551 * is addressed to... but do we really care? 552 * Note that Microsoft sometimes does funny 553 * stuff with the HOST: line. 554 */ 555 #if 0 /* could be */ 556 data += token_length(data); 557 data += word_separation_length(data); 558 if (*data != ':') 559 goto bad; 560 data++; 561 data += word_separation_length(data); 562 /* UPNP_MULTICAST_ADDRESS */ 563 if (!str_starts(data, "239.255.255.250")) 564 goto bad; 565 data += os_strlen("239.255.255.250"); 566 if (*data == ':') { 567 if (!str_starts(data, ":1900")) 568 goto bad; 569 } 570 #endif /* could be */ 571 got_host = 1; 572 continue; 573 } else if (token_eq(data, "st")) { 574 /* There are a number of forms; we look 575 * for one that matches our case. 576 */ 577 got_st = 1; 578 data += token_length(data); 579 data += word_separation_length(data); 580 if (*data != ':') 581 continue; 582 data++; 583 data += word_separation_length(data); 584 if (str_starts(data, "ssdp:all")) { 585 st_match = 1; 586 continue; 587 } 588 if (str_starts(data, "upnp:rootdevice")) { 589 st_match = 1; 590 continue; 591 } 592 if (str_starts(data, "uuid:")) { 593 char uuid_string[80]; 594 struct upnp_wps_device_interface *iface; 595 iface = dl_list_first( 596 &sm->interfaces, 597 struct upnp_wps_device_interface, 598 list); 599 data += os_strlen("uuid:"); 600 uuid_bin2str(iface->wps->uuid, uuid_string, 601 sizeof(uuid_string)); 602 if (str_starts(data, uuid_string)) 603 st_match = 1; 604 continue; 605 } 606 #if 0 607 /* FIX: should we really reply to IGD string? */ 608 if (str_starts(data, "urn:schemas-upnp-org:device:" 609 "InternetGatewayDevice:1")) { 610 st_match = 1; 611 continue; 612 } 613 #endif 614 if (str_starts(data, "urn:schemas-wifialliance-org:" 615 "service:WFAWLANConfig:1")) { 616 st_match = 1; 617 continue; 618 } 619 if (str_starts(data, "urn:schemas-wifialliance-org:" 620 "device:WFADevice:1")) { 621 st_match = 1; 622 continue; 623 } 624 continue; 625 } else if (token_eq(data, "man")) { 626 data += token_length(data); 627 data += word_separation_length(data); 628 if (*data != ':') 629 continue; 630 data++; 631 data += word_separation_length(data); 632 if (!str_starts(data, "\"ssdp:discover\"")) { 633 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected " 634 "M-SEARCH man-field"); 635 goto bad; 636 } 637 got_man = 1; 638 continue; 639 } else if (token_eq(data, "mx")) { 640 data += token_length(data); 641 data += word_separation_length(data); 642 if (*data != ':') 643 continue; 644 data++; 645 data += word_separation_length(data); 646 mx = atol(data); 647 got_mx = 1; 648 continue; 649 } 650 /* ignore anything else */ 651 } 652 if (!got_host || !got_st || !got_man || !got_mx || mx < 0) { 653 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d " 654 "%d mx=%d", got_host, got_st, got_man, got_mx, mx); 655 goto bad; 656 } 657 if (!st_match) { 658 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST " 659 "match)"); 660 return; 661 } 662 if (mx > 120) 663 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */ 664 msearchreply_state_machine_start(sm, client, mx); 665 return; 666 667 bad: 668 wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH"); 669 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start); 670 } 671 672 673 /* Listening for (UDP) discovery (M-SEARCH) packets */ 674 675 /** 676 * ssdp_listener_stop - Stop SSDP listered 677 * @sm: WPS UPnP state machine from upnp_wps_device_init() 678 * 679 * This function stops the SSDP listener that was started by calling 680 * ssdp_listener_start(). 681 */ 682 void ssdp_listener_stop(struct upnp_wps_device_sm *sm) 683 { 684 if (sm->ssdp_sd_registered) { 685 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ); 686 sm->ssdp_sd_registered = 0; 687 } 688 689 if (sm->ssdp_sd != -1) { 690 close(sm->ssdp_sd); 691 sm->ssdp_sd = -1; 692 } 693 694 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, 695 ELOOP_ALL_CTX); 696 } 697 698 699 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx) 700 { 701 struct upnp_wps_device_sm *sm = sock_ctx; 702 struct sockaddr_in addr; /* client address */ 703 socklen_t addr_len; 704 int nread; 705 char buf[MULTICAST_MAX_READ], *pos; 706 707 addr_len = sizeof(addr); 708 nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0, 709 (struct sockaddr *) &addr, &addr_len); 710 if (nread <= 0) 711 return; 712 buf[nread] = '\0'; /* need null termination for algorithm */ 713 714 if (str_starts(buf, "NOTIFY ")) { 715 /* 716 * Silently ignore NOTIFYs to avoid filling debug log with 717 * unwanted messages. 718 */ 719 return; 720 } 721 722 pos = os_strchr(buf, '\n'); 723 if (pos) 724 *pos = '\0'; 725 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: " 726 "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf); 727 if (pos) 728 *pos = '\n'; 729 730 /* Parse first line */ 731 if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 && 732 !isgraph(buf[strlen("M-SEARCH")])) { 733 ssdp_parse_msearch(sm, &addr, buf); 734 return; 735 } 736 737 /* Ignore anything else */ 738 } 739 740 741 int ssdp_listener_open(void) 742 { 743 struct sockaddr_in addr; 744 struct ip_mreq mcast_addr; 745 int on = 1; 746 /* per UPnP spec, keep IP packet time to live (TTL) small */ 747 unsigned char ttl = 4; 748 int sd; 749 750 sd = socket(AF_INET, SOCK_DGRAM, 0); 751 if (sd < 0) 752 goto fail; 753 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) 754 goto fail; 755 if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on))) 756 goto fail; 757 os_memset(&addr, 0, sizeof(addr)); 758 addr.sin_family = AF_INET; 759 addr.sin_addr.s_addr = htonl(INADDR_ANY); 760 addr.sin_port = htons(UPNP_MULTICAST_PORT); 761 if (bind(sd, (struct sockaddr *) &addr, sizeof(addr))) 762 goto fail; 763 os_memset(&mcast_addr, 0, sizeof(mcast_addr)); 764 mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY); 765 mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 766 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, 767 (char *) &mcast_addr, sizeof(mcast_addr))) 768 goto fail; 769 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, 770 &ttl, sizeof(ttl))) 771 goto fail; 772 773 return sd; 774 775 fail: 776 if (sd >= 0) 777 close(sd); 778 return -1; 779 } 780 781 782 /** 783 * ssdp_listener_start - Set up for receiving discovery (UDP) packets 784 * @sm: WPS UPnP state machine from upnp_wps_device_init() 785 * Returns: 0 on success, -1 on failure 786 * 787 * The SSDP listener is stopped by calling ssdp_listener_stop(). 788 */ 789 int ssdp_listener_start(struct upnp_wps_device_sm *sm) 790 { 791 sm->ssdp_sd = ssdp_listener_open(); 792 793 if (eloop_register_sock(sm->ssdp_sd, EVENT_TYPE_READ, 794 ssdp_listener_handler, NULL, sm)) 795 goto fail; 796 sm->ssdp_sd_registered = 1; 797 return 0; 798 799 fail: 800 /* Error */ 801 wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed"); 802 ssdp_listener_stop(sm); 803 return -1; 804 } 805 806 807 /** 808 * add_ssdp_network - Add routing entry for SSDP 809 * @net_if: Selected network interface name 810 * Returns: 0 on success, -1 on failure 811 * 812 * This function assures that the multicast address will be properly 813 * handled by Linux networking code (by a modification to routing tables). 814 * This must be done per network interface. It really only needs to be done 815 * once after booting up, but it does not hurt to call this more frequently 816 * "to be safe". 817 */ 818 int add_ssdp_network(const char *net_if) 819 { 820 #ifdef __linux__ 821 int ret = -1; 822 int sock = -1; 823 struct rtentry rt; 824 struct sockaddr_in *sin; 825 826 if (!net_if) 827 goto fail; 828 829 os_memset(&rt, 0, sizeof(rt)); 830 sock = socket(AF_INET, SOCK_DGRAM, 0); 831 if (sock < 0) 832 goto fail; 833 834 rt.rt_dev = (char *) net_if; 835 sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in); 836 sin->sin_family = AF_INET; 837 sin->sin_port = 0; 838 sin->sin_addr.s_addr = inet_addr(SSDP_TARGET); 839 sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in); 840 sin->sin_family = AF_INET; 841 sin->sin_port = 0; 842 sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK); 843 rt.rt_flags = RTF_UP; 844 if (ioctl(sock, SIOCADDRT, &rt) < 0) { 845 if (errno == EPERM) { 846 wpa_printf(MSG_DEBUG, "add_ssdp_network: No " 847 "permissions to add routing table entry"); 848 /* Continue to allow testing as non-root */ 849 } else if (errno != EEXIST) { 850 wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno " 851 "%d (%s)", errno, strerror(errno)); 852 goto fail; 853 } 854 } 855 856 ret = 0; 857 858 fail: 859 if (sock >= 0) 860 close(sock); 861 862 return ret; 863 #else /* __linux__ */ 864 return 0; 865 #endif /* __linux__ */ 866 } 867 868 869 int ssdp_open_multicast_sock(u32 ip_addr) 870 { 871 int sd; 872 /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet 873 * time to live (TTL) small */ 874 unsigned char ttl = 4; 875 876 sd = socket(AF_INET, SOCK_DGRAM, 0); 877 if (sd < 0) 878 return -1; 879 880 #if 0 /* maybe ok if we sometimes block on writes */ 881 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) 882 return -1; 883 #endif 884 885 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF, 886 &ip_addr, sizeof(ip_addr))) { 887 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_IF) %x: " 888 "%d (%s)", ip_addr, errno, strerror(errno)); 889 return -1; 890 } 891 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, 892 &ttl, sizeof(ttl))) { 893 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_TTL): " 894 "%d (%s)", errno, strerror(errno)); 895 return -1; 896 } 897 898 #if 0 /* not needed, because we don't receive using multicast_sd */ 899 { 900 struct ip_mreq mreq; 901 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 902 mreq.imr_interface.s_addr = ip_addr; 903 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr " 904 "0x%x", 905 mreq.imr_multiaddr.s_addr, 906 mreq.imr_interface.s_addr); 907 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, 908 sizeof(mreq))) { 909 wpa_printf(MSG_ERROR, 910 "WPS UPnP: setsockopt " 911 "IP_ADD_MEMBERSHIP errno %d (%s)", 912 errno, strerror(errno)); 913 return -1; 914 } 915 } 916 #endif /* not needed */ 917 918 /* 919 * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default? 920 * which aids debugging I suppose but isn't really necessary? 921 */ 922 923 return sd; 924 } 925 926 927 /** 928 * ssdp_open_multicast - Open socket for sending multicast SSDP messages 929 * @sm: WPS UPnP state machine from upnp_wps_device_init() 930 * Returns: 0 on success, -1 on failure 931 */ 932 int ssdp_open_multicast(struct upnp_wps_device_sm *sm) 933 { 934 sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr); 935 if (sm->multicast_sd < 0) 936 return -1; 937 return 0; 938 } 939
