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) 2009-2013, 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 #ifdef __linux__ 17 #include <net/if.h> 18 #endif /* __linux__ */ 19 20 #include "common.h" 21 #include "uuid.h" 22 #include "eloop.h" 23 #include "wps.h" 24 #include "wps_upnp.h" 25 #include "wps_upnp_i.h" 26 27 #define UPNP_CACHE_SEC (UPNP_CACHE_SEC_MIN + 1) /* cache time we use */ 28 #define UPNP_CACHE_SEC_MIN 1800 /* min cachable time per UPnP standard */ 29 #define UPNP_ADVERTISE_REPEAT 2 /* no more than 3 */ 30 #define MAX_MSEARCH 20 /* max simultaneous M-SEARCH replies ongoing */ 31 #define SSDP_TARGET "239.0.0.0" 32 #define SSDP_NETMASK "255.0.0.0" 33 34 35 /* Check tokens for equality, where tokens consist of letters, digits, 36 * underscore and hyphen, and are matched case insensitive. 37 */ 38 static int token_eq(const char *s1, const char *s2) 39 { 40 int c1; 41 int c2; 42 int end1 = 0; 43 int end2 = 0; 44 for (;;) { 45 c1 = *s1++; 46 c2 = *s2++; 47 if (isalpha(c1) && isupper(c1)) 48 c1 = tolower(c1); 49 if (isalpha(c2) && isupper(c2)) 50 c2 = tolower(c2); 51 end1 = !(isalnum(c1) || c1 == '_' || c1 == '-'); 52 end2 = !(isalnum(c2) || c2 == '_' || c2 == '-'); 53 if (end1 || end2 || c1 != c2) 54 break; 55 } 56 return end1 && end2; /* reached end of both words? */ 57 } 58 59 60 /* Return length of token (see above for definition of token) */ 61 static int token_length(const char *s) 62 { 63 const char *begin = s; 64 for (;; s++) { 65 int c = *s; 66 int end = !(isalnum(c) || c == '_' || c == '-'); 67 if (end) 68 break; 69 } 70 return s - begin; 71 } 72 73 74 /* return length of interword separation. 75 * This accepts only spaces/tabs and thus will not traverse a line 76 * or buffer ending. 77 */ 78 static int word_separation_length(const char *s) 79 { 80 const char *begin = s; 81 for (;; s++) { 82 int c = *s; 83 if (c == ' ' || c == '\t') 84 continue; 85 break; 86 } 87 return s - begin; 88 } 89 90 91 /* No. of chars through (including) end of line */ 92 static int line_length(const char *l) 93 { 94 const char *lp = l; 95 while (*lp && *lp != '\n') 96 lp++; 97 if (*lp == '\n') 98 lp++; 99 return lp - l; 100 } 101 102 103 static int str_starts(const char *str, const char *start) 104 { 105 return os_strncmp(str, start, os_strlen(start)) == 0; 106 } 107 108 109 /*************************************************************************** 110 * Advertisements. 111 * These are multicast to the world to tell them we are here. 112 * The individual packets are spread out in time to limit loss, 113 * and then after a much longer period of time the whole sequence 114 * is repeated again (for NOTIFYs only). 115 **************************************************************************/ 116 117 /** 118 * next_advertisement - Build next message and advance the state machine 119 * @a: Advertisement state 120 * @islast: Buffer for indicating whether this is the last message (= 1) 121 * Returns: The new message (caller is responsible for freeing this) 122 * 123 * Note: next_advertisement is shared code with msearchreply_* functions 124 */ 125 static struct wpabuf * 126 next_advertisement(struct upnp_wps_device_sm *sm, 127 struct advertisement_state_machine *a, int *islast) 128 { 129 struct wpabuf *msg; 130 char *NTString = ""; 131 char uuid_string[80]; 132 struct upnp_wps_device_interface *iface; 133 134 *islast = 0; 135 iface = dl_list_first(&sm->interfaces, 136 struct upnp_wps_device_interface, list); 137 if (!iface) 138 return NULL; 139 uuid_bin2str(iface->wps->uuid, uuid_string, sizeof(uuid_string)); 140 msg = wpabuf_alloc(800); /* more than big enough */ 141 if (msg == NULL) 142 return NULL; 143 switch (a->type) { 144 case ADVERTISE_UP: 145 case ADVERTISE_DOWN: 146 NTString = "NT"; 147 wpabuf_put_str(msg, "NOTIFY * HTTP/1.1\r\n"); 148 wpabuf_printf(msg, "HOST: %s:%d\r\n", 149 UPNP_MULTICAST_ADDRESS, UPNP_MULTICAST_PORT); 150 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n", 151 UPNP_CACHE_SEC); 152 wpabuf_printf(msg, "NTS: %s\r\n", 153 (a->type == ADVERTISE_UP ? 154 "ssdp:alive" : "ssdp:byebye")); 155 break; 156 case MSEARCH_REPLY: 157 NTString = "ST"; 158 wpabuf_put_str(msg, "HTTP/1.1 200 OK\r\n"); 159 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n", 160 UPNP_CACHE_SEC); 161 162 wpabuf_put_str(msg, "DATE: "); 163 format_date(msg); 164 wpabuf_put_str(msg, "\r\n"); 165 166 wpabuf_put_str(msg, "EXT:\r\n"); 167 break; 168 } 169 170 if (a->type != ADVERTISE_DOWN) { 171 /* Where others may get our XML files from */ 172 wpabuf_printf(msg, "LOCATION: http://%s:%d/%s\r\n", 173 sm->ip_addr_text, sm->web_port, 174 UPNP_WPS_DEVICE_XML_FILE); 175 } 176 177 /* The SERVER line has three comma-separated fields: 178 * operating system / version 179 * upnp version 180 * software package / version 181 * However, only the UPnP version is really required, the 182 * others can be place holders... for security reasons 183 * it is better to NOT provide extra information. 184 */ 185 wpabuf_put_str(msg, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n"); 186 187 switch (a->state / UPNP_ADVERTISE_REPEAT) { 188 case 0: 189 wpabuf_printf(msg, "%s: upnp:rootdevice\r\n", NTString); 190 wpabuf_printf(msg, "USN: uuid:%s::upnp:rootdevice\r\n", 191 uuid_string); 192 break; 193 case 1: 194 wpabuf_printf(msg, "%s: uuid:%s\r\n", NTString, uuid_string); 195 wpabuf_printf(msg, "USN: uuid:%s\r\n", uuid_string); 196 break; 197 case 2: 198 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:device:" 199 "WFADevice:1\r\n", NTString); 200 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-" 201 "org:device:WFADevice:1\r\n", uuid_string); 202 break; 203 case 3: 204 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:service:" 205 "WFAWLANConfig:1\r\n", NTString); 206 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-" 207 "org:service:WFAWLANConfig:1\r\n", uuid_string); 208 break; 209 } 210 wpabuf_put_str(msg, "\r\n"); 211 212 if (a->state + 1 >= 4 * UPNP_ADVERTISE_REPEAT) 213 *islast = 1; 214 215 return msg; 216 } 217 218 219 static void advertisement_state_machine_handler(void *eloop_data, 220 void *user_ctx); 221 222 223 /** 224 * advertisement_state_machine_stop - Stop SSDP advertisements 225 * @sm: WPS UPnP state machine from upnp_wps_device_init() 226 * @send_byebye: Send byebye advertisement messages immediately 227 */ 228 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm, 229 int send_byebye) 230 { 231 struct advertisement_state_machine *a = &sm->advertisement; 232 int islast = 0; 233 struct wpabuf *msg; 234 struct sockaddr_in dest; 235 236 eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm); 237 if (!send_byebye || sm->multicast_sd < 0) 238 return; 239 240 a->type = ADVERTISE_DOWN; 241 a->state = 0; 242 243 os_memset(&dest, 0, sizeof(dest)); 244 dest.sin_family = AF_INET; 245 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 246 dest.sin_port = htons(UPNP_MULTICAST_PORT); 247 248 while (!islast) { 249 msg = next_advertisement(sm, a, &islast); 250 if (msg == NULL) 251 break; 252 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 253 0, (struct sockaddr *) &dest, sizeof(dest)) < 0) { 254 wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto " 255 "failed: %d (%s)", errno, strerror(errno)); 256 } 257 wpabuf_free(msg); 258 a->state++; 259 } 260 } 261 262 263 static void advertisement_state_machine_handler(void *eloop_data, 264 void *user_ctx) 265 { 266 struct upnp_wps_device_sm *sm = user_ctx; 267 struct advertisement_state_machine *a = &sm->advertisement; 268 struct wpabuf *msg; 269 int next_timeout_msec = 100; 270 int next_timeout_sec = 0; 271 struct sockaddr_in dest; 272 int islast = 0; 273 274 /* 275 * Each is sent twice (in case lost) w/ 100 msec delay between; 276 * spec says no more than 3 times. 277 * One pair for rootdevice, one pair for uuid, and a pair each for 278 * each of the two urns. 279 * The entire sequence must be repeated before cache control timeout 280 * (which is min 1800 seconds), 281 * recommend random portion of half of the advertised cache control age 282 * to ensure against loss... perhaps 1800/4 + rand*1800/4 ? 283 * Delay random interval < 100 msec prior to initial sending. 284 * TTL of 4 285 */ 286 287 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state); 288 msg = next_advertisement(sm, a, &islast); 289 if (msg == NULL) 290 return; 291 292 os_memset(&dest, 0, sizeof(dest)); 293 dest.sin_family = AF_INET; 294 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 295 dest.sin_port = htons(UPNP_MULTICAST_PORT); 296 297 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0, 298 (struct sockaddr *) &dest, sizeof(dest)) == -1) { 299 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:" 300 "%d (%s)", errno, strerror(errno)); 301 next_timeout_msec = 0; 302 next_timeout_sec = 10; /* ... later */ 303 } else if (islast) { 304 a->state = 0; /* wrap around */ 305 if (a->type == ADVERTISE_DOWN) { 306 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP"); 307 a->type = ADVERTISE_UP; 308 /* do it all over again right away */ 309 } else { 310 u16 r; 311 /* 312 * Start over again after a long timeout 313 * (see notes above) 314 */ 315 next_timeout_msec = 0; 316 if (os_get_random((void *) &r, sizeof(r)) < 0) 317 r = 32768; 318 next_timeout_sec = UPNP_CACHE_SEC / 4 + 319 (((UPNP_CACHE_SEC / 4) * r) >> 16); 320 sm->advertise_count++; 321 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); " 322 "next in %d sec", 323 sm->advertise_count, next_timeout_sec); 324 } 325 } else { 326 a->state++; 327 } 328 329 wpabuf_free(msg); 330 331 eloop_register_timeout(next_timeout_sec, next_timeout_msec, 332 advertisement_state_machine_handler, NULL, sm); 333 } 334 335 336 /** 337 * advertisement_state_machine_start - Start SSDP advertisements 338 * @sm: WPS UPnP state machine from upnp_wps_device_init() 339 * Returns: 0 on success, -1 on failure 340 */ 341 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm) 342 { 343 struct advertisement_state_machine *a = &sm->advertisement; 344 int next_timeout_msec; 345 346 advertisement_state_machine_stop(sm, 0); 347 348 /* 349 * Start out advertising down, this automatically switches 350 * to advertising up which signals our restart. 351 */ 352 a->type = ADVERTISE_DOWN; 353 a->state = 0; 354 /* (other fields not used here) */ 355 356 /* First timeout should be random interval < 100 msec */ 357 next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8; 358 return eloop_register_timeout(0, next_timeout_msec, 359 advertisement_state_machine_handler, 360 NULL, sm); 361 } 362 363 364 /*************************************************************************** 365 * M-SEARCH replies 366 * These are very similar to the multicast advertisements, with some 367 * small changes in data content; and they are sent (UDP) to a specific 368 * unicast address instead of multicast. 369 * They are sent in response to a UDP M-SEARCH packet. 370 **************************************************************************/ 371 372 /** 373 * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine 374 * @a: Selected advertisement/reply state 375 */ 376 void msearchreply_state_machine_stop(struct advertisement_state_machine *a) 377 { 378 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop"); 379 dl_list_del(&a->list); 380 os_free(a); 381 } 382 383 384 static void msearchreply_state_machine_handler(void *eloop_data, 385 void *user_ctx) 386 { 387 struct advertisement_state_machine *a = user_ctx; 388 struct upnp_wps_device_sm *sm = eloop_data; 389 struct wpabuf *msg; 390 int next_timeout_msec = 100; 391 int next_timeout_sec = 0; 392 int islast = 0; 393 394 /* 395 * Each response is sent twice (in case lost) w/ 100 msec delay 396 * between; spec says no more than 3 times. 397 * One pair for rootdevice, one pair for uuid, and a pair each for 398 * each of the two urns. 399 */ 400 401 /* TODO: should only send the requested response types */ 402 403 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)", 404 a->state, inet_ntoa(a->client.sin_addr), 405 ntohs(a->client.sin_port)); 406 msg = next_advertisement(sm, a, &islast); 407 if (msg == NULL) 408 return; 409 410 /* 411 * Send it on the multicast socket to avoid having to set up another 412 * socket. 413 */ 414 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0, 415 (struct sockaddr *) &a->client, sizeof(a->client)) < 0) { 416 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto " 417 "errno %d (%s) for %s:%d", 418 errno, strerror(errno), 419 inet_ntoa(a->client.sin_addr), 420 ntohs(a->client.sin_port)); 421 /* Ignore error and hope for the best */ 422 } 423 wpabuf_free(msg); 424 if (islast) { 425 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done"); 426 msearchreply_state_machine_stop(a); 427 return; 428 } 429 a->state++; 430 431 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec", 432 next_timeout_sec, next_timeout_msec); 433 eloop_register_timeout(next_timeout_sec, next_timeout_msec, 434 msearchreply_state_machine_handler, sm, a); 435 } 436 437 438 /** 439 * msearchreply_state_machine_start - Reply to M-SEARCH discovery request 440 * @sm: WPS UPnP state machine from upnp_wps_device_init() 441 * @client: Client address 442 * @mx: Maximum delay in seconds 443 * 444 * Use TTL of 4 (this was done when socket set up). 445 * A response should be given in randomized portion of min(MX,120) seconds 446 * 447 * UPnP-arch-DeviceArchitecture, 1.2.3: 448 * To be found, a device must send a UDP response to the source IP address and 449 * port that sent the request to the multicast channel. Devices respond if the 450 * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:" 451 * followed by a UUID that exactly matches one advertised by the device. 452 */ 453 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm, 454 struct sockaddr_in *client, 455 int mx) 456 { 457 struct advertisement_state_machine *a; 458 int next_timeout_sec; 459 int next_timeout_msec; 460 int replies; 461 462 replies = dl_list_len(&sm->msearch_replies); 463 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d " 464 "outstanding)", replies); 465 if (replies >= MAX_MSEARCH) { 466 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding " 467 "M-SEARCH replies"); 468 return; 469 } 470 471 a = os_zalloc(sizeof(*a)); 472 if (a == NULL) 473 return; 474 a->type = MSEARCH_REPLY; 475 a->state = 0; 476 os_memcpy(&a->client, client, sizeof(*client)); 477 /* Wait time depending on MX value */ 478 next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8; 479 next_timeout_sec = next_timeout_msec / 1000; 480 next_timeout_msec = next_timeout_msec % 1000; 481 if (eloop_register_timeout(next_timeout_sec, next_timeout_msec, 482 msearchreply_state_machine_handler, sm, 483 a)) { 484 /* No way to recover (from malloc failure) */ 485 goto fail; 486 } 487 /* Remember for future cleanup */ 488 dl_list_add(&sm->msearch_replies, &a->list); 489 return; 490 491 fail: 492 wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!"); 493 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a); 494 os_free(a); 495 } 496 497 498 /** 499 * ssdp_parse_msearch - Process a received M-SEARCH 500 * @sm: WPS UPnP state machine from upnp_wps_device_init() 501 * @client: Client address 502 * @data: NULL terminated M-SEARCH message 503 * 504 * Given that we have received a header w/ M-SEARCH, act upon it 505 * 506 * Format of M-SEARCH (case insensitive!): 507 * 508 * First line must be: 509 * M-SEARCH * HTTP/1.1 510 * Other lines in arbitrary order: 511 * HOST:239.255.255.250:1900 512 * ST:<varies -- must match> 513 * MAN:"ssdp:discover" 514 * MX:<varies> 515 * 516 * It should be noted that when Microsoft Vista is still learning its IP 517 * address, it sends out host lines like: HOST:[FF02::C]:1900 518 */ 519 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm, 520 struct sockaddr_in *client, const char *data) 521 { 522 #ifndef CONFIG_NO_STDOUT_DEBUG 523 const char *start = data; 524 #endif /* CONFIG_NO_STDOUT_DEBUG */ 525 int got_host = 0; 526 int got_st = 0, st_match = 0; 527 int got_man = 0; 528 int got_mx = 0; 529 int mx = 0; 530 531 /* 532 * Skip first line M-SEARCH * HTTP/1.1 533 * (perhaps we should check remainder of the line for syntax) 534 */ 535 data += line_length(data); 536 537 /* Parse remaining lines */ 538 for (; *data != '\0'; data += line_length(data)) { 539 if (token_eq(data, "host")) { 540 /* The host line indicates who the packet 541 * is addressed to... but do we really care? 542 * Note that Microsoft sometimes does funny 543 * stuff with the HOST: line. 544 */ 545 #if 0 /* could be */ 546 data += token_length(data); 547 data += word_separation_length(data); 548 if (*data != ':') 549 goto bad; 550 data++; 551 data += word_separation_length(data); 552 /* UPNP_MULTICAST_ADDRESS */ 553 if (!str_starts(data, "239.255.255.250")) 554 goto bad; 555 data += os_strlen("239.255.255.250"); 556 if (*data == ':') { 557 if (!str_starts(data, ":1900")) 558 goto bad; 559 } 560 #endif /* could be */ 561 got_host = 1; 562 continue; 563 } else if (token_eq(data, "st")) { 564 /* There are a number of forms; we look 565 * for one that matches our case. 566 */ 567 got_st = 1; 568 data += token_length(data); 569 data += word_separation_length(data); 570 if (*data != ':') 571 continue; 572 data++; 573 data += word_separation_length(data); 574 if (str_starts(data, "ssdp:all")) { 575 st_match = 1; 576 continue; 577 } 578 if (str_starts(data, "upnp:rootdevice")) { 579 st_match = 1; 580 continue; 581 } 582 if (str_starts(data, "uuid:")) { 583 char uuid_string[80]; 584 struct upnp_wps_device_interface *iface; 585 iface = dl_list_first( 586 &sm->interfaces, 587 struct upnp_wps_device_interface, 588 list); 589 if (!iface) 590 continue; 591 data += os_strlen("uuid:"); 592 uuid_bin2str(iface->wps->uuid, uuid_string, 593 sizeof(uuid_string)); 594 if (str_starts(data, uuid_string)) 595 st_match = 1; 596 continue; 597 } 598 #if 0 599 /* FIX: should we really reply to IGD string? */ 600 if (str_starts(data, "urn:schemas-upnp-org:device:" 601 "InternetGatewayDevice:1")) { 602 st_match = 1; 603 continue; 604 } 605 #endif 606 if (str_starts(data, "urn:schemas-wifialliance-org:" 607 "service:WFAWLANConfig:1")) { 608 st_match = 1; 609 continue; 610 } 611 if (str_starts(data, "urn:schemas-wifialliance-org:" 612 "device:WFADevice:1")) { 613 st_match = 1; 614 continue; 615 } 616 continue; 617 } else if (token_eq(data, "man")) { 618 data += token_length(data); 619 data += word_separation_length(data); 620 if (*data != ':') 621 continue; 622 data++; 623 data += word_separation_length(data); 624 if (!str_starts(data, "\"ssdp:discover\"")) { 625 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected " 626 "M-SEARCH man-field"); 627 goto bad; 628 } 629 got_man = 1; 630 continue; 631 } else if (token_eq(data, "mx")) { 632 data += token_length(data); 633 data += word_separation_length(data); 634 if (*data != ':') 635 continue; 636 data++; 637 data += word_separation_length(data); 638 mx = atol(data); 639 got_mx = 1; 640 continue; 641 } 642 /* ignore anything else */ 643 } 644 if (!got_host || !got_st || !got_man || !got_mx || mx < 0) { 645 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d " 646 "%d mx=%d", got_host, got_st, got_man, got_mx, mx); 647 goto bad; 648 } 649 if (!st_match) { 650 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST " 651 "match)"); 652 return; 653 } 654 if (mx > 120) 655 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */ 656 msearchreply_state_machine_start(sm, client, mx); 657 return; 658 659 bad: 660 wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH"); 661 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start); 662 } 663 664 665 /* Listening for (UDP) discovery (M-SEARCH) packets */ 666 667 /** 668 * ssdp_listener_stop - Stop SSDP listered 669 * @sm: WPS UPnP state machine from upnp_wps_device_init() 670 * 671 * This function stops the SSDP listener that was started by calling 672 * ssdp_listener_start(). 673 */ 674 void ssdp_listener_stop(struct upnp_wps_device_sm *sm) 675 { 676 if (sm->ssdp_sd_registered) { 677 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ); 678 sm->ssdp_sd_registered = 0; 679 } 680 681 if (sm->ssdp_sd != -1) { 682 close(sm->ssdp_sd); 683 sm->ssdp_sd = -1; 684 } 685 686 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, 687 ELOOP_ALL_CTX); 688 } 689 690 691 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx) 692 { 693 struct upnp_wps_device_sm *sm = sock_ctx; 694 struct sockaddr_in addr; /* client address */ 695 socklen_t addr_len; 696 int nread; 697 char buf[MULTICAST_MAX_READ], *pos; 698 699 addr_len = sizeof(addr); 700 nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0, 701 (struct sockaddr *) &addr, &addr_len); 702 if (nread <= 0) 703 return; 704 buf[nread] = '\0'; /* need null termination for algorithm */ 705 706 if (str_starts(buf, "NOTIFY ")) { 707 /* 708 * Silently ignore NOTIFYs to avoid filling debug log with 709 * unwanted messages. 710 */ 711 return; 712 } 713 714 pos = os_strchr(buf, '\n'); 715 if (pos) 716 *pos = '\0'; 717 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: " 718 "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf); 719 if (pos) 720 *pos = '\n'; 721 722 /* Parse first line */ 723 if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 && 724 !isgraph(buf[strlen("M-SEARCH")])) { 725 ssdp_parse_msearch(sm, &addr, buf); 726 return; 727 } 728 729 /* Ignore anything else */ 730 } 731 732 733 int ssdp_listener_open(void) 734 { 735 struct sockaddr_in addr; 736 struct ip_mreq mcast_addr; 737 int on = 1; 738 /* per UPnP spec, keep IP packet time to live (TTL) small */ 739 unsigned char ttl = 4; 740 int sd; 741 742 sd = socket(AF_INET, SOCK_DGRAM, 0); 743 if (sd < 0 || 744 fcntl(sd, F_SETFL, O_NONBLOCK) != 0 || 745 setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on))) 746 goto fail; 747 os_memset(&addr, 0, sizeof(addr)); 748 addr.sin_family = AF_INET; 749 addr.sin_addr.s_addr = htonl(INADDR_ANY); 750 addr.sin_port = htons(UPNP_MULTICAST_PORT); 751 if (bind(sd, (struct sockaddr *) &addr, sizeof(addr))) 752 goto fail; 753 os_memset(&mcast_addr, 0, sizeof(mcast_addr)); 754 mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY); 755 mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 756 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, 757 (char *) &mcast_addr, sizeof(mcast_addr)) || 758 setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, 759 &ttl, sizeof(ttl))) 760 goto fail; 761 762 return sd; 763 764 fail: 765 if (sd >= 0) 766 close(sd); 767 return -1; 768 } 769 770 771 /** 772 * ssdp_listener_start - Set up for receiving discovery (UDP) packets 773 * @sm: WPS UPnP state machine from upnp_wps_device_init() 774 * Returns: 0 on success, -1 on failure 775 * 776 * The SSDP listener is stopped by calling ssdp_listener_stop(). 777 */ 778 int ssdp_listener_start(struct upnp_wps_device_sm *sm) 779 { 780 sm->ssdp_sd = ssdp_listener_open(); 781 782 if (eloop_register_sock(sm->ssdp_sd, EVENT_TYPE_READ, 783 ssdp_listener_handler, NULL, sm)) 784 goto fail; 785 sm->ssdp_sd_registered = 1; 786 return 0; 787 788 fail: 789 /* Error */ 790 wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed"); 791 ssdp_listener_stop(sm); 792 return -1; 793 } 794 795 796 /** 797 * add_ssdp_network - Add routing entry for SSDP 798 * @net_if: Selected network interface name 799 * Returns: 0 on success, -1 on failure 800 * 801 * This function assures that the multicast address will be properly 802 * handled by Linux networking code (by a modification to routing tables). 803 * This must be done per network interface. It really only needs to be done 804 * once after booting up, but it does not hurt to call this more frequently 805 * "to be safe". 806 */ 807 int add_ssdp_network(const char *net_if) 808 { 809 #ifdef __linux__ 810 int ret = -1; 811 int sock = -1; 812 struct rtentry rt; 813 struct sockaddr_in *sin; 814 815 if (!net_if) 816 goto fail; 817 818 os_memset(&rt, 0, sizeof(rt)); 819 sock = socket(AF_INET, SOCK_DGRAM, 0); 820 if (sock < 0) 821 goto fail; 822 823 rt.rt_dev = (char *) net_if; 824 sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in); 825 sin->sin_family = AF_INET; 826 sin->sin_port = 0; 827 sin->sin_addr.s_addr = inet_addr(SSDP_TARGET); 828 sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in); 829 sin->sin_family = AF_INET; 830 sin->sin_port = 0; 831 sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK); 832 rt.rt_flags = RTF_UP; 833 if (ioctl(sock, SIOCADDRT, &rt) < 0) { 834 if (errno == EPERM) { 835 wpa_printf(MSG_DEBUG, "add_ssdp_network: No " 836 "permissions to add routing table entry"); 837 /* Continue to allow testing as non-root */ 838 } else if (errno != EEXIST) { 839 wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno " 840 "%d (%s)", errno, strerror(errno)); 841 goto fail; 842 } 843 } 844 845 ret = 0; 846 847 fail: 848 if (sock >= 0) 849 close(sock); 850 851 return ret; 852 #else /* __linux__ */ 853 return 0; 854 #endif /* __linux__ */ 855 } 856 857 858 int ssdp_open_multicast_sock(u32 ip_addr, const char *forced_ifname) 859 { 860 int sd; 861 /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet 862 * time to live (TTL) small */ 863 unsigned char ttl = 4; 864 865 sd = socket(AF_INET, SOCK_DGRAM, 0); 866 if (sd < 0) 867 return -1; 868 869 if (forced_ifname) { 870 #ifdef __linux__ 871 struct ifreq req; 872 os_memset(&req, 0, sizeof(req)); 873 os_strlcpy(req.ifr_name, forced_ifname, sizeof(req.ifr_name)); 874 if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &req, 875 sizeof(req)) < 0) { 876 wpa_printf(MSG_INFO, "WPS UPnP: Failed to bind " 877 "multicast socket to ifname %s: %s", 878 forced_ifname, strerror(errno)); 879 close(sd); 880 return -1; 881 } 882 #endif /* __linux__ */ 883 } 884 885 #if 0 /* maybe ok if we sometimes block on writes */ 886 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) { 887 close(sd); 888 return -1; 889 } 890 #endif 891 892 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF, 893 &ip_addr, sizeof(ip_addr))) { 894 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_IF) %x: " 895 "%d (%s)", ip_addr, errno, strerror(errno)); 896 close(sd); 897 return -1; 898 } 899 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, 900 &ttl, sizeof(ttl))) { 901 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_TTL): " 902 "%d (%s)", errno, strerror(errno)); 903 close(sd); 904 return -1; 905 } 906 907 #if 0 /* not needed, because we don't receive using multicast_sd */ 908 { 909 struct ip_mreq mreq; 910 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS); 911 mreq.imr_interface.s_addr = ip_addr; 912 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr " 913 "0x%x", 914 mreq.imr_multiaddr.s_addr, 915 mreq.imr_interface.s_addr); 916 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, 917 sizeof(mreq))) { 918 wpa_printf(MSG_ERROR, 919 "WPS UPnP: setsockopt " 920 "IP_ADD_MEMBERSHIP errno %d (%s)", 921 errno, strerror(errno)); 922 close(sd); 923 return -1; 924 } 925 } 926 #endif /* not needed */ 927 928 /* 929 * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default? 930 * which aids debugging I suppose but isn't really necessary? 931 */ 932 933 return sd; 934 } 935 936 937 /** 938 * ssdp_open_multicast - Open socket for sending multicast SSDP messages 939 * @sm: WPS UPnP state machine from upnp_wps_device_init() 940 * Returns: 0 on success, -1 on failure 941 */ 942 int ssdp_open_multicast(struct upnp_wps_device_sm *sm) 943 { 944 sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr, NULL); 945 if (sm->multicast_sd < 0) 946 return -1; 947 return 0; 948 } 949
