contrib/hostapd/src/wps/wps_upnp_ssdp.c

   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  * @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 }