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