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