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