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