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                 goto fail;
 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 fail:
 218         wpabuf_free(msg);
 219         return NULL;
 220 }
 221
 222
 223 static void advertisement_state_machine_handler(void *eloop_data,
 224                                                 void *user_ctx);
 225
 226
 227 /**
 228  * advertisement_state_machine_stop - Stop SSDP advertisements
 229  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 230  * @send_byebye: Send byebye advertisement messages immediately
 231  */
 232 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm,
 233                                       int send_byebye)
 234 {
 235         struct advertisement_state_machine *a = &sm->advertisement;
 236         int islast = 0;
 237         struct wpabuf *msg;
 238         struct sockaddr_in dest;
 239
 240         eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm);
 241         if (!send_byebye || sm->multicast_sd < 0)
 242                 return;
 243
 244         a->type = ADVERTISE_DOWN;
 245         a->state = 0;
 246
 247         os_memset(&dest, 0, sizeof(dest));
 248         dest.sin_family = AF_INET;
 249         dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 250         dest.sin_port = htons(UPNP_MULTICAST_PORT);
 251
 252         while (!islast) {
 253                 msg = next_advertisement(sm, a, &islast);
 254                 if (msg == NULL)
 255                         break;
 256                 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg),
 257                            0, (struct sockaddr *) &dest, sizeof(dest)) < 0) {
 258                         wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto "
 259                                    "failed: %d (%s)", errno, strerror(errno));
 260                 }
 261                 wpabuf_free(msg);
 262                 a->state++;
 263         }
 264 }
 265
 266
 267 static void advertisement_state_machine_handler(void *eloop_data,
 268                                                 void *user_ctx)
 269 {
 270         struct upnp_wps_device_sm *sm = user_ctx;
 271         struct advertisement_state_machine *a = &sm->advertisement;
 272         struct wpabuf *msg;
 273         int next_timeout_msec = 100;
 274         int next_timeout_sec = 0;
 275         struct sockaddr_in dest;
 276         int islast = 0;
 277
 278         /*
 279          * Each is sent twice (in case lost) w/ 100 msec delay between;
 280          * spec says no more than 3 times.
 281          * One pair for rootdevice, one pair for uuid, and a pair each for
 282          * each of the two urns.
 283          * The entire sequence must be repeated before cache control timeout
 284          * (which  is min  1800 seconds),
 285          * recommend random portion of half of the advertised cache control age
 286          * to ensure against loss... perhaps 1800/4 + rand*1800/4 ?
 287          * Delay random interval < 100 msec prior to initial sending.
 288          * TTL of 4
 289          */
 290
 291         wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state);
 292         msg = next_advertisement(sm, a, &islast);
 293         if (msg == NULL)
 294                 return;
 295
 296         os_memset(&dest, 0, sizeof(dest));
 297         dest.sin_family = AF_INET;
 298         dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 299         dest.sin_port = htons(UPNP_MULTICAST_PORT);
 300
 301         if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
 302                    (struct sockaddr *) &dest, sizeof(dest)) == -1) {
 303                 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:"
 304                            "%d (%s)", errno, strerror(errno));
 305                 next_timeout_msec = 0;
 306                 next_timeout_sec = 10; /* ... later */
 307         } else if (islast) {
 308                 a->state = 0; /* wrap around */
 309                 if (a->type == ADVERTISE_DOWN) {
 310                         wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP");
 311                         a->type = ADVERTISE_UP;
 312                         /* do it all over again right away */
 313                 } else {
 314                         u16 r;
 315                         /*
 316                          * Start over again after a long timeout
 317                          * (see notes above)
 318                          */
 319                         next_timeout_msec = 0;
 320                         if (os_get_random((void *) &r, sizeof(r)) < 0)
 321                                 r = 32768;
 322                         next_timeout_sec = UPNP_CACHE_SEC / 4 +
 323                                 (((UPNP_CACHE_SEC / 4) * r) >> 16);
 324                         sm->advertise_count++;
 325                         wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); "
 326                                    "next in %d sec",
 327                                    sm->advertise_count, next_timeout_sec);
 328                 }
 329         } else {
 330                 a->state++;
 331         }
 332
 333         wpabuf_free(msg);
 334
 335         eloop_register_timeout(next_timeout_sec, next_timeout_msec,
 336                                advertisement_state_machine_handler, NULL, sm);
 337 }
 338
 339
 340 /**
 341  * advertisement_state_machine_start - Start SSDP advertisements
 342  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 343  * Returns: 0 on success, -1 on failure
 344  */
 345 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm)
 346 {
 347         struct advertisement_state_machine *a = &sm->advertisement;
 348         int next_timeout_msec;
 349
 350         advertisement_state_machine_stop(sm, 0);
 351
 352         /*
 353          * Start out advertising down, this automatically switches
 354          * to advertising up which signals our restart.
 355          */
 356         a->type = ADVERTISE_DOWN;
 357         a->state = 0;
 358         /* (other fields not used here) */
 359
 360         /* First timeout should be random interval < 100 msec */
 361         next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8;
 362         return eloop_register_timeout(0, next_timeout_msec,
 363                                       advertisement_state_machine_handler,
 364                                       NULL, sm);
 365 }
 366
 367
 368 /***************************************************************************
 369  * M-SEARCH replies
 370  * These are very similar to the multicast advertisements, with some
 371  * small changes in data content; and they are sent (UDP) to a specific
 372  * unicast address instead of multicast.
 373  * They are sent in response to a UDP M-SEARCH packet.
 374  **************************************************************************/
 375
 376 /**
 377  * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine
 378  * @a: Selected advertisement/reply state
 379  */
 380 void msearchreply_state_machine_stop(struct advertisement_state_machine *a)
 381 {
 382         wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop");
 383         dl_list_del(&a->list);
 384         os_free(a);
 385 }
 386
 387
 388 static void msearchreply_state_machine_handler(void *eloop_data,
 389                                                void *user_ctx)
 390 {
 391         struct advertisement_state_machine *a = user_ctx;
 392         struct upnp_wps_device_sm *sm = eloop_data;
 393         struct wpabuf *msg;
 394         int next_timeout_msec = 100;
 395         int next_timeout_sec = 0;
 396         int islast = 0;
 397
 398         /*
 399          * Each response is sent twice (in case lost) w/ 100 msec delay
 400          * between; spec says no more than 3 times.
 401          * One pair for rootdevice, one pair for uuid, and a pair each for
 402          * each of the two urns.
 403          */
 404
 405         /* TODO: should only send the requested response types */
 406
 407         wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)",
 408                    a->state, inet_ntoa(a->client.sin_addr),
 409                    ntohs(a->client.sin_port));
 410         msg = next_advertisement(sm, a, &islast);
 411         if (msg == NULL)
 412                 return;
 413
 414         /*
 415          * Send it on the multicast socket to avoid having to set up another
 416          * socket.
 417          */
 418         if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
 419                    (struct sockaddr *) &a->client, sizeof(a->client)) < 0) {
 420                 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto "
 421                            "errno %d (%s) for %s:%d",
 422                            errno, strerror(errno),
 423                            inet_ntoa(a->client.sin_addr),
 424                            ntohs(a->client.sin_port));
 425                 /* Ignore error and hope for the best */
 426         }
 427         wpabuf_free(msg);
 428         if (islast) {
 429                 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done");
 430                 msearchreply_state_machine_stop(a);
 431                 return;
 432         }
 433         a->state++;
 434
 435         wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec",
 436                    next_timeout_sec, next_timeout_msec);
 437         eloop_register_timeout(next_timeout_sec, next_timeout_msec,
 438                                msearchreply_state_machine_handler, sm, a);
 439 }
 440
 441
 442 /**
 443  * msearchreply_state_machine_start - Reply to M-SEARCH discovery request
 444  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 445  * @client: Client address
 446  * @mx: Maximum delay in seconds
 447  *
 448  * Use TTL of 4 (this was done when socket set up).
 449  * A response should be given in randomized portion of min(MX,120) seconds
 450  *
 451  * UPnP-arch-DeviceArchitecture, 1.2.3:
 452  * To be found, a device must send a UDP response to the source IP address and
 453  * port that sent the request to the multicast channel. Devices respond if the
 454  * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:"
 455  * followed by a UUID that exactly matches one advertised by the device.
 456  */
 457 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm,
 458                                              struct sockaddr_in *client,
 459                                              int mx)
 460 {
 461         struct advertisement_state_machine *a;
 462         int next_timeout_sec;
 463         int next_timeout_msec;
 464         int replies;
 465
 466         replies = dl_list_len(&sm->msearch_replies);
 467         wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d "
 468                    "outstanding)", replies);
 469         if (replies >= MAX_MSEARCH) {
 470                 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding "
 471                            "M-SEARCH replies");
 472                 return;
 473         }
 474
 475         a = os_zalloc(sizeof(*a));
 476         if (a == NULL)
 477                 return;
 478         a->type = MSEARCH_REPLY;
 479         a->state = 0;
 480         os_memcpy(&a->client, client, sizeof(*client));
 481         /* Wait time depending on MX value */
 482         next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8;
 483         next_timeout_sec = next_timeout_msec / 1000;
 484         next_timeout_msec = next_timeout_msec % 1000;
 485         if (eloop_register_timeout(next_timeout_sec, next_timeout_msec,
 486                                    msearchreply_state_machine_handler, sm,
 487                                    a)) {
 488                 /* No way to recover (from malloc failure) */
 489                 goto fail;
 490         }
 491         /* Remember for future cleanup */
 492         dl_list_add(&sm->msearch_replies, &a->list);
 493         return;
 494
 495 fail:
 496         wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!");
 497         eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a);
 498         os_free(a);
 499 }
 500
 501
 502 /**
 503  * ssdp_parse_msearch - Process a received M-SEARCH
 504  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 505  * @client: Client address
 506  * @data: NULL terminated M-SEARCH message
 507  *
 508  * Given that we have received a header w/ M-SEARCH, act upon it
 509  *
 510  * Format of M-SEARCH (case insensitive!):
 511  *
 512  * First line must be:
 513  *      M-SEARCH * HTTP/1.1
 514  * Other lines in arbitrary order:
 515  *      HOST:239.255.255.250:1900
 516  *      ST:<varies -- must match>
 517  *      MAN:"ssdp:discover"
 518  *      MX:<varies>
 519  *
 520  * It should be noted that when Microsoft Vista is still learning its IP
 521  * address, it sends out host lines like: HOST:[FF02::C]:1900
 522  */
 523 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm,
 524                                struct sockaddr_in *client, const char *data)
 525 {
 526 #ifndef CONFIG_NO_STDOUT_DEBUG
 527         const char *start = data;
 528 #endif /* CONFIG_NO_STDOUT_DEBUG */
 529         int got_host = 0;
 530         int got_st = 0, st_match = 0;
 531         int got_man = 0;
 532         int got_mx = 0;
 533         int mx = 0;
 534
 535         /*
 536          * Skip first line M-SEARCH * HTTP/1.1
 537          * (perhaps we should check remainder of the line for syntax)
 538          */
 539         data += line_length(data);
 540
 541         /* Parse remaining lines */
 542         for (; *data != '\0'; data += line_length(data)) {
 543                 if (token_eq(data, "host")) {
 544                         /* The host line indicates who the packet
 545                          * is addressed to... but do we really care?
 546                          * Note that Microsoft sometimes does funny
 547                          * stuff with the HOST: line.
 548                          */
 549 #if 0   /* could be */
 550                         data += token_length(data);
 551                         data += word_separation_length(data);
 552                         if (*data != ':')
 553                                 goto bad;
 554                         data++;
 555                         data += word_separation_length(data);
 556                         /* UPNP_MULTICAST_ADDRESS */
 557                         if (!str_starts(data, "239.255.255.250"))
 558                                 goto bad;
 559                         data += os_strlen("239.255.255.250");
 560                         if (*data == ':') {
 561                                 if (!str_starts(data, ":1900"))
 562                                         goto bad;
 563                         }
 564 #endif  /* could be */
 565                         got_host = 1;
 566                         continue;
 567                 } else if (token_eq(data, "st")) {
 568                         /* There are a number of forms; we look
 569                          * for one that matches our case.
 570                          */
 571                         got_st = 1;
 572                         data += token_length(data);
 573                         data += word_separation_length(data);
 574                         if (*data != ':')
 575                                 continue;
 576                         data++;
 577                         data += word_separation_length(data);
 578                         if (str_starts(data, "ssdp:all")) {
 579                                 st_match = 1;
 580                                 continue;
 581                         }
 582                         if (str_starts(data, "upnp:rootdevice")) {
 583                                 st_match = 1;
 584                                 continue;
 585                         }
 586                         if (str_starts(data, "uuid:")) {
 587                                 char uuid_string[80];
 588                                 struct upnp_wps_device_interface *iface;
 589                                 iface = dl_list_first(
 590                                         &sm->interfaces,
 591                                         struct upnp_wps_device_interface,
 592                                         list);
 593                                 if (!iface)
 594                                         continue;
 595                                 data += os_strlen("uuid:");
 596                                 uuid_bin2str(iface->wps->uuid, uuid_string,
 597                                              sizeof(uuid_string));
 598                                 if (str_starts(data, uuid_string))
 599                                         st_match = 1;
 600                                 continue;
 601                         }
 602 #if 0
 603                         /* FIX: should we really reply to IGD string? */
 604                         if (str_starts(data, "urn:schemas-upnp-org:device:"
 605                                        "InternetGatewayDevice:1")) {
 606                                 st_match = 1;
 607                                 continue;
 608                         }
 609 #endif
 610                         if (str_starts(data, "urn:schemas-wifialliance-org:"
 611                                        "service:WFAWLANConfig:1")) {
 612                                 st_match = 1;
 613                                 continue;
 614                         }
 615                         if (str_starts(data, "urn:schemas-wifialliance-org:"
 616                                        "device:WFADevice:1")) {
 617                                 st_match = 1;
 618                                 continue;
 619                         }
 620                         continue;
 621                 } else if (token_eq(data, "man")) {
 622                         data += token_length(data);
 623                         data += word_separation_length(data);
 624                         if (*data != ':')
 625                                 continue;
 626                         data++;
 627                         data += word_separation_length(data);
 628                         if (!str_starts(data, "\"ssdp:discover\"")) {
 629                                 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected "
 630                                            "M-SEARCH man-field");
 631                                 goto bad;
 632                         }
 633                         got_man = 1;
 634                         continue;
 635                 } else if (token_eq(data, "mx")) {
 636                         data += token_length(data);
 637                         data += word_separation_length(data);
 638                         if (*data != ':')
 639                                 continue;
 640                         data++;
 641                         data += word_separation_length(data);
 642                         mx = atol(data);
 643                         got_mx = 1;
 644                         continue;
 645                 }
 646                 /* ignore anything else */
 647         }
 648         if (!got_host || !got_st || !got_man || !got_mx || mx < 0) {
 649                 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d "
 650                            "%d mx=%d", got_host, got_st, got_man, got_mx, mx);
 651                 goto bad;
 652         }
 653         if (!st_match) {
 654                 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST "
 655                            "match)");
 656                 return;
 657         }
 658         if (mx > 120)
 659                 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */
 660         msearchreply_state_machine_start(sm, client, mx);
 661         return;
 662
 663 bad:
 664         wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH");
 665         wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start);
 666 }
 667
 668
 669 /* Listening for (UDP) discovery (M-SEARCH) packets */
 670
 671 /**
 672  * ssdp_listener_stop - Stop SSDP listered
 673  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 674  *
 675  * This function stops the SSDP listener that was started by calling
 676  * ssdp_listener_start().
 677  */
 678 void ssdp_listener_stop(struct upnp_wps_device_sm *sm)
 679 {
 680         if (sm->ssdp_sd_registered) {
 681                 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ);
 682                 sm->ssdp_sd_registered = 0;
 683         }
 684
 685         if (sm->ssdp_sd != -1) {
 686                 close(sm->ssdp_sd);
 687                 sm->ssdp_sd = -1;
 688         }
 689
 690         eloop_cancel_timeout(msearchreply_state_machine_handler, sm,
 691                              ELOOP_ALL_CTX);
 692 }
 693
 694
 695 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx)
 696 {
 697         struct upnp_wps_device_sm *sm = sock_ctx;
 698         struct sockaddr_in addr; /* client address */
 699         socklen_t addr_len;
 700         int nread;
 701         char buf[MULTICAST_MAX_READ], *pos;
 702
 703         addr_len = sizeof(addr);
 704         nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0,
 705                          (struct sockaddr *) &addr, &addr_len);
 706         if (nread <= 0)
 707                 return;
 708         buf[nread] = '\0'; /* need null termination for algorithm */
 709
 710         if (str_starts(buf, "NOTIFY ")) {
 711                 /*
 712                  * Silently ignore NOTIFYs to avoid filling debug log with
 713                  * unwanted messages.
 714                  */
 715                 return;
 716         }
 717
 718         pos = os_strchr(buf, '\n');
 719         if (pos)
 720                 *pos = '\0';
 721         wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: "
 722                    "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf);
 723         if (pos)
 724                 *pos = '\n';
 725
 726         /* Parse first line */
 727         if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 &&
 728             !isgraph(buf[strlen("M-SEARCH")])) {
 729                 ssdp_parse_msearch(sm, &addr, buf);
 730                 return;
 731         }
 732
 733         /* Ignore anything else */
 734 }
 735
 736
 737 int ssdp_listener_open(void)
 738 {
 739         struct sockaddr_in addr;
 740         struct ip_mreq mcast_addr;
 741         int on = 1;
 742         /* per UPnP spec, keep IP packet time to live (TTL) small */
 743         unsigned char ttl = 4;
 744         int sd;
 745
 746         sd = socket(AF_INET, SOCK_DGRAM, 0);
 747         if (sd < 0)
 748                 goto fail;
 749         if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
 750                 goto fail;
 751         if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
 752                 goto fail;
 753         os_memset(&addr, 0, sizeof(addr));
 754         addr.sin_family = AF_INET;
 755         addr.sin_addr.s_addr = htonl(INADDR_ANY);
 756         addr.sin_port = htons(UPNP_MULTICAST_PORT);
 757         if (bind(sd, (struct sockaddr *) &addr, sizeof(addr)))
 758                 goto fail;
 759         os_memset(&mcast_addr, 0, sizeof(mcast_addr));
 760         mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY);
 761         mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 762         if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 763                        (char *) &mcast_addr, sizeof(mcast_addr)))
 764                 goto fail;
 765         if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
 766                        &ttl, sizeof(ttl)))
 767                 goto fail;
 768
 769         return sd;
 770
 771 fail:
 772         if (sd >= 0)
 773                 close(sd);
 774         return -1;
 775 }
 776
 777
 778 /**
 779  * ssdp_listener_start - Set up for receiving discovery (UDP) packets
 780  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 781  * Returns: 0 on success, -1 on failure
 782  *
 783  * The SSDP listener is stopped by calling ssdp_listener_stop().
 784  */
 785 int ssdp_listener_start(struct upnp_wps_device_sm *sm)
 786 {
 787         sm->ssdp_sd = ssdp_listener_open();
 788
 789         if (eloop_register_sock(sm->ssdp_sd, EVENT_TYPE_READ,
 790                                 ssdp_listener_handler, NULL, sm))
 791                 goto fail;
 792         sm->ssdp_sd_registered = 1;
 793         return 0;
 794
 795 fail:
 796         /* Error */
 797         wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed");
 798         ssdp_listener_stop(sm);
 799         return -1;
 800 }
 801
 802
 803 /**
 804  * add_ssdp_network - Add routing entry for SSDP
 805  * @net_if: Selected network interface name
 806  * Returns: 0 on success, -1 on failure
 807  *
 808  * This function assures that the multicast address will be properly
 809  * handled by Linux networking code (by a modification to routing tables).
 810  * This must be done per network interface. It really only needs to be done
 811  * once after booting up, but it does not hurt to call this more frequently
 812  * "to be safe".
 813  */
 814 int add_ssdp_network(const char *net_if)
 815 {
 816 #ifdef __linux__
 817         int ret = -1;
 818         int sock = -1;
 819         struct rtentry rt;
 820         struct sockaddr_in *sin;
 821
 822         if (!net_if)
 823                 goto fail;
 824
 825         os_memset(&rt, 0, sizeof(rt));
 826         sock = socket(AF_INET, SOCK_DGRAM, 0);
 827         if (sock < 0)
 828                 goto fail;
 829
 830         rt.rt_dev = (char *) net_if;
 831         sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in);
 832         sin->sin_family = AF_INET;
 833         sin->sin_port = 0;
 834         sin->sin_addr.s_addr = inet_addr(SSDP_TARGET);
 835         sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in);
 836         sin->sin_family = AF_INET;
 837         sin->sin_port = 0;
 838         sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK);
 839         rt.rt_flags = RTF_UP;
 840         if (ioctl(sock, SIOCADDRT, &rt) < 0) {
 841                 if (errno == EPERM) {
 842                         wpa_printf(MSG_DEBUG, "add_ssdp_network: No "
 843                                    "permissions to add routing table entry");
 844                         /* Continue to allow testing as non-root */
 845                 } else if (errno != EEXIST) {
 846                         wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno "
 847                                    "%d (%s)", errno, strerror(errno));
 848                         goto fail;
 849                 }
 850         }
 851
 852         ret = 0;
 853
 854 fail:
 855         if (sock >= 0)
 856                 close(sock);
 857
 858         return ret;
 859 #else /* __linux__ */
 860         return 0;
 861 #endif /* __linux__ */
 862 }
 863
 864
 865 int ssdp_open_multicast_sock(u32 ip_addr, const char *forced_ifname)
 866 {
 867         int sd;
 868          /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet
 869           * time to live (TTL) small */
 870         unsigned char ttl = 4;
 871
 872         sd = socket(AF_INET, SOCK_DGRAM, 0);
 873         if (sd < 0)
 874                 return -1;
 875
 876         if (forced_ifname) {
 877 #ifdef __linux__
 878                 struct ifreq req;
 879                 os_memset(&req, 0, sizeof(req));
 880                 os_strlcpy(req.ifr_name, forced_ifname, sizeof(req.ifr_name));
 881                 if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &req,
 882                                sizeof(req)) < 0) {
 883                         wpa_printf(MSG_INFO, "WPS UPnP: Failed to bind "
 884                                    "multicast socket to ifname %s: %s",
 885                                    forced_ifname, strerror(errno));
 886                         close(sd);
 887                         return -1;
 888                 }
 889 #endif /* __linux__ */
 890         }
 891
 892 #if 0   /* maybe ok if we sometimes block on writes */
 893         if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) {
 894                 close(sd);
 895                 return -1;
 896         }
 897 #endif
 898
 899         if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF,
 900                        &ip_addr, sizeof(ip_addr))) {
 901                 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_IF) %x: "
 902                            "%d (%s)", ip_addr, errno, strerror(errno));
 903                 close(sd);
 904                 return -1;
 905         }
 906         if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
 907                        &ttl, sizeof(ttl))) {
 908                 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_TTL): "
 909                            "%d (%s)", errno, strerror(errno));
 910                 close(sd);
 911                 return -1;
 912         }
 913
 914 #if 0   /* not needed, because we don't receive using multicast_sd */
 915         {
 916                 struct ip_mreq mreq;
 917                 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 918                 mreq.imr_interface.s_addr = ip_addr;
 919                 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr "
 920                            "0x%x",
 921                            mreq.imr_multiaddr.s_addr,
 922                            mreq.imr_interface.s_addr);
 923                 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq,
 924                                 sizeof(mreq))) {
 925                         wpa_printf(MSG_ERROR,
 926                                    "WPS UPnP: setsockopt "
 927                                    "IP_ADD_MEMBERSHIP errno %d (%s)",
 928                                    errno, strerror(errno));
 929                         close(sd);
 930                         return -1;
 931                 }
 932         }
 933 #endif  /* not needed */
 934
 935         /*
 936          * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default?
 937          * which aids debugging I suppose but isn't really necessary?
 938          */
 939
 940         return sd;
 941 }
 942
 943
 944 /**
 945  * ssdp_open_multicast - Open socket for sending multicast SSDP messages
 946  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 947  * Returns: 0 on success, -1 on failure
 948  */
 949 int ssdp_open_multicast(struct upnp_wps_device_sm *sm)
 950 {
 951         sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr, NULL);
 952         if (sm->multicast_sd < 0)
 953                 return -1;
 954         return 0;
 955 }