contrib/hostapd/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         uuid_bin2str(iface->wps->uuid, uuid_string, sizeof(uuid_string));
 138         msg = wpabuf_alloc(800); /* more than big enough */
 139         if (msg == NULL)
 140                 goto fail;
 141         switch (a->type) {
 142         case ADVERTISE_UP:
 143         case ADVERTISE_DOWN:
 144                 NTString = "NT";
 145                 wpabuf_put_str(msg, "NOTIFY * HTTP/1.1\r\n");
 146                 wpabuf_printf(msg, "HOST: %s:%d\r\n",
 147                               UPNP_MULTICAST_ADDRESS, UPNP_MULTICAST_PORT);
 148                 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
 149                               UPNP_CACHE_SEC);
 150                 wpabuf_printf(msg, "NTS: %s\r\n",
 151                               (a->type == ADVERTISE_UP ?
 152                                "ssdp:alive" : "ssdp:byebye"));
 153                 break;
 154         case MSEARCH_REPLY:
 155                 NTString = "ST";
 156                 wpabuf_put_str(msg, "HTTP/1.1 200 OK\r\n");
 157                 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
 158                               UPNP_CACHE_SEC);
 159
 160                 wpabuf_put_str(msg, "DATE: ");
 161                 format_date(msg);
 162                 wpabuf_put_str(msg, "\r\n");
 163
 164                 wpabuf_put_str(msg, "EXT:\r\n");
 165                 break;
 166         }
 167
 168         if (a->type != ADVERTISE_DOWN) {
 169                 /* Where others may get our XML files from */
 170                 wpabuf_printf(msg, "LOCATION: http://%s:%d/%s\r\n",
 171                               sm->ip_addr_text, sm->web_port,
 172                               UPNP_WPS_DEVICE_XML_FILE);
 173         }
 174
 175         /* The SERVER line has three comma-separated fields:
 176          *      operating system / version
 177          *      upnp version
 178          *      software package / version
 179          * However, only the UPnP version is really required, the
 180          * others can be place holders... for security reasons
 181          * it is better to NOT provide extra information.
 182          */
 183         wpabuf_put_str(msg, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");
 184
 185         switch (a->state / UPNP_ADVERTISE_REPEAT) {
 186         case 0:
 187                 wpabuf_printf(msg, "%s: upnp:rootdevice\r\n", NTString);
 188                 wpabuf_printf(msg, "USN: uuid:%s::upnp:rootdevice\r\n",
 189                               uuid_string);
 190                 break;
 191         case 1:
 192                 wpabuf_printf(msg, "%s: uuid:%s\r\n", NTString, uuid_string);
 193                 wpabuf_printf(msg, "USN: uuid:%s\r\n", uuid_string);
 194                 break;
 195         case 2:
 196                 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:device:"
 197                               "WFADevice:1\r\n", NTString);
 198                 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
 199                               "org:device:WFADevice:1\r\n", uuid_string);
 200                 break;
 201         case 3:
 202                 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:service:"
 203                               "WFAWLANConfig:1\r\n", NTString);
 204                 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
 205                               "org:service:WFAWLANConfig:1\r\n", uuid_string);
 206                 break;
 207         }
 208         wpabuf_put_str(msg, "\r\n");
 209
 210         if (a->state + 1 >= 4 * UPNP_ADVERTISE_REPEAT)
 211                 *islast = 1;
 212
 213         return msg;
 214
 215 fail:
 216         wpabuf_free(msg);
 217         return NULL;
 218 }
 219
 220
 221 static void advertisement_state_machine_handler(void *eloop_data,
 222                                                 void *user_ctx);
 223
 224
 225 /**
 226  * advertisement_state_machine_stop - Stop SSDP advertisements
 227  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 228  * @send_byebye: Send byebye advertisement messages immediately
 229  */
 230 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm,
 231                                       int send_byebye)
 232 {
 233         struct advertisement_state_machine *a = &sm->advertisement;
 234         int islast = 0;
 235         struct wpabuf *msg;
 236         struct sockaddr_in dest;
 237
 238         eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm);
 239         if (!send_byebye || sm->multicast_sd < 0)
 240                 return;
 241
 242         a->type = ADVERTISE_DOWN;
 243         a->state = 0;
 244
 245         os_memset(&dest, 0, sizeof(dest));
 246         dest.sin_family = AF_INET;
 247         dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 248         dest.sin_port = htons(UPNP_MULTICAST_PORT);
 249
 250         while (!islast) {
 251                 msg = next_advertisement(sm, a, &islast);
 252                 if (msg == NULL)
 253                         break;
 254                 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg),
 255                            0, (struct sockaddr *) &dest, sizeof(dest)) < 0) {
 256                         wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto "
 257                                    "failed: %d (%s)", errno, strerror(errno));
 258                 }
 259                 wpabuf_free(msg);
 260                 a->state++;
 261         }
 262 }
 263
 264
 265 static void advertisement_state_machine_handler(void *eloop_data,
 266                                                 void *user_ctx)
 267 {
 268         struct upnp_wps_device_sm *sm = user_ctx;
 269         struct advertisement_state_machine *a = &sm->advertisement;
 270         struct wpabuf *msg;
 271         int next_timeout_msec = 100;
 272         int next_timeout_sec = 0;
 273         struct sockaddr_in dest;
 274         int islast = 0;
 275
 276         /*
 277          * Each is sent twice (in case lost) w/ 100 msec delay between;
 278          * spec says no more than 3 times.
 279          * One pair for rootdevice, one pair for uuid, and a pair each for
 280          * each of the two urns.
 281          * The entire sequence must be repeated before cache control timeout
 282          * (which  is min  1800 seconds),
 283          * recommend random portion of half of the advertised cache control age
 284          * to ensure against loss... perhaps 1800/4 + rand*1800/4 ?
 285          * Delay random interval < 100 msec prior to initial sending.
 286          * TTL of 4
 287          */
 288
 289         wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state);
 290         msg = next_advertisement(sm, a, &islast);
 291         if (msg == NULL)
 292                 return;
 293
 294         os_memset(&dest, 0, sizeof(dest));
 295         dest.sin_family = AF_INET;
 296         dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 297         dest.sin_port = htons(UPNP_MULTICAST_PORT);
 298
 299         if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
 300                    (struct sockaddr *) &dest, sizeof(dest)) == -1) {
 301                 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:"
 302                            "%d (%s)", errno, strerror(errno));
 303                 next_timeout_msec = 0;
 304                 next_timeout_sec = 10; /* ... later */
 305         } else if (islast) {
 306                 a->state = 0; /* wrap around */
 307                 if (a->type == ADVERTISE_DOWN) {
 308                         wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP");
 309                         a->type = ADVERTISE_UP;
 310                         /* do it all over again right away */
 311                 } else {
 312                         u16 r;
 313                         /*
 314                          * Start over again after a long timeout
 315                          * (see notes above)
 316                          */
 317                         next_timeout_msec = 0;
 318                         os_get_random((void *) &r, sizeof(r));
 319                         next_timeout_sec = UPNP_CACHE_SEC / 4 +
 320                                 (((UPNP_CACHE_SEC / 4) * r) >> 16);
 321                         sm->advertise_count++;
 322                         wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); "
 323                                    "next in %d sec",
 324                                    sm->advertise_count, next_timeout_sec);
 325                 }
 326         } else {
 327                 a->state++;
 328         }
 329
 330         wpabuf_free(msg);
 331
 332         eloop_register_timeout(next_timeout_sec, next_timeout_msec,
 333                                advertisement_state_machine_handler, NULL, sm);
 334 }
 335
 336
 337 /**
 338  * advertisement_state_machine_start - Start SSDP advertisements
 339  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 340  * Returns: 0 on success, -1 on failure
 341  */
 342 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm)
 343 {
 344         struct advertisement_state_machine *a = &sm->advertisement;
 345         int next_timeout_msec;
 346
 347         advertisement_state_machine_stop(sm, 0);
 348
 349         /*
 350          * Start out advertising down, this automatically switches
 351          * to advertising up which signals our restart.
 352          */
 353         a->type = ADVERTISE_DOWN;
 354         a->state = 0;
 355         /* (other fields not used here) */
 356
 357         /* First timeout should be random interval < 100 msec */
 358         next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8;
 359         return eloop_register_timeout(0, next_timeout_msec,
 360                                       advertisement_state_machine_handler,
 361                                       NULL, sm);
 362 }
 363
 364
 365 /***************************************************************************
 366  * M-SEARCH replies
 367  * These are very similar to the multicast advertisements, with some
 368  * small changes in data content; and they are sent (UDP) to a specific
 369  * unicast address instead of multicast.
 370  * They are sent in response to a UDP M-SEARCH packet.
 371  **************************************************************************/
 372
 373 /**
 374  * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine
 375  * @a: Selected advertisement/reply state
 376  */
 377 void msearchreply_state_machine_stop(struct advertisement_state_machine *a)
 378 {
 379         wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop");
 380         dl_list_del(&a->list);
 381         os_free(a);
 382 }
 383
 384
 385 static void msearchreply_state_machine_handler(void *eloop_data,
 386                                                void *user_ctx)
 387 {
 388         struct advertisement_state_machine *a = user_ctx;
 389         struct upnp_wps_device_sm *sm = eloop_data;
 390         struct wpabuf *msg;
 391         int next_timeout_msec = 100;
 392         int next_timeout_sec = 0;
 393         int islast = 0;
 394
 395         /*
 396          * Each response is sent twice (in case lost) w/ 100 msec delay
 397          * between; spec says no more than 3 times.
 398          * One pair for rootdevice, one pair for uuid, and a pair each for
 399          * each of the two urns.
 400          */
 401
 402         /* TODO: should only send the requested response types */
 403
 404         wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)",
 405                    a->state, inet_ntoa(a->client.sin_addr),
 406                    ntohs(a->client.sin_port));
 407         msg = next_advertisement(sm, a, &islast);
 408         if (msg == NULL)
 409                 return;
 410
 411         /*
 412          * Send it on the multicast socket to avoid having to set up another
 413          * socket.
 414          */
 415         if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
 416                    (struct sockaddr *) &a->client, sizeof(a->client)) < 0) {
 417                 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto "
 418                            "errno %d (%s) for %s:%d",
 419                            errno, strerror(errno),
 420                            inet_ntoa(a->client.sin_addr),
 421                            ntohs(a->client.sin_port));
 422                 /* Ignore error and hope for the best */
 423         }
 424         wpabuf_free(msg);
 425         if (islast) {
 426                 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done");
 427                 msearchreply_state_machine_stop(a);
 428                 return;
 429         }
 430         a->state++;
 431
 432         wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec",
 433                    next_timeout_sec, next_timeout_msec);
 434         eloop_register_timeout(next_timeout_sec, next_timeout_msec,
 435                                msearchreply_state_machine_handler, sm, a);
 436 }
 437
 438
 439 /**
 440  * msearchreply_state_machine_start - Reply to M-SEARCH discovery request
 441  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 442  * @client: Client address
 443  * @mx: Maximum delay in seconds
 444  *
 445  * Use TTL of 4 (this was done when socket set up).
 446  * A response should be given in randomized portion of min(MX,120) seconds
 447  *
 448  * UPnP-arch-DeviceArchitecture, 1.2.3:
 449  * To be found, a device must send a UDP response to the source IP address and
 450  * port that sent the request to the multicast channel. Devices respond if the
 451  * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:"
 452  * followed by a UUID that exactly matches one advertised by the device.
 453  */
 454 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm,
 455                                              struct sockaddr_in *client,
 456                                              int mx)
 457 {
 458         struct advertisement_state_machine *a;
 459         int next_timeout_sec;
 460         int next_timeout_msec;
 461         int replies;
 462
 463         replies = dl_list_len(&sm->msearch_replies);
 464         wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d "
 465                    "outstanding)", replies);
 466         if (replies >= MAX_MSEARCH) {
 467                 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding "
 468                            "M-SEARCH replies");
 469                 return;
 470         }
 471
 472         a = os_zalloc(sizeof(*a));
 473         if (a == NULL)
 474                 return;
 475         a->type = MSEARCH_REPLY;
 476         a->state = 0;
 477         os_memcpy(&a->client, client, sizeof(*client));
 478         /* Wait time depending on MX value */
 479         next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8;
 480         next_timeout_sec = next_timeout_msec / 1000;
 481         next_timeout_msec = next_timeout_msec % 1000;
 482         if (eloop_register_timeout(next_timeout_sec, next_timeout_msec,
 483                                    msearchreply_state_machine_handler, sm,
 484                                    a)) {
 485                 /* No way to recover (from malloc failure) */
 486                 goto fail;
 487         }
 488         /* Remember for future cleanup */
 489         dl_list_add(&sm->msearch_replies, &a->list);
 490         return;
 491
 492 fail:
 493         wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!");
 494         eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a);
 495         os_free(a);
 496 }
 497
 498
 499 /**
 500  * ssdp_parse_msearch - Process a received M-SEARCH
 501  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 502  * @client: Client address
 503  * @data: NULL terminated M-SEARCH message
 504  *
 505  * Given that we have received a header w/ M-SEARCH, act upon it
 506  *
 507  * Format of M-SEARCH (case insensitive!):
 508  *
 509  * First line must be:
 510  *      M-SEARCH * HTTP/1.1
 511  * Other lines in arbitrary order:
 512  *      HOST:239.255.255.250:1900
 513  *      ST:<varies -- must match>
 514  *      MAN:"ssdp:discover"
 515  *      MX:<varies>
 516  *
 517  * It should be noted that when Microsoft Vista is still learning its IP
 518  * address, it sends out host lines like: HOST:[FF02::C]:1900
 519  */
 520 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm,
 521                                struct sockaddr_in *client, const char *data)
 522 {
 523 #ifndef CONFIG_NO_STDOUT_DEBUG
 524         const char *start = data;
 525 #endif /* CONFIG_NO_STDOUT_DEBUG */
 526         int got_host = 0;
 527         int got_st = 0, st_match = 0;
 528         int got_man = 0;
 529         int got_mx = 0;
 530         int mx = 0;
 531
 532         /*
 533          * Skip first line M-SEARCH * HTTP/1.1
 534          * (perhaps we should check remainder of the line for syntax)
 535          */
 536         data += line_length(data);
 537
 538         /* Parse remaining lines */
 539         for (; *data != '\0'; data += line_length(data)) {
 540                 if (token_eq(data, "host")) {
 541                         /* The host line indicates who the packet
 542                          * is addressed to... but do we really care?
 543                          * Note that Microsoft sometimes does funny
 544                          * stuff with the HOST: line.
 545                          */
 546 #if 0   /* could be */
 547                         data += token_length(data);
 548                         data += word_separation_length(data);
 549                         if (*data != ':')
 550                                 goto bad;
 551                         data++;
 552                         data += word_separation_length(data);
 553                         /* UPNP_MULTICAST_ADDRESS */
 554                         if (!str_starts(data, "239.255.255.250"))
 555                                 goto bad;
 556                         data += os_strlen("239.255.255.250");
 557                         if (*data == ':') {
 558                                 if (!str_starts(data, ":1900"))
 559                                         goto bad;
 560                         }
 561 #endif  /* could be */
 562                         got_host = 1;
 563                         continue;
 564                 } else if (token_eq(data, "st")) {
 565                         /* There are a number of forms; we look
 566                          * for one that matches our case.
 567                          */
 568                         got_st = 1;
 569                         data += token_length(data);
 570                         data += word_separation_length(data);
 571                         if (*data != ':')
 572                                 continue;
 573                         data++;
 574                         data += word_separation_length(data);
 575                         if (str_starts(data, "ssdp:all")) {
 576                                 st_match = 1;
 577                                 continue;
 578                         }
 579                         if (str_starts(data, "upnp:rootdevice")) {
 580                                 st_match = 1;
 581                                 continue;
 582                         }
 583                         if (str_starts(data, "uuid:")) {
 584                                 char uuid_string[80];
 585                                 struct upnp_wps_device_interface *iface;
 586                                 iface = dl_list_first(
 587                                         &sm->interfaces,
 588                                         struct upnp_wps_device_interface,
 589                                         list);
 590                                 data += os_strlen("uuid:");
 591                                 uuid_bin2str(iface->wps->uuid, uuid_string,
 592                                              sizeof(uuid_string));
 593                                 if (str_starts(data, uuid_string))
 594                                         st_match = 1;
 595                                 continue;
 596                         }
 597 #if 0
 598                         /* FIX: should we really reply to IGD string? */
 599                         if (str_starts(data, "urn:schemas-upnp-org:device:"
 600                                        "InternetGatewayDevice:1")) {
 601                                 st_match = 1;
 602                                 continue;
 603                         }
 604 #endif
 605                         if (str_starts(data, "urn:schemas-wifialliance-org:"
 606                                        "service:WFAWLANConfig:1")) {
 607                                 st_match = 1;
 608                                 continue;
 609                         }
 610                         if (str_starts(data, "urn:schemas-wifialliance-org:"
 611                                        "device:WFADevice:1")) {
 612                                 st_match = 1;
 613                                 continue;
 614                         }
 615                         continue;
 616                 } else if (token_eq(data, "man")) {
 617                         data += token_length(data);
 618                         data += word_separation_length(data);
 619                         if (*data != ':')
 620                                 continue;
 621                         data++;
 622                         data += word_separation_length(data);
 623                         if (!str_starts(data, "\"ssdp:discover\"")) {
 624                                 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected "
 625                                            "M-SEARCH man-field");
 626                                 goto bad;
 627                         }
 628                         got_man = 1;
 629                         continue;
 630                 } else if (token_eq(data, "mx")) {
 631                         data += token_length(data);
 632                         data += word_separation_length(data);
 633                         if (*data != ':')
 634                                 continue;
 635                         data++;
 636                         data += word_separation_length(data);
 637                         mx = atol(data);
 638                         got_mx = 1;
 639                         continue;
 640                 }
 641                 /* ignore anything else */
 642         }
 643         if (!got_host || !got_st || !got_man || !got_mx || mx < 0) {
 644                 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d "
 645                            "%d mx=%d", got_host, got_st, got_man, got_mx, mx);
 646                 goto bad;
 647         }
 648         if (!st_match) {
 649                 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST "
 650                            "match)");
 651                 return;
 652         }
 653         if (mx > 120)
 654                 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */
 655         msearchreply_state_machine_start(sm, client, mx);
 656         return;
 657
 658 bad:
 659         wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH");
 660         wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start);
 661 }
 662
 663
 664 /* Listening for (UDP) discovery (M-SEARCH) packets */
 665
 666 /**
 667  * ssdp_listener_stop - Stop SSDP listered
 668  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 669  *
 670  * This function stops the SSDP listener that was started by calling
 671  * ssdp_listener_start().
 672  */
 673 void ssdp_listener_stop(struct upnp_wps_device_sm *sm)
 674 {
 675         if (sm->ssdp_sd_registered) {
 676                 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ);
 677                 sm->ssdp_sd_registered = 0;
 678         }
 679
 680         if (sm->ssdp_sd != -1) {
 681                 close(sm->ssdp_sd);
 682                 sm->ssdp_sd = -1;
 683         }
 684
 685         eloop_cancel_timeout(msearchreply_state_machine_handler, sm,
 686                              ELOOP_ALL_CTX);
 687 }
 688
 689
 690 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx)
 691 {
 692         struct upnp_wps_device_sm *sm = sock_ctx;
 693         struct sockaddr_in addr; /* client address */
 694         socklen_t addr_len;
 695         int nread;
 696         char buf[MULTICAST_MAX_READ], *pos;
 697
 698         addr_len = sizeof(addr);
 699         nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0,
 700                          (struct sockaddr *) &addr, &addr_len);
 701         if (nread <= 0)
 702                 return;
 703         buf[nread] = '\0'; /* need null termination for algorithm */
 704
 705         if (str_starts(buf, "NOTIFY ")) {
 706                 /*
 707                  * Silently ignore NOTIFYs to avoid filling debug log with
 708                  * unwanted messages.
 709                  */
 710                 return;
 711         }
 712
 713         pos = os_strchr(buf, '\n');
 714         if (pos)
 715                 *pos = '\0';
 716         wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: "
 717                    "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf);
 718         if (pos)
 719                 *pos = '\n';
 720
 721         /* Parse first line */
 722         if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 &&
 723             !isgraph(buf[strlen("M-SEARCH")])) {
 724                 ssdp_parse_msearch(sm, &addr, buf);
 725                 return;
 726         }
 727
 728         /* Ignore anything else */
 729 }
 730
 731
 732 int ssdp_listener_open(void)
 733 {
 734         struct sockaddr_in addr;
 735         struct ip_mreq mcast_addr;
 736         int on = 1;
 737         /* per UPnP spec, keep IP packet time to live (TTL) small */
 738         unsigned char ttl = 4;
 739         int sd;
 740
 741         sd = socket(AF_INET, SOCK_DGRAM, 0);
 742         if (sd < 0)
 743                 goto fail;
 744         if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
 745                 goto fail;
 746         if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
 747                 goto fail;
 748         os_memset(&addr, 0, sizeof(addr));
 749         addr.sin_family = AF_INET;
 750         addr.sin_addr.s_addr = htonl(INADDR_ANY);
 751         addr.sin_port = htons(UPNP_MULTICAST_PORT);
 752         if (bind(sd, (struct sockaddr *) &addr, sizeof(addr)))
 753                 goto fail;
 754         os_memset(&mcast_addr, 0, sizeof(mcast_addr));
 755         mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY);
 756         mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 757         if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 758                        (char *) &mcast_addr, sizeof(mcast_addr)))
 759                 goto fail;
 760         if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
 761                        &ttl, sizeof(ttl)))
 762                 goto fail;
 763
 764         return sd;
 765
 766 fail:
 767         if (sd >= 0)
 768                 close(sd);
 769         return -1;
 770 }
 771
 772
 773 /**
 774  * ssdp_listener_start - Set up for receiving discovery (UDP) packets
 775  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 776  * Returns: 0 on success, -1 on failure
 777  *
 778  * The SSDP listener is stopped by calling ssdp_listener_stop().
 779  */
 780 int ssdp_listener_start(struct upnp_wps_device_sm *sm)
 781 {
 782         sm->ssdp_sd = ssdp_listener_open();
 783
 784         if (eloop_register_sock(sm->ssdp_sd, EVENT_TYPE_READ,
 785                                 ssdp_listener_handler, NULL, sm))
 786                 goto fail;
 787         sm->ssdp_sd_registered = 1;
 788         return 0;
 789
 790 fail:
 791         /* Error */
 792         wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed");
 793         ssdp_listener_stop(sm);
 794         return -1;
 795 }
 796
 797
 798 /**
 799  * add_ssdp_network - Add routing entry for SSDP
 800  * @net_if: Selected network interface name
 801  * Returns: 0 on success, -1 on failure
 802  *
 803  * This function assures that the multicast address will be properly
 804  * handled by Linux networking code (by a modification to routing tables).
 805  * This must be done per network interface. It really only needs to be done
 806  * once after booting up, but it does not hurt to call this more frequently
 807  * "to be safe".
 808  */
 809 int add_ssdp_network(const char *net_if)
 810 {
 811 #ifdef __linux__
 812         int ret = -1;
 813         int sock = -1;
 814         struct rtentry rt;
 815         struct sockaddr_in *sin;
 816
 817         if (!net_if)
 818                 goto fail;
 819
 820         os_memset(&rt, 0, sizeof(rt));
 821         sock = socket(AF_INET, SOCK_DGRAM, 0);
 822         if (sock < 0)
 823                 goto fail;
 824
 825         rt.rt_dev = (char *) net_if;
 826         sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in);
 827         sin->sin_family = AF_INET;
 828         sin->sin_port = 0;
 829         sin->sin_addr.s_addr = inet_addr(SSDP_TARGET);
 830         sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in);
 831         sin->sin_family = AF_INET;
 832         sin->sin_port = 0;
 833         sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK);
 834         rt.rt_flags = RTF_UP;
 835         if (ioctl(sock, SIOCADDRT, &rt) < 0) {
 836                 if (errno == EPERM) {
 837                         wpa_printf(MSG_DEBUG, "add_ssdp_network: No "
 838                                    "permissions to add routing table entry");
 839                         /* Continue to allow testing as non-root */
 840                 } else if (errno != EEXIST) {
 841                         wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno "
 842                                    "%d (%s)", errno, strerror(errno));
 843                         goto fail;
 844                 }
 845         }
 846
 847         ret = 0;
 848
 849 fail:
 850         if (sock >= 0)
 851                 close(sock);
 852
 853         return ret;
 854 #else /* __linux__ */
 855         return 0;
 856 #endif /* __linux__ */
 857 }
 858
 859
 860 int ssdp_open_multicast_sock(u32 ip_addr, const char *forced_ifname)
 861 {
 862         int sd;
 863          /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet
 864           * time to live (TTL) small */
 865         unsigned char ttl = 4;
 866
 867         sd = socket(AF_INET, SOCK_DGRAM, 0);
 868         if (sd < 0)
 869                 return -1;
 870
 871         if (forced_ifname) {
 872 #ifdef __linux__
 873                 struct ifreq req;
 874                 os_memset(&req, 0, sizeof(req));
 875                 os_strlcpy(req.ifr_name, forced_ifname, sizeof(req.ifr_name));
 876                 if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &req,
 877                                sizeof(req)) < 0) {
 878                         wpa_printf(MSG_INFO, "WPS UPnP: Failed to bind "
 879                                    "multicast socket to ifname %s: %s",
 880                                    forced_ifname, strerror(errno));
 881                         close(sd);
 882                         return -1;
 883                 }
 884 #endif /* __linux__ */
 885         }
 886
 887 #if 0   /* maybe ok if we sometimes block on writes */
 888         if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) {
 889                 close(sd);
 890                 return -1;
 891         }
 892 #endif
 893
 894         if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF,
 895                        &ip_addr, sizeof(ip_addr))) {
 896                 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_IF) %x: "
 897                            "%d (%s)", ip_addr, errno, strerror(errno));
 898                 close(sd);
 899                 return -1;
 900         }
 901         if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
 902                        &ttl, sizeof(ttl))) {
 903                 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_TTL): "
 904                            "%d (%s)", errno, strerror(errno));
 905                 close(sd);
 906                 return -1;
 907         }
 908
 909 #if 0   /* not needed, because we don't receive using multicast_sd */
 910         {
 911                 struct ip_mreq mreq;
 912                 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 913                 mreq.imr_interface.s_addr = ip_addr;
 914                 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr "
 915                            "0x%x",
 916                            mreq.imr_multiaddr.s_addr,
 917                            mreq.imr_interface.s_addr);
 918                 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq,
 919                                 sizeof(mreq))) {
 920                         wpa_printf(MSG_ERROR,
 921                                    "WPS UPnP: setsockopt "
 922                                    "IP_ADD_MEMBERSHIP errno %d (%s)",
 923                                    errno, strerror(errno));
 924                         close(sd);
 925                         return -1;
 926                 }
 927         }
 928 #endif  /* not needed */
 929
 930         /*
 931          * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default?
 932          * which aids debugging I suppose but isn't really necessary?
 933          */
 934
 935         return sd;
 936 }
 937
 938
 939 /**
 940  * ssdp_open_multicast - Open socket for sending multicast SSDP messages
 941  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 942  * Returns: 0 on success, -1 on failure
 943  */
 944 int ssdp_open_multicast(struct upnp_wps_device_sm *sm)
 945 {
 946         sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr, NULL);
 947         if (sm->multicast_sd < 0)
 948                 return -1;
 949         return 0;
 950 }