src/wps/wps_upnp_ssdp.c

   1 /*
   2  * UPnP SSDP for WPS
   3  * Copyright (c) 2000-2003 Intel Corporation
   4  * Copyright (c) 2006-2007 Sony Corporation
   5  * Copyright (c) 2008-2009 Atheros Communications
   6  * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
   7  *
   8  * See wps_upnp.c for more details on licensing and code history.
   9  */
  10
  11 #include "includes.h"
  12
  13 #include <fcntl.h>
  14 #include <sys/ioctl.h>
  15 #include <net/route.h>
  16
  17 #include "common.h"
  18 #include "uuid.h"
  19 #include "eloop.h"
  20 #include "wps.h"
  21 #include "wps_upnp.h"
  22 #include "wps_upnp_i.h"
  23
  24 #define UPNP_CACHE_SEC (UPNP_CACHE_SEC_MIN + 1) /* cache time we use */
  25 #define UPNP_CACHE_SEC_MIN 1800 /* min cachable time per UPnP standard */
  26 #define UPNP_ADVERTISE_REPEAT 2 /* no more than 3 */
  27 #define MAX_MSEARCH 20          /* max simultaneous M-SEARCH replies ongoing */
  28 #define SSDP_TARGET  "239.0.0.0"
  29 #define SSDP_NETMASK "255.0.0.0"
  30
  31
  32 /* Check tokens for equality, where tokens consist of letters, digits,
  33  * underscore and hyphen, and are matched case insensitive.
  34  */
  35 static int token_eq(const char *s1, const char *s2)
  36 {
  37         int c1;
  38         int c2;
  39         int end1 = 0;
  40         int end2 = 0;
  41         for (;;) {
  42                 c1 = *s1++;
  43                 c2 = *s2++;
  44                 if (isalpha(c1) && isupper(c1))
  45                         c1 = tolower(c1);
  46                 if (isalpha(c2) && isupper(c2))
  47                         c2 = tolower(c2);
  48                 end1 = !(isalnum(c1) || c1 == '_' || c1 == '-');
  49                 end2 = !(isalnum(c2) || c2 == '_' || c2 == '-');
  50                 if (end1 || end2 || c1 != c2)
  51                         break;
  52         }
  53         return end1 && end2; /* reached end of both words? */
  54 }
  55
  56
  57 /* Return length of token (see above for definition of token) */
  58 static int token_length(const char *s)
  59 {
  60         const char *begin = s;
  61         for (;; s++) {
  62                 int c = *s;
  63                 int end = !(isalnum(c) || c == '_' || c == '-');
  64                 if (end)
  65                         break;
  66         }
  67         return s - begin;
  68 }
  69
  70
  71 /* return length of interword separation.
  72  * This accepts only spaces/tabs and thus will not traverse a line
  73  * or buffer ending.
  74  */
  75 static int word_separation_length(const char *s)
  76 {
  77         const char *begin = s;
  78         for (;; s++) {
  79                 int c = *s;
  80                 if (c == ' ' || c == '\t')
  81                         continue;
  82                 break;
  83         }
  84         return s - begin;
  85 }
  86
  87
  88 /* No. of chars through (including) end of line */
  89 static int line_length(const char *l)
  90 {
  91         const char *lp = l;
  92         while (*lp && *lp != '\n')
  93                 lp++;
  94         if (*lp == '\n')
  95                 lp++;
  96         return lp - l;
  97 }
  98
  99
 100 /* No. of chars excluding trailing whitespace */
 101 static int line_length_stripped(const char *l)
 102 {
 103         const char *lp = l + line_length(l);
 104         while (lp > l && !isgraph(lp[-1]))
 105                 lp--;
 106         return lp - l;
 107 }
 108
 109
 110 static int str_starts(const char *str, const char *start)
 111 {
 112         return os_strncmp(str, start, os_strlen(start)) == 0;
 113 }
 114
 115
 116 /***************************************************************************
 117  * Advertisements.
 118  * These are multicast to the world to tell them we are here.
 119  * The individual packets are spread out in time to limit loss,
 120  * and then after a much longer period of time the whole sequence
 121  * is repeated again (for NOTIFYs only).
 122  **************************************************************************/
 123
 124 /**
 125  * next_advertisement - Build next message and advance the state machine
 126  * @a: Advertisement state
 127  * @islast: Buffer for indicating whether this is the last message (= 1)
 128  * Returns: The new message (caller is responsible for freeing this)
 129  *
 130  * Note: next_advertisement is shared code with msearchreply_* functions
 131  */
 132 static struct wpabuf *
 133 next_advertisement(struct advertisement_state_machine *a, int *islast)
 134 {
 135         struct wpabuf *msg;
 136         char *NTString = "";
 137         char uuid_string[80];
 138
 139         *islast = 0;
 140         uuid_bin2str(a->sm->wps->uuid, uuid_string, sizeof(uuid_string));
 141         msg = wpabuf_alloc(800); /* more than big enough */
 142         if (msg == NULL)
 143                 goto fail;
 144         switch (a->type) {
 145         case ADVERTISE_UP:
 146         case ADVERTISE_DOWN:
 147                 NTString = "NT";
 148                 wpabuf_put_str(msg, "NOTIFY * HTTP/1.1\r\n");
 149                 wpabuf_printf(msg, "HOST: %s:%d\r\n",
 150                               UPNP_MULTICAST_ADDRESS, UPNP_MULTICAST_PORT);
 151                 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
 152                               UPNP_CACHE_SEC);
 153                 wpabuf_printf(msg, "NTS: %s\r\n",
 154                               (a->type == ADVERTISE_UP ?
 155                                "ssdp:alive" : "ssdp:byebye"));
 156                 break;
 157         case MSEARCH_REPLY:
 158                 NTString = "ST";
 159                 wpabuf_put_str(msg, "HTTP/1.1 200 OK\r\n");
 160                 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
 161                               UPNP_CACHE_SEC);
 162
 163                 wpabuf_put_str(msg, "DATE: ");
 164                 format_date(msg);
 165                 wpabuf_put_str(msg, "\r\n");
 166
 167                 wpabuf_put_str(msg, "EXT:\r\n");
 168                 break;
 169         }
 170
 171         if (a->type != ADVERTISE_DOWN) {
 172                 /* Where others may get our XML files from */
 173                 wpabuf_printf(msg, "LOCATION: http://%s:%d/%s\r\n",
 174                               a->sm->ip_addr_text, a->sm->web_port,
 175                               UPNP_WPS_DEVICE_XML_FILE);
 176         }
 177
 178         /* The SERVER line has three comma-separated fields:
 179          *      operating system / version
 180          *      upnp version
 181          *      software package / version
 182          * However, only the UPnP version is really required, the
 183          * others can be place holders... for security reasons
 184          * it is better to NOT provide extra information.
 185          */
 186         wpabuf_put_str(msg, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");
 187
 188         switch (a->state / UPNP_ADVERTISE_REPEAT) {
 189         case 0:
 190                 wpabuf_printf(msg, "%s: upnp:rootdevice\r\n", NTString);
 191                 wpabuf_printf(msg, "USN: uuid:%s::upnp:rootdevice\r\n",
 192                               uuid_string);
 193                 break;
 194         case 1:
 195                 wpabuf_printf(msg, "%s: uuid:%s\r\n", NTString, uuid_string);
 196                 wpabuf_printf(msg, "USN: uuid:%s\r\n", uuid_string);
 197                 break;
 198         case 2:
 199                 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:device:"
 200                               "WFADevice:1\r\n", NTString);
 201                 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
 202                               "org:device:WFADevice:1\r\n", uuid_string);
 203                 break;
 204         case 3:
 205                 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:service:"
 206                               "WFAWLANConfig:1\r\n", NTString);
 207                 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
 208                               "org:service:WFAWLANConfig:1\r\n", uuid_string);
 209                 break;
 210         }
 211         wpabuf_put_str(msg, "\r\n");
 212
 213         if (a->state + 1 >= 4 * UPNP_ADVERTISE_REPEAT)
 214                 *islast = 1;
 215
 216         return msg;
 217
 218 fail:
 219         wpabuf_free(msg);
 220         return NULL;
 221 }
 222
 223
 224 static void advertisement_state_machine_handler(void *eloop_data,
 225                                                 void *user_ctx);
 226
 227
 228 /**
 229  * advertisement_state_machine_stop - Stop SSDP advertisements
 230  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 231  */
 232 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm)
 233 {
 234         eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm);
 235 }
 236
 237
 238 static void advertisement_state_machine_handler(void *eloop_data,
 239                                                 void *user_ctx)
 240 {
 241         struct upnp_wps_device_sm *sm = user_ctx;
 242         struct advertisement_state_machine *a = &sm->advertisement;
 243         struct wpabuf *msg;
 244         int next_timeout_msec = 100;
 245         int next_timeout_sec = 0;
 246         struct sockaddr_in dest;
 247         int islast = 0;
 248
 249         /*
 250          * Each is sent twice (in case lost) w/ 100 msec delay between;
 251          * spec says no more than 3 times.
 252          * One pair for rootdevice, one pair for uuid, and a pair each for
 253          * each of the two urns.
 254          * The entire sequence must be repeated before cache control timeout
 255          * (which  is min  1800 seconds),
 256          * recommend random portion of half of the advertised cache control age
 257          * to ensure against loss... perhaps 1800/4 + rand*1800/4 ?
 258          * Delay random interval < 100 msec prior to initial sending.
 259          * TTL of 4
 260          */
 261
 262         wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state);
 263         msg = next_advertisement(a, &islast);
 264         if (msg == NULL)
 265                 return;
 266
 267         os_memset(&dest, 0, sizeof(dest));
 268         dest.sin_family = AF_INET;
 269         dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 270         dest.sin_port = htons(UPNP_MULTICAST_PORT);
 271
 272         if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
 273                    (struct sockaddr *) &dest, sizeof(dest)) == -1) {
 274                 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:"
 275                            "%d (%s)", errno, strerror(errno));
 276                 next_timeout_msec = 0;
 277                 next_timeout_sec = 10; /* ... later */
 278         } else if (islast) {
 279                 a->state = 0; /* wrap around */
 280                 if (a->type == ADVERTISE_DOWN) {
 281                         wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP");
 282                         a->type = ADVERTISE_UP;
 283                         /* do it all over again right away */
 284                 } else {
 285                         u16 r;
 286                         /*
 287                          * Start over again after a long timeout
 288                          * (see notes above)
 289                          */
 290                         next_timeout_msec = 0;
 291                         os_get_random((void *) &r, sizeof(r));
 292                         next_timeout_sec = UPNP_CACHE_SEC / 4 +
 293                                 (((UPNP_CACHE_SEC / 4) * r) >> 16);
 294                         sm->advertise_count++;
 295                         wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); "
 296                                    "next in %d sec",
 297                                    sm->advertise_count, next_timeout_sec);
 298                 }
 299         } else {
 300                 a->state++;
 301         }
 302
 303         wpabuf_free(msg);
 304
 305         eloop_register_timeout(next_timeout_sec, next_timeout_msec,
 306                                advertisement_state_machine_handler, NULL, sm);
 307 }
 308
 309
 310 /**
 311  * advertisement_state_machine_start - Start SSDP advertisements
 312  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 313  * Returns: 0 on success, -1 on failure
 314  */
 315 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm)
 316 {
 317         struct advertisement_state_machine *a = &sm->advertisement;
 318         int next_timeout_msec;
 319
 320         advertisement_state_machine_stop(sm);
 321
 322         /*
 323          * Start out advertising down, this automatically switches
 324          * to advertising up which signals our restart.
 325          */
 326         a->type = ADVERTISE_DOWN;
 327         a->state = 0;
 328         a->sm = sm;
 329         /* (other fields not used here) */
 330
 331         /* First timeout should be random interval < 100 msec */
 332         next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8;
 333         return eloop_register_timeout(0, next_timeout_msec,
 334                                       advertisement_state_machine_handler,
 335                                       NULL, sm);
 336 }
 337
 338
 339 /***************************************************************************
 340  * M-SEARCH replies
 341  * These are very similar to the multicast advertisements, with some
 342  * small changes in data content; and they are sent (UDP) to a specific
 343  * unicast address instead of multicast.
 344  * They are sent in response to a UDP M-SEARCH packet.
 345  **************************************************************************/
 346
 347 static void msearchreply_state_machine_handler(void *eloop_data,
 348                                                void *user_ctx);
 349
 350
 351 /**
 352  * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine
 353  * @a: Selected advertisement/reply state
 354  */
 355 void msearchreply_state_machine_stop(struct advertisement_state_machine *a)
 356 {
 357         struct upnp_wps_device_sm *sm = a->sm;
 358         wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop");
 359         if (a->next == a) {
 360                 sm->msearch_replies = NULL;
 361         } else {
 362                 if (sm->msearch_replies == a)
 363                         sm->msearch_replies = a->next;
 364                 a->next->prev = a->prev;
 365                 a->prev->next = a->next;
 366         }
 367         os_free(a);
 368         sm->n_msearch_replies--;
 369 }
 370
 371
 372 static void msearchreply_state_machine_handler(void *eloop_data,
 373                                                void *user_ctx)
 374 {
 375         struct advertisement_state_machine *a = user_ctx;
 376         struct upnp_wps_device_sm *sm = a->sm;
 377         struct wpabuf *msg;
 378         int next_timeout_msec = 100;
 379         int next_timeout_sec = 0;
 380         int islast = 0;
 381
 382         /*
 383          * Each response is sent twice (in case lost) w/ 100 msec delay
 384          * between; spec says no more than 3 times.
 385          * One pair for rootdevice, one pair for uuid, and a pair each for
 386          * each of the two urns.
 387          */
 388
 389         /* TODO: should only send the requested response types */
 390
 391         wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)",
 392                    a->state, inet_ntoa(a->client.sin_addr),
 393                    ntohs(a->client.sin_port));
 394         msg = next_advertisement(a, &islast);
 395         if (msg == NULL)
 396                 return;
 397
 398         /*
 399          * Send it on the multicast socket to avoid having to set up another
 400          * socket.
 401          */
 402         if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
 403                    (struct sockaddr *) &a->client, sizeof(a->client)) < 0) {
 404                 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto "
 405                            "errno %d (%s) for %s:%d",
 406                            errno, strerror(errno),
 407                            inet_ntoa(a->client.sin_addr),
 408                            ntohs(a->client.sin_port));
 409                 /* Ignore error and hope for the best */
 410         }
 411         wpabuf_free(msg);
 412         if (islast) {
 413                 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done");
 414                 msearchreply_state_machine_stop(a);
 415                 return;
 416         }
 417         a->state++;
 418
 419         wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec",
 420                    next_timeout_sec, next_timeout_msec);
 421         eloop_register_timeout(next_timeout_sec, next_timeout_msec,
 422                                msearchreply_state_machine_handler, sm, a);
 423 }
 424
 425
 426 /**
 427  * msearchreply_state_machine_start - Reply to M-SEARCH discovery request
 428  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 429  * @client: Client address
 430  * @mx: Maximum delay in seconds
 431  *
 432  * Use TTL of 4 (this was done when socket set up).
 433  * A response should be given in randomized portion of min(MX,120) seconds
 434  *
 435  * UPnP-arch-DeviceArchitecture, 1.2.3:
 436  * To be found, a device must send a UDP response to the source IP address and
 437  * port that sent the request to the multicast channel. Devices respond if the
 438  * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:"
 439  * followed by a UUID that exactly matches one advertised by the device.
 440  */
 441 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm,
 442                                              struct sockaddr_in *client,
 443                                              int mx)
 444 {
 445         struct advertisement_state_machine *a;
 446         int next_timeout_sec;
 447         int next_timeout_msec;
 448
 449         wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d "
 450                    "outstanding)", sm->n_msearch_replies);
 451         if (sm->n_msearch_replies >= MAX_MSEARCH) {
 452                 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding "
 453                            "M-SEARCH replies");
 454                 return;
 455         }
 456
 457         a = os_zalloc(sizeof(*a));
 458         if (a == NULL)
 459                 return;
 460         a->type = MSEARCH_REPLY;
 461         a->state = 0;
 462         a->sm = sm;
 463         os_memcpy(&a->client, client, sizeof(*client));
 464         /* Wait time depending on MX value */
 465         next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8;
 466         next_timeout_sec = next_timeout_msec / 1000;
 467         next_timeout_msec = next_timeout_msec % 1000;
 468         if (eloop_register_timeout(next_timeout_sec, next_timeout_msec,
 469                                    msearchreply_state_machine_handler, sm,
 470                                    a)) {
 471                 /* No way to recover (from malloc failure) */
 472                 goto fail;
 473         }
 474         /* Remember for future cleanup */
 475         if (sm->msearch_replies) {
 476                 a->next = sm->msearch_replies;
 477                 a->prev = a->next->prev;
 478                 a->prev->next = a;
 479                 a->next->prev = a;
 480         } else {
 481                 sm->msearch_replies = a->next = a->prev = a;
 482         }
 483         sm->n_msearch_replies++;
 484         return;
 485
 486 fail:
 487         wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!");
 488         eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a);
 489         os_free(a);
 490 }
 491
 492
 493 /**
 494  * ssdp_parse_msearch - Process a received M-SEARCH
 495  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 496  * @client: Client address
 497  * @data: NULL terminated M-SEARCH message
 498  *
 499  * Given that we have received a header w/ M-SEARCH, act upon it
 500  *
 501  * Format of M-SEARCH (case insensitive!):
 502  *
 503  * First line must be:
 504  *      M-SEARCH * HTTP/1.1
 505  * Other lines in arbitrary order:
 506  *      HOST:239.255.255.250:1900
 507  *      ST:<varies -- must match>
 508  *      MAN:"ssdp:discover"
 509  *      MX:<varies>
 510  *
 511  * It should be noted that when Microsoft Vista is still learning its IP
 512  * address, it sends out host lines like: HOST:[FF02::C]:1900
 513  */
 514 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm,
 515                                struct sockaddr_in *client, const char *data)
 516 {
 517         const char *start = data;
 518         const char *end;
 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                 end = data + line_length_stripped(data);
 534                 if (token_eq(data, "host")) {
 535                         /* The host line indicates who the packet
 536                          * is addressed to... but do we really care?
 537                          * Note that Microsoft sometimes does funny
 538                          * stuff with the HOST: line.
 539                          */
 540 #if 0   /* could be */
 541                         data += token_length(data);
 542                         data += word_separation_length(data);
 543                         if (*data != ':')
 544                                 goto bad;
 545                         data++;
 546                         data += word_separation_length(data);
 547                         /* UPNP_MULTICAST_ADDRESS */
 548                         if (!str_starts(data, "239.255.255.250"))
 549                                 goto bad;
 550                         data += os_strlen("239.255.255.250");
 551                         if (*data == ':') {
 552                                 if (!str_starts(data, ":1900"))
 553                                         goto bad;
 554                         }
 555 #endif  /* could be */
 556                         got_host = 1;
 557                         continue;
 558                 } else if (token_eq(data, "st")) {
 559                         /* There are a number of forms; we look
 560                          * for one that matches our case.
 561                          */
 562                         got_st = 1;
 563                         data += token_length(data);
 564                         data += word_separation_length(data);
 565                         if (*data != ':')
 566                                 continue;
 567                         data++;
 568                         data += word_separation_length(data);
 569                         if (str_starts(data, "ssdp:all")) {
 570                                 st_match = 1;
 571                                 continue;
 572                         }
 573                         if (str_starts(data, "upnp:rootdevice")) {
 574                                 st_match = 1;
 575                                 continue;
 576                         }
 577                         if (str_starts(data, "uuid:")) {
 578                                 char uuid_string[80];
 579                                 data += os_strlen("uuid:");
 580                                 uuid_bin2str(sm->wps->uuid, uuid_string,
 581                                              sizeof(uuid_string));
 582                                 if (str_starts(data, uuid_string))
 583                                         st_match = 1;
 584                                 continue;
 585                         }
 586 #if 0
 587                         /* FIX: should we really reply to IGD string? */
 588                         if (str_starts(data, "urn:schemas-upnp-org:device:"
 589                                        "InternetGatewayDevice:1")) {
 590                                 st_match = 1;
 591                                 continue;
 592                         }
 593 #endif
 594                         if (str_starts(data, "urn:schemas-wifialliance-org:"
 595                                        "service:WFAWLANConfig:1")) {
 596                                 st_match = 1;
 597                                 continue;
 598                         }
 599                         if (str_starts(data, "urn:schemas-wifialliance-org:"
 600                                        "device:WFADevice:1")) {
 601                                 st_match = 1;
 602                                 continue;
 603                         }
 604                         continue;
 605                 } else if (token_eq(data, "man")) {
 606                         data += token_length(data);
 607                         data += word_separation_length(data);
 608                         if (*data != ':')
 609                                 continue;
 610                         data++;
 611                         data += word_separation_length(data);
 612                         if (!str_starts(data, "\"ssdp:discover\"")) {
 613                                 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected "
 614                                            "M-SEARCH man-field");
 615                                 goto bad;
 616                         }
 617                         got_man = 1;
 618                         continue;
 619                 } else if (token_eq(data, "mx")) {
 620                         data += token_length(data);
 621                         data += word_separation_length(data);
 622                         if (*data != ':')
 623                                 continue;
 624                         data++;
 625                         data += word_separation_length(data);
 626                         mx = atol(data);
 627                         got_mx = 1;
 628                         continue;
 629                 }
 630                 /* ignore anything else */
 631         }
 632         if (!got_host || !got_st || !got_man || !got_mx || mx < 0) {
 633                 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d "
 634                            "%d mx=%d", got_host, got_st, got_man, got_mx, mx);
 635                 goto bad;
 636         }
 637         if (!st_match) {
 638                 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST "
 639                            "match)");
 640                 return;
 641         }
 642         if (mx > 120)
 643                 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */
 644         msearchreply_state_machine_start(sm, client, mx);
 645         return;
 646
 647 bad:
 648         wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH");
 649         wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start);
 650 }
 651
 652
 653 /* Listening for (UDP) discovery (M-SEARCH) packets */
 654
 655 /**
 656  * ssdp_listener_stop - Stop SSDP listered
 657  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 658  *
 659  * This function stops the SSDP listener that was started by calling
 660  * ssdp_listener_start().
 661  */
 662 void ssdp_listener_stop(struct upnp_wps_device_sm *sm)
 663 {
 664         if (sm->ssdp_sd_registered) {
 665                 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ);
 666                 sm->ssdp_sd_registered = 0;
 667         }
 668
 669         if (sm->ssdp_sd != -1) {
 670                 close(sm->ssdp_sd);
 671                 sm->ssdp_sd = -1;
 672         }
 673
 674         eloop_cancel_timeout(msearchreply_state_machine_handler, sm,
 675                              ELOOP_ALL_CTX);
 676 }
 677
 678
 679 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx)
 680 {
 681         struct upnp_wps_device_sm *sm = sock_ctx;
 682         struct sockaddr_in addr; /* client address */
 683         socklen_t addr_len;
 684         int nread;
 685         char buf[MULTICAST_MAX_READ], *pos;
 686
 687         addr_len = sizeof(addr);
 688         nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0,
 689                          (struct sockaddr *) &addr, &addr_len);
 690         if (nread <= 0)
 691                 return;
 692         buf[nread] = '\0'; /* need null termination for algorithm */
 693
 694         if (str_starts(buf, "NOTIFY ")) {
 695                 /*
 696                  * Silently ignore NOTIFYs to avoid filling debug log with
 697                  * unwanted messages.
 698                  */
 699                 return;
 700         }
 701
 702         pos = os_strchr(buf, '\n');
 703         if (pos)
 704                 *pos = '\0';
 705         wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: "
 706                    "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf);
 707         if (pos)
 708                 *pos = '\n';
 709
 710         /* Parse first line */
 711         if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 &&
 712             !isgraph(buf[strlen("M-SEARCH")])) {
 713                 ssdp_parse_msearch(sm, &addr, buf);
 714                 return;
 715         }
 716
 717         /* Ignore anything else */
 718 }
 719
 720
 721 int ssdp_listener_open(void)
 722 {
 723         struct sockaddr_in addr;
 724         struct ip_mreq mcast_addr;
 725         int on = 1;
 726         /* per UPnP spec, keep IP packet time to live (TTL) small */
 727         unsigned char ttl = 4;
 728         int sd;
 729
 730         sd = socket(AF_INET, SOCK_DGRAM, 0);
 731         if (sd < 0)
 732                 goto fail;
 733         if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
 734                 goto fail;
 735         if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
 736                 goto fail;
 737         os_memset(&addr, 0, sizeof(addr));
 738         addr.sin_family = AF_INET;
 739         addr.sin_addr.s_addr = htonl(INADDR_ANY);
 740         addr.sin_port = htons(UPNP_MULTICAST_PORT);
 741         if (bind(sd, (struct sockaddr *) &addr, sizeof(addr)))
 742                 goto fail;
 743         os_memset(&mcast_addr, 0, sizeof(mcast_addr));
 744         mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY);
 745         mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 746         if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 747                        (char *) &mcast_addr, sizeof(mcast_addr)))
 748                 goto fail;
 749         if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
 750                        &ttl, sizeof(ttl)))
 751                 goto fail;
 752
 753         return sd;
 754
 755 fail:
 756         if (sd >= 0)
 757                 close(sd);
 758         return -1;
 759 }
 760
 761
 762 /**
 763  * ssdp_listener_start - Set up for receiving discovery (UDP) packets
 764  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 765  * Returns: 0 on success, -1 on failure
 766  *
 767  * The SSDP listener is stopped by calling ssdp_listener_stop().
 768  */
 769 int ssdp_listener_start(struct upnp_wps_device_sm *sm)
 770 {
 771         sm->ssdp_sd = ssdp_listener_open();
 772
 773         if (eloop_register_sock(sm->ssdp_sd, EVENT_TYPE_READ,
 774                                 ssdp_listener_handler, NULL, sm))
 775                 goto fail;
 776         sm->ssdp_sd_registered = 1;
 777         return 0;
 778
 779 fail:
 780         /* Error */
 781         wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed");
 782         ssdp_listener_stop(sm);
 783         return -1;
 784 }
 785
 786
 787 /**
 788  * add_ssdp_network - Add routing entry for SSDP
 789  * @net_if: Selected network interface name
 790  * Returns: 0 on success, -1 on failure
 791  *
 792  * This function assures that the multicast address will be properly
 793  * handled by Linux networking code (by a modification to routing tables).
 794  * This must be done per network interface. It really only needs to be done
 795  * once after booting up, but it does not hurt to call this more frequently
 796  * "to be safe".
 797  */
 798 int add_ssdp_network(const char *net_if)
 799 {
 800 #ifdef __linux__
 801         int ret = -1;
 802         int sock = -1;
 803         struct rtentry rt;
 804         struct sockaddr_in *sin;
 805
 806         if (!net_if)
 807                 goto fail;
 808
 809         os_memset(&rt, 0, sizeof(rt));
 810         sock = socket(AF_INET, SOCK_DGRAM, 0);
 811         if (sock < 0)
 812                 goto fail;
 813
 814         rt.rt_dev = (char *) net_if;
 815         sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in);
 816         sin->sin_family = AF_INET;
 817         sin->sin_port = 0;
 818         sin->sin_addr.s_addr = inet_addr(SSDP_TARGET);
 819         sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in);
 820         sin->sin_family = AF_INET;
 821         sin->sin_port = 0;
 822         sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK);
 823         rt.rt_flags = RTF_UP;
 824         if (ioctl(sock, SIOCADDRT, &rt) < 0) {
 825                 if (errno == EPERM) {
 826                         wpa_printf(MSG_DEBUG, "add_ssdp_network: No "
 827                                    "permissions to add routing table entry");
 828                         /* Continue to allow testing as non-root */
 829                 } else if (errno != EEXIST) {
 830                         wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno "
 831                                    "%d (%s)", errno, strerror(errno));
 832                         goto fail;
 833                 }
 834         }
 835
 836         ret = 0;
 837
 838 fail:
 839         if (sock >= 0)
 840                 close(sock);
 841
 842         return ret;
 843 #else /* __linux__ */
 844         return 0;
 845 #endif /* __linux__ */
 846 }
 847
 848
 849 int ssdp_open_multicast_sock(u32 ip_addr)
 850 {
 851         int sd;
 852          /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet
 853           * time to live (TTL) small */
 854         unsigned char ttl = 4;
 855
 856         sd = socket(AF_INET, SOCK_DGRAM, 0);
 857         if (sd < 0)
 858                 return -1;
 859
 860 #if 0   /* maybe ok if we sometimes block on writes */
 861         if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
 862                 return -1;
 863 #endif
 864
 865         if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF,
 866                        &ip_addr, sizeof(ip_addr)))
 867                 return -1;
 868         if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
 869                        &ttl, sizeof(ttl)))
 870                 return -1;
 871
 872 #if 0   /* not needed, because we don't receive using multicast_sd */
 873         {
 874                 struct ip_mreq mreq;
 875                 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
 876                 mreq.imr_interface.s_addr = ip_addr;
 877                 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr "
 878                            "0x%x",
 879                            mreq.imr_multiaddr.s_addr,
 880                            mreq.imr_interface.s_addr);
 881                 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq,
 882                                 sizeof(mreq))) {
 883                         wpa_printf(MSG_ERROR,
 884                                    "WPS UPnP: setsockopt "
 885                                    "IP_ADD_MEMBERSHIP errno %d (%s)",
 886                                    errno, strerror(errno));
 887                         return -1;
 888                 }
 889         }
 890 #endif  /* not needed */
 891
 892         /*
 893          * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default?
 894          * which aids debugging I suppose but isn't really necessary?
 895          */
 896
 897         return sd;
 898 }
 899
 900
 901 /**
 902  * ssdp_open_multicast - Open socket for sending multicast SSDP messages
 903  * @sm: WPS UPnP state machine from upnp_wps_device_init()
 904  * Returns: 0 on success, -1 on failure
 905  */
 906 int ssdp_open_multicast(struct upnp_wps_device_sm *sm)
 907 {
 908         sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr);
 909         if (sm->multicast_sd < 0)
 910                 return -1;
 911         return 0;
 912 }