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