• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 MULTICAST_MAX_READ 1600 /* max bytes we'll read for UPD request */
28 #define MAX_MSEARCH 20          /* max simultaneous M-SEARCH replies ongoing */
29 #define SSDP_TARGET  "239.0.0.0"
30 #define SSDP_NETMASK "255.0.0.0"
31 
32 
33 /* Check tokens for equality, where tokens consist of letters, digits,
34  * underscore and hyphen, and are matched case insensitive.
35  */
token_eq(const char * s1,const char * s2)36 static int token_eq(const char *s1, const char *s2)
37 {
38 	int c1;
39 	int c2;
40 	int end1 = 0;
41 	int end2 = 0;
42 	for (;;) {
43 		c1 = *s1++;
44 		c2 = *s2++;
45 		if (isalpha(c1) && isupper(c1))
46 			c1 = tolower(c1);
47 		if (isalpha(c2) && isupper(c2))
48 			c2 = tolower(c2);
49 		end1 = !(isalnum(c1) || c1 == '_' || c1 == '-');
50 		end2 = !(isalnum(c2) || c2 == '_' || c2 == '-');
51 		if (end1 || end2 || c1 != c2)
52 			break;
53 	}
54 	return end1 && end2; /* reached end of both words? */
55 }
56 
57 
58 /* Return length of token (see above for definition of token) */
token_length(const char * s)59 static int token_length(const char *s)
60 {
61 	const char *begin = s;
62 	for (;; s++) {
63 		int c = *s;
64 		int end = !(isalnum(c) || c == '_' || c == '-');
65 		if (end)
66 			break;
67 	}
68 	return s - begin;
69 }
70 
71 
72 /* return length of interword separation.
73  * This accepts only spaces/tabs and thus will not traverse a line
74  * or buffer ending.
75  */
word_separation_length(const char * s)76 static int word_separation_length(const char *s)
77 {
78 	const char *begin = s;
79 	for (;; s++) {
80 		int c = *s;
81 		if (c == ' ' || c == '\t')
82 			continue;
83 		break;
84 	}
85 	return s - begin;
86 }
87 
88 
89 /* No. of chars through (including) end of line */
line_length(const char * l)90 static int line_length(const char *l)
91 {
92 	const char *lp = l;
93 	while (*lp && *lp != '\n')
94 		lp++;
95 	if (*lp == '\n')
96 		lp++;
97 	return lp - l;
98 }
99 
100 
101 /* No. of chars excluding trailing whitespace */
line_length_stripped(const char * l)102 static int line_length_stripped(const char *l)
103 {
104 	const char *lp = l + line_length(l);
105 	while (lp > l && !isgraph(lp[-1]))
106 		lp--;
107 	return lp - l;
108 }
109 
110 
str_starts(const char * str,const char * start)111 static int str_starts(const char *str, const char *start)
112 {
113 	return os_strncmp(str, start, os_strlen(start)) == 0;
114 }
115 
116 
117 /***************************************************************************
118  * Advertisements.
119  * These are multicast to the world to tell them we are here.
120  * The individual packets are spread out in time to limit loss,
121  * and then after a much longer period of time the whole sequence
122  * is repeated again (for NOTIFYs only).
123  **************************************************************************/
124 
125 /**
126  * next_advertisement - Build next message and advance the state machine
127  * @a: Advertisement state
128  * @islast: Buffer for indicating whether this is the last message (= 1)
129  * Returns: The new message (caller is responsible for freeing this)
130  *
131  * Note: next_advertisement is shared code with msearchreply_* functions
132  */
133 static struct wpabuf *
next_advertisement(struct advertisement_state_machine * a,int * islast)134 next_advertisement(struct advertisement_state_machine *a, int *islast)
135 {
136 	struct wpabuf *msg;
137 	char *NTString = "";
138 	char uuid_string[80];
139 
140 	*islast = 0;
141 	uuid_bin2str(a->sm->wps->uuid, uuid_string, sizeof(uuid_string));
142 	msg = wpabuf_alloc(800); /* more than big enough */
143 	if (msg == NULL)
144 		goto fail;
145 	switch (a->type) {
146 	case ADVERTISE_UP:
147 	case ADVERTISE_DOWN:
148 		NTString = "NT";
149 		wpabuf_put_str(msg, "NOTIFY * HTTP/1.1\r\n");
150 		wpabuf_printf(msg, "HOST: %s:%d\r\n",
151 			      UPNP_MULTICAST_ADDRESS, UPNP_MULTICAST_PORT);
152 		wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
153 			      UPNP_CACHE_SEC);
154 		wpabuf_printf(msg, "NTS: %s\r\n",
155 			      (a->type == ADVERTISE_UP ?
156 			       "ssdp:alive" : "ssdp:byebye"));
157 		break;
158 	case MSEARCH_REPLY:
159 		NTString = "ST";
160 		wpabuf_put_str(msg, "HTTP/1.1 200 OK\r\n");
161 		wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
162 			      UPNP_CACHE_SEC);
163 
164 		wpabuf_put_str(msg, "DATE: ");
165 		format_date(msg);
166 		wpabuf_put_str(msg, "\r\n");
167 
168 		wpabuf_put_str(msg, "EXT:\r\n");
169 		break;
170 	}
171 
172 	if (a->type != ADVERTISE_DOWN) {
173 		/* Where others may get our XML files from */
174 		wpabuf_printf(msg, "LOCATION: http://%s:%d/%s\r\n",
175 			      a->sm->ip_addr_text, a->sm->web_port,
176 			      UPNP_WPS_DEVICE_XML_FILE);
177 	}
178 
179 	/* The SERVER line has three comma-separated fields:
180 	 *      operating system / version
181 	 *      upnp version
182 	 *      software package / version
183 	 * However, only the UPnP version is really required, the
184 	 * others can be place holders... for security reasons
185 	 * it is better to NOT provide extra information.
186 	 */
187 	wpabuf_put_str(msg, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");
188 
189 	switch (a->state / UPNP_ADVERTISE_REPEAT) {
190 	case 0:
191 		wpabuf_printf(msg, "%s: upnp:rootdevice\r\n", NTString);
192 		wpabuf_printf(msg, "USN: uuid:%s::upnp:rootdevice\r\n",
193 			      uuid_string);
194 		break;
195 	case 1:
196 		wpabuf_printf(msg, "%s: uuid:%s\r\n", NTString, uuid_string);
197 		wpabuf_printf(msg, "USN: uuid:%s\r\n", uuid_string);
198 		break;
199 	case 2:
200 		wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:device:"
201 			      "WFADevice:1\r\n", NTString);
202 		wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
203 			      "org:device:WFADevice:1\r\n", uuid_string);
204 		break;
205 	case 3:
206 		wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:service:"
207 			      "WFAWLANConfig:1\r\n", NTString);
208 		wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
209 			      "org:service:WFAWLANConfig:1\r\n", uuid_string);
210 		break;
211 	}
212 	wpabuf_put_str(msg, "\r\n");
213 
214 	if (a->state + 1 >= 4 * UPNP_ADVERTISE_REPEAT)
215 		*islast = 1;
216 
217 	return msg;
218 
219 fail:
220 	wpabuf_free(msg);
221 	return NULL;
222 }
223 
224 
225 static void advertisement_state_machine_handler(void *eloop_data,
226 						void *user_ctx);
227 
228 
229 /**
230  * advertisement_state_machine_stop - Stop SSDP advertisements
231  * @sm: WPS UPnP state machine from upnp_wps_device_init()
232  * @send_byebye: Send byebye advertisement messages immediately
233  */
advertisement_state_machine_stop(struct upnp_wps_device_sm * sm,int send_byebye)234 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm,
235 				      int send_byebye)
236 {
237 	struct advertisement_state_machine *a = &sm->advertisement;
238 	int islast = 0;
239 	struct wpabuf *msg;
240 	struct sockaddr_in dest;
241 
242 	eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm);
243 	if (!send_byebye || sm->multicast_sd < 0)
244 		return;
245 
246 	a->type = ADVERTISE_DOWN;
247 	a->state = 0;
248 	a->sm = sm;
249 
250 	os_memset(&dest, 0, sizeof(dest));
251 	dest.sin_family = AF_INET;
252 	dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
253 	dest.sin_port = htons(UPNP_MULTICAST_PORT);
254 
255 	while (!islast) {
256 		msg = next_advertisement(a, &islast);
257 		if (msg == NULL)
258 			break;
259 		if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg),
260 			   0, (struct sockaddr *) &dest, sizeof(dest)) < 0) {
261 			wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto "
262 				   "failed: %d (%s)", errno, strerror(errno));
263 		}
264 		wpabuf_free(msg);
265 		a->state++;
266 	}
267 }
268 
269 
advertisement_state_machine_handler(void * eloop_data,void * user_ctx)270 static void advertisement_state_machine_handler(void *eloop_data,
271 						void *user_ctx)
272 {
273 	struct upnp_wps_device_sm *sm = user_ctx;
274 	struct advertisement_state_machine *a = &sm->advertisement;
275 	struct wpabuf *msg;
276 	int next_timeout_msec = 100;
277 	int next_timeout_sec = 0;
278 	struct sockaddr_in dest;
279 	int islast = 0;
280 
281 	/*
282 	 * Each is sent twice (in case lost) w/ 100 msec delay between;
283 	 * spec says no more than 3 times.
284 	 * One pair for rootdevice, one pair for uuid, and a pair each for
285 	 * each of the two urns.
286 	 * The entire sequence must be repeated before cache control timeout
287 	 * (which  is min  1800 seconds),
288 	 * recommend random portion of half of the advertised cache control age
289 	 * to ensure against loss... perhaps 1800/4 + rand*1800/4 ?
290 	 * Delay random interval < 100 msec prior to initial sending.
291 	 * TTL of 4
292 	 */
293 
294 	wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state);
295 	msg = next_advertisement(a, &islast);
296 	if (msg == NULL)
297 		return;
298 
299 	os_memset(&dest, 0, sizeof(dest));
300 	dest.sin_family = AF_INET;
301 	dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
302 	dest.sin_port = htons(UPNP_MULTICAST_PORT);
303 
304 	if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
305 		   (struct sockaddr *) &dest, sizeof(dest)) == -1) {
306 		wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:"
307 			   "%d (%s)", errno, strerror(errno));
308 		next_timeout_msec = 0;
309 		next_timeout_sec = 10; /* ... later */
310 	} else if (islast) {
311 		a->state = 0; /* wrap around */
312 		if (a->type == ADVERTISE_DOWN) {
313 			wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP");
314 			a->type = ADVERTISE_UP;
315 			/* do it all over again right away */
316 		} else {
317 			u16 r;
318 			/*
319 			 * Start over again after a long timeout
320 			 * (see notes above)
321 			 */
322 			next_timeout_msec = 0;
323 			os_get_random((void *) &r, sizeof(r));
324 			next_timeout_sec = UPNP_CACHE_SEC / 4 +
325 				(((UPNP_CACHE_SEC / 4) * r) >> 16);
326 			sm->advertise_count++;
327 			wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); "
328 				   "next in %d sec",
329 				   sm->advertise_count, next_timeout_sec);
330 		}
331 	} else {
332 		a->state++;
333 	}
334 
335 	wpabuf_free(msg);
336 
337 	eloop_register_timeout(next_timeout_sec, next_timeout_msec,
338 			       advertisement_state_machine_handler, NULL, sm);
339 }
340 
341 
342 /**
343  * advertisement_state_machine_start - Start SSDP advertisements
344  * @sm: WPS UPnP state machine from upnp_wps_device_init()
345  * Returns: 0 on success, -1 on failure
346  */
advertisement_state_machine_start(struct upnp_wps_device_sm * sm)347 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm)
348 {
349 	struct advertisement_state_machine *a = &sm->advertisement;
350 	int next_timeout_msec;
351 
352 	advertisement_state_machine_stop(sm, 0);
353 
354 	/*
355 	 * Start out advertising down, this automatically switches
356 	 * to advertising up which signals our restart.
357 	 */
358 	a->type = ADVERTISE_DOWN;
359 	a->state = 0;
360 	a->sm = sm;
361 	/* (other fields not used here) */
362 
363 	/* First timeout should be random interval < 100 msec */
364 	next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8;
365 	return eloop_register_timeout(0, next_timeout_msec,
366 				      advertisement_state_machine_handler,
367 				      NULL, sm);
368 }
369 
370 
371 /***************************************************************************
372  * M-SEARCH replies
373  * These are very similar to the multicast advertisements, with some
374  * small changes in data content; and they are sent (UDP) to a specific
375  * unicast address instead of multicast.
376  * They are sent in response to a UDP M-SEARCH packet.
377  **************************************************************************/
378 
379 static void msearchreply_state_machine_handler(void *eloop_data,
380 					       void *user_ctx);
381 
382 
383 /**
384  * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine
385  * @a: Selected advertisement/reply state
386  */
msearchreply_state_machine_stop(struct advertisement_state_machine * a)387 void msearchreply_state_machine_stop(struct advertisement_state_machine *a)
388 {
389 	struct upnp_wps_device_sm *sm = a->sm;
390 	wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop");
391 	if (a->next == a) {
392 		sm->msearch_replies = NULL;
393 	} else {
394 		if (sm->msearch_replies == a)
395 			sm->msearch_replies = a->next;
396 		a->next->prev = a->prev;
397 		a->prev->next = a->next;
398 	}
399 	os_free(a);
400 	sm->n_msearch_replies--;
401 }
402 
403 
msearchreply_state_machine_handler(void * eloop_data,void * user_ctx)404 static void msearchreply_state_machine_handler(void *eloop_data,
405 					       void *user_ctx)
406 {
407 	struct advertisement_state_machine *a = user_ctx;
408 	struct upnp_wps_device_sm *sm = a->sm;
409 	struct wpabuf *msg;
410 	int next_timeout_msec = 100;
411 	int next_timeout_sec = 0;
412 	int islast = 0;
413 
414 	/*
415 	 * Each response is sent twice (in case lost) w/ 100 msec delay
416 	 * between; spec says no more than 3 times.
417 	 * One pair for rootdevice, one pair for uuid, and a pair each for
418 	 * each of the two urns.
419 	 */
420 
421 	/* TODO: should only send the requested response types */
422 
423 	wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)",
424 		   a->state, inet_ntoa(a->client.sin_addr),
425 		   ntohs(a->client.sin_port));
426 	msg = next_advertisement(a, &islast);
427 	if (msg == NULL)
428 		return;
429 
430 	/*
431 	 * Send it on the multicast socket to avoid having to set up another
432 	 * socket.
433 	 */
434 	if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
435 		   (struct sockaddr *) &a->client, sizeof(a->client)) < 0) {
436 		wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto "
437 			   "errno %d (%s) for %s:%d",
438 			   errno, strerror(errno),
439 			   inet_ntoa(a->client.sin_addr),
440 			   ntohs(a->client.sin_port));
441 		/* Ignore error and hope for the best */
442 	}
443 	wpabuf_free(msg);
444 	if (islast) {
445 		wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done");
446 		msearchreply_state_machine_stop(a);
447 		return;
448 	}
449 	a->state++;
450 
451 	wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec",
452 		   next_timeout_sec, next_timeout_msec);
453 	eloop_register_timeout(next_timeout_sec, next_timeout_msec,
454 			       msearchreply_state_machine_handler, sm, a);
455 }
456 
457 
458 /**
459  * msearchreply_state_machine_start - Reply to M-SEARCH discovery request
460  * @sm: WPS UPnP state machine from upnp_wps_device_init()
461  * @client: Client address
462  * @mx: Maximum delay in seconds
463  *
464  * Use TTL of 4 (this was done when socket set up).
465  * A response should be given in randomized portion of min(MX,120) seconds
466  *
467  * UPnP-arch-DeviceArchitecture, 1.2.3:
468  * To be found, a device must send a UDP response to the source IP address and
469  * port that sent the request to the multicast channel. Devices respond if the
470  * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:"
471  * followed by a UUID that exactly matches one advertised by the device.
472  */
msearchreply_state_machine_start(struct upnp_wps_device_sm * sm,struct sockaddr_in * client,int mx)473 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm,
474 					     struct sockaddr_in *client,
475 					     int mx)
476 {
477 	struct advertisement_state_machine *a;
478 	int next_timeout_sec;
479 	int next_timeout_msec;
480 
481 	wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d "
482 		   "outstanding)", sm->n_msearch_replies);
483 	if (sm->n_msearch_replies >= MAX_MSEARCH) {
484 		wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding "
485 			   "M-SEARCH replies");
486 		return;
487 	}
488 
489 	a = os_zalloc(sizeof(*a));
490 	if (a == NULL)
491 		return;
492 	a->type = MSEARCH_REPLY;
493 	a->state = 0;
494 	a->sm = sm;
495 	os_memcpy(&a->client, client, sizeof(*client));
496 	/* Wait time depending on MX value */
497 	next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8;
498 	next_timeout_sec = next_timeout_msec / 1000;
499 	next_timeout_msec = next_timeout_msec % 1000;
500 	if (eloop_register_timeout(next_timeout_sec, next_timeout_msec,
501 				   msearchreply_state_machine_handler, sm,
502 				   a)) {
503 		/* No way to recover (from malloc failure) */
504 		goto fail;
505 	}
506 	/* Remember for future cleanup */
507 	if (sm->msearch_replies) {
508 		a->next = sm->msearch_replies;
509 		a->prev = a->next->prev;
510 		a->prev->next = a;
511 		a->next->prev = a;
512 	} else {
513 		sm->msearch_replies = a->next = a->prev = a;
514 	}
515 	sm->n_msearch_replies++;
516 	return;
517 
518 fail:
519 	wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!");
520 	eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a);
521 	os_free(a);
522 }
523 
524 
525 /**
526  * ssdp_parse_msearch - Process a received M-SEARCH
527  * @sm: WPS UPnP state machine from upnp_wps_device_init()
528  * @client: Client address
529  * @data: NULL terminated M-SEARCH message
530  *
531  * Given that we have received a header w/ M-SEARCH, act upon it
532  *
533  * Format of M-SEARCH (case insensitive!):
534  *
535  * First line must be:
536  *      M-SEARCH * HTTP/1.1
537  * Other lines in arbitrary order:
538  *      HOST:239.255.255.250:1900
539  *      ST:<varies -- must match>
540  *      MAN:"ssdp:discover"
541  *      MX:<varies>
542  *
543  * It should be noted that when Microsoft Vista is still learning its IP
544  * address, it sends out host lines like: HOST:[FF02::C]:1900
545  */
ssdp_parse_msearch(struct upnp_wps_device_sm * sm,struct sockaddr_in * client,const char * data)546 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm,
547 			       struct sockaddr_in *client, const char *data)
548 {
549 	const char *start = data;
550 	const char *end;
551 	int got_host = 0;
552 	int got_st = 0, st_match = 0;
553 	int got_man = 0;
554 	int got_mx = 0;
555 	int mx = 0;
556 
557 	/*
558 	 * Skip first line M-SEARCH * HTTP/1.1
559 	 * (perhaps we should check remainder of the line for syntax)
560 	 */
561 	data += line_length(data);
562 
563 	/* Parse remaining lines */
564 	for (; *data != '\0'; data += line_length(data)) {
565 		end = data + line_length_stripped(data);
566 		if (token_eq(data, "host")) {
567 			/* The host line indicates who the packet
568 			 * is addressed to... but do we really care?
569 			 * Note that Microsoft sometimes does funny
570 			 * stuff with the HOST: line.
571 			 */
572 #if 0   /* could be */
573 			data += token_length(data);
574 			data += word_separation_length(data);
575 			if (*data != ':')
576 				goto bad;
577 			data++;
578 			data += word_separation_length(data);
579 			/* UPNP_MULTICAST_ADDRESS */
580 			if (!str_starts(data, "239.255.255.250"))
581 				goto bad;
582 			data += os_strlen("239.255.255.250");
583 			if (*data == ':') {
584 				if (!str_starts(data, ":1900"))
585 					goto bad;
586 			}
587 #endif  /* could be */
588 			got_host = 1;
589 			continue;
590 		} else if (token_eq(data, "st")) {
591 			/* There are a number of forms; we look
592 			 * for one that matches our case.
593 			 */
594 			got_st = 1;
595 			data += token_length(data);
596 			data += word_separation_length(data);
597 			if (*data != ':')
598 				continue;
599 			data++;
600 			data += word_separation_length(data);
601 			if (str_starts(data, "ssdp:all")) {
602 				st_match = 1;
603 				continue;
604 			}
605 			if (str_starts(data, "upnp:rootdevice")) {
606 				st_match = 1;
607 				continue;
608 			}
609 			if (str_starts(data, "uuid:")) {
610 				char uuid_string[80];
611 				data += os_strlen("uuid:");
612 				uuid_bin2str(sm->wps->uuid, uuid_string,
613 					     sizeof(uuid_string));
614 				if (str_starts(data, uuid_string))
615 					st_match = 1;
616 				continue;
617 			}
618 #if 0
619 			/* FIX: should we really reply to IGD string? */
620 			if (str_starts(data, "urn:schemas-upnp-org:device:"
621 				       "InternetGatewayDevice:1")) {
622 				st_match = 1;
623 				continue;
624 			}
625 #endif
626 			if (str_starts(data, "urn:schemas-wifialliance-org:"
627 				       "service:WFAWLANConfig:1")) {
628 				st_match = 1;
629 				continue;
630 			}
631 			if (str_starts(data, "urn:schemas-wifialliance-org:"
632 				       "device:WFADevice:1")) {
633 				st_match = 1;
634 				continue;
635 			}
636 			continue;
637 		} else if (token_eq(data, "man")) {
638 			data += token_length(data);
639 			data += word_separation_length(data);
640 			if (*data != ':')
641 				continue;
642 			data++;
643 			data += word_separation_length(data);
644 			if (!str_starts(data, "\"ssdp:discover\"")) {
645 				wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected "
646 					   "M-SEARCH man-field");
647 				goto bad;
648 			}
649 			got_man = 1;
650 			continue;
651 		} else if (token_eq(data, "mx")) {
652 			data += token_length(data);
653 			data += word_separation_length(data);
654 			if (*data != ':')
655 				continue;
656 			data++;
657 			data += word_separation_length(data);
658 			mx = atol(data);
659 			got_mx = 1;
660 			continue;
661 		}
662 		/* ignore anything else */
663 	}
664 	if (!got_host || !got_st || !got_man || !got_mx || mx < 0) {
665 		wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d "
666 			   "%d mx=%d", got_host, got_st, got_man, got_mx, mx);
667 		goto bad;
668 	}
669 	if (!st_match) {
670 		wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST "
671 			   "match)");
672 		return;
673 	}
674 	if (mx > 120)
675 		mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */
676 	msearchreply_state_machine_start(sm, client, mx);
677 	return;
678 
679 bad:
680 	wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH");
681 	wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start);
682 }
683 
684 
685 /* Listening for (UDP) discovery (M-SEARCH) packets */
686 
687 /**
688  * ssdp_listener_stop - Stop SSDP listered
689  * @sm: WPS UPnP state machine from upnp_wps_device_init()
690  *
691  * This function stops the SSDP listerner that was started by calling
692  * ssdp_listener_start().
693  */
ssdp_listener_stop(struct upnp_wps_device_sm * sm)694 void ssdp_listener_stop(struct upnp_wps_device_sm *sm)
695 {
696 	if (sm->ssdp_sd_registered) {
697 		eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ);
698 		sm->ssdp_sd_registered = 0;
699 	}
700 
701 	if (sm->ssdp_sd != -1) {
702 		close(sm->ssdp_sd);
703 		sm->ssdp_sd = -1;
704 	}
705 
706 	eloop_cancel_timeout(msearchreply_state_machine_handler, sm,
707 			     ELOOP_ALL_CTX);
708 }
709 
710 
ssdp_listener_handler(int sd,void * eloop_ctx,void * sock_ctx)711 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx)
712 {
713 	struct upnp_wps_device_sm *sm = sock_ctx;
714 	struct sockaddr_in addr; /* client address */
715 	socklen_t addr_len;
716 	int nread;
717 	char buf[MULTICAST_MAX_READ], *pos;
718 
719 	addr_len = sizeof(addr);
720 	nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0,
721 			 (struct sockaddr *) &addr, &addr_len);
722 	if (nread <= 0)
723 		return;
724 	buf[nread] = '\0'; /* need null termination for algorithm */
725 
726 	if (str_starts(buf, "NOTIFY ")) {
727 		/*
728 		 * Silently ignore NOTIFYs to avoid filling debug log with
729 		 * unwanted messages.
730 		 */
731 		return;
732 	}
733 
734 	pos = os_strchr(buf, '\n');
735 	if (pos)
736 		*pos = '\0';
737 	wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: "
738 		   "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf);
739 	if (pos)
740 		*pos = '\n';
741 
742 	/* Parse first line */
743 	if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 &&
744 	    !isgraph(buf[strlen("M-SEARCH")])) {
745 		ssdp_parse_msearch(sm, &addr, buf);
746 		return;
747 	}
748 
749 	/* Ignore anything else */
750 }
751 
752 
753 /**
754  * ssdp_listener_start - Set up for receiving discovery (UDP) packets
755  * @sm: WPS UPnP state machine from upnp_wps_device_init()
756  * Returns: 0 on success, -1 on failure
757  *
758  * The SSDP listerner is stopped by calling ssdp_listener_stop().
759  */
ssdp_listener_start(struct upnp_wps_device_sm * sm)760 int ssdp_listener_start(struct upnp_wps_device_sm *sm)
761 {
762 	int sd = -1;
763 	struct sockaddr_in addr;
764 	struct ip_mreq mcast_addr;
765 	int on = 1;
766 	/* per UPnP spec, keep IP packet time to live (TTL) small */
767 	unsigned char ttl = 4;
768 
769 	sm->ssdp_sd = sd = socket(AF_INET, SOCK_DGRAM, 0);
770 	if (sd < 0)
771 		goto fail;
772 	if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
773 		goto fail;
774 	if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
775 		goto fail;
776 	os_memset(&addr, 0, sizeof(addr));
777 	addr.sin_family = AF_INET;
778 	addr.sin_addr.s_addr = htonl(INADDR_ANY);
779 	addr.sin_port = htons(UPNP_MULTICAST_PORT);
780 	if (bind(sd, (struct sockaddr *) &addr, sizeof(addr)))
781 		goto fail;
782 	os_memset(&mcast_addr, 0, sizeof(mcast_addr));
783 	mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY);
784 	mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
785 	if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
786 		       (char *) &mcast_addr, sizeof(mcast_addr)))
787 		goto fail;
788 	if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
789 		       &ttl, sizeof(ttl)))
790 		goto fail;
791 	if (eloop_register_sock(sd, EVENT_TYPE_READ, ssdp_listener_handler,
792 				NULL, sm))
793 		goto fail;
794 	sm->ssdp_sd_registered = 1;
795 	return 0;
796 
797 fail:
798 	/* Error */
799 	wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed");
800 	ssdp_listener_stop(sm);
801 	return -1;
802 }
803 
804 
805 /**
806  * add_ssdp_network - Add routing entry for SSDP
807  * @net_if: Selected network interface name
808  * Returns: 0 on success, -1 on failure
809  *
810  * This function assures that the multicast address will be properly
811  * handled by Linux networking code (by a modification to routing tables).
812  * This must be done per network interface. It really only needs to be done
813  * once after booting up, but it does not hurt to call this more frequently
814  * "to be safe".
815  */
add_ssdp_network(char * net_if)816 int add_ssdp_network(char *net_if)
817 {
818 #ifdef __linux__
819 	int ret = -1;
820 	int sock = -1;
821 	struct rtentry rt;
822 	struct sockaddr_in *sin;
823 
824 	if (!net_if)
825 		goto fail;
826 
827 	os_memset(&rt, 0, sizeof(rt));
828 	sock = socket(AF_INET, SOCK_DGRAM, 0);
829 	if (sock < 0)
830 		goto fail;
831 
832 	rt.rt_dev = net_if;
833 	sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in);
834 	sin->sin_family = AF_INET;
835 	sin->sin_port = 0;
836 	sin->sin_addr.s_addr = inet_addr(SSDP_TARGET);
837 	sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in);
838 	sin->sin_family = AF_INET;
839 	sin->sin_port = 0;
840 	sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK);
841 	rt.rt_flags = RTF_UP;
842 	if (ioctl(sock, SIOCADDRT, &rt) < 0) {
843 		if (errno == EPERM) {
844 			wpa_printf(MSG_DEBUG, "add_ssdp_network: No "
845 				   "permissions to add routing table entry");
846 			/* Continue to allow testing as non-root */
847 		} else if (errno != EEXIST) {
848 			wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno "
849 				   "%d (%s)", errno, strerror(errno));
850 			goto fail;
851 		}
852 	}
853 
854 	ret = 0;
855 
856 fail:
857 	if (sock >= 0)
858 		close(sock);
859 
860 	return ret;
861 #else /* __linux__ */
862 	return 0;
863 #endif /* __linux__ */
864 }
865 
866 
867 /**
868  * ssdp_open_multicast - Open socket for sending multicast SSDP messages
869  * @sm: WPS UPnP state machine from upnp_wps_device_init()
870  * Returns: 0 on success, -1 on failure
871  */
ssdp_open_multicast(struct upnp_wps_device_sm * sm)872 int ssdp_open_multicast(struct upnp_wps_device_sm *sm)
873 {
874 	int sd = -1;
875 	 /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet
876 	  * time to live (TTL) small */
877 	unsigned char ttl = 4;
878 
879 	sm->multicast_sd = sd = socket(AF_INET, SOCK_DGRAM, 0);
880 	if (sd < 0)
881 		return -1;
882 
883 #if 0   /* maybe ok if we sometimes block on writes */
884 	if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
885 		return -1;
886 #endif
887 
888 	if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF,
889 		       &sm->ip_addr, sizeof(sm->ip_addr)))
890 		return -1;
891 	if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
892 		       &ttl, sizeof(ttl)))
893 		return -1;
894 
895 #if 0   /* not needed, because we don't receive using multicast_sd */
896 	{
897 		struct ip_mreq mreq;
898 		mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
899 		mreq.imr_interface.s_addr = sm->ip_addr;
900 		wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr "
901 			   "0x%x",
902 			   mreq.imr_multiaddr.s_addr,
903 			   mreq.imr_interface.s_addr);
904 		if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq,
905 				sizeof(mreq))) {
906 			wpa_printf(MSG_ERROR,
907 				   "WPS UPnP: setsockopt "
908 				   "IP_ADD_MEMBERSHIP errno %d (%s)",
909 				   errno, strerror(errno));
910 			return -1;
911 		}
912 	}
913 #endif  /* not needed */
914 
915 	/*
916 	 * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default?
917 	 * which aids debugging I suppose but isn't really necessary?
918 	 */
919 
920 	return 0;
921 }
922