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
str_starts(const char * str,const char * start)103 static int str_starts(const char *str, const char *start)
104 {
105 return os_strncmp(str, start, os_strlen(start)) == 0;
106 }
107
108
109 /***************************************************************************
110 * Advertisements.
111 * These are multicast to the world to tell them we are here.
112 * The individual packets are spread out in time to limit loss,
113 * and then after a much longer period of time the whole sequence
114 * is repeated again (for NOTIFYs only).
115 **************************************************************************/
116
117 /**
118 * next_advertisement - Build next message and advance the state machine
119 * @a: Advertisement state
120 * @islast: Buffer for indicating whether this is the last message (= 1)
121 * Returns: The new message (caller is responsible for freeing this)
122 *
123 * Note: next_advertisement is shared code with msearchreply_* functions
124 */
125 static struct wpabuf *
next_advertisement(struct upnp_wps_device_sm * sm,struct advertisement_state_machine * a,int * islast)126 next_advertisement(struct upnp_wps_device_sm *sm,
127 struct advertisement_state_machine *a, int *islast)
128 {
129 struct wpabuf *msg;
130 char *NTString = "";
131 char uuid_string[80];
132 struct upnp_wps_device_interface *iface;
133
134 *islast = 0;
135 iface = dl_list_first(&sm->interfaces,
136 struct upnp_wps_device_interface, list);
137 if (!iface)
138 return NULL;
139 uuid_bin2str(iface->wps->uuid, uuid_string, sizeof(uuid_string));
140 msg = wpabuf_alloc(800); /* more than big enough */
141 if (msg == NULL)
142 goto fail;
143 switch (a->type) {
144 case ADVERTISE_UP:
145 case ADVERTISE_DOWN:
146 NTString = "NT";
147 wpabuf_put_str(msg, "NOTIFY * HTTP/1.1\r\n");
148 wpabuf_printf(msg, "HOST: %s:%d\r\n",
149 UPNP_MULTICAST_ADDRESS, UPNP_MULTICAST_PORT);
150 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
151 UPNP_CACHE_SEC);
152 wpabuf_printf(msg, "NTS: %s\r\n",
153 (a->type == ADVERTISE_UP ?
154 "ssdp:alive" : "ssdp:byebye"));
155 break;
156 case MSEARCH_REPLY:
157 NTString = "ST";
158 wpabuf_put_str(msg, "HTTP/1.1 200 OK\r\n");
159 wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
160 UPNP_CACHE_SEC);
161
162 wpabuf_put_str(msg, "DATE: ");
163 format_date(msg);
164 wpabuf_put_str(msg, "\r\n");
165
166 wpabuf_put_str(msg, "EXT:\r\n");
167 break;
168 }
169
170 if (a->type != ADVERTISE_DOWN) {
171 /* Where others may get our XML files from */
172 wpabuf_printf(msg, "LOCATION: http://%s:%d/%s\r\n",
173 sm->ip_addr_text, sm->web_port,
174 UPNP_WPS_DEVICE_XML_FILE);
175 }
176
177 /* The SERVER line has three comma-separated fields:
178 * operating system / version
179 * upnp version
180 * software package / version
181 * However, only the UPnP version is really required, the
182 * others can be place holders... for security reasons
183 * it is better to NOT provide extra information.
184 */
185 wpabuf_put_str(msg, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");
186
187 switch (a->state / UPNP_ADVERTISE_REPEAT) {
188 case 0:
189 wpabuf_printf(msg, "%s: upnp:rootdevice\r\n", NTString);
190 wpabuf_printf(msg, "USN: uuid:%s::upnp:rootdevice\r\n",
191 uuid_string);
192 break;
193 case 1:
194 wpabuf_printf(msg, "%s: uuid:%s\r\n", NTString, uuid_string);
195 wpabuf_printf(msg, "USN: uuid:%s\r\n", uuid_string);
196 break;
197 case 2:
198 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:device:"
199 "WFADevice:1\r\n", NTString);
200 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
201 "org:device:WFADevice:1\r\n", uuid_string);
202 break;
203 case 3:
204 wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:service:"
205 "WFAWLANConfig:1\r\n", NTString);
206 wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
207 "org:service:WFAWLANConfig:1\r\n", uuid_string);
208 break;
209 }
210 wpabuf_put_str(msg, "\r\n");
211
212 if (a->state + 1 >= 4 * UPNP_ADVERTISE_REPEAT)
213 *islast = 1;
214
215 return msg;
216
217 fail:
218 wpabuf_free(msg);
219 return NULL;
220 }
221
222
223 static void advertisement_state_machine_handler(void *eloop_data,
224 void *user_ctx);
225
226
227 /**
228 * advertisement_state_machine_stop - Stop SSDP advertisements
229 * @sm: WPS UPnP state machine from upnp_wps_device_init()
230 * @send_byebye: Send byebye advertisement messages immediately
231 */
advertisement_state_machine_stop(struct upnp_wps_device_sm * sm,int send_byebye)232 void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm,
233 int send_byebye)
234 {
235 struct advertisement_state_machine *a = &sm->advertisement;
236 int islast = 0;
237 struct wpabuf *msg;
238 struct sockaddr_in dest;
239
240 eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm);
241 if (!send_byebye || sm->multicast_sd < 0)
242 return;
243
244 a->type = ADVERTISE_DOWN;
245 a->state = 0;
246
247 os_memset(&dest, 0, sizeof(dest));
248 dest.sin_family = AF_INET;
249 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
250 dest.sin_port = htons(UPNP_MULTICAST_PORT);
251
252 while (!islast) {
253 msg = next_advertisement(sm, a, &islast);
254 if (msg == NULL)
255 break;
256 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg),
257 0, (struct sockaddr *) &dest, sizeof(dest)) < 0) {
258 wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto "
259 "failed: %d (%s)", errno, strerror(errno));
260 }
261 wpabuf_free(msg);
262 a->state++;
263 }
264 }
265
266
advertisement_state_machine_handler(void * eloop_data,void * user_ctx)267 static void advertisement_state_machine_handler(void *eloop_data,
268 void *user_ctx)
269 {
270 struct upnp_wps_device_sm *sm = user_ctx;
271 struct advertisement_state_machine *a = &sm->advertisement;
272 struct wpabuf *msg;
273 int next_timeout_msec = 100;
274 int next_timeout_sec = 0;
275 struct sockaddr_in dest;
276 int islast = 0;
277
278 /*
279 * Each is sent twice (in case lost) w/ 100 msec delay between;
280 * spec says no more than 3 times.
281 * One pair for rootdevice, one pair for uuid, and a pair each for
282 * each of the two urns.
283 * The entire sequence must be repeated before cache control timeout
284 * (which is min 1800 seconds),
285 * recommend random portion of half of the advertised cache control age
286 * to ensure against loss... perhaps 1800/4 + rand*1800/4 ?
287 * Delay random interval < 100 msec prior to initial sending.
288 * TTL of 4
289 */
290
291 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state);
292 msg = next_advertisement(sm, a, &islast);
293 if (msg == NULL)
294 return;
295
296 os_memset(&dest, 0, sizeof(dest));
297 dest.sin_family = AF_INET;
298 dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
299 dest.sin_port = htons(UPNP_MULTICAST_PORT);
300
301 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
302 (struct sockaddr *) &dest, sizeof(dest)) == -1) {
303 wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:"
304 "%d (%s)", errno, strerror(errno));
305 next_timeout_msec = 0;
306 next_timeout_sec = 10; /* ... later */
307 } else if (islast) {
308 a->state = 0; /* wrap around */
309 if (a->type == ADVERTISE_DOWN) {
310 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP");
311 a->type = ADVERTISE_UP;
312 /* do it all over again right away */
313 } else {
314 u16 r;
315 /*
316 * Start over again after a long timeout
317 * (see notes above)
318 */
319 next_timeout_msec = 0;
320 if (os_get_random((void *) &r, sizeof(r)) < 0)
321 r = 32768;
322 next_timeout_sec = UPNP_CACHE_SEC / 4 +
323 (((UPNP_CACHE_SEC / 4) * r) >> 16);
324 sm->advertise_count++;
325 wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); "
326 "next in %d sec",
327 sm->advertise_count, next_timeout_sec);
328 }
329 } else {
330 a->state++;
331 }
332
333 wpabuf_free(msg);
334
335 eloop_register_timeout(next_timeout_sec, next_timeout_msec,
336 advertisement_state_machine_handler, NULL, sm);
337 }
338
339
340 /**
341 * advertisement_state_machine_start - Start SSDP advertisements
342 * @sm: WPS UPnP state machine from upnp_wps_device_init()
343 * Returns: 0 on success, -1 on failure
344 */
advertisement_state_machine_start(struct upnp_wps_device_sm * sm)345 int advertisement_state_machine_start(struct upnp_wps_device_sm *sm)
346 {
347 struct advertisement_state_machine *a = &sm->advertisement;
348 int next_timeout_msec;
349
350 advertisement_state_machine_stop(sm, 0);
351
352 /*
353 * Start out advertising down, this automatically switches
354 * to advertising up which signals our restart.
355 */
356 a->type = ADVERTISE_DOWN;
357 a->state = 0;
358 /* (other fields not used here) */
359
360 /* First timeout should be random interval < 100 msec */
361 next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8;
362 return eloop_register_timeout(0, next_timeout_msec,
363 advertisement_state_machine_handler,
364 NULL, sm);
365 }
366
367
368 /***************************************************************************
369 * M-SEARCH replies
370 * These are very similar to the multicast advertisements, with some
371 * small changes in data content; and they are sent (UDP) to a specific
372 * unicast address instead of multicast.
373 * They are sent in response to a UDP M-SEARCH packet.
374 **************************************************************************/
375
376 /**
377 * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine
378 * @a: Selected advertisement/reply state
379 */
msearchreply_state_machine_stop(struct advertisement_state_machine * a)380 void msearchreply_state_machine_stop(struct advertisement_state_machine *a)
381 {
382 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop");
383 dl_list_del(&a->list);
384 os_free(a);
385 }
386
387
msearchreply_state_machine_handler(void * eloop_data,void * user_ctx)388 static void msearchreply_state_machine_handler(void *eloop_data,
389 void *user_ctx)
390 {
391 struct advertisement_state_machine *a = user_ctx;
392 struct upnp_wps_device_sm *sm = eloop_data;
393 struct wpabuf *msg;
394 int next_timeout_msec = 100;
395 int next_timeout_sec = 0;
396 int islast = 0;
397
398 /*
399 * Each response is sent twice (in case lost) w/ 100 msec delay
400 * between; spec says no more than 3 times.
401 * One pair for rootdevice, one pair for uuid, and a pair each for
402 * each of the two urns.
403 */
404
405 /* TODO: should only send the requested response types */
406
407 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)",
408 a->state, inet_ntoa(a->client.sin_addr),
409 ntohs(a->client.sin_port));
410 msg = next_advertisement(sm, a, &islast);
411 if (msg == NULL)
412 return;
413
414 /*
415 * Send it on the multicast socket to avoid having to set up another
416 * socket.
417 */
418 if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
419 (struct sockaddr *) &a->client, sizeof(a->client)) < 0) {
420 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto "
421 "errno %d (%s) for %s:%d",
422 errno, strerror(errno),
423 inet_ntoa(a->client.sin_addr),
424 ntohs(a->client.sin_port));
425 /* Ignore error and hope for the best */
426 }
427 wpabuf_free(msg);
428 if (islast) {
429 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done");
430 msearchreply_state_machine_stop(a);
431 return;
432 }
433 a->state++;
434
435 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec",
436 next_timeout_sec, next_timeout_msec);
437 eloop_register_timeout(next_timeout_sec, next_timeout_msec,
438 msearchreply_state_machine_handler, sm, a);
439 }
440
441
442 /**
443 * msearchreply_state_machine_start - Reply to M-SEARCH discovery request
444 * @sm: WPS UPnP state machine from upnp_wps_device_init()
445 * @client: Client address
446 * @mx: Maximum delay in seconds
447 *
448 * Use TTL of 4 (this was done when socket set up).
449 * A response should be given in randomized portion of min(MX,120) seconds
450 *
451 * UPnP-arch-DeviceArchitecture, 1.2.3:
452 * To be found, a device must send a UDP response to the source IP address and
453 * port that sent the request to the multicast channel. Devices respond if the
454 * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:"
455 * followed by a UUID that exactly matches one advertised by the device.
456 */
msearchreply_state_machine_start(struct upnp_wps_device_sm * sm,struct sockaddr_in * client,int mx)457 static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm,
458 struct sockaddr_in *client,
459 int mx)
460 {
461 struct advertisement_state_machine *a;
462 int next_timeout_sec;
463 int next_timeout_msec;
464 int replies;
465
466 replies = dl_list_len(&sm->msearch_replies);
467 wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d "
468 "outstanding)", replies);
469 if (replies >= MAX_MSEARCH) {
470 wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding "
471 "M-SEARCH replies");
472 return;
473 }
474
475 a = os_zalloc(sizeof(*a));
476 if (a == NULL)
477 return;
478 a->type = MSEARCH_REPLY;
479 a->state = 0;
480 os_memcpy(&a->client, client, sizeof(*client));
481 /* Wait time depending on MX value */
482 next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8;
483 next_timeout_sec = next_timeout_msec / 1000;
484 next_timeout_msec = next_timeout_msec % 1000;
485 if (eloop_register_timeout(next_timeout_sec, next_timeout_msec,
486 msearchreply_state_machine_handler, sm,
487 a)) {
488 /* No way to recover (from malloc failure) */
489 goto fail;
490 }
491 /* Remember for future cleanup */
492 dl_list_add(&sm->msearch_replies, &a->list);
493 return;
494
495 fail:
496 wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!");
497 eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a);
498 os_free(a);
499 }
500
501
502 /**
503 * ssdp_parse_msearch - Process a received M-SEARCH
504 * @sm: WPS UPnP state machine from upnp_wps_device_init()
505 * @client: Client address
506 * @data: NULL terminated M-SEARCH message
507 *
508 * Given that we have received a header w/ M-SEARCH, act upon it
509 *
510 * Format of M-SEARCH (case insensitive!):
511 *
512 * First line must be:
513 * M-SEARCH * HTTP/1.1
514 * Other lines in arbitrary order:
515 * HOST:239.255.255.250:1900
516 * ST:<varies -- must match>
517 * MAN:"ssdp:discover"
518 * MX:<varies>
519 *
520 * It should be noted that when Microsoft Vista is still learning its IP
521 * address, it sends out host lines like: HOST:[FF02::C]:1900
522 */
ssdp_parse_msearch(struct upnp_wps_device_sm * sm,struct sockaddr_in * client,const char * data)523 static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm,
524 struct sockaddr_in *client, const char *data)
525 {
526 #ifndef CONFIG_NO_STDOUT_DEBUG
527 const char *start = data;
528 #endif /* CONFIG_NO_STDOUT_DEBUG */
529 int got_host = 0;
530 int got_st = 0, st_match = 0;
531 int got_man = 0;
532 int got_mx = 0;
533 int mx = 0;
534
535 /*
536 * Skip first line M-SEARCH * HTTP/1.1
537 * (perhaps we should check remainder of the line for syntax)
538 */
539 data += line_length(data);
540
541 /* Parse remaining lines */
542 for (; *data != '\0'; data += line_length(data)) {
543 if (token_eq(data, "host")) {
544 /* The host line indicates who the packet
545 * is addressed to... but do we really care?
546 * Note that Microsoft sometimes does funny
547 * stuff with the HOST: line.
548 */
549 #if 0 /* could be */
550 data += token_length(data);
551 data += word_separation_length(data);
552 if (*data != ':')
553 goto bad;
554 data++;
555 data += word_separation_length(data);
556 /* UPNP_MULTICAST_ADDRESS */
557 if (!str_starts(data, "239.255.255.250"))
558 goto bad;
559 data += os_strlen("239.255.255.250");
560 if (*data == ':') {
561 if (!str_starts(data, ":1900"))
562 goto bad;
563 }
564 #endif /* could be */
565 got_host = 1;
566 continue;
567 } else if (token_eq(data, "st")) {
568 /* There are a number of forms; we look
569 * for one that matches our case.
570 */
571 got_st = 1;
572 data += token_length(data);
573 data += word_separation_length(data);
574 if (*data != ':')
575 continue;
576 data++;
577 data += word_separation_length(data);
578 if (str_starts(data, "ssdp:all")) {
579 st_match = 1;
580 continue;
581 }
582 if (str_starts(data, "upnp:rootdevice")) {
583 st_match = 1;
584 continue;
585 }
586 if (str_starts(data, "uuid:")) {
587 char uuid_string[80];
588 struct upnp_wps_device_interface *iface;
589 iface = dl_list_first(
590 &sm->interfaces,
591 struct upnp_wps_device_interface,
592 list);
593 if (!iface)
594 continue;
595 data += os_strlen("uuid:");
596 uuid_bin2str(iface->wps->uuid, uuid_string,
597 sizeof(uuid_string));
598 if (str_starts(data, uuid_string))
599 st_match = 1;
600 continue;
601 }
602 #if 0
603 /* FIX: should we really reply to IGD string? */
604 if (str_starts(data, "urn:schemas-upnp-org:device:"
605 "InternetGatewayDevice:1")) {
606 st_match = 1;
607 continue;
608 }
609 #endif
610 if (str_starts(data, "urn:schemas-wifialliance-org:"
611 "service:WFAWLANConfig:1")) {
612 st_match = 1;
613 continue;
614 }
615 if (str_starts(data, "urn:schemas-wifialliance-org:"
616 "device:WFADevice:1")) {
617 st_match = 1;
618 continue;
619 }
620 continue;
621 } else if (token_eq(data, "man")) {
622 data += token_length(data);
623 data += word_separation_length(data);
624 if (*data != ':')
625 continue;
626 data++;
627 data += word_separation_length(data);
628 if (!str_starts(data, "\"ssdp:discover\"")) {
629 wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected "
630 "M-SEARCH man-field");
631 goto bad;
632 }
633 got_man = 1;
634 continue;
635 } else if (token_eq(data, "mx")) {
636 data += token_length(data);
637 data += word_separation_length(data);
638 if (*data != ':')
639 continue;
640 data++;
641 data += word_separation_length(data);
642 mx = atol(data);
643 got_mx = 1;
644 continue;
645 }
646 /* ignore anything else */
647 }
648 if (!got_host || !got_st || !got_man || !got_mx || mx < 0) {
649 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d "
650 "%d mx=%d", got_host, got_st, got_man, got_mx, mx);
651 goto bad;
652 }
653 if (!st_match) {
654 wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST "
655 "match)");
656 return;
657 }
658 if (mx > 120)
659 mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */
660 msearchreply_state_machine_start(sm, client, mx);
661 return;
662
663 bad:
664 wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH");
665 wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start);
666 }
667
668
669 /* Listening for (UDP) discovery (M-SEARCH) packets */
670
671 /**
672 * ssdp_listener_stop - Stop SSDP listered
673 * @sm: WPS UPnP state machine from upnp_wps_device_init()
674 *
675 * This function stops the SSDP listener that was started by calling
676 * ssdp_listener_start().
677 */
ssdp_listener_stop(struct upnp_wps_device_sm * sm)678 void ssdp_listener_stop(struct upnp_wps_device_sm *sm)
679 {
680 if (sm->ssdp_sd_registered) {
681 eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ);
682 sm->ssdp_sd_registered = 0;
683 }
684
685 if (sm->ssdp_sd != -1) {
686 close(sm->ssdp_sd);
687 sm->ssdp_sd = -1;
688 }
689
690 eloop_cancel_timeout(msearchreply_state_machine_handler, sm,
691 ELOOP_ALL_CTX);
692 }
693
694
ssdp_listener_handler(int sd,void * eloop_ctx,void * sock_ctx)695 static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx)
696 {
697 struct upnp_wps_device_sm *sm = sock_ctx;
698 struct sockaddr_in addr; /* client address */
699 socklen_t addr_len;
700 int nread;
701 char buf[MULTICAST_MAX_READ], *pos;
702
703 addr_len = sizeof(addr);
704 nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0,
705 (struct sockaddr *) &addr, &addr_len);
706 if (nread <= 0)
707 return;
708 buf[nread] = '\0'; /* need null termination for algorithm */
709
710 if (str_starts(buf, "NOTIFY ")) {
711 /*
712 * Silently ignore NOTIFYs to avoid filling debug log with
713 * unwanted messages.
714 */
715 return;
716 }
717
718 pos = os_strchr(buf, '\n');
719 if (pos)
720 *pos = '\0';
721 wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: "
722 "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf);
723 if (pos)
724 *pos = '\n';
725
726 /* Parse first line */
727 if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 &&
728 !isgraph(buf[strlen("M-SEARCH")])) {
729 ssdp_parse_msearch(sm, &addr, buf);
730 return;
731 }
732
733 /* Ignore anything else */
734 }
735
736
ssdp_listener_open(void)737 int ssdp_listener_open(void)
738 {
739 struct sockaddr_in addr;
740 struct ip_mreq mcast_addr;
741 int on = 1;
742 /* per UPnP spec, keep IP packet time to live (TTL) small */
743 unsigned char ttl = 4;
744 int sd;
745
746 sd = socket(AF_INET, SOCK_DGRAM, 0);
747 if (sd < 0)
748 goto fail;
749 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
750 goto fail;
751 if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
752 goto fail;
753 os_memset(&addr, 0, sizeof(addr));
754 addr.sin_family = AF_INET;
755 addr.sin_addr.s_addr = htonl(INADDR_ANY);
756 addr.sin_port = htons(UPNP_MULTICAST_PORT);
757 if (bind(sd, (struct sockaddr *) &addr, sizeof(addr)))
758 goto fail;
759 os_memset(&mcast_addr, 0, sizeof(mcast_addr));
760 mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY);
761 mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
762 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
763 (char *) &mcast_addr, sizeof(mcast_addr)))
764 goto fail;
765 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
766 &ttl, sizeof(ttl)))
767 goto fail;
768
769 return sd;
770
771 fail:
772 if (sd >= 0)
773 close(sd);
774 return -1;
775 }
776
777
778 /**
779 * ssdp_listener_start - Set up for receiving discovery (UDP) packets
780 * @sm: WPS UPnP state machine from upnp_wps_device_init()
781 * Returns: 0 on success, -1 on failure
782 *
783 * The SSDP listener is stopped by calling ssdp_listener_stop().
784 */
ssdp_listener_start(struct upnp_wps_device_sm * sm)785 int ssdp_listener_start(struct upnp_wps_device_sm *sm)
786 {
787 sm->ssdp_sd = ssdp_listener_open();
788
789 if (eloop_register_sock(sm->ssdp_sd, EVENT_TYPE_READ,
790 ssdp_listener_handler, NULL, sm))
791 goto fail;
792 sm->ssdp_sd_registered = 1;
793 return 0;
794
795 fail:
796 /* Error */
797 wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed");
798 ssdp_listener_stop(sm);
799 return -1;
800 }
801
802
803 /**
804 * add_ssdp_network - Add routing entry for SSDP
805 * @net_if: Selected network interface name
806 * Returns: 0 on success, -1 on failure
807 *
808 * This function assures that the multicast address will be properly
809 * handled by Linux networking code (by a modification to routing tables).
810 * This must be done per network interface. It really only needs to be done
811 * once after booting up, but it does not hurt to call this more frequently
812 * "to be safe".
813 */
add_ssdp_network(const char * net_if)814 int add_ssdp_network(const char *net_if)
815 {
816 #ifdef __linux__
817 int ret = -1;
818 int sock = -1;
819 struct rtentry rt;
820 struct sockaddr_in *sin;
821
822 if (!net_if)
823 goto fail;
824
825 os_memset(&rt, 0, sizeof(rt));
826 sock = socket(AF_INET, SOCK_DGRAM, 0);
827 if (sock < 0)
828 goto fail;
829
830 rt.rt_dev = (char *) net_if;
831 sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in);
832 sin->sin_family = AF_INET;
833 sin->sin_port = 0;
834 sin->sin_addr.s_addr = inet_addr(SSDP_TARGET);
835 sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in);
836 sin->sin_family = AF_INET;
837 sin->sin_port = 0;
838 sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK);
839 rt.rt_flags = RTF_UP;
840 if (ioctl(sock, SIOCADDRT, &rt) < 0) {
841 if (errno == EPERM) {
842 wpa_printf(MSG_DEBUG, "add_ssdp_network: No "
843 "permissions to add routing table entry");
844 /* Continue to allow testing as non-root */
845 } else if (errno != EEXIST) {
846 wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno "
847 "%d (%s)", errno, strerror(errno));
848 goto fail;
849 }
850 }
851
852 ret = 0;
853
854 fail:
855 if (sock >= 0)
856 close(sock);
857
858 return ret;
859 #else /* __linux__ */
860 return 0;
861 #endif /* __linux__ */
862 }
863
864
ssdp_open_multicast_sock(u32 ip_addr,const char * forced_ifname)865 int ssdp_open_multicast_sock(u32 ip_addr, const char *forced_ifname)
866 {
867 int sd;
868 /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet
869 * time to live (TTL) small */
870 unsigned char ttl = 4;
871
872 sd = socket(AF_INET, SOCK_DGRAM, 0);
873 if (sd < 0)
874 return -1;
875
876 if (forced_ifname) {
877 #ifdef __linux__
878 struct ifreq req;
879 os_memset(&req, 0, sizeof(req));
880 os_strlcpy(req.ifr_name, forced_ifname, sizeof(req.ifr_name));
881 if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &req,
882 sizeof(req)) < 0) {
883 wpa_printf(MSG_INFO, "WPS UPnP: Failed to bind "
884 "multicast socket to ifname %s: %s",
885 forced_ifname, strerror(errno));
886 close(sd);
887 return -1;
888 }
889 #endif /* __linux__ */
890 }
891
892 #if 0 /* maybe ok if we sometimes block on writes */
893 if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) {
894 close(sd);
895 return -1;
896 }
897 #endif
898
899 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF,
900 &ip_addr, sizeof(ip_addr))) {
901 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_IF) %x: "
902 "%d (%s)", ip_addr, errno, strerror(errno));
903 close(sd);
904 return -1;
905 }
906 if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
907 &ttl, sizeof(ttl))) {
908 wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_TTL): "
909 "%d (%s)", errno, strerror(errno));
910 close(sd);
911 return -1;
912 }
913
914 #if 0 /* not needed, because we don't receive using multicast_sd */
915 {
916 struct ip_mreq mreq;
917 mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
918 mreq.imr_interface.s_addr = ip_addr;
919 wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr "
920 "0x%x",
921 mreq.imr_multiaddr.s_addr,
922 mreq.imr_interface.s_addr);
923 if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq,
924 sizeof(mreq))) {
925 wpa_printf(MSG_ERROR,
926 "WPS UPnP: setsockopt "
927 "IP_ADD_MEMBERSHIP errno %d (%s)",
928 errno, strerror(errno));
929 close(sd);
930 return -1;
931 }
932 }
933 #endif /* not needed */
934
935 /*
936 * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default?
937 * which aids debugging I suppose but isn't really necessary?
938 */
939
940 return sd;
941 }
942
943
944 /**
945 * ssdp_open_multicast - Open socket for sending multicast SSDP messages
946 * @sm: WPS UPnP state machine from upnp_wps_device_init()
947 * Returns: 0 on success, -1 on failure
948 */
ssdp_open_multicast(struct upnp_wps_device_sm * sm)949 int ssdp_open_multicast(struct upnp_wps_device_sm *sm)
950 {
951 sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr, NULL);
952 if (sm->multicast_sd < 0)
953 return -1;
954 return 0;
955 }
956