1 /*
2 * UPnP WPS Device - Event processing
3 * Copyright (c) 2000-2003 Intel Corporation
4 * Copyright (c) 2006-2007 Sony Corporation
5 * Copyright (c) 2008-2009 Atheros Communications
6 * Copyright (c) 2009-2010, 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 #include <assert.h>
13
14 #include "common.h"
15 #include "eloop.h"
16 #include "uuid.h"
17 #include "http_client.h"
18 #include "wps_defs.h"
19 #include "wps_upnp.h"
20 #include "wps_upnp_i.h"
21
22 /*
23 * Event message generation (to subscribers)
24 *
25 * We make a separate copy for each message for each subscriber. This memory
26 * wasted could be limited (adding code complexity) by sharing copies, keeping
27 * a usage count and freeing when zero.
28 *
29 * Sending a message requires using a HTTP over TCP NOTIFY
30 * (like a PUT) which requires a number of states..
31 */
32
33 #define MAX_EVENTS_QUEUED 20 /* How far behind queued events */
34 #define MAX_FAILURES 10 /* Drop subscription after this many failures */
35
36 /* How long to wait before sending event */
37 #define EVENT_DELAY_SECONDS 0
38 #define EVENT_DELAY_MSEC 0
39
40 /*
41 * Event information that we send to each subscriber is remembered in this
42 * struct. The event cannot be sent by simple UDP; it has to be sent by a HTTP
43 * over TCP transaction which requires various states.. It may also need to be
44 * retried at a different address (if more than one is available).
45 *
46 * TODO: As an optimization we could share data between subscribers.
47 */
48 struct wps_event_ {
49 struct dl_list list;
50 struct subscription *s; /* parent */
51 unsigned subscriber_sequence; /* which event for this subscription*/
52 unsigned int retry; /* which retry */
53 struct subscr_addr *addr; /* address to connect to */
54 struct wpabuf *data; /* event data to send */
55 struct http_client *http_event;
56 };
57
58
59 /* event_clean -- clean sockets etc. of event
60 * Leaves data, retry count etc. alone.
61 */
event_clean(struct wps_event_ * e)62 static void event_clean(struct wps_event_ *e)
63 {
64 if (e->s->current_event == e)
65 e->s->current_event = NULL;
66 http_client_free(e->http_event);
67 e->http_event = NULL;
68 }
69
70
71 /* event_delete -- delete single unqueued event
72 * (be sure to dequeue first if need be)
73 */
event_delete(struct wps_event_ * e)74 static void event_delete(struct wps_event_ *e)
75 {
76 wpa_printf(MSG_DEBUG, "WPS UPnP: Delete event %p", e);
77 event_clean(e);
78 wpabuf_free(e->data);
79 os_free(e);
80 }
81
82
83 /* event_dequeue -- get next event from the queue
84 * Returns NULL if empty.
85 */
event_dequeue(struct subscription * s)86 static struct wps_event_ *event_dequeue(struct subscription *s)
87 {
88 struct wps_event_ *e;
89 e = dl_list_first(&s->event_queue, struct wps_event_, list);
90 if (e) {
91 wpa_printf(MSG_DEBUG, "WPS UPnP: Dequeue event %p for "
92 "subscription %p", e, s);
93 dl_list_del(&e->list);
94 }
95 return e;
96 }
97
98
99 /* event_delete_all -- delete entire event queue and current event */
event_delete_all(struct subscription * s)100 void event_delete_all(struct subscription *s)
101 {
102 struct wps_event_ *e;
103 while ((e = event_dequeue(s)) != NULL)
104 event_delete(e);
105 if (s->current_event) {
106 event_delete(s->current_event);
107 /* will set: s->current_event = NULL; */
108 }
109 }
110
111
112 /**
113 * event_retry - Called when we had a failure delivering event msg
114 * @e: Event
115 * @do_next_address: skip address e.g. on connect fail
116 */
event_retry(struct wps_event_ * e,int do_next_address)117 static void event_retry(struct wps_event_ *e, int do_next_address)
118 {
119 struct subscription *s = e->s;
120 struct upnp_wps_device_sm *sm = s->sm;
121
122 wpa_printf(MSG_DEBUG, "WPS UPnP: Retry event %p for subscription %p",
123 e, s);
124 event_clean(e);
125 /* will set: s->current_event = NULL; */
126
127 if (do_next_address) {
128 e->retry++;
129 wpa_printf(MSG_DEBUG, "WPS UPnP: Try address %d", e->retry);
130 }
131 if (e->retry >= dl_list_len(&s->addr_list)) {
132 wpa_printf(MSG_DEBUG, "WPS UPnP: Giving up on sending event "
133 "for %s", e->addr->domain_and_port);
134 event_delete(e);
135 s->last_event_failed = 1;
136 if (!dl_list_empty(&s->event_queue))
137 event_send_all_later(s->sm);
138 return;
139 }
140 dl_list_add(&s->event_queue, &e->list);
141 event_send_all_later(sm);
142 }
143
144
event_build_message(struct wps_event_ * e)145 static struct wpabuf * event_build_message(struct wps_event_ *e)
146 {
147 struct wpabuf *buf;
148 char *b;
149
150 buf = wpabuf_alloc(1000 + wpabuf_len(e->data));
151 if (buf == NULL)
152 return NULL;
153 wpabuf_printf(buf, "NOTIFY %s HTTP/1.1\r\n", e->addr->path);
154 wpabuf_put_str(buf, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");
155 wpabuf_printf(buf, "HOST: %s\r\n", e->addr->domain_and_port);
156 wpabuf_put_str(buf, "CONTENT-TYPE: text/xml; charset=\"utf-8\"\r\n"
157 "NT: upnp:event\r\n"
158 "NTS: upnp:propchange\r\n");
159 wpabuf_put_str(buf, "SID: uuid:");
160 b = wpabuf_put(buf, 0);
161 uuid_bin2str(e->s->uuid, b, 80);
162 wpabuf_put(buf, os_strlen(b));
163 wpabuf_put_str(buf, "\r\n");
164 wpabuf_printf(buf, "SEQ: %u\r\n", e->subscriber_sequence);
165 wpabuf_printf(buf, "CONTENT-LENGTH: %d\r\n",
166 (int) wpabuf_len(e->data));
167 wpabuf_put_str(buf, "\r\n"); /* terminating empty line */
168 wpabuf_put_buf(buf, e->data);
169 return buf;
170 }
171
172
event_addr_failure(struct wps_event_ * e)173 static void event_addr_failure(struct wps_event_ *e)
174 {
175 struct subscription *s = e->s;
176
177 e->addr->num_failures++;
178 wpa_printf(MSG_DEBUG, "WPS UPnP: Failed to send event %p to %s "
179 "(num_failures=%u)",
180 e, e->addr->domain_and_port, e->addr->num_failures);
181
182 if (e->addr->num_failures < MAX_FAILURES) {
183 /* Try other addresses, if available */
184 event_retry(e, 1);
185 return;
186 }
187
188 /*
189 * If other side doesn't like what we say, forget about them.
190 * (There is no way to tell other side that we are dropping them...).
191 */
192 wpa_printf(MSG_DEBUG, "WPS UPnP: Deleting subscription %p "
193 "address %s due to errors", s, e->addr->domain_and_port);
194 dl_list_del(&e->addr->list);
195 subscr_addr_delete(e->addr);
196 e->addr = NULL;
197
198 if (dl_list_empty(&s->addr_list)) {
199 /* if we've given up on all addresses */
200 wpa_printf(MSG_DEBUG, "WPS UPnP: Removing subscription %p "
201 "with no addresses", s);
202 dl_list_del(&s->list);
203 subscription_destroy(s);
204 return;
205 }
206
207 /* Try other addresses, if available */
208 event_retry(e, 0);
209 }
210
211
event_http_cb(void * ctx,struct http_client * c,enum http_client_event event)212 static void event_http_cb(void *ctx, struct http_client *c,
213 enum http_client_event event)
214 {
215 struct wps_event_ *e = ctx;
216 struct subscription *s = e->s;
217
218 wpa_printf(MSG_DEBUG, "WPS UPnP: HTTP client callback: e=%p c=%p "
219 "event=%d", e, c, event);
220 switch (event) {
221 case HTTP_CLIENT_OK:
222 wpa_printf(MSG_DEBUG,
223 "WPS UPnP: Got event %p reply OK from %s",
224 e, e->addr->domain_and_port);
225 e->addr->num_failures = 0;
226 s->last_event_failed = 0;
227 event_delete(e);
228
229 /* Schedule sending more if there is more to send */
230 if (!dl_list_empty(&s->event_queue))
231 event_send_all_later(s->sm);
232 break;
233 case HTTP_CLIENT_FAILED:
234 wpa_printf(MSG_DEBUG, "WPS UPnP: Event send failure");
235 event_addr_failure(e);
236 break;
237 case HTTP_CLIENT_INVALID_REPLY:
238 wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid reply");
239 event_addr_failure(e);
240 break;
241 case HTTP_CLIENT_TIMEOUT:
242 wpa_printf(MSG_DEBUG, "WPS UPnP: Event send timeout");
243 event_addr_failure(e);
244 break;
245 }
246 }
247
248
249 /* event_send_start -- prepare to send a event message to subscriber
250 *
251 * This gets complicated because:
252 * -- The message is sent via TCP and we have to keep the stream open
253 * for 30 seconds to get a response... then close it.
254 * -- But we might have other event happen in the meantime...
255 * we have to queue them, if we lose them then the subscriber will
256 * be forced to unsubscribe and subscribe again.
257 * -- If multiple URLs are provided then we are supposed to try successive
258 * ones after 30 second timeout.
259 * -- The URLs might use domain names instead of dotted decimal addresses,
260 * and resolution of those may cause unwanted sleeping.
261 * -- Doing the initial TCP connect can take a while, so we have to come
262 * back after connection and then send the data.
263 *
264 * Returns nonzero on error;
265 *
266 * Prerequisite: No current event send (s->current_event == NULL)
267 * and non-empty queue.
268 */
event_send_start(struct subscription * s)269 static int event_send_start(struct subscription *s)
270 {
271 struct wps_event_ *e;
272 unsigned int itry;
273 struct wpabuf *buf;
274
275 /*
276 * Assume we are called ONLY with no current event and ONLY with
277 * nonempty event queue and ONLY with at least one address to send to.
278 */
279 if (dl_list_empty(&s->addr_list) ||
280 s->current_event ||
281 dl_list_empty(&s->event_queue))
282 return -1;
283
284 s->current_event = e = event_dequeue(s);
285
286 /* Use address according to number of retries */
287 itry = 0;
288 dl_list_for_each(e->addr, &s->addr_list, struct subscr_addr, list)
289 if (itry++ == e->retry)
290 break;
291 if (itry < e->retry)
292 return -1;
293
294 buf = event_build_message(e);
295 if (buf == NULL) {
296 event_retry(e, 0);
297 return -1;
298 }
299
300 e->http_event = http_client_addr(&e->addr->saddr, buf, 0,
301 event_http_cb, e);
302 if (e->http_event == NULL) {
303 wpabuf_free(buf);
304 event_retry(e, 0);
305 return -1;
306 }
307
308 return 0;
309 }
310
311
312 /* event_send_all_later_handler -- actually send events as needed */
event_send_all_later_handler(void * eloop_data,void * user_ctx)313 static void event_send_all_later_handler(void *eloop_data, void *user_ctx)
314 {
315 struct upnp_wps_device_sm *sm = user_ctx;
316 struct subscription *s, *tmp;
317 int nerrors = 0;
318
319 sm->event_send_all_queued = 0;
320 dl_list_for_each_safe(s, tmp, &sm->subscriptions, struct subscription,
321 list) {
322 if (s->current_event == NULL /* not busy */ &&
323 !dl_list_empty(&s->event_queue) /* more to do */) {
324 if (event_send_start(s))
325 nerrors++;
326 }
327 }
328
329 if (nerrors) {
330 /* Try again later */
331 event_send_all_later(sm);
332 }
333 }
334
335
336 /* event_send_all_later -- schedule sending events to all subscribers
337 * that need it.
338 * This avoids two problems:
339 * -- After getting a subscription, we should not send the first event
340 * until after our reply is fully queued to be sent back,
341 * -- Possible stack depth or infinite recursion issues.
342 */
event_send_all_later(struct upnp_wps_device_sm * sm)343 void event_send_all_later(struct upnp_wps_device_sm *sm)
344 {
345 /*
346 * The exact time in the future isn't too important. Waiting a bit
347 * might let us do several together.
348 */
349 if (sm->event_send_all_queued)
350 return;
351 sm->event_send_all_queued = 1;
352 eloop_register_timeout(EVENT_DELAY_SECONDS, EVENT_DELAY_MSEC,
353 event_send_all_later_handler, NULL, sm);
354 }
355
356
357 /* event_send_stop_all -- cleanup */
event_send_stop_all(struct upnp_wps_device_sm * sm)358 void event_send_stop_all(struct upnp_wps_device_sm *sm)
359 {
360 if (sm->event_send_all_queued)
361 eloop_cancel_timeout(event_send_all_later_handler, NULL, sm);
362 sm->event_send_all_queued = 0;
363 }
364
365
366 /**
367 * event_add - Add a new event to a queue
368 * @s: Subscription
369 * @data: Event data (is copied; caller retains ownership)
370 * @probereq: Whether this is a Probe Request event
371 * Returns: 0 on success, -1 on error, 1 on max event queue limit reached
372 */
event_add(struct subscription * s,const struct wpabuf * data,int probereq)373 int event_add(struct subscription *s, const struct wpabuf *data, int probereq)
374 {
375 struct wps_event_ *e;
376 unsigned int len;
377
378 len = dl_list_len(&s->event_queue);
379 if (len >= MAX_EVENTS_QUEUED) {
380 wpa_printf(MSG_DEBUG, "WPS UPnP: Too many events queued for "
381 "subscriber %p", s);
382 if (probereq)
383 return 1;
384
385 /* Drop oldest entry to allow EAP event to be stored. */
386 e = event_dequeue(s);
387 if (!e)
388 return 1;
389 event_delete(e);
390 }
391
392 if (s->last_event_failed && probereq && len > 0) {
393 /*
394 * Avoid queuing frames for subscribers that may have left
395 * without unsubscribing.
396 */
397 wpa_printf(MSG_DEBUG, "WPS UPnP: Do not queue more Probe "
398 "Request frames for subscription %p since last "
399 "delivery failed", s);
400 return -1;
401 }
402
403 e = os_zalloc(sizeof(*e));
404 if (e == NULL)
405 return -1;
406 dl_list_init(&e->list);
407 e->s = s;
408 e->data = wpabuf_dup(data);
409 if (e->data == NULL) {
410 os_free(e);
411 return -1;
412 }
413 e->subscriber_sequence = s->next_subscriber_sequence++;
414 if (s->next_subscriber_sequence == 0)
415 s->next_subscriber_sequence++;
416 wpa_printf(MSG_DEBUG, "WPS UPnP: Queue event %p for subscriber %p "
417 "(queue len %u)", e, s, len + 1);
418 dl_list_add_tail(&s->event_queue, &e->list);
419 event_send_all_later(s->sm);
420 return 0;
421 }
422