workbench/network/WirelessManager/src/wps/wps_upnp_event.c

   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, 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 EVENT_TIMEOUT_SEC 30   /* Drop sending event after timeout */
  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  */
  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  */
  74 static void event_delete(struct wps_event_ *e)
  75 {
  76         event_clean(e);
  77         wpabuf_free(e->data);
  78         os_free(e);
  79 }
  80
  81
  82 /* event_dequeue -- get next event from the queue
  83  * Returns NULL if empty.
  84  */
  85 static struct wps_event_ *event_dequeue(struct subscription *s)
  86 {
  87         struct wps_event_ *e;
  88         e = dl_list_first(&s->event_queue, struct wps_event_, list);
  89         if (e)
  90                 dl_list_del(&e->list);
  91         return e;
  92 }
  93
  94
  95 /* event_delete_all -- delete entire event queue and current event */
  96 void event_delete_all(struct subscription *s)
  97 {
  98         struct wps_event_ *e;
  99         while ((e = event_dequeue(s)) != NULL)
 100                 event_delete(e);
 101         if (s->current_event) {
 102                 event_delete(s->current_event);
 103                 /* will set: s->current_event = NULL;  */
 104         }
 105 }
 106
 107
 108 /**
 109  * event_retry - Called when we had a failure delivering event msg
 110  * @e: Event
 111  * @do_next_address: skip address e.g. on connect fail
 112  */
 113 static void event_retry(struct wps_event_ *e, int do_next_address)
 114 {
 115         struct subscription *s = e->s;
 116         struct upnp_wps_device_sm *sm = s->sm;
 117
 118         event_clean(e);
 119         /* will set: s->current_event = NULL; */
 120
 121         if (do_next_address)
 122                 e->retry++;
 123         if (e->retry >= dl_list_len(&s->addr_list)) {
 124                 wpa_printf(MSG_DEBUG, "WPS UPnP: Giving up on sending event "
 125                            "for %s", e->addr->domain_and_port);
 126                 return;
 127         }
 128         dl_list_add(&s->event_queue, &e->list);
 129         event_send_all_later(sm);
 130 }
 131
 132
 133 static struct wpabuf * event_build_message(struct wps_event_ *e)
 134 {
 135         struct wpabuf *buf;
 136         char *b;
 137
 138         buf = wpabuf_alloc(1000 + wpabuf_len(e->data));
 139         if (buf == NULL)
 140                 return NULL;
 141         wpabuf_printf(buf, "NOTIFY %s HTTP/1.1\r\n", e->addr->path);
 142         wpabuf_put_str(buf, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");
 143         wpabuf_printf(buf, "HOST: %s\r\n", e->addr->domain_and_port);
 144         wpabuf_put_str(buf, "CONTENT-TYPE: text/xml; charset=\"utf-8\"\r\n"
 145                        "NT: upnp:event\r\n"
 146                        "NTS: upnp:propchange\r\n");
 147         wpabuf_put_str(buf, "SID: uuid:");
 148         b = wpabuf_put(buf, 0);
 149         uuid_bin2str(e->s->uuid, b, 80);
 150         wpabuf_put(buf, os_strlen(b));
 151         wpabuf_put_str(buf, "\r\n");
 152         wpabuf_printf(buf, "SEQ: %u\r\n", e->subscriber_sequence);
 153         wpabuf_printf(buf, "CONTENT-LENGTH: %d\r\n",
 154                       (int) wpabuf_len(e->data));
 155         wpabuf_put_str(buf, "\r\n"); /* terminating empty line */
 156         wpabuf_put_buf(buf, e->data);
 157         return buf;
 158 }
 159
 160
 161 static void event_http_cb(void *ctx, struct http_client *c,
 162                           enum http_client_event event)
 163 {
 164         struct wps_event_ *e = ctx;
 165         struct subscription *s = e->s;
 166
 167         switch (event) {
 168         case HTTP_CLIENT_OK:
 169                 wpa_printf(MSG_DEBUG,
 170                            "WPS UPnP: Got event reply OK from "
 171                            "%s", e->addr->domain_and_port);
 172                 event_delete(e);
 173
 174                 /* Schedule sending more if there is more to send */
 175                 if (!dl_list_empty(&s->event_queue))
 176                         event_send_all_later(s->sm);
 177                 break;
 178         case HTTP_CLIENT_FAILED:
 179         case HTTP_CLIENT_INVALID_REPLY:
 180                 wpa_printf(MSG_DEBUG, "WPS UPnP: Failed to send event to %s",
 181                            e->addr->domain_and_port);
 182
 183                 /*
 184                  * If other side doesn't like what we say, forget about them.
 185                  * (There is no way to tell other side that we are dropping
 186                  * them...).
 187                  * Alternately, we could just do event_delete(e)
 188                  */
 189                 wpa_printf(MSG_DEBUG, "WPS UPnP: Deleting subscription due to "
 190                            "errors");
 191                 dl_list_del(&s->list);
 192                 subscription_destroy(s);
 193                 break;
 194         case HTTP_CLIENT_TIMEOUT:
 195                 wpa_printf(MSG_DEBUG, "WPS UPnP: Event send timeout");
 196                 event_retry(e, 1);
 197         }
 198 }
 199
 200
 201 /* event_send_start -- prepare to send a event message to subscriber
 202  *
 203  * This gets complicated because:
 204  * -- The message is sent via TCP and we have to keep the stream open
 205  *      for 30 seconds to get a response... then close it.
 206  * -- But we might have other event happen in the meantime...
 207  *      we have to queue them, if we lose them then the subscriber will
 208  *      be forced to unsubscribe and subscribe again.
 209  * -- If multiple URLs are provided then we are supposed to try successive
 210  *      ones after 30 second timeout.
 211  * -- The URLs might use domain names instead of dotted decimal addresses,
 212  *      and resolution of those may cause unwanted sleeping.
 213  * -- Doing the initial TCP connect can take a while, so we have to come
 214  *      back after connection and then send the data.
 215  *
 216  * Returns nonzero on error;
 217  *
 218  * Prerequisite: No current event send (s->current_event == NULL)
 219  *      and non-empty queue.
 220  */
 221 static int event_send_start(struct subscription *s)
 222 {
 223         struct wps_event_ *e;
 224         unsigned int itry;
 225         struct wpabuf *buf;
 226
 227         /*
 228          * Assume we are called ONLY with no current event and ONLY with
 229          * nonempty event queue and ONLY with at least one address to send to.
 230          */
 231         assert(!dl_list_empty(&s->addr_list));
 232         assert(s->current_event == NULL);
 233         assert(!dl_list_empty(&s->event_queue));
 234
 235         s->current_event = e = event_dequeue(s);
 236
 237         /* Use address according to number of retries */
 238         itry = 0;
 239         dl_list_for_each(e->addr, &s->addr_list, struct subscr_addr, list)
 240                 if (itry++ == e->retry)
 241                         break;
 242         if (itry < e->retry)
 243                 return -1;
 244
 245         buf = event_build_message(e);
 246         if (buf == NULL) {
 247                 event_retry(e, 0);
 248                 return -1;
 249         }
 250
 251         e->http_event = http_client_addr(&e->addr->saddr, buf, 0,
 252                                          event_http_cb, e);
 253         if (e->http_event == NULL) {
 254                 wpabuf_free(buf);
 255                 event_retry(e, 0);
 256                 return -1;
 257         }
 258
 259         return 0;
 260 }
 261
 262
 263 /* event_send_all_later_handler -- actually send events as needed */
 264 static void event_send_all_later_handler(void *eloop_data, void *user_ctx)
 265 {
 266         struct upnp_wps_device_sm *sm = user_ctx;
 267         struct subscription *s, *tmp;
 268         int nerrors = 0;
 269
 270         sm->event_send_all_queued = 0;
 271         dl_list_for_each_safe(s, tmp, &sm->subscriptions, struct subscription,
 272                               list) {
 273                 if (dl_list_empty(&s->addr_list)) {
 274                         /* if we've given up on all addresses */
 275                         wpa_printf(MSG_DEBUG, "WPS UPnP: Removing "
 276                                    "subscription with no addresses");
 277                         dl_list_del(&s->list);
 278                         subscription_destroy(s);
 279                 } else {
 280                         if (s->current_event == NULL /* not busy */ &&
 281                             !dl_list_empty(&s->event_queue) /* more to do */) {
 282                                 if (event_send_start(s))
 283                                         nerrors++;
 284                         }
 285                 }
 286         }
 287
 288         if (nerrors) {
 289                 /* Try again later */
 290                 event_send_all_later(sm);
 291         }
 292 }
 293
 294
 295 /* event_send_all_later -- schedule sending events to all subscribers
 296  * that need it.
 297  * This avoids two problems:
 298  * -- After getting a subscription, we should not send the first event
 299  *      until after our reply is fully queued to be sent back,
 300  * -- Possible stack depth or infinite recursion issues.
 301  */
 302 void event_send_all_later(struct upnp_wps_device_sm *sm)
 303 {
 304         /*
 305          * The exact time in the future isn't too important. Waiting a bit
 306          * might let us do several together.
 307          */
 308         if (sm->event_send_all_queued)
 309                 return;
 310         sm->event_send_all_queued = 1;
 311         eloop_register_timeout(EVENT_DELAY_SECONDS, EVENT_DELAY_MSEC,
 312                                event_send_all_later_handler, NULL, sm);
 313 }
 314
 315
 316 /* event_send_stop_all -- cleanup */
 317 void event_send_stop_all(struct upnp_wps_device_sm *sm)
 318 {
 319         if (sm->event_send_all_queued)
 320                 eloop_cancel_timeout(event_send_all_later_handler, NULL, sm);
 321         sm->event_send_all_queued = 0;
 322 }
 323
 324
 325 /**
 326  * event_add - Add a new event to a queue
 327  * @s: Subscription
 328  * @data: Event data (is copied; caller retains ownership)
 329  * Returns: 0 on success, 1 on error
 330  */
 331 int event_add(struct subscription *s, const struct wpabuf *data)
 332 {
 333         struct wps_event_ *e;
 334
 335         if (dl_list_len(&s->event_queue) >= MAX_EVENTS_QUEUED) {
 336                 wpa_printf(MSG_DEBUG, "WPS UPnP: Too many events queued for "
 337                            "subscriber");
 338                 return 1;
 339         }
 340
 341         e = os_zalloc(sizeof(*e));
 342         if (e == NULL)
 343                 return 1;
 344         dl_list_init(&e->list);
 345         e->s = s;
 346         e->data = wpabuf_dup(data);
 347         if (e->data == NULL) {
 348                 os_free(e);
 349                 return 1;
 350         }
 351         e->subscriber_sequence = s->next_subscriber_sequence++;
 352         if (s->next_subscriber_sequence == 0)
 353                 s->next_subscriber_sequence++;
 354         dl_list_add_tail(&s->event_queue, &e->list);
 355         event_send_all_later(s->sm);
 356         return 0;
 357 }