presencestate.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2011-2012, Digium, Inc.
 *
 * David Vossel <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Presence state management
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

/*** DOCUMENTATION
   <managerEvent language="en_US" name="PresenceStateChange">
      <managerEventInstance class="EVENT_FLAG_CALL">
         <synopsis>Raised when a presence state changes</synopsis>
         <syntax>
            <parameter name="Presentity">
               <para>The entity whose presence state has changed</para>
            </parameter>
            <parameter name="Status">
               <para>The new status of the presentity</para>
            </parameter>
            <parameter name="Subtype">
               <para>The new subtype of the presentity</para>
            </parameter>
            <parameter name="Message">
               <para>The new message of the presentity</para>
            </parameter>
         </syntax>
         <description>
            <para>This differs from the <literal>PresenceStatus</literal>
            event because this event is raised for all presence state changes,
            not only for changes that affect dialplan hints.</para>
         </description>
         <see-also>
            <ref type="managerEvent">PresenceStatus</ref>
         </see-also>
      </managerEventInstance>
   </managerEvent>
***/

#include "asterisk.h"

#include "asterisk/_private.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"
#include "asterisk/linkedlists.h"
#include "asterisk/presencestate.h"
#include "asterisk/pbx.h"
#include "asterisk/app.h"
#include "asterisk/test.h"

/*! \brief Device state strings for printing */
static const struct {
   const char *string;
   enum ast_presence_state state;

} state2string[] = {
   { "not_set", AST_PRESENCE_NOT_SET},
   { "unavailable", AST_PRESENCE_UNAVAILABLE },
   { "available", AST_PRESENCE_AVAILABLE},
   { "away", AST_PRESENCE_AWAY},
   { "xa", AST_PRESENCE_XA},
   { "chat", AST_PRESENCE_CHAT},
   { "dnd", AST_PRESENCE_DND},
};

static struct ast_manager_event_blob *presence_state_to_ami(struct stasis_message *msg);

STASIS_MESSAGE_TYPE_DEFN(ast_presence_state_message_type,
   .to_ami = presence_state_to_ami,
);
struct stasis_topic *presence_state_topic_all;
struct stasis_cache *presence_state_cache;
struct stasis_caching_topic *presence_state_topic_cached;

/*! \brief  A presence state provider */
struct presence_state_provider {
   char label[40];
   ast_presence_state_prov_cb_type callback;
   AST_RWLIST_ENTRY(presence_state_provider) list;
};

/*! \brief A list of providers */
static AST_RWLIST_HEAD_STATIC(presence_state_providers, presence_state_provider);

const char *ast_presence_state2str(enum ast_presence_state state)
{
   int i;
   for (i = 0; i < ARRAY_LEN(state2string); i++) {
      if (state == state2string[i].state) {
         return state2string[i].string;
      }
   }
   return "";
}

enum ast_presence_state ast_presence_state_val(const char *val)
{
   int i;
   for (i = 0; i < ARRAY_LEN(state2string); i++) {
      if (!strcasecmp(val, state2string[i].string)) {
         return state2string[i].state;
      }
   }
   return AST_PRESENCE_INVALID;
}

static enum ast_presence_state presence_state_cached(const char *presence_provider, char **subtype, char **message)
{
   enum ast_presence_state res = AST_PRESENCE_INVALID;
   RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
   struct ast_presence_state_message *presence_state;

   msg = stasis_cache_get(ast_presence_state_cache(), ast_presence_state_message_type(), presence_provider);

   if (!msg) {
      return res;
   }

   presence_state = stasis_message_data(msg);
   res = presence_state->state;

   *subtype = !ast_strlen_zero(presence_state->subtype) ? ast_strdup(presence_state->subtype) : NULL;
   *message = !ast_strlen_zero(presence_state->message) ? ast_strdup(presence_state->message) : NULL;

   return res;
}

static enum ast_presence_state ast_presence_state_helper(const char *presence_provider, char **subtype, char **message, int check_cache)
{
   char *labels = ast_strdupa(presence_provider);
   char *label;
   enum ast_presence_state state = AST_PRESENCE_INVALID;
   enum ast_presence_state state_order[] = {
      [AST_PRESENCE_INVALID]     = 0,
      [AST_PRESENCE_NOT_SET]     = 1,
      [AST_PRESENCE_AVAILABLE]   = 2,
      [AST_PRESENCE_UNAVAILABLE] = 3,
      [AST_PRESENCE_CHAT]        = 4,
      [AST_PRESENCE_AWAY]        = 5,
      [AST_PRESENCE_XA]          = 6,
      [AST_PRESENCE_DND]         = 7
   };

   *subtype = NULL;
   *message = NULL;

   while ((label = strsep(&labels, "&"))) {
      enum ast_presence_state next_state = AST_PRESENCE_INVALID;
      char *next_subtype = NULL;
      char *next_message = NULL;

      if (check_cache) {
         next_state = presence_state_cached(label, &next_subtype, &next_message);
      }

      if (next_state == AST_PRESENCE_INVALID) {
         struct presence_state_provider *provider;
         const struct ast_channel_tech *chan_tech;
         char *address;

         if ((address = strchr(label, '/'))) {
            *address++ = '\0';

            if ((chan_tech = ast_get_channel_tech(label)) && chan_tech->presencestate) {
               next_state = chan_tech->presencestate(address, &next_subtype, &next_message);
            }
         } else if ((address = strchr(label, ':'))) {
            *address++ = '\0';

            AST_RWLIST_RDLOCK(&presence_state_providers);
            AST_RWLIST_TRAVERSE(&presence_state_providers, provider, list) {
               ast_debug(5, "Checking provider %s with %s\n", provider->label, label);

               if (!strcasecmp(provider->label, label)) {
                  next_state = provider->callback(address, &next_subtype, &next_message);
                  break;
               }
            }
            AST_RWLIST_UNLOCK(&presence_state_providers);

            if (!provider) {
               ast_log(LOG_WARNING, "No provider found for label: %s\n", label);
            }
         } else {
            ast_log(LOG_WARNING, "No label found for presence state provider: %s\n", label);
         }
      }

      if (state_order[next_state] > state_order[state]) {
         state = next_state;

         ast_free(*subtype);
         ast_free(*message);

         *subtype = next_subtype;
         *message = next_message;
      }
   }

   return state;
}

enum ast_presence_state ast_presence_state(const char *presence_provider, char **subtype, char **message)
{
   return ast_presence_state_helper(presence_provider, subtype, message, 1);
}

enum ast_presence_state ast_presence_state_nocache(const char *presence_provider, char **subtype, char **message)
{
   return ast_presence_state_helper(presence_provider, subtype, message, 0);
}

int ast_presence_state_prov_add(const char *label, ast_presence_state_prov_cb_type callback)
{
   struct presence_state_provider *provider;

   if (!callback || !(provider = ast_calloc(1, sizeof(*provider)))) {
      return -1;
   }

   provider->callback = callback;
   ast_copy_string(provider->label, label, sizeof(provider->label));

   AST_RWLIST_WRLOCK(&presence_state_providers);
   AST_RWLIST_INSERT_HEAD(&presence_state_providers, provider, list);
   AST_RWLIST_UNLOCK(&presence_state_providers);

   return 0;
}
int ast_presence_state_prov_del(const char *label)
{
   struct presence_state_provider *provider;
   int res = -1;

   AST_RWLIST_WRLOCK(&presence_state_providers);
   AST_RWLIST_TRAVERSE_SAFE_BEGIN(&presence_state_providers, provider, list) {
      if (!strcasecmp(provider->label, label)) {
         AST_RWLIST_REMOVE_CURRENT(list);
         ast_free(provider);
         res = 0;
         break;
      }
   }
   AST_RWLIST_TRAVERSE_SAFE_END;
   AST_RWLIST_UNLOCK(&presence_state_providers);

   return res;
}

static void presence_state_dtor(void *obj)
{
   struct ast_presence_state_message *presence_state = obj;
   ast_string_field_free_memory(presence_state);
}

static struct ast_presence_state_message *presence_state_alloc(const char *provider,
      enum ast_presence_state state,
      const char *subtype,
      const char *message)
{
   RAII_VAR(struct ast_presence_state_message *, presence_state, ao2_alloc(sizeof(*presence_state), presence_state_dtor), ao2_cleanup);

   if (!presence_state || ast_string_field_init(presence_state, 256)) {
      return NULL;
   }

   presence_state->state = state;
   ast_string_field_set(presence_state, provider, provider);
   ast_string_field_set(presence_state, subtype, S_OR(subtype, ""));
   ast_string_field_set(presence_state, message, S_OR(message, ""));

   ao2_ref(presence_state, +1);
   return presence_state;
}

static void presence_state_event(const char *provider,
      enum ast_presence_state state,
      const char *subtype,
      const char *message)
{
   RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
   RAII_VAR(struct ast_presence_state_message *, presence_state, NULL, ao2_cleanup);

   if (!ast_presence_state_message_type()) {
      return;
   }

   presence_state = presence_state_alloc(provider, state, subtype, message);
   if (!presence_state) {
      return;
   }

   msg = stasis_message_create(ast_presence_state_message_type(), presence_state);
   if (!msg) {
      return;
   }

   stasis_publish(ast_presence_state_topic_all(), msg);
}

static void do_presence_state_change(const char *provider)
{
   char *subtype = NULL;
   char *message = NULL;
   enum ast_presence_state state;

   state = ast_presence_state_helper(provider, &subtype, &message, 0);

   if (state == AST_PRESENCE_INVALID) {
      return;
   }

   presence_state_event(provider, state, subtype, message);
   ast_free(subtype);
   ast_free(message);
}

int ast_presence_state_changed_literal(enum ast_presence_state state,
      const char *subtype,
      const char *message,
      const char *presence_provider)
{
   if (state == AST_PRESENCE_NOT_SET) {
      do_presence_state_change(presence_provider);
   } else {
      presence_state_event(presence_provider, state, subtype, message);
   }

   return 0;
}

int ast_presence_state_changed(enum ast_presence_state state,
      const char *subtype,
      const char *message,
      const char *fmt, ...)
{
   char buf[AST_MAX_EXTENSION];
   va_list ap;

   va_start(ap, fmt);
   vsnprintf(buf, sizeof(buf), fmt, ap);
   va_end(ap);

   return ast_presence_state_changed_literal(state, subtype, message, buf);
}

struct stasis_topic *ast_presence_state_topic_all(void)
{
   return presence_state_topic_all;
}

struct stasis_cache *ast_presence_state_cache(void)
{
   return presence_state_cache;
}

struct stasis_topic *ast_presence_state_topic_cached(void)
{
   return stasis_caching_get_topic(presence_state_topic_cached);
}

static const char *presence_state_get_id(struct stasis_message *msg)
{
   struct ast_presence_state_message *presence_state = stasis_message_data(msg);

   if (stasis_message_type(msg) != ast_presence_state_message_type()) {
      return NULL;
   }

   return presence_state->provider;
}

#if defined(TEST_FRAMEWORK)

#define TEST_CATEGORY "/main/presence/"

static int presence_test_alice_state = AST_PRESENCE_UNAVAILABLE;
static int presence_test_bob_state = AST_PRESENCE_UNAVAILABLE;

static int presence_test_presencestate(const char *label, char **subtype, char **message)
{
   if (!strcmp(label, "Alice")) {
      return presence_test_alice_state;
   } else if (!strcmp(label, "Bob")) {
      return presence_test_bob_state;
   } else {
      return AST_PRESENCE_UNAVAILABLE;
   }
}

static struct ast_channel_tech presence_test_tech = {
   .type = "PresenceTestChannel",
   .description = "Presence test technology",
   .presencestate = presence_test_presencestate,
};

AST_TEST_DEFINE(test_presence_chan)
{
   int res = AST_TEST_FAIL;
   char provider[80];
   enum ast_presence_state state;
   char *subtype = NULL, *message = NULL;

   switch (cmd) {
   case TEST_INIT:
      info->name = "channel_presence";
      info->category = TEST_CATEGORY;
      info->summary = "Channel presence state tests";
      info->description = "Creates test channel technology and then test the presence state callback";
      return AST_TEST_NOT_RUN;
   case TEST_EXECUTE:
      break;
   }

   if (ast_channel_register(&presence_test_tech)) {
      ast_log(LOG_WARNING, "Unable to register channel type '%s'\n", presence_test_tech.type);
      goto presence_test_cleanup;
   }

   /* Check Alice's state */
   snprintf(provider, sizeof(provider), "%s/Alice", presence_test_tech.type);

   presence_test_alice_state = AST_PRESENCE_AVAILABLE;
   state = ast_presence_state_nocache(provider, &subtype, &message);

   if (state != presence_test_alice_state) {
      ast_log(LOG_WARNING, "Presence state of '%s' returned '%s' instead of the expected value '%s'\n",
         provider, ast_presence_state2str(state), ast_presence_state2str(presence_test_alice_state));
      goto presence_test_cleanup;
   }

   /* Check Alice's and Bob's state, Alice's should win as DND > AVAILABLE */
   snprintf(provider, sizeof(provider), "%s/Alice&%s/Bob", presence_test_tech.type, presence_test_tech.type);

   presence_test_alice_state = AST_PRESENCE_DND;
   presence_test_bob_state = AST_PRESENCE_UNAVAILABLE;
   state = ast_presence_state_nocache(provider, &subtype, &message);

   if (state != presence_test_alice_state) {
      ast_log(LOG_WARNING, "Presence state of '%s' returned '%s' instead of the expected value '%s'\n",
         provider, ast_presence_state2str(state), ast_presence_state2str(presence_test_alice_state));
      goto presence_test_cleanup;
        }

   /* Check Alice's and Bob's state, Bob's should now win as AVAILABLE < UNAVAILABLE */
   presence_test_alice_state = AST_PRESENCE_AVAILABLE;
   state = ast_presence_state_nocache(provider, &subtype, &message);

   if (state != presence_test_bob_state) {
      ast_log(LOG_WARNING, "Presence state of '%s' returned '%s' instead of the expected value '%s'\n",
         provider, ast_presence_state2str(state), ast_presence_state2str(presence_test_bob_state));
      goto presence_test_cleanup;
   }

   res = AST_TEST_PASS;

presence_test_cleanup:
   ast_channel_unregister(&presence_test_tech);
   ast_free(subtype);
   ast_free(message);

   return res;
}
#endif

static void presence_state_engine_cleanup(void)
{
   ao2_cleanup(presence_state_topic_all);
   presence_state_topic_all = NULL;
   ao2_cleanup(presence_state_cache);
   presence_state_cache = NULL;
   presence_state_topic_cached = stasis_caching_unsubscribe_and_join(presence_state_topic_cached);
   STASIS_MESSAGE_TYPE_CLEANUP(ast_presence_state_message_type);
   AST_TEST_UNREGISTER(test_presence_chan);
}

int ast_presence_state_engine_init(void)
{
   ast_register_cleanup(presence_state_engine_cleanup);

   if (STASIS_MESSAGE_TYPE_INIT(ast_presence_state_message_type) != 0) {
      return -1;
   }

   presence_state_topic_all = stasis_topic_create("presence_state:all");
   if (!presence_state_topic_all) {
      return -1;
   }

   presence_state_cache = stasis_cache_create(presence_state_get_id);
   if (!presence_state_cache) {
      return -1;
   }

   presence_state_topic_cached = stasis_caching_topic_create(presence_state_topic_all, presence_state_cache);
   if (!presence_state_topic_cached) {
      return -1;
   }
   stasis_caching_accept_message_type(presence_state_topic_cached, ast_presence_state_message_type());
   stasis_caching_set_filter(presence_state_topic_cached, STASIS_SUBSCRIPTION_FILTER_SELECTIVE);

   AST_TEST_REGISTER(test_presence_chan);

   return 0;
}

static struct ast_manager_event_blob *presence_state_to_ami(struct stasis_message *msg)
{
   struct ast_presence_state_message *presence_state = stasis_message_data(msg);
   struct ast_manager_event_blob *res;

   char *subtype = ast_escape_c_alloc(presence_state->subtype);
   char *message = ast_escape_c_alloc(presence_state->message);

   res = ast_manager_event_blob_create(EVENT_FLAG_CALL, "PresenceStateChange",
      "Presentity: %s\r\n"
      "Status: %s\r\n"
      "Subtype: %s\r\n"
      "Message: %s\r\n",
      presence_state->provider,
      ast_presence_state2str(presence_state->state),
      subtype ?: "",
                message ?: "");

   ast_free(subtype);
   ast_free(message);

   return res;
}