bridge_after.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2007 - 2009, Digium, Inc.
 *
 * Richard Mudgett <[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 After Bridge Execution API
 *
 * \author Richard Mudgett <[email protected]>
 *
 * See Also:
 * \arg \ref AstCREDITS
 */

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

#include "asterisk.h"

#include "asterisk/logger.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/bridge_after.h"

struct after_bridge_cb_node {
   /*! Next list node. */
   AST_LIST_ENTRY(after_bridge_cb_node) list;
   /*! Desired callback function. */
   ast_bridge_after_cb callback;
   /*! After bridge callback will not be called and destroy any resources data may contain. */
   ast_bridge_after_cb_failed failed;
   /*! Extra data to pass to the callback. */
   void *data;
   /*! Reason the after bridge callback failed. */
   enum ast_bridge_after_cb_reason reason;
};

struct after_bridge_cb_ds {
   /*! After bridge callbacks container. */
   AST_LIST_HEAD(, after_bridge_cb_node) callbacks;
};

/*!
 * \internal
 * \brief Indicate after bridge callback failed.
 * \since 12.0.0
 *
 * \param node After bridge callback node.
 *
 * \return Nothing
 */
static void after_bridge_cb_failed(struct after_bridge_cb_node *node)
{
   if (node->failed) {
      node->failed(node->reason, node->data);
      node->failed = NULL;
   }
}

/*!
 * \internal
 * \brief Run discarding any after bridge callbacks.
 * \since 12.0.0
 *
 * \param after_bridge After bridge callback container process.
 * \param reason Why are we doing this.
 *
 * \return Nothing
 */
static void after_bridge_cb_run_discard(struct after_bridge_cb_ds *after_bridge, enum ast_bridge_after_cb_reason reason)
{
   struct after_bridge_cb_node *node;

   for (;;) {
      AST_LIST_LOCK(&after_bridge->callbacks);
      node = AST_LIST_REMOVE_HEAD(&after_bridge->callbacks, list);
      AST_LIST_UNLOCK(&after_bridge->callbacks);
      if (!node) {
         break;
      }
      if (!node->reason) {
         node->reason = reason;
      }
      after_bridge_cb_failed(node);
      ast_free(node);
   }
}

/*!
 * \internal
 * \brief Destroy the after bridge callback datastore.
 * \since 12.0.0
 *
 * \param data After bridge callback data to destroy.
 *
 * \return Nothing
 */
static void after_bridge_cb_destroy(void *data)
{
   struct after_bridge_cb_ds *after_bridge = data;

   after_bridge_cb_run_discard(after_bridge, AST_BRIDGE_AFTER_CB_REASON_DESTROY);

   AST_LIST_HEAD_DESTROY(&after_bridge->callbacks);
   ast_free(after_bridge);
}

static struct after_bridge_cb_ds *after_bridge_cb_find(struct ast_channel *chan);

/*!
 * \internal
 * \brief Fixup the after bridge callback datastore.
 * \since 12.0.0
 *
 * \param data After bridge callback data to fixup.
 * \param old_chan The datastore is moving from this channel.
 * \param new_chan The datastore is moving to this channel.
 *
 * \return Nothing
 */
static void after_bridge_cb_fixup(void *data, struct ast_channel *old_chan, struct ast_channel *new_chan)
{
   struct after_bridge_cb_ds *after_bridge;
   struct after_bridge_cb_node *node;

   after_bridge = after_bridge_cb_find(new_chan);
   if (!after_bridge) {
      return;
   }

   AST_LIST_LOCK(&after_bridge->callbacks);
   node = AST_LIST_LAST(&after_bridge->callbacks);
   if (node && !node->reason) {
      node->reason = AST_BRIDGE_AFTER_CB_REASON_MASQUERADE;
   }
   AST_LIST_UNLOCK(&after_bridge->callbacks);
}

static const struct ast_datastore_info after_bridge_cb_info = {
   .type = "after-bridge-cb",
   .destroy = after_bridge_cb_destroy,
   .chan_fixup = after_bridge_cb_fixup,
};

/*!
 * \internal
 * \brief Find an after bridge callback datastore container.
 * \since 12.0.0
 *
 * \param chan Channel to find the after bridge callback container on.
 *
 * \retval after_bridge datastore container on success.
 * \retval NULL on error.
 */
static struct after_bridge_cb_ds *after_bridge_cb_find(struct ast_channel *chan)
{
   struct ast_datastore *datastore;
   SCOPED_CHANNELLOCK(lock, chan);

   datastore = ast_channel_datastore_find(chan, &after_bridge_cb_info, NULL);
   if (!datastore) {
      return NULL;
   }
   return datastore->data;
}

/*!
 * \internal
 * \brief Setup/create an after bridge callback datastore container.
 * \since 12.0.0
 *
 * \param chan Channel to setup/create the after bridge callback container on.
 *
 * \retval after_bridge datastore container on success.
 * \retval NULL on error.
 */
static struct after_bridge_cb_ds *after_bridge_cb_setup(struct ast_channel *chan)
{
   struct ast_datastore *datastore;
   struct after_bridge_cb_ds *after_bridge;
   SCOPED_CHANNELLOCK(lock, chan);

   datastore = ast_channel_datastore_find(chan, &after_bridge_cb_info, NULL);
   if (datastore) {
      return datastore->data;
   }

   /* Create a new datastore. */
   datastore = ast_datastore_alloc(&after_bridge_cb_info, NULL);
   if (!datastore) {
      return NULL;
   }
   after_bridge = ast_calloc(1, sizeof(*after_bridge));
   if (!after_bridge) {
      ast_datastore_free(datastore);
      return NULL;
   }
   AST_LIST_HEAD_INIT(&after_bridge->callbacks);
   datastore->data = after_bridge;
   ast_channel_datastore_add(chan, datastore);

   return datastore->data;
}

void ast_bridge_run_after_callback(struct ast_channel *chan)
{
   struct after_bridge_cb_ds *after_bridge;
   struct after_bridge_cb_node *node;

   after_bridge = after_bridge_cb_find(chan);
   if (!after_bridge) {
      return;
   }

   for (;;) {
      AST_LIST_LOCK(&after_bridge->callbacks);
      node = AST_LIST_REMOVE_HEAD(&after_bridge->callbacks, list);
      AST_LIST_UNLOCK(&after_bridge->callbacks);
      if (!node) {
         break;
      }
      if (node->reason) {
         after_bridge_cb_failed(node);
      } else {
         node->failed = NULL;
         node->callback(chan, node->data);
      }
      ast_free(node);
   }
}

void ast_bridge_discard_after_callback(struct ast_channel *chan, enum ast_bridge_after_cb_reason reason)
{
   struct after_bridge_cb_ds *after_bridge;

   after_bridge = after_bridge_cb_find(chan);
   if (!after_bridge) {
      return;
   }

   after_bridge_cb_run_discard(after_bridge, reason);
}

int ast_bridge_set_after_callback(struct ast_channel *chan, ast_bridge_after_cb callback, ast_bridge_after_cb_failed failed, void *data)
{
   struct after_bridge_cb_ds *after_bridge;
   struct after_bridge_cb_node *new_node;
   struct after_bridge_cb_node *last_node;

   /* Sanity checks. */
   ast_assert(chan != NULL);
   if (!chan || !callback) {
      return -1;
   }

   after_bridge = after_bridge_cb_setup(chan);
   if (!after_bridge) {
      return -1;
   }

   /* Create a new callback node. */
   new_node = ast_calloc(1, sizeof(*new_node));
   if (!new_node) {
      return -1;
   }
   new_node->callback = callback;
   new_node->failed = failed;
   new_node->data = data;

   /* Put it in the container disabling any previously active one. */
   AST_LIST_LOCK(&after_bridge->callbacks);
   last_node = AST_LIST_LAST(&after_bridge->callbacks);
   if (last_node && !last_node->reason) {
      last_node->reason = AST_BRIDGE_AFTER_CB_REASON_REPLACED;
   }
   AST_LIST_INSERT_TAIL(&after_bridge->callbacks, new_node, list);
   AST_LIST_UNLOCK(&after_bridge->callbacks);
   return 0;
}

const char *ast_bridge_after_cb_reason_string(enum ast_bridge_after_cb_reason reason)
{
   switch (reason) {
   case AST_BRIDGE_AFTER_CB_REASON_DESTROY:
      return "Channel destroyed (hungup)";
   case AST_BRIDGE_AFTER_CB_REASON_REPLACED:
      return "Callback was replaced";
   case AST_BRIDGE_AFTER_CB_REASON_MASQUERADE:
      return "Channel masqueraded";
   case AST_BRIDGE_AFTER_CB_REASON_DEPART:
      return "Channel was departed from bridge";
   case AST_BRIDGE_AFTER_CB_REASON_REMOVED:
      return "Callback was removed";
   case AST_BRIDGE_AFTER_CB_REASON_IMPART_FAILED:
      return "Channel failed joining the bridge";
   }
   return "Unknown";
}

struct after_bridge_goto_ds {
   /*! Goto string that can be parsed by ast_parseable_goto(). */
   const char *parseable_goto;
   /*! Specific goto context or default context for parseable_goto. */
   const char *context;
   /*! Specific goto exten or default exten for parseable_goto. */
   const char *exten;
   /*! Specific goto priority or default priority for parseable_goto. */
   int priority;
   /*! TRUE if the peer should run the h exten. */
   unsigned int run_h_exten:1;
   /*! Specific goto location */
   unsigned int specific:1;
};

/*!
 * \internal
 * \brief Destroy the after bridge goto datastore.
 * \since 12.0.0
 *
 * \param data After bridge goto data to destroy.
 *
 * \return Nothing
 */
static void after_bridge_goto_destroy(void *data)
{
   struct after_bridge_goto_ds *after_bridge = data;

   ast_free((char *) after_bridge->parseable_goto);
   ast_free((char *) after_bridge->context);
   ast_free((char *) after_bridge->exten);
   ast_free((char *) after_bridge);
}

/*!
 * \internal
 * \brief Fixup the after bridge goto datastore.
 * \since 12.0.0
 *
 * \param data After bridge goto data to fixup.
 * \param old_chan The datastore is moving from this channel.
 * \param new_chan The datastore is moving to this channel.
 *
 * \return Nothing
 */
static void after_bridge_goto_fixup(void *data, struct ast_channel *old_chan, struct ast_channel *new_chan)
{
   /* There can be only one.  Discard any already on the new channel. */
   ast_bridge_discard_after_goto(new_chan);
}

static const struct ast_datastore_info after_bridge_goto_info = {
   .type = "after-bridge-goto",
   .destroy = after_bridge_goto_destroy,
   .chan_fixup = after_bridge_goto_fixup,
};

/*!
 * \internal
 * \brief Remove channel goto location after the bridge and return it.
 * \since 12.0.0
 *
 * \param chan Channel to remove after bridge goto location.
 *
 * \retval datastore on success.
 * \retval NULL on error or not found.
 */
static struct ast_datastore *after_bridge_goto_remove(struct ast_channel *chan)
{
   struct ast_datastore *datastore;

   ast_channel_lock(chan);
   datastore = ast_channel_datastore_find(chan, &after_bridge_goto_info, NULL);
   if (datastore && ast_channel_datastore_remove(chan, datastore)) {
      datastore = NULL;
   }
   ast_channel_unlock(chan);

   return datastore;
}

void ast_bridge_discard_after_goto(struct ast_channel *chan)
{
   struct ast_datastore *datastore;

   datastore = after_bridge_goto_remove(chan);
   if (datastore) {
      ast_datastore_free(datastore);
   }
}

void ast_bridge_read_after_goto(struct ast_channel *chan, char *buffer, size_t buf_size)
{
   struct ast_datastore *datastore;
   struct after_bridge_goto_ds *after_bridge;
   char *current_pos = buffer;
   size_t remaining_size = buf_size;

   SCOPED_CHANNELLOCK(lock, chan);

   datastore = ast_channel_datastore_find(chan, &after_bridge_goto_info, NULL);
   if (!datastore) {
      buffer[0] = '\0';
      return;
   }

   after_bridge = datastore->data;

   if (after_bridge->parseable_goto) {
      snprintf(buffer, buf_size, "%s", after_bridge->parseable_goto);
      return;
   }

   if (!ast_strlen_zero(after_bridge->context)) {
      snprintf(current_pos, remaining_size, "%s,", after_bridge->context);
      remaining_size = remaining_size - strlen(current_pos);
      current_pos += strlen(current_pos);
   }

   if (after_bridge->run_h_exten) {
      snprintf(current_pos, remaining_size, "h,");
      remaining_size = remaining_size - strlen(current_pos);
      current_pos += strlen(current_pos);
   } else if (!ast_strlen_zero(after_bridge->exten)) {
      snprintf(current_pos, remaining_size, "%s,", after_bridge->exten);
      remaining_size = remaining_size - strlen(current_pos);
      current_pos += strlen(current_pos);
   }

   snprintf(current_pos, remaining_size, "%d", after_bridge->priority);
}

int ast_bridge_setup_after_goto(struct ast_channel *chan)
{
   struct ast_datastore *datastore;
   struct after_bridge_goto_ds *after_bridge;
   int goto_failed = -1;

   /* We are going to be leaving the bridging system now;
    * clear any pending unbridge flags
    */
   ast_channel_set_unbridged(chan, 0);

   /* Determine if we are going to setup a dialplan location and where. */
   if (ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_ASYNCGOTO) {
      /* An async goto has already setup a location. */
      ast_channel_clear_softhangup(chan, AST_SOFTHANGUP_ASYNCGOTO);
      if (!ast_check_hangup(chan)) {
         goto_failed = 0;
      }
      return goto_failed;
   }

   /* Get after bridge goto datastore. */
   datastore = after_bridge_goto_remove(chan);
   if (!datastore) {
      return goto_failed;
   }

   after_bridge = datastore->data;
   if (after_bridge->run_h_exten) {
      if (ast_exists_extension(chan, after_bridge->context, "h", 1,
         S_COR(ast_channel_caller(chan)->id.number.valid,
            ast_channel_caller(chan)->id.number.str, NULL))) {
         ast_debug(1, "Running after bridge goto h exten %s,h,1\n",
            ast_channel_context(chan));
         ast_pbx_h_exten_run(chan, after_bridge->context);
      }
   } else if (!ast_check_hangup(chan)) {
      /* Clear the outgoing flag */
      ast_channel_clear_flag(chan, AST_FLAG_OUTGOING);

      if (after_bridge->specific) {
         goto_failed = ast_explicit_goto(chan, after_bridge->context,
            after_bridge->exten, after_bridge->priority);
      } else if (!ast_strlen_zero(after_bridge->parseable_goto)) {
         char *context;
         char *exten;
         int priority;

         /* Option F(x) for Bridge(), Dial(), and Queue() */

         /* Save current dialplan location in case of failure. */
         context = ast_strdupa(ast_channel_context(chan));
         exten = ast_strdupa(ast_channel_exten(chan));
         priority = ast_channel_priority(chan);

         /* Set current dialplan position to default dialplan position */
         ast_explicit_goto(chan, after_bridge->context, after_bridge->exten,
            after_bridge->priority);

         /* Then perform the goto */
         goto_failed = ast_parseable_goto(chan, after_bridge->parseable_goto);
         if (goto_failed) {
            /* Restore original dialplan location. */
            ast_channel_context_set(chan, context);
            ast_channel_exten_set(chan, exten);
            ast_channel_priority_set(chan, priority);
         }
      } else {
         /* Option F() for Bridge(), Dial(), and Queue() */
         goto_failed = ast_goto_if_exists(chan, after_bridge->context,
            after_bridge->exten, after_bridge->priority + 1);
      }
      if (!goto_failed) {
         if (ast_test_flag(ast_channel_flags(chan), AST_FLAG_IN_AUTOLOOP)) {
            ast_channel_priority_set(chan, ast_channel_priority(chan) + 1);
         }

         ast_debug(1, "Setup after bridge goto location to %s,%s,%d.\n",
            ast_channel_context(chan),
            ast_channel_exten(chan),
            ast_channel_priority(chan));
      }
   }

   /* Discard after bridge goto datastore. */
   ast_datastore_free(datastore);

   return goto_failed;
}

void ast_bridge_run_after_goto(struct ast_channel *chan)
{
   int goto_failed;

   goto_failed = ast_bridge_setup_after_goto(chan);
   if (goto_failed || ast_pbx_run(chan)) {
      ast_hangup(chan);
   }
}

/*!
 * \internal
 * \brief Set after bridge goto location of channel.
 * \since 12.0.0
 *
 * \param chan Channel to setup after bridge goto location.
 * \param run_h_exten TRUE if the h exten should be run.
 * \param specific TRUE if the context/exten/priority is exactly specified.
 * \param context Context to goto after bridge.
 * \param exten Exten to goto after bridge. (Could be NULL if run_h_exten)
 * \param priority Priority to goto after bridge.
 * \param parseable_goto User specified goto string. (Could be NULL)
 *
 * \details Add a channel datastore to setup the goto location
 * when the channel leaves the bridge and run a PBX from there.
 *
 * If run_h_exten then execute the h exten found in the given context.
 * Else if specific then goto the given context/exten/priority.
 * Else if parseable_goto then use the given context/exten/priority
 *   as the relative position for the parseable_goto.
 * Else goto the given context/exten/priority+1.
 *
 * \return Nothing
 */
static void __after_bridge_set_goto(struct ast_channel *chan, int run_h_exten, int specific, const char *context, const char *exten, int priority, const char *parseable_goto)
{
   struct ast_datastore *datastore;
   struct after_bridge_goto_ds *after_bridge;

   /* Sanity checks. */
   ast_assert(chan != NULL);
   if (!chan) {
      return;
   }
   if (run_h_exten) {
      ast_assert(run_h_exten && context);
      if (!context) {
         return;
      }
   } else {
      ast_assert(context && exten && 0 < priority);
      if (!context || !exten || priority < 1) {
         return;
      }
   }

   /* Create a new datastore. */
   datastore = ast_datastore_alloc(&after_bridge_goto_info, NULL);
   if (!datastore) {
      return;
   }
   after_bridge = ast_calloc(1, sizeof(*after_bridge));
   if (!after_bridge) {
      ast_datastore_free(datastore);
      return;
   }

   /* Initialize it. */
   after_bridge->parseable_goto = ast_strdup(parseable_goto);
   after_bridge->context = ast_strdup(context);
   after_bridge->exten = ast_strdup(exten);
   after_bridge->priority = priority;
   after_bridge->run_h_exten = run_h_exten ? 1 : 0;
   after_bridge->specific = specific ? 1 : 0;
   datastore->data = after_bridge;
   if ((parseable_goto && !after_bridge->parseable_goto)
      || (context && !after_bridge->context)
      || (exten && !after_bridge->exten)) {
      ast_datastore_free(datastore);
      return;
   }

   /* Put it on the channel replacing any existing one. */
   ast_channel_lock(chan);
   ast_bridge_discard_after_goto(chan);
   ast_channel_datastore_add(chan, datastore);
   ast_channel_unlock(chan);
}

void ast_bridge_set_after_goto(struct ast_channel *chan, const char *context, const char *exten, int priority)
{
   __after_bridge_set_goto(chan, 0, 1, context, exten, priority, NULL);
}

void ast_bridge_set_after_h(struct ast_channel *chan, const char *context)
{
   __after_bridge_set_goto(chan, 1, 0, context, NULL, 1, NULL);
}

void ast_bridge_set_after_go_on(struct ast_channel *chan, const char *context, const char *exten, int priority, const char *parseable_goto)
{
   char *p_goto;

   if (!ast_strlen_zero(parseable_goto)) {
      p_goto = ast_strdupa(parseable_goto);
      ast_replace_subargument_delimiter(p_goto);
   } else {
      p_goto = NULL;
   }
   __after_bridge_set_goto(chan, 0, 0, context, exten, priority, p_goto);
}