ARI: Adding a channel to a bridge while a live recording is active blocks

Added the ability to have rules that are checked when adding and/or removing
channels to/from a bridge.  In this case, if a channel is currently recording
and someone attempts to add it to a bridge an "is recording" rule is checked,
fails, and a 409 conflict is returned.

Also command functions now return an integer value that can be descriptive of
what kind of problems, if any, occurred before or during execution.

(closes issue ASTERISK-22624)
Reported by: Joshua Colp
Review: https://reviewboard.asterisk.org/r/2947/
........

Merged revisions 403749 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@403750 65c4cc65-6c06-0410-ace0-fbb531ad65f3

2 files changed, 69 insertions, 4 deletions

diff --git a/include/asterisk/stasis_app.h b/include/asterisk/stasis_app.h
index 0c22a6c30..56e039b43 100644
--- a/include/asterisk/stasis_app.h
+++ b/include/asterisk/stasis_app.h
@@ -277,6 +277,60 @@ enum stasis_app_subscribe_res stasis_app_unsubscribe(const char *app_name,
 /*! \brief Handler for controlling a channel that's in a Stasis application */
 struct stasis_app_control;
 
+/*! \brief Rule to check to see if an operation is allowed */
+struct stasis_app_control_rule {
+	/*!
+	 * \brief Checks to see if an operation is allowed on the control
+	 *
+	 * \param control Control object to check
+	 * \return 0 on success, otherwise a failure code
+	 */
+	enum stasis_app_control_channel_result (*check_rule)(
+		const struct stasis_app_control *control);
+	/*! Next item in the list */
+	AST_LIST_ENTRY(stasis_app_control_rule) next;
+};
+
+/*!
+ * \brief Registers an add channel to bridge rule.
+ *
+ * \param control Control object
+ * \param rule The rule to register
+ */
+void stasis_app_control_register_add_rule(
+	struct stasis_app_control *control,
+	struct stasis_app_control_rule *rule);
+
+/*!
+ * \brief UnRegister an add channel to bridge rule.
+ *
+ * \param control Control object
+ * \param rule The rule to unregister
+ */
+void stasis_app_control_unregister_add_rule(
+	struct stasis_app_control *control,
+	struct stasis_app_control_rule *rule);
+
+/*!
+ * \brief Registers a remove channel from bridge rule.
+ *
+ * \param control Control object
+ * \param rule The rule to register
+ */
+void stasis_app_control_register_remove_rule(
+	struct stasis_app_control *control,
+	struct stasis_app_control_rule *rule);
+
+/*!
+ * \brief Unregisters a remove channel from bridge rule.
+ *
+ * \param control Control object
+ * \param rule The rule to unregister
+ */
+void stasis_app_control_unregister_remove_rule(
+	struct stasis_app_control *control,
+	struct stasis_app_control_rule *rule);
+
 /*!
  * \brief Returns the handler for the given channel.
  * \param chan Channel to handle.
@@ -582,6 +636,16 @@ int stasis_app_bridge_moh_stop(
 	struct ast_bridge *bridge);
 
 /*!
+ * \brief Result codes used when adding/removing channels to/from bridges.
+ */
+enum stasis_app_control_channel_result {
+	/*! The channel is okay to be added/removed */
+	STASIS_APP_CHANNEL_OKAY = 0,
+	/*! The channel is currently recording */
+	STASIS_APP_CHANNEL_RECORDING
+};
+
+/*!
  * \brief Add a channel to the bridge.
  *
  * \param control Control whose channel should be added to the bridge
diff --git a/include/asterisk/stasis_app_impl.h b/include/asterisk/stasis_app_impl.h
index d4b467756..a8c8c0586 100644
--- a/include/asterisk/stasis_app_impl.h
+++ b/include/asterisk/stasis_app_impl.h
@@ -49,7 +49,7 @@ int stasis_app_exec(struct ast_channel *chan, const char *app_name, int argc,
 	char *argv[]);
 
 /*! Callback type for stasis app commands */
-typedef void *(*stasis_app_command_cb)(struct stasis_app_control *control,
+typedef int (*stasis_app_command_cb)(struct stasis_app_control *control,
 	struct ast_channel *chan, void *data);
 
 /*!
@@ -63,10 +63,11 @@ typedef void *(*stasis_app_command_cb)(struct stasis_app_control *control,
  * \param control Control object for the channel to send the command to.
  * \param command Command function to execute.
  * \param data Optional data to pass along with the control function.
- * \return Return value from \a command.
- * \return \c NULL on error.
+ *
+ * \return zero on success.
+ * \return error code otherwise.
  */
-void *stasis_app_send_command(struct stasis_app_control *control,
+int stasis_app_send_command(struct stasis_app_control *control,
 	stasis_app_command_cb command, void *data);
 
 /*!