Run predial routine on local;2 channel where you would expect.

Before this patch, the predial routine executes on the ;1 channel of a
local channel pair.  Executing predial on the ;1 channel of a local
channel pair is of limited utility.  Any channel variables set by the
predial routine executing on the ;1 channel will not be available when the
local channel executes dialplan on the ;2 channel.

* Create ast_pre_call() and an associated pre_call() technology callback
to handle running the predial routine.  If a channel technology does not
provide the callback, the predial routine is simply run on the channel.

Review: https://reviewboard.asterisk.org/r/1903/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@366183 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_dial.c

@@ -2478,7 +2478,7 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
 		ast_autoservice_start(chan);
 		ast_replace_subargument_delimiter(opt_args[OPT_ARG_PREDIAL_CALLEE]);
 		AST_LIST_TRAVERSE(&out_chans, tmp, node) {
-			ast_app_exec_sub(NULL, tmp->chan, opt_args[OPT_ARG_PREDIAL_CALLEE]);
+			ast_pre_call(tmp->chan, opt_args[OPT_ARG_PREDIAL_CALLEE]);
 		}
 		ast_autoservice_stop(chan);
 	}

channels/chan_local.c

@@ -95,6 +95,7 @@ static struct ast_jb_conf g_jb_conf = {
 static struct ast_channel *local_request(const char *type, struct ast_format_cap *cap, const struct ast_channel *requestor, const char *data, int *cause);
 static int local_digit_begin(struct ast_channel *ast, char digit);
 static int local_digit_end(struct ast_channel *ast, char digit, unsigned int duration);
+static int local_pre_call(struct ast_channel *ast, const char *sub_args);
 static int local_call(struct ast_channel *ast, const char *dest, int timeout);
 static int local_hangup(struct ast_channel *ast);
 static int local_answer(struct ast_channel *ast);
@@ -116,6 +117,7 @@ static struct ast_channel_tech local_tech = {
 	.requester = local_request,
 	.send_digit_begin = local_digit_begin,
 	.send_digit_end = local_digit_end,
+	.pre_call = local_pre_call,
 	.call = local_call,
 	.hangup = local_hangup,
 	.answer = local_answer,
@@ -1257,6 +1259,34 @@ static struct ast_channel *local_request(const char *type, struct ast_format_cap
 	return chan;
 }
 
+static int local_pre_call(struct ast_channel *ast, const char *sub_args)
+{
+	struct local_pvt *p = ast_channel_tech_pvt(ast);
+	struct ast_channel *chan;
+	int res;
+
+	ao2_lock(p);
+	chan = p->chan;
+	if (chan) {
+		ast_channel_ref(chan);
+	}
+	ao2_unlock(p);
+	if (!chan) {
+		return -1;
+	}
+
+	/*
+	 * Execute the predial routine on the ;2 channel so any channel
+	 * variables set by the predial will be available to the local
+	 * channel PBX.
+	 */
+	ast_channel_unlock(ast);
+	res = ast_app_exec_sub(NULL, chan, sub_args);
+	ast_channel_unref(chan);
+	ast_channel_lock(ast);
+	return res;
+}
+
 /*! \brief CLI command "local show channels" */
 static char *locals_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 {

include/asterisk/channel.h

@@ -676,6 +676,20 @@ struct ast_channel_tech {
 	 * parameters as a parameter.
 	 */
 	int (* cc_callback)(struct ast_channel *inbound, const char *dest, ast_cc_callback_fn callback);
+
+	/*!
+	 * \brief Execute a Gosub call on the channel in a technology specific way before a call is placed.
+	 * \since 11.0
+	 *
+	 * \param chan Channel to execute Gosub in a tech specific way.
+	 * \param sub_args Gosub application parameter string.
+	 *
+	 * \note The chan is locked before calling.
+	 *
+	 * \retval 0 on success.
+	 * \retval -1 on error.
+	 */
+	int (*pre_call)(struct ast_channel *chan, const char *sub_args);
 };
 
 /*! Kill the channel channel driver technology descriptor. */
@@ -1526,6 +1540,24 @@ int ast_raw_answer(struct ast_channel *chan, int cdr_answer);
  */
 int __ast_answer(struct ast_channel *chan, unsigned int delay, int cdr_answer);
 
+/*!
+ * \brief Execute a Gosub call on the channel before a call is placed.
+ * \since 11.0
+ *
+ * \details
+ * This is called between ast_request() and ast_call() to
+ * execute a predial routine on the newly created channel.
+ *
+ * \param chan Channel to execute Gosub.
+ * \param sub_args Gosub application parameter string.
+ *
+ * \note Absolutely _NO_ channel locks should be held before calling this function.
+ *
+ * \retval 0 on success.
+ * \retval -1 on error.
+ */
+int ast_pre_call(struct ast_channel *chan, const char *sub_args);
+
 /*!
  * \brief Make a call
  * \note Absolutely _NO_ channel locks should be held before calling this function.

main/channel.c

@@ -5671,6 +5671,23 @@ struct ast_channel *ast_request(const char *type, struct ast_format_cap *request
 	return NULL;
 }
 
+int ast_pre_call(struct ast_channel *chan, const char *sub_args)
+{
+	int (*pre_call)(struct ast_channel *chan, const char *sub_args);
+
+	ast_channel_lock(chan);
+	pre_call = ast_channel_tech(chan)->pre_call;
+	if (pre_call) {
+		int res;
+
+		res = pre_call(chan, sub_args);
+		ast_channel_unlock(chan);
+		return res;
+	}
+	ast_channel_unlock(chan);
+	return ast_app_exec_sub(NULL, chan, sub_args);
+}
+
 int ast_call(struct ast_channel *chan, const char *addr, int timeout)
 {
 	/* Place an outgoing call, but don't wait any longer than timeout ms before returning.