res_agi: Prevent an AGI from eating frames it should not. (Re-do)

A dialplan intercept routine is equivalent to an interrupt routine.  As
such, the routine must be done quickly and you do not have access to the
media stream.  These restrictions are necessary because the media stream
is the responsibility of some other code and interfering with or delaying
that processing is bad.  A possible future dialplan processing
architecture change may allow the interception routine to run in a
different thread from the main thread handling the media and remove the
execution time restriction.

* Made res_agi.c:run_agi() running an AGI in an interception routine run
in DeadAGI mode.  No touchy channel frames.

ASTERISK-25951

ASTERISK-26343

ASTERISK-26716

Change-Id: I638f147ca7a7f2590d7194a8ef4090eb191e4e43

1 files changed, 38 insertions, 0 deletions

diff --git a/main/channel.c b/main/channel.c
index 7c8d3a989..1c7743a2f 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -10300,6 +10300,36 @@ void ast_channel_queue_redirecting_update(struct ast_channel *chan, const struct
 	ast_queue_control_data(chan, AST_CONTROL_REDIRECTING, data, datalen);
 }
 
+/*!
+ * Storage to determine if the current thread is running an intercept dialplan routine.
+ */
+AST_THREADSTORAGE_RAW(in_intercept_routine);
+
+/*!
+ * \internal
+ * \brief Set the current intercept dialplan routine status mode.
+ * \since 13.14.0
+ *
+ * \param in_intercept_mode New intercept mode.  (Non-zero if in intercept mode)
+ *
+ * \return Nothing
+ */
+static void channel_set_intercept_mode(int in_intercept_mode)
+{
+	int status;
+
+	status = ast_threadstorage_set_ptr(&in_intercept_routine,
+		in_intercept_mode ? (void *) 1 : (void *) 0);
+	if (status) {
+		ast_log(LOG_ERROR, "Failed to set dialplan intercept mode\n");
+	}
+}
+
+int ast_channel_get_intercept_mode(void)
+{
+	return ast_threadstorage_get_ptr(&in_intercept_routine) ? 1 : 0;
+}
+
 int ast_channel_connected_line_macro(struct ast_channel *autoservice_chan, struct ast_channel *macro_chan, const void *connected_info, int is_caller, int is_frame)
 {
 	static int deprecation_warning = 0;
@@ -10335,7 +10365,9 @@ int ast_channel_connected_line_macro(struct ast_channel *autoservice_chan, struc
 	}
 	ast_channel_unlock(macro_chan);
 
+	channel_set_intercept_mode(1);
 	retval = ast_app_run_macro(autoservice_chan, macro_chan, macro, macro_args);
+	channel_set_intercept_mode(0);
 	if (!retval) {
 		struct ast_party_connected_line saved_connected;
 
@@ -10385,7 +10417,9 @@ int ast_channel_redirecting_macro(struct ast_channel *autoservice_chan, struct a
 	}
 	ast_channel_unlock(macro_chan);
 
+	channel_set_intercept_mode(1);
 	retval = ast_app_run_macro(autoservice_chan, macro_chan, macro, macro_args);
+	channel_set_intercept_mode(0);
 	if (!retval) {
 		struct ast_party_redirecting saved_redirecting;
 
@@ -10428,7 +10462,9 @@ int ast_channel_connected_line_sub(struct ast_channel *autoservice_chan, struct
 	}
 	ast_channel_unlock(sub_chan);
 
+	channel_set_intercept_mode(1);
 	retval = ast_app_run_sub(autoservice_chan, sub_chan, sub, sub_args, 0);
+	channel_set_intercept_mode(0);
 	if (!retval) {
 		struct ast_party_connected_line saved_connected;
 
@@ -10471,7 +10507,9 @@ int ast_channel_redirecting_sub(struct ast_channel *autoservice_chan, struct ast
 	}
 	ast_channel_unlock(sub_chan);
 
+	channel_set_intercept_mode(1);
 	retval = ast_app_run_sub(autoservice_chan, sub_chan, sub, sub_args, 0);
+	channel_set_intercept_mode(0);
 	if (!retval) {
 		struct ast_party_redirecting saved_redirecting;