AMI: Add AMI event to expose hook flash events

Although Asterisk can receive and propogate flash events, it currently
provides no mechanism for doing anything with them itself.

This AMI event allows flash events to be processed by Asterisk.
Additionally, AST_CONTROL_FLASH is included in a switch statement
in channel.c to avoid throwing a warning when we shouldn't.

ASTERISK-29380

Change-Id: Ie17ffe65086e0282c88542e38eed6a461ec79e81

configs/samples/stasis.conf.sample

@@ -53,6 +53,7 @@
 ; decline=ast_channel_hangup_request_type
 ; decline=ast_channel_dtmf_begin_type
 ; decline=ast_channel_dtmf_end_type
+; decline=ast_channel_flash_type
 ; decline=ast_channel_hold_type
 ; decline=ast_channel_unhold_type
 ; decline=ast_channel_chanspy_start_type

doc/CHANGES-staging/flash_ami_event.txt

@@ -0,0 +1,3 @@
+Subject: AMI Flash event
+
+Hook flash events are now exposed as AMI events.

include/asterisk/stasis_channels.h

@@ -525,6 +525,13 @@ struct stasis_message_type *ast_channel_dtmf_begin_type(void);
  */
 struct stasis_message_type *ast_channel_dtmf_end_type(void);
 
+/*!
+ * \brief Message type for when a hook flash occurs on a channel.
+ *
+ * \retval A stasis message type
+ */
+struct stasis_message_type *ast_channel_flash_type(void);
+
 /*!
  * \since 12
  * \brief Message type for when a channel is placed on hold.

main/channel.c

@@ -3315,6 +3315,7 @@ int ast_waitfordigit_full(struct ast_channel *c, int timeout_ms, const char *bre
 				case AST_CONTROL_UPDATE_RTP_PEER:
 				case AST_CONTROL_HOLD:
 				case AST_CONTROL_UNHOLD:
+				case AST_CONTROL_FLASH:
 				case -1:
 					/* Unimportant */
 					break;
@@ -3393,6 +3394,11 @@ static void send_dtmf_end_event(struct ast_channel *chan,
 	ast_channel_publish_blob(chan, ast_channel_dtmf_end_type(), blob);
 }
 
+static void send_flash_event(struct ast_channel *chan)
+{
+	ast_channel_publish_blob(chan, ast_channel_flash_type(), NULL);
+}
+
 static void ast_read_generator_actions(struct ast_channel *chan, struct ast_frame *f)
 {
 	struct ast_generator *generator;
@@ -3859,6 +3865,8 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio, int
 				 */
 				ast_frfree(f);
 				f = &ast_null_frame;
+			} else if (f->subclass.integer == AST_CONTROL_FLASH) {
+				send_flash_event(chan);
 			}
 			break;
 		case AST_FRAME_DTMF_END:

main/manager_channels.c

@@ -968,6 +968,24 @@ static void channel_dtmf_end_cb(void *data, struct stasis_subscription *sub,
 		digit, duration_ms, direction);
 }
 
+static void channel_flash_cb(void *data, struct stasis_subscription *sub,
+	struct stasis_message *message)
+{
+	struct ast_channel_blob *obj = stasis_message_data(message);
+	struct ast_str *channel_event_string;
+
+	channel_event_string = ast_manager_build_channel_state_string(obj->snapshot);
+	if (!channel_event_string) {
+		return;
+	}
+
+	manager_event(EVENT_FLAG_CALL, "Flash",
+		"%s",
+		ast_str_buffer(channel_event_string));
+
+	ast_free(channel_event_string);
+}
+
 static void channel_hangup_handler_cb(void *data, struct stasis_subscription *sub,
 		struct stasis_message *message)
 {
@@ -1327,6 +1345,9 @@ int manager_channels_init(void)
 	ret |= stasis_message_router_add(message_router,
 		ast_channel_dtmf_end_type(), channel_dtmf_end_cb, NULL);
 
+	ret |= stasis_message_router_add(message_router,
+		ast_channel_flash_type(), channel_flash_cb, NULL);
+
 	ret |= stasis_message_router_add(message_router,
 		ast_channel_hangup_request_type(), channel_hangup_request_cb,
 		NULL);

main/stasis.c

@@ -120,6 +120,7 @@
 							<enum name="ast_channel_hangup_request_type" />
 							<enum name="ast_channel_dtmf_begin_type" />
 							<enum name="ast_channel_dtmf_end_type" />
+							<enum name="ast_channel_flash_type" />
 							<enum name="ast_channel_hold_type" />
 							<enum name="ast_channel_unhold_type" />
 							<enum name="ast_channel_chanspy_start_type" />

main/stasis_channels.c

@@ -1598,6 +1598,7 @@ STASIS_MESSAGE_TYPE_DEFN(ast_channel_hold_type,
 STASIS_MESSAGE_TYPE_DEFN(ast_channel_unhold_type,
 	.to_json = unhold_to_json,
 	);
+STASIS_MESSAGE_TYPE_DEFN(ast_channel_flash_type);
 STASIS_MESSAGE_TYPE_DEFN(ast_channel_chanspy_start_type);
 STASIS_MESSAGE_TYPE_DEFN(ast_channel_chanspy_stop_type);
 STASIS_MESSAGE_TYPE_DEFN(ast_channel_fax_type);
@@ -1642,6 +1643,7 @@ static void stasis_channels_cleanup(void)
 	STASIS_MESSAGE_TYPE_CLEANUP(ast_channel_masquerade_type);
 	STASIS_MESSAGE_TYPE_CLEANUP(ast_channel_dtmf_begin_type);
 	STASIS_MESSAGE_TYPE_CLEANUP(ast_channel_dtmf_end_type);
+	STASIS_MESSAGE_TYPE_CLEANUP(ast_channel_flash_type);
 	STASIS_MESSAGE_TYPE_CLEANUP(ast_channel_hold_type);
 	STASIS_MESSAGE_TYPE_CLEANUP(ast_channel_unhold_type);
 	STASIS_MESSAGE_TYPE_CLEANUP(ast_channel_chanspy_start_type);
@@ -1695,6 +1697,7 @@ int ast_stasis_channels_init(void)
 	res |= STASIS_MESSAGE_TYPE_INIT(ast_channel_masquerade_type);
 	res |= STASIS_MESSAGE_TYPE_INIT(ast_channel_dtmf_begin_type);
 	res |= STASIS_MESSAGE_TYPE_INIT(ast_channel_dtmf_end_type);
+	res |= STASIS_MESSAGE_TYPE_INIT(ast_channel_flash_type);
 	res |= STASIS_MESSAGE_TYPE_INIT(ast_channel_hold_type);
 	res |= STASIS_MESSAGE_TYPE_INIT(ast_channel_unhold_type);
 	res |= STASIS_MESSAGE_TYPE_INIT(ast_channel_chanspy_start_type);