From 193b7a81fe1d3d9830d060688976dc98ff5ab299 Mon Sep 17 00:00:00 2001
From: Naveen Albert <asterisk@phreaknet.org>
Date: Sat, 26 Feb 2022 12:37:08 +0000
Subject: [PATCH] chan_pjsip: Add ability to send flash events.

PJSIP currently is capable of receiving flash events
and converting them to FLASH control frames, but it
currently lacks support for doing the reverse: taking
a FLASH control frame and converting it into a flash
event in the SIP domain.

This adds the ability for PJSIP to process flash control
frames by converting them into the appropriate SIP INFO
message, which can then be sent to the peer. This allows,
for example, flash events to be sent between Asterisk
systems using PJSIP.

ASTERISK-29941 #close

Change-Id: I1590221a4d238597f79672fa5825dd4a920c94dd
---
 channels/chan_pjsip.c                    | 24 ++++++++++++++++++++++++
 doc/CHANGES-staging/chan_pjsip_flash.txt |  4 ++++
 2 files changed, 28 insertions(+)
 create mode 100644 doc/CHANGES-staging/chan_pjsip_flash.txt

diff --git a/channels/chan_pjsip.c b/channels/chan_pjsip.c
index d55bdf9f2e..b70b210cec 100644
--- a/channels/chan_pjsip.c
+++ b/channels/chan_pjsip.c
@@ -1601,6 +1601,10 @@ static int handle_topology_request_change(struct ast_sip_session *session,
 	SCOPE_EXIT_RTN_VALUE(res, "RC: %d\n", res);
 }
 
+/* Forward declarations */
+static int transmit_info_dtmf(void *data);
+static struct info_dtmf_data *info_dtmf_data_alloc(struct ast_sip_session *session, char digit, unsigned int duration);
+
 /*! \brief Function called by core to ask the channel to indicate some sort of condition */
 static int chan_pjsip_indicate(struct ast_channel *ast, int condition, const void *data, size_t datalen)
 {
@@ -1621,6 +1625,10 @@ static int chan_pjsip_indicate(struct ast_channel *ast, int condition, const voi
 		.data.ptr = (void *)data,
 	};
 	char condition_name[256];
+	unsigned int duration;
+	char digit;
+	struct info_dtmf_data *dtmf_data;
+
 	SCOPE_ENTER(3, "%s: Indicated %s\n", ast_channel_name(ast),
 		ast_frame_subclass2str(&f, condition_name, sizeof(condition_name), NULL, 0));
 
@@ -1680,6 +1688,22 @@ static int chan_pjsip_indicate(struct ast_channel *ast, int condition, const voi
 		}
 		ast_devstate_changed(AST_DEVICE_UNKNOWN, AST_DEVSTATE_CACHABLE, "PJSIP/%s", ast_sorcery_object_get_id(channel->session->endpoint));
 		break;
+	case AST_CONTROL_FLASH:
+		duration = 300;
+		digit = '!';
+		dtmf_data = info_dtmf_data_alloc(channel->session, digit, duration);
+
+		if (!dtmf_data) {
+			res = -1;
+			break;
+		}
+
+		if (ast_sip_push_task(channel->session->serializer, transmit_info_dtmf, dtmf_data)) {
+			ast_log(LOG_WARNING, "Error sending FLASH via INFO on channel %s\n", ast_channel_name(ast));
+			ao2_ref(dtmf_data, -1); /* dtmf_data can't be null here */
+			res = -1;
+		}
+		break;
 	case AST_CONTROL_VIDUPDATE:
 		for (i = 0; i < AST_VECTOR_SIZE(&channel->session->active_media_state->sessions); ++i) {
 			media = AST_VECTOR_GET(&channel->session->active_media_state->sessions, i);
diff --git a/doc/CHANGES-staging/chan_pjsip_flash.txt b/doc/CHANGES-staging/chan_pjsip_flash.txt
new file mode 100644
index 0000000000..34da796857
--- /dev/null
+++ b/doc/CHANGES-staging/chan_pjsip_flash.txt
@@ -0,0 +1,4 @@
+Subject: chan_pjsip
+
+Hook flash events can now be sent on a PJSIP channel
+if requested to do so.
-- 
GitLab