chan_pjsip: Add support for passing hold and unhold requests through.

This change adds an option, moh_passthrough, that when enabled will pass
hold and unhold requests through using a SIP re-invite. When placing on
hold a re-invite with sendonly will be sent and when taking off hold a
re-invite with sendrecv will be sent. This allows remote servers to handle
the musiconhold instead of the local Asterisk instance being responsible.

Review: https://reviewboard.asterisk.org/r/4103/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@427112 65c4cc65-6c06-0410-ace0-fbb531ad65f3

3 files changed, 13 insertions, 5 deletions

diff --git a/res/res_pjsip.c b/res/res_pjsip.c
index b350b7b77..dcf771bb3 100644
--- a/res/res_pjsip.c
+++ b/res/res_pjsip.c
@@ -576,6 +576,9 @@
 				<configOption name="user_eq_phone" default="no">
 					<synopsis>Determines whether a user=phone parameter is placed into the request URI if the user is determined to be a phone number</synopsis>
 				</configOption>
+				<configOption name="moh_passthrough" default="no">
+					<synopsis>Determines whether hold and unhold will be passed through using re-INVITEs with recvonly and sendrecv to the remote side</synopsis>
+				</configOption>
 				<configOption name="sdp_owner" default="-">
 					<synopsis>String placed as the username portion of an SDP origin (o=) line.</synopsis>
 				</configOption>
@@ -1560,6 +1563,9 @@
 				<parameter name="UserEqPhone">
 					<para><xi:include xpointer="xpointer(/docs/configInfo[@name='res_pjsip']/configFile[@name='pjsip.conf']/configObject[@name='endpoint']/configOption[@name='user_eq_phone']/synopsis/node())"/></para>
 				</parameter>
+				<parameter name="MohPassthrough">
+					<para><xi:include xpointer="xpointer(/docs/configInfo[@name='res_pjsip']/configFile[@name='pjsip.conf']/configObject[@name='endpoint']/configOption[@name='moh_passthrough']/synopsis/node())"/></para>
+				</parameter>
 				<parameter name="SdpOwner">
 					<para><xi:include xpointer="xpointer(/docs/configInfo[@name='res_pjsip']/configFile[@name='pjsip.conf']/configObject[@name='endpoint']/configOption[@name='sdp_owner']/synopsis/node())"/></para>
 				</parameter>
diff --git a/res/res_pjsip/pjsip_configuration.c b/res/res_pjsip/pjsip_configuration.c
index dabbfaed8..798066777 100644
--- a/res/res_pjsip/pjsip_configuration.c
+++ b/res/res_pjsip/pjsip_configuration.c
@@ -1733,6 +1733,7 @@ int ast_res_pjsip_initialize_configuration(const struct ast_module_info *ast_mod
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "record_off_feature", "automixmon", OPT_STRINGFIELD_T, 0, STRFLDSET(struct ast_sip_endpoint, info.recording.offfeature));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "allow_transfer", "yes", OPT_BOOL_T, 1, FLDSET(struct ast_sip_endpoint, allowtransfer));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "user_eq_phone", "no", OPT_BOOL_T, 1, FLDSET(struct ast_sip_endpoint, usereqphone));
+	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "moh_passthrough", "no", OPT_BOOL_T, 1, FLDSET(struct ast_sip_endpoint, moh_passthrough));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "sdp_owner", "-", OPT_STRINGFIELD_T, 0, STRFLDSET(struct ast_sip_endpoint, media.sdpowner));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "sdp_session", "Asterisk", OPT_STRINGFIELD_T, 0, STRFLDSET(struct ast_sip_endpoint, media.sdpsession));
 	ast_sorcery_object_field_register_custom(sip_sorcery, "endpoint", "tos_audio", "0", tos_handler, tos_audio_to_str, NULL, 0, 0);
diff --git a/res/res_pjsip_sdp_rtp.c b/res/res_pjsip_sdp_rtp.c
index 1f863008f..74c980d39 100644
--- a/res/res_pjsip_sdp_rtp.c
+++ b/res/res_pjsip_sdp_rtp.c
@@ -887,6 +887,7 @@ static int create_outgoing_sdp_stream(struct ast_sip_session *session, struct as
 	static const pj_str_t STR_IP4 = { "IP4", 3};
 	static const pj_str_t STR_IP6 = { "IP6", 3};
 	static const pj_str_t STR_SENDRECV = { "sendrecv", 8 };
+	static const pj_str_t STR_SENDONLY = { "sendonly", 8 };
 	pjmedia_sdp_media *media;
 	char hostip[PJ_INET6_ADDRSTRLEN+2];
 	struct ast_sockaddr addr;
@@ -1046,7 +1047,7 @@ static int create_outgoing_sdp_stream(struct ast_sip_session *session, struct as
 
 	/* Add the sendrecv attribute - we purposely don't keep track because pjmedia-sdp will automatically change our offer for us */
 	attr = PJ_POOL_ZALLOC_T(pool, pjmedia_sdp_attr);
-	attr->name = STR_SENDRECV;
+	attr->name = !session_media->locally_held ? STR_SENDRECV : STR_SENDONLY;
 	media->attr[media->attr_count++] = attr;
 
 	/* Add the media stream to the SDP */
@@ -1122,18 +1123,18 @@ static int apply_negotiated_sdp_stream(struct ast_sip_session *session, struct a
 	if (ast_sockaddr_isnull(addrs) ||
 		ast_sockaddr_is_any(addrs) ||
 		pjmedia_sdp_media_find_attr2(remote_stream, "sendonly", NULL)) {
-		if (!session_media->held) {
+		if (!session_media->remotely_held) {
 			/* The remote side has put us on hold */
 			ast_queue_hold(session->channel, session->endpoint->mohsuggest);
 			ast_rtp_instance_stop(session_media->rtp);
 			ast_queue_frame(session->channel, &ast_null_frame);
-			session_media->held = 1;
+			session_media->remotely_held = 1;
 		}
-	} else if (session_media->held) {
+	} else if (session_media->remotely_held) {
 		/* The remote side has taken us off hold */
 		ast_queue_unhold(session->channel);
 		ast_queue_frame(session->channel, &ast_null_frame);
-		session_media->held = 0;
+		session_media->remotely_held = 0;
 	}
 
 	return 1;