res/res_pjsip: Add preferred_codec_only config to pjsip endpoint.

This patch add config to pjsip by endpoint.
;preferred_codec_only=yes
; Respond to a SIP invite with the single most preferred codec
; rather than advertising all joint codec capabilities. This
; limits the other side's codec choice to exactly what we prefer.

ASTERISK-26317 #close
Reported by: AaronAn
Tested by: AaronAn

Change-Id: Iad04dc55055403bbf5ec050997aee2dadc4f0762

4 files changed, 20 insertions, 4 deletions

diff --git a/res/res_pjsip.c b/res/res_pjsip.c
index 34edc8ca5..7bb10c07f 100644
--- a/res/res_pjsip.c
+++ b/res/res_pjsip.c
@@ -833,6 +833,9 @@
 						have this accountcode set on it.
 					</para></description>
 				</configOption>
+				<configOption name="preferred_codec_only" default="no">
+					<synopsis>Respond to a SIP invite with the single most preferred codec rather than advertising all joint codec capabilities. This limits the other side's codec choice to exactly what we prefer.</synopsis>
+				</configOption>
 				<configOption name="rtp_keepalive">
 					<synopsis>Number of seconds between RTP comfort noise keepalive packets.</synopsis>
 					<description><para>
@@ -2022,6 +2025,9 @@
 				<parameter name="Accountcode">
 					<para><xi:include xpointer="xpointer(/docs/configInfo[@name='res_pjsip']/configFile[@name='pjsip.conf']/configObject[@name='endpoint']/configOption[@name='accountcode']/synopsis/node())"/></para>
 				</parameter>
+				<parameter name="PreferredCodecOnly">
+					<para><xi:include xpointer="xpointer(/docs/configInfo[@name='res_pjsip']/configFile[@name='pjsip.conf']/configObject[@name='endpoint']/configOption[@name='preferred_codec_only']/synopsis/node())"/></para>
+				</parameter>
 				<parameter name="DeviceState">
 					<para>The aggregate device state for this endpoint.</para>
 				</parameter>
diff --git a/res/res_pjsip/pjsip_configuration.c b/res/res_pjsip/pjsip_configuration.c
index 333be7143..97c357a9e 100644
--- a/res/res_pjsip/pjsip_configuration.c
+++ b/res/res_pjsip/pjsip_configuration.c
@@ -1933,6 +1933,7 @@ int ast_res_pjsip_initialize_configuration(void)
 	ast_sorcery_object_field_register_custom(sip_sorcery, "endpoint", "contact_acl", "", endpoint_acl_handler, contact_acl_to_str, NULL, 0, 0);
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "subscribe_context", "", OPT_CHAR_ARRAY_T, 0, CHARFLDSET(struct ast_sip_endpoint, subscription.context));
 	ast_sorcery_object_field_register_custom(sip_sorcery, "endpoint", "contact_user", "", contact_user_handler, contact_user_to_str, NULL, 0, 0);
+	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "preferred_codec_only", "no", OPT_BOOL_T, 1, FLDSET(struct ast_sip_endpoint, preferred_codec_only));
 
 	if (ast_sip_initialize_sorcery_transport()) {
 		ast_log(LOG_ERROR, "Failed to register SIP transport support with sorcery\n");
diff --git a/res/res_pjsip_sdp_rtp.c b/res/res_pjsip_sdp_rtp.c
index 6610ef126..68d5fdb56 100644
--- a/res/res_pjsip_sdp_rtp.c
+++ b/res/res_pjsip_sdp_rtp.c
@@ -360,8 +360,13 @@ static int set_caps(struct ast_sip_session *session,
 		ast_format_cap_append_from_cap(caps, ast_channel_nativeformats(session->channel),
 			AST_MEDIA_TYPE_UNKNOWN);
 		ast_format_cap_remove_by_type(caps, media_type);
-		ast_format_cap_append_from_cap(caps, joint, media_type);
-
+		if (session->endpoint->preferred_codec_only){
+			struct ast_format *preferred_fmt = ast_format_cap_get_format(joint, 0);
+			ast_format_cap_append(caps, preferred_fmt, 0);
+			ao2_ref(preferred_fmt, -1);
+		} else {
+			ast_format_cap_append_from_cap(caps, joint, media_type);
+		}
 		/*
 		 * Apply the new formats to the channel, potentially changing
 		 * raw read/write formats and translation path while doing so.
diff --git a/res/res_pjsip_session.c b/res/res_pjsip_session.c
index 315393fdb..0ab45c74e 100644
--- a/res/res_pjsip_session.c
+++ b/res/res_pjsip_session.c
@@ -1247,7 +1247,9 @@ int ast_sip_session_create_invite(struct ast_sip_session *session, pjsip_tx_data
 	pjsip_inv_set_local_sdp(session->inv_session, offer);
 	pjmedia_sdp_neg_set_prefer_remote_codec_order(session->inv_session->neg, PJ_FALSE);
 #ifdef PJMEDIA_SDP_NEG_ANSWER_MULTIPLE_CODECS
-	pjmedia_sdp_neg_set_answer_multiple_codecs(session->inv_session->neg, PJ_TRUE);
+	if (!session->endpoint->preferred_codec_only) {
+		pjmedia_sdp_neg_set_answer_multiple_codecs(session->inv_session->neg, PJ_TRUE);
+	}
 #endif
 
 	/*
@@ -2141,7 +2143,9 @@ static int new_invite(void *data)
 		pjsip_inv_set_local_sdp(invite->session->inv_session, local);
 		pjmedia_sdp_neg_set_prefer_remote_codec_order(invite->session->inv_session->neg, PJ_FALSE);
 #ifdef PJMEDIA_SDP_NEG_ANSWER_MULTIPLE_CODECS
-		pjmedia_sdp_neg_set_answer_multiple_codecs(invite->session->inv_session->neg, PJ_TRUE);
+		if (!invite->session->endpoint->preferred_codec_only) {
+			pjmedia_sdp_neg_set_answer_multiple_codecs(invite->session->inv_session->neg, PJ_TRUE);
+		}
 #endif
 	}