res_pjsip_sdp_rtp: Fix multiple keepalive scheduled items.

The keepalive support in res_pjsip_sdp_rtp currently assumes
that a stream will only be negotiated once. This is false.
If the stream is replaced and later added back it can be
negotiated again causing multiple keepalive scheduled items
to exist. This change explicitly deletes the existing
keepalive scheduled item before adding the new one.

The res_pjsip_sdp_rtp module also does not stop RTP
keepalives or timeout timer if the stream has been
replaced. This change adds a callback to the session media
interface to allow a media stream to be stopped without
the resources being destroyed. This allows the scheduled
items and RTP to be stopped when the stream no longer
exists.

ASTERISK-25356 #close

Change-Id: Ibe6a7cc0927c87326fd5f1c0d4ad889dbfbea1de

diff --git a/include/asterisk/res_pjsip_session.h b/include/asterisk/res_pjsip_session.h
index 734a887b31d4c4569a59c7c569bcbbab3d6a4c91..61398471306928911010d3fa31d8cde89469c42c 100644 (file)
--- a/include/asterisk/res_pjsip_session.h
+++ b/include/asterisk/res_pjsip_session.h
@@ -356,6 +356,12 @@ struct ast_sip_session_sdp_handler {
         */
        int (*apply_negotiated_sdp_stream)(struct ast_sip_session *session, struct ast_sip_session_media *session_media, const struct pjmedia_sdp_session *local, const struct pjmedia_sdp_media *local_stream,
                const struct pjmedia_sdp_session *remote, const struct pjmedia_sdp_media *remote_stream);
+       /*!
+        * \brief Stop a session_media created by this handler but do not destroy resources
+        * \param session The session for which media is being stopped
+        * \param session_media The media to destroy
+        */
+       void (*stream_stop)(struct ast_sip_session_media *session_media);
        /*!
         * \brief Destroy a session_media created by this handler
         * \param session The session for which media is being destroyed

diff --git a/res/res_pjsip_sdp_rtp.c b/res/res_pjsip_sdp_rtp.c
index f7fd5b85fd92c1f5faac4a07b92865fc269778c6..a66aebb36433246047314532e23fdb20375eb20e 100644 (file)
--- a/res/res_pjsip_sdp_rtp.c
+++ b/res/res_pjsip_sdp_rtp.c
@@ -1317,6 +1317,7 @@ static int apply_negotiated_sdp_stream(struct ast_sip_session *session, struct a
                 * a NAT. This way there won't be an awkward delay before media starts flowing in some
                 * scenarios.
                 */
+               AST_SCHED_DEL(sched, session_media->keepalive_sched_id);
                session_media->keepalive_sched_id = ast_sched_add_variable(sched, 500, send_keepalive,
                        session_media, 1);
        }
@@ -1368,13 +1369,23 @@ static void change_outgoing_sdp_stream_media_address(pjsip_tx_data *tdata, struc
        pj_strdup2(tdata->pool, &stream->conn->addr, transport->external_media_address);
 }
 
+/*! \brief Function which stops the RTP instance */
+static void stream_stop(struct ast_sip_session_media *session_media)
+{
+       if (!session_media->rtp) {
+               return;
+       }
+
+       AST_SCHED_DEL(sched, session_media->keepalive_sched_id);
+       AST_SCHED_DEL(sched, session_media->timeout_sched_id);
+       ast_rtp_instance_stop(session_media->rtp);
+}
+
 /*! \brief Function which destroys the RTP instance when session ends */
 static void stream_destroy(struct ast_sip_session_media *session_media)
 {
        if (session_media->rtp) {
-               AST_SCHED_DEL(sched, session_media->keepalive_sched_id);
-               AST_SCHED_DEL(sched, session_media->timeout_sched_id);
-               ast_rtp_instance_stop(session_media->rtp);
+               stream_stop(session_media);
                ast_rtp_instance_destroy(session_media->rtp);
        }
        session_media->rtp = NULL;
@@ -1387,6 +1398,7 @@ static struct ast_sip_session_sdp_handler audio_sdp_handler = {
        .create_outgoing_sdp_stream = create_outgoing_sdp_stream,
        .apply_negotiated_sdp_stream = apply_negotiated_sdp_stream,
        .change_outgoing_sdp_stream_media_address = change_outgoing_sdp_stream_media_address,
+       .stream_stop = stream_stop,
        .stream_destroy = stream_destroy,
 };
 
@@ -1397,6 +1409,7 @@ static struct ast_sip_session_sdp_handler video_sdp_handler = {
        .create_outgoing_sdp_stream = create_outgoing_sdp_stream,
        .apply_negotiated_sdp_stream = apply_negotiated_sdp_stream,
        .change_outgoing_sdp_stream_media_address = change_outgoing_sdp_stream_media_address,
+       .stream_stop = stream_stop,
        .stream_destroy = stream_destroy,
 };
 

diff --git a/res/res_pjsip_session.c b/res/res_pjsip_session.c
index 801746459b14dab1d1fda1f907d6527245a38cc2..1dcac7e972bb880b9868c950a29ccbfc5ee5f853 100644 (file)
--- a/res/res_pjsip_session.c
+++ b/res/res_pjsip_session.c
@@ -362,6 +362,13 @@ static int handle_negotiated_sdp_session_media(void *obj, void *arg, int flags)
                        }
                }
        }
+
+       if (session_media->handler && session_media->handler->stream_stop) {
+               ast_debug(1, "Stopping SDP media stream '%s' as it is not currently negotiated\n",
+                       session_media->stream_type);
+               session_media->handler->stream_stop(session_media);
+       }
+
        return CMP_MATCH;
 }