Added options in pjmedia UDP transport to disable source address checking

git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@483 74dad513-b988-da41-8d7b-12977e46ad98

2 files changed, 80 insertions, 22 deletions

diff --git a/pjmedia/include/pjmedia/transport_udp.h b/pjmedia/include/pjmedia/transport_udp.h
index a84da98c..e0b25ed6 100644
--- a/pjmedia/include/pjmedia/transport_udp.h
+++ b/pjmedia/include/pjmedia/transport_udp.h
@@ -29,25 +29,64 @@
 
 
 /**
- * Create UDP stream transport.
+ * Options that can be specified when creating UDP transport.
+ */
+enum pjmedia_transport_udp_options
+{
+    /**
+     * Normally the UDP transport will continuously check the source address
+     * of incoming packets to see if it is different than the configured
+     * remote address, and switch the remote address to the source address
+     * of the packet if they are different after several packets are
+     * received.
+     * Specifying this option will disable this feature.
+     */
+    PJMEDIA_UDP_NO_SRC_ADDR_CHECKING = 1,
+};
+
+
+/**
+ * Create an RTP and RTCP sockets and bind RTP the socket to the specified
+ * port to create media transport.
+ *
+ * @param endpt	    The media endpoint instance.
+ * @param name	    Optional name to be assigned to the transport.
+ * @param port	    UDP port number for the RTP socket. The RTCP port number
+ *		    will be set to one above RTP port.
+ * @param options   Options, bitmask of #pjmedia_transport_udp_options.
+ * @param p_tp	    Pointer to receive the transport instance.
+ *
+ * @return	    PJ_SUCCESS on success.
  */
 PJ_DECL(pj_status_t) pjmedia_transport_udp_create(pjmedia_endpt *endpt,
 						  const char *name,
 						  int port,
+						  unsigned options,
 						  pjmedia_transport **p_tp);
 
 
 /**
- * Create UDP stream transport from existing socket info.
+ * Create UDP stream transport from existing sockets. Use this function when
+ * the sockets have previously been created.
+ *
+ * @param endpt	    The media endpoint instance.
+ * @param name	    Optional name to be assigned to the transport.
+ * @param si	    Media socket info containing the RTP and RTCP sockets.
+ * @param options   Options, bitmask of #pjmedia_transport_udp_options.
+ * @param p_tp	    Pointer to receive the transport instance.
+ *
+ * @return	    PJ_SUCCESS on success.
  */
 PJ_DECL(pj_status_t) pjmedia_transport_udp_attach(pjmedia_endpt *endpt,
 						  const char *name,
 						  const pjmedia_sock_info *si,
+						  unsigned options,
 						  pjmedia_transport **p_tp);
 
 
 /**
- * Close UDP transport.
+ * Close UDP transport. Application can also use the "destroy" member of
+ * media transport interface to close the UDP transport.
  */
 PJ_DECL(pj_status_t) pjmedia_transport_udp_close(pjmedia_transport *tp);
 
diff --git a/pjmedia/src/pjmedia/transport_udp.c b/pjmedia/src/pjmedia/transport_udp.c
index 5ee8968a..6af2b124 100644
--- a/pjmedia/src/pjmedia/transport_udp.c
+++ b/pjmedia/src/pjmedia/transport_udp.c
@@ -36,7 +36,7 @@ struct transport_udp
     pjmedia_transport	base;		/**< Base transport.		    */
 
     pj_pool_t	       *pool;		/**< Memory pool		    */
-
+    unsigned		options;	/**< Transport options.		    */
     pjmedia_stream     *stream;		/**< Stream user (may be NULL)	    */
     pj_sockaddr_in	rem_rtp_addr;	/**< Remote RTP address		    */
     pj_sockaddr_in	rem_rtcp_addr;	/**< Remote RTCP address	    */
@@ -108,6 +108,7 @@ static pjmedia_transport_op transport_udp_op =
 PJ_DEF(pj_status_t) pjmedia_transport_udp_create( pjmedia_endpt *endpt,
 						  const char *name,
 						  int port,
+						  unsigned options,
 						  pjmedia_transport **p_tp)
 {
     pjmedia_sock_info si;
@@ -152,7 +153,7 @@ PJ_DEF(pj_status_t) pjmedia_transport_udp_create( pjmedia_endpt *endpt,
 
     
     /* Create UDP transport by attaching socket info */
-    return pjmedia_transport_udp_attach( endpt, name, &si, p_tp);
+    return pjmedia_transport_udp_attach( endpt, name, &si, options, p_tp);
 
 
 on_error:
@@ -170,6 +171,7 @@ on_error:
 PJ_DEF(pj_status_t) pjmedia_transport_udp_attach( pjmedia_endpt *endpt,
 						  const char *name,
 						  const pjmedia_sock_info *si,
+						  unsigned options,
 						  pjmedia_transport **p_tp)
 {
     struct transport_udp *tp;
@@ -198,6 +200,7 @@ PJ_DEF(pj_status_t) pjmedia_transport_udp_attach( pjmedia_endpt *endpt,
 
     tp = pj_pool_zalloc(pool, sizeof(struct transport_udp));
     tp->pool = pool;
+    tp->options = options;
     pj_ansi_strcpy(tp->base.name, name);
     tp->base.op = &transport_udp_op;
 
@@ -319,24 +322,40 @@ static void on_rx_rtp( pj_ioqueue_key_t *key,
 	    (*cb)(stream, udp->rtp_pkt, bytes_read);
 
 	/* See if source address of RTP packet is different than the 
-	 * configured address.
+	 * configured address, and switch RTP remote address to 
+	 * source packet address after several consecutive packets
+	 * have been received.
 	 */
-	if ((udp->rem_rtp_addr.sin_addr.s_addr != 
-	     udp->rtp_src_addr.sin_addr.s_addr) ||
-	    (udp->rem_rtp_addr.sin_port != 
-	     udp->rtp_src_addr.sin_port))
-	{
-	    udp->rtp_src_cnt++;
-
-	    if (udp->rtp_src_cnt >= PJMEDIA_RTP_NAT_PROBATION_CNT) {
-	    
-		udp->rem_rtp_addr = udp->rtp_src_addr;
-		udp->rtp_src_cnt = 0;
-
-		PJ_LOG(4,(udp->base.name,
-			  "Remote RTP address switched to %s:%d",
-			  pj_inet_ntoa(udp->rtp_src_addr.sin_addr),
-			  pj_ntohs(udp->rtp_src_addr.sin_port)));
+	if ((udp->options & PJMEDIA_UDP_NO_SRC_ADDR_CHECKING)==0) {
+	    if ((udp->rem_rtp_addr.sin_addr.s_addr != 
+		 udp->rtp_src_addr.sin_addr.s_addr) ||
+		(udp->rem_rtp_addr.sin_port != 
+		 udp->rtp_src_addr.sin_port))
+	    {
+		udp->rtp_src_cnt++;
+
+		if (udp->rtp_src_cnt >= PJMEDIA_RTP_NAT_PROBATION_CNT) {
+		
+		    pj_uint16_t port;
+
+		    /* Set remote RTP address to source address */
+		    udp->rem_rtp_addr = udp->rtp_src_addr;
+
+		    /* Also update remote RTCP address */
+		    pj_memcpy(&udp->rem_rtcp_addr, &udp->rem_rtp_addr, 
+			      sizeof(pj_sockaddr_in));
+		    port = (pj_uint16_t)
+			   (pj_ntohs(udp->rem_rtp_addr.sin_port)+1);
+		    udp->rem_rtcp_addr.sin_port = pj_htons(port);
+
+		    /* Reset counter */
+		    udp->rtp_src_cnt = 0;
+
+		    PJ_LOG(4,(udp->base.name,
+			      "Remote RTP address switched to %s:%d",
+			      pj_inet_ntoa(udp->rtp_src_addr.sin_addr),
+			      pj_ntohs(udp->rtp_src_addr.sin_port)));
+		}
 	    }
 	}