Fixed ticket #171: SDP media direction negotiation bug (thanks Phil Torre)

git-svn-id: http://svn.pjsip.org/repos/pjproject/branches/pjproject-0.5-stable@1057 74dad513-b988-da41-8d7b-12977e46ad98

1 files changed, 66 insertions, 30 deletions

diff --git a/pjmedia/src/pjmedia/sdp_neg.c b/pjmedia/src/pjmedia/sdp_neg.c
index 27f4bcc0..aab409e3 100644
--- a/pjmedia/src/pjmedia/sdp_neg.c
+++ b/pjmedia/src/pjmedia/sdp_neg.c
@@ -368,53 +368,89 @@ static void update_media_direction(pj_pool_t *pool,
 				   const pjmedia_sdp_media *remote,
 				   pjmedia_sdp_media *local)
 {
-   if (pjmedia_sdp_media_find_attr2(remote, "inactive", NULL) != NULL) {
-	/* If remote has "a=inactive", then local is inactive too */
+    pjmedia_dir old_dir = PJMEDIA_DIR_ENCODING_DECODING,
+	        new_dir;
 
-	pjmedia_sdp_attr *a;
+    /* Get the media direction of local SDP */
+    if (pjmedia_sdp_media_find_attr2(local, "sendonly", NULL))
+	old_dir = PJMEDIA_DIR_ENCODING;
+    else if (pjmedia_sdp_media_find_attr2(local, "recvonly", NULL))
+	old_dir = PJMEDIA_DIR_DECODING;
+    else if (pjmedia_sdp_media_find_attr2(local, "inactive", NULL))
+	old_dir = PJMEDIA_DIR_NONE;
 
-	remove_all_media_directions(local);
+    new_dir = old_dir;
+
+    /* Adjust local media direction based on remote media direction */
+    if (pjmedia_sdp_media_find_attr2(remote, "inactive", NULL) != NULL) {
+	/* If remote has "a=inactive", then local is inactive too */
 
-	a = pjmedia_sdp_attr_create(pool, "inactive", NULL);
-	pjmedia_sdp_media_add_attr(local, a);
+	new_dir = PJMEDIA_DIR_NONE;
 
     } else if(pjmedia_sdp_media_find_attr2(remote, "sendonly", NULL) != NULL) {
 	/* If remote has "a=sendonly", then set local to "recvonly" if
-	 * it is currently "sendrecv".
+	 * it is currently "sendrecv". Otherwise if local is NOT "recvonly",
+	 * then set local direction to "inactive".
 	 */
-    
-	pjmedia_sdp_attr *a;
-
-	remove_all_media_directions(local);
-
-	a = pjmedia_sdp_attr_create(pool, "recvonly", NULL);
-	pjmedia_sdp_media_add_attr(local, a);
+	switch (old_dir) {
+	case PJMEDIA_DIR_ENCODING_DECODING:
+	    new_dir = PJMEDIA_DIR_DECODING;
+	    break;
+	case PJMEDIA_DIR_DECODING:
+	    /* No change */
+	    break;
+	default:
+	    new_dir = PJMEDIA_DIR_NONE;
+	    break;
+	}
 
     } else if(pjmedia_sdp_media_find_attr2(remote, "recvonly", NULL) != NULL) {
 	/* If remote has "a=recvonly", then set local to "sendonly" if
-	 * it is currently "sendrecv".
+	 * it is currently "sendrecv". Otherwise if local is NOT "sendonly",
+	 * then set local direction to "inactive"
 	 */
     
-	pjmedia_sdp_attr *a;
-
-	remove_all_media_directions(local);
-
-	a = pjmedia_sdp_attr_create(pool, "sendonly", NULL);
-	pjmedia_sdp_media_add_attr(local, a);
+	switch (old_dir) {
+	case PJMEDIA_DIR_ENCODING_DECODING:
+	    new_dir = PJMEDIA_DIR_ENCODING;
+	    break;
+	case PJMEDIA_DIR_ENCODING:
+	    /* No change */
+	    break;
+	default:
+	    new_dir = PJMEDIA_DIR_NONE;
+	    break;
+	}
 
-    } else if(pjmedia_sdp_media_find_attr2(remote, "sendrecv", NULL) != NULL) {
+    } else {
+	/* Remote indicates "sendrecv" capability. No change to local 
+	 * direction 
+	 */
+    }
 
-	pjmedia_sdp_attr *a;
+    if (new_dir != old_dir) {
+	pjmedia_sdp_attr *a = NULL;
 
 	remove_all_media_directions(local);
 
-	a = pjmedia_sdp_attr_create(pool, "sendrecv", NULL);
-	pjmedia_sdp_media_add_attr(local, a);
-
-    } else {
-	/* Otherwise remote is set to "sendrecv".
-	 */
-	remove_all_media_directions(local);
+	switch (new_dir) {
+	case PJMEDIA_DIR_NONE:
+	    a = pjmedia_sdp_attr_create(pool, "inactive", NULL);
+	    break;
+	case PJMEDIA_DIR_ENCODING:
+	    a = pjmedia_sdp_attr_create(pool, "sendonly", NULL);
+	    break;
+	case PJMEDIA_DIR_DECODING:
+	    a = pjmedia_sdp_attr_create(pool, "recvonly", NULL);
+	    break;
+	default:
+	    /* sendrecv */
+	    break;
+	}
+	
+	if (a) {
+	    pjmedia_sdp_media_add_attr(local, a);
+	}
     }
 }