msrp_ua: fix re-negociation on reINVITE

Set the proper state for the UA session(established dialog) on the ACK
for the reINVITE. Also properly handle late SDP negocication for reINVITEs.

(cherry picked from commit 2b951e5)

modules/msrp_ua/msrp_ua.c

@@ -810,16 +810,57 @@ static int update_peer_path(struct msrpua_session *sess)
 	return -1;
 }
 
+static int msrpua_update_send_200ok(struct msrpua_session *sess, int etype)
+{
+	int code;
+	str reason;
+	str *sdp;
+
+	sess->sdp_sess_vers++;
+
+	sdp = msrpua_build_sdp(sess, &sess->accept_types);
+	if (!sdp) {
+		LM_ERR("Failed to build SDP answer\n");
+		code = 500;
+		reason = str_init("Internal Server Error");
+		goto err_reply;
+	}
+
+	if (msrpua_b2b_reply(etype, &sess->b2b_key, METHOD_INVITE,
+		200, &str_init("OK"), sdp) < 0) {
+		LM_ERR("Failed to send 200 OK\n");
+		pkg_free(sdp->s);
+		goto err;
+	}
+
+	sess->dlg_state = MSRPUA_DLG_CONF;
+
+	pkg_free(sdp->s);
+
+	return 0;
+
+err_reply:
+	if (msrpua_b2b_reply(etype, &sess->b2b_key, METHOD_INVITE,
+		code, &reason, NULL) < 0) {
+		LM_ERR("Failed to send error reply\n");
+	}
+err:
+	if (msrpua_b2b_request(etype, &sess->b2b_key, &str_init("BYE")) < 0)
+		LM_ERR("Failed to send BYE on error\n");
+	msrpua_delete_session(sess);
+
+	return -1;
+}
+
 #define REASON_488_STR "Not Acceptable Here"
 
 static int msrpua_update_session(struct msrpua_session *sess,
-	struct sip_msg *msg, int etype)
+	struct sip_msg *msg, int etype, int is_reinvite)
 {
 	str peer_accept_types;
 	str peer_path;
 	int code;
 	str reason;
-	str *sdp;
 	int del_sess = 0;
 
 	if (get_sdp_peer_info(msg, &peer_accept_types, &peer_path) < 0) {
@@ -875,38 +916,17 @@ static int msrpua_update_session(struct msrpua_session *sess,
 		goto err_reply;
 	}
 
-	sess->sdp_sess_vers++;
-
-	sdp = msrpua_build_sdp(sess, &sess->accept_types);
-	if (!sdp) {
-		LM_ERR("Failed to build SDP answer\n");
-		code = 500;
-		reason = str_init("Internal Server Error");
-		del_sess = 1;
-		goto err_reply;
-	}
-
-	if (msrpua_b2b_reply(etype, &sess->b2b_key, METHOD_INVITE,
-		200, &str_init("OK"), sdp) < 0) {
-		LM_ERR("Failed to send 200 OK\n");
-		pkg_free(sdp->s);
-		del_sess = 1;
-		goto err;
-	}
-
-	sess->dlg_state = MSRPUA_DLG_CONF;
-
-	pkg_free(sdp->s);
-
-	return 0;
+	if (is_reinvite)
+		return msrpua_update_send_200ok(sess, etype);
+	else
+		return 0;
 
 err_reply:
-	if (msrpua_b2b_reply(etype, &sess->b2b_key, METHOD_INVITE,
+	if (is_reinvite && msrpua_b2b_reply(etype, &sess->b2b_key, METHOD_INVITE,
 		code, &reason, NULL) < 0) {
 		LM_ERR("Failed to send error reply\n");
 		del_sess = 1;
 	}
-err:
 	if (del_sess) {
 		if (msrpua_b2b_request(etype, &sess->b2b_key, &str_init("BYE")) < 0)
 			LM_ERR("Failed to send BYE on error\n");
@@ -1004,6 +1024,7 @@ static int b2b_notify_request(int etype, struct sip_msg *msg, str *key,
 	struct msrp_ua_notify_params cb_params = {};
 	struct msrp_ua_handler hdl = {};
 	int raise_ev = 0;
+	str body;
 
 	hentry = hash_entry(msrpua_sessions, sess->session_id);
 	hash_lock(msrpua_sessions, hentry);
@@ -1013,8 +1034,15 @@ static int b2b_notify_request(int etype, struct sip_msg *msg, str *key,
 
 	switch (msg->REQ_METHOD) {
 	case METHOD_INVITE:
-		if (msrpua_update_session(sess, msg, etype) < 0)
-			LM_ERR("Failed to update session on reInvite\n");
+		if (get_body(msg, &body) == 0 && body.len == 0) {
+			/* no SDP -> late negociation */
+
+			if (msrpua_update_send_200ok(sess, etype) < 0)
+				LM_ERR("Failed to send 200 OK on reInvite with no SDP\n");
+		} else {
+			if (msrpua_update_session(sess, msg, etype, 1) < 0)
+				LM_ERR("Failed to update session on reInvite\n");
+		}
 
 		hash_unlock(msrpua_sessions, hentry);
 		break;
@@ -1057,6 +1085,21 @@ static int b2b_notify_request(int etype, struct sip_msg *msg, str *key,
 
 			pkg_free(sess_id.s);
 			pkg_free(accept_types.s);
+		} else if (!(flags & B2B_NOTIFY_FL_ACK_NEG)) {
+			/* ACK for reINVITE */
+
+			if (get_body(msg, &body) == 0 && body.len == 0) {
+				/* no SDP -> no late negociation, just update state */
+				sess->dlg_state = MSRPUA_DLG_EST;
+			} else {
+				/* ACK with SDP -> update session */
+				if (msrpua_update_session(sess, msg, etype, 0) < 0)
+					LM_ERR("Failed to update session on ACK for reInvite\n");
+
+				sess->dlg_state = MSRPUA_DLG_EST;
+			}
+
+			hash_unlock(msrpua_sessions, hentry);
 		} else {
 			hash_unlock(msrpua_sessions, hentry);
 		}