Ticket #831: ticket831.patch

pjsip/src/pjsip/sip_util.c

@@ -1181 +1181 @@
     /* Copy server addresses */
     pj_memcpy( &stateless_data->addr, addr, sizeof(pjsip_server_addresses));
 
+    /* RFC 3261 section 18.1.1:
+     * If a request is within 200 bytes of the path MTU, or if it is larger
+     * than 1300 bytes and the path MTU is unknown, the request MUST be sent
+     * using an RFC 2914 [43] congestion controlled transport protocol, such
+     * as TCP.
+     */
+    if (stateless_data->tdata->msg->type == PJSIP_REQUEST_MSG &&
+        addr->count > 0 && 
+        addr->entry[0].type == PJSIP_TRANSPORT_UDP)
+    {
+        char buf[1500];
+        int len;
+
+        /* Check if request message is larger than 1300 bytes. */
+        len = pjsip_msg_print(stateless_data->tdata->msg, buf, 1300);
+        if (len < 0) {
+            int i;
+            int count = stateless_data->addr.count;
+
+            /* Insert "TCP version" of resolved UDP addresses at the
+             * beginning.
+             */
+            if (count * 2 > PJSIP_MAX_RESOLVED_ADDRESSES)
+                count = PJSIP_MAX_RESOLVED_ADDRESSES / 2;
+            for (i = 0; i < count; ++i) {
+                pj_memcpy(&stateless_data->addr.entry[i+count],
+                          &stateless_data->addr.entry[i],
+                          sizeof(stateless_data->addr.entry[0]));
+                stateless_data->addr.entry[i].type = PJSIP_TRANSPORT_TCP;
+            }
+            stateless_data->addr.count = count * 2;
+        }
+    }
+
     /* Process the addresses. */
     stateless_send_transport_cb( stateless_data, stateless_data->tdata,
                                  -PJ_EPENDING);