sip_transport: tcp: shutdown transport if unable to keep decoding stream

If pjsip_find_msg() starts failing because there's some missing header
like Content-Length, log the issue and shutdown the transport to avoid
staying in a broken state.

pjsip/src/pjsip/sip_parser.c

@@ -937,6 +937,8 @@ PJ_DEF(pj_status_t) pjsip_find_msg( const char *buf, pj_size_t size,
 
     /* Found Content-Length? */
     if (content_length == -1) {
+        /* As per RFC3261 7.4.2, 7.5, 20.14, Content-Length is mandatory over TCP. */
+        PJ_LOG(2, (THIS_FILE, "Field Content-Length not found!"));
         return status;
     }
 

pjsip/src/pjsip/sip_transport.c

@@ -2068,41 +2068,57 @@ PJ_DEF(pj_ssize_t) pjsip_tpmgr_receive_packet( pjsip_tpmgr *mgr,
             pj_status_t msg_status;
             msg_status = pjsip_find_msg(current_pkt, remaining_len, PJ_FALSE, 
                                         &msg_fragment_size);
-            if (msg_status != PJ_SUCCESS) {
-                if (remaining_len == PJSIP_MAX_PKT_LEN) {
-                    mgr->on_rx_msg(mgr->endpt, PJSIP_ERXOVERFLOW, rdata);
-                    
-                    /* Notify application about the message overflow */
-                    if (mgr->tp_drop_data_cb) {
-                        pjsip_tp_dropped_data dd;
-                        pj_bzero(&dd, sizeof(dd));
-                        dd.tp = tr;
-                        dd.data = current_pkt;
-                        dd.len = msg_fragment_size;
-                        dd.status = PJSIP_ERXOVERFLOW;
-                        (*mgr->tp_drop_data_cb)(&dd);
-                    }
-
-                    if (rdata->tp_info.transport->idle_timer.id == 
-                                                         INITIAL_IDLE_TIMER_ID)
-                    {
-                        /* We are not getting the first valid SIP message 
-                         * as expected, close the transport.
-                         */
-                        PJ_LOG(4, (THIS_FILE, "Unexpected data was received "\
-                            "while waiting for a valid initial SIP messages. "\
-                            "Shutting down transport %s",
-                            rdata->tp_info.transport->obj_name));
-
-                        pjsip_transport_shutdown(rdata->tp_info.transport);
-                    }
-                    
-                    /* Exhaust all data. */
-                    return rdata->pkt_info.len;
-                } else {
+            switch (msg_status) {
+            case PJ_SUCCESS;
+                /* continue below */
+                break;
+            case PJSIP_EPARTIALMSG:
+                if (remaining_len != PJSIP_MAX_PKT_LEN) {
                     /* Not enough data in packet. */
                     return total_processed;
                 }
+                mgr->on_rx_msg(mgr->endpt, PJSIP_ERXOVERFLOW, rdata);
+
+                /* Notify application about the message overflow */
+                if (mgr->tp_drop_data_cb) {
+                    pjsip_tp_dropped_data dd;
+                    pj_bzero(&dd, sizeof(dd));
+                    dd.tp = tr;
+                    dd.data = current_pkt;
+                    dd.len = msg_fragment_size;
+                    dd.status = PJSIP_ERXOVERFLOW;
+                    (*mgr->tp_drop_data_cb)(&dd);
+                }
+
+                if (rdata->tp_info.transport->idle_timer.id ==
+                                                        INITIAL_IDLE_TIMER_ID)
+                {
+                    /* We are not getting the first valid SIP message
+                        * as expected, close the transport.
+                        */
+                    PJ_LOG(4, (THIS_FILE, "Unexpected data was received "\
+                        "while waiting for a valid initial SIP messages. "\
+                        "Shutting down transport %s",
+                        rdata->tp_info.transport->obj_name));
+
+                    pjsip_transport_shutdown(rdata->tp_info.transport);
+                }
+                /* Exhaust all data. */
+                return rdata->pkt_info.len;
+            case PJSIP_EMISSINGHDR:
+            case PJSIP_EINVALIDHDR:
+            default:
+                {
+                char errbuf[128];
+                PJ_LOG(1, (THIS_FILE, "Unable to match whole message (%s)."\
+                    "Shutting down transport %s",
+                    pjsip_strerror(msg_status, errbuf, sizeof(errbuf));
+                    rdata->tp_info.transport->obj_name));
+
+                pjsip_transport_shutdown(rdata->tp_info.transport);
+                return rdata->pkt_info.len;
+                break;
+                }
             }
         }