Ticket #2676: udp-dont-wait-too-long.patch

xpra/net/udp_protocol.py

@@ -128 +128 @@
         super().__init__(*args)
         self.mtu = 0
         self.last_sequence = -1     #the most recent packet sequence we processed in full
+        self.last_sequence_time = 0
         self.highest_sequence = -1
         self.jitter = 20            #20ms
         self.uuid = kwargs.get("uuid", 0)
@@ -179 +180 @@
         if self._closed:
             return False
         missing = self._get_missing()
+        log.info("send_control() missing=%s", missing)
         packet = ("udp-control", self.mtu, self.asynchronous_receive_enabled,
                   self.last_sequence, self.highest_sequence, missing, tuple(self.cancel))
         log("send_control() packet(%s)=%s", self.pending_packets, ellipsizer(packet))
@@ -368 +370 @@
                 if synchronous:
                     #we have to wait for the missing chunks / packets
                     log("process_udp_data: queuing %i as we're still waiting for %i", seqno, self.last_sequence+1)
+                    if self.last_sequence_time:
+                        elapsed = self.last_sequence_time-monotonic_time()
+                        if elapsed>10:
+                            log.error("Error: UDP protocol error")
+                            log.error(" sequence %i is taking far too long", self.last_sequence+1)
+                            self.close()
                     return
             missing = tuple(i for i, x in enumerate(ip.chunks) if x is None)
             if missing:
@@ -394 +402 @@
             seqno, len(data), chunk, synchronous!=0)
         if seqno==self.last_sequence+1:
             self.last_sequence = seqno
+            self.last_sequence_time = monotonic_time()
         else:
             assert not synchronous
             self.can_skip.add(seqno)
@@ -419 +428 @@
                     pass
                 self.can_skip.remove(seqno)
                 self.last_sequence = seqno
+                self.last_sequence_time = monotonic_time()
                 continue
             ip = self.pending_packets.get(seqno)
             if not ip or not ip.chunks:
@@ -432 +442 @@
             data = b"".join(ip.chunks)
             log("process_pending: adding packet sequence %5i to read queue", seqno)
             self.last_sequence = seqno
+            self.last_sequence_time = monotonic_time()
             self._read_queue_put(data)
 
     def raw_write(self, packet_type, items, start_cb=None, end_cb=None, fail_cb=None, synchronous=True, _more=False):