mirror of
https://github.com/mirage/qubes-mirage-firewall.git
synced 2024-10-01 01:05:39 -04:00
e55c304160
With lots of VMs updating, the firewall quit with:
2017-04-23 20:47:52 -00:00: INF [frameQ] Queue length for 10.137.3.11: incr to 474
2017-04-23 20:47:52 -00:00: INF [memory_pressure] Writing meminfo: free 2648 / 17504 kB (15.13 %)
[...]
Fatal error: out of memory.
The firewall will now drop frames when more than 10 are queued (note
that queuing only starts once the network driver's transmit buffer is
already full).
33 lines
932 B
OCaml
33 lines
932 B
OCaml
(* Copyright (C) 2016, Thomas Leonard <thomas.leonard@unikernel.com>
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See the README file for details. *)
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let src = Logs.Src.create "frameQ" ~doc:"Interface output queue"
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module Log = (val Logs.src_log src : Logs.LOG)
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type t = {
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name : string;
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mutable items : int;
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}
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let create name = { name; items = 0 }
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(* Note: the queue is only used if we already filled the transmit buffer. *)
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let max_qlen = 10
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let send q fn =
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if q.items = max_qlen then (
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Log.warn (fun f -> f "Maximim queue length exceeded for %s: dropping frame" q.name);
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Lwt.return_unit
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) else (
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let sent = fn () in
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if Lwt.state sent = Lwt.Sleep then (
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q.items <- q.items + 1;
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Log.info (fun f -> f "Queue length for %s: incr to %d" q.name q.items);
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Lwt.on_termination sent (fun () ->
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q.items <- q.items - 1;
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Log.info (fun f -> f "Queue length for %s: decr to %d" q.name q.items);
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)
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);
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sent
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)
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