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https://github.com/mirage/qubes-mirage-firewall.git
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43 lines
1.3 KiB
OCaml
43 lines
1.3 KiB
OCaml
(* Copyright (C) 2015, Thomas Leonard <thomas.leonard@unikernel.com>
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See the README file for details. *)
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open Utils
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let src = Logs.Src.create "router" ~doc:"Router"
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module Log = (val Logs.src_log src : Logs.LOG)
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type t = {
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client_eth : Client_eth.t;
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default_gateway : interface;
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}
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let create ~client_eth ~default_gateway = { client_eth; default_gateway }
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let client_eth t = t.client_eth
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let target t buf =
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let open Wire_structs.Ipv4_wire in
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let dst_ip = get_ipv4_dst buf |> Ipaddr.V4.of_int32 in
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Log.debug "Got IPv4: dst=%s" (fun f -> f (Ipaddr.V4.to_string dst_ip));
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if Ipaddr.V4.Prefix.mem dst_ip (Client_eth.prefix t.client_eth) then (
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match Client_eth.lookup t.client_eth dst_ip with
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| Some client_link -> Some (client_link :> interface)
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| None ->
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Log.warn "Packet to unknown internal client %a - dropping"
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(fun f -> f Ipaddr.V4.pp_hum dst_ip);
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None
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) else Some t.default_gateway
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let add_client t = Client_eth.add_client t.client_eth
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let remove_client t = Client_eth.remove_client t.client_eth
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let forward_ipv4 router buf =
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match Memory_pressure.status () with
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| `Memory_critical -> (* TODO: should happen before copying and async *)
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Log.warn "Memory low - dropping packet" Logs.unit;
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return ()
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| `Ok ->
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match target router buf with
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| Some iface -> iface#writev [buf]
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| None -> return ()
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