qubes-mirage-firewall/uplink.ml

98 lines
3.4 KiB
OCaml

(* Copyright (C) 2015, Thomas Leonard <thomas.leonard@unikernel.com>
See the README file for details. *)
open Lwt.Infix
open Fw_utils
module Eth = Ethernet.Make(Netif)
let src = Logs.Src.create "uplink" ~doc:"Network connection to NetVM"
module Log = (val Logs.src_log src : Logs.LOG)
module Make (R:Mirage_random.S) (Clock : Mirage_clock.MCLOCK) = struct
module Arp = Arp.Make(Eth)(OS.Time)
module I = Static_ipv4.Make(R)(Clock)(Eth)(Arp)
module U = Udp.Make(I)(R)
type t = {
net : Netif.t;
eth : Eth.t;
arp : Arp.t;
interface : interface;
mutable fragments : Fragments.Cache.t;
ip : I.t;
udp: U.t;
}
class netvm_iface eth mac ~my_ip ~other_ip : interface = object
val queue = FrameQ.create (Ipaddr.V4.to_string other_ip)
method my_mac = Eth.mac eth
method my_ip = my_ip
method other_ip = other_ip
method writev ethertype fillfn =
FrameQ.send queue (fun () ->
mac >>= fun dst ->
Eth.write eth dst ethertype fillfn >|= or_raise "Write to uplink" Eth.pp_error
)
end
let send_dns_client_query t ~src_port ~dst ~dst_port buf =
U.write ~src_port ~dst ~dst_port t.udp buf >|= function
| Error s -> Log.err (fun f -> f "error sending udp packet: %a" U.pp_error s); Error (`Msg "failure")
| Ok () -> Ok ()
let listen t get_ts dns_responses router =
let handle_packet ip_header ip_packet =
let open Udp_packet in
Log.debug (fun f -> f "received ipv4 packet from %a on uplink" Ipaddr.V4.pp ip_header.Ipv4_packet.src);
match ip_packet with
| `UDP (header, packet) when Ports.mem header.dst_port !(router.Router.ports.My_nat.dns_udp) ->
Log.debug (fun f -> f "found a DNS packet whose dst_port (%d) was in the list of dns_client ports" header.dst_port);
Lwt_mvar.put dns_responses (header, packet)
| _ ->
Firewall.ipv4_from_netvm router (`IPv4 (ip_header, ip_packet))
in
Netif.listen t.net ~header_size:Ethernet_wire.sizeof_ethernet (fun frame ->
(* Handle one Ethernet frame from NetVM *)
Eth.input t.eth
~arpv4:(Arp.input t.arp)
~ipv4:(fun ip ->
let cache, r =
Nat_packet.of_ipv4_packet t.fragments ~now:(get_ts ()) ip
in
t.fragments <- cache;
match r with
| Error e ->
Log.warn (fun f -> f "Ignored unknown IPv4 message from uplink: %a" Nat_packet.pp_error e);
Lwt.return ()
| Ok None -> Lwt.return_unit
| Ok (Some (`IPv4 (header, packet))) -> handle_packet header packet
)
~ipv6:(fun _ip -> Lwt.return_unit)
frame
) >|= or_raise "Uplink listen loop" Netif.pp_error
let interface t = t.interface
let connect config =
let my_ip = config.Dao.uplink_our_ip in
let gateway = config.Dao.uplink_netvm_ip in
Netif.connect "0" >>= fun net ->
Eth.connect net >>= fun eth ->
Arp.connect eth >>= fun arp ->
Arp.add_ip arp my_ip >>= fun () ->
let cidr = Ipaddr.V4.Prefix.make 0 my_ip in
I.connect ~cidr ~gateway eth arp >>= fun ip ->
U.connect ip >>= fun udp ->
let netvm_mac =
Arp.query arp gateway
>|= or_raise "Getting MAC of our NetVM" Arp.pp_error in
let interface = new netvm_iface eth netvm_mac
~my_ip
~other_ip:config.Dao.uplink_netvm_ip in
let fragments = Fragments.Cache.empty (256 * 1024) in
Lwt.return { net; eth; arp; interface ; fragments ; ip ; udp }
end