2025-08-04 04:44:15 -04:00
35 changed files with 1331 additions and 1599 deletions
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@ -19,14 +19,14 @@ jobs:
    steps:
      - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v2
      - run: ./build-with.sh docker
-      - run: sh -exc 'if [ "$(sha256sum dist/qubes-firewall.xen)" = "$(cat qubes-firewall.sha256)" ]; then echo "SHA256 MATCHES"; else exit 42; fi'
+      - run: sh -exc 'if [ $(sha256sum dist/qubes-firewall.xen | cut -d " " -f 1) = $(grep "SHA2 last known" build-with.sh | rev | cut -d ":" -f 1 | rev | cut -d "\"" -f 1 | tr -d " ") ]; then echo "SHA256 MATCHES"; else exit 42; fi'
      - name: Upload Artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v3
        with:
-          name: qubes-firewall.xen
+          name: mirage-firewall.tar.bz2
-          path: qubes-firewall.xen
+          path: mirage-firewall.tar.bz2
--- a/.github/workflows/format.yml
+++ b/.github/workflows/format.yml
@ -1,42 +0,0 @@
 name: ocamlformat
 on: [push]
 jobs:
  format:
    name: ocamlformat
    strategy:
      fail-fast: false
      matrix:
        ocaml-version: ["4.14.2"]
        operating-system: [ubuntu-latest]
    runs-on: ${{ matrix.operating-system }}
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
      - name: Use OCaml ${{ matrix.ocaml-version }}
        uses: ocaml/setup-ocaml@v3
        with:
          ocaml-compiler: ${{ matrix.ocaml-version }}
      - name: Install ocamlformat
        run: grep ^version .ocamlformat | cut -d '=' -f 2 | xargs -I V opam install ocamlformat=V
      - name: Format code
        run: git ls-files '*.ml' '*.mli' | xargs opam exec -- ocamlformat --inplace
      - name: Check for modified files
        id: git-check
        run: echo "modified=$(if git diff-index --quiet HEAD --; then echo "false"; else echo "true"; fi)" >> $GITHUB_OUTPUT
      - name: Commit and push changes
        if: steps.git-check.outputs.modified == 'true'
        run: |
          git config --global user.name "Automated ocamlformat GitHub action, developed by robur.coop"
          git config --global user.email "autoformat@robur.coop"
          git commit -m "formatted code" .
          git push
--- a/.github/workflows/podman.yml
+++ b/.github/workflows/podman.yml
@ -19,14 +19,14 @@ jobs:
    steps:
      - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v2
      - run: ./build-with.sh podman
-      - run: sh -exc 'if [ "$(sha256sum dist/qubes-firewall.xen)" = "$(cat qubes-firewall.sha256)" ]; then echo "SHA256 MATCHES"; else exit 42; fi'
+      - run: sh -exc 'if [ $(sha256sum dist/qubes-firewall.xen | cut -d " " -f 1) = $(grep "SHA2 last known" build-with.sh | rev | cut -d ":" -f 1 | rev | cut -d "\"" -f 1 | tr -d " ") ]; then echo "SHA256 MATCHES"; else exit 42; fi'
      - name: Upload Artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v3
        with:
-          name: qubes-firewall.xen
+          name: mirage-firewall.tar.bz2
-          path: qubes-firewall.xen
+          path: mirage-firewall.tar.bz2
--- a/.ocamlformat
+++ b/.ocamlformat
@ -1,3 +0,0 @@
 version = 0.27.0
 profile = conventional
 parse-docstrings = true
--- a/CHANGES.md
+++ b/CHANGES.md
@ -1,29 +1,3 @@
 ### 0.9.4 (2025-02-10)
 - Fix an issue when qubes-mirage-firewall is used a a mullvad AppVM client. If
  our netvm does not reply to our ARP requests we can not construct the ethernet
  header. However in Linux VMs, Qubes adds a default netvm address associated to
  `fe:ff:ff:ff:ff:ff`, so if ARP fails, we fall back on that address.
  (#213, @palainp, reported in the Qubes forum #212, reviewed by @hannesm)
 ### 0.9.3 (2025-01-04)
 - Fix an issue when qubes-mirage-firewall is used along with *BSD sys-net
  (#209, @palainp, reported in the Qubes forum #208, reviewed by @dinosaure)
 ### 0.9.2 (2024-10-16)
 - Code refactoring and improvements (#197, @dinosaure)
 - Build tooling updates: opam 2.2.1, solo5 0.9, mirage 4.8.1 (#199, #201, #202,
  #203, @hannesm)
 ### 0.9.1 (2024-05-10)
 - Drop astring dependency, update mirage-net-xen, and OCaml 4.14.2 -- the
  latest LTS release (#193, @hannesm)
 - Allow the firewall to use domains requests in rules (#193, @palainp,
  reported in the Qubes forum, fix confirmed by @neoniobium)
 ### 0.9.0 (2024-04-24)
 - Fix an incorrect free memory estimation (fix in mirage/ocaml-solo5#135
--- a/12
+++ b/12
@ -12,10 +12,10 @@ RUN printf "deb [check-valid-until=no] http://snapshot.debian.org/archive/debian
 RUN printf "deb [check-valid-until=no] http://snapshot.debian.org/archive/debian-security/20240419T111010Z bookworm-security main\n" >> /etc/apt/sources.list
 RUN apt update && apt install --no-install-recommends --no-install-suggests -y wget ca-certificates git patch unzip bzip2 make gcc g++ libc-dev
-RUN wget -O /usr/bin/opam https://github.com/ocaml/opam/releases/download/2.3.0/opam-2.3.0-i686-linux && chmod 755 /usr/bin/opam
+RUN wget -O /usr/bin/opam https://github.com/ocaml/opam/releases/download/2.1.5/opam-2.1.5-i686-linux && chmod 755 /usr/bin/opam
 # taken from https://raw.githubusercontent.com/ocaml/opam/master/shell/install.sh
 RUN test `sha512sum /usr/bin/opam | cut -d' ' -f1` = \
-"4c0e8771889a36bad4d5f964e2e662d5b611e6f112777d3d4eea3eea919d109cd17826beba38e6cfa1ad9553a0a989d9268f911ea5485968da04b1e08efc7de2" || exit
+"38802b3079eeceb27aab3465bfd0f9f05a710dccf9487eb35fa2c02fbaf9a0659e1447aa19dd36df9cd01f760229de28c523c08c1c86a3aa3f5e25dbe7b551dd" || exit
 ENV OPAMROOT=/tmp
 ENV OPAMCONFIRMLEVEL=unsafe-yes
@ -23,13 +23,13 @@ ENV OPAMCONFIRMLEVEL=unsafe-yes
 # Remove this line (and the base image pin above) if you want to test with the
 # latest versions.
 # taken from https://github.com/ocaml/opam-repository
-RUN opam init --disable-sandboxing -a --bare https://github.com/ocaml/opam-repository.git#8f63148a9025a7b775a069a6c0b0385c22ad51d3
+RUN opam init --disable-sandboxing -a --bare https://github.com/ocaml/opam-repository.git#4399f486aa6edefdc96d5e206a65ce42288ebfdd
-RUN opam switch create myswitch 4.14.2
+RUN opam switch create myswitch 4.14.1
 RUN opam exec -- opam install -y mirage opam-monorepo ocaml-solo5
 RUN mkdir /tmp/orb-build
 ADD config.ml /tmp/orb-build/config.ml
 WORKDIR /tmp/orb-build
 CMD opam exec -- sh -exc 'mirage configure -t xen --extra-repos=\
-opam-overlays:https://github.com/dune-universe/opam-overlays.git#f2bec38beca4aea9e481f2fd3ee319c519124649,\
+opam-overlays:https://github.com/dune-universe/opam-overlays.git#4e75ee36715b27550d5bdb87686bb4ae4c9e89c4,\
 mirage-overlays:https://github.com/dune-universe/mirage-opam-overlays.git#797cb363df3ff763c43c8fbec5cd44de2878757e \
-&& make depend && make unikernel'
+&& make depend && make tar'
--- a/LICENSE.md
+++ b/LICENSE.md
@ -1,23 +0,0 @@
 Copyright (X) 2015-2024, the Qubes Mirage Firewall authors
 All rights reserved.
 Redistribution and use in source and binary forms, with or without modification,
 are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, this
  list of conditions and the following disclaimer in the documentation and/or
  other materials provided with the distribution.
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--- a/Makefile.builder
+++ b/Makefile.builder
@ -1,5 +1,5 @@
 MIRAGE_KERNEL_NAME = dist/qubes-firewall.xen
-OCAML_VERSION ?= 4.14.2
+OCAML_VERSION ?= 4.14.0
 SOURCE_BUILD_DEP := firewall-build-dep
 firewall-build-dep:
--- a/Makefile.user
+++ b/Makefile.user
@ -1,8 +1,13 @@
-unikernel: build
+tar: build
 	rm -rf _build/mirage-firewall
 	mkdir _build/mirage-firewall
 	cp dist/qubes-firewall.xen dist/qubes-firewall.xen.debug
 	strip dist/qubes-firewall.xen
-	cp dist/qubes-firewall.xen .
+	cp dist/qubes-firewall.xen _build/mirage-firewall/vmlinuz
-	sha256sum qubes-firewall.xen
+	touch _build/mirage-firewall/modules.img
 	cat /dev/null | gzip -n > _build/mirage-firewall/initramfs
 	tar cjf mirage-firewall.tar.bz2 -C _build --mtime=./build-with.sh mirage-firewall
 	sha256sum mirage-firewall.tar.bz2 > mirage-firewall.sha256
 fetchmotron: qubes_firewall.xen
 	test-mirage qubes_firewall.xen mirage-fw-test &
--- a/README.md
+++ b/README.md
@ -48,7 +48,7 @@ It's OK to install the Docker or Podman package in a template VM if you want it
 after a reboot, but the build of the firewall itself should be done in a regular AppVM.
 You can also build without that script, as for any normal Mirage unikernel;
-see [the Mirage installation instructions](https://mirageos.org/wiki/install) for details.
+see [the Mirage installation instructions](https://mirage.io/wiki/install) for details.
 The build script fixes the versions of the libraries it uses, ensuring that you will get
 exactly the same binary that is in the release. If you build without it, it will build
@ -58,15 +58,20 @@ However, it should still work fine.
 ## Deploy
 ### Manual deployment
-If you want to deploy manually, you just need to download `qubes-firewall.xen` and
+If you want to deploy manually, unpack `mirage-firewall.tar.bz2` in domU. The tarball contains `vmlinuz`,
-`qubes-firewall.sha256` in domU and check that the `.xen` file has a corresponding
+which is the unikernel itself, plus a dummy initramfs file that Qubes requires:
-hashsum. `qubes-firewall.xen` is the unikernel itself and should be copied to
+
-`vmlinuz` in the `/var/lib/qubes/vm-kernels/mirage-firewall` directory in dom0, e.g.
+    [user@dev ~]$ tar xjf mirage-firewall.tar.bz2
-(if `dev` is the AppVM where you built it):
+
 Copy `vmlinuz` to `/var/lib/qubes/vm-kernels/mirage-firewall` directory in dom0, e.g. (if `dev` is the AppVM where you built it):
    [tal@dom0 ~]$ mkdir -p /var/lib/qubes/vm-kernels/mirage-firewall/
    [tal@dom0 ~]$ cd /var/lib/qubes/vm-kernels/mirage-firewall/
-    [tal@dom0 mirage-firewall]$ qvm-run -p dev 'cat mirage-firewall/qubes-firewall.xen' > vmlinuz
+    [tal@dom0 mirage-firewall]$ qvm-run -p dev 'cat mirage-firewall/vmlinuz' > vmlinuz
 Finally, create [a dummy file required by Qubes OS](https://github.com/QubesOS/qubes-issues/issues/5516):
    [tal@dom0 mirage-firewall]$ gzip -n9 < /dev/null > initramfs
 Run this command in dom0 to create a `mirage-firewall` VM using the `mirage-firewall` kernel you added above
@ -207,7 +212,16 @@ See [issues tagged "security"](https://github.com/mirage/qubes-mirage-firewall/i
 # LICENSE
-See [LICENSE.md](https://github.com/mirage/qubes-mirage-firewall/blob/main/LICENSE.md)
+Copyright (c) 2019, Thomas Leonard
 All rights reserved.
 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 [test-mirage]: https://github.com/talex5/qubes-test-mirage
 [mirage-qubes]: https://github.com/mirage/mirage-qubes
--- a/SaltScriptToDownloadAndInstallMirageFirewallInQubes.sls
+++ b/SaltScriptToDownloadAndInstallMirageFirewallInQubes.sls
@ -10,14 +10,13 @@
 {% set DownloadVM = "DownloadVmMirage" %}
 {% set MirageFW = "sys-mirage-fw" %}
 {% set GithubUrl = "https://github.com/mirage/qubes-mirage-firewall" %}
-{% set Kernel = "qubes-firewall.xen" %}
+{% set Filename = "mirage-firewall.tar.bz2" %}
 {% set Shasum = "qubes-firewall-release.sha256" %}
 {% set MirageInstallDir = "/var/lib/qubes/vm-kernels/mirage-firewall" %}
 #download and install the latest version
 {% set Release = salt['cmd.shell']("qvm-run --dispvm " ~ DispVM ~ " --pass-io \"curl --silent --location -o /dev/null -w %{url_effective} " ~ GithubUrl ~ "/releases/latest | rev | cut -d \"/\" -f 1 | rev\"") %}
-{% if Release != salt['cmd.shell']("test -e " ~ MirageInstallDir ~ "/version.txt" ~ " || mkdir " ~ MirageInstallDir ~ " ; touch " ~ MirageInstallDir ~ "/version.txt" ~ " ; cat " ~ MirageInstallDir ~ "/version.txt") %}
+{% if Release != salt['cmd.shell']("[ ! -f " ~ MirageInstallDir ~ "/version.txt" ~ " ] && touch " ~ MirageInstallDir ~ "/version.txt" ~ ";cat " ~ MirageInstallDir ~ "/version.txt") %}
 create-downloader-VM:
  qvm.vm:
@ -29,14 +28,13 @@ create-downloader-VM:
       - template: {{ DownloadVMTemplate }}
       - include-in-backups: false
-{% set DownloadBinary = GithubUrl ~ "/releases/download/" ~ Release ~ "/" ~ Kernel %}
+{% set DownloadBinary = GithubUrl ~ "/releases/download/" ~ Release ~ "/" ~ Filename %}
 {% set DownloadShasum = GithubUrl ~ "/releases/download/" ~ Release ~ "/" ~ Shasum %}
 download-and-unpack-in-DownloadVM4mirage:
  cmd.run: 
    - names:
      - qvm-run --pass-io {{ DownloadVM }} {{ "curl -L -O " ~ DownloadBinary }}
-      - qvm-run --pass-io {{ DownloadVM }} {{ "curl -L -O " ~ DownloadShasum }}
+      - qvm-run --pass-io {{ DownloadVM }} {{ "tar -xvjf " ~ Filename }}
    - require: 
      - create-downloader-VM
@ -44,22 +42,23 @@ download-and-unpack-in-DownloadVM4mirage:
 check-checksum-in-DownloadVM:
  cmd.run: 
    - names:
-      - qvm-run --pass-io {{ DownloadVM }} {{ "\"echo \\\"Checksum of release on github:\\\";cat " ~ Shasum ~ " | cut -d\' \' -f1\"" }}
+      - qvm-run --pass-io {{ DownloadVM }} {{ "\"echo \\\"Checksum of last build on github:\\\";curl -s https://raw.githubusercontent.com/mirage/qubes-mirage-firewall/main/build-with.sh  | grep \\\"SHA2 last known:\\\" | cut -d\' \' -f5 | tr -d \\\\\\\"\"" }}
-      - qvm-run --pass-io {{ DownloadVM }} {{ "\"echo \\\"Checksum of downloaded local file:\\\";sha256sum " ~ Kernel ~ " | cut -d\' \' -f1\"" }}
+      - qvm-run --pass-io {{ DownloadVM }} {{ "\"echo \\\"Checksum of downloaded local file:\\\";sha256sum ~/mirage-firewall/vmlinuz | cut -d\' \' -f1\"" }}
-      - qvm-run --pass-io {{ DownloadVM }} {{ "\"diff <(cat " ~ Shasum ~ " | cut -d\' \' -f1) <(sha256sum " ~ Kernel ~ " | cut -d\' \' -f1) && echo \\\"Checksums DO match.\\\" || (echo \\\"Checksums do NOT match.\\\";exit 101)\"" }}
+      - qvm-run --pass-io {{ DownloadVM }} {{ "\"diff <(curl -s https://raw.githubusercontent.com/mirage/qubes-mirage-firewall/main/build-with.sh  | grep \\\"SHA2 last known:\\\" | cut -d\' \' -f5 | tr -d \\\\\\\") <(sha256sum ~/mirage-firewall/vmlinuz | cut -d\' \' -f1) && echo \\\"Checksums DO match.\\\" || (echo \\\"Checksums do NOT match.\\\";exit 101)\"" }} #~/mirage-firewall/modules.img
    - require: 
      - download-and-unpack-in-DownloadVM4mirage
 copy-mirage-kernel-to-dom0:
  cmd.run: 
-    - name: mkdir -p {{ MirageInstallDir }}; qvm-run --pass-io --no-gui {{ DownloadVM }} {{ "cat " ~ Kernel }} > {{ MirageInstallDir ~ "/vmlinuz" }}
+    - name: mkdir -p {{ MirageInstallDir }}; qvm-run --pass-io --no-gui {{ DownloadVM }} "cat ~/mirage-firewall/vmlinuz" > {{ MirageInstallDir ~ "/vmlinuz" }}
    - require: 
      - download-and-unpack-in-DownloadVM4mirage
      - check-checksum-in-DownloadVM
-update-version:
+create-initramfs:
  cmd.run: 
    - names: 
      - gzip -n9 < /dev/null > {{ MirageInstallDir ~ "/initramfs" }}
      - echo {{ Release }} > {{ MirageInstallDir ~ "/version.txt" }}
    - require: 
      - copy-mirage-kernel-to-dom0
@ -91,9 +90,9 @@ create-sys-mirage-fw:
 cleanup-in-DownloadVM:
  cmd.run:
   - names:
-      - qvm-run -a --pass-io --no-gui {{ DownloadVM }} "{{ "rm " ~ Kernel ~ " " ~ Shasum }}"
+      - qvm-run -a --pass-io --no-gui {{ DownloadVM }} "{{ "rm " ~ Filename ~ "; rm -R ~/mirage-firewall" }}"
   - require: 
-     - update-version 
+     - create-initramfs
 remove-DownloadVM4mirage:
  qvm.absent:
--- a/build-with.sh
+++ b/build-with.sh
@ -19,7 +19,6 @@ echo Building $builder image with dependencies..
 $builder build -t qubes-mirage-firewall .
 echo Building Firewall...
 $builder run --rm -i -v `pwd`:/tmp/orb-build:Z qubes-mirage-firewall
-echo "SHA2 of build:     $(sha256sum ./dist/qubes-firewall.xen | cut -d' ' -f1)"
+echo "SHA2 of build:   $(sha256sum ./dist/qubes-firewall.xen)"
-echo "SHA2 current head: $(cat qubes-firewall.sha256 | cut -d' ' -f1)"
+echo "SHA2 last known:  163991ea96842e03d378501a0be99057ad2489440aff8ae81d850624d98fd3f0"
-echo "SHA2 last release: $(cat qubes-firewall-release.sha256 | cut -d' ' -f1)"
+echo "(hashes should match for released versions)"
 echo "(hashes should match for head versions)"
--- a/cleanup.ml
+++ b/cleanup.ml
@ -4,7 +4,9 @@
 type t = (unit -> unit) list ref
 let create () = ref []
-let on_cleanup t fn = t := fn :: !t
+
 let on_cleanup t fn =
  t := fn :: !t
 let cleanup t =
  let tasks = !t in
--- a/cleanup.mli
+++ b/cleanup.mli
@ -1,8 +1,8 @@
 (* Copyright (C) 2015, Thomas Leonard <thomas.leonard@unikernel.com>
   See the README file for details. *)
-(** Register actions to take when a resource is finished. Like [Lwt_switch], but
+(** Register actions to take when a resource is finished.
-    synchronous. *)
+    Like [Lwt_switch], but synchronous. *)
 type t
--- a/client_eth.ml
+++ b/client_eth.ml
@ -4,63 +4,59 @@
 open Fw_utils
 open Lwt.Infix
-let src =
+let src = Logs.Src.create "client_eth" ~doc:"Ethernet networks for NetVM clients"
  Logs.Src.create "client_eth" ~doc:"Ethernet networks for NetVM clients"
 module Log = (val Logs.src_log src : Logs.LOG)
 type t = {
-  mutable iface_of_ip : client_link Ipaddr.V4.Map.t;
+  mutable iface_of_ip : client_link IpMap.t;
-  changed : unit Lwt_condition.t; (* Fires when [iface_of_ip] changes. *)
+  changed : unit Lwt_condition.t;   (* Fires when [iface_of_ip] changes. *)
-  my_ip : Ipaddr.V4.t;
+  my_ip : Ipaddr.V4.t;  (* The IP that clients are given as their default gateway. *)
      (* The IP that clients are given as their default gateway. *)
 }
-type host = [ `Client of client_link | `Firewall | `External of Ipaddr.t ]
+type host =
  [ `Client of client_link
  | `Firewall
  | `External of Ipaddr.t ]
 let create config =
  let changed = Lwt_condition.create () in
  let my_ip = config.Dao.our_ip in
-  Lwt.return { iface_of_ip = Ipaddr.V4.Map.empty; my_ip; changed }
+  Lwt.return { iface_of_ip = IpMap.empty; my_ip; changed }
 let client_gw t = t.my_ip
 let add_client t iface =
  let ip = iface#other_ip in
  let rec aux () =
-    match Ipaddr.V4.Map.find_opt ip t.iface_of_ip with
+    match IpMap.find ip t.iface_of_ip with
    | Some old ->
-        (* Wait for old client to disappear before adding one with the same IP address.
+      (* Wait for old client to disappear before adding one with the same IP address.
         Otherwise, its [remove_client] call will remove the new client instead. *)
-        Log.info (fun f ->
+      Log.info (fun f -> f ~header:iface#log_header "Waiting for old client %s to go away before accepting new one" old#log_header);
-            f ~header:iface#log_header
+      Lwt_condition.wait t.changed >>= aux
              "Waiting for old client %s to go away before accepting new one"
              old#log_header);
        Lwt_condition.wait t.changed >>= aux
    | None ->
-        t.iface_of_ip <- t.iface_of_ip |> Ipaddr.V4.Map.add ip iface;
+      t.iface_of_ip <- t.iface_of_ip |> IpMap.add ip iface;
-        Lwt_condition.broadcast t.changed ();
+      Lwt_condition.broadcast t.changed ();
-        Lwt.return_unit
+      Lwt.return_unit
  in
  aux ()
 let remove_client t iface =
  let ip = iface#other_ip in
-  assert (Ipaddr.V4.Map.mem ip t.iface_of_ip);
+  assert (IpMap.mem ip t.iface_of_ip);
-  t.iface_of_ip <- t.iface_of_ip |> Ipaddr.V4.Map.remove ip;
+  t.iface_of_ip <- t.iface_of_ip |> IpMap.remove ip;
  Lwt_condition.broadcast t.changed ()
-let lookup t ip = Ipaddr.V4.Map.find_opt ip t.iface_of_ip
+let lookup t ip = IpMap.find ip t.iface_of_ip
 let classify t ip =
  match ip with
  | Ipaddr.V6 _ -> `External ip
-  | Ipaddr.V4 ip4 -> (
+  | Ipaddr.V4 ip4 ->
-      if ip4 = t.my_ip then `Firewall
+    if ip4 = t.my_ip then `Firewall
-      else
+    else match lookup t ip4 with
-        match lookup t ip4 with
+      | Some client_link -> `Client client_link
-        | Some client_link -> `Client client_link
+      | None -> `External ip
        | None -> `External ip)
 let resolve t : host -> Ipaddr.t = function
  | `Client client_link -> Ipaddr.V4 client_link#other_ip
@ -68,53 +64,50 @@ let resolve t : host -> Ipaddr.t = function
  | `External addr -> addr
 module ARP = struct
-  type arp = { net : t; client_link : client_link }
+  type arp = {
    net : t;
    client_link : client_link;
  }
  let lookup t ip =
    if ip = t.net.my_ip then Some t.client_link#my_mac
    else if (Ipaddr.V4.to_octets ip).[3] = '\x01' then (
-      Log.info (fun f ->
+      Log.info (fun f -> f ~header:t.client_link#log_header
-          f ~header:t.client_link#log_header
+                   "Request for %a is invalid, but pretending it's me (see Qubes issue #5022)" Ipaddr.V4.pp ip);
-            "Request for %a is invalid, but pretending it's me (see Qubes \
+      Some t.client_link#my_mac
-             issue #5022)"
+    ) else None
            Ipaddr.V4.pp ip);
      Some t.client_link#my_mac)
    else None
  (* We're now treating client networks as point-to-point links,
     so we no longer respond on behalf of other clients. *)
-  (*
+    (*
-    else match Ipaddr.V4.Map.find_opt ip t.net.iface_of_ip with
+    else match IpMap.find ip t.net.iface_of_ip with
    | Some client_iface -> Some client_iface#other_mac
    | None -> None
     *)
-  let create ~net client_link = { net; client_link }
+  let create ~net client_link = {net; client_link}
  let input_query t arp =
    let req_ipv4 = arp.Arp_packet.target_ip in
    let pf (f : ?header:string -> ?tags:_ -> _) fmt =
-      f ~header:t.client_link#log_header ("who-has %a? " ^^ fmt) Ipaddr.V4.pp
+      f ~header:t.client_link#log_header ("who-has %a? " ^^ fmt) Ipaddr.V4.pp req_ipv4
        req_ipv4
    in
    if req_ipv4 = t.client_link#other_ip then (
      Log.info (fun f -> pf f "ignoring request for client's own IP");
-      None)
+      None
-    else
+    ) else match lookup t req_ipv4 with
      match lookup t req_ipv4 with
      | None ->
-          Log.info (fun f -> pf f "unknown address; not responding");
+        Log.info (fun f -> pf f "unknown address; not responding");
-          None
+        None
      | Some req_mac ->
-          Log.info (fun f -> pf f "responding with %a" Macaddr.pp req_mac);
+        Log.info (fun f -> pf f "responding with %a" Macaddr.pp req_mac);
-          Some
+        Some { Arp_packet.
-            {
+               operation = Arp_packet.Reply;
-              Arp_packet.operation = Arp_packet.Reply;
+               (* The Target Hardware Address and IP are copied from the request *)
-              (* The Target Hardware Address and IP are copied from the request *)
+               target_ip = arp.Arp_packet.source_ip;
-              target_ip = arp.Arp_packet.source_ip;
+               target_mac = arp.Arp_packet.source_mac;
-              target_mac = arp.Arp_packet.source_mac;
+               source_ip = req_ipv4;
-              source_ip = req_ipv4;
+               source_mac = req_mac;
-              source_mac = req_mac;
+             }
            }
  let input_gratuitous t arp =
    let source_ip = arp.Arp_packet.source_ip in
@ -122,28 +115,18 @@ module ARP = struct
    let header = t.client_link#log_header in
    match lookup t source_ip with
    | Some real_mac when Macaddr.compare source_mac real_mac = 0 ->
-        Log.info (fun f ->
+      Log.info (fun f -> f ~header "client suggests updating %s -> %s (as expected)"
-            f ~header "client suggests updating %s -> %s (as expected)"
+                   (Ipaddr.V4.to_string source_ip) (Macaddr.to_string source_mac));
              (Ipaddr.V4.to_string source_ip)
              (Macaddr.to_string source_mac))
    | Some other_mac ->
-        Log.warn (fun f ->
+      Log.warn (fun f -> f ~header "client suggests incorrect update %s -> %s (should be %s)"
-            f ~header "client suggests incorrect update %s -> %s (should be %s)"
+                   (Ipaddr.V4.to_string source_ip) (Macaddr.to_string source_mac) (Macaddr.to_string other_mac));
              (Ipaddr.V4.to_string source_ip)
              (Macaddr.to_string source_mac)
              (Macaddr.to_string other_mac))
    | None ->
-        Log.warn (fun f ->
+      Log.warn (fun f -> f ~header "client suggests incorrect update %s -> %s (unexpected IP)"
-            f ~header
+                   (Ipaddr.V4.to_string source_ip) (Macaddr.to_string source_mac))
              "client suggests incorrect update %s -> %s (unexpected IP)"
              (Ipaddr.V4.to_string source_ip)
              (Macaddr.to_string source_mac))
  let input t arp =
    let op = arp.Arp_packet.operation in
    match op with
    | Arp_packet.Request -> input_query t arp
-    | Arp_packet.Reply ->
+    | Arp_packet.Reply -> input_gratuitous t arp; None
        input_gratuitous t arp;
        None
 end
--- a/client_eth.mli
+++ b/client_eth.mli
@ -1,32 +1,34 @@
 (* Copyright (C) 2016, Thomas Leonard <thomas.leonard@unikernel.com>
   See the README file for details. *)
-(** The ethernet networks connecting us to our client AppVMs. Note: each AppVM
+(** The ethernet networks connecting us to our client AppVMs.
-    is on a point-to-point link, each link being considered to be a separate
+    Note: each AppVM is on a point-to-point link, each link being considered to be a separate Ethernet network. *)
    Ethernet network. *)
 open Fw_utils
 type t
 (** A collection of clients. *)
-type host = [ `Client of client_link | `Firewall | `External of Ipaddr.t ]
+type host =
  [ `Client of client_link
  | `Firewall
  | `External of Ipaddr.t ]
 (* Note: Qubes does not allow us to distinguish between an external address and a
   disconnected client.
   See: https://github.com/talex5/qubes-mirage-firewall/issues/9#issuecomment-246956850 *)
 val create : Dao.network_config -> t Lwt.t
-(** [create ~client_gw] is a network of client machines. Qubes will have
+(** [create ~client_gw] is a network of client machines.
-    configured the client machines to use [client_gw] as their default gateway.
+    Qubes will have configured the client machines to use [client_gw] as their default gateway. *)
 *)
 val add_client : t -> client_link -> unit Lwt.t
-(** [add_client t client] registers a new client. If a client with this IP
+(** [add_client t client] registers a new client. If a client with this IP address is already registered,
-    address is already registered, it waits for [remove_client] to be called on
+    it waits for [remove_client] to be called on that before adding the new client and returning. *)
    that before adding the new client and returning. *)
 val remove_client : t -> client_link -> unit
 val client_gw : t -> Ipaddr.V4.t
 val classify : t -> Ipaddr.t -> host
 val resolve : t -> host -> Ipaddr.t
@ -34,18 +36,18 @@ val lookup : t -> Ipaddr.V4.t -> client_link option
 (** [lookup t addr] is the client with IP address [addr], if connected. *)
 module ARP : sig
-  (** We already know the correct mapping of IP addresses to MAC addresses, so
+  (** We already know the correct mapping of IP addresses to MAC addresses, so we never
-      we never allow clients to update it. We log a warning if a client attempts
+      allow clients to update it. We log a warning if a client attempts to set incorrect
-      to set incorrect information. *)
+      information. *)
  type arp
  (** An ARP-responder for one client. *)
  val create : net:t -> client_link -> arp
-  (** [create ~net client_link] is an ARP responder for [client_link]. It
+  (** [create ~net client_link] is an ARP responder for [client_link].
-      answers only for the client's gateway address. *)
+      It answers only for the client's gateway address. *)
  val input : arp -> Arp_packet.t -> Arp_packet.t option
-  (** Process one ethernet frame containing an ARP message. Returns a response
+  (** Process one ethernet frame containing an ARP message.
-      frame, if one is needed. *)
+      Returns a response frame, if one is needed. *)
 end
--- a/command.ml
+++ b/command.ml
@ -4,30 +4,24 @@
 (** Commands we provide via qvm-run. *)
 open Lwt
 module Flow = Qubes.RExec.Flow
 let src = Logs.Src.create "command" ~doc:"qrexec command handler"
 module Log = (val Logs.src_log src : Logs.LOG)
 let set_date_time flow =
  Flow.read_line flow >|= function
-  | `Eof ->
+  | `Eof -> Log.warn (fun f -> f "EOF reading time from dom0"); 1
-      Log.warn (fun f -> f "EOF reading time from dom0");
+  | `Ok line -> Log.info (fun f -> f "TODO: set time to %S" line); 0
      1
  | `Ok line ->
      Log.info (fun f -> f "TODO: set time to %S" line);
      0
 let handler ~user:_ cmd flow =
  (* Write a message to the client and return an exit status of 1. *)
  let error fmt =
-    fmt
+    fmt |> Printf.ksprintf @@ fun s ->
-    |> Printf.ksprintf @@ fun s ->
+    Log.warn (fun f -> f "<< %s" s);
-       Log.warn (fun f -> f "<< %s" s);
+    Flow.ewritef flow "%s [while processing %S]" s cmd >|= fun () -> 1 in
       Flow.ewritef flow "%s [while processing %S]" s cmd >|= fun () -> 1
  in
  match cmd with
  | "QUBESRPC qubes.SetDateTime dom0" -> set_date_time flow
-  | "QUBESRPC qubes.WaitForSession none" -> return 0 (* Always ready! *)
+  | "QUBESRPC qubes.WaitForSession none" -> return 0  (* Always ready! *)
  | cmd -> error "Unknown command %S" cmd
--- a/config.ml
+++ b/config.ml
@ -1,4 +1,4 @@
-(* mirage >= 4.9.0 & < 4.10.0 *)
+(* mirage >= 4.5.0 & < 5.0.0 *)
 (* Copyright (C) 2017, Thomas Leonard <thomas.leonard@unikernel.com>
   See the README file for details. *)
@ -6,25 +6,34 @@
 open Mirage
-let main =
+let nat_table_size = runtime_arg ~pos:__POS__ "Unikernel.nat_table_size"
-  main
+let ipv4 = runtime_arg ~pos:__POS__ "Unikernel.ipv4"
-    ~packages:
+let ipv4_gw = runtime_arg ~pos:__POS__ "Unikernel.ipv4_gw"
-      [
+let ipv4_dns = runtime_arg ~pos:__POS__ "Unikernel.ipv4_dns"
-        package "vchan" ~min:"4.0.2";
+let ipv4_dns2 = runtime_arg ~pos:__POS__ "Unikernel.ipv4_dns2"
        package "cstruct";
        package "tcpip" ~min:"3.7.0";
        package ~min:"2.3.0" ~sublibs:[ "mirage" ] "arp";
        package ~min:"3.0.0" "ethernet";
        package "shared-memory-ring" ~min:"3.0.0";
        package "mirage-net-xen" ~min:"2.1.4";
        package "ipaddr" ~min:"5.2.0";
        package "mirage-qubes" ~min:"0.9.1";
        package ~min:"3.0.1" "mirage-nat";
        package "mirage-logs";
        package "mirage-xen" ~min:"8.0.0";
        package ~min:"6.4.0" "dns-client";
        package "pf-qubes";
      ]
    "Unikernel" job
-let () = register "qubes-firewall" [ main ]
+let main =
   main
    ~runtime_args:[ nat_table_size; ipv4; ipv4_gw; ipv4_dns; ipv4_dns2; ]
    ~packages:[
      package "vchan" ~min:"4.0.2";
      package "cstruct";
      package "astring";
      package "tcpip" ~min:"3.7.0";
      package ~min:"2.3.0" ~sublibs:["mirage"] "arp";
      package ~min:"3.0.0" "ethernet";
      package "shared-memory-ring" ~min:"3.0.0";
      package ~min:"2.1.3" "netchannel";
      package "mirage-net-xen" ~min:"2.1.3";
      package "ipaddr" ~min:"5.2.0";
      package "mirage-qubes" ~min:"0.9.1";
      package ~min:"3.0.1" "mirage-nat";
      package "mirage-logs";
      package "mirage-xen" ~min:"8.0.0";
      package ~min:"6.4.0" "dns-client";
      package "pf-qubes";
    ]
    "Unikernel.Main" (random @-> mclock @-> time @-> job)
 let () =
  register "qubes-firewall" [main $ default_random $ default_monotonic_clock $ default_time]
--- a/dao.ml
+++ b/dao.ml
@ -3,36 +3,38 @@
 open Lwt.Infix
 open Qubes
 open Astring
 let src = Logs.Src.create "dao" ~doc:"QubesDB data access"
 module Log = (val Logs.src_log src : Logs.LOG)
 module ClientVif = struct
-  type t = { domid : int; device_id : int }
+  type t = {
    domid : int;
    device_id : int;
  }
-  let pp f { domid; device_id } =
+  let pp f { domid; device_id } = Fmt.pf f "{domid=%d;device_id=%d}" domid device_id
    Fmt.pf f "{domid=%d;device_id=%d}" domid device_id
  let compare = compare
 end
 module VifMap = struct
-  include Map.Make (ClientVif)
+  include Map.Make(ClientVif)
  let rec of_list = function
    | [] -> empty
    | (k, v) :: rest -> add k v (of_list rest)
-
+  let find key t =
-  let find key t = try Some (find key t) with Not_found -> None
+    try Some (find key t)
    with Not_found -> None
 end
 let directory ~handle dir =
  Xen_os.Xs.directory handle dir >|= function
-  | [ "" ] -> [] (* XenStore client bug *)
+  | [""] -> []      (* XenStore client bug *)
  | items -> items
-let db_root client_ip = "/qubes-firewall/" ^ Ipaddr.V4.to_string client_ip
+let db_root client_ip =
  "/qubes-firewall/" ^ (Ipaddr.V4.to_string client_ip)
 let read_rules rules client_ip =
  let root = db_root client_ip in
@ -41,101 +43,89 @@ let read_rules rules client_ip =
    Log.debug (fun f -> f "reading %s" pattern);
    match Qubes.DB.KeyMap.find_opt pattern rules with
    | None ->
-        Log.debug (fun f -> f "rule %d does not exist; won't look for more" n);
+      Log.debug (fun f -> f "rule %d does not exist; won't look for more" n);
-        Ok (List.rev l)
+      Ok (List.rev l)
-    | Some rule -> (
+    | Some rule ->
-        Log.debug (fun f -> f "rule %d: %s" n rule);
+      Log.debug (fun f -> f "rule %d: %s" n rule);
-        match Pf_qubes.Parse_qubes.parse_qubes ~number:n rule with
+      match Pf_qubes.Parse_qubes.parse_qubes ~number:n rule with
-        | Error e ->
+      | Error e -> Log.warn (fun f -> f "Error parsing rule %d: %s" n e); Error e
-            Log.warn (fun f -> f "Error parsing rule %d: %s" n e);
+      | Ok rule ->
-            Error e
+        Log.debug (fun f -> f "parsed rule: %a" Pf_qubes.Parse_qubes.pp_rule rule);
-        | Ok rule ->
+        get_rule (n+1) (rule :: l)
            Log.debug (fun f ->
                f "parsed rule: %a" Pf_qubes.Parse_qubes.pp_rule rule);
            get_rule (n + 1) (rule :: l))
  in
  match get_rule 0 [] with
  | Ok l -> l
  | Error e ->
-      Log.warn (fun f ->
+    Log.warn (fun f -> f "Defaulting to deny-all because of rule parse failure (%s)" e);
-          f "Defaulting to deny-all because of rule parse failure (%s)" e);
+    [ Pf_qubes.Parse_qubes.({action = Drop;
-      [
+                             proto = None;
-        Pf_qubes.Parse_qubes.
+                             specialtarget = None;
-          {
+                             dst = `any;
-            action = Drop;
+                             dstports = None;
-            proto = None;
+                             icmp_type = None;
-            specialtarget = None;
+                             number = 0;})]
            dst = `any;
            dstports = None;
            icmp_type = None;
            number = 0;
          };
      ]
 let vifs client domid =
-  let open Lwt.Syntax in
+  match String.to_int domid with
-  match int_of_string_opt domid with
+  | None -> Log.err (fun f -> f "Invalid domid %S" domid); Lwt.return []
  | None ->
      Log.err (fun f -> f "Invalid domid %S" domid);
      Lwt.return []
  | Some domid ->
-      let path = Fmt.str "backend/vif/%d" domid in
+    let path = Printf.sprintf "backend/vif/%d" domid in
-      let vifs_of_domain handle =
+    Xen_os.Xs.immediate client (fun handle ->
-        let* devices = directory ~handle path in
+        directory ~handle path >>=
-        let ip_of_vif device_id =
+        Lwt_list.filter_map_p (fun device_id ->
-          match int_of_string_opt device_id with
+            match String.to_int device_id with
-          | None ->
+            | None -> Log.err (fun f -> f "Invalid device ID %S for domid %d" device_id domid); Lwt.return_none
-              Log.err (fun f ->
+            | Some device_id ->
                  f "Invalid device ID %S for domid %d" device_id domid);
              Lwt.return_none
          | Some device_id -> (
              let vif = { ClientVif.domid; device_id } in
-              let get_client_ip () =
+              Lwt.try_bind
-                let* str =
+                (fun () -> Xen_os.Xs.read handle (Printf.sprintf "%s/%d/ip" path device_id))
-                  Xen_os.Xs.read handle (Fmt.str "%s/%d/ip" path device_id)
+                (fun client_ip ->
-                in
+                   let client_ip' = match String.cuts ~sep:" " client_ip with
-                let client_ip = List.hd (String.split_on_char ' ' str) in
+                     | [] -> Log.err (fun m -> m "unexpected empty list"); ""
-                (* NOTE(dinosaure): it's safe to use [List.hd] here,
+                     | [ ip ] -> ip
-               [String.split_on_char] can not return an empty list. *)
+                     | ip::rest ->
-                Lwt.return_some (vif, Ipaddr.V4.of_string_exn client_ip)
+                       Log.warn (fun m -> m "ignoring IPs %s from %a, we support one IP per client"
-              in
+                                    (String.concat ~sep:" " rest) ClientVif.pp vif);
-              Lwt.catch get_client_ip @@ function
+                       ip
-              | Xs_protocol.Enoent _ -> Lwt.return_none
+                   in
-              | Ipaddr.Parse_error (msg, client_ip) ->
+                   match Ipaddr.V4.of_string client_ip' with
-                  Log.err (fun f ->
+                   | Ok ip -> Lwt.return (Some (vif, ip))
-                      f "Error parsing IP address of %a from %s: %s"
+                   | Error `Msg msg  ->
-                        ClientVif.pp vif client_ip msg);
+                     Log.err (fun f -> f "Error parsing IP address of %a from %s: %s"
-                  Lwt.return_none
+                                 ClientVif.pp vif client_ip msg);
-              | exn ->
+                     Lwt.return None
-                  Log.err (fun f ->
+                )
-                      f "Error getting IP address of %a: %s" ClientVif.pp vif
+                (function
-                        (Printexc.to_string exn));
+                  | Xs_protocol.Enoent _ -> Lwt.return None
-                  Lwt.return_none)
+                  | ex ->
-        in
+                    Log.err (fun f -> f "Error getting IP address of %a: %s"
-        Lwt_list.filter_map_p ip_of_vif devices
+                                ClientVif.pp vif (Printexc.to_string ex));
-      in
+                    Lwt.return None
-      Xen_os.Xs.immediate client vifs_of_domain
+                )
          ))
 let watch_clients fn =
  Xen_os.Xs.make () >>= fun xs ->
  let backend_vifs = "backend/vif" in
  Log.info (fun f -> f "Watching %s" backend_vifs);
  Xen_os.Xs.wait xs (fun handle ->
-      Lwt.catch
+    begin Lwt.catch
-        (fun () -> directory ~handle backend_vifs)
+      (fun () -> directory ~handle backend_vifs)
-        (function Xs_protocol.Enoent _ -> Lwt.return [] | ex -> Lwt.fail ex)
+      (function
-      >>= fun items ->
+        | Xs_protocol.Enoent _ -> Lwt.return []
-      Xen_os.Xs.make () >>= fun xs ->
+        | ex -> Lwt.fail ex)
-      Lwt_list.map_p (vifs xs) items >>= fun items ->
+    end >>= fun items ->
-      fn (List.concat items |> VifMap.of_list) >>= fun () ->
+    Xen_os.Xs.make () >>= fun xs ->
-      (* Wait for further updates *)
+    Lwt_list.map_p (vifs xs) items >>= fun items ->
-      Lwt.fail Xs_protocol.Eagain)
+    fn (List.concat items |> VifMap.of_list);
    (* Wait for further updates *)
    Lwt.fail Xs_protocol.Eagain
  )
 type network_config = {
-  from_cmdline : bool;
+  from_cmdline : bool;         (* Specify if we have network configuration from command line or from qubesDB*)
-      (* Specify if we have network configuration from command line or from qubesDB*)
+  netvm_ip : Ipaddr.V4.t;      (* The IP address of NetVM (our gateway) *)
-  netvm_ip : Ipaddr.V4.t; (* The IP address of NetVM (our gateway) *)
+  our_ip : Ipaddr.V4.t;        (* The IP address of our interface to NetVM *)
  our_ip : Ipaddr.V4.t; (* The IP address of our interface to NetVM *)
  dns : Ipaddr.V4.t;
  dns2 : Ipaddr.V4.t;
 }
@ -146,36 +136,31 @@ let try_read_network_config db =
  let get name =
    match DB.KeyMap.find_opt name db with
    | None -> raise (Missing_key name)
-    | Some value -> Ipaddr.V4.of_string_exn value
+    | Some value -> Ipaddr.V4.of_string_exn value in
-  in
+  let our_ip = get "/qubes-ip" in (* - IP address for this VM (only when VM has netvm set) *)
-  let our_ip = get "/qubes-ip" in
+  let netvm_ip = get "/qubes-gateway" in (* - default gateway IP (only when VM has netvm set); VM should add host route to this address directly via eth0 (or whatever default interface name is) *)
  (* - IP address for this VM (only when VM has netvm set) *)
  let netvm_ip = get "/qubes-gateway" in
  (* - default gateway IP (only when VM has netvm set); VM should add host route to this address directly via eth0 (or whatever default interface name is) *)
  let dns = get "/qubes-primary-dns" in
  let dns2 = get "/qubes-secondary-dns" in
-  { from_cmdline = false; netvm_ip; our_ip; dns; dns2 }
+  { from_cmdline=false; netvm_ip ; our_ip ; dns ; dns2 }
 let read_network_config qubesDB =
  let rec aux bindings =
    try Lwt.return (try_read_network_config bindings)
    with Missing_key key ->
-      Log.warn (fun f ->
+      Log.warn (fun f -> f "QubesDB key %S not (yet) present; waiting for QubesDB to change..." key);
          f "QubesDB key %S not (yet) present; waiting for QubesDB to change..."
            key);
      DB.after qubesDB bindings >>= aux
  in
  aux (DB.bindings qubesDB)
 let print_network_config config =
-  Log.info (fun f ->
+  Log.info (fun f -> f "@[<v2>Current network configuration (QubesDB or command line):@,\
-      f
+                        NetVM IP on uplink network: %a@,\
-        "@[<v2>Current network configuration (QubesDB or command line):@,\
+                        Our IP on client networks:  %a@,\
-         NetVM IP on uplink network: %a@,\
+                        DNS primary resolver:       %a@,\
-         Our IP on client networks:  %a@,\
+                        DNS secondary resolver:     %a@]"
-         DNS primary resolver:       %a@,\
+               Ipaddr.V4.pp config.netvm_ip
-         DNS secondary resolver:     %a@]"
+               Ipaddr.V4.pp config.our_ip
-        Ipaddr.V4.pp config.netvm_ip Ipaddr.V4.pp config.our_ip Ipaddr.V4.pp
+               Ipaddr.V4.pp config.dns
-        config.dns Ipaddr.V4.pp config.dns2)
+               Ipaddr.V4.pp config.dns2)
 let set_iptables_error db = Qubes.DB.write db "/qubes-iptables-error"
--- a/dao.mli
+++ b/dao.mli
@ -4,43 +4,40 @@
 (** Wrapper for XenStore and QubesDB databases. *)
 module ClientVif : sig
-  type t = { domid : int; device_id : int }
+  type t = {
-
+    domid : int;
    device_id : int;
  }
  val pp : t Fmt.t
 end
 module VifMap : sig
  include Map.S with type key = ClientVif.t
  val find : key -> 'a t -> 'a option
 end
-val watch_clients : (Ipaddr.V4.t VifMap.t -> unit Lwt.t) -> 'a Lwt.t
+val watch_clients : (Ipaddr.V4.t VifMap.t -> unit) -> 'a Lwt.t
-(** [watch_clients fn] calls [fn clients] with the list of backend clients in
+(** [watch_clients fn] calls [fn clients] with the list of backend clients
-    XenStore, and again each time XenStore updates. *)
+    in XenStore, and again each time XenStore updates. *)
 type network_config = {
-  from_cmdline : bool;
+  from_cmdline : bool;         (* Specify if we have network configuration from command line or from qubesDB*)
-      (* Specify if we have network configuration from command line or from qubesDB*)
+  netvm_ip : Ipaddr.V4.t;      (* The IP address of NetVM (our gateway) *)
-  netvm_ip : Ipaddr.V4.t; (* The IP address of NetVM (our gateway) *)
+  our_ip : Ipaddr.V4.t;        (* The IP address of our interface to NetVM *)
  our_ip : Ipaddr.V4.t; (* The IP address of our interface to NetVM *)
  dns : Ipaddr.V4.t;
  dns2 : Ipaddr.V4.t;
 }
 val read_network_config : Qubes.DB.t -> network_config Lwt.t
-(** [read_network_config db] fetches the configuration from QubesDB. If it isn't
+(** [read_network_config db] fetches the configuration from QubesDB.
-    there yet, it waits until it is. *)
+    If it isn't there yet, it waits until it is. *)
 val db_root : Ipaddr.V4.t -> string
-(** Returns the root path of the firewall rules in the QubesDB for a given IP
+(** Returns the root path of the firewall rules in the QubesDB for a given IP address. *)
    address. *)
-val read_rules :
+val read_rules : string Qubes.DB.KeyMap.t -> Ipaddr.V4.t -> Pf_qubes.Parse_qubes.rule list
-  string Qubes.DB.KeyMap.t -> Ipaddr.V4.t -> Pf_qubes.Parse_qubes.rule list
+(** [read_rules bindings ip] extracts firewall rule information for [ip] from [bindings].
-(** [read_rules bindings ip] extracts firewall rule information for [ip] from
+    If any rules fail to parse, it will return only one rule denying all traffic. *)
    [bindings]. If any rules fail to parse, it will return only one rule denying
    all traffic. *)
 val print_network_config : network_config -> unit
 val set_iptables_error : Qubes.DB.t -> string -> unit Lwt.t
--- a/dispatcher.ml
+++ b/dispatcher.ml
--- a/fw_utils.ml
+++ b/fw_utils.ml
@ -3,6 +3,14 @@
 (** General utility functions. *)
 module IpMap = struct
  include Map.Make(Ipaddr.V4)
  let find x map =
    try Some (find x map)
    with Not_found -> None
    | _ -> Logs.err( fun f -> f "uncaught exception in find...%!"); None
 end
 (** An Ethernet interface. *)
 class type interface = object
  method my_mac : Macaddr.t
@ -15,16 +23,14 @@ end
 class type client_link = object
  inherit interface
  method other_mac : Macaddr.t
-  method log_header : string (* For log messages *)
+  method log_header : string  (* For log messages *)
-  method get_rules : Pf_qubes.Parse_qubes.rule list
+  method get_rules: Pf_qubes.Parse_qubes.rule list
-  method set_rules : string Qubes.DB.KeyMap.t -> unit
+  method set_rules: string Qubes.DB.KeyMap.t -> unit
 end
-(** An Ethernet header from [src]'s MAC address to [dst]'s with an IPv4 payload.
+(** An Ethernet header from [src]'s MAC address to [dst]'s with an IPv4 payload. *)
 *)
 let eth_header ethertype ~src ~dst =
-  Ethernet.Packet.make_cstruct
+  Ethernet.Packet.make_cstruct { Ethernet.Packet.source = src; destination = dst; ethertype }
    { Ethernet.Packet.source = src; destination = dst; ethertype }
 let error fmt =
  let err s = Failure s in
--- a/memory_pressure.ml
+++ b/memory_pressure.ml
@ -2,14 +2,14 @@
   See the README file for details. *)
 let src = Logs.Src.create "memory_pressure" ~doc:"Memory pressure monitor"
 module Log = (val Logs.src_log src : Logs.LOG)
 let fraction_free stats =
  let { Xen_os.Memory.free_words; heap_words; _ } = stats in
  float free_words /. float heap_words
-let init () = Gc.full_major ()
+let init () =
  Gc.full_major ()
 let status () =
  let stats = Xen_os.Memory.quick_stat () in
@ -18,4 +18,6 @@ let status () =
    Gc.full_major ();
    Xen_os.Memory.trim ();
    let stats = Xen_os.Memory.quick_stat () in
-    if fraction_free stats < 0.6 then `Memory_critical else `Ok)
+    if fraction_free stats < 0.6 then `Memory_critical
    else `Ok
  )
--- a/memory_pressure.mli
+++ b/memory_pressure.mli
@ -8,5 +8,5 @@ val status : unit -> [ `Ok | `Memory_critical ]
 (** Check the memory situation. If we're running low, do a GC (work-around for
    http://caml.inria.fr/mantis/view.php?id=7100 and OCaml GC needing to malloc
    extra space to run finalisers). Returns [`Memory_critical] if memory is
-    still low - caller should take action to reduce memory use. After GC,
+    still low - caller should take action to reduce memory use.
-    updates meminfo in XenStore. *)
+    After GC, updates meminfo in XenStore. *)
--- a/my_dns.ml
+++ b/my_dns.ml
@ -1,81 +1,74 @@
 open Lwt.Infix
-type +'a io = 'a Lwt.t
+module Transport (R : Mirage_random.S) (C : Mirage_clock.MCLOCK) (Time : Mirage_time.S) = struct
-type io_addr = Ipaddr.V4.t * int
+  type +'a io = 'a Lwt.t
  type io_addr = Ipaddr.V4.t * int
  module Dispatcher = Dispatcher.Make(R)(C)(Time)
  type stack = Dispatcher.t * (src_port:int -> dst:Ipaddr.V4.t -> dst_port:int -> Cstruct.t -> (unit, [ `Msg of string ]) result Lwt.t) * (Udp_packet.t * Cstruct.t) Lwt_mvar.t
-type stack =
+  module IM = Map.Make(Int)
  Dispatcher.t
  * (src_port:int ->
    dst:Ipaddr.V4.t ->
    dst_port:int ->
    string ->
    (unit, [ `Msg of string ]) result Lwt.t)
  * (Udp_packet.t * string) Lwt_mvar.t
-module IM = Map.Make (Int)
+  type t = {
    protocol : Dns.proto ;
    nameserver : io_addr ;
    stack : stack ;
    timeout_ns : int64 ;
    mutable requests : Cstruct.t Lwt_condition.t IM.t ;
  }
  type context = t
-type t = {
+  let nameservers { protocol ; nameserver ; _ } = protocol, [ nameserver ]
-  protocol : Dns.proto;
+  let rng = R.generate ?g:None
-  nameserver : io_addr;
+  let clock = C.elapsed_ns
  stack : stack;
  timeout_ns : int64;
  mutable requests : string Lwt_condition.t IM.t;
 }
-type context = t
+  let rec read t =
    let _, _, answer = t.stack in
    Lwt_mvar.take answer >>= fun (_, data) ->
    if Cstruct.length data > 2 then begin
      match IM.find_opt (Cstruct.BE.get_uint16 data 0) t.requests with
      | Some cond -> Lwt_condition.broadcast cond data
      | None -> ()
    end;
    read t
-let nameservers { protocol; nameserver; _ } = (protocol, [ nameserver ])
+  let create ?nameservers ~timeout stack =
-let rng = Mirage_crypto_rng.generate ?g:None
+    let protocol, nameserver = match nameservers with
-let clock = Mirage_mtime.elapsed_ns
+      | None | Some (_, []) -> invalid_arg "no nameserver found"
      | Some (proto, ns :: _) -> proto, ns
    in
    let t =
      { protocol ; nameserver ; stack ; timeout_ns = timeout ; requests = IM.empty }
    in
    Lwt.async (fun () -> read t);
    t
-let rec read t =
+  let with_timeout timeout_ns f =
-  let _, _, answer = t.stack in
+    let timeout = Time.sleep_ns timeout_ns >|= fun () -> Error (`Msg "DNS request timeout") in
-  Lwt_mvar.take answer >>= fun (_, data) ->
+    Lwt.pick [ f ; timeout ]
  (if String.length data > 2 then
     match IM.find_opt (String.get_uint16_be data 0) t.requests with
     | Some cond -> Lwt_condition.broadcast cond data
     | None -> ());
  read t
-let create ?nameservers ~timeout stack =
+  let connect (t : t) = Lwt.return (Ok (t.protocol, t))
  let protocol, nameserver =
    match nameservers with
    | None | Some (_, []) -> invalid_arg "no nameserver found"
    | Some (proto, ns :: _) -> (proto, ns)
  in
  let t =
    { protocol; nameserver; stack; timeout_ns = timeout; requests = IM.empty }
  in
  Lwt.async (fun () -> read t);
  t
-let with_timeout timeout_ns f =
+  let send_recv (ctx : context) buf : (Cstruct.t, [> `Msg of string ]) result Lwt.t =
-  let timeout =
+    let dst, dst_port = ctx.nameserver in
-    Mirage_sleep.ns timeout_ns >|= fun () -> Error (`Msg "DNS request timeout")
+    let router, send_udp, _ = ctx.stack in
-  in
+    let src_port, evict =
-  Lwt.pick [ f; timeout ]
+      My_nat.free_udp_port router.nat ~src:router.config.our_ip ~dst ~dst_port:53
    in
    let id = Cstruct.BE.get_uint16 buf 0 in
    with_timeout ctx.timeout_ns
      (let cond = Lwt_condition.create () in
       ctx.requests <- IM.add id cond ctx.requests;
       (send_udp ~src_port ~dst ~dst_port buf >|= Rresult.R.open_error_msg) >>= function
       | Ok () -> Lwt_condition.wait cond >|= fun dns_response -> Ok dns_response
       | Error _ as e -> Lwt.return e) >|= fun result ->
    ctx.requests <- IM.remove id ctx.requests;
    evict ();
    result
-let connect (t : t) = Lwt.return (Ok (t.protocol, t))
+  let close _ = Lwt.return_unit
-let send_recv (ctx : context) buf : (string, [> `Msg of string ]) result Lwt.t =
+  let bind = Lwt.bind
-  let dst, dst_port = ctx.nameserver in
+
-  let router, send_udp, _ = ctx.stack in
+  let lift = Lwt.return
-  let src_port, evict =
+end
    My_nat.free_udp_port router.nat ~src:router.config.our_ip ~dst ~dst_port:53
  in
  let id = String.get_uint16_be buf 0 in
  with_timeout ctx.timeout_ns
    (let cond = Lwt_condition.create () in
     ctx.requests <- IM.add id cond ctx.requests;
     send_udp ~src_port ~dst ~dst_port buf >|= Rresult.R.open_error_msg
     >>= function
     | Ok () -> Lwt_condition.wait cond >|= fun dns_response -> Ok dns_response
     | Error _ as e -> Lwt.return e)
  >|= fun result ->
  ctx.requests <- IM.remove id ctx.requests;
  evict ();
  result
 let close _ = Lwt.return_unit
 let bind = Lwt.bind
 let lift = Lwt.return
--- a/my_nat.ml
+++ b/my_nat.ml
@ -2,57 +2,65 @@
   See the README file for details. *)
 let src = Logs.Src.create "my-nat" ~doc:"NAT shim"
 module Log = (val Logs.src_log src : Logs.LOG)
-type action = [ `NAT | `Redirect of Mirage_nat.endpoint ]
+type action = [
  | `NAT
  | `Redirect of Mirage_nat.endpoint
 ]
 module Nat = Mirage_nat_lru
-module S = Set.Make (struct
+module S =
-  type t = int
+  Set.Make(struct type t = int let compare (a : int) (b : int) = compare a b end)
-  let compare (a : int) (b : int) = compare a b
+type t = {
-end)
+  table : Nat.t;
  mutable udp_dns : S.t;
  last_resort_port : int
 }
-type t = { table : Nat.t; mutable udp_dns : S.t; last_resort_port : int }
+let pick_port () =
-
+  1024 + Random.int (0xffff - 1024)
 let pick_port () = 1024 + Random.int (0xffff - 1024)
 let create ~max_entries =
  let tcp_size = 7 * max_entries / 8 in
  let udp_size = max_entries - tcp_size in
  let table = Nat.empty ~tcp_size ~udp_size ~icmp_size:100 in
  let last_resort_port = pick_port () in
-  { table; udp_dns = S.empty; last_resort_port }
+  { table ; udp_dns = S.empty ; last_resort_port }
 let pick_free_port t proto =
  let rec go retries =
-    if retries = 0 then None
+    if retries = 0 then
      None
    else
      let p = 1024 + Random.int (0xffff - 1024) in
      match proto with
-      | `Udp when S.mem p t.udp_dns || p = t.last_resort_port -> go (retries - 1)
+      | `Udp when S.mem p t.udp_dns || p = t.last_resort_port ->
        go (retries - 1)
      | _ -> Some p
  in
  go 10
 let free_udp_port t ~src ~dst ~dst_port =
  let rec go retries =
-    if retries = 0 then (t.last_resort_port, Fun.id)
+    if retries = 0 then
      t.last_resort_port, Fun.id
    else
      let src_port =
        Option.value ~default:t.last_resort_port (pick_free_port t `Udp)
      in
-      if Nat.is_port_free t.table `Udp ~src ~dst ~src_port ~dst_port then
+      if Nat.is_port_free t.table `Udp ~src ~dst ~src_port ~dst_port then begin
        let remove =
-          if src_port <> t.last_resort_port then (
+          if src_port <> t.last_resort_port then begin
            t.udp_dns <- S.add src_port t.udp_dns;
-            fun () -> t.udp_dns <- S.remove src_port t.udp_dns)
+            (fun () -> t.udp_dns <- S.remove src_port t.udp_dns)
-          else Fun.id
+          end else Fun.id
        in
-        (src_port, remove)
+        src_port, remove
-      else go (retries - 1)
+      end else
        go (retries - 1)
  in
  go 10
@ -60,27 +68,27 @@ let dns_port t port = S.mem port t.udp_dns || port = t.last_resort_port
 let translate t packet =
  match Nat.translate t.table packet with
-  | Error ((`Untranslated | `TTL_exceeded) as e) ->
+  | Error (`Untranslated | `TTL_exceeded as e) ->
-      Log.debug (fun f ->
+    Log.debug (fun f -> f "Failed to NAT %a: %a"
-          f "Failed to NAT %a: %a" Nat_packet.pp packet Mirage_nat.pp_error e);
+                  Nat_packet.pp packet
-      None
+                  Mirage_nat.pp_error e
              );
    None
  | Ok packet -> Some packet
-let remove_connections t ip = ignore (Nat.remove_connections t.table ip)
+let remove_connections t ip =
  ignore (Nat.remove_connections t.table ip)
 let add_nat_rule_and_translate t ~xl_host action packet =
-  let proto =
+  let proto = match packet with
    match packet with
    | `IPv4 (_, `TCP _) -> `Tcp
    | `IPv4 (_, `UDP _) -> `Udp
    | `IPv4 (_, `ICMP _) -> `Icmp
  in
-  match
+  match Nat.add t.table packet xl_host (fun () -> pick_free_port t proto) action with
    Nat.add t.table packet xl_host (fun () -> pick_free_port t proto) action
  with
  | Error `Overlap -> Error "Too many retries"
  | Error `Cannot_NAT -> Error "Cannot NAT this packet"
  | Ok () ->
-      Log.debug (fun f -> f "Updated NAT table: %a" Nat.pp_summary t.table);
+    Log.debug (fun f -> f "Updated NAT table: %a" Nat.pp_summary t.table);
-      Option.to_result ~none:"No NAT entry, even after adding one!"
+    Option.to_result ~none:"No NAT entry, even after adding one!"
-        (translate t packet)
+      (translate t packet)
--- a/my_nat.mli
+++ b/my_nat.mli
@ -4,23 +4,17 @@
 (* Abstract over NAT interface (todo: remove this) *)
 type t
 type action = [ `NAT | `Redirect of Mirage_nat.endpoint ]
-val free_udp_port :
+type action = [
-  t ->
+  | `NAT
-  src:Ipaddr.V4.t ->
+  | `Redirect of Mirage_nat.endpoint
-  dst:Ipaddr.V4.t ->
+]
-  dst_port:int ->
+
 val free_udp_port : t -> src:Ipaddr.V4.t -> dst:Ipaddr.V4.t -> dst_port:int ->
  int * (unit -> unit)
 val dns_port : t -> int -> bool
 val create : max_entries:int -> t
 val remove_connections : t -> Ipaddr.V4.t -> unit
 val translate : t -> Nat_packet.t -> Nat_packet.t option
-
+val add_nat_rule_and_translate : t ->
-val add_nat_rule_and_translate :
+  xl_host:Ipaddr.V4.t -> action -> Nat_packet.t -> (Nat_packet.t, string) result
  t ->
  xl_host:Ipaddr.V4.t ->
  action ->
  Nat_packet.t ->
  (Nat_packet.t, string) result
--- a/packet.ml
+++ b/packet.ml
@ -8,8 +8,9 @@ type port = int
 type host =
  [ `Client of client_link | `Firewall | `NetVM | `External of Ipaddr.t ]
-type transport_header =
+type transport_header = [`TCP of Tcp.Tcp_packet.t
-  [ `TCP of Tcp.Tcp_packet.t | `UDP of Udp_packet.t | `ICMP of Icmpv4_packet.t ]
+                        |`UDP of Udp_packet.t
                        |`ICMP of Icmpv4_packet.t]
 type ('src, 'dst) t = {
  ipv4_header : Ipv4_packet.t;
@ -18,14 +19,13 @@ type ('src, 'dst) t = {
  src : 'src;
  dst : 'dst;
 }
 let pp_transport_header f = function
  | `ICMP h -> Icmpv4_packet.pp f h
  | `TCP h -> Tcp.Tcp_packet.pp f h
  | `UDP h -> Udp_packet.pp f h
 let pp_host fmt = function
-  | `Client c -> Ipaddr.V4.pp fmt c#other_ip
+  | `Client c -> Ipaddr.V4.pp fmt (c#other_ip)
  | `Unknown_client ip -> Format.fprintf fmt "unknown-client(%a)" Ipaddr.pp ip
  | `NetVM -> Format.pp_print_string fmt "net-vm"
  | `External ip -> Format.fprintf fmt "external(%a)" Ipaddr.pp ip
@ -33,28 +33,32 @@ let pp_host fmt = function
 let to_mirage_nat_packet t : Nat_packet.t =
  match t.transport_header with
-  | `TCP h -> `IPv4 (t.ipv4_header, `TCP (h, t.transport_payload))
+  | `TCP h  -> `IPv4 (t.ipv4_header, (`TCP (h, t.transport_payload)))
-  | `UDP h -> `IPv4 (t.ipv4_header, `UDP (h, t.transport_payload))
+  | `UDP h  -> `IPv4 (t.ipv4_header, (`UDP (h, t.transport_payload)))
-  | `ICMP h -> `IPv4 (t.ipv4_header, `ICMP (h, t.transport_payload))
+  | `ICMP h -> `IPv4 (t.ipv4_header, (`ICMP (h, t.transport_payload)))
 let of_mirage_nat_packet ~src ~dst packet : ('a, 'b) t option =
-  let (`IPv4 (ipv4_header, ipv4_payload)) = packet in
+  let `IPv4 (ipv4_header, ipv4_payload) = packet in
-  let transport_header, transport_payload =
+  let transport_header, transport_payload = match ipv4_payload with
-    match ipv4_payload with
+    | `TCP (h, p) -> `TCP h, p
-    | `TCP (h, p) -> (`TCP h, p)
+    | `UDP (h, p) -> `UDP h, p
-    | `UDP (h, p) -> (`UDP h, p)
+    | `ICMP (h, p) -> `ICMP h, p
    | `ICMP (h, p) -> (`ICMP h, p)
  in
-  Some { ipv4_header; transport_header; transport_payload; src; dst }
+  Some {
    ipv4_header;
    transport_header;
    transport_payload;
    src;
    dst;
  }
 (* possible actions to take for a packet: *)
-type action =
+type action = [
-  [ `Accept (* Send to destination, unmodified. *)
+  | `Accept (* Send to destination, unmodified. *)
-  | `NAT
+  | `NAT    (* Rewrite source field to the firewall's IP, with a fresh source port.
    (* Rewrite source field to the firewall's IP, with a fresh source port.
               Also, add translation rules for future traffic in both directions,
               between these hosts on these ports, and corresponding ICMP error traffic. *)
-  | `NAT_to of host * port
+  | `NAT_to of host * port (* As for [`NAT], but also rewrite the packet's
    (* As for [`NAT], but also rewrite the packet's
                              destination fields so it will be sent to [host:port]. *)
-  | `Drop of string (* Drop packet for this reason. *) ]
+  | `Drop of string (* Drop packet for this reason. *)
 ]
--- a/packet.mli
+++ b/packet.mli
@ -1,13 +1,15 @@
 type port = int
 type host =
-  [ `Client of Fw_utils.client_link  (** an IP address on the private network *)
+  [ `Client of Fw_utils.client_link (** an IP address on the private network *)
-  | `Firewall  (** the firewall's IP on the private network *)
+  | `Firewall (** the firewall's IP on the private network *)
-  | `NetVM  (** the IP of the firewall's default route *)
+  | `NetVM (** the IP of the firewall's default route *)
-  | `External of Ipaddr.t  (** an IP on the public network *) ]
+  | `External of Ipaddr.t (** an IP on the public network *)
  ]
-type transport_header =
+type transport_header = [`TCP of Tcp.Tcp_packet.t
-  [ `TCP of Tcp.Tcp_packet.t | `UDP of Udp_packet.t | `ICMP of Icmpv4_packet.t ]
+                        |`UDP of Udp_packet.t
                        |`ICMP of Icmpv4_packet.t]
 type ('src, 'dst) t = {
  ipv4_header : Ipv4_packet.t;
@ -18,18 +20,20 @@ type ('src, 'dst) t = {
 }
 val pp_transport_header : Format.formatter -> transport_header -> unit
 val pp_host : Format.formatter -> host -> unit
 val to_mirage_nat_packet : ('a, 'b) t -> Nat_packet.t
 val of_mirage_nat_packet : src:'a -> dst:'b -> Nat_packet.t -> ('a, 'b) t option
 (* possible actions to take for a packet: *)
-type action =
+type action = [
-  [ `Accept (* Send to destination, unmodified. *)
+  | `Accept (* Send to destination, unmodified. *)
-  | `NAT
+  | `NAT    (* Rewrite source field to the firewall's IP, with a fresh source port.
    (* Rewrite source field to the firewall's IP, with a fresh source port.
               Also, add translation rules for future traffic in both directions,
               between these hosts on these ports, and corresponding ICMP error traffic. *)
-  | `NAT_to of host * port
+  | `NAT_to of host * port (* As for [`NAT], but also rewrite the packet's
    (* As for [`NAT], but also rewrite the packet's
                              destination fields so it will be sent to [host:port]. *)
-  | `Drop of string (* Drop packet for this reason. *) ]
+  | `Drop of string (* Drop packet for this reason. *)
 ]
--- a/qubes-firewall-release.sha256
+++ b/qubes-firewall-release.sha256
@ -1 +0,0 @@
 0c3c2c0e62a834112c69d7cddc5dd6f70ecb93afa988768fb860ed26e423b1f8  dist/qubes-firewall.xen
--- a/qubes-firewall.sha256
+++ b/qubes-firewall.sha256
@ -1 +0,0 @@
 ac049069b35f786fa11b18a2261d7dbecd588301af0363ef6888ec9d924dc989  dist/qubes-firewall.xen
--- a/rules.ml
+++ b/rules.ml
@ -8,115 +8,93 @@ open Lwt.Infix
 module Q = Pf_qubes.Parse_qubes
 let src = Logs.Src.create "rules" ~doc:"Firewall rules"
 module Log = (val Logs.src_log src : Logs.LOG)
 let dns_port = 53
 module Classifier = struct
-  let matches_port dstports (port : int) =
+
-    match dstports with
+  let matches_port dstports (port : int) = match dstports with
    | None -> true
    | Some (Q.Range_inclusive (min, max)) -> min <= port && port <= max
-  let matches_proto rule dns_servers packet =
+  let matches_proto rule dns_servers packet = match rule.Q.proto, rule.Q.specialtarget with
    match (rule.Q.proto, rule.Q.specialtarget) with
    | None, None -> true
-    | None, Some `dns
+    | None, Some `dns when List.mem packet.ipv4_header.Ipv4_packet.dst dns_servers -> begin
-      when List.mem packet.ipv4_header.Ipv4_packet.dst dns_servers -> (
+      (* specialtarget=dns applies only to the specialtarget destination IPs, and
        (* specialtarget=dns applies only to the specialtarget destination IPs, and
         specialtarget=dns is also implicitly tcp/udp port 53 *)
-        match packet.transport_header with
+      match packet.transport_header with
        | `TCP header -> header.Tcp.Tcp_packet.dst_port = dns_port
        | `UDP header -> header.Udp_packet.dst_port = dns_port
-        | _ -> false)
+        | _ -> false
-    (* DNS rules can only match traffic headed to the specialtarget hosts, so any other destination
+      end
   (* DNS rules can only match traffic headed to the specialtarget hosts, so any other destination
   isn't a match for DNS rules *)
    | None, Some `dns -> false
-    | Some rule_proto, _ -> (
+    | Some rule_proto, _ -> match rule_proto, packet.transport_header with
-        match (rule_proto, packet.transport_header) with
+      | `tcp, `TCP header -> matches_port rule.Q.dstports header.Tcp.Tcp_packet.dst_port
-        | `tcp, `TCP header ->
+      | `udp, `UDP header -> matches_port rule.Q.dstports header.Udp_packet.dst_port
-            matches_port rule.Q.dstports header.Tcp.Tcp_packet.dst_port
+      | `icmp, `ICMP header ->
-        | `udp, `UDP header ->
+      begin
-            matches_port rule.Q.dstports header.Udp_packet.dst_port
+        match rule.Q.icmp_type with
-        | `icmp, `ICMP header -> (
+        | None -> true
-            match rule.Q.icmp_type with
+        | Some rule_icmp_type ->
-            | None -> true
+          0 = compare rule_icmp_type @@ Icmpv4_wire.ty_to_int header.Icmpv4_packet.ty
-            | Some rule_icmp_type ->
+      end
-                0
+      | _, _ -> false
                = compare rule_icmp_type
                  @@ Icmpv4_wire.ty_to_int header.Icmpv4_packet.ty)
        | _, _ -> false)
  let matches_dest dns_client rule packet =
    let ip = packet.ipv4_header.Ipv4_packet.dst in
    match rule.Q.dst with
-    | `any -> Lwt.return @@ `Match rule
+    | `any ->  Lwt.return @@ `Match rule
    | `hosts subnet ->
-        Lwt.return
+      Lwt.return @@ if (Ipaddr.Prefix.mem Ipaddr.(V4 ip) subnet) then `Match rule else `No_match
-        @@
+    | `dnsname name ->
-        if Ipaddr.Prefix.mem Ipaddr.(V4 ip) subnet then `Match rule
+      Log.debug (fun f -> f "Resolving %a" Domain_name.pp name);
      dns_client name >|= function
      | Ok (_ttl, found_ips) ->
        if Ipaddr.V4.Set.mem ip found_ips
        then `Match rule
        else `No_match
-    | `dnsname name -> (
+      | Error (`Msg m) ->
-        Log.debug (fun f -> f "Resolving %a" Domain_name.pp name);
+        Log.warn (fun f -> f "Ignoring rule %a, could not resolve" Q.pp_rule rule);
-        dns_client name >|= function
+        Log.debug (fun f -> f "%s" m);
-        | Ok (_ttl, found_ips) ->
+        `No_match
-            if Ipaddr.V4.Set.mem ip found_ips then `Match rule else `No_match
+      | Error _ -> assert false (* TODO: fix type of dns_client so that this case can go *)
-        | Error (`Msg m) ->
+
            Log.warn (fun f ->
                f "Ignoring rule %a, could not resolve" Q.pp_rule rule);
            Log.debug (fun f -> f "%s" m);
            `No_match
        | Error _ ->
            assert
              false (* TODO: fix type of dns_client so that this case can go *))
 end
 let find_first_match dns_client dns_servers packet acc rule =
  match acc with
  | `No_match ->
-      if Classifier.matches_proto rule dns_servers packet then
+    if Classifier.matches_proto rule dns_servers packet
-        Classifier.matches_dest dns_client rule packet
+    then Classifier.matches_dest dns_client rule packet
-      else Lwt.return `No_match
+    else Lwt.return `No_match
  | q -> Lwt.return q
 (* Does the packet match our rules? *)
-let classify_client_packet dns_client dns_servers
+let classify_client_packet dns_client dns_servers (packet : ([`Client of Fw_utils.client_link], _) Packet.t)  =
    (packet : ([ `Client of Fw_utils.client_link ], _) Packet.t) =
  let (`Client client_link) = packet.src in
  let rules = client_link#get_rules in
-  Lwt_list.fold_left_s
+  Lwt_list.fold_left_s (find_first_match dns_client dns_servers packet) `No_match rules >|= function
    (find_first_match dns_client dns_servers packet)
    `No_match rules
  >|= function
  | `No_match -> `Drop "No matching rule; assuming default drop"
-  | `Match { Q.action = Q.Accept; _ } -> `Accept
+  | `Match {Q.action = Q.Accept; _} -> `Accept
-  | `Match ({ Q.action = Q.Drop; _ } as rule) ->
+  | `Match ({Q.action = Q.Drop; _} as rule) ->
-      `Drop
+    `Drop (Format.asprintf "rule number %a explicitly drops this packet" Q.pp_rule rule)
        (Format.asprintf "rule number %a explicitly drops this packet" Q.pp_rule
           rule)
 let translate_accepted_packets dns_client dns_servers packet =
  classify_client_packet dns_client dns_servers packet >|= function
  | `Accept -> `NAT
  | `Drop s -> `Drop s
-(** Packets from the private interface that don't match any NAT table entry are
+(** Packets from the private interface that don't match any NAT table entry are being checked against the fw rules here *)
-    being checked against the fw rules here *)
+let from_client dns_client dns_servers (packet : ([`Client of Fw_utils.client_link], _) Packet.t) : Packet.action Lwt.t =
 let from_client dns_client dns_servers
    (packet : ([ `Client of Fw_utils.client_link ], _) Packet.t) :
    Packet.action Lwt.t =
  match packet with
-  | { dst = `External _; _ } | { dst = `NetVM; _ } ->
+  | { dst = `External _ ; _ } | { dst = `NetVM; _ } -> translate_accepted_packets dns_client dns_servers packet
-      translate_accepted_packets dns_client dns_servers packet
+  | { dst = `Firewall ; _ } -> Lwt.return @@ `Drop "packet addressed to firewall itself"
-  | { dst = `Firewall; _ } ->
+  | { dst = `Client _ ; _ } -> classify_client_packet dns_client dns_servers packet
      Lwt.return @@ `Drop "packet addressed to firewall itself"
  | { dst = `Client _; _ } ->
      classify_client_packet dns_client dns_servers packet
  | _ -> Lwt.return @@ `Drop "could not classify packet"
-(** Packets from the outside world that don't match any NAT table entry are
+(** Packets from the outside world that don't match any NAT table entry are being dropped by default *)
-    being dropped by default *)
+let from_netvm (_packet : ([`NetVM | `External of _], _) Packet.t) : Packet.action Lwt.t =
 let from_netvm (_packet : ([ `NetVM | `External of _ ], _) Packet.t) :
    Packet.action Lwt.t =
  Lwt.return @@ `Drop "drop by default"
--- a/test/config.ml
+++ b/test/config.ml
@ -2,32 +2,26 @@ open Mirage
 let pin = "git+https://github.com/roburio/alcotest.git#mirage"
-let packages =
+let packages = [
-  [
+  package "ethernet";
-    package "ethernet";
+  package "arp";
-    package "arp";
+  package "arp-mirage";
-    package "arp-mirage";
+  package "ipaddr";
-    package "ipaddr";
+  package "tcpip" ~sublibs:["stack-direct"; "icmpv4"; "ipv4"; "udp"; "tcp"];
-    package "tcpip" ~sublibs:[ "stack-direct"; "icmpv4"; "ipv4"; "udp"; "tcp" ];
+  package "mirage-qubes";
-    package "mirage-qubes";
+  package "mirage-qubes-ipv4";
-    package "mirage-qubes-ipv4";
+  package "dns-client" ~sublibs:["mirage"];
-    package "dns-client" ~sublibs:[ "mirage" ];
+  package ~pin "alcotest";
-    package ~pin "alcotest";
+  package ~pin "alcotest-mirage";
-    package ~pin "alcotest-mirage";
+]
  ]
 let client =
-  foreign ~packages "Unikernel.Client"
+  foreign ~packages
-  @@ random @-> time @-> mclock @-> network @-> qubesdb @-> job
+    "Unikernel.Client" @@ random @-> time @-> mclock @-> network @-> qubesdb @-> job
 let db = default_qubesdb
 let network = default_network
 let () =
-  let job =
+  let job =  [ client $ default_random $ default_time $ default_monotonic_clock $ network $ db ] in
    [
      client $ default_random $ default_time $ default_monotonic_clock $ network
      $ db;
    ]
  in
  register "http-fetch" job
--- a/test/unikernel.ml
+++ b/test/unikernel.ml
@ -1,8 +1,6 @@
 open Lwt.Infix
 (* https://www.qubes-os.org/doc/vm-interface/#firewall-rules-in-4x *)
 let src = Logs.Src.create "firewall test" ~doc:"Firewalltest"
 module Log = (val Logs.src_log src : Logs.LOG)
 (* TODO
@ -41,24 +39,18 @@ module Log = (val Logs.src_log src : Logs.LOG)
 (* Point-to-point links out of a netvm always have this IP TODO clarify with Marek *)
 let netvm = "10.137.0.5"
 (* default "nameserver"s, which netvm redirects to whatever its real nameservers are *)
-let nameserver_1, nameserver_2 = ("10.139.1.1", "10.139.1.2")
+let nameserver_1, nameserver_2 = "10.139.1.1", "10.139.1.2"
-module Client
+module Client (R: Mirage_random.S) (Time: Mirage_time.S) (Clock : Mirage_clock.MCLOCK) (NET: Mirage_net.S) (DB : Qubes.S.DB) = struct
-    (R : Mirage_crypto_rng_mirage.S)
+  module E = Ethernet.Make(NET)
-    (Time : Mirage_time.S)
+  module A = Arp.Make(E)(Time)
-    (Clock : Mirage_clock.MCLOCK)
+  module I = Qubesdb_ipv4.Make(DB)(R)(Clock)(E)(A)
-    (NET : Mirage_net.S)
+  module Icmp = Icmpv4.Make(I)
-    (DB : Qubes.S.DB) =
+  module U = Udp.Make(I)(R)
-struct
+  module T = Tcp.Flow.Make(I)(Time)(Clock)(R)
-  module E = Ethernet.Make (NET)
+
-  module A = Arp.Make (E) (Time)
+  module Alcotest = Alcotest_mirage.Make(Clock)
  module I = Qubesdb_ipv4.Make (DB) (R) (Clock) (E) (A)
  module Icmp = Icmpv4.Make (I)
  module U = Udp.Make (I) (R)
  module T = Tcp.Flow.Make (I) (Time) (Clock) (R)
  module Alcotest = Alcotest_mirage.Make (Clock)
  module Stack = struct
    (* A Mirage_stack.V4 implementation which diverts DHCP messages to a DHCP
@ -74,77 +66,67 @@ struct
    module IPV4 = I
    type t = {
-      net : NET.t;
+      net : NET.t ; eth : E.t ; arp : A.t ;
-      eth : E.t;
+      ip : I.t ; icmp : Icmp.t ; udp : U.t ; tcp : T.t ;
-      arp : A.t;
+      udp_listeners : (int, U.callback) Hashtbl.t ;
-      ip : I.t;
+      tcp_listeners : (int, T.listener) Hashtbl.t ;
-      icmp : Icmp.t;
+      mutable icmp_listener : (src:Ipaddr.V4.t -> dst:Ipaddr.V4.t -> Cstruct.t -> unit Lwt.t) option ;
      udp : U.t;
      tcp : T.t;
      udp_listeners : (int, U.callback) Hashtbl.t;
      tcp_listeners : (int, T.listener) Hashtbl.t;
      mutable icmp_listener :
        (src:Ipaddr.V4.t -> dst:Ipaddr.V4.t -> Cstruct.t -> unit Lwt.t) option;
    }
-    let ipv4 { ip; _ } = ip
+    let ipv4 { ip ; _ } = ip
-    let udpv4 { udp; _ } = udp
+    let udpv4 { udp ; _ } = udp
-    let tcpv4 { tcp; _ } = tcp
+    let tcpv4 { tcp ; _ } = tcp
-    let icmpv4 { icmp; _ } = icmp
+    let icmpv4 { icmp ; _ } = icmp
    let listener h port = Hashtbl.find_opt h port
    let udp_listener h ~dst_port = listener h dst_port
-    let listen_udpv4 { udp_listeners; _ } ~port cb =
+    let listen_udpv4 { udp_listeners ; _ } ~port cb =
      Hashtbl.replace udp_listeners port cb
-    let stop_listen_udpv4 { udp_listeners; _ } ~port =
+    let stop_listen_udpv4 { udp_listeners ; _ } ~port =
      Hashtbl.remove udp_listeners port
-    let listen_tcpv4 ?keepalive { tcp_listeners; _ } ~port cb =
+    let listen_tcpv4 ?keepalive { tcp_listeners ; _ } ~port cb =
-      Hashtbl.replace tcp_listeners port { T.process = cb; T.keepalive }
+      Hashtbl.replace tcp_listeners port { T.process = cb ; T.keepalive }
-    let stop_listen_tcpv4 { tcp_listeners; _ } ~port =
+    let stop_listen_tcpv4 { tcp_listeners ; _ } ~port =
      Hashtbl.remove tcp_listeners port
    let listen_icmp t cb = t.icmp_listener <- cb
    let listen t =
      let ethif_listener =
-        E.input ~arpv4:(A.input t.arp)
+        E.input
-          ~ipv4:
+          ~arpv4:(A.input t.arp)
-            (I.input
+          ~ipv4:(
-               ~tcp:(T.input t.tcp ~listeners:(listener t.tcp_listeners))
+            I.input
-               ~udp:(U.input t.udp ~listeners:(udp_listener t.udp_listeners))
+              ~tcp:(T.input t.tcp ~listeners:(listener t.tcp_listeners))
-               ~default:(fun ~proto ~src ~dst buf ->
+              ~udp:(U.input t.udp ~listeners:(udp_listener t.udp_listeners))
-                 match proto with
+              ~default:(fun ~proto ~src ~dst buf ->
-                 | 1 -> (
+                  match proto with
-                     match t.icmp_listener with
+                  | 1 ->
                     begin match t.icmp_listener with
                     | None -> Icmp.input t.icmp ~src ~dst buf
-                     | Some cb -> cb ~src ~dst buf)
+                     | Some cb -> cb ~src ~dst buf
-                 | _ -> Lwt.return_unit)
+                     end
-               t.ip)
+                  | _ -> Lwt.return_unit)
              t.ip)
          ~ipv6:(fun _ -> Lwt.return_unit)
          t.eth
      in
      NET.listen t.net ~header_size:Ethernet_wire.sizeof_ethernet ethif_listener
      >>= function
      | Error e ->
-          Logs.warn (fun p -> p "%a" NET.pp_error e);
+        Logs.warn (fun p -> p "%a" NET.pp_error e) ;
-          Lwt.return_unit
+        Lwt.return_unit
      | Ok _res -> Lwt.return_unit
    let connect net eth arp ip icmp udp tcp =
-      {
+      { net ; eth ; arp ; ip ; icmp ; udp ; tcp ;
-        net;
+        udp_listeners = Hashtbl.create 2 ;
-        eth;
+        tcp_listeners = Hashtbl.create 2 ;
-        arp;
+        icmp_listener = None ;
        ip;
        icmp;
        udp;
        tcp;
        udp_listeners = Hashtbl.create 2;
        tcp_listeners = Hashtbl.create 2;
        icmp_listener = None;
      }
    let disconnect _ =
@ -152,39 +134,31 @@ struct
      Lwt.return_unit
  end
-  module Dns = Dns_client_mirage.Make (R) (Time) (Clock) (Stack)
+  module Dns = Dns_client_mirage.Make(R)(Time)(Clock)(Stack)
  let make_ping_packet payload =
-    let echo_request =
+    let echo_request = { Icmpv4_packet.code = 0; (* constant for echo request/reply *)
-      {
+                         ty = Icmpv4_wire.Echo_request;
-        Icmpv4_packet.code = 0;
+                         subheader = Icmpv4_packet.(Id_and_seq (0, 0)); } in
        (* constant for echo request/reply *)
        ty = Icmpv4_wire.Echo_request;
        subheader = Icmpv4_packet.(Id_and_seq (0, 0));
      }
    in
    Icmpv4_packet.Marshal.make_cstruct echo_request ~payload
  let is_ping_reply src server packet =
-    (0 = Ipaddr.V4.(compare src @@ of_string_exn server))
+    0 = Ipaddr.V4.(compare src @@ of_string_exn server) &&
-    && packet.Icmpv4_packet.code = 0
+    packet.Icmpv4_packet.code = 0 &&
-    && packet.Icmpv4_packet.ty = Icmpv4_wire.Echo_reply
+    packet.Icmpv4_packet.ty = Icmpv4_wire.Echo_reply &&
-    && packet.Icmpv4_packet.subheader = Icmpv4_packet.(Id_and_seq (0, 0))
+    packet.Icmpv4_packet.subheader = Icmpv4_packet.(Id_and_seq (0, 0))
  let ping_denied_listener server resp_received stack =
    let icmp_listener ~src ~dst:_ buf =
      (* hopefully this is a reply to an ICMP echo request we sent *)
-      Log.info (fun f ->
+      Log.info (fun f -> f "ping test: ICMP message received from %a: %a" I.pp_ipaddr src Cstruct.hexdump_pp buf);
          f "ping test: ICMP message received from %a: %a" I.pp_ipaddr src
            Cstruct.hexdump_pp buf);
      match Icmpv4_packet.Unmarshal.of_cstruct buf with
-      | Error e ->
+      | Error e -> Log.err (fun f -> f "couldn't parse ICMP packet: %s" e);
-          Log.err (fun f -> f "couldn't parse ICMP packet: %s" e);
+                   Lwt.return_unit
          Lwt.return_unit
      | Ok (packet, _payload) ->
-          Log.info (fun f -> f "ICMP message: %a" Icmpv4_packet.pp packet);
+         Log.info (fun f -> f "ICMP message: %a" Icmpv4_packet.pp packet);
-          if is_ping_reply src server packet then resp_received := true;
+         if is_ping_reply src server packet then resp_received := true;
-          Lwt.return_unit
+         Lwt.return_unit
    in
    Stack.listen_icmp stack (Some icmp_listener)
@ -192,68 +166,49 @@ struct
    let resp_received = ref false in
    Log.info (fun f -> f "Entering ping test: %s" server);
    ping_denied_listener server resp_received stack;
-    Icmp.write (Stack.icmpv4 stack)
+    Icmp.write (Stack.icmpv4 stack) ~dst:(Ipaddr.V4.of_string_exn server) (make_ping_packet (Cstruct.of_string "hi")) >>= function
-      ~dst:(Ipaddr.V4.of_string_exn server)
+    | Error e -> Log.err (fun f -> f "ping test: error sending ping: %a" Icmp.pp_error e); Lwt.return_unit
      (make_ping_packet (Cstruct.of_string "hi"))
    >>= function
    | Error e ->
        Log.err (fun f -> f "ping test: error sending ping: %a" Icmp.pp_error e);
        Lwt.return_unit
    | Ok () ->
-        Log.info (fun f -> f "ping test: sent ping to %s" server);
+      Log.info (fun f -> f "ping test: sent ping to %s" server);
-        Time.sleep_ns 2_000_000_000L >>= fun () ->
+      Time.sleep_ns 2_000_000_000L >>= fun () ->
-        if !resp_received then
+      (if !resp_received then
-          Log.err (fun f ->
+        Log.err (fun f -> f "ping test failed: server %s got a response, block expected :(" server)
-              f "ping test failed: server %s got a response, block expected :("
+      else
-                server)
+        Log.err (fun f -> f "ping test passed: successfully blocked :)")
-        else Log.err (fun f -> f "ping test passed: successfully blocked :)");
+      );
-        Stack.listen_icmp stack None;
+      Stack.listen_icmp stack None;
-        Lwt.return_unit
+      Lwt.return_unit
  let icmp_error_type stack () =
    let resp_correct = ref false in
    let echo_server = Ipaddr.V4.of_string_exn netvm in
    let icmp_callback ~src ~dst:_ buf =
-      (if Ipaddr.V4.compare src echo_server = 0 then
+      if Ipaddr.V4.compare src echo_server = 0 then begin
-         (* TODO: check that packet is error packet *)
+          (* TODO: check that packet is error packet *)
-         match Icmpv4_packet.Unmarshal.of_cstruct buf with
+          match Icmpv4_packet.Unmarshal.of_cstruct buf with
-         | Error e -> Log.err (fun f -> f "Error parsing icmp packet %s" e)
+          | Error e -> Log.err (fun f -> f "Error parsing icmp packet %s" e)
-         | Ok (packet, _) ->
+          | Ok (packet, _) ->
             (* TODO don't hardcode the numbers, make a datatype *)
-             if
+             if packet.Icmpv4_packet.code = 10 (* unreachable, admin prohibited *)
               packet.Icmpv4_packet.code
               = 10 (* unreachable, admin prohibited *)
             then resp_correct := true
-             else
+             else Log.debug (fun f -> f "Unrelated icmp packet %a" Icmpv4_packet.pp packet)
-               Log.debug (fun f ->
+        end;
                   f "Unrelated icmp packet %a" Icmpv4_packet.pp packet));
      Lwt.return_unit
    in
    let content = Cstruct.of_string "important data" in
    Stack.listen_icmp stack (Some icmp_callback);
-    U.write ~src_port:1337 ~dst:echo_server ~dst_port:1338 (Stack.udpv4 stack)
+    U.write ~src_port:1337 ~dst:echo_server ~dst_port:1338 (Stack.udpv4 stack) content >>= function
-      content
+    | Ok () -> (* .. listener: test with accept rule, if we get reply we're good *)
-    >>= function
+       Time.sleep_ns 1_000_000_000L >>= fun () ->
-    | Ok () ->
+       if !resp_correct
-        (* .. listener: test with accept rule, if we get reply we're good *)
+       then Log.info (fun m -> m "UDP fetch test to port %d succeeded :)" 1338)
-        Time.sleep_ns 1_000_000_000L >>= fun () ->
+       else Log.err (fun f -> f "UDP fetch test to port %d: failed. :( correct response not received" 1338);
-        if !resp_correct then
+       Stack.listen_icmp stack None;
-          Log.info (fun m -> m "UDP fetch test to port %d succeeded :)" 1338)
+       Lwt.return_unit
        else
          Log.err (fun f ->
              f
                "UDP fetch test to port %d: failed. :( correct response not \
                 received"
                1338);
        Stack.listen_icmp stack None;
        Lwt.return_unit
    | Error e ->
-        Log.err (fun f ->
+       Log.err (fun f -> f "UDP fetch test to port %d failed: :( couldn't write the packet: %a"
-            f
+                           1338 U.pp_error e);
-              "UDP fetch test to port %d failed: :( couldn't write the packet: \
+      Lwt.return_unit
               %a"
              1338 U.pp_error e);
        Lwt.return_unit
  let tcp_connect msg server port tcp () =
    Log.info (fun f -> f "Entering tcp connect test: %s:%d" server port);
@ -261,141 +216,98 @@ struct
    let msg' = Printf.sprintf "TCP connect test %s to %s:%d" msg server port in
    T.create_connection tcp (ip, port) >>= function
    | Ok flow ->
-        Log.info (fun f -> f "%s passed :)" msg');
+      Log.info (fun f -> f "%s passed :)" msg');
-        T.close flow
+      T.close flow
-    | Error e ->
+    | Error e -> Log.err (fun f -> f "%s failed: Connection failed (%a) :(" msg' T.pp_error e);
-        Log.err (fun f ->
+      Lwt.return_unit
            f "%s failed: Connection failed (%a) :(" msg' T.pp_error e);
        Lwt.return_unit
  let tcp_connect_denied msg server port tcp () =
    let ip = Ipaddr.V4.of_string_exn server in
-    let msg' =
+    let msg' = Printf.sprintf "TCP connect denied test %s to %s:%d" msg server port in
-      Printf.sprintf "TCP connect denied test %s to %s:%d" msg server port
+    let connect = (T.create_connection tcp (ip, port) >>= function
    | Ok flow ->
      Log.err (fun f -> f "%s failed: Connection should be denied, but was not. :(" msg');
      T.close flow
    | Error e -> Log.info (fun f -> f "%s passed (error text: %a) :)" msg' T.pp_error e);
      Lwt.return_unit)
    in
-    let connect =
+    let timeout = (
      T.create_connection tcp (ip, port) >>= function
      | Ok flow ->
          Log.err (fun f ->
              f "%s failed: Connection should be denied, but was not. :(" msg');
          T.close flow
      | Error e ->
          Log.info (fun f ->
              f "%s passed (error text: %a) :)" msg' T.pp_error e);
          Lwt.return_unit
    in
    let timeout =
      Time.sleep_ns 1_000_000_000L >>= fun () ->
      Log.info (fun f -> f "%s passed :)" msg');
-      Lwt.return_unit
+      Lwt.return_unit)
    in
-    Lwt.pick [ connect; timeout ]
+    Lwt.pick [ connect ; timeout ]
  let udp_fetch ~src_port ~echo_server_port stack () =
-    Log.info (fun f ->
+    Log.info (fun f -> f "Entering udp fetch test: %d -> %s:%d"
-        f "Entering udp fetch test: %d -> %s:%d" src_port netvm echo_server_port);
+                 src_port netvm echo_server_port);
    let resp_correct = ref false in
    let echo_server = Ipaddr.V4.of_string_exn netvm in
    let content = Cstruct.of_string "important data" in
-    let udp_listener : U.callback =
+    let udp_listener : U.callback = (fun ~src ~dst:_ ~src_port buf ->
-     fun ~src ~dst:_ ~src_port buf ->
+        Log.debug (fun f -> f "listen_udpv4 function invoked for packet: %a" Cstruct.hexdump_pp buf);
-      Log.debug (fun f ->
+        if ((0 = Ipaddr.V4.compare echo_server src) && src_port = echo_server_port) then
-          f "listen_udpv4 function invoked for packet: %a" Cstruct.hexdump_pp
+          match Cstruct.equal buf content with
-            buf);
+          | true -> (* yay *)
-      if 0 = Ipaddr.V4.compare echo_server src && src_port = echo_server_port
+            Log.info (fun f -> f "UDP fetch test to port %d: passed :)" echo_server_port);
      then (
        match Cstruct.equal buf content with
        | true ->
            (* yay *)
            Log.info (fun f ->
                f "UDP fetch test to port %d: passed :)" echo_server_port);
            resp_correct := true;
            Lwt.return_unit
-        | false ->
+          | false -> (* oh no *)
-            (* oh no *)
+            Log.err (fun f -> f "UDP fetch test to port %d: failed. :( Packet corrupted; expected %a but got %a"
-            Log.err (fun f ->
+                        echo_server_port Cstruct.hexdump_pp content Cstruct.hexdump_pp buf);
-                f
+            Lwt.return_unit
-                  "UDP fetch test to port %d: failed. :( Packet corrupted; \
+        else
-                   expected %a but got %a"
+          begin
-                  echo_server_port Cstruct.hexdump_pp content Cstruct.hexdump_pp
+            (* disregard this packet *)
-                  buf);
+            Log.debug (fun f -> f "packet is not from the echo server or has the wrong source port (%d but we wanted %d)"
-            Lwt.return_unit)
+                      src_port echo_server_port);
-      else (
+            (* don't cancel the listener, since we want to keep listening *)
-        (* disregard this packet *)
+            Lwt.return_unit
-        Log.debug (fun f ->
+          end
-            f
+      )
              "packet is not from the echo server or has the wrong source port \
               (%d but we wanted %d)"
              src_port echo_server_port);
        (* don't cancel the listener, since we want to keep listening *)
        Lwt.return_unit)
    in
    Stack.listen_udpv4 stack ~port:src_port udp_listener;
-    U.write ~src_port ~dst:echo_server ~dst_port:echo_server_port
+    U.write ~src_port ~dst:echo_server ~dst_port:echo_server_port (Stack.udpv4 stack) content >>= function
-      (Stack.udpv4 stack) content
+    | Ok () -> (* .. listener: test with accept rule, if we get reply we're good *)
-    >>= function
+      Time.sleep_ns 1_000_000_000L >>= fun () ->
-    | Ok () ->
+      Stack.stop_listen_udpv4 stack ~port:src_port;
-        (* .. listener: test with accept rule, if we get reply we're good *)
+      if !resp_correct then Lwt.return_unit else begin
-        Time.sleep_ns 1_000_000_000L >>= fun () ->
+        Log.err (fun f -> f "UDP fetch test to port %d: failed. :( correct response not received" echo_server_port);
        Stack.stop_listen_udpv4 stack ~port:src_port;
        if !resp_correct then Lwt.return_unit
        else (
          Log.err (fun f ->
              f
                "UDP fetch test to port %d: failed. :( correct response not \
                 received"
                echo_server_port);
          Lwt.return_unit)
    | Error e ->
        Log.err (fun f ->
            f
              "UDP fetch test to port %d failed: :( couldn't write the packet: \
               %a"
              echo_server_port U.pp_error e);
        Lwt.return_unit
      end
    | Error e ->
      Log.err (fun f -> f "UDP fetch test to port %d failed: :( couldn't write the packet: %a"
                  echo_server_port U.pp_error e);
      Lwt.return_unit
  let dns_expect_failure ~nameserver ~hostname stack () =
    let lookup = Domain_name.(of_string_exn hostname |> host_exn) in
-    let nameserver' = (`UDP, (Ipaddr.V4.of_string_exn nameserver, 53)) in
+    let nameserver' = `UDP, (Ipaddr.V4.of_string_exn nameserver, 53) in
    let dns = Dns.create ~nameserver:nameserver' stack in
    Dns.gethostbyname dns lookup >>= function
-    | Error (`Msg s) when String.compare s "Truncated UDP response" <> 0 ->
+    | Error (`Msg s) when String.compare s "Truncated UDP response" <> 0 -> Log.debug (fun f -> f "DNS test to %s failed as expected: %s"
-        Log.debug (fun f ->
+                                      nameserver s);
-            f "DNS test to %s failed as expected: %s" nameserver s);
+      Log.info (fun f -> f "DNS traffic to %s correctly blocked :)" nameserver);
-        Log.info (fun f ->
+      Lwt.return_unit
            f "DNS traffic to %s correctly blocked :)" nameserver);
        Lwt.return_unit
    | Error (`Msg s) ->
-        Log.debug (fun f ->
+       Log.debug (fun f -> f "DNS test to %s failed unexpectedly (truncated response): %s :("
-            f "DNS test to %s failed unexpectedly (truncated response): %s :("
+                             nameserver s);
-              nameserver s);
+       Lwt.return_unit
-        Lwt.return_unit
+    | Ok addr -> Log.err (fun f -> f "DNS test to %s should have been blocked, but looked up %s:%a" nameserver hostname Ipaddr.V4.pp addr);
-    | Ok addr ->
+      Lwt.return_unit
        Log.err (fun f ->
            f "DNS test to %s should have been blocked, but looked up %s:%a"
              nameserver hostname Ipaddr.V4.pp addr);
        Lwt.return_unit
  let dns_then_tcp_denied server stack () =
    let parsed_server = Domain_name.(of_string_exn server |> host_exn) in
    (* ask dns about server *)
-    Log.debug (fun f ->
+    Log.debug (fun f -> f "going to make a dns thing using nameserver %s" nameserver_1);
-        f "going to make a dns thing using nameserver %s" nameserver_1);
+    let dns = Dns.create ~nameserver:(`UDP, ((Ipaddr.V4.of_string_exn nameserver_1), 53)) stack in
    let dns =
      Dns.create
        ~nameserver:(`UDP, (Ipaddr.V4.of_string_exn nameserver_1, 53))
        stack
    in
    Log.debug (fun f -> f "OK, going to look up %s now" server);
    Dns.gethostbyname dns parsed_server >>= function
-    | Error (`Msg s) ->
+    | Error (`Msg s) -> Log.err (fun f -> f "couldn't look up ip for %s: %s" server s); Lwt.return_unit
        Log.err (fun f -> f "couldn't look up ip for %s: %s" server s);
        Lwt.return_unit
    | Ok addr ->
-        Log.debug (fun f ->
+      Log.debug (fun f -> f "looked up ip for %s: %a" server Ipaddr.V4.pp addr);
-            f "looked up ip for %s: %a" server Ipaddr.V4.pp addr);
+      Log.err (fun f -> f "Do more stuff here!!!! :(");
-        Log.err (fun f -> f "Do more stuff here!!!! :(");
+      Lwt.return_unit
        Lwt.return_unit
  let start _random _time _clock network db =
    E.connect network >>= fun ethernet ->
@ -404,64 +316,42 @@ struct
    Icmp.connect ipv4 >>= fun icmp ->
    U.connect ipv4 >>= fun udp ->
    T.connect ipv4 >>= fun tcp ->
-    let stack = Stack.connect network ethernet arp ipv4 icmp udp tcp in
+
    let stack = Stack.connect network ethernet arp ipv4 icmp udp tcp  in
    Lwt.async (fun () -> Stack.listen stack);
    (* put this first because tcp_connect_denied tests also generate icmp messages *)
-    let general_tests : unit Alcotest.test =
+    let general_tests : unit Alcotest.test = ("firewall tests", [
-      ( "firewall tests",
+        ("UDP fetch", `Quick,  udp_fetch ~src_port:9090 ~echo_server_port:1235 stack);
-        [
+        ("Ping expect failure", `Quick, ping_expect_failure "8.8.8.8" stack );
-          ( "UDP fetch",
+        (* TODO: ping_expect_success to the netvm, for which we have an icmptype rule in update-firewall.sh *)
-            `Quick,
+        ("ICMP error type", `Quick, icmp_error_type stack)
-            udp_fetch ~src_port:9090 ~echo_server_port:1235 stack );
+       ] ) in
          ("Ping expect failure", `Quick, ping_expect_failure "8.8.8.8" stack);
          (* TODO: ping_expect_success to the netvm, for which we have an icmptype rule in update-firewall.sh *)
          ("ICMP error type", `Quick, icmp_error_type stack);
        ] )
    in
    Alcotest.run ~and_exit:false "name" [ general_tests ] >>= fun () ->
-    let tcp_tests : unit Alcotest.test =
+    let tcp_tests : unit Alcotest.test = ("tcp tests", [
-      ( "tcp tests",
+        (* this test fails on 4.0R3
        [
          (* this test fails on 4.0R3
        ("TCP connect", `Quick, tcp_connect "when trying specialtarget" nameserver_1 53 tcp); *)
-          ("TCP connect", `Quick, tcp_connect_denied "" netvm 53 tcp);
+        ("TCP connect", `Quick, tcp_connect_denied "" netvm 53 tcp);
-          ( "TCP connect",
+        ("TCP connect", `Quick, tcp_connect_denied "when trying below range" netvm 6667 tcp);
-            `Quick,
+        ("TCP connect", `Quick, tcp_connect "when trying lower bound in range" netvm 6668 tcp);
-            tcp_connect_denied "when trying below range" netvm 6667 tcp );
+        ("TCP connect", `Quick, tcp_connect "when trying upper bound in range" netvm 6670 tcp);
-          ( "TCP connect",
+        ("TCP connect", `Quick, tcp_connect_denied "when trying above range" netvm 6671 tcp);
-            `Quick,
+        ("TCP connect", `Quick, tcp_connect_denied "" netvm 8082 tcp);
-            tcp_connect "when trying lower bound in range" netvm 6668 tcp );
+      ] ) in
          ( "TCP connect",
            `Quick,
            tcp_connect "when trying upper bound in range" netvm 6670 tcp );
          ( "TCP connect",
            `Quick,
            tcp_connect_denied "when trying above range" netvm 6671 tcp );
          ("TCP connect", `Quick, tcp_connect_denied "" netvm 8082 tcp);
        ] )
    in
    (* replace the udp-related listeners with the right one for tcp *)
    Alcotest.run "name" [ tcp_tests ] >>= fun () ->
    (* use the stack abstraction only after the other tests have run, since it's not friendly with outside use of its modules *)
-    let stack_tests =
+    let stack_tests = "stack tests", [
-      ( "stack tests",
+        ("DNS expect failure", `Quick, dns_expect_failure ~nameserver:"8.8.8.8" ~hostname:"mirage.io" stack);
-        [
+
-          ( "DNS expect failure",
+        (* the test below won't work on @linse's internet,
            `Quick,
            dns_expect_failure ~nameserver:"8.8.8.8" ~hostname:"mirage.io" stack
          );
          (* the test below won't work on @linse's internet,
         * because the nameserver there doesn't answer on TCP port 53,
         * only UDP port 53.  Dns_mirage_client.ml disregards our request
         * to use UDP and uses TCP anyway, so this request can never work there. *)
-          (* If we can figure out a way to have this test unikernel do a UDP lookup with minimal pain,
+        (* If we can figure out a way to have this test unikernel do a UDP lookup with minimal pain,
         * we should re-enable this test. *)
-          ( "DNS lookup + TCP connect",
+        ("DNS lookup + TCP connect", `Quick, dns_then_tcp_denied "google.com" stack);
-            `Quick,
+      ] in
            dns_then_tcp_denied "google.com" stack );
        ] )
    in
    Alcotest.run "name" [ stack_tests ]
 end
--- a/unikernel.ml
+++ b/unikernel.ml
@ -6,121 +6,115 @@ open Qubes
 open Cmdliner
 let src = Logs.Src.create "unikernel" ~doc:"Main unikernel code"
 module Log = (val Logs.src_log src : Logs.LOG)
 let nat_table_size =
-  let doc =
+  let doc = Arg.info ~doc:"The number of NAT entries to allocate." [ "nat-table-size" ] in
-    Arg.info ~doc:"The number of NAT entries to allocate." [ "nat-table-size" ]
+  Arg.(value & opt int 5_000 doc)
  in
  Mirage_runtime.register_arg Arg.(value & opt int 5_000 doc)
 let ipv4 =
  let doc = Arg.info ~doc:"Manual IP setting." [ "ipv4" ] in
-  Mirage_runtime.register_arg Arg.(value & opt string "0.0.0.0" doc)
+  Arg.(value & opt string "0.0.0.0" doc)
 let ipv4_gw =
  let doc = Arg.info ~doc:"Manual Gateway IP setting." [ "ipv4-gw" ] in
-  Mirage_runtime.register_arg Arg.(value & opt string "0.0.0.0" doc)
+  Arg.(value & opt string "0.0.0.0" doc)
 let ipv4_dns =
  let doc = Arg.info ~doc:"Manual DNS IP setting." [ "ipv4-dns" ] in
-  Mirage_runtime.register_arg Arg.(value & opt string "10.139.1.1" doc)
+  Arg.(value & opt string "10.139.1.1" doc)
 let ipv4_dns2 =
  let doc = Arg.info ~doc:"Manual Second DNS IP setting." [ "ipv4-dns2" ] in
-  Mirage_runtime.register_arg Arg.(value & opt string "10.139.1.2" doc)
+  Arg.(value & opt string "10.139.1.2" doc)
-module Dns_client = Dns_client.Make (My_dns)
+module Main (R : Mirage_random.S)(Clock : Mirage_clock.MCLOCK)(Time : Mirage_time.S) = struct
  module Dispatcher = Dispatcher.Make(R)(Clock)(Time)
  module Dns_transport = My_dns.Transport(R)(Clock)(Time)
  module Dns_client = Dns_client.Make(Dns_transport)
-(* Set up networking and listen for incoming packets. *)
+  (* Set up networking and listen for incoming packets. *)
-let network dns_client dns_responses dns_servers qubesDB router =
+  let network dns_client dns_responses dns_servers qubesDB router =
-  (* Report success *)
+    (* Report success *)
-  Dao.set_iptables_error qubesDB "" >>= fun () ->
+    Dao.set_iptables_error qubesDB "" >>= fun () ->
-  (* Handle packets from both networks *)
+    (* Handle packets from both networks *)
-  Lwt.choose
+    Lwt.choose [
-    [
+      Dispatcher.wait_clients Clock.elapsed_ns dns_client dns_servers qubesDB router ;
-      Dispatcher.wait_clients Mirage_mtime.elapsed_ns dns_client dns_servers
+      Dispatcher.uplink_wait_update qubesDB router ;
-        qubesDB router;
+      Dispatcher.uplink_listen Clock.elapsed_ns dns_responses router
      Dispatcher.uplink_wait_update qubesDB router;
      Dispatcher.uplink_listen Mirage_mtime.elapsed_ns dns_responses router;
    ]
-(* Main unikernel entry point (called from auto-generated main.ml). *)
+  (* Main unikernel entry point (called from auto-generated main.ml). *)
-let start () =
+  let start _random _clock _time nat_table_size ipv4 ipv4_gw ipv4_dns ipv4_dns2 =
-  let open Lwt.Syntax in
+    let start_time = Clock.elapsed_ns () in
-  let start_time = Mirage_mtime.elapsed_ns () in
+    (* Start qrexec agent and QubesDB agent in parallel *)
-  (* Start qrexec agent and QubesDB agent in parallel *)
+    let qrexec = RExec.connect ~domid:0 () in
-  let* qrexec = RExec.connect ~domid:0 () in
+    let qubesDB = DB.connect ~domid:0 () in
  let agent_listener = RExec.listen qrexec Command.handler in
  let* qubesDB = DB.connect ~domid:0 () in
  let startup_time =
    let ( - ) = Int64.sub in
    let time_in_ns = Mirage_mtime.elapsed_ns () - start_time in
    Int64.to_float time_in_ns /. 1e9
  in
  Log.info (fun f ->
      f "QubesDB and qrexec agents connected in %.3f s" startup_time);
  (* Watch for shutdown requests from Qubes *)
  let shutdown_rq =
    Xen_os.Lifecycle.await_shutdown_request () >>= fun (`Poweroff | `Reboot) ->
    Lwt.return_unit
  in
  (* Set up networking *)
  let nat = My_nat.create ~max_entries:(nat_table_size ()) in
-  let netvm_ip = Ipaddr.V4.of_string_exn (ipv4_gw ()) in
+    (* Wait for clients to connect *)
-  let our_ip = Ipaddr.V4.of_string_exn (ipv4 ()) in
+    qrexec >>= fun qrexec ->
-  let dns = Ipaddr.V4.of_string_exn (ipv4_dns ()) in
+    let agent_listener = RExec.listen qrexec Command.handler in
-  let dns2 = Ipaddr.V4.of_string_exn (ipv4_dns2 ()) in
+    qubesDB >>= fun qubesDB ->
    let startup_time =
      let (-) = Int64.sub in
      let time_in_ns = Clock.elapsed_ns () - start_time in
      Int64.to_float time_in_ns /. 1e9
    in
    Log.info (fun f -> f "QubesDB and qrexec agents connected in %.3f s" startup_time);
    (* Watch for shutdown requests from Qubes *)
    let shutdown_rq =
      Xen_os.Lifecycle.await_shutdown_request () >>= fun (`Poweroff | `Reboot) ->
      Lwt.return_unit in
    (* Set up networking *)
    let nat = My_nat.create ~max_entries:nat_table_size in
-  let zero_ip = Ipaddr.V4.any in
+    let netvm_ip = Ipaddr.V4.of_string_exn ipv4_gw in
    let our_ip = Ipaddr.V4.of_string_exn ipv4 in
    let dns = Ipaddr.V4.of_string_exn ipv4_dns in
    let dns2 = Ipaddr.V4.of_string_exn ipv4_dns2 in
    let zero_ip = (Ipaddr.V4.make 0 0 0 0) in
    let network_config  =
      if (netvm_ip = zero_ip && our_ip = zero_ip) then (* Read network configuration from QubesDB *)
        Dao.read_network_config qubesDB >>= fun config ->
        if config.netvm_ip = zero_ip || config.our_ip = zero_ip then
          Log.info (fun f -> f "We currently have no netvm nor command line for setting it up, aborting...");
        assert (config.netvm_ip <> zero_ip && config.our_ip <> zero_ip);
        Lwt.return config
      else begin
        let config:Dao.network_config = {from_cmdline=true; netvm_ip; our_ip; dns; dns2} in
        Lwt.return config
      end
    in
    network_config >>= fun config ->
-  let network_config =
+    (* We now must have a valid netvm IP address and our IP address or crash *)
-    if netvm_ip = zero_ip && our_ip = zero_ip then (
+    Dao.print_network_config config ;
      (* Read network configuration from QubesDB *)
      Dao.read_network_config qubesDB
      >>= fun config ->
      if config.netvm_ip = zero_ip || config.our_ip = zero_ip then
        Log.info (fun f ->
            f
              "We currently have no netvm nor command line for setting it up, \
               aborting...");
      assert (config.netvm_ip <> zero_ip && config.our_ip <> zero_ip);
      Lwt.return config)
    else
      let config : Dao.network_config =
        { from_cmdline = true; netvm_ip; our_ip; dns; dns2 }
      in
      Lwt.return config
  in
  network_config >>= fun config ->
  (* We now must have a valid netvm IP address and our IP address or crash *)
  Dao.print_network_config config;
-  (* Set up client-side networking *)
+    (* Set up client-side networking *)
-  let* clients = Client_eth.create config in
+    Client_eth.create config >>= fun clients ->
-  (* Set up routing between networks and hosts *)
+    (* Set up routing between networks and hosts *)
-  let router = Dispatcher.create ~config ~clients ~nat ~uplink:None in
+    let router = Dispatcher.create
      ~config
      ~clients
      ~nat
      ~uplink:None
    in
-  let send_dns_query = Dispatcher.send_dns_client_query router in
+    let send_dns_query = Dispatcher.send_dns_client_query None in
-  let dns_mvar = Lwt_mvar.create_empty () in
+    let dns_mvar = Lwt_mvar.create_empty () in
-  let nameservers = (`Udp, [ (config.Dao.dns, 53); (config.Dao.dns2, 53) ]) in
+    let nameservers = `Udp, [ config.Dao.dns, 53 ; config.Dao.dns2, 53 ] in
-  let dns_client =
+    let dns_client = Dns_client.create ~nameservers (router, send_dns_query, dns_mvar) in
    Dns_client.create ~nameservers (router, send_dns_query, dns_mvar)
  in
-  let dns_servers = [ config.Dao.dns; config.Dao.dns2 ] in
+    let dns_servers = [ config.Dao.dns ; config.Dao.dns2 ] in
-  let net_listener =
+    let net_listener = network (Dns_client.getaddrinfo dns_client Dns.Rr_map.A) dns_mvar dns_servers qubesDB router in
    network
      (Dns_client.getaddrinfo dns_client Dns.Rr_map.A)
      dns_mvar dns_servers qubesDB router
  in
-  (* Report memory usage to XenStore *)
+    (* Report memory usage to XenStore *)
-  Memory_pressure.init ();
+    Memory_pressure.init ();
-  (* Run until something fails or we get a shutdown request. *)
+    (* Run until something fails or we get a shutdown request. *)
-  Lwt.choose [ agent_listener; net_listener; shutdown_rq ] >>= fun () ->
+    Lwt.choose [agent_listener; net_listener; shutdown_rq] >>= fun () ->
-  (* Give the console daemon time to show any final log messages. *)
+    (* Give the console daemon time to show any final log messages. *)
-  Mirage_sleep.ns (1.0 *. 1e9 |> Int64.of_float)
+    Time.sleep_ns (1.0 *. 1e9 |> Int64.of_float)
 end
		`@ -1 +0,0 @@`
			`0c3c2c0e62a834112c69d7cddc5dd6f70ecb93afa988768fb860ed26e423b1f8 dist/qubes-firewall.xen`
		`@ -1 +0,0 @@`
			`ac049069b35f786fa11b18a2261d7dbecd588301af0363ef6888ec9d924dc989 dist/qubes-firewall.xen`