add pppoe

README.md

@@ -95,3 +95,5 @@ took full advantage of the basic application armoring features
 provided by the operating system. Indeed, only one or two models even
 came close, and no brand did well consistently across all models
 tested"
+
+* [A PPPoE Implementation for Linux](https://static.usenix.org/publications/library/proceedings/als00/2000papers/papers/full_papers/skoll/skoll_html/index.html): "Many DSL service providers use PPPoE for residential broadband Internet access. This paper briefly describes the PPPoE protocol, presents strategies for implementing it under Linux and describes in detail a user-space implementation of a PPPoE client."

overlay.nix

@@ -3,4 +3,50 @@ final: prev: {
   s6-init-files = final.callPackage ./pkgs/s6-init-files {};
   strace = prev.strace.override { libunwind = null; };
   liminix = final.callPackage ./pkgs/liminix-tools {};
+  pppoe = prev.rpPPPoE.overrideAttrs (o: {
+    # use newer rp-pppoe, it builds cleanly
+    src = final.fetchFromGitHub {
+      owner = "dfskoll";
+      repo = "rp-pppoe";
+      rev = "7cfd8c0405d14cf1c8d799d41d8207fd707979c1";
+      hash = "sha256-MFdCwNj8c52blxEuXH5ltT2yYDmKMH5MLUgtddZV25E=";
+    };
+  });
+  ppp =
+    (prev.ppp.override {
+      libpcap = null;
+    }).overrideAttrs (o : {
+      stripAllList = [ "bin" ];
+      buildInputs = [];
+
+      # patches =
+      #   o.patches ++
+      #   [(final.fetchpatch {
+      #     name = "ipv6-script-options.patch";
+      #     url = "https://github.com/ppp-project/ppp/commit/874c2a4a9684bf6938643c7fa5ff1dd1cf80aea4.patch";
+      #     sha256 = "sha256-K46CKpDpm1ouj6jFtDs9IUMHzlRMRP+rMPbMovLy3o4=";
+      #   })];
+
+      postPatch = ''
+        sed -i -e  's@_PATH_VARRUN@"/run/"@'  pppd/main.c
+        sed -i -e  's@^FILTER=y@# FILTER unset@'  pppd/Makefile.linux
+        sed -i -e  's/-DIPX_CHANGE/-UIPX_CHANGE/g'  pppd/Makefile.linux
+      '';
+      buildPhase = ''
+        runHook preBuild
+        make -C pppd CC=$CC USE_TDB= HAVE_MULTILINK= USE_EAPTLS= USE_CRYPT=y
+        make -C pppd/plugins/pppoe CC=$CC
+        make -C pppd/plugins/pppol2tp CC=$CC
+        runHook postBuild;
+      '';
+      installPhase = ''
+        runHook preInstall
+        mkdir -p $out/bin $out/lib/pppd/2.4.9
+        cp pppd/pppd pppd/plugins/pppoe/pppoe-discovery $out/bin
+        cp pppd/plugins/pppoe/pppoe.so $out/lib/pppd/2.4.9
+        cp pppd/plugins/pppol2tp/{open,pppo}l2tp.so $out/lib/pppd/2.4.9
+        runHook postInstall
+      '';
+      postFixup = "";
+    });
 }

pkgs/liminix-tools/default.nix

@@ -77,6 +77,7 @@ in {
       name = "${interface.device}.odhcp";
       run = "odhcpcd ${interface.device}";
     };
+    pppoe = callPackage ./networking/pppoe.nix {};
   };
   services = {
     inherit longrun oneshot bundle target;

pkgs/liminix-tools/networking/pppoe.nix

@@ -0,0 +1,48 @@
+{
+  liminix
+, lib
+, busybox
+, ppp
+, pppoe
+, writeShellScript
+} :
+let
+  inherit (liminix.services) longrun;
+  ip-up = writeShellScript "ip-up" ''
+action=$1
+env > /run/udhcp.values
+
+set_address() {
+    ip address replace $ip/$mask dev $interface
+    mkdir -p data/outputs
+    for i in lease mask ip router siaddr dns serverid subnet opt53 interface ; do
+        echo ''${!i} > data/outputs/$i
+    done
+}
+case $action in
+  deconfig)
+    ip address flush $interface
+    ip link set up dev $interface
+    ;;
+  bound)
+    # this doesn't actually replace, it adds a new address.
+    set_address
+    ;;
+  renew)
+    set_address
+    ;;
+  nak)
+    echo "received NAK on $interface"
+    ;;
+esac
+'';
+
+in
+interface: {
+  synchronous ? false
+, ppp-options ? []
+, ...
+} @ args: longrun {
+  name = "${interface.device}.ppppoe";
+  run = "${ppp}/bin/pppd pty '${pppoe}/bin/pppoe -I ${interface.device}' ${lib.concatStringsSep " " ppp-options}" ;
+}

tests/pppoe/configuration.nix

@@ -0,0 +1,47 @@
+{ config, pkgs, ... } :
+let
+  inherit (pkgs.liminix.networking) interface address pppoe;
+  inherit (pkgs.liminix.services) oneshot longrun bundle target output;
+in rec {
+  services.loopback =
+    let iface = interface { type = "loopback"; device = "lo";};
+    in bundle {
+      name = "loopback";
+      contents = [
+        (address iface { family = "inet4"; addr ="127.0.0.1";})
+        (address iface { family = "inet6"; addr ="::1";})
+      ];
+    };
+
+  kernel.config = {
+    "PPP" = "y";
+    "PPPOE" = "y";
+    "PPPOL2TP" = "y";
+  };
+
+  services.pppoe =
+    let iface = interface { type = "hardware"; device = "eth0"; };
+    in pppoe iface {};
+
+  services.defaultroute4 =
+    let iface = services.pppoe;
+    in oneshot {
+      name = "defaultroute4";
+      up = ''
+        ip route add default gw $(cat ${output iface "address"})
+        echo "1" > /sys/net/ipv4/$(cat ${output iface "ifname"})
+      '';
+      down = ''
+        ip route del default gw $(cat ${output iface "address"})
+        echo "0" > /sys/net/ipv4/$(cat ${output iface "ifname"})
+      '';
+      dependencies = [iface];
+    };
+
+  services.default = target {
+    name = "default";
+    contents = with services; [ loopback defaultroute4 ];
+  };
+
+  systemPackages = [ pkgs.hello ] ;
+}

tests/pppoe/run.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env sh
+
+
+set -e
+
+cleanup(){
+    echo "do cleanup";
+}
+trap cleanup EXIT
+trap 'echo "command $(eval echo $BASH_COMMAND) failed with exit code $?"; exit $?' ERR
+
+NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1 nix-build '<liminix>' -I liminix-config=./configuration.nix --arg device "import <liminix/devices/qemu.nix>" -A outputs.default $*
+
+
+if ! ( echo "cont" | socat -   unix-connect:../support/ppp-server/qemu-monitor); then
+    echo "need pppoe server running"
+    exit 1
+fi
+
+../../scripts/run-qemu.sh result/vmlinux result/squashfs