make "shutdown" work

create a package for the s6-compatible shutdown/halt/poweroff
commands and put it on the path ahead of busybox

THOUGHTS.txt

@@ -75,7 +75,7 @@ Sun Sep 25 20:56:28 BST 2022
 
 TODO - bugs, missing bits, other infelicities as they occur to me:
 
-1) shutdown doesn't work as its using the busybox one not s6.
+DONE 1) shutdown doesn't work as its using the busybox one not s6.
 
 2) perhaps we shouldn't have process-based services like dhcp, ppp
 implement "address provider interface" - instead have a separate
@@ -102,7 +102,7 @@ look for obvious wastes of space
 8) some of configuration.nix (e.g. defining routes) should be moved into
 tools
 
-9) split tools up instead of having it all one file
+DONE 9) split tools up instead of having it all one file
 
 10) is it OK to depend on squashfs pseudofiles if we might want to
 switch to ubifs? will there always be a squashfs underneath? might
@@ -120,10 +120,12 @@ we want to change the pseudofiles in an overlay?
 is that specified or fluke?
 
 16) tighten up the module specs. (DONE) services.foo should be a s6-rc
-service, kernel config should be checked in some way
+service, (DONE) kernel config should be checked in some way
 
 DONE 17) rename nixwrt references in kernel builder
 
 18) maybe stop suffixing all the service names with .service
 
+19) syslogd - use busybox or s6?
+
 chat -s -S ogin:--ogin: root / "ip address show dev ppp0 | grep ppp0" 192.168.100.1  "/nix/store/*-s6-linux-init-*/bin/s6-linux-init-hpr -p"

make-image.nix

@@ -39,7 +39,7 @@ let
   };
   s6-pseudofiles = pkgs.s6-init-files;
   profile  = writeScript ".profile" ''
-    PATH=${lib.makeBinPath (with pkgs; [busybox execline s6-linux-init s6-rc])}
+    PATH=${lib.makeBinPath (with pkgs; [ s6-init-bin busybox execline s6-linux-init s6-rc])}
     export PATH
   '';
   pseudofiles = writeText "pseudofiles" ''
@@ -60,7 +60,7 @@ let
      /sys d 0555 root root
      /dev/pts d 0755 0 0
      /etc/init.d d 0755 0 0
-     /bin/init s 0755 0 0 /etc/s6-linux-init/current/bin/init
+     /bin/init s 0755 0 0 ${pkgs.s6-init-bin}/bin/init
      /bin/sh s 0755 0 0 ${pkgs.pkgsStatic.busybox}/bin/sh
      /bin/busybox s 0755 0 0 ${pkgs.busybox}/bin/busybox
      /etc/s6-rc d 0755 0 0

modules/base.nix

@@ -15,8 +15,15 @@ in {
     services = mkOption {
       type = types.attrsOf type_service;
     };
-    kernel = mkOption {
+    kernel = {
-      type = types.anything;
+      config = mkOption {
+        # mostly the values are y n or m, but sometimes
+        # other strings are also used
+        type = types.attrsOf types.nonEmptyStr;
+      };
+      checkedConfig = mkOption {
+        type = types.attrsOf types.nonEmptyStr;
+      };
     };
   };
 }

overlay.nix

@@ -2,9 +2,14 @@ final: prev: {
   pseudofile = final.callPackage ./pkgs/pseudofile {};
   s6-init-files = final.callPackage ./pkgs/s6-init-files {};
   strace = prev.strace.override { libunwind = null; };
-  liminix = final.callPackage ./pkgs/liminix-tools {};
+  liminix = {
+    services = final.callPackage ./pkgs/liminix-tools/services {};
+    networking =  final.callPackage ./pkgs/liminix-tools/networking {};
+  };
   writeAshScript = final.callPackage ./pkgs/write-ash-script {};
 
+  s6-init-bin =  final.callPackage ./pkgs/s6-init-bin {};
+
   pppoe = prev.rpPPPoE.overrideAttrs (o: {
     # use newer rp-pppoe, it builds cleanly
     src = final.fetchFromGitHub {

pkgs/liminix-tools/networking/default.nix

@@ -0,0 +1,39 @@
+{
+  callPackage
+, liminix
+}:
+let inherit (liminix.services) oneshot longrun;
+in {
+  interface = { type, device }  @ args: oneshot {
+    name = "${device}.link";
+    up = "ip link set up dev ${device}";
+    down = "ip link set down dev ${device}";
+  } // {
+    inherit device;
+  };
+  address = interface: { family, prefixLength, address } @ args:
+    let inherit (builtins) toString;
+    in oneshot {
+      dependencies = [ interface ];
+      name = "${interface.device}.addr.${address}";
+      up = "ip address add ${address}/${toString prefixLength} dev ${interface.device} ";
+      down = "ip address del ${address}/${toString prefixLength} dev ${interface.device} ";
+    };
+  udhcpc = callPackage ./udhcpc.nix {};
+  odhcpc = interface: { ... } @ args: longrun {
+    name = "${interface.device}.odhcp";
+    run = "odhcpcd ${interface.device}";
+  };
+  pppoe = callPackage ./pppoe.nix {};
+  route = { name, target, via, dependencies }:
+    oneshot {
+      inherit name;
+      up = ''
+        ip route add ${target} via ${via}
+      '';
+      down = ''
+        ip route del ${target} via ${via}
+      '';
+      inherit dependencies;
+    };
+}

pkgs/liminix-tools/services/default.nix

@@ -5,8 +5,10 @@
 , busybox
 , callPackage
 , writeAshScript
-} :let
+}:
+let
   inherit (builtins) concatStringsSep;
+  output = service: name: "/run/service-state/${service.name}/${name}";
   longrun = {
     name
     , run
@@ -61,33 +63,6 @@
     builder = ./builder.sh;
   };
   bundle = { name, ... } @args : target (args // { name = "${name}.bundle";});
-
 in {
-  networking = {
+  inherit target bundle oneshot longrun output;
-    interface = { type, device }  @ args: oneshot {
-      name = "${device}.link";
-      up = "ip link set up dev ${device}";
-      down = "ip link set down dev ${device}";
-    } // {
-      inherit device;
-    };
-    address = interface: { family, prefixLength, address } @ args:
-      let inherit (builtins) toString;
-      in oneshot {
-        dependencies = [ interface ];
-        name = "${interface.device}.addr.${address}";
-        up = "ip address add ${address}/${toString prefixLength} dev ${interface.device} ";
-        down = "ip address del ${address}/${toString prefixLength} dev ${interface.device} ";
-      };
-    udhcpc = callPackage ./networking/udhcpc.nix {};
-    odhcpc = interface: { ... } @ args: longrun {
-      name = "${interface.device}.odhcp";
-      run = "odhcpcd ${interface.device}";
-    };
-    pppoe = callPackage ./networking/pppoe.nix {};
-  };
-  services = {
-    inherit longrun oneshot bundle target;
-    output = service: name: "/run/service-state/${service.name}/${name}";
-  };
 }

pkgs/s6-init-bin/default.nix

@@ -0,0 +1,33 @@
+{
+  s6-linux-init
+, execline
+, writeScript
+, stdenvNoCC
+, lib
+, busybox
+, s6-rc
+}:
+let
+  hpr = name: arg: writeScript name ''
+    #!${execline}/bin/execlineb -S0
+    ${s6-linux-init}/bin/s6-linux-init-hpr ${arg} \$@
+  '';
+  init = writeScript "init" ''
+    #!${execline}/bin/execlineb -S0
+    ${s6-linux-init}/bin/s6-linux-init -c /etc/s6-linux-init/current -m 0022 -p ${lib.makeBinPath [busybox execline s6-linux-init s6-rc]}:/usr/bin:/bin -d /dev -- "\$@"
+  '';
+in stdenvNoCC.mkDerivation {
+  name = "s6-init-bin";
+  phases = ["installPhase"];
+  installPhase = ''
+    bin=$out/bin
+    mkdir -p $bin
+    cd $bin
+    ln -s ${s6-linux-init}/bin/s6-linux-init-shutdown shutdown
+    ln -s ${s6-linux-init}/bin/s6-linux-init-telinit telinit
+    ln -s ${hpr "reboot" "-r"} reboot
+    ln -s ${hpr "poweroff" "-p"} poweroff
+    ln -s ${hpr "halt" "-h"} halt
+    ln -s ${init} init
+  '';
+}

pkgs/s6-init-files/default.nix

@@ -23,18 +23,6 @@ let
   };
   dir = contents: { type = "d"; inherit contents; };
   symlink = target: { type = "s"; inherit target; };
-  hpr = arg: "#!${execline}/bin/execlineb -S0\n${s6-linux-init}/bin/s6-linux-init-hpr ${arg} \$@";
-  bin = dir {
-    shutdown = symlink "${s6-linux-init}/bin/s6-linux-init-shutdown";
-    telinit = symlink "${s6-linux-init}/bin/s6-linux-init-telinit";
-    reboot = { type="f"; file = hpr "-r"; mode="0755"; };
-    poweroff = { type="f"; file = hpr "-p"; mode="0755"; };
-    halt = { type="f"; file = hpr "-h"; mode="0755"; };
-    init = {
-      type="f"; mode="0755";
-      file = "#!${execline}/bin/execlineb -S0\n${s6-linux-init}/bin/s6-linux-init -c /etc/s6-linux-init/current -m 0022 -p ${lib.makeBinPath [busybox execline s6-linux-init s6-rc]}:/usr/bin:/bin -d /dev -- \"\\$@\"";
-    };
-  };
   scripts = symlink "${initscripts}/scripts";
   env = dir {};
   run-image = dir {
@@ -150,7 +138,7 @@ let
     uncaught-logs = (dir {}) // {mode = "2750";};
   };
   structure = { etc = dir { s6-linux-init = dir { current = dir {
-    inherit bin scripts env run-image;
+    inherit scripts env run-image;
   };};};};
 
 in pseudofile "pseudo.s6-init" structure

tests/pppoe/configuration.nix

@@ -1,6 +1,6 @@
 { config, pkgs, ... } :
 let
-  inherit (pkgs.liminix.networking) interface address pppoe;
+  inherit (pkgs.liminix.networking) interface address pppoe route;
   inherit (pkgs.liminix.services) oneshot longrun bundle target output;
 in rec {
   services.loopback =
@@ -40,24 +40,32 @@ in rec {
       ];
     };
 
-  services.defaultroute4 =
+  services.defaultroute4 = route {
-    let iface = services.pppoe;
+    name = "defautlrote";
+    via = "$(cat ${output services.pppoe "address"})";
+    target = "default";
+    dependencies = [ services.pppoe ];
+  };
+
+  services.packet_forwarding =
+    let
+      iface = services.pppoe;
+      filename = "/proc/sys/net/ipv4/conf/$(cat ${output iface "ifname"})/forwarding";
     in oneshot {
-      name = "defaultroute4";
+      name = "let-the-ip-flow";
-      up = ''
+      up = "echo 1 > ${filename}";
-        ip route add default via $(cat ${output iface "address"})
+      down = "echo 0 > ${filename}";
-        echo "1" > /proc/sys/net/ipv4/conf/$(cat ${output iface "ifname"}/forwarding)
-      '';
-      down = ''
-        ip route del default via $(cat ${output iface "address"})
-        echo "0" > /proc/sys/net/ipv4/conf/$(cat ${output iface "ifname"}/forwarding)
-      '';
       dependencies = [iface];
     };
 
   services.default = target {
     name = "default";
-    contents = with services; [ loopback defaultroute4 syslogd ];
+    contents = with services; [
+      loopback
+      defaultroute4
+      packet_forwarding
+      syslogd
+    ];
   };
 
   systemPackages = [ pkgs.hello ] ;

tests/pppoe/getaddress.expect

@@ -12,6 +12,7 @@ while { $FINISHED < 5 } {
   expect {
     "192.168.100.1" { set FINISHED 10; set EXIT 0; }
     "can't find device" { send_user "waiting ..." ; send "\r\n"; sleep 3 }
+    "DOWN" { send_user "waiting ..." ; send "\r\n"; sleep 2 }
   }
   set FINISHED [ expr $FINISHED + 1 ]
 }

tests/smoke/configuration.nix

@@ -1,6 +1,6 @@
 { config, pkgs, ... } :
 let
-  inherit (pkgs.liminix.networking) interface address udhcpc odhcpc;
+  inherit (pkgs.liminix.networking) interface address udhcpc odhcpc route;
   inherit (pkgs.liminix.services) oneshot longrun bundle target output;
 in rec {
   services.loopback =
@@ -40,18 +40,22 @@ in rec {
     dependencies = [services.dhcpv4];
   };
 
-  services.defaultroute4 =
+  services.defaultroute4 = route {
-    let inherit (services) dhcpv4;
+    name = "defautlrote";
+    via = "$(cat ${output services.dhcpv4 "address"})";
+    target = "default";
+    dependencies = [ services.dhcpv4 ];
+  };
+
+  services.packet_forwarding =
+    let
+      iface = services.dhcpv4;
+      filename = "/proc/sys/net/ipv4/conf/$(cat ${output iface "ifname"})/forwarding";
     in oneshot {
-      name = "defaultroute4";
+      name = "let-the-ip-flow";
-      up = ''
+      up = "echo 1 > ${filename}";
-        ip route add default gw $(cat ${output dhcpv4 "address"})
+      down = "echo 0 > ${filename}";
-        echo "1" > /sys/net/ipv4/$(cat ${output dhcpv4 "ifname"})
+      dependencies = [iface];
-      '';
-      down = ''
-        ip route del default gw $(cat ${output dhcpv4 "address"})
-        echo "0" > /sys/net/ipv4/$(cat ${output dhcpv4 "ifname"})
-      '';
     };
 
   services.default = target {