convert network link/address to module-based-service

... and make bridge use it.

We also had to convert bridge back into a pair of services.
Downstreams want to depend on the bridge it self being configured
even if not necessarily all the members are up. e.g. don't want
to break ssh on lan if there's a misconfigured wlan device

devices/gl-ar750/default.nix

@@ -80,6 +80,8 @@
       inherit (pkgs.pseudofile) dir symlink;
       inherit (pkgs.liminix.networking) interface;
     in {
+      imports = [ ../../modules/network];
+
       programs.busybox.options = {
         FEATURE_DD_IBS_OBS = "y"; # ath10k_cal_data needs skip_bytes,fullblock
       };
@@ -100,16 +102,17 @@
           ];
         };
 
-        networkInterfaces = {
-          lan = interface { device = "eth0"; };
-          wan = interface { device = "eth1"; };
-
-          wlan_24 = interface {
-            device = "wlan0";
+        networkInterfaces =
+          let inherit (config.system.service.network) link;
+          in {
+            lan = link.build { ifname = "eth0"; };
+            wan = link.build { ifname = "eth1"; };
+            wlan_24 = link.build {
+              ifname = "wlan0";
               dependencies = [ mac80211 ];
             };
-          wlan_5 = interface {
-            device = "wlan1";
+            wlan_5 = link.build {
+              ifname = "wlan1";
               dependencies = [ mac80211 ath10k_cal_data ];
             };
           };

examples/rotuer.nix

@@ -44,6 +44,7 @@ in rec {
   imports = [
     ../modules/wlan.nix
     ../modules/standard.nix
+    ../modules/network
     ../modules/ppp
     ../modules/dnsmasq
     ../modules/firewall
@@ -78,15 +79,15 @@ in rec {
     } // wirelessConfig;
   };
 
-  services.int =
-    let iface = svc.bridge.build {
-          ifname = "int";
-          members = with config.hardware.networkInterfaces;  [
-            wlan_24 lan wlan_5
-          ];
+  services.int = svc.network.address.build {
+    interface = svc.bridge.primary.build { ifname = "int"; };# services.int;
+    family = "inet"; address ="10.8.0.1"; prefixLength = 16;
   };
-    in address iface {
-      family = "inet4"; address ="10.8.0.1"; prefixLength = 16;
+
+  services.bridge =  svc.bridge.members.build {
+    primary = services.int;
+    members = with config.hardware.networkInterfaces;
+      [ wlan_24 wlan_5  lan ];
   };
 
   services.ntp = svc.ntp.build {
@@ -204,8 +205,8 @@ in rec {
     name = "default";
     contents = with config.services; [
       config.hardware.networkInterfaces.lo
-      config.hardware.networkInterfaces.lan
       int
+      bridge
       hostap
       hostap5
       ntp

modules/bridge/default.nix

@@ -15,21 +15,29 @@ let
 in
 {
   options = {
-    system.service.bridge = mkOption {
-      type = liminix.lib.types.serviceDefn;
+    system.service.bridge = {
+      primary = mkOption { type = liminix.lib.types.serviceDefn; };
+      members = mkOption { type = liminix.lib.types.serviceDefn; };
     };
   };
-  config.system.service = {
-    bridge = liminix.callService ./service.nix {
-      members = mkOption {
-        type = types.listOf liminix.lib.types.service;
-        description = "interfaces to add to the bridge";
-      };
+  config.system.service.bridge = {
+    primary = liminix.callService ./primary.nix {
       ifname = mkOption {
         type = types.str;
         description = "bridge interface name to create";
       };
     };
+    members = liminix.callService ./members.nix {
+      primary = mkOption {
+        type = liminix.lib.types.interface;
+        description = "primary bridge interface";
+      };
+
+      members = mkOption {
+        type = types.listOf liminix.lib.types.interface;
+        description = "interfaces to add to the bridge";
+      };
+    };
   };
   config.kernel.config.BRIDGE = "y";
 }

modules/bridge/members.nix

@@ -0,0 +1,25 @@
+{
+  liminix
+, ifwait
+, lib
+}:
+{ members, primary } :
+
+let
+  inherit (liminix.networking) interface;
+  inherit (liminix.services) bundle oneshot;
+  inherit (lib) mkOption types;
+  addif = member :
+    oneshot {
+      name = "${primary.name}.member.${member.name}";
+      up = ''
+        dev=$(output ${member} ifname)
+        ${ifwait}/bin/ifwait $dev running && ip link set dev $dev master $(output ${primary} ifname)
+      '';
+      down = "ip link set dev $(output ${member} ifname) nomaster";
+      dependencies = [ primary member ];
+    };
+in bundle {
+  name = "${primary.name}.members";
+  contents = map addif members;
+}

modules/bridge/primary.nix

@@ -0,0 +1,18 @@
+{
+  liminix
+, ifwait
+, lib
+}:
+{ ifname } :
+let
+  inherit (liminix.networking) interface;
+  inherit (liminix.services) bundle oneshot;
+  inherit (lib) mkOption types;
+in oneshot rec {
+  name = "${ifname}.link";
+  up = ''
+    ip link add name ${ifname} type bridge
+    ${liminix.networking.ifup name ifname}
+  '';
+  down = "ip link set down dev ${ifname}";
+}

modules/bridge/service.nix

@@ -1,27 +0,0 @@
-{
-  liminix
-, ifwait
-, lib
-}:
-{ members, ifname } :
-let
-  inherit (liminix.networking) interface;
-  inherit (liminix.services) bundle oneshot;
-  inherit (lib) mkOption types;
-  primary = interface {
-    device = ifname;
-    type = "bridge";
-  };
-  addif = member :
-    let ifname = "$(output ${member} ifname)";
-    in oneshot {
-      name = "add-${member.name}-to-br-${primary.name}";
-      up = "${ifwait}/bin/ifwait ${ifname} running && ip link set dev ${ifname} master $(output ${primary} ifname)";
-      down = "ip link set dev ${ifname} nomaster";
-      dependencies = [ primary member ];
-    };
-
-in bundle {
-  name = "bridge-${primary.name}-members";
-  contents = [ primary ] ++ map addif members;
-}

modules/network/address.nix

@@ -0,0 +1,29 @@
+{
+  liminix
+, ifwait
+, serviceFns
+, lib
+}:
+{interface, family, address, prefixLength} :
+let
+  inherit (liminix.services) oneshot;
+  # rather depending on the assumption that nobody will
+  # ever add two addresses which are the same but with different
+  # prefixes, or the same but different protocols
+  name = "${interface.name}.a.${address}";
+  up = ''
+    . ${serviceFns}
+    dev=$(output ${interface} ifname)
+    ip address add ${address}/${toString prefixLength} dev $dev
+    (in_outputs ${name}
+     echo ${address} > address
+     echo ${toString prefixLength} > prefix-length
+     echo ${family} > family
+     echo $dev > ifname
+    )
+  '';
+in oneshot {
+  inherit name up;
+  down = "true";                # this has been broken for ~ ages
+  dependencies = [ interface ];
+}

modules/network/default.nix

@@ -0,0 +1,54 @@
+## Network
+## =======
+##
+## Basic network services for creating hardware ethernet devices
+## and adding addresses
+
+
+{ lib, pkgs, config, ...}:
+let
+  inherit (lib) mkOption types;
+  inherit (pkgs) liminix;
+in {
+  options = {
+    system.service.network = {
+      link = mkOption {
+        description = "hardware network interface";
+        type = liminix.lib.types.serviceDefn;
+      };
+      address = mkOption {
+        description = "network interface address";
+        type = liminix.lib.types.serviceDefn;
+      };
+    };
+  };
+  config = {
+    system.service.network = {
+      link = liminix.callService ./link.nix {
+        ifname = mkOption {
+          type = types.str;
+          example = "eth0";
+        };
+        # other "ip link add" options could go here as well
+        mtu = mkOption {
+          type = types.nullOr types.int;
+          example = 1480;
+        };
+      };
+      address = liminix.callService ./address.nix {
+        interface = mkOption {
+          type = liminix.lib.types.service;
+        };
+        family = mkOption {
+          type = types.enum [ "inet" "inet6" ];
+        };
+        address = mkOption {
+          type = types.str;
+        };
+        prefixLength = mkOption {
+          type = types.ints.between 0 128;
+        };
+      };
+    };
+  };
+}

modules/network/link.nix

@@ -0,0 +1,16 @@
+{
+  liminix
+, ifwait
+, serviceFns
+, lib
+}:
+{ifname, mtu} :
+let
+  inherit (liminix.services) longrun oneshot;
+  inherit (lib) concatStringsSep;
+  name = "${ifname}.link";
+  up = liminix.networking.ifup name ifname;
+in oneshot {
+  inherit name up;
+  down = "ip link set down dev ${ifname}";
+}