partly support getting IPv6 addresses

- gets interface id from ppp
- runs odhcpc to get RA and prefix delegation
- doesn't do anything useful with the data yet

examples/rotuer.nix

@@ -232,6 +232,25 @@ in rec {
       down = "echo 0 > ${filename}";
     };
 
+  services.dhcp6 =
+    let
+      name = "dhcp6c.wan";
+      luafile = pkgs.runCommand "udhcpc-script" {} ''
+        ${pkgs.luaSmall.pkgs.fennel}/bin/fennel --compile  ${./udhcp6-script.fnl} > $out
+      '';
+      script = pkgs.writeAshScript "dhcp6-notify" {} ''
+        . ${serviceFns}
+        (in_outputs ${name}; ${pkgs.luaSmall}/bin/lua ${luafile} "$@")
+      '';
+    in longrun {
+      inherit name;
+      run = ''
+        ${pkgs.odhcp6c}/bin/odhcp6c -s ${script} -e -v -p /run/${name}.pid -P 48 $(output ${services.wan} ifname)
+        )
+      '';
+      dependencies = [ services.wan ];
+    };
+
   services.default = target {
     name = "default";
     contents = with config.services; [
@@ -248,6 +267,7 @@ in rec {
       resolvconf
       sshd
       config.services.hostname
+      dhcp6
     ];
   };
   defaultProfile.packages = with pkgs;  [min-collect-garbage nftables tcpdump] ;

examples/udhcp6-script.fnl

@@ -0,0 +1,47 @@
+
+
+(fn write-value [name value]
+  (with-open [fout (io.open name :w)]
+    (when value (fout:write value))))
+
+(write-value "state" (. arg 2))
+(write-value "ifname" (. arg 1))
+
+(fn write-value-from-env [name]
+  (write-value name (os.getenv (string.upper name))))
+
+(let [wanted
+      [
+       :addresses
+       :aftr
+       :cer
+       :domains
+       :lw406
+       :mape
+       :mapt
+       :ntp_fqdn
+       :ntp_ip
+       :option_1
+       :option_2
+       :option_3
+       :option_4
+       :option_5
+       :passthru
+       :prefixes
+       :ra_addresses
+       :ra_dns
+       :ra_domains
+       :ra_hoplimit
+       :ra_mtu
+       :ra_reachable
+       :ra_retransmit
+       :ra_routes
+       :rdnss
+       :server
+       :sip_domain
+       :sip_ip
+       :sntp_ip
+       :sntp_fqdn
+       ]]
+  (each [_ n (ipairs wanted)]
+    (write-value-from-env n)))