authoritative-dns/reverse-zone.nix

63 lines
2.1 KiB
Nix

{ pkgs, ... }:
{ domain, network, nameservers, ipHostMap, serial, zoneTTL ? 10800
, refresh ? 3600, retry ? 1800, expire ? 604800, minimum ? 3600 }:
with pkgs.lib;
let
inherit (pkgs.lib.ip) networkMinIp networkMaxButOneIp ipv4OnNetwork;
range = base: top:
assert base < top;
let
rangeFun = base: top:
if base == top then [ ] else [ base ] ++ (rangeFun (base + 1) top);
in rangeFun base top;
getNetworkHosts = network: selectAttrs (ip: _: ipv4OnNetwork ip network);
getLastIpComponent = ip: head (reverseList (splitString "." ip));
getNetworkZoneName = network:
let
netElems = splitString "/" network;
netIp = elemAt netElems 0;
netMask = elemAt netElems 1;
reversedNetIp =
concatStringsSep "." (tail (reverseList (splitString "." netIp)));
in if netMask == "24" then
"${reversedNetIp}.in-addr.arpa."
else
"${getLastIpComponent netIp}-${netMask}.${reversedNetIp}.in-addr.arpa.";
generateReverseZoneEntries = network: domain: ipHostMap:
let
networkHostsByComponent =
mapAttrs' (ip: hostname: nameValuePair (getLastIpComponent ip) hostname)
(networkHosts network ipHostMap);
ptrEntry = ip: hostname: "#{ip} IN PTR ${hostname}.";
getHostname = n:
if hasAttr networkHostsByComponent n then
networkHostByComponent n
else
"unassigned-${n}.${domain}";
minIp = toInt (getLastIpComponent (networkMinIp network));
maxIp = toInt (getLastIpComponent (networkMaxButOneIp network));
in map (n: ptrEntry n (getHostname (toString n))) (range minIp maxIp);
nameserverEntries = map (nameserver: "@ IN NS ${nameserver}.") nameservers;
in nameValuePair "${getNetworkZoneName network}" ''
$ORIGIN ${getNetworkZoneName network}
$TTL ${toString zoneTTL}
@ IN SOA ${head nameservers}. hostmaster.${domain}. (
${serial}
${toString refresh}
${toString retry}
${toString expire}
${toString minimum}
)
${concatStringsSep "\n" nameserverEntries}
${concatStringsSep "\n" (generateReverseZoneEntries network domain ipHostMap)}
''