Initial attempt at reverse zones

2023-11-01 10:13:33 -07:00
parent d3272846b4
commit 793be43cc2
2 changed files with 91 additions and 11 deletions
@@ -0,0 +1,61 @@
+{ pkgs, ... }:
+
+{ domain, network, nameservers, ipHostMap, serial, zoneTTL ? 10800
+, refresh ? 3600, retry ? 1800, expire ? 604800, minimum ? 3600 }:
+
+with pkgs.lib;
+let
+  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: _: pkgs.lib.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)}
+''