From 31ec2b64895a5de9bfeb4d561c77e7f824431ed2 Mon Sep 17 00:00:00 2001
From: Felix Albrigtsen <felix@albrigtsen.it>
Date: Sun, 18 Jan 2026 15:07:32 +0100
Subject: [PATCH] Add/fix reverse ipv4

---
 zoneConfig.nix         |  4 +++-
 zones/reverse-ipv4.nix | 32 +++++++++++++++++++++++---------
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/zoneConfig.nix b/zoneConfig.nix
index 8df1a78..d9bf773 100644
--- a/zoneConfig.nix
+++ b/zoneConfig.nix
@@ -13,7 +13,7 @@ let
       {
         "pvv.ntnu.no" = ./zones/pvv.ntnu.no.nix;
         "pvv.org" = ./zones/pvv.org.nix;
-        "reverse-ipv4" = ./zones/reverse-ipv4.nix;
+        "in-addr.arpa" = ./zones/reverse-ipv4.nix;
         #"reverse-ipv6" = ./zones/reverse-ipv6.nix;
       };
 in
@@ -27,4 +27,6 @@ stdenvNoCC.mkDerivation {
 
     ''
     + (lib.concatMapAttrsStringSep "\n" (name: path: "cp ${path} $out/zones/${name}.zone") zoneConfigs);
+
+  # TODO: Write named.conf to include the zones, set allow-transfer, etc.
 }
diff --git a/zones/reverse-ipv4.nix b/zones/reverse-ipv4.nix
index 9feeebd..29eba02 100644
--- a/zones/reverse-ipv4.nix
+++ b/zones/reverse-ipv4.nix
@@ -2,11 +2,29 @@
 
 with dns.lib.combinators;
 let
-  hosts = import ../hosts.nix;
-  ptrdnameSuffix = ".pvv.ntnu.no.";
+  pvvv4 = hostPart: "129.241.210.${toString hostPart}";
+  domainSuffix = ".pvv.ntnu.no.";
+  flipV4 = ip: lib.concatStringsSep "." (lib.reverseList (lib.splitString "." ip));
+
+  pvvHostRecords = import ../pvv-subdomains.nix { inherit dns lib; };
+  # Take all the A-records, and flip them to generate opposing PTR records
+  # TODO: Handle duplicates?
+  pvvHostReverseRecords = builtins.listToAttrs (
+      lib.concatLists (
+        lib.mapAttrsToList ( target: host:
+          lib.map
+          (aRecord: { name = flipV4 aRecord; value.PTR = [ (target + domainSuffix) ]; })
+            (host.A or [])
+          ) pvvHostRecords
+        )
+      );
+
+  additionalReverseRecords = {
+    "${flipV4 "129.241.210.129"}".PTR = [ "el-swd.nettel.ntnu.no." ]; # Gateway router/switch
+  };
 in
 {
-  useOrigin = true; # Don't output fully qualified names
+  useOrigin = false; # Use fully qualified names
 
   SOA = {
     nameServer = "dvask.pvv.ntnu.no";
@@ -18,10 +36,6 @@ in
     "nn.unintett.no"
   ];
 
-  subdomains = let
-    ptr = ptrdname: { PTR = [ ptrdname ]; };
-    pvvptr = ptrdname: ptr (ptrdname + ptrdnameSuffix);
-  in {
-    "129" = ptr "el-swd.nettel.ntnu.no."; # Gateway router/switch
-  };
+  # Additional
+  subdomains = pvvHostReverseRecords // additionalReverseRecords;
 }