From 39a6ea69f64dee26259610b042d01dd6f47005fb Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Thu, 13 Jul 2023 13:56:10 +0800
Subject: [PATCH] nixbld: altnet setup

---
 nixbld-etc-nixos/configuration.nix            | 94 +++++++++++++++++++
 .../named/200-29.98.206.103.in-addr.arpa      | 17 ++++
 nixbld-etc-nixos/named/m-labs.hk              |  6 +-
 3 files changed, 116 insertions(+), 1 deletion(-)
 create mode 100644 nixbld-etc-nixos/named/200-29.98.206.103.in-addr.arpa

diff --git a/nixbld-etc-nixos/configuration.nix b/nixbld-etc-nixos/configuration.nix
index c4c20ba1..5908bcc6 100644
--- a/nixbld-etc-nixos/configuration.nix
+++ b/nixbld-etc-nixos/configuration.nix
@@ -104,6 +104,15 @@ in
         address = "2001:470:f891:1::";
         prefixLength = 64;
       }];
+      # https://unix.stackexchange.com/questions/423502/iproute2-inherit-or-copy-table
+      # we just copy what matters here. Ugly but easier.
+      ipv4.routes = [
+        {
+          address = "192.168.1.0";
+          prefixLength = 24;
+          options.table = "1";
+        }
+      ];
     };
     interfaces."${netifWifi}" = {
       ipv4.addresses = [{
@@ -161,12 +170,80 @@ in
       addresses = [{ address = "2001:470:18:390::2"; prefixLength = 64; }];
       routes = [{ address = "::"; prefixLength = 0; }];
     };
+    greTunnels.alt0 = {
+      dev = netifWan;
+      remote = "103.206.98.1";
+      local = "94.190.212.123";
+      ttl = 255;
+      type = "tun";
+    };
+    interfaces.alt0 = {
+      ipv4.addresses = [
+        {
+          address = "103.206.98.227";
+          prefixLength = 31;
+        }
+      ];
+      ipv4.routes = [
+        {
+          address = "0.0.0.0";
+          prefixLength = 0;
+          via = "103.206.98.226";
+          options.table = "1";
+        }
+      ];
+    };
+    vlans = {
+      vlan0 = {
+        id = 2;
+        interface = netifLan;
+      };
+    };
+    interfaces.vlan0 = {
+      ipv4.addresses = [{
+        address = "103.206.98.200";
+        prefixLength = 29;
+      }];
+    };
   };
   boot.kernel.sysctl."net.ipv6.conf.all.forwarding" = "1";
   boot.kernel.sysctl."net.ipv6.conf.default.forwarding" = "1";
   boot.kernel.sysctl."net.ipv6.conf.${netifLan}.accept_dad" = "0";
   boot.kernel.sysctl."net.ipv6.conf.${netifWifi}.accept_dad" = "0";
 
+  services.strongswan-swanctl.enable = true;
+  services.strongswan-swanctl.swanctl.connections.altnet = {
+    local_addrs = [ "94.190.212.123" ];
+    remote_addrs = [ "103.206.98.1" ];
+    local.main = {
+      auth = "pubkey";
+      id = "fqdn:m-labs.hk";
+      pubkeys = [ "/etc/swanctl/pubkey/m-labs.hk" ];
+    };
+    remote.main = {
+      auth = "pubkey";
+      id = "fqdn:igw0.hkg.as150788.net";
+      pubkeys = [ "/etc/swanctl/pubkey/igw0.hkg.as150788.net" ];
+    };
+    children.alt0 = {
+      mode = "transport";
+      ah_proposals = [ "sha256-curve25519" ];
+      remote_ts = [ "103.206.98.1[gre]" ];
+      local_ts = [ "94.190.212.123[gre]" ];
+      start_action = "start";
+    };
+  };
+
+  systemd.services.custom-network-setup = {
+    wantedBy = [ "network.target" ];
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+      ExecStart = "${pkgs.iproute2}/bin/ip rule add from 103.206.98.200/29 table 1";
+      ExecStop = "${pkgs.iproute2}/bin/ip rule del table 1";
+    };
+  };
+
   # https://kb.isc.org/docs/dnssec-key-and-signing-policy
   # chown named.named /etc/nixos/named
   services.bind = {
@@ -212,6 +289,23 @@ in
           "216.218.133.2" "2001:470:600::2"       # slave.dns.he.net
         ];
       };
+      "200-29.98.206.103.in-addr.arpa" = {
+        name = "200-29.98.206.103.in-addr.arpa";
+        master = true;
+        file = "/etc/nixos/named/200-29.98.206.103.in-addr.arpa";
+        extraConfig =
+           ''
+           dnssec-policy "default";
+           inline-signing yes;
+           notify explicit;
+           also-notify {
+             216.218.130.2;   # ns1.he.net
+           };
+           '';
+        slaves = [
+          "216.218.133.2" "2001:470:600::2"       # slave.dns.he.net
+        ];
+      };
     };
     extraConfig = ''
       zone "mil." IN {
diff --git a/nixbld-etc-nixos/named/200-29.98.206.103.in-addr.arpa b/nixbld-etc-nixos/named/200-29.98.206.103.in-addr.arpa
new file mode 100644
index 00000000..0d86ace4
--- /dev/null
+++ b/nixbld-etc-nixos/named/200-29.98.206.103.in-addr.arpa
@@ -0,0 +1,17 @@
+$TTL 7200
+
+@						SOA	NS.XN--WBTZ5WPQAJ35CFXC.XN--J6W193G. sb.m-labs.hk. (
+							2023071303
+							7200
+							3600
+							86400
+							600)
+
+
+						NS		NS.XN--WBTZ5WPQAJ35CFXC.XN--J6W193G.
+						NS		ns1.he.net.
+
+200	PTR	router.alt.m-labs.hk.
+201	PTR	stewardship1.alt.m-labs.hk.
+202	PTR	stewardship2.alt.m-labs.hk.
+
diff --git a/nixbld-etc-nixos/named/m-labs.hk b/nixbld-etc-nixos/named/m-labs.hk
index 9093d243..639d8610 100644
--- a/nixbld-etc-nixos/named/m-labs.hk
+++ b/nixbld-etc-nixos/named/m-labs.hk
@@ -1,7 +1,7 @@
 $TTL 7200
 
 @						SOA	NS.XN--WBTZ5WPQAJ35CFXC.XN--J6W193G. sb.m-labs.hk. (
-							2023040501
+							2023071301
 							7200
 							3600
 							86400
@@ -51,3 +51,7 @@ hestia					AAAA	2001:470:f891:1:881c:f409:a090:8401
 vulcan					AAAA	2001:470:f891:1:105d:3f15:bd53:c5ac
 
 aux						A		42.200.147.171
+
+router.alt				A		103.206.98.200
+stewardship1.alt		A		103.206.98.201
+stewardship2.alt		A		103.206.98.202