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{ config, hostName, lib, pkgs, ... }:
with lib;
let
listenPort = 51820;
udp2rawPort = 51821;
wgSubnet = "2a03:4000:52:ada:1";
wgSubnetLength = 80;
wgHostLength = wgSubnetLength + 16;
batSubnet = "2a03:4000:52:ada:2";
batSubnetLength = 80;
batHostLength = batSubnetLength + 16;
links = mkLinks [
{ from = "vidhar";
to = "surtr";
endpointHost = "202.61.241.61";
udp2raw = true;
PersistentKeepalive = 25;
}
{ from = "sif";
to = "surtr";
endpointHost = "202.61.241.61";
udp2raw = true;
PersistentKeepalive = 25;
}
{ from = "sif";
to = "vidhar";
endpointHost = "192.168.2.168";
PersistentKeepalive = 25;
}
];
wgHostIPs = {
surtr = "${wgSubnet}::/${toString wgHostLength}";
vidhar = "${wgSubnet}:1::/${toString wgHostLength}";
sif = "${wgSubnet}:2::/${toString wgHostLength}";
};
greHostMACPrefixes = {
surtr = "02:00:00:00:00";
vidhar = "02:00:00:00:01";
sif = "02:00:00:00:02";
};
batHostIPs = {
surtr = ["${batSubnet}::/${toString batHostLength}"];
vidhar = ["${batSubnet}:1::/${toString batHostLength}"];
sif = ["${batSubnet}:2::/${toString batHostLength}"];
};
mkPublicKeyPath = host: ./hosts + "/${host}.pub";
mkPrivateKeyPath = host: ./hosts + "/${host}.priv";
kernel = config.boot.kernelPackages;
publicKeyPath = mkPublicKeyPath hostName;
privateKeyPath = mkPrivateKeyPath hostName;
inNetwork = pathExists privateKeyPath && pathExists publicKeyPath;
hostLinks = filter ({ from, to, ... }: from == hostName || to == hostName) links;
linkToPeer = opts@{from, to, ...}:
let
other = if from == hostName then to else from;
in {
AllowedIPs = wgHostIPs.${other};
PublicKey = trim (readFile (mkPublicKeyPath other));
} // (optionalAttrs (from == hostName) (filterAttrs (n: _v: !(elem n ["from" "to" "endpointHost" "udp2raw"])) opts // optionalAttrs (opts ? "endpointHost" && from == hostName) (if opts ? "udp2raw" then { Endpoint = "127.0.0.1:${toString (udp2rawPort + opts.udp2raw)}"; } else { Endpoint = "${opts.endpointHost}:${toString listenPort}"; })));
linkToGreDev = opts@{from, to, ...}:
let
other = if from == hostName then to else from;
in nameValuePair "yggre-${other}" {
netdevConfig = {
Name = "yggre-${other}";
Kind = "ip6gretap";
MTUBytes = toString (1280 + 32);
};
tunnelConfig = {
Local = stripSubnet wgHostIPs.${hostName};
Remote = stripSubnet wgHostIPs.${other};
};
};
linkToGreNetwork = ix: opts@{from, to, ...}:
let
other = if from == hostName then to else from;
hexIx = let
hexIx' = toHexString ix;
in if (stringLength hexIx' < 2) then "0${hexIx'}" else hexIx';
in nameValuePair "yggre-${other}" {
matchConfig = {
Name = "yggre-${other}";
};
linkConfig = {
MACAddress = "${greHostMACPrefixes.${hostName}}:${hexIx}";
RequiredForOnline = false;
};
networkConfig = {
BatmanAdvanced = "yggdrasil";
LinkLocalAddressing = "no";
};
};
trim = str: if hasSuffix "\n" str then trim (removeSuffix "\n" str) else str;
stripSubnet = addr: let matchRes = builtins.match "^(.*)/[0-9]+$" addr; in if matchRes == null then addr else elemAt matchRes 0;
optIx = optName: xs: let
withOpts = listToAttrs (imap0 (ix: x: nameValuePair x.name (x.value // { ${optName} = ix; })) (filter (x: x.value.${optName} or false) (imap0 (ix: nameValuePair (toString ix)) xs)));
withoutOpts = listToAttrs (map (nv: nameValuePair nv.name (removeAttrs nv.value [optName])) (filter (x: !(x.value.${optName} or false)) (imap0 (ix: nameValuePair (toString ix)) xs)));
in genList (ix: withOpts.${toString ix} or withoutOpts.${toString ix}) (length xs);
mkLinks = optIx "udp2raw";
in {
config = {
assertions = [
{ assertion = inNetwork || !(pathExists privateKeyPath || pathExists publicKeyPath);
message = "yggdrasil-wg: Either both public and private keys must exist or neither.";
}
{ assertion = !inNetwork || (wgHostIPs ? "${hostName}");
message = "yggdrasil-wg: Entry in wgHostIPs must exist.";
}
] ++ map ({from, to, ...}: let other = if from == hostName then to else from; in { assertion = pathExists (mkPublicKeyPath other); message = "yggdrasil-wg: This host (${hostName}) has a link with ‘${other}’, but no public key is available for ‘${other}’."; }) hostLinks;
systemd.network = mkIf inNetwork {
enable = true;
netdevs = {
yggdrasil-wg = {
netdevConfig = {
Name = "yggdrasil-wg";
Kind = "wireguard";
MTUBytes = toString (1280 + 32 + 70);
};
wireguardConfig = {
PrivateKeyFile = config.sops.secrets."yggdrasil-wg.priv".path;
ListenPort = listenPort;
};
wireguardPeers = map (opts@{to, from, ...}: { wireguardPeerConfig = linkToPeer opts; }) hostLinks;
};
yggdrasil = {
netdevConfig = {
Name = "yggdrasil";
Kind = "batadv";
MTUBytes = toString 1280;
};
};
} // listToAttrs (map linkToGreDev hostLinks);
networks = {
yggdrasil-wg = {
name = "yggdrasil-wg";
matchConfig = {
Name = "yggdrasil-wg";
};
address = [wgHostIPs.${hostName}];
routes = [
{ routeConfig = {
Destination = "${wgSubnet}::/${toString wgSubnetLength}";
};
}
];
linkConfig = {
RequiredForOnline = false;
};
networkConfig = {
Tunnel = map (opts@{from, to, ...}: let other = if from == hostName then to else from; in "yggre-${other}") hostLinks;
};
};
yggdrasil = {
name = "yggdrasil";
matchConfig = {
Name = "yggdrasil";
};
address = batHostIPs.${hostName};
routes = [
{ routeConfig = {
Destination = "${batSubnet}::/${toString batSubnetLength}";
};
}
];
linkConfig = {
RequiredForOnline = false;
};
};
} // listToAttrs (imap0 linkToGreNetwork hostLinks);
};
systemd.services = listToAttrs (filter ({ value, ...}: value != null) (map (opts@{to, from, ...}: let other = if from == hostName then to else from; in nameValuePair "yggdrasil-udp2raw@${other}" (if opts ? "endpointHost" && opts ? "udp2raw" then {
path = with pkgs; [iptables];
serviceConfig = {
RuntimeDirectory = ["udp2raw-config-${other}"];
RuntimeDirectoryMode = "0700";
ExecStartPre = pkgs.writeShellScript "udp2raw-mkconfig-${other}.sh" ''
umask 0077
secret=$(cat ${config.sops.secrets."yggdrasil-udp2raw-secret".path})
cat >''${RUNTIME_DIRECTORY}/udp2raw.conf <<EOF
${if from == hostName then ''
-c
-l 127.0.0.1:${toString (udp2rawPort + opts.udp2raw)}
-r ${opts.endpointHost}:${toString (udp2rawPort + opts.udp2raw)}
'' else ''
-s
-l 0.0.0.0:${toString (udp2rawPort + opts.udp2raw)}
-r 127.0.0.1:${toString listenPort}
''}
-k $secret
--auth-mode hmac_sha1
--raw-mode faketcp
--seq-mode 4
-a
--retry-on-error
EOF
'';
ExecStart = "${pkgs.udp2raw}/bin/udp2raw --conf-file \${RUNTIME_DIRECTORY}/udp2raw.conf";
Restart = "always";
};
} else null)) hostLinks));
sops.secrets = {
"yggdrasil-wg.priv" = mkIf (pathExists privateKeyPath) {
format = "binary";
sopsFile = privateKeyPath;
mode = "0640";
owner = "root";
group = "systemd-network";
};
"yggdrasil-udp2raw-secret" = mkIf (any (opts@{to, from, ...}: opts ? "endpointHost" && opts ? "udp2raw") hostLinks) {
format = "binary";
sopsFile = ./udp2raw-secret;
};
};
networking.hosts = mkIf inNetwork (listToAttrs (concatMap ({name, value}: map (ip: nameValuePair (stripSubnet ip) ["${name}.yggdrasil"]) value) (mapAttrsToList nameValuePair batHostIPs)));
boot.extraModulePackages = optional (versionOlder kernel.kernel.version "5.6") kernel.wireguard ++ [kernel.batman_adv];
environment.systemPackages = with pkgs; [ wireguard-tools batctl ];
};
}
|
