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|
{ config, hostName, lib, pkgs, ... }:
with lib;
let
listenPort = 51820;
udp2rawPort = 51821;
subnet = "2a03:4000:52:ada:1";
subnetLength = 80;
hostLength = subnetLength + 16;
links = [
{ from = "vidhar";
to = "surtr";
endpointHost = "202.61.241.61";
persistentKeepalive = 25;
dynamicEndpointRefreshSeconds = 86400;
}
{ from = "sif";
to = "surtr";
endpointHost = "202.61.241.61";
persistentKeepalive = 25;
dynamicEndpointRefreshSeconds = 86400;
}
];
routes = [
{ from = "sif";
to = "vidhar";
via = "surtr";
}
{ from = "vidhar";
to = "sif";
via = "surtr";
}
];
hostIPs = {
surtr = ["${subnet}::/${toString hostLength}"];
vidhar = ["${subnet}:1::/${toString hostLength}"];
sif = ["${subnet}:2::/${toString hostLength}"];
};
mkPublicKeyPath = host: ./hosts + "/${host}.pub";
mkPrivateKeyPath = host: ./hosts + "/${host}.priv";
publicKeyPath = mkPublicKeyPath hostName;
privateKeyPath = mkPrivateKeyPath hostName;
inNetwork = pathExists privateKeyPath && pathExists publicKeyPath;
hostLinks = filter ({ from, to, ... }: from == hostName || to == hostName) links;
hostRoutes = filter ({ from, to, ... }: from == hostName || to == hostName) routes;
isRouter = inNetwork && any ({via, ...}: via == hostName) routes;
linkToPeer = ix: opts@{from, to, ...}:
let
other = if from == hostName then to else from;
in {
allowedIPs = hostIPs.${other} ++ concatMap (rArgs: if rArgs.from != hostName || rArgs.via != to then [] else hostIPs.${rArgs.to}) routes;
publicKey = trim (readFile (mkPublicKeyPath other));
} // (optionalAttrs (from == hostName) (filterAttrs (n: _v: !(elem n ["from" "to" "endpointHost"])) opts // optionalAttrs (opts ? "endpointHost") { endpoint = "127.0.0.1:${toString (udp2rawPort + ix)}"; }));
trim = str: if hasSuffix "\n" str then trim (removeSuffix "\n" str) else str;
stripSubnet = addr: let matchRes = builtins.match "^(.*)/[0-9]+$" addr; in if matchRes == null then addr else elemAt matchRes 0;
in {
config = {
assertions = [
{ assertion = inNetwork || !(pathExists privateKeyPath || pathExists publicKeyPath);
message = "yggdrasil-wg: Either both public and private keys must exist or neither.";
}
{ assertion = !inNetwork || (hostIPs ? "${hostName}");
message = "yggdrasil-wg: Entry in hostIPs must exist.";
}
] ++ map ({from, to, ...}: let other = if from == hostName then to else from; in { assertion = pathExists (mkPublicKeyPath other); message = "yggdrasil-wg: This host (${hostName}) has a link with ‘${other}’, but no public key is available for ‘${other}’."; }) hostLinks;
networking.wireguard.interfaces = mkIf inNetwork {
yggdrasil = {
allowedIPsAsRoutes = false;
inherit listenPort;
ips = hostIPs.${hostName};
peers = imap0 linkToPeer hostLinks;
privateKeyFile = config.sops.secrets."yggdrasil-wg.priv".path;
postSetup = ''
${concatMapStringsSep "\n" (linkArgs: let other = if linkArgs.from == hostName then linkArgs.to else linkArgs.from; in concatMapStringsSep "\n" (otherIP: "ip route replace \"${otherIP}\" dev \"yggdrasil\" table \"main\"") hostIPs.${other}) hostLinks}
${concatMapStringsSep "\n" (routeArgs: let other = if routeArgs.from == hostName then routeArgs.to else routeArgs.from; in concatMapStringsSep "\n" (otherIP: concatMapStringsSep "\n" (viaIP: "ip route replace \"${otherIP}\" via \"${viaIP}\" dev \"yggdrasil\" table \"main\"") (map stripSubnet hostIPs.${routeArgs.via})) hostIPs.${other}) hostRoutes}
'';
};
};
systemd.services = listToAttrs (filter ({ value, ...}: value != null) (imap0 (ix: opts@{to, from, ...}: let other = if from == hostName then to else from; in nameValuePair "yggdrasil-udp2raw@${other}" (if opts ? "endpointHost" && (from == hostName || to == hostName) then {
path = with pkgs; [iptables];
serviceConfig = {
ExecStart = "${pkgs.udp2raw}/bin/udp2raw ${if from == hostName then "-c -l 127.0.0.1:${toString (udp2rawPort + ix)} -r ${opts.endpointHost}:${toString (udp2rawPort + ix)}" else "-s -l 0.0.0.0:${toString (udp2rawPort + ix)} -r 127.0.0.1:${toString listenPort}"} -k tmpkey --auth-mode hmac_sha1 --raw-mode faketcp -a";
};
} else null)) links)) // {
"wireguard-yggdrasil" = {
requires = filter (value: value != null) (map (opts@{to, from, ...}: let other = if from == hostName then to else from; in if opts ? "endpointHost" then "yggdrasil-udp2raw@${other}" else null) hostLinks);
after = filter (value: value != null) (map (opts@{to, from, ...}: let other = if from == hostName then to else from; in if opts ? "endpointHost" then "yggdrasil-udp2raw@${other}" else null) hostLinks);
};
firewall.path = optionals isRouter [pkgs.procps];
};
sops.secrets = mkIf (pathExists privateKeyPath) {
"yggdrasil-wg.priv" = {
format = "binary";
sopsFile = privateKeyPath;
};
};
networking.hosts = mkIf inNetwork (listToAttrs (concatMap ({name, value}: map (ip: nameValuePair (stripSubnet ip) ["${name}.yggdrasil"]) value) (mapAttrsToList nameValuePair hostIPs)));
networking.firewall = mkIf isRouter {
extraCommands = ''
ip6tables -A FORWARD -i yggdrasil -o yggdrasil -j nixos-fw-accept
ip46tables -A FORWARD -j nixos-fw-log-refuse
sysctl net.ipv6.conf.all.forwarding=1
'';
extraStopCommands = ''
sysctl net.ipv6.conf.all.forwarding=0
ip46tables -D FORWARD -j nixos-fw-log-refuse || true
ip6tables -D FORWARD -i yggdrasil -o yggdrasil -j nixos-fw-accept || true
'';
};
};
}
|
