nix-dotfiles/modules/wstunnel.nix

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2024-06-29 02:14:31 +02:00
{ config
, lib
, pkgs
, ...
}:
let
cfg = config.services.wstunnel;
hostPortToString = { host, port }: "${host}:${toString port}";
hostPortSubmodule = {
options = {
host = lib.mkOption {
description = "The hostname.";
type = lib.types.str;
};
port = lib.mkOption {
description = "The port.";
type = lib.types.port;
};
};
};
commonOptions = {
enable = lib.mkEnableOption "this `wstunnel` instance." // {
default = true;
};
package = lib.mkPackageOption pkgs "wstunnel" { };
autoStart =
lib.mkEnableOption "starting this wstunnel instance automatically." // {
default = true;
};
extraArgs = lib.mkOption {
description = ''
Extra command line arguments to pass to `wstunnel`.
Attributes of the form `argName = true;` will be translated to `--argName`,
and `argName = \"value\"` to `--argName value`.
'';
type = with lib.types; attrsOf (either str bool);
default = { };
example = {
"someNewOption" = true;
"someNewOptionWithValue" = "someValue";
};
};
loggingLevel = lib.mkOption {
description = ''
Passed to --log-lvl
Control the log verbosity. i.e: TRACE, DEBUG, INFO, WARN, ERROR, OFF
For more details, checkout [EnvFilter](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#example-syntax)
'';
type = lib.types.nullOr lib.types.str;
example = "INFO";
default = null;
};
environmentFile = lib.mkOption {
description = ''
Environment file to be passed to the systemd service.
Useful for passing secrets to the service to prevent them from being
world-readable in the Nix store.
Note however that the secrets are passed to `wstunnel` through
the command line, which makes them locally readable for all users of
the system at runtime.
'';
type = lib.types.nullOr lib.types.path;
default = null;
example = "/var/lib/secrets/wstunnelSecrets";
};
};
serverSubmodule = { config, ... }: {
options = commonOptions // {
listen = lib.mkOption {
description = ''
Address and port to listen on.
Setting the port to a value below 1024 will also give the process
the required `CAP_NET_BIND_SERVICE` capability.
'';
type = lib.types.submodule hostPortSubmodule;
default = {
host = "0.0.0.0";
port = if config.enableHTTPS then 443 else 80;
};
defaultText = lib.literalExpression ''
{
host = "0.0.0.0";
port = if enableHTTPS then 443 else 80;
}
'';
};
restrictTo = lib.mkOption {
description = ''
Accepted traffic will be forwarded only to this service.
'';
type = lib.types.listOf (lib.types.submodule hostPortSubmodule);
default = [ ];
example = [{
host = "127.0.0.1";
port = 51820;
}];
};
enableHTTPS = lib.mkOption {
description = "Use HTTPS for the tunnel server.";
type = lib.types.bool;
default = true;
};
tlsCertificate = lib.mkOption {
description = ''
TLS certificate to use instead of the hardcoded one in case of HTTPS connections.
Use together with `tlsKey`.
'';
type = lib.types.nullOr lib.types.path;
default = null;
example = "/var/lib/secrets/cert.pem";
};
tlsKey = lib.mkOption {
description = ''
TLS key to use instead of the hardcoded on in case of HTTPS connections.
Use together with `tlsCertificate`.
'';
type = lib.types.nullOr lib.types.path;
default = null;
example = "/var/lib/secrets/key.pem";
};
useACMEHost = lib.mkOption {
description = ''
Use a certificate generated by the NixOS ACME module for the given host.
Note that this will not generate a new certificate - you will need to do so with `security.acme.certs`.
'';
type = lib.types.nullOr lib.types.str;
default = null;
example = "example.com";
};
};
};
clientSubmodule = { config, ... }: {
options = commonOptions // {
connectTo = lib.mkOption {
description = "Server address and port to connect to.";
type = lib.types.str;
example = "https://wstunnel.server.com:8443";
};
localToRemote = lib.mkOption {
description = ''Listen on local and forwards traffic from remote.'';
type = lib.types.listOf (lib.types.str);
default = [ ];
example = [
"tcp://1212:google.com:443"
"unix:///tmp/wstunnel.sock:g.com:443"
];
};
remoteToLocal = lib.mkOption {
description = "Listen on remote and forwards traffic from local. Only tcp is supported";
type = lib.types.listOf lib.types.str;
default = [ ];
example = [
"tcp://1212:google.com:443"
"unix://wstunnel.sock:g.com:443"
];
};
addNetBind = lib.mkEnableOption "Whether add CAP_NET_BIND_SERVICE to the tunnel service, this should be enabled if you want to bind port < 1024";
httpProxy = lib.mkOption {
description = ''
Proxy to use to connect to the wstunnel server (`USER:PASS@HOST:PORT`).
::: {.warning}
Passwords specified here will be world-readable in the Nix store!
To pass a password to the service, point the `environmentFile` option
to a file containing `PROXY_PASSWORD=<your-password-here>` and set
this option to `<user>:$PROXY_PASSWORD@<host>:<port>`.
Note however that this will also locally leak the passwords at
runtime via e.g. /proc/<pid>/cmdline.
:::
'';
type = lib.types.nullOr lib.types.str;
default = null;
};
soMark = lib.mkOption {
description = ''
Mark network packets with the SO_MARK sockoption with the specified value.
Setting this option will also enable the required `CAP_NET_ADMIN` capability
for the systemd service.
'';
type = lib.types.nullOr lib.types.ints.unsigned;
default = null;
};
upgradePathPrefix = lib.mkOption {
description = ''
Use a specific HTTP path prefix that will show up in the upgrade
request to the `wstunnel` server.
Useful when running `wstunnel` behind a reverse proxy.
'';
type = lib.types.nullOr lib.types.str;
default = null;
example = "wstunnel";
};
tlsSNI = lib.mkOption {
description = "Use this as the SNI while connecting via TLS. Useful for circumventing hostname-based firewalls.";
type = lib.types.nullOr lib.types.str;
default = null;
};
tlsVerifyCertificate = lib.mkOption {
description = "Whether to verify the TLS certificate of the server. It might be useful to set this to `false` when working with the `tlsSNI` option.";
type = lib.types.bool;
default = true;
};
# The original argument name `websocketPingFrequency` is a misnomer, as the frequency is the inverse of the interval.
websocketPingInterval = lib.mkOption {
description = "Frequency at which the client will send websocket ping to the server.";
type = lib.types.nullOr lib.types.ints.unsigned;
default = null;
};
upgradeCredentials = lib.mkOption {
description = ''
Use these credentials to authenticate during the HTTP upgrade request
(Basic authorization type, `USER:[PASS]`).
::: {.warning}
Passwords specified here will be world-readable in the Nix store!
To pass a password to the service, point the `environmentFile` option
to a file containing `HTTP_PASSWORD=<your-password-here>` and set this
option to `<user>:$HTTP_PASSWORD`.
Note however that this will also locally leak the passwords at runtime
via e.g. /proc/<pid>/cmdline.
:::
'';
type = lib.types.nullOr lib.types.str;
default = null;
};
customHeaders = lib.mkOption {
description = "Custom HTTP headers to send during the upgrade request.";
type = lib.types.attrsOf lib.types.str;
default = { };
example = {
"X-Some-Header" = "some-value";
};
};
};
};
generateServerUnit = name: serverCfg: {
name = "wstunnel-server-${name}";
value =
let
certConfig = config.security.acme.certs.${serverCfg.useACMEHost};
in
{
description = "wstunnel server - ${name}";
requires = [ "network.target" "network-online.target" ];
after = [ "network.target" "network-online.target" ];
wantedBy = lib.optional serverCfg.autoStart "multi-user.target";
environment.RUST_LOG = serverCfg.loggingLevel;
serviceConfig = {
Type = "exec";
EnvironmentFile =
lib.optional (serverCfg.environmentFile != null) serverCfg.environmentFile;
DynamicUser = true;
SupplementaryGroups =
lib.optional (serverCfg.useACMEHost != null) certConfig.group;
PrivateTmp = true;
AmbientCapabilities =
lib.optionals (serverCfg.listen.port < 1024) [ "CAP_NET_BIND_SERVICE" ];
NoNewPrivileges = true;
RestrictNamespaces = "uts ipc pid user cgroup";
ProtectSystem = "strict";
ProtectHome = true;
ProtectKernelTunables = true;
ProtectKernelModules = true;
ProtectControlGroups = true;
PrivateDevices = true;
RestrictSUIDSGID = true;
Restart = "on-failure";
RestartSec = 2;
RestartSteps = 20;
RestartMaxDelaySec = "5min";
};
script = with serverCfg; ''
${lib.getExe package} \
server \
${lib.cli.toGNUCommandLineShell { } (
lib.recursiveUpdate
{
restrict-to = map hostPortToString restrictTo;
# TODO: fix this upstream
# tls-certificate = if useACMEHost != null
# then "${certConfig.directory}/fullchain.pem"
# else "${tlsCertificate}";
# tls-private-key = if useACMEHost != null
# then "${certConfig.directory}/key.pem"
# else "${tlsKey}";
}
extraArgs
)} \
${lib.escapeShellArg "${if enableHTTPS then "wss" else "ws"}://${hostPortToString listen}"}
'';
};
};
generateClientUnit = name: clientCfg: {
name = "wstunnel-client-${name}";
value = {
description = "wstunnel client - ${name}";
requires = [ "network.target" "network-online.target" ];
after = [ "network.target" "network-online.target" ];
wantedBy = lib.optional clientCfg.autoStart "multi-user.target";
environment.RUST_LOG = clientCfg.loggingLevel;
serviceConfig = {
Type = "exec";
EnvironmentFile =
lib.optional (clientCfg.environmentFile != null) clientCfg.environmentFile;
DynamicUser = true;
PrivateTmp = true;
AmbientCapabilities =
(lib.optionals clientCfg.addNetBind [ "CAP_NET_BIND_SERVICE" ]) ++
(lib.optionals (clientCfg.soMark != null) [ "CAP_NET_ADMIN" ]);
NoNewPrivileges = true;
RestrictNamespaces = "uts ipc pid user cgroup";
ProtectSystem = "strict";
ProtectHome = true;
ProtectKernelTunables = true;
ProtectKernelModules = true;
ProtectControlGroups = true;
PrivateDevices = true;
RestrictSUIDSGID = true;
Restart = "on-failure";
RestartSec = 2;
RestartSteps = 20;
RestartMaxDelaySec = "5min";
};
script = with clientCfg; ''
${lib.getExe package} \
client \
${lib.cli.toGNUCommandLineShell { } (
lib.recursiveUpdate
{
local-to-remote = localToRemote;
remote-to-local = remoteToLocal;
http-headers = lib.mapAttrsToList (n: v: "${n}:${v}") customHeaders;
http-proxy = httpProxy;
socket-so-mark = soMark;
http-upgrade-path-prefix = upgradePathPrefix;
tls-sni-override = tlsSNI;
tls-verify-certificate = tlsVerifyCertificate;
websocket-ping-frequency-sec = websocketPingInterval;
http-upgrade-credentials = upgradeCredentials;
}
extraArgs
)} \
${lib.escapeShellArg connectTo}
'';
};
};
in
{
options.services.wstunnel = {
enable = lib.mkEnableOption "wstunnel";
servers = lib.mkOption {
description = "`wstunnel` servers to set up.";
type = lib.types.attrsOf (lib.types.submodule serverSubmodule);
default = { };
example = {
"wg-tunnel" = {
listen = {
host = "0.0.0.0";
port = 8080;
};
enableHTTPS = true;
tlsCertificate = "/var/lib/secrets/fullchain.pem";
tlsKey = "/var/lib/secrets/key.pem";
restrictTo = [{
host = "127.0.0.1";
port = 51820;
}];
};
};
};
clients = lib.mkOption {
description = "`wstunnel` clients to set up.";
type = lib.types.attrsOf (lib.types.submodule clientSubmodule);
default = { };
example = {
"wg-tunnel" = {
connectTo = "wss://wstunnel.server.com:8443";
localToRemote = [
"tcp://1212:google.com:443"
"tcp://2:n.lan:4?proxy_protocol"
];
remoteToLocal = [
"socks5://[::1]:1212"
"unix://wstunnel.sock:g.com:443"
];
};
};
};
};
config = lib.mkIf cfg.enable {
systemd.services =
(lib.mapAttrs' generateServerUnit (lib.filterAttrs (n: v: v.enable) cfg.servers)) //
(lib.mapAttrs' generateClientUnit (lib.filterAttrs (n: v: v.enable) cfg.clients));
assertions =
(lib.mapAttrsToList
(name: serverCfg: {
assertion =
!(serverCfg.useACMEHost != null && serverCfg.tlsCertificate != null);
message = ''
Options services.wstunnel.servers."${name}".useACMEHost and services.wstunnel.servers."${name}".{tlsCertificate, tlsKey} are mutually exclusive.
'';
})
cfg.servers) ++
(lib.mapAttrsToList
(name: serverCfg: {
assertion =
(serverCfg.tlsCertificate == null && serverCfg.tlsKey == null) ||
(serverCfg.tlsCertificate != null && serverCfg.tlsKey != null);
message = ''
services.wstunnel.servers."${name}".tlsCertificate and services.wstunnel.servers."${name}".tlsKey need to be set together.
'';
})
cfg.servers) ++
(lib.mapAttrsToList
(name: clientCfg: {
assertion = !(clientCfg.localToRemote == [ ] && clientCfg.remoteToLocal == [ ]);
message = ''
Either one of services.wstunnel.clients."${name}".localToRemote or services.wstunnel.clients."${name}".remoteToLocal must be set.
'';
})
cfg.clients);
};
meta.maintainers = with lib.maintainers; [ alyaeanyx rvdp neverbehave ];
}