nix-bitcoin/pkgs/lib.nix
Erik Arvstedt 9bda7305fd
services: add tor.* options
Split `enforceTor` into `tor.proxy` and `tor.enforce`.
By enabling `tor.proxy` without `tor.enforce`, a service can accept
incoming clearnet connections.
E.g., this allows setting up a Tor-proxied bitcoind node that accepts
RPC connections from LAN.
2021-11-29 13:22:43 +01:00

107 lines
3.2 KiB
Nix

lib: pkgs:
with lib;
# See `man systemd.exec` and `man systemd.resource-control` for an explanation
# of the systemd-related options available through this file.
let self = {
# These settings roughly follow systemd's "strict" security profile
defaultHardening = {
PrivateTmp = "true";
ProtectSystem = "strict";
ProtectHome = "true";
NoNewPrivileges = "true";
PrivateDevices = "true";
MemoryDenyWriteExecute = "true";
ProtectKernelTunables = "true";
ProtectKernelModules = "true";
ProtectKernelLogs = "true";
ProtectClock = "true";
ProtectProc = "invisible";
ProcSubset = "pid";
ProtectControlGroups = "true";
RestrictAddressFamilies = "AF_UNIX AF_INET AF_INET6";
RestrictNamespaces = "true";
LockPersonality = "true";
IPAddressDeny = "any";
PrivateUsers = "true";
RestrictSUIDSGID = "true";
RemoveIPC = "true";
RestrictRealtime = "true";
ProtectHostname = "true";
CapabilityBoundingSet = "";
# @system-service whitelist and docker seccomp blacklist (except for "clone"
# which is a core requirement for systemd services)
# @system-service is defined in src/shared/seccomp-util.c (systemd source)
SystemCallFilter = [ "@system-service" "~add_key clone3 get_mempolicy kcmp keyctl mbind move_pages name_to_handle_at personality process_vm_readv process_vm_writev request_key set_mempolicy setns unshare userfaultfd" ];
SystemCallArchitectures = "native";
};
allowNetlink = {
RestrictAddressFamilies = self.defaultHardening.RestrictAddressFamilies + " AF_NETLINK";
};
# nodejs applications apparently rely on memory write execute
nodejs = { MemoryDenyWriteExecute = "false"; };
# Allow takes precedence over Deny.
allowLocalIPAddresses = {
IPAddressAllow = "127.0.0.1/32 ::1/128 169.254.0.0/16";
};
allowAllIPAddresses = { IPAddressAllow = "any"; };
allowTor = self.allowLocalIPAddresses;
allowedIPAddresses = onlyLocal:
if onlyLocal
then self.allowLocalIPAddresses
else self.allowAllIPAddresses;
tor = {
proxy = mkOption {
type = types.bool;
default = false;
description = "Whether to proxy outgoing connections with Tor.";
};
enforce = mkOption {
type = types.bool;
default = false;
description = ''
Whether to enforce Tor on a service by only allowing connections
from and to localhost and link-local addresses.
'';
};
};
script = name: src: pkgs.writers.writeBash name ''
set -eo pipefail
${src}
'';
# Used for ExecStart*
rootScript = name: src: "+${self.script name src}";
cliExec = mkOption {
# Used by netns-isolation to execute the cli in the service's private netns
internal = true;
type = types.str;
default = "exec";
};
mkOnionService = map: {
map = [ map ];
version = 3;
};
# Convert a bind address, which may be a special INADDR_ANY address,
# to an actual IP address
address = addr:
if addr == "0.0.0.0" then
"127.0.0.1"
else if addr == "::" then
"::1"
else
addr;
addressWithPort = addr: port: "${self.address addr}:${toString port}";
}; in self