stockholm/krebs/3modules/setuid.nix
2022-10-31 18:26:10 +01:00

92 lines
2.5 KiB
Nix

with import <stockholm/lib>;
{ config, pkgs, ... }: let
out = {
options.krebs.setuid = api;
config = mkIf (config.krebs.setuid != {}) imp;
};
api = mkOption {
default = {};
type = let
inherit (config.users) groups users;
in types.attrsOf (types.submodule (self: let cfg = self.config; in {
options = {
name = mkOption {
type = types.filename;
default = cfg._module.args.name;
};
envp = mkOption {
type = types.nullOr (types.attrsOf types.str);
default = null;
};
filename = mkOption {
type = mkOptionType {
# TODO unyuck string and merge with toC
name = "derivation or string";
check = x:
isDerivation x ||
isString x;
};
apply = toString;
};
capabilities = mkOption {
default = [];
type = types.listOf types.str;
};
owner = mkOption {
default = "root";
type = types.enum (attrNames users);
};
group = mkOption {
default = "root";
type = types.enum (attrNames groups);
};
mode = mkOption {
default = "4710";
type = mkOptionType {
# TODO admit symbolic mode
name = "octal mode";
check = test "[0-7][0-7][0-7][0-7]";
merge = mergeOneOption;
};
};
wrapperDir = mkOption {
default = config.security.wrapperDir;
type = types.absolute-pathname;
};
activate = mkOption {
type = types.str;
visible = false;
readOnly = true;
};
};
config.activate = let
src = pkgs.exec cfg.name {
inherit (cfg) envp filename;
};
dst = "${cfg.wrapperDir}/${cfg.name}";
in /* sh */ ''
mkdir -p ${cfg.wrapperDir}
cp ${src} ${dst}
chown ${cfg.owner}:${cfg.group} ${dst}
chmod ${cfg.mode} ${dst}
${optionalString (cfg.capabilities != []) /* sh */ ''
${pkgs.libcap.out}/bin/setcap ${concatMapStringsSep "," shell.escape cfg.capabilities} ${dst}
''}
'';
}));
};
imp = {
system.activationScripts."krebs.setuid" = stringAfter [ "wrappers" ]
(concatMapStringsSep "\n"
(cfg: /* sh */ ''
${cfg.activate}
rm -f ${cfg.wrapperDir}/${cfg.name}.real
'')
(attrValues config.krebs.setuid));
};
in out