1 files changed, 391 insertions, 0 deletions

diff --git a/modules/uucp.nix b/modules/uucp.nix
new file mode 100644
index 00000000..8d8ac1a2
--- /dev/null
+++ b/modules/uucp.nix
@@ -0,0 +1,391 @@
+{ flake, config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  portSpec = name: node: concatStringsSep "\n" (map (port: ''
+    port ${name}.${port}
+    type pipe
+    protocol ${node.protocols}
+    reliable true
+    command ${pkgs.openssh}/bin/ssh -x -o batchmode=yes ${name}.${port}
+  '') node.hostnames);
+  sysSpec = name: node: ''
+    system ${name}
+    time any
+    chat-seven-bit false
+    chat . ""
+    protocol ${node.protocols}
+    command-path ${concatStringsSep " " cfg.commandPath}
+    commands ${concatStringsSep " " node.commands}
+    ${concatStringsSep "\nalternate\n" (map (port: ''
+      port ${name}.${port}
+    '') node.hostnames)}
+  '';
+  sshConfig = name: node: concatStringsSep "\n" (map (port: ''
+    Host ${name}.${port}
+      Hostname ${port}
+      IdentitiesOnly Yes
+      IdentityFile ${cfg.sshKeyDir}/${name}
+  '') node.hostnames);
+  sshKeyGen = name: node: ''
+    if [[ ! -e ${cfg.sshKeyDir}/${name} ]]; then
+      ${pkgs.openssh}/bin/ssh-keygen ${escapeShellArgs node.generateKey} -f ${cfg.sshKeyDir}/${name}
+    fi
+  '';
+  restrictKey = key: ''
+    restrict,command="${chat}" ${key}
+  '';
+  chat = pkgs.writeScript "chat" ''
+    #!${pkgs.stdenv.shell}
+
+    echo .
+    exec ${config.security.wrapperDir}/uucico
+  '';
+
+  nodeCfg = {
+    options = {
+      commands = mkOption {
+        type = types.listOf types.str;
+        default = cfg.defaultCommands;
+        description = "Commands to allow for this remote";
+      };
+
+      protocols = mkOption {
+        type = types.separatedString "";
+              default = cfg.defaultProtocols;
+              description = "UUCP protocols to use for this remote";
+      };
+
+      publicKeys = mkOption {
+        type = types.listOf types.str;
+        default = [];
+        description = "SSH client public keys for this node";
+      };
+
+      generateKey = mkOption {
+        type = types.listOf types.str;
+        default = [ "-t" "ed25519" "-N" "" ];
+        description = "Arguments to pass to `ssh-keygen` to generate a keypair for communication with this host";
+      };
+
+      hostnames = mkOption {
+        type = types.listOf types.str;
+        default = [];
+        description = "Hostnames to try in order when connecting";
+      };
+    };
+  };
+
+  cfg = config.services.uucp;
+in {
+  options = {
+    services.uucp = {
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          If enabled we set up an account accesible via uucp over ssh
+        '';
+      };
+
+      nodeName = mkOption {
+        type = types.str;
+        default = "nixos";
+        description = "uucp node name";
+      };
+
+      sshUser = mkOption { 
+        type = types.attrs;
+        default = {};
+        description = "Overrides for the local uucp linux-user";
+      };
+
+      extraSSHConfig = mkOption {
+        type = types.str;
+        default = "";
+        description = "Extra SSH config";
+      };
+
+      remoteNodes = mkOption {
+        type = types.attrsOf (types.submodule nodeCfg);
+        default = {};
+        description = ''
+          Ports to set up
+          Names will probably need to be configured in sshConfig
+        '';
+      };
+
+      commandPath = mkOption {
+        type = types.listOf types.path;
+        default = [ "${pkgs.rmail}/bin" ];
+        description = ''
+          Command search path for all systems
+        '';
+      };
+
+      defaultCommands = mkOption {
+        type = types.listOf types.str;
+        default = ["rmail"];
+        description = "Commands allowed for remotes without explicit override";
+      };
+
+      defaultProtocols = mkOption {
+        type = types.separatedString "";
+              default = "te";
+              description = "UUCP protocol to use within ssh unless overriden";
+      };
+
+      incomingProtocols = mkOption {
+        type = types.separatedString "";
+        default = "te";
+        description = "UUCP protocols to use when called";
+      };
+
+      homeDir = mkOption {
+        type = types.path;
+        default = "/var/uucp";
+        description = "Home of the uucp user";
+      };
+
+      sshKeyDir = mkOption {
+        type = types.path;
+        default = "${cfg.homeDir}/.ssh/";
+        description = "Directory to store ssh keypairs";
+      };
+
+      spoolDir = mkOption {
+        type = types.path;
+        default = "/var/spool/uucp";
+        description = "Spool directory";
+      };
+
+      lockDir = mkOption {
+        type = types.path;
+        default = "/var/spool/uucp";
+        description = "Lock directory";
+      };
+
+      pubDir = mkOption {
+        type = types.path;
+        default = "/var/spool/uucppublic";
+        description = "Public directory";
+      };
+
+      logFile = mkOption {
+        type = types.path;
+        default = "/var/log/uucp";
+        description = "Log file";
+      };
+
+      statFile = mkOption {
+        type = types.path;
+        default = "/var/log/uucp.stat";
+        description = "Statistics file";
+      };
+
+      debugFile = mkOption {
+        type = types.path;
+        default = "/var/log/uucp.debug";
+        description = "Debug file";
+      };
+
+      interval = mkOption {
+        type = types.nullOr types.str;
+        default = "1h";
+        description = ''
+          Specification of when to run `uucico' in format used by systemd timers
+          The default is to do so every hour
+        '';
+      };
+
+      nmDispatch = mkOption {
+        type = types.bool;
+        default = config.networking.networkmanager.enable;
+        description = ''
+          Install a network-manager dispatcher script to automatically
+          call all remotes when networking is available
+        '';
+      };
+
+      extraConfig = mkOption {
+        type = types.lines;
+        default = ''
+          run-uuxqt 1
+        '';
+        description = "Extra configuration to append verbatim to `/etc/uucp/config'";
+      };
+
+      extraSys = mkOption {
+        type = types.lines;
+        default = ''
+          protocol-parameter g packet-size 4096
+        '';
+              description = "Extra configuration to prepend verbatim to `/etc/uucp/sys`";
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment.etc."uucp/config" = {
+      text = ''
+        hostname ${cfg.nodeName}
+      
+        spool ${cfg.spoolDir}
+        lockdir ${cfg.lockDir}
+        pubdir ${cfg.pubDir}
+        logfile ${cfg.logFile}
+        statfile ${cfg.statFile}
+        debugfile ${cfg.debugFile}
+        
+        ${cfg.extraConfig}
+      '';
+    };
+
+    users.users."uucp" = {
+      name = "uucp";
+      isSystemUser = true;
+      isNormalUser = false;
+      createHome = true;
+      home = cfg.homeDir;
+      description = "User for uucp over ssh";
+      useDefaultShell = true;
+      openssh.authorizedKeys.keys = map restrictKey (concatLists (mapAttrsToList (name: node: node.publicKeys) cfg.remoteNodes));
+    } // cfg.sshUser;
+
+    system.activationScripts."uucp-sshconfig" = ''
+      mkdir -p ${config.users.users."uucp".home}/.ssh
+      chown ${config.users.users."uucp".name}:${config.users.users."uucp".group} ${config.users.users."uucp".home}/.ssh
+      chmod 700 ${config.users.users."uucp".home}/.ssh
+      ln -fs ${builtins.toFile "ssh-config" ''
+        ${concatStringsSep "\n" (mapAttrsToList sshConfig cfg.remoteNodes)}
+      
+        ${cfg.extraSSHConfig}
+      ''} ${config.users.users."uucp".home}/.ssh/config
+
+      mkdir -p ${cfg.sshKeyDir}
+      chown ${config.users.users."uucp".name}:${config.users.users."uucp".group} ${cfg.sshKeyDir}
+      chmod 700 ${cfg.sshKeyDir}
+
+      ${concatStringsSep "\n" (mapAttrsToList sshKeyGen cfg.remoteNodes)}
+    '';
+
+    system.activationScripts."uucp-logs" = ''
+      touch ${cfg.logFile}
+      chown ${config.users.users."uucp".name}:${config.users.users."uucp".group} ${cfg.logFile}
+      chmod 644 ${cfg.logFile}
+      touch ${cfg.statFile}
+      chown ${config.users.users."uucp".name}:${config.users.users."uucp".group} ${cfg.statFile}
+      chmod 644 ${cfg.statFile}
+      touch ${cfg.debugFile}
+      chown ${config.users.users."uucp".name}:${config.users.users."uucp".group} ${cfg.debugFile}
+      chmod 644 ${cfg.debugFile}
+    '';
+
+    environment.etc."uucp/port" = {
+      text = ''
+        port ssh
+        type stdin
+        protocol ${cfg.incomingProtocols}
+      '' + concatStringsSep "\n" (mapAttrsToList portSpec cfg.remoteNodes);
+    };
+    environment.etc."uucp/sys" = {
+      text = cfg.extraSys + "\n" + concatStringsSep "\n" (mapAttrsToList sysSpec cfg.remoteNodes);
+    };
+
+    security.wrappers = let
+      wrapper = p: {
+        name = p;
+        value = {
+          source = "${pkgs.uucp}/bin/${p}";
+          owner = "root";
+          group = "root";
+          setuid = true;
+          setgid = false;
+        };
+      };
+    in listToAttrs (map wrapper ["uucico" "cu" "uucp" "uuname" "uustat" "uux" "uuxqt"]);
+
+    nixpkgs.overlays = [(self: super: {
+      uucp = super.stdenv.lib.overrideDerivation super.uucp (oldAttrs: {
+        configureFlags = "--with-newconfigdir=/etc/uucp";
+        patches = [
+          (super.writeText "mailprogram" ''
+             policy.h | 2 +-
+             1 file changed, 1 insertion(+), 1 deletion(-)
+
+            diff --git a/policy.h b/policy.h
+            index 5afe34b..8e92c8b 100644
+            --- a/policy.h
+            +++ b/policy.h
+            @@ -240,7 +240,7 @@
+                the sendmail choice below.  Otherwise, select one of the other
+                choices as appropriate.  */
+             #if 1
+            -#define MAIL_PROGRAM "/usr/lib/sendmail -t"
+            +#define MAIL_PROGRAM "${config.security.wrapperDir}/sendmail -t"
+             /* #define MAIL_PROGRAM "/usr/sbin/sendmail -t" */
+             #define MAIL_PROGRAM_TO_BODY 1
+             #define MAIL_PROGRAM_SUBJECT_BODY 1
+          '')
+        ];
+      });
+      rmail = super.writeScriptBin "rmail" ''
+          #!${super.stdenv.shell}
+
+          # Dummy UUCP rmail command for postfix/qmail systems
+
+          IFS=" " read junk from junk junk junk junk junk junk junk relay
+
+          case "$from" in
+            *[@!]*) ;;
+            *) from="$from@$relay";;
+          esac
+
+          exec ${config.security.wrapperDir}/sendmail -G -i -f "$from" -- "$@"
+        '';
+    })];
+
+    environment.systemPackages = with pkgs; [
+      uucp
+    ];
+
+    systemd.services."uucico@" = {
+      serviceConfig = {
+        User = "uucp";
+        Type = "oneshot";
+        ExecStart = "${config.security.wrapperDir}/uucico -D -S %i";
+      };
+    };
+
+    systemd.timers."uucico@" = {
+      timerConfig.OnActiveSec = cfg.interval;
+      timerConfig.OnUnitActiveSec = cfg.interval;
+    };
+
+    systemd.targets."multi-user" = {
+      wants = mapAttrsToList (name: node: "uucico@${name}.timer") cfg.remoteNodes;
+    };
+
+    systemd.kill-user.enable = true;
+    systemd.targets."sleep" = {
+      after = [ "kill-user@uucp.service" ];
+      wants = [ "kill-user@uucp.service" ];
+    };
+    
+    networking.networkmanager.dispatcherScripts = optional cfg.nmDispatch {
+      type = "basic";
+      source = pkgs.writeScript "callRemotes.sh" ''
+        #!${pkgs.stdenv.shell}
+
+        shopt -s extglob
+
+        case "''${2}" in
+          (?(vpn-)up)
+            ${concatStringsSep "\n    " (mapAttrsToList (name: node: "${pkgs.systemd}/bin/systemctl start uucico@${name}.service") cfg.remoteNodes)}
+            ;;
+        esac
+      '';
+    };
+  };
+}