From ebd199184d7273753e9ee51553927cd22a9ffd61 Mon Sep 17 00:00:00 2001
From: Richard Marko <srk@48.io>
Date: Tue, 28 Apr 2020 18:32:22 +0200
Subject: [PATCH] nixos/proxychains: init

---
 nixos/modules/module-list.nix          |   1 +
 nixos/modules/programs/proxychains.nix | 165 +++++++++++++++++++++++++
 2 files changed, 166 insertions(+)
 create mode 100644 nixos/modules/programs/proxychains.nix

diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index c54bc6098d3..d70d95f61c4 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -143,6 +143,7 @@
   ./programs/npm.nix
   ./programs/oblogout.nix
   ./programs/plotinus.nix
+  ./programs/proxychains.nix
   ./programs/qt5ct.nix
   ./programs/screen.nix
   ./programs/sedutil.nix
diff --git a/nixos/modules/programs/proxychains.nix b/nixos/modules/programs/proxychains.nix
new file mode 100644
index 00000000000..7743f79c1c0
--- /dev/null
+++ b/nixos/modules/programs/proxychains.nix
@@ -0,0 +1,165 @@
+{ config, lib, pkgs, ... }:
+with lib;
+let
+
+  cfg = config.programs.proxychains;
+
+  configFile = ''
+    ${cfg.chain.type}_chain
+    ${optionalString (cfg.chain.type == "random")
+    "chain_len = ${builtins.toString cfg.chain.length}"}
+    ${optionalString cfg.proxyDNS "proxy_dns"}
+    ${optionalString cfg.quietMode "quiet_mode"}
+    remote_dns_subnet ${builtins.toString cfg.remoteDNSSubnet}
+    tcp_read_time_out ${builtins.toString cfg.tcpReadTimeOut}
+    tcp_connect_time_out ${builtins.toString cfg.tcpConnectTimeOut}
+    localnet ${cfg.localnet}
+    [ProxyList]
+    ${builtins.concatStringsSep "\n"
+      (lib.mapAttrsToList (k: v: "${v.type} ${v.host} ${builtins.toString v.port}")
+        (lib.filterAttrs (k: v: v.enable) cfg.proxies))}
+  '';
+
+  proxyOptions = {
+    options = {
+      enable = mkEnableOption "this proxy";
+
+      type = mkOption {
+        type = types.enum [ "http" "socks4" "socks5" ];
+        description = "Proxy type.";
+      };
+
+      host = mkOption {
+        type = types.str;
+        description = "Proxy host or IP address.";
+      };
+
+      port = mkOption {
+        type = types.port;
+        description = "Proxy port";
+      };
+    };
+  };
+
+in {
+
+  ###### interface
+
+  options = {
+
+    programs.proxychains = {
+
+      enable = mkEnableOption "installing proxychains configuration";
+
+      chain = {
+        type = mkOption {
+          type = types.enum [ "dynamic" "strict" "random" ];
+          default = "strict";
+          description = ''
+            <literal>dynamic</literal> - Each connection will be done via chained proxies
+            all proxies chained in the order as they appear in the list
+            at least one proxy must be online to play in chain
+            (dead proxies are skipped)
+            otherwise <literal>EINTR</literal> is returned to the app.
+
+            <literal>strict</literal> - Each connection will be done via chained proxies
+            all proxies chained in the order as they appear in the list
+            all proxies must be online to play in chain
+            otherwise <literal>EINTR</literal> is returned to the app.
+
+            <literal>random</literal> - Each connection will be done via random proxy
+            (or proxy chain, see <option>programs.proxychains.chain.length</option>) from the list.
+          '';
+        };
+        length = mkOption {
+          type = types.nullOr types.int;
+          default = null;
+          description = ''
+            Chain length for random chain.
+          '';
+        };
+      };
+
+      proxyDNS = mkOption {
+        type = types.bool;
+        default = true;
+        description = "Proxy DNS requests - no leak for DNS data.";
+      };
+
+      quietMode = mkEnableOption "Quiet mode (no output from the library).";
+
+      remoteDNSSubnet = mkOption {
+        type = types.enum [ 10 127 224 ];
+        default = 224;
+        description = ''
+          Set the class A subnet number to use for the internal remote DNS mapping, uses the reserved 224.x.x.x range by default.
+        '';
+      };
+
+      tcpReadTimeOut = mkOption {
+        type = types.int;
+        default = 15000;
+        description = "Connection read time-out in milliseconds.";
+      };
+
+      tcpConnectTimeOut = mkOption {
+        type = types.int;
+        default = 8000;
+        description = "Connection time-out in milliseconds.";
+      };
+
+      localnet = mkOption {
+        type = types.str;
+        default = "127.0.0.0/255.0.0.0";
+        description = "By default enable localnet for loopback address ranges.";
+      };
+
+      proxies = mkOption {
+        type = types.attrsOf (types.submodule proxyOptions);
+        description = ''
+          Proxies to be used by proxychains.
+        '';
+
+        example = literalExample ''
+          { myproxy =
+            { type = "socks4";
+              host = "127.0.0.1";
+              port = 1337;
+            };
+          }
+        '';
+      };
+
+    };
+
+  };
+
+  ###### implementation
+
+  meta.maintainers = with maintainers; [ sorki ];
+
+  config = mkIf cfg.enable {
+
+    assertions = singleton {
+      assertion = cfg.chain.type != "random" && cfg.chain.length == null;
+      message = ''
+        Option `programs.proxychains.chain.length`
+        only makes sense with `programs.proxychains.chain.type` = "random".
+      '';
+    };
+
+    programs.proxychains.proxies = mkIf config.services.tor.client.enable
+      {
+        torproxy = mkDefault {
+          enable = true;
+          type = "socks4";
+          host = "127.0.0.1";
+          port = 9050;
+        };
+      };
+
+    environment.etc."proxychains.conf".text = configFile;
+    environment.systemPackages = [ pkgs.proxychains ];
+  };
+
+}