lisp/erc/erc-identd.el

   1 ;;; erc-identd.el --- RFC1413 (identd authentication protocol) server
   2
   3 ;; Copyright (C) 2003, 2006-2012 Free Software Foundation, Inc.
   4
   5 ;; Author: John Wiegley <johnw@gnu.org>
   6 ;; Keywords: comm, processes
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; This module allows you to run a local identd server on port 8113.
  26 ;; You will need to set up DNAT to bind 113->8113, or use a proxy.
  27
  28 ;; To use this module, add identd to `erc-modules' and run
  29 ;; `erc-update-modules'.
  30
  31 ;; Here is an example /etc/inetd.conf rule that forwards identd
  32 ;; traffic to port 8113.  You will need simpleproxy installed for it
  33 ;; to work.
  34
  35 ;; 113 stream tcp nowait nobody /usr/sbin/tcpd /usr/bin/simpleproxy simpleproxy -i -R 127.0.0.1:8113
  36
  37 ;;; Code:
  38
  39 (require 'erc)
  40
  41 (defvar erc-identd-process nil)
  42
  43 (defgroup erc-identd nil
  44   "Run a local identd server."
  45   :group 'erc)
  46
  47 (defcustom erc-identd-port 8113
  48   "Port to run the identd server on if not specified in the argument for
  49 `erc-identd-start'.
  50
  51 This can be either a string or a number."
  52   :group 'erc-identd
  53   :type '(choice (const :tag "None" nil)
  54                  (integer :tag "Port number")
  55                  (string :tag "Port string")))
  56
  57 ;;;###autoload (autoload 'erc-identd-mode "erc-identd")
  58 (define-erc-module identd nil
  59   "This mode launches an identd server on port 8113."
  60   ((add-hook 'erc-connect-pre-hook 'erc-identd-quickstart)
  61    (add-hook 'erc-disconnected-hook 'erc-identd-stop))
  62   ((remove-hook 'erc-connect-pre-hook 'erc-identd-quickstart)
  63    (remove-hook 'erc-disconnected-hook 'erc-identd-stop)))
  64
  65 (defun erc-identd-filter (proc string)
  66   "This filter implements RFC1413 (identd authentication protocol)."
  67   (let ((erc-identd-process proc))
  68     (when (string-match "\\([0-9]+\\)\\s-*,\\s-*\\([0-9]+\\)" string)
  69       (let ((port-on-server (match-string 1 string))
  70             (port-on-client (match-string 2 string)))
  71         (send-string erc-identd-process
  72                      (format "%s, %s : USERID : %s : %s\n"
  73                              port-on-server port-on-client
  74                              system-type (user-login-name)))
  75         (stop-process erc-identd-process)
  76         (delete-process proc)))))
  77
  78 ;;;###autoload
  79 (defun erc-identd-start (&optional port)
  80   "Start an identd server listening to port 8113.
  81 Port 113 (auth) will need to be redirected to port 8113 on your
  82 machine -- using iptables, or a program like redir which can be
  83 run from inetd.  The idea is to provide a simple identd server
  84 when you need one, without having to install one globally on your
  85 system."
  86   (interactive (list (read-string "Serve identd requests on port: " "8113")))
  87   (unless port (setq port erc-identd-port))
  88   (when (stringp port)
  89     (setq port (string-to-number port)))
  90   (when erc-identd-process
  91     (delete-process erc-identd-process))
  92   (setq erc-identd-process
  93         (make-network-process :name "identd"
  94                               :buffer nil
  95                               :host 'local :service port
  96                               :server t :noquery t :nowait t
  97                               :filter 'erc-identd-filter))
  98   (set-process-query-on-exit-flag erc-identd-process nil))
  99
 100 (defun erc-identd-quickstart (&rest ignored)
 101   "Start the identd server with the default port.
 102 The default port is specified by `erc-identd-port'."
 103   (erc-identd-start))
 104
 105 ;;;###autoload
 106 (defun erc-identd-stop (&rest ignore)
 107   (interactive)
 108   (when erc-identd-process
 109     (delete-process erc-identd-process)
 110     (setq erc-identd-process nil)))
 111
 112 (provide 'erc-identd)
 113
 114 ;;; erc-identd.el ends here
 115 ;;
 116 ;; Local Variables:
 117 ;; indent-tabs-mode: t
 118 ;; tab-width: 8
 119 ;; End:
 120