1;;; erc-identd.el --- RFC1413 (identd authentication protocol) server
2
3;; Copyright (C) 2003, 2006, 2007 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 2, or (at your option)
13;; 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; see the file COPYING.  If not, write to the
22;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
23;; Boston, MA 02110-1301, USA.
24
25;;; Commentary:
26
27;; This module allows you to run a local identd server on port 8113.
28;; You will need to set up DNAT to bind 113->8113, or use a proxy.
29
30;; To use this module, add identd to `erc-modules' and run
31;; `erc-update-modules'.
32
33;; Here is an example /etc/inetd.conf rule that forwards identd
34;; traffic to port 8113.  You will need simpleproxy installed for it
35;; to work.
36
37;; 113 stream tcp nowait nobody /usr/sbin/tcpd /usr/bin/simpleproxy simpleproxy -i -R 127.0.0.1:8113
38
39;;; Code:
40
41(require 'erc)
42
43(defvar erc-identd-process nil)
44
45(defgroup erc-identd nil
46  "Run a local identd server."
47  :group 'erc)
48
49(defcustom erc-identd-port 8113
50  "Port to run the identd server on if not specified in the argument for
51`erc-identd-start'.
52
53This can be either a string or a number."
54  :group 'erc-identd
55  :type '(choice (const :tag "None" nil)
56		 (integer :tag "Port number")
57		 (string :tag "Port string")))
58
59;;;###autoload (autoload 'erc-identd-mode "erc-identd")
60(define-erc-module identd nil
61  "This mode launches an identd server on port 8113."
62  ((add-hook 'erc-connect-pre-hook 'erc-identd-quickstart)
63   (add-hook 'erc-disconnected-hook 'erc-identd-stop))
64  ((remove-hook 'erc-connect-pre-hook 'erc-identd-quickstart)
65   (remove-hook 'erc-disconnected-hook 'erc-identd-stop)))
66
67(defun erc-identd-filter (proc string)
68  "This filter implements RFC1413 (identd authentication protocol)."
69  (let ((erc-identd-process proc))
70    (when (string-match "\\([0-9]+\\)\\s-*,\\s-*\\([0-9]+\\)" string)
71      (let ((port-on-server (match-string 1 string))
72	    (port-on-client (match-string 2 string)))
73	(send-string erc-identd-process
74		     (format "%s, %s : USERID : %s : %s\n"
75			     port-on-server port-on-client
76			     system-type (user-login-name)))
77	(process-send-eof erc-identd-process)))))
78
79;;;###autoload
80(defun erc-identd-start (&optional port)
81  "Start an identd server listening to port 8113.
82Port 113 (auth) will need to be redirected to port 8113 on your
83machine -- using iptables, or a program like redir which can be
84run from inetd.  The idea is to provide a simple identd server
85when you need one, without having to install one globally on your
86system."
87  (interactive (list (read-string "Serve identd requests on port: " "8113")))
88  (unless port (setq port erc-identd-port))
89  (when (stringp port)
90    (setq port (string-to-number port)))
91  (when erc-identd-process
92    (delete-process erc-identd-process))
93  (setq erc-identd-process
94	(make-network-process :name "identd"
95			      :buffer nil
96			      :host 'local :service port
97			      :server t :noquery t :nowait t
98			      :filter 'erc-identd-filter))
99  (set-process-query-on-exit-flag erc-identd-process nil))
100
101(defun erc-identd-quickstart (&rest ignored)
102  "Start the identd server with the default port.
103The default port is specified by `erc-identd-port'."
104  (erc-identd-start))
105
106;;;###autoload
107(defun erc-identd-stop (&rest ignore)
108  (interactive)
109  (when erc-identd-process
110    (delete-process erc-identd-process)
111    (setq erc-identd-process nil)))
112
113(provide 'erc-identd)
114
115;;; erc-identd.el ends here
116;;
117;; Local Variables:
118;; indent-tabs-mode: t
119;; tab-width: 8
120;; End:
121
122;; arch-tag: e0b5f926-0f35-40b9-8ddb-ca06b62a7544
123