(require 'erc)
(defvar erc-identd-process nil)
(defgroup erc-identd nil
"Run a local identd server."
:group 'erc)
(defcustom erc-identd-port 8113
"Port to run the identd server on if not specified in the argument for
`erc-identd-start'.
This can be either a string or a number."
:group 'erc-identd
:type '(choice (const :tag "None" nil)
(integer :tag "Port number")
(string :tag "Port string")))
(define-erc-module identd nil
"This mode launches an identd server on port 8113."
((add-hook 'erc-connect-pre-hook 'erc-identd-quickstart)
(add-hook 'erc-disconnected-hook 'erc-identd-stop))
((remove-hook 'erc-connect-pre-hook 'erc-identd-quickstart)
(remove-hook 'erc-disconnected-hook 'erc-identd-stop)))
(defun erc-identd-filter (proc string)
"This filter implements RFC1413 (identd authentication protocol)."
(let ((erc-identd-process proc))
(when (string-match "\\([0-9]+\\)\\s-*,\\s-*\\([0-9]+\\)" string)
(let ((port-on-server (match-string 1 string))
(port-on-client (match-string 2 string)))
(send-string erc-identd-process
(format "%s, %s : USERID : %s : %s\n"
port-on-server port-on-client
system-type (user-login-name)))
(process-send-eof erc-identd-process)))))
(defun erc-identd-start (&optional port)
"Start an identd server listening to port 8113.
Port 113 (auth) will need to be redirected to port 8113 on your
machine -- using iptables, or a program like redir which can be
run from inetd. The idea is to provide a simple identd server
when you need one, without having to install one globally on your
system."
(interactive (list (read-string "Serve identd requests on port: " "8113")))
(unless port (setq port erc-identd-port))
(when (stringp port)
(setq port (string-to-number port)))
(when erc-identd-process
(delete-process erc-identd-process))
(setq erc-identd-process
(make-network-process :name "identd"
:buffer nil
:host 'local :service port
:server t :noquery t :nowait t
:filter 'erc-identd-filter))
(set-process-query-on-exit-flag erc-identd-process nil))
(defun erc-identd-quickstart (&rest ignored)
"Start the identd server with the default port.
The default port is specified by `erc-identd-port'."
(erc-identd-start))
(defun erc-identd-stop (&rest ignore)
(interactive)
(when erc-identd-process
(delete-process erc-identd-process)
(setq erc-identd-process nil)))
(provide 'erc-identd)