lisp/url/url-gw.el

   1 ;;; url-gw.el --- Gateway munging for URL loading
   2
   3 ;; Copyright (C) 1997-1998, 2004-2012  Free Software Foundation, Inc.
   4
   5 ;; Author: Bill Perry <wmperry@gnu.org>
   6 ;; Keywords: comm, data, 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 ;;; Code:
  24
  25 (eval-when-compile (require 'cl))
  26 (require 'url-vars)
  27
  28 ;; Fixme: support SSH explicitly or via a url-gateway-rlogin-program?
  29
  30 (autoload 'socks-open-network-stream "socks")
  31
  32 (defgroup url-gateway nil
  33   "URL gateway variables."
  34   :group 'url)
  35
  36 (defcustom url-gateway-local-host-regexp nil
  37   "A regular expression specifying local hostnames/machines."
  38   :type '(choice (const nil) regexp)
  39   :group 'url-gateway)
  40
  41 (defcustom url-gateway-prompt-pattern
  42   "^[^#$%>;]*[#$%>;] *" ;; "bash\\|\$ *\r?$\\|> *\r?"
  43   "A regular expression matching a shell prompt."
  44   :type 'regexp
  45   :group 'url-gateway)
  46
  47 (defcustom url-gateway-rlogin-host nil
  48   "What hostname to actually rlog into before doing a telnet."
  49   :type '(choice (const nil) string)
  50   :group 'url-gateway)
  51
  52 (defcustom url-gateway-rlogin-user-name nil
  53   "Username to log into the remote machine with when using rlogin."
  54   :type '(choice (const nil) string)
  55   :group 'url-gateway)
  56
  57 (defcustom url-gateway-rlogin-parameters '("telnet" "-8")
  58   "Parameters to `url-open-rlogin'.
  59 This list will be used as the parameter list given to rsh."
  60   :type '(repeat string)
  61   :group 'url-gateway)
  62
  63 (defcustom url-gateway-telnet-host nil
  64   "What hostname to actually login to before doing a telnet."
  65   :type '(choice (const nil) string)
  66   :group 'url-gateway)
  67
  68 (defcustom url-gateway-telnet-parameters '("exec" "telnet" "-8")
  69   "Parameters to `url-open-telnet'.
  70 This list will be executed as a command after logging in via telnet."
  71   :type '(repeat string)
  72   :group 'url-gateway)
  73
  74 (defcustom url-gateway-telnet-login-prompt "^\r*.?login:"
  75   "Prompt that tells us we should send our username when logging in w/telnet."
  76   :type 'regexp
  77   :group 'url-gateway)
  78
  79 (defcustom url-gateway-telnet-password-prompt "^\r*.?password:"
  80   "Prompt that tells us we should send our password when logging in w/telnet."
  81   :type 'regexp
  82   :group 'url-gateway)
  83
  84 (defcustom url-gateway-telnet-user-name nil
  85   "User name to log in via telnet with."
  86   :type '(choice (const nil) string)
  87   :group 'url-gateway)
  88
  89 (defcustom url-gateway-telnet-password nil
  90   "Password to use to log in via telnet with."
  91   :type '(choice (const nil) string)
  92   :group 'url-gateway)
  93
  94 (defcustom url-gateway-broken-resolution nil
  95   "Whether to use nslookup to resolve hostnames.
  96 This should be used when your version of Emacs cannot correctly use DNS,
  97 but your machine can.  This usually happens if you are running a statically
  98 linked Emacs under SunOS 4.x."
  99   :type 'boolean
 100   :group 'url-gateway)
 101
 102 (defcustom url-gateway-nslookup-program "nslookup"
 103   "If non-nil then a string naming nslookup program."
 104   :type '(choice (const :tag "None" :value nil) string)
 105   :group 'url-gateway)
 106
 107 ;; Stolen from ange-ftp
 108 ;;;###autoload
 109 (defun url-gateway-nslookup-host (host)
 110   "Attempt to resolve the given HOST using nslookup if possible."
 111   (interactive "sHost:  ")
 112   (if url-gateway-nslookup-program
 113       (let ((proc (start-process " *nslookup*" " *nslookup*"
 114                                  url-gateway-nslookup-program host))
 115             (res host))
 116         (set-process-query-on-exit-flag proc nil)
 117         (with-current-buffer (process-buffer proc)
 118           (while (memq (process-status proc) '(run open))
 119             (accept-process-output proc))
 120           (goto-char (point-min))
 121           (if (re-search-forward "Name:.*\nAddress: *\\(.*\\)$" nil t)
 122               (setq res (buffer-substring (match-beginning 1)
 123                                           (match-end 1))))
 124           (kill-buffer (current-buffer)))
 125         res)
 126     host))
 127
 128 ;; Stolen from red gnus nntp.el
 129 (defun url-wait-for-string (regexp proc)
 130   "Wait until string matching REGEXP arrives in process PROC's buffer."
 131   (let ((buf (current-buffer)))
 132     (goto-char (point-min))
 133     (while (not (re-search-forward regexp nil t))
 134       (accept-process-output proc)
 135       (set-buffer buf)
 136       (goto-char (point-min)))))
 137
 138 ;; Stolen from red gnus nntp.el
 139 (defun url-open-rlogin (name buffer host service)
 140   "Open a connection using rsh."
 141   (if (not (stringp service))
 142       (setq service (int-to-string service)))
 143   (let ((proc (if url-gateway-rlogin-user-name
 144                   (start-process
 145                    name buffer "rsh"
 146                    url-gateway-rlogin-host "-l" url-gateway-rlogin-user-name
 147                    (mapconcat 'identity
 148                               (append url-gateway-rlogin-parameters
 149                                       (list host service)) " "))
 150                 (start-process
 151                  name buffer "rsh" url-gateway-rlogin-host
 152                  (mapconcat 'identity
 153                             (append url-gateway-rlogin-parameters
 154                                     (list host service))
 155                             " ")))))
 156     (set-buffer buffer)
 157     (url-wait-for-string "^\r*200" proc)
 158     (beginning-of-line)
 159     (delete-region (point-min) (point))
 160     proc))
 161
 162 ;; Stolen from red gnus nntp.el
 163 (defun url-open-telnet (name buffer host service)
 164   (if (not (stringp service))
 165       (setq service (int-to-string service)))
 166   (with-current-buffer (get-buffer-create buffer)
 167     (erase-buffer)
 168     (let ((proc (start-process name buffer "telnet" "-8"))
 169           (case-fold-search t))
 170       (when (memq (process-status proc) '(open run))
 171         (process-send-string proc "set escape \^X\n")
 172         (process-send-string proc (concat
 173                                    "open " url-gateway-telnet-host "\n"))
 174         (url-wait-for-string url-gateway-telnet-login-prompt proc)
 175         (process-send-string
 176          proc (concat
 177                (or url-gateway-telnet-user-name
 178                    (setq url-gateway-telnet-user-name (read-string "login: ")))
 179                "\n"))
 180         (url-wait-for-string url-gateway-telnet-password-prompt proc)
 181         (process-send-string
 182          proc (concat
 183                (or url-gateway-telnet-password
 184                    (setq url-gateway-telnet-password
 185                          (read-passwd "Password: ")))
 186                "\n"))
 187         (erase-buffer)
 188         (url-wait-for-string url-gateway-prompt-pattern proc)
 189         (process-send-string
 190          proc (concat (mapconcat 'identity
 191                                  (append url-gateway-telnet-parameters
 192                                          (list host service)) " ") "\n"))
 193         (url-wait-for-string "^\r*Escape character.*\r*\n+" proc)
 194         (delete-region (point-min) (match-end 0))
 195         (process-send-string proc "\^]\n")
 196         (url-wait-for-string "^telnet" proc)
 197         (process-send-string proc "mode character\n")
 198         (accept-process-output proc 1)
 199         (sit-for 1)
 200         (goto-char (point-min))
 201         (forward-line 1)
 202         (delete-region (point) (point-max)))
 203       proc)))
 204
 205 ;;;###autoload
 206 (defun url-open-stream (name buffer host service)
 207   "Open a stream to HOST, possibly via a gateway.
 208 Args per `open-network-stream'.
 209 Will not make a connection if `url-gateway-unplugged' is non-nil.
 210 Might do a non-blocking connection; use `process-status' to check."
 211   (unless url-gateway-unplugged
 212     (let ((gw-method (if (and url-gateway-local-host-regexp
 213                               (not (eq 'tls url-gateway-method))
 214                               (not (eq 'ssl url-gateway-method))
 215                               (string-match
 216                                url-gateway-local-host-regexp
 217                                host))
 218                          'native
 219                        url-gateway-method))
 220           ;; An attempt to deal with denied connections, and attempt
 221           ;; to reconnect
 222           (cur-retries 0)
 223           (retry t)
 224           (errobj nil)
 225           (conn nil))
 226
 227       ;; If the user told us to do DNS for them, do it.
 228       (if url-gateway-broken-resolution
 229           (setq host (url-gateway-nslookup-host host)))
 230
 231       (condition-case errobj
 232           ;; This is a clean way to ensure the new process inherits the
 233           ;; right coding systems in both Emacs and XEmacs.
 234           (let ((coding-system-for-read 'binary)
 235                 (coding-system-for-write 'binary))
 236             (setq conn (case gw-method
 237                          ((tls ssl native)
 238                           (if (eq gw-method 'native)
 239                               (setq gw-method 'plain))
 240                           (open-network-stream
 241                            name buffer host service
 242                            :type gw-method
 243                            ;; Use non-blocking socket if we can.
 244                            :nowait (featurep 'make-network-process
 245                                              '(:nowait t))))
 246                          (socks
 247                           (socks-open-network-stream name buffer host service))
 248                          (telnet
 249                           (url-open-telnet name buffer host service))
 250                          (rlogin
 251                           (url-open-rlogin name buffer host service))
 252                          (otherwise
 253                           (error "Bad setting of url-gateway-method: %s"
 254                                  url-gateway-method))))))
 255       conn)))
 256
 257 (provide 'url-gw)
 258
 259 ;;; url-gw.el ends here