lisp/net/socks.el

   1 ;;; socks.el --- A Socks v5 Client for Emacs
   2
   3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2002,
   4 ;;   2007, 2008, 2009 Free Software Foundation, Inc.
   5
   6 ;; Author: William M. Perry <wmperry@gnu.org>
   7 ;;         Dave Love <fx@gnu.org>
   8 ;; Keywords: comm, firewalls
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; This is an implementation of the SOCKS v5 protocol as defined in
  28 ;; RFC 1928.
  29
  30 ;; TODO
  31 ;; - Finish the redirection rules stuff
  32 ;; - Implement composition of servers.  Recursively evaluate the
  33 ;;   redirection rules and do SOCKS-over-HTTP and SOCKS-in-SOCKS
  34
  35 (eval-when-compile
  36   (require 'wid-edit))
  37 (require 'custom)
  38
  39 (if (not (fboundp 'split-string))
  40     (defun split-string (string &optional pattern)
  41       "Return a list of substrings of STRING which are separated by PATTERN.
  42 If PATTERN is omitted, it defaults to \"[ \\f\\t\\n\\r\\v]+\"."
  43       (or pattern
  44           (setq pattern "[ \f\t\n\r\v]+"))
  45       (let (parts (start 0))
  46         (while (string-match pattern string start)
  47           (setq parts (cons (substring string start (match-beginning 0)) parts)
  48                 start (match-end 0)))
  49         (nreverse (cons (substring string start) parts)))))
  50 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  51 ;;; Custom widgets
  52 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  53 (define-widget 'dynamic-choice 'menu-choice
  54   "A pretty simple dynamic dropdown list"
  55   :format "%[%t%]: %v"
  56   :tag "Network"
  57   :case-fold t
  58   :void '(item :format "invalid (%t)\n")
  59   :value-create 's5-widget-value-create
  60   :value-delete 'widget-children-value-delete
  61   :value-get 'widget-choice-value-get
  62   :value-inline 'widget-choice-value-inline
  63   :mouse-down-action 'widget-choice-mouse-down-action
  64   :action 'widget-choice-action
  65   :error "Make a choice"
  66   :validate 'widget-choice-validate
  67   :match 's5-dynamic-choice-match
  68   :match-inline 's5-dynamic-choice-match-inline)
  69
  70 (defun s5-dynamic-choice-match (widget value)
  71   (let ((choices (funcall (widget-get widget :choice-function)))
  72         current found)
  73     (while (and choices (not found))
  74       (setq current (car choices)
  75             choices (cdr choices)
  76             found (widget-apply current :match value)))
  77     found))
  78
  79 (defun s5-dynamic-choice-match-inline (widget value)
  80   (let ((choices (funcall (widget-get widget :choice-function)))
  81         current found)
  82     (while (and choices (not found))
  83       (setq current (car choices)
  84             choices (cdr choices)
  85             found (widget-match-inline current value)))
  86     found))
  87
  88 (defun s5-widget-value-create (widget)
  89   (let ((choices (funcall (widget-get widget :choice-function)))
  90         (value (widget-get widget :value)))
  91     (if (not value)
  92         (widget-put widget :value (widget-value (car choices))))
  93     (widget-put widget :args choices)
  94     (widget-choice-value-create widget)))
  95
  96 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  97 ;;; Customization support
  98 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  99 (defgroup socks nil
 100   "SOCKS Support"
 101   :version "22.2"
 102   :prefix "socks-"
 103   :group 'processes)
 104
 105 '(defcustom socks-server-aliases nil
 106   "A list of server aliases for use in access control and filtering rules."
 107   :group 'socks
 108   :type '(repeat (list :format "%v"
 109                        :value ("" "" 1080 5)
 110                        (string :tag "Alias")
 111                        (string :tag "Hostname/IP Address")
 112                        (integer :tag "Port #")
 113                        (choice :tag "SOCKS Version"
 114                                (integer :tag "SOCKS v4" :value 4)
 115                                (integer :tag "SOCKS v5" :value 5)))))
 116
 117 '(defcustom socks-network-aliases
 118   '(("Anywhere" (netmask "0.0.0.0" "0.0.0.0")))
 119   "A list of network aliases for use in subsequent rules."
 120   :group 'socks
 121   :type '(repeat (list :format "%v"
 122                        :value (netmask "" "255.255.255.0")
 123                        (string :tag "Alias")
 124                        (radio-button-choice
 125                         :format "%v"
 126                         (list :tag  "IP address range"
 127                               (const :format "" :value range)
 128                               (string :tag "From")
 129                               (string :tag "To"))
 130                         (list :tag  "IP address/netmask"
 131                               (const :format "" :value netmask)
 132                               (string :tag "IP Address")
 133                               (string :tag "Netmask"))
 134                         (list :tag  "Domain Name"
 135                               (const :format "" :value domain)
 136                               (string :tag "Domain name"))
 137                         (list :tag  "Unique hostname/IP address"
 138                               (const :format "" :value exact)
 139                               (string :tag "Hostname/IP Address"))))))
 140
 141 '(defun s5-servers-filter ()
 142   (if socks-server-aliases
 143       (mapcar (lambda (x) (list 'const :tag (car x) :value (car x))) s5-server-aliases)
 144     '((const :tag "No aliases defined" :value nil))))
 145
 146 '(defun s5-network-aliases-filter ()
 147   (mapcar (lambda (x) (list 'const :tag (car x) :value (car x)))
 148           socks-network-aliases))
 149
 150 '(defcustom socks-redirection-rules
 151    nil
 152    "A list of redirection rules."
 153    :group 'socks
 154    :type '(repeat (list :format "%v"
 155                         :value ("Anywhere" nil)
 156                         (dynamic-choice :choice-function s5-network-aliases-filter
 157                                         :tag "Destination network")
 158                         (radio-button-choice
 159                          :tag "Connection type"
 160                          (const :tag "Direct connection" :value nil)
 161                          (dynamic-choice :format "%t: %[%v%]"
 162                                          :choice-function s5-servers-filter
 163                                          :tag "Proxy chain via")))))
 164
 165 (defcustom socks-server
 166   (list "Default server" "socks" 1080 5)
 167   ""
 168   :group 'socks
 169   :type '(list
 170           (string :format "" :value "Default server")
 171           (string :tag "Server")
 172           (integer :tag "Port")
 173           (radio-button-choice :tag "SOCKS Version"
 174                                :format "%t: %v"
 175                                (const :tag "SOCKS v4  " :format "%t" :value 4)
 176                                (const :tag "SOCKS v5"   :format "%t" :value 5))))
 177
 178
 179 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 180 ;;; Get down to the nitty gritty
 181 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 182 (defconst socks-version 5)
 183 (defvar socks-debug nil)
 184
 185 ;; Common socks v5 commands
 186 (defconst socks-connect-command 1)
 187 (defconst socks-bind-command 2)
 188 (defconst socks-udp-associate-command 3)
 189
 190 ;; Miscellaneous other socks constants
 191 (defconst socks-authentication-null 0)
 192 (defconst socks-authentication-failure 255)
 193
 194 ;; Response codes
 195 (defconst socks-response-success               0)
 196 (defconst socks-response-general-failure       1)
 197 (defconst socks-response-access-denied         2)
 198 (defconst socks-response-network-unreachable   3)
 199 (defconst socks-response-host-unreachable      4)
 200 (defconst socks-response-connection-refused    5)
 201 (defconst socks-response-ttl-expired           6)
 202 (defconst socks-response-cmd-not-supported     7)
 203 (defconst socks-response-address-not-supported 8)
 204
 205 (defvar socks-errors
 206   '("Succeeded"
 207     "General SOCKS server failure"
 208     "Connection not allowed by ruleset"
 209     "Network unreachable"
 210     "Host unreachable"
 211     "Connection refused"
 212     "Time-to-live expired"
 213     "Command not supported"
 214     "Address type not supported"))
 215
 216 ;; The socks v5 address types
 217 (defconst socks-address-type-v4   1)
 218 (defconst socks-address-type-name 3)
 219 (defconst socks-address-type-v6   4)
 220
 221 ;; Base variables
 222 (defvar socks-timeout 5)
 223 (defvar socks-connections (make-hash-table :size 13))
 224
 225 ;; Miscellaneous stuff for authentication
 226 (defvar socks-authentication-methods nil)
 227 (defvar socks-username (user-login-name))
 228 (defvar socks-password nil)
 229
 230 (defun socks-register-authentication-method (id desc callback)
 231   (let ((old (assq id socks-authentication-methods)))
 232     (if old
 233         (setcdr old (cons desc callback))
 234       (setq socks-authentication-methods
 235             (cons (cons id (cons desc callback))
 236                   socks-authentication-methods)))))
 237
 238 (defun socks-unregister-authentication-method (id)
 239   (let ((old (assq id socks-authentication-methods)))
 240     (if old
 241         (setq socks-authentication-methods
 242               (delq old socks-authentication-methods)))))
 243
 244 (socks-register-authentication-method 0 "No authentication" 'identity)
 245
 246 (defun socks-build-auth-list ()
 247   (let ((num 0)
 248         (retval ""))
 249     (mapc
 250      (function
 251       (lambda (x)
 252         (if (fboundp (cdr (cdr x)))
 253             (setq retval (format "%s%c" retval (car x))
 254                   num (1+ num)))))
 255      (reverse socks-authentication-methods))
 256     (format "%c%s" num retval)))
 257
 258 (defconst socks-state-waiting-for-auth 0)
 259 (defconst socks-state-submethod-negotiation 1)
 260 (defconst socks-state-authenticated 2)
 261 (defconst socks-state-waiting 3)
 262 (defconst socks-state-connected 4)
 263
 264 (defmacro socks-wait-for-state-change (proc htable cur-state)
 265   `(while (and (= (gethash 'state ,htable) ,cur-state)
 266                (memq (process-status ,proc) '(run open)))
 267      (accept-process-output ,proc socks-timeout)))
 268
 269 (defun socks-filter (proc string)
 270   (let ((info (gethash proc socks-connections))
 271         state version desired-len)
 272     (or info (error "socks-filter called on non-SOCKS connection %S" proc))
 273     (setq state (gethash 'state info))
 274     (cond
 275      ((= state socks-state-waiting-for-auth)
 276       (puthash 'scratch (concat string (gethash 'scratch info)) info)
 277       (setq string (gethash 'scratch info))
 278       (if (< (length string) 2)
 279           nil                           ; We need to spin some more
 280         (puthash 'authtype (aref string 1) info)
 281         (puthash 'scratch (substring string 2 nil) info)
 282         (puthash 'state socks-state-submethod-negotiation info)))
 283      ((= state socks-state-submethod-negotiation)
 284       )
 285      ((= state socks-state-authenticated)
 286       )
 287      ((= state socks-state-waiting)
 288       (puthash 'scratch (concat string (gethash 'scratch info)) info)
 289       (setq string (gethash 'scratch info))
 290       (setq version (gethash 'server-protocol info))
 291       (cond
 292        ((equal version 'http)
 293         (if (not (string-match "\r\n\r\n" string))
 294             nil                 ; Need to spin some more
 295           (puthash 'state socks-state-connected info)
 296           (puthash 'reply 0 info)
 297           (puthash 'response string info)))
 298        ((equal version 4)
 299         (if (< (length string) 2)
 300             nil                 ; Can't know how much to read yet
 301           (setq desired-len
 302                 (+ 4 ; address length
 303                    2 ; port
 304                    2 ; initial data
 305                    ))
 306           (if (< (length string) desired-len)
 307               nil                       ; need to spin some more
 308             (let ((response (aref string 1)))
 309               (if (= response 90)
 310                   (setq response 0))
 311               (puthash 'state socks-state-connected info)
 312               (puthash 'reply response info)
 313               (puthash 'response string info)))))
 314        ((equal version 5)
 315         (if (< (length string) 4)
 316             nil
 317           (setq desired-len
 318                 (+ 6                    ; Standard socks header
 319                    (cond
 320                     ((= (aref string 3) socks-address-type-v4) 4)
 321                     ((= (aref string 3) socks-address-type-v6) 16)
 322                     ((= (aref string 3) socks-address-type-name)
 323                      (if (< (length string) 5)
 324                          255
 325                        (+ 1 (aref string 4)))))))
 326           (if (< (length string) desired-len)
 327               nil                       ; Need to spin some more
 328             (puthash 'state socks-state-connected info)
 329             (puthash 'reply (aref string 1) info)
 330             (puthash 'response string info))))))
 331      ((= state socks-state-connected)
 332       )
 333      )
 334     )
 335   )
 336
 337 (declare-function socks-original-open-network-stream "socks") ; fset
 338
 339 (defvar socks-override-functions nil
 340   "*Whether to overwrite the open-network-stream function with the SOCKSified
 341 version.")
 342
 343 (if (fboundp 'socks-original-open-network-stream)
 344     nil                         ; Do nothing, we've been here already
 345   (defalias 'socks-original-open-network-stream
 346     (symbol-function 'open-network-stream))
 347   (if socks-override-functions
 348       (defalias 'open-network-stream 'socks-open-network-stream)))
 349
 350 (defun socks-open-connection (server-info)
 351   (interactive)
 352   (save-excursion
 353     (let ((proc (socks-original-open-network-stream "socks"
 354                                                     nil
 355                                                     (nth 1 server-info)
 356                                                     (nth 2 server-info)))
 357           (info (make-hash-table :size 13))
 358           (authtype nil)
 359           version)
 360
 361       ;; Initialize process and info about the process
 362       (set-process-filter proc 'socks-filter)
 363       (set-process-query-on-exit-flag proc nil)
 364       (puthash proc info socks-connections)
 365       (puthash 'state socks-state-waiting-for-auth info)
 366       (puthash 'authtype socks-authentication-failure info)
 367       (puthash 'server-protocol (nth 3 server-info) info)
 368       (puthash 'server-name (nth 1 server-info) info)
 369       (setq version (nth 3 server-info))
 370       (cond
 371        ((equal version 'http)
 372         ;; Don't really have to do any connection setup under http
 373         nil)
 374        ((equal version 4)
 375         ;; Don't really have to do any connection setup under v4
 376         nil)
 377        ((equal version 5)
 378         ;; Need to handle all the authentication crap under v5
 379         ;; Send what we think we can handle for authentication types
 380         (process-send-string proc (format "%c%s" socks-version
 381                                           (socks-build-auth-list)))
 382
 383         ;; Basically just do a select() until we change states.
 384         (socks-wait-for-state-change proc info socks-state-waiting-for-auth)
 385         (setq authtype (gethash 'authtype info))
 386         (cond
 387          ((= authtype socks-authentication-null)
 388           (and socks-debug (message "No authentication necessary")))
 389          ((= authtype socks-authentication-failure)
 390           (error "No acceptable authentication methods found"))
 391          (t
 392           (let* ((auth-type (gethash 'authtype info))
 393                  (auth-handler (assoc auth-type socks-authentication-methods))
 394                  (auth-func (and auth-handler (cdr (cdr auth-handler))))
 395                  (auth-desc (and auth-handler (car (cdr auth-handler)))))
 396             (set-process-filter proc nil)
 397             (if (and auth-func (fboundp auth-func)
 398                      (funcall auth-func proc))
 399                 nil                     ; We succeeded!
 400               (delete-process proc)
 401               (error "Failed to use auth method: %s (%d)"
 402                      (or auth-desc "Unknown") auth-type))
 403             )
 404           )
 405          )
 406         (puthash 'state socks-state-authenticated info)
 407         (set-process-filter proc 'socks-filter)))
 408       proc)))
 409
 410 (defun socks-send-command (proc command atype address port)
 411   (let ((addr (cond
 412                ((or (= atype socks-address-type-v4)
 413                     (= atype socks-address-type-v6))
 414                 address)
 415                ((= atype socks-address-type-name)
 416                 (format "%c%s" (length address) address))
 417                (t
 418                 (error "Unkown address type: %d" atype))))
 419         (info (gethash proc socks-connections))
 420         request version)
 421     (or info (error "socks-send-command called on non-SOCKS connection %S"
 422                     proc))
 423     (puthash 'state socks-state-waiting info)
 424     (setq version (gethash 'server-protocol info))
 425     (cond
 426      ((equal version 'http)
 427       (setq request (format (eval-when-compile
 428                               (concat
 429                                "CONNECT %s:%d HTTP/1.0\r\n"
 430                                "User-Agent: Emacs/SOCKS v1.0\r\n"
 431                                "\r\n"))
 432                             (cond
 433                              ((equal atype socks-address-type-name) address)
 434                              (t
 435                               (error "Unsupported address type for HTTP: %d" atype)))
 436                             port)))
 437      ((equal version 4)
 438       (setq request (format
 439                      "%c%c%c%c%s%s%c"
 440                      version            ; version
 441                      command            ; command
 442                      (lsh port -8)      ; port, high byte
 443                      (- port (lsh (lsh port -8) 8)) ; port, low byte
 444                      addr               ; address
 445                      (user-full-name)   ; username
 446                      0                  ; terminate username
 447                      )))
 448      ((equal version 5)
 449       (setq request (format
 450                      "%c%c%c%c%s%c%c"
 451                      version            ; version
 452                      command            ; command
 453                      0                  ; reserved
 454                      atype              ; address type
 455                      addr               ; address
 456                      (lsh port -8)      ; port, high byte
 457                      (- port (lsh (lsh port -8) 8)) ; port, low byte
 458                      )))
 459      (t
 460       (error "Unknown protocol version: %d" version)))
 461     (process-send-string proc request)
 462     (socks-wait-for-state-change proc info socks-state-waiting)
 463     (process-status proc)
 464     (if (= (or (gethash 'reply info) 1) socks-response-success)
 465         nil                             ; Sweet sweet success!
 466       (delete-process proc)
 467       (error "SOCKS: %s" (nth (or (gethash 'reply info) 1) socks-errors)))
 468     proc))
 469
 470 \f
 471 ;; Replacement functions for open-network-stream, etc.
 472 (defvar socks-noproxy nil
 473   "*List of regexps matching hosts that we should not socksify connections to")
 474
 475 (defun socks-find-route (host service)
 476   (let ((route socks-server)
 477         (noproxy socks-noproxy))
 478     (while noproxy
 479       (if (eq ?! (aref (car noproxy) 0))
 480           (if (string-match (substring (car noproxy) 1) host)
 481               (setq noproxy nil))
 482         (if (string-match (car noproxy) host)
 483             (setq route nil
 484                   noproxy nil)))
 485       (setq noproxy (cdr noproxy)))
 486     route))
 487
 488 (defvar socks-services-file "/etc/services")
 489 (defvar socks-tcp-services (make-hash-table :size 13 :test 'equal))
 490 (defvar socks-udp-services (make-hash-table :size 13 :test 'equal))
 491
 492 (defun socks-parse-services ()
 493   (if (not (and (file-exists-p socks-services-file)
 494                 (file-readable-p socks-services-file)))
 495       (error "Could not find services file: %s" socks-services-file))
 496   (clrhash socks-tcp-services)
 497   (clrhash socks-udp-services)
 498   (with-current-buffer (get-buffer-create " *socks-tmp*")
 499     (erase-buffer)
 500     (insert-file-contents socks-services-file)
 501     ;; Nuke comments
 502     (goto-char (point-min))
 503     (while (re-search-forward "#.*" nil t)
 504       (replace-match ""))
 505     ;; Nuke empty lines
 506     (goto-char (point-min))
 507     (while (re-search-forward "^[ \t\n]+" nil t)
 508       (replace-match ""))
 509     ;; Now find all the lines
 510     (goto-char (point-min))
 511     (let (name port type)
 512       (while (re-search-forward "^\\([^ \t]+\\)[ \t]+\\([0-9]+\\)/\\([a-z]+\\)"
 513                                 nil t)
 514         (setq name (downcase (match-string 1))
 515               port (string-to-number (match-string 2))
 516               type (downcase (match-string 3)))
 517         (puthash name port (if (equal type "udp")
 518                                socks-udp-services
 519                              socks-tcp-services))))))
 520
 521 (defun socks-find-services-entry (service &optional udp)
 522   "Return the port # associated with SERVICE"
 523   (if (= (hash-table-count socks-tcp-services) 0)
 524       (socks-parse-services))
 525   (gethash (downcase service)
 526               (if udp socks-udp-services socks-tcp-services)))
 527
 528 (defun socks-open-network-stream (name buffer host service)
 529   (let* ((route (socks-find-route host service))
 530          proc info version atype)
 531     (if (not route)
 532         (socks-original-open-network-stream name buffer host service)
 533       (setq proc (socks-open-connection route)
 534             info (gethash proc socks-connections)
 535             version (gethash 'server-protocol info))
 536       (cond
 537        ((equal version 4)
 538         (setq host (socks-nslookup-host host))
 539         (if (not (listp host))
 540             (error "Could not get IP address for: %s" host))
 541         (setq host (apply 'format "%c%c%c%c" host))
 542         (setq atype socks-address-type-v4))
 543        (t
 544         (setq atype socks-address-type-name)))
 545       (socks-send-command proc
 546                           socks-connect-command
 547                           atype
 548                           host
 549                           (if (stringp service)
 550                               (or
 551                                (socks-find-services-entry service)
 552                                (error "Unknown service: %s" service))
 553                             service))
 554       (puthash 'buffer buffer info)
 555       (puthash 'host host info)
 556       (puthash 'service host info)
 557       (set-process-filter proc nil)
 558       (set-process-buffer proc (if buffer (get-buffer-create buffer)))
 559       proc)))
 560
 561 ;; Authentication modules go here
 562 \f
 563 ;; Basic username/password authentication, ala RFC 1929
 564 (socks-register-authentication-method 2 "Username/Password"
 565                                       'socks-username/password-auth)
 566
 567 (defconst socks-username/password-auth-version 1)
 568
 569 (defun socks-username/password-auth-filter (proc str)
 570   (let ((info (gethash proc socks-connections)))
 571     (or info (error "socks-filter called on non-SOCKS connection %S" proc))
 572     (puthash 'scratch (concat (gethash 'scratch info) str) info)
 573     (if (< (length (gethash 'scratch info)) 2)
 574         nil
 575       (puthash 'password-auth-status (aref (gethash 'scratch info) 1) info)
 576       (puthash 'state socks-state-authenticated info))))
 577
 578 (defun socks-username/password-auth (proc)
 579   (let* ((info (gethash proc socks-connections))
 580          (state (gethash 'state info)))
 581     (if (not socks-password)
 582         (setq socks-password (read-passwd
 583                               (format "Password for %s@%s: "
 584                                       socks-username
 585                                       (gethash 'server-name info)))))
 586     (puthash 'scratch "" info)
 587     (set-process-filter proc 'socks-username/password-auth-filter)
 588     (process-send-string proc
 589                          (format "%c%c%s%c%s"
 590                                  socks-username/password-auth-version
 591                                  (length socks-username)
 592                                  socks-username
 593                                  (length socks-password)
 594                                  socks-password))
 595     (socks-wait-for-state-change proc info state)
 596     (= (gethash 'password-auth-status info) 0)))
 597
 598 \f
 599 ;; More advanced GSS/API stuff, not yet implemented - volunteers?
 600 ;; (socks-register-authentication-method 1 "GSS/API" 'socks-gssapi-auth)
 601
 602 (defun socks-gssapi-auth (proc)
 603   nil)
 604
 605 \f
 606 ;; CHAP stuff
 607 ;; (socks-register-authentication-method 3 "CHAP" 'socks-chap-auth)
 608 (defun socks-chap-auth (proc)
 609   nil)
 610
 611 \f
 612 ;; CRAM stuff
 613 ;; (socks-register-authentication-method 5 "CRAM" 'socks-cram-auth)
 614 (defun socks-cram-auth (proc)
 615   nil)
 616
 617 \f
 618 (defcustom socks-nslookup-program "nslookup"
 619   "*If non-NIL then a string naming the nslookup program."
 620   :type '(choice (const :tag "None" :value nil) string)
 621   :group 'socks)
 622
 623 (defun socks-nslookup-host (host)
 624   "Attempt to resolve the given HOSTNAME using nslookup if possible."
 625   (interactive "sHost:  ")
 626   (if socks-nslookup-program
 627       (let ((proc (start-process " *nslookup*" " *nslookup*"
 628                                  socks-nslookup-program host))
 629             (res host))
 630         (set-process-query-on-exit-flag proc nil)
 631         (with-current-buffer (process-buffer proc)
 632           (while (progn
 633                    (accept-process-output proc)
 634                    (memq (process-status proc) '(run open))))
 635           (goto-char (point-min))
 636           (if (re-search-forward "Name:.*\nAddress\\(es\\)?: *\\([0-9.]+\\)$" nil t)
 637               (progn
 638                 (setq res (buffer-substring (match-beginning 2)
 639                                             (match-end 2))
 640                       res (mapcar 'string-to-int (split-string res "\\.")))))
 641           (kill-buffer (current-buffer)))
 642         res)
 643     host))
 644
 645 (provide 'socks)
 646
 647 ;; arch-tag: 67aef0d9-f4f7-4056-89c3-b4c9bf93ce7f
 648 ;;; socks.el ends here