--- /dev/null
+;;; socks.el --- A Socks v5 Client for Emacs
+
+;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2002,
+;; 2007 Free Software Foundation, Inc.
+
+;; Author: William M. Perry <wmperry@gnu.org>
+;; Dave Love <fx@gnu.org>
+;; Keywords: comm, firewalls
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+
+;;; Commentary:
+
+;; This is an implementation of the SOCKS v5 protocol as defined in
+;; RFC 1928.
+
+;; TODO
+;; - Finish the redirection rules stuff
+;; - Implement composition of servers. Recursively evaluate the
+;; redirection rules and do SOCKS-over-HTTP and SOCKS-in-SOCKS
+
+(eval-when-compile
+ (require 'wid-edit))
+(require 'custom)
+
+(if (not (fboundp 'split-string))
+ (defun split-string (string &optional pattern)
+ "Return a list of substrings of STRING which are separated by PATTERN.
+If PATTERN is omitted, it defaults to \"[ \\f\\t\\n\\r\\v]+\"."
+ (or pattern
+ (setq pattern "[ \f\t\n\r\v]+"))
+ (let (parts (start 0))
+ (while (string-match pattern string start)
+ (setq parts (cons (substring string start (match-beginning 0)) parts)
+ start (match-end 0)))
+ (nreverse (cons (substring string start) parts)))))
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;; Custom widgets
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+(define-widget 'dynamic-choice 'menu-choice
+ "A pretty simple dynamic dropdown list"
+ :format "%[%t%]: %v"
+ :tag "Network"
+ :case-fold t
+ :void '(item :format "invalid (%t)\n")
+ :value-create 's5-widget-value-create
+ :value-delete 'widget-children-value-delete
+ :value-get 'widget-choice-value-get
+ :value-inline 'widget-choice-value-inline
+ :mouse-down-action 'widget-choice-mouse-down-action
+ :action 'widget-choice-action
+ :error "Make a choice"
+ :validate 'widget-choice-validate
+ :match 's5-dynamic-choice-match
+ :match-inline 's5-dynamic-choice-match-inline)
+
+(defun s5-dynamic-choice-match (widget value)
+ (let ((choices (funcall (widget-get widget :choice-function)))
+ current found)
+ (while (and choices (not found))
+ (setq current (car choices)
+ choices (cdr choices)
+ found (widget-apply current :match value)))
+ found))
+
+(defun s5-dynamic-choice-match-inline (widget value)
+ (let ((choices (funcall (widget-get widget :choice-function)))
+ current found)
+ (while (and choices (not found))
+ (setq current (car choices)
+ choices (cdr choices)
+ found (widget-match-inline current value)))
+ found))
+
+(defun s5-widget-value-create (widget)
+ (let ((choices (funcall (widget-get widget :choice-function)))
+ (value (widget-get widget :value)))
+ (if (not value)
+ (widget-put widget :value (widget-value (car choices))))
+ (widget-put widget :args choices)
+ (widget-choice-value-create widget)))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;; Customization support
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+(defgroup socks nil
+ "SOCKS Support"
+ :prefix "socks-"
+ :group 'processes)
+
+'(defcustom socks-server-aliases nil
+ "A list of server aliases for use in access control and filtering rules."
+ :group 'socks
+ :type '(repeat (list :format "%v"
+ :value ("" "" 1080 5)
+ (string :tag "Alias")
+ (string :tag "Hostname/IP Address")
+ (integer :tag "Port #")
+ (choice :tag "SOCKS Version"
+ (integer :tag "SOCKS v4" :value 4)
+ (integer :tag "SOCKS v5" :value 5)))))
+
+'(defcustom socks-network-aliases
+ '(("Anywhere" (netmask "0.0.0.0" "0.0.0.0")))
+ "A list of network aliases for use in subsequent rules."
+ :group 'socks
+ :type '(repeat (list :format "%v"
+ :value (netmask "" "255.255.255.0")
+ (string :tag "Alias")
+ (radio-button-choice
+ :format "%v"
+ (list :tag "IP address range"
+ (const :format "" :value range)
+ (string :tag "From")
+ (string :tag "To"))
+ (list :tag "IP address/netmask"
+ (const :format "" :value netmask)
+ (string :tag "IP Address")
+ (string :tag "Netmask"))
+ (list :tag "Domain Name"
+ (const :format "" :value domain)
+ (string :tag "Domain name"))
+ (list :tag "Unique hostname/IP address"
+ (const :format "" :value exact)
+ (string :tag "Hostname/IP Address"))))))
+
+'(defun s5-servers-filter ()
+ (if socks-server-aliases
+ (mapcar (lambda (x) (list 'const :tag (car x) :value (car x))) s5-server-aliases)
+ '((const :tag "No aliases defined" :value nil))))
+
+'(defun s5-network-aliases-filter ()
+ (mapcar (lambda (x) (list 'const :tag (car x) :value (car x)))
+ socks-network-aliases))
+
+'(defcustom socks-redirection-rules
+ nil
+ "A list of redirection rules."
+ :group 'socks
+ :type '(repeat (list :format "%v"
+ :value ("Anywhere" nil)
+ (dynamic-choice :choice-function s5-network-aliases-filter
+ :tag "Destination network")
+ (radio-button-choice
+ :tag "Connection type"
+ (const :tag "Direct connection" :value nil)
+ (dynamic-choice :format "%t: %[%v%]"
+ :choice-function s5-servers-filter
+ :tag "Proxy chain via")))))
+
+(defcustom socks-server
+ (list "Default server" "socks" 1080 5)
+ ""
+ :group 'socks
+ :type '(list
+ (string :format "" :value "Default server")
+ (string :tag "Server")
+ (integer :tag "Port")
+ (radio-button-choice :tag "SOCKS Version"
+ :format "%t: %v"
+ (const :tag "SOCKS v4 " :format "%t" :value 4)
+ (const :tag "SOCKS v5" :format "%t" :value 5))))
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;; Get down to the nitty gritty
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+(defconst socks-version 5)
+(defvar socks-debug nil)
+
+;; Common socks v5 commands
+(defconst socks-connect-command 1)
+(defconst socks-bind-command 2)
+(defconst socks-udp-associate-command 3)
+
+;; Miscellaneous other socks constants
+(defconst socks-authentication-null 0)
+(defconst socks-authentication-failure 255)
+
+;; Response codes
+(defconst socks-response-success 0)
+(defconst socks-response-general-failure 1)
+(defconst socks-response-access-denied 2)
+(defconst socks-response-network-unreachable 3)
+(defconst socks-response-host-unreachable 4)
+(defconst socks-response-connection-refused 5)
+(defconst socks-response-ttl-expired 6)
+(defconst socks-response-cmd-not-supported 7)
+(defconst socks-response-address-not-supported 8)
+
+(defvar socks-errors
+ '("Succeeded"
+ "General SOCKS server failure"
+ "Connection not allowed by ruleset"
+ "Network unreachable"
+ "Host unreachable"
+ "Connection refused"
+ "Time-to-live expired"
+ "Command not supported"
+ "Address type not supported"))
+
+;; The socks v5 address types
+(defconst socks-address-type-v4 1)
+(defconst socks-address-type-name 3)
+(defconst socks-address-type-v6 4)
+
+;; Base variables
+(defvar socks-timeout 5)
+(defvar socks-connections (make-hash-table :size 13))
+
+;; Miscellaneous stuff for authentication
+(defvar socks-authentication-methods nil)
+(defvar socks-username (user-login-name))
+(defvar socks-password nil)
+
+(defun socks-register-authentication-method (id desc callback)
+ (let ((old (assq id socks-authentication-methods)))
+ (if old
+ (setcdr old (cons desc callback))
+ (setq socks-authentication-methods
+ (cons (cons id (cons desc callback))
+ socks-authentication-methods)))))
+
+(defun socks-unregister-authentication-method (id)
+ (let ((old (assq id socks-authentication-methods)))
+ (if old
+ (setq socks-authentication-methods
+ (delq old socks-authentication-methods)))))
+
+(socks-register-authentication-method 0 "No authentication" 'identity)
+
+(defun socks-build-auth-list ()
+ (let ((num 0)
+ (retval ""))
+ (mapcar
+ (function
+ (lambda (x)
+ (if (fboundp (cdr (cdr x)))
+ (setq retval (format "%s%c" retval (car x))
+ num (1+ num)))))
+ (reverse socks-authentication-methods))
+ (format "%c%s" num retval)))
+
+(defconst socks-state-waiting-for-auth 0)
+(defconst socks-state-submethod-negotiation 1)
+(defconst socks-state-authenticated 2)
+(defconst socks-state-waiting 3)
+(defconst socks-state-connected 4)
+
+(defmacro socks-wait-for-state-change (proc htable cur-state)
+ (`
+ (while (and (= (gethash 'state (, htable)) (, cur-state))
+ (memq (process-status (, proc)) '(run open)))
+ (accept-process-output (, proc) socks-timeout))))
+
+(defun socks-filter (proc string)
+ (let ((info (gethash proc socks-connections))
+ state version desired-len)
+ (or info (error "socks-filter called on non-SOCKS connection %S" proc))
+ (setq state (gethash 'state info))
+ (cond
+ ((= state socks-state-waiting-for-auth)
+ (puthash 'scratch (concat string (gethash 'scratch info)) info)
+ (setq string (gethash 'scratch info))
+ (if (< (length string) 2)
+ nil ; We need to spin some more
+ (puthash 'authtype (aref string 1) info)
+ (puthash 'scratch (substring string 2 nil) info)
+ (puthash 'state socks-state-submethod-negotiation info)))
+ ((= state socks-state-submethod-negotiation)
+ )
+ ((= state socks-state-authenticated)
+ )
+ ((= state socks-state-waiting)
+ (puthash 'scratch (concat string (gethash 'scratch info)) info)
+ (setq string (gethash 'scratch info))
+ (setq version (gethash 'server-protocol info))
+ (cond
+ ((equal version 'http)
+ (if (not (string-match "\r\n\r\n" string))
+ nil ; Need to spin some more
+ (puthash 'state socks-state-connected info)
+ (puthash 'reply 0 info)
+ (puthash 'response string info)))
+ ((equal version 4)
+ (if (< (length string) 2)
+ nil ; Can't know how much to read yet
+ (setq desired-len
+ (+ 4 ; address length
+ 2 ; port
+ 2 ; initial data
+ ))
+ (if (< (length string) desired-len)
+ nil ; need to spin some more
+ (let ((response (aref string 1)))
+ (if (= response 90)
+ (setq response 0))
+ (puthash 'state socks-state-connected info)
+ (puthash 'reply response info)
+ (puthash 'response string info)))))
+ ((equal version 5)
+ (if (< (length string) 4)
+ nil
+ (setq desired-len
+ (+ 6 ; Standard socks header
+ (cond
+ ((= (aref string 3) socks-address-type-v4) 4)
+ ((= (aref string 3) socks-address-type-v6) 16)
+ ((= (aref string 3) socks-address-type-name)
+ (if (< (length string) 5)
+ 255
+ (+ 1 (aref string 4)))))))
+ (if (< (length string) desired-len)
+ nil ; Need to spin some more
+ (puthash 'state socks-state-connected info)
+ (puthash 'reply (aref string 1) info)
+ (puthash 'response string info))))))
+ ((= state socks-state-connected)
+ )
+ )
+ )
+ )
+
+(defun socks-open-connection (server-info)
+ (interactive)
+ (save-excursion
+ (let ((proc (socks-original-open-network-stream "socks"
+ nil
+ (nth 1 server-info)
+ (nth 2 server-info)))
+ (info (make-hash-table :size 13))
+ (authtype nil)
+ version)
+
+ ;; Initialize process and info about the process
+ (set-process-filter proc 'socks-filter)
+ (set-process-query-on-exit-flag proc nil)
+ (puthash proc info socks-connections)
+ (puthash 'state socks-state-waiting-for-auth info)
+ (puthash 'authtype socks-authentication-failure info)
+ (puthash 'server-protocol (nth 3 server-info) info)
+ (puthash 'server-name (nth 1 server-info) info)
+ (setq version (nth 3 server-info))
+ (cond
+ ((equal version 'http)
+ ;; Don't really have to do any connection setup under http
+ nil)
+ ((equal version 4)
+ ;; Don't really have to do any connection setup under v4
+ nil)
+ ((equal version 5)
+ ;; Need to handle all the authentication crap under v5
+ ;; Send what we think we can handle for authentication types
+ (process-send-string proc (format "%c%s" socks-version
+ (socks-build-auth-list)))
+
+ ;; Basically just do a select() until we change states.
+ (socks-wait-for-state-change proc info socks-state-waiting-for-auth)
+ (setq authtype (gethash 'authtype info))
+ (cond
+ ((= authtype socks-authentication-null)
+ (and socks-debug (message "No authentication necessary")))
+ ((= authtype socks-authentication-failure)
+ (error "No acceptable authentication methods found."))
+ (t
+ (let* ((auth-type (gethash 'authtype info))
+ (auth-handler (assoc auth-type socks-authentication-methods))
+ (auth-func (and auth-handler (cdr (cdr auth-handler))))
+ (auth-desc (and auth-handler (car (cdr auth-handler)))))
+ (set-process-filter proc nil)
+ (if (and auth-func (fboundp auth-func)
+ (funcall auth-func proc))
+ nil ; We succeeded!
+ (delete-process proc)
+ (error "Failed to use auth method: %s (%d)"
+ (or auth-desc "Unknown") auth-type))
+ )
+ )
+ )
+ (puthash 'state socks-state-authenticated info)
+ (set-process-filter proc 'socks-filter)))
+ proc)))
+
+(defun socks-send-command (proc command atype address port)
+ (let ((addr (cond
+ ((or (= atype socks-address-type-v4)
+ (= atype socks-address-type-v6))
+ address)
+ ((= atype socks-address-type-name)
+ (format "%c%s" (length address) address))
+ (t
+ (error "Unkown address type: %d" atype))))
+ (info (gethash proc socks-connections))
+ request version)
+ (or info (error "socks-send-command called on non-SOCKS connection %S"
+ proc))
+ (puthash 'state socks-state-waiting info)
+ (setq version (gethash 'server-protocol info))
+ (cond
+ ((equal version 'http)
+ (setq request (format (eval-when-compile
+ (concat
+ "CONNECT %s:%d HTTP/1.0\r\n"
+ "User-Agent: Emacs/SOCKS v1.0\r\n"
+ "\r\n"))
+ (cond
+ ((equal atype socks-address-type-name) address)
+ (t
+ (error "Unsupported address type for HTTP: %d" atype)))
+ port)))
+ ((equal version 4)
+ (setq request (format
+ "%c%c%c%c%s%s%c"
+ version ; version
+ command ; command
+ (lsh port -8) ; port, high byte
+ (- port (lsh (lsh port -8) 8)) ; port, low byte
+ addr ; address
+ (user-full-name) ; username
+ 0 ; terminate username
+ )))
+ ((equal version 5)
+ (setq request (format
+ "%c%c%c%c%s%c%c"
+ version ; version
+ command ; command
+ 0 ; reserved
+ atype ; address type
+ addr ; address
+ (lsh port -8) ; port, high byte
+ (- port (lsh (lsh port -8) 8)) ; port, low byte
+ )))
+ (t
+ (error "Unknown protocol version: %d" version)))
+ (process-send-string proc request)
+ (socks-wait-for-state-change proc info socks-state-waiting)
+ (process-status proc)
+ (if (= (or (gethash 'reply info) 1) socks-response-success)
+ nil ; Sweet sweet success!
+ (delete-process proc)
+ (error "SOCKS: %s" (nth (or (gethash 'reply info) 1) socks-errors)))
+ proc))
+
+\f
+;; Replacement functions for open-network-stream, etc.
+(defvar socks-noproxy nil
+ "*List of regexps matching hosts that we should not socksify connections to")
+
+(defun socks-find-route (host service)
+ (let ((route socks-server)
+ (noproxy socks-noproxy))
+ (while noproxy
+ (if (eq ?! (aref (car noproxy) 0))
+ (if (string-match (substring (car noproxy) 1) host)
+ (setq noproxy nil))
+ (if (string-match (car noproxy) host)
+ (setq route nil
+ noproxy nil)))
+ (setq noproxy (cdr noproxy)))
+ route))
+
+(defvar socks-override-functions nil
+ "*Whether to overwrite the open-network-stream function with the SOCKSified
+version.")
+
+(if (fboundp 'socks-original-open-network-stream)
+ nil ; Do nothing, we've been here already
+ (defalias 'socks-original-open-network-stream
+ (symbol-function 'open-network-stream))
+ (if socks-override-functions
+ (defalias 'open-network-stream 'socks-open-network-stream)))
+
+(defvar socks-services-file "/etc/services")
+(defvar socks-tcp-services (make-hash-table :size 13 :test 'equal))
+(defvar socks-udp-services (make-hash-table :size 13 :test 'equal))
+
+(defun socks-parse-services ()
+ (if (not (and (file-exists-p socks-services-file)
+ (file-readable-p socks-services-file)))
+ (error "Could not find services file: %s" socks-services-file))
+ (save-excursion
+ (clrhash socks-tcp-services)
+ (clrhash socks-udp-services)
+ (set-buffer (get-buffer-create " *socks-tmp*"))
+ (erase-buffer)
+ (insert-file-contents socks-services-file)
+ ;; Nuke comments
+ (goto-char (point-min))
+ (while (re-search-forward "#.*" nil t)
+ (replace-match ""))
+ ;; Nuke empty lines
+ (goto-char (point-min))
+ (while (re-search-forward "^[ \t\n]+" nil t)
+ (replace-match ""))
+ ;; Now find all the lines
+ (goto-char (point-min))
+ (let (name port type)
+ (while (re-search-forward "^\\([^ \t]+\\)[ \t]+\\([0-9]+\\)/\\([a-z]+\\)"
+ nil t)
+ (setq name (downcase (match-string 1))
+ port (string-to-number (match-string 2))
+ type (downcase (match-string 3)))
+ (puthash name port (if (equal type "udp")
+ socks-udp-services
+ socks-tcp-services))))))
+
+(defun socks-find-services-entry (service &optional udp)
+ "Return the port # associated with SERVICE"
+ (if (= (hash-table-count socks-tcp-services) 0)
+ (socks-parse-services))
+ (gethash (downcase service)
+ (if udp socks-udp-services socks-tcp-services)))
+
+(defun socks-open-network-stream (name buffer host service)
+ (let* ((route (socks-find-route host service))
+ proc info version atype)
+ (if (not route)
+ (socks-original-open-network-stream name buffer host service)
+ (setq proc (socks-open-connection route)
+ info (gethash proc socks-connections)
+ version (gethash 'server-protocol info))
+ (cond
+ ((equal version 4)
+ (setq host (socks-nslookup-host host))
+ (if (not (listp host))
+ (error "Could not get IP address for: %s" host))
+ (setq host (apply 'format "%c%c%c%c" host))
+ (setq atype socks-address-type-v4))
+ (t
+ (setq atype socks-address-type-name)))
+ (socks-send-command proc
+ socks-connect-command
+ atype
+ host
+ (if (stringp service)
+ (socks-find-services-entry service)
+ service))
+ (puthash 'buffer buffer info)
+ (puthash 'host host info)
+ (puthash 'service host info)
+ (set-process-filter proc nil)
+ (set-process-buffer proc (if buffer (get-buffer-create buffer)))
+ proc)))
+
+;; Authentication modules go here
+\f
+;; Basic username/password authentication, ala RFC 1929
+(socks-register-authentication-method 2 "Username/Password"
+ 'socks-username/password-auth)
+
+(defconst socks-username/password-auth-version 1)
+
+(defun socks-username/password-auth-filter (proc str)
+ (let ((info (gethash proc socks-connections))
+ state desired-len)
+ (or info (error "socks-filter called on non-SOCKS connection %S" proc))
+ (setq state (gethash 'state info))
+ (puthash 'scratch (concat (gethash 'scratch info) str) info)
+ (if (< (length (gethash 'scratch info)) 2)
+ nil
+ (puthash 'password-auth-status (aref (gethash 'scratch info) 1) info)
+ (puthash 'state socks-state-authenticated info))))
+
+(defun socks-username/password-auth (proc)
+ (let* ((info (gethash proc socks-connections))
+ (state (gethash 'state info)))
+ (if (not socks-password)
+ (setq socks-password (read-passwd
+ (format "Password for %s@%s: "
+ socks-username
+ (gethash 'server-name info)))))
+ (puthash 'scratch "" info)
+ (set-process-filter proc 'socks-username/password-auth-filter)
+ (process-send-string proc
+ (format "%c%c%s%c%s"
+ socks-username/password-auth-version
+ (length socks-username)
+ socks-username
+ (length socks-password)
+ socks-password))
+ (socks-wait-for-state-change proc info state)
+ (= (gethash 'password-auth-status info) 0)))
+
+\f
+;; More advanced GSS/API stuff, not yet implemented - volunteers?
+;; (socks-register-authentication-method 1 "GSS/API" 'socks-gssapi-auth)
+
+(defun socks-gssapi-auth (proc)
+ nil)
+
+\f
+;; CHAP stuff
+;; (socks-register-authentication-method 3 "CHAP" 'socks-chap-auth)
+(defun socks-chap-auth (proc)
+ nil)
+
+\f
+;; CRAM stuff
+;; (socks-register-authentication-method 5 "CRAM" 'socks-cram-auth)
+(defun socks-cram-auth (proc)
+ nil)
+
+\f
+(defcustom socks-nslookup-program "nslookup"
+ "*If non-NIL then a string naming the nslookup program."
+ :type '(choice (const :tag "None" :value nil) string)
+ :group 'socks)
+
+(defun socks-nslookup-host (host)
+ "Attempt to resolve the given HOSTNAME using nslookup if possible."
+ (interactive "sHost: ")
+ (if socks-nslookup-program
+ (let ((proc (start-process " *nslookup*" " *nslookup*"
+ socks-nslookup-program host))
+ (res host))
+ (set-process-query-on-exit-flag proc nil)
+ (save-excursion
+ (set-buffer (process-buffer proc))
+ (while (progn
+ (accept-process-output proc)
+ (memq (process-status proc) '(run open))))
+ (goto-char (point-min))
+ (if (re-search-forward "Name:.*\nAddress\\(es\\)?: *\\([0-9.]+\\)$" nil t)
+ (progn
+ (setq res (buffer-substring (match-beginning 2)
+ (match-end 2))
+ res (mapcar 'string-to-int (split-string res "\\.")))))
+ (kill-buffer (current-buffer)))
+ res)
+ host))
+
+(provide 'socks)
+
+;; arch-tag: 67aef0d9-f4f7-4056-89c3-b4c9bf93ce7f
+;;; socks.el ends here
projects / emacs.git / commitdiff