1
0
mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-11-30 08:09:04 +00:00
emacs/lisp/net/socks.el
2010-01-13 00:35:10 -08:00

651 lines
22 KiB
EmacsLisp
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

;;; socks.el --- A Socks v5 Client for Emacs
;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2002,
;; 2007, 2008, 2009, 2010 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 3 of the License, 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. If not, see <http://www.gnu.org/licenses/>.
;;; 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"
:version "22.2"
: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 ""))
(mapc
(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)
)
)
)
)
(declare-function socks-original-open-network-stream "socks") ; fset
(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)))
(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 (string-make-unibyte
(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 (string-make-unibyte
(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))
;; 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-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))
(clrhash socks-tcp-services)
(clrhash socks-udp-services)
(with-current-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)
(or
(socks-find-services-entry service)
(error "Unknown service: %s" 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
;; 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)))
(or info (error "socks-filter called on non-SOCKS connection %S" proc))
(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)))
;; 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)
;; CHAP stuff
;; (socks-register-authentication-method 3 "CHAP" 'socks-chap-auth)
(defun socks-chap-auth (proc)
nil)
;; CRAM stuff
;; (socks-register-authentication-method 5 "CRAM" 'socks-cram-auth)
(defun socks-cram-auth (proc)
nil)
(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)
(with-current-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