;;; server.el --- Lisp code for GNU Emacs running as server process
-;; Copyright (C) 1986, 87, 92, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002
+;; Copyright (C) 1986,87,92,94,95,96,97,98,99,2000,01,02,03,2004
;; Free Software Foundation, Inc.
;; Author: William Sommerfeld <wesommer@athena.mit.edu>
are done with it in the server.")
(make-variable-buffer-local 'server-existing-buffer)
-;; Fixme: This doesn't look secure. If it really is, it deserves a
-;; comment, but I'd expect it to be created in a protected subdir as
-;; normal. -- fx
(defvar server-socket-name
- (format "/tmp/esrv%d-%s" (user-uid)
- (substring (system-name) 0 (string-match "\\." (system-name)))))
+ (format "/tmp/emacs%d/server" (user-uid)))
(defun server-log (string &optional client)
"If a *server* buffer exists, write STRING to it for logging purposes."
(t " ")))
arg t t))
+(defun server-ensure-safe-dir (dir)
+ "Make sure DIR is a directory with no race-condition issues.
+Creates the directory if necessary and makes sure:
+- there's no symlink involved
+- it's owned by us
+- it's not readable/writable by anybody else."
+ (setq dir (directory-file-name dir))
+ (let ((attrs (file-attributes dir)))
+ (unless attrs
+ (letf (((default-file-modes) ?\700)) (make-directory dir))
+ (setq attrs (file-attributes dir)))
+ ;; Check that it's safe for use.
+ (unless (and (eq t (car attrs)) (eq (nth 2 attrs) (user-uid))
+ (zerop (logand ?\077 (file-modes dir))))
+ (error "The directory %s is unsafe" dir))))
+
;;;###autoload
(defun server-start (&optional leave-dead)
"Allow this Emacs process to be a server for client processes.
Prefix arg means just kill any existing server communications subprocess."
(interactive "P")
+ ;; Make sure there is a safe directory in which to place the socket.
+ (server-ensure-safe-dir (file-name-directory server-socket-name))
;; kill it dead!
- (condition-case () (delete-process server-process) (error nil))
+ (if server-process
+ (condition-case () (delete-process server-process) (error nil)))
;; Delete the socket files made by previous server invocations.
(condition-case () (delete-file server-socket-name) (error nil))
;; If this Emacs already had a server, clear out associated status.
(unless leave-dead
(if server-process
(server-log (message "Restarting server")))
- (let ((umask (default-file-modes)))
- (unwind-protect
- (progn
- (set-default-file-modes ?\700)
- (setq server-process
- (make-network-process
- :name "server" :family 'local :server t :noquery t
- :service server-socket-name
- :sentinel 'server-sentinel :filter 'server-process-filter
- ;; We must receive file names without being decoded.
- ;; Those are decoded by server-process-filter according
- ;; to file-name-coding-system.
- :coding 'raw-text)))
- (set-default-file-modes umask)))))
+ (letf (((default-file-modes) ?\700))
+ (setq server-process
+ (make-network-process
+ :name "server" :family 'local :server t :noquery t
+ :service server-socket-name
+ :sentinel 'server-sentinel :filter 'server-process-filter
+ ;; We must receive file names without being decoded.
+ ;; Those are decoded by server-process-filter according
+ ;; to file-name-coding-system.
+ :coding 'raw-text)))))
;;;###autoload
(define-minor-mode server-mode
;; Fixme: Should this check for an existing server socket and do
;; nothing if there is one (for multiple Emacs sessions)?
(server-start (not server-mode)))
-(custom-add-version 'server-mode "21.4")
\f
(defun server-process-filter (proc string)
"Process a request from the server to edit some files.
(setq string (substring string (match-end 0)))
(setq client (cons proc nil))
(while (string-match "[^ ]* " request)
- (let ((arg (substring request (match-beginning 0) (1- (match-end 0))))
- (pos 0))
+ (let ((arg (substring request (match-beginning 0) (1- (match-end 0)))))
(setq request (substring request (match-end 0)))
(cond
((equal "-nowait" arg) (setq nowait t))
-;;; This is not safe unless we make sure other users can't send commands.
-;;; ((equal "-eval" arg) (setq eval t))
+ ((equal "-eval" arg) (setq eval t))
((and (equal "-display" arg) (string-match "\\([^ ]*\\) " request))
(let ((display (server-unquote-arg (match-string 1 request))))
(setq request (substring request (match-end 0)))
\f
(provide 'server)
+;;; arch-tag: 1f7ecb42-f00a-49f8-906d-61995d84c8d6
;;; server.el ends here