;;; dns.el --- Domain Name Service lookups
-;; Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
+;; Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
;; Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
-;; Keywords: network
+;; Keywords: network comm
;; This file is part of GNU Emacs.
-;; GNU Emacs is free software; you can redistribute it and/or modify
+;; 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, or (at your option)
-;; any later version.
+;; 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
+;; 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.
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
"How many seconds to wait when doing DNS queries.")
(defvar dns-servers nil
- "Which DNS servers to query.
-If nil, /etc/resolv.conf will be consulted.")
+ "List of DNS servers to query.
+If nil, /etc/resolv.conf and nslookup will be consulted.")
;;; Internal code:
(defun dns-read-string-name (string buffer)
(with-temp-buffer
- (set-buffer-multibyte nil)
+ (unless (featurep 'xemacs) (set-buffer-multibyte nil))
(insert string)
(goto-char (point-min))
(dns-read-name buffer)))
"Write a DNS packet according to SPEC.
If TCP-P, the first two bytes of the package with be the length field."
(with-temp-buffer
- (set-buffer-multibyte nil)
+ (unless (featurep 'xemacs) (set-buffer-multibyte nil))
(dns-write-bytes (dns-get 'id spec) 2)
(dns-write-bytes
(logior
(lsh (if (dns-get 'truncated-p spec) 1 0) -1)
(lsh (if (dns-get 'recursion-desired-p spec) 1 0) 0)))
(dns-write-bytes
- (cond
+ (cond
((eq (dns-get 'response-code spec) 'no-error) 0)
((eq (dns-get 'response-code spec) 'format-error) 1)
((eq (dns-get 'response-code spec) 'server-failure) 2)
(defun dns-read (packet)
(with-temp-buffer
- (set-buffer-multibyte nil)
+ (unless (featurep 'xemacs) (set-buffer-multibyte nil))
(let ((spec nil)
queries answers authorities additionals)
(insert packet)
(point (point)))
(prog1
(with-temp-buffer
- (set-buffer-multibyte nil)
+ (unless (featurep 'xemacs) (set-buffer-multibyte nil))
(insert string)
(goto-char (point-min))
(cond
(t string)))
(goto-char point))))
-(defun dns-parse-resolv-conf ()
- (when (file-exists-p "/etc/resolv.conf")
- (with-temp-buffer
- (insert-file-contents "/etc/resolv.conf")
- (goto-char (point-min))
- (while (re-search-forward "^nameserver[\t ]+\\([^ \t\n]+\\)" nil t)
- (push (match-string 1) dns-servers))
- (setq dns-servers (nreverse dns-servers)))))
+(defun dns-set-servers ()
+ "Set `dns-servers' to a list of DNS servers or nil if none are found.
+Parses \"/etc/resolv.conf\" or calls \"nslookup\"."
+ (or (when (file-exists-p "/etc/resolv.conf")
+ (setq dns-servers nil)
+ (with-temp-buffer
+ (insert-file-contents "/etc/resolv.conf")
+ (goto-char (point-min))
+ (while (re-search-forward "^nameserver[\t ]+\\([^ \t\n]+\\)" nil t)
+ (push (match-string 1) dns-servers))
+ (setq dns-servers (nreverse dns-servers))))
+ (when (executable-find "nslookup")
+ (with-temp-buffer
+ (call-process "nslookup" nil t nil "localhost")
+ (goto-char (point-min))
+ (re-search-forward
+ "^Address:[ \t]*\\([0-9]+\\.[0-9]+\\.[0-9]+\\.[0-9]+\\)" nil t)
+ (setq dns-servers (list (match-string 1)))))))
(defun dns-read-txt (string)
(if (> (length string) 1)
(defvar dns-cache (make-vector 4096 0))
-(defun query-dns-cached (name &optional type fullp reversep)
+(defun dns-query-cached (name &optional type fullp reversep)
(let* ((key (format "%s:%s:%s:%s" name type fullp reversep))
(sym (intern-soft key dns-cache)))
(if (and sym
(boundp sym))
(symbol-value sym)
- (let ((result (query-dns name type fullp reversep)))
+ (let ((result (dns-query name type fullp reversep)))
(set (intern key dns-cache) result)
result))))
-(defun query-dns (name &optional type fullp reversep)
+;; The old names `query-dns' and `query-dns-cached' weren't used in Emacs 23
+;; yet, so no alias are provided. --rsteib
+
+(defun dns-query (name &optional type fullp reversep)
"Query a DNS server for NAME of TYPE.
If FULLP, return the entire record returned.
If REVERSEP, look up an IP address."
(setq type (or type 'A))
(unless dns-servers
- (dns-parse-resolv-conf))
+ (dns-set-servers))
(when reversep
(setq name (concat
(if (not dns-servers)
(message "No DNS server configuration found")
(with-temp-buffer
- (set-buffer-multibyte nil)
+ (unless (featurep 'xemacs) (set-buffer-multibyte nil))
(let ((process (condition-case ()
(dns-make-network-process (car dns-servers))
(error
(provide 'dns)
-;; arch-tag: d0edd0c4-4cce-4538-ae92-06c3356ee80a
;;; dns.el ends here