X-Git-Url: http://cgit.sxemacs.org/?p=gnus;a=blobdiff_plain;f=lisp%2Fdns.el;h=7910261125aadc7a1421a82bebaab089c650d1b6;hp=24bce62c604fa1f4fcbe4d2de36626dc6f807d5d;hb=9b139a13c0650a18872ebd64849560a97554afa8;hpb=9c12c8a1215cda2d292be3989354e925ea19b143

diff --git a/lisp/dns.el b/lisp/dns.el
index 24bce62c6..791026112 100644
--- a/lisp/dns.el
+++ b/lisp/dns.el
@@ -1,5 +1,6 @@
 ;;; dns.el --- Domain Name Service lookups
-;; Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+
+;; Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
 
 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
 ;; Keywords: network
@@ -8,7 +9,7 @@
 
 ;; 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)
+;; the Free Software Foundation; either version 3, or (at your option)
 ;; any later version.
 
 ;; GNU Emacs is distributed in the hope that it will be useful,
@@ -18,8 +19,8 @@
 
 ;; 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., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
 
 ;;; Commentary:
 
@@ -306,6 +307,25 @@ If TCP-P, the first two bytes of the package with be the length field."
 	(push (match-string 1) dns-servers))
       (setq dns-servers (nreverse dns-servers)))))
 
+(defun dns-read-txt (string)
+  (if (> (length string) 1)
+      (substring string 1)
+    string))
+
+(defun dns-get-txt-answer (answers)
+  (let ((result "")
+	(do-next nil))
+    (dolist (answer answers)
+      (dolist (elem answer)
+	(when (consp elem)
+	  (cond
+	   ((eq (car elem) 'type)
+	    (setq do-next (eq (cadr elem) 'TXT)))
+	   ((eq (car elem) 'data)
+	    (when do-next
+	      (setq result (concat result (dns-read-txt (cadr elem))))))))))
+    result))
+
 ;;; Interface functions.
 (defmacro dns-make-network-process (server)
   (if (featurep 'xemacs)
@@ -329,13 +349,32 @@ If TCP-P, the first two bytes of the package with be the length field."
 	 ;; connection to the DNS server.
 	 (open-network-stream "dns" (current-buffer) server "domain")))))
 
-(defun query-dns (name &optional type fullp)
+(defvar dns-cache (make-vector 4096 0))
+
+(defun query-dns-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)))
+	(set (intern key dns-cache) result)
+	result))))
+
+(defun query-dns (name &optional type fullp reversep)
   "Query a DNS server for NAME of TYPE.
-If FULLP, return the entire record returned."
+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))
 
+  (when reversep
+    (setq name (concat
+		(mapconcat 'identity (nreverse (split-string name "\\.")) ".")
+		".in-addr.arpa")
+	  type 'PTR))
+
   (if (not dns-servers)
       (message "No DNS server configuration found")
     (mm-with-unibyte-buffer
@@ -360,20 +399,26 @@ If FULLP, return the entire record returned."
 		      tcp-p))
 	  (while (and (zerop (buffer-size))
 		      (> times 0))
+	    (sit-for (/ step 1000.0))
 	    (accept-process-output process 0 step)
 	    (decf times step))
 	  (ignore-errors
 	    (delete-process process))
-	  (when tcp-p
+	  (when (and tcp-p
+		     (>= (buffer-size) 2))
 	    (goto-char (point-min))
 	    (delete-region (point) (+ (point) 2)))
-	  (unless (zerop (buffer-size))
+	  (when (and (>= (buffer-size) 2)
+		     ;; We had a time-out.
+		     (> times 0))
 	    (let ((result (dns-read (buffer-string))))
 	      (if fullp
 		  result
 		(let ((answer (car (dns-get 'answers result))))
 		  (when (eq type (dns-get 'type answer))
-		    (dns-get 'data answer)))))))))))
+		    (if (eq type 'TXT)
+			(dns-get-txt-answer (dns-get 'answers result))
+		      (dns-get 'data answer))))))))))))
 
 (provide 'dns)