X-Git-Url: http://cgit.sxemacs.org/?p=gnus;a=blobdiff_plain;f=lisp%2Fdns.el;h=ba6523f6f5fc8f193eba58459aa96a4e4a703258;hp=05b2f7329b6427160fa9758d06023e4bd1bda841;hb=94f288135f95ca48fb50f5aa43bc09f9669c5c23;hpb=fe43a4640929b89f7517f423090f710568c87fc0 diff --git a/lisp/dns.el b/lisp/dns.el index 05b2f7329..ba6523f6f 100644 --- a/lisp/dns.el +++ b/lisp/dns.el @@ -1,41 +1,41 @@ ;;; dns.el --- Domain Name Service lookups -;; Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. +;; Copyright (C) 2002-2015 Free Software Foundation, Inc. ;; Author: Lars Magne Ingebrigtsen -;; 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 2, 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 . ;;; Commentary: ;;; Code: -(eval-when-compile (require 'cl)) - -(require 'mm-util) - (defvar dns-timeout 5 "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.") + +(defvar dns-servers-valid-for-interfaces nil + "The return value of `network-interface-list' when `dns-servers' was set. +If the set of network interfaces and/or their IP addresses +change, then presumably the list of DNS servers needs to be +updated. Set this variable to t to disable the check.") ;;; Internal code: @@ -105,7 +105,8 @@ If nil, /etc/resolv.conf will be consulted.") (dns-write-bytes 0)) (defun dns-read-string-name (string buffer) - (mm-with-unibyte-buffer + (with-temp-buffer + (unless (featurep 'xemacs) (set-buffer-multibyte nil)) (insert string) (goto-char (point-min)) (dns-read-name buffer))) @@ -139,6 +140,7 @@ If nil, /etc/resolv.conf will be consulted.") "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 + (unless (featurep 'xemacs) (set-buffer-multibyte nil)) (dns-write-bytes (dns-get 'id spec) 2) (dns-write-bytes (logior @@ -154,7 +156,7 @@ If TCP-P, the first two bytes of the package with be the length field." (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) @@ -188,75 +190,76 @@ If TCP-P, the first two bytes of the package with be the length field." (buffer-string))) (defun dns-read (packet) - (mm-with-unibyte-buffer + (with-temp-buffer + (unless (featurep 'xemacs) (set-buffer-multibyte nil)) (let ((spec nil) - queries answers authorities additionals) + queries answers authorities additionals) (insert packet) (goto-char (point-min)) (push (list 'id (dns-read-bytes 2)) spec) (let ((byte (dns-read-bytes 1))) - (push (list 'response-p (if (zerop (logand byte (lsh 1 7))) nil t)) - spec) - (let ((opcode (logand byte (lsh 7 3)))) - (push (list 'opcode - (cond ((eq opcode 0) 'query) - ((eq opcode 1) 'inverse-query) - ((eq opcode 2) 'status))) - spec)) - (push (list 'authoritative-p (if (zerop (logand byte (lsh 1 2))) - nil t)) spec) - (push (list 'truncated-p (if (zerop (logand byte (lsh 1 2))) nil t)) - spec) - (push (list 'recursion-desired-p - (if (zerop (logand byte (lsh 1 0))) nil t)) spec)) + (push (list 'response-p (if (zerop (logand byte (lsh 1 7))) nil t)) + spec) + (let ((opcode (logand byte (lsh 7 3)))) + (push (list 'opcode + (cond ((eq opcode 0) 'query) + ((eq opcode 1) 'inverse-query) + ((eq opcode 2) 'status))) + spec)) + (push (list 'authoritative-p (if (zerop (logand byte (lsh 1 2))) + nil t)) spec) + (push (list 'truncated-p (if (zerop (logand byte (lsh 1 2))) nil t)) + spec) + (push (list 'recursion-desired-p + (if (zerop (logand byte (lsh 1 0))) nil t)) spec)) (let ((rc (logand (dns-read-bytes 1) 15))) - (push (list 'response-code - (cond - ((eq rc 0) 'no-error) - ((eq rc 1) 'format-error) - ((eq rc 2) 'server-failure) - ((eq rc 3) 'name-error) - ((eq rc 4) 'not-implemented) - ((eq rc 5) 'refused))) - spec)) + (push (list 'response-code + (cond + ((eq rc 0) 'no-error) + ((eq rc 1) 'format-error) + ((eq rc 2) 'server-failure) + ((eq rc 3) 'name-error) + ((eq rc 4) 'not-implemented) + ((eq rc 5) 'refused))) + spec)) (setq queries (dns-read-bytes 2)) (setq answers (dns-read-bytes 2)) (setq authorities (dns-read-bytes 2)) (setq additionals (dns-read-bytes 2)) (let ((qs nil)) - (dotimes (i queries) - (push (list (dns-read-name) - (list 'type (dns-inverse-get (dns-read-bytes 2) - dns-query-types)) - (list 'class (dns-inverse-get (dns-read-bytes 2) - dns-classes))) - qs)) - (push (list 'queries qs) spec)) - (dolist (slot '(answers authorities additionals)) - (let ((qs nil) - type) - (dotimes (i (symbol-value slot)) - (push (list (dns-read-name) - (list 'type - (setq type (dns-inverse-get (dns-read-bytes 2) - dns-query-types))) - (list 'class (dns-inverse-get (dns-read-bytes 2) - dns-classes)) - (list 'ttl (dns-read-bytes 4)) - (let ((length (dns-read-bytes 2))) - (list 'data - (dns-read-type - (buffer-substring - (point) - (progn (forward-char length) (point))) - type)))) - qs)) - (push (list slot qs) spec))) - (nreverse spec)))) + (dotimes (i queries) + (push (list (dns-read-name) + (list 'type (dns-inverse-get (dns-read-bytes 2) + dns-query-types)) + (list 'class (dns-inverse-get (dns-read-bytes 2) + dns-classes))) + qs)) + (push (list 'queries qs) spec)) + (dolist (slot '(answers authorities additionals)) + (let ((qs nil) + type) + (dotimes (i (symbol-value slot)) + (push (list (dns-read-name) + (list 'type + (setq type (dns-inverse-get (dns-read-bytes 2) + dns-query-types))) + (list 'class (dns-inverse-get (dns-read-bytes 2) + dns-classes)) + (list 'ttl (dns-read-bytes 4)) + (let ((length (dns-read-bytes 2))) + (list 'data + (dns-read-type + (buffer-substring + (point) + (progn (forward-char length) (point))) + type)))) + qs)) + (push (list slot qs) spec))) + (nreverse spec)))) (defun dns-read-int32 () - ;; Full 32 bit Integers can't be handled by Emacs. If we use - ;; floats, it works. + ;; Full 32 bit Integers can't be handled by 32-bit Emacsen. If we + ;; use floats, it works. (format "%.0f" (+ (* (dns-read-bytes 1) 16777216.0) (dns-read-bytes 3)))) @@ -264,48 +267,73 @@ If TCP-P, the first two bytes of the package with be the length field." (let ((buffer (current-buffer)) (point (point))) (prog1 - (mm-with-unibyte-buffer - (insert string) - (goto-char (point-min)) - (cond - ((eq type 'A) - (let ((bytes nil)) - (dotimes (i 4) - (push (dns-read-bytes 1) bytes)) - (mapconcat 'number-to-string (nreverse bytes) "."))) - ((eq type 'AAAA) - (let (hextets) - (dotimes (i 8) - (push (dns-read-bytes 2) hextets)) - (mapconcat (lambda (n) (format "%x" n)) (nreverse hextets) ":"))) - ((eq type 'SOA) - (list (list 'mname (dns-read-name buffer)) - (list 'rname (dns-read-name buffer)) - (list 'serial (dns-read-int32)) - (list 'refresh (dns-read-int32)) - (list 'retry (dns-read-int32)) - (list 'expire (dns-read-int32)) - (list 'minimum (dns-read-int32)))) - ((eq type 'SRV) - (list (list 'priority (dns-read-bytes 2)) - (list 'weight (dns-read-bytes 2)) - (list 'port (dns-read-bytes 2)) - (list 'target (dns-read-name buffer)))) - ((eq type 'MX) - (cons (dns-read-bytes 2) (dns-read-name buffer))) - ((or (eq type 'CNAME) (eq type 'NS) (eq type 'PTR)) - (dns-read-string-name string buffer)) - (t string))) + (with-temp-buffer + (unless (featurep 'xemacs) (set-buffer-multibyte nil)) + (insert string) + (goto-char (point-min)) + (cond + ((eq type 'A) + (let ((bytes nil)) + (dotimes (i 4) + (push (dns-read-bytes 1) bytes)) + (mapconcat 'number-to-string (nreverse bytes) "."))) + ((eq type 'AAAA) + (let (hextets) + (dotimes (i 8) + (push (dns-read-bytes 2) hextets)) + (mapconcat (lambda (n) (format "%x" n)) + (nreverse hextets) ":"))) + ((eq type 'SOA) + (list (list 'mname (dns-read-name buffer)) + (list 'rname (dns-read-name buffer)) + (list 'serial (dns-read-int32)) + (list 'refresh (dns-read-int32)) + (list 'retry (dns-read-int32)) + (list 'expire (dns-read-int32)) + (list 'minimum (dns-read-int32)))) + ((eq type 'SRV) + (list (list 'priority (dns-read-bytes 2)) + (list 'weight (dns-read-bytes 2)) + (list 'port (dns-read-bytes 2)) + (list 'target (dns-read-name buffer)))) + ((eq type 'MX) + (cons (dns-read-bytes 2) (dns-read-name buffer))) + ((or (eq type 'CNAME) (eq type 'NS) (eq type 'PTR)) + (dns-read-string-name string buffer)) + (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))))) +(declare-function network-interface-list "process.c") + +(defun dns-servers-up-to-date-p () + "Return false if we need to recheck the list of DNS servers." + (and dns-servers + (or (eq dns-servers-valid-for-interfaces t) + ;; `network-interface-list' was introduced in Emacs 22.1. + (not (fboundp 'network-interface-list)) + (equal dns-servers-valid-for-interfaces + (network-interface-list))))) + +(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)))))) + (when (fboundp 'network-interface-list) + (setq dns-servers-valid-for-interfaces (network-interface-list)))) (defun dns-read-txt (string) (if (> (length string) 1) @@ -351,23 +379,26 @@ If TCP-P, the first two bytes of the package with be the length field." (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)) + (unless (dns-servers-up-to-date-p) + (dns-set-servers)) (when reversep (setq name (concat @@ -377,48 +408,52 @@ If REVERSEP, look up an IP address." (if (not dns-servers) (message "No DNS server configuration found") - (mm-with-unibyte-buffer + (with-temp-buffer + (unless (featurep 'xemacs) (set-buffer-multibyte nil)) (let ((process (condition-case () - (dns-make-network-process (car dns-servers)) - (error - (message "dns: Got an error while trying to talk to %s" - (car dns-servers)) - nil))) - (tcp-p (and (not (fboundp 'make-network-process)) - (not (featurep 'xemacs)))) - (step 100) - (times (* dns-timeout 1000)) - (id (random 65000))) - (when process - (process-send-string - process - (dns-write `((id ,id) - (opcode query) - (queries ((,name (type ,type)))) - (recursion-desired-p t)) - 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 (and tcp-p - (>= (buffer-size) 2)) - (goto-char (point-min)) - (delete-region (point) (+ (point) 2))) - (when (>= (buffer-size) 2) - (let ((result (dns-read (buffer-string)))) - (if fullp - result - (let ((answer (car (dns-get 'answers result)))) - (when (eq type (dns-get 'type answer)) - (if (eq type 'TXT) - (dns-get-txt-answer (dns-get 'answers result)) - (dns-get 'data answer)))))))))))) + (dns-make-network-process (car dns-servers)) + (error + (message + "dns: Got an error while trying to talk to %s" + (car dns-servers)) + nil))) + (tcp-p (and (not (fboundp 'make-network-process)) + (not (featurep 'xemacs)))) + (step 100) + (times (* dns-timeout 1000)) + (id (random 65000))) + (when process + (process-send-string + process + (dns-write `((id ,id) + (opcode query) + (queries ((,name (type ,type)))) + (recursion-desired-p t)) + tcp-p)) + (while (and (zerop (buffer-size)) + (> times 0)) + (sit-for (/ step 1000.0)) + (accept-process-output process 0 step) + (setq times (- times step))) + (condition-case nil + (delete-process process) + (error nil)) + (when (and tcp-p + (>= (buffer-size) 2)) + (goto-char (point-min)) + (delete-region (point) (+ (point) 2))) + (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)) + (if (eq type 'TXT) + (dns-get-txt-answer (dns-get 'answers result)) + (dns-get 'data answer)))))))))))) (provide 'dns) -;;; arch-tag: d0edd0c4-4cce-4538-ae92-06c3356ee80a ;;; dns.el ends here