lisp/net/dig.el

   1 ;;; dig.el --- Domain Name System dig interface
   2
   3 ;; Copyright (C) 2000, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   5
   6 ;; Author: Simon Josefsson <simon@josefsson.org>
   7 ;; Keywords: DNS BIND dig
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; This provide an interface for "dig".
  27 ;;
  28 ;; For interactive use, try M-x dig and type a hostname.  Use `q' to quit
  29 ;; dig buffer.
  30 ;;
  31 ;; For use in elisp programs, call `dig-invoke' and use
  32 ;; `dig-extract-rr' to extract resource records.
  33
  34 ;;; Release history:
  35
  36 ;; 2000-10-28  posted on gnu.emacs.sources
  37
  38 ;;; Code:
  39
  40 (eval-when-compile (require 'cl))
  41
  42 (defgroup dig nil
  43   "Dig configuration."
  44   :group 'comm)
  45
  46 (defcustom dig-program "dig"
  47   "Name of dig (domain information groper) binary."
  48   :type 'file
  49   :group 'dig)
  50
  51 (defcustom dig-dns-server nil
  52   "DNS server to query.
  53 If nil, use system defaults."
  54   :type '(choice (const :tag "System defaults")
  55                  string)
  56   :group 'dig)
  57
  58 (defcustom dig-font-lock-keywords
  59   '(("^;; [A-Z]+ SECTION:" 0 font-lock-keyword-face)
  60     ("^;;.*" 0 font-lock-comment-face)
  61     ("^; <<>>.*" 0 font-lock-type-face)
  62     ("^;.*" 0 font-lock-function-name-face))
  63   "Default expressions to highlight in dig mode."
  64   :type 'sexp
  65   :group 'dig)
  66
  67 (defun dig-invoke (domain &optional
  68                           query-type query-class query-option
  69                           dig-option server)
  70   "Call dig with given arguments and return buffer containing output.
  71 DOMAIN is a string with a DNS domain. QUERY-TYPE is an optional string
  72 with a DNS type. QUERY-CLASS is an optional string with a DNS class.
  73 QUERY-OPTION is an optional string with dig \"query options\".
  74 DIG-OPTIONS is an optional string with parameters for the dig program.
  75 SERVER is an optional string with a domain name server to query.
  76
  77 Dig is an external program found in the BIND name server distribution,
  78 and is a commonly available debugging tool."
  79   (let (buf cmdline)
  80     (setq buf (generate-new-buffer "*dig output*"))
  81     (if dig-option (push dig-option cmdline))
  82     (if query-option (push query-option cmdline))
  83     (if query-class (push query-class cmdline))
  84     (if query-type (push query-type cmdline))
  85     (push domain cmdline)
  86     (if server (push (concat "@" server) cmdline)
  87       (if dig-dns-server (push (concat "@" dig-dns-server) cmdline)))
  88     (apply 'call-process dig-program nil buf nil cmdline)
  89     buf))
  90
  91 (defun dig-extract-rr (domain &optional type class)
  92   "Extract resource records for DOMAIN, TYPE and CLASS from buffer.
  93 Buffer should contain output generated by `dig-invoke'."
  94   (save-excursion
  95     (goto-char (point-min))
  96     (if (re-search-forward
  97          (concat domain "\\.?[\t ]+[0-9wWdDhHmMsS]+[\t ]+"
  98                  (upcase (or class "IN")) "[\t ]+" (upcase (or type "A")))
  99          nil t)
 100         (let (b e)
 101           (end-of-line)
 102           (setq e (point))
 103           (beginning-of-line)
 104           (setq b (point))
 105           (when (search-forward " (" e t)
 106             (search-forward " )"))
 107           (end-of-line)
 108           (setq e (point))
 109           (buffer-substring b e))
 110       (and (re-search-forward (concat domain "\\.?[\t ]+[0-9wWdDhHmMsS]+[\t ]+"
 111                                       (upcase (or class "IN"))
 112                                       "[\t ]+CNAME[\t ]+\\(.*\\)$") nil t)
 113            (dig-extract-rr (match-string 1) type class)))))
 114
 115 (defun dig-rr-get-pkix-cert (rr)
 116   (let (b e str)
 117     (string-match "[^\t ]+[\t ]+[0-9wWdDhHmMsS]+[\t ]+IN[\t ]+CERT[\t ]+\\(1\\|PKIX\\)[\t ]+[0-9]+[\t ]+[0-9]+[\t ]+(?" rr)
 118     (setq b (match-end 0))
 119     (string-match ")" rr)
 120     (setq e (match-beginning 0))
 121     (setq str (substring rr b e))
 122     (while (string-match "[\t \n\r]" str)
 123       (setq str (replace-match "" nil nil str)))
 124     str))
 125
 126 ;; XEmacs does it like this.  For Emacs, we have to set the
 127 ;; `font-lock-defaults' buffer-local variable.
 128 (put 'dig-mode 'font-lock-defaults '(dig-font-lock-keywords t))
 129
 130 (put 'dig-mode 'mode-class 'special)
 131
 132 (defvar dig-mode-map nil)
 133 (unless dig-mode-map
 134   (setq dig-mode-map (make-sparse-keymap))
 135   (suppress-keymap dig-mode-map)
 136
 137   (define-key dig-mode-map "q" 'dig-exit))
 138
 139 (defun dig-mode ()
 140   "Major mode for displaying dig output."
 141   (interactive)
 142   (kill-all-local-variables)
 143   (setq mode-name "dig")
 144   (setq major-mode 'dig-mode)
 145   (use-local-map dig-mode-map)
 146   (buffer-disable-undo)
 147   (unless (featurep 'xemacs)
 148     (set (make-local-variable 'font-lock-defaults)
 149          '(dig-font-lock-keywords t)))
 150   (when (featurep 'font-lock)
 151     (font-lock-set-defaults))
 152   (save-current-buffer
 153     (if (fboundp 'run-mode-hooks)
 154         (run-mode-hooks 'dig-mode-hook)
 155       (run-hooks 'dig-mode-hook))))
 156
 157 (defun dig-exit ()
 158   "Quit dig output buffer."
 159   (interactive)
 160   (kill-buffer (current-buffer)))
 161
 162 (defun dig (domain &optional
 163                    query-type query-class query-option dig-option server)
 164   "Query addresses of a DOMAIN using dig, by calling `dig-invoke'.
 165 Optional arguments are passed to `dig-invoke'."
 166   (interactive "sHost: ")
 167   (switch-to-buffer
 168    (dig-invoke domain query-type query-class query-option dig-option server))
 169   (goto-char (point-min))
 170   (and (search-forward ";; ANSWER SECTION:" nil t)
 171        (forward-line))
 172   (dig-mode)
 173   (setq buffer-read-only t)
 174   (set-buffer-modified-p nil))
 175
 176 ;; named for consistency with query-dns in dns.el
 177 (defun query-dig (domain &optional
 178                          query-type query-class query-option dig-option server)
 179   "Query addresses of a DOMAIN using dig.
 180 It works by calling `dig-invoke' and `dig-extract-rr'.  Optional
 181 arguments are passed to `dig-invoke' and `dig-extract-rr'.  Returns
 182 nil for domain/class/type queries that results in no data."
 183 (let ((buffer (dig-invoke domain query-type query-class
 184                           query-option dig-option server)))
 185   (when buffer
 186     (switch-to-buffer buffer)
 187     (let ((digger (dig-extract-rr domain query-type query-class)))
 188       (kill-buffer buffer)
 189       digger))))
 190
 191 (provide 'dig)
 192
 193 ;; arch-tag: 1d61726e-9400-4013-9ae7-4035e0c7f7d6
 194 ;;; dig.el ends here