1;;; dig.el --- Domain Name System dig interface
2
3;; Copyright (C) 2000, 2001, 2002, 2003, 2004,
4;;   2005, 2006, 2007 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
13;; by the Free Software Foundation; either version 2, or (at your
14;; option) any later version.
15
16;; GNU Emacs is distributed in the hope that it will be useful, but
17;; WITHOUT ANY WARRANTY; without even the implied warranty of
18;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19;; 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; see the file COPYING.  If not, write to the
23;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24;; Boston, MA 02110-1301, USA.
25
26;;; Commentary:
27
28;; This provide an interface for "dig".
29;;
30;; For interactive use, try M-x dig and type a hostname.  Use `q' to quit
31;; dig buffer.
32;;
33;; For use in elisp programs, call `dig-invoke' and use
34;; `dig-extract-rr' to extract resource records.
35
36;;; Release history:
37
38;; 2000-10-28  posted on gnu.emacs.sources
39
40;;; Code:
41
42(eval-when-compile (require 'cl))
43
44(defgroup dig nil
45  "Dig configuration."
46  :group 'comm)
47
48(defcustom dig-program "dig"
49  "Name of dig (domain information groper) binary."
50  :type 'file
51  :group 'dig)
52
53(defcustom dig-dns-server nil
54  "DNS server to query.
55If nil, use system defaults."
56  :type '(choice (const :tag "System defaults")
57		 string)
58  :group 'dig)
59
60(defcustom dig-font-lock-keywords
61  '(("^;; [A-Z]+ SECTION:" 0 font-lock-keyword-face)
62    ("^;;.*" 0 font-lock-comment-face)
63    ("^; <<>>.*" 0 font-lock-type-face)
64    ("^;.*" 0 font-lock-function-name-face))
65  "Default expressions to highlight in dig mode."
66  :type 'sexp
67  :group 'dig)
68
69(defun dig-invoke (domain &optional
70			  query-type query-class query-option
71			  dig-option server)
72  "Call dig with given arguments and return buffer containing output.
73DOMAIN is a string with a DNS domain. QUERY-TYPE is an optional string
74with a DNS type. QUERY-CLASS is an optional string with a DNS class.
75QUERY-OPTION is an optional string with dig \"query options\".
76DIG-OPTIONS is an optional string with parameters for the dig program.
77SERVER is an optional string with a domain name server to query.
78
79Dig is an external program found in the BIND name server distribution,
80and is a commonly available debugging tool."
81  (let (buf cmdline)
82    (setq buf (generate-new-buffer "*dig output*"))
83    (if dig-option (push dig-option cmdline))
84    (if query-option (push query-option cmdline))
85    (if query-class (push query-class cmdline))
86    (if query-type (push query-type cmdline))
87    (push domain cmdline)
88    (if server (push (concat "@" server) cmdline)
89      (if dig-dns-server (push (concat "@" dig-dns-server) cmdline)))
90    (apply 'call-process dig-program nil buf nil cmdline)
91    buf))
92
93(defun dig-extract-rr (domain &optional type class)
94  "Extract resource records for DOMAIN, TYPE and CLASS from buffer.
95Buffer should contain output generated by `dig-invoke'."
96  (save-excursion
97    (goto-char (point-min))
98    (if (re-search-forward
99	 (concat domain "\\.?[\t ]+[0-9wWdDhHmMsS]+[\t ]+"
100		 (upcase (or class "IN")) "[\t ]+" (upcase (or type "A")))
101	 nil t)
102	(let (b e)
103	  (end-of-line)
104	  (setq e (point))
105	  (beginning-of-line)
106	  (setq b (point))
107	  (when (search-forward " (" e t)
108	    (search-forward " )"))
109	  (end-of-line)
110	  (setq e (point))
111	  (buffer-substring b e))
112      (and (re-search-forward (concat domain "\\.?[\t ]+[0-9wWdDhHmMsS]+[\t ]+"
113				      (upcase (or class "IN"))
114				      "[\t ]+CNAME[\t ]+\\(.*\\)$") nil t)
115	   (dig-extract-rr (match-string 1) type class)))))
116
117(defun dig-rr-get-pkix-cert (rr)
118  (let (b e str)
119    (string-match "[^\t ]+[\t ]+[0-9wWdDhHmMsS]+[\t ]+IN[\t ]+CERT[\t ]+\\(1\\|PKIX\\)[\t ]+[0-9]+[\t ]+[0-9]+[\t ]+(?" rr)
120    (setq b (match-end 0))
121    (string-match ")" rr)
122    (setq e (match-beginning 0))
123    (setq str (substring rr b e))
124    (while (string-match "[\t \n\r]" str)
125      (setq str (replace-match "" nil nil str)))
126    str))
127
128;; XEmacs does it like this.  For Emacs, we have to set the
129;; `font-lock-defaults' buffer-local variable.
130(put 'dig-mode 'font-lock-defaults '(dig-font-lock-keywords t))
131
132(put 'dig-mode 'mode-class 'special)
133
134(defvar dig-mode-map nil)
135(unless dig-mode-map
136  (setq dig-mode-map (make-sparse-keymap))
137  (suppress-keymap dig-mode-map)
138
139  (define-key dig-mode-map "q" 'dig-exit))
140
141(defun dig-mode ()
142  "Major mode for displaying dig output."
143  (interactive)
144  (kill-all-local-variables)
145  (setq mode-name "dig")
146  (setq major-mode 'dig-mode)
147  (use-local-map dig-mode-map)
148  (buffer-disable-undo)
149  (unless (featurep 'xemacs)
150    (set (make-local-variable 'font-lock-defaults)
151	 '(dig-font-lock-keywords t)))
152  (when (featurep 'font-lock)
153    (font-lock-set-defaults))
154  (gnus-run-mode-hooks 'dig-mode-hook))
155
156(defun dig-exit ()
157  "Quit dig output buffer."
158  (interactive)
159  (kill-buffer (current-buffer)))
160
161(defun dig (domain &optional
162		   query-type query-class query-option dig-option server)
163  "Query addresses of a DOMAIN using dig, by calling `dig-invoke'.
164Optional arguments are passed to `dig-invoke'."
165  (interactive "sHost: ")
166  (switch-to-buffer
167   (dig-invoke domain query-type query-class query-option dig-option server))
168  (goto-char (point-min))
169  (and (search-forward ";; ANSWER SECTION:" nil t)
170       (forward-line))
171  (dig-mode)
172  (setq buffer-read-only t)
173  (set-buffer-modified-p nil))
174
175;; named for consistency with query-dns in dns.el
176(defun query-dig (domain &optional
177			 query-type query-class query-option dig-option server)
178  "Query addresses of a DOMAIN using dig.
179It works by calling `dig-invoke' and `dig-extract-rr'.  Optional
180arguments are passed to `dig-invoke' and `dig-extract-rr'.  Returns
181nil for domain/class/type queries that results in no data."
182(let ((buffer (dig-invoke domain query-type query-class
183			  query-option dig-option server)))
184  (when buffer
185    (switch-to-buffer buffer)
186    (let ((digger (dig-extract-rr domain query-type query-class)))
187      (kill-buffer buffer)
188      digger))))
189
190(provide 'dig)
191
192;;; arch-tag: 1d61726e-9400-4013-9ae7-4035e0c7f7d6
193;;; dig.el ends here
194