(defvar dns-mode-map
(let ((map (make-sparse-keymap)))
(define-key map "\C-c\C-s" 'dns-mode-soa-increment-serial)
+ (define-key map "\C-c\C-e" 'dns-mode-ipv6-to-nibbles)
map)
"Keymap for DNS master file mode.")
(easy-menu-define dns-mode-menu dns-mode-map
"DNS Menu."
'("DNS"
- ["Increment SOA serial" dns-mode-soa-increment-serial t]))
+ ["Increment SOA serial" dns-mode-soa-increment-serial t]
+ ["Convert IPv6 address to nibbles" dns-mode-ipv6-to-nibbles t]))
;; Mode.
;; We return nil in case this is used in write-contents-functions.
nil)))
+;;;###autoload
+(defun dns-mode-ipv6-to-nibbles (&optional negate-prefix)
+ "Convert an IPv6 address around or before point.
+Replace the address by its ip6.arpa-representation for use in
+reverse zone files, placing the original address in the kill ring.
+
+The address can be: a complete address (no prefix designator);
+with a normal prefix designator (e.g. /48), in which case only
+the required number of nibbles are output; or with a negative
+prefix designator (e.g. /-112), in which case only the part of
+the address *not* covered by the absolute value of the prefix
+length is output, as a relative address (without \".ip6.arpa.\" at
+the end). This is useful when $ORIGIN is specified in the zone file.
+
+Optional prefix argument NEGATE-PREFIX negates the value of the
+detected prefix length.
+
+Examples:
+
+2001:db8::12 =>
+2.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.
+
+2001:db8::12/32 =>
+8.b.d.0.1.0.0.2.ip6.arpa.
+
+2001:db8::12/-32 =>
+2.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0
+
+::42/112 (with prefix argument) =>
+2.4.0.0"
+ (interactive "P")
+ (skip-syntax-backward " ")
+ (skip-syntax-backward "w_.")
+ (re-search-forward "\\([[:xdigit:]:]+\\)\\(/-?[0-9]\\{2,3\\}\\)?")
+ (kill-new (match-string 0))
+ (let ((address (match-string 1))
+ (prefix-length (match-string 2)))
+ (when prefix-length
+ (setq prefix-length (string-to-number (substring prefix-length 1)))
+ (if negate-prefix
+ (setq prefix-length (- prefix-length))))
+ (replace-match
+ (save-match-data
+ (dns-mode-reverse-and-expand-ipv6 address prefix-length)))))
+
+(defun dns-mode-reverse-and-expand-ipv6 (address &optional prefix-length)
+ "Convert an IPv6 address to (parts of) an ip6.arpa nibble format.
+ADDRESS is an IPv6 address in the usual colon-separated
+format, without a prefix designator at the end.
+
+Optional PREFIX-LENGTH is a number whose absolute value is the
+length in bits of the network part of the address. If nil,
+return an absolute address representing the full IPv6 address.
+If positive, return an absolute address representing the network
+prefix indicated. If negative, return a relative address
+representing the host parts of the address with respect to the
+indicated network prefix.
+
+See `dns-mode-ipv6-to-nibbles' for examples."
+ (let* ((chunks (split-string address ":"))
+ (prefix-length-nibbles (if prefix-length
+ (ceiling (abs prefix-length) 4)
+ 32))
+ (filler-chunks (- 8 (length (remove "" chunks))))
+ (expanded-address
+ (apply #'concat
+ (cl-loop with filler-done = nil
+ for chunk in chunks
+ if (and (not filler-done)
+ (string= "" chunk))
+ append (prog1
+ (cl-loop repeat filler-chunks
+ collect "0000")
+ (setq filler-done t))
+ else
+ if (not (string= "" chunk))
+ collect (format "%04x"
+ (string-to-number chunk 16)))))
+ (rev-address-nibbles
+ (nreverse (if (and prefix-length
+ (cl-minusp prefix-length))
+ (substring expanded-address prefix-length-nibbles)
+ (substring expanded-address 0 prefix-length-nibbles)))))
+ (with-temp-buffer
+ (cl-loop for char across rev-address-nibbles
+ do
+ (insert char)
+ (insert "."))
+ (if (and prefix-length
+ (cl-minusp prefix-length))
+ (delete-char -1)
+ (insert "ip6.arpa."))
+ (insert " ")
+ (buffer-string))))
+
(provide 'dns-mode)
;;; dns-mode.el ends here
--- /dev/null
+;;; dns-mode-tests.el --- Test suite for dns-mode -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2017 Free Software Foundation, Inc.
+
+;; Author: Peder O. Klingenberg <peder@klingenberg.no>
+;; Keywords: dns zone
+
+;; This file is part of GNU Emacs.
+
+;; 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 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
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+(require 'dns-mode)
+
+;;; IPv6 reverse zones
+(ert-deftest dns-mode-ipv6-conversion ()
+ (let ((address "2001:db8::42"))
+ (should (equal (dns-mode-reverse-and-expand-ipv6 address)
+ "2.4.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa. "))
+ (should (equal (dns-mode-reverse-and-expand-ipv6 address 32)
+ "8.b.d.0.1.0.0.2.ip6.arpa. "))
+ (should (equal (dns-mode-reverse-and-expand-ipv6 address -112)
+ "2.4.0.0 "))))
+
+(ert-deftest dns-mode-ipv6-text-replacement ()
+ (let ((address "2001:db8::42/32"))
+ (with-temp-buffer
+ ;; Conversion with point directly after address
+ (insert address)
+ (dns-mode-ipv6-to-nibbles nil)
+ (should (equal (buffer-string) "8.b.d.0.1.0.0.2.ip6.arpa. "))
+ ;; Kill ring contains the expected
+ (erase-buffer)
+ (yank)
+ (should (equal (buffer-string) address))
+ ;; Point at beginning of address (and prefix arg to command)
+ (goto-char (point-min))
+ (dns-mode-ipv6-to-nibbles t)
+ (should (equal (buffer-string) "2.4.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0 "))
+ ;; Point separated from address by whitespace
+ (erase-buffer)
+ (insert address)
+ (insert " ")
+ (dns-mode-ipv6-to-nibbles nil)
+ (should (equal (buffer-string) "8.b.d.0.1.0.0.2.ip6.arpa. ")))))
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