X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/zone/blobdiff_plain/7fff37978d8a36109b20a60b9beaf90e137d3c64..babb8dd20692a2dcdd87b507116b6a94f60463cc:/zone.lisp

diff --git a/zone.lisp b/zone.lisp
index 7e6da2b..6b84dac 100644
--- a/zone.lisp
+++ b/zone.lisp
@@ -1,7 +1,5 @@
 ;;; -*-lisp-*-
 ;;;
-;;; $Id$
-;;;
 ;;; DNS zone generation
 ;;;
 ;;; (c) 2005 Straylight/Edgeware
@@ -27,16 +25,10 @@
 ;;; Packaging.
 
 (defpackage #:zone
-  (:use #:common-lisp #:mdw.base #:mdw.str #:collect #:safely #:net)
-  (:export #:soa #:mx #:zone #:zone-record #:zone-subdomain
-	   #:*default-zone-source* #:*default-zone-refresh*
-	     #:*default-zone-retry* #:*default-zone-expire*
-	     #:*default-zone-min-ttl* #:*default-zone-ttl*
-	     #:*default-mx-priority* #:*default-zone-admin*
-	     #:zone-find #:zone-parse #:zone-write #:zone-create #:defzone
-	     #:defrevzone #:zone-save
-	   #:defzoneparse #:zone-parse-host
-	   #:timespec-seconds #:make-zone-serial))
+  (:use #:common-lisp
+	#:mdw.base #:mdw.str #:collect #:safely
+	#:net #:services)
+  (:import-from #:net #:round-down #:round-up))
 
 (in-package #:zone)
 
@@ -68,10 +60,12 @@ (defun to-mixed-base (base val)
 	(push r a)
 	(setf val q)))))
 
+(export 'timespec-seconds)
 (defun timespec-seconds (ts)
-  "Convert a timespec TS to seconds.  A timespec may be a real count of
-   seconds, or a list (COUNT UNIT): UNIT may be any of a number of obvious
-   time units."
+  "Convert a timespec TS to seconds.
+
+   A timespec may be a real count of seconds, or a list (COUNT UNIT).  UNIT
+   may be any of a number of obvious time units."
   (cond ((null ts) 0)
 	((realp ts) (floor ts))
 	((atom ts)
@@ -98,10 +92,11 @@ (defun hash-table-keys (ht)
     (maphash (lambda (key val) (declare (ignore val)) (collect key)) ht)))
 
 (defun iso-date (&optional time &key datep timep (sep #\ ))
-  "Construct a textual date or time in ISO format.  The TIME is the universal
-   time to convert, which defaults to now; DATEP is whether to emit the date;
-   TIMEP is whether to emit the time, and SEP (default is space) is how to
-   separate the two."
+  "Construct a textual date or time in ISO format.
+
+   The TIME is the universal time to convert, which defaults to now; DATEP is
+   whether to emit the date; TIMEP is whether to emit the time, and
+   SEP (default is space) is how to separate the two."
   (multiple-value-bind
       (sec min hr day mon yr dow dstp tz)
       (decode-universal-time (if (or (null time) (eq time :now))
@@ -119,6 +114,7 @@ (defun iso-date (&optional time &key datep timep (sep #\ ))
 ;;;--------------------------------------------------------------------------
 ;;; Zone types.
 
+(export 'soa)
 (defstruct (soa (:predicate soap))
   "Start-of-authority record information."
   source
@@ -129,11 +125,13 @@ (defstruct (soa (:predicate soap))
   min-ttl
   serial)
 
+(export 'mx)
 (defstruct (mx (:predicate mxp))
   "Mail-exchange record information."
   priority
   domain)
 
+(export 'zone)
 (defstruct (zone (:predicate zonep))
   "Zone information."
   soa
@@ -144,49 +142,160 @@ (defstruct (zone (:predicate zonep))
 ;;;--------------------------------------------------------------------------
 ;;; Zone defaults.  It is intended that scripts override these.
 
-#+ecl
-(cffi:defcfun gethostname :int
-  (name :pointer)
-  (len :uint))
-
+(export '*default-zone-source*)
 (defvar *default-zone-source*
-  (let ((hn #+cmu (unix:unix-gethostname)
-	    #+clisp (unix:get-host-name)
-	    #+ecl (cffi:with-foreign-pointer-as-string (buffer 256 len)
-		    (let ((rc (gethostname buffer len)))
-		      (unless (zerop rc)
-			(error "gethostname(2) failed (rc = ~A)." rc))))))
+  (let ((hn (gethostname)))
     (and hn (concatenate 'string (canonify-hostname hn) ".")))
   "The default zone source: the current host's name.")
 
+(export '*default-zone-refresh*)
 (defvar *default-zone-refresh* (* 24 60 60)
   "Default zone refresh interval: one day.")
 
+(export '*default-zone-admin*)
 (defvar *default-zone-admin* nil
   "Default zone administrator's email address.")
 
+(export '*default-zone-retry*)
 (defvar *default-zone-retry* (* 60 60)
   "Default znoe retry interval: one hour.")
 
+(export '*default-zone-expire*)
 (defvar *default-zone-expire* (* 14 24 60 60)
   "Default zone expiry time: two weeks.")
 
+(export '*default-zone-min-ttl*)
 (defvar *default-zone-min-ttl* (* 4 60 60)
   "Default zone minimum TTL/negative TTL: four hours.")
 
+(export '*default-zone-ttl*)
 (defvar *default-zone-ttl* (* 8 60 60)
   "Default zone TTL (for records without explicit TTLs): 8 hours.")
 
+(export '*default-mx-priority*)
 (defvar *default-mx-priority* 50
   "Default MX priority.")
 
+;;;--------------------------------------------------------------------------
+;;; Zone variables and structures.
+
+(defvar *zones* (make-hash-table :test #'equal)
+  "Map of known zones.")
+
+(export 'zone-find)
+(defun zone-find (name)
+  "Find a zone given its NAME."
+  (gethash (string-downcase (stringify name)) *zones*))
+(defun (setf zone-find) (zone name)
+  "Make the zone NAME map to ZONE."
+  (setf (gethash (string-downcase (stringify name)) *zones*) zone))
+
+(export 'zone-record)
+(defstruct (zone-record (:conc-name zr-))
+  "A zone record."
+  (name '<unnamed>)
+  ttl
+  type
+  (make-ptr-p nil)
+  data)
+
+(export 'zone-subdomain)
+(defstruct (zone-subdomain (:conc-name zs-))
+  "A subdomain.
+
+   Slightly weird.  Used internally by `zone-process-records', and shouldn't
+   escape."
+  name
+  ttl
+  records)
+
+(export '*zone-output-path*)
+(defvar *zone-output-path* nil
+  "Pathname defaults to merge into output files.
+
+   If this is nil then use the prevailing `*default-pathname-defaults*'.
+   This is not the same as capturing the `*default-pathname-defaults*' from
+   load time.")
+
+(export '*preferred-subnets*)
+(defvar *preferred-subnets* nil
+  "Subnets to prefer when selecting defaults.")
+
+;;;--------------------------------------------------------------------------
+;;; Zone infrastructure.
+
+(defun zone-file-name (zone type)
+  "Choose a file name for a given ZONE and TYPE."
+  (merge-pathnames (make-pathname :name (string-downcase zone)
+				  :type (string-downcase type))
+		   (or *zone-output-path* *default-pathname-defaults*)))
+
+(export 'zone-preferred-subnet-p)
+(defun zone-preferred-subnet-p (name)
+  "Answer whether NAME (a string or symbol) names a preferred subnet."
+  (member name *preferred-subnets* :test #'string-equal))
+
+(export 'preferred-subnet-case)
+(defmacro preferred-subnet-case (&body clauses)
+  "Execute a form based on which networks are considered preferred.
+
+   The CLAUSES have the form (SUBNETS . FORMS) -- evaluate the first FORMS
+   whose SUBNETS (a list or single symbol, not evaluated) are listed in
+   `*preferred-subnets*'.  If SUBNETS is the symbol `t' then the clause
+   always matches."
+  `(cond
+    ,@(mapcar (lambda (clause)
+		(let ((subnets (car clause)))
+		  (cons (cond ((eq subnets t)
+			       t)
+			      ((listp subnets)
+			       `(or ,@(mapcar (lambda (subnet)
+						`(zone-preferred-subnet-p
+						  ',subnet))
+					      subnets)))
+			      (t
+			       `(zone-preferred-subnet-p ',subnets)))
+			(cdr clause))))
+	      clauses)))
+
+(export 'zone-parse-host)
+(defun zone-parse-host (f zname)
+  "Parse a host name F.
+
+   If F ends in a dot then it's considered absolute; otherwise it's relative
+   to ZNAME."
+  (setf f (stringify f))
+  (cond ((string= f "@") (stringify zname))
+	((and (plusp (length f))
+	      (char= (char f (1- (length f))) #\.))
+	 (string-downcase (subseq f 0 (1- (length f)))))
+	(t (string-downcase (concatenate 'string f "."
+					 (stringify zname))))))
+
+(export 'zone-make-name)
+(defun zone-make-name (prefix zone-name)
+  "Compute a full domain name from a PREFIX and a ZONE-NAME.
+
+   If the PREFIX ends with `.' then it's absolute already; otherwise, append
+   the ZONE-NAME, separated with a `.'.  If PREFIX is nil, or `@', then
+   return the ZONE-NAME only."
+  (if (or (not prefix) (string= prefix "@"))
+      zone-name
+      (let ((len (length prefix)))
+	(if (or (zerop len) (char/= (char prefix (1- len)) #\.))
+	    (join-strings #\. (list prefix zone-name))
+	    prefix))))
+
 ;;;--------------------------------------------------------------------------
 ;;; Serial numbering.
 
+(export 'make-zone-serial)
 (defun make-zone-serial (name)
-  "Given a zone NAME, come up with a new serial number.  This will (very
-   carefully) update a file ZONE.serial in the current directory."
-  (let* ((file (format nil "~(~A~).serial" name))
+  "Given a zone NAME, come up with a new serial number.
+
+   This will (very carefully) update a file ZONE.serial in the current
+   directory."
+  (let* ((file (zone-file-name name :serial))
 	 (last (with-open-file (in file
 				   :direction :input
 				   :if-does-not-exist nil)
@@ -203,48 +312,57 @@ (defun make-zone-serial (name)
     (safely-writing (out file)
       (format out
 	      ";; Serial number file for zone ~A~%~
-               ;;   (LAST-SEQ DAY MONTH YEAR)~%~
-               ~S~%"
+	       ;;   (LAST-SEQ DAY MONTH YEAR)~%~
+	       ~S~%"
 	      name
 	      (cons seq now)))
     (from-mixed-base '(100 100 100) (reverse (cons seq now)))))
 
 ;;;--------------------------------------------------------------------------
-;;; Zone variables and structures.
+;;; Zone form parsing.
 
-(defvar *zones* (make-hash-table :test #'equal)
-  "Map of known zones.")
+(defun zone-process-records (rec ttl func)
+  "Sort out the list of records in REC, calling FUNC for each one.
 
-(defun zone-find (name)
-  "Find a zone given its NAME."
-  (gethash (string-downcase (stringify name)) *zones*))
+   TTL is the default time-to-live for records which don't specify one.
 
-(defun (setf zone-find) (zone name)
-  "Make the zone NAME map to ZONE."
-  (setf (gethash (string-downcase (stringify name)) *zones*) zone))
+   REC is a list of records of the form
 
-(defstruct (zone-record (:conc-name zr-))
-  "A zone record."
-  (name '<unnamed>)
-  ttl
-  type
-  (defsubp nil)
-  data)
+	({ :ttl TTL | TYPE DATA | (LABEL . REC) }*)
 
-(defstruct (zone-subdomain (:conc-name zs-))
-  "A subdomain.  Slightly weird.  Used internally by zone-process-records
-   below, and shouldn't escape."
-  name
-  ttl
-  records)
+   The various kinds of entries have the following meanings.
 
-;;;--------------------------------------------------------------------------
-;;; Zone infrastructure.
+   :ttl TTL		Set the TTL for subsequent records (at this level of
+			  nesting only).
+
+   TYPE DATA		Define a record with a particular TYPE and DATA.
+			  Record types are defined using `defzoneparse' and
+			  the syntax of the data is idiosyncratic.
+
+   ((LABEL ...) . REC)	Define records for labels within the zone.  Any
+			  records defined within REC will have their domains
+			  prefixed by each of the LABELs.  A singleton list
+			  of labels may instead be written as a single
+			  label.  Note, therefore, that
+
+				(host (sub :a \"169.254.1.1\"))
+
+			  defines a record for `host.sub' -- not `sub.host'.
+
+   If REC contains no top-level records, but it does define records for a
+   label listed in `*preferred-subnets*', then the records for the first such
+   label are also promoted to top-level.
+
+   The FUNC is called for each record encountered, represented as a
+   `zone-record' object.  Zone parsers are not called: you get the record
+   types and data from the input form; see `zone-parse-records' if you want
+   the raw output."
 
-(defun zone-process-records (rec ttl func)
-  "Sort out the list of records in REC, calling FUNC for each one.  TTL is
-   the default time-to-live for records which don't specify one."
   (labels ((sift (rec ttl)
+	     ;; Parse the record list REC into lists of `zone-record' and
+	     ;; `zone-subdomain' objects, sorting out TTLs and so on.
+	     ;; Returns them as two values.
+
 	     (collecting (top sub)
 	       (loop
 		 (unless rec
@@ -265,194 +383,46 @@ (defun zone-process-records (rec ttl func)
 				     sub)))
 			 (t
 			  (error "Unexpected record form ~A" (car r))))))))
-	   (process (rec dom ttl defsubp)
+
+	   (process (rec dom ttl)
+	     ;; Recursirvely process the record list REC, with a list DOM of
+	     ;; prefix labels, and a default TTL.  Promote records for a
+	     ;; preferred subnet to toplevel if there are no toplevel records
+	     ;; already.
+
 	     (multiple-value-bind (top sub) (sift rec ttl)
 	       (if (and dom (null top) sub)
-		   (let ((s (pop sub)))
-		     (process (zs-records s)
-			      dom
-			      (zs-ttl s)
-			      defsubp)
-		     (process (zs-records s)
-			      (cons (zs-name s) dom)
-			      (zs-ttl s)
-			      t))
-		 (let ((name (and dom
-				  (string-downcase
-				   (join-strings #\. (reverse dom))))))
-		   (dolist (zr top)
-		     (setf (zr-name zr) name)
-		     (setf (zr-defsubp zr) defsubp)
-		     (funcall func zr))))
+		   (let ((preferred
+			  (or (find-if (lambda (s)
+					 (some #'zone-preferred-subnet-p
+					       (listify (zs-name s))))
+				       sub)
+			      (car sub))))
+		     (when preferred
+		       (process (zs-records preferred)
+				dom
+				(zs-ttl preferred))))
+		   (let ((name (and dom
+				    (string-downcase
+				     (join-strings #\. (reverse dom))))))
+		     (dolist (zr top)
+		       (setf (zr-name zr) name)
+		       (funcall func zr))))
 	       (dolist (s sub)
 		 (process (zs-records s)
 			  (cons (zs-name s) dom)
-			  (zs-ttl s)
-			  defsubp)))))
-    (process rec nil ttl nil)))
-
-(defun zone-parse-host (f zname)
-  "Parse a host name F: if F ends in a dot then it's considered absolute;
-   otherwise it's relative to ZNAME."
-  (setf f (stringify f))
-  (cond ((string= f "@") (stringify zname))
-	((and (plusp (length f))
-	      (char= (char f (1- (length f))) #\.))
-	 (string-downcase (subseq f 0 (1- (length f)))))
-	(t (string-downcase (concatenate 'string f "."
-					 (stringify zname))))))
-(defun default-rev-zone (base bytes)
-  "Return the default reverse-zone name for the given BASE address and number
-   of fixed leading BYTES."
-  (join-strings #\. (collecting ()
-		      (loop for i from (- 3 bytes) downto 0
-			    do (collect (ipaddr-byte base i)))
-		      (collect "in-addr.arpa"))))
-
-(defun zone-name-from-net (net &optional bytes)
-  "Given a NET, and maybe the BYTES to use, convert to the appropriate
-   subdomain of in-addr.arpa."
-  (let ((ipn (net-get-as-ipnet net)))
-    (with-ipnet (net mask) ipn
-      (unless bytes
-	(setf bytes (- 4 (ipnet-changeable-bytes mask))))
-      (join-strings #\.
-		    (append (loop
-			       for i from (- 4 bytes) below 4
-			       collect (logand #xff (ash net (* -8 i))))
-			    (list "in-addr.arpa"))))))
-
-(defun zone-net-from-name (name)
-  "Given a NAME in the in-addr.arpa space, convert it to an ipnet."
-  (let* ((name (string-downcase (stringify name)))
-	 (len (length name))
-	 (suffix ".in-addr.arpa")
-	 (sufflen (length suffix))
-	 (addr 0)
-	 (n 0)
-	 (end (- len sufflen)))
-    (unless (and (> len sufflen)
-		 (string= name suffix :start1 end))
-      (error "`~A' not in ~A." name suffix))
-    (loop
-       with start = 0
-       for dot = (position #\. name :start start :end end)
-       for byte = (parse-integer name
-				 :start start
-				 :end (or dot end))
-       do (setf addr (logior addr (ash byte (* 8 n))))
-	  (incf n)
-       when (>= n 4)
-       do (error "Can't deduce network from ~A." name)
-       while dot
-       do (setf start (1+ dot)))
-    (setf addr (ash addr (* 8 (- 4 n))))
-    (make-ipnet addr (* 8 n))))
-
-(defun zone-reverse-records (records net list bytes dom)
-  "Construct a reverse zone given a forward zone's RECORDS list, the NET that
-   the reverse zone is to serve, a LIST to collect the records into, how many
-   BYTES of data need to end up in the zone, and the DOM-ain suffix."
-  (dolist (zr records)
-    (when (and (eq (zr-type zr) :a)
-	       (not (zr-defsubp zr))
-	       (ipaddr-networkp (zr-data zr) net))
-      (collect (make-zone-record
-		:name (string-downcase
-		       (join-strings
-			#\.
-			(collecting ()
-			  (dotimes (i bytes)
-			    (collect (logand #xff (ash (zr-data zr)
-						       (* -8 i)))))
-			  (collect dom))))
-		:type :ptr
-		:ttl (zr-ttl zr)
-		:data (zr-name zr))
-	       list))))
-
-(defun zone-reverse (data name list)
-  "Process a :reverse record's DATA, for a domain called NAME, and add the
-   records to the LIST."
-  (destructuring-bind
-      (net &key bytes zones)
-      (listify data)
-    (setf net (zone-parse-net net name))
-    (dolist (z (or (listify zones)
-		   (hash-table-keys *zones*)))
-      (zone-reverse-records (zone-records (zone-find z))
-			    net
-			    list
-			    (or bytes
-				(ipnet-changeable-bytes (ipnet-mask net)))
-			    name))))
-
-(defun zone-parse-net (net name)
-  "Given a NET, and the NAME of a domain to guess from if NET is null, return
-   the ipnet for the network."
-  (if net
-      (net-get-as-ipnet net)
-      (zone-net-from-name name)))
-
-(defun zone-cidr-delg-default-name (ipn bytes)
-  "Given a delegated net IPN and the parent's number of changing BYTES,
-   return the default deletate zone prefix."
-  (with-ipnet (net mask) ipn
-    (join-strings #\.
-		  (reverse
-		   (loop
-		      for i from (1- bytes) downto 0
-		      until (zerop (logand mask (ash #xff (* 8 i))))
-		      collect (logand #xff (ash net (* -8 i))))))))
-
-(defun zone-cidr-delegation (data name ttl list)
-  "Given :cidr-delegation info DATA, for a record called NAME and the current
-   TTL, write lots of CNAME records to LIST."
-  (destructuring-bind
-      (net &key bytes)
-      (listify (car data))
-    (setf net (zone-parse-net net name))
-    (unless bytes
-      (setf bytes (ipnet-changeable-bytes (ipnet-mask net))))
-    (dolist (map (cdr data))
-      (destructuring-bind
-	  (tnet &optional tdom)
-	  (listify map)
-	(setf tnet (zone-parse-net tnet name))
-	(unless (ipnet-subnetp net tnet)
-	  (error "~A is not a subnet of ~A."
-		 (ipnet-pretty tnet)
-		 (ipnet-pretty net)))
-	(unless tdom
-	  (setf tdom
-		(join-strings #\.
-			      (list (zone-cidr-delg-default-name tnet bytes)
-				    name))))
-	(setf tdom (string-downcase tdom))
-	(dotimes (i (ipnet-hosts tnet))
-	  (let* ((addr (ipnet-host tnet i))
-		 (tail (join-strings #\.
-				     (loop
-					for i from 0 below bytes
-					collect
-					  (logand #xff
-						  (ash addr (* 8 i)))))))
-	    (collect (make-zone-record
-		      :name (join-strings #\.
-					  (list tail name))
-		      :type :cname
-		      :ttl ttl
-		      :data (join-strings #\. (list tail tdom)))
-		     list)))))))
+			  (zs-ttl s))))))
 
-;;;--------------------------------------------------------------------------
-;;; Zone form parsing.
+    ;; Process the records we're given with no prefix.
+    (process rec nil ttl)))
 
 (defun zone-parse-head (head)
-  "Parse the HEAD of a zone form.  This has the form
+  "Parse the HEAD of a zone form.
+
+   This has the form
 
      (NAME &key :source :admin :refresh :retry
-                :expire :min-ttl :ttl :serial)
+		:expire :min-ttl :ttl :serial)
 
    though a singleton NAME needn't be a list.  Returns the default TTL and an
    soa structure representing the zone head."
@@ -469,7 +439,7 @@ (defun zone-parse-head (head)
        (ttl min-ttl)
        (serial (make-zone-serial zname)))
       (listify head)
-    (values zname
+    (values (string-downcase zname)
 	    (timespec-seconds ttl)
 	    (make-soa :admin admin
 		      :source (zone-parse-host source zname)
@@ -479,13 +449,17 @@ (defun zone-parse-head (head)
 		      :min-ttl (timespec-seconds min-ttl)
 		      :serial serial))))
 
+(export 'defzoneparse)
 (defmacro defzoneparse (types (name data list
-			       &key (zname (gensym "ZNAME"))
-			            (ttl (gensym "TTL"))
-				    (defsubp (gensym "DEFSUBP")))
+			       &key (prefix (gensym "PREFIX"))
+				    (zname (gensym "ZNAME"))
+				    (ttl (gensym "TTL")))
 			&body body)
-  "Define a new zone record type (or TYPES -- a list of synonyms is
-   permitted).  The arguments are as follows:
+  "Define a new zone record type.
+
+   The arguments are as follows:
+
+   TYPES	A singleton type symbol, or a list of aliases.
 
    NAME		The name of the record to be added.
 
@@ -494,79 +468,69 @@ 				    (defsubp (gensym "DEFSUBP")))
 
    LIST		A function to add a record to the zone.  See below.
 
+   PREFIX	The prefix tag used in the original form.
+
    ZNAME	The name of the zone being constructed.
 
    TTL		The TTL for this record.
 
-   DEFSUBP	Whether this is the default subdomain for this entry.
-
-   You get to choose your own names for these.  ZNAME, TTL and DEFSUBP are
+   You get to choose your own names for these.  ZNAME, PREFIX and TTL are
    optional: you don't have to accept them if you're not interested.
 
    The LIST argument names a function to be bound in the body to add a new
    low-level record to the zone.  It has the prototype
 
-     (LIST &key :name :type :data :ttl :defsubp)
+     (LIST &key :name :type :data :ttl :make-ptr-p)
 
-   Except for defsubp, these default to the above arguments (even if you
-   didn't accept the arguments)."
+   These (except MAKE-PTR-P, which defaults to nil) default to the above
+   arguments (even if you didn't accept the arguments)."
   (setf types (listify types))
   (let* ((type (car types))
 	 (func (intern (format nil "ZONE-PARSE/~:@(~A~)" type))))
     (with-parsed-body (body decls doc) body
-      (with-gensyms (col tname ttype tttl tdata tdefsubp i)
+      (with-gensyms (col tname ttype tttl tdata tmakeptrp i)
 	`(progn
 	   (dolist (,i ',types)
 	     (setf (get ,i 'zone-parse) ',func))
-	   (defun ,func (,name ,data ,ttl ,col ,zname ,defsubp)
+	   (defun ,func (,prefix ,zname ,data ,ttl ,col)
 	     ,@doc
 	     ,@decls
-	     (declare (ignorable ,zname ,defsubp))
-	     (flet ((,list (&key ((:name ,tname) ,name)
-				 ((:type ,ttype) ,type)
-				 ((:data ,tdata) ,data)
-				 ((:ttl ,tttl) ,ttl)
-				 ((:defsubp ,tdefsubp) nil))
-		      (collect (make-zone-record :name ,tname
-						 :type ,ttype
-						 :data ,tdata
-						 :ttl ,tttl
-						 :defsubp ,tdefsubp)
-			       ,col)))
-	       ,@body))
+	     (let ((,name (zone-make-name ,prefix ,zname)))
+	       (flet ((,list (&key ((:name ,tname) ,name)
+				   ((:type ,ttype) ,type)
+				   ((:data ,tdata) ,data)
+				   ((:ttl ,tttl) ,ttl)
+				   ((:make-ptr-p ,tmakeptrp) nil))
+			#+cmu (declare (optimize ext:inhibit-warnings))
+			(collect (make-zone-record :name ,tname
+						   :type ,ttype
+						   :data ,tdata
+						   :ttl ,tttl
+						   :make-ptr-p ,tmakeptrp)
+				 ,col)))
+		 ,@body)))
 	   ',type)))))
 
-(defun zone-parse-records (zone records)
-  (let ((zname (zone-name zone)))
-    (with-collection (rec)
-	(flet ((parse-record (zr)
-		 (let ((func (or (get (zr-type zr) 'zone-parse)
-				 (error "No parser for record ~A."
-					(zr-type zr))))
-		       (name (and (zr-name zr)
-				  (stringify (zr-name zr)))))
-		   (if (or (not name)
-			   (string= name "@"))
-		       (setf name zname)
-		       (let ((len (length name)))
-			 (if (or (zerop len)
-				 (char/= (char name (1- len)) #\.))
-			     (setf name (join-strings #\.
-						      (list name zname))))))
-		   (funcall func
-			    name
-			    (zr-data zr)
-			    (zr-ttl zr)
-			    rec
-			    zname
-			    (zr-defsubp zr)))))
-	  (zone-process-records records
-				(zone-default-ttl zone)
-				#'parse-record))
-      (setf (zone-records zone) (nconc (zone-records zone) rec)))))
-
+(export 'zone-parse-records)
+(defun zone-parse-records (zname ttl records)
+  "Parse a sequence of RECORDS and return a list of raw records.
+
+   The records are parsed relative to the zone name ZNAME, and using the
+   given default TTL."
+  (collecting (rec)
+    (flet ((parse-record (zr)
+	     (let ((func (or (get (zr-type zr) 'zone-parse)
+			     (error "No parser for record ~A."
+				    (zr-type zr))))
+		   (name (and (zr-name zr) (stringify (zr-name zr)))))
+	       (funcall func name zname (zr-data zr) (zr-ttl zr) rec))))
+      (zone-process-records records ttl #'parse-record))))
+
+(export 'zone-parse)
 (defun zone-parse (zf)
-  "Parse a ZONE form.  The syntax of a zone form is as follows:
+  "Parse a ZONE form.
+
+   The syntax of a zone form is as follows:
 
    ZONE-FORM:
      ZONE-HEAD ZONE-RECORD*
@@ -575,13 +539,12 @@ (defun zone-parse (zf)
      ((NAME*) ZONE-RECORD*)
    | SYM ARGS"
   (multiple-value-bind (zname ttl soa) (zone-parse-head (car zf))
-    (let ((zone (make-zone :name zname
-			   :default-ttl ttl
-			   :soa soa
-			   :records nil)))
-      (zone-parse-records zone (cdr zf))
-      zone)))
+    (make-zone :name zname
+	       :default-ttl ttl
+	       :soa soa
+	       :records (zone-parse-records zname ttl (cdr zf)))))
 
+(export 'zone-create)
 (defun zone-create (zf)
   "Zone construction function.  Given a zone form ZF, construct the zone and
    add it to the table."
@@ -590,26 +553,75 @@ (defun zone-create (zf)
     (setf (zone-find name) zone)
     name))
 
-(defmacro defzone (soa &rest zf)
+(export 'defzone)
+(defmacro defzone (soa &body zf)
   "Zone definition macro."
   `(zone-create '(,soa ,@zf)))
 
-(defmacro defrevzone (head &rest zf)
+(export '*address-family*)
+(defvar *address-family* t
+  "The default address family.  This is bound by `defrevzone'.")
+
+(export 'defrevzone)
+(defmacro defrevzone (head &body zf)
   "Define a reverse zone, with the correct name."
-  (destructuring-bind
-      (net &rest soa-args)
+  (destructuring-bind (nets &rest args
+			    &key &allow-other-keys
+				 (family '*address-family*)
+				 prefix-bits)
       (listify head)
-    (let ((bytes nil))
-      (when (and soa-args (integerp (car soa-args)))
-	(setf bytes (pop soa-args)))
-      `(zone-create '((,(zone-name-from-net net bytes) ,@soa-args) ,@zf)))))
+    (with-gensyms (ipn)
+      `(dolist (,ipn (net-parse-to-ipnets ',nets ,family))
+	 (let ((*address-family* (ipnet-family ,ipn)))
+	   (zone-create `((,(reverse-domain ,ipn ,prefix-bits)
+			    ,@',(loop for (k v) on args by #'cddr
+				      unless (member k
+						     '(:family :prefix-bits))
+				      nconc (list k v)))
+			  ,@',zf)))))))
+
+(export 'map-host-addresses)
+(defun map-host-addresses (func addr &key (family *address-family*))
+  "Call FUNC for each address denoted by ADDR (a `host-parse' address)."
+
+  (dolist (a (host-addrs (host-parse addr family)))
+    (funcall func a)))
+
+(export 'do-host)
+(defmacro do-host ((addr spec &key (family *address-family*)) &body body)
+  "Evaluate BODY, binding ADDR to each address denoted by SPEC."
+  `(dolist (,addr (host-addrs (host-parse ,spec ,family)))
+     ,@body))
+
+(export 'zone-set-address)
+(defun zone-set-address (rec addrspec &rest args
+			 &key (family *address-family*) name ttl make-ptr-p)
+  "Write records (using REC) defining addresses for ADDRSPEC."
+  (declare (ignore name ttl make-ptr-p))
+  (let ((key-args (loop for (k v) on args by #'cddr
+			unless (eq k :family)
+			nconc (list k v))))
+    (do-host (addr addrspec :family family)
+      (apply rec :type (ipaddr-rrtype addr) :data addr key-args))))
 
 ;;;--------------------------------------------------------------------------
 ;;; Zone record parsers.
 
-(defzoneparse :a (name data rec :defsubp defsubp)
+(defzoneparse :a (name data rec)
   ":a IPADDR"
-  (rec :data (parse-ipaddr data) :defsubp defsubp))
+  (zone-set-address #'rec data :make-ptr-p t :family :ipv4))
+
+(defzoneparse :aaaa (name data rec)
+  ":aaaa IPADDR"
+  (zone-set-address #'rec data :make-ptr-p t :family :ipv6))
+
+(defzoneparse :addr (name data rec)
+  ":addr IPADDR"
+  (zone-set-address #'rec data :make-ptr-p t))
+
+(defzoneparse :svc (name data rec)
+  ":svc IPADDR"
+  (zone-set-address #'rec data))
 
 (defzoneparse :ptr (name data rec :zname zname)
   ":ptr HOST"
@@ -619,6 +631,102 @@ (defzoneparse :cname (name data rec :zname zname)
   ":cname HOST"
   (rec :data (zone-parse-host data zname)))
 
+(defzoneparse :txt (name data rec)
+  ":txt TEXT"
+  (rec :data data))
+
+(export '*dkim-pathname-defaults*)
+(defvar *dkim-pathname-defaults*
+  (make-pathname :directory '(:relative "keys")
+		 :type "dkim"))
+
+(defzoneparse :dkim (name data rec)
+  ":dkim (KEYFILE {:TAG VALUE}*)"
+  (destructuring-bind (file &rest plist) (listify data)
+    (let ((things nil) (out nil))
+      (labels ((flush ()
+		 (when out
+		   (push (get-output-stream-string out) things)
+		   (setf out nil)))
+	       (emit (text)
+		 (let ((len (length text)))
+		   (when (and out (> (+ (file-position out)
+					(length text))
+				     64))
+		     (flush))
+		   (when (plusp len)
+		     (cond ((< len 64)
+			    (unless out (setf out (make-string-output-stream)))
+			    (write-string text out))
+			   (t
+			    (do ((i 0 j)
+				 (j 64 (+ j 64)))
+				((>= i len))
+			      (push (subseq text i (min j len)) things))))))))
+	(do ((p plist (cddr p)))
+	    ((endp p))
+	  (emit (format nil "~(~A~)=~A;" (car p) (cadr p))))
+	(emit (with-output-to-string (out)
+		(write-string "p=" out)
+		(when file
+		  (with-open-file
+		      (in (merge-pathnames file *dkim-pathname-defaults*))
+		    (loop
+		      (when (string= (read-line in)
+				     "-----BEGIN PUBLIC KEY-----")
+			(return)))
+		    (loop
+		      (let ((line (read-line in)))
+			(if (string= line "-----END PUBLIC KEY-----")
+			    (return)
+			    (write-string line out)))))))))
+      (rec :type :txt
+	   :data (nreverse things)))))
+
+(eval-when (:load-toplevel :execute)
+  (dolist (item '((sshfp-algorithm rsa 1)
+		  (sshfp-algorithm dsa 2)
+		  (sshfp-algorithm ecdsa 3)
+		  (sshfp-type sha-1 1)
+		  (sshfp-type sha-256 2)))
+    (destructuring-bind (prop sym val) item
+      (setf (get sym prop) val)
+      (export sym))))
+
+(export '*sshfp-pathname-defaults*)
+(defvar *sshfp-pathname-defaults*
+  (make-pathname :directory '(:relative "keys")
+		 :type "sshfp"))
+
+(defzoneparse :sshfp (name data rec)
+  ":sshfp { FILENAME | ((FPR :alg ALG :type HASH)*) }"
+  (if (stringp data)
+      (with-open-file (in (merge-pathnames data *sshfp-pathname-defaults*))
+	(loop (let ((line (read-line in nil)))
+		(unless line (return))
+		(let ((words (str-split-words line)))
+		  (pop words)
+		  (when (string= (car words) "IN") (pop words))
+		  (unless (and (string= (car words) "SSHFP")
+			       (= (length words) 4))
+		    (error "Invalid SSHFP record."))
+		  (pop words)
+		  (destructuring-bind (alg type fpr) words
+		    (rec :data (list (parse-integer alg)
+				     (parse-integer type)
+				     fpr)))))))
+      (flet ((lookup (what prop)
+	       (etypecase what
+		 (fixnum what)
+		 (symbol (or (get what prop)
+			     (error "~S is not a known ~A" what prop))))))
+	(dolist (item (listify data))
+	  (destructuring-bind (fpr &key (alg 'rsa) (type 'sha-1))
+	      (listify item)
+	    (rec :data (list (lookup alg 'sshfp-algorithm)
+			     (lookup type 'sshfp-type)
+			     fpr)))))))
+
 (defzoneparse :mx (name data rec :zname zname)
   ":mx ((HOST :prio INT :ip IPADDR)*)"
   (dolist (mx (listify data))
@@ -626,7 +734,7 @@ (defzoneparse :mx (name data rec :zname zname)
 	(mxname &key (prio *default-mx-priority*) ip)
 	(listify mx)
       (let ((host (zone-parse-host mxname zname)))
-	(when ip (rec :name host :type :a :data (parse-ipaddr ip)))
+	(when ip (zone-set-address #'rec ip :name host))
 	(rec :data (cons host prio))))))
 
 (defzoneparse :ns (name data rec :zname zname)
@@ -636,7 +744,7 @@ (defzoneparse :ns (name data rec :zname zname)
 	(nsname &key ip)
 	(listify ns)
       (let ((host (zone-parse-host nsname zname)))
-	(when ip (rec :name host :type :a :data (parse-ipaddr ip)))
+	(when ip (zone-set-address #'rec ip :name host))
 	(rec :data host)))))
 
 (defzoneparse :alias (name data rec :zname zname)
@@ -646,121 +754,191 @@ (defzoneparse :alias (name data rec :zname zname)
 	 :type :cname
 	 :data name)))
 
+(defzoneparse :srv (name data rec :zname zname)
+  ":srv (((SERVICE &key :port) (PROVIDER &key :port :prio :weight :ip)*)*)"
+  (dolist (srv data)
+    (destructuring-bind (servopts &rest providers) srv
+      (destructuring-bind
+	  (service &key ((:port default-port)) (protocol :tcp))
+	  (listify servopts)
+	(unless default-port
+	  (let ((serv (serv-by-name service protocol)))
+	    (setf default-port (and serv (serv-port serv)))))
+	(let ((rname (format nil "~(_~A._~A~).~A" service protocol name)))
+	  (dolist (prov providers)
+	    (destructuring-bind
+		(srvname
+		 &key
+		 (port default-port)
+		 (prio *default-mx-priority*)
+		 (weight 0)
+		 ip)
+		(listify prov)
+	      (let ((host (zone-parse-host srvname zname)))
+		(when ip (zone-set-address #'rec ip :name host))
+		(rec :name rname
+		     :data (list prio weight port host))))))))))
+
 (defzoneparse :net (name data rec)
   ":net (NETWORK*)"
   (dolist (net (listify data))
-    (let ((n (net-get-as-ipnet net)))
-      (rec :name (zone-parse-host "net" name)
-	   :type :a
-	   :data (ipnet-net n))
-      (rec :name (zone-parse-host "mask" name)
-	   :type :a
-	   :data (ipnet-mask n))
-      (rec :name (zone-parse-host "broadcast" name)
-	   :type :a
-	   :data (ipnet-broadcast n)))))
+    (dolist (ipn (net-ipnets (net-must-find net)))
+      (let* ((base (ipnet-net ipn))
+	     (rrtype (ipaddr-rrtype base)))
+	(flet ((frob (kind addr)
+		 (when addr
+		   (rec :name (zone-parse-host kind name)
+			:type rrtype
+			:data addr))))
+	  (frob "net" base)
+	  (frob "mask" (ipaddr (ipnet-mask ipn) (ipnet-family ipn)))
+	  (frob "bcast" (ipnet-broadcast ipn)))))))
 
 (defzoneparse (:rev :reverse) (name data rec)
-  ":reverse ((NET :bytes BYTES) ZONE*)"
+  ":reverse ((NET &key :prefix-bits :family) ZONE*)
+
+   Add a reverse record each host in the ZONEs (or all zones) that lies
+   within NET."
   (setf data (listify data))
-  (destructuring-bind
-      (net &key bytes)
+  (destructuring-bind (net &key prefix-bits (family *address-family*))
       (listify (car data))
-    (setf net (zone-parse-net net name))
-    (unless bytes
-      (setf bytes (ipnet-changeable-bytes (ipnet-mask net))))
-    (dolist (z (or (cdr data)
-		   (hash-table-keys *zones*)))
-      (dolist (zr (zone-records (zone-find z)))
-	(when (and (eq (zr-type zr) :a)
-		   (not (zr-defsubp zr))
-		   (ipaddr-networkp (zr-data zr) net))
-	  (rec :name (string-downcase
-		      (join-strings
-		       #\.
-		       (collecting ()
-			 (dotimes (i bytes)
-			   (collect (logand #xff (ash (zr-data zr)
-						      (* -8 i)))))
-			 (collect name))))
-	       :type :ptr
-	       :ttl (zr-ttl zr)
-	       :data (zr-name zr)))))))
-
-(defzoneparse (:cidr-delegation :cidr) (name data rec)
-  ":cidr-delegation ((NET :bytes BYTES) (TARGET-NET [TARGET-ZONE])*)"
-  (destructuring-bind
-      (net &key bytes)
+
+    (dolist (ipn (net-parse-to-ipnets net family))
+      (let* ((seen (make-hash-table :test #'equal))
+	     (width (ipnet-width ipn))
+	     (frag-len (if prefix-bits (- width prefix-bits)
+			   (ipnet-changeable-bits width (ipnet-mask ipn)))))
+	(dolist (z (or (cdr data) (hash-table-keys *zones*)))
+	  (dolist (zr (zone-records (zone-find z)))
+	    (when (and (eq (zr-type zr) (ipaddr-rrtype (ipnet-net ipn)))
+		       (zr-make-ptr-p zr)
+		       (ipaddr-networkp (ipaddr-addr (zr-data zr)) ipn))
+	      (let* ((frag (reverse-domain-fragment (zr-data zr)
+						    0 frag-len))
+		     (name (concatenate 'string frag "." name)))
+		(unless (gethash name seen)
+		  (rec :name name :type :ptr
+		       :ttl (zr-ttl zr) :data (zr-name zr))
+		  (setf (gethash name seen) t))))))))))
+
+(defzoneparse :multi (name data rec :zname zname :ttl ttl)
+  ":multi (((NET*) &key :start :end :family :suffix) . REC)
+
+   Output multiple records covering a portion of the reverse-resolution
+   namespace corresponding to the particular NETs.  The START and END bounds
+   default to the most significant variable component of the
+   reverse-resolution domain.
+
+   The REC tail is a sequence of record forms (as handled by
+   `zone-process-records') to be emitted for each covered address.  Within
+   the bodies of these forms, the symbol `*' will be replaced by the
+   domain-name fragment corresponding to the current host, optionally
+   followed by the SUFFIX.
+
+   Examples:
+
+	(:multi ((delegated-subnet :start 8)
+		 :ns (some.ns.delegated.example :ip \"169.254.5.2\")))
+
+	(:multi ((tiny-subnet :suffix \"128.10.254.169.in-addr.arpa\")
+		 :cname *))
+
+   Obviously, nested `:multi' records won't work well."
+
+  (destructuring-bind (nets &key start end (family *address-family*) suffix)
       (listify (car data))
-    (setf net (zone-parse-net net name))
-    (unless bytes
-      (setf bytes (ipnet-changeable-bytes (ipnet-mask net))))
-    (dolist (map (cdr data))
-      (destructuring-bind
-	  (tnet &optional tdom)
-	  (listify map)
-	(setf tnet (zone-parse-net tnet name))
-	(unless (ipnet-subnetp net tnet)
-	  (error "~A is not a subnet of ~A."
-		 (ipnet-pretty tnet)
-		 (ipnet-pretty net)))
-	(unless tdom
-	  (with-ipnet (net mask) tnet
-	    (setf tdom
-		  (join-strings
-		   #\.
-		   (append (reverse (loop
-				       for i from (1- bytes) downto 0
-				       until (zerop (logand mask
-							    (ash #xff
-								 (* 8 i))))
-				       collect (logand #xff
-						       (ash net (* -8 i)))))
-			   (list name))))))
-	(setf tdom (string-downcase tdom))
-	(dotimes (i (ipnet-hosts tnet))
-	  (let* ((addr (ipnet-host tnet i))
-		 (tail (join-strings #\.
-				     (loop
-					for i from 0 below bytes
-					collect
-					  (logand #xff
-						  (ash addr (* 8 i)))))))
-	    (rec :name (format nil "~A.~A" tail name)
-		 :type :cname
-		 :data (format nil "~A.~A" tail tdom))))))))
+    (dolist (net (listify nets))
+      (dolist (ipn (net-parse-to-ipnets net family))
+	(let* ((addr (ipnet-net ipn))
+	       (width (ipaddr-width addr))
+	       (comp-width (reverse-domain-component-width addr))
+	       (end (round-up (or end
+				  (ipnet-changeable-bits width
+							 (ipnet-mask ipn)))
+			      comp-width))
+	       (start (round-down (or start (- end comp-width))
+				  comp-width))
+	       (map (ipnet-host-map ipn)))
+	  (multiple-value-bind (host-step host-limit)
+	      (ipnet-index-bounds map start end)
+	    (do ((index 0 (+ index host-step)))
+		((> index host-limit))
+	      (let* ((addr (ipnet-index-host map index))
+		     (frag (reverse-domain-fragment addr start end))
+		     (target (concatenate 'string
+					  (zone-make-name
+					   (if (not suffix) frag
+					       (concatenate 'string
+							    frag "." suffix))
+					   zname)
+					  ".")))
+		(dolist (zr (zone-parse-records (zone-make-name frag zname)
+						ttl
+						(subst target '*
+						       (cdr data))))
+		  (rec :name (zr-name zr)
+		       :type (zr-type zr)
+		       :data (zr-data zr)
+		       :ttl (zr-ttl zr)
+		       :make-ptr-p (zr-make-ptr-p zr)))))))))))
 
 ;;;--------------------------------------------------------------------------
 ;;; Zone file output.
 
-(defun zone-write (zone &optional (stream *standard-output*))
-  "Write a ZONE's records to STREAM."
-  (labels ((fix-admin (a)
-	     (let ((at (position #\@ a))
-		   (s (concatenate 'string (string-downcase a) ".")))
-	       (when s
-		 (setf (char s at) #\.))
-	       s))
-	   (fix-host (h)
-	     (if (not h)
-		 "@"
-		 (let* ((h (string-downcase (stringify h)))
-			(hl (length h))
-			(r (string-downcase (zone-name zone)))
-			(rl (length r)))
-		   (cond ((string= r h) "@")
-			 ((and (> hl rl)
-			       (char= (char h (- hl rl 1)) #\.)
-			       (string= h r :start1 (- hl rl)))
-			  (subseq h 0 (- hl rl 1)))
-			 (t (concatenate 'string h "."))))))
-	   (printrec (zr)
-	     (format stream "~A~20T~@[~8D~]~30TIN ~A~40T"
-		     (fix-host (zr-name zr))
-		     (and (/= (zr-ttl zr) (zone-default-ttl zone))
-			  (zr-ttl zr))
-		     (string-upcase (symbol-name (zr-type zr))))))
-    (format stream "~
+(export 'zone-write)
+(defgeneric zone-write (format zone stream)
+  (:documentation "Write ZONE's records to STREAM in the specified FORMAT."))
+
+(defvar *writing-zone* nil
+  "The zone currently being written.")
+
+(defvar *zone-output-stream* nil
+  "Stream to write zone data on.")
+
+(defmethod zone-write :around (format zone stream)
+  (declare (ignore format))
+  (let ((*writing-zone* zone)
+	(*zone-output-stream* stream))
+    (call-next-method)))
+
+(export 'zone-save)
+(defun zone-save (zones &key (format :bind))
+  "Write the named ZONES to files.  If no zones are given, write all the
+   zones."
+  (unless zones
+    (setf zones (hash-table-keys *zones*)))
+  (safely (safe)
+    (dolist (z zones)
+      (let ((zz (zone-find z)))
+	(unless zz
+	  (error "Unknown zone `~A'." z))
+	(let ((stream (safely-open-output-stream safe
+						 (zone-file-name z :zone))))
+	  (zone-write format zz stream))))))
+
+;;;--------------------------------------------------------------------------
+;;; Bind format output.
+
+(export 'bind-hostname)
+(defun bind-hostname (hostname)
+  (if (not hostname)
+      "@"
+      (let* ((h (string-downcase (stringify hostname)))
+	     (hl (length h))
+	     (r (string-downcase (zone-name *writing-zone*)))
+	     (rl (length r)))
+	(cond ((string= r h) "@")
+	      ((and (> hl rl)
+		    (char= (char h (- hl rl 1)) #\.)
+		    (string= h r :start1 (- hl rl)))
+	       (subseq h 0 (- hl rl 1)))
+	      (t (concatenate 'string h "."))))))
+
+(export 'bind-record)
+(defgeneric bind-record (type zr))
+
+(defmethod zone-write ((format (eql :bind)) zone stream)
+  (format stream "~
 ;;; Zone file `~(~A~)'
 ;;;   (generated ~A)
 
@@ -769,55 +947,70 @@ (defun zone-write (zone &optional (stream *standard-output*))
 	    (zone-name zone)
 	    (iso-date :now :datep t :timep t)
 	    (zone-default-ttl zone))
-    (let ((soa (zone-soa zone)))
+  (let* ((soa (zone-soa zone))
+	 (admin (let* ((name (soa-admin soa))
+		       (at (position #\@ name))
+		       (copy (format nil "~(~A~)." name)))
+		  (when at
+		    (setf (char copy at) #\.))
+		  copy)))
       (format stream "~
-~A~30TIN SOA~40T~A ~A (
+~A~30TIN SOA~40T~A (
+~55@A~60T ;administrator
 ~45T~10D~60T ;serial
 ~45T~10D~60T ;refresh
 ~45T~10D~60T ;retry
 ~45T~10D~60T ;expire
 ~45T~10D )~60T ;min-ttl~2%"
-	      (fix-host (zone-name zone))
-	      (fix-host (soa-source soa))
-	      (fix-admin (soa-admin soa))
+	      (bind-hostname (zone-name zone))
+	      (bind-hostname (soa-source soa))
+	      admin
 	      (soa-serial soa)
 	      (soa-refresh soa)
 	      (soa-retry soa)
 	      (soa-expire soa)
 	      (soa-min-ttl soa)))
-    (dolist (zr (zone-records zone))
-      (case (zr-type zr)
-	(:a
-	 (printrec zr)
-	 (format stream "~A~%" (ipaddr-string (zr-data zr))))
-	((:ptr :cname)
-	 (printrec zr)
-	 (format stream "~A~%" (fix-host (zr-data zr))))
-	(:ns
-	 (printrec zr)
-	 (format stream "~A~%" (fix-host (zr-data zr))))
-	(:mx
-	 (printrec zr)
-	 (let ((mx (zr-data zr)))
-	   (format stream "~2D ~A~%" (cdr mx) (fix-host (car mx)))))
-	(:txt
-	 (printrec zr)
-	 (format stream "~S~%" (stringify (zr-data zr))))))))
-
-(defun zone-save (zones)
-  "Write the named ZONES to files.  If no zones are given, write all the
-   zones."
-  (unless zones
-    (setf zones (hash-table-keys *zones*)))
-  (safely (safe)
-    (dolist (z zones)
-      (let ((zz (zone-find z)))
-	(unless zz
-	  (error "Unknown zone `~A'." z))
-	(let ((stream (safely-open-output-stream safe
-						 (format nil
-							 "~(~A~).zone"
-							 z))))
-	  (zone-write zz stream))))))
+  (dolist (zr (zone-records zone))
+    (bind-record (zr-type zr) zr)))
+
+(export 'bind-format-record)
+(defun bind-format-record (name ttl type format args)
+  (format *zone-output-stream*
+	  "~A~20T~@[~8D~]~30TIN ~A~40T~?~%"
+	  (bind-hostname name)
+	  (and (/= ttl (zone-default-ttl *writing-zone*))
+	       ttl)
+	  (string-upcase (symbol-name type))
+	  format args))
+
+(export 'bind-record-type)
+(defgeneric bind-record-type (type)
+  (:method (type) type))
+
+(export 'bind-record-format-args)
+(defgeneric bind-record-format-args (type data)
+  (:method ((type (eql :a)) data) (list "~A" (ipaddr-string data)))
+  (:method ((type (eql :aaaa)) data) (list "~A" (ipaddr-string data)))
+  (:method ((type (eql :ptr)) data) (list "~A" (bind-hostname data)))
+  (:method ((type (eql :cname)) data) (list "~A" (bind-hostname data)))
+  (:method ((type (eql :ns)) data) (list "~A" (bind-hostname data)))
+  (:method ((type (eql :mx)) data)
+    (list "~2D ~A" (cdr data) (bind-hostname (car data))))
+  (:method ((type (eql :srv)) data)
+    (destructuring-bind (prio weight port host) data
+      (list "~2D ~5D ~5D ~A" prio weight port (bind-hostname host))))
+  (:method ((type (eql :sshfp)) data)
+    (cons "~2D ~2D ~A" data))
+  (:method ((type (eql :txt)) data)
+    (cons "~#[\"\"~;~S~:;(~@{~%~8T~S~} )~]"
+	  (mapcar #'stringify (listify data)))))
+
+(defmethod bind-record (type zr)
+  (destructuring-bind (format &rest args)
+      (bind-record-format-args type (zr-data zr))
+    (bind-format-record (zr-name zr)
+			(zr-ttl zr)
+			(bind-record-type type)
+			format args)))
 
 ;;;----- That's all, folks --------------------------------------------------