mdw@git.distorted.org.uk Git - zone/blob - zone.lisp

   1 ;;; -*-lisp-*-
   2 ;;;
   3 ;;; $Id$
   4 ;;;
   5 ;;; DNS zone generation
   6 ;;;
   7 ;;; (c) 2005 Straylight/Edgeware
   8 ;;;
   9
  10 ;;;----- Licensing notice ---------------------------------------------------
  11 ;;;
  12 ;;; This program is free software; you can redistribute it and/or modify
  13 ;;; it under the terms of the GNU General Public License as published by
  14 ;;; the Free Software Foundation; either version 2 of the License, or
  15 ;;; (at your option) any later version.
  16 ;;;
  17 ;;; This program is distributed in the hope that it will be useful,
  18 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;;; GNU General Public License for more details.
  21 ;;;
  22 ;;; You should have received a copy of the GNU General Public License
  23 ;;; along with this program; if not, write to the Free Software Foundation,
  24 ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 ;;;--------------------------------------------------------------------------
  27 ;;; Packaging.
  28
  29 (defpackage #:zone
  30   (:use #:common-lisp #:mdw.base #:mdw.str #:collect #:safely #:net)
  31   (:export #:soa #:mx #:zone #:zone-record #:zone-subdomain
  32            #:*default-zone-source* #:*default-zone-refresh*
  33              #:*default-zone-retry* #:*default-zone-expire*
  34              #:*default-zone-min-ttl* #:*default-zone-ttl*
  35              #:*default-mx-priority* #:*default-zone-admin*
  36              #:zone-find #:zone-parse #:zone-write #:zone-create #:defzone
  37              #:defrevzone #:zone-save
  38            #:defzoneparse #:zone-parse-host
  39            #:timespec-seconds #:make-zone-serial))
  40
  41 (in-package #:zone)
  42
  43 ;;;--------------------------------------------------------------------------
  44 ;;; Various random utilities.
  45
  46 (defun to-integer (x)
  47   "Convert X to an integer in the most straightforward way."
  48   (floor (rational x)))
  49
  50 (defun from-mixed-base (base val)
  51   "BASE is a list of the ranges for the `digits' of a mixed-base
  52 representation.  Convert VAL, a list of digits, into an integer."
  53   (do ((base base (cdr base))
  54        (val (cdr val) (cdr val))
  55        (a (car val) (+ (* a (car base)) (car val))))
  56       ((or (null base) (null val)) a)))
  57
  58 (defun to-mixed-base (base val)
  59   "BASE is a list of the ranges for the `digits' of a mixed-base
  60 representation.  Convert VAL, an integer, into a list of digits."
  61   (let ((base (reverse base))
  62         (a nil))
  63     (loop
  64       (unless base
  65         (push val a)
  66         (return a))
  67       (multiple-value-bind (q r) (floor val (pop base))
  68         (push r a)
  69         (setf val q)))))
  70
  71 (defun timespec-seconds (ts)
  72   "Convert a timespec TS to seconds.  A timespec may be a real count of
  73 seconds, or a list (COUNT UNIT): UNIT may be any of a number of obvious time
  74 units."
  75   (cond ((null ts) 0)
  76         ((realp ts) (floor ts))
  77         ((atom ts)
  78          (error "Unknown timespec format ~A" ts))
  79         ((null (cdr ts))
  80          (timespec-seconds (car ts)))
  81         (t (+ (to-integer (* (car ts)
  82                              (case (intern (string-upcase
  83                                             (stringify (cadr ts)))
  84                                            '#:zone)
  85                                ((s sec secs second seconds) 1)
  86                                ((m min mins minute minutes) 60)
  87                                ((h hr hrs hour hours) #.(* 60 60))
  88                                ((d dy dys day days) #.(* 24 60 60))
  89                                ((w wk wks week weeks) #.(* 7 24 60 60))
  90                                ((y yr yrs year years) #.(* 365 24 60 60))
  91                                (t (error "Unknown time unit ~A"
  92                                          (cadr ts))))))
  93               (timespec-seconds (cddr ts))))))
  94
  95 (defun hash-table-keys (ht)
  96   "Return a list of the keys in hashtable HT."
  97   (collecting ()
  98     (maphash (lambda (key val) (declare (ignore val)) (collect key)) ht)))
  99
 100 (defun iso-date (&optional time &key datep timep (sep #\ ))
 101   "Construct a textual date or time in ISO format.  The TIME is the universal
 102 time to convert, which defaults to now; DATEP is whether to emit the date;
 103 TIMEP is whether to emit the time, and SEP (default is space) is how to
 104 separate the two."
 105   (multiple-value-bind
 106       (sec min hr day mon yr dow dstp tz)
 107       (decode-universal-time (if (or (null time) (eq time :now))
 108                                  (get-universal-time)
 109                                  time))
 110     (declare (ignore dow dstp tz))
 111     (with-output-to-string (s)
 112       (when datep
 113         (format s "~4,'0D-~2,'0D-~2,'0D" yr mon day)
 114         (when timep
 115           (write-char sep s)))
 116       (when timep
 117         (format s "~2,'0D:~2,'0D:~2,'0D" hr min sec)))))
 118
 119 ;;;--------------------------------------------------------------------------
 120 ;;; Zone types.
 121
 122 (defstruct (soa (:predicate soap))
 123   "Start-of-authority record information."
 124   source
 125   admin
 126   refresh
 127   retry
 128   expire
 129   min-ttl
 130   serial)
 131
 132 (defstruct (mx (:predicate mxp))
 133   "Mail-exchange record information."
 134   priority
 135   domain)
 136
 137 (defstruct (zone (:predicate zonep))
 138   "Zone information."
 139   soa
 140   default-ttl
 141   name
 142   records)
 143
 144 ;;;--------------------------------------------------------------------------
 145 ;;; Zone defaults.  It is intended that scripts override these.
 146
 147 (defvar *default-zone-source*
 148   (let ((hn (unix:unix-gethostname)))
 149     (and hn (concatenate 'string (canonify-hostname hn) ".")))
 150   "The default zone source: the current host's name.")
 151
 152 (defvar *default-zone-refresh* (* 24 60 60)
 153   "Default zone refresh interval: one day.")
 154
 155 (defvar *default-zone-admin* nil
 156   "Default zone administrator's email address.")
 157
 158 (defvar *default-zone-retry* (* 60 60)
 159   "Default znoe retry interval: one hour.")
 160
 161 (defvar *default-zone-expire* (* 14 24 60 60)
 162   "Default zone expiry time: two weeks.")
 163
 164 (defvar *default-zone-min-ttl* (* 4 60 60)
 165   "Default zone minimum TTL/negative TTL: four hours.")
 166
 167 (defvar *default-zone-ttl* (* 8 60 60)
 168   "Default zone TTL (for records without explicit TTLs): 8 hours.")
 169
 170 (defvar *default-mx-priority* 50
 171   "Default MX priority.")
 172
 173 ;;;--------------------------------------------------------------------------
 174 ;;; Serial numbering.
 175
 176 (defun make-zone-serial (name)
 177   "Given a zone NAME, come up with a new serial number.  This will (very
 178 carefully) update a file ZONE.serial in the current directory."
 179   (let* ((file (format nil "~(~A~).serial" name))
 180          (last (with-open-file (in file
 181                                    :direction :input
 182                                    :if-does-not-exist nil)
 183                  (if in (read in)
 184                      (list 0 0 0 0))))
 185          (now (multiple-value-bind
 186                   (sec min hr dy mon yr dow dstp tz)
 187                   (get-decoded-time)
 188                 (declare (ignore sec min hr dow dstp tz))
 189                 (list dy mon yr)))
 190          (seq (cond ((not (equal now (cdr last))) 0)
 191                     ((< (car last) 99) (1+ (car last)))
 192                     (t (error "Run out of sequence numbers for ~A" name)))))
 193     (safely-writing (out file)
 194       (format out
 195               ";; Serial number file for zone ~A~%~
 196                ;;   (LAST-SEQ DAY MONTH YEAR)~%~
 197                ~S~%"
 198               name
 199               (cons seq now)))
 200     (from-mixed-base '(100 100 100) (reverse (cons seq now)))))
 201
 202 ;;;--------------------------------------------------------------------------
 203 ;;; Zone variables and structures.
 204
 205 (defvar *zones* (make-hash-table :test #'equal)
 206   "Map of known zones.")
 207
 208 (defun zone-find (name)
 209   "Find a zone given its NAME."
 210   (gethash (string-downcase (stringify name)) *zones*))
 211
 212 (defun (setf zone-find) (zone name)
 213   "Make the zone NAME map to ZONE."
 214   (setf (gethash (string-downcase (stringify name)) *zones*) zone))
 215
 216 (defstruct (zone-record (:conc-name zr-))
 217   "A zone record."
 218   (name '<unnamed>)
 219   ttl
 220   type
 221   (defsubp nil)
 222   data)
 223
 224 (defstruct (zone-subdomain (:conc-name zs-))
 225   "A subdomain.  Slightly weird.  Used internally by zone-process-records
 226 below, and shouldn't escape."
 227   name
 228   ttl
 229   records)
 230
 231 ;;;--------------------------------------------------------------------------
 232 ;;; Zone infrastructure.
 233
 234 (defun zone-process-records (rec ttl func)
 235   "Sort out the list of records in REC, calling FUNC for each one.  TTL is
 236 the default time-to-live for records which don't specify one."
 237   (labels ((sift (rec ttl)
 238              (collecting (top sub)
 239                (loop
 240                  (unless rec
 241                    (return))
 242                  (let ((r (pop rec)))
 243                    (cond ((eq r :ttl)
 244                           (setf ttl (pop rec)))
 245                          ((symbolp r)
 246                           (collect (make-zone-record :type r
 247                                                      :ttl ttl
 248                                                      :data (pop rec))
 249                                    top))
 250                          ((listp r)
 251                           (dolist (name (listify (car r)))
 252                             (collect (make-zone-subdomain :name name
 253                                                           :ttl ttl
 254                                                           :records (cdr r))
 255                                      sub)))
 256                          (t
 257                           (error "Unexpected record form ~A" (car r))))))))
 258            (process (rec dom ttl defsubp)
 259              (multiple-value-bind (top sub) (sift rec ttl)
 260                (if (and dom (null top) sub)
 261                    (let ((s (pop sub)))
 262                      (process (zs-records s)
 263                               dom
 264                               (zs-ttl s)
 265                               defsubp)
 266                      (process (zs-records s)
 267                               (cons (zs-name s) dom)
 268                               (zs-ttl s)
 269                               t))
 270                  (let ((name (and dom
 271                                   (string-downcase
 272                                    (join-strings #\. (reverse dom))))))
 273                    (dolist (zr top)
 274                      (setf (zr-name zr) name)
 275                      (setf (zr-defsubp zr) defsubp)
 276                      (funcall func zr))))
 277                (dolist (s sub)
 278                  (process (zs-records s)
 279                           (cons (zs-name s) dom)
 280                           (zs-ttl s)
 281                           defsubp)))))
 282     (process rec nil ttl nil)))
 283
 284 (defun zone-parse-host (f zname)
 285   "Parse a host name F: if F ends in a dot then it's considered absolute;
 286 otherwise it's relative to ZNAME."
 287   (setf f (stringify f))
 288   (cond ((string= f "@") (stringify zname))
 289         ((and (plusp (length f))
 290               (char= (char f (1- (length f))) #\.))
 291          (string-downcase (subseq f 0 (1- (length f)))))
 292         (t (string-downcase (concatenate 'string f "."
 293                                          (stringify zname))))))
 294 (defun default-rev-zone (base bytes)
 295   "Return the default reverse-zone name for the given BASE address and number
 296 of fixed leading BYTES."
 297   (join-strings #\. (collecting ()
 298                       (loop for i from (- 3 bytes) downto 0
 299                             do (collect (ipaddr-byte base i)))
 300                       (collect "in-addr.arpa"))))
 301
 302 (defun zone-name-from-net (net &optional bytes)
 303   "Given a NET, and maybe the BYTES to use, convert to the appropriate
 304 subdomain of in-addr.arpa."
 305   (let ((ipn (net-get-as-ipnet net)))
 306     (with-ipnet (net mask) ipn
 307       (unless bytes
 308         (setf bytes (- 4 (ipnet-changeable-bytes mask))))
 309       (join-strings #\.
 310                     (append (loop
 311                                for i from (- 4 bytes) below 4
 312                                collect (logand #xff (ash net (* -8 i))))
 313                             (list "in-addr.arpa"))))))
 314
 315 (defun zone-net-from-name (name)
 316   "Given a NAME in the in-addr.arpa space, convert it to an ipnet."
 317   (let* ((name (string-downcase (stringify name)))
 318          (len (length name))
 319          (suffix ".in-addr.arpa")
 320          (sufflen (length suffix))
 321          (addr 0)
 322          (n 0)
 323          (end (- len sufflen)))
 324     (unless (and (> len sufflen)
 325                  (string= name suffix :start1 end))
 326       (error "`~A' not in ~A." name suffix))
 327     (loop
 328        with start = 0
 329        for dot = (position #\. name :start start :end end)
 330        for byte = (parse-integer name
 331                                  :start start
 332                                  :end (or dot end))
 333        do (setf addr (logior addr (ash byte (* 8 n))))
 334           (incf n)
 335        when (>= n 4)
 336        do (error "Can't deduce network from ~A." name)
 337        while dot
 338        do (setf start (1+ dot)))
 339     (setf addr (ash addr (* 8 (- 4 n))))
 340     (make-ipnet addr (* 8 n))))
 341
 342 (defun zone-reverse-records (records net list bytes dom)
 343   "Construct a reverse zone given a forward zone's RECORDS list, the NET that
 344 the reverse zone is to serve, a LIST to collect the records into, how
 345 many BYTES of data need to end up in the zone, and the DOM-ain suffix."
 346   (dolist (zr records)
 347     (when (and (eq (zr-type zr) :a)
 348                (not (zr-defsubp zr))
 349                (ipaddr-networkp (zr-data zr) net))
 350       (collect (make-zone-record
 351                 :name (string-downcase
 352                        (join-strings
 353                         #\.
 354                         (collecting ()
 355                           (dotimes (i bytes)
 356                             (collect (logand #xff (ash (zr-data zr)
 357                                                        (* -8 i)))))
 358                           (collect dom))))
 359                 :type :ptr
 360                 :ttl (zr-ttl zr)
 361                 :data (zr-name zr))
 362                list))))
 363
 364 (defun zone-reverse (data name list)
 365   "Process a :reverse record's DATA, for a domain called NAME, and add the
 366 records to the LIST."
 367   (destructuring-bind
 368       (net &key bytes zones)
 369       (listify data)
 370     (setf net (zone-parse-net net name))
 371     (dolist (z (or (listify zones)
 372                    (hash-table-keys *zones*)))
 373       (zone-reverse-records (zone-records (zone-find z))
 374                             net
 375                             list
 376                             (or bytes
 377                                 (ipnet-changeable-bytes (ipnet-mask net)))
 378                             name))))
 379
 380 (defun zone-parse-net (net name)
 381   "Given a NET, and the NAME of a domain to guess from if NET is null,
 382 return the ipnet for the network."
 383   (if net
 384       (net-get-as-ipnet net)
 385       (zone-net-from-name name)))
 386
 387 (defun zone-cidr-delg-default-name (ipn bytes)
 388   "Given a delegated net IPN and the parent's number of changing BYTES,
 389 return the default deletate zone prefix."
 390   (with-ipnet (net mask) ipn
 391     (join-strings #\.
 392                   (reverse
 393                    (loop
 394                       for i from (1- bytes) downto 0
 395                       until (zerop (logand mask (ash #xff (* 8 i))))
 396                       collect (logand #xff (ash net (* -8 i))))))))
 397
 398 (defun zone-cidr-delegation (data name ttl list)
 399   "Given :cidr-delegation info DATA, for a record called NAME and the current
 400 TTL, write lots of CNAME records to LIST."
 401   (destructuring-bind
 402       (net &key bytes)
 403       (listify (car data))
 404     (setf net (zone-parse-net net name))
 405     (unless bytes
 406       (setf bytes (ipnet-changeable-bytes (ipnet-mask net))))
 407     (dolist (map (cdr data))
 408       (destructuring-bind
 409           (tnet &optional tdom)
 410           (listify map)
 411         (setf tnet (zone-parse-net tnet name))
 412         (unless (ipnet-subnetp net tnet)
 413           (error "~A is not a subnet of ~A."
 414                  (ipnet-pretty tnet)
 415                  (ipnet-pretty net)))
 416         (unless tdom
 417           (setf tdom
 418                 (join-strings #\.
 419                               (list (zone-cidr-delg-default-name tnet bytes)
 420                                     name))))
 421         (setf tdom (string-downcase tdom))
 422         (dotimes (i (ipnet-hosts tnet))
 423           (let* ((addr (ipnet-host tnet i))
 424                  (tail (join-strings #\.
 425                                      (loop
 426                                         for i from 0 below bytes
 427                                         collect
 428                                           (logand #xff
 429                                                   (ash addr (* 8 i)))))))
 430             (collect (make-zone-record
 431                       :name (join-strings #\.
 432                                           (list tail name))
 433                       :type :cname
 434                       :ttl ttl
 435                       :data (join-strings #\. (list tail tdom)))
 436                      list)))))))
 437
 438 ;;;--------------------------------------------------------------------------
 439 ;;; Zone form parsing.
 440
 441 (defun zone-parse-head (head)
 442   "Parse the HEAD of a zone form.  This has the form
 443
 444      (NAME &key :source :admin :refresh :retry
 445                 :expire :min-ttl :ttl :serial)
 446
 447 though a singleton NAME needn't be a list.  Returns the default TTL and an
 448 soa structure representing the zone head."
 449   (destructuring-bind
 450       (zname
 451        &key
 452        (source *default-zone-source*)
 453        (admin (or *default-zone-admin*
 454                   (format nil "hostmaster@~A" zname)))
 455        (refresh *default-zone-refresh*)
 456        (retry *default-zone-retry*)
 457        (expire *default-zone-expire*)
 458        (min-ttl *default-zone-min-ttl*)
 459        (ttl min-ttl)
 460        (serial (make-zone-serial zname)))
 461       (listify head)
 462     (values zname
 463             (timespec-seconds ttl)
 464             (make-soa :admin admin
 465                       :source (zone-parse-host source zname)
 466                       :refresh (timespec-seconds refresh)
 467                       :retry (timespec-seconds retry)
 468                       :expire (timespec-seconds expire)
 469                       :min-ttl (timespec-seconds min-ttl)
 470                       :serial serial))))
 471
 472 (defmacro defzoneparse (types (name data list
 473                                &key (zname (gensym "ZNAME"))
 474                                     (ttl (gensym "TTL"))
 475                                     (defsubp (gensym "DEFSUBP")))
 476                         &body body)
 477   "Define a new zone record type (or TYPES -- a list of synonyms is
 478 permitted).  The arguments are as follows:
 479
 480 NAME    The name of the record to be added.
 481
 482 DATA    The content of the record to be added (a single object, unevaluated).
 483
 484 LIST    A function to add a record to the zone.  See below.
 485
 486 ZNAME   The name of the zone being constructed.
 487
 488 TTL     The TTL for this record.
 489
 490 DEFSUBP Whether this is the default subdomain for this entry.
 491
 492 You get to choose your own names for these.  ZNAME, TTL and DEFSUBP are
 493 optional: you don't have to accept them if you're not interested.
 494
 495 The LIST argument names a function to be bound in the body to add a new
 496 low-level record to the zone.  It has the prototype
 497
 498   (LIST &key :name :type :data :ttl :defsubp)
 499
 500 Except for defsubp, these default to the above arguments (even if you didn't
 501 accept the arguments)."
 502   (setf types (listify types))
 503   (let* ((type (car types))
 504          (func (intern (format nil "ZONE-PARSE/~:@(~A~)" type))))
 505     (with-gensyms (col tname ttype tttl tdata tdefsubp i)
 506       `(progn
 507          (dolist (,i ',types)
 508            (setf (get ,i 'zone-parse) ',func))
 509          (defun ,func (,name ,data ,ttl ,col ,zname ,defsubp)
 510            (declare (ignorable ,zname ,defsubp))
 511            (flet ((,list (&key ((:name ,tname) ,name)
 512                                ((:type ,ttype) ,type)
 513                                ((:data ,tdata) ,data)
 514                                ((:ttl ,tttl) ,ttl)
 515                                ((:defsubp ,tdefsubp) nil))
 516                     (collect (make-zone-record :name ,tname
 517                                                :type ,ttype
 518                                                :data ,tdata
 519                                                :ttl ,tttl
 520                                                :defsubp ,tdefsubp)
 521                              ,col)))
 522              ,@body))
 523          ',type))))
 524
 525 (defun zone-parse-records (zone records)
 526   (let ((zname (zone-name zone)))
 527     (with-collection (rec)
 528         (flet ((parse-record (zr)
 529                  (let ((func (or (get (zr-type zr) 'zone-parse)
 530                                  (error "No parser for record ~A."
 531                                         (zr-type zr))))
 532                        (name (and (zr-name zr)
 533                                   (stringify (zr-name zr)))))
 534                    (if (or (not name)
 535                            (string= name "@"))
 536                        (setf name zname)
 537                        (let ((len (length name)))
 538                          (if (or (zerop len)
 539                                  (char/= (char name (1- len)) #\.))
 540                              (setf name (join-strings #\.
 541                                                       (list name zname))))))
 542                    (funcall func
 543                             name
 544                             (zr-data zr)
 545                             (zr-ttl zr)
 546                             rec
 547                             zname
 548                             (zr-defsubp zr)))))
 549           (zone-process-records records
 550                                 (zone-default-ttl zone)
 551                                 #'parse-record ))
 552       (setf (zone-records zone) (nconc (zone-records zone) rec)))))
 553
 554 (defun zone-parse (zf)
 555   "Parse a ZONE form.  The syntax of a zone form is as follows:
 556
 557 ZONE-FORM:
 558   ZONE-HEAD ZONE-RECORD*
 559
 560 ZONE-RECORD:
 561   ((NAME*) ZONE-RECORD*)
 562 | SYM ARGS"
 563   (multiple-value-bind (zname ttl soa) (zone-parse-head (car zf))
 564     (let ((zone (make-zone :name zname
 565                            :default-ttl ttl
 566                            :soa soa
 567                            :records nil)))
 568       (zone-parse-records zone (cdr zf))
 569       zone)))
 570
 571 (defun zone-create (zf)
 572   "Zone construction function.  Given a zone form ZF, construct the zone and
 573 add it to the table."
 574   (let* ((zone (zone-parse zf))
 575          (name (zone-name zone)))
 576     (setf (zone-find name) zone)
 577     name))
 578
 579 (defmacro defzone (soa &rest zf)
 580   "Zone definition macro."
 581   `(zone-create '(,soa ,@zf)))
 582
 583 (defmacro defrevzone (head &rest zf)
 584   "Define a reverse zone, with the correct name."
 585   (destructuring-bind
 586       (net &rest soa-args)
 587       (listify head)
 588     (let ((bytes nil))
 589       (when (and soa-args (integerp (car soa-args)))
 590         (setf bytes (pop soa-args)))
 591       `(zone-create '((,(zone-name-from-net net bytes) ,@soa-args) ,@zf)))))
 592
 593 ;;;--------------------------------------------------------------------------
 594 ;;; Zone record parsers.
 595
 596 (defzoneparse :a (name data rec :defsubp defsubp)
 597   ":a IPADDR"
 598   (rec :data (parse-ipaddr data) :defsubp defsubp))
 599
 600 (defzoneparse :ptr (name data rec :zname zname)
 601   ":ptr HOST"
 602   (rec :data (zone-parse-host data zname)))
 603
 604 (defzoneparse :cname (name data rec :zname zname)
 605   ":cname HOST"
 606   (rec :data (zone-parse-host data zname)))
 607
 608 (defzoneparse :mx (name data rec :zname zname)
 609   ":mx ((HOST :prio INT :ip IPADDR)*)"
 610   (dolist (mx (listify data))
 611     (destructuring-bind
 612         (mxname &key (prio *default-mx-priority*) ip)
 613         (listify mx)
 614       (let ((host (zone-parse-host mxname zname)))
 615         (when ip (rec :name host :type :a :data (parse-ipaddr ip)))
 616         (rec :data (cons host prio))))))
 617
 618 (defzoneparse :ns (name data rec :zname zname)
 619   ":ns ((HOST :ip IPADDR)*)"
 620   (dolist (ns (listify data))
 621     (destructuring-bind
 622         (nsname &key ip)
 623         (listify ns)
 624       (let ((host (zone-parse-host nsname zname)))
 625         (when ip (rec :name host :type :a :data (parse-ipaddr ip)))
 626         (rec :data host)))))
 627
 628 (defzoneparse :alias (name data rec :zname zname)
 629   ":alias (LABEL*)"
 630   (dolist (a (listify data))
 631     (rec :name (zone-parse-host a zname)
 632          :type :cname
 633          :data name)))
 634
 635 (defzoneparse :net (name data rec)
 636   ":net (NETWORK*)"
 637   (dolist (net (listify data))
 638     (let ((n (net-get-as-ipnet net)))
 639       (rec :name (zone-parse-host "net" name)
 640            :type :a
 641            :data (ipnet-net n))
 642       (rec :name (zone-parse-host "mask" name)
 643            :type :a
 644            :data (ipnet-mask n))
 645       (rec :name (zone-parse-host "broadcast" name)
 646            :type :a
 647            :data (ipnet-broadcast n)))))
 648
 649 (defzoneparse (:rev :reverse) (name data rec)
 650   ":reverse ((NET :bytes BYTES) ZONE*)"
 651   (setf data (listify data))
 652   (destructuring-bind
 653       (net &key bytes)
 654       (listify (car data))
 655     (setf net (zone-parse-net net name))
 656     (unless bytes
 657       (setf bytes (ipnet-changeable-bytes (ipnet-mask net))))
 658     (dolist (z (or (cdr data)
 659                    (hash-table-keys *zones*)))
 660       (dolist (zr (zone-records (zone-find z)))
 661         (when (and (eq (zr-type zr) :a)
 662                    (not (zr-defsubp zr))
 663                    (ipaddr-networkp (zr-data zr) net))
 664           (rec :name (string-downcase
 665                       (join-strings
 666                        #\.
 667                        (collecting ()
 668                          (dotimes (i bytes)
 669                            (collect (logand #xff (ash (zr-data zr)
 670                                                       (* -8 i)))))
 671                          (collect name))))
 672                :type :ptr
 673                :ttl (zr-ttl zr)
 674                :data (zr-name zr)))))))
 675
 676 (defzoneparse (:cidr-delegation :cidr) (name data rec)
 677   ":cidr-delegation ((NET :bytes BYTES) (TARGET-NET [TARGET-ZONE])*)"
 678   (destructuring-bind
 679       (net &key bytes)
 680       (listify (car data))
 681     (setf net (zone-parse-net net name))
 682     (unless bytes
 683       (setf bytes (ipnet-changeable-bytes (ipnet-mask net))))
 684     (dolist (map (cdr data))
 685       (destructuring-bind
 686           (tnet &optional tdom)
 687           (listify map)
 688         (setf tnet (zone-parse-net tnet name))
 689         (unless (ipnet-subnetp net tnet)
 690           (error "~A is not a subnet of ~A."
 691                  (ipnet-pretty tnet)
 692                  (ipnet-pretty net)))
 693         (unless tdom
 694           (with-ipnet (net mask) tnet
 695             (setf tdom
 696                   (join-strings
 697                    #\.
 698                    (append (reverse (loop
 699                                        for i from (1- bytes) downto 0
 700                                        until (zerop (logand mask
 701                                                             (ash #xff
 702                                                                  (* 8 i))))
 703                                        collect (logand #xff
 704                                                        (ash net (* -8 i)))))
 705                            (list name))))))
 706         (setf tdom (string-downcase tdom))
 707         (dotimes (i (ipnet-hosts tnet))
 708           (let* ((addr (ipnet-host tnet i))
 709                  (tail (join-strings #\.
 710                                      (loop
 711                                         for i from 0 below bytes
 712                                         collect
 713                                           (logand #xff
 714                                                   (ash addr (* 8 i)))))))
 715             (rec :name (format nil "~A.~A" tail name)
 716                  :type :cname
 717                  :data (format nil "~A.~A" tail tdom))))))))
 718
 719 ;;;--------------------------------------------------------------------------
 720 ;;; Zone file output.
 721
 722 (defun zone-write (zone &optional (stream *standard-output*))
 723   "Write a ZONE's records to STREAM."
 724   (labels ((fix-admin (a)
 725              (let ((at (position #\@ a))
 726                    (s (concatenate 'string (string-downcase a) ".")))
 727                (when s
 728                  (setf (char s at) #\.))
 729                s))
 730            (fix-host (h)
 731              (if (not h)
 732                  "@"
 733                  (let* ((h (string-downcase (stringify h)))
 734                         (hl (length h))
 735                         (r (string-downcase (zone-name zone)))
 736                         (rl (length r)))
 737                    (cond ((string= r h) "@")
 738                          ((and (> hl rl)
 739                                (char= (char h (- hl rl 1)) #\.)
 740                                (string= h r :start1 (- hl rl)))
 741                           (subseq h 0 (- hl rl 1)))
 742                          (t (concatenate 'string h "."))))))
 743            (printrec (zr)
 744              (format stream "~A~20T~@[~8D~]~30TIN ~A~40T"
 745                      (fix-host (zr-name zr))
 746                      (and (/= (zr-ttl zr) (zone-default-ttl zone))
 747                           (zr-ttl zr))
 748                      (string-upcase (symbol-name (zr-type zr))))))
 749     (format stream "~
 750 ;;; Zone file `~(~A~)'
 751 ;;;   (generated ~A)
 752
 753 $ORIGIN ~@0*~(~A.~)
 754 $TTL ~@2*~D~2%"
 755             (zone-name zone)
 756             (iso-date :now :datep t :timep t)
 757             (zone-default-ttl zone))
 758     (let ((soa (zone-soa zone)))
 759       (format stream "~
 760 ~A~30TIN SOA~40T~A ~A (
 761 ~45T~10D~60T ;serial
 762 ~45T~10D~60T ;refresh
 763 ~45T~10D~60T ;retry
 764 ~45T~10D~60T ;expire
 765 ~45T~10D )~60T ;min-ttl~2%"
 766               (fix-host (zone-name zone))
 767               (fix-host (soa-source soa))
 768               (fix-admin (soa-admin soa))
 769               (soa-serial soa)
 770               (soa-refresh soa)
 771               (soa-retry soa)
 772               (soa-expire soa)
 773               (soa-min-ttl soa)))
 774     (dolist (zr (zone-records zone))
 775       (case (zr-type zr)
 776         (:a
 777          (printrec zr)
 778          (format stream "~A~%" (ipaddr-string (zr-data zr))))
 779         ((:ptr :cname)
 780          (printrec zr)
 781          (format stream "~A~%" (fix-host (zr-data zr))))
 782         (:ns
 783          (printrec zr)
 784          (format stream "~A~%" (fix-host (zr-data zr))))
 785         (:mx
 786          (printrec zr)
 787          (let ((mx (zr-data zr)))
 788            (format stream "~2D ~A~%" (cdr mx) (fix-host (car mx)))))
 789         (:txt
 790          (printrec zr)
 791          (format stream "~S~%" (stringify (zr-data zr))))))))
 792
 793 (defun zone-save (zones)
 794   "Write the named ZONES to files.  If no zones are given, write all the
 795 zones."
 796   (unless zones
 797     (setf zones (hash-table-keys *zones*)))
 798   (safely (safe)
 799     (dolist (z zones)
 800       (let ((zz (zone-find z)))
 801         (unless zz
 802           (error "Unknown zone `~A'." z))
 803         (let ((stream (safely-open-output-stream safe
 804                                                  (format nil
 805                                                          "~(~A~).zone"
 806                                                          z))))
 807           (zone-write zz stream))))))
 808
 809 ;;;----- That's all, folks --------------------------------------------------