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1 | ;;; -*-lisp-*- |
2 | ;;; | |
9c44003b MW |
3 | ;;; Network (numbering) tools |
4 | ;;; | |
5 | ;;; (c) 2006 Straylight/Edgeware | |
6 | ;;; | |
7 | ||
8 | ;;;----- Licensing notice --------------------------------------------------- | |
9 | ;;; | |
10 | ;;; This program is free software; you can redistribute it and/or modify | |
11 | ;;; it under the terms of the GNU General Public License as published by | |
12 | ;;; the Free Software Foundation; either version 2 of the License, or | |
13 | ;;; (at your option) any later version. | |
7fff3797 | 14 | ;;; |
9c44003b MW |
15 | ;;; This program is distributed in the hope that it will be useful, |
16 | ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;;; GNU General Public License for more details. | |
7fff3797 | 19 | ;;; |
9c44003b MW |
20 | ;;; You should have received a copy of the GNU General Public License |
21 | ;;; along with this program; if not, write to the Free Software Foundation, | |
22 | ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
23 | ||
9c44003b MW |
24 | (in-package #:net) |
25 | ||
26 | ;;;-------------------------------------------------------------------------- | |
32ebbe9b | 27 | ;;; Various random utilities. |
9c44003b | 28 | |
32ebbe9b | 29 | (declaim (inline mask)) |
9c44003b MW |
30 | (defun mask (n) |
31 | "Return 2^N - 1: i.e., a mask of N set bits." | |
32 | (1- (ash 1 n))) | |
33 | ||
32ebbe9b MW |
34 | (defun find-first-bit-transition |
35 | (mask &optional (low 0) (high (integer-length mask))) | |
36 | "Find the first (lowest bit-position) transition in MASK within the bounds. | |
9c44003b | 37 | |
32ebbe9b MW |
38 | The LOW bound is inclusive; the high bound is exclusive. A transition is |
39 | a change from zero to one, or vice-versa. The return value is the | |
40 | upper (exclusive) bound on the initial run, and the lower (inclusive) | |
41 | bound on the new run. | |
9c44003b | 42 | |
32ebbe9b MW |
43 | If there is no transition within the bounds, then return HIGH." |
44 | ||
45 | ;; Arrange that the initial run is ones. | |
46 | (unless (logbitp low mask) (setf mask (lognot mask))) | |
47 | ||
48 | ;; Now, note that MASK + 2^LOW is identical to MASK in all bit positions | |
49 | ;; except for (a) the run of one bits starting at LOW, and (b) the zero bit | |
50 | ;; just above it. So MASK xor (MASK + 2^LOW) is zero except for these | |
51 | ;; bits; so all we need now is to find the position of its most significant | |
52 | ;; set bit. | |
53 | (let ((pos (1- (integer-length (logxor mask (+ mask (ash 1 low))))))) | |
54 | (if (<= low pos high) pos high))) | |
9c44003b MW |
55 | |
56 | (defun count-low-zero-bits (n) | |
57 | "Return the number of low-order zero bits in the integer N." | |
32ebbe9b MW |
58 | (cond ((zerop n) nil) |
59 | ((oddp n) 0) | |
60 | (t (find-first-bit-transition n)))) | |
61 | ||
62 | (declaim (inline round-down)) | |
63 | (defun round-down (n step) | |
64 | "Return the largest multiple of STEP not greater than N." | |
65 | (* step (floor n step))) | |
66 | ||
67 | (declaim (inline round-up)) | |
68 | (defun round-up (n step) | |
69 | "Return the smallest multiple of STEP not less than N." | |
70 | (* step (ceiling n step))) | |
71 | ||
72 | (defgeneric extract-class-name (object) | |
73 | (:documentation "Turn OBJECT into a class name.") | |
74 | (:method ((instance standard-object)) | |
75 | (extract-class-name (class-of instance))) | |
76 | (:method ((class standard-class)) | |
77 | (class-name class)) | |
78 | (:method ((name symbol)) | |
79 | name)) | |
80 | ||
81 | (defclass savable-object () | |
82 | ()) | |
83 | (defmethod make-load-form ((object savable-object) &optional environment) | |
84 | (make-load-form-saving-slots object :environment environment)) | |
85 | ||
86 | ;;;-------------------------------------------------------------------------- | |
87 | ;;; Parsing primitives for addresses. | |
88 | ||
89 | (defun parse-partial-address | |
90 | (str | |
91 | &key (start 0) (end nil) (delim #\.) | |
92 | (width 8) (radix 10) (min 1) (max 32) (shiftp t) | |
93 | (what "address")) | |
94 | "Parse a partial address from STR, which should be a sequence of integers | |
95 | in the given RADIX, separated by the DELIM character, with each integer | |
96 | N_i in the interval 0 <= N_i < 2^WIDTH. If the sequence is N_1, N_2, ..., | |
97 | N_k, then the basic partial address BPA is the sum | |
98 | ||
99 | SUM_{1<=i<=k} 2^{WIDTH (k-i)} N_i | |
100 | ||
101 | If SHIFTP is true (the default) then let OFFSET be the smallest multiple | |
102 | of WIDTH not less than MAX - k WIDTH; otherwise, let OFFSET be zero. The | |
103 | partial address PA is BPA 2^SHIFT. | |
104 | ||
105 | The return values are: PA, OFFSET, k WIDTH + OFFSET; i.e., the partial | |
106 | address, and (inclusive) lower and (exclusive) upper bounds on the bits | |
107 | specified by STR." | |
108 | ||
109 | (setf-default end (length str)) | |
110 | (let ((addr 0) (nbits 0) (limit (ash 1 width))) | |
111 | (when (< start end) | |
112 | (loop | |
113 | (when (>= nbits max) | |
114 | (error "Too many elements in ~A" what)) | |
115 | (let* ((pos (position delim str :start start :end end)) | |
116 | (w (parse-integer str :radix radix | |
117 | :start start :end (or pos end)))) | |
118 | (unless (and (<= 0 w) (< w limit)) | |
119 | (error "Element out of range in ~A" what)) | |
120 | (setf addr (logior (ash addr width) w)) | |
121 | (incf nbits width) | |
122 | (unless pos (return)) | |
123 | (setf start (1+ pos))))) | |
124 | (when (< nbits min) | |
125 | (error "Not enough elements in ~A" what)) | |
126 | (if shiftp | |
127 | (let* ((top (round-up max width)) | |
128 | (shift (- top nbits))) | |
129 | (values (ash addr shift) shift top)) | |
130 | (values addr 0 nbits)))) | |
9c44003b MW |
131 | |
132 | ;;;-------------------------------------------------------------------------- | |
32ebbe9b MW |
133 | ;;; Simple messing about with IP addresses. |
134 | ||
135 | (export 'ipaddr) | |
136 | (export 'ipaddr-addr) | |
137 | (defclass ipaddr (savable-object) | |
138 | () | |
139 | (:documentation | |
140 | "Base class for IP addresses.")) | |
141 | ||
142 | (export 'ipaddr-family) | |
143 | (defgeneric ipaddr-family (addr)) | |
144 | ||
145 | (export 'family-addrclass) | |
146 | (defgeneric family-addrclass (family) | |
147 | (:method ((af symbol)) nil)) | |
148 | ||
149 | (export 'ipaddr-width) | |
150 | (defgeneric ipaddr-width (class) | |
151 | (:method ((object t)) (ipaddr-width (extract-class-name object)))) | |
152 | ||
153 | (export 'ipaddr-comparable-p) | |
154 | (defgeneric ipaddr-comparable-p (addr-a addr-b) | |
155 | (:method ((addr-a ipaddr) (addr-b ipaddr)) | |
156 | (eq (class-of addr-a) (class-of addr-b)))) | |
157 | ||
158 | (defun guess-address-class (str &key (start 0) (end nil)) | |
a2267e14 MW |
159 | (cond ((position #\: str :start start :end end) 'ip6addr) |
160 | (t 'ip4addr))) | |
32ebbe9b MW |
161 | |
162 | (defgeneric parse-partial-ipaddr (class str &key start end min max) | |
163 | (:method ((object t) str &rest keywords) | |
164 | (apply #'parse-partial-ipaddr (extract-class-name object) str keywords))) | |
9c44003b | 165 | |
e1528fd6 | 166 | (export 'string-ipaddr) |
9c44003b | 167 | (defun string-ipaddr (str &key (start 0) (end nil)) |
32ebbe9b | 168 | "Parse STR into an address; guess what kind is intended by the user. |
f4e0c48f MW |
169 | |
170 | STR may be anything at all: it's converted as if by `stringify'. | |
171 | The START and END arguments may be used to parse out a substring." | |
9c44003b | 172 | (setf str (stringify str)) |
32ebbe9b MW |
173 | (let* ((class (guess-address-class str :start start :end end)) |
174 | (width (ipaddr-width class))) | |
175 | (make-instance class :addr | |
176 | (parse-partial-ipaddr class str | |
177 | :start start :end end | |
178 | :min width :max width)))) | |
179 | ||
180 | (export 'integer-ipaddr) | |
181 | (defgeneric integer-ipaddr (int like) | |
182 | (:documentation "Convert INT into an address of type indicated by LIKE. | |
183 | ||
184 | Specifically, if LIKE is an address object, then use its type; if it's | |
185 | a class, then use it directly; if it's a symbol, then use the class it | |
186 | names.") | |
187 | (:method (int (like t)) (integer-ipaddr int (class-of like))) | |
188 | (:method (int (like symbol)) | |
189 | (make-instance (or (family-addrclass like) like) :addr int)) | |
190 | (:method (int (like standard-class)) (make-instance like :addr int))) | |
9c44003b | 191 | |
e1528fd6 | 192 | (export 'ipaddr-string) |
32ebbe9b MW |
193 | (defgeneric ipaddr-string (ip) |
194 | (:documentation | |
195 | "Transform the address IP into a string in dotted-quad form.")) | |
196 | ||
197 | (defmethod print-object ((addr ipaddr) stream) | |
198 | (print-unreadable-object (addr stream :type t) | |
199 | (write-string (ipaddr-string addr) stream))) | |
9c44003b | 200 | |
e1528fd6 | 201 | (export 'ipaddrp) |
9c44003b MW |
202 | (defun ipaddrp (ip) |
203 | "Answer true if IP is a valid IP address in integer form." | |
204 | (typep ip 'ipaddr)) | |
205 | ||
32ebbe9b MW |
206 | (defun ipaddr (ip &optional like) |
207 | "Convert IP to an IP address, of type similar to LIKE. | |
f4e0c48f | 208 | |
32ebbe9b MW |
209 | If it's an IP address, just return it unchanged; If it's an integer, |
210 | capture it; otherwise convert by `string-ipaddr'." | |
9c44003b MW |
211 | (typecase ip |
212 | (ipaddr ip) | |
32ebbe9b | 213 | (integer (integer-ipaddr ip like)) |
9c44003b MW |
214 | (t (string-ipaddr ip)))) |
215 | ||
32ebbe9b MW |
216 | (export 'ipaddr-rrtype) |
217 | (defgeneric ipaddr-rrtype (addr) | |
218 | (:documentation "Return the proper resource record type for ADDR.")) | |
219 | ||
9c44003b MW |
220 | ;;;-------------------------------------------------------------------------- |
221 | ;;; Netmasks. | |
222 | ||
e1528fd6 | 223 | (export 'integer-netmask) |
32ebbe9b MW |
224 | (defun integer-netmask (n i) |
225 | "Given an integer I, return an N-bit netmask with its I top bits set." | |
226 | (- (ash 1 n) (ash 1 (- n i)))) | |
9c44003b | 227 | |
e1528fd6 | 228 | (export 'ipmask-cidl-slash) |
32ebbe9b | 229 | (defun ipmask-cidl-slash (width mask) |
f4e0c48f MW |
230 | "Given a netmask MASK, try to compute a prefix length. |
231 | ||
32ebbe9b MW |
232 | Return an integer N such that (integer-netmask WIDTH N) = MASK, or nil if |
233 | this is impossible." | |
234 | (let* ((low (logxor mask (mask width))) | |
235 | (bits (integer-length low))) | |
236 | (and (= low (mask bits)) (- width bits)))) | |
237 | ||
238 | (export 'ipmask) | |
239 | (defgeneric ipmask (addr mask) | |
240 | (:documentation "Convert MASK into a suitable netmask for ADDR.") | |
241 | (:method ((addr ipaddr) (mask null)) | |
242 | (mask (ipaddr-width addr))) | |
243 | (:method ((addr ipaddr) (mask integer)) | |
244 | (let ((w (ipaddr-width addr))) | |
245 | (if (<= 0 mask w) | |
246 | (integer-netmask w mask) | |
b496b60f | 247 | (error "Prefix length out of range."))))) |
32ebbe9b MW |
248 | |
249 | (export 'mask-ipaddr) | |
250 | (defun mask-ipaddr (addr mask) | |
251 | "Apply the MASK to the ADDR, returning the base address." | |
252 | (integer-ipaddr (logand mask (ipaddr-addr addr)) addr)) | |
9c44003b MW |
253 | |
254 | ;;;-------------------------------------------------------------------------- | |
255 | ;;; Networks: pairing an address and netmask. | |
256 | ||
e1528fd6 | 257 | (export 'ipnet) |
32ebbe9b MW |
258 | (export 'ipnet-net) |
259 | (export 'ipnet-mask) | |
260 | (defclass ipnet (savable-object) | |
261 | () | |
262 | (:documentation "Base class for IP networks.")) | |
9c44003b | 263 | |
32ebbe9b MW |
264 | (export 'ipnet-family) |
265 | (defgeneric ipnet-family (ipn) | |
266 | (:method ((ipn ipnet)) (ipaddr-family (ipnet-net ipn)))) | |
9c44003b | 267 | |
32ebbe9b MW |
268 | (export 'ipnet-addr) |
269 | (defun ipnet-addr (ipn) | |
270 | "Return the base network address of IPN as a raw integer." | |
271 | (ipaddr-addr (ipnet-net ipn))) | |
9c44003b | 272 | |
32ebbe9b MW |
273 | (export 'ipaddr-ipnet) |
274 | (defgeneric ipaddr-ipnet (addr mask) | |
275 | (:documentation "Construct an `ipnet' object given a base ADDR and MASK.")) | |
276 | ||
277 | (export 'make-ipnet) | |
278 | (defun make-ipnet (net mask) | |
279 | "Construct an IP-network object given the NET and MASK; these are | |
280 | transformed as though by `ipaddr' and `ipmask'." | |
281 | (let* ((net (ipaddr net)) | |
282 | (mask (ipmask net mask))) | |
283 | (ipaddr-ipnet (mask-ipaddr net mask) mask))) | |
9c44003b | 284 | |
e1528fd6 | 285 | (export 'with-ipnet) |
32ebbe9b | 286 | (defmacro with-ipnet ((net addr mask) ipn &body body) |
f4e0c48f MW |
287 | "Evaluate the BODY with components of IPN in scope. |
288 | ||
32ebbe9b MW |
289 | The NET is bound to the underlying network base address, as an `ipaddr'; |
290 | ADDR is bound to the integer value of this address; and MASK is bound to | |
291 | the netmask, again as an integer. Any (or all) of these may be nil if not | |
292 | wanted." | |
9c44003b MW |
293 | (with-gensyms tmp |
294 | `(let ((,tmp ,ipn)) | |
295 | (let (,@(and net `((,net (ipnet-net ,tmp)))) | |
32ebbe9b | 296 | ,@(and addr `((,addr (ipnet-addr ,tmp)))) |
9c44003b MW |
297 | ,@(and mask `((,mask (ipnet-mask ,tmp))))) |
298 | ,@body)))) | |
299 | ||
32ebbe9b MW |
300 | (export 'ipnet-width) |
301 | (defun ipnet-width (ipn) | |
302 | "Return the underlying bit width of the addressing system." | |
303 | (ipaddr-width (ipnet-net ipn))) | |
9c44003b | 304 | |
e1528fd6 | 305 | (export 'ipnet-string) |
9c44003b MW |
306 | (defun ipnet-string (ipn) |
307 | "Convert IPN to a string." | |
32ebbe9b | 308 | (with-ipnet (net nil mask) ipn |
9c44003b MW |
309 | (format nil "~A/~A" |
310 | (ipaddr-string net) | |
32ebbe9b MW |
311 | (or (ipmask-cidl-slash (ipnet-width ipn) mask) |
312 | (ipaddr-string (make-instance (class-of net) :addr mask)))))) | |
313 | ||
314 | (defmethod print-object ((ipn ipnet) stream) | |
315 | (print-unreadable-object (ipn stream :type t) | |
316 | (write-string (ipnet-string ipn) stream))) | |
317 | ||
eebb70af | 318 | (defun parse-subnet (class width max str &key (start 0) (end nil)) |
32ebbe9b MW |
319 | "Parse a subnet description from a (substring of) STR." |
320 | (setf-default end (length str)) | |
321 | (let ((sl (position #\/ str :start start :end end))) | |
322 | (multiple-value-bind (addr lo hi) | |
323 | (parse-partial-ipaddr class str :max max | |
324 | :start start :end (or sl end)) | |
325 | (let* ((present (integer-netmask hi (- hi lo))) | |
326 | (mask (cond ((not sl) | |
327 | present) | |
328 | ((every #'digit-char-p (subseq str (1+ sl) end)) | |
329 | (let ((length (parse-integer str | |
330 | :start (1+ sl) | |
331 | :end end))) | |
332 | (unless (>= length (- width max)) | |
333 | (error "Mask doesn't reach subnet boundary")) | |
334 | (integer-netmask max (- length (- width max))))) | |
335 | (t | |
336 | (parse-partial-ipaddr class str :max max | |
337 | :start (1+ sl) :end end))))) | |
338 | (unless (zerop (logandc2 mask present)) | |
339 | (error "Mask selects bits not present in base address")) | |
340 | (values addr mask))))) | |
341 | ||
342 | (export 'ipnet-subnet) | |
343 | (defun ipnet-subnet (base-ipn sub-net sub-mask) | |
344 | "Construct a subnet of IPN, using the NET and MASK. | |
345 | ||
346 | The NET must either be zero or agree with IPN at all positions indicated | |
347 | by their respective masks." | |
348 | (with-ipnet (base-net base-addr base-mask) base-ipn | |
349 | (let* ((sub-net (ipaddr sub-net (ipnet-net base-ipn))) | |
350 | (sub-addr (ipaddr-addr sub-net)) | |
351 | (sub-mask (ipmask sub-net sub-mask)) | |
352 | (common (logand base-mask sub-mask)) | |
353 | (base-overlap (logand base-addr common)) | |
354 | (sub-overlap (logand sub-addr common)) | |
355 | (full-mask (logior base-mask sub-mask))) | |
356 | (unless (or (zerop sub-overlap) | |
357 | (= sub-overlap base-overlap)) | |
358 | (error "Subnet doesn't match base network")) | |
359 | (ipaddr-ipnet (integer-ipaddr (logand full-mask | |
360 | (logior base-addr sub-addr)) | |
361 | base-net) | |
362 | full-mask)))) | |
363 | ||
364 | (export 'string-ipnet) | |
365 | (defun string-ipnet (str &key (start 0) (end nil)) | |
366 | "Parse an IP-network from the string STR." | |
367 | (setf str (stringify str)) | |
368 | (setf-default end (length str)) | |
369 | (let ((addr-class (guess-address-class str :start start :end end))) | |
370 | (multiple-value-bind (addr mask) | |
371 | (let ((width (ipaddr-width addr-class))) | |
372 | (parse-subnet addr-class width width str | |
373 | :start start :end end)) | |
374 | (make-ipnet (make-instance addr-class :addr addr) | |
375 | (make-instance addr-class :addr mask))))) | |
376 | ||
377 | (export 'string-subipnet) | |
378 | (defun string-subipnet (ipn str &key (start 0) (end nil)) | |
379 | (setf str (stringify str)) | |
380 | (let* ((addr-class (extract-class-name (ipnet-net ipn))) | |
381 | (width (ipaddr-width addr-class)) | |
382 | (max (- width | |
383 | (or (ipmask-cidl-slash width (ipnet-mask ipn)) | |
384 | (error "Base network has complex netmask"))))) | |
385 | (multiple-value-bind (addr mask) | |
386 | (parse-subnet addr-class width max str :start start :end end) | |
387 | (ipnet-subnet ipn | |
388 | (make-instance addr-class :addr addr) | |
389 | (make-instance addr-class :addr mask))))) | |
390 | ||
391 | (defun ipnet (net) | |
392 | "Construct an IP-network object from the given argument. | |
393 | ||
394 | A number of forms are acceptable: | |
395 | ||
396 | * ADDR -- a single address, equivalent to (ADDR . N). | |
397 | * (NET . MASK|nil) -- a single-object representation. | |
398 | * IPNET -- return an equivalent (`equal', not necessarily `eql') | |
399 | version." | |
400 | (typecase net | |
401 | (ipnet net) | |
402 | ((or string symbol) (string-ipnet net)) | |
403 | (t (apply #'make-ipnet (pairify net nil))))) | |
9c44003b | 404 | |
e1528fd6 | 405 | (export 'ipnet-broadcast) |
32ebbe9b MW |
406 | (defgeneric ipnet-broadcast (ipn) |
407 | (:documentation "Return the broadcast address for the network IPN. | |
408 | ||
409 | Returns nil if there isn't one.")) | |
9c44003b | 410 | |
e1528fd6 | 411 | (export 'ipnet-hosts) |
9c44003b MW |
412 | (defun ipnet-hosts (ipn) |
413 | "Return the number of available addresses in network IPN." | |
32ebbe9b MW |
414 | (ash 1 (- (ipnet-width ipn) (logcount (ipnet-mask ipn))))) |
415 | ||
416 | (defstruct host-map | |
417 | "An internal object used by `ipnet-index-host' and `ipnet-host-index'. | |
418 | ||
419 | Our objective is to be able to convert between flat host indices and a | |
420 | possibly crazy non-flat host space. We record the underlying IPNET for | |
421 | convenience, and a list of byte-specifications for the runs of zero bits | |
422 | in the netmask, in ascending order." | |
423 | ipnet | |
424 | bytes) | |
425 | ||
426 | (export 'ipnet-host-map) | |
427 | (defun ipnet-host-map (ipn) | |
428 | "Work out how to enumerate the variable portion of IPN. | |
429 | ||
430 | Returns an object which can be passed to `ipnet-index-host' and | |
431 | `ipnet-host-index'." | |
432 | (let* ((mask (ipnet-mask ipn)) (bytes nil) (i 0) | |
433 | (len (integer-length mask)) (width (ipnet-width ipn))) | |
434 | (when (logbitp i mask) (setf i (find-first-bit-transition mask i))) | |
435 | (loop | |
436 | (unless (< i len) (return)) | |
437 | (let ((next (find-first-bit-transition mask i width))) | |
438 | (push (byte (- next i) i) bytes) | |
439 | (setf i (find-first-bit-transition mask next width)))) | |
440 | (when (< len width) (push (byte (- width len) len) bytes)) | |
441 | (make-host-map :ipnet ipn :bytes (nreverse bytes)))) | |
442 | ||
443 | (export 'ipnet-index-host) | |
444 | (defun ipnet-index-host (map host) | |
445 | "Convert a HOST index to its address." | |
446 | (let* ((ipn (host-map-ipnet map)) | |
447 | (addr (logand (ipnet-addr ipn) (ipnet-mask ipn)))) | |
448 | (dolist (byte (host-map-bytes map)) | |
449 | (setf (ldb byte addr) host | |
450 | host (ash host (- (byte-size byte))))) | |
451 | (unless (zerop host) | |
452 | (error "Host index out of range.")) | |
453 | (integer-ipaddr addr (ipnet-net ipn)))) | |
454 | ||
455 | (export 'ipnet-host-index) | |
456 | (defun ipnet-host-index (map addr) | |
457 | "Convert an ADDR into a host index." | |
458 | (let ((addr (ipaddr-addr addr)) | |
459 | (host 0) (offset 0)) | |
460 | (dolist (byte (host-map-bytes map)) | |
461 | (setf host (logior host | |
462 | (ash (ldb byte addr) offset)) | |
463 | offset (+ offset (byte-size byte)))) | |
464 | host)) | |
465 | ||
466 | (export 'ipnet-index-bounds) | |
467 | (defun ipnet-index-bounds (map start end) | |
468 | "Return host-index bounds corresponding to the given bit-position bounds." | |
469 | (flet ((hack (frob-map good-byte tweak-addr) | |
470 | (dolist (byte (funcall frob-map (host-map-bytes map))) | |
471 | (let* ((low (byte-position byte)) | |
472 | (high (+ low (byte-size byte))) | |
473 | (good (funcall good-byte low high))) | |
474 | (when good | |
475 | (return-from hack | |
476 | (ipnet-host-index map | |
477 | (ipaddr (funcall tweak-addr | |
478 | (ash 1 good)) | |
479 | (ipnet-net | |
480 | (host-map-ipnet map)))))))) | |
481 | (error "No variable bits in range."))) | |
482 | (values (hack #'identity | |
483 | (lambda (low high) | |
484 | (and (< start high) (max start low))) | |
485 | #'identity) | |
486 | (hack #'reverse | |
487 | (lambda (low high) | |
488 | (and (>= end low) (min end high))) | |
489 | #'1-)))) | |
9c44003b | 490 | |
e1528fd6 | 491 | (export 'ipnet-host) |
9c44003b | 492 | (defun ipnet-host (ipn host) |
f4e0c48f MW |
493 | "Return the address of the given HOST in network IPN. |
494 | ||
495 | This works even with a non-contiguous netmask." | |
32ebbe9b | 496 | (ipnet-index-host (ipnet-host-map ipn) host)) |
9c44003b | 497 | |
e1528fd6 | 498 | (export 'ipaddr-networkp) |
9c44003b | 499 | (defun ipaddr-networkp (ip ipn) |
32ebbe9b MW |
500 | "Returns true if numeric address IP is within network IPN." |
501 | (with-ipnet (nil addr mask) ipn | |
502 | (= addr (logand ip mask)))) | |
9c44003b | 503 | |
e1528fd6 | 504 | (export 'ipnet-subnetp) |
9c44003b MW |
505 | (defun ipnet-subnetp (ipn subn) |
506 | "Returns true if SUBN is a (non-strict) subnet of IPN." | |
32ebbe9b MW |
507 | (with-ipnet (net addr mask) ipn |
508 | (with-ipnet (subnet subaddr submask) subn | |
509 | (and (ipaddr-comparable-p net subnet) | |
510 | (= addr (logand subaddr mask)) | |
9c44003b MW |
511 | (= submask (logior mask submask)))))) |
512 | ||
32ebbe9b MW |
513 | (export 'ipnet-overlapp) |
514 | (defun ipnet-overlapp (ipn-a ipn-b) | |
515 | "Returns true if IPN-A and IPN-B have any addresses in common." | |
516 | (with-ipnet (net-a addr-a mask-a) ipn-a | |
517 | (with-ipnet (net-b addr-b mask-b) ipn-b | |
518 | ||
519 | ;; In the case of an overlap, we explicitly construct a common | |
520 | ;; address. If this fails, we know that the networks don't overlap | |
521 | ;; after all. | |
522 | (flet ((narrow (addr-a mask-a addr-b mask-b) | |
523 | ;; Narrow network A towards B, by setting bits in A's base | |
524 | ;; address towards which A is indifferent, but B is not; | |
525 | ;; return the resulting base address. This address is still | |
526 | ;; within network A, since we only set bits to which A is | |
527 | ;; indifferent. | |
528 | (logior addr-a (logand addr-b (logandc2 mask-a mask-b))))) | |
529 | ||
530 | (and (ipaddr-comparable-p net-a net-b) | |
531 | (= (narrow addr-a mask-a addr-b mask-b) | |
532 | (narrow addr-b mask-b addr-a mask-a))))))) | |
533 | ||
534 | (export 'ipnet-changeable-bits) | |
535 | (defun ipnet-changeable-bits (width mask) | |
536 | "Work out the number of changeable bits in a network, given its MASK. | |
537 | ||
538 | This is a conservative estimate in the case of noncontiguous masks. The | |
539 | WIDTH is the total width of an address." | |
540 | ||
541 | ;; We bisect the address. If the low-order bits are changeable then we | |
542 | ;; recurse on them; otherwise we look at the high-order bits. A mask M of | |
543 | ;; width W is changeable if it's not all-ones, i.e., if M /= 2^W. If the | |
544 | ;; top half is changeable then we don't need to look at the bottom half. | |
545 | (labels ((recurse (width mask offset) | |
546 | (if (= width 1) | |
547 | (if (zerop mask) (1+ offset) offset) | |
548 | (let* ((lowwidth (floor width 2)) | |
549 | (highwidth (- width lowwidth)) | |
550 | (highmask (ash mask (- lowwidth)))) | |
551 | (if (logbitp highwidth (1+ highmask)) | |
552 | (recurse lowwidth | |
553 | (logand mask (mask lowwidth)) | |
554 | offset) | |
555 | (recurse highwidth highmask (+ offset lowwidth))))))) | |
556 | (recurse width mask 0))) | |
9c44003b MW |
557 | |
558 | ;;;-------------------------------------------------------------------------- | |
32ebbe9b MW |
559 | ;;; Reverse lookups. |
560 | ||
561 | (export 'reverse-domain-component-width) | |
562 | (defgeneric reverse-domain-component-width (ipaddr) | |
563 | (:documentation "Return the component width for splitting IPADDR.")) | |
564 | ||
565 | (export 'reverse-domain-component-radix) | |
566 | (defgeneric reverse-domain-radix (ipaddr) | |
567 | (:documentation "Return the radix for representing IPADDR components.")) | |
568 | ||
569 | (export 'reverse-domain-component-suffix) | |
570 | (defgeneric reverse-domain-suffix (ipaddr) | |
571 | (:documentation "Return the reverse-lookup domain suffix for IPADDR.")) | |
572 | ||
573 | (export 'reverse-domain-fragment) | |
574 | (defgeneric reverse-domain-fragment (ipaddr start end &key partialp) | |
575 | (:documentation | |
576 | "Return a portion of an IPADDR's reverse-resolution domain name. | |
577 | ||
578 | Specifically, return the portion of the name which covers the bits of an | |
579 | IPADDR between bits START (inclusive) and END (exclusive). Address | |
580 | components which are only partially within the given bounds are included | |
581 | unless PARTIALP is nil.") | |
582 | (:method ((ipaddr ipaddr) start end &key (partialp t)) | |
583 | ||
584 | (let ((addr (ipaddr-addr ipaddr)) | |
585 | (comp-width (reverse-domain-component-width ipaddr)) | |
586 | (radix (reverse-domain-radix ipaddr))) | |
587 | ||
588 | (with-output-to-string (out) | |
589 | (do ((i (funcall (if partialp #'round-down #'round-up) | |
590 | start comp-width) | |
591 | (+ i comp-width)) | |
592 | (limit (funcall (if partialp #'round-up #'round-down) | |
593 | end comp-width)) | |
594 | (sep nil t)) | |
595 | ((>= i limit)) | |
596 | (format out "~:[~;.~]~(~vR~)" | |
597 | sep radix (ldb (byte comp-width i) addr))))))) | |
598 | ||
599 | (export 'reverse-domain) | |
600 | (defgeneric reverse-domain (ipaddr-or-ipn &optional prefix-len) | |
601 | (:documentation "Return a reverse-resolution domain name for IPADDR-OR-IPN. | |
602 | ||
603 | If PREFIX-LEN is nil then it defaults to the length of the network's fixed | |
604 | prefix.") | |
605 | (:method ((ipn ipnet) &optional prefix-len) | |
606 | (let* ((addr (ipnet-net ipn)) | |
607 | (mask (ipnet-mask ipn)) | |
608 | (width (ipaddr-width addr))) | |
609 | (concatenate 'string | |
610 | (reverse-domain-fragment | |
611 | addr | |
612 | (if prefix-len | |
613 | (- width prefix-len) | |
614 | (ipnet-changeable-bits width mask)) | |
615 | width | |
616 | :partialp nil) | |
617 | "." | |
618 | (reverse-domain-suffix addr)))) | |
619 | (:method ((addr ipaddr) &optional prefix-len) | |
620 | (let* ((width (ipaddr-width addr))) | |
621 | (reverse-domain (make-ipnet addr (mask width)) | |
622 | (or prefix-len width))))) | |
9c44003b MW |
623 | |
624 | ;;;-------------------------------------------------------------------------- | |
625 | ;;; Network names and specifiers. | |
626 | ||
e1528fd6 | 627 | (export 'net) |
32ebbe9b MW |
628 | (export 'net-name) |
629 | (export 'net-ipnets) | |
630 | (defclass net () | |
631 | ((name :type string :initarg :name :reader net-name) | |
632 | (ipnets :type list :initarg :ipnets :initform nil :accessor net-ipnets) | |
633 | (next :type unsigned-byte :initform 1 :accessor net-next))) | |
634 | ||
635 | (defmethod print-object ((net net) stream) | |
636 | (print-unreadable-object (net stream :type t) | |
637 | (format stream "~A~@[ = ~{~A~^, ~}~]" | |
638 | (net-name net) | |
639 | (mapcar #'ipnet-string (net-ipnets net))))) | |
9c44003b MW |
640 | |
641 | (defvar *networks* (make-hash-table :test #'equal) | |
642 | "The table of known networks.") | |
643 | ||
e1528fd6 | 644 | (export 'net-find) |
9c44003b MW |
645 | (defun net-find (name) |
646 | "Find a network by NAME." | |
647 | (gethash (string-downcase (stringify name)) *networks*)) | |
9c44003b MW |
648 | (defun (setf net-find) (net name) |
649 | "Make NAME map to NET." | |
650 | (setf (gethash (string-downcase (stringify name)) *networks*) net)) | |
651 | ||
32ebbe9b MW |
652 | (export 'net-must-find) |
653 | (defun net-must-find (name) | |
654 | (or (net-find name) | |
655 | (error "Unknown network ~A." name))) | |
656 | ||
657 | (defun net-ipnet (net family) | |
658 | (find family (net-ipnets net) :key #'ipnet-family)) | |
659 | (defun (setf net-ipnet) (ipnet net family) | |
660 | (assert (eq (ipnet-family ipnet) family)) | |
661 | (let ((ipns (net-ipnets net))) | |
662 | (if (find family ipns :key #'ipnet-family) | |
663 | (nsubstitute ipnet family ipns :key #'ipnet-family) | |
664 | (setf (net-ipnets net) (cons ipnet ipns))))) | |
665 | ||
666 | (defun process-net-form (name addr subnets) | |
f4e0c48f MW |
667 | "Unpack a net-form. |
668 | ||
32ebbe9b MW |
669 | A net-form looks like (NAME ADDR [SUBNET ...]) where: |
670 | ||
671 | * NAME is the name for the network. | |
672 | ||
673 | * ADDR is the subnet address (acceptable to `string-subipnet'); at | |
674 | top-level, this is a plain network address (acceptable to | |
675 | `string-ipnet'). Alternatively (for compatibility) the ADDR for a | |
676 | non-top-level network can be an integer number of addresses to | |
677 | allocate to this subnet; the subnet's base address is implicitly just | |
678 | past the previous subnet's limit address (or, for the first subnet, | |
679 | it's the parent network's base address). This won't work at all well | |
680 | if your subnets have crazy netmasks. | |
681 | ||
682 | * The SUBNETs are further net-forms, of the same form, whose addresses | |
683 | are interpreted relative to the parent network's address. | |
684 | ||
685 | The return value is a list of items of the form (NAME . IPNET)." | |
686 | ||
687 | (labels ((process-subnets (subnets parent) | |
688 | (let ((finger (ipnet-addr parent)) | |
689 | (list nil)) | |
690 | (dolist (subnet subnets list) | |
691 | (destructuring-bind (name addr &rest subs) subnet | |
692 | (let ((net (etypecase addr | |
693 | (integer | |
694 | (when (or (> (count-low-zero-bits addr) | |
695 | (count-low-zero-bits finger)) | |
696 | (not (zerop (logand addr | |
697 | (1- addr))))) | |
698 | (error "Bad subnet size for ~A." name)) | |
699 | (make-ipnet | |
700 | (ipaddr finger (ipnet-net parent)) | |
701 | (ipaddr (- (ash 1 (ipnet-width parent)) | |
702 | addr) | |
703 | (ipnet-net parent)))) | |
704 | ((or string symbol) | |
705 | (string-subipnet parent addr))))) | |
706 | ||
707 | (unless (ipnet-subnetp parent net) | |
708 | (error "Network `~A' (~A) falls outside parent ~A." | |
709 | name (ipnet-string net) (ipnet-string parent))) | |
710 | ||
711 | (dolist (entry list nil) | |
712 | (let ((ipn (cdr entry))) | |
713 | (when (ipnet-overlapp ipn net) | |
714 | (error "Network `~A' (~A) overlaps `~A' (~A)." | |
715 | name (ipnet-string net) | |
716 | (car entry) (ipnet-string ipn))))) | |
717 | ||
718 | (setf finger | |
719 | (1+ (logior | |
720 | (ipnet-addr net) | |
721 | (logxor (ipnet-mask net) | |
722 | (1- (ash 1 (ipnet-width net))))))) | |
723 | ||
724 | (when name | |
725 | (push (cons name net) list)) | |
726 | ||
727 | (when subs | |
728 | (setf list (nconc (process-subnets subs net) | |
729 | list))))))))) | |
730 | ||
731 | (let* ((top (string-ipnet addr)) | |
732 | (list (nreverse (process-subnets subnets top)))) | |
733 | (when name (push (cons name top) list)) | |
734 | list))) | |
9c44003b | 735 | |
e1528fd6 | 736 | (export 'net-create) |
9c44003b | 737 | (defun net-create (name net) |
f4e0c48f MW |
738 | "Construct a new network called NAME and add it to the map. |
739 | ||
32ebbe9b MW |
740 | The NET describes the new network, in a form acceptable to the `ipnet' |
741 | function. A named network may have multiple addresses with different | |
742 | families: each `net-create' call adds a new family, or modifies the net's | |
743 | address in an existing family." | |
744 | (let ((ipn (ipnet net)) | |
745 | (net (net-find name))) | |
746 | (if net | |
747 | (progn (setf (net-ipnet net (ipnet-family ipn)) ipn) net) | |
748 | (setf (net-find name) | |
749 | (make-instance 'net | |
750 | :name (string-downcase (stringify name)) | |
751 | :ipnets (list ipn)))))) | |
9c44003b | 752 | |
e1528fd6 | 753 | (export 'defnet) |
9c44003b | 754 | (defmacro defnet (name net &rest subnets) |
f4e0c48f MW |
755 | "Main network definition macro. |
756 | ||
757 | None of the arguments is evaluated." | |
9c44003b | 758 | `(progn |
32ebbe9b MW |
759 | ,@(mapcar (lambda (item) |
760 | (let ((name (car item)) (ipn (cdr item))) | |
761 | `(net-create ',name ',ipn))) | |
762 | (process-net-form name net subnets)) | |
763 | ',name)) | |
764 | ||
765 | (export 'net-parse-to-ipnets) | |
766 | (defun net-parse-to-ipnets (form &optional (family t)) | |
767 | (flet ((hack (form family) | |
768 | (let* ((form (if (and (consp form) | |
769 | (endp (cdr form))) | |
770 | (car form) | |
771 | form)) | |
772 | (net (net-find form)) | |
773 | (ipns (if net (net-ipnets net) | |
774 | (list (ipnet form))))) | |
775 | (if (eq family t) ipns | |
776 | (remove family ipns | |
777 | :key #'ipnet-family | |
778 | :test-not #'eq))))) | |
779 | (let* ((ipns (if (and (listp form) | |
780 | (every (lambda (clause) | |
781 | (and (listp clause) | |
782 | (symbolp (car clause)) | |
783 | (or (eq (car clause) t) | |
784 | (family-addrclass | |
785 | (car clause))))) | |
786 | form)) | |
787 | (mappend (lambda (clause) | |
788 | (hack (cdr clause) (car clause))) | |
789 | form) | |
790 | (hack form family))) | |
791 | (merged (reduce (lambda (ipns ipn) | |
792 | (if (find (ipnet-family ipn) ipns | |
793 | :key #'ipnet-family) | |
794 | ipns | |
795 | (cons ipn ipns))) | |
796 | ipns | |
797 | :initial-value nil))) | |
798 | (or merged (error "No matching addresses."))))) | |
9c44003b | 799 | |
e1528fd6 | 800 | (export 'net-host) |
32ebbe9b MW |
801 | (defun net-host (net-form host &optional (family t)) |
802 | "Return the given HOST on the NET, as an anonymous `host' object. | |
f4e0c48f MW |
803 | |
804 | HOST may be an index (in range, of course), or one of the keywords: | |
2f1d381d | 805 | |
32ebbe9b MW |
806 | :next next host, as by net-next-host |
807 | :net network base address | |
808 | :broadcast network broadcast address | |
809 | ||
810 | If FAMILY is not `t', then only return an address with that family; | |
811 | otherwise return all available addresses." | |
812 | (flet ((hosts (ipns host) | |
813 | (mapcar (lambda (ipn) (ipnet-host ipn host)) | |
814 | (remove host ipns :key #'ipnet-hosts :test-not #'<)))) | |
815 | (let* ((net (and (typep net-form '(or string symbol)) | |
816 | (net-find net-form))) | |
817 | (ipns (net-parse-to-ipnets net-form family)) | |
818 | (addrs (case host | |
819 | (:next | |
820 | (if net | |
821 | (prog1 (hosts ipns (net-next net)) | |
822 | (incf (net-next net))) | |
823 | (error "Can't use `:next' without a named net."))) | |
824 | (:net (mapcar #'ipnet-net ipns)) | |
825 | (:broadcast (remove nil (mapcar #'ipnet-broadcast ipns))) | |
826 | (t (hosts ipns host))))) | |
827 | (unless addrs | |
828 | (error "No networks have that address.")) | |
829 | (make-instance 'host :addrs addrs)))) | |
830 | ||
831 | ;;;-------------------------------------------------------------------------- | |
832 | ;;; Host names and specifiers. | |
833 | ||
834 | (export 'host) | |
835 | (export 'host-name) | |
836 | (export 'host-addrs) | |
837 | (defclass host () | |
838 | ((name :type (or string null) :initform nil | |
839 | :initarg :name :reader host-name) | |
840 | (addrs :type list :initarg :addrs :initform nil :accessor host-addrs))) | |
841 | ||
842 | (defmethod print-object ((host host) stream) | |
843 | (print-unreadable-object (host stream :type t) | |
844 | (format stream "~:[<anonymous>~;~@*~A~]~@[ = ~{~A~^, ~}~]" | |
845 | (host-name host) | |
846 | (mapcar #'ipaddr-string (host-addrs host))))) | |
847 | ||
848 | (defvar *hosts* (make-hash-table :test #'equal) | |
849 | "The table of known hostnames.") | |
850 | ||
851 | (export 'host-find) | |
852 | (defun host-find (name) | |
853 | "Find a host by NAME." | |
854 | (gethash (string-downcase (stringify name)) *hosts*)) | |
855 | (defun (setf host-find) (addr name) | |
856 | "Make NAME map to ADDR (must be an ipaddr in integer form)." | |
857 | (setf (gethash (string-downcase (stringify name)) *hosts*) addr)) | |
858 | ||
859 | (defun merge-addresses (addrs-a addrs-b) | |
860 | (append (remove-if (lambda (addr) | |
861 | (member (ipaddr-family addr) addrs-b | |
862 | :key #'ipaddr-family)) | |
863 | addrs-a) | |
864 | addrs-b)) | |
865 | ||
866 | (export 'host-parse) | |
867 | (defun host-parse (addr &optional (family t)) | |
868 | "Convert the ADDR into a (possibly anonymous) `host' object. | |
869 | ||
870 | The ADDR can be one of a number of different things. | |
871 | ||
872 | HOST a host name defined using `defhost' | |
873 | ||
874 | (NET INDEX) a particular host in a network | |
875 | ||
876 | IPADDR an address form acceptable to `ipnet' | |
877 | ||
878 | ((FAMILY . ADDR) ...) the above, restricted to a particular address | |
879 | FAMILY (i.e., one of the keywords `:ipv4', | |
880 | etc.)" | |
881 | ||
882 | (labels ((filter-addresses (addrs family) | |
883 | (make-instance 'host | |
884 | :addrs (if (eq family t) addrs | |
885 | (remove family addrs | |
886 | :key #'ipaddr-family | |
887 | :test-not #'eq)))) | |
888 | (host-addresses (host family) | |
889 | (if (eq family t) host | |
890 | (filter-addresses (host-addrs host) family))) | |
891 | (hack (addr family) | |
892 | (let* ((form (listify addr)) | |
893 | (indic (car form)) | |
894 | (host (and (null (cdr form)) | |
895 | (host-find indic)))) | |
896 | (cond (host | |
897 | (host-addresses host family)) | |
898 | ((and (consp (cdr form)) | |
899 | (endp (cddr form))) | |
900 | (net-host (car form) (cadr form) family)) | |
901 | (t | |
902 | (filter-addresses (list (ipaddr indic)) family)))))) | |
903 | (let ((host (cond | |
904 | ((not (eq family t)) | |
905 | (hack addr family)) | |
906 | ((and (listp addr) | |
907 | (every (lambda (clause) | |
908 | (and (listp clause) | |
909 | (symbolp (car clause)) | |
910 | (or (eq (car clause) t) | |
911 | (family-addrclass (car clause))))) | |
912 | addr)) | |
913 | (make-instance 'host | |
914 | :addrs (reduce #'merge-addresses | |
915 | (mapcar | |
916 | (lambda (clause) | |
917 | (host-addrs | |
918 | (hack (cdr clause) | |
919 | (car clause)))) | |
920 | (reverse addr)) | |
921 | :initial-value nil))) | |
922 | (t | |
923 | (hack addr t))))) | |
924 | (unless (host-addrs host) | |
925 | (error "No matching addresses.")) | |
926 | host))) | |
927 | ||
928 | (export 'host-create) | |
929 | (defun host-create (name addr) | |
930 | "Make host NAME map to ADDR (anything acceptable to `host-parse')." | |
931 | (let ((existing (host-find name)) | |
932 | (new (host-parse addr))) | |
933 | (if (not existing) | |
934 | (setf (host-find name) | |
935 | (make-instance 'host | |
936 | :name (string-downcase (stringify name)) | |
937 | :addrs (host-addrs new))) | |
938 | (progn | |
939 | (setf (host-addrs existing) | |
940 | (merge-addresses (host-addrs existing) (host-addrs new))) | |
941 | existing)))) | |
942 | ||
943 | (export 'defhost) | |
944 | (defmacro defhost (name addr) | |
945 | "Main host definition macro. Neither NAME nor ADDR is evaluated." | |
946 | `(progn | |
947 | (host-create ',name ',addr) | |
948 | ',name)) | |
9c44003b MW |
949 | |
950 | ;;;----- That's all, folks -------------------------------------------------- |