2 * Copyright (c) 1996 by Internet Software Consortium.
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
9 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
11 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
13 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
17 * $FreeBSD: src/lib/libc/net/ns_name.c,v 1.2 1999/08/28 00:00:14 peter Exp $
18 * $DragonFly: src/lib/libc/net/ns_name.c,v 1.3 2005/11/13 02:04:47 swildner Exp $
21 #include <sys/types.h>
23 #include <netinet/in.h>
24 #include <arpa/nameser.h>
32 static char digits
[] = "0123456789";
36 static int special(int);
37 static int printable(int);
38 static int dn_find(const u_char
*, const u_char
*,
39 const u_char
* const *,
40 const u_char
* const *);
45 * ns_name_ntop(src, dst, dstsiz)
46 * Convert an encoded domain name to printable ascii as per RFC1035.
48 * Number of bytes written to buffer, or -1 (with errno set)
50 * The root is returned as "."
51 * All other domains are returned in non absolute form
54 ns_name_ntop(const u_char
*src
, char *dst
, size_t dstsiz
) {
64 while ((n
= *cp
++) != 0) {
65 if ((n
& NS_CMPRSFLGS
) != 0) {
66 /* Some kind of compression pointer. */
90 } else if (!printable(c
)) {
96 *dn
++ = digits
[c
/ 100];
97 *dn
++ = digits
[(c
% 100) / 10];
98 *dn
++ = digits
[c
% 10];
124 * ns_name_pton(src, dst, dstsiz)
125 * Convert a ascii string into an encoded domain name as per RFC1035.
128 * 1 if string was fully qualified
129 * 0 is string was not fully qualified
131 * Enforces label and domain length limits.
135 ns_name_pton(const char *src
, u_char
*dst
, size_t dstsiz
) {
136 u_char
*label
, *bp
, *eom
;
145 while ((c
= *src
++) != 0) {
147 if ((cp
= strchr(digits
, c
)) != NULL
) {
148 n
= (cp
- digits
) * 100;
149 if ((c
= *src
++) == 0 ||
150 (cp
= strchr(digits
, c
)) == NULL
) {
154 n
+= (cp
- digits
) * 10;
155 if ((c
= *src
++) == 0 ||
156 (cp
= strchr(digits
, c
)) == NULL
) {
168 } else if (c
== '\\') {
171 } else if (c
== '.') {
172 c
= (bp
- label
- 1);
173 if ((c
& NS_CMPRSFLGS
) != 0) { /* Label too big. */
182 /* Fully qualified ? */
191 if ((bp
- dst
) > MAXCDNAME
) {
210 c
= (bp
- label
- 1);
211 if ((c
& NS_CMPRSFLGS
) != 0) { /* Label too big. */
227 if ((bp
- dst
) > MAXCDNAME
) { /* src too big */
235 * ns_name_unpack(msg, eom, src, dst, dstsiz)
236 * Unpack a domain name from a message, source may be compressed.
238 * -1 if it fails, or consumed octets if it succeeds.
241 ns_name_unpack(const u_char
*msg
, const u_char
*eom
, const u_char
*src
,
242 u_char
*dst
, size_t dstsiz
)
244 const u_char
*srcp
, *dstlim
;
252 dstlim
= dst
+ dstsiz
;
253 if (srcp
< msg
|| srcp
>= eom
) {
257 /* Fetch next label in domain name. */
258 while ((n
= *srcp
++) != 0) {
259 /* Check for indirection. */
260 switch (n
& NS_CMPRSFLGS
) {
263 if (dstp
+ n
+ 1 >= dstlim
|| srcp
+ n
>= eom
) {
269 memcpy(dstp
, srcp
, n
);
280 len
= srcp
- src
+ 1;
281 srcp
= msg
+ (((n
& 0x3f) << 8) | (*srcp
& 0xff));
282 if (srcp
< msg
|| srcp
>= eom
) { /* Out of range. */
288 * Check for loops in the compressed name;
289 * if we've looked at the whole message,
290 * there must be a loop.
292 if (checked
>= eom
- msg
) {
300 return (-1); /* flag error */
310 * ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr)
311 * Pack domain name 'domain' into 'comp_dn'.
313 * Size of the compressed name, or -1.
315 * 'dnptrs' is an array of pointers to previous compressed names.
316 * dnptrs[0] is a pointer to the beginning of the message. The array
318 * 'lastdnptr' is a pointer to the end of the array pointed to
321 * The list of pointers in dnptrs is updated for labels inserted into
322 * the message as we compress the name. If 'dnptr' is NULL, we don't
323 * try to compress names. If 'lastdnptr' is NULL, we don't update the
327 ns_name_pack(const u_char
*src
, u_char
*dst
, int dstsiz
,
328 const u_char
**dnptrs
, const u_char
**lastdnptr
)
331 const u_char
**cpp
, **lpp
, *eob
, *msg
;
339 if (dnptrs
!= NULL
) {
340 if ((msg
= *dnptrs
++) != NULL
) {
341 for (cpp
= dnptrs
; *cpp
!= NULL
; cpp
++)
343 lpp
= cpp
; /* end of list to search */
348 /* make sure the domain we are about to add is legal */
352 if ((n
& NS_CMPRSFLGS
) != 0) {
366 /* Look to see if we can use pointers. */
368 if (n
!= 0 && msg
!= NULL
) {
369 l
= dn_find(srcp
, msg
, (const u_char
* const *)dnptrs
,
370 (const u_char
* const *)lpp
);
372 if (dstp
+ 1 >= eob
) {
376 *dstp
++ = (l
>> 8) | NS_CMPRSFLGS
;
380 /* Not found, save it. */
381 if (lastdnptr
!= NULL
&& cpp
< lastdnptr
- 1 &&
382 (dstp
- msg
) < 0x4000) {
387 /* copy label to buffer */
388 if (n
& NS_CMPRSFLGS
) { /* Should not happen. */
392 if (dstp
+ 1 + n
>= eob
) {
396 memcpy(dstp
, srcp
, n
+ 1);
411 * ns_name_uncompress(msg, eom, src, dst, dstsiz)
412 * Expand compressed domain name to presentation format.
414 * Number of bytes read out of `src', or -1 (with errno set).
416 * Root domain returns as "." not "".
419 ns_name_uncompress(const u_char
*msg
, const u_char
*eom
, const u_char
*src
,
420 char *dst
, size_t dstsiz
)
422 u_char tmp
[NS_MAXCDNAME
];
425 if ((n
= ns_name_unpack(msg
, eom
, src
, tmp
, sizeof tmp
)) == -1)
427 if (ns_name_ntop(tmp
, dst
, dstsiz
) == -1)
433 * ns_name_compress(src, dst, dstsiz, dnptrs, lastdnptr)
434 * Compress a domain name into wire format, using compression pointers.
436 * Number of bytes consumed in `dst' or -1 (with errno set).
438 * 'dnptrs' is an array of pointers to previous compressed names.
439 * dnptrs[0] is a pointer to the beginning of the message.
440 * The list ends with NULL. 'lastdnptr' is a pointer to the end of the
441 * array pointed to by 'dnptrs'. Side effect is to update the list of
442 * pointers for labels inserted into the message as we compress the name.
443 * If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
444 * is NULL, we don't update the list.
447 ns_name_compress(const char *src
, u_char
*dst
, size_t dstsiz
,
448 const u_char
**dnptrs
, const u_char
**lastdnptr
)
450 u_char tmp
[NS_MAXCDNAME
];
452 if (ns_name_pton(src
, tmp
, sizeof tmp
) == -1)
454 return (ns_name_pack(tmp
, dst
, dstsiz
, dnptrs
, lastdnptr
));
458 * ns_name_skip(ptrptr, eom)
459 * Advance *ptrptr to skip over the compressed name it points at.
461 * 0 on success, -1 (with errno set) on failure.
464 ns_name_skip(const u_char
**ptrptr
, const u_char
*eom
) {
469 while (cp
< eom
&& (n
= *cp
++) != 0) {
470 /* Check for indirection. */
471 switch (n
& NS_CMPRSFLGS
) {
472 case 0: /* normal case, n == len */
475 case NS_CMPRSFLGS
: /* indirection */
478 default: /* illegal type */
496 * Thinking in noninternationalized USASCII (per the DNS spec),
497 * is this characted special ("in need of quoting") ?
507 case 0x5C: /* '\\' */
508 /* Special modifiers in zone files. */
519 * Thinking in noninternationalized USASCII (per the DNS spec),
520 * is this character visible and not a space when printed ?
526 return (ch
> 0x20 && ch
< 0x7f);
530 * Thinking in noninternationalized USASCII (per the DNS spec),
531 * convert this character to lower case if it's upper case.
535 if (ch
>= 0x41 && ch
<= 0x5A)
541 * dn_find(domain, msg, dnptrs, lastdnptr)
542 * Search for the counted-label name in an array of compressed names.
544 * offset from msg if found, or -1.
546 * dnptrs is the pointer to the first name on the list,
547 * not the pointer to the start of the message.
550 dn_find(const u_char
*domain
, const u_char
*msg
,
551 const u_char
* const *dnptrs
,
552 const u_char
* const *lastdnptr
)
554 const u_char
*dn
, *cp
, *sp
;
555 const u_char
* const *cpp
;
558 for (cpp
= dnptrs
; cpp
< lastdnptr
; cpp
++) {
561 while ((n
= *cp
++) != 0) {
563 * check for indirection
565 switch (n
& NS_CMPRSFLGS
) {
566 case 0: /* normal case, n == len */
570 if (mklower(*dn
++) != mklower(*cp
++))
572 /* Is next root for both ? */
573 if (*dn
== '\0' && *cp
== '\0')
579 case NS_CMPRSFLGS
: /* indirection */
580 cp
= msg
+ (((n
& 0x3f) << 8) | *cp
);
583 default: /* illegal type */