2 * Copyright (c) 1996,1999 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
18 #if !defined(_LIBC) && !defined(lint)
19 static const char rcsid[] = "$BINDId: ns_name.c,v 8.15 2000/03/30 22:53:46 vixie Exp $";
22 #include <sys/types.h>
24 #include <netinet/in.h>
25 #include <arpa/nameser.h>
35 static const char digits[] = "0123456789";
39 static int special(int);
40 static int printable(int);
41 static int dn_find(const u_char *, const u_char *,
42 const u_char * const *,
43 const u_char * const *);
48 * ns_name_ntop(src, dst, dstsiz)
49 * Convert an encoded domain name to printable ascii as per RFC1035.
51 * Number of bytes written to buffer, or -1 (with errno set)
53 * The root is returned as "."
54 * All other domains are returned in non absolute form
57 ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) {
67 while ((n = *cp++) != 0) {
68 if ((n & NS_CMPRSFLGS) != 0 && n != 0x41) {
69 /* Some kind of compression pointer. */
70 __set_errno (EMSGSIZE);
75 __set_errno (EMSGSIZE);
83 if (dn + n * 2 + 4 >= eom) {
84 __set_errno (EMSGSIZE);
94 *dn++ = u > 9 ? 'a' + u - 10 : '0' + u;
96 *dn++ = u > 9 ? 'a' + u - 10 : '0' + u;
104 __set_errno (EMSGSIZE);
107 for ((void)NULL; n > 0; n--) {
111 __set_errno (EMSGSIZE);
116 } else if (!printable(c)) {
118 __set_errno (EMSGSIZE);
122 *dn++ = digits[c / 100];
123 *dn++ = digits[(c % 100) / 10];
124 *dn++ = digits[c % 10];
127 __set_errno (EMSGSIZE);
136 __set_errno (EMSGSIZE);
142 __set_errno (EMSGSIZE);
148 libresolv_hidden_def (ns_name_ntop)
151 * ns_name_pton(src, dst, dstsiz)
152 * Convert a ascii string into an encoded domain name as per RFC1035.
155 * 1 if string was fully qualified
156 * 0 is string was not fully qualified
158 * Enforces label and domain length limits.
162 ns_name_pton(const char *src, u_char *dst, size_t dstsiz) {
163 u_char *label, *bp, *eom;
172 while ((c = *src++) != 0) {
174 if ((cp = strchr(digits, c)) != NULL) {
175 n = (cp - digits) * 100;
176 if ((c = *src++) == 0 ||
177 (cp = strchr(digits, c)) == NULL) {
178 __set_errno (EMSGSIZE);
181 n += (cp - digits) * 10;
182 if ((c = *src++) == 0 ||
183 (cp = strchr(digits, c)) == NULL) {
184 __set_errno (EMSGSIZE);
189 __set_errno (EMSGSIZE);
193 } else if (c == '[' && label == bp - 1 && *src == 'x') {
194 /* Theoretically we would have to handle \[o
195 as well but we do not since we do not need
200 while (isxdigit (*src)) {
201 n = *src > '9' ? *src - 'a' + 10 : *src - '0';
203 if (! isxdigit(*src)) {
204 __set_errno (EMSGSIZE);
208 n += *src > '9' ? *src - 'a' + 10 : *src - '0';
210 __set_errno (EMSGSIZE);
216 *label = (bp - label - 1) * 8;
217 if (*src++ != ']' || *src++ != '.') {
218 __set_errno (EMSGSIZE);
224 __set_errno (EMSGSIZE);
230 } else if (c == '\\') {
233 } else if (c == '.') {
234 c = (bp - label - 1);
235 if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */
236 __set_errno (EMSGSIZE);
240 __set_errno (EMSGSIZE);
244 /* Fully qualified ? */
248 __set_errno (EMSGSIZE);
253 if ((bp - dst) > MAXCDNAME) {
254 __set_errno (EMSGSIZE);
259 if (c == 0 || *src == '.') {
260 __set_errno (EMSGSIZE);
267 __set_errno (EMSGSIZE);
272 c = (bp - label - 1);
273 if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */
274 __set_errno (EMSGSIZE);
278 __set_errno (EMSGSIZE);
284 __set_errno (EMSGSIZE);
289 if ((bp - dst) > MAXCDNAME) { /* src too big */
290 __set_errno (EMSGSIZE);
297 * ns_name_ntol(src, dst, dstsiz)
298 * Convert a network strings labels into all lowercase.
300 * Number of bytes written to buffer, or -1 (with errno set)
302 * Enforces label and domain length limits.
306 ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz) {
316 while ((n = *cp++) != 0) {
317 if ((n & NS_CMPRSFLGS) != 0) {
318 /* Some kind of compression pointer. */
319 __set_errno (EMSGSIZE);
324 __set_errno (EMSGSIZE);
327 for ((void)NULL; n > 0; n--) {
340 * ns_name_unpack(msg, eom, src, dst, dstsiz)
341 * Unpack a domain name from a message, source may be compressed.
343 * -1 if it fails, or consumed octets if it succeeds.
346 ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
347 u_char *dst, size_t dstsiz)
349 const u_char *srcp, *dstlim;
357 dstlim = dst + dstsiz;
358 if (srcp < msg || srcp >= eom) {
359 __set_errno (EMSGSIZE);
362 /* Fetch next label in domain name. */
363 while ((n = *srcp++) != 0) {
364 /* Check for indirection. */
365 switch (n & NS_CMPRSFLGS) {
368 if (dstp + 1 >= dstlim) {
369 __set_errno (EMSGSIZE);
376 __set_errno (EMSGSIZE);
377 return (-1); /* flag error */
382 if (dstp + n + 1 >= dstlim || srcp + n >= eom) {
383 __set_errno (EMSGSIZE);
387 dstp = mempcpy(dstp, srcp - 1, n + 1);
393 __set_errno (EMSGSIZE);
397 len = srcp - src + 1;
398 srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
399 if (srcp < msg || srcp >= eom) { /* Out of range. */
400 __set_errno (EMSGSIZE);
405 * Check for loops in the compressed name;
406 * if we've looked at the whole message,
407 * there must be a loop.
409 if (checked >= eom - msg) {
410 __set_errno (EMSGSIZE);
416 __set_errno (EMSGSIZE);
417 return (-1); /* flag error */
425 libresolv_hidden_def (ns_name_unpack)
428 * ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr)
429 * Pack domain name 'domain' into 'comp_dn'.
431 * Size of the compressed name, or -1.
433 * 'dnptrs' is an array of pointers to previous compressed names.
434 * dnptrs[0] is a pointer to the beginning of the message. The array
436 * 'lastdnptr' is a pointer to the end of the array pointed to
439 * The list of pointers in dnptrs is updated for labels inserted into
440 * the message as we compress the name. If 'dnptr' is NULL, we don't
441 * try to compress names. If 'lastdnptr' is NULL, we don't update the
445 ns_name_pack(const u_char *src, u_char *dst, int dstsiz,
446 const u_char **dnptrs, const u_char **lastdnptr)
449 const u_char **cpp, **lpp, *eob, *msg;
457 if (dnptrs != NULL) {
458 if ((msg = *dnptrs++) != NULL) {
459 for (cpp = dnptrs; *cpp != NULL; cpp++)
461 lpp = cpp; /* end of list to search */
466 /* make sure the domain we are about to add is legal */
470 if ((n & NS_CMPRSFLGS) != 0 && n != 0x41) {
471 __set_errno (EMSGSIZE);
478 __set_errno (EMSGSIZE);
484 /* from here on we need to reset compression pointer array on error */
487 /* Look to see if we can use pointers. */
489 if (n != 0 && n != 0x41 && msg != NULL) {
490 l = dn_find(srcp, msg, (const u_char * const *)dnptrs,
491 (const u_char * const *)lpp);
493 if (dstp + 1 >= eob) {
496 *dstp++ = (l >> 8) | NS_CMPRSFLGS;
500 /* Not found, save it. */
501 if (lastdnptr != NULL && cpp < lastdnptr - 1 &&
502 (dstp - msg) < 0x4000 && first) {
508 /* copy label to buffer */
509 if ((n & NS_CMPRSFLGS) != 0 && n != 0x41) { /* Should not happen. */
518 if (dstp + 1 + n >= eob) {
521 memcpy(dstp, srcp, n + 1);
530 __set_errno (EMSGSIZE);
537 * ns_name_uncompress(msg, eom, src, dst, dstsiz)
538 * Expand compressed domain name to presentation format.
540 * Number of bytes read out of `src', or -1 (with errno set).
542 * Root domain returns as "." not "".
545 ns_name_uncompress(const u_char *msg, const u_char *eom, const u_char *src,
546 char *dst, size_t dstsiz)
548 u_char tmp[NS_MAXCDNAME];
551 if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
553 if (ns_name_ntop(tmp, dst, dstsiz) == -1)
559 * ns_name_compress(src, dst, dstsiz, dnptrs, lastdnptr)
560 * Compress a domain name into wire format, using compression pointers.
562 * Number of bytes consumed in `dst' or -1 (with errno set).
564 * 'dnptrs' is an array of pointers to previous compressed names.
565 * dnptrs[0] is a pointer to the beginning of the message.
566 * The list ends with NULL. 'lastdnptr' is a pointer to the end of the
567 * array pointed to by 'dnptrs'. Side effect is to update the list of
568 * pointers for labels inserted into the message as we compress the name.
569 * If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
570 * is NULL, we don't update the list.
573 ns_name_compress(const char *src, u_char *dst, size_t dstsiz,
574 const u_char **dnptrs, const u_char **lastdnptr)
576 u_char tmp[NS_MAXCDNAME];
578 if (ns_name_pton(src, tmp, sizeof tmp) == -1)
580 return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));
584 * Reset dnptrs so that there are no active references to pointers at or
588 ns_name_rollback(const u_char *src, const u_char **dnptrs,
589 const u_char **lastdnptr)
591 while (dnptrs < lastdnptr && *dnptrs != NULL) {
592 if (*dnptrs >= src) {
601 * ns_name_skip(ptrptr, eom)
602 * Advance *ptrptr to skip over the compressed name it points at.
604 * 0 on success, -1 (with errno set) on failure.
607 ns_name_skip(const u_char **ptrptr, const u_char *eom) {
612 while (cp < eom && (n = *cp++) != 0) {
613 /* Check for indirection. */
614 switch (n & NS_CMPRSFLGS) {
615 case 0: /* normal case, n == len */
618 case NS_CMPRSFLGS: /* indirection */
621 default: /* illegal type */
622 __set_errno (EMSGSIZE);
628 __set_errno (EMSGSIZE);
639 * Thinking in noninternationalized USASCII (per the DNS spec),
640 * is this characted special ("in need of quoting") ?
650 case 0x5C: /* '\\' */
651 /* Special modifiers in zone files. */
662 * Thinking in noninternationalized USASCII (per the DNS spec),
663 * is this character visible and not a space when printed ?
669 return (ch > 0x20 && ch < 0x7f);
673 * Thinking in noninternationalized USASCII (per the DNS spec),
674 * convert this character to lower case if it's upper case.
678 if (ch >= 0x41 && ch <= 0x5A)
684 * dn_find(domain, msg, dnptrs, lastdnptr)
685 * Search for the counted-label name in an array of compressed names.
687 * offset from msg if found, or -1.
689 * dnptrs is the pointer to the first name on the list,
690 * not the pointer to the start of the message.
693 dn_find(const u_char *domain, const u_char *msg,
694 const u_char * const *dnptrs,
695 const u_char * const *lastdnptr)
697 const u_char *dn, *cp, *sp;
698 const u_char * const *cpp;
701 for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
704 * terminate search on:
706 * compression pointer
709 while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 &&
710 (sp - msg) < 0x4000) {
713 while ((n = *cp++) != 0) {
715 * check for indirection
717 switch (n & NS_CMPRSFLGS) {
718 case 0: /* normal case, n == len */
721 for ((void)NULL; n > 0; n--)
722 if (mklower(*dn++) !=
725 /* Is next root for both ? */
726 if (*dn == '\0' && *cp == '\0')
732 case NS_CMPRSFLGS: /* indirection */
733 cp = msg + (((n & 0x3f) << 8) | *cp);
736 default: /* illegal type */
737 __set_errno (EMSGSIZE);
745 __set_errno (ENOENT);