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971 lines
21 KiB
C
971 lines
21 KiB
C
/*
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* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
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* Copyright (c) 1996,1999 by Internet Software Consortium.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
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* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <sys/types.h>
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#include <netinet/in.h>
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#include <arpa/nameser.h>
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#include <errno.h>
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#include <resolv.h>
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#include <string.h>
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#include <ctype.h>
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#include <stdlib.h>
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#include <limits.h>
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# define SPRINTF(x) ((size_t)sprintf x)
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#define NS_TYPE_ELT 0x40 /*%< EDNS0 extended label type */
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#define DNS_LABELTYPE_BITSTRING 0x41
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/* Data. */
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static const char digits[] = "0123456789";
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static const char digitvalue[256] = {
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*16*/
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*32*/
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*48*/
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /*64*/
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-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*80*/
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*96*/
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-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*112*/
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*128*/
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*256*/
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};
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/* Forward. */
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static int special(int);
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static int printable(int);
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static int dn_find(const u_char *, const u_char *,
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const u_char * const *,
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const u_char * const *);
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static int encode_bitstring(const char **, const char *,
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unsigned char **, unsigned char **,
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unsigned const char *);
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static int labellen(const u_char *);
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static int decode_bitstring(const unsigned char **,
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char *, const char *);
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/* Public. */
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/*%
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* Convert an encoded domain name to printable ascii as per RFC1035.
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* return:
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*\li Number of bytes written to buffer, or -1 (with errno set)
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*
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* notes:
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*\li The root is returned as "."
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*\li All other domains are returned in non absolute form
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*/
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int
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ns_name_ntop(const u_char *src, char *dst, size_t dstsiz)
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{
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const u_char *cp;
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char *dn, *eom;
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u_char c;
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u_int n;
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int l;
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cp = src;
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dn = dst;
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eom = dst + dstsiz;
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while ((n = *cp++) != 0) {
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if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
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/* Some kind of compression pointer. */
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__set_errno (EMSGSIZE);
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return (-1);
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}
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if (dn != dst) {
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if (dn >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*dn++ = '.';
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}
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if ((l = labellen(cp - 1)) < 0) {
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__set_errno (EMSGSIZE);
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return(-1);
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}
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if (dn + l >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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if ((n & NS_CMPRSFLGS) == NS_TYPE_ELT) {
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int m;
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if (n != DNS_LABELTYPE_BITSTRING) {
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/* XXX: labellen should reject this case */
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__set_errno (EINVAL);
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return(-1);
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}
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if ((m = decode_bitstring(&cp, dn, eom)) < 0)
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{
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__set_errno (EMSGSIZE);
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return(-1);
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}
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dn += m;
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continue;
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}
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for ((void)NULL; l > 0; l--) {
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c = *cp++;
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if (special(c)) {
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if (dn + 1 >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*dn++ = '\\';
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*dn++ = (char)c;
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} else if (!printable(c)) {
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if (dn + 3 >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*dn++ = '\\';
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*dn++ = digits[c / 100];
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*dn++ = digits[(c % 100) / 10];
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*dn++ = digits[c % 10];
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} else {
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if (dn >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*dn++ = (char)c;
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}
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}
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}
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if (dn == dst) {
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if (dn >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*dn++ = '.';
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}
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if (dn >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*dn++ = '\0';
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return (dn - dst);
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}
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libresolv_hidden_def (ns_name_ntop)
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strong_alias (ns_name_ntop, __ns_name_ntop)
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/*%
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* Convert an ascii string into an encoded domain name as per RFC1035.
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*
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* return:
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*
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*\li -1 if it fails
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*\li 1 if string was fully qualified
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*\li 0 is string was not fully qualified
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*
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* notes:
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*\li Enforces label and domain length limits.
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*/
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int
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ns_name_pton(const char *src, u_char *dst, size_t dstsiz)
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{
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u_char *label, *bp, *eom;
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int c, n, escaped, e = 0;
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char *cp;
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escaped = 0;
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bp = dst;
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eom = dst + dstsiz;
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label = bp++;
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while ((c = *src++) != 0) {
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if (escaped) {
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if (c == '[') { /*%< start a bit string label */
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if ((cp = strchr(src, ']')) == NULL) {
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__set_errno (EINVAL);
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return(-1);
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}
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if ((e = encode_bitstring(&src, cp + 2,
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&label, &bp, eom))
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!= 0) {
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__set_errno (e);
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return(-1);
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}
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escaped = 0;
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label = bp++;
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if ((c = *src++) == 0)
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goto done;
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else if (c != '.') {
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__set_errno (EINVAL);
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return(-1);
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}
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continue;
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}
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else if ((cp = strchr(digits, c)) != NULL) {
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n = (cp - digits) * 100;
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if ((c = *src++) == 0 ||
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(cp = strchr(digits, c)) == NULL) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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n += (cp - digits) * 10;
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if ((c = *src++) == 0 ||
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(cp = strchr(digits, c)) == NULL) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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n += (cp - digits);
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if (n > 255) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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c = n;
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}
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escaped = 0;
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} else if (c == '\\') {
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escaped = 1;
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continue;
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} else if (c == '.') {
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c = (bp - label - 1);
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if ((c & NS_CMPRSFLGS) != 0) { /*%< Label too big. */
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__set_errno (EMSGSIZE);
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return (-1);
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}
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if (label >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*label = c;
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/* Fully qualified ? */
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if (*src == '\0') {
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if (c != 0) {
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if (bp >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*bp++ = '\0';
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}
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if ((bp - dst) > MAXCDNAME) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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return (1);
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}
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if (c == 0 || *src == '.') {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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label = bp++;
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continue;
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}
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if (bp >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*bp++ = (u_char)c;
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}
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c = (bp - label - 1);
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if ((c & NS_CMPRSFLGS) != 0) { /*%< Label too big. */
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__set_errno (EMSGSIZE);
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return (-1);
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}
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done:
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if (label >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*label = c;
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if (c != 0) {
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if (bp >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*bp++ = 0;
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}
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if ((bp - dst) > MAXCDNAME) { /*%< src too big */
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__set_errno (EMSGSIZE);
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return (-1);
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}
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return (0);
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}
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libresolv_hidden_def (ns_name_pton)
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/*%
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* Convert a network strings labels into all lowercase.
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*
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* return:
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*\li Number of bytes written to buffer, or -1 (with errno set)
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*
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* notes:
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*\li Enforces label and domain length limits.
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*/
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int
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ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz)
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{
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const u_char *cp;
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u_char *dn, *eom;
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u_char c;
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u_int n;
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int l;
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cp = src;
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dn = dst;
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eom = dst + dstsiz;
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if (dn >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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while ((n = *cp++) != 0) {
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if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
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/* Some kind of compression pointer. */
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__set_errno (EMSGSIZE);
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return (-1);
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}
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*dn++ = n;
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if ((l = labellen(cp - 1)) < 0) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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if (dn + l >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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for ((void)NULL; l > 0; l--) {
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c = *cp++;
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if (isupper(c))
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*dn++ = tolower(c);
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else
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*dn++ = c;
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}
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}
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*dn++ = '\0';
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return (dn - dst);
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}
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/*%
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* Unpack a domain name from a message, source may be compressed.
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*
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* return:
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*\li -1 if it fails, or consumed octets if it succeeds.
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*/
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int
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ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
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u_char *dst, size_t dstsiz)
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{
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const u_char *srcp, *dstlim;
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u_char *dstp;
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int n, len, checked, l;
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len = -1;
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checked = 0;
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dstp = dst;
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srcp = src;
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dstlim = dst + dstsiz;
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if (srcp < msg || srcp >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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/* Fetch next label in domain name. */
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while ((n = *srcp++) != 0) {
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/* Check for indirection. */
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switch (n & NS_CMPRSFLGS) {
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case 0:
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case NS_TYPE_ELT:
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/* Limit checks. */
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if ((l = labellen(srcp - 1)) < 0) {
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__set_errno (EMSGSIZE);
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return(-1);
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}
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if (dstp + l + 1 >= dstlim || srcp + l >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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checked += l + 1;
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*dstp++ = n;
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memcpy(dstp, srcp, l);
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dstp += l;
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srcp += l;
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break;
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case NS_CMPRSFLGS:
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if (srcp >= eom) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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if (len < 0)
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len = srcp - src + 1;
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srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
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if (srcp < msg || srcp >= eom) { /*%< Out of range. */
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__set_errno (EMSGSIZE);
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return (-1);
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}
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checked += 2;
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/*
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* Check for loops in the compressed name;
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* if we've looked at the whole message,
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* there must be a loop.
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*/
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if (checked >= eom - msg) {
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__set_errno (EMSGSIZE);
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return (-1);
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}
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break;
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default:
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__set_errno (EMSGSIZE);
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return (-1); /*%< flag error */
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}
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}
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*dstp = '\0';
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if (len < 0)
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len = srcp - src;
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return (len);
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}
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libresolv_hidden_def (ns_name_unpack)
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strong_alias (ns_name_unpack, __ns_name_unpack)
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|
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/*%
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* Pack domain name 'domain' into 'comp_dn'.
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*
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* return:
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*\li Size of the compressed name, or -1.
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*
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* notes:
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*\li 'dnptrs' is an array of pointers to previous compressed names.
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*\li dnptrs[0] is a pointer to the beginning of the message. The array
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* ends with NULL.
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*\li 'lastdnptr' is a pointer to the end of the array pointed to
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* by 'dnptrs'.
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*
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* Side effects:
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*\li The list of pointers in dnptrs is updated for labels inserted into
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* the message as we compress the name. If 'dnptr' is NULL, we don't
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* try to compress names. If 'lastdnptr' is NULL, we don't update the
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* list.
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*/
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int
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ns_name_pack(const u_char *src, u_char *dst, int dstsiz,
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const u_char **dnptrs, const u_char **lastdnptr)
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{
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u_char *dstp;
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const u_char **cpp, **lpp, *eob, *msg;
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const u_char *srcp;
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int n, l, first = 1;
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srcp = src;
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dstp = dst;
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eob = dstp + dstsiz;
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lpp = cpp = NULL;
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if (dnptrs != NULL) {
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if ((msg = *dnptrs++) != NULL) {
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for (cpp = dnptrs; *cpp != NULL; cpp++)
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(void)NULL;
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lpp = cpp; /*%< end of list to search */
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}
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} else
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msg = NULL;
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|
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/* make sure the domain we are about to add is legal */
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l = 0;
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do {
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int l0;
|
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|
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n = *srcp;
|
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if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
|
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__set_errno (EMSGSIZE);
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return (-1);
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}
|
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if ((l0 = labellen(srcp)) < 0) {
|
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__set_errno (EINVAL);
|
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return(-1);
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}
|
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l += l0 + 1;
|
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if (l > MAXCDNAME) {
|
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__set_errno (EMSGSIZE);
|
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return (-1);
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}
|
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srcp += l0 + 1;
|
|
} while (n != 0);
|
|
|
|
/* from here on we need to reset compression pointer array on error */
|
|
srcp = src;
|
|
do {
|
|
/* Look to see if we can use pointers. */
|
|
n = *srcp;
|
|
if (n != 0 && msg != NULL) {
|
|
l = dn_find(srcp, msg, (const u_char * const *)dnptrs,
|
|
(const u_char * const *)lpp);
|
|
if (l >= 0) {
|
|
if (dstp + 1 >= eob) {
|
|
goto cleanup;
|
|
}
|
|
*dstp++ = (l >> 8) | NS_CMPRSFLGS;
|
|
*dstp++ = l % 256;
|
|
return (dstp - dst);
|
|
}
|
|
/* Not found, save it. */
|
|
if (lastdnptr != NULL && cpp < lastdnptr - 1 &&
|
|
(dstp - msg) < 0x4000 && first) {
|
|
*cpp++ = dstp;
|
|
*cpp = NULL;
|
|
first = 0;
|
|
}
|
|
}
|
|
/* copy label to buffer */
|
|
if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
|
|
/* Should not happen. */
|
|
goto cleanup;
|
|
}
|
|
n = labellen(srcp);
|
|
if (dstp + 1 + n >= eob) {
|
|
goto cleanup;
|
|
}
|
|
memcpy(dstp, srcp, n + 1);
|
|
srcp += n + 1;
|
|
dstp += n + 1;
|
|
} while (n != 0);
|
|
|
|
if (dstp > eob) {
|
|
cleanup:
|
|
if (msg != NULL)
|
|
*lpp = NULL;
|
|
__set_errno (EMSGSIZE);
|
|
return (-1);
|
|
}
|
|
return (dstp - dst);
|
|
}
|
|
libresolv_hidden_def (ns_name_pack)
|
|
|
|
/*%
|
|
* Expand compressed domain name to presentation format.
|
|
*
|
|
* return:
|
|
*\li Number of bytes read out of `src', or -1 (with errno set).
|
|
*
|
|
* note:
|
|
*\li Root domain returns as "." not "".
|
|
*/
|
|
int
|
|
ns_name_uncompress(const u_char *msg, const u_char *eom, const u_char *src,
|
|
char *dst, size_t dstsiz)
|
|
{
|
|
u_char tmp[NS_MAXCDNAME];
|
|
int n;
|
|
|
|
if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
|
|
return (-1);
|
|
if (ns_name_ntop(tmp, dst, dstsiz) == -1)
|
|
return (-1);
|
|
return (n);
|
|
}
|
|
libresolv_hidden_def (ns_name_uncompress)
|
|
|
|
/*%
|
|
* Compress a domain name into wire format, using compression pointers.
|
|
*
|
|
* return:
|
|
*\li Number of bytes consumed in `dst' or -1 (with errno set).
|
|
*
|
|
* notes:
|
|
*\li 'dnptrs' is an array of pointers to previous compressed names.
|
|
*\li dnptrs[0] is a pointer to the beginning of the message.
|
|
*\li The list ends with NULL. 'lastdnptr' is a pointer to the end of the
|
|
* array pointed to by 'dnptrs'. Side effect is to update the list of
|
|
* pointers for labels inserted into the message as we compress the name.
|
|
*\li If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
|
|
* is NULL, we don't update the list.
|
|
*/
|
|
int
|
|
ns_name_compress(const char *src, u_char *dst, size_t dstsiz,
|
|
const u_char **dnptrs, const u_char **lastdnptr)
|
|
{
|
|
u_char tmp[NS_MAXCDNAME];
|
|
|
|
if (ns_name_pton(src, tmp, sizeof tmp) == -1)
|
|
return (-1);
|
|
return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));
|
|
}
|
|
libresolv_hidden_def (ns_name_compress)
|
|
|
|
/*%
|
|
* Reset dnptrs so that there are no active references to pointers at or
|
|
* after src.
|
|
*/
|
|
void
|
|
ns_name_rollback(const u_char *src, const u_char **dnptrs,
|
|
const u_char **lastdnptr)
|
|
{
|
|
while (dnptrs < lastdnptr && *dnptrs != NULL) {
|
|
if (*dnptrs >= src) {
|
|
*dnptrs = NULL;
|
|
break;
|
|
}
|
|
dnptrs++;
|
|
}
|
|
}
|
|
|
|
/*%
|
|
* Advance *ptrptr to skip over the compressed name it points at.
|
|
*
|
|
* return:
|
|
*\li 0 on success, -1 (with errno set) on failure.
|
|
*/
|
|
int
|
|
ns_name_skip(const u_char **ptrptr, const u_char *eom)
|
|
{
|
|
const u_char *cp;
|
|
u_int n;
|
|
int l;
|
|
|
|
cp = *ptrptr;
|
|
while (cp < eom && (n = *cp++) != 0) {
|
|
/* Check for indirection. */
|
|
switch (n & NS_CMPRSFLGS) {
|
|
case 0: /*%< normal case, n == len */
|
|
cp += n;
|
|
continue;
|
|
case NS_TYPE_ELT: /*%< EDNS0 extended label */
|
|
if ((l = labellen(cp - 1)) < 0) {
|
|
__set_errno (EMSGSIZE);
|
|
return(-1);
|
|
}
|
|
cp += l;
|
|
continue;
|
|
case NS_CMPRSFLGS: /*%< indirection */
|
|
cp++;
|
|
break;
|
|
default: /*%< illegal type */
|
|
__set_errno (EMSGSIZE);
|
|
return (-1);
|
|
}
|
|
break;
|
|
}
|
|
if (cp > eom) {
|
|
__set_errno (EMSGSIZE);
|
|
return (-1);
|
|
}
|
|
*ptrptr = cp;
|
|
return (0);
|
|
}
|
|
libresolv_hidden_def (ns_name_skip)
|
|
|
|
/* Private. */
|
|
|
|
/*%
|
|
* Thinking in noninternationalized USASCII (per the DNS spec),
|
|
* is this character special ("in need of quoting") ?
|
|
*
|
|
* return:
|
|
*\li boolean.
|
|
*/
|
|
static int
|
|
special(int ch) {
|
|
switch (ch) {
|
|
case 0x22: /*%< '"' */
|
|
case 0x2E: /*%< '.' */
|
|
case 0x3B: /*%< ';' */
|
|
case 0x5C: /*%< '\\' */
|
|
case 0x28: /*%< '(' */
|
|
case 0x29: /*%< ')' */
|
|
/* Special modifiers in zone files. */
|
|
case 0x40: /*%< '@' */
|
|
case 0x24: /*%< '$' */
|
|
return (1);
|
|
default:
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
/*%
|
|
* Thinking in noninternationalized USASCII (per the DNS spec),
|
|
* is this character visible and not a space when printed ?
|
|
*
|
|
* return:
|
|
*\li boolean.
|
|
*/
|
|
static int
|
|
printable(int ch) {
|
|
return (ch > 0x20 && ch < 0x7f);
|
|
}
|
|
|
|
/*%
|
|
* Thinking in noninternationalized USASCII (per the DNS spec),
|
|
* convert this character to lower case if it's upper case.
|
|
*/
|
|
static int
|
|
mklower(int ch) {
|
|
if (ch >= 0x41 && ch <= 0x5A)
|
|
return (ch + 0x20);
|
|
return (ch);
|
|
}
|
|
|
|
/*%
|
|
* Search for the counted-label name in an array of compressed names.
|
|
*
|
|
* return:
|
|
*\li offset from msg if found, or -1.
|
|
*
|
|
* notes:
|
|
*\li dnptrs is the pointer to the first name on the list,
|
|
*\li not the pointer to the start of the message.
|
|
*/
|
|
static int
|
|
dn_find(const u_char *domain, const u_char *msg,
|
|
const u_char * const *dnptrs,
|
|
const u_char * const *lastdnptr)
|
|
{
|
|
const u_char *dn, *cp, *sp;
|
|
const u_char * const *cpp;
|
|
u_int n;
|
|
|
|
for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
|
|
sp = *cpp;
|
|
/*
|
|
* terminate search on:
|
|
* root label
|
|
* compression pointer
|
|
* unusable offset
|
|
*/
|
|
while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 &&
|
|
(sp - msg) < 0x4000) {
|
|
dn = domain;
|
|
cp = sp;
|
|
while ((n = *cp++) != 0) {
|
|
/*
|
|
* check for indirection
|
|
*/
|
|
switch (n & NS_CMPRSFLGS) {
|
|
case 0: /*%< normal case, n == len */
|
|
n = labellen(cp - 1); /*%< XXX */
|
|
if (n != *dn++)
|
|
goto next;
|
|
|
|
for ((void)NULL; n > 0; n--)
|
|
if (mklower(*dn++) !=
|
|
mklower(*cp++))
|
|
goto next;
|
|
/* Is next root for both ? */
|
|
if (*dn == '\0' && *cp == '\0')
|
|
return (sp - msg);
|
|
if (*dn)
|
|
continue;
|
|
goto next;
|
|
case NS_CMPRSFLGS: /*%< indirection */
|
|
cp = msg + (((n & 0x3f) << 8) | *cp);
|
|
break;
|
|
|
|
default: /*%< illegal type */
|
|
__set_errno (EMSGSIZE);
|
|
return (-1);
|
|
}
|
|
}
|
|
next: ;
|
|
sp += *sp + 1;
|
|
}
|
|
}
|
|
__set_errno (ENOENT);
|
|
return (-1);
|
|
}
|
|
|
|
static int
|
|
decode_bitstring(const unsigned char **cpp, char *dn, const char *eom)
|
|
{
|
|
const unsigned char *cp = *cpp;
|
|
char *beg = dn, tc;
|
|
int b, blen, plen, i;
|
|
|
|
if ((blen = (*cp & 0xff)) == 0)
|
|
blen = 256;
|
|
plen = (blen + 3) / 4;
|
|
plen += sizeof("\\[x/]") + (blen > 99 ? 3 : (blen > 9) ? 2 : 1);
|
|
if (dn + plen >= eom)
|
|
return(-1);
|
|
|
|
cp++;
|
|
i = SPRINTF((dn, "\\[x"));
|
|
if (i < 0)
|
|
return (-1);
|
|
dn += i;
|
|
for (b = blen; b > 7; b -= 8, cp++) {
|
|
i = SPRINTF((dn, "%02x", *cp & 0xff));
|
|
if (i < 0)
|
|
return (-1);
|
|
dn += i;
|
|
}
|
|
if (b > 4) {
|
|
tc = *cp++;
|
|
i = SPRINTF((dn, "%02x", tc & (0xff << (8 - b))));
|
|
if (i < 0)
|
|
return (-1);
|
|
dn += i;
|
|
} else if (b > 0) {
|
|
tc = *cp++;
|
|
i = SPRINTF((dn, "%1x",
|
|
((tc >> 4) & 0x0f) & (0x0f << (4 - b))));
|
|
if (i < 0)
|
|
return (-1);
|
|
dn += i;
|
|
}
|
|
i = SPRINTF((dn, "/%d]", blen));
|
|
if (i < 0)
|
|
return (-1);
|
|
dn += i;
|
|
|
|
*cpp = cp;
|
|
return(dn - beg);
|
|
}
|
|
|
|
static int
|
|
encode_bitstring(const char **bp, const char *end, unsigned char **labelp,
|
|
unsigned char ** dst, unsigned const char *eom)
|
|
{
|
|
int afterslash = 0;
|
|
const char *cp = *bp;
|
|
unsigned char *tp;
|
|
char c;
|
|
const char *beg_blen;
|
|
char *end_blen = NULL;
|
|
int value = 0, count = 0, tbcount = 0, blen = 0;
|
|
|
|
beg_blen = end_blen = NULL;
|
|
|
|
/* a bitstring must contain at least 2 characters */
|
|
if (end - cp < 2)
|
|
return(EINVAL);
|
|
|
|
/* XXX: currently, only hex strings are supported */
|
|
if (*cp++ != 'x')
|
|
return(EINVAL);
|
|
if (!isxdigit((*cp) & 0xff)) /*%< reject '\[x/BLEN]' */
|
|
return(EINVAL);
|
|
|
|
for (tp = *dst + 1; cp < end && tp < eom; cp++) {
|
|
switch((c = *cp)) {
|
|
case ']': /*%< end of the bitstring */
|
|
if (afterslash) {
|
|
if (beg_blen == NULL)
|
|
return(EINVAL);
|
|
blen = (int)strtol(beg_blen, &end_blen, 10);
|
|
if (*end_blen != ']')
|
|
return(EINVAL);
|
|
}
|
|
if (count)
|
|
*tp++ = ((value << 4) & 0xff);
|
|
cp++; /*%< skip ']' */
|
|
goto done;
|
|
case '/':
|
|
afterslash = 1;
|
|
break;
|
|
default:
|
|
if (afterslash) {
|
|
if (!isdigit(c&0xff))
|
|
return(EINVAL);
|
|
if (beg_blen == NULL) {
|
|
|
|
if (c == '0') {
|
|
/* blen never begings with 0 */
|
|
return(EINVAL);
|
|
}
|
|
beg_blen = cp;
|
|
}
|
|
} else {
|
|
if (!isxdigit(c&0xff))
|
|
return(EINVAL);
|
|
value <<= 4;
|
|
value += digitvalue[(int)c];
|
|
count += 4;
|
|
tbcount += 4;
|
|
if (tbcount > 256)
|
|
return(EINVAL);
|
|
if (count == 8) {
|
|
*tp++ = value;
|
|
count = 0;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
done:
|
|
if (cp >= end || tp >= eom)
|
|
return(EMSGSIZE);
|
|
|
|
/*
|
|
* bit length validation:
|
|
* If a <length> is present, the number of digits in the <bit-data>
|
|
* MUST be just sufficient to contain the number of bits specified
|
|
* by the <length>. If there are insignificant bits in a final
|
|
* hexadecimal or octal digit, they MUST be zero.
|
|
* RFC2673, Section 3.2.
|
|
*/
|
|
if (blen > 0) {
|
|
int traillen;
|
|
|
|
if (((blen + 3) & ~3) != tbcount)
|
|
return(EINVAL);
|
|
traillen = tbcount - blen; /*%< between 0 and 3 */
|
|
if (((value << (8 - traillen)) & 0xff) != 0)
|
|
return(EINVAL);
|
|
}
|
|
else
|
|
blen = tbcount;
|
|
if (blen == 256)
|
|
blen = 0;
|
|
|
|
/* encode the type and the significant bit fields */
|
|
**labelp = DNS_LABELTYPE_BITSTRING;
|
|
**dst = blen;
|
|
|
|
*bp = cp;
|
|
*dst = tp;
|
|
|
|
return(0);
|
|
}
|
|
|
|
static int
|
|
labellen(const u_char *lp)
|
|
{
|
|
int bitlen;
|
|
u_char l = *lp;
|
|
|
|
if ((l & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
|
|
/* should be avoided by the caller */
|
|
return(-1);
|
|
}
|
|
|
|
if ((l & NS_CMPRSFLGS) == NS_TYPE_ELT) {
|
|
if (l == DNS_LABELTYPE_BITSTRING) {
|
|
if ((bitlen = *(lp + 1)) == 0)
|
|
bitlen = 256;
|
|
return((bitlen + 7 ) / 8 + 1);
|
|
}
|
|
return(-1); /*%< unknwon ELT */
|
|
}
|
|
return(l);
|
|
}
|
|
|
|
/*! \file */
|