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vlmcsd/ns_parse.c

207 lines
5.1 KiB
C

/*
* Copyright (c) 1996,1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
*/
/*
* Modified by Hotbird64 for use with vlmcs.
*/
#ifndef CONFIG
#define CONFIG "config.h"
#endif // CONFIG
#include CONFIG
#ifdef DNS_PARSER_INTERNAL
#ifndef NO_DNS
/* Import. */
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#include "types.h"
#include "endian.h"
#include "ns_name.h"
#include "ns_parse.h"
/* Macros. */
#define NS_GET16_VLMCSD(s, cp) do { \
(s) = GET_UA16BE(cp); \
(cp) += NS_INT16SZ; \
} while (0)
#define NS_GET32_VLMCSD(l, cp) do { \
(l) = GET_UA32BE(cp); \
(cp) += NS_INT32SZ; \
} while (0)
#define RETERR(err) do { errno = (err); return (-1); } while (0)
/* Forward. */
static void setsection_vlmcsd(ns_msg_vlmcsd *msg, ns_sect_vlmcsd sect);
static int dn_skipname_vlmcsd(const unsigned char *s, const unsigned char *end)
{
const unsigned char *p;
for (p=s; p<end; p++)
if (!*p) return p-s+1;
else if (*p>=192)
{if (p+1<end) return p-s+2;
else break;}
return -1;
}
static int
ns_skiprr_vlmcsd(const uint8_t *ptr, const uint8_t *eom, ns_sect_vlmcsd section, int count) {
const uint8_t *optr = ptr;
for ((void)NULL; count > 0; count--) {
int b, rdlength;
b = dn_skipname_vlmcsd(ptr, eom);
if (b < 0)
RETERR(EMSGSIZE);
ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
if (section != ns_s_qd_vlmcsd) {
if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
RETERR(EMSGSIZE);
ptr += NS_INT32SZ/*TTL*/;
NS_GET16_VLMCSD(rdlength, ptr);
ptr += rdlength/*RData*/;
}
}
if (ptr > eom)
RETERR(EMSGSIZE);
return (ptr - optr);
}
int
ns_initparse_vlmcsd(const uint8_t *msg, int msglen, ns_msg_vlmcsd *handle) {
const uint8_t *eom = msg + msglen;
int i;
memset(handle, 0x5e, sizeof *handle);
handle->_msg = msg;
handle->_eom = eom;
if (msg + NS_INT16SZ > eom)
RETERR(EMSGSIZE);
NS_GET16_VLMCSD(handle->_id, msg);
if (msg + NS_INT16SZ > eom)
RETERR(EMSGSIZE);
NS_GET16_VLMCSD(handle->_flags, msg);
for (i = 0; i < ns_s_max_vlmcsd; i++) {
if (msg + NS_INT16SZ > eom)
RETERR(EMSGSIZE);
NS_GET16_VLMCSD(handle->_counts[i], msg);
}
for (i = 0; i < ns_s_max_vlmcsd; i++)
if (handle->_counts[i] == 0)
handle->_sections[i] = NULL;
else {
int b = ns_skiprr_vlmcsd(msg, eom, (ns_sect_vlmcsd)i,
handle->_counts[i]);
if (b < 0)
return (-1);
handle->_sections[i] = msg;
msg += b;
}
if (msg > eom)
RETERR(EMSGSIZE);
handle->_eom = msg;
setsection_vlmcsd(handle, ns_s_max_vlmcsd);
return (0);
}
int
ns_parserr_vlmcsd(ns_msg_vlmcsd *handle, ns_sect_vlmcsd section, int rrnum, ns_rr_vlmcsd *rr) {
int b;
/* Make section right. */
if (section >= ns_s_max_vlmcsd)
RETERR(ENODEV);
if (section != handle->_sect)
setsection_vlmcsd(handle, section);
/* Make rrnum right. */
if (rrnum == -1)
rrnum = handle->_rrnum;
if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
RETERR(ENODEV);
if (rrnum < handle->_rrnum)
setsection_vlmcsd(handle, section);
if (rrnum > handle->_rrnum) {
b = ns_skiprr_vlmcsd(handle->_msg_ptr, handle->_eom, section,
rrnum - handle->_rrnum);
if (b < 0)
return (-1);
handle->_msg_ptr += b;
handle->_rrnum = rrnum;
}
/* Do the parse. */
b = ns_name_uncompress_vlmcsd(handle->_msg, handle->_eom,
handle->_msg_ptr, rr->name, NS_MAXDNAME);
if (b < 0)
return (-1);
handle->_msg_ptr += b;
if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
RETERR(EMSGSIZE);
NS_GET16_VLMCSD(rr->type, handle->_msg_ptr);
NS_GET16_VLMCSD(rr->rr_class, handle->_msg_ptr);
if (section == ns_s_qd_vlmcsd) {
rr->ttl = 0;
rr->rdlength = 0;
rr->rdata = NULL;
} else {
if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
RETERR(EMSGSIZE);
NS_GET32_VLMCSD(rr->ttl, handle->_msg_ptr);
NS_GET16_VLMCSD(rr->rdlength, handle->_msg_ptr);
if (handle->_msg_ptr + rr->rdlength > handle->_eom)
RETERR(EMSGSIZE);
rr->rdata = handle->_msg_ptr;
handle->_msg_ptr += rr->rdlength;
}
if (++handle->_rrnum > handle->_counts[(int)section])
setsection_vlmcsd(handle, (ns_sect_vlmcsd)((int)section + 1));
/* All done. */
return (0);
}
/* Private. */
static void
setsection_vlmcsd(ns_msg_vlmcsd *msg, ns_sect_vlmcsd sect) {
msg->_sect = sect;
if (sect == ns_s_max_vlmcsd) {
msg->_rrnum = -1;
msg->_msg_ptr = NULL;
} else {
msg->_rrnum = 0;
msg->_msg_ptr = msg->_sections[(int)sect];
}
}
#endif // !NO_DNS
#endif // DNS_PARSER_INTERNAL