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/* $OpenBSD: unpack_dns.h,v 1.2 2021/06/14 17:58:16 eric Exp $ */
/*
* Copyright (c) 2011-2014 Eric Faurot <eric@faurot.net>
*
* 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
*/
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
struct unpack {
const char *buf;
size_t len;
size_t offset;
const char *err;
};
struct dns_header {
uint16_t id;
uint16_t flags;
uint16_t qdcount;
uint16_t ancount;
uint16_t nscount;
uint16_t arcount;
};
struct dns_query {
char q_dname[MAXDNAME];
uint16_t q_type;
uint16_t q_class;
};
struct dns_rr {
char rr_dname[MAXDNAME];
uint16_t rr_type;
uint16_t rr_class;
uint32_t rr_ttl;
union {
struct {
char cname[MAXDNAME];
} cname;
struct {
uint16_t preference;
char exchange[MAXDNAME];
} mx;
struct {
char nsname[MAXDNAME];
} ns;
struct {
char ptrname[MAXDNAME];
} ptr;
struct {
char mname[MAXDNAME];
char rname[MAXDNAME];
uint32_t serial;
uint32_t refresh;
uint32_t retry;
uint32_t expire;
uint32_t minimum;
} soa;
struct {
struct in_addr addr;
} in_a;
struct {
struct in6_addr addr6;
} in_aaaa;
struct {
uint16_t rdlen;
const void *rdata;
} other;
} rr;
};
void unpack_init(struct unpack *, const char *, size_t);
int unpack_header(struct unpack *, struct dns_header *);
int unpack_rr(struct unpack *, struct dns_rr *);
int unpack_query(struct unpack *, struct dns_query *);
char *print_dname(const char *, char *, size_t);
ssize_t dname_expand(const unsigned char *, size_t, size_t, size_t *,
char *, size_t);
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