/
omg_dns.c
1153 lines (957 loc) · 28.1 KB
/
omg_dns.c
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/*
* Author Jerry Lundström <jerry@dns-oarc.net>
* Copyright (c) 2017, OARC, Inc.
* All rights reserved.
*
* This file is part of omg-dns.
*
* omg-dns is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* omg-dns is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with omg-dns. If not, see <http://www.gnu.org/licenses/>.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include "omg_dns.h"
/*
* Version
*/
static const char* _version = OMG_DNS_VERSION_STR;
inline const char* omg_dns_version_str(void)
{
return _version;
}
inline int omg_dns_version_major(void)
{
return OMG_DNS_VERSION_MAJOR;
}
inline int omg_dns_version_minor(void)
{
return OMG_DNS_VERSION_MINOR;
}
inline int omg_dns_version_patch(void)
{
return OMG_DNS_VERSION_PATCH;
}
/*
* Buffer inlines and macros
*/
#define need8(v, p, l) \
if (l < 1) { \
return OMG_DNS_EINCOMP; \
} \
v = *p; \
p += 1; \
l -= 1
#define need16(v, p, l) \
if (l < 2) { \
return OMG_DNS_EINCOMP; \
} \
v = (*p << 8) + *(p + 1); \
p += 2; \
l -= 2
#define need32(v, p, l) \
if (l < 4) { \
return OMG_DNS_EINCOMP; \
} \
v = (*p << 24) + (*(p + 1) << 16) + (*(p + 2) << 8) + *(p + 3); \
p += 4; \
l -= 4
#define need64(v, p, l) \
if (l < 8) { \
return OMG_DNS_EINCOMP; \
} \
v = (*p << 56) + (*(p + 1) << 48) + (*(p + 2) << 40) + (*(p + 3) << 32) + (*(p + 4) << 24) + (*(p + 5) << 16) + (*(p + 6) << 8) + *(p + 7); \
p += 8; \
l -= 8
#define needxb(b, x, p, l) \
if (l < x) { \
return OMG_DNS_EINCOMP; \
} \
memcpy(b, p, x); \
p += x; \
l -= x
#define advancexb(x, p, l) \
if (l < x) { \
return OMG_DNS_EINCOMP; \
} \
p += x; \
l -= x
/*
* Label structure functions
*/
inline int omg_dns_label_is_end(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->is_end;
}
inline int omg_dns_label_have_length(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->have_length;
}
inline int omg_dns_label_have_offset(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->have_offset;
}
inline int omg_dns_label_have_extension_bits(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->have_extension_bits;
}
inline int omg_dns_label_have_dn(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->have_dn;
}
inline int omg_dns_label_is_complete(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->is_complete;
}
inline uint8_t omg_dns_label_length(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->length;
}
inline uint16_t omg_dns_label_offset(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->offset;
}
inline unsigned short omg_dns_label_extension_bits(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->extension_bits;
}
inline size_t omg_dns_label_dn_offset(const omg_dns_label_t* label)
{
omg_dns_assert(label);
return label->dn_offset;
}
/*
* Resource record structure callback functions
*/
inline omg_dns_label_callback_t omg_dns_rr_label_callback(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->label_callback;
}
inline void* omg_dns_rr_label_callback_context(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->label_callback_context;
}
inline void omg_dns_rr_set_label_callback(omg_dns_rr_t* rr, omg_dns_label_callback_t label_callback, void* label_callback_context)
{
omg_dns_assert(rr);
rr->label_callback = label_callback;
rr->label_callback_context = label_callback_context;
}
/*
* Resource record structure functions
*/
inline int omg_dns_rr_is_question(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->is_question;
}
inline int omg_dns_rr_have_labels(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->have_labels;
}
inline int omg_dns_rr_have_type(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->have_type;
}
inline int omg_dns_rr_have_class(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->have_class;
}
inline int omg_dns_rr_have_ttl(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->have_ttl;
}
inline int omg_dns_rr_have_rdlength(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->have_rdlength;
}
inline int omg_dns_rr_have_rdata(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->have_rdata;
}
inline int omg_dns_rr_have_rdata_labels(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->have_rdata_labels;
}
inline int omg_dns_rr_have_padding(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->have_padding;
}
inline int omg_dns_rr_is_complete(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->is_complete;
}
inline size_t omg_dns_rr_bytes_parsed(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->bytes_parsed;
}
inline size_t omg_dns_rr_labels(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->labels;
}
inline uint16_t omg_dns_rr_type(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->type;
}
inline uint16_t omg_dns_rr_class(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->class;
}
inline uint32_t omg_dns_rr_ttl(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->ttl;
}
inline uint16_t omg_dns_rr_rdlength(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->rdlength;
}
inline size_t omg_dns_rr_rdata_offset(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->rdata_offset;
}
inline size_t omg_dns_rr_rdata_labels(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->rdata_labels;
}
inline size_t omg_dns_rr_padding_offset(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->padding_offset;
}
inline size_t omg_dns_rr_padding_length(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
return rr->padding_length;
}
inline size_t omg_dns_rr_num_rdata_labels(const omg_dns_rr_t* rr)
{
omg_dns_assert(rr);
switch (rr->type) {
case OMG_DNS_TYPE_NS:
case OMG_DNS_TYPE_MD:
case OMG_DNS_TYPE_MF:
case OMG_DNS_TYPE_CNAME:
case OMG_DNS_TYPE_MB:
case OMG_DNS_TYPE_MG:
case OMG_DNS_TYPE_MR:
case OMG_DNS_TYPE_PTR:
case OMG_DNS_TYPE_NXT:
case OMG_DNS_TYPE_DNAME:
case OMG_DNS_TYPE_NSEC:
case OMG_DNS_TYPE_TKEY:
case OMG_DNS_TYPE_TSIG:
return 1;
case OMG_DNS_TYPE_SOA:
case OMG_DNS_TYPE_MINFO:
case OMG_DNS_TYPE_RP:
case OMG_DNS_TYPE_TALINK:
return 2;
case OMG_DNS_TYPE_MX:
case OMG_DNS_TYPE_AFSDB:
case OMG_DNS_TYPE_RT:
case OMG_DNS_TYPE_KX:
case OMG_DNS_TYPE_LP:
return 1;
case OMG_DNS_TYPE_PX:
return 2;
case OMG_DNS_TYPE_SIG:
case OMG_DNS_TYPE_RRSIG:
return 1;
case OMG_DNS_TYPE_SRV:
return 1;
case OMG_DNS_TYPE_NAPTR:
return 1;
case OMG_DNS_TYPE_HIP:
return 1;
default:
break;
}
return 0;
}
/*
* DNS structure callback functions
*/
inline omg_dns_label_callback_t omg_dns_label_callback(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->label_callback;
}
inline void* omg_dns_label_callback_context(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->label_callback_context;
}
inline void omg_dns_set_label_callback(omg_dns_t* dns, omg_dns_label_callback_t label_callback, void* label_callback_context)
{
omg_dns_assert(dns);
dns->label_callback = label_callback;
dns->label_callback_context = label_callback_context;
}
inline omg_dns_rr_callback_t omg_dns_rr_callback(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->rr_callback;
}
inline void* omg_dns_rr_callback_context(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->rr_callback_context;
}
inline void omg_dns_set_rr_callback(omg_dns_t* dns, omg_dns_rr_callback_t rr_callback, void* rr_callback_context)
{
omg_dns_assert(dns);
dns->rr_callback = rr_callback;
dns->rr_callback_context = rr_callback_context;
}
/*
* DNS structure functions
*/
inline int omg_dns_have_id(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_id;
}
inline int omg_dns_have_qr(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_qr;
}
inline int omg_dns_have_opcode(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_opcode;
}
inline int omg_dns_have_aa(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_aa;
}
inline int omg_dns_have_tc(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_tc;
}
inline int omg_dns_have_rd(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_rd;
}
inline int omg_dns_have_ra(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_ra;
}
inline int omg_dns_have_z(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_z;
}
inline int omg_dns_have_ad(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_ad;
}
inline int omg_dns_have_cd(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_cd;
}
inline int omg_dns_have_rcode(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_rcode;
}
inline int omg_dns_have_qdcount(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_qdcount;
}
inline int omg_dns_have_ancount(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_ancount;
}
inline int omg_dns_have_nscount(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_nscount;
}
inline int omg_dns_have_arcount(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_arcount;
}
inline int omg_dns_have_questions(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_questions;
}
inline int omg_dns_have_answers(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_answers;
}
inline int omg_dns_have_authorities(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_authorities;
}
inline int omg_dns_have_additionals(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_additionals;
}
inline int omg_dns_have_padding(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_padding;
}
inline int omg_dns_have_header(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_header;
}
inline int omg_dns_have_body(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->have_body;
}
inline int omg_dns_is_complete(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->is_complete;
}
inline size_t omg_dns_bytes_parsed(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->bytes_parsed;
}
inline uint16_t omg_dns_id(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->id;
}
inline int omg_dns_qr(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->qr;
}
inline int omg_dns_opcode(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->opcode;
}
inline int omg_dns_aa(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->aa;
}
inline int omg_dns_tc(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->tc;
}
inline int omg_dns_rd(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->rd;
}
inline int omg_dns_ra(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->ra;
}
inline int omg_dns_z(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->z;
}
inline int omg_dns_ad(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->ad;
}
inline int omg_dns_cd(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->cd;
}
inline int omg_dns_rcode(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->rcode;
}
inline uint16_t omg_dns_qdcount(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->qdcount;
}
inline uint16_t omg_dns_ancount(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->ancount;
}
inline uint16_t omg_dns_nscount(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->nscount;
}
inline uint16_t omg_dns_arcount(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->arcount;
}
inline size_t omg_dns_questions(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->questions;
}
inline size_t omg_dns_answers(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->answers;
}
inline size_t omg_dns_authorities(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->authorities;
}
inline size_t omg_dns_additionals(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->additionals;
}
inline size_t omg_dns_padding_offset(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->padding_offset;
}
inline size_t omg_dns_padding_length(const omg_dns_t* dns)
{
omg_dns_assert(dns);
return dns->padding_length;
}
/*
* Parsers
*/
int omg_dns_parse_header(omg_dns_t* dns, const uint8_t* buffer, size_t length)
{
uint8_t byte;
if (!dns) {
return OMG_DNS_EINVAL;
}
need16(dns->id, buffer, length);
dns->bytes_parsed += 2;
dns->have_id = 1;
need8(byte, buffer, length);
dns->bytes_parsed += 1;
dns->qr = byte & (1 << 7) ? 1 : 0;
dns->opcode = (byte >> 3) & 0xf;
dns->aa = byte & (1 << 2) ? 1 : 0;
dns->tc = byte & (1 << 1) ? 1 : 0;
dns->rd = byte & (1 << 0) ? 1 : 0;
dns->have_qr = dns->have_opcode = dns->have_aa = dns->have_tc = dns->have_rd = 1;
need8(byte, buffer, length);
dns->bytes_parsed += 1;
dns->ra = byte & (1 << 7) ? 1 : 0;
dns->z = byte & (1 << 6) ? 1 : 0;
dns->ad = byte & (1 << 5) ? 1 : 0;
dns->cd = byte & (1 << 4) ? 1 : 0;
dns->rcode = byte & 0xf;
dns->have_ra = dns->have_z = dns->have_ad = dns->have_cd = dns->have_rcode = 1;
need16(dns->qdcount, buffer, length);
dns->bytes_parsed += 2;
dns->have_qdcount = 1;
need16(dns->ancount, buffer, length);
dns->bytes_parsed += 2;
dns->have_ancount = 1;
need16(dns->nscount, buffer, length);
dns->bytes_parsed += 2;
dns->have_nscount = 1;
need16(dns->arcount, buffer, length);
dns->bytes_parsed += 2;
dns->have_arcount = 1;
dns->have_header = 1;
return OMG_DNS_OK;
}
int omg_dns_parse_body(omg_dns_t* dns, const uint8_t* buffer, size_t length)
{
size_t n;
int ret;
if (!dns) {
return OMG_DNS_EINVAL;
}
for (n = dns->qdcount; n; n--) {
omg_dns_rr_t rr = OMG_DNS_RR_T_INIT;
rr._offset = dns->bytes_parsed;
rr.is_question = 1;
if (dns->label_callback)
omg_dns_rr_set_label_callback(&rr, dns->label_callback, dns->label_callback_context);
ret = omg_dns_parse_rr(&rr, buffer, length);
if (dns->rr_callback)
ret = dns->rr_callback(ret, &rr, dns->rr_callback_context);
if (ret != OMG_DNS_OK)
return ret;
buffer += rr.bytes_parsed;
length -= rr.bytes_parsed;
dns->bytes_parsed += rr.bytes_parsed;
dns->questions++;
}
dns->have_questions = 1;
for (n = dns->ancount; n; n--) {
omg_dns_rr_t rr = OMG_DNS_RR_T_INIT;
rr._offset = dns->bytes_parsed;
if (dns->label_callback)
omg_dns_rr_set_label_callback(&rr, dns->label_callback, dns->label_callback_context);
ret = omg_dns_parse_rr(&rr, buffer, length);
if (dns->rr_callback)
ret = dns->rr_callback(ret, &rr, dns->rr_callback_context);
if (ret != OMG_DNS_OK)
return ret;
buffer += rr.bytes_parsed;
length -= rr.bytes_parsed;
dns->bytes_parsed += rr.bytes_parsed;
dns->answers++;
}
dns->have_answers = 1;
for (n = dns->nscount; n; n--) {
omg_dns_rr_t rr = OMG_DNS_RR_T_INIT;
rr._offset = dns->bytes_parsed;
if (dns->label_callback)
omg_dns_rr_set_label_callback(&rr, dns->label_callback, dns->label_callback_context);
ret = omg_dns_parse_rr(&rr, buffer, length);
if (dns->rr_callback)
ret = dns->rr_callback(ret, &rr, dns->rr_callback_context);
if (ret != OMG_DNS_OK)
return ret;
buffer += rr.bytes_parsed;
length -= rr.bytes_parsed;
dns->bytes_parsed += rr.bytes_parsed;
dns->authorities++;
}
dns->have_authorities = 1;
for (n = dns->arcount; n; n--) {
omg_dns_rr_t rr = OMG_DNS_RR_T_INIT;
rr._offset = dns->bytes_parsed;
if (dns->label_callback)
omg_dns_rr_set_label_callback(&rr, dns->label_callback, dns->label_callback_context);
ret = omg_dns_parse_rr(&rr, buffer, length);
if (dns->rr_callback)
ret = dns->rr_callback(ret, &rr, dns->rr_callback_context);
if (ret != OMG_DNS_OK)
return ret;
buffer += rr.bytes_parsed;
length -= rr.bytes_parsed;
dns->bytes_parsed += rr.bytes_parsed;
dns->additionals++;
}
dns->have_additionals = 1;
if (length) {
dns->padding_offset = dns->bytes_parsed;
dns->padding_length = length;
dns->have_padding = 1;
}
dns->have_body = 1;
return OMG_DNS_OK;
}
int omg_dns_parse(omg_dns_t* dns, const uint8_t* buffer, size_t length)
{
int ret;
if (!dns) {
return OMG_DNS_EINVAL;
}
if ((ret = omg_dns_parse_header(dns, buffer, length)) != OMG_DNS_OK) {
return ret;
}
if (length <= dns->bytes_parsed) {
return OMG_DNS_EINCOMP;
}
buffer += dns->bytes_parsed;
length -= dns->bytes_parsed;
if ((ret = omg_dns_parse_body(dns, buffer, length)) != OMG_DNS_OK) {
return ret;
}
dns->is_complete = 1;
return OMG_DNS_OK;
}
int omg_dns_parse_rr(omg_dns_rr_t* rr, const uint8_t* buffer, size_t length)
{
int ret;
size_t labels;
if (!rr) {
return OMG_DNS_EINVAL;
}
while (length) {
omg_dns_label_t label = OMG_DNS_LABEL_T_INIT;
label._offset = rr->_offset + rr->bytes_parsed;
need8(label.length, buffer, length);
rr->bytes_parsed += 1;
if ((label.length & 0xc0) == 0xc0) {
need8(label.offset, buffer, length);
label.offset |= (label.length & 0x3f) << 8;
rr->bytes_parsed += 1;
label.have_offset = 1;
label.is_complete = 1;
if (rr->label_callback) {
ret = rr->label_callback(&label, rr->label_callback_context);
if (ret != OMG_DNS_OK)
return ret;
}
rr->labels++;
break;
} else if (label.length & 0xc0) {
label.extension_bits = label.length >> 6;
label.have_extension_bits = 1;
label.is_complete = 1;
if (rr->label_callback) {
ret = rr->label_callback(&label, rr->label_callback_context);
if (ret != OMG_DNS_OK)
return ret;
}
rr->labels++;
break;
} else if (label.length) {
label.have_length = 1;
label.offset = label._offset;
label.dn_offset = label._offset + 1;
advancexb(label.length, buffer, length);
rr->bytes_parsed += label.length;
label.have_dn = 1;
label.is_complete = 1;
if (rr->label_callback) {
ret = rr->label_callback(&label, rr->label_callback_context);
if (ret != OMG_DNS_OK)
return ret;
}
rr->labels++;
} else {
label.is_end = 1;
label.is_complete = 1;
if (rr->label_callback) {
ret = rr->label_callback(&label, rr->label_callback_context);
if (ret != OMG_DNS_OK)
return ret;
}
break;
}
}
rr->have_labels = 1;
need16(rr->type, buffer, length);
rr->bytes_parsed += 2;
rr->have_type = 1;
need16(rr->class, buffer, length);
rr->bytes_parsed += 2;
rr->have_class = 1;
if (rr->is_question) {
rr->is_complete = 1;
return OMG_DNS_OK;
}
need32(rr->ttl, buffer, length);
rr->bytes_parsed += 4;
rr->have_ttl = 1;
need16(rr->rdlength, buffer, length);
rr->bytes_parsed += 2;
rr->have_rdlength = 1;
rr->rdata_offset = rr->_offset + rr->bytes_parsed;
if ((labels = omg_dns_rr_num_rdata_labels(rr))) {
size_t bytes_parsed = 0;
switch (rr->type) {
case OMG_DNS_TYPE_MX:
case OMG_DNS_TYPE_AFSDB:
case OMG_DNS_TYPE_RT:
case OMG_DNS_TYPE_KX:
case OMG_DNS_TYPE_LP:
case OMG_DNS_TYPE_PX:
advancexb(2, buffer, length);
rr->bytes_parsed += 2;
bytes_parsed += 2;
break;
case OMG_DNS_TYPE_SIG:
case OMG_DNS_TYPE_RRSIG:
advancexb(18, buffer, length);
rr->bytes_parsed += 18;
bytes_parsed += 18;
break;
case OMG_DNS_TYPE_SRV:
advancexb(6, buffer, length);
rr->bytes_parsed += 6;
bytes_parsed += 6;
break;
case OMG_DNS_TYPE_NAPTR: {
uint8_t naptr_length;
/* 2x 16 bits */
advancexb(4, buffer, length);
rr->bytes_parsed += 4;
bytes_parsed += 4;
need8(naptr_length, buffer, length);
rr->bytes_parsed += 1;
bytes_parsed += 1;