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/* Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include "packet/query.h"
#include "util/wire.h"
#include "libknot/common.h"
/*----------------------------------------------------------------------------*/
int knot_query_rr_to_wire(const knot_rrset_t *rrset, const knot_rdata_t *rdata,
uint8_t **wire, uint8_t *endp)
{
/* Store owner. */
knot_dname_t *owner = rrset->owner;
if (*wire + owner->size > endp) {
return KNOT_ENOMEM;
}
memcpy(*wire, owner->name, owner->size);
*wire += owner->size;
if (*wire + 10 > endp) {
return KNOT_ENOMEM;
}
/* Write RR header. */
knot_wire_write_u16(*wire, rrset->type); *wire += 2;
knot_wire_write_u16(*wire, rrset->rclass); *wire += 2;
knot_wire_write_u32(*wire, rrset->ttl); *wire += 4;
knot_wire_write_u16(*wire, 0); *wire += 2; /* RDLENGTH reserve. */
uint8_t *rdlength_p = *wire - 2;
uint16_t rdlength = 0;
/* Write data. */
knot_dname_t *dname = 0;
uint16_t *raw_data = 0;
knot_rrtype_descriptor_t *desc =
knot_rrtype_descriptor_by_type(rrset->type);
for (int i = 0; i < rdata->count; ++i) {
switch (desc->wireformat[i]) {
case KNOT_RDATA_WF_COMPRESSED_DNAME:
case KNOT_RDATA_WF_UNCOMPRESSED_DNAME:
case KNOT_RDATA_WF_LITERAL_DNAME:
/* Check space for dname. */
dname = knot_rdata_item(rdata, i)->dname;
if (*wire + dname->size > endp) {
return KNOT_ESPACE;
}
/* Save domain name. */
memcpy(*wire, dname->name, dname->size);
*wire += dname->size;
rdlength += dname->size;
break;
default:
raw_data = knot_rdata_item(rdata, i)->raw_data;
if (*wire + raw_data[0] > endp) {
return KNOT_ESPACE;
}
/* Copy data. */
memcpy(*wire, raw_data + 1, raw_data[0]);
*wire += raw_data[0];
rdlength += raw_data[0];
break;
}
}
/* Store rdlength. */
knot_wire_write_u16(rdlength_p, rdlength);
return KNOT_EOK;
}
/*----------------------------------------------------------------------------*/
int knot_query_dnssec_requested(const knot_packet_t *query)
{
if (query == NULL) {
return KNOT_EINVAL;
}
return ((knot_edns_get_version(&query->opt_rr) != EDNS_NOT_SUPPORTED)
&& knot_edns_do(&query->opt_rr));
}
/*----------------------------------------------------------------------------*/
int knot_query_nsid_requested(const knot_packet_t *query)
{
if (query == NULL) {
return KNOT_EINVAL;
}
return ((knot_edns_get_version(&query->opt_rr) != EDNS_NOT_SUPPORTED)
&& knot_edns_has_option(&query->opt_rr, EDNS_OPTION_NSID));
}
/*----------------------------------------------------------------------------*/
int knot_query_edns_supported(const knot_packet_t *query)
{
if (query == NULL) {
return KNOT_EINVAL;
}
return (knot_edns_get_version(&query->opt_rr) != EDNS_NOT_SUPPORTED);
}
/*----------------------------------------------------------------------------*/
int knot_query_init(knot_packet_t *query)
{
if (query == NULL) {
return KNOT_EINVAL;
}
// set the qr bit to 0
knot_wire_flags_clear_qr(&query->header.flags1);
uint8_t *pos = query->wireformat;
knot_packet_header_to_wire(&query->header, &pos, &query->size);
return KNOT_EOK;
}
/*----------------------------------------------------------------------------*/
int knot_query_set_question(knot_packet_t *query,
const knot_question_t *question)
{
if (query == NULL || question == NULL) {
return KNOT_EINVAL;
}
query->question.qname = question->qname;
query->question.qclass = question->qclass;
query->question.qtype = question->qtype;
query->header.qdcount = 1;
// convert the Question to wire format right away
knot_packet_question_to_wire(query);
return KNOT_EOK;
}
/*----------------------------------------------------------------------------*/
int knot_query_set_opcode(knot_packet_t *query, uint8_t opcode)
{
if (query == NULL) {
return KNOT_EINVAL;
}
// set the OPCODE in the structure
knot_wire_flags_set_opcode(&query->header.flags1, opcode);
// set the OPCODE in the wire format
knot_wire_set_opcode(query->wireformat, opcode);
return KNOT_EOK;
}
/*----------------------------------------------------------------------------*/
int knot_query_add_rrset_authority(knot_packet_t *query,
const knot_rrset_t *rrset)
{
if (query == NULL || rrset == NULL) {
return KNOT_EINVAL;
}
if (query->ns_rrsets == query->max_ns_rrsets) {
size_t oldsize = query->max_ns_rrsets * sizeof(knot_rrset_t *);
++query->max_ns_rrsets;
size_t newsize = query->max_ns_rrsets * sizeof(knot_rrset_t *);
const knot_rrset_t ** na = malloc(newsize);
if (na == 0) {
query->max_ns_rrsets = 0;
return KNOT_ENOMEM;
} else {
memcpy(na, query->authority, oldsize);
free(query->authority);
query->authority = na;
}
}
/* Append to packet. */
query->authority[query->ns_rrsets] = rrset;
/* Write to wire. */
uint8_t *startp = query->wireformat + query->size;
uint8_t *endp = query->wireformat + query->max_size;
assert(endp - startp > query->opt_rr.size + query->tsig_size);
// reserve space for OPT RR
/*! \todo Why here??? */
endp -= query->opt_rr.size;
/* Reserve space for TSIG RR */
endp -= query->tsig_size;
uint8_t *pos = startp;
const knot_rdata_t *rdata = 0;
while ((rdata = knot_rrset_rdata_next(rrset, rdata))) {
knot_query_rr_to_wire(rrset, rdata, &pos, endp);
}
size_t written = (pos - startp);
query->size += written;
++query->ns_rrsets;
++query->header.nscount;
return KNOT_EOK;
}
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