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/*
* query.h -- manipulation with the queries
*
* Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
*
* See LICENSE for the license.
*
*/
#ifndef _QUERY_H_
#define _QUERY_H_
#include <assert.h>
#include <string.h>
#include "namedb.h"
#include "nsd.h"
#include "packet.h"
#include "tsig.h"
enum query_state {
QUERY_PROCESSED,
QUERY_DISCARDED,
QUERY_IN_AXFR
};
typedef enum query_state query_state_type;
/* Query as we pass it around */
typedef struct query query_type;
struct query {
/*
* Memory region freed whenever the query is reset.
*/
region_type *region;
/*
* The address the query was received from.
*/
#ifdef INET6
struct sockaddr_storage addr;
#else
struct sockaddr_in addr;
#endif
socklen_t addrlen;
/*
* Maximum supported query size.
*/
size_t maxlen;
/*
* Space reserved for optional records like EDNS.
*/
size_t reserved_space;
/* EDNS information provided by the client. */
edns_record_type edns;
/* TSIG record information and running hash for query-response */
tsig_record_type tsig;
/* tsig actions can be overridden, for axfr transfer. */
int tsig_prepare_it, tsig_update_it, tsig_sign_it;
int tcp;
uint16_t tcplen;
buffer_type *packet;
/* Normalized query domain name. */
const dname_type *qname;
/* Query type and class in host byte order. */
uint16_t qtype;
uint16_t qclass;
/* The zone used to answer the query. */
zone_type *zone;
/* The delegation domain, if any. */
domain_type *delegation_domain;
/* The delegation NS rrset, if any. */
rrset_type *delegation_rrset;
/* Original opcode. */
uint8_t opcode;
/*
* The number of CNAMES followed. After a CNAME is followed
* we no longer change the RCODE to NXDOMAIN and no longer add
* SOA records to the authority section in case of NXDOMAIN
* and NODATA.
* Also includes number of DNAMES followed.
*/
int cname_count;
/* Used for dname compression. */
uint16_t compressed_dname_count;
domain_type **compressed_dnames;
/*
* Indexed by domain->number, index 0 is reserved for the
* query name when generated from a wildcard record.
*/
uint16_t *compressed_dname_offsets;
size_t compressed_dname_offsets_size;
/* number of temporary domains used for the query */
size_t number_temporary_domains;
/*
* Used for AXFR processing.
*/
int axfr_is_done;
zone_type *axfr_zone;
domain_type *axfr_current_domain;
rrset_type *axfr_current_rrset;
uint16_t axfr_current_rr;
#ifdef RATELIMIT
/* if we encountered a wildcard, its domain */
domain_type *wildcard_domain;
#endif
};
/* Check if the last write resulted in an overflow. */
static inline int query_overflow(struct query *q);
/*
* Store the offset of the specified domain in the dname compression
* table.
*/
void query_put_dname_offset(struct query *query,
domain_type *domain,
uint16_t offset);
/*
* Lookup the offset of the specified domain in the dname compression
* table. Offset 0 is used to indicate the domain is not yet in the
* compression table.
*/
static inline
uint16_t query_get_dname_offset(struct query *query, domain_type *domain)
{
return query->compressed_dname_offsets[domain->number];
}
/*
* Remove all compressed dnames that have an offset that points beyond
* the end of the current answer. This must be done after some RRs
* are truncated and before adding new RRs. Otherwise dnames may be
* compressed using truncated data!
*/
void query_clear_dname_offsets(struct query *query, size_t max_offset);
/*
* Clear the compression tables.
*/
void query_clear_compression_tables(struct query *query);
/*
* Enter the specified domain into the compression table starting at
* the specified offset.
*/
void query_add_compression_domain(struct query *query,
domain_type *domain,
uint16_t offset);
/*
* Create a new query structure.
*/
query_type *query_create(region_type *region,
uint16_t *compressed_dname_offsets,
size_t compressed_dname_size,
domain_type **compressed_dnames);
/*
* Reset a query structure so it is ready for receiving and processing
* a new query.
*/
void query_reset(query_type *query, size_t maxlen, int is_tcp);
/*
* Process a query and write the response in the query I/O buffer.
*/
query_state_type query_process(query_type *q, nsd_type *nsd);
/*
* Prepare the query structure for writing the response. The packet
* data up-to the current packet limit is preserved. This usually
* includes the packet header and question section. Space is reserved
* for the optional EDNS record, if required.
*/
void query_prepare_response(query_type *q);
/*
* Add EDNS0 information to the response if required.
*/
void query_add_optional(query_type *q, nsd_type *nsd);
/*
* Write an error response into the query structure with the indicated
* RCODE.
*/
query_state_type query_error(query_type *q, nsd_rc_type rcode);
static inline int
query_overflow(query_type *q)
{
return buffer_position(q->packet) > (q->maxlen - q->reserved_space);
}
#endif /* _QUERY_H_ */
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