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/*
* util/data/msgencode.h - encode compressed DNS messages.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains temporary data structures and routines to create
* compressed DNS messages.
*/
#ifndef UTIL_DATA_MSGENCODE_H
#define UTIL_DATA_MSGENCODE_H
struct sldns_buffer;
struct query_info;
struct reply_info;
struct regional;
struct edns_data;
/**
* Generate answer from reply_info.
* @param qinf: query information that provides query section in packet.
* @param rep: reply to fill in.
* @param id: id word from the query.
* @param qflags: flags word from the query.
* @param dest: buffer to put message into; will truncate if it does not fit.
* @param timenow: time to subtract.
* @param cached: set true if a cached reply (so no AA bit).
* set false for the first reply.
* @param region: where to allocate temp variables (for compression).
* @param udpsize: size of the answer, 512, from EDNS, or 64k for TCP.
* @param edns: EDNS data included in the answer, NULL for none.
* or if edns_present = 0, it is not included.
* @param dnssec: if 0 DNSSEC records are omitted from the answer.
* @param secure: if 1, the AD bit is set in the reply.
* @return: 0 on error (server failure).
*/
int reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep,
uint16_t id, uint16_t qflags, struct sldns_buffer* dest, time_t timenow,
int cached, struct regional* region, uint16_t udpsize,
struct edns_data* edns, int dnssec, int secure);
/**
* Regenerate the wireformat from the stored msg reply.
* If the buffer is too small then the message is truncated at a whole
* rrset and the TC bit set, or whole rrsets are left out of the additional
* and the TC bit is not set.
* @param qinfo: query info to store.
* @param rep: reply to store.
* @param id: id value to store, network order.
* @param flags: flags value to store, host order.
* @param buffer: buffer to store the packet into.
* @param timenow: time now, to adjust ttl values.
* @param region: to store temporary data in.
* @param udpsize: size of the answer, 512, from EDNS, or 64k for TCP.
* @param dnssec: if 0 DNSSEC records are omitted from the answer.
* @return: nonzero is success, or
* 0 on error: malloc failure (no log_err has been done).
*/
int reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
uint16_t id, uint16_t flags, struct sldns_buffer* buffer, time_t timenow,
struct regional* region, uint16_t udpsize, int dnssec);
/**
* Encode query packet. Assumes the buffer is large enough.
* @param pkt: where to store the packet.
* @param qinfo: query info.
*/
void qinfo_query_encode(struct sldns_buffer* pkt, struct query_info* qinfo);
/**
* Estimate size of EDNS record in packet. EDNS record will be no larger.
* @param edns: edns data or NULL.
* @return octets to reserve for EDNS.
*/
uint16_t calc_edns_field_size(struct edns_data* edns);
/**
* Attach EDNS record to buffer. Buffer has complete packet. There must
* be enough room left for the EDNS record.
* @param pkt: packet added to.
* @param edns: if NULL or present=0, nothing is added to the packet.
*/
void attach_edns_record(struct sldns_buffer* pkt, struct edns_data* edns);
/**
* Encode an error. With QR and RA set.
*
* @param pkt: where to store the packet.
* @param r: RCODE value to encode.
* @param qinfo: if not NULL, the query is included.
* @param qid: query ID to set in packet. network order.
* @param qflags: original query flags (to copy RD and CD bits). host order.
* @param edns: if not NULL, this is the query edns info,
* and an edns reply is attached. Only attached if EDNS record fits reply.
*/
void error_encode(struct sldns_buffer* pkt, int r, struct query_info* qinfo,
uint16_t qid, uint16_t qflags, struct edns_data* edns);
#endif /* UTIL_DATA_MSGENCODE_H */
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