/* * 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 */