2 * util/data/msgencode.h - encode compressed DNS messages.
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
6 * This software is open source.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
39 * This file contains temporary data structures and routines to create
40 * compressed DNS messages.
43 #ifndef UTIL_DATA_MSGENCODE_H
44 #define UTIL_DATA_MSGENCODE_H
51 * Generate answer from reply_info.
52 * @param qinf: query information that provides query section in packet.
53 * @param rep: reply to fill in.
54 * @param id: id word from the query.
55 * @param qflags: flags word from the query.
56 * @param dest: buffer to put message into; will truncate if it does not fit.
57 * @param timenow: time to subtract.
58 * @param cached: set true if a cached reply (so no AA bit).
59 * set false for the first reply.
60 * @param region: where to allocate temp variables (for compression).
61 * @param udpsize: size of the answer, 512, from EDNS, or 64k for TCP.
62 * @param edns: EDNS data included in the answer, NULL for none.
63 * or if edns_present = 0, it is not included.
64 * @param dnssec: if 0 DNSSEC records are omitted from the answer.
65 * @param secure: if 1, the AD bit is set in the reply.
66 * @return: 0 on error (server failure).
68 int reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep,
69 uint16_t id, uint16_t qflags, ldns_buffer* dest, uint32_t timenow,
70 int cached, struct regional* region, uint16_t udpsize,
71 struct edns_data* edns, int dnssec, int secure);
74 * Regenerate the wireformat from the stored msg reply.
75 * If the buffer is too small then the message is truncated at a whole
76 * rrset and the TC bit set, or whole rrsets are left out of the additional
77 * and the TC bit is not set.
78 * @param qinfo: query info to store.
79 * @param rep: reply to store.
80 * @param id: id value to store, network order.
81 * @param flags: flags value to store, host order.
82 * @param buffer: buffer to store the packet into.
83 * @param timenow: time now, to adjust ttl values.
84 * @param region: to store temporary data in.
85 * @param udpsize: size of the answer, 512, from EDNS, or 64k for TCP.
86 * @param dnssec: if 0 DNSSEC records are omitted from the answer.
87 * @return: nonzero is success, or
88 * 0 on error: malloc failure (no log_err has been done).
90 int reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
91 uint16_t id, uint16_t flags, ldns_buffer* buffer, uint32_t timenow,
92 struct regional* region, uint16_t udpsize, int dnssec);
95 * Encode query packet. Assumes the buffer is large enough.
96 * @param pkt: where to store the packet.
97 * @param qinfo: query info.
99 void qinfo_query_encode(ldns_buffer* pkt, struct query_info* qinfo);
102 * Estimate size of EDNS record in packet. EDNS record will be no larger.
103 * @param edns: edns data or NULL.
104 * @return octets to reserve for EDNS.
106 uint16_t calc_edns_field_size(struct edns_data* edns);
109 * Attach EDNS record to buffer. Buffer has complete packet. There must
110 * be enough room left for the EDNS record.
111 * @param pkt: packet added to.
112 * @param edns: if NULL or present=0, nothing is added to the packet.
114 void attach_edns_record(ldns_buffer* pkt, struct edns_data* edns);
117 * Encode an error. With QR and RA set.
119 * @param pkt: where to store the packet.
120 * @param r: RCODE value to encode.
121 * @param qinfo: if not NULL, the query is included.
122 * @param qid: query ID to set in packet. network order.
123 * @param qflags: original query flags (to copy RD and CD bits). host order.
124 * @param edns: if not NULL, this is the query edns info,
125 * and an edns reply is attached. Only attached if EDNS record fits reply.
127 void error_encode(ldns_buffer* pkt, int r, struct query_info* qinfo,
128 uint16_t qid, uint16_t qflags, struct edns_data* edns);
130 #endif /* UTIL_DATA_MSGENCODE_H */