1/*
2 * util/edns.h - handle base EDNS options.
3 *
4 * Copyright (c) 2018, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
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.
18 *
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.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36/**
37 * \file
38 *
39 * This file contains functions for base EDNS options.
40 */
41
42#ifndef UTIL_EDNS_H
43#define UTIL_EDNS_H
44
45#include "util/storage/dnstree.h"
46
47struct edns_data;
48struct config_file;
49struct comm_point;
50struct regional;
51
52/**
53 * Structure containing all EDNS strings.
54 */
55struct edns_strings {
56	/** Tree of EDNS client strings to use in upstream queries, per address
57	 * prefix. Contains nodes of type edns_string_addr. */
58	rbtree_type client_strings;
59	/** EDNS opcode to use for client strings */
60	uint16_t client_string_opcode;
61	/** region to allocate tree nodes in */
62	struct regional* region;
63};
64
65/**
66 * EDNS string. Node of rbtree, containing string and prefix.
67 */
68struct edns_string_addr {
69	/** node in address tree, used for tree lookups. Need to be the first
70	 * member of this struct. */
71	struct addr_tree_node node;
72	/** string, ascii format */
73	uint8_t* string;
74	/** length of string */
75	size_t string_len;
76};
77
78/**
79 * Create structure to hold EDNS strings
80 * @return: newly created edns_strings, NULL on alloc failure.
81 */
82struct edns_strings* edns_strings_create(void);
83
84/** Delete EDNS strings structure
85 * @param edns_strings: struct to delete
86 */
87void edns_strings_delete(struct edns_strings* edns_strings);
88
89/**
90 * Add configured EDNS strings
91 * @param edns_strings: edns strings to apply config to
92 * @param config: struct containing EDNS strings configuration
93 * @return 0 on error
94 */
95int edns_strings_apply_cfg(struct edns_strings* edns_strings,
96	struct config_file* config);
97
98/**
99 * Find string for address.
100 * @param tree: tree containing EDNS strings per address prefix.
101 * @param addr: address to use for tree lookup
102 * @param addrlen: length of address
103 * @return: matching tree node, NULL otherwise
104 */
105struct edns_string_addr*
106edns_string_addr_lookup(rbtree_type* tree, struct sockaddr_storage* addr,
107	socklen_t addrlen);
108
109/**
110 * Apply common EDNS options.
111 *
112 * @param edns_out: initialised edns information with outbound edns.
113 * @param edns_in: initialised edns information with received edns.
114 * @param cfg: configuration.
115 * @param c: comm channel.
116 * @param region: the region to allocate the edns options in.
117 */
118int apply_edns_options(struct edns_data* edns_out, struct edns_data* edns_in,
119	struct config_file* cfg, struct comm_point* c, struct regional* region);
120
121#endif
122