unbound/util/edns.h

122 lines
3.9 KiB
C

/*
* util/edns.h - handle base EDNS options.
*
* Copyright (c) 2018, 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 functions for base EDNS options.
*/
#ifndef UTIL_EDNS_H
#define UTIL_EDNS_H
#include "util/storage/dnstree.h"
struct edns_data;
struct config_file;
struct comm_point;
struct regional;
/**
* Structure containing all EDNS strings.
*/
struct edns_strings {
/** Tree of EDNS client strings to use in upstream queries, per address
* prefix. Contains nodes of type edns_string_addr. */
rbtree_type client_strings;
/** EDNS opcode to use for client strings */
uint16_t client_string_opcode;
/** region to allocate tree nodes in */
struct regional* region;
};
/**
* EDNS string. Node of rbtree, containing string and prefix.
*/
struct edns_string_addr {
/** node in address tree, used for tree lookups. Need to be the first
* member of this struct. */
struct addr_tree_node node;
/** string, ascii format */
uint8_t* string;
/** length of string */
size_t string_len;
};
/**
* Create structure to hold EDNS strings
* @return: newly created edns_strings, NULL on alloc failure.
*/
struct edns_strings* edns_strings_create(void);
/** Delete EDNS strings structure
* @param edns_strings: struct to delete
*/
void edns_strings_delete(struct edns_strings* edns_strings);
/**
* Add configured EDNS strings
* @param edns_strings: edns strings to apply config to
* @param config: struct containing EDNS strings configuration
* @return 0 on error
*/
int edns_strings_apply_cfg(struct edns_strings* edns_strings,
struct config_file* config);
/**
* Find string for address.
* @param tree: tree containing EDNS strings per address prefix.
* @param addr: address to use for tree lookup
* @param addrlen: length of address
* @return: matching tree node, NULL otherwise
*/
struct edns_string_addr*
edns_string_addr_lookup(rbtree_type* tree, struct sockaddr_storage* addr,
socklen_t addrlen);
/**
* Apply common EDNS options.
*
* @param edns_out: initialised edns information with outbound edns.
* @param edns_in: initialised edns information with received edns.
* @param cfg: configuration.
* @param c: comm channel.
* @param region: the region to allocate the edns options in.
*/
int apply_edns_options(struct edns_data* edns_out, struct edns_data* edns_in,
struct config_file* cfg, struct comm_point* c, struct regional* region);
#endif