rspamd/contrib/librdns/compression.h

/* Copyright (c) 2014, Vsevolod Stakhov
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED ''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 AUTHOR 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.
 */
#ifndef COMPRESSION_H_
#define COMPRESSION_H_

#include "dns_private.h"
#include "khash.h"

struct rdns_compression_name {
	const char *suffix;	 /**< suffix packed */
	unsigned int suffix_len; /**< length of the suffix */
	unsigned int offset; /**< offset in the packet */
};


KHASH_DECLARE(rdns_compression_hash, struct rdns_compression_name, char);

/**
 * Try to compress name passed or write it 'as is'
 * @return
 */
bool rdns_write_name_compressed (struct rdns_request *req,
		const char *name, unsigned int namelen,
		khash_t(rdns_compression_hash) **comp);

void rdns_compression_free (khash_t(rdns_compression_hash) *comp);

#endif /* COMPRESSION_H_ */