/* * Copyright (C) 2004-2007, 2009 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1999-2002 Internet Software Consortium. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */ /* $Id: compress.h,v 1.42 2009/01/17 23:47:43 tbox Exp $ */ #ifndef DNS_COMPRESS_H #define DNS_COMPRESS_H 1 #include <isc/lang.h> #include <isc/region.h> #include <dns/types.h> ISC_LANG_BEGINDECLS #define DNS_COMPRESS_NONE 0x00 /*%< no compression */ #define DNS_COMPRESS_GLOBAL14 0x01 /*%< "normal" compression. */ #define DNS_COMPRESS_ALL 0x01 /*%< all compression. */ #define DNS_COMPRESS_CASESENSITIVE 0x02 /*%< case sensitive compression. */ /*! \file dns/compress.h * Direct manipulation of the structures is strongly discouraged. */ #define DNS_COMPRESS_TABLESIZE 64 #define DNS_COMPRESS_INITIALNODES 16 typedef struct dns_compressnode dns_compressnode_t; struct dns_compressnode { isc_region_t r; isc_uint16_t offset; isc_uint16_t count; isc_uint8_t labels; dns_compressnode_t *next; }; struct dns_compress { unsigned int magic; /*%< Magic number. */ unsigned int allowed; /*%< Allowed methods. */ int edns; /*%< Edns version or -1. */ /*% Global compression table. */ dns_compressnode_t *table[DNS_COMPRESS_TABLESIZE]; /*% Preallocated nodes for the table. */ dns_compressnode_t initialnodes[DNS_COMPRESS_INITIALNODES]; isc_uint16_t count; /*%< Number of nodes. */ isc_mem_t *mctx; /*%< Memory context. */ }; typedef enum { DNS_DECOMPRESS_ANY, /*%< Any compression */ DNS_DECOMPRESS_STRICT, /*%< Allowed compression */ DNS_DECOMPRESS_NONE /*%< No compression */ } dns_decompresstype_t; struct dns_decompress { unsigned int magic; /*%< Magic number. */ unsigned int allowed; /*%< Allowed methods. */ int edns; /*%< Edns version or -1. */ dns_decompresstype_t type; /*%< Strict checking */ }; isc_result_t dns_compress_init(dns_compress_t *cctx, int edns, isc_mem_t *mctx); /*%< * Initialise the compression context structure pointed to by 'cctx'. * * Requires: * \li 'cctx' is a valid dns_compress_t structure. * \li 'mctx' is an initialized memory context. * Ensures: * \li cctx->global is initialized. * * Returns: * \li #ISC_R_SUCCESS * \li failures from dns_rbt_create() */ void dns_compress_invalidate(dns_compress_t *cctx); /*%< * Invalidate the compression structure pointed to by cctx. * * Requires: *\li 'cctx' to be initialized. */ void dns_compress_setmethods(dns_compress_t *cctx, unsigned int allowed); /*%< * Sets allowed compression methods. * * Requires: *\li 'cctx' to be initialized. */ unsigned int dns_compress_getmethods(dns_compress_t *cctx); /*%< * Gets allowed compression methods. * * Requires: *\li 'cctx' to be initialized. * * Returns: *\li allowed compression bitmap. */ void dns_compress_setsensitive(dns_compress_t *cctx, isc_boolean_t sensitive); /* * Preserve the case of compressed domain names. * * Requires: * 'cctx' to be initialized. */ isc_boolean_t dns_compress_getsensitive(dns_compress_t *cctx); /* * Return whether case is to be preserved when compressing * domain names. * * Requires: * 'cctx' to be initialized. */ int dns_compress_getedns(dns_compress_t *cctx); /*%< * Gets edns value. * * Requires: *\li 'cctx' to be initialized. * * Returns: *\li -1 .. 255 */ isc_boolean_t dns_compress_findglobal(dns_compress_t *cctx, const dns_name_t *name, dns_name_t *prefix, isc_uint16_t *offset); /*%< * Finds longest possible match of 'name' in the global compression table. * * Requires: *\li 'cctx' to be initialized. *\li 'name' to be a absolute name. *\li 'prefix' to be initialized. *\li 'offset' to point to an isc_uint16_t. * * Ensures: *\li 'prefix' and 'offset' are valid if ISC_TRUE is returned. * * Returns: *\li #ISC_TRUE / #ISC_FALSE */ void dns_compress_add(dns_compress_t *cctx, const dns_name_t *name, const dns_name_t *prefix, isc_uint16_t offset); /*%< * Add compression pointers for 'name' to the compression table, * not replacing existing pointers. * * Requires: *\li 'cctx' initialized * *\li 'name' must be initialized and absolute, and must remain * valid until the message compression is complete. * *\li 'prefix' must be a prefix returned by * dns_compress_findglobal(), or the same as 'name'. */ void dns_compress_rollback(dns_compress_t *cctx, isc_uint16_t offset); /*%< * Remove any compression pointers from global table >= offset. * * Requires: *\li 'cctx' is initialized. */ void dns_decompress_init(dns_decompress_t *dctx, int edns, dns_decompresstype_t type); /*%< * Initializes 'dctx'. * Records 'edns' and 'type' into the structure. * * Requires: *\li 'dctx' to be a valid pointer. */ void dns_decompress_invalidate(dns_decompress_t *dctx); /*%< * Invalidates 'dctx'. * * Requires: *\li 'dctx' to be initialized */ void dns_decompress_setmethods(dns_decompress_t *dctx, unsigned int allowed); /*%< * Sets 'dctx->allowed' to 'allowed'. * * Requires: *\li 'dctx' to be initialized */ unsigned int dns_decompress_getmethods(dns_decompress_t *dctx); /*%< * Returns 'dctx->allowed' * * Requires: *\li 'dctx' to be initialized */ int dns_decompress_edns(dns_decompress_t *dctx); /*%< * Returns 'dctx->edns' * * Requires: *\li 'dctx' to be initialized */ dns_decompresstype_t dns_decompress_type(dns_decompress_t *dctx); /*%< * Returns 'dctx->type' * * Requires: *\li 'dctx' to be initialized */ ISC_LANG_ENDDECLS #endif /* DNS_COMPRESS_H */