00b67f09dd
Also known as ISC bind. This import adds utilities such as host(1), dig(1), and nslookup(1), as well as many other tools and libraries. Change-Id: I035ca46e64f1965d57019e773f4ff0ef035e4aa3
145 lines
4.8 KiB
C
145 lines
4.8 KiB
C
/* $NetBSD: symtab.h,v 1.5 2014/12/10 04:38:00 christos Exp $ */
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/*
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* Copyright (C) 2004-2007, 2009, 2011-2013 Internet Systems Consortium, Inc. ("ISC")
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* Copyright (C) 1996-2001 Internet Software Consortium.
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
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* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
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* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
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* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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*/
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/* Id */
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#ifndef ISC_SYMTAB_H
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#define ISC_SYMTAB_H 1
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/*****
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***** Module Info
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*****/
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/*! \file isc/symtab.h
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* \brief Provides a simple memory-based symbol table.
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*
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* Keys are C strings, and key comparisons are case-insensitive. A type may
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* be specified when looking up, defining, or undefining. A type value of
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* 0 means "match any type"; any other value will only match the given
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* type.
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*
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* It's possible that a client will attempt to define a <key, type, value>
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* tuple when a tuple with the given key and type already exists in the table.
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* What to do in this case is specified by the client. Possible policies are:
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*
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*\li #isc_symexists_reject Disallow the define, returning #ISC_R_EXISTS
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*\li #isc_symexists_replace Replace the old value with the new. The
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* undefine action (if provided) will be called
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* with the old <key, type, value> tuple.
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*\li #isc_symexists_add Add the new tuple, leaving the old tuple in
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* the table. Subsequent lookups will retrieve
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* the most-recently-defined tuple.
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*
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* A lookup of a key using type 0 will return the most-recently defined
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* symbol with that key. An undefine of a key using type 0 will undefine the
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* most-recently defined symbol with that key. Trying to define a key with
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* type 0 is illegal.
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*
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* The symbol table library does not make a copy the key field, so the
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* caller must ensure that any key it passes to isc_symtab_define() will not
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* change until it calls isc_symtab_undefine() or isc_symtab_destroy().
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*
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* A user-specified action will be called (if provided) when a symbol is
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* undefined. It can be used to free memory associated with keys and/or
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* values.
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*
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* A symbol table is implemented as a hash table of lists; the size of the
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* hash table is set by the 'size' parameter to isc_symtbl_create(). When
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* the number of entries in the symbol table reaches three quarters of this
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* value, the hash table is reallocated with size doubled, in order to
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* optimize lookup performance. This has a negative effect on insertion
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* performance, which can be mitigated by sizing the table appropriately
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* when creating it.
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*
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* \li MP:
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* The callers of this module must ensure any required synchronization.
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*
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* \li Reliability:
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* No anticipated impact.
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*
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* \li Resources:
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* TBS
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*
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* \li Security:
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* No anticipated impact.
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*
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* \li Standards:
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* None.
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*/
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/***
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*** Imports.
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***/
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#include <isc/lang.h>
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#include <isc/types.h>
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/*
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*** Symbol Tables.
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***/
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/*% Symbol table value. */
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typedef union isc_symvalue {
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void * as_pointer;
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const void * as_cpointer;
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int as_integer;
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unsigned int as_uinteger;
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} isc_symvalue_t;
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typedef void (*isc_symtabaction_t)(char *key, unsigned int type,
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isc_symvalue_t value, void *userarg);
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/*% Symbol table exists. */
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typedef enum {
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isc_symexists_reject = 0, /*%< Disallow the define */
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isc_symexists_replace = 1, /*%< Replace the old value with the new */
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isc_symexists_add = 2 /*%< Add the new tuple */
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} isc_symexists_t;
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ISC_LANG_BEGINDECLS
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/*% Create a symbol table. */
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isc_result_t
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isc_symtab_create(isc_mem_t *mctx, unsigned int size,
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isc_symtabaction_t undefine_action, void *undefine_arg,
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isc_boolean_t case_sensitive, isc_symtab_t **symtabp);
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/*% Destroy a symbol table. */
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void
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isc_symtab_destroy(isc_symtab_t **symtabp);
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/*% Lookup a symbol table. */
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isc_result_t
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isc_symtab_lookup(isc_symtab_t *symtab, const char *key, unsigned int type,
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isc_symvalue_t *value);
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/*% Define a symbol table. */
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isc_result_t
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isc_symtab_define(isc_symtab_t *symtab, const char *key, unsigned int type,
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isc_symvalue_t value, isc_symexists_t exists_policy);
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/*% Undefine a symbol table. */
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isc_result_t
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isc_symtab_undefine(isc_symtab_t *symtab, const char *key, unsigned int type);
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/*% Return the number of items in a symbol table. */
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unsigned int
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isc_symtab_count(isc_symtab_t *symtab);
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ISC_LANG_ENDDECLS
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#endif /* ISC_SYMTAB_H */
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