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2024-04-16 00:01 @18.222.69.152 CrawledBy claudebot
LWRES_GABN(3) BIND9 LWRES_GABN(3)
NAME
lwres_gabnrequest_render, lwres_gabnresponse_render, lwres_gabnrequest_parse,
lwres_gabnresponse_parse, lwres_gabnresponse_free, lwres_gabnrequest_free - lightweight
resolver getaddrbyname message handling
SYNOPSIS
#include <lwres/lwres.h>
lwres_result_t lwres_gabnrequest_render(lwres_context_t *ctx, lwres_gabnrequest_t *req,
lwres_lwpacket_t *pkt, lwres_buffer_t *b);
lwres_result_t lwres_gabnresponse_render(lwres_context_t *ctx, lwres_gabnresponse_t *req,
lwres_lwpacket_t *pkt, lwres_buffer_t *b);
lwres_result_t lwres_gabnrequest_parse(lwres_context_t *ctx, lwres_buffer_t *b,
lwres_lwpacket_t *pkt,
lwres_gabnrequest_t **structp);
lwres_result_t lwres_gabnresponse_parse(lwres_context_t *ctx, lwres_buffer_t *b,
lwres_lwpacket_t *pkt,
lwres_gabnresponse_t **structp);
void lwres_gabnresponse_free(lwres_context_t *ctx, lwres_gabnresponse_t **structp);
void lwres_gabnrequest_free(lwres_context_t *ctx, lwres_gabnrequest_t **structp);
DESCRIPTION
These are low-level routines for creating and parsing lightweight resolver name-to-address
lookup request and response messages.
There are four main functions for the getaddrbyname opcode. One render function converts a
getaddrbyname request structure -- lwres_gabnrequest_t -- to the lightweight resolver's
canonical format. It is complemented by a parse function that converts a packet in this
canonical format to a getaddrbyname request structure. Another render function converts
the getaddrbyname response structure -- lwres_gabnresponse_t -- to the canonical format.
This is complemented by a parse function which converts a packet in canonical format to a
getaddrbyname response structure.
These structures are defined in <lwres/lwres.h>. They are shown below.
#define LWRES_OPCODE_GETADDRSBYNAME 0x00010001U
typedef struct lwres_addr lwres_addr_t;
typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
typedef struct {
lwres_uint32_t flags;
lwres_uint32_t addrtypes;
lwres_uint16_t namelen;
char *name;
} lwres_gabnrequest_t;
typedef struct {
lwres_uint32_t flags;
lwres_uint16_t naliases;
lwres_uint16_t naddrs;
char *realname;
char **aliases;
lwres_uint16_t realnamelen;
lwres_uint16_t *aliaslen;
lwres_addrlist_t addrs;
void *base;
size_t baselen;
} lwres_gabnresponse_t;
lwres_gabnrequest_render() uses resolver context ctx to convert getaddrbyname request
structure req to canonical format. The packet header structure pkt is initialised and
transferred to buffer b. The contents of *req are then appended to the buffer in canonical
format. lwres_gabnresponse_render() performs the same task, except it converts a
getaddrbyname response structure lwres_gabnresponse_t to the lightweight resolver's
canonical format.
lwres_gabnrequest_parse() uses context ctx to convert the contents of packet pkt to a
lwres_gabnrequest_t structure. Buffer b provides space to be used for storing this
structure. When the function succeeds, the resulting lwres_gabnrequest_t is made available
through *structp. lwres_gabnresponse_parse() offers the same semantics as
lwres_gabnrequest_parse() except it yields a lwres_gabnresponse_t structure.
lwres_gabnresponse_free() and lwres_gabnrequest_free() release the memory in resolver
context ctx that was allocated to the lwres_gabnresponse_t or lwres_gabnrequest_t
structures referenced via structp. Any memory associated with ancillary buffers and
strings for those structures is also discarded.
RETURN VALUES
The getaddrbyname opcode functions lwres_gabnrequest_render(),
lwres_gabnresponse_render()lwres_gabnrequest_parse() and lwres_gabnresponse_parse() all
return LWRES_R_SUCCESS on success. They return LWRES_R_NOMEMORY if memory allocation
fails. LWRES_R_UNEXPECTEDEND is returned if the available space in the buffer b is too
small to accommodate the packet header or the lwres_gabnrequest_t and lwres_gabnresponse_t
structures. lwres_gabnrequest_parse() and lwres_gabnresponse_parse() will return
LWRES_R_UNEXPECTEDEND if the buffer is not empty after decoding the received packet. These
functions will return LWRES_R_FAILURE if pktflags in the packet header structure
lwres_lwpacket_t indicate that the packet is not a response to an earlier query.
SEE ALSO
lwres_packet(3)
AUTHOR
Internet Systems Consortium, Inc.
COPYRIGHT
Copyright (C) 2000, 2001, 2004, 2005, 2007, 2014-2016, 2018 Internet Systems Consortium,
Inc. ("ISC")
ISC 2007-06-18 LWRES_GABN(3)
Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache
Under GNU General Public License
2024-04-16 00:01 @18.222.69.152 CrawledBy claudebot