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LWRES_GNBA(3) BIND9 LWRES_GNBA(3)
NAME
lwres_gnbarequest_render, lwres_gnbaresponse_render, lwres_gnbarequest_parse,
lwres_gnbaresponse_parse, lwres_gnbaresponse_free, lwres_gnbarequest_free - lightweight
resolver getnamebyaddress message handling
SYNOPSIS
#include <lwres/lwres.h>
lwres_result_t lwres_gnbarequest_render(lwres_context_t *ctx, lwres_gnbarequest_t *req,
lwres_lwpacket_t *pkt, lwres_buffer_t *b);
lwres_result_t lwres_gnbaresponse_render(lwres_context_t *ctx, lwres_gnbaresponse_t *req,
lwres_lwpacket_t *pkt, lwres_buffer_t *b);
lwres_result_t lwres_gnbarequest_parse(lwres_context_t *ctx, lwres_buffer_t *b,
lwres_lwpacket_t *pkt,
lwres_gnbarequest_t **structp);
lwres_result_t lwres_gnbaresponse_parse(lwres_context_t *ctx, lwres_buffer_t *b,
lwres_lwpacket_t *pkt,
lwres_gnbaresponse_t **structp);
void lwres_gnbaresponse_free(lwres_context_t *ctx, lwres_gnbaresponse_t **structp);
void lwres_gnbarequest_free(lwres_context_t *ctx, lwres_gnbarequest_t **structp);
DESCRIPTION
These are low-level routines for creating and parsing lightweight resolver address-to-name
lookup request and response messages.
There are four main functions for the getnamebyaddr opcode. One render function converts a
getnamebyaddr request structure -- lwres_gnbarequest_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 getnamebyaddr request structure. Another render function converts
the getnamebyaddr response structure -- lwres_gnbaresponse_t to the canonical format. This
is complemented by a parse function which converts a packet in canonical format to a
getnamebyaddr response structure.
These structures are defined in lwres/lwres.h. They are shown below.
#define LWRES_OPCODE_GETNAMEBYADDR 0x00010002U
typedef struct {
lwres_uint32_t flags;
lwres_addr_t addr;
} lwres_gnbarequest_t;
typedef struct {
lwres_uint32_t flags;
lwres_uint16_t naliases;
char *realname;
char **aliases;
lwres_uint16_t realnamelen;
lwres_uint16_t *aliaslen;
void *base;
size_t baselen;
} lwres_gnbaresponse_t;
lwres_gnbarequest_render() uses resolver context ctx to convert getnamebyaddr 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_gnbaresponse_render() performs the same task, except it converts a
getnamebyaddr response structure lwres_gnbaresponse_t to the lightweight resolver's
canonical format.
lwres_gnbarequest_parse() uses context ctx to convert the contents of packet pkt to a
lwres_gnbarequest_t structure. Buffer b provides space to be used for storing this
structure. When the function succeeds, the resulting lwres_gnbarequest_t is made available
through *structp. lwres_gnbaresponse_parse() offers the same semantics as
lwres_gnbarequest_parse() except it yields a lwres_gnbaresponse_t structure.
lwres_gnbaresponse_free() and lwres_gnbarequest_free() release the memory in resolver
context ctx that was allocated to the lwres_gnbaresponse_t or lwres_gnbarequest_t
structures referenced via structp. Any memory associated with ancillary buffers and
strings for those structures is also discarded.
RETURN VALUES
The getnamebyaddr opcode functions lwres_gnbarequest_render(),
lwres_gnbaresponse_render()lwres_gnbarequest_parse() and lwres_gnbaresponse_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_gnbarequest_t and lwres_gnbaresponse_t
structures. lwres_gnbarequest_parse() and lwres_gnbaresponse_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_GNBA(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
2024-04-19 12:36 @3.16.70.101 CrawledBy Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)