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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 handlingSYNOPSIS¶
#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;
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).COPYRIGHT¶
Copyright © 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")June 30, 2000 | BIND9 |