contrib/bind-9.3/lib/lwres/man/lwres_gnba.3

   1 .\" Copyright (C) 2004, 2005 Internet Systems Consortium, Inc. ("ISC")
   2 .\" Copyright (C) 2000, 2001 Internet Software Consortium.
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  16 .\" $Id: lwres_gnba.3,v 1.13.2.1.8.6 2006/06/29 13:02:31 marka Exp $
  17 .\"
  18 .hy 0
  19 .ad l
  20 .\"     Title: lwres_gnba
  21 .\"    Author:
  22 .\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/>
  23 .\"      Date: Jun 30, 2000
  24 .\"    Manual: BIND9
  25 .\"    Source: BIND9
  26 .\"
  27 .TH "LWRES_GNBA" "3" "Jun 30, 2000" "BIND9" "BIND9"
  28 .\" disable hyphenation
  29 .nh
  30 .\" disable justification (adjust text to left margin only)
  31 .ad l
  32 .SH "NAME"
  33 lwres_gnbarequest_render, lwres_gnbaresponse_render, lwres_gnbarequest_parse, lwres_gnbaresponse_parse, lwres_gnbaresponse_free, lwres_gnbarequest_free \- lightweight resolver getnamebyaddress message handling
  34 .SH "SYNOPSIS"
  35 .nf
  36 #include <lwres/lwres.h>
  37 .fi
  38 .HP 40
  39 .BI "lwres_result_t lwres_gnbarequest_render(lwres_context_t\ *" "ctx" ", lwres_gnbarequest_t\ *" "req" ", lwres_lwpacket_t\ *" "pkt" ", lwres_buffer_t\ *" "b" ");"
  40 .HP 41
  41 .BI "lwres_result_t lwres_gnbaresponse_render(lwres_context_t\ *ctx, lwres_gnbaresponse_t\ *req, lwres_lwpacket_t\ *pkt, lwres_buffer_t\ *b);"
  42 .HP 39
  43 .BI "lwres_result_t lwres_gnbarequest_parse(lwres_context_t\ *ctx, lwres_buffer_t\ *b, lwres_lwpacket_t\ *pkt, lwres_gnbarequest_t\ **structp);"
  44 .HP 40
  45 .BI "lwres_result_t lwres_gnbaresponse_parse(lwres_context_t\ *ctx, lwres_buffer_t\ *b, lwres_lwpacket_t\ *pkt, lwres_gnbaresponse_t\ **structp);"
  46 .HP 29
  47 .BI "void lwres_gnbaresponse_free(lwres_context_t\ *ctx, lwres_gnbaresponse_t\ **structp);"
  48 .HP 28
  49 .BI "void lwres_gnbarequest_free(lwres_context_t\ *ctx, lwres_gnbarequest_t\ **structp);"
  50 .SH "DESCRIPTION"
  51 .PP
  52 These are low\-level routines for creating and parsing lightweight resolver address\-to\-name lookup request and response messages.
  53 .PP
  54 There are four main functions for the getnamebyaddr opcode. One render function converts a getnamebyaddr request structure \(em
  55 \fBlwres_gnbarequest_t\fR
  56 \(em 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 \(em
  57 \fBlwres_gnbaresponse_t\fR
  58 to the canonical format. This is complemented by a parse function which converts a packet in canonical format to a getnamebyaddr response structure.
  59 .PP
  60 These structures are defined in
  61 \fIlwres/lwres.h\fR. They are shown below.
  62 .sp
  63 .RS 3n
  64 .nf
  65 #define LWRES_OPCODE_GETNAMEBYADDR      0x00010002U
  66 typedef struct {
  67         lwres_uint32_t  flags;
  68         lwres_addr_t    addr;
  69 } lwres_gnbarequest_t;
  70 typedef struct {
  71         lwres_uint32_t  flags;
  72         lwres_uint16_t  naliases;
  73         char           *realname;
  74         char          **aliases;
  75         lwres_uint16_t  realnamelen;
  76         lwres_uint16_t *aliaslen;
  77         void           *base;
  78         size_t          baselen;
  79 } lwres_gnbaresponse_t;
  80 .fi
  81 .RE
  82 .sp
  83 .PP
  84 \fBlwres_gnbarequest_render()\fR
  85 uses resolver context
  86 \fIctx\fR
  87 to convert getnamebyaddr request structure
  88 \fIreq\fR
  89 to canonical format. The packet header structure
  90 \fIpkt\fR
  91 is initialised and transferred to buffer
  92 \fIb\fR. The contents of
  93 \fI*req\fR
  94 are then appended to the buffer in canonical format.
  95 \fBlwres_gnbaresponse_render()\fR
  96 performs the same task, except it converts a getnamebyaddr response structure
  97 \fBlwres_gnbaresponse_t\fR
  98 to the lightweight resolver's canonical format.
  99 .PP
 100 \fBlwres_gnbarequest_parse()\fR
 101 uses context
 102 \fIctx\fR
 103 to convert the contents of packet
 104 \fIpkt\fR
 105 to a
 106 \fBlwres_gnbarequest_t\fR
 107 structure. Buffer
 108 \fIb\fR
 109 provides space to be used for storing this structure. When the function succeeds, the resulting
 110 \fBlwres_gnbarequest_t\fR
 111 is made available through
 112 \fI*structp\fR.
 113 \fBlwres_gnbaresponse_parse()\fR
 114 offers the same semantics as
 115 \fBlwres_gnbarequest_parse()\fR
 116 except it yields a
 117 \fBlwres_gnbaresponse_t\fR
 118 structure.
 119 .PP
 120 \fBlwres_gnbaresponse_free()\fR
 121 and
 122 \fBlwres_gnbarequest_free()\fR
 123 release the memory in resolver context
 124 \fIctx\fR
 125 that was allocated to the
 126 \fBlwres_gnbaresponse_t\fR
 127 or
 128 \fBlwres_gnbarequest_t\fR
 129 structures referenced via
 130 \fIstructp\fR. Any memory associated with ancillary buffers and strings for those structures is also discarded.
 131 .SH "RETURN VALUES"
 132 .PP
 133 The getnamebyaddr opcode functions
 134 \fBlwres_gnbarequest_render()\fR,
 135 \fBlwres_gnbaresponse_render()\fR
 136 \fBlwres_gnbarequest_parse()\fR
 137 and
 138 \fBlwres_gnbaresponse_parse()\fR
 139 all return
 140 \fBLWRES_R_SUCCESS\fR
 141 on success. They return
 142 \fBLWRES_R_NOMEMORY\fR
 143 if memory allocation fails.
 144 \fBLWRES_R_UNEXPECTEDEND\fR
 145 is returned if the available space in the buffer
 146 \fIb\fR
 147 is too small to accommodate the packet header or the
 148 \fBlwres_gnbarequest_t\fR
 149 and
 150 \fBlwres_gnbaresponse_t\fR
 151 structures.
 152 \fBlwres_gnbarequest_parse()\fR
 153 and
 154 \fBlwres_gnbaresponse_parse()\fR
 155 will return
 156 \fBLWRES_R_UNEXPECTEDEND\fR
 157 if the buffer is not empty after decoding the received packet. These functions will return
 158 \fBLWRES_R_FAILURE\fR
 159 if
 160 pktflags
 161 in the packet header structure
 162 \fBlwres_lwpacket_t\fR
 163 indicate that the packet is not a response to an earlier query.
 164 .SH "SEE ALSO"
 165 .PP
 166 \fBlwres_packet\fR(3).
 167 .SH "COPYRIGHT"
 168 Copyright \(co 2004, 2005 Internet Systems Consortium, Inc. ("ISC")