contrib/bind-9.5.2/lib/lwres/man/lwres_gnba.3

   1 .\" Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
   2 .\" Copyright (C) 2000, 2001 Internet Software Consortium.
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  16 .\" $Id: lwres_gnba.3,v 1.27.214.1 2009/07/11 01:43:31 tbox Exp $
  17 .\"
  18 .hy 0
  19 .ad l
  20 .\"     Title: lwres_gnba
  21 .\"    Author:
  22 .\" Generator: DocBook XSL Stylesheets v1.71.1 <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 .PP
  63 .RS 4
  64 .nf
  65 #define LWRES_OPCODE_GETNAMEBYADDR      0x00010002U
  66 .fi
  67 .RE
  68 .sp
  69 .PP
  70 .RS 4
  71 .nf
  72 typedef struct {
  73         lwres_uint32_t  flags;
  74         lwres_addr_t    addr;
  75 } lwres_gnbarequest_t;
  76 .fi
  77 .RE
  78 .sp
  79 .PP
  80 .RS 4
  81 .nf
  82 typedef struct {
  83         lwres_uint32_t  flags;
  84         lwres_uint16_t  naliases;
  85         char           *realname;
  86         char          **aliases;
  87         lwres_uint16_t  realnamelen;
  88         lwres_uint16_t *aliaslen;
  89         void           *base;
  90         size_t          baselen;
  91 } lwres_gnbaresponse_t;
  92 .fi
  93 .RE
  94 .sp
  95 .PP
  96 \fBlwres_gnbarequest_render()\fR
  97 uses resolver context
  98 \fIctx\fR
  99 to convert getnamebyaddr request structure
 100 \fIreq\fR
 101 to canonical format. The packet header structure
 102 \fIpkt\fR
 103 is initialised and transferred to buffer
 104 \fIb\fR. The contents of
 105 \fI*req\fR
 106 are then appended to the buffer in canonical format.
 107 \fBlwres_gnbaresponse_render()\fR
 108 performs the same task, except it converts a getnamebyaddr response structure
 109 \fBlwres_gnbaresponse_t\fR
 110 to the lightweight resolver's canonical format.
 111 .PP
 112 \fBlwres_gnbarequest_parse()\fR
 113 uses context
 114 \fIctx\fR
 115 to convert the contents of packet
 116 \fIpkt\fR
 117 to a
 118 \fBlwres_gnbarequest_t\fR
 119 structure. Buffer
 120 \fIb\fR
 121 provides space to be used for storing this structure. When the function succeeds, the resulting
 122 \fBlwres_gnbarequest_t\fR
 123 is made available through
 124 \fI*structp\fR.
 125 \fBlwres_gnbaresponse_parse()\fR
 126 offers the same semantics as
 127 \fBlwres_gnbarequest_parse()\fR
 128 except it yields a
 129 \fBlwres_gnbaresponse_t\fR
 130 structure.
 131 .PP
 132 \fBlwres_gnbaresponse_free()\fR
 133 and
 134 \fBlwres_gnbarequest_free()\fR
 135 release the memory in resolver context
 136 \fIctx\fR
 137 that was allocated to the
 138 \fBlwres_gnbaresponse_t\fR
 139 or
 140 \fBlwres_gnbarequest_t\fR
 141 structures referenced via
 142 \fIstructp\fR. Any memory associated with ancillary buffers and strings for those structures is also discarded.
 143 .SH "RETURN VALUES"
 144 .PP
 145 The getnamebyaddr opcode functions
 146 \fBlwres_gnbarequest_render()\fR,
 147 \fBlwres_gnbaresponse_render()\fR
 148 \fBlwres_gnbarequest_parse()\fR
 149 and
 150 \fBlwres_gnbaresponse_parse()\fR
 151 all return
 152 \fBLWRES_R_SUCCESS\fR
 153 on success. They return
 154 \fBLWRES_R_NOMEMORY\fR
 155 if memory allocation fails.
 156 \fBLWRES_R_UNEXPECTEDEND\fR
 157 is returned if the available space in the buffer
 158 \fIb\fR
 159 is too small to accommodate the packet header or the
 160 \fBlwres_gnbarequest_t\fR
 161 and
 162 \fBlwres_gnbaresponse_t\fR
 163 structures.
 164 \fBlwres_gnbarequest_parse()\fR
 165 and
 166 \fBlwres_gnbaresponse_parse()\fR
 167 will return
 168 \fBLWRES_R_UNEXPECTEDEND\fR
 169 if the buffer is not empty after decoding the received packet. These functions will return
 170 \fBLWRES_R_FAILURE\fR
 171 if
 172 pktflags
 173 in the packet header structure
 174 \fBlwres_lwpacket_t\fR
 175 indicate that the packet is not a response to an earlier query.
 176 .SH "SEE ALSO"
 177 .PP
 178 \fBlwres_packet\fR(3).
 179 .SH "COPYRIGHT"
 180 Copyright \(co 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
 181 .br
 182 Copyright \(co 2000, 2001 Internet Software Consortium.
 183 .br