contrib/bind-9.3/lib/lwres/man/lwres_gabn.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_gabn.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_gabn
  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_GABN" "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_gabnrequest_render, lwres_gabnresponse_render, lwres_gabnrequest_parse, lwres_gabnresponse_parse, lwres_gabnresponse_free, lwres_gabnrequest_free \- lightweight resolver getaddrbyname message handling
  34 .SH "SYNOPSIS"
  35 .nf
  36 #include <lwres/lwres.h>
  37 .fi
  38 .HP 40
  39 .BI "lwres_result_t lwres_gabnrequest_render(lwres_context_t\ *ctx, lwres_gabnrequest_t\ *req, lwres_lwpacket_t\ *pkt, lwres_buffer_t\ *b);"
  40 .HP 41
  41 .BI "lwres_result_t lwres_gabnresponse_render(lwres_context_t\ *ctx, lwres_gabnresponse_t\ *req, lwres_lwpacket_t\ *pkt, lwres_buffer_t\ *b);"
  42 .HP 39
  43 .BI "lwres_result_t lwres_gabnrequest_parse(lwres_context_t\ *ctx, lwres_buffer_t\ *b, lwres_lwpacket_t\ *pkt, lwres_gabnrequest_t\ **structp);"
  44 .HP 40
  45 .BI "lwres_result_t lwres_gabnresponse_parse(lwres_context_t\ *ctx, lwres_buffer_t\ *b, lwres_lwpacket_t\ *pkt, lwres_gabnresponse_t\ **structp);"
  46 .HP 29
  47 .BI "void lwres_gabnresponse_free(lwres_context_t\ *ctx, lwres_gabnresponse_t\ **structp);"
  48 .HP 28
  49 .BI "void lwres_gabnrequest_free(lwres_context_t\ *ctx, lwres_gabnrequest_t\ **structp);"
  50 .SH "DESCRIPTION"
  51 .PP
  52 These are low\-level routines for creating and parsing lightweight resolver name\-to\-address lookup request and response messages.
  53 .PP
  54 There are four main functions for the getaddrbyname opcode. One render function converts a getaddrbyname request structure \(em
  55 \fBlwres_gabnrequest_t\fR
  56 \(em to the lighweight 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 \(em
  57 \fBlwres_gabnresponse_t\fR
  58 \(em to the canonical format. This is complemented by a parse function which converts a packet in canonical format to a getaddrbyname response structure.
  59 .PP
  60 These structures are defined in
  61 \fI<lwres/lwres.h>\fR. They are shown below.
  62 .sp
  63 .RS 3n
  64 .nf
  65 #define LWRES_OPCODE_GETADDRSBYNAME     0x00010001U
  66 typedef struct lwres_addr lwres_addr_t;
  67 typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
  68 typedef struct {
  69         lwres_uint32_t  flags;
  70         lwres_uint32_t  addrtypes;
  71         lwres_uint16_t  namelen;
  72         char           *name;
  73 } lwres_gabnrequest_t;
  74 typedef struct {
  75         lwres_uint32_t          flags;
  76         lwres_uint16_t          naliases;
  77         lwres_uint16_t          naddrs;
  78         char                   *realname;
  79         char                  **aliases;
  80         lwres_uint16_t          realnamelen;
  81         lwres_uint16_t         *aliaslen;
  82         lwres_addrlist_t        addrs;
  83         void                   *base;
  84         size_t                  baselen;
  85 } lwres_gabnresponse_t;
  86 .fi
  87 .RE
  88 .sp
  89 .PP
  90 \fBlwres_gabnrequest_render()\fR
  91 uses resolver context
  92 \fIctx\fR
  93 to convert getaddrbyname request structure
  94 \fIreq\fR
  95 to canonical format. The packet header structure
  96 \fIpkt\fR
  97 is initialised and transferred to buffer
  98 \fIb\fR. The contents of
  99 \fI*req\fR
 100 are then appended to the buffer in canonical format.
 101 \fBlwres_gabnresponse_render()\fR
 102 performs the same task, except it converts a getaddrbyname response structure
 103 \fBlwres_gabnresponse_t\fR
 104 to the lightweight resolver's canonical format.
 105 .PP
 106 \fBlwres_gabnrequest_parse()\fR
 107 uses context
 108 \fIctx\fR
 109 to convert the contents of packet
 110 \fIpkt\fR
 111 to a
 112 \fBlwres_gabnrequest_t\fR
 113 structure. Buffer
 114 \fIb\fR
 115 provides space to be used for storing this structure. When the function succeeds, the resulting
 116 \fBlwres_gabnrequest_t\fR
 117 is made available through
 118 \fI*structp\fR.
 119 \fBlwres_gabnresponse_parse()\fR
 120 offers the same semantics as
 121 \fBlwres_gabnrequest_parse()\fR
 122 except it yields a
 123 \fBlwres_gabnresponse_t\fR
 124 structure.
 125 .PP
 126 \fBlwres_gabnresponse_free()\fR
 127 and
 128 \fBlwres_gabnrequest_free()\fR
 129 release the memory in resolver context
 130 \fIctx\fR
 131 that was allocated to the
 132 \fBlwres_gabnresponse_t\fR
 133 or
 134 \fBlwres_gabnrequest_t\fR
 135 structures referenced via
 136 \fIstructp\fR. Any memory associated with ancillary buffers and strings for those structures is also discarded.
 137 .SH "RETURN VALUES"
 138 .PP
 139 The getaddrbyname opcode functions
 140 \fBlwres_gabnrequest_render()\fR,
 141 \fBlwres_gabnresponse_render()\fR
 142 \fBlwres_gabnrequest_parse()\fR
 143 and
 144 \fBlwres_gabnresponse_parse()\fR
 145 all return
 146 \fBLWRES_R_SUCCESS\fR
 147 on success. They return
 148 \fBLWRES_R_NOMEMORY\fR
 149 if memory allocation fails.
 150 \fBLWRES_R_UNEXPECTEDEND\fR
 151 is returned if the available space in the buffer
 152 \fIb\fR
 153 is too small to accommodate the packet header or the
 154 \fBlwres_gabnrequest_t\fR
 155 and
 156 \fBlwres_gabnresponse_t\fR
 157 structures.
 158 \fBlwres_gabnrequest_parse()\fR
 159 and
 160 \fBlwres_gabnresponse_parse()\fR
 161 will return
 162 \fBLWRES_R_UNEXPECTEDEND\fR
 163 if the buffer is not empty after decoding the received packet. These functions will return
 164 \fBLWRES_R_FAILURE\fR
 165 if
 166 pktflags
 167 in the packet header structure
 168 \fBlwres_lwpacket_t\fR
 169 indicate that the packet is not a response to an earlier query.
 170 .SH "SEE ALSO"
 171 .PP
 172 \fBlwres_packet\fR(3 )
 173 .SH "COPYRIGHT"
 174 Copyright \(co 2004, 2005 Internet Systems Consortium, Inc. ("ISC")