contrib/bind-9.5.2/lib/lwres/man/lwres_gabn.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_gabn.3,v 1.27.214.1 2009/07/11 01:43:32 tbox Exp $
  17 .\"
  18 .hy 0
  19 .ad l
  20 .\"     Title: lwres_gabn
  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_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 .PP
  63 .RS 4
  64 .nf
  65 #define LWRES_OPCODE_GETADDRSBYNAME     0x00010001U
  66 .fi
  67 .RE
  68 .sp
  69 .PP
  70 .RS 4
  71 .nf
  72 typedef struct lwres_addr lwres_addr_t;
  73 typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
  74 .fi
  75 .RE
  76 .sp
  77 .PP
  78 .RS 4
  79 .nf
  80 typedef struct {
  81         lwres_uint32_t  flags;
  82         lwres_uint32_t  addrtypes;
  83         lwres_uint16_t  namelen;
  84         char           *name;
  85 } lwres_gabnrequest_t;
  86 .fi
  87 .RE
  88 .sp
  89 .PP
  90 .RS 4
  91 .nf
  92 typedef struct {
  93         lwres_uint32_t          flags;
  94         lwres_uint16_t          naliases;
  95         lwres_uint16_t          naddrs;
  96         char                   *realname;
  97         char                  **aliases;
  98         lwres_uint16_t          realnamelen;
  99         lwres_uint16_t         *aliaslen;
 100         lwres_addrlist_t        addrs;
 101         void                   *base;
 102         size_t                  baselen;
 103 } lwres_gabnresponse_t;
 104 .fi
 105 .RE
 106 .sp
 107 .PP
 108 \fBlwres_gabnrequest_render()\fR
 109 uses resolver context
 110 \fIctx\fR
 111 to convert getaddrbyname request structure
 112 \fIreq\fR
 113 to canonical format. The packet header structure
 114 \fIpkt\fR
 115 is initialised and transferred to buffer
 116 \fIb\fR. The contents of
 117 \fI*req\fR
 118 are then appended to the buffer in canonical format.
 119 \fBlwres_gabnresponse_render()\fR
 120 performs the same task, except it converts a getaddrbyname response structure
 121 \fBlwres_gabnresponse_t\fR
 122 to the lightweight resolver's canonical format.
 123 .PP
 124 \fBlwres_gabnrequest_parse()\fR
 125 uses context
 126 \fIctx\fR
 127 to convert the contents of packet
 128 \fIpkt\fR
 129 to a
 130 \fBlwres_gabnrequest_t\fR
 131 structure. Buffer
 132 \fIb\fR
 133 provides space to be used for storing this structure. When the function succeeds, the resulting
 134 \fBlwres_gabnrequest_t\fR
 135 is made available through
 136 \fI*structp\fR.
 137 \fBlwres_gabnresponse_parse()\fR
 138 offers the same semantics as
 139 \fBlwres_gabnrequest_parse()\fR
 140 except it yields a
 141 \fBlwres_gabnresponse_t\fR
 142 structure.
 143 .PP
 144 \fBlwres_gabnresponse_free()\fR
 145 and
 146 \fBlwres_gabnrequest_free()\fR
 147 release the memory in resolver context
 148 \fIctx\fR
 149 that was allocated to the
 150 \fBlwres_gabnresponse_t\fR
 151 or
 152 \fBlwres_gabnrequest_t\fR
 153 structures referenced via
 154 \fIstructp\fR. Any memory associated with ancillary buffers and strings for those structures is also discarded.
 155 .SH "RETURN VALUES"
 156 .PP
 157 The getaddrbyname opcode functions
 158 \fBlwres_gabnrequest_render()\fR,
 159 \fBlwres_gabnresponse_render()\fR
 160 \fBlwres_gabnrequest_parse()\fR
 161 and
 162 \fBlwres_gabnresponse_parse()\fR
 163 all return
 164 \fBLWRES_R_SUCCESS\fR
 165 on success. They return
 166 \fBLWRES_R_NOMEMORY\fR
 167 if memory allocation fails.
 168 \fBLWRES_R_UNEXPECTEDEND\fR
 169 is returned if the available space in the buffer
 170 \fIb\fR
 171 is too small to accommodate the packet header or the
 172 \fBlwres_gabnrequest_t\fR
 173 and
 174 \fBlwres_gabnresponse_t\fR
 175 structures.
 176 \fBlwres_gabnrequest_parse()\fR
 177 and
 178 \fBlwres_gabnresponse_parse()\fR
 179 will return
 180 \fBLWRES_R_UNEXPECTEDEND\fR
 181 if the buffer is not empty after decoding the received packet. These functions will return
 182 \fBLWRES_R_FAILURE\fR
 183 if
 184 pktflags
 185 in the packet header structure
 186 \fBlwres_lwpacket_t\fR
 187 indicate that the packet is not a response to an earlier query.
 188 .SH "SEE ALSO"
 189 .PP
 190 \fBlwres_packet\fR(3)
 191 .SH "COPYRIGHT"
 192 Copyright \(co 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
 193 .br
 194 Copyright \(co 2000, 2001 Internet Software Consortium.
 195 .br