external/bsd/bind/dist/lib/lwres/man/lwres_gabn.3

   1 .\"     $NetBSD: lwres_gabn.3,v 1.5 2014/12/10 04:38:02 christos Exp $
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   3 .\" Copyright (C) 2004, 2005, 2007, 2014 Internet Systems Consortium, Inc. ("ISC")
   4 .\" Copyright (C) 2000, 2001 Internet Software Consortium.
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  18 .\" Id
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  20 .hy 0
  21 .ad l
  22 .\"     Title: lwres_gabn
  23 .\"    Author:
  24 .\" Generator: DocBook XSL Stylesheets v1.71.1 <http://docbook.sf.net/>
  25 .\"      Date: June 18, 2007
  26 .\"    Manual: BIND9
  27 .\"    Source: BIND9
  28 .\"
  29 .TH "LWRES_GABN" "3" "June 18, 2007" "BIND9" "BIND9"
  30 .\" disable hyphenation
  31 .nh
  32 .\" disable justification (adjust text to left margin only)
  33 .ad l
  34 .SH "NAME"
  35 lwres_gabnrequest_render, lwres_gabnresponse_render, lwres_gabnrequest_parse, lwres_gabnresponse_parse, lwres_gabnresponse_free, lwres_gabnrequest_free \- lightweight resolver getaddrbyname message handling
  36 .SH "SYNOPSIS"
  37 .nf
  38 #include <lwres/lwres.h>
  39 .fi
  40 .HP 40
  41 .BI "lwres_result_t lwres_gabnrequest_render(lwres_context_t\ *" "ctx" ", lwres_gabnrequest_t\ *" "req" ", lwres_lwpacket_t\ *" "pkt" ", lwres_buffer_t\ *" "b" ");"
  42 .HP 41
  43 .BI "lwres_result_t lwres_gabnresponse_render(lwres_context_t\ *" "ctx" ", lwres_gabnresponse_t\ *" "req" ", lwres_lwpacket_t\ *" "pkt" ", lwres_buffer_t\ *" "b" ");"
  44 .HP 39
  45 .BI "lwres_result_t lwres_gabnrequest_parse(lwres_context_t\ *" "ctx" ", lwres_buffer_t\ *" "b" ", lwres_lwpacket_t\ *" "pkt" ", lwres_gabnrequest_t\ **" "structp" ");"
  46 .HP 40
  47 .BI "lwres_result_t lwres_gabnresponse_parse(lwres_context_t\ *" "ctx" ", lwres_buffer_t\ *" "b" ", lwres_lwpacket_t\ *" "pkt" ", lwres_gabnresponse_t\ **" "structp" ");"
  48 .HP 29
  49 .BI "void lwres_gabnresponse_free(lwres_context_t\ *" "ctx" ", lwres_gabnresponse_t\ **" "structp" ");"
  50 .HP 28
  51 .BI "void lwres_gabnrequest_free(lwres_context_t\ *" "ctx" ", lwres_gabnrequest_t\ **" "structp" ");"
  52 .SH "DESCRIPTION"
  53 .PP
  54 These are low\-level routines for creating and parsing lightweight resolver name\-to\-address lookup request and response messages.
  55 .PP
  56 There are four main functions for the getaddrbyname opcode. One render function converts a getaddrbyname request structure \(em
  57 \fBlwres_gabnrequest_t\fR
  58 \(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 getaddrbyname request structure. Another render function converts the getaddrbyname response structure \(em
  59 \fBlwres_gabnresponse_t\fR
  60 \(em to the canonical format. This is complemented by a parse function which converts a packet in canonical format to a getaddrbyname response structure.
  61 .PP
  62 These structures are defined in
  63 \fI<lwres/lwres.h>\fR. They are shown below.
  64 .PP
  65 .RS 4
  66 .nf
  67 #define LWRES_OPCODE_GETADDRSBYNAME     0x00010001U
  68 .fi
  69 .RE
  70 .sp
  71 .PP
  72 .RS 4
  73 .nf
  74 typedef struct lwres_addr lwres_addr_t;
  75 typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
  76 .fi
  77 .RE
  78 .sp
  79 .PP
  80 .RS 4
  81 .nf
  82 typedef struct {
  83         lwres_uint32_t  flags;
  84         lwres_uint32_t  addrtypes;
  85         lwres_uint16_t  namelen;
  86         char           *name;
  87 } lwres_gabnrequest_t;
  88 .fi
  89 .RE
  90 .sp
  91 .PP
  92 .RS 4
  93 .nf
  94 typedef struct {
  95         lwres_uint32_t          flags;
  96         lwres_uint16_t          naliases;
  97         lwres_uint16_t          naddrs;
  98         char                   *realname;
  99         char                  **aliases;
 100         lwres_uint16_t          realnamelen;
 101         lwres_uint16_t         *aliaslen;
 102         lwres_addrlist_t        addrs;
 103         void                   *base;
 104         size_t                  baselen;
 105 } lwres_gabnresponse_t;
 106 .fi
 107 .RE
 108 .sp
 109 .PP
 110 \fBlwres_gabnrequest_render()\fR
 111 uses resolver context
 112 \fIctx\fR
 113 to convert getaddrbyname request structure
 114 \fIreq\fR
 115 to canonical format. The packet header structure
 116 \fIpkt\fR
 117 is initialised and transferred to buffer
 118 \fIb\fR. The contents of
 119 \fI*req\fR
 120 are then appended to the buffer in canonical format.
 121 \fBlwres_gabnresponse_render()\fR
 122 performs the same task, except it converts a getaddrbyname response structure
 123 \fBlwres_gabnresponse_t\fR
 124 to the lightweight resolver's canonical format.
 125 .PP
 126 \fBlwres_gabnrequest_parse()\fR
 127 uses context
 128 \fIctx\fR
 129 to convert the contents of packet
 130 \fIpkt\fR
 131 to a
 132 \fBlwres_gabnrequest_t\fR
 133 structure. Buffer
 134 \fIb\fR
 135 provides space to be used for storing this structure. When the function succeeds, the resulting
 136 \fBlwres_gabnrequest_t\fR
 137 is made available through
 138 \fI*structp\fR.
 139 \fBlwres_gabnresponse_parse()\fR
 140 offers the same semantics as
 141 \fBlwres_gabnrequest_parse()\fR
 142 except it yields a
 143 \fBlwres_gabnresponse_t\fR
 144 structure.
 145 .PP
 146 \fBlwres_gabnresponse_free()\fR
 147 and
 148 \fBlwres_gabnrequest_free()\fR
 149 release the memory in resolver context
 150 \fIctx\fR
 151 that was allocated to the
 152 \fBlwres_gabnresponse_t\fR
 153 or
 154 \fBlwres_gabnrequest_t\fR
 155 structures referenced via
 156 \fIstructp\fR. Any memory associated with ancillary buffers and strings for those structures is also discarded.
 157 .SH "RETURN VALUES"
 158 .PP
 159 The getaddrbyname opcode functions
 160 \fBlwres_gabnrequest_render()\fR,
 161 \fBlwres_gabnresponse_render()\fR
 162 \fBlwres_gabnrequest_parse()\fR
 163 and
 164 \fBlwres_gabnresponse_parse()\fR
 165 all return
 166 \fBLWRES_R_SUCCESS\fR
 167 on success. They return
 168 \fBLWRES_R_NOMEMORY\fR
 169 if memory allocation fails.
 170 \fBLWRES_R_UNEXPECTEDEND\fR
 171 is returned if the available space in the buffer
 172 \fIb\fR
 173 is too small to accommodate the packet header or the
 174 \fBlwres_gabnrequest_t\fR
 175 and
 176 \fBlwres_gabnresponse_t\fR
 177 structures.
 178 \fBlwres_gabnrequest_parse()\fR
 179 and
 180 \fBlwres_gabnresponse_parse()\fR
 181 will return
 182 \fBLWRES_R_UNEXPECTEDEND\fR
 183 if the buffer is not empty after decoding the received packet. These functions will return
 184 \fBLWRES_R_FAILURE\fR
 185 if
 186 pktflags
 187 in the packet header structure
 188 \fBlwres_lwpacket_t\fR
 189 indicate that the packet is not a response to an earlier query.
 190 .SH "SEE ALSO"
 191 .PP
 192 \fBlwres_packet\fR(3)
 193 .SH "COPYRIGHT"
 194 Copyright \(co 2004, 2005, 2007, 2014 Internet Systems Consortium, Inc. ("ISC")
 195 .br
 196 Copyright \(co 2000, 2001 Internet Software Consortium.
 197 .br