/contrib/bind9/lib/lwres/man/lwres_gabn.3
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1.\" Copyright (C) 2004, 2005, 2007, 2012 Internet Systems Consortium, Inc. ("ISC") 2.\" Copyright (C) 2000, 2001 Internet Software Consortium. 3.\" 4.\" Permission to use, copy, modify, and/or distribute this software for any 5.\" purpose with or without fee is hereby granted, provided that the above 6.\" copyright notice and this permission notice appear in all copies. 7.\" 8.\" THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 9.\" REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 10.\" AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 11.\" INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 12.\" LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 13.\" OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 14.\" PERFORMANCE OF THIS SOFTWARE. 15.\" 16.\" $Id$ 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" 33lwres_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 52These are low\-level routines for creating and parsing lightweight resolver name\-to\-address lookup request and response messages. 53.PP 54There 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 60These 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 72typedef struct lwres_addr lwres_addr_t; 73typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t; 74.fi 75.RE 76.sp 77.PP 78.RS 4 79.nf 80typedef 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 92typedef 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 109uses resolver context 110\fIctx\fR 111to convert getaddrbyname request structure 112\fIreq\fR 113to canonical format. The packet header structure 114\fIpkt\fR 115is initialised and transferred to buffer 116\fIb\fR. The contents of 117\fI*req\fR 118are then appended to the buffer in canonical format. 119\fBlwres_gabnresponse_render()\fR 120performs the same task, except it converts a getaddrbyname response structure 121\fBlwres_gabnresponse_t\fR 122to the lightweight resolver's canonical format. 123.PP 124\fBlwres_gabnrequest_parse()\fR 125uses context 126\fIctx\fR 127to convert the contents of packet 128\fIpkt\fR 129to a 130\fBlwres_gabnrequest_t\fR 131structure. Buffer 132\fIb\fR 133provides space to be used for storing this structure. When the function succeeds, the resulting 134\fBlwres_gabnrequest_t\fR 135is made available through 136\fI*structp\fR. 137\fBlwres_gabnresponse_parse()\fR 138offers the same semantics as 139\fBlwres_gabnrequest_parse()\fR 140except it yields a 141\fBlwres_gabnresponse_t\fR 142structure. 143.PP 144\fBlwres_gabnresponse_free()\fR 145and 146\fBlwres_gabnrequest_free()\fR 147release the memory in resolver context 148\fIctx\fR 149that was allocated to the 150\fBlwres_gabnresponse_t\fR 151or 152\fBlwres_gabnrequest_t\fR 153structures 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 157The getaddrbyname opcode functions 158\fBlwres_gabnrequest_render()\fR, 159\fBlwres_gabnresponse_render()\fR 160\fBlwres_gabnrequest_parse()\fR 161and 162\fBlwres_gabnresponse_parse()\fR 163all return 164\fBLWRES_R_SUCCESS\fR 165on success. They return 166\fBLWRES_R_NOMEMORY\fR 167if memory allocation fails. 168\fBLWRES_R_UNEXPECTEDEND\fR 169is returned if the available space in the buffer 170\fIb\fR 171is too small to accommodate the packet header or the 172\fBlwres_gabnrequest_t\fR 173and 174\fBlwres_gabnresponse_t\fR 175structures. 176\fBlwres_gabnrequest_parse()\fR 177and 178\fBlwres_gabnresponse_parse()\fR 179will return 180\fBLWRES_R_UNEXPECTEDEND\fR 181if the buffer is not empty after decoding the received packet. These functions will return 182\fBLWRES_R_FAILURE\fR 183if 184pktflags 185in the packet header structure 186\fBlwres_lwpacket_t\fR 187indicate 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" 192Copyright \(co 2004, 2005, 2007, 2012 Internet Systems Consortium, Inc. ("ISC") 193.br 194Copyright \(co 2000, 2001 Internet Software Consortium. 195.br