1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
|
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"
[<!ENTITY mdash "—">]>
<!--
- Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
- Copyright (C) 2000, 2001 Internet Software Consortium.
-
- Permission to use, copy, modify, and/or distribute this software for any
- purpose with or without fee is hereby granted, provided that the above
- copyright notice and this permission notice appear in all copies.
-
- THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
- REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
- AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
- INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
- LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
- OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
- PERFORMANCE OF THIS SOFTWARE.
-->
<!-- $Id: lwres_gabn.docbook,v 1.10 2007/06/18 23:47:51 tbox Exp $ -->
<refentry>
<refentryinfo>
<date>Jun 30, 2000</date>
</refentryinfo>
<refmeta>
<refentrytitle>lwres_gabn</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>BIND9</refmiscinfo>
</refmeta>
<docinfo>
<copyright>
<year>2004</year>
<year>2005</year>
<year>2007</year>
<holder>Internet Systems Consortium, Inc. ("ISC")</holder>
</copyright>
<copyright>
<year>2000</year>
<year>2001</year>
<holder>Internet Software Consortium.</holder>
</copyright>
</docinfo>
<refnamediv>
<refname>lwres_gabnrequest_render</refname>
<refname>lwres_gabnresponse_render</refname>
<refname>lwres_gabnrequest_parse</refname>
<refname>lwres_gabnresponse_parse</refname>
<refname>lwres_gabnresponse_free</refname>
<refname>lwres_gabnrequest_free</refname>
<refpurpose>lightweight resolver getaddrbyname message handling</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include <lwres/lwres.h></funcsynopsisinfo>
<funcprototype>
<funcdef>
lwres_result_t
<function>lwres_gabnrequest_render</function></funcdef>
<paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
<paramdef>lwres_gabnrequest_t *<parameter>req</parameter></paramdef>
<paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef>
<paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>
lwres_result_t
<function>lwres_gabnresponse_render</function></funcdef>
<paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
<paramdef>lwres_gabnresponse_t *<parameter>req</parameter></paramdef>
<paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef>
<paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>
lwres_result_t
<function>lwres_gabnrequest_parse</function></funcdef>
<paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
<paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>
<paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef>
<paramdef>lwres_gabnrequest_t **<parameter>structp</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>
lwres_result_t
<function>lwres_gabnresponse_parse</function></funcdef>
<paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
<paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>
<paramdef>lwres_lwpacket_t *<parameter>pkt</parameter></paramdef>
<paramdef>lwres_gabnresponse_t **<parameter>structp</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>
void
<function>lwres_gabnresponse_free</function></funcdef>
<paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
<paramdef>lwres_gabnresponse_t **<parameter>structp</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>
void
<function>lwres_gabnrequest_free</function></funcdef>
<paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef>
<paramdef>lwres_gabnrequest_t **<parameter>structp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>DESCRIPTION</title>
<para>
These are low-level routines for creating and parsing
lightweight resolver name-to-address lookup request and
response messages.
</para>
<para>
There are four main functions for the getaddrbyname opcode.
One render function converts a getaddrbyname request structure —
<type>lwres_gabnrequest_t</type> —
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
— <type>lwres_gabnresponse_t</type> —
to the canonical format.
This is complemented by a parse function which converts a packet in
canonical format to a getaddrbyname response structure.
</para>
<para>
These structures are defined in
<filename><lwres/lwres.h></filename>.
They are shown below.
</para>
<para><programlisting>
#define LWRES_OPCODE_GETADDRSBYNAME 0x00010001U
</programlisting>
</para>
<para><programlisting>
typedef struct lwres_addr lwres_addr_t;
typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
</programlisting>
</para>
<para><programlisting>
typedef struct {
lwres_uint32_t flags;
lwres_uint32_t addrtypes;
lwres_uint16_t namelen;
char *name;
} lwres_gabnrequest_t;
</programlisting>
</para>
<para><programlisting>
typedef struct {
lwres_uint32_t flags;
lwres_uint16_t naliases;
lwres_uint16_t naddrs;
char *realname;
char **aliases;
lwres_uint16_t realnamelen;
lwres_uint16_t *aliaslen;
lwres_addrlist_t addrs;
void *base;
size_t baselen;
} lwres_gabnresponse_t;
</programlisting>
</para>
<para><function>lwres_gabnrequest_render()</function>
uses resolver context <parameter>ctx</parameter> to convert
getaddrbyname request structure <parameter>req</parameter> to
canonical format. The packet header structure
<parameter>pkt</parameter> is initialised and transferred to
buffer <parameter>b</parameter>.
The contents of <parameter>*req</parameter> are then appended to
the buffer in canonical format.
<function>lwres_gabnresponse_render()</function> performs the
same task, except it converts a getaddrbyname response structure
<type>lwres_gabnresponse_t</type> to the lightweight resolver's
canonical format.
</para>
<para><function>lwres_gabnrequest_parse()</function>
uses context <parameter>ctx</parameter> to convert the contents
of packet <parameter>pkt</parameter> to a
<type>lwres_gabnrequest_t</type> structure. Buffer
<parameter>b</parameter> provides space to be used for storing
this structure. When the function succeeds, the resulting
<type>lwres_gabnrequest_t</type> is made available through
<parameter>*structp</parameter>.
<function>lwres_gabnresponse_parse()</function> offers the same
semantics as <function>lwres_gabnrequest_parse()</function>
except it yields a <type>lwres_gabnresponse_t</type> structure.
</para>
<para><function>lwres_gabnresponse_free()</function>
and <function>lwres_gabnrequest_free()</function> release the
memory in resolver context <parameter>ctx</parameter> that was
allocated to the <type>lwres_gabnresponse_t</type> or
<type>lwres_gabnrequest_t</type> structures referenced via
<parameter>structp</parameter>.
Any memory associated with ancillary buffers and strings for
those structures is also discarded.
</para>
</refsect1>
<refsect1>
<title>RETURN VALUES</title>
<para>
The getaddrbyname opcode functions
<function>lwres_gabnrequest_render()</function>,
<function>lwres_gabnresponse_render()</function>
<function>lwres_gabnrequest_parse()</function>
and
<function>lwres_gabnresponse_parse()</function>
all return
<errorcode>LWRES_R_SUCCESS</errorcode>
on success.
They return
<errorcode>LWRES_R_NOMEMORY</errorcode>
if memory allocation fails.
<errorcode>LWRES_R_UNEXPECTEDEND</errorcode>
is returned if the available space in the buffer
<parameter>b</parameter>
is too small to accommodate the packet header or the
<type>lwres_gabnrequest_t</type>
and
<type>lwres_gabnresponse_t</type>
structures.
<function>lwres_gabnrequest_parse()</function>
and
<function>lwres_gabnresponse_parse()</function>
will return
<errorcode>LWRES_R_UNEXPECTEDEND</errorcode>
if the buffer is not empty after decoding the received packet.
These functions will return
<errorcode>LWRES_R_FAILURE</errorcode>
if
<structfield>pktflags</structfield>
in the packet header structure
<type>lwres_lwpacket_t</type>
indicate that the packet is not a response to an earlier query.
</para>
</refsect1>
<refsect1>
<title>SEE ALSO</title>
<para><citerefentry>
<refentrytitle>lwres_packet</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>
</para>
</refsect1>
</refentry><!--
- Local variables:
- mode: sgml
- End:
-->
|
