diff options
Diffstat (limited to 'lib/lwres/man/lwres_resutil.docbook')
| -rw-r--r-- | lib/lwres/man/lwres_resutil.docbook | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/lib/lwres/man/lwres_resutil.docbook b/lib/lwres/man/lwres_resutil.docbook new file mode 100644 index 0000000..e6184d9 --- /dev/null +++ b/lib/lwres/man/lwres_resutil.docbook @@ -0,0 +1,238 @@ +<!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_resutil.docbook,v 1.12 2007/06/18 23:47:51 tbox Exp $ --> +<refentry> + + <refentryinfo> + <date>Jun 30, 2000</date> + </refentryinfo> + + <refmeta> + <refentrytitle>lwres_resutil</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_string_parse</refname> + <refname>lwres_addr_parse</refname> + <refname>lwres_getaddrsbyname</refname> + <refname>lwres_getnamebyaddr</refname> + <refpurpose>lightweight resolver utility functions</refpurpose> + </refnamediv> + <refsynopsisdiv> + <funcsynopsis> +<funcsynopsisinfo>#include <lwres/lwres.h></funcsynopsisinfo> +<funcprototype> + <funcdef> +lwres_result_t +<function>lwres_string_parse</function></funcdef> + <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef> + <paramdef>char **<parameter>c</parameter></paramdef> + <paramdef>lwres_uint16_t *<parameter>len</parameter></paramdef> + </funcprototype> +<funcprototype> + <funcdef> +lwres_result_t +<function>lwres_addr_parse</function></funcdef> + <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef> + <paramdef>lwres_addr_t *<parameter>addr</parameter></paramdef> + </funcprototype> +<funcprototype> + <funcdef> +lwres_result_t +<function>lwres_getaddrsbyname</function></funcdef> + <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef> + <paramdef>const char *<parameter>name</parameter></paramdef> + <paramdef>lwres_uint32_t <parameter>addrtypes</parameter></paramdef> + <paramdef>lwres_gabnresponse_t **<parameter>structp</parameter></paramdef> + </funcprototype> +<funcprototype> + <funcdef> +lwres_result_t +<function>lwres_getnamebyaddr</function></funcdef> + <paramdef>lwres_context_t *<parameter>ctx</parameter></paramdef> + <paramdef>lwres_uint32_t <parameter>addrtype</parameter></paramdef> + <paramdef>lwres_uint16_t <parameter>addrlen</parameter></paramdef> + <paramdef>const unsigned char *<parameter>addr</parameter></paramdef> + <paramdef>lwres_gnbaresponse_t **<parameter>structp</parameter></paramdef> + </funcprototype> +</funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>DESCRIPTION</title> + + <para><function>lwres_string_parse()</function> + retrieves a DNS-encoded string starting the current pointer of + lightweight resolver buffer <parameter>b</parameter>: i.e. + <constant>b->current</constant>. When the function returns, + the address of the first byte of the encoded string is returned + via <parameter>*c</parameter> and the length of that string is + given by <parameter>*len</parameter>. The buffer's current + pointer is advanced to point at the character following the + string length, the encoded string, and the trailing + <type>NULL</type> character. + </para> + + <para><function>lwres_addr_parse()</function> + extracts an address from the buffer <parameter>b</parameter>. + The buffer's current pointer <constant>b->current</constant> + is presumed to point at an encoded address: the address preceded + by a 32-bit protocol family identifier and a 16-bit length + field. The encoded address is copied to + <constant>addr->address</constant> and + <constant>addr->length</constant> indicates the size in bytes + of the address that was copied. + <constant>b->current</constant> is advanced to point at the + next byte of available data in the buffer following the encoded + address. + </para> + + <para><function>lwres_getaddrsbyname()</function> + and <function>lwres_getnamebyaddr()</function> use the + <type>lwres_gnbaresponse_t</type> structure defined below: + </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> + The contents of this structure are not manipulated directly but + they are controlled through the + <citerefentry> + <refentrytitle>lwres_gabn</refentrytitle><manvolnum>3</manvolnum> + </citerefentry> + functions. + </para> + + <para> + The lightweight resolver uses + <function>lwres_getaddrsbyname()</function> to perform + foward lookups. + Hostname <parameter>name</parameter> is looked up using the + resolver + context <parameter>ctx</parameter> for memory allocation. + <parameter>addrtypes</parameter> is a bitmask indicating + which type of + addresses are to be looked up. Current values for this bitmask are + <type>LWRES_ADDRTYPE_V4</type> for IPv4 addresses and + <type>LWRES_ADDRTYPE_V6</type> for IPv6 addresses. Results of the + lookup are returned in <parameter>*structp</parameter>. + </para> + + <para><function>lwres_getnamebyaddr()</function> + performs reverse lookups. Resolver context + <parameter>ctx</parameter> is used for memory allocation. The + address type is indicated by <parameter>addrtype</parameter>: + <type>LWRES_ADDRTYPE_V4</type> or + <type>LWRES_ADDRTYPE_V6</type>. The address to be looked up is + given by <parameter>addr</parameter> and its length is + <parameter>addrlen</parameter> bytes. The result of the + function call is made available through + <parameter>*structp</parameter>. + </para> + </refsect1> + + <refsect1> + <title>RETURN VALUES</title> + <para> + Successful calls to + <function>lwres_string_parse()</function> + and + <function>lwres_addr_parse()</function> + return + <errorcode>LWRES_R_SUCCESS.</errorcode> + Both functions return + <errorcode>LWRES_R_FAILURE</errorcode> + if the buffer is corrupt or + <errorcode>LWRES_R_UNEXPECTEDEND</errorcode> + if the buffer has less space than expected for the components of the + encoded string or address. + </para> + + <para><function>lwres_getaddrsbyname()</function> + returns <errorcode>LWRES_R_SUCCESS</errorcode> on success and it + returns <errorcode>LWRES_R_NOTFOUND</errorcode> if the hostname + <parameter>name</parameter> could not be found. + </para> + <para><errorcode>LWRES_R_SUCCESS</errorcode> + is returned by a successful call to + <function>lwres_getnamebyaddr()</function>. + </para> + + <para> + Both + <function>lwres_getaddrsbyname()</function> + and + <function>lwres_getnamebyaddr()</function> + return + <errorcode>LWRES_R_NOMEMORY</errorcode> + when memory allocation requests fail and + <errorcode>LWRES_R_UNEXPECTEDEND</errorcode> + if the buffers used for sending queries and receiving replies are too + small. + </para> + + </refsect1> + <refsect1> + <title>SEE ALSO</title> + <para><citerefentry> + <refentrytitle>lwres_buffer</refentrytitle><manvolnum>3</manvolnum> + </citerefentry>, + + <citerefentry> + <refentrytitle>lwres_gabn</refentrytitle><manvolnum>3</manvolnum> + </citerefentry>. + </para> + + </refsect1> +</refentry><!-- + - Local variables: + - mode: sgml + - End: +--> |