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Diffstat (limited to 'lib/lwres/man/lwres_resutil.3')
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diff --git a/lib/lwres/man/lwres_resutil.3 b/lib/lwres/man/lwres_resutil.3 new file mode 100644 index 0000000..d26f77c --- /dev/null +++ b/lib/lwres/man/lwres_resutil.3 @@ -0,0 +1,170 @@ +.\" Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") +.\" Copyright (C) 2000, 2001 Internet Software Consortium. +.\" +.\" Permission to use, copy, modify, and 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.3,v 1.28 2007/01/30 00:24:59 marka Exp $ +.\" +.hy 0 +.ad l +.\" Title: lwres_resutil +.\" Author: +.\" Generator: DocBook XSL Stylesheets v1.71.1 <http://docbook.sf.net/> +.\" Date: Jun 30, 2000 +.\" Manual: BIND9 +.\" Source: BIND9 +.\" +.TH "LWRES_RESUTIL" "3" "Jun 30, 2000" "BIND9" "BIND9" +.\" disable hyphenation +.nh +.\" disable justification (adjust text to left margin only) +.ad l +.SH "NAME" +lwres_string_parse, lwres_addr_parse, lwres_getaddrsbyname, lwres_getnamebyaddr \- lightweight resolver utility functions +.SH "SYNOPSIS" +.nf +#include <lwres/lwres.h> +.fi +.HP 34 +.BI "lwres_result_t lwres_string_parse(lwres_buffer_t\ *" "b" ", char\ **" "c" ", lwres_uint16_t\ *" "len" ");" +.HP 32 +.BI "lwres_result_t lwres_addr_parse(lwres_buffer_t\ *" "b" ", lwres_addr_t\ *" "addr" ");" +.HP 36 +.BI "lwres_result_t lwres_getaddrsbyname(lwres_context_t\ *" "ctx" ", const\ char\ *" "name" ", lwres_uint32_t\ " "addrtypes" ", lwres_gabnresponse_t\ **" "structp" ");" +.HP 35 +.BI "lwres_result_t lwres_getnamebyaddr(lwres_context_t\ *" "ctx" ", lwres_uint32_t\ " "addrtype" ", lwres_uint16_t\ " "addrlen" ", const\ unsigned\ char\ *" "addr" ", lwres_gnbaresponse_t\ **" "structp" ");" +.SH "DESCRIPTION" +.PP +\fBlwres_string_parse()\fR +retrieves a DNS\-encoded string starting the current pointer of lightweight resolver buffer +\fIb\fR: i.e. +\fBb\->current\fR. When the function returns, the address of the first byte of the encoded string is returned via +\fI*c\fR +and the length of that string is given by +\fI*len\fR. The buffer's current pointer is advanced to point at the character following the string length, the encoded string, and the trailing +\fBNULL\fR +character. +.PP +\fBlwres_addr_parse()\fR +extracts an address from the buffer +\fIb\fR. The buffer's current pointer +\fBb\->current\fR +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 +\fBaddr\->address\fR +and +\fBaddr\->length\fR +indicates the size in bytes of the address that was copied. +\fBb\->current\fR +is advanced to point at the next byte of available data in the buffer following the encoded address. +.PP +\fBlwres_getaddrsbyname()\fR +and +\fBlwres_getnamebyaddr()\fR +use the +\fBlwres_gnbaresponse_t\fR +structure defined below: +.PP +.RS 4 +.nf +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; +.fi +.RE +.PP +The contents of this structure are not manipulated directly but they are controlled through the +\fBlwres_gabn\fR(3) +functions. +.PP +The lightweight resolver uses +\fBlwres_getaddrsbyname()\fR +to perform foward lookups. Hostname +\fIname\fR +is looked up using the resolver context +\fIctx\fR +for memory allocation. +\fIaddrtypes\fR +is a bitmask indicating which type of addresses are to be looked up. Current values for this bitmask are +\fBLWRES_ADDRTYPE_V4\fR +for IPv4 addresses and +\fBLWRES_ADDRTYPE_V6\fR +for IPv6 addresses. Results of the lookup are returned in +\fI*structp\fR. +.PP +\fBlwres_getnamebyaddr()\fR +performs reverse lookups. Resolver context +\fIctx\fR +is used for memory allocation. The address type is indicated by +\fIaddrtype\fR: +\fBLWRES_ADDRTYPE_V4\fR +or +\fBLWRES_ADDRTYPE_V6\fR. The address to be looked up is given by +\fIaddr\fR +and its length is +\fIaddrlen\fR +bytes. The result of the function call is made available through +\fI*structp\fR. +.SH "RETURN VALUES" +.PP +Successful calls to +\fBlwres_string_parse()\fR +and +\fBlwres_addr_parse()\fR +return +\fBLWRES_R_SUCCESS.\fR +Both functions return +\fBLWRES_R_FAILURE\fR +if the buffer is corrupt or +\fBLWRES_R_UNEXPECTEDEND\fR +if the buffer has less space than expected for the components of the encoded string or address. +.PP +\fBlwres_getaddrsbyname()\fR +returns +\fBLWRES_R_SUCCESS\fR +on success and it returns +\fBLWRES_R_NOTFOUND\fR +if the hostname +\fIname\fR +could not be found. +.PP +\fBLWRES_R_SUCCESS\fR +is returned by a successful call to +\fBlwres_getnamebyaddr()\fR. +.PP +Both +\fBlwres_getaddrsbyname()\fR +and +\fBlwres_getnamebyaddr()\fR +return +\fBLWRES_R_NOMEMORY\fR +when memory allocation requests fail and +\fBLWRES_R_UNEXPECTEDEND\fR +if the buffers used for sending queries and receiving replies are too small. +.SH "SEE ALSO" +.PP +\fBlwres_buffer\fR(3), +\fBlwres_gabn\fR(3). +.SH "COPYRIGHT" +Copyright \(co 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") +.br +Copyright \(co 2000, 2001 Internet Software Consortium. +.br |