b6cbf7203b
This patch imports the unmodified current version of NetBSD libc. The NetBSD includes are in /nbsd_include, while the libc code itself is split between lib/nbsd_libc and common/lib/libc.
338 lines
9.3 KiB
Groff
338 lines
9.3 KiB
Groff
.\" $NetBSD: inet6_opt_init.3,v 1.1 2006/05/05 00:03:21 rpaulo Exp $
|
|
.\" $KAME: inet6_opt_init.3,v 1.7 2004/12/27 05:08:23 itojun Exp $
|
|
.\"
|
|
.\" Copyright (C) 2004 WIDE Project.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the project nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.Dd December 23, 2004
|
|
.Dt INET6_OPT_INIT 3
|
|
.Os
|
|
.\"
|
|
.Sh NAME
|
|
.Nm inet6_opt_init ,
|
|
.Nm inet6_opt_append ,
|
|
.Nm inet6_opt_finish ,
|
|
.Nm inet6_opt_set_val ,
|
|
.Nm inet6_opt_next ,
|
|
.Nm inet6_opt_find ,
|
|
.Nm inet6_opt_get_val
|
|
.Nd IPv6 Hop-by-Hop and Destination Options manipulation
|
|
.\"
|
|
.Sh SYNOPSIS
|
|
.In netinet/in.h
|
|
.Ft "int"
|
|
.Fn inet6_opt_init "void *extbuf" "socklen_t extlen"
|
|
.Ft "int"
|
|
.Fn inet6_opt_append "void *extbuf" "socklen_t extlen" "int offset" "u_int8_t type" "socklen_t len" "u_int8_t align" "void **databufp"
|
|
.Ft "int"
|
|
.Fn inet6_opt_finish "void *extbuf" "socklen_t extlen" "int offset"
|
|
.Ft "int"
|
|
.Fn inet6_opt_set_val "void *databuf" "int offset" "void *val" "socklen_t vallen"
|
|
.Ft "int"
|
|
.Fn inet6_opt_next "void *extbuf" "socklen_t extlen" "int offset" "u_int8_t *typep" "socklen_t *lenp" "void **databufp"
|
|
.Ft "int"
|
|
.Fn inet6_opt_find "void *extbuf" "socklen_t extlen" "int offset" "u_int8_t type" "socklen_t *lenp" "void **databufp"
|
|
.Ft "int"
|
|
.Fn inet6_opt_get_val "void *databuf" "socklen_t offset" "void *val" "socklen_t vallen"
|
|
.\"
|
|
.Sh DESCRIPTION
|
|
Building and parsing the Hop-by-Hop and Destination options is
|
|
complicated.
|
|
The advanced sockets API defines a set of functions to
|
|
help applications create and manipulate Hop-by-Hope and Destination
|
|
options.
|
|
.\"This man page describes the functions specified in
|
|
.\"IETF Draft RFC3542 while the
|
|
.\".Xr inet6_options_space 3
|
|
.\"man page documents the functions defined in RFC 2292.
|
|
.\"It is expected
|
|
.\"that this set of functions will supersede those in RFC 2292 but for
|
|
.\"the time being both APIs are retained.
|
|
These functions use the
|
|
formatting rules specified in Appendix B in RFC2460, i.e., that the
|
|
largest field is placed last in the option.
|
|
The function prototypes
|
|
for these functions are all contained in the
|
|
.In netinet/in.h
|
|
header file.
|
|
.\"
|
|
.Ss inet6_opt_init
|
|
The
|
|
.Fn inet6_opt_init
|
|
function
|
|
returns the number of bytes needed for an empty
|
|
extension header, one without any options.
|
|
If the
|
|
.Va extbuf
|
|
argument points to a valid section of memory
|
|
then the
|
|
.Fn inet6_opt_init
|
|
function also initializes the extension header's length field.
|
|
When attempting to initialize an extension buffer passed in the
|
|
.Va extbuf argument
|
|
.Fa extlen
|
|
must be a positive multiple of 8 or else the function fails and
|
|
returns \-1 to the caller.
|
|
.\"
|
|
.Ss inet6_opt_append
|
|
The
|
|
.Fn inet6_opt_append
|
|
function can perform to different jobs.
|
|
When a valid
|
|
.Fa extbuf
|
|
argument is supplied it appends an option to the extension buffer and
|
|
returns the updated total length as well as a pointer to the newly
|
|
created option in
|
|
.Fa databufp .
|
|
If the value
|
|
of
|
|
.Fa extbuf
|
|
is
|
|
.Dv NULL
|
|
then the
|
|
.Fn inet6_opt_append function only reports what the total length would
|
|
be if the option were actually appended.
|
|
The
|
|
.Fa len
|
|
and
|
|
.Fa align
|
|
arguments specify the length of the option and the required data
|
|
alignment which must be used when appending the option.
|
|
The
|
|
.Fa offset
|
|
argument should be the length returned by the
|
|
.Fn inet6_opt_init
|
|
function or a previous call to
|
|
.Fn inet6_opt_append .
|
|
.Pp
|
|
The
|
|
.Fa type
|
|
argument is the 8-bit option type.
|
|
.Pp
|
|
After
|
|
.Fn inet6_opt_append
|
|
has been called, the application can use the buffer pointed to by
|
|
.Fa databufp
|
|
directly, or use
|
|
.Fn inet6_opt_set_val
|
|
to specify the data to be contained in the option.
|
|
.Pp
|
|
Option types of
|
|
.Li 0
|
|
and
|
|
.Li 1
|
|
are reserved for the
|
|
.Li Pad1
|
|
and
|
|
.Li PadN
|
|
options.
|
|
All other values from 2 through 255 may be used by applications.
|
|
.Pp
|
|
The length of the option data is contained in an 8-bit value and so
|
|
may contain any value from 0 through 255.
|
|
.Pp
|
|
The
|
|
.Fa align
|
|
parameter must have a value of 1, 2, 4, or 8 and cannot exceed the
|
|
value of
|
|
.Fa len .
|
|
The alignment values represent no alignment, 16 bit, 32 bit and 64 bit
|
|
alignments respectively.
|
|
.\"
|
|
.Ss inet6_opt_finish
|
|
The
|
|
.Fn inet6_opt_finish
|
|
calculates the final padding necessary to make the extension header a
|
|
multiple of 8 bytes, as required by the IPv6 extension header
|
|
specification, and returns the extension header's updated total
|
|
length.
|
|
The
|
|
.Fa offset
|
|
argument should be the length returned by
|
|
.Fn inet6_opt_init
|
|
or
|
|
.Fn inet6_opt_append .
|
|
When
|
|
.Fa extbuf
|
|
is not
|
|
.Dv NULL
|
|
the function also sets up the appropriate padding bytes by inserting a
|
|
Pad1 or PadN option of the proper length.
|
|
.Pp
|
|
If the extension header is too small to contain the proper padding
|
|
then an error of \-1 is returned to the caller.
|
|
.\"
|
|
.Ss inet6_opt_set_val
|
|
The
|
|
.Fn inet6_opt_set_val
|
|
function inserts data items of various sizes into the data portion of
|
|
the option.
|
|
The
|
|
.Fa databuf
|
|
argument is a pointer to memory that was returned by the
|
|
.Fn inet6_opt_append
|
|
call and the
|
|
.Fa offset argument specifies where the option should be placed in the
|
|
data buffer.
|
|
The
|
|
.Fa val
|
|
argument points to an area of memory containing the data to be
|
|
inserted into the extension header, and the
|
|
.Fa vallen
|
|
argument indicates how much data to copy.
|
|
.Pp
|
|
The caller should ensure that each field is aligned on its natural
|
|
boundaries as described in Appendix B of RFC2460.
|
|
.Pp
|
|
The function returns the offset for the next field which is calculated as
|
|
.Fa offset
|
|
+
|
|
.Fa vallen
|
|
and is used when composing options with multiple fields.
|
|
.\"
|
|
.Ss inet6_opt_next
|
|
The
|
|
.Fn inet6_opt_next
|
|
function parses received extension headers.
|
|
The
|
|
.Fa extbuf
|
|
and
|
|
.Fa extlen
|
|
arguments specify the location and length of the extension header
|
|
being parsed.
|
|
The
|
|
.Fa offset
|
|
argument should either be zero, for the first option, or the length value
|
|
returned by a previous call to
|
|
.Fn inet6_opt_next
|
|
or
|
|
.Fn inet6_opt_find .
|
|
The return value specifies the position where to continue scanning the
|
|
extension buffer.
|
|
The option is returned in the arguments
|
|
.Fa typep , lenp ,
|
|
and
|
|
.Fa databufp .
|
|
.Fa typep, lenp,
|
|
and
|
|
.Fa databufp
|
|
point to the 8-bit option type, the 8-bit option length and the option
|
|
data respectively.
|
|
This function does not return any PAD1 or PADN options.
|
|
When an error occurs or there are no more options the return
|
|
value is \-1.
|
|
.\"
|
|
.Ss inet6_opt_find
|
|
The
|
|
.Fn inet6_opt_find
|
|
function searches the extension buffer for a particular option type,
|
|
passed in through the
|
|
.Fa type
|
|
argument.
|
|
If the option is found then the
|
|
.Fa lenp
|
|
and
|
|
.Fa databufp
|
|
arguments are updated to point to the option's length and data
|
|
respectively.
|
|
.Fa extbuf
|
|
and
|
|
.Fa extlen
|
|
must point to a valid extension buffer and give its length.
|
|
The
|
|
.Fa offset
|
|
argument can be used to search from a location anywhere in the
|
|
extension header.
|
|
.Ss inet6_opt_get_val
|
|
The
|
|
.Fn inet6_opt_get_val
|
|
function extracts data items of various sizes in the data portion of
|
|
the option.
|
|
The
|
|
.Fa databuf
|
|
is a pointer returned by the
|
|
.Fn inet6_opt_next
|
|
or
|
|
.Fn inet6_opt_find
|
|
functions.
|
|
The
|
|
.Fa val
|
|
argument points where the data will be extracted.
|
|
The
|
|
.Fa offset
|
|
argument specifies from where in the data portion of the option the
|
|
value should be extracted; the first byte of option data is specified
|
|
by an offset of zero.
|
|
.Pp
|
|
It is expected that each field is aligned on its natural boundaries as
|
|
described in Appendix B of RFC2460.
|
|
.Pp
|
|
The function returns the offset for the next field
|
|
by calculating
|
|
.Fa offset
|
|
+
|
|
.Fa vallen
|
|
which can be used when extracting option content with multiple fields.
|
|
Robust receivers must verify alignment before calling this function.
|
|
.\"
|
|
.Sh DIAGNOSTICS
|
|
All the functions return
|
|
\-1
|
|
on an error.
|
|
.\"
|
|
.Sh EXAMPLES
|
|
RFC3542 gives comprehensive examples in Section 23.
|
|
.Pp
|
|
KAME also provides examples in the
|
|
.Pa advapitest
|
|
directory of its kit.
|
|
.\"
|
|
.Sh SEE ALSO
|
|
.Rs
|
|
.%A W. Stevens
|
|
.%A M. Thomas
|
|
.%A E. Nordmark
|
|
.%A T. Jinmei
|
|
.%T "Advanced Sockets API for IPv6"
|
|
.%N RFC3542
|
|
.%D October 2002
|
|
.Re
|
|
.Rs
|
|
.%A S. Deering
|
|
.%A R. Hinden
|
|
.%T "Internet Protocol, Version 6 (IPv6) Specification"
|
|
.%N RFC2460
|
|
.%D December 1998
|
|
.Re
|
|
.Sh HISTORY
|
|
The implementation first appeared in KAME advanced networking kit.
|
|
.Sh STANDARDS
|
|
The functions are documented in
|
|
.Dq Advanced Sockets API for IPv6
|
|
.Pq RFC3542 .
|
|
.\"
|