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.
322 lines
8.6 KiB
Groff
322 lines
8.6 KiB
Groff
.\" $NetBSD: inet6_rthdr_space.3,v 1.16 2010/03/22 19:30:54 joerg Exp $
|
|
.\" $KAME: inet6_rthdr_space.3,v 1.8 2000/05/17 14:30:15 itojun Exp $
|
|
.\"
|
|
.\" Copyright (c) 1983, 1987, 1991, 1993
|
|
.\" The Regents of the University of California. 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 University 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 REGENTS 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 REGENTS 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 10, 1999
|
|
.Dt INET6_RTHDR_SPACE 3
|
|
.Os
|
|
.\"
|
|
.Sh NAME
|
|
.Nm inet6_rthdr_space ,
|
|
.Nm inet6_rthdr_init ,
|
|
.Nm inet6_rthdr_add ,
|
|
.Nm inet6_rthdr_lasthop ,
|
|
.Nm inet6_rthdr_reverse ,
|
|
.Nm inet6_rthdr_segments ,
|
|
.Nm inet6_rthdr_getaddr ,
|
|
.Nm inet6_rthdr_getflags
|
|
.Nd IPv6 Routing Header Options manipulation
|
|
.\"
|
|
.Sh SYNOPSIS
|
|
.In netinet/in.h
|
|
.Ft size_t
|
|
.Fn inet6_rthdr_space "int type" "int segments"
|
|
.Ft "struct cmsghdr *"
|
|
.Fn inet6_rthdr_init "void *bp" "int type"
|
|
.Ft int
|
|
.Fn inet6_rthdr_add "struct cmsghdr *cmsg" "const struct in6_addr *addr" "unsigned int flags"
|
|
.Ft int
|
|
.Fn inet6_rthdr_lasthop "struct cmsghdr *cmsg" "unsigned int flags"
|
|
.Ft int
|
|
.Fn inet6_rthdr_reverse "const struct cmsghdr *in" "struct cmsghdr *out"
|
|
.Ft int
|
|
.Fn inet6_rthdr_segments "const struct cmsghdr *cmsg"
|
|
.Ft "struct in6_addr *"
|
|
.Fn inet6_rthdr_getaddr "struct cmsghdr *cmsg" "int index"
|
|
.Ft int
|
|
.Fn inet6_rthdr_getflags "const struct cmsghdr *cmsg" "int index"
|
|
.\"
|
|
.Sh DESCRIPTION
|
|
RFC 2292 IPv6 advanced API defines eight
|
|
functions that the application calls to build and examine a Routing
|
|
header.
|
|
Four functions build a Routing header:
|
|
.Bl -hang
|
|
.It Fn inet6_rthdr_space
|
|
return #bytes required for ancillary data
|
|
.It Fn inet6_rthdr_init
|
|
initialize ancillary data for Routing header
|
|
.It Fn inet6_rthdr_add
|
|
add IPv6 address \*[Am] flags to Routing header
|
|
.It Fn inet6_rthdr_lasthop
|
|
specify the flags for the final hop
|
|
.El
|
|
.Pp
|
|
Four functions deal with a returned Routing header:
|
|
.Bl -hang
|
|
.It Fn inet6_rthdr_reverse
|
|
reverse a Routing header
|
|
.It Fn inet6_rthdr_segments
|
|
return #segments in a Routing header
|
|
.It Fn inet6_rthdr_getaddr
|
|
fetch one address from a Routing header
|
|
.It Fn inet6_rthdr_getflags
|
|
fetch one flag from a Routing header
|
|
.El
|
|
.Pp
|
|
The function prototypes for these functions are all in the
|
|
.In netinet/in.h
|
|
header.
|
|
.\"
|
|
.Ss inet6_rthdr_space
|
|
This function returns the number of bytes required to hold a Routing
|
|
header of the specified
|
|
.Fa type
|
|
containing the specified number of
|
|
.Fa segments
|
|
.Pq addresses .
|
|
For an IPv6 Type 0 Routing header, the number
|
|
of segments must be between 1 and 23, inclusive.
|
|
The return value
|
|
includes the size of the cmsghdr structure that precedes the Routing
|
|
header, and any required padding.
|
|
.Pp
|
|
If the return value is 0, then either the type of the Routing header
|
|
is not supported by this implementation or the number of segments is
|
|
invalid for this type of Routing header.
|
|
.Pp
|
|
Note: This function returns the size but does not allocate the space
|
|
required for the ancillary data.
|
|
This allows an application to
|
|
allocate a larger buffer, if other ancillary data objects are
|
|
desired, since all the ancillary data objects must be specified to
|
|
.Xr sendmsg 2
|
|
as a single
|
|
.Li msg_control
|
|
buffer.
|
|
.\"
|
|
.Ss inet6_rthdr_init
|
|
This function initializes the buffer pointed to by
|
|
.Fa bp
|
|
to contain a
|
|
.Li cmsghdr
|
|
structure followed by a Routing header of the specified
|
|
.Fa type .
|
|
The
|
|
.Li cmsg_len
|
|
member of the
|
|
.Li cmsghdr
|
|
structure is initialized to the
|
|
size of the structure plus the amount of space required by the
|
|
Routing header.
|
|
The
|
|
.Li cmsg_level
|
|
and
|
|
.Li cmsg_type
|
|
members are also initialized as required.
|
|
.Pp
|
|
The caller must allocate the buffer and its size can be determined by
|
|
calling
|
|
.Fn inet6_rthdr_space .
|
|
.Pp
|
|
Upon success the return value is the pointer to the
|
|
.Li cmsghdr
|
|
structure, and this is then used as the first argument to the next
|
|
two functions.
|
|
Upon an error the return value is
|
|
.Dv NULL .
|
|
.\"
|
|
.Ss inet6_rthdr_add
|
|
This function adds the address pointed to by
|
|
.Fa addr
|
|
to the end of the
|
|
Routing header being constructed and sets the type of this hop to the
|
|
value of
|
|
.Fa flags .
|
|
For an IPv6 Type 0 Routing header,
|
|
.Fa flags
|
|
must be
|
|
either
|
|
.Dv IPV6_RTHDR_LOOSE
|
|
or
|
|
.Dv IPV6_RTHDR_STRICT .
|
|
.Pp
|
|
If successful, the
|
|
.Li cmsg_len
|
|
member of the
|
|
.Li cmsghdr
|
|
structure is
|
|
updated to account for the new address in the Routing header and the
|
|
return value of the function is 0.
|
|
Upon an error the return value of
|
|
the function is -1.
|
|
.\"
|
|
.Ss inet6_rthdr_lasthop
|
|
This function specifies the Strict/Loose flag for the final hop of a
|
|
Routing header.
|
|
For an IPv6 Type 0 Routing header,
|
|
.Fa flags
|
|
must be either
|
|
.Dv IPV6_RTHDR_LOOSE
|
|
or
|
|
.Dv IPV6_RTHDR_STRICT .
|
|
.Pp
|
|
The return value of the function is 0 upon success, or -1 upon an error.
|
|
.Pp
|
|
Notice that a Routing header specifying
|
|
.Li N
|
|
intermediate nodes requires
|
|
.Li N+1
|
|
Strict/Loose flags.
|
|
This requires
|
|
.Li N
|
|
calls to
|
|
.Fn inet6_rthdr_add
|
|
followed by one call to
|
|
.Fn inet6_rthdr_lasthop .
|
|
.\"
|
|
.Ss inet6_rthdr_reverse
|
|
This function takes a Routing header that was received as ancillary
|
|
data
|
|
.Po
|
|
pointed to by the first argument,
|
|
.Fa in
|
|
.Pc
|
|
and writes a new Routing
|
|
header that sends datagrams along the reverse of that route.
|
|
Both
|
|
arguments are allowed to point to the same buffer
|
|
.Pq that is, the reversal can occur in place .
|
|
.Pp
|
|
The return value of the function is 0 on success, or -1 upon an
|
|
error.
|
|
.\"
|
|
.Ss inet6_rthdr_segments
|
|
This function returns the number of segments
|
|
.Pq addresses
|
|
contained in
|
|
the Routing header described by
|
|
.Fa cmsg .
|
|
On success the return value is
|
|
between 1 and 23, inclusive.
|
|
The return value of the function is -1 upon an error.
|
|
.\"
|
|
.Ss inet6_rthdr_getaddr
|
|
This function returns a pointer to the IPv6 address specified by
|
|
.Fa index
|
|
.Po
|
|
which must have a value between 1 and the value returned by
|
|
.Fn inet6_rthdr_segments
|
|
.Pc
|
|
in the Routing header described by
|
|
.Fa cmsg .
|
|
An
|
|
application should first call
|
|
.Fn inet6_rthdr_segments
|
|
to obtain the number of segments in the Routing header.
|
|
.Pp
|
|
Upon an error the return value of the function is
|
|
.Dv NULL .
|
|
.\"
|
|
.Ss inet6_rthdr_getflags
|
|
This function returns the flags value specified by
|
|
.Fa index
|
|
.Po
|
|
which must
|
|
have a value between 0 and the value returned by
|
|
.Fn inet6_rthdr_segments
|
|
.Pc
|
|
in the Routing header described by
|
|
.Fa cmsg .
|
|
For an IPv6 Type 0 Routing header the return value will be either
|
|
.Dv IPV6_RTHDR_LOOSE
|
|
or
|
|
.Dv IPV6_RTHDR_STRICT .
|
|
.Pp
|
|
Upon an error the return value of the function is -1.
|
|
.Pp
|
|
Note: Addresses are indexed starting at 1, and flags starting at 0,
|
|
to maintain consistency with the terminology and figures in RFC 2460.
|
|
.\"
|
|
.Sh EXAMPLES
|
|
RFC 2292 gives comprehensive examples in chapter 8.
|
|
.\"
|
|
.Sh DIAGNOSTICS
|
|
.Fn inet6_rthdr_space
|
|
returns 0 on errors.
|
|
.Pp
|
|
.Fn inet6_rthdr_add ,
|
|
.Fn inet6_rthdr_lasthop
|
|
and
|
|
.Fn inet6_rthdr_reverse
|
|
return 0 on success, and returns -1 on error.
|
|
.Pp
|
|
.Fn inet6_rthdr_init
|
|
and
|
|
.Fn inet6_rthdr_getaddr
|
|
return
|
|
.Dv NULL
|
|
on error.
|
|
.Pp
|
|
.Fn inet6_rthdr_segments
|
|
and
|
|
.Fn inet6_rthdr_getflags
|
|
return -1 on error.
|
|
.\"
|
|
.Sh SEE ALSO
|
|
.Rs
|
|
.%A W. Stevens
|
|
.%A M. Thomas
|
|
.%T "Advanced Sockets API for IPv6"
|
|
.%N RFC 2292
|
|
.%D February 1998
|
|
.Re
|
|
.Rs
|
|
.%A S. Deering
|
|
.%A R. Hinden
|
|
.%T "Internet Protocol, Version 6 (IPv6) Specification"
|
|
.%N RFC 2460
|
|
.%D December 1998
|
|
.Re
|
|
.\"
|
|
.Sh STANDARDS
|
|
The functions
|
|
are documented in
|
|
.Dq Advanced Sockets API for IPv6
|
|
.Pq RFC 2292 .
|
|
.\"
|
|
.Sh HISTORY
|
|
The implementation first appeared in KAME advanced networking kit.
|
|
.\"
|
|
.Sh BUGS
|
|
The text was shamelessly copied from RFC 2292.
|
|
.Pp
|
|
.Fn inet6_rthdr_reverse
|
|
is not implemented yet.
|