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Revision 1.1, Thu May 20 23:13:02 2004 UTC (16 years, 9 months ago) by christos
Add the remaining files from net that are going to be moved here and the Makefile glue.
.\" $NetBSD: inet6_rthdr_space.3,v 1.1 2004/05/20 23:13:02 christos 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 .Aq Pa 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.