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Diffstat (limited to 'newlib/libc/sys/linux/net/inet6_rthdr_space.3')
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diff --git a/newlib/libc/sys/linux/net/inet6_rthdr_space.3 b/newlib/libc/sys/linux/net/inet6_rthdr_space.3 new file mode 100644 index 000000000..d2c575dca --- /dev/null +++ b/newlib/libc/sys/linux/net/inet6_rthdr_space.3 @@ -0,0 +1,323 @@ +.\" 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. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. 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. +.\" +.\" $Id$ +.\" $FreeBSD: src/lib/libc/net/inet6_rthdr_space.3,v 1.8 2001/10/01 16:08:55 ru Exp $ +.\" +.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 LIBRARY +.Lb libc +.Sh SYNOPSIS +.In sys/types.h +.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 +RFC2292 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 & 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 Li 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 +(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 is not yet implemented. +When implemented, this should behave as follows. +.Pp +This function takes a Routing header that was received as ancillary +data +(pointed to by the first argument, +.Fa in ) +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 +(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 +(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 +(which must have a value between 1 and the value returned by +.Fn inet6_rthdr_segments ) +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 +(which must +have a value between 0 and the value returned by +.Fn inet6_rthdr_segments ) +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 RFC2460. +.\" +.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 EXAMPLES +RFC2292 gives comprehensive examples in chapter 8. +.\" +.Sh SEE ALSO +.Rs +.%A W. Stevens +.%A M. Thomas +.%T "Advanced Sockets API for IPv6" +.%N RFC2292 +.%D February 1998 +.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 +(RFC2292). +.\" +.Sh BUGS +The text was shamelessly copied from RFC2292. +.Pp +.Fn inet6_rthdr_reverse +is not implemented yet. |