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Diffstat (limited to 'lib/libc/net/inet6_rth_space.3')
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diff --git a/lib/libc/net/inet6_rth_space.3 b/lib/libc/net/inet6_rth_space.3 new file mode 100644 index 0000000..1289b11 --- /dev/null +++ b/lib/libc/net/inet6_rth_space.3 @@ -0,0 +1,254 @@ +.\" $KAME: kame/kame/kame/libinet6/inet6_rth_space.3,v 1.4 2002/10/17 14:13:48 jinmei Exp $ +.\" $FreeBSD$ +.\" +.\" Copyright (C) 2000 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. +.\" +.\" $FreeBSD$ +.\" +.Dd February 5, 2000 +.Dt INET6_RTH_SPACE 3 +.Os +.\" +.Sh NAME +.Nm inet6_rth_space +.Nm inet6_rth_init +.Nm inet6_rth_add +.Nm inet6_rth_reverse +.Nm inet6_rth_segments +.Nm inet6_rth_getaddr +.Nd IPv6 Routing Header Options manipulation +.\" +.Sh SYNOPSIS +.In netinet/in.h +.Ft socklen_t +.Fn inet6_rth_space "int" "int" +.Ft "void *" +.Fn inet6_rth_init "void *" "socklen_t" "int" "int" +.Ft int +.Fn inet6_rth_add "void *" "const struct in6_addr *" +.Ft int +.Fn inet6_rth_reverse "const void *" "void *" +.Ft int +.Fn inet6_rth_segments "const void *" +.Ft "struct in6_addr *" +.Fn inet6_rth_getaddr "const void *" "int" +.\" +.Sh DESCRIPTION +The IPv6 advanced API defines six +functions that the application calls to build and examine a Routing +header, and the ability to use sticky options or ancillary data to +communicate this information between the application and the kernel +using the IPV6_RTHDR option. +.Pp +Three functions build a Routing header: +.Bl -hang +.It Fn inet6_rth_space +returns #bytes required for Routing header +.It Fn inet6_rth_init +initializes buffer data for Routing header +.It Fn inet6_rth_add +adds one IPv6 address to the Routing header +.El +.Pp +Three functions deal with a returned Routing header: +.Bl -hang +.It Fn inet6_rth_reverse +reverses a Routing header +.It Fn inet6_rth_segments +returns #segments in a Routing header +.It Fn inet6_rth_getaddr +fetches one address from a Routing header +.El +.Pp +The function prototypes for these functions are defined as a result +of including the +.Aq Li netinet/in.h +header. +.\" +.Ss inet6_rth_space +.Fn inet6_rth_space +returns the number of bytes required to hold a Routing +header of the specified type containing the specified number of +.Li segments +.Po addresses. +.Pc +For an IPv6 Type 0 Routing header, the number +of +.Li segments +must be between 0 and 127, inclusive. +The return value is just the space for the Routing header. +When the application uses +ancillary data it must pass the returned length to +.Fn CMSG_LEN +to determine how much memory is needed for the ancillary data object +.Po +including the cmsghdr structure. +.Pc +.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 +.Fn sendmsg +as a single msg_control buffer. +.Ss inet6_rth_init +.Fn inet6_rth_init +initializes the buffer pointed to by +.Li bp +to contain a +Routing header of the specified type and sets ip6r_len based on the +.Li segments +parameter. +.Li bp_len +is only used to verify that the buffer is +large enough. +The ip6r_segleft field is set to zero; +.Fn inet6_rth_add +will increment it. +.Pp +When the application uses ancillary data the application must +initialize any cmsghdr fields. +.Pp +The caller must allocate the buffer and its size can be determined by +calling +.Fn inet6_rth_space . +.Pp +Upon success the return value is the pointer to the buffer +.Li bp , +and this is then used as the first argument to the next two functions. +Upon an error the return value is NULL. +.\" +.Ss inet6_rth_add +.Fn inet6_rth_add +adds the IPv6 address pointed to by +.Li addr +to the end of the Routing header being constructed. +.Pp +If successful, the segleft member of the Routing Header 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_rth_reverse +.Fn inet6_rth_reverse +takes a Routing header extension header +.Po +pointed to by the first argument +.Li 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 +.Po +that is, the reversal can occur in place. +.Pc +.Pp +The return value of the function is 0 on success, or -1 upon an error. +.\" +.Ss inet6_rth_segments +.Fn inet6_rth_segments +returns the number of segments +.Po +addresses +.Pc +contained in the Routing header described by +.Li bp . +On success the return value is +zero or greater. +The return value of the function is -1 upon an error. +.\" +.Ss inet6_rth_getaddr +.Fn inet6_rth_getaddr +returns a pointer to the IPv6 address specified by +.Li index +.Po +which must have a value between 0 and one less than the value +returned by +.Fn inet6_rth_segments +.Pc +in the Routing header described by +.Li bp . +An application should first call +.Fn inet6_rth_segments +to obtain the number of segments in the Routing header. +.Pp +Upon an error the return value of the function is NULL. +.\" +.Sh DIAGNOSTICS +.Fn inet6_rth_space +and +.FN inet6_rth_getaddr +return 0 on errors. +.Pp +.Fn inet6_rthdr_init +returns +.Dv NULL +on error. +.Fn inet6_rth_add +and +.Fn inet6_rth_reverse +return0 on success, or -1 upon an error. +.\" +.Sh EXAMPLES +draft-ietf-ipngwg-rfc2292bis-08.txt +gives comprehensive examples in Section 22. +.Pp +KAME also provides examples in the advapitest directry of its kit. +.\" +.Sh SEE ALSO +.Rs +.%A W. Stevens +.%A M. Thomas +.%A E. Nordmark +.%A E. Jinmei +.%T "Advanced Sockets API for IPv6" +.%N draft-ietf-ipngwg-rfc2292bis-08 +.%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 draft-ietf-ipngwg-rfc2292bis-08.txt . +.\" +.Sh BUGS +The text was shamelessly copied from internet-drafts for RFC2292bis. |