inet6_rthdr_init()

Initialize an IPv6 routing header

Synopsis:

#include <netinet/in.h>

struct cmsghdr * inet6_rthdr_init(void *bp, 
                                  int type);

Arguments:

bp

A pointer to the buffer where the function can build a cmsghdr structure followed by a Routing header of the specified type.

type

The type of IPv6 Routing header (e.g. Type 0 as defined in <netinet/in.h>).

Library:

libsocket

Use the -l socket option to qcc to link against this library.

Description:

This function initializes the buffer pointed to by bp to contain a cmsghdr structure followed by a Routing header of the specified type. The cmsg_len member of the cmsghdr structure is initialized to the size of the structure plus the amount of space required by the Routing header.

The cmsg_level and cmsg_type members are also initialized as required.

You must allocate the buffer before calling this function. To determine the size of the buffer, call inet6_rthdr_space().

Returns:

A pointer to the cmsghdr structure, which you'll pass to other functions (and used as the first argument to list functions) or NULL if an error occured.

Classification:

RFC 2292

See also:

inet6_rthdr_add(), inet6_rthdr_getaddr(), inet6_rthdr_getflags(), inet6_rthdr_lasthop(), inet6_rthdr_reverse(), inet6_rthdr_segments(), inet6_rthdr_space()

Based on:

• W. Stevens and M. Thomas, Advanced Sockets API for IPv6, RFC 2292, February 1998. Contains good examples.
• S. Deering and R. Hinden, Internet Protocol, Version 6 (IPv6) Specification, RFC 2460, December 1998.