inet6_rth_space.3n (2010 09)

inet6_rth_space(3N) inet6_rth_space(3N)

the function is -1.

Note: If the Routing header is type 2, this function can only be called once.

inet6_rth_reverse()

This function takes a Routing header extension header pointed to by the ﬁrst argument in and

writes a new Routing header. The new Routing header sends datagrams along the reverse of that

route. The function reverses the order of the addresses and sets the

segleft member in the new

routing header to the number of segments. Both arguments are allowed to point to the same buffer

(that is, the reversal can occur in place).

The return value of the function is 0 on success, or -1 upon an error.

Note: If Routing header is type 2, this function returns -1 (RFC 4584).

inet6_rth_segments()

This function returns the number of segments (addresses) contained in the Routing header

described by bp which can be 0 or greater.

The return value of the function is -1 upon an error.

inet6_rth_getaddr()

This function returns a pointer to the IPv6 address speciﬁed by index (which must be a value

between 0 and one less than the value returned by inet6_rth_segments()

) in the Routing

header described by bp.

An application should ﬁrst call

inet6_rth_segments()

to obtain the number of segments in the

Routing header.

Upon an error, the return value of the function is NULL.

Note: If Routing header is type 2, this function returns a pointer to the IPv6 home address speciﬁed

by the ip6r2_homeaddr ﬁeld in

ip6_rthdr2, which is pointed by bp. The index must be zero.

Notes

To use these functions, the application must be compiled with:

-D_HPUX_SOURCE -lipv6

To receive a Routing header, the application must enable the IPV6_RECVRTHDR

socket option:

int on = 1;

setsockopt(fd, IPPROTO_IPV6, IPV6_RECVRTHDR, &on, sizeof(on));

To send a Routing header, the application speciﬁes it either as ancillary data in a call to

sendmsg() or

using

setsockopt() (see send (2) and getsockopt (2), respectively).

EXAMPLES

RFC 3542 gives a comprehensive example in Appendix B.