NAME    [Toc]    [Back]

       inet6_rth_space  - Return the number of bytes required for
       an IPv6 Routing header

SYNOPSIS    [Toc]    [Back]

       #include <netinet/ip6.h>

       size_t inet6_rth_space(
               int type,
               int segments );

LIBRARY    [Toc]    [Back]

       Standard C Library (libc)

PARAMETERS    [Toc]    [Back]

       Specifies the type of Routing header. The valid  value  is
       IPV6_RTHDR_TYPE_0  for IPv6 Routing header type 0.  Specifies
 the number of segments or addresses that  are  to  be
       included in the Routing header.  The valid value is from 0
       to 127, inclusive.

DESCRIPTION    [Toc]    [Back]

       The inet6_rth_space() function determines  the  amount  of
       space,  in  bytes, required for a Routing header. Although
       the function returns the amount of space required, it does
       not allocate buffer space. This enables the application to
       allocate a larger buffer.

       If the application uses ancillary data, it must  pass  the
       returned  length  to CMSG_LEN() to determine the amount of
       memory required for the ancillary data  object,  including
       the cmsghdr structure.

                                  Note

       If  an  application  wants  to  send  other ancillary data
       objects, it must specify them to  sendmsg()  as  a  single
       msg_control buffer.

RETURN VALUES    [Toc]    [Back]

       Upon successful completion, the inet6_rth_space() function
       returns the length, in bytes, of the  Routing  header  and
       the specified number of segments.  If the type is not supported
 or the number of segments is invalid for  the  type
       of Routing header, the function returns 0.

SEE ALSO    [Toc]    [Back]

       Functions:     inet6_rth_add(3),     inet6_rth_getaddr(3),
       inet6_rth_init(3),  inet6_rth_reverse(3),   inet6_rth_segments(3).

       Network Programmer's Guide



                                               inet6_rth_space(3)