| INET6_RTHDR_SPACE(3) | Library Functions Manual | INET6_RTHDR_SPACE(3) | 
inet6_rthdr_space,
  inet6_rthdr_init,
  inet6_rthdr_add,
  inet6_rthdr_lasthop,
  inet6_rthdr_reverse,
  inet6_rthdr_segments,
  inet6_rthdr_getaddr,
  inet6_rthdr_getflags —
#include <netinet/in.h>
size_t
  
  inet6_rthdr_space(int
    type, int
    segments);
struct cmsghdr *
  
  inet6_rthdr_init(void
    *bp, int type);
int
  
  inet6_rthdr_add(struct
    cmsghdr *cmsg, const
    struct in6_addr *addr,
    unsigned int flags);
int
  
  inet6_rthdr_lasthop(struct
    cmsghdr *cmsg, unsigned
    int flags);
int
  
  inet6_rthdr_reverse(const
    struct cmsghdr *in,
    struct cmsghdr *out);
int
  
  inet6_rthdr_segments(const
    struct cmsghdr *cmsg);
struct in6_addr *
  
  inet6_rthdr_getaddr(struct
    cmsghdr *cmsg, int
    index);
int
  
  inet6_rthdr_getflags(const
    struct cmsghdr *cmsg, int
    index);
inet6_rthdr_space()inet6_rthdr_init()inet6_rthdr_add()inet6_rthdr_lasthop()Four functions deal with a returned Routing header:
inet6_rthdr_reverse()inet6_rthdr_segments()inet6_rthdr_getaddr()inet6_rthdr_getflags()The function prototypes for these functions are all in the
    <netinet/in.h> header.
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.
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
    sendmsg(2) as a single
    msg_control buffer.
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.
The caller must allocate the buffer and its size can be determined
    by calling inet6_rthdr_space().
Upon success the return value is the pointer to the
    cmsghdr structure, and this is then used as the
    first argument to the next two functions. Upon an error the return value is
    NULL.
IPV6_RTHDR_LOOSE or
  IPV6_RTHDR_STRICT.
If successful, the cmsg_len member of the
    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.
IPV6_RTHDR_LOOSE or
  IPV6_RTHDR_STRICT.
The return value of the function is 0 upon success, or -1 upon an error.
Notice that a Routing header specifying N
    intermediate nodes requires N+1 Strict/Loose flags.
    This requires N calls to
    inet6_rthdr_add() followed by one call to
    inet6_rthdr_lasthop().
The return value of the function is 0 on success, or -1 upon an error.
inet6_rthdr_segments()) in the Routing
  header described by cmsg. An application should first
  call inet6_rthdr_segments() to obtain the number of
  segments in the Routing header.
Upon an error the return value of the function is
    NULL.
inet6_rthdr_segments()) in the Routing header
  described by cmsg. For an IPv6 Type 0 Routing header the
  return value will be either IPV6_RTHDR_LOOSE or
  IPV6_RTHDR_STRICT.
Upon an error the return value of the function is -1.
Note: Addresses are indexed starting at 1, and flags starting at 0, to maintain consistency with the terminology and figures in RFC 2460.
inet6_rthdr_space() returns 0 on errors.
inet6_rthdr_add(),
    inet6_rthdr_lasthop() and
    inet6_rthdr_reverse() return 0 on success, and
    returns -1 on error.
inet6_rthdr_init() and
    inet6_rthdr_getaddr() return
    NULL on error.
inet6_rthdr_segments() and
    inet6_rthdr_getflags() return -1 on error.
W. Stevens and M. Thomas, Advanced Sockets API for IPv6, RFC 2292, February 1998.
S. Deering and R. Hinden, Internet Protocol, Version 6 (IPv6) Specification, RFC 2460, December 1998.
inet6_rthdr_reverse() is not implemented
    yet.
| December 10, 1999 | NetBSD 9.3 |