INET6_RTH_SPACE(3) | Library Functions Manual | INET6_RTH_SPACE(3) |
inet6_rth_space
, inet6_rth_init
,
inet6_rth_add
,
inet6_rth_reverse
,
inet6_rth_segments
,
inet6_rth_getaddr
—
#include <netinet/in.h>
socklen_t
inet6_rth_space
(int,
int);
void *
inet6_rth_init
(void
*, socklen_t,
int,
int);
int
inet6_rth_add
(void
*, const struct in6_addr
*);
int
inet6_rth_reverse
(const
void *, void
*);
int
inet6_rth_segments
(const
void *);
struct in6_addr *
inet6_rth_getaddr
(const
void *, int);
<netinet/in.h>
header file.
The functions described in this manual page all operate on routing header
structures which are defined in
<netinet/ip6.h>
but which
should not need to be modified outside the use of this API. The size and shape
of the route header structures may change, so using the APIs is a more
portable, long term, solution.
The functions in the API are split into two groups, those that build a routing header and those that parse a received routing header. We will describe the builder functions followed by the parser functions.
inet6_rth_space
() function returns the number of
bytes required to hold a Routing Header of the type, specified in the
type argument and containing the number of addresses
specified in the segments argumment. When the type is
IPV6_RTHDR_TYPE_0
the number of segments must be from
0 through 127. Routing headers of type
IPV6_RTHDR_TYPE_2
contain only one segment, and are
only used with Mobile IPv6. The return value from this function is the number
of bytes required to store the routing header. If the value 0 is returned then
either the route header type was not recognized or another error occurred.
inet6_rth_init
() function initializes the
pre-allocated buffer pointed to by bp to contain a
routing header of the specified type The bp_len argument
is used to verify that the buffer is large enough. The caller must allocate
the buffer pointed to by bp. The necessary buffer size should be determined by
calling inet6_rth_space
() described in the previous
sections.
The inet6_rth_init
() function returns a
pointer to bp on success and
NULL
when there is an error.
inet6_rth_add
() function adds the IPv6 address
pointed to by addr to the end of the routing header
being constructed.
A successful addition results in the function returning 0, otherwise -1 is returned.
inet6_rth_reverse
() function takes a routing header,
pointed to by the argument in, and writes a new routing
header into the argument pointed to by out. The routing
header at that sends datagrams along the reverse of that route. Both arguments
are allowed to point to the same buffer meaning that the reversal can occur in
place.
The return value of the function is 0 on success, or -1 when there is an error.
The next set of functions operate on a routing header that the application wants to parse. In the usual case such a routing header is received from the network, although these functions can also be used with routing headers that the application itself created.
inet6_rth_segments
() function returns the number of
segments contained in the routing header pointed to by
bp. The return value is the number of segments contained
in the routing header, or -1 if an error occurred. It is not an error for 0 to
be returned as a routing header may contain 0 segments.
inet6_rth_getaddr
() function is used to retrieve a
single address from a routing header. The index is the
location in the routing header from which the application wants to retrieve an
address. The index parameter must have a value between 0
and one less than the number of segments present in the routing header. The
inet6_rth_segments
() function, described in the last
section, should be used to determine the total number of segments in the
routing header. The inet6_rth_getaddr
() function
returns a pointer to an IPv6 address on success or
NULL
when an error has occurred.
KAME also provides examples in the advapitest directory of its kit.
inet6_rth_space
() and
inet6_rth_getaddr
() functions return 0 on errors.
The inet6_rthdr_init
() function returns
NULL
on error. The
inet6_rth_add
() and
inet6_rth_reverse
() functions return 0 on success,
or -1 upon an error.
W. Stevens, M. Thomas, E. Nordmark, and T. Jinmei, Advanced Sockets API for IPv6, RFC 3542, May 2003.
S. Deering and R. Hinden, Internet Protocol, Version 6 (IPv6) Specification, RFC2460, December 1998.
December 24, 2004 | NetBSD 9.0 |