ip6.7p (2010 09)

i
IPv6(7P) IPv6(7P)
IPV6_RECVRTHDRDSTOPTS
(integer; boolean) When this option is enabled, the inbound
packet’s destination options appearing before a routing header (when
present) is returned as ancillary data by recvmsg()
. By default this
option is disabled.
IPV6_RECVPATHMTU
(boolean) When this option is enabled, path MTU information will be
delivered as ancillary data in the form of
struct ip6_mtuinfo to
recvmsg() when either the application sends packets that are too big
for the path MTU, or when those packets are sent from a socket on which
the IPV6_DONTFRAG
option is enabled and the packet size is larger
than the MTU of the outgoing interface. (See recvmsg (2).) The
struct
ip6_mtuinfo structure is defined in <
netinet/in6.h> as:
struct ip6_mtuinfo {
struct sockaddr_in6 ip6m_addr;
uint32_t ip6m_mtu;
};
In this situation,
recvmsg() will return zero but there will be a
cmsghdr with cmsg_type set to IPV6_PATHMTU, and
cmsg_len
will indicate that cmsg_data is sizeof(struct ip6_mtuinfo)
bytes long. This option is not supported on SOCK_STREAM sockets. By
default this option is disabled.
IPV6_PATHMTU (struct ip6_mtuinfo) This get-only option retrieves the current path
MTU value for the destination of a connected socket. This option cannot
be used with setsockopt().
IPV6_V6ONLY (boolean) When this option is enabled on a socket, the socket can be
used to send and receive IPv6 packets only. By default this option is dis-
abled.
The next ten socket options can be used with both
setsockopt() and as option name in ancillary data
to sendmsg(). (See sendmsg(2).)
IPV6_PKTINFO (struct in6_pktinfo) Used to set the source address and interface
index for outgoing packets.
IPV6_HOPLIMIT (integer) Used to set the hop limit for outbound packets. This hop
limit is valid for only a single output operation. To set hop limit for all
unicast or multicast IPv6 packets use IPV6_UNICAST_HOPS
or
IPV6_MULTICAST_HOPS
options respectively.
IPV6_TCLASS (integer) Used to set the traffic class for outbound packets. If it is
specified via ancillary data, this traffic class is valid for only a single out-
put operation. To set traffic class for all outbound IPv6 packets,
set-
sockopt() should be used. Valid values range from -1 to 255,
inclusive. If the value is equal to -1, the default value (0) is used. If the
value is between 0 and 255 inclusive, the specified value is used.
IPV6_NEXTHOP (struct sockaddr_in6) Used to set the next hop address. The node
identified by this address must be a neighbor of the sending host. When
this address is the same as the destination IPv6 address then this is
equivalent to SO_DONTROUTE socket option.
IPV6_RTHDR (variable length) Used to specify the routing header for outgoing
packets. Only Type 0 routing header is currently supported.
IPV6_DSTOPTS (variable length) Used to specify one or more destination options to
be sent in subsequent IPv6 packets.
IPV6_HOPOPTS (variable length) Used to specify one or more hop-by-hop options to
be sent in subsequent IPv6 packets.
IPV6_RTHDRDSTOPTS (variable length) Used to specify one or more destination options
preceding a routing header. This option will be silently ignored when
sending packets unless a routing header is also specified.
HP-UX 11i Version 3: September 2010 − 5 − Hewlett-Packard Company 5