setsockopt(3XNET)X/Open Networking Services Library Functionssetsockopt(3XNET)NAMEsetsockopt - set the socket options
SYNOPSIS
cc [ flag... ] file... -lxnet [ library... ]
#include <sys/socket.h>
int setsockopt(int socket, int level, int option_name,
const void*option_value, socklen_t option_len);
DESCRIPTION
The setsockopt() function sets the option specified by the option_name
argument, at the protocol level specified by the level argument, to the
value pointed to by the option_value argument for the socket associated
with the file descriptor specified by the socket argument.
The level argument specifies the protocol level at which the option
resides. To set options at the socket level, specify the level argu‐
ment as SOL_SOCKET. To set options at other levels, supply the appro‐
priate protocol number for the protocol controlling the option. For
example, to indicate that an option will be interpreted by the TCP
(Transport Control Protocol), set level to the protocol number of TCP,
as defined in the<netinet/in.h> header, or as determined by using get‐
protobyname(3XNET).
The option_name argument specifies a single option to set. The
option_name argument and any specified options are passed uninterpreted
to the appropriate protocol module for interpretations. The
<sys/socket.h> header defines the socket level options. The options are
as follow
SO_DEBUG Turns on recording of debugging information. This
option enables or disables debugging in the underlying
protocol modules. This option takes an int value.
This is a boolean option.
SO_BROADCAST Permits sending of broadcast messages, if this is sup‐
ported by the protocol. This option takes an int
value. This is a boolean option.
SO_REUSEADDR Specifies that the rules used in validating addresses
supplied to bind(3XNET) should allow reuse of local
addresses, if this is supported by the protocol. This
option takes an int value. This is a boolean option.
SO_KEEPALIVE Keeps connections active by enabling the periodic
transmission of messages, if this is supported by the
protocol. This option takes an int value.
If the connected socket fails to respond to these mes‐
sages, the connection is broken and threads writing to
that socket are notified with a SIGPIPE signal.
This is a boolean option.
SO_LINGER Lingers on a close(2) if data is present. This option
controls the action taken when unsent messages queue
on a socket and close(2) is performed. If SO_LINGER
is set, the system blocks the process during close(2)
until it can transmit the data or until the time
expires. If SO_LINGER is not specified, and close(2)
is issued, the system handles the call in a way that
allows the process to continue as quickly as possible.
This option takes a linger structure, as defined in
the <sys/socket.h> header, to specify the state of the
option and linger interval.
SO_OOBINLINE Leaves received out-of-band data (data marked urgent)
in line. This option takes an int value. This is a
boolean option.
SO_SNDBUF Sets send buffer size. This option takes an int
value.
SO_RCVBUF Sets receive buffer size. This option takes an int
value.
SO_DONTROUTE Requests that outgoing messages bypass the standard
routing facilities. The destination must be on a
directly-connected network, and messages are directed
to the appropriate network interface according to the
destination address. The effect, if any, of this
option depends on what protocol is in use. This option
takes an int value. This is a boolean option.
SO_MAC_EXEMPT Sets the mandatory access control on the socket. A
socket that has this option enabled can communicate
with an unlabeled peer if the socket is in the global
zone or has a label that dominates the default label
of the peer. Otherwise, the socket must have a label
that is equal to the default label of the unlabeled
peer. SO_MAC_EXEMPT is a boolean option that is avail‐
able only when the system is configured with Trusted
Extensions.
SO_ALLZONES Bypasses zone boundaries (privileged). This option
stores an int value. This is a boolean option.
The SO_ALLZONES option can be used to bypass zone
boundaries between shared-IP zones. Normally, the sys‐
tem prevents a socket from being bound to an address
that is not assigned to the current zone. It also pre‐
vents a socket that is bound to a wildcard address
from receiving traffic for other zones. However, some
daemons which run in the global zone might need to
send and receive traffic using addresses that belong
to other shared-IP zones. If set before a socket is
bound, SO_ALLZONES causes the socket to ignore zone
boundaries between shared-IP zones and permits the
socket to be bound to any address assigned to the
shared-IP zones. If the socket is bound to a wildcard
address, it receives traffic intended for all shared-
IP zones and behaves as if an equivalent socket were
bound in each active shared-IP zone. Applications that
use the SO_ALLZONES option to initiate connections or
send datagram traffic should specify the source
address for outbound traffic by binding to a specific
address. There is no effect from setting this option
in an exclusive-IP zone. Setting this option requires
the sys_net_config privilege. See zones(5).
For boolean options, 0 indicates that the option is disabled and 1
indicates that the option is enabled.
Options at other protocol levels vary in format and name.
USAGE
The setsockopt() function provides an application program with the
means to control socket behavior. An application program can use set‐
sockopt() to allocate buffer space, control timeouts, or permit socket
data broadcasts. The <sys/socket.h> header defines the socket-level
options available to setsockopt().
Options may exist at multiple protocol levels. The SO_ options are
always present at the uppermost socket level.
RETURN VALUES
Upon successful completion, setsockopt() returns 0. Otherwise, -1 is
returned and errno is set to indicate the error.
ERRORS
The setsockopt() function will fail if:
EBADF The socket argument is not a valid file descriptor.
EDOM The send and receive timeout values are too big to fit
into the timeout fields in the socket structure.
EFAULT The option_value parameter can not be accessed or writ‐
ten.
EINVAL The specified option is invalid at the specified socket
level or the socket has been shut down.
EISCONN The socket is already connected, and a specified option
can not be set while the socket is connected.
ENOPROTOOPT The option is not supported by the protocol.
ENOTSOCK The socket argument does not refer to a socket.
The setsockopt() function may fail if:
ENOMEM There was insufficient memory available for the operation to
complete.
ENOBUFS Insufficient resources are available in the system to com‐
plete the call.
ENOSR There were insufficient STREAMS resources available for the
operation to complete.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Standard │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSObind(3XNET), endprotoent(3XNET), getsockopt(3XNET), socket(3XNET),
attributes(5), standards(5)SunOS 5.10 21 Jan 2007 setsockopt(3XNET)