Open System Services System Calls Reference Manual (G06.25+, H06.03+)

setsockopt(2) OSS System Calls Reference Manual
TCP_SACKENA
Specifies whether TCP selective acknowledgments are enabled.
option_value takes an int value. A nonzero value indicates that
selective acknowledgments are enabled. A 0 (zero) value indi-
cates that selective acknowledgments should not be used.
TCP_TOTRXMTVAL
Sets the total maximum retransmission duration in multiples of
500 milliseconds. Once the duration is reached, the TCP
cpnnection is dropped.
option_value takes an int value. Valid values are in the range 1
through 28800. When the value specified for the
TCP_RXMTCNT option is multiplied by the value used for the
TCP_MAXRMT option and the result is less than the value
used for TCP_TOTRXMTVAL, the TCP connection will be
dropped before the TCP_TOTRXMTVAL value is reached.
Options at other protocol levels vary in format and name.
option_value Points to the buffer containing the appropriate option value. For options that can
be classified as disabled or enabled, a value of 0 (zero) indicates that the option
should be disabled and a value of 1 indicates that the option should be enabled.
option_len Contains the size of the buffer pointed to by the option_value parameter.
DESCRIPTION
The setsockopt( ) function sets options associated with a socket. Options can exist at multiple
protocol levels. The SO_* options are always present at the uppermost socket level.
The setsockopt( ) function provides an application program with the means to control socket
communication. An application program can use the setsockopt() function to enable debugging
at the protocol level, allocate buffer space, control time-outs, or permit socket data broadcasts.
The sys/socket.h header file defines all the SO_* options available to the setsockopt( ) function.
RETURN VALUES
Upon successful completion, the setsockopt( ) function returns the value 0 (zero). Otherwise, the
value -1 is returned and errno is set to indicate the error.
ERRORS
If any of the following conditions occurs, the setsockopt() function sets errno to the correspond-
ing value:
[EBADF] The socket parameter is not a valid file descriptor.
[ECONNRESET]
One of the following conditions occurred:
• The transport-provider process for this socket is no longer available.
• The TCP/IP subsystem for this socket is no longer available.
• The connection was forcibly closed by the peer socket.
The socket can only be closed.
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