Socket Options

Sockets have a number of options that can be fetched with getsockopt(3N) and set with setsockopt(3N). These functions can be used at the native socket level (level = SOL_SOCKET), in which case the socket option name must be specified. To manipulate options at any other level the protocol number of the desired protocol controlling the option of interest must be specified (see getprotoent(3N)).