Full Generic System V ABI

t_optmgmtTLIUnder TLI the following options may be accessible through t _ o p t m g m t:XFigure 12-10: TCP Options_________________⎜_________________T C P _ N O D E L A Y ⎜Figure 12-11: IP Options___________________________________________⎜I P O P T _ E O L End of options list⎜⎜I P O P T _ N O P No operation⎜⎜⎜⎜I P O P T _ L S R R Loose source and record route ⎜_ ⎜__________________________________________I P O P T _ S S R R Strict source and record route ⎜Options are specified in an options buffer with the o p t h d r data structure format.An options buffer contains one or more options, with each followed by 0 or morevalues. The len field of o p t h d r specifies the length of the option value in bytes.This length must be a multiple of sizeof(long)Options may be manipulated at the TCP level and the IP level via the TLIt _ o p t m g m t call. To manipulate options at the TCP level, I P P R O T O _ T C P is specifiedto t _ o p t m g m t. For the IP level, I P P R O T O _ I P should be specified for t _ o p t m g m t.The header contains the definitions for TCP level options,while the IP level options are defined in .All TCP level options are 4 bytes long. A b o o l e a n option is either set or reset.Any non-zero value will assert (set) the option while only zero will clear theoption.The IP options consist of a string of I P O P T _* values. These options will be set inevery outgoing datagram. Options whose function is not explicitly specifiedabove are copied directly into the output. See IP and RFC 1122 for details.TCP Level Options If the T C P _ N O D E L A Y option is set, a conforming system shall notdelay sending data in order to coalesce small packets. When the option is reset, asystem may defer sending data in an effort to coalesce small packets to conservenetwork bandwidth.12-10 NETWORKING