Packet construction

packet.def (actually packet4.def and packet6.def, see above) defines headers for IPv4, IPv6, TCP, UDP, ICMP, and IGMP, and it also provides macros for constructing entire packets.

The following sections describe the header structures, the variables used to populate header fields, and their default values. Values which are only set globally, and which retain their value after each change (see section ) are marked with global.

The variable names in packet.def are the same used in fields.tc. Section describes fields.tc in more detail.

Note that packet.def includes values.tc, described in section .