Packet.TcpSourceTCP frame of a packet.
type t = {src : tpPort;Source port.
*)dst : tpPort;Destination port.
*)seq : int32;Sequence number.
*)ack : int32;Acknowledgement number.
*)offset : int8;Data offset.
*)flags : Flags.t;TCP header flags.
*)window : int16;Window size.
*)chksum : int8;Checksum.
*)urgent : int8;Urgent pointer.
*)payload : Cstruct.t;TCP payload.
*)}