Method, apparatus and software for packet modification

摘要

Embodiments provide an apparatus, method and software configured to modify a transmission control protocol packet so as to become a user datagram protocol datagram, or to modify a user datagram protocol datagram so as to become a transmission control protocol packet. An embodiment uses a mapping between TCP packet format, such as TCP wire packet format, and an UDP-encapsulated TCP packet format, such as UDP-encapsulated TCP wire packet format, allowing direct re-use of any TCP protocol implementation. TCP frames can be modified into valid UDP datagrams before being transmitted, and inverse modifications can be done when receiving datagrams from the network.

主权项

1. An apparatus comprising a processor and a memory including computer program code, the computer program code configured, with the processor, to cause the apparatus to:
modify a transmission control protocol packet so as to become a user datagram protocol datagram in response to determining that the user datagram protocol datagram has the same length as the original transmission control protocol packet, wherein the computer program code is further configured, with the processor, to cause the apparatus to modify a user datagram protocol packet to recover a transmission control protocol packet by performing at least one of:
recomputing the transmission control protocol checksum,assuming a bit indicating urgent mode and urgent pointer to be zero,setting back a protocol value in the header, anddelivering the packet to a transmission control protocol state machine; and wherein the computer program code is further configured, with the processor, to cause the apparatus to multiplex modified transmission control protocol frames with user datagram protocol packets to support user datagram protocol hole punching.