8 August 2011: document and sample are available

TCPExposure provides useful libraries to send and receive raw TCP packets in a Python script. It uses a Bpf device or a raw IP socket. TCPExposure contains a libpcap wrapper for Python (pcaplib.py) and higher level abstraction to craft, send and receive TCP packets (tcpsrlib.py and tcplib.py).

TCPExposure is used in our large-scale measurement study of middlebox behaviors in the Internet (See our IMC 2011 paper). Document is very rough, questions are welcome!

[document (pdf)]  [files and a sample (tar.gz)]

System requirements: libpcap, Python 2.5 or higher, Mac OSX/FreeBSD/Linux

7 Nov 2011: Fast handoff implementation is merged into Linux net-next tree!

3 June 2011: Auto_ASCONF implementation is merged into Linux net-next-2.6 tree!

AUTO_ASCONF is an SCTP functionality, which transmits ASCONF chunks that reconfigure the IP address in existing SCTP associations. This functionality supports applications can continue communication even when the IP address has been changed (e.g., due to migration to a different network segment).

This implementation also enables fasthandoff based on a new retransmission trigger, which retransmits packet without waiting for retransmission timeout when source address changes. This is just Linux implementation of the paper.

For enabling AUTO_ASCONF and the fast handover feature, please set a sysctl parameter "default_auto_asconf" to 1.