SAPAN BHATIA
ASSOCIATE RESEARCH SCHOLAR

Coordinates

35, Olden Street
Princeton University
Princeton, NJ
sapanb @ cs . princeton . edu
WWW:    http://www.cs.princeton.edu/~sapanb/
Office:  318B

(New) vsys: A programmable sudo. Sapan Bhatia, Giovanni Di Stasi, Thom Haddow, Andy Bavier, Steve Muir and Larry Peterson. USENIX 'ATC 2011.
The presentation was picked up by Slashdot and PC World.

(New) sfatables: A firewall-like policy engine for federated systems. Sapan Bhatia, Andy Bavier, Larry Peterson, Soner Sevinc. ICDCS 2011.

Research

For my old publications, please visit here.

Development



sfatables
Sfatables is a firewall-like administrative tool for federated systems. If you have resources in any form (host resources, bandwidth) and you would like to make them available to a third party without losing control over their use, then sfatables is for you.

patchdep
Patch dependency analyzer. You specify the set of patches that you would like in your kernel, along with the set that you don't support and patchdep will compute the minimal subset of patches that you need along with the conflicts you need to resolve.

PlanetFlow2
PlanetFlow2 is PlanetLab's Netflow collection and query system. It uses an extended version of fprobe to collect and store data, and silk-tools to archive and query it. Audits between 5-10 Terabytes of data every day.

vnet+
VNET+ consists of an iptables match that associates packets with VM ids on PlanetLab; as well as additions to the network stack for using this association to filter traffic. The iptables match is available to all iptables targets and can be used for slice-specific filtering, policy routing etc.

vsys
vsys is to PlanetLab, what the /sys directory is to a Linux server. It is a mechanism to export privileged scripts to PlanetLab slices. vsys has a backend directory, located in root context on the node, and a frontend directory, which appears in the context of a slice. Scripts stored at the backend appear at the frontend as FIFO pipes, which slices can use to invoke and manage the scripts. vsys is written in ocaml and can be checked out of the Planet-Lab CVS.

shortbridge
We found that bridging ethernet devices has a high overhead and can reduce the throughput of forwarding experiments by up to a factor of 5. Shortbridge (abbr. for 'short-circuit bridge') overcomes this problem for pairs of devices, by cross-wiring the corresponding device objects. Implemented as a kernel module + patch for linux 2.6.20. New It looks like the macvlan module for Linux, released recently, subsumes the above functionality, and will probably replace shortbridge.

Misc

My favorite iPhone apps :-)
Handwriting App for the iPhone/iPad

Pain

I'm going to start collecting bugs that I have a hard time finding, in the hope that somebody looking for the same information will find it.
Inotify sometimes misses events because it coalesces them