Date: September 29, 2020
Time: 3:30-4:30pm ET


Programmable packet-processing devices such as programmable switches and network interface cards are becoming mainstream. These devices are programmed in a domain-specific language such as P4, using a compiler to translate packet-processing programs into instructions for different targets. As networks with programmable devices become widespread, it is critical that these compilers are dependable.

This paper considers the problem of finding bugs in compilers for packet processing in the context of P4-16. We introduce domain-specific techniques to induce both abnormal termination of the compiler (crash bugs) and miscompilation (semantic bugs). We apply these techniques to (1) the open-source P4 compiler (P4C) infrastructure, which serves as a common base for different P4 back ends; (2) the P4 back end for the P4 reference software switch; and (3) the P4 back end for the Barefoot Tofino switch. Across the 3 platforms, over 4 months of bug finding, our tool Gauntlet detected 92 new and distinct bugs (58 crash and 34 semantic), which we confirmed with the respective compiler developers. 48 have been fixed (28 crash and 20 semantic); the remaining have been assigned to a developer. Our bug-finding efforts also led to 6 P4 specification changes. We have open sourced Gauntlet at


Fabian is a PhD student in the systems lab at New York University. He works with Anirudh Sivaraman on problems related to data center networking, more specifically programmable networks. Previously, he was a Master’s student in the Networks, Systems, and Security lab of the University of British Columbia, where he was advised by Ivan Beschastnikh.