Stefan Schmid | TU Delft Repository

Runtime Verification for Programmable Switches

Journal article (2023) - Apoorv Shukla, Kevin Hudemann, Zsolt Vagi, Lily Hugerich, Georgios Smaragdakis, Artur Hecker, Stefan Schmid, Anja Feldmann

We introduce a runtime verification framework for programmable switches that complements static analysis. To evaluate our approach, we design and develop P6, a runtime verification system that automatically detects, localizes, and patches software bugs in P4 programs. Bugs are reported via a violation of pre-specified expected behavior that is captured by P6. P6 is based on machine learning-guided fuzzing that tests P4 switch non-intrusively, i.e., without modifying the P4 program for detecting runtime bugs. This enables an automated and real-time localization and patching of bugs. We used a P6 prototype to detect and patch existing bugs in various publicly available P4 application programs deployed on two different switch platforms, namely, behavioral model (bmv2) and Tofino. Our evaluation shows that P6 significantly outperforms bug detection baselines while generating fewer packets and patches bugs in large P4 programs, e.g., switch.p4 without triggering any regressions. ...

Lanelet2 for nuScenes

Enabling Spatial Semantic Relationships and Diverse Map-based Anchor Paths

Conference paper (2023) - Alexander Naumann, Felix Hertlein, Daniel Grimm, Maximilian Zipf, Steffen Thoma, Achim Rettinger, Lavdim Halilaj, Juergen Luettin, Stefan Schmid, Holger Caesar

Motion prediction and planning are key components to enable autonomous driving. Although high definition (HD) maps provide important contextual information that constrains the action space of traffic participants, most approaches are not able to fully exploit this heterogeneous information. In this work, we enrich the existing road geometry of the popular nuScenes dataset and convert it into the open-source map framework Lanelet2. This allows easy access to the road topology and thus, enables the usage of (1) spatial semantic information, such as agents driving on intersecting roads and (2) map-generated anchor paths for target vehicles that can help to improve trajectory prediction performance. Further, we present DMAP, a simple, yet effective approach for diverse map-based anchor path generation and filtering. We show that combining DMAP with ground truth velocity profile information yields high-quality motion prediction results on nuScenes (MinADE5=1.09, MissRate5,2=0.18, Offroad rate=0.00). While it is obviously unfair to compare us against the state-of-the-art, it shows that our HD map accurately depicts the road geometry and topology. Future approaches can leverage this by focusing on data-driven sampling of map-based anchor paths and estimating velocity profiles. Moreover, our HD map can be used for map construction tasks and supplement perception. Code and data are made publicly available at https://felixhertlein.github.io/lanelet4nuscenes. ...

Fix with P6

Verifying programmable switches at runtime

Conference paper (2021) - Apoorv Shukla, Kevin Hudemann, Zsolt Vagi, Lily Hugerich, Georgios Smaragdakis, Artur Hecker, Stefan Schmid, Anja Feldmann

We design, develop, and evaluate P6, an automated approach to (a) detect, (b) localize, and (c) patch software bugs in P4 programs. Bugs are reported via a violation of pre-specified expected behavior that is captured by P6. P6 is based on machine learning-guided fuzzing that tests P4 switch non-intrusively, i.e., without modifying the P4 program for detecting runtime bugs. This enables an automated and real-time localization and patching of bugs. We used a P6 prototype to detect and patch existing bugs in various publicly available P4 application programs deployed on two different switch platforms: behavioral model (bmv2) and Tofino. Our evaluation shows that P6 significantly outperforms bug detection baselines while generating fewer packets and patches bugs in large P4 programs such as switch.p4 without triggering any regressions. ...

Taking Control of SDN-based Cloud Systems via the Data Plane

Conference paper (2018) - Kashyap Thimmaraju, Bhargava Shastry, Tobias Fiebig, Felicitas Hetzelt, Jean-Pierre Seifert, Anja Feldmann, Stefan Schmid

Virtual switches are a crucial component of SDN-based cloud systems, enabling the interconnection of virtual machines in a flexible and “software-defined” manner. This paper raises the alarm on the security implications of virtual switches. In particular, we show that virtual switches not only increase the attack surface of the cloud, but virtual switch vulnerabilities can also lead to attacks of much higher impact compared to traditional switches. We present a systematic security analysis and identify four design decisions which introduce vulnerabilities. Our findings motivate us to revisit existing threat models for SDN-based cloud setups, and introduce a new attacker model for SDN-based cloud systems using virtual switches. ...

Static Program Analysis as a Fuzzing Aid

Conference paper (2017) - Bhargava Shastry, Markus Leutner, Tobias Fiebig, Kashyap Thimmaraju, Fabian Yamaguchi, Konrad Rieck, Stefan Schmid, Jean-Pierre Seifert, Anja Feldmann