FLECS: A Data-Driven Framework for Rapid Protocol Prototyping

Flecs is a framework for facilitating rapid implementation of communication protocols. Forwarding functionality of protocols can be modeled as a combination of packet processing components called abstract switching elements or Ases. The design of Ases is constrained by the axioms of communication which enables us to formally analyze forwarding mechanisms in communication networks. Ases can be connected in a directed graph to define complex forwarding functionality. We have developed Flecs on top of the Click modular router. The compilers in the Flecs framework translate protocol specifications into its Click implementation. We claim that the use of our framework reduces the implementation time by allowing the programmer to specify Ases and the forwarding configuration in a high-level meta-language and produces reasonably efficient implementations. It allows rapid prototyping through configuration, as well as specialized implementation of performance-critical functionality through inheritance

Virtualization of network I/O on modern operating systems

Network I/O of modern operating systems is incomplete. In this networkage, users and their applications are still unable to control theirown traffic, even on their local host. Network I/O is a sharedresource of a host machine, and traditionally, to address problemswith a shared resource, system research has virtualized the resource.Therefore, it is reasonable to ask if the virtualization can providesolutions to problems in network I/O of modern operating systems, inthe same way as the other components of computer systems, such asmemory and CPU. With the aim of establishing the virtualization ofnetwork I/O as a design principle of operating systems, thisdissertation first presents a virtualization model, hierarchicalvirtualization of network interface. Systematic evaluation illustratesthat the virtualization model possesses desirable properties forvirtualization of network I/O, namely flexible control granularity,resource protection, partitioning of resource consumption, properaccess control and generality as a control model. The implementedprototype exhibits practical performance with expected functionality,and allowed flexible and dynamic network control by users andapplications, unlike existing systems designed solely for systemadministrators. However, because the implementation was hardcoded inkernel source code, the prototype was not perfect in its functionalcoverage and flexibility. Accordingly, this dissertation investigatedhow to decouple OS kernels and packet processing code throughvirtualization, and studied three degrees of code virtualization,namely, limited virtualization, partial virtualization, and completevirtualization. In this process, a novel programming model waspresented, based on embedded Java technology, and the prototypeimplementation exhibited the following characteristics, which aredesirable for network code virtualization. First, users program inJava to carry out safe and simple programming for packetprocessing. Second, anyone, even untrusted applications, can performinjection of packet processing code in the kernel, due to isolation ofcode execution. Third, the prototype implementation empirically provedthat such a virtualization does not jeopardize system performance.These cases illustrate advantages of virtualization, and suggest thatthe hierarchical virtualization of network interfaces can be aneffective solution to problems in network I/O of modern operatingsystems, both in the control model and in implementation

Prolac--a language for protocol compilation

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 81-83).by Eddie Kohler.M.S