core
dettrace
core | dettrace | |
---|---|---|
4 | 2 | |
639 | 29 | |
1.7% | - | |
6.4 | 2.6 | |
2 months ago | over 3 years ago | |
Python | C++ | |
BSD 2-clause "Simplified" License | GNU General Public License v3.0 or later |
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core
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Twenty-five open-source network emulators and simulators you can use in 2023
CORE has been updated twice since the list was created. Itβs actively maintained. CORE emulates mobile, changing networks like IoT devices, phones, or network-connected vehicles.
GitHub - https://github.com/coreemu/core
Community Discord - https://discord.gg/AKd7kmP
- Core: Common Open Research Emulator
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Common Open Research Emulator (CORE) is a tool for emulating networks (added support for LXD/LXC and Docker
CORE: https://github.com/coreemu/core 3 The Common Open Research Emulator (CORE) is a tool for emulating networks on one or more machines. You can connect these emulated networks to live networks. CORE consists of a GUI for drawing topologies of lightweight virtual machines, and Python modules for scripting network emulation.
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Shadow Simlulator β run real applications over a simulated Internet topology
A quick look (by searching for bgp) suggests that this handles the upper layers, but doesn't try to simulate some of the deeper layers of a network such as bgp. Which something that emulators like core can do [0].
0. https://github.com/coreemu/core.
dettrace
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Deterministic Linux for Controlled Testing and Software Bug-Finding
Note that this is a follow-on project from the earlier Dettrace system, which was applied mainly to reproducible builds (as in the academic paper, https://dl.acm.org/doi/10.1145/3373376.3378519, and presented to the Debian Reproducible Builds summit):
- https://github.com/dettrace/dettrace
And one cool part of it is this Rust program instrumentation layer:
- https://github.com/facebookexperimental/reverie
It's good for building OS-emulator style projects or tracing tools.
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Shadow Simlulator β run real applications over a simulated Internet topology
We've started looking into eBPF a bit - IIUC eBPF by itself doesn't give us the ability to service or arbitrarily manipulate the traced process's syscalls.
We have recently learned of an interesting technique that dettrace [1] uses of combining seccomp with an eBPF filter and ptrace. Instead of generating a ptrace-stop for every syscall (as we do now, using PTRACE_SYSEMU), they use a seccomp policy with an eBPF filter, s.t. a ptrace-stop is only generated for syscalls that violate the policy, allowing them to emulate the result of those syscalls. syscalls that don't violate the policy are allowed to execute natively, saving a lot of overhead.
[1]: https://github.com/dettrace/dettrace
This works great for them since they want to emulate a relatively small subset of syscalls. In our case we want to emulate most syscalls, so it's not as clear-cut of a win. We have found though that if we use an LD_PRELOAD'd shim in the target process to intercept syscalls and then service them via IPC, that's substantially faster than catching them with ptrace. That runs back into the problems with LD_PRELOAD in general of there being various ways of missing syscalls. but, we may be able to use that technique along with ptrace+seccomp+ebpf to intercept any syscalls that we'd otherwise miss. The seccomp technique would allow us to exempt the syscalls that our shim itself is making to do the IPC.
What are some alternatives?
mininet - Emulator for rapid prototyping of Software Defined Networks
kickthemout - π€ Kick devices off your network by performing an ARP Spoof attack.
shadow - Shadow is a discrete-event network simulator that directly executes real application code, enabling you to simulate distributed systems with thousands of network-connected processes in realistic and scalable private network experiments using your laptop, desktop, or server running Linux.
shadow-plugin-tor - A Shadow plug-in that runs the Tor anonymity software
labrea - Scripting other people's programs.
imunes - Integrated Multiprotocol Network Emulator/Simulator
reverie - An ergonomic and safe syscall interception framework for Linux.
mn-wifi-ebook
testground - π§ͺ A platform for testing, benchmarking, and simulating distributed and p2p systems at scale.