bpftool
pwru
| bpftool | pwru | |
|---|---|---|
| 2 | 7 | |
| 303 | 2,464 | |
| 6.6% | 4.2% | |
| 9.1 | 9.1 | |
| 7 days ago | 5 days ago | |
| C | C | |
| GNU General Public License v3.0 or later | Apache License 2.0 |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
bpftool
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BPF for Hid Drivers
In the same way out-of-tree kernel modules are enforced to license themselves as GPL if they intend to use a lot (if not most) of the available functionality, eBPF programs fall under the same restrictions.
bpftool[0] allows to see which the programs are currently running in your system, their bpf asm instructions and whether they are GPL-compliant through `bpftool prog show`
Of course, we still need companies to actually release the source code of their eBPF programs somewhere for the promise to be fulfilled.
[0] https://github.com/libbpf/bpftool
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How to tell what created/owns each BPF program running in my system ?
Your distro might not ship the newer version but source is available on Github so you don't have to pull the entire kernel repo to build it.
pwru
- GitHub - cilium/pwru: Packet, where are you? -- eBPF-based Linux kernel networking debugger
- cilium/pwru: Packet, where are you? -- eBPF-based Linux kernel networking debugger
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Packet, where are you? – eBPF-based Linux kernel networking debugger
if you have a recent enough kernel, this change https://github.com/cilium/pwru/pull/148 means that it will print the reason the packet was dropped in the output - see https://lwn.net/Articles/885729/
There's a whole heap of reasons a packet can be dropped:
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A list of new(ish) command line tools – Julia Evans
[pwru](https://github.com/cilium/pwru) is a fun new tool from the Cilium folks for tracing network packets in the kernel. Like tcpdump but it shows you the full path including kernel syscalls. Lets you debug much deeper than "when the packet gets to this port it gets dropped".
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Better visibility into Linux packet-dropping decisions
I recently came across another useful utility for debugging unexpected packet drops - PWRU[0] (Packet, Where Are You) by Cilium.
It uses eBPF to try to trace the path of the packet through the kernel. Haven't needed to use it yet, but it could have saved me a lot of trouble in the past.
[0]: https://github.com/cilium/pwru
What are some alternatives?
libbpf - Automated upstream mirror for libbpf stand-alone build.
parca-agent - eBPF based always-on profiler auto-discovering targets in Kubernetes and systemd, zero code changes or restarts needed!
TripleCross - A Linux eBPF rootkit with a backdoor, C2, library injection, execution hijacking, persistence and stealth capabilities.
fsmon - monitor filesystem on iOS / OS X / Android / FirefoxOS / Linux
traffico - Shape your traffic the BPF way
bmc-cache - In-kernel cache based on eBPF.
bpfcov - Source-code based coverage for eBPF programs actually running in the Linux kernel
bpftune - bpftune uses BPF to auto-tune Linux systems
glow - Render markdown on the CLI, with pizzazz! 💅🏻
bpf-developer-tutorial - eBPF Developer Tutorial: Learning eBPF Step by Step with Examples
up - Ultimate Plumber is a tool for writing Linux pipes with instant live preview