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Show HN: A pure ARM64 Assembly web server, now on Linux with CGI for no reason (github.com)

51 points by imtomt ↗ HN
This is ymawky, a now-dynamic web server written entirely in ARM64 Assembly. I've previously posted about ymawky here: https://news.ycombinator.com/item?id=48080587

In the past month and a half, I've made some pretty major improvements: I've added CGI scripting support, so the server now supports query strings and dynamic content; and I've fully ported ymawky to run on Linux, rather than macOS-only.

In addition to GET/PUT/HEAD/DELETE/OPTIONS requests, because of CGI support ymawky also accepts POST requests (only to CGI resources for now).

I've also updated the more detailed writeup to reflect CGI support and the Linux port: https://imtomt.github.io/ymawky/

19 comments

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tosti
This isn't a bad thing per se. I imagine this could be a thing for an embedded side project or a tiny rescue system.

Edit: or learning arm64 assembly :)

benj111
Cool. I particularly like the O'Reilly book cover that never was. Although I fear you may have misunderstood what wasm is...

Question/critique. Isn't getting the mime type by file extension a bit windowsy? Would it not be easier to read the magic number when you're at the assembly level?

imtomt
You could do that, but it's not really necessary, and adds extra overhead and complexity. And as the other commenter pointed out, it wouldn't work for text file types without magic numbers. I considered reading the magic number at first, but after doing more research, I've found most web servers (nginx and apache, anyway) just match based on file extension. I figure if it's good enough for them, it's good enough for ymawky.
kunley
Ahh, this little gem ported to Linux, great! That opens much more possibilities to play with it, thanks
hparadiz
I love projects like this because I think eventually all common computing tasks will be broken down in constituent most computationally optimized components
nickcw
I love it :-)

Back in the distant past I wrote some really big ARM 32 assembly projects. 64 bit ARM is really very similar!

I had a look through the code. Some ENTRY/EXIT macros to help with the drudgery of save restore registers & stack frame would probably help. Also some register renaming would help readability (eg if a register points to incoming data throughout a subroutine rename it pdata).

I salute your effort and please enjoy the core dumps :-)

imtomt
Thank you! Definitely, some macros would probably be super helpful. Register renaming, too, I'm sure. When I started this project I didn't even know about register renaming lol, and at this point it's so big I'd have to dig pretty deep to find 'em all. Definitely worth doing, though, I'm sure.
wewewedxfgdf
There's critical security flaws in this web server. Consult your local LLM for a security analysis.
radhitya
"raw syscalls only: no libc wrappers"

insane! i wonder how many times you have spent to learn about them!

imtomt
Honestly it's easier than you'd think! All the syscall numbers are in /usr/include/asm-generic/unistd.h (on linux), and you can read the man page for any of them.
sylware
arm64 is an IP-locked ISA, namely it is not worth assembly writting, stick to plain and simple C.

RISC-V is. I am self-hosting many of my internet thingies. I plan to move to RISC-V only hardware and to rewrite my internet software directly in mono-threaded paranoid RISC-V assembly.

imtomt
For sure. My laptop has an arm64 chip, which is why this is written in arm64. If I had an intel chip, it would be written in x86_64. RISC-V is very interesting, though, and I'd love to learn more at some point.

Good luck with your RISC-V asm stuff! Hit me up if you publish any of it :)

sylware
I have a good set of RISC-V thingies on internet already, but not cleanely in some git repositories (obsviously not on microsoft github.com or gitlab).

I am currently attempting to define some binary specifications for a wayland compositor on linux, and to do that I write RISC-V assembly which I run on x86_64 thx to a very small interpreter. So the "cleanup" will happen "after" I get my own real-life wayland compositor (I am currently finishing the memory layout for keyboard and mouse support if you were curious about it).

Letting people know here is seriously compromised: HN started to aggressively block web browsers which are not based on one of the 'whatwg cartel' web engines, or their security provider is in love with gogol, dunno, could be my internet lines actively filtered too :) noscript/basic HTML is the only way for web freedom.

Lucasoato
Is an assembly webserver more performant than webservers written in other languages? Are there any hard limits on how much you can squeeze when using a particular framework?
imtomt
The language matters much less than the architecture of the web server. A server written in assembly using a fork-on-request model like ymawky is going to be much slower than a server written in C using an async event loop like nginx, because forking is very inefficient at scale. Plus a big bottleneck is the networking syscalls, rather than the code itself, so two servers with the same model written in Assembly and C would likely be roughly equal.
ntm3c
Assembly can provide the best raw performance because it's closer to the hardware. However, writing and maintaining a web server in Assembly takes much more time, and in many cases the performance gain over a well-written C program is small.
mrbluecoat
> written entirely by-hand in ARM64 assembly as a fun project. It's probably got a lot of vulnerabilities I'm unaware of

Impressive, but that second part worries me. I hope one day AI security scans upon commit (or integrated in the IDE) will alleviate that risk.

What's the current security gold standard for web servers? Hiawatha? https://hiawatha.leisink.net/

imtomt
Well, if security is a major concern, definitely don't use ymawky in production! That said, I did try my best to harden it. I've fuzzed the parser extensively with afl-fuzz, and got several hours without a single hang or crash. There's no major vulns I'm aware of, but in a ~4500 SLOC assembly project, there's probably gonna be some vulnerabilities that are hiding.