#487 Add ways to set Path Discovery MTU for Linux on a Socket. #515
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This contribution use setsocketops to configure Dont Fragment (DF) bit and OS behavior related to PMTU. It introduce PathMtuDiscoveringMode enum to manage it rust-way and 4 functions respectively for ipv4/v6 and set/get. Omit and Interface exist but are not widely documented.
src/sys/unix.rs
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| #[cfg_attr(docsrs, doc(cfg(all(feature = "all", target_os = "linux"))))] | ||
| #[repr(C)] | ||
| #[derive(Debug)] | ||
| pub enum PathMtuDiscoveringMode { |
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I'm not sure about this enum.
Maybe it's better as a type alias with constants for the options? This way we don't have to do the conversion and we don't have to deal with the case where the kernel returns a value we don't support yet.
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Ok I agree, I may do a patch to the linux man page since some are not explicitly documented outside of the in.h/in6.h
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Maybe it's better as a type alias with constants for the options? This way we don't have to do the conversion and we don't have to deal with the case where the kernel returns a value we don't support yet.
I reused the pattern used for Type and Protocol code tell me if wasn't the best move. :)
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Hello, thanks for the review, will do the changes today. |
Co-authored-by: Thomas de Zeeuw <thomasdezeeuw@gmail.com>
I reused the pattern used elsewhere to have handful short hands documented, while yet permiting futur constant not exposed in the lib. Also expose MtuDiscovering Mode types..
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| #[cfg(all(feature = "all", target_os = "linux"))] | ||
| #[cfg_attr(docsrs, doc(cfg(all(feature = "all", target_os = "linux"))))] | ||
| impl PathMtuDiscoveringModeV6 { |
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It involve some code duplication alas but it's code that... never change except for adding new mode since API don't change for Linux.
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Sorry @darnuria I didn't have time to review this last weekend and I don't think I'll have time the next two weeks either, so it's going to take a little while. |
Hello first contribution here! It may need some careful review since MTU management is a bit complicated and not so portable.
Add ways to set Path Discovery MTU for Linux on a Socket. (it may not work on freebsd EDIT: CI confirmed it! but may work on Windows subsystem and winsock: https://learn.microsoft.com/en-us/windows/win32/winsock/ipproto-ip-socket-options.
This contribution use
setsocketopsto configure Dont Fragment (DF) bit and OSbehavior related to PMTU.
It introduce
PathMtuDiscoveringModeenum to manage it rust-way and 4 functionsrespectively for ipv4/v6 and set/get.
Omit and Interface exist but are not widely documented.
Initially It started by preparing a PR for the patch purposed here: #487
Context: Why it can be needed in a rust library? Some protocols such as DNS in UDP or traceroute needs to manage the MTU on a socket level.
Exemples: