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Rollup merge of rust-lang#94094 - chrisnc:tcp-nodelay-windows-bool, r…
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…=dtolnay

use BOOL for TCP_NODELAY setsockopt value on Windows

This issue was found by the Wine project and mitigated there [^1].

Windows' setsockopt expects a BOOL (a typedef for int) for TCP_NODELAY
[^2]. Windows itself is forgiving and will accept any positive optlen and
interpret the first byte of *optval as the value, so this bug does not
affect Windows itself, but does affect systems implementing Windows'
interface more strictly, such as Wine. Wine was previously passing this
through to the host's setsockopt, where, e.g., Linux requires that
optlen be correct for the chosen option, and TCP_NODELAY expects an int.

[^1]: https://source.winehq.org/git/wine.git/commit/d6ea38f32dfd3edbe107a255c37e9f7f3da06ae7
[^2]: https://docs.microsoft.com/en-us/windows/win32/api/winsock/nf-winsock-setsockopt
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matthiaskrgr committed Feb 19, 2022
2 parents 149168b + e5f7239 commit a8cb229
Showing 1 changed file with 2 additions and 2 deletions.
4 changes: 2 additions & 2 deletions library/std/src/sys/windows/net.rs
Original file line number Diff line number Diff line change
Expand Up @@ -407,11 +407,11 @@ impl Socket {
}

pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
net::setsockopt(self, c::IPPROTO_TCP, c::TCP_NODELAY, nodelay as c::BYTE)
net::setsockopt(self, c::IPPROTO_TCP, c::TCP_NODELAY, nodelay as c::BOOL)
}

pub fn nodelay(&self) -> io::Result<bool> {
let raw: c::BYTE = net::getsockopt(self, c::IPPROTO_TCP, c::TCP_NODELAY)?;
let raw: c::BOOL = net::getsockopt(self, c::IPPROTO_TCP, c::TCP_NODELAY)?;
Ok(raw != 0)
}

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