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

Author: Dylan-DPC

std/src/sys/windows/net.rs

@@ -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)
     }
 

std/src/sys_common/net.rs

@@ -58,21 +58,36 @@ cfg_if::cfg_if! {
 // sockaddr and misc bindings
 ////////////////////////////////////////////////////////////////////////////////
 
-pub fn setsockopt<T>(sock: &Socket, opt: c_int, val: c_int, payload: T) -> io::Result<()> {
+pub fn setsockopt<T>(
+    sock: &Socket,
+    level: c_int,
+    option_name: c_int,
+    option_value: T,
+) -> io::Result<()> {
     unsafe {
-        let payload = &payload as *const T as *const c_void;
-        cvt(c::setsockopt(sock.as_raw(), opt, val, payload, mem::size_of::<T>() as c::socklen_t))?;
+        cvt(c::setsockopt(
+            sock.as_raw(),
+            level,
+            option_name,
+            &option_value as *const T as *const _,
+            mem::size_of::<T>() as c::socklen_t,
+        ))?;
         Ok(())
     }
 }
 
-pub fn getsockopt<T: Copy>(sock: &Socket, opt: c_int, val: c_int) -> io::Result<T> {
+pub fn getsockopt<T: Copy>(sock: &Socket, level: c_int, option_name: c_int) -> io::Result<T> {
     unsafe {
-        let mut slot: T = mem::zeroed();
-        let mut len = mem::size_of::<T>() as c::socklen_t;
-        cvt(c::getsockopt(sock.as_raw(), opt, val, &mut slot as *mut _ as *mut _, &mut len))?;
-        assert_eq!(len as usize, mem::size_of::<T>());
-        Ok(slot)
+        let mut option_value: T = mem::zeroed();
+        let mut option_len = mem::size_of::<T>() as c::socklen_t;
+        cvt(c::getsockopt(
+            sock.as_raw(),
+            level,
+            option_name,
+            &mut option_value as *mut T as *mut _,
+            &mut option_len,
+        ))?;
+        Ok(option_value)
     }
 }