Rollup merge of #129638 - nickrum:wasip2-net, r=alexcrichton

Hook up std::net to wasi-libc on wasm32-wasip2 target

One of the improvements of the `wasm32-wasip2` target over `wasm32-wasip1` is better support for networking. Right now, p2 is just re-using the `std::net` implementation from p1. This PR adds a new net module for p2 that makes use of net from `sys_common` and calls wasi-libc functions directly.

There are currently a few limitations:

- Duplicating a socket is not supported by WASIp2 (directly returns an error)
- Peeking is not yet implemented in wasi-libc (we could let wasi-libc handle this, but I opted to directly return an error instead)
- Vectored reads/writes are not supported by WASIp2 (the necessary functions are available in wasi-libc, but they call WASIp1 functions which do not support sockets, so I opted to directly return an error instead)
- Getting/setting `TCP_NODELAY` is faked in wasi-libc (uses the fake implementation instead of returning an error)
- Getting/setting `SO_LINGER` is not supported by WASIp2 (directly returns an error)
- Setting `SO_REUSEADDR` is faked in wasi-libc (since this is done from `sys_common`, the fake implementation is used instead of returning an error)
- Getting/setting `IPV6_V6ONLY` is not supported by WASIp2 and will always be set for IPv6 sockets (since this is done from `sys_common`, wasi-libc will return an error)
- UDP broadcast/multicast is not supported by WASIp2 (since this is configured from `sys_common`, wasi-libc will return appropriate errors)
- The `MSG_NOSIGNAL` send flag is a no-op because there are no signals in WASIp2 (since explicitly setting this flag would require a change to `sys_common` and the result would be exactly the same, I opted to not set it)

Do those decisions make sense?

While working on this PR, I noticed that there is a `std::os::wasi::net::TcpListenerExt` trait that adds a `sock_accept()` method to `std::net::TcpListener`. Now that WASIp2 supports standard accept, would it make sense to remove this?

cc `@alexcrichton`

2 files changed, 2 insertions, 2 deletions

diff --git a/library/std/src/thread/local.rs b/library/std/src/thread/local.rs
index f147c5fdcd1..88bf186700f 100644
--- a/library/std/src/thread/local.rs
+++ b/library/std/src/thread/local.rs
@@ -2,7 +2,7 @@
 
 #![unstable(feature = "thread_local_internals", issue = "none")]
 
-#[cfg(all(test, not(target_os = "emscripten")))]
+#[cfg(all(test, not(any(target_os = "emscripten", target_os = "wasi"))))]
 mod tests;
 
 #[cfg(test)]
diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index 686f5055ac1..22d65583365 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -155,7 +155,7 @@
 // Under `test`, `__FastLocalKeyInner` seems unused.
 #![cfg_attr(test, allow(dead_code))]
 
-#[cfg(all(test, not(target_os = "emscripten")))]
+#[cfg(all(test, not(any(target_os = "emscripten", target_os = "wasi"))))]
 mod tests;
 
 use crate::any::Any;