util: rust: Support detecting socket file descriptors

Useful for Pipewire passthrough.

Signed-off-by: Val Packett <val@invisiblethingslab.com>
Signed-off-by: Gurchetan Singh <gurchetan.singh.foss@gmail.com>
Reviewed-by: David Gilhooley <djgilhooley@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/41754>

src/util/rust/defines.rs

@@ -88,6 +88,7 @@ pub enum DescriptorType {
     Memory(u32, u32), // (size, handle_type)
     WritePipe,
     Event,
+    Socket(TubeType),
 }
 
 /// # Safety

src/util/rust/meson.build

@@ -1,6 +1,12 @@
 # Copyright © 2024 Google
 # SPDX-License-Identifier: MIT
 
+dep_log = dependency('log',
+  version: '>= 0.4.22',
+  fallback: ['log-0.4-rs', 'dep_log'],
+  required: true,
+)
+
 dep_cfg_if = dependency('cfg-if',
   version: '>= 1.0.0',
   fallback: ['cfg-if-1-rs', 'dep_cfg_if'],
@@ -25,7 +31,8 @@ dep_zerocopy = dependency('zerocopy',
   required: true,
 )
 
-dep_mesa3d_util = [dep_cfg_if, dep_thiserror, dep_remain, dep_zerocopy]
+dep_mesa3d_util = [dep_cfg_if, dep_thiserror, dep_remain, dep_zerocopy,
+                   dep_log]
 
 supported_systems = ['linux', 'windows', 'darwin', 'macos']
 supported_host_machine = host_machine.system() in supported_systems

src/util/rust/sys/linux/descriptor.rs

@@ -16,11 +16,14 @@ use std::os::unix::io::RawFd;
 
 use rustix::fs::fcntl_get_seals;
 use rustix::fs::fcntl_getfl;
+use rustix::fs::fstat;
 use rustix::fs::seek;
+use rustix::fs::FileType;
 use rustix::fs::OFlags;
 use rustix::fs::SealFlags;
 use rustix::fs::SeekFrom;
 use rustix::io::Errno;
+use rustix::net::sockopt::socket_type;
 
 use crate::descriptor::AsRawDescriptor;
 use crate::descriptor::FromRawDescriptor;
@@ -55,6 +58,15 @@ impl OwnedDescriptor {
             }
         }
 
+        if let Ok(fd_stat) = fstat(&self.owned) {
+            let fd_type = FileType::from_raw_mode(fd_stat.st_mode);
+            if fd_type == FileType::Socket {
+                return Ok(DescriptorType::Socket(
+                    socket_type(&self.owned)?.try_into()?,
+                ));
+            }
+        }
+
         match seek(&self.owned, SeekFrom::End(0)) {
             Ok(seek_size) => {
                 let size: u32 = seek_size

src/util/rust/sys/linux/tube.rs

@@ -1,6 +1,8 @@
 // Copyright 2025 Google
 // SPDX-License-Identifier: MIT
 
+use std::io::Error;
+use std::io::ErrorKind;
 use std::io::IoSlice;
 use std::io::IoSliceMut;
 use std::mem::MaybeUninit;
@@ -41,6 +43,21 @@ pub struct Tube {
     socket: OwnedDescriptor,
 }
 
+impl TryFrom<SocketType> for TubeType {
+    type Error = std::io::Error;
+
+    fn try_from(ty: SocketType) -> Result<Self, Self::Error> {
+        match ty {
+            SocketType::SEQPACKET => Ok(TubeType::Packet),
+            SocketType::STREAM => Ok(TubeType::Stream),
+            ty => {
+                log::warn!("Unsupported socket type {ty:?}");
+                Err(Error::from(ErrorKind::Unsupported))
+            }
+        }
+    }
+}
+
 impl Tube {
     pub fn new<P: AsRef<Path> + Arg>(path: P, kind: TubeType) -> MesaResult<Tube> {
         let socket = match kind {