From 5e61f17a3ab59f0fba9725e009219a6b8d165138 Mon Sep 17 00:00:00 2001
From: "Ibuki.O" <isan.ethen@gmail.com>
Date: Sun, 8 Feb 2026 12:09:08 +0900
Subject: [PATCH] feat: Implement MSG_CMSG_CLOEXEC handling to recvmsg

---
 src/header/sys_socket/constants.rs | 1 +
 src/platform/redox/socket.rs       | 9 ++++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/header/sys_socket/constants.rs b/src/header/sys_socket/constants.rs
index 7d6c8b972f..ec42889bf5 100644
--- a/src/header/sys_socket/constants.rs
+++ b/src/header/sys_socket/constants.rs
@@ -50,6 +50,7 @@ pub const MSG_PEEK: c_int = 2;
 pub const MSG_TRUNC: c_int = 32;
 pub const MSG_DONTWAIT: c_int = 64;
 pub const MSG_WAITALL: c_int = 256;
+pub const MSG_CMSG_CLOEXEC: c_int = 0x40000000;
 
 pub const IP_ADD_SOURCE_MEMBERSHIP: c_int = 70;
 pub const IP_DROP_SOURCE_MEMBERSHIP: c_int = 71;
diff --git a/src/platform/redox/socket.rs b/src/platform/redox/socket.rs
index 26cd6930d3..82cd715dad 100644
--- a/src/platform/redox/socket.rs
+++ b/src/platform/redox/socket.rs
@@ -394,6 +394,7 @@ unsafe fn deserialize_ancillary_data_from_stream(
     msg_stream: &[u8],
     cursor: &mut usize,
     cmsg_space_provided: usize,
+    flags: c_int,
 ) -> Result<()> {
     let mut current_cmsg_ptr_in_user_buf = if !mhdr.msg_control.is_null() && cmsg_space_provided > 0
     {
@@ -449,7 +450,12 @@ unsafe fn deserialize_ancillary_data_from_stream(
                     )
                 };
 
-                redox_rt::sys::sys_call_ro(socket as usize, fds_bytes, CallFlags::FD, &[])?;
+                let mut call_flags = CallFlags::FD;
+                if flags & MSG_CMSG_CLOEXEC == MSG_CMSG_CLOEXEC {
+                    call_flags |= CallFlags::FD_CLOEXEC;
+                }
+
+                redox_rt::sys::sys_call_ro(socket as usize, fds_bytes, call_flags, &[])?;
 
                 for fd in fds_usize {
                     temp_posix_cmsg_data_buf.extend_from_slice(&(fd as c_int).to_le_bytes());
@@ -908,6 +914,7 @@ impl PalSocket for Sys {
                     &msg_stream,
                     &mut cursor,
                     cmsg_space_provided_by_user as usize,
+                    flags,
                 )
             })?;
         } else {