[libos] Add status_flags support for stdio

src/libos/src/fs/event_file.rs

@@ -83,12 +83,7 @@ impl File for EventFile {
     }
 
     fn set_status_flags(&self, new_status_flags: StatusFlags) -> Result<()> {
-        let valid_flags_mask = StatusFlags::O_APPEND
+        let raw_status_flags = (new_status_flags & STATUS_FLAGS_MASK).bits();
-            | StatusFlags::O_ASYNC
-            | StatusFlags::O_DIRECT
-            | StatusFlags::O_NOATIME
-            | StatusFlags::O_NONBLOCK;
-        let raw_status_flags = (new_status_flags & valid_flags_mask).bits();
         try_libc!(libc::ocall::fcntl_arg1(
             self.host_fd(),
             libc::F_SETFL,

src/libos/src/fs/file_ops/file_flags.rs

@@ -111,6 +111,15 @@ bitflags! {
         const O_PATH = 1 << 21;
     }
 }
+// On Linux, F_SETFL can change only the O_APPEND,
+// O_ASYNC, O_DIRECT, O_NOATIME, and O_NONBLOCK flags
+pub const STATUS_FLAGS_MASK: StatusFlags = StatusFlags::from_bits_truncate(
+    StatusFlags::O_APPEND.bits()
+        | StatusFlags::O_ASYNC.bits()
+        | StatusFlags::O_DIRECT.bits()
+        | StatusFlags::O_NOATIME.bits()
+        | StatusFlags::O_NONBLOCK.bits(),
+);
 
 impl StatusFlags {
     pub fn always_append(&self) -> bool {

src/libos/src/fs/file_ops/mod.rs

@@ -8,7 +8,7 @@ pub use self::close::do_close;
 pub use self::dup::{do_dup, do_dup2, do_dup3};
 pub use self::fallocate::{do_fallocate, FallocateFlags};
 pub use self::fcntl::{do_fcntl, FcntlCmd};
-pub use self::file_flags::{AccessMode, CreationFlags, StatusFlags};
+pub use self::file_flags::{AccessMode, CreationFlags, StatusFlags, STATUS_FLAGS_MASK};
 pub use self::flock::do_flock;
 pub use self::fspath::{get_abs_path_by_fd, FsPath, AT_FDCWD};
 pub use self::fsync::{do_fdatasync, do_fsync};

src/libos/src/fs/inode_file.rs

@@ -176,14 +176,8 @@ impl File for INodeFile {
 
     fn set_status_flags(&self, new_status_flags: StatusFlags) -> Result<()> {
         let mut status_flags = self.status_flags.write().unwrap();
-        // Currently, F_SETFL can change only the O_APPEND,
+        status_flags.remove(STATUS_FLAGS_MASK);
-        // O_ASYNC, O_NOATIME, and O_NONBLOCK flags
+        status_flags.insert(new_status_flags & STATUS_FLAGS_MASK);
-        let valid_flags_mask = StatusFlags::O_APPEND
-            | StatusFlags::O_ASYNC
-            | StatusFlags::O_NOATIME
-            | StatusFlags::O_NONBLOCK;
-        status_flags.remove(valid_flags_mask);
-        status_flags.insert(new_status_flags & valid_flags_mask);
         Ok(())
     }
 

src/libos/src/fs/mod.rs

@@ -21,6 +21,7 @@ pub use self::file::{File, FileRef};
 pub use self::file_ops::{
     occlum_ocall_ioctl, utimbuf_t, AccessMode, BuiltinIoctlNum, CreationFlags, FallocateFlags,
     FileMode, IfConf, IoctlCmd, Stat, StatusFlags, StructuredIoctlArgType, StructuredIoctlNum,
+    STATUS_FLAGS_MASK,
 };
 pub use self::file_table::{FileDesc, FileTable, FileTableEvent, FileTableNotifier};
 pub use self::fs_ops::Statfs;

src/libos/src/fs/stdio.rs

@@ -213,6 +213,24 @@ impl File for StdoutFile {
         Ok(ret)
     }
 
+    fn status_flags(&self) -> Result<StatusFlags> {
+        let ret = try_libc!(libc::ocall::fcntl_arg0(
+            self.host_fd() as i32,
+            libc::F_GETFL
+        ));
+        Ok(StatusFlags::from_bits_truncate(ret as u32))
+    }
+
+    fn set_status_flags(&self, new_status_flags: StatusFlags) -> Result<()> {
+        let raw_status_flags = (new_status_flags & STATUS_FLAGS_MASK).bits();
+        try_libc!(libc::ocall::fcntl_arg1(
+            self.host_fd() as i32,
+            libc::F_SETFL,
+            raw_status_flags as c_int
+        ));
+        Ok(())
+    }
+
     fn as_any(&self) -> &dyn Any {
         self
     }
@@ -375,6 +393,24 @@ impl File for StdinFile {
         Ok(ret)
     }
 
+    fn status_flags(&self) -> Result<StatusFlags> {
+        let ret = try_libc!(libc::ocall::fcntl_arg0(
+            self.host_fd() as i32,
+            libc::F_GETFL
+        ));
+        Ok(StatusFlags::from_bits_truncate(ret as u32))
+    }
+
+    fn set_status_flags(&self, new_status_flags: StatusFlags) -> Result<()> {
+        let raw_status_flags = (new_status_flags & STATUS_FLAGS_MASK).bits();
+        try_libc!(libc::ocall::fcntl_arg1(
+            self.host_fd() as i32,
+            libc::F_SETFL,
+            raw_status_flags as c_int
+        ));
+        Ok(())
+    }
+
     fn as_any(&self) -> &dyn Any {
         self
     }

src/libos/src/fs/timer_file.rs

@@ -130,12 +130,7 @@ impl File for TimerFile {
     }
 
     fn set_status_flags(&self, new_status_flags: StatusFlags) -> Result<()> {
-        let valid_flags_mask = StatusFlags::O_APPEND
+        let raw_status_flags = (new_status_flags & STATUS_FLAGS_MASK).bits();
-            | StatusFlags::O_ASYNC
-            | StatusFlags::O_DIRECT
-            | StatusFlags::O_NOATIME
-            | StatusFlags::O_NONBLOCK;
-        let raw_status_flags = (new_status_flags & valid_flags_mask).bits();
         try_libc!(libc::ocall::fcntl_arg1(
             self.host_fd(),
             libc::F_SETFL,

src/libos/src/net/socket/host/socket_file.rs

@@ -6,7 +6,7 @@ use atomic::{Atomic, Ordering};
 use super::*;
 use crate::fs::{
     occlum_ocall_ioctl, AccessMode, AtomicIoEvents, CreationFlags, File, FileRef, HostFd, IoEvents,
-    IoctlCmd, StatusFlags,
+    IoctlCmd, StatusFlags, STATUS_FLAGS_MASK,
 };
 
 //TODO: refactor write syscall to allow zero length with non-zero buffer
@@ -63,12 +63,7 @@ impl File for HostSocket {
     }
 
     fn set_status_flags(&self, new_status_flags: StatusFlags) -> Result<()> {
-        let valid_flags_mask = StatusFlags::O_APPEND
+        let raw_status_flags = (new_status_flags & STATUS_FLAGS_MASK).bits();
-            | StatusFlags::O_ASYNC
-            | StatusFlags::O_DIRECT
-            | StatusFlags::O_NOATIME
-            | StatusFlags::O_NONBLOCK;
-        let raw_status_flags = (new_status_flags & valid_flags_mask).bits();
         try_libc!(libc::ocall::fcntl_arg1(
             self.raw_host_fd() as i32,
             libc::F_SETFL,