Change the flags used in sendmsg/recvmsg from raw int to memory-safe type

src/libos/src/net/mod.rs

@@ -11,7 +11,7 @@ mod unix_socket;
 
 pub use self::iovs::{Iovs, IovsMut, SliceAsLibcIovec};
 pub use self::msg::{msghdr, msghdr_mut, MsgHdr, MsgHdrMut};
-pub use self::msg_flags::MsgFlags;
+pub use self::msg_flags::{MsgHdrFlags, RecvFlags, SendFlags};
 pub use self::socket_file::{AsSocket, SocketFile};
 pub use self::syscalls::*;
 pub use self::unix_socket::{AsUnixSocket, UnixSocketFile};

src/libos/src/net/msg.rs

@@ -32,7 +32,7 @@ pub struct MsgHdr<'a> {
     name: Option<&'a [u8]>,
     iovs: Iovs<'a>,
     control: Option<&'a [u8]>,
-    flags: MsgFlags,
+    flags: MsgHdrFlags,
     c_self: &'a msghdr,
 }
 
@@ -51,7 +51,7 @@ impl<'a> MsgHdr<'a> {
             c_msg.msg_controllen as usize,
         );
 
-        let flags = MsgFlags::from_u32(c_msg.msg_flags as u32)?;
+        let flags = MsgHdrFlags::from_bits_truncate(c_msg.msg_flags);
 
         let iovs = {
             let iovs_vec = match iovs_opt_slice {
@@ -85,7 +85,7 @@ impl<'a> MsgHdr<'a> {
         self.control
     }
 
-    pub fn get_flags(&self) -> MsgFlags {
+    pub fn get_flags(&self) -> MsgHdrFlags {
         self.flags
     }
 }
@@ -95,7 +95,7 @@ pub struct MsgHdrMut<'a> {
     name: Option<&'a mut [u8]>,
     iovs: IovsMut<'a>,
     control: Option<&'a mut [u8]>,
-    flags: MsgFlags,
+    flags: MsgHdrFlags,
     c_self: &'a mut msghdr_mut,
 }
 
@@ -111,7 +111,7 @@ impl<'a> MsgHdrMut<'a> {
         let control_opt_slice =
             new_optional_slice_mut(c_msg.msg_control as *mut u8, c_msg.msg_controllen as usize);
 
-        let flags = MsgFlags::from_u32(c_msg.msg_flags as u32)?;
+        let flags = MsgHdrFlags::from_bits_truncate(c_msg.msg_flags);
 
         let iovs = {
             let iovs_vec = match iovs_opt_slice {
@@ -149,7 +149,7 @@ impl<'a> MsgHdrMut<'a> {
         self.control.as_ref().map(|control| &control[..])
     }
 
-    pub fn get_flags(&self) -> MsgFlags {
+    pub fn get_flags(&self) -> MsgHdrFlags {
         self.flags
     }
 
@@ -203,9 +203,9 @@ impl<'a> MsgHdrMut<'a> {
         )
     }
 
-    pub fn set_flags(&mut self, flags: MsgFlags) {
+    pub fn set_flags(&mut self, flags: MsgHdrFlags) {
         self.flags = flags;
-        self.c_self.msg_flags = flags.to_u32() as i32;
+        self.c_self.msg_flags = flags.bits();
     }
 }
 

src/libos/src/net/msg_flags.rs

@@ -1,17 +1,36 @@
 use super::*;
 
-// TODO: use bitflag! to make this memory safe
+bitflags! {
-#[derive(Debug, Copy, Clone, Default)]
+    pub struct SendFlags: i32 {
-pub struct MsgFlags {
+        const MSG_OOB          = 0x01;
-    bits: u32,
+        const MSG_DONTROUTE    = 0x04;
+        const MSG_DONTWAIT     = 0x40;       // Nonblocking io
+        const MSG_EOR          = 0x80;       // End of record
+        const MSG_CONFIRM      = 0x0800;     // Confirm path validity
+        const MSG_NOSIGNAL     = 0x4000;     // Do not generate SIGPIPE
+        const MSG_MORE         = 0x8000;     // Sender will send more
+    }
 }
 
-impl MsgFlags {
+bitflags! {
-    pub fn from_u32(c_flags: u32) -> Result<MsgFlags> {
+    pub struct RecvFlags: i32 {
-        Ok(MsgFlags { bits: 0 })
+        const MSG_OOB          = 0x01;
+        const MSG_PEEK         = 0x02;
+        const MSG_TRUNC        = 0x20;
+        const MSG_DONTWAIT     = 0x40;       // Nonblocking io
+        const MSG_WAITALL      = 0x0100;     // Wait for a full request
+        const MSG_ERRQUEUE     = 0x2000;     // Fetch message from error queue
+        const MSG_CMSG_CLOEXEC = 0x40000000; // Set close_on_exec for file descriptor received through M_RIGHTS
+    }
 }
 
-    pub fn to_u32(&self) -> u32 {
+bitflags! {
-        self.bits
+    pub struct MsgHdrFlags: i32 {
+        const MSG_OOB          = 0x01;
+        const MSG_CTRUNC       = 0x08;
+        const MSG_TRUNC        = 0x20;
+        const MSG_EOR          = 0x80;       // End of record
+        const MSG_ERRQUEUE     = 0x2000;     // Fetch message from error queue
+        const MSG_NOTIFICATION = 0x8000;     // Only applicable to SCTP socket
     }
 }

src/libos/src/net/socket_file/recv.rs

@@ -4,12 +4,12 @@ use crate::untrusted::{SliceAsMutPtrAndLen, SliceAsPtrAndLen, UntrustedSliceAllo
 impl SocketFile {
     // TODO: need sockaddr type to implement send/sento
     /*
-    pub fn recv(&self, buf: &mut [u8], flags: MsgFlags) -> Result<usize> {
+    pub fn recv(&self, buf: &mut [u8], flags: MsgHdrFlags) -> Result<usize> {
         let (bytes_recvd, _) = self.recvfrom(buf, flags, None)?;
         Ok(bytes_recvd)
     }
 
-    pub fn recvfrom(&self, buf: &mut [u8], flags: MsgFlags, src_addr: Option<&mut [u8]>) -> Result<(usize, usize)> {
+    pub fn recvfrom(&self, buf: &mut [u8], flags: MsgHdrFlags, src_addr: Option<&mut [u8]>) -> Result<(usize, usize)> {
         let (bytes_recvd, src_addr_len, _, _) = self.do_recvmsg(
             &mut buf[..],
             flags,
@@ -19,7 +19,7 @@ impl SocketFile {
         Ok((bytes_recvd, src_addr_len))
     }*/
 
-    pub fn recvmsg<'a, 'b>(&self, msg: &'b mut MsgHdrMut<'a>, flags: MsgFlags) -> Result<usize> {
+    pub fn recvmsg<'a, 'b>(&self, msg: &'b mut MsgHdrMut<'a>, flags: RecvFlags) -> Result<usize> {
         // Alloc untrusted iovecs to receive data via OCall
         let msg_iov = msg.get_iovs();
         let u_slice_alloc = UntrustedSliceAlloc::new(msg_iov.total_bytes())?;
@@ -62,10 +62,10 @@ impl SocketFile {
     fn do_recvmsg(
         &self,
         data: &mut [&mut [u8]],
-        flags: MsgFlags,
+        flags: RecvFlags,
         mut name: Option<&mut [u8]>,
         mut control: Option<&mut [u8]>,
-    ) -> Result<(usize, usize, usize, MsgFlags)> {
+    ) -> Result<(usize, usize, usize, MsgHdrFlags)> {
         // Prepare the arguments for OCall
         // Host socket fd
         let host_fd = self.host_fd;
@@ -82,7 +82,7 @@ impl SocketFile {
         let msg_control = msg_control as *mut c_void;
         let mut msg_controllen_recvd = 0;
         // Flags
-        let flags = flags.to_u32() as i32;
+        let flags = flags.bits();
         let mut msg_flags_recvd = 0;
 
         // Do OCall
@@ -123,7 +123,7 @@ impl SocketFile {
         let msg_namelen_recvd = msg_namelen_recvd as usize;
         assert!(msg_namelen_recvd <= msg_namelen);
         assert!(msg_controllen_recvd <= msg_controllen);
-        let flags_recvd = MsgFlags::from_u32(msg_flags_recvd as u32)?;
+        let flags_recvd = MsgHdrFlags::from_bits(msg_flags_recvd).unwrap();
 
         Ok((
             bytes_recvd,

src/libos/src/net/socket_file/send.rs

@@ -18,7 +18,7 @@ impl SocketFile {
     }
     */
 
-    pub fn sendmsg<'a, 'b>(&self, msg: &'b MsgHdr<'a>, flags: MsgFlags) -> Result<usize> {
+    pub fn sendmsg<'a, 'b>(&self, msg: &'b MsgHdr<'a>, flags: SendFlags) -> Result<usize> {
         // Copy message's iovecs into untrusted iovecs
         let msg_iov = msg.get_iovs();
         let u_slice_alloc = UntrustedSliceAlloc::new(msg_iov.total_bytes())?;
@@ -39,7 +39,7 @@ impl SocketFile {
     fn do_sendmsg(
         &self,
         data: &[&[u8]],
-        flags: MsgFlags,
+        flags: SendFlags,
         name: Option<&[u8]>,
         control: Option<&[u8]>,
     ) -> Result<usize> {
@@ -57,7 +57,7 @@ impl SocketFile {
         let (msg_control, msg_controllen) = control.as_ptr_and_len();
         let msg_control = msg_control as *const c_void;
         // Flags
-        let flags = flags.to_u32() as i32;
+        let flags = flags.bits();
 
         let bytes_sent = try_libc!({
             // Do OCall

src/libos/src/net/syscalls.rs

@@ -23,7 +23,7 @@ pub fn do_sendmsg(fd: c_int, msg_ptr: *const msghdr, flags_c: c_int) -> Result<i
         };
         let msg = unsafe { MsgHdr::from_c(&msg_c)? };
 
-        let flags = MsgFlags::from_u32(flags_c as u32)?;
+        let flags = SendFlags::from_bits_truncate(flags_c);
 
         socket
             .sendmsg(&msg, flags)
@@ -53,7 +53,7 @@ pub fn do_recvmsg(fd: c_int, msg_mut_ptr: *mut msghdr_mut, flags_c: c_int) -> Re
         };
         let mut msg_mut = unsafe { MsgHdrMut::from_c(msg_mut_c)? };
 
-        let flags = MsgFlags::from_u32(flags_c as u32)?;
+        let flags = RecvFlags::from_bits_truncate(flags_c);
 
         socket
             .recvmsg(&mut msg_mut, flags)