Add DevFS for device files

README.md

@@ -162,6 +162,10 @@ Occlum can be configured easily via a configuration file named `Occlum.json`, wh
             "options": {
                 "temporary": true
             }
+        },
+        {
+            "target": "/dev",
+            "type": "devfs"
         }
     ]
 }

etc/template/Occlum.json

@@ -58,6 +58,10 @@
             "options": {
                 "temporary": true
             }
+        },
+        {
+            "target": "/dev",
+            "type": "devfs"
         }
     ]
 }

src/libos/Cargo.lock

@@ -13,6 +13,7 @@ dependencies = [
  "log",
  "memoffset",
  "rcore-fs",
+ "rcore-fs-devfs",
  "rcore-fs-mountfs",
  "rcore-fs-ramfs",
  "rcore-fs-sefs",
@@ -395,6 +396,15 @@ dependencies = [
  "spin",
 ]
 
+[[package]]
+name = "rcore-fs-devfs"
+version = "0.1.0"
+dependencies = [
+ "log",
+ "rcore-fs",
+ "spin",
+]
+
 [[package]]
 name = "rcore-fs-mountfs"
 version = "0.1.0"

src/libos/Cargo.toml

@@ -21,6 +21,7 @@ rcore-fs-sefs = { path = "../../deps/sefs/rcore-fs-sefs" }
 rcore-fs-ramfs = { path = "../../deps/sefs/rcore-fs-ramfs" }
 rcore-fs-mountfs = { path = "../../deps/sefs/rcore-fs-mountfs" }
 rcore-fs-unionfs = { path = "../../deps/sefs/rcore-fs-unionfs" }
+rcore-fs-devfs = { path = "../../deps/sefs/rcore-fs-devfs" }
 serde = { path = "../../deps/serde-sgx/serde", features = ["derive"] }
 serde_json = { path = "../../deps/serde-json-sgx" }
 memoffset = "0.6.1"

src/libos/src/config.rs

@@ -125,6 +125,7 @@ pub enum ConfigMountFsType {
     TYPE_HOSTFS,
     TYPE_RAMFS,
     TYPE_UNIONFS,
+    TYPE_DEVFS,
 }
 
 #[derive(Debug)]
@@ -199,13 +200,14 @@ impl ConfigEnv {
 
 impl ConfigMount {
     fn from_input(input: &InputConfigMount) -> Result<ConfigMount> {
-        const ALL_FS_TYPES: [&str; 4] = ["sefs", "hostfs", "ramfs", "unionfs"];
+        const ALL_FS_TYPES: [&str; 5] = ["sefs", "hostfs", "ramfs", "unionfs", "devfs"];
 
         let type_ = match input.type_.as_str() {
             "sefs" => ConfigMountFsType::TYPE_SEFS,
             "hostfs" => ConfigMountFsType::TYPE_HOSTFS,
             "ramfs" => ConfigMountFsType::TYPE_RAMFS,
             "unionfs" => ConfigMountFsType::TYPE_UNIONFS,
+            "devfs" => ConfigMountFsType::TYPE_DEVFS,
             _ => {
                 return_errno!(EINVAL, "Unsupported file system type");
             }

src/libos/src/fs/dev_fs/dev_null.rs

@@ -3,24 +3,43 @@ use super::*;
 #[derive(Debug)]
 pub struct DevNull;
 
-impl File for DevNull {
-    fn write(&self, _buf: &[u8]) -> Result<usize> {
-        Ok(_buf.len())
+impl INode for DevNull {
+    fn read_at(&self, offset: usize, buf: &mut [u8]) -> vfs::Result<usize> {
+        Ok(0)
     }
 
-    fn write_at(&self, _offset: usize, _buf: &[u8]) -> Result<usize> {
-        Ok(_buf.len())
+    fn write_at(&self, offset: usize, buf: &[u8]) -> vfs::Result<usize> {
+        Ok(buf.len())
     }
 
-    fn writev(&self, bufs: &[&[u8]]) -> Result<usize> {
-        Ok(bufs.iter().map(|buf| buf.len()).sum())
+    fn poll(&self) -> vfs::Result<vfs::PollStatus> {
+        Ok(vfs::PollStatus {
+            read: true,
+            write: true,
+            error: false,
+        })
     }
 
-    fn poll_new(&self) -> IoEvents {
-        IoEvents::IN
+    fn metadata(&self) -> vfs::Result<Metadata> {
+        Ok(Metadata {
+            dev: 1,
+            inode: 0,
+            size: 0,
+            blk_size: 0,
+            blocks: 0,
+            atime: Timespec { sec: 0, nsec: 0 },
+            mtime: Timespec { sec: 0, nsec: 0 },
+            ctime: Timespec { sec: 0, nsec: 0 },
+            type_: vfs::FileType::CharDevice,
+            mode: 0o666,
+            nlinks: 1,
+            uid: 0,
+            gid: 0,
+            rdev: 0,
+        })
     }
 
-    fn as_any(&self) -> &dyn Any {
+    fn as_any_ref(&self) -> &dyn Any {
         self
     }
 }

src/libos/src/fs/dev_fs/dev_random.rs

@@ -1,42 +1,30 @@
 use super::*;
-use crate::net::PollEventFlags;
 use crate::util::random;
 
 #[derive(Debug)]
 pub struct DevRandom;
 
-impl File for DevRandom {
-    fn read(&self, _buf: &mut [u8]) -> Result<usize> {
-        random::get_random(_buf)?;
-        Ok(_buf.len())
+impl INode for DevRandom {
+    fn read_at(&self, offset: usize, buf: &mut [u8]) -> vfs::Result<usize> {
+        random::get_random(buf).map_err(|_| FsError::Again)?;
+        Ok(buf.len())
     }
 
-    fn read_at(&self, _offset: usize, _buf: &mut [u8]) -> Result<usize> {
-        self.read(_buf)
+    fn write_at(&self, offset: usize, buf: &[u8]) -> vfs::Result<usize> {
+        Err(FsError::PermError)
     }
 
-    fn readv(&self, bufs: &mut [&mut [u8]]) -> Result<usize> {
-        let mut total_nbytes = 0;
-        for buf in bufs {
-            match self.read(buf) {
-                Ok(this_nbytes) => {
-                    total_nbytes += this_nbytes;
-                }
-                Err(e) => {
-                    if total_nbytes > 0 {
-                        break;
-                    } else {
-                        return Err(e);
-                    }
-                }
-            }
-        }
-        Ok(total_nbytes)
+    fn poll(&self) -> vfs::Result<vfs::PollStatus> {
+        Ok(vfs::PollStatus {
+            read: true,
+            write: false,
+            error: false,
+        })
     }
 
-    fn metadata(&self) -> Result<Metadata> {
+    fn metadata(&self) -> vfs::Result<Metadata> {
         Ok(Metadata {
-            dev: 0,
+            dev: 1,
             inode: 0,
             size: 0,
             blk_size: 0,
@@ -44,36 +32,16 @@ impl File for DevRandom {
             atime: Timespec { sec: 0, nsec: 0 },
             mtime: Timespec { sec: 0, nsec: 0 },
             ctime: Timespec { sec: 0, nsec: 0 },
-            type_: FileType::CharDevice,
-            mode: (FileMode::S_IRUSR | FileMode::S_IRGRP | FileMode::S_IROTH).bits(),
-            nlinks: 0,
+            type_: vfs::FileType::CharDevice,
+            mode: 0o444,
+            nlinks: 1,
             uid: 0,
             gid: 0,
             rdev: 0,
         })
     }
 
-    fn poll(&self) -> Result<(PollEventFlags)> {
-        Ok(PollEventFlags::POLLIN)
-    }
-
-    fn poll_new(&self) -> IoEvents {
-        IoEvents::IN
-    }
-
-    fn as_any(&self) -> &dyn Any {
+    fn as_any_ref(&self) -> &dyn Any {
         self
     }
 }
-
-pub trait AsDevRandom {
-    fn as_dev_random(&self) -> Result<&DevRandom>;
-}
-
-impl AsDevRandom for FileRef {
-    fn as_dev_random(&self) -> Result<&DevRandom> {
-        self.as_any()
-            .downcast_ref::<DevRandom>()
-            .ok_or_else(|| errno!(EBADF, "not random device"))
-    }
-}

src/libos/src/fs/dev_fs/dev_sgx/mod.rs

@@ -15,7 +15,54 @@ extern "C" {
 #[derive(Debug)]
 pub struct DevSgx;
 
-impl File for DevSgx {
+impl INode for DevSgx {
+    fn read_at(&self, offset: usize, buf: &mut [u8]) -> vfs::Result<usize> {
+        Err(FsError::PermError)
+    }
+
+    fn write_at(&self, offset: usize, buf: &[u8]) -> vfs::Result<usize> {
+        Err(FsError::PermError)
+    }
+
+    fn poll(&self) -> vfs::Result<vfs::PollStatus> {
+        Err(FsError::PermError)
+    }
+
+    fn metadata(&self) -> vfs::Result<Metadata> {
+        Ok(Metadata {
+            dev: 1,
+            inode: 0,
+            size: 0,
+            blk_size: 0,
+            blocks: 0,
+            atime: Timespec { sec: 0, nsec: 0 },
+            mtime: Timespec { sec: 0, nsec: 0 },
+            ctime: Timespec { sec: 0, nsec: 0 },
+            type_: vfs::FileType::CharDevice,
+            mode: 0o666,
+            nlinks: 1,
+            uid: 0,
+            gid: 0,
+            rdev: 0,
+        })
+    }
+
+    fn io_control(&self, _cmd: u32, _data: usize) -> vfs::Result<()> {
+        let mut ioctl_cmd =
+            unsafe { IoctlCmd::new(_cmd, _data as *mut u8).map_err(|_| FsError::InvalidParam)? };
+        self.ioctl(&mut ioctl_cmd).map_err(|e| {
+            error!("{}", e.backtrace());
+            FsError::IOCTLError
+        })?;
+        Ok(())
+    }
+
+    fn as_any_ref(&self) -> &dyn Any {
+        self
+    }
+}
+
+impl DevSgx {
     fn ioctl(&self, cmd: &mut IoctlCmd) -> Result<i32> {
         let nonbuiltin_cmd = match cmd {
             IoctlCmd::NonBuiltin(nonbuiltin_cmd) => nonbuiltin_cmd,
@@ -180,14 +227,6 @@ impl File for DevSgx {
         }
         Ok(0)
     }
-
-    fn poll_new(&self) -> IoEvents {
-        IoEvents::IN
-    }
-
-    fn as_any(&self) -> &dyn Any {
-        self
-    }
 }
 
 lazy_static! {

src/libos/src/fs/dev_fs/dev_zero.rs

@@ -3,31 +3,46 @@ use super::*;
 #[derive(Debug)]
 pub struct DevZero;
 
-impl File for DevZero {
-    fn read(&self, _buf: &mut [u8]) -> Result<usize> {
-        for b in _buf.iter_mut() {
+impl INode for DevZero {
+    fn read_at(&self, offset: usize, buf: &mut [u8]) -> vfs::Result<usize> {
+        for b in buf.iter_mut() {
             *b = 0;
         }
-        Ok(_buf.len())
+        Ok(buf.len())
     }
 
-    fn read_at(&self, _offset: usize, _buf: &mut [u8]) -> Result<usize> {
-        self.read(_buf)
+    fn write_at(&self, offset: usize, buf: &[u8]) -> vfs::Result<usize> {
+        Ok(buf.len())
     }
 
-    fn readv(&self, bufs: &mut [&mut [u8]]) -> Result<usize> {
-        let mut total_nbytes = 0;
-        for buf in bufs {
-            total_nbytes += self.read(buf)?;
-        }
-        Ok(total_nbytes)
+    fn poll(&self) -> vfs::Result<vfs::PollStatus> {
+        Ok(vfs::PollStatus {
+            read: true,
+            write: true,
+            error: false,
+        })
     }
 
-    fn poll_new(&self) -> IoEvents {
-        IoEvents::IN
+    fn metadata(&self) -> vfs::Result<Metadata> {
+        Ok(Metadata {
+            dev: 1,
+            inode: 0,
+            size: 0,
+            blk_size: 0,
+            blocks: 0,
+            atime: Timespec { sec: 0, nsec: 0 },
+            mtime: Timespec { sec: 0, nsec: 0 },
+            ctime: Timespec { sec: 0, nsec: 0 },
+            type_: vfs::FileType::CharDevice,
+            mode: 0o666,
+            nlinks: 1,
+            uid: 0,
+            gid: 0,
+            rdev: 0,
+        })
     }
 
-    fn as_any(&self) -> &dyn Any {
+    fn as_any_ref(&self) -> &dyn Any {
         self
     }
 }

src/libos/src/fs/dev_fs/mod.rs

@@ -1,11 +1,30 @@
 use super::*;
+use rcore_fs::vfs;
+use rcore_fs_devfs::DevFS;
 
-pub use self::dev_null::DevNull;
-pub use self::dev_random::{AsDevRandom, DevRandom};
-pub use self::dev_sgx::DevSgx;
-pub use self::dev_zero::DevZero;
+use self::dev_null::DevNull;
+use self::dev_random::DevRandom;
+use self::dev_sgx::DevSgx;
+use self::dev_zero::DevZero;
 
 mod dev_null;
 mod dev_random;
 mod dev_sgx;
 mod dev_zero;
+
+/// API to initialize the DevFS
+pub fn init_devfs() -> Result<Arc<DevFS>> {
+    let devfs = DevFS::new();
+    let dev_null = Arc::new(DevNull) as _;
+    devfs.add("null", dev_null)?;
+    let dev_zero = Arc::new(DevZero) as _;
+    devfs.add("zero", dev_zero)?;
+    let dev_random = Arc::new(DevRandom) as _;
+    devfs.add("random", Arc::clone(&dev_random))?;
+    devfs.add("urandom", Arc::clone(&dev_random))?;
+    devfs.add("arandom", Arc::clone(&dev_random))?;
+    let dev_sgx = Arc::new(DevSgx) as _;
+    devfs.add("sgx", dev_sgx)?;
+    // TODO: Add stdio(stdin, stdout, stderr) into DevFS
+    Ok(devfs)
+}

src/libos/src/fs/events.rs

@@ -25,6 +25,20 @@ impl IoEvents {
         Self::from_bits_truncate(raw)
     }
 
+    pub fn from_poll_status(poll_status: &crate::rcore_fs::vfs::PollStatus) -> Self {
+        if poll_status.error {
+            return Self::ERR;
+        }
+        let mut events = Self::empty();
+        if poll_status.read {
+            events |= Self::IN
+        }
+        if poll_status.write {
+            events |= Self::OUT
+        }
+        events
+    }
+
     fn contains_unrecognizable_bits(raw: u32) -> bool {
         // Help to detect four valid but mostly useless flags that we do not
         // handle, yet: POLLRDNORM, POLLRDBAND, POLLWRNORM, annd POLLWRBAND.

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

@@ -1,4 +1,3 @@
-use super::dev_fs::{DevNull, DevRandom, DevSgx, DevZero};
 use super::*;
 use process::Process;
 

src/libos/src/fs/fs_view.rs

@@ -1,4 +1,3 @@
-use super::dev_fs::{DevNull, DevRandom, DevSgx, DevZero};
 /// Present a per-process view of FS.
 use super::*;
 
@@ -40,18 +39,6 @@ impl FsView {
 
     /// Open a file on the process. But DO NOT add it to file table.
     pub fn open_file(&self, path: &str, flags: u32, mode: u32) -> Result<Arc<dyn File>> {
-        if path == "/dev/null" {
-            return Ok(Arc::new(DevNull));
-        }
-        if path == "/dev/zero" {
-            return Ok(Arc::new(DevZero));
-        }
-        if path == "/dev/random" || path == "/dev/urandom" || path == "/dev/arandom" {
-            return Ok(Arc::new(DevRandom));
-        }
-        if path == "/dev/sgx" {
-            return Ok(Arc::new(DevSgx));
-        }
         let creation_flags = CreationFlags::from_bits_truncate(flags);
         let inode = if creation_flags.no_follow_symlink() {
             match self.lookup_inode_no_follow(path) {

src/libos/src/fs/inode_file.rs

@@ -1,4 +1,5 @@
 use super::*;
+use crate::net::PollEventFlags;
 use rcore_fs_sefs::dev::SefsMac;
 
 pub struct INodeFile {
@@ -196,6 +197,20 @@ impl File for INodeFile {
         Ok(())
     }
 
+    fn ioctl(&self, cmd: &mut IoctlCmd) -> Result<i32> {
+        let cmd_num = cmd.cmd_num();
+        let cmd_argp = cmd.arg_ptr() as usize;
+        self.inode.io_control(cmd_num, cmd_argp)?;
+        Ok(0)
+    }
+
+    fn poll_new(&self) -> IoEvents {
+        match self.inode.poll() {
+            Ok(poll_status) => IoEvents::from_poll_status(&poll_status),
+            Err(_) => IoEvents::empty(),
+        }
+    }
+
     fn as_any(&self) -> &dyn Any {
         self
     }

src/libos/src/fs/mod.rs

@@ -10,7 +10,6 @@ use std::mem::MaybeUninit;
 use std::path::Path;
 use untrusted::{SliceAsMutPtrAndLen, SliceAsPtrAndLen};
 
-pub use self::dev_fs::AsDevRandom;
 pub use self::event_file::{AsEvent, EventCreationFlags, EventFile};
 pub use self::events::{AtomicIoEvents, IoEvents, IoNotifier};
 pub use self::file::{File, FileRef};

src/libos/src/fs/rootfs.rs

@@ -1,3 +1,4 @@
+use super::dev_fs;
 use super::hostfs::HostFS;
 use super::sefs::{SgxStorage, SgxUuidProvider};
 use super::*;
@@ -144,6 +145,10 @@ fn mount_nonroot_fs_according_to(mount_config: &Vec<ConfigMount>, root: &MNode)
                 let ramfs = RamFS::new();
                 mount_fs_at(ramfs, root, &mc.target)?;
             }
+            TYPE_DEVFS => {
+                let devfs = dev_fs::init_devfs()?;
+                mount_fs_at(devfs, root, &mc.target)?;
+            }
             TYPE_UNIONFS => {
                 return_errno!(EINVAL, "Cannot mount UnionFS at non-root path");
             }

src/libos/src/lib.rs

@@ -38,6 +38,7 @@ extern crate lazy_static;
 #[macro_use]
 extern crate log;
 extern crate rcore_fs;
+extern crate rcore_fs_devfs;
 extern crate rcore_fs_mountfs;
 extern crate rcore_fs_ramfs;
 extern crate rcore_fs_sefs;

src/libos/src/net/io_multiplexing/mod.rs

@@ -15,7 +15,7 @@ pub use self::poll::{do_poll, PollEvent, PollEventFlags};
 pub use self::poll_new::{do_poll_new, PollFd};
 pub use self::select::{do_select, FdSetExt};
 
-use fs::{AsDevRandom, AsEvent, CreationFlags, File, FileDesc, FileRef, HostFd, PipeType};
+use fs::{AsEvent, AsINodeFile, CreationFlags, File, FileDesc, FileRef, HostFd, PipeType};
 use std::any::Any;
 use std::convert::TryFrom;
 use std::fmt;

src/libos/src/net/io_multiplexing/poll.rs

@@ -93,7 +93,6 @@ pub fn do_poll(pollfds: &mut [PollEvent], timeout: *mut timeval_t) -> Result<usi
         if file_ref.as_unix_socket().is_ok()
             || file_ref.as_pipe_reader().is_ok()
             || file_ref.as_pipe_writer().is_ok()
-            || file_ref.as_dev_random().is_ok()
         {
             let events = file_ref.poll()?;
             debug!("polled events are {:?}", events);

test/Occlum.json

@@ -61,6 +61,10 @@
             "options": {
                 "temporary": true
             }
+        },
+        {
+            "target": "/dev",
+            "type": "devfs"
         }
     ]
 }

tools/gen_internal_conf/src/main.rs

@@ -258,6 +258,10 @@ fn gen_mount_config(occlum_conf_root_fs_mac: String) -> serde_json::Value {
                 "options": {
                     "temporary": true
                 }
+            },
+            {
+                "target": "/dev",
+                "type": "devfs"
             }
         ]
     });

tools/occlum

@@ -148,6 +148,7 @@ cmd_init() {
     mkdir -p image/root
     mkdir -p image/host
     mkdir -p image/tmp
+    mkdir -p image/dev
     local occlum_glibc_lib=/opt/occlum/glibc/lib
     local cpu_lib=/sys/devices/system/cpu
     if [ -d "$occlum_glibc_lib" ]; then