Implement more system calls

kernel/scheme/env.rs

@@ -1,8 +1,10 @@
 use collections::BTreeMap;
+use core::cmp;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use spin::RwLock;
 
 use syscall::error::*;
+use syscall::flag::{SEEK_SET, SEEK_CUR, SEEK_END};
 use syscall::scheme::Scheme;
 
 struct Handle {
@@ -76,6 +78,20 @@ impl Scheme for EnvScheme {
         Ok(i)
     }
 
+    fn seek(&self, id: usize, pos: usize, whence: usize) -> Result<usize> {
+        let mut handles = self.handles.write();
+        let mut handle = handles.get_mut(&id).ok_or(Error::new(EBADF))?;
+
+        handle.seek = match whence {
+            SEEK_SET => cmp::min(handle.data.len(), pos),
+            SEEK_CUR => cmp::max(0, cmp::min(handle.data.len() as isize, handle.seek as isize + pos as isize)) as usize,
+            SEEK_END => cmp::max(0, cmp::min(handle.data.len() as isize, handle.data.len() as isize + pos as isize)) as usize,
+            _ => return Err(Error::new(EINVAL))
+        };
+
+        Ok(handle.seek)
+    }
+
     fn fsync(&self, _file: usize) -> Result<usize> {
         Ok(0)
     }

kernel/scheme/initfs.rs

@@ -1,8 +1,10 @@
 use collections::BTreeMap;
+use core::cmp;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use spin::RwLock;
 
 use syscall::error::*;
+use syscall::flag::{SEEK_SET, SEEK_CUR, SEEK_END};
 use syscall::scheme::Scheme;
 
 struct Handle {
@@ -48,29 +50,29 @@ impl Scheme for InitFsScheme {
         Ok(id)
     }
 
-    fn dup(&self, file: usize) -> Result<usize> {
+    fn dup(&self, id: usize) -> Result<usize> {
         let (data, seek) = {
             let handles = self.handles.read();
-            let handle = handles.get(&file).ok_or(Error::new(EBADF))?;
+            let handle = handles.get(&id).ok_or(Error::new(EBADF))?;
             (handle.data, handle.seek)
         };
 
-        let id = self.next_id.fetch_add(1, Ordering::SeqCst);
-        self.handles.write().insert(id, Handle {
+        let new_id = self.next_id.fetch_add(1, Ordering::SeqCst);
+        self.handles.write().insert(new_id, Handle {
             data: data,
             seek: seek
         });
 
-        Ok(id)
+        Ok(new_id)
     }
 
-    fn read(&self, file: usize, buffer: &mut [u8]) -> Result<usize> {
+    fn read(&self, id: usize, buf: &mut [u8]) -> Result<usize> {
         let mut handles = self.handles.write();
-        let mut handle = handles.get_mut(&file).ok_or(Error::new(EBADF))?;
+        let mut handle = handles.get_mut(&id).ok_or(Error::new(EBADF))?;
 
         let mut i = 0;
-        while i < buffer.len() && handle.seek < handle.data.len() {
-            buffer[i] = handle.data[handle.seek];
+        while i < buf.len() && handle.seek < handle.data.len() {
+            buf[i] = handle.data[handle.seek];
             i += 1;
             handle.seek += 1;
         }
@@ -78,11 +80,25 @@ impl Scheme for InitFsScheme {
         Ok(i)
     }
 
-    fn fsync(&self, _file: usize) -> Result<usize> {
+    fn seek(&self, id: usize, pos: usize, whence: usize) -> Result<usize> {
+        let mut handles = self.handles.write();
+        let mut handle = handles.get_mut(&id).ok_or(Error::new(EBADF))?;
+
+        handle.seek = match whence {
+            SEEK_SET => cmp::min(handle.data.len(), pos),
+            SEEK_CUR => cmp::max(0, cmp::min(handle.data.len() as isize, handle.seek as isize + pos as isize)) as usize,
+            SEEK_END => cmp::max(0, cmp::min(handle.data.len() as isize, handle.data.len() as isize + pos as isize)) as usize,
+            _ => return Err(Error::new(EINVAL))
+        };
+
+        Ok(handle.seek)
+    }
+
+    fn fsync(&self, _id: usize) -> Result<usize> {
         Ok(0)
     }
 
-    fn close(&self, file: usize) -> Result<usize> {
-        self.handles.write().remove(&file).ok_or(Error::new(EBADF)).and(Ok(0))
+    fn close(&self, id: usize) -> Result<usize> {
+        self.handles.write().remove(&id).ok_or(Error::new(EBADF)).and(Ok(0))
     }
 }

kernel/scheme/user.rs

@@ -9,20 +9,11 @@ use arch::paging::{InactivePageTable, Page, VirtualAddress, entry};
 use arch::paging::temporary_page::TemporaryPage;
 use context::{self, Context};
 use context::memory::Grant;
+use syscall::data::{Packet, Stat};
 use syscall::error::*;
 use syscall::number::*;
 use syscall::scheme::Scheme;
 
-#[derive(Copy, Clone, Debug, Default)]
-#[repr(packed)]
-pub struct Packet {
-    pub id: usize,
-    pub a: usize,
-    pub b: usize,
-    pub c: usize,
-    pub d: usize
-}
-
 pub struct UserInner {
     next_id: AtomicUsize,
     context: Weak<RwLock<Context>>,
@@ -224,7 +215,20 @@ impl Scheme for UserScheme {
     fn write(&self, file: usize, buf: &[u8]) -> Result<usize> {
         let inner = self.inner.upgrade().ok_or(Error::new(ENODEV))?;
         let address = inner.capture(buf)?;
-        let result = inner.call(SYS_WRITE, file, buf.as_ptr() as usize, buf.len());
+        let result = inner.call(SYS_WRITE, file, address, buf.len());
+        let _ = inner.release(address);
+        result
+    }
+
+    fn seek(&self, file: usize, position: usize, whence: usize) -> Result<usize> {
+        let inner = self.inner.upgrade().ok_or(Error::new(ENODEV))?;
+        inner.call(SYS_FSYNC, file, position, whence)
+    }
+
+    fn fstat(&self, file: usize, stat: &mut Stat) -> Result<usize> {
+        let inner = self.inner.upgrade().ok_or(Error::new(ENODEV))?;
+        let address = inner.capture_mut(stat)?;
+        let result = inner.call(SYS_FSTAT, file, address, 0);
         let _ = inner.release(address);
         result
     }
@@ -234,6 +238,11 @@ impl Scheme for UserScheme {
         inner.call(SYS_FSYNC, file, 0, 0)
     }
 
+    fn ftruncate(&self, file: usize, len: usize) -> Result<usize> {
+        let inner = self.inner.upgrade().ok_or(Error::new(ENODEV))?;
+        inner.call(SYS_FTRUNCATE, file, len, 0)
+    }
+
     fn close(&self, file: usize) -> Result<usize> {
         let inner = self.inner.upgrade().ok_or(Error::new(ENODEV))?;
         inner.call(SYS_CLOSE, file, 0, 0)

kernel/syscall/fs.rs

@@ -2,6 +2,7 @@
 
 use context;
 use scheme;
+use syscall::data::Stat;
 use syscall::error::*;
 
 /// Change the current working directory
@@ -97,6 +98,24 @@ pub fn dup(fd: usize) -> Result<usize> {
     scheme.dup(file.number)
 }
 
+/// Get information about the file
+pub fn fstat(fd: usize, stat: &mut Stat) -> Result<usize> {
+    let file = {
+        let contexts = context::contexts();
+        let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
+        let context = context_lock.read();
+        let file = context.get_file(fd).ok_or(Error::new(EBADF))?;
+        file
+    };
+
+    let scheme = {
+        let schemes = scheme::schemes();
+        let scheme = schemes.get(file.scheme).ok_or(Error::new(EBADF))?;
+        scheme.clone()
+    };
+    scheme.fstat(file.number, stat)
+}
+
 /// Sync the file descriptor
 pub fn fsync(fd: usize) -> Result<usize> {
     let file = {
@@ -115,6 +134,24 @@ pub fn fsync(fd: usize) -> Result<usize> {
     scheme.fsync(file.number)
 }
 
+/// Seek to an offset
+pub fn lseek(fd: usize, pos: usize, whence: usize) -> Result<usize> {
+    let file = {
+        let contexts = context::contexts();
+        let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
+        let context = context_lock.read();
+        let file = context.get_file(fd).ok_or(Error::new(EBADF))?;
+        file
+    };
+
+    let scheme = {
+        let schemes = scheme::schemes();
+        let scheme = schemes.get(file.scheme).ok_or(Error::new(EBADF))?;
+        scheme.clone()
+    };
+    scheme.seek(file.number, pos, whence)
+}
+
 /// Read syscall
 pub fn read(fd: usize, buf: &mut [u8]) -> Result<usize> {
     let file = {

kernel/syscall/mod.rs

@@ -2,14 +2,16 @@
 
 extern crate syscall;
 
-pub use self::syscall::{error, number, scheme};
+pub use self::syscall::{data, error, flag, number, scheme};
 
-use self::error::{Error, Result, ENOSYS};
-use self::number::*;
 pub use self::fs::*;
 pub use self::process::*;
 pub use self::validate::*;
 
+use self::data::Stat;
+use self::error::{Error, Result, ENOSYS};
+use self::number::*;
+
 /// Filesystem syscalls
 pub mod fs;
 
@@ -32,7 +34,9 @@ pub extern fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize
             SYS_WAITPID => waitpid(b, c, d),
             SYS_EXECVE => exec(validate_slice(b as *const u8, c)?, validate_slice(d as *const [usize; 2], e)?),
             SYS_CHDIR => chdir(validate_slice(b as *const u8, c)?),
+            SYS_LSEEK => lseek(b, c, d),
             SYS_GETPID => getpid(),
+            SYS_FSTAT => fstat(b, &mut validate_slice_mut(b as *mut Stat, 1)?[0]),
             SYS_DUP => dup(b),
             SYS_BRK => brk(b),
             SYS_IOPL => iopl(b),

syscall/src/data.rs

@@ -0,0 +1,69 @@
+use core::ops::{Deref, DerefMut};
+use core::{mem, slice};
+
+#[derive(Copy, Clone, Debug, Default)]
+#[repr(packed)]
+pub struct Packet {
+    pub id: usize,
+    pub a: usize,
+    pub b: usize,
+    pub c: usize,
+    pub d: usize
+}
+
+impl Deref for Packet {
+    type Target = [u8];
+    fn deref(&self) -> &[u8] {
+        unsafe {
+            slice::from_raw_parts(self as *const Packet as *const u8, mem::size_of::<Packet>()) as &[u8]
+        }
+    }
+}
+
+impl DerefMut for Packet {
+    fn deref_mut(&mut self) -> &mut [u8] {
+        unsafe {
+            slice::from_raw_parts_mut(self as *mut Packet as *mut u8, mem::size_of::<Packet>()) as &mut [u8]
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug, Default)]
+#[repr(packed)]
+pub struct Stat {
+    pub st_dev: u16,
+    pub st_ino: u16,
+    pub st_mode: u16,
+    pub st_nlink: u16,
+    pub st_uid: u16,
+    pub st_gid: u16,
+    pub st_rdev: u16,
+    pub st_size: u32,
+    pub st_atime: u32,
+    pub st_mtime: u32,
+    pub st_ctime: u32
+}
+
+impl Deref for Stat {
+    type Target = [u8];
+    fn deref(&self) -> &[u8] {
+        unsafe {
+            slice::from_raw_parts(self as *const Stat as *const u8, mem::size_of::<Stat>()) as &[u8]
+        }
+    }
+}
+
+impl DerefMut for Stat {
+    fn deref_mut(&mut self) -> &mut [u8] {
+        unsafe {
+            slice::from_raw_parts_mut(self as *mut Stat as *mut u8, mem::size_of::<Stat>()) as &mut [u8]
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug, Default)]
+#[repr(packed)]
+pub struct TimeSpec {
+    pub tv_sec: i64,
+    pub tv_nsec: i32,
+}

syscall/src/flag.rs

@@ -0,0 +1,40 @@
+pub const CLONE_VM: usize = 0x100;
+pub const CLONE_FS: usize = 0x200;
+pub const CLONE_FILES: usize = 0x400;
+pub const CLONE_VFORK: usize = 0x4000;
+/// Mark this clone as supervised.
+///
+/// This means that the process can run in supervised mode, even not being connected to
+/// a supervisor yet. In other words, the parent can later on supervise the process and handle
+/// the potential blocking syscall.
+///
+/// This is an important security measure, since otherwise the process would be able to fork it
+/// self right after starting, making supervising it impossible.
+pub const CLONE_SUPERVISE: usize = 0x400000;
+pub const CLOCK_REALTIME: usize = 1;
+pub const CLOCK_MONOTONIC: usize = 4;
+
+pub const MODE_DIR: u16 = 0x4000;
+pub const MODE_FILE: u16 = 0x8000;
+pub const MODE_ALL: u16 = MODE_DIR | MODE_FILE;
+
+pub const FUTEX_WAIT: usize = 0;
+pub const FUTEX_WAKE: usize = 1;
+pub const FUTEX_REQUEUE: usize = 2;
+
+pub const SEEK_SET: usize = 0;
+pub const SEEK_CUR: usize = 1;
+pub const SEEK_END: usize = 2;
+
+pub const O_RDONLY: usize = 0;
+pub const O_WRONLY: usize = 1;
+pub const O_RDWR: usize = 2;
+pub const O_NONBLOCK: usize = 4;
+pub const O_APPEND: usize = 8;
+pub const O_SHLOCK: usize = 0x10;
+pub const O_EXLOCK: usize = 0x20;
+pub const O_ASYNC: usize = 0x40;
+pub const O_FSYNC: usize = 0x80;
+pub const O_CREAT: usize = 0x200;
+pub const O_TRUNC: usize = 0x400;
+pub const O_EXCL: usize = 0x800;

syscall/src/lib.rs

@@ -2,7 +2,9 @@
 #![no_std]
 
 pub use self::arch::*;
+pub use self::data::*;
 pub use self::error::*;
+pub use self::flag::*;
 pub use self::number::*;
 pub use self::scheme::*;
 
@@ -14,76 +16,16 @@ mod arch;
 #[path="x86_64.rs"]
 mod arch;
 
+pub mod data;
+
 pub mod error;
 
+pub mod flag;
+
 pub mod number;
 
 pub mod scheme;
 
-pub const CLONE_VM: usize = 0x100;
-pub const CLONE_FS: usize = 0x200;
-pub const CLONE_FILES: usize = 0x400;
-pub const CLONE_VFORK: usize = 0x4000;
-/// Mark this clone as supervised.
-///
-/// This means that the process can run in supervised mode, even not being connected to
-/// a supervisor yet. In other words, the parent can later on supervise the process and handle
-/// the potential blocking syscall.
-///
-/// This is an important security measure, since otherwise the process would be able to fork it
-/// self right after starting, making supervising it impossible.
-pub const CLONE_SUPERVISE: usize = 0x400000;
-pub const CLOCK_REALTIME: usize = 1;
-pub const CLOCK_MONOTONIC: usize = 4;
-
-pub const MODE_DIR: u16 = 0x4000;
-pub const MODE_FILE: u16 = 0x8000;
-pub const MODE_ALL: u16 = MODE_DIR | MODE_FILE;
-
-pub const FUTEX_WAIT: usize = 0;
-pub const FUTEX_WAKE: usize = 1;
-pub const FUTEX_REQUEUE: usize = 2;
-
-pub const SEEK_SET: usize = 0;
-pub const SEEK_CUR: usize = 1;
-pub const SEEK_END: usize = 2;
-
-pub const O_RDONLY: usize = 0;
-pub const O_WRONLY: usize = 1;
-pub const O_RDWR: usize = 2;
-pub const O_NONBLOCK: usize = 4;
-pub const O_APPEND: usize = 8;
-pub const O_SHLOCK: usize = 0x10;
-pub const O_EXLOCK: usize = 0x20;
-pub const O_ASYNC: usize = 0x40;
-pub const O_FSYNC: usize = 0x80;
-pub const O_CREAT: usize = 0x200;
-pub const O_TRUNC: usize = 0x400;
-pub const O_EXCL: usize = 0x800;
-
-#[derive(Copy, Clone, Debug, Default)]
-#[repr(packed)]
-pub struct Stat {
-    pub st_dev: u16,
-    pub st_ino: u16,
-    pub st_mode: u16,
-    pub st_nlink: u16,
-    pub st_uid: u16,
-    pub st_gid: u16,
-    pub st_rdev: u16,
-    pub st_size: u32,
-    pub st_atime: u32,
-    pub st_mtime: u32,
-    pub st_ctime: u32
-}
-
-#[derive(Copy, Clone, Debug, Default)]
-#[repr(packed)]
-pub struct TimeSpec {
-    pub tv_sec: i64,
-    pub tv_nsec: i32,
-}
-
 pub unsafe fn brk(addr: usize) -> Result<usize> {
     syscall1(SYS_BRK, addr)
 }

syscall/src/scheme.rs

@@ -1,35 +1,7 @@
-use core::ops::{Deref, DerefMut};
-use core::{mem, slice};
+use core::slice;
 
 use super::*;
 
-#[derive(Copy, Clone, Debug, Default)]
-#[repr(packed)]
-pub struct Packet {
-    pub id: usize,
-    pub a: usize,
-    pub b: usize,
-    pub c: usize,
-    pub d: usize
-}
-
-impl Deref for Packet {
-    type Target = [u8];
-    fn deref(&self) -> &[u8] {
-        unsafe {
-            slice::from_raw_parts(self as *const Packet as *const u8, mem::size_of::<Packet>()) as &[u8]
-        }
-    }
-}
-
-impl DerefMut for Packet {
-    fn deref_mut(&mut self) -> &mut [u8] {
-        unsafe {
-            slice::from_raw_parts_mut(self as *mut Packet as *mut u8, mem::size_of::<Packet>()) as &mut [u8]
-        }
-    }
-}
-
 pub trait Scheme {
     fn handle(&self, packet: &mut Packet) {
         packet.a = Error::mux(match packet.a {
@@ -69,11 +41,6 @@ pub trait Scheme {
         Err(Error::new(ENOENT))
     }
 
-    #[allow(unused_variables)]
-    fn stat(&self, path: &[u8], stat: &mut Stat) -> Result<usize> {
-        Err(Error::new(ENOENT))
-    }
-
     #[allow(unused_variables)]
     fn unlink(&self, path: &[u8]) -> Result<usize> {
         Err(Error::new(ENOENT))