Add readv and writev

src/libos/src/file.rs

@@ -8,8 +8,9 @@ use std::io::{Read, Write, Seek, SeekFrom};
 pub trait File : Debug + Sync + Send {
     fn read(&self, buf: &mut [u8]) -> Result<usize, Error>;
     fn write(&self, buf: &[u8]) -> Result<usize, Error>;
+    fn readv<'a, 'b>(&self, bufs: &'a mut [&'b mut [u8]]) -> Result<usize, Error>;
+    fn writev<'a, 'b>(&self, bufs: &'a [&'b [u8]]) -> Result<usize, Error>;
     //pub seek(&mut self, ) -> Result<usize, Error>;
-
 }
 
 pub type FileRef = Arc<Box<File>>;
@@ -48,6 +49,18 @@ impl File for SgxFile {
         let inner = inner_guard.borrow_mut();
         inner.write(buf)
     }
+
+    fn readv<'a, 'b>(&self, bufs: &'a mut [&'b mut [u8]]) -> Result<usize, Error> {
+        let mut inner_guard = self.inner.lock().unwrap();
+        let inner = inner_guard.borrow_mut();
+        inner.readv(bufs)
+    }
+
+    fn writev<'a, 'b>(&self, bufs: &'a [&'b [u8]]) -> Result<usize, Error> {
+        let mut inner_guard = self.inner.lock().unwrap();
+        let inner = inner_guard.borrow_mut();
+        inner.writev(bufs)
+    }
 }
 
 #[derive(Clone)]
@@ -67,6 +80,7 @@ impl SgxFileInner {
         let file = file_guard.borrow_mut();
 
         let seek_pos = SeekFrom::Start(self.pos as u64);
+        // TODO: recover from error
         file.seek(seek_pos).map_err(
             |e| Error::new(Errno::EINVAL, "Failed to seek to a position"))?;
 
@@ -95,6 +109,70 @@ impl SgxFileInner {
         self.pos += read_len;
         Ok(read_len)
     }
+
+    pub fn writev<'a, 'b>(&mut self, bufs: &'a [&'b [u8]]) -> Result<usize, Error> {
+        let mut file_guard = self.file.lock().unwrap();
+        let file = file_guard.borrow_mut();
+
+        let seek_pos = SeekFrom::Start(self.pos as u64);
+        file.seek(seek_pos).map_err(
+            |e| Error::new(Errno::EINVAL, "Failed to seek to a position"))?;
+
+        let mut total_bytes = 0;
+        for buf in bufs {
+            match file.write(buf) {
+                Ok(this_bytes) => {
+                    if this_bytes == 0 { break; }
+
+                    total_bytes += this_bytes;
+                    if this_bytes < buf.len() { break; }
+                }
+                Err(e) => {
+                    match total_bytes {
+                        // a complete failure
+                        0 => return Err(Error::new(Errno::EINVAL, "Failed to write")),
+                        // a partially failure
+                        _ => break,
+                    }
+                }
+            }
+        }
+
+        self.pos += total_bytes;
+        Ok(total_bytes)
+    }
+
+    fn readv<'a, 'b>(&mut self, bufs: &'a mut [&'b mut [u8]]) -> Result<usize, Error> {
+        let mut file_guard = self.file.lock().unwrap();
+        let file = file_guard.borrow_mut();
+
+        let seek_pos = SeekFrom::Start(self.pos as u64);
+        file.seek(seek_pos).map_err(
+            |e| Error::new(Errno::EINVAL, "Failed to seek to a position"))?;
+
+        let mut total_bytes = 0;
+        for buf in bufs {
+            match file.read(buf) {
+                Ok(this_bytes) => {
+                    if this_bytes == 0 { break; }
+
+                    total_bytes += this_bytes;
+                    if this_bytes < buf.len() { break; }
+                }
+                Err(e) => {
+                    match total_bytes {
+                        // a complete failure
+                        0 => return Err(Error::new(Errno::EINVAL, "Failed to write")),
+                        // a partially failure
+                        _ => break,
+                    }
+                }
+            }
+        }
+
+        self.pos += total_bytes;
+        Ok(total_bytes)
+    }
 }
 
 unsafe impl Send for SgxFileInner {}
@@ -130,6 +208,33 @@ impl File for StdoutFile {
     fn read(&self, buf: &mut [u8]) -> Result<usize, Error> {
         Err(Error::new(Errno::EBADF, "Stdout does not support reading"))
     }
+
+    fn writev<'a, 'b>(&self, bufs: &'a [&'b [u8]]) -> Result<usize, Error> {
+        let mut guard = self.inner.lock();
+        let mut total_bytes = 0;
+        for buf in bufs {
+            match guard.write(buf) {
+                Ok(this_len) => {
+                    if this_len == 0 { break; }
+                    total_bytes += this_len;
+                    if this_len < buf.len() { break; }
+                }
+                Err(e) => {
+                    match total_bytes {
+                        // a complete failure
+                        0 => return Err(Error::new(Errno::EINVAL, "Failed to write")),
+                        // a partially failure
+                        _ => break,
+                    }
+                }
+            }
+        }
+        Ok(total_bytes)
+    }
+
+    fn readv<'a, 'b>(&self, bufs: &'a mut [&'b mut [u8]]) -> Result<usize, Error> {
+        Err(Error::new(Errno::EBADF, "Stdout does not support reading"))
+    }
 }
 
 impl Debug for StdoutFile {
@@ -165,6 +270,33 @@ impl File for StdinFile {
     fn write(&self, buf: &[u8]) -> Result<usize, Error> {
         Err(Error::new(Errno::EBADF, "Stdin does not support reading"))
     }
+
+    fn readv<'a, 'b>(&self, bufs: &'a mut [&'b mut [u8]]) -> Result<usize, Error> {
+        let mut guard = self.inner.lock();
+        let mut total_bytes = 0;
+        for buf in bufs {
+            match guard.read(buf) {
+                Ok(this_len) => {
+                    if this_len == 0 { break; }
+                    total_bytes += this_len;
+                    if this_len < buf.len() { break; }
+                }
+                Err(e) => {
+                    match total_bytes {
+                        // a complete failure
+                        0 => return Err(Error::new(Errno::EINVAL, "Failed to write")),
+                        // a partially failure
+                        _ => break,
+                    }
+                }
+            }
+        }
+        Ok(total_bytes)
+    }
+
+    fn writev<'a, 'b>(&self, bufs: &'a [&'b [u8]]) -> Result<usize, Error> {
+        Err(Error::new(Errno::EBADF, "Stdin does not support reading"))
+    }
 }
 
 impl Debug for StdinFile {

src/libos/src/fs.rs

@@ -63,6 +63,22 @@ pub fn do_read(fd: FileDesc, buf: &mut [u8]) -> Result<usize, Error> {
     file_ref.read(buf)
 }
 
+pub fn do_writev<'a, 'b>(fd: FileDesc, bufs: &'a [&'b [u8]]) -> Result<usize, Error> {
+    let current_ref = process::get_current();
+    let current_process = current_ref.lock().unwrap();
+    let file_ref = current_process.file_table.get(fd)
+        .ok_or_else(|| Error::new(Errno::EBADF, "Invalid file descriptor [do_write]"))?;
+    file_ref.writev(bufs)
+}
+
+pub fn do_readv<'a, 'b>(fd: FileDesc, bufs: &'a mut [&'b mut [u8]]) -> Result<usize, Error> {
+    let current_ref = process::get_current();
+    let current_process = current_ref.lock().unwrap();
+    let file_ref = current_process.file_table.get(fd)
+        .ok_or_else(|| Error::new(Errno::EBADF, "Invalid file descriptor [do_read]"))?;
+    file_ref.readv(bufs)
+}
+
 pub fn do_close(fd: FileDesc) -> Result<(), Error> {
     let current_ref = process::get_current();
     let mut current_process = current_ref.lock().unwrap();

src/libos/src/process.rs

@@ -77,6 +77,7 @@ pub fn do_spawn<P: AsRef<Path>>(elf_path: &P, argv: &[CString], envp: &[CString]
             //let stdin = Arc::new(SgxMutex::new(Box::new(StdinFile::new())));
             let stdin : Arc<Box<File>> = Arc::new(Box::new(StdinFile::new()));
             let stdout : Arc<Box<File>> = Arc::new(Box::new(StdoutFile::new()));
+            // TODO: implement and use a real stderr
             let stderr = stdout.clone();
             file_table.put(stdin);
             file_table.put(stdout);

src/libos/src/syscall.h

@@ -4,6 +4,8 @@
 #include <sys/types.h>
 #include "syscall_nr.h"
 
+struct iovec;
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -12,6 +14,8 @@ extern int occlum_open(const char* path, int flags, int mode);
 extern int occlum_close(int fd);
 extern ssize_t occlum_read(int fd, void* buf, size_t size);
 extern ssize_t occlum_write(int fd, const void* buf, size_t size);
+extern ssize_t occlum_readv(int fd, struct iovec* iov, int count);
+extern ssize_t occlum_writev(int fd, const struct iovec* iov, int count);
 extern int occlum_spawn(int* child_pid, const char* path,
                         const char** argv,
                         const char** envp);

src/libos/src/syscall.rs

@@ -5,18 +5,33 @@ use std::ffi::{CStr, CString};
 //use std::libc_fs as fs;
 //use std::libc_io as io;
 
-fn check_ptr_from_user<T>(user_ptr: *const T) -> Result<*const T, Error> {
-    Ok(user_ptr)
+#[allow(non_camel_case_types)]
+pub struct iovec_t {
+    base: *const c_void,
+    len: size_t,
 }
 
-fn check_mut_ptr_from_user<T>(user_ptr: *mut T) -> Result<*mut T, Error> {
-    Ok(user_ptr)
+
+fn check_ptr_from_user<T>(user_ptr: *const T) -> Result<(), Error> {
+    Ok(())
+}
+
+fn check_mut_ptr_from_user<T>(user_ptr: *mut T) -> Result<(), Error> {
+    Ok(())
+}
+
+fn check_array_from_user<T>(user_buf: *const T, count: usize) -> Result<(), Error> {
+    Ok(())
+}
+
+fn check_mut_array_from_user<T>(user_buf: *mut T, count: usize) -> Result<(), Error> {
+    Ok(())
 }
 
 fn clone_string_from_user_safely(user_ptr: *const c_char)
     -> Result<String, Error>
 {
-    let user_ptr = check_ptr_from_user(user_ptr)?;
+    check_ptr_from_user(user_ptr)?;
     let string = unsafe {
         CStr::from_ptr(user_ptr).to_string_lossy().into_owned()
     };
@@ -31,6 +46,93 @@ fn clone_cstrings_from_user_safely(user_ptr: *const *const c_char)
 }
 
 
+fn do_read(fd: c_int, buf: *mut c_void, size: size_t)
+    -> Result<size_t, Error>
+{
+    let fd = fd as file_table::FileDesc;
+    let safe_buf = {
+        let buf = buf as *mut u8;
+        let size = size as usize;
+        check_mut_array_from_user(buf, size)?;
+        unsafe { std::slice::from_raw_parts_mut(buf, size) }
+    };
+    fs::do_read(fd, safe_buf)
+}
+
+fn do_write(fd: c_int, buf: *const c_void, size: size_t)
+    -> Result<size_t, Error>
+{
+    let fd = fd as file_table::FileDesc;
+    let safe_buf = {
+        let buf = buf as *mut u8;
+        let size = size as usize;
+        check_array_from_user(buf, size)?;
+        unsafe { std::slice::from_raw_parts(buf, size) }
+    };
+    fs::do_write(fd, safe_buf)
+}
+
+fn do_writev(fd: c_int, iov: *const iovec_t, count: c_int)
+    -> Result<size_t, Error>
+{
+    let fd = fd as file_table::FileDesc;
+
+    let count = {
+        if count < 0 {
+            return Err(Error::new(Errno::EINVAL, "Invalid count of iovec"));
+        }
+        count as usize
+    };
+
+    check_array_from_user(iov, count);
+    let bufs_vec = {
+        let mut bufs_vec = Vec::with_capacity(count);
+        for iov_i in 0..count {
+            let iov_ptr = unsafe { iov.offset(iov_i as isize) };
+            let iov = unsafe { &*iov_ptr };
+            let buf = unsafe {
+                std::slice::from_raw_parts(iov.base as * const u8, iov.len)
+            };
+            bufs_vec[iov_i] = buf;
+        }
+        bufs_vec
+    };
+    let bufs = &bufs_vec[..];
+
+    fs::do_writev(fd, bufs)
+}
+
+fn do_readv(fd: c_int, iov: *mut iovec_t, count: c_int)
+    -> Result<size_t, Error>
+{
+    let fd = fd as file_table::FileDesc;
+
+    let count = {
+        if count < 0 {
+            return Err(Error::new(Errno::EINVAL, "Invalid count of iovec"));
+        }
+        count as usize
+    };
+
+    check_array_from_user(iov, count);
+    let mut bufs_vec = {
+        let mut bufs_vec = Vec::with_capacity(count);
+        for iov_i in 0..count {
+            let iov_ptr = unsafe { iov.offset(iov_i as isize) };
+            let iov = unsafe { &*iov_ptr };
+            let buf = unsafe {
+                std::slice::from_raw_parts_mut(iov.base as * mut u8, iov.len)
+            };
+            bufs_vec[iov_i] = buf;
+        }
+        bufs_vec
+    };
+    let bufs = &mut bufs_vec[..];
+
+    fs::do_readv(fd, bufs)
+}
+
+
 #[no_mangle]
 pub extern "C" fn occlum_open(path_buf: * const c_char, flags: c_int, mode: c_int) -> c_int {
     let path = unsafe {
@@ -60,10 +162,7 @@ pub extern "C" fn occlum_close(fd: c_int) -> c_int {
 
 #[no_mangle]
 pub extern "C" fn occlum_read(fd: c_int, buf: * mut c_void, size: size_t) -> ssize_t {
-    let buf = unsafe {
-        std::slice::from_raw_parts_mut(buf as *mut u8, size as usize)
-    };
-    match fs::do_read(fd as file_table::FileDesc, buf) {
+    match do_read(fd, buf, size) {
         Ok(read_len) => {
             read_len as ssize_t
         },
@@ -75,16 +174,7 @@ pub extern "C" fn occlum_read(fd: c_int, buf: * mut c_void, size: size_t) -> ssi
 
 #[no_mangle]
 pub extern "C" fn occlum_write(fd: c_int, buf: * const c_void, size: size_t) -> ssize_t {
-/*    let str_from_c = unsafe {
-        CStr::from_ptr(buf as * const i8).to_string_lossy().into_owned()
-    };
-    println!("occlum_write: {}", str_from_c);
-    size as ssize_t
-*/
-    let buf = unsafe {
-        std::slice::from_raw_parts(buf as *const u8, size as usize)
-    };
-    match fs::do_write(fd as file_table::FileDesc, buf) {
+    match do_write(fd, buf, size) {
         Ok(write_len) => {
             write_len as ssize_t
         },
@@ -94,6 +184,31 @@ pub extern "C" fn occlum_write(fd: c_int, buf: * const c_void, size: size_t) ->
     }
 }
 
+#[no_mangle]
+pub extern "C" fn occlum_readv(fd: c_int, iov: * mut iovec_t, count: c_int) -> ssize_t {
+    match do_readv(fd, iov, count) {
+        Ok(read_len) => {
+            read_len as ssize_t
+        },
+        Err(e) => {
+            e.errno.as_retval() as ssize_t
+        }
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn occlum_writev(fd: c_int, iov: * const iovec_t, count: c_int) -> ssize_t {
+    match do_writev(fd, iov, count) {
+        Ok(write_len) => {
+            write_len as ssize_t
+        },
+        Err(e) => {
+            e.errno.as_retval() as ssize_t
+        }
+    }
+}
+
+
 #[no_mangle]
 pub extern "C" fn occlum_getpid() -> c_uint
 {
@@ -118,7 +233,7 @@ fn do_spawn(child_pid_ptr: *mut c_uint,
             envp: *const *const c_char)
     -> Result<(), Error>
 {
-    let child_pid_ptr = check_mut_ptr_from_user(child_pid_ptr)?;
+    check_mut_ptr_from_user(child_pid_ptr)?;
     let path = clone_string_from_user_safely(path)?;
     let argv = clone_cstrings_from_user_safely(argv)?;
     let envp = clone_cstrings_from_user_safely(envp)?;

src/libos/src/syscall_entry.c

@@ -40,6 +40,20 @@ long dispatch_syscall(int num, long arg0, long arg1, long arg2, long arg3, long
         ret = occlum_read(fd, buf, buf_size);
         break;
     }
+    case SYS_writev: {
+        DECL_SYSCALL_ARG(int, fd, arg0);
+        DECL_SYSCALL_ARG(const struct iovec*, iov, arg1);
+        DECL_SYSCALL_ARG(int, count, arg2);
+        ret = occlum_writev(fd, iov, count);
+        break;
+    }
+    case SYS_readv: {
+        DECL_SYSCALL_ARG(int, fd, arg0);
+        DECL_SYSCALL_ARG(struct iovec*, iov, arg1);
+        DECL_SYSCALL_ARG(int, count, arg2);
+        ret = occlum_readv(fd, iov, count);
+        break;
+    }
     case SYS_spawn: {
         DECL_SYSCALL_ARG(int*, child_pid, arg0);
         DECL_SYSCALL_ARG(const char*, path, arg1);