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Fix incorrect fd_readdir behaviour

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* when executed twice in a row, need to manually reset the stream
  by calling seekdir with __WASI_DIRCOOKIE_START, if __WASI_DIRCOOKIE_START
  was specified
* fix mapping between d_type and __wasi_filetype_t
* include minor refactor - removes use of wasm32 module on the
  host's side
This commit is contained in:
Jakub Konka
2019-08-26 14:40:59 +02:00
committed by Jakub Konka
parent 417ec0be01
commit 3609a82dc9
2 changed files with 53 additions and 20 deletions
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39
src/sys/unix/host_impl.rs
View File

@@ -2,7 +2,7 @@
#![allow(non_camel_case_types)]
#![allow(non_snake_case)]
#![allow(dead_code)]
use crate::{host, memory, wasm32, Result};
use crate::{host, memory, Result};
use std::ffi::OsStr;
use std::os::unix::prelude::OsStrExt;
@@ -228,29 +228,54 @@ pub(crate) fn filestat_from_nix(
})
}
pub(crate) fn dirent_filetype_from_host(
host_entry: &nix::libc::dirent,
) -> Result<host::__wasi_filetype_t> {
match host_entry.d_type {
libc::DT_FIFO => Ok(host::__WASI_FILETYPE_UNKNOWN),
libc::DT_CHR => Ok(host::__WASI_FILETYPE_CHARACTER_DEVICE),
libc::DT_DIR => Ok(host::__WASI_FILETYPE_DIRECTORY),
libc::DT_BLK => Ok(host::__WASI_FILETYPE_BLOCK_DEVICE),
libc::DT_REG => Ok(host::__WASI_FILETYPE_REGULAR_FILE),
libc::DT_LNK => Ok(host::__WASI_FILETYPE_SYMBOLIC_LINK),
libc::DT_SOCK => {
// TODO how to discriminate between STREAM and DGRAM?
// Perhaps, we should create a more general WASI filetype
// such as __WASI_FILETYPE_SOCKET, and then it would be
// up to the client to check whether it's actually
// STREAM or DGRAM?
Ok(host::__WASI_FILETYPE_UNKNOWN)
}
libc::DT_UNKNOWN => Ok(host::__WASI_FILETYPE_UNKNOWN),
_ => Err(host::__WASI_EINVAL),
}
}
#[cfg(target_os = "linux")]
pub(crate) fn dirent_from_host(host_entry: &nix::libc::dirent) -> Result<wasm32::__wasi_dirent_t> {
let mut entry = unsafe { std::mem::zeroed::<wasm32::__wasi_dirent_t>() };
pub(crate) fn dirent_from_host(host_entry: &nix::libc::dirent) -> Result<host::__wasi_dirent_t> {
let mut entry = unsafe { std::mem::zeroed::<host::__wasi_dirent_t>() };
let d_namlen = unsafe { std::ffi::CStr::from_ptr(host_entry.d_name.as_ptr()) }
.to_bytes()
.len();
if d_namlen > u32::max_value() as usize {
return Err(host::__WASI_EIO);
}
let d_type = dirent_filetype_from_host(host_entry)?;
entry.d_ino = memory::enc_inode(host_entry.d_ino);
entry.d_next = memory::enc_dircookie(host_entry.d_off as u64);
entry.d_namlen = memory::enc_u32(d_namlen as u32);
entry.d_type = memory::enc_filetype(host_entry.d_type);
entry.d_type = memory::enc_filetype(d_type);
Ok(entry)
}
#[cfg(not(target_os = "linux"))]
pub(crate) fn dirent_from_host(host_entry: &nix::libc::dirent) -> Result<wasm32::__wasi_dirent_t> {
let mut entry = unsafe { std::mem::zeroed::<wasm32::__wasi_dirent_t>() };
pub(crate) fn dirent_from_host(host_entry: &nix::libc::dirent) -> Result<host::__wasi_dirent_t> {
let mut entry = unsafe { std::mem::zeroed::<host::__wasi_dirent_t>() };
let d_type = dirent_filetype_from_host(host_entry)?;
entry.d_ino = memory::enc_inode(host_entry.d_ino);
entry.d_next = memory::enc_dircookie(host_entry.d_seekoff);
entry.d_namlen = memory::enc_u32(u32::from(host_entry.d_namlen));
entry.d_type = memory::enc_filetype(host_entry.d_type);
entry.d_type = memory::enc_filetype(d_type);
Ok(entry)
}

26
src/sys/unix/hostcalls_impl/fs.rs
View File

@@ -5,7 +5,7 @@ use crate::helpers::systemtime_to_timestamp;
use crate::hostcalls_impl::PathGet;
use crate::sys::errno_from_ioerror;
use crate::sys::host_impl;
use crate::{host, wasm32, Result};
use crate::{host, Result};
use nix::libc::{self, c_long, c_void};
use std::convert::TryInto;
use std::ffi::CString;
@@ -213,7 +213,7 @@ pub(crate) fn fd_readdir(
host_buf: &mut [u8],
cookie: host::__wasi_dircookie_t,
) -> Result<usize> {
use libc::{dirent, fdopendir, memcpy, readdir_r, seekdir};
use libc::{dirent, fdopendir, memcpy, readdir_r, rewinddir, seekdir};
let host_buf_ptr = host_buf.as_mut_ptr();
let host_buf_len = host_buf.len();
@@ -221,9 +221,15 @@ pub(crate) fn fd_readdir(
if dir.is_null() {
return Err(host_impl::errno_from_nix(nix::errno::Errno::last()));
}
if cookie != wasm32::__WASI_DIRCOOKIE_START {
if cookie != host::__WASI_DIRCOOKIE_START {
unsafe { seekdir(dir, cookie as c_long) };
} else {
// If cookie set to __WASI_DIRCOOKIE_START, rewind the dir ptr
// to the start of the stream.
unsafe { rewinddir(dir) };
}
let mut entry_buf = unsafe { std::mem::uninitialized::<dirent>() };
let mut left = host_buf_len;
let mut host_buf_offset: usize = 0;
@@ -236,7 +242,7 @@ pub(crate) fn fd_readdir(
if host_entry.is_null() {
break;
}
let entry: wasm32::__wasi_dirent_t = host_impl::dirent_from_host(&unsafe { *host_entry })?;
let entry: host::__wasi_dirent_t = host_impl::dirent_from_host(&unsafe { *host_entry })?;
let name_len = entry.d_namlen as usize;
let required_space = std::mem::size_of_val(&entry) + name_len;
if required_space > left {
@@ -244,7 +250,7 @@ pub(crate) fn fd_readdir(
}
unsafe {
let ptr = host_buf_ptr.offset(host_buf_offset as isize) as *mut c_void
as *mut wasm32::__wasi_dirent_t;
as *mut host::__wasi_dirent_t;
*ptr = entry;
}
host_buf_offset += std::mem::size_of_val(&entry);
@@ -344,8 +350,8 @@ pub(crate) fn fd_filestat_get_impl(file: &std::fs::File) -> Result<host::__wasi_
}
fn filetype(file: &File, metadata: &Metadata) -> Result<host::__wasi_filetype_t> {
use std::os::unix::fs::FileTypeExt;
use nix::sys::socket::{self, SockType};
use std::os::unix::fs::FileTypeExt;
let ftype = metadata.file_type();
if ftype.is_file() {
Ok(host::__WASI_FILETYPE_REGULAR_FILE)
@@ -360,8 +366,10 @@ fn filetype(file: &File, metadata: &Metadata) -> Result<host::__wasi_filetype_t>
} else if ftype.is_fifo() {
Ok(host::__WASI_FILETYPE_SOCKET_STREAM)
} else if ftype.is_socket() {
match socket::getsockopt(file.as_raw_fd(), socket::sockopt::SockType).map_err(|err|
err.as_errno().unwrap()).map_err(host_impl::errno_from_nix)? {
match socket::getsockopt(file.as_raw_fd(), socket::sockopt::SockType)
.map_err(|err| err.as_errno().unwrap())
.map_err(host_impl::errno_from_nix)?
{
SockType::Datagram => Ok(host::__WASI_FILETYPE_SOCKET_DGRAM),
SockType::Stream => Ok(host::__WASI_FILETYPE_SOCKET_STREAM),
_ => Ok(host::__WASI_FILETYPE_UNKNOWN),
@@ -425,7 +433,7 @@ pub(crate) fn path_filestat_set_times(
}
let atflags = match dirflags {
wasm32::__WASI_LOOKUP_SYMLINK_FOLLOW => UtimensatFlags::FollowSymlink,
host::__WASI_LOOKUP_SYMLINK_FOLLOW => UtimensatFlags::FollowSymlink,
_ => UtimensatFlags::NoFollowSymlink,
};