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Rewrite majority of impl reusing libstd (#34)

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* Rewrite FdEntry reusing as much libstd as possible

* Use the new FdEntry, FdObject, Descriptor struct in *nix impl

* Adapt Windows impl

* Remove unnecessary check in fd_read

Check `host_nread == 0` caused premature FdEntry closure and removal
which ultimately was resulting in an attempt at "double closing" of
the same file descriptor at the end of the Wasm program:
...
fd_close(fd=4)
    -> errno=WASI_ESUCCESS
fd_close(fd=4)
    -> errno=WASI_EBADF

* Use libstd vectored IO

* Use std:🧵:yield_now to implement sched_yield

* Add logging to integration tests

* Add preliminary support for host-specific errors

* Operate on std::fs::File in path_get on *nix

* Add cross-platform RawString type encapsulating OsStrExt

* Fix Windows build

* Update Travis and README to Rust v1.36

* Remove unused winx::handle::close helper

* Refactor Descriptor into raw handles/fds

* Strip readlinkat in prep for path_get host-independent

* Strip openat in prep for path_get host-independent

* Move ManuallyDrop up one level from Descriptor to FdObject

* Make (c)iovec host fns unsafe

* Swap unwraps/expects for Results in fdentry_impl on nix

* Rewrite fd_pread/write and implement for Win

* Use File::sync_all to impl fd_sync

* Use File::sync_data to impl fd_datasync

* Rewind file cursor after fd_p{read, write} on Windows

* Add fd_p{read, write} tests

* Handle errors instead of panicking in path_get

* Use File::set_len to impl fd_allocate

* Add test for fd_allocate

* Replace all panics with Results

* Document the point of RawString
This commit is contained in:
Jakub Konka
2019-07-16 00:34:28 +02:00
committed by Dan Gohman
parent 93e1657bae
commit 667f272edd
32 changed files with 977 additions and 1045 deletions
Download Patch File Download Diff File Expand all files Collapse all files

172
src/ctx.rs
View File

@@ -1,13 +1,10 @@
use crate::host;
use crate::sys::dev_null;
use crate::sys::fdentry::FdEntry;
use failure::{bail, format_err, Error};
use super::fdentry::FdEntry;
use super::host;
use super::sys::{dev_null, errno_from_host};
use std::borrow::Borrow;
use std::collections::HashMap;
use std::ffi::{CStr, CString};
use std::ffi::CString;
use std::fs::File;
use std::io::{stderr, stdin, stdout};
use std::path::{Path, PathBuf};
pub struct WasiCtxBuilder {
@@ -19,7 +16,7 @@ pub struct WasiCtxBuilder {
impl WasiCtxBuilder {
/// Builder for a new `WasiCtx`.
pub fn new() -> Self {
pub fn new() -> Result<Self, host::__wasi_errno_t> {
let mut builder = Self {
fds: HashMap::new(),
preopens: HashMap::new(),
@@ -27,77 +24,66 @@ impl WasiCtxBuilder {
env: HashMap::new(),
};
builder.fds.insert(0, FdEntry::from_file(dev_null()));
builder.fds.insert(1, FdEntry::from_file(dev_null()));
builder.fds.insert(2, FdEntry::from_file(dev_null()));
builder.fds.insert(0, FdEntry::from(dev_null()?)?);
builder.fds.insert(1, FdEntry::from(dev_null()?)?);
builder.fds.insert(2, FdEntry::from(dev_null()?)?);
builder
Ok(builder)
}
pub fn args(mut self, args: &[&str]) -> Self {
self.args = args
.into_iter()
.map(|arg| CString::new(*arg).expect("argument can be converted to a CString"))
pub fn args<S: AsRef<str>>(
mut self,
args: impl Iterator<Item = S>,
) -> Result<Self, host::__wasi_errno_t> {
let args: Result<Vec<CString>, _> = args
.map(|arg| CString::new(arg.as_ref()).map_err(|_| host::__WASI_ENOTCAPABLE))
.collect();
self
self.args = args?;
Ok(self)
}
pub fn arg(mut self, arg: &str) -> Self {
pub fn arg(mut self, arg: &str) -> Result<Self, host::__wasi_errno_t> {
self.args
.push(CString::new(arg).expect("argument can be converted to a CString"));
self
.push(CString::new(arg).map_err(|_| host::__WASI_ENOTCAPABLE)?);
Ok(self)
}
pub fn c_args<S: AsRef<CStr>>(mut self, args: &[S]) -> Self {
self.args = args
.into_iter()
.map(|arg| arg.as_ref().to_owned())
.collect();
self
pub fn inherit_stdio(mut self) -> Result<Self, host::__wasi_errno_t> {
self.fds.insert(0, FdEntry::duplicate_stdin()?);
self.fds.insert(1, FdEntry::duplicate_stdout()?);
self.fds.insert(2, FdEntry::duplicate_stderr()?);
Ok(self)
}
pub fn c_arg<S: AsRef<CStr>>(mut self, arg: S) -> Self {
self.args.push(arg.as_ref().to_owned());
self
pub fn inherit_env(self) -> Result<Self, host::__wasi_errno_t> {
self.envs(std::env::vars())
}
pub fn inherit_stdio(mut self) -> Self {
self.fds.insert(0, FdEntry::duplicate(&stdin()));
self.fds.insert(1, FdEntry::duplicate(&stdout()));
self.fds.insert(2, FdEntry::duplicate(&stderr()));
self
pub fn env<S: AsRef<str>>(mut self, k: S, v: S) -> Result<Self, host::__wasi_errno_t> {
self.env.insert(
CString::new(k.as_ref()).map_err(|_| host::__WASI_ENOTCAPABLE)?,
CString::new(v.as_ref()).map_err(|_| host::__WASI_ENOTCAPABLE)?,
);
Ok(self)
}
pub fn inherit_env(mut self) -> Self {
self.env = std::env::vars()
.map(|(k, v)| {
// TODO: handle errors, and possibly assert that the key is valid per POSIX
(
CString::new(k).expect("environment key can be converted to a CString"),
CString::new(v).expect("environment value can be converted to a CString"),
)
pub fn envs<S: AsRef<str>, T: Borrow<(S, S)>>(
mut self,
envs: impl Iterator<Item = T>,
) -> Result<Self, host::__wasi_errno_t> {
let env: Result<HashMap<CString, CString>, _> = envs
.map(|t| {
let (k, v) = t.borrow();
let k = CString::new(k.as_ref()).map_err(|_| host::__WASI_ENOTCAPABLE);
let v = CString::new(v.as_ref()).map_err(|_| host::__WASI_ENOTCAPABLE);
match (k, v) {
(Ok(k), Ok(v)) => Ok((k, v)),
_ => Err(host::__WASI_ENOTCAPABLE),
}
})
.collect();
self
}
pub fn env(mut self, k: &str, v: &str) -> Self {
self.env.insert(
// TODO: handle errors, and possibly assert that the key is valid per POSIX
CString::new(k).expect("environment key can be converted to a CString"),
CString::new(v).expect("environment value can be converted to a CString"),
);
self
}
pub fn c_env<S, T>(mut self, k: S, v: T) -> Self
where
S: AsRef<CStr>,
T: AsRef<CStr>,
{
self.env
.insert(k.as_ref().to_owned(), v.as_ref().to_owned());
self
self.env = env?;
Ok(self)
}
pub fn preopened_dir<P: AsRef<Path>>(mut self, dir: File, guest_path: P) -> Self {
@@ -105,20 +91,22 @@ impl WasiCtxBuilder {
self
}
pub fn build(mut self) -> Result<WasiCtx, Error> {
pub fn build(mut self) -> Result<WasiCtx, host::__wasi_errno_t> {
// startup code starts looking at fd 3 for preopens
let mut preopen_fd = 3;
for (guest_path, dir) in self.preopens {
if !dir.metadata()?.is_dir() {
bail!("preopened file is not a directory");
if !dir
.metadata()
.map_err(|err| err.raw_os_error().map_or(host::__WASI_EIO, errno_from_host))?
.is_dir()
{
return Err(host::__WASI_EBADF);
}
while self.fds.contains_key(&preopen_fd) {
preopen_fd = preopen_fd
.checked_add(1)
.ok_or(format_err!("not enough file handles"))?;
preopen_fd = preopen_fd.checked_add(1).ok_or(host::__WASI_ENFILE)?;
}
let mut fe = FdEntry::from_file(dir);
let mut fe = FdEntry::from(dir)?;
fe.preopen_path = Some(guest_path);
self.fds.insert(preopen_fd, fe);
preopen_fd += 1;
@@ -159,13 +147,12 @@ impl WasiCtx {
/// - Environment variables are inherited from the host process.
///
/// To override these behaviors, use `WasiCtxBuilder`.
pub fn new(args: &[&str]) -> Self {
pub fn new<S: AsRef<str>>(args: impl Iterator<Item = S>) -> Result<Self, host::__wasi_errno_t> {
WasiCtxBuilder::new()
.args(args)
.inherit_stdio()
.inherit_env()
.build()
.expect("default options don't fail")
.and_then(|ctx| ctx.args(args))
.and_then(|ctx| ctx.inherit_stdio())
.and_then(|ctx| ctx.inherit_env())
.and_then(|ctx| ctx.build())
}
pub fn get_fd_entry(
@@ -175,18 +162,37 @@ impl WasiCtx {
rights_inheriting: host::__wasi_rights_t,
) -> Result<&FdEntry, host::__wasi_errno_t> {
if let Some(fe) = self.fds.get(&fd) {
// validate rights
if !fe.rights_base & rights_base != 0 || !fe.rights_inheriting & rights_inheriting != 0
{
Err(host::__WASI_ENOTCAPABLE)
} else {
Ok(fe)
}
Self::validate_rights(fe, rights_base, rights_inheriting).and(Ok(fe))
} else {
Err(host::__WASI_EBADF)
}
}
pub fn get_fd_entry_mut(
&mut self,
fd: host::__wasi_fd_t,
rights_base: host::__wasi_rights_t,
rights_inheriting: host::__wasi_rights_t,
) -> Result<&mut FdEntry, host::__wasi_errno_t> {
if let Some(fe) = self.fds.get_mut(&fd) {
Self::validate_rights(fe, rights_base, rights_inheriting).and(Ok(fe))
} else {
Err(host::__WASI_EBADF)
}
}
fn validate_rights(
fe: &FdEntry,
rights_base: host::__wasi_rights_t,
rights_inheriting: host::__wasi_rights_t,
) -> Result<(), host::__wasi_errno_t> {
if !fe.rights_base & rights_base != 0 || !fe.rights_inheriting & rights_inheriting != 0 {
Err(host::__WASI_ENOTCAPABLE)
} else {
Ok(())
}
}
pub fn insert_fd_entry(
&mut self,
fe: FdEntry,