* Introduce WasiCtxBuilderError error type
`WasiCtxBuilderError` is the `wasi-common` client-facing error type
which is exclusively thrown when building a new `WasiCtx` instance.
As such, building such an instance should not require the client to
understand different WASI errno values as was assumed until now.
This commit is a first step at streamlining error handling in
`wasi-common` and makes way for the `wiggle` crate.
When adding the `WasiCtxBuilderError`, I've had to do two things of
notable importance:
1. I've removed a couple of `ok_or` calls in `WasiCtxBuilder::build`
and replaced them with `unwrap`s, following the same pattern in
different builder methods above. This is fine since we _always_
operate on non-empty `Option`s in `WasiCtxBuilder` thus `unwrap`ing
will never fail. On the other hand, this might be a good opportunity
to rethink the structure of our builder, and how we good remove
the said `Option`s especially since we always populate them with
empty containers to begin with. I understand this is to make
chaining of builder methods easier which take and return `&mut self`
and the same applies to `WasiCtxBuilder::build(&mut self)` method,
but perhaps it would more cleanly signal the intentions if we simply
moved `WasiCtxBuilder` instance around. Food for thought!
2. Methods specific to determining rights of passed around `std::fs::File`
objects when populating `WasiCtx` `FdEntry` entities now return
`io::Error` directly so that we can reuse them in `WasiCtxBuilder` methods
(returning `WasiCtxBuilderError` error type), and in syscalls
(returning WASI errno).
* Return WasiError directly in syscalls
Also, removes `error::Error` type altogether. Now, `io::Error` and
related are automatically converted to their corresponding WASI
errno value encapsulated as `WasiError`.
While here, it made sense to me to move `WasiError` to `wasi` module
which will align itself well with the upcoming changes introduced
by `wiggle`. To different standard `Result` from WASI specific, I've
created a helper alias `WasiResult` also residing in `wasi` module.
* Update wig
* Add from ffi::NulError and pass context to NotADirectory
* Add dummy commit to test CI
* Winx now returns io::Error
This commit is a spiritual follower of #1242 in the sense that it
adjusts `winx` to also return `io::Error` directly rather than
tossing a custom error type here and there.
* Adapt wasi-common to changes in winx
* Run cargo fmt
* Swap overly big map_err with explicit match
* Add support for virtual files (eg, not backed by an OS file).
Virtual files are implemented through trait objects, with a default
implementation that tries to behave like on-disk files, but entirely
backed by in-memory structures.
Co-authored-by: Dan Gohman <sunfish@mozilla.com>
This commit implements `fd_fdstat_set_flags` for Windows.
Additionally, it fixes a problem where `O_APPEND` was not working correctly
because `GENERIC_WRITE` was always being set; as a result, `FILE_WRITE_DATA`
could not be removed from the permission set to properly enable append-only
mode.
It also treats `O_TRUNC` with `O_APPEND` as an invalid argument error. This is
because Windows cannot support these two flags together. To support `O_TRUNC`,
the `GENERIC_WRITE` bit must be set for the file access flags. Setting this
bit will cause `FILE_WRITE_DATA` to be set, which will not properly treat the
file as append-only (it requires `FILE_APPEND_DATA` without `FILE_WRITE_DATA`).
* Clean up fd_filestat_get implementation
This commit does 4 things:
* Adds `yanix::file::fstat`, a wrapper around `libc::fstat`.
* It essentially reverts 89fbde2 for Unix hosts -- in other words,
it brings back the use of `fstat` to obtain `libc::stat` from a
file descriptor, rather than relying on `std::fs::Metadata`. This
way, we reuse `host_impl::filestat_from_nix` in
`hostcalls_impl::fd_filestat_get` implementation rather than
unnecessarily duplicate code for converting filestats into
`__wasi_filestat_t`.
* Moves `crate::helpers::systemtime_to_timestamp` to Windows `host_impl`
module. It does the same thing with helpers which assist in converting
`std::fs::Metadata` into `__wasi_filestat_t`. This should retain symmetry
between *nix and Windows impls.
* Makes timestamp conversions in `host_impl::filestat_from_nix` fallible.
* Backport changes to snapshot0
* Signal no overflow with `from` rather than `as` cast
* Add yanix crate
This commit adds `yanix` crate as a Unix dependency for `wasi-common`.
`yanix` stands for Yet Another Nix crate and is exactly what the name
suggests: a crate in the spirit of the `nix` crate, but which takes a different
approach, using lower-level interfaces with less abstraction, so that it fits
better with its main use case, implementation of WASI syscalls.
* Replace nix with yanix crate
Having introduced `yanix` crate as an in-house replacement for the
`nix` crate, this commit makes the necessary changes to `wasi-common`
to depend _only_ on `yanix` crate.
* Address review comments
* make `fd_dup` unsafe
* rename `get_fd` to `get_fd_flags`, etc.
* reuse `io::Error::last_os_error()` to get the last errno value
* Address more comments
* make all `fcntl` fns unsafe
* adjust `wasi-common` impl appropriately
* Make all fns operating on RawFd unsafe
* Fix linux build
* Address more comments
* Support fd_fdstat_get on stdin/stdout/stderr.
Add a routine for obtaining an `OsFile` containing a file descriptor for
stdin/stdout/stderr so that we can do fd_fdstat_get on them.
* Add a testcase for fd_fdstat_get etc. on stdin etc.
* Don't dup file descriptors in fd_renumber.
* Fix compilation on macOS
* Rename OsFile to OsHandle
This commits renames `OsFile` to `OsHandle` which seems to make
more sense semantically as it is permitted to hold a valid OS handle
to OS entities other than simply file/dir (e.g., socket, stream, etc.).
As such, this commit also renames methods on `Descriptor` struct
from `as_actual_file` to `as_file` as this in reality does pertain
ops on FS entities such as files/dirs, and `as_file` to `as_os_handle`
as in this case it can be anything, from file, through a socket, to
a stream.
* Fix compilation on Linux
* Introduce `OsHandleRef` for borrowing OS resources.
To prevent a `ManuallyDrop<OsHandleRef>` from outliving the resource it
holds on to, create an `OsHandleRef` class parameterized on the lifetime
of the `Descriptor`.
* Fix scoping to pub-priv and backport to snapshot_0
This commit fully implements `__wasi_fd_fdstat_get` on Windows so that
the descriptor flags can be determined.
It does this by calling into `NtQueryInformationFile` (safe to call from
user mode) to get the open mode and access of the underlying OS handle.
`NtQueryInformationFile` isn't included in the `winapi` crate, so it is
manually being linked against.
This commit also fixes several bugs on Windows:
* Ignore `__WASI_FDFLAG_NONBLOCK` by not setting `FILE_FLAG_OVERLAPPED`
on file handles (the POSIX behavior for `O_NONBLOCK` on files).
* Use `FILE_FLAG_WRITE_THROUGH` for the `__WASI_FDFLAG_?SYNC` flags.
* `__WASI_FDFLAG_APPEND` should disallow `FILE_WRITE_DATA` access to
force append-only on write operations.
* Use `GENERIC_READ` and `GENERIC_WRITE` access flags. The
latter is required when opening a file for truncation.
* Unify fd_readdir impl between *nixes
This commit unifies the implementation of `fd_readdir` between Linux
and BSD hosts. In particular, it re-uses the `Dirent`, `Entry`, and
`Dir` (among others) building blocks introduced recently when
`fd_readdir` was being implemented on Windows.
Notable changes:
* on BSD, wraps `readdir` syscall in an `Iterator` of the mutex-locked
`Dir` struct
* on BSD, removes `DirStream` struct from `OsFile`; `OsFile` now holds a
mutex to `Dir`
* makes `Dir` iterators implementation specific (Linux has its own,
and so does BSD)
* Lock mutex once only; explain dir in OsFile
* Add more comments
* Add support for wasi_snapshot_preview1.
This adds support for the new ABI, while preserving compatibility
support for the old ABI.
* Fix compilation on platforms where nlink_t isn't 64-bit.
* rustfmt
* Fix Windows build errors.
