Commit Graph

6 Commits

Author SHA1 Message Date
Jakub Konka
773915b4bf [wasi-common]: clean up error handling (#1253)
* 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
2020-03-09 22:58:55 +01:00
iximeow
7e0d9decbf Virtual file support (#701)
* 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>
2020-03-06 11:08:13 -08:00
Marcin Mielniczuk
f7f10c12b3 Fix rights checks across the codebase.
* Fix path_open granting more rights than requested
* Add missing rights checks in: fd_fdstat_set_flags, fd_filestat_get, poll_oneoff
* Fix `open_scratch_directory` not requesting any rights.
* Properly request needed rights in various tests
* Add some extra trace-level logging
* Remove a no-op restriction of rights to the ones returned by
  `determine_type_rights`. It was redundant, because `FdEntry:from`
  internally also called `determine_type_rights` and only dropped some of them.
2020-01-09 10:01:01 -08:00
Dan Gohman
1d810a5de9 Initial support for securing tty I/O. (#684)
* Initial support for securing tty I/O.

* Update the tests.

* Fix warnings

* Update crates/wasi-common/src/fdentry.rs

Co-Authored-By: Jakub Konka <jakub.konka@golem.network>

* Properly sandbox stderr.

* Document why the scratch buffer is 4 elements long.

* Update crates/wasi-common/src/sandboxed_tty_writer.rs

Co-Authored-By: Jakub Konka <jakub.konka@golem.network>

* Update crates/wasi-common/src/sandboxed_tty_writer.rs

Co-Authored-By: Jakub Konka <jakub.konka@golem.network>

* Add comments explaining how we report the number of bytes written.

* Always sanitize stderr.

* Port the changes to the snapshot_0 directory.

* Fix snapshot_0 compilation error.

* Replace the scratch buffer with a temporary buffer.

* Update crates/wasi-common/src/sandboxed_tty_writer.rs

Co-Authored-By: bjorn3 <bjorn3@users.noreply.github.com>

* Format with latest stable rustfmt.

Co-authored-by: Jakub Konka <kubkon@jakubkonka.com>
Co-authored-by: bjorn3 <bjorn3@users.noreply.github.com>
2020-01-02 11:53:26 +01:00
Dan Gohman
1f9d764d5d Support fd_fdstat_get and fd_renumber on stdin/stdout/stderr (#631)
* 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
2019-11-28 14:36:18 +01:00
Dan Gohman
22641de629 Initial reorg.
This is largely the same as #305, but updated for the current tree.
2019-11-08 06:35:40 -08:00