773915b4bf
* 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
97 lines
3.2 KiB
Rust
97 lines
3.2 KiB
Rust
//! WASI host types. These are types that contain raw pointers and `usize`
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//! values, and so are platform-specific.
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#![allow(non_camel_case_types)]
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#![allow(non_snake_case)]
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use crate::wasi::*;
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use std::{convert::TryInto, io, mem, slice};
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use wig::witx_host_types;
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witx_host_types!("snapshot" "wasi_snapshot_preview1");
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pub(crate) unsafe fn ciovec_to_host(ciovec: &__wasi_ciovec_t) -> io::IoSlice {
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let slice = slice::from_raw_parts(ciovec.buf as *const u8, ciovec.buf_len);
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io::IoSlice::new(slice)
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}
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pub(crate) unsafe fn iovec_to_host_mut(iovec: &mut __wasi_iovec_t) -> io::IoSliceMut {
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let slice = slice::from_raw_parts_mut(iovec.buf as *mut u8, iovec.buf_len);
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io::IoSliceMut::new(slice)
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}
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#[allow(dead_code)] // trouble with sockets
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#[derive(Clone, Copy, Debug, PartialEq)]
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#[repr(u8)]
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pub enum FileType {
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Unknown = __WASI_FILETYPE_UNKNOWN,
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BlockDevice = __WASI_FILETYPE_BLOCK_DEVICE,
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CharacterDevice = __WASI_FILETYPE_CHARACTER_DEVICE,
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Directory = __WASI_FILETYPE_DIRECTORY,
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RegularFile = __WASI_FILETYPE_REGULAR_FILE,
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SocketDgram = __WASI_FILETYPE_SOCKET_DGRAM,
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SocketStream = __WASI_FILETYPE_SOCKET_STREAM,
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Symlink = __WASI_FILETYPE_SYMBOLIC_LINK,
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}
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impl FileType {
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pub(crate) fn to_wasi(&self) -> __wasi_filetype_t {
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*self as __wasi_filetype_t
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}
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pub(crate) fn from_wasi(wasi_filetype: u8) -> Option<Self> {
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use FileType::*;
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match wasi_filetype {
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__WASI_FILETYPE_UNKNOWN => Some(Unknown),
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__WASI_FILETYPE_BLOCK_DEVICE => Some(BlockDevice),
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__WASI_FILETYPE_CHARACTER_DEVICE => Some(CharacterDevice),
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__WASI_FILETYPE_DIRECTORY => Some(Directory),
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__WASI_FILETYPE_REGULAR_FILE => Some(RegularFile),
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__WASI_FILETYPE_SOCKET_DGRAM => Some(SocketDgram),
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__WASI_FILETYPE_SOCKET_STREAM => Some(SocketStream),
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__WASI_FILETYPE_SYMBOLIC_LINK => Some(Symlink),
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_ => None,
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}
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}
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}
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#[derive(Debug, Clone)]
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pub struct Dirent {
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pub name: String,
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pub ftype: FileType,
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pub ino: u64,
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pub cookie: __wasi_dircookie_t,
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}
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impl Dirent {
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/// Serialize the directory entry to the format define by `__wasi_fd_readdir`,
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/// so that the serialized entries can be concatenated by the implementation.
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pub fn to_wasi_raw(&self) -> WasiResult<Vec<u8>> {
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let name = self.name.as_bytes();
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let namlen = name.len();
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let dirent_size = mem::size_of::<__wasi_dirent_t>();
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let offset = dirent_size
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.checked_add(namlen)
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.ok_or(WasiError::EOVERFLOW)?;
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let mut raw = Vec::<u8>::with_capacity(offset);
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raw.resize(offset, 0);
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let sys_dirent = raw.as_mut_ptr() as *mut __wasi_dirent_t;
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unsafe {
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sys_dirent.write_unaligned(__wasi_dirent_t {
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d_namlen: namlen.try_into()?,
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d_ino: self.ino,
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d_next: self.cookie,
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d_type: self.ftype.to_wasi(),
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});
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}
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let sys_name = unsafe { sys_dirent.offset(1) as *mut u8 };
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let sys_name = unsafe { slice::from_raw_parts_mut(sys_name, namlen) };
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sys_name.copy_from_slice(&name);
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Ok(raw)
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}
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}
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