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Add experimental struct with views memory and ctxs

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This struct is heavily taking from Lucet's Vmctx struct.
This commit is contained in:
Jakub Konka
2019-05-10 20:13:50 +02:00
parent 328b8f3d91
commit 751a1a1f7b
5 changed files with 202 additions and 103 deletions
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10
src/ctx.rs
View File

@@ -198,6 +198,16 @@ pub struct WasiCtx {
pub env: Vec<CString>,
}
impl Default for WasiCtx {
fn default() -> Self {
Self {
fds: HashMap::new(),
args: Vec::new(),
env: Vec::new(),
}
}
}
impl WasiCtx {
/// Make a new `WasiCtx` with some default settings.
///

172
src/hostcalls.rs
View File

@@ -11,9 +11,9 @@
#![allow(non_camel_case_types)]
#![allow(unused_unsafe)]
#![allow(unused)]
use crate::ctx::VmContext;
use crate::fdentry::{determine_type_rights, FdEntry};
use crate::memory::*;
use crate::vmctx::VmContextView;
use crate::{host, wasm32};
use cast::From as _0;
@@ -25,21 +25,21 @@ use std::os::unix::prelude::{FromRawFd, OsStrExt, OsStringExt, RawFd};
use std::time::SystemTime;
use std::{cmp, slice};
pub unsafe fn proc_exit(_vmctx: &mut VmContext, rval: wasm32::__wasi_exitcode_t) -> () {
pub unsafe fn proc_exit(_vmctx: &mut VmContextView, rval: wasm32::__wasi_exitcode_t) -> () {
std::process::exit(dec_exitcode(rval) as i32);
}
pub unsafe fn args_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
argv_ptr: wasm32::uintptr_t,
argv_buf: wasm32::uintptr_t,
) -> wasm32::__wasi_errno_t {
let ctx = (*vmctx).as_wasi_ctx();
let ctx = vmctx.get_wasi_ctx();
let mut argv_buf_offset = 0;
let mut argv = vec![];
for arg in (*ctx).args.iter() {
for arg in ctx.args.iter() {
let arg_bytes = arg.as_bytes_with_nul();
let arg_ptr = argv_buf + argv_buf_offset;
@@ -67,13 +67,13 @@ pub unsafe fn args_get(
}
pub unsafe fn args_sizes_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
argc_ptr: wasm32::uintptr_t,
argv_buf_size_ptr: wasm32::uintptr_t,
) -> wasm32::__wasi_errno_t {
let ctx = (*vmctx).as_wasi_ctx();
let ctx = vmctx.get_wasi_ctx();
let argc = (*ctx).args.len();
let argc = ctx.args.len();
let argv_size = (*ctx)
.args
.iter()
@@ -92,7 +92,7 @@ pub unsafe fn args_sizes_get(
}
pub unsafe fn clock_res_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
clock_id: wasm32::__wasi_clockid_t,
resolution_ptr: wasm32::uintptr_t,
) -> wasm32::__wasi_errno_t {
@@ -134,7 +134,7 @@ pub unsafe fn clock_res_get(
}
pub unsafe fn clock_time_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
clock_id: wasm32::__wasi_clockid_t,
// ignored for now, but will be useful once we put optional limits on precision to reduce side
// channels
@@ -171,16 +171,16 @@ pub unsafe fn clock_time_get(
}
pub unsafe fn environ_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
environ_ptr: wasm32::uintptr_t,
environ_buf: wasm32::uintptr_t,
) -> wasm32::__wasi_errno_t {
let ctx = (*vmctx).as_wasi_ctx();
let ctx = vmctx.get_wasi_ctx();
let mut environ_buf_offset = 0;
let mut environ = vec![];
for pair in (*ctx).env.iter() {
for pair in ctx.env.iter() {
let env_bytes = pair.as_bytes_with_nul();
let env_ptr = environ_buf + environ_buf_offset;
@@ -208,14 +208,14 @@ pub unsafe fn environ_get(
}
pub unsafe fn environ_sizes_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
environ_count_ptr: wasm32::uintptr_t,
environ_size_ptr: wasm32::uintptr_t,
) -> wasm32::__wasi_errno_t {
let ctx = (*vmctx).as_wasi_ctx();
let ctx = vmctx.get_wasi_ctx();
let environ_count = (*ctx).env.len();
if let Some(environ_size) = (*ctx).env.iter().try_fold(0, |acc: u32, pair| {
let environ_count = ctx.env.len();
if let Some(environ_size) = ctx.env.iter().try_fold(0, |acc: u32, pair| {
acc.checked_add(pair.as_bytes_with_nul().len() as u32)
}) {
unsafe {
@@ -232,16 +232,19 @@ pub unsafe fn environ_sizes_get(
}
}
pub unsafe fn fd_close(vmctx: *mut VmContext, fd: wasm32::__wasi_fd_t) -> wasm32::__wasi_errno_t {
let ctx = (*vmctx).as_wasi_ctx_mut();
pub unsafe fn fd_close(
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
) -> wasm32::__wasi_errno_t {
let mut ctx = vmctx.get_wasi_ctx_mut();
let fd = dec_fd(fd);
if let Some(fdent) = (*ctx).fds.get(&fd) {
if let Some(fdent) = ctx.fds.get(&fd) {
// can't close preopened files
if fdent.preopen_path.is_some() {
return wasm32::__WASI_ENOTSUP;
}
}
if let Some(mut fdent) = (*ctx).fds.remove(&fd) {
if let Some(mut fdent) = ctx.fds.remove(&fd) {
fdent.fd_object.needs_close = false;
match nix::unistd::close(fdent.fd_object.rawfd) {
Ok(_) => wasm32::__WASI_ESUCCESS,
@@ -253,7 +256,7 @@ pub unsafe fn fd_close(vmctx: *mut VmContext, fd: wasm32::__wasi_fd_t) -> wasm32
}
pub unsafe fn fd_fdstat_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
fdstat_ptr: wasm32::uintptr_t, // *mut wasm32::__wasi_fdstat_t
) -> wasm32::__wasi_errno_t {
@@ -263,8 +266,8 @@ pub unsafe fn fd_fdstat_get(
Err(e) => return enc_errno(e),
};
let ctx = (*vmctx).as_wasi_ctx_mut();
let errno = if let Some(fe) = (*ctx).fds.get(&host_fd) {
let ctx = vmctx.get_wasi_ctx();
let errno = if let Some(fe) = ctx.fds.get(&host_fd) {
host_fdstat.fs_filetype = fe.fd_object.ty;
host_fdstat.fs_rights_base = fe.rights_base;
host_fdstat.fs_rights_inheriting = fe.rights_inheriting;
@@ -289,7 +292,7 @@ pub unsafe fn fd_fdstat_get(
}
pub unsafe fn fd_fdstat_set_flags(
vmctx: &mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
fdflags: wasm32::__wasi_fdflags_t,
) -> wasm32::__wasi_errno_t {
@@ -297,9 +300,9 @@ pub unsafe fn fd_fdstat_set_flags(
let host_fdflags = dec_fdflags(fdflags);
let nix_flags = host::nix_from_fdflags(host_fdflags);
let ctx = (*vmctx).as_wasi_ctx_mut();
let ctx = vmctx.get_wasi_ctx();
if let Some(fe) = (*ctx).fds.get(&host_fd) {
if let Some(fe) = ctx.fds.get(&host_fd) {
match nix::fcntl::fcntl(fe.fd_object.rawfd, nix::fcntl::F_SETFL(nix_flags)) {
Ok(_) => wasm32::__WASI_ESUCCESS,
Err(e) => wasm32::errno_from_nix(e.as_errno().unwrap()),
@@ -310,13 +313,13 @@ pub unsafe fn fd_fdstat_set_flags(
}
pub unsafe fn fd_seek(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
offset: wasm32::__wasi_filedelta_t,
whence: wasm32::__wasi_whence_t,
newoffset: wasm32::uintptr_t,
) -> wasm32::__wasi_errno_t {
let ctx = (*vmctx).as_wasi_ctx_mut();
let ctx = vmctx.get_wasi_ctx();
let fd = dec_fd(fd);
let offset = dec_filedelta(offset);
let whence = dec_whence(whence);
@@ -335,7 +338,7 @@ pub unsafe fn fd_seek(
} else {
host::__WASI_RIGHT_FD_SEEK | host::__WASI_RIGHT_FD_TELL
};
match (*ctx).get_fd_entry(fd, rights.into(), 0) {
match ctx.get_fd_entry(fd, rights.into(), 0) {
Ok(fe) => match lseek(fe.fd_object.rawfd, offset, nwhence) {
Ok(newoffset) => newoffset,
Err(e) => return wasm32::errno_from_nix(e.as_errno().unwrap()),
@@ -352,14 +355,14 @@ pub unsafe fn fd_seek(
}
pub unsafe fn fd_prestat_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
prestat_ptr: wasm32::uintptr_t,
) -> wasm32::__wasi_errno_t {
let ctx = (*vmctx).as_wasi_ctx();
let ctx = vmctx.get_wasi_ctx();
let fd = dec_fd(fd);
// TODO: is this the correct right for this?
match (*ctx).get_fd_entry(fd, host::__WASI_RIGHT_PATH_OPEN.into(), 0) {
match ctx.get_fd_entry(fd, host::__WASI_RIGHT_PATH_OPEN.into(), 0) {
Ok(fe) => {
if let Some(po_path) = &fe.preopen_path {
if fe.fd_object.ty != host::__WASI_FILETYPE_DIRECTORY {
@@ -391,14 +394,17 @@ pub unsafe fn fd_prestat_get(
}
pub unsafe fn fd_prestat_dir_name(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
path_ptr: wasm32::uintptr_t,
path_len: wasm32::size_t,
) -> wasm32::__wasi_errno_t {
let fd = dec_fd(fd);
match (*(*vmctx).as_wasi_ctx()).get_fd_entry(fd, host::__WASI_RIGHT_PATH_OPEN.into(), 0) {
match vmctx
.get_wasi_ctx()
.get_fd_entry(fd, host::__WASI_RIGHT_PATH_OPEN.into(), 0)
{
Ok(fe) => {
if let Some(po_path) = &fe.preopen_path {
if fe.fd_object.ty != host::__WASI_FILETYPE_DIRECTORY {
@@ -422,7 +428,7 @@ pub unsafe fn fd_prestat_dir_name(
}
pub unsafe fn fd_read(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
iovs_ptr: wasm32::uintptr_t,
iovs_len: wasm32::size_t,
@@ -436,8 +442,8 @@ pub unsafe fn fd_read(
Err(e) => return enc_errno(e),
};
let ctx = (*vmctx).as_wasi_ctx_mut();
let fe = match (*ctx).get_fd_entry(fd, host::__WASI_RIGHT_FD_READ.into(), 0) {
let mut ctx = vmctx.get_wasi_ctx_mut();
let fe = match ctx.get_fd_entry(fd, host::__WASI_RIGHT_FD_READ.into(), 0) {
Ok(fe) => fe,
Err(e) => return enc_errno(e),
};
@@ -454,7 +460,7 @@ pub unsafe fn fd_read(
if host_nread == 0 {
// we hit eof, so remove the fdentry from the context
let mut fe = (*ctx).fds.remove(&fd).expect("file entry is still there");
let mut fe = ctx.fds.remove(&fd).expect("file entry is still there");
fe.fd_object.needs_close = false;
}
@@ -466,7 +472,7 @@ pub unsafe fn fd_read(
}
pub unsafe fn fd_write(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
iovs_ptr: wasm32::uintptr_t,
iovs_len: wasm32::size_t,
@@ -480,8 +486,8 @@ pub unsafe fn fd_write(
Err(e) => return enc_errno(e),
};
let ctx = (*vmctx).as_wasi_ctx();
let fe = match (*ctx).get_fd_entry(fd, host::__WASI_RIGHT_FD_WRITE.into(), 0) {
let ctx = vmctx.get_wasi_ctx();
let fe = match ctx.get_fd_entry(fd, host::__WASI_RIGHT_FD_WRITE.into(), 0) {
Ok(fe) => fe,
Err(e) => return enc_errno(e),
};
@@ -504,7 +510,7 @@ pub unsafe fn fd_write(
}
pub unsafe fn path_open(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
dirfd: wasm32::__wasi_fd_t,
dirflags: wasm32::__wasi_lookupflags_t,
path_ptr: wasm32::uintptr_t,
@@ -627,7 +633,7 @@ pub unsafe fn path_open(
let mut fe = unsafe { FdEntry::from_raw_fd(new_fd) };
fe.rights_base &= max_base;
fe.rights_inheriting &= max_inheriting;
match (*(*vmctx).as_wasi_ctx_mut()).insert_fd_entry(fe) {
match vmctx.get_wasi_ctx_mut().insert_fd_entry(fe) {
Ok(fd) => fd,
Err(e) => return enc_errno(e),
}
@@ -642,14 +648,14 @@ pub unsafe fn path_open(
}
pub unsafe fn random_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
buf_ptr: wasm32::uintptr_t,
buf_len: wasm32::size_t,
) -> wasm32::__wasi_errno_t {
use rand::{thread_rng, RngCore};
let buf_len = dec_usize(buf_len);
let buf_ptr = match unsafe { (*vmctx).dec_ptr(buf_ptr, buf_len) } {
let buf_ptr = match unsafe { dec_ptr(vmctx, buf_ptr, buf_len) } {
Ok(ptr) => ptr,
Err(e) => return enc_errno(e),
};
@@ -662,7 +668,7 @@ pub unsafe fn random_get(
}
pub unsafe fn poll_oneoff(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
input: wasm32::uintptr_t,
output: wasm32::uintptr_t,
nsubscriptions: wasm32::size_t,
@@ -751,16 +757,16 @@ pub unsafe fn poll_oneoff(
}
pub unsafe fn fd_filestat_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
filestat_ptr: wasm32::uintptr_t,
) -> wasm32::__wasi_errno_t {
use nix::sys::stat::fstat;
let host_fd = dec_fd(fd);
let ctx = (*vmctx).as_wasi_ctx_mut();
let ctx = vmctx.get_wasi_ctx_mut();
let errno = if let Some(fe) = (*ctx).fds.get(&host_fd) {
let errno = if let Some(fe) = ctx.fds.get(&host_fd) {
match fstat(fe.fd_object.rawfd) {
Err(e) => wasm32::errno_from_nix(e.as_errno().unwrap()),
Ok(filestat) => {
@@ -779,7 +785,7 @@ pub unsafe fn fd_filestat_get(
}
pub unsafe fn path_filestat_get(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
dirfd: wasm32::__wasi_fd_t,
dirflags: wasm32::__wasi_lookupflags_t,
path_ptr: wasm32::uintptr_t,
@@ -825,7 +831,7 @@ pub unsafe fn path_filestat_get(
}
pub unsafe fn path_create_directory(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
dirfd: wasm32::__wasi_fd_t,
path_ptr: wasm32::uintptr_t,
path_len: wasm32::size_t,
@@ -862,7 +868,7 @@ pub unsafe fn path_create_directory(
}
pub unsafe fn path_unlink_file(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
dirfd: wasm32::__wasi_fd_t,
path_ptr: wasm32::uintptr_t,
path_len: wasm32::size_t,
@@ -899,14 +905,14 @@ pub unsafe fn path_unlink_file(
}
pub unsafe fn fd_datasync(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
) -> wasm32::__wasi_errno_t {
unimplemented!("fd_datasync")
}
pub unsafe fn fd_pread(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
iovs: wasm32::uintptr_t,
iovs_len: wasm32::size_t,
@@ -917,7 +923,7 @@ pub unsafe fn fd_pread(
}
pub unsafe fn fd_pwrite(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
iovs: wasm32::uintptr_t,
iovs_len: wasm32::size_t,
@@ -928,7 +934,7 @@ pub unsafe fn fd_pwrite(
}
pub unsafe fn fd_renumber(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
from: wasm32::__wasi_fd_t,
to: wasm32::__wasi_fd_t,
) -> wasm32::__wasi_errno_t {
@@ -936,7 +942,7 @@ pub unsafe fn fd_renumber(
}
pub unsafe fn fd_tell(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
newoffset: wasm32::uintptr_t,
) -> wasm32::__wasi_errno_t {
@@ -944,7 +950,7 @@ pub unsafe fn fd_tell(
}
pub unsafe fn fd_fdstat_set_rights(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
fs_rights_base: wasm32::__wasi_rights_t,
fs_rights_inheriting: wasm32::__wasi_rights_t,
@@ -952,12 +958,15 @@ pub unsafe fn fd_fdstat_set_rights(
unimplemented!("fd_fdstat_set_rights")
}
pub unsafe fn fd_sync(vmctx: *mut VmContext, fd: wasm32::__wasi_fd_t) -> wasm32::__wasi_errno_t {
pub unsafe fn fd_sync(
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
) -> wasm32::__wasi_errno_t {
unimplemented!("fd_sync")
}
pub unsafe fn fd_advise(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
offset: wasm32::__wasi_filesize_t,
len: wasm32::__wasi_filesize_t,
@@ -967,7 +976,7 @@ pub unsafe fn fd_advise(
}
pub unsafe fn fd_allocate(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
offset: wasm32::__wasi_filesize_t,
len: wasm32::__wasi_filesize_t,
@@ -976,7 +985,7 @@ pub unsafe fn fd_allocate(
}
pub unsafe fn path_link(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd0: wasm32::__wasi_fd_t,
flags0: wasm32::__wasi_lookupflags_t,
path0: wasm32::uintptr_t,
@@ -989,7 +998,7 @@ pub unsafe fn path_link(
}
pub unsafe fn fd_readdir(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
buf: wasm32::uintptr_t,
buf_len: wasm32::size_t,
@@ -1000,7 +1009,7 @@ pub unsafe fn fd_readdir(
}
pub unsafe fn path_readlink(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
path: wasm32::uintptr_t,
path_len: wasm32::size_t,
@@ -1012,7 +1021,7 @@ pub unsafe fn path_readlink(
}
pub unsafe fn path_rename(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd0: wasm32::__wasi_fd_t,
path0: wasm32::uintptr_t,
path_len0: wasm32::size_t,
@@ -1024,7 +1033,7 @@ pub unsafe fn path_rename(
}
pub unsafe fn fd_filestat_set_times(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
st_atim: wasm32::__wasi_timestamp_t,
st_mtim: wasm32::__wasi_timestamp_t,
@@ -1034,7 +1043,7 @@ pub unsafe fn fd_filestat_set_times(
}
pub unsafe fn fd_filestat_set_size(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
size: wasm32::__wasi_filesize_t,
) -> wasm32::__wasi_errno_t {
@@ -1042,7 +1051,7 @@ pub unsafe fn fd_filestat_set_size(
}
pub unsafe fn path_filestat_set_times(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
flags: wasm32::__wasi_lookupflags_t,
path: wasm32::uintptr_t,
@@ -1055,7 +1064,7 @@ pub unsafe fn path_filestat_set_times(
}
pub unsafe fn path_symlink(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
path0: wasm32::uintptr_t,
path_len0: wasm32::size_t,
fd: wasm32::__wasi_fd_t,
@@ -1066,7 +1075,7 @@ pub unsafe fn path_symlink(
}
pub unsafe fn path_remove_directory(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
fd: wasm32::__wasi_fd_t,
path: wasm32::uintptr_t,
path_len: wasm32::size_t,
@@ -1075,18 +1084,18 @@ pub unsafe fn path_remove_directory(
}
pub unsafe fn proc_raise(
_vmctx: *mut VmContext,
_vmctx: &mut VmContextView,
_sig: wasm32::__wasi_signal_t,
) -> wasm32::__wasi_errno_t {
unimplemented!("proc_raise")
}
pub unsafe fn sched_yield(_vmctx: *mut VmContext) -> wasm32::__wasi_errno_t {
pub unsafe fn sched_yield(_vmctx: &mut VmContextView) -> wasm32::__wasi_errno_t {
unimplemented!("sched_yield")
}
pub unsafe fn sock_recv(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
sock: wasm32::__wasi_fd_t,
ri_data: wasm32::uintptr_t,
ri_data_len: wasm32::size_t,
@@ -1098,7 +1107,7 @@ pub unsafe fn sock_recv(
}
pub unsafe fn sock_send(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
sock: wasm32::__wasi_fd_t,
si_data: wasm32::uintptr_t,
si_data_len: wasm32::size_t,
@@ -1109,7 +1118,7 @@ pub unsafe fn sock_send(
}
pub unsafe fn sock_shutdown(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
sock: wasm32::__wasi_fd_t,
how: wasm32::__wasi_sdflags_t,
) -> wasm32::__wasi_errno_t {
@@ -1146,7 +1155,7 @@ struct FdEventData {
}
fn poll_oneoff_handle_timeout_event(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
output_slice: &mut [wasm32::__wasi_event_t],
nevents: wasm32::uintptr_t,
timeout: Option<ClockEventData>,
@@ -1177,7 +1186,7 @@ fn poll_oneoff_handle_timeout_event(
}
fn poll_oneoff_handle_fd_event<'t>(
vmctx: *mut VmContext,
vmctx: &mut VmContextView,
output_slice: &mut [wasm32::__wasi_event_t],
nevents: wasm32::uintptr_t,
events: impl Iterator<Item = (&'t FdEventData, &'t nix::poll::PollFd)>,
@@ -1263,7 +1272,7 @@ fn poll_oneoff_handle_fd_event<'t>(
///
/// This is a workaround for not having Capsicum support in the OS.
pub fn path_get<P: AsRef<OsStr>>(
vmctx: &VmContext,
vmctx: &VmContextView,
dirfd: host::__wasi_fd_t,
dirflags: host::__wasi_lookupflags_t,
path: P,
@@ -1307,9 +1316,8 @@ pub fn path_get<P: AsRef<OsStr>>(
Err(errno)
}
let ctx = (*vmctx).as_wasi_ctx();
let dirfe = unsafe { (*ctx).get_fd_entry(dirfd, needed_base, needed_inheriting)? };
let ctx = vmctx.get_wasi_ctx();
let dirfe = ctx.get_fd_entry(dirfd, needed_base, needed_inheriting)?;
// Stack of directory file descriptors. Index 0 always corresponds with the directory provided
// to this function. Entering a directory causes a file descriptor to be pushed, while handling

1
src/lib.rs
View File

@@ -25,6 +25,7 @@ pub mod fdentry;
pub mod host;
pub mod hostcalls;
pub mod memory;
pub mod vmctx;
pub mod wasm32;
pub use ctx::{WasiCtx, WasiCtxBuilder};

63
src/memory.rs
View File

@@ -9,7 +9,7 @@
//!
//! This sort of manual encoding will hopefully be obsolete once the IDL is developed.
use crate::ctx::VmContext;
use crate::vmctx::VmContextView;
use crate::{host, wasm32};
use cast;
@@ -23,26 +23,47 @@ macro_rules! bail_errno {
};
}
pub unsafe fn dec_ptr(
vmctx: &VmContextView,
ptr: wasm32::uintptr_t,
len: usize,
) -> Result<*mut u8, host::__wasi_errno_t> {
let mut heap = vmctx.memory_mut();
// check that `len` fits in the wasm32 address space
if len > wasm32::UINTPTR_MAX as usize {
bail_errno!(__WASI_EOVERFLOW);
}
// check that `ptr` and `ptr + len` are both within the guest heap
if ptr as usize > heap.len() || ptr as usize + len > heap.len() {
bail_errno!(__WASI_EFAULT);
}
// translate the pointer
Ok(heap.as_mut_ptr().offset(ptr as isize))
}
pub unsafe fn dec_ptr_to<T>(
vmctx: *mut VmContext,
vmctx: &VmContextView,
ptr: wasm32::uintptr_t,
) -> Result<*mut T, host::__wasi_errno_t> {
// check that the ptr is aligned
if ptr as usize % align_of::<T>() != 0 {
bail_errno!(__WASI_EINVAL);
}
(*vmctx).dec_ptr(ptr, size_of::<T>()).map(|p| p as *mut T)
dec_ptr(vmctx, ptr, size_of::<T>()).map(|p| p as *mut T)
}
pub unsafe fn dec_pointee<T>(
vmctx: *mut VmContext,
vmctx: &VmContextView,
ptr: wasm32::uintptr_t,
) -> Result<T, host::__wasi_errno_t> {
dec_ptr_to::<T>(vmctx, ptr).map(|p| p.read())
}
pub unsafe fn enc_pointee<T>(
vmctx: *mut VmContext,
vmctx: &VmContextView,
ptr: wasm32::uintptr_t,
t: T,
) -> Result<(), host::__wasi_errno_t> {
@@ -50,7 +71,7 @@ pub unsafe fn enc_pointee<T>(
}
pub unsafe fn dec_slice_of<T>(
vmctx: *mut VmContext,
vmctx: &VmContextView,
ptr: wasm32::uintptr_t,
len: wasm32::size_t,
) -> Result<(*mut T, usize), host::__wasi_errno_t> {
@@ -65,13 +86,13 @@ pub unsafe fn dec_slice_of<T>(
return Err(host::__WASI_EOVERFLOW);
};
let ptr = (*vmctx).dec_ptr(ptr, len_bytes)? as *mut T;
let ptr = dec_ptr(vmctx, ptr, len_bytes)? as *mut T;
Ok((ptr, len))
}
pub unsafe fn enc_slice_of<T>(
vmctx: *mut VmContext,
vmctx: &VmContextView,
slice: &[T],
ptr: wasm32::uintptr_t,
) -> Result<(), host::__wasi_errno_t> {
@@ -87,7 +108,7 @@ pub unsafe fn enc_slice_of<T>(
};
// get the pointer into guest memory, and copy the bytes
let ptr = (*vmctx).dec_ptr(ptr, len_bytes)? as *mut libc::c_void;
let ptr = dec_ptr(vmctx, ptr, len_bytes)? as *mut libc::c_void;
libc::memcpy(ptr, slice.as_ptr() as *const libc::c_void, len_bytes);
Ok(())
@@ -100,7 +121,7 @@ macro_rules! dec_enc_scalar {
}
pub unsafe fn $dec_byref(
vmctx: *mut VmContext,
vmctx: &VmContextView,
ptr: wasm32::uintptr_t,
) -> Result<host::$ty, host::__wasi_errno_t> {
dec_pointee::<wasm32::$ty>(vmctx, ptr).map($dec)
@@ -111,7 +132,7 @@ macro_rules! dec_enc_scalar {
}
pub unsafe fn $enc_byref(
vmctx: *mut VmContext,
vmctx: &VmContextView,
ptr: wasm32::uintptr_t,
x: host::$ty,
) -> Result<(), host::__wasi_errno_t> {
@@ -121,18 +142,18 @@ macro_rules! dec_enc_scalar {
}
pub unsafe fn dec_ciovec(
vmctx: *mut VmContext,
vmctx: &VmContextView,
ciovec: &wasm32::__wasi_ciovec_t,
) -> Result<host::__wasi_ciovec_t, host::__wasi_errno_t> {
let len = dec_usize(ciovec.buf_len);
Ok(host::__wasi_ciovec_t {
buf: (*vmctx).dec_ptr(ciovec.buf, len)? as *const host::void,
buf: dec_ptr(vmctx, ciovec.buf, len)? as *const host::void,
buf_len: len,
})
}
pub unsafe fn dec_ciovec_slice(
vmctx: *mut VmContext,
vmctx: &VmContextView,
ptr: wasm32::uintptr_t,
len: wasm32::size_t,
) -> Result<Vec<host::__wasi_ciovec_t>, host::__wasi_errno_t> {
@@ -206,7 +227,7 @@ pub fn dec_filestat(filestat: wasm32::__wasi_filestat_t) -> host::__wasi_filesta
}
pub unsafe fn dec_filestat_byref(
vmctx: *mut VmContext,
vmctx: &VmContextView,
filestat_ptr: wasm32::uintptr_t,
) -> Result<host::__wasi_filestat_t, host::__wasi_errno_t> {
dec_pointee::<wasm32::__wasi_filestat_t>(vmctx, filestat_ptr).map(dec_filestat)
@@ -226,7 +247,7 @@ pub fn enc_filestat(filestat: host::__wasi_filestat_t) -> wasm32::__wasi_filesta
}
pub unsafe fn enc_filestat_byref(
vmctx: *mut VmContext,
vmctx: &VmContextView,
filestat_ptr: wasm32::uintptr_t,
host_filestat: host::__wasi_filestat_t,
) -> Result<(), host::__wasi_errno_t> {
@@ -244,7 +265,7 @@ pub fn dec_fdstat(fdstat: wasm32::__wasi_fdstat_t) -> host::__wasi_fdstat_t {
}
pub unsafe fn dec_fdstat_byref(
vmctx: *mut VmContext,
vmctx: &VmContextView,
fdstat_ptr: wasm32::uintptr_t,
) -> Result<host::__wasi_fdstat_t, host::__wasi_errno_t> {
dec_pointee::<wasm32::__wasi_fdstat_t>(vmctx, fdstat_ptr).map(dec_fdstat)
@@ -261,7 +282,7 @@ pub fn enc_fdstat(fdstat: host::__wasi_fdstat_t) -> wasm32::__wasi_fdstat_t {
}
pub unsafe fn enc_fdstat_byref(
vmctx: *mut VmContext,
vmctx: &VmContextView,
fdstat_ptr: wasm32::uintptr_t,
host_fdstat: host::__wasi_fdstat_t,
) -> Result<(), host::__wasi_errno_t> {
@@ -328,7 +349,7 @@ pub fn dec_prestat(
}
pub unsafe fn dec_prestat_byref(
vmctx: *mut VmContext,
vmctx: &VmContextView,
prestat_ptr: wasm32::uintptr_t,
) -> Result<host::__wasi_prestat_t, host::__wasi_errno_t> {
dec_pointee::<wasm32::__wasi_prestat_t>(vmctx, prestat_ptr).and_then(dec_prestat)
@@ -354,7 +375,7 @@ pub fn enc_prestat(
}
pub unsafe fn enc_prestat_byref(
vmctx: *mut VmContext,
vmctx: &VmContextView,
prestat_ptr: wasm32::uintptr_t,
host_prestat: host::__wasi_prestat_t,
) -> Result<(), host::__wasi_errno_t> {
@@ -386,7 +407,7 @@ pub fn enc_usize(size: usize) -> wasm32::size_t {
}
pub unsafe fn enc_usize_byref(
vmctx: *mut VmContext,
vmctx: &VmContextView,
usize_ptr: wasm32::uintptr_t,
host_usize: usize,
) -> Result<(), host::__wasi_errno_t> {

59
src/vmctx.rs Normal file
View File

@@ -0,0 +1,59 @@
//! This code borrows heavily from Lucet's Vmctx implementation
//! https://github.com/fastly/lucet/blob/master/lucet-runtime/lucet-runtime-internals/src/vmctx.rs
use crate::ctx::WasiCtx;
use std::borrow::{Borrow, BorrowMut};
use std::cell::{Ref, RefCell, RefMut};
pub trait AsVmContextView {
unsafe fn as_vm_context_view(&mut self) -> VmContextView;
}
#[derive(Debug)]
pub struct VmContextView {
pub memory_view: RefCell<Box<[u8]>>,
pub wasi_ctx_view: RefCell<Box<WasiCtx>>,
}
impl Drop for VmContextView {
fn drop(&mut self) {
let memory_view = self.memory_view.replace(Box::new([]));
let wasi_ctx_view = self.wasi_ctx_view.replace(Box::new(WasiCtx::default()));
Box::leak(memory_view);
Box::leak(wasi_ctx_view);
}
}
impl VmContextView {
pub fn memory(&self) -> Ref<[u8]> {
let r = self
.memory_view
.try_borrow()
.expect("memory not already borrowed mutably");
Ref::map(r, |b| b.borrow())
}
pub fn memory_mut(&self) -> RefMut<[u8]> {
let r = self
.memory_view
.try_borrow_mut()
.expect("memory not already borrowed");
RefMut::map(r, |b| b.borrow_mut())
}
pub fn get_wasi_ctx(&self) -> Ref<WasiCtx> {
let r = self
.wasi_ctx_view
.try_borrow()
.expect("WASI context not already borrowed mutably");
Ref::map(r, |b| b.borrow())
}
pub fn get_wasi_ctx_mut(&self) -> RefMut<WasiCtx> {
let r = self
.wasi_ctx_view
.try_borrow_mut()
.expect("WASI context not already borrowed");
RefMut::map(r, |b| b.borrow_mut())
}
}