1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133

#![cfg_attr(io_lifetimes_use_std, feature(io_safety))]

mod dir;
mod file;
pub mod net;
pub mod sched;
pub mod stdio;

use std::future::Future;
use std::path::Path;
pub use wasi_cap_std_sync::{clocks_ctx, random_ctx};
use wasi_common::{Error, Table, WasiCtx, WasiFile};

pub use dir::Dir;
pub use file::File;
pub use net::*;
use wasi_cap_std_sync::net::Socket;
use wasi_common::file::FileCaps;

use crate::sched::sched_ctx;

pub struct WasiCtxBuilder(WasiCtx);

impl WasiCtxBuilder {
    pub fn new() -> Self {
        WasiCtxBuilder(WasiCtx::new(
            random_ctx(),
            clocks_ctx(),
            sched_ctx(),
            Table::new(),
        ))
    }
    pub fn env(mut self, var: &str, value: &str) -> Result<Self, wasi_common::StringArrayError> {
        self.0.push_env(var, value)?;
        Ok(self)
    }
    pub fn envs(mut self, env: &[(String, String)]) -> Result<Self, wasi_common::StringArrayError> {
        for (k, v) in env {
            self.0.push_env(k, v)?;
        }
        Ok(self)
    }
    pub fn inherit_env(mut self) -> Result<Self, wasi_common::StringArrayError> {
        for (key, value) in std::env::vars() {
            self.0.push_env(&key, &value)?;
        }
        Ok(self)
    }
    pub fn arg(mut self, arg: &str) -> Result<Self, wasi_common::StringArrayError> {
        self.0.push_arg(arg)?;
        Ok(self)
    }
    pub fn args(mut self, arg: &[String]) -> Result<Self, wasi_common::StringArrayError> {
        for a in arg {
            self.0.push_arg(&a)?;
        }
        Ok(self)
    }
    pub fn inherit_args(mut self) -> Result<Self, wasi_common::StringArrayError> {
        for arg in std::env::args() {
            self.0.push_arg(&arg)?;
        }
        Ok(self)
    }
    pub fn stdin(self, f: Box<dyn WasiFile>) -> Self {
        self.0.set_stdin(f);
        self
    }
    pub fn stdout(self, f: Box<dyn WasiFile>) -> Self {
        self.0.set_stdout(f);
        self
    }
    pub fn stderr(self, f: Box<dyn WasiFile>) -> Self {
        self.0.set_stderr(f);
        self
    }
    pub fn inherit_stdin(self) -> Self {
        self.stdin(Box::new(crate::stdio::stdin()))
    }
    pub fn inherit_stdout(self) -> Self {
        self.stdout(Box::new(crate::stdio::stdout()))
    }
    pub fn inherit_stderr(self) -> Self {
        self.stderr(Box::new(crate::stdio::stderr()))
    }
    pub fn inherit_stdio(self) -> Self {
        self.inherit_stdin().inherit_stdout().inherit_stderr()
    }
    pub fn preopened_dir(
        self,
        dir: cap_std::fs::Dir,
        guest_path: impl AsRef<Path>,
    ) -> Result<Self, Error> {
        let dir = Box::new(crate::dir::Dir::from_cap_std(dir));
        self.0.push_preopened_dir(dir, guest_path)?;
        Ok(self)
    }
    pub fn preopened_socket(self, fd: u32, socket: impl Into<Socket>) -> Result<Self, Error> {
        let socket: Socket = socket.into();
        let file: Box<dyn WasiFile> = socket.into();

        let caps = FileCaps::FDSTAT_SET_FLAGS
            | FileCaps::FILESTAT_GET
            | FileCaps::READ
            | FileCaps::POLL_READWRITE;

        self.0.insert_file(fd, file, caps);
        Ok(self)
    }

    pub fn build(self) -> WasiCtx {
        self.0
    }
}

// Much of this crate is implemented in terms of `async` methods from the
// wasi-cap-std-sync crate. These methods may be async in signature, however,
// they are synchronous in implementation (always Poll::Ready on first poll)
// and perform blocking syscalls.
//
// This function takes this blocking code and executes it using a dummy executor
// to assert its immediate readiness. We tell tokio this is a blocking operation
// with the block_in_place function.
pub(crate) fn block_on_dummy_executor<'a, F, Fut, T>(f: F) -> Result<T, Error>
where
    F: FnOnce() -> Fut + Send + 'a,
    Fut: Future<Output = Result<T, Error>>,
    T: Send + 'static,
{
    tokio::task::block_in_place(move || {
        wiggle::run_in_dummy_executor(f()).expect("wrapped operation should be synchronous")
    })
}