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

use super::*;
use crate::syscalls::*;

/// ### `fd_dup()`
/// Duplicates the file handle
/// Inputs:
/// - `Fd fd`
///   File handle to be cloned
/// Outputs:
/// - `Fd fd`
///   The new file handle that is a duplicate of the original
#[instrument(level = "trace", skip_all, fields(%fd, ret_fd = field::Empty), ret)]
pub fn fd_dup<M: MemorySize>(
    mut ctx: FunctionEnvMut<'_, WasiEnv>,
    fd: WasiFd,
    ret_fd: WasmPtr<WasiFd, M>,
) -> Result<Errno, WasiError> {
    let copied_fd = wasi_try_ok!(fd_dup_internal(&mut ctx, fd));
    let env = ctx.data();

    #[cfg(feature = "journal")]
    if env.enable_journal {
        JournalEffector::save_fd_duplicate(&mut ctx, fd, copied_fd).map_err(|err| {
            tracing::error!("failed to save file descriptor duplicate event - {}", err);
            WasiError::Exit(ExitCode::from(Errno::Fault))
        })?;
    }

    Span::current().record("ret_fd", copied_fd);
    let env = ctx.data();
    let (memory, state) = unsafe { env.get_memory_and_wasi_state(&ctx, 0) };
    wasi_try_mem_ok!(ret_fd.write(&memory, copied_fd));

    Ok(Errno::Success)
}

pub(crate) fn fd_dup_internal(
    ctx: &mut FunctionEnvMut<'_, WasiEnv>,
    fd: WasiFd,
) -> Result<WasiFd, Errno> {
    let env = ctx.data();
    let (memory, state) = unsafe { env.get_memory_and_wasi_state(&ctx, 0) };
    let fd = state.fs.clone_fd(fd)?;
    Ok(fd)
}