Function wasi_path_readlink

src/wrappers.rs:632–659

(
    ctx: &mut VmCtx,
    v_fd: u32,
    pathname: u32,
    path_len: u32,
    ptr: u32,
    len: u32,
)

#[ensures(ctx_safe(ctx))]
#[ensures(trace_safe(trace, ctx))]
pub fn wasi_path_readlink(
    ctx: &mut VmCtx,
    v_fd: u32,
    pathname: u32,
    path_len: u32,
    ptr: u32,
    len: u32,
) -> RuntimeResult<u32> {
    // let fd = ctx.fdmap.fd_to_native(v_fd)?;
    if v_fd != HOMEDIR_FD {
        return Err(Enotcapable);
    }
    assert!(v_fd == HOMEDIR_FD);
    let fd = ctx.homedir_host_fd;

    let should_follow = false; // readlink never follows symlink (it reads it!)
                               // TODO: replace once we can support the ? again
    let host_pathname = ctx.translate_path(pathname, path_len, should_follow, fd);
    unwrap_result!(host_pathname);

    if !ctx.fits_in_lin_mem(ptr, len) {
        return Err(Efault);
    }

    let res = trace_readlinkat(ctx, fd, host_pathname, ptr, len as usize)?;
    let res = res as u32;
    Ok(res)
}

// https://github.com/WebAssembly/WASI/blob/main/phases/snapshot/docs.md#path_remove_directory
// modifies: none