cap_primitives/fs/
create_dir.rs

1//! This defines `create_dir`, the primary entrypoint to sandboxed directory
2//! creation.
3
4#[cfg(racy_asserts)]
5use crate::fs::{
6    canonicalize, create_dir_unchecked, map_result, stat_unchecked, FollowSymlinks, Metadata,
7};
8use crate::fs::{create_dir_impl, DirOptions};
9use std::path::Path;
10use std::{fs, io};
11
12/// Perform a `mkdirat`-like operation, ensuring that the resolution of the
13/// path never escapes the directory tree rooted at `start`.
14#[cfg_attr(not(racy_asserts), allow(clippy::let_and_return))]
15#[inline]
16pub fn create_dir(start: &fs::File, path: &Path, options: &DirOptions) -> io::Result<()> {
17    #[cfg(racy_asserts)]
18    let stat_before = stat_unchecked(start, path, FollowSymlinks::No);
19
20    // Call the underlying implementation.
21    let result = create_dir_impl(start, path, options);
22
23    #[cfg(racy_asserts)]
24    let stat_after = stat_unchecked(start, path, FollowSymlinks::No);
25
26    #[cfg(racy_asserts)]
27    check_create_dir(start, path, options, &stat_before, &result, &stat_after);
28
29    result
30}
31
32#[cfg(racy_asserts)]
33#[allow(clippy::enum_glob_use)]
34fn check_create_dir(
35    start: &fs::File,
36    path: &Path,
37    options: &DirOptions,
38    stat_before: &io::Result<Metadata>,
39    result: &io::Result<()>,
40    stat_after: &io::Result<Metadata>,
41) {
42    use io::ErrorKind::*;
43
44    match (
45        map_result(stat_before),
46        map_result(result),
47        map_result(stat_after),
48    ) {
49        (Err((NotFound, _)), Ok(()), Ok(metadata)) => {
50            assert!(metadata.is_dir());
51            assert_same_file_metadata!(
52                &stat_unchecked(
53                    start,
54                    &canonicalize(start, path).unwrap(),
55                    FollowSymlinks::No
56                )
57                .unwrap(),
58                &metadata
59            );
60        }
61
62        (Ok(metadata_before), Err((AlreadyExists, _)), Ok(metadata_after)) => {
63            assert_same_file_metadata!(&metadata_before, &metadata_after);
64        }
65
66        (_, Err((kind, message)), _) => {
67            // TODO: Checking in the case it does end with ".".
68            if !path.to_string_lossy().ends_with(".") {
69                match map_result(&canonicalize(start, path)) {
70                    Ok(canon) => match map_result(&create_dir_unchecked(start, &canon, options)) {
71                        Err((unchecked_kind, unchecked_message)) => {
72                            assert_eq!(
73                                kind,
74                                unchecked_kind,
75                                "unexpected error kind from create_dir start='{:?}', \
76                                 path='{}':\nstat_before={:#?}\nresult={:#?}\nstat_after={:#?}",
77                                start,
78                                path.display(),
79                                stat_before,
80                                result,
81                                stat_after
82                            );
83                            assert_eq!(message, unchecked_message);
84                        }
85                        _ => panic!("unsandboxed create_dir success"),
86                    },
87                    Err((_canon_kind, _canon_message)) => {
88                        /* TODO: Check error messages
89                        assert_eq!(kind, canon_kind);
90                        assert_eq!(message, canon_message);
91                        */
92                    }
93                }
94            }
95        }
96
97        other => panic!(
98            "inconsistent create_dir checks: start='{:?}' path='{}':\n{:#?}",
99            start,
100            path.display(),
101            other,
102        ),
103    }
104}