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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148

//! This defines `remove_dir`, the primary entrypoint to sandboxed file
//! removal.

use crate::fs::remove_dir_impl;
#[cfg(racy_asserts)]
use crate::fs::{
    manually, map_result, remove_dir_unchecked, stat_unchecked, FollowSymlinks, Metadata,
};
use std::path::Path;
use std::{fs, io};

/// Perform a `rmdirat`-like operation, ensuring that the resolution of the
/// path never escapes the directory tree rooted at `start`.
#[cfg_attr(not(racy_asserts), allow(clippy::let_and_return))]
#[inline]
pub fn remove_dir(start: &fs::File, path: &Path) -> io::Result<()> {
    #[cfg(racy_asserts)]
    let stat_before = stat_unchecked(start, path, FollowSymlinks::No);

    // Call the underlying implementation.
    let result = remove_dir_impl(start, path);

    #[cfg(racy_asserts)]
    let stat_after = stat_unchecked(start, path, FollowSymlinks::No);

    #[cfg(racy_asserts)]
    check_remove_dir(start, path, &stat_before, &result, &stat_after);

    result
}

#[cfg(racy_asserts)]
#[allow(clippy::enum_glob_use)]
fn check_remove_dir(
    start: &fs::File,
    path: &Path,
    stat_before: &io::Result<Metadata>,
    result: &io::Result<()>,
    stat_after: &io::Result<Metadata>,
) {
    use io::ErrorKind::*;

    match (
        map_result(stat_before),
        map_result(result),
        map_result(stat_after),
    ) {
        (Ok(metadata), Ok(()), Err((NotFound, _))) => {
            // TODO: Check that the path was inside the sandbox.
            assert!(metadata.is_dir());
        }

        (Err((Other, _)), Ok(()), Err((NotFound, _))) => {
            // TODO: Check that the path was inside the sandbox.
        }

        (_, Err((InvalidInput, _)), _) => {
            // `remove_dir(".")` apparently returns `EINVAL`
        }

        (_, Err((kind, message)), _) => {
            match map_result(&manually::canonicalize_with(
                start,
                path,
                FollowSymlinks::No,
            )) {
                Ok(canon) => match map_result(&remove_dir_unchecked(start, &canon)) {
                    Err((_unchecked_kind, _unchecked_message)) => {
                        /* TODO: Check error messages.
                        assert_eq!(
                            kind,
                            unchecked_kind,
                            "unexpected error kind from remove_dir start='{:?}', \
                             path='{}':\nstat_before={:#?}\nresult={:#?}\nstat_after={:#?}",
                            start,
                            path.display(),
                            stat_before,
                            result,
                            stat_after
                        );
                        assert_eq!(message, unchecked_message);
                        */
                    }
                    _ => {
                        // TODO: Checking in the case it does end with ".".
                        if !path.to_string_lossy().ends_with(".") {
                            panic!(
                                "unsandboxed remove_dir success on start={:?} path={:?}; expected \
                                 {:?}: {}",
                                start, path, kind, message
                            );
                        }
                    }
                },
                Err((_canon_kind, _canon_message)) => {
                    /* TODO: Check error messages.
                    assert_eq!(kind, canon_kind, "'{}' vs '{}'", message, canon_message);
                    assert_eq!(message, canon_message);
                    */
                }
            }
        }

        other => panic!(
            "inconsistent remove_dir checks: start='{:?}' path='{}':\n{:#?}",
            start,
            path.display(),
            other,
        ),
    }

    match stat_after {
        Ok(unchecked_metadata) => match &result {
            Ok(()) => panic!(
                "file still exists after remove_dir start='{:?}', path='{}'",
                start,
                path.display()
            ),
            Err(e) => match e.kind() {
                #[cfg(io_error_more)]
                io::ErrorKind::NotADirectory => assert!(!unchecked_metadata.is_dir()),
                #[cfg(io_error_more)]
                io::ErrorKind::DirectoryNotEmpty => (),
                io::ErrorKind::PermissionDenied
                | io::ErrorKind::InvalidInput // `remove_dir(".")` apparently returns `EINVAL`
                | io::ErrorKind::Other => (),        // directory not empty, among other things
                _ => panic!(
                    "unexpected error remove_dir'ing start='{:?}', path='{}': {:?}",
                    start,
                    path.display(),
                    e
                ),
            },
        },
        Err(_unchecked_error) => match &result {
            Ok(()) => (),
            Err(result_error) => match result_error.kind() {
                io::ErrorKind::PermissionDenied => (),
                _ => {
                    /* TODO: Check error messages.
                    assert_eq!(result_error.to_string(), unchecked_error.to_string());
                    assert_eq!(result_error.kind(), unchecked_error.kind());
                    */
                }
            },
        },
    }
}