dvm_api/
file.rs

1use std::fmt;
2
3use serde::{Deserialize, Serialize};
4
5/// A file's path in a sandbox, checked: absolute, or from its image's
6/// working directory. `PUT` and `GET /api/sandboxes/{id}/files?path=` name
7/// a file by it.
8#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
9#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
10#[cfg_attr(feature = "typescript", ts(export_to = "controller-api.ts"))]
11#[serde(try_from = "String", into = "String")]
12#[cfg_attr(feature = "typescript", ts(type = "string"))]
13pub struct SandboxPath(String);
14
15impl SandboxPath {
16    /// The longest a path may be, as Linux's `PATH_MAX` has it.
17    const MOST_BYTES: usize = 4096;
18
19    pub fn as_str(&self) -> &str {
20        &self.0
21    }
22}
23
24impl TryFrom<String> for SandboxPath {
25    type Error = String;
26
27    /// Not empty, no NUL, and no longer than `PATH_MAX`.
28    fn try_from(path: String) -> Result<Self, String> {
29        if path.is_empty() {
30            return Err("a file's path is empty".to_owned());
31        }
32        if path.contains('\0') {
33            return Err("a file's path can't hold a NUL character".to_owned());
34        }
35        if path.len() > Self::MOST_BYTES {
36            return Err(format!(
37                "a file's path is {} bytes, past {}",
38                path.len(),
39                Self::MOST_BYTES
40            ));
41        }
42        Ok(Self(path))
43    }
44}
45
46impl From<SandboxPath> for String {
47    fn from(path: SandboxPath) -> Self {
48        path.0
49    }
50}
51
52impl fmt::Display for SandboxPath {
53    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
54        f.write_str(&self.0)
55    }
56}
57
58/// A file's mode, as a file written into a sandbox is made with: its
59/// permission bits, at most `0o7777`; `0o644` unless given.
60#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
61#[cfg_attr(feature = "typescript", derive(ts_rs::TS))]
62#[cfg_attr(feature = "typescript", ts(export_to = "controller-api.ts"))]
63#[serde(try_from = "u32", into = "u32")]
64#[cfg_attr(feature = "typescript", ts(type = "number"))]
65pub struct FileMode(u32);
66
67impl FileMode {
68    const MOST: u32 = 0o7777;
69
70    pub fn bits(self) -> u32 {
71        self.0
72    }
73
74    /// The mode as `chmod` reads it: octal digits, `644` or `0755`.
75    pub fn from_octal(digits: &str) -> Result<Self, String> {
76        let bits = u32::from_str_radix(digits, 8)
77            .map_err(|_| format!("a mode is octal digits, as chmod takes them: {digits:?}"))?;
78        Self::try_from(bits)
79    }
80}
81
82impl Default for FileMode {
83    /// `rw-r--r--`.
84    fn default() -> Self {
85        Self(0o644)
86    }
87}
88
89impl TryFrom<u32> for FileMode {
90    type Error = String;
91
92    fn try_from(bits: u32) -> Result<Self, String> {
93        if bits > Self::MOST {
94            return Err(format!("a mode is at most 7777, not {bits:o}"));
95        }
96        Ok(Self(bits))
97    }
98}
99
100impl From<FileMode> for u32 {
101    fn from(mode: FileMode) -> Self {
102        mode.0
103    }
104}
105
106#[cfg(test)]
107mod tests {
108    use super::*;
109
110    #[test]
111    fn a_path_is_checked() {
112        assert_eq!(
113            SandboxPath::try_from("/repo/fix.diff".to_owned())
114                .unwrap()
115                .as_str(),
116            "/repo/fix.diff"
117        );
118        assert!(SandboxPath::try_from("out.txt".to_owned()).is_ok());
119        for wrong in [String::new(), "a\0b".to_owned(), "a".repeat(4097)] {
120            assert!(SandboxPath::try_from(wrong).is_err());
121        }
122        assert!(serde_json::from_str::<SandboxPath>(r#""""#).is_err());
123    }
124
125    #[test]
126    fn a_mode_is_octal_as_chmod_reads_it() {
127        assert_eq!(FileMode::from_octal("755").unwrap().bits(), 0o755);
128        assert_eq!(FileMode::from_octal("0600").unwrap().bits(), 0o600);
129        assert_eq!(FileMode::default().bits(), 0o644);
130        for wrong in ["", "9", "17777", "rw"] {
131            assert!(FileMode::from_octal(wrong).is_err(), "{wrong}");
132        }
133    }
134}
dvm_api/file.rs

dvm_api/
file.rs
