[pve-devel] [RFC proxmox 2/7] sys: add make_tmp_dir
Lukas Wagner
l.wagner at proxmox.com
Mon Aug 21 15:44:39 CEST 2023
Under the hood, this function calls `mkdtemp` from libc. Unfortunatly
the nix crate did not provide bindings for this function, so we have
to call into libc directly.
Signed-off-by: Lukas Wagner <l.wagner at proxmox.com>
---
proxmox-sys/src/fs/dir.rs | 73 +++++++++++++++++++++++++++++++++++++--
1 file changed, 71 insertions(+), 2 deletions(-)
diff --git a/proxmox-sys/src/fs/dir.rs b/proxmox-sys/src/fs/dir.rs
index 6aee316..72bf1ad 100644
--- a/proxmox-sys/src/fs/dir.rs
+++ b/proxmox-sys/src/fs/dir.rs
@@ -1,6 +1,8 @@
-use std::ffi::CStr;
+use std::ffi::{CStr, CString, OsStr};
+use std::fs::File;
+use std::os::unix::ffi::OsStrExt;
use std::os::unix::io::{AsRawFd, OwnedFd};
-use std::path::Path;
+use std::path::{Path, PathBuf};
use anyhow::{bail, Error};
use nix::errno::Errno;
@@ -8,6 +10,8 @@ use nix::fcntl::OFlag;
use nix::sys::stat;
use nix::unistd;
+use proxmox_lang::try_block;
+
use crate::fs::{fchown, CreateOptions};
/// Creates directory at the provided path with specified ownership.
@@ -152,6 +156,54 @@ fn create_path_at_do(
}
}
+/// Create a temporary directory.
+///
+/// `prefix` determines where the temporary directory will be created. For instance, if
+/// `prefix` is `/tmp`, on success the function will return a path in the style of
+/// `/tmp/tmp_XXXXXX`, where X stands for a random string, ensuring that the path is unique.
+///
+/// By default, the created directory has `0o700` permissions. If this is not desired, custom
+/// [`CreateOptions`] can be passed via the `option` parameter.
+pub fn make_tmp_dir<P: AsRef<Path>>(
+ prefix: P,
+ options: Option<CreateOptions>,
+) -> Result<PathBuf, Error> {
+ let mut template = prefix.as_ref().to_owned();
+ template = template.join("tmp_XXXXXX");
+ let template = CString::new(template.into_os_string().as_bytes())?;
+
+ let raw_template_buffer = template.into_raw();
+
+ let path = unsafe {
+ let raw_returned_buffer = libc::mkdtemp(raw_template_buffer);
+ if raw_returned_buffer.is_null() {
+ // The returned pointer points to the same buffer, so in case
+ // of an error we need to make sure to claim it back to that
+ // it is freed properly.
+ drop(CString::from_raw(raw_template_buffer));
+ return Err(std::io::Error::last_os_error().into());
+ }
+ CString::from_raw(raw_returned_buffer)
+ };
+
+ let path = OsStr::from_bytes(path.as_bytes());
+ let path = PathBuf::from(path);
+
+ if let Some(options) = options {
+ if let Err(err) = try_block!({
+ let fd = crate::fd::open(&path, OFlag::O_DIRECTORY, stat::Mode::empty())?;
+ let mut file = File::from(fd);
+ options.apply_to(&mut file, &path)?;
+ Ok::<(), Error>(())
+ }) {
+ let _ = unistd::unlink(&path);
+ bail!("could not apply create options to new temporary directory: {err}");
+ }
+ }
+
+ Ok(path)
+}
+
#[cfg(test)]
mod tests {
use super::*;
@@ -169,4 +221,21 @@ mod tests {
)
.expect("expected create_path to work");
}
+
+ #[test]
+ fn test_make_tmp_dir() -> Result<(), Error> {
+ let options = CreateOptions::new()
+ .owner(unistd::Uid::effective())
+ .group(unistd::Gid::effective())
+ .perm(stat::Mode::from_bits_truncate(0o755));
+
+ let path = make_tmp_dir("/tmp", Some(options))?;
+
+ assert!(path.exists());
+ assert!(path.is_dir());
+
+ std::fs::remove_dir_all(&path)?;
+
+ Ok(())
+ }
}
--
2.39.2
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