pxar, acl: cleanup acl helper usage

use NixPath for Acl::set_file to avoid memduping the c
string

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

src/pxar/metadata.rs

@@ -10,12 +10,12 @@ use nix::sys::stat::Mode;
 
 use pxar::Metadata;
 
+use proxmox::c_result;
 use proxmox::sys::error::SysError;
 use proxmox::tools::fd::RawFdNum;
-use proxmox::{c_result, c_try};
 
-use crate::pxar::Flags;
 use crate::pxar::tools::perms_from_metadata;
+use crate::pxar::Flags;
 use crate::tools::{acl, fs, xattr};
 
 //
@@ -97,7 +97,6 @@ pub fn apply_with_path<T: AsRef<Path>>(
 
 pub fn apply(flags: Flags, metadata: &Metadata, fd: RawFd, file_name: &CStr) -> Result<(), Error> {
     let c_proc_path = CString::new(format!("/proc/self/fd/{}", fd)).unwrap();
-    let c_proc_path = c_proc_path.as_ptr();
 
     if metadata.stat.flags != 0 {
         todo!("apply flags!");
@@ -106,7 +105,7 @@ pub fn apply(flags: Flags, metadata: &Metadata, fd: RawFd, file_name: &CStr) ->
     unsafe {
         // UID and GID first, as this fails if we lose access anyway.
         c_result!(libc::chown(
-            c_proc_path,
+            c_proc_path.as_ptr(),
             metadata.stat.uid,
             metadata.stat.gid
         ))
@@ -115,23 +114,25 @@ pub fn apply(flags: Flags, metadata: &Metadata, fd: RawFd, file_name: &CStr) ->
     }
 
     let mut skip_xattrs = false;
-    apply_xattrs(flags, c_proc_path, metadata, &mut skip_xattrs)?;
+    apply_xattrs(flags, c_proc_path.as_ptr(), metadata, &mut skip_xattrs)?;
-    add_fcaps(flags, c_proc_path, metadata, &mut skip_xattrs)?;
+    add_fcaps(flags, c_proc_path.as_ptr(), metadata, &mut skip_xattrs)?;
-    apply_acls(flags, c_proc_path, metadata)?;
+    apply_acls(flags, &c_proc_path, metadata)?;
     apply_quota_project_id(flags, fd, metadata)?;
 
     // Finally mode and time. We may lose access with mode, but the changing the mode also
     // affects times.
     if !metadata.is_symlink() {
-        c_result!(unsafe { libc::chmod(c_proc_path, perms_from_metadata(metadata)?.bits()) })
+        c_result!(unsafe {
-            .map(drop)
+            libc::chmod(c_proc_path.as_ptr(), perms_from_metadata(metadata)?.bits())
-            .or_else(allow_notsupp)?;
+        })
+        .map(drop)
+        .or_else(allow_notsupp)?;
     }
 
     let res = c_result!(unsafe {
         libc::utimensat(
             libc::AT_FDCWD,
-            c_proc_path,
+            c_proc_path.as_ptr(),
             nsec_to_update_timespec(metadata.stat.mtime).as_ptr(),
             0,
         )
@@ -216,11 +217,7 @@ fn apply_xattrs(
     Ok(())
 }
 
-fn apply_acls(
+fn apply_acls(flags: Flags, c_proc_path: &CStr, metadata: &Metadata) -> Result<(), Error> {
-    flags: Flags,
-    c_proc_path: *const libc::c_char,
-    metadata: &Metadata,
-) -> Result<(), Error> {
     if !flags.contains(Flags::WITH_ACL) || metadata.acl.is_empty() {
         return Ok(());
     }
@@ -270,7 +267,7 @@ fn apply_acls(
         bail!("Error while restoring ACL - ACL invalid");
     }
 
-    c_try!(unsafe { acl::acl_set_file(c_proc_path, acl::ACL_TYPE_ACCESS, acl.ptr,) });
+    acl.set_file(c_proc_path, acl::ACL_TYPE_ACCESS)?;
     drop(acl);
 
     // acl type default:
@@ -299,7 +296,7 @@ fn apply_acls(
             bail!("Error while restoring ACL - ACL invalid");
         }
 
-        c_try!(unsafe { acl::acl_set_file(c_proc_path, acl::ACL_TYPE_DEFAULT, acl.ptr,) });
+        acl.set_file(c_proc_path, acl::ACL_TYPE_DEFAULT)?;
     }
 
     Ok(())

src/tools/acl.rs

@@ -12,6 +12,7 @@ use std::ptr;
 
 use libc::{c_char, c_int, c_uint, c_void};
 use nix::errno::Errno;
+use nix::NixPath;
 
 // from: acl/include/acl.h
 pub const ACL_UNDEFINED_ID: u32 = 0xffffffff;
@@ -49,8 +50,7 @@ pub const ACL_EA_VERSION: u32 = 0x0002;
 #[link(name = "acl")]
 extern "C" {
     fn acl_get_file(path: *const c_char, acl_type: ACLType) -> *mut c_void;
-    // FIXME: remove 'pub' after the cleanup
+    fn acl_set_file(path: *const c_char, acl_type: ACLType, acl: *mut c_void) -> c_int;
-    pub(crate) fn acl_set_file(path: *const c_char, acl_type: ACLType, acl: *mut c_void) -> c_int;
     fn acl_get_fd(fd: RawFd) -> *mut c_void;
     fn acl_get_entry(acl: *const c_void, entry_id: c_int, entry: *mut *mut c_void) -> c_int;
     fn acl_create_entry(acl: *mut *mut c_void, entry: *mut *mut c_void) -> c_int;
@@ -69,8 +69,7 @@ extern "C" {
 
 #[derive(Debug)]
 pub struct ACL {
-    // FIXME: remove 'pub' after the cleanup
+    ptr: *mut c_void,
-    pub(crate) ptr: *mut c_void,
 }
 
 impl Drop for ACL {
@@ -102,14 +101,11 @@ impl ACL {
         Ok(ACL { ptr })
     }
 
-    pub fn set_file<P: AsRef<Path>>(&self, path: P, acl_type: ACLType) -> Result<(), nix::errno::Errno> {
+    pub fn set_file<P: NixPath + ?Sized>(&self, path: &P, acl_type: ACLType) -> nix::Result<()> {
-        let path_cstr = CString::new(path.as_ref().as_os_str().as_bytes()).unwrap();
+        path.with_nix_path(|path| {
-        let res = unsafe { acl_set_file(path_cstr.as_ptr(), acl_type, self.ptr) };
+            Errno::result(unsafe { acl_set_file(path.as_ptr(), acl_type, self.ptr) })
-        if res < 0 {
+        })?
-            return Err(Errno::last());
+        .map(drop)
-        }
- 
-        Ok(())
     }
 
     pub fn get_fd(fd: RawFd) -> Result<ACL, nix::errno::Errno> {