[pbs-devel] [PATCH v3 proxmox 2/3] compression: Add support for symlinks in zip files
Wolfgang Bumiller
w.bumiller at proxmox.com
Wed Dec 20 14:20:10 CET 2023
With the link of a symlink being encoded in the contents, I wonder if we
should just do the same in the code. Not normally what I'd go for in
rust, but...
On Thu, Dec 14, 2023 at 03:48:21PM +0100, Filip Schauer wrote:
> Add support for symlinks to ZipEntry. A symlink is encoded by or-ing its
> attributes with S_IFLNK as seen in the kernel in
> include/uapi/linux/stat.h
>
> Signed-off-by: Filip Schauer <f.schauer at proxmox.com>
> ---
> proxmox-compression/src/zip.rs | 32 +++++++++++++++++++++++++-------
> 1 file changed, 25 insertions(+), 7 deletions(-)
>
> diff --git a/proxmox-compression/src/zip.rs b/proxmox-compression/src/zip.rs
> index 069e8bc..a3b2346 100644
> --- a/proxmox-compression/src/zip.rs
> +++ b/proxmox-compression/src/zip.rs
> @@ -74,6 +74,7 @@ fn epoch_to_dos(epoch: i64) -> (u16, u16) {
> pub enum FileType {
> Directory,
> Regular,
> + Symlink(OsString),
... then this enum could be #[repr(u32)] using the values from the hunk
below as discriminants here directly.
And without the OsString in there this could be all of `Clone + Copy +
Eq + PartialEq`, turning all the `matches!()` in this series into
comparisons with `==`.
> }
>
> #[derive(Endian)]
> @@ -350,6 +351,7 @@ impl ZipEntry {
(maybe include a comment that these are the same as the S_IF* constants,
since Dominik had asked about more documentation in the previous
version ;-) )
> let file_type_attr = match self.file_type {
> FileType::Regular => 0o100000,
> FileType::Directory => 0o040000,
> + FileType::Symlink(_) => 0o120000,
> };
>
> write_struct(
> @@ -497,22 +499,28 @@ impl<W: AsyncWrite + Unpin> ZipEncoder<W> {
> .ok_or_else(|| format_err!("had no target during add entry"))?;
> entry.offset = self.byte_count.try_into()?;
> self.byte_count += entry.write_local_header(&mut target).await?;
> - if let Some(content) = content {
> - let mut reader = HashWrapper::new(content);
> +
> + if content.is_some() || matches!(entry.file_type, FileType::Symlink(_)) {
> let mut enc = DeflateEncoder::with_quality(target, Level::Fastest);
>
> - enc.compress(&mut reader).await?;
> + if let Some(content) = content {
> + let mut reader = HashWrapper::new(content);
> + enc.compress(&mut reader).await?;
> + entry.crc32 = reader.finish().0;
> + } else if let FileType::Symlink(symlink_target) = &entry.file_type {
> + let cursor = std::io::Cursor::new(symlink_target.as_bytes());
> + let mut reader = HashWrapper::new(cursor);
> + enc.compress(&mut reader).await?;
> + entry.crc32 = reader.finish().0;
^ and AFAICT this entire hunk would simply disappear?
> + }
> +
> let total_in = enc.total_in();
> let total_out = enc.total_out();
> target = enc.into_inner();
>
> - let (crc32, _reader) = reader.finish();
> -
> self.byte_count += total_out as usize;
> entry.compressed_size = total_out;
> entry.uncompressed_size = total_in;
> -
> - entry.crc32 = crc32;
> }
>
> self.byte_count += entry.write_data_descriptor(&mut target).await?;
> @@ -676,6 +684,16 @@ where
> let ze = ZipEntry::new(entry_path_no_base, mtime, mode, FileType::Directory);
> let content: Option<tokio::fs::File> = None;
> Ok(Some((ze, content)))
> + } else if entry.file_type().is_symlink() {
> + let target = std::fs::read_link(entry.path())?;
> + let ze = ZipEntry::new(
> + entry_path_no_base,
> + mtime,
> + mode,
> + FileType::Symlink(target.into()),
> + );
> + let content: Option<tokio::fs::File> = None;
> + Ok(Some((ze, content)))
> } else {
> // ignore other file types
> Ok::<_, Error>(None)
> --
> 2.39.2
More information about the pbs-devel
mailing list