Let targz type conversions support bgzip format

code reference https://github.com/madler/zlib/blob/master/examples/zran.c

at present, zran and normal targz do not consider the support for
bgzip when decompressing, so there will be problems when encountering
this kind of image, and this PR is used to support the bgzip format.

bgzip: http://www.htslib.org/doc/bgzip.html

Signed-off-by: zyfjeff <[email protected]>

misc/top_images/image_list.txt

@@ -43,4 +43,5 @@ kong
 solr
 sentry
 zookeeper
-ghcr.io/dragonflyoss/image-service/pax-uid-test
+ghcr.io/dragonflyoss/image-service/pax-uid-test
+cgr.dev/chainguard/busybox

utils/src/compress/mod.rs

@@ -142,7 +142,7 @@ pub fn decompress(src: &[u8], dst: &mut [u8], algorithm: Algorithm) -> Result<us
 /// Stream decoder for gzip/lz4/zstd.
 pub enum Decoder<'a, R: Read> {
     None(R),
-    Gzip(flate2::bufread::GzDecoder<BufReader<R>>),
+    Gzip(flate2::bufread::MultiGzDecoder<BufReader<R>>),
     Zstd(zstd::stream::Decoder<'a, BufReader<R>>),
 }
 
@@ -152,7 +152,7 @@ impl<'a, R: Read> Decoder<'a, R> {
         let decoder = match algorithm {
             Algorithm::None => Decoder::None(reader),
             Algorithm::GZip => {
-                Decoder::Gzip(flate2::bufread::GzDecoder::new(BufReader::new(reader)))
+                Decoder::Gzip(flate2::bufread::MultiGzDecoder::new(BufReader::new(reader)))
             }
             Algorithm::Lz4Block => panic!("Decoder doesn't support lz4_block"),
             Algorithm::Zstd => Decoder::Zstd(zstd::stream::Decoder::new(reader)?),
@@ -173,14 +173,14 @@ impl<'a, R: Read> Read for Decoder<'a, R> {
 
 /// Stream decoder for zlib/gzip.
 pub struct ZlibDecoder<R> {
-    stream: flate2::bufread::GzDecoder<BufReader<R>>,
+    stream: flate2::bufread::MultiGzDecoder<BufReader<R>>,
 }
 
 impl<R: Read> ZlibDecoder<R> {
     /// Create a new instance of `ZlibDecoder`.
     pub fn new(reader: R) -> Self {
         ZlibDecoder {
-            stream: flate2::bufread::GzDecoder::new(BufReader::new(reader)),
+            stream: flate2::bufread::MultiGzDecoder::new(BufReader::new(reader)),
         }
     }
 }

utils/src/compress/zlib_random.rs

@@ -14,7 +14,7 @@ use std::{mem, ptr};
 
 use libz_sys::{
     inflate, inflateEnd, inflateInit2_, inflatePrime, inflateReset, inflateSetDictionary, uInt,
-    z_stream, zlibVersion, Z_BLOCK, Z_BUF_ERROR, Z_OK, Z_STREAM_END,
+    z_stream, zlibVersion, Z_BLOCK, Z_BUF_ERROR, Z_OK, Z_STREAM_END, inflateReset2,
 };
 use sha2::{Digest, Sha256};
 
@@ -118,19 +118,57 @@ impl ZranDecoder {
         self.stream.set_dict(dict)?;
 
         self.stream.set_next_in(input);
-        self.stream.set_next_out(output);
-        self.stream.set_avail_out(ctx.out_len as uInt);
-        let ret = self.stream.inflate(true);
-        match ret {
-            Z_OK => {
-                let count = self.stream.next_out() as usize - output.as_ptr() as usize;
-                if count != ctx.out_len as usize {
-                    Err(eio!("failed to decode data from stream, size mismatch"))
-                } else {
-                    Ok(count)
+
+        let mut left = ctx.out_len;
+        loop {
+            let used = (ctx.out_len - left) as usize;
+            self.stream.set_next_out(&mut output[used..]);
+            self.stream.set_avail_out(left as uInt);
+            let mut got = self.stream.avail_out();
+            let mut ret = self.stream.raw_inflate(0);
+            got -= self.stream.avail_out();
+            left -= got;
+
+            match ret {
+                Z_OK => {
+                    let count = self.stream.next_out() as usize - output.as_ptr() as usize;
+                    if count != ctx.out_len as usize {
+                        return Err(eio!("failed to decode data from stream, size mismatch"))
+                    } else {
+                        return Ok(count)
+                    }
+                }
+                Z_STREAM_END => {
+                    // Discard the gzip trailer.
+                    let drop = 8;
+                    if self.stream.avail_in() >= drop {
+                        let avail_in = self.stream.avail_in();
+                        let used = input.len() - avail_in as usize + drop as usize;
+                        self.stream.set_next_in(&input[used..]);
+                    } else {
+                        // The input does not have a complete trailer.
+                        return Err(eio!("the input does not have a complete gzip trailer"));
+                    }
+                    // Use inflate to skip the gzip header and resume the raw inflate there.
+                    self.stream.reset2(true)?;
+                    let mut discard = vec![0u8; ZRAN_DICT_WIN_SIZE as usize];
+                    loop {
+                        self.stream.set_next_out(&mut discard);
+                        self.stream.set_avail_out(ZRAN_DICT_WIN_SIZE as u32);
+                        ret = self.stream.raw_inflate(Z_BLOCK);  // stop at end of header
+                        if ret == Z_OK && (self.stream.data_type() & 0x80) ==0 {
+                            continue
+                        }
+
+                        if ret != Z_OK {
+                            return Err(eio!(format!("failed to handle gzip multi member, ret: {:?}", ret)))
+                        }
+                        self.stream.reset2(false)?;
+                        break;
+                    }
                 }
+                e => return Err(eio!(format!("failed to decode data from compressed data stream, ret: {}", e))),
             }
-            _ => Err(eio!("failed to decode data from compressed data stream")),
         }
     }
 }
@@ -531,12 +569,16 @@ impl ZranStream {
         let mode = if decode { 0 } else { Z_BLOCK };
         self.total_in += self.stream.avail_in as u64;
         self.total_out += self.stream.avail_out as u64;
-        let ret = unsafe { inflate(self.stream.deref_mut() as *mut z_stream, mode) };
+        let ret = self.raw_inflate(mode);
         self.total_in -= self.stream.avail_in as u64;
         self.total_out -= self.stream.avail_out as u64;
         ret
     }
 
+    fn raw_inflate(&mut self, mode: i32) -> i32 {
+        unsafe { inflate(self.stream.deref_mut() as *mut z_stream, mode) }
+    }
+
     fn reset(&mut self) -> Result<()> {
         let ret = unsafe { inflateReset(self.stream.deref_mut() as *mut z_stream) };
         if ret != Z_OK {
@@ -545,6 +587,15 @@ impl ZranStream {
         Ok(())
     }
 
+    fn reset2(&mut self, is_gzip: bool) -> Result<()> {
+        let winodw_bits = if is_gzip { 31 } else { -15 };
+        let ret = unsafe { inflateReset2(self.stream.deref_mut() as *mut z_stream, winodw_bits) };
+        if ret != Z_OK {
+            return Err(einval!("failed to reset zlib inflate context"));
+        }
+        Ok(())
+    }
+
     fn get_compression_info(&mut self, buf: &[u8], stream_switched: u8) -> ZranCompInfo {
         let previous_byte = if self.stream.data_type & 0x7 != 0 {
             assert!(self.stream.next_in as usize >= buf.as_ptr() as usize);
@@ -618,6 +669,14 @@ impl ZranStream {
         self.stream.avail_in
     }
 
+    fn avail_out(&self) -> u32 {
+        self.stream.avail_out
+    }
+
+    fn data_type(&self) -> i32 {
+        self.stream.data_type
+    }
+
     fn set_avail_in(&mut self, avail_in: u32) {
         self.stream.avail_in = avail_in;
     }
@@ -844,6 +903,48 @@ mod tests {
         assert_eq!(ctx.len(), 3);
     }
 
+    #[test]
+    fn test_zran_bgzip() {
+        let root_dir = &std::env::var("CARGO_MANIFEST_DIR").expect("$CARGO_MANIFEST_DIR");
+        let path = PathBuf::from(root_dir).join("../tests/texture/zran/bgzip.tar.gz");
+        let file = OpenOptions::new().read(true).open(&path).unwrap();
+        let reader = ZranReader::new(file).unwrap();
+        let mut tar = Archive::new(reader.clone());
+        tar.set_ignore_zeros(true);
+        let mut generator = ZranGenerator::new(reader);
+        generator.set_min_compressed_size(1024);
+        generator.set_max_compressed_size(2048);
+        generator.set_max_uncompressed_size(4096);
+
+        let entries = tar.entries().unwrap();
+        for entry in entries {
+            let mut entry = entry.unwrap();
+            if entry.header().entry_type() == EntryType::Regular {
+                loop {
+                    let _start = generator.begin_read(512).unwrap();
+                    let mut buf = vec![0u8; 512];
+                    let sz = entry.read(&mut buf).unwrap();
+                    let _info = generator.end_read().unwrap();
+                    if sz == 0 {
+                        break;
+                    }
+                }
+            }
+        }
+
+        let ctx_array = generator.get_compression_ctx_array();
+        for ctx in ctx_array.iter() {
+            let mut c_buf = vec![0u8; ctx.in_len as usize];
+            let mut file = OpenOptions::new().read(true).open(&path).unwrap();
+            file.seek(SeekFrom::Start(ctx.in_offset)).unwrap();
+            file.read_exact(&mut c_buf).unwrap();
+
+            let mut d_buf = vec![0u8; ctx.out_len as usize];
+            let mut decoder = ZranDecoder::new().unwrap();
+            decoder.uncompress(ctx, None, &c_buf, &mut d_buf).unwrap();
+        }
+    }
+
     #[test]
     fn test_zran_decoder() {
         let root_dir = &std::env::var("CARGO_MANIFEST_DIR").expect("$CARGO_MANIFEST_DIR");