test code v1

decompressor_deflate.c

@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/* Minimal DEFLATE decompressor for EROFS FreeBSD */
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <contrib/zlib/zlib.h>
+
+#include "internal.h"
+
+int
+z_erofs_load_deflate_config(struct erofs_mount *em, const void *data,
+    size_t size)
+{
+	const struct z_erofs_deflate_cfgs *deflate;
+
+	if (size < sizeof(*deflate))
+		return (EINVAL);
+	deflate = data;
+	if (deflate->windowbits < 8 || deflate->windowbits > 15)
+		return (EOPNOTSUPP);
+	em->deflate_windowbits = deflate->windowbits;
+	return (0);
+}
+
+int
+deflate_decompress(void *src, size_t srclen, void *dst, size_t dstlen, int n,
+    bool partial)
+{
+	z_stream strm;
+	uInt in_before, out_before;
+	int endret, ret;
+
+	if (n < 8 || n > MAX_WBITS || srclen > (size_t)(uInt)-1 ||
+	    dstlen > (size_t)(uInt)-1 || dstlen == 0)
+		return (-1);
+
+	bzero(&strm, sizeof(strm));
+	strm.next_in = src;
+	strm.avail_in = srclen;
+	strm.next_out = dst;
+	strm.avail_out = dstlen;
+
+	ret = inflateInit2(&strm, -n);
+	if (ret != Z_OK)
+		return (-1);
+
+	ret = Z_OK;
+	while (strm.avail_out != 0) {
+		in_before = strm.avail_in;
+		out_before = strm.avail_out;
+		ret = inflate(&strm, Z_SYNC_FLUSH);
+		if (ret == Z_STREAM_END)
+			break;
+		if (ret != Z_OK ||
+		    (strm.avail_in == in_before && strm.avail_out == out_before))
+			break;
+	}
+	endret = inflateEnd(&strm);
+	if (endret != Z_OK || strm.avail_out != 0)
+		return (-1);
+	if (partial)
+		return (ret == Z_OK || ret == Z_STREAM_END ? 0 : -1);
+	if (ret != Z_STREAM_END || strm.avail_in != 0)
+		return (-1);
+
+	return (0);
+}