update

decompressor_lzma.c

@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * EROFS MicroLZMA wrapper around FreeBSD's bundled XZ Embedded decoder.
+ * The decoder source is compiled with private symbol names because the
+ * stock xz.ko does not enable its optional MicroLZMA entry points.
+ */
+
+#include <sys/param.h>
+#include <sys/malloc.h>
+#include <sys/systm.h>
+
+#include "internal.h"
+
+#define XZ_DEC_MICROLZMA
+#define xz_dec_lzma2_create erofs_xz_dec_lzma2_create
+#define xz_dec_lzma2_reset erofs_xz_dec_lzma2_reset
+#define xz_dec_lzma2_run erofs_xz_dec_lzma2_run
+#define xz_dec_lzma2_end erofs_xz_dec_lzma2_end
+#define xz_dec_microlzma_alloc erofs_xz_dec_microlzma_alloc
+#define xz_dec_microlzma_reset erofs_xz_dec_microlzma_reset
+#define xz_dec_microlzma_run erofs_xz_dec_microlzma_run
+#define xz_dec_microlzma_end erofs_xz_dec_microlzma_end
+#define xz_malloc erofs_xz_malloc
+#define xz_free erofs_xz_free
+
+static void *
+erofs_xz_malloc(unsigned long size)
+{
+	return (malloc(size, M_EROFS, M_WAITOK));
+}
+
+static void
+erofs_xz_free(void *ptr)
+{
+	free(ptr, M_EROFS);
+}
+
+#include <contrib/xz-embedded/linux/lib/xz/xz_dec_lzma2.c>
+
+#undef bool
+#undef false
+#undef true
+#undef min
+
+int
+z_erofs_load_lzma_config(struct erofs_mount *em, const void *data,
+    size_t size)
+{
+	const struct z_erofs_lzma_cfgs *lzma;
+	uint32_t dict_size;
+
+	if (size < sizeof(*lzma))
+		return (EINVAL);
+	lzma = data;
+	if (le16toh(lzma->format) != 0)
+		return (EOPNOTSUPP);
+	dict_size = le32toh(lzma->dict_size);
+	if (dict_size < 4096 || dict_size > Z_EROFS_LZMA_MAX_DICT_SIZE)
+		return (EOPNOTSUPP);
+	em->lzma_dict_size = dict_size;
+	return (0);
+}
+
+int
+lzma_decompress(const void *src, size_t srclen, void *dst, size_t dstlen,
+    uint32_t dict_size, bool partial)
+{
+	struct xz_dec_microlzma *state;
+	struct xz_buf buffer;
+	enum xz_ret ret;
+
+	if (srclen > UINT32_MAX || dstlen > UINT32_MAX)
+		return (-1);
+	state = xz_dec_microlzma_alloc(XZ_SINGLE, dict_size);
+	if (state == NULL)
+		return (-1);
+	bzero(&buffer, sizeof(buffer));
+	buffer.in = src;
+	buffer.in_size = srclen;
+	buffer.out = dst;
+	buffer.out_size = dstlen;
+	xz_dec_microlzma_reset(state, (uint32_t)srclen, (uint32_t)dstlen,
+	    !partial);
+	ret = xz_dec_microlzma_run(state, &buffer);
+	xz_dec_microlzma_end(state);
+	if (buffer.out_pos != dstlen)
+		return (-1);
+	if (partial)
+		return (ret == XZ_OK || ret == XZ_STREAM_END ? 0 : -1);
+	return (ret == XZ_STREAM_END && buffer.in_pos == srclen ? 0 : -1);
+}