initial commit

SQUASHFS/squashfs-tools-4.4/squashfs-tools/lzma_xz_wrapper.c

@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2010, 2013
+ * Phillip Lougher <phillip@squashfs.org.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * lzma_xz_wrapper.c
+ *
+ * Support for LZMA1 compression using XZ Utils liblzma http://tukaani.org/xz/
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <lzma.h>
+
+#include "squashfs_fs.h"
+#include "compressor.h"
+
+#define LZMA_PROPS_SIZE 5
+#define LZMA_UNCOMP_SIZE 8
+#define LZMA_HEADER_SIZE (LZMA_PROPS_SIZE + LZMA_UNCOMP_SIZE)
+
+#define LZMA_OPTIONS 5
+#define MEMLIMIT (32 * 1024 * 1024)
+
+static int lzma_compress(void *dummy, void *dest, void *src,  int size,
+	int block_size, int *error)
+{
+	unsigned char *d = (unsigned char *) dest;
+	lzma_options_lzma opt;
+	lzma_stream strm = LZMA_STREAM_INIT;
+	int res;
+
+	lzma_lzma_preset(&opt, LZMA_OPTIONS);
+	opt.dict_size = block_size;
+
+	res = lzma_alone_encoder(&strm, &opt);
+	if(res != LZMA_OK) {
+		lzma_end(&strm);
+		goto failed;
+	}
+
+	strm.next_out = dest;
+	strm.avail_out = block_size;
+	strm.next_in = src;
+	strm.avail_in = size;
+
+	res = lzma_code(&strm, LZMA_FINISH);
+	lzma_end(&strm);
+
+	if(res == LZMA_STREAM_END) {
+		/*
+	 	 * Fill in the 8 byte little endian uncompressed size field in
+		 * the LZMA header.  8 bytes is excessively large for squashfs
+		 * but this is the standard LZMA header and which is expected by
+		 * the kernel code
+	 	 */
+
+		d[LZMA_PROPS_SIZE] = size & 255;
+		d[LZMA_PROPS_SIZE + 1] = (size >> 8) & 255;
+		d[LZMA_PROPS_SIZE + 2] = (size >> 16) & 255;
+		d[LZMA_PROPS_SIZE + 3] = (size >> 24) & 255;
+		d[LZMA_PROPS_SIZE + 4] = 0;
+		d[LZMA_PROPS_SIZE + 5] = 0;
+		d[LZMA_PROPS_SIZE + 6] = 0;
+		d[LZMA_PROPS_SIZE + 7] = 0;
+
+		return (int) strm.total_out;
+	}
+
+	if(res == LZMA_OK)
+		/*
+	 	 * Output buffer overflow.  Return out of buffer space
+	 	 */
+		return 0;
+
+failed:
+	/*
+	 * All other errors return failure, with the compressor
+	 * specific error code in *error
+	 */
+	*error = res;
+	return -1;
+}
+
+
+static int lzma_uncompress(void *dest, void *src, int size, int outsize,
+	int *error)
+{
+	lzma_stream strm = LZMA_STREAM_INIT;
+	int uncompressed_size = 0, res;
+	unsigned char lzma_header[LZMA_HEADER_SIZE];
+
+	res = lzma_alone_decoder(&strm, MEMLIMIT);
+	if(res != LZMA_OK) {
+		lzma_end(&strm);
+		goto failed;
+	}
+
+	memcpy(lzma_header, src, LZMA_HEADER_SIZE);
+	uncompressed_size = lzma_header[LZMA_PROPS_SIZE] |
+		(lzma_header[LZMA_PROPS_SIZE + 1] << 8) |
+		(lzma_header[LZMA_PROPS_SIZE + 2] << 16) |
+		(lzma_header[LZMA_PROPS_SIZE + 3] << 24);
+
+	if(uncompressed_size > outsize) {
+		res = 0;
+		goto failed;
+	}
+
+	memset(lzma_header + LZMA_PROPS_SIZE, 255, LZMA_UNCOMP_SIZE);
+
+	strm.next_out = dest;
+	strm.avail_out = outsize;
+	strm.next_in = lzma_header;
+	strm.avail_in = LZMA_HEADER_SIZE;
+
+	res = lzma_code(&strm, LZMA_RUN);
+
+	if(res != LZMA_OK || strm.avail_in != 0) {
+		lzma_end(&strm);
+		goto failed;
+	}
+
+	strm.next_in = src + LZMA_HEADER_SIZE;
+	strm.avail_in = size - LZMA_HEADER_SIZE;
+
+	res = lzma_code(&strm, LZMA_FINISH);
+	lzma_end(&strm);
+
+	if(res == LZMA_STREAM_END || (res == LZMA_OK &&
+		strm.total_out >= uncompressed_size && strm.avail_in == 0))
+		return uncompressed_size;
+
+failed:
+	*error = res;
+	return -1;
+}
+
+
+struct compressor lzma_comp_ops = {
+	.init = NULL,
+	.compress = lzma_compress,
+	.uncompress = lzma_uncompress,
+	.options = NULL,
+	.usage = NULL,
+	.id = LZMA_COMPRESSION,
+	.name = "lzma",
+	.supported = 1
+};
+