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|
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -265,6 +265,9 @@ config LZMA_COMPRESS
config LZMA_DECOMPRESS
tristate
+config RLE_DECOMPRESS
+ tristate
+
#
# These all provide a common interface (hence the apparent duplication with
# ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -135,6 +135,7 @@ obj-$(CONFIG_XZ_DEC) += xz/
obj-$(CONFIG_RAID6_PQ) += raid6/
obj-$(CONFIG_LZMA_COMPRESS) += lzma/
obj-$(CONFIG_LZMA_DECOMPRESS) += lzma/
+obj-$(CONFIG_RLE_DECOMPRESS) += rle.o
lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
--- /dev/null
+++ b/include/linux/rle.h
@@ -0,0 +1,18 @@
+#ifndef _RLE_H_
+#define _RLE_H_
+
+#ifdef CONFIG_RLE_DECOMPRESS
+int rle_decode(const unsigned char *src, size_t srclen,
+ unsigned char *dst, size_t dstlen,
+ size_t *src_done, size_t *dst_done);
+#else
+static inline int
+rle_decode(const unsigned char *src, size_t srclen,
+ unsigned char *dst, size_t dstlen,
+ size_t *src_done, size_t *dst_done)
+{
+ return -ENOTSUPP;
+}
+#endif /* CONFIG_RLE_DECOMPRESS */
+
+#endif /* _RLE_H_ */
--- /dev/null
+++ b/lib/rle.c
@@ -0,0 +1,78 @@
+/*
+ * RLE decoding routine
+ *
+ * Copyright (C) 2012 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rle.h>
+
+int rle_decode(const unsigned char *src, size_t srclen,
+ unsigned char *dst, size_t dstlen,
+ size_t *src_done, size_t *dst_done)
+{
+ size_t srcpos, dstpos;
+ int ret;
+
+ srcpos = 0;
+ dstpos = 0;
+ ret = -EINVAL;
+
+ /* sanity checks */
+ if (!src || !srclen || !dst || !dstlen)
+ goto out;
+
+ while (1) {
+ char count;
+
+ if (srcpos >= srclen)
+ break;
+
+ count = (char) src[srcpos++];
+ if (count == 0) {
+ ret = 0;
+ break;
+ }
+
+ if (count > 0) {
+ unsigned char c;
+
+ if (srcpos >= srclen)
+ break;
+
+ c = src[srcpos++];
+
+ while (count--) {
+ if (dstpos >= dstlen)
+ break;
+
+ dst[dstpos++] = c;
+ }
+ } else {
+ count *= -1;
+
+ while (count--) {
+ if (srcpos >= srclen)
+ break;
+ if (dstpos >= dstlen)
+ break;
+ dst[dstpos++] = src[srcpos++];
+ }
+ }
+ }
+
+out:
+ if (src_done)
+ *src_done = srcpos;
+ if (dst_done)
+ *dst_done = dstpos;
+
+ return ret;
+}
+
+EXPORT_SYMBOL_GPL(rle_decode);
|
