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- --- a/lib/Kconfig
- +++ b/lib/Kconfig
- @@ -247,6 +247,9 @@ 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
- @@ -109,6 +109,7 @@ 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);
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