| 1 | --- a/lib/Kconfig |
| 2 | +++ b/lib/Kconfig |
| 3 | @@ -124,6 +124,9 @@ config LZMA_COMPRESS |
| 4 | config LZMA_DECOMPRESS |
| 5 | tristate |
| 6 | |
| 7 | +config RLE_DECOMPRESS |
| 8 | + tristate |
| 9 | + |
| 10 | # |
| 11 | # These all provide a common interface (hence the apparent duplication with |
| 12 | # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.) |
| 13 | --- a/lib/Makefile |
| 14 | +++ b/lib/Makefile |
| 15 | @@ -85,6 +85,7 @@ obj-$(CONFIG_XZ_DEC) += xz/ |
| 16 | obj-$(CONFIG_RAID6_PQ) += raid6/ |
| 17 | obj-$(CONFIG_LZMA_COMPRESS) += lzma/ |
| 18 | obj-$(CONFIG_LZMA_DECOMPRESS) += lzma/ |
| 19 | +obj-$(CONFIG_RLE_DECOMPRESS) += rle.o |
| 20 | |
| 21 | lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o |
| 22 | lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o |
| 23 | --- /dev/null |
| 24 | +++ b/include/linux/rle.h |
| 25 | @@ -0,0 +1,8 @@ |
| 26 | +#ifndef _RLE_H_ |
| 27 | +#define _RLE_H_ |
| 28 | + |
| 29 | +int rle_decode(const unsigned char *src, size_t srclen, |
| 30 | + unsigned char *dst, size_t dstlen, |
| 31 | + size_t *src_done, size_t *dst_done); |
| 32 | + |
| 33 | +#endif /* _RLE_H_ */ |
| 34 | --- /dev/null |
| 35 | +++ b/lib/rle.c |
| 36 | @@ -0,0 +1,78 @@ |
| 37 | +/* |
| 38 | + * RLE decoding routine |
| 39 | + * |
| 40 | + * Copyright (C) 2012 Gabor Juhos <juhosg@openwrt.org> |
| 41 | + * |
| 42 | + * This program is free software; you can redistribute it and/or modify it |
| 43 | + * under the terms of the GNU General Public License version 2 as published |
| 44 | + * by the Free Software Foundation. |
| 45 | + */ |
| 46 | + |
| 47 | +#include <linux/kernel.h> |
| 48 | +#include <linux/module.h> |
| 49 | +#include <linux/rle.h> |
| 50 | + |
| 51 | +int rle_decode(const unsigned char *src, size_t srclen, |
| 52 | + unsigned char *dst, size_t dstlen, |
| 53 | + size_t *src_done, size_t *dst_done) |
| 54 | +{ |
| 55 | + size_t srcpos, dstpos; |
| 56 | + int ret; |
| 57 | + |
| 58 | + srcpos = 0; |
| 59 | + dstpos = 0; |
| 60 | + ret = -EINVAL; |
| 61 | + |
| 62 | + /* sanity checks */ |
| 63 | + if (!src || !srclen || !dst || !dstlen) |
| 64 | + goto out; |
| 65 | + |
| 66 | + while (1) { |
| 67 | + char count; |
| 68 | + |
| 69 | + if (srcpos >= srclen) |
| 70 | + break; |
| 71 | + |
| 72 | + count = (char) src[srcpos++]; |
| 73 | + if (count == 0) { |
| 74 | + ret = 0; |
| 75 | + break; |
| 76 | + } |
| 77 | + |
| 78 | + if (count > 0) { |
| 79 | + unsigned char c; |
| 80 | + |
| 81 | + if (srcpos >= srclen) |
| 82 | + break; |
| 83 | + |
| 84 | + c = src[srcpos++]; |
| 85 | + |
| 86 | + while (count--) { |
| 87 | + if (dstpos >= dstlen) |
| 88 | + break; |
| 89 | + |
| 90 | + dst[dstpos++] = c; |
| 91 | + } |
| 92 | + } else { |
| 93 | + count *= -1; |
| 94 | + |
| 95 | + while (count--) { |
| 96 | + if (srcpos >= srclen) |
| 97 | + break; |
| 98 | + if (dstpos >= dstlen) |
| 99 | + break; |
| 100 | + dst[dstpos++] = src[srcpos++]; |
| 101 | + } |
| 102 | + } |
| 103 | + } |
| 104 | + |
| 105 | +out: |
| 106 | + if (src_done) |
| 107 | + *src_done = srcpos; |
| 108 | + if (dst_done) |
| 109 | + *dst_done = dstpos; |
| 110 | + |
| 111 | + return ret; |
| 112 | +} |
| 113 | + |
| 114 | +EXPORT_SYMBOL_GPL(rle_decode); |
| 115 | |
