diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/842/842.h | 2 | ||||
| -rw-r--r-- | lib/842/842_compress.c | 13 | ||||
| -rw-r--r-- | lib/842/842_decompress.c | 17 |
3 files changed, 32 insertions, 0 deletions
diff --git a/lib/842/842.h b/lib/842/842.h index 7c20003..e0a122bc 100644 --- a/lib/842/842.h +++ b/lib/842/842.h @@ -76,6 +76,7 @@ #include <linux/module.h> #include <linux/kernel.h> #include <linux/bitops.h> +#include <linux/crc32.h> #include <asm/unaligned.h> #include <linux/sw842.h> @@ -98,6 +99,7 @@ #define I2_BITS (8) #define I4_BITS (9) #define I8_BITS (8) +#define CRC_BITS (32) #define REPEAT_BITS_MAX (0x3f) #define SHORT_DATA_BITS_MAX (0x7) diff --git a/lib/842/842_compress.c b/lib/842/842_compress.c index 7ce6894..4051339 100644 --- a/lib/842/842_compress.c +++ b/lib/842/842_compress.c @@ -490,6 +490,7 @@ int sw842_compress(const u8 *in, unsigned int ilen, int ret; u64 last, next, pad, total; u8 repeat_count = 0; + u32 crc; BUILD_BUG_ON(sizeof(*p) > SW842_MEM_COMPRESS); @@ -580,6 +581,18 @@ skip_comp: if (ret) return ret; + /* + * crc(0:31) is appended to target data starting with the next + * bit after End of stream template. + * nx842 calculates CRC for data in big-endian format. So doing + * same here so that sw842 decompression can be used for both + * compressed data. + */ + crc = crc32_be(0, in, ilen); + ret = add_bits(p, crc, CRC_BITS); + if (ret) + return ret; + if (p->bit) { p->out++; p->olen--; diff --git a/lib/842/842_decompress.c b/lib/842/842_decompress.c index 5446ff0..8881dad 100644 --- a/lib/842/842_decompress.c +++ b/lib/842/842_decompress.c @@ -285,6 +285,7 @@ int sw842_decompress(const u8 *in, unsigned int ilen, struct sw842_param p; int ret; u64 op, rep, tmp, bytes, total; + u64 crc; p.in = (u8 *)in; p.bit = 0; @@ -375,6 +376,22 @@ int sw842_decompress(const u8 *in, unsigned int ilen, } } while (op != OP_END); + /* + * crc(0:31) is saved in compressed data starting with the + * next bit after End of stream template. + */ + ret = next_bits(&p, &crc, CRC_BITS); + if (ret) + return ret; + + /* + * Validate CRC saved in compressed data. + */ + if (crc != (u64)crc32_be(0, out, total - p.olen)) { + pr_debug("CRC mismatch for decompression\n"); + return -EINVAL; + } + if (unlikely((total - p.olen) > UINT_MAX)) return -ENOSPC; |
