LXR uboot/lib/lz4

   1// SPDX-License-Identifier: GPL 2.0+ OR BSD-3-Clause
   2/*
   3 * Copyright 2015 Google Inc.
   4 */
   5
   6#include <common.h>
   7#include <compiler.h>
   8#include <image.h>
   9#include <lz4.h>
  10#include <linux/kernel.h>
  11#include <linux/types.h>
  12#include <asm/unaligned.h>
  13
  14static u16 LZ4_readLE16(const void *src) { return le16_to_cpu(*(u16 *)src); }
  15static void LZ4_copy4(void *dst, const void *src) { *(u32 *)dst = *(u32 *)src; }
  16static void LZ4_copy8(void *dst, const void *src) { *(u64 *)dst = *(u64 *)src; }
  17
  18typedef  uint8_t BYTE;
  19typedef uint16_t U16;
  20typedef uint32_t U32;
  21typedef  int32_t S32;
  22typedef uint64_t U64;
  23
  24#define FORCE_INLINE static inline __attribute__((always_inline))
  25
  26/* lz4.c is unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */
  27#include "lz4.c"        /* #include for inlining, do not link! */
  28
  29#define LZ4F_BLOCKUNCOMPRESSED_FLAG 0x80000000U
  30
  31int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn)
  32{
  33        const void *end = dst + *dstn;
  34        const void *in = src;
  35        void *out = dst;
  36        int has_block_checksum;
  37        int ret;
  38        *dstn = 0;
  39
  40        { /* With in-place decompression the header may become invalid later. */
  41                u32 magic;
  42                u8 flags, version, independent_blocks, has_content_size;
  43                u8 block_desc;
  44
  45                if (srcn < sizeof(u32) + 3*sizeof(u8))
  46                        return -EINVAL; /* input overrun */
  47
  48                magic = get_unaligned_le32(in);
  49                in += sizeof(u32);
  50                flags = *(u8 *)in;
  51                in += sizeof(u8);
  52                block_desc = *(u8 *)in;
  53                in += sizeof(u8);
  54
  55                version = (flags >> 6) & 0x3;
  56                independent_blocks = (flags >> 5) & 0x1;
  57                has_block_checksum = (flags >> 4) & 0x1;
  58                has_content_size = (flags >> 3) & 0x1;
  59
  60                /* We assume there's always only a single, standard frame. */
  61                if (magic != LZ4F_MAGIC || version != 1)
  62                        return -EPROTONOSUPPORT;        /* unknown format */
  63                if ((flags & 0x03) || (block_desc & 0x8f))
  64                        return -EINVAL; /* reserved bits must be zero */
  65                if (!independent_blocks)
  66                        return -EPROTONOSUPPORT; /* we can't support this yet */
  67
  68                if (has_content_size) {
  69                        if (srcn < sizeof(u32) + 3*sizeof(u8) + sizeof(u64))
  70                                return -EINVAL; /* input overrun */
  71                        in += sizeof(u64);
  72                }
  73                /* Header checksum byte */
  74                in += sizeof(u8);
  75        }
  76
  77        while (1) {
  78                u32 block_header, block_size;
  79
  80                block_header = get_unaligned_le32(in);
  81                in += sizeof(u32);
  82                block_size = block_header & ~LZ4F_BLOCKUNCOMPRESSED_FLAG;
  83
  84                if (in - src + block_size > srcn) {
  85                        ret = -EINVAL;          /* input overrun */
  86                        break;
  87                }
  88
  89                if (!block_size) {
  90                        ret = 0;        /* decompression successful */
  91                        break;
  92                }
  93
  94                if (block_header & LZ4F_BLOCKUNCOMPRESSED_FLAG) {
  95                        size_t size = min((ptrdiff_t)block_size, end - out);
  96                        memcpy(out, in, size);
  97                        out += size;
  98                        if (size < block_size) {
  99                                ret = -ENOBUFS; /* output overrun */
 100                                break;
 101                        }
 102                } else {
 103                        /* constant folding essential, do not touch params! */
 104                        ret = LZ4_decompress_generic(in, out, block_size,
 105                                        end - out, endOnInputSize,
 106                                        full, 0, noDict, out, NULL, 0);
 107                        if (ret < 0) {
 108                                ret = -EPROTO;  /* decompression error */
 109                                break;
 110                        }
 111                        out += ret;
 112                }
 113
 114                in += block_size;
 115                if (has_block_checksum)
 116                        in += sizeof(u32);
 117        }
 118
 119        *dstn = out - dst;
 120        return ret;
 121}
 122