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 <linux/kernel.h>
   9#include <linux/types.h>
  10
  11static u16 LZ4_readLE16(const void *src) { return le16_to_cpu(*(u16 *)src); }
  12static void LZ4_copy4(void *dst, const void *src) { *(u32 *)dst = *(u32 *)src; }
  13static void LZ4_copy8(void *dst, const void *src) { *(u64 *)dst = *(u64 *)src; }
  14
  15typedef  uint8_t BYTE;
  16typedef uint16_t U16;
  17typedef uint32_t U32;
  18typedef  int32_t S32;
  19typedef uint64_t U64;
  20
  21#define FORCE_INLINE static inline __attribute__((always_inline))
  22
  23/* Unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */
  24#include "lz4.c"        /* #include for inlining, do not link! */
  25
  26#define LZ4F_MAGIC 0x184D2204
  27
  28struct lz4_frame_header {
  29        u32 magic;
  30        union {
  31                u8 flags;
  32                struct {
  33                        u8 reserved0:2;
  34                        u8 has_content_checksum:1;
  35                        u8 has_content_size:1;
  36                        u8 has_block_checksum:1;
  37                        u8 independent_blocks:1;
  38                        u8 version:2;
  39                };
  40        };
  41        union {
  42                u8 block_descriptor;
  43                struct {
  44                        u8 reserved1:4;
  45                        u8 max_block_size:3;
  46                        u8 reserved2:1;
  47                };
  48        };
  49        /* + u64 content_size iff has_content_size is set */
  50        /* + u8 header_checksum */
  51} __packed;
  52
  53struct lz4_block_header {
  54        union {
  55                u32 raw;
  56                struct {
  57                        u32 size:31;
  58                        u32 not_compressed:1;
  59                };
  60        };
  61        /* + size bytes of data */
  62        /* + u32 block_checksum iff has_block_checksum is set */
  63} __packed;
  64
  65int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn)
  66{
  67        const void *end = dst + *dstn;
  68        const void *in = src;
  69        void *out = dst;
  70        int has_block_checksum;
  71        int ret;
  72        *dstn = 0;
  73
  74        { /* With in-place decompression the header may become invalid later. */
  75                const struct lz4_frame_header *h = in;
  76
  77                if (srcn < sizeof(*h) + sizeof(u64) + sizeof(u8))
  78                        return -EINVAL; /* input overrun */
  79
  80                /* We assume there's always only a single, standard frame. */
  81                if (le32_to_cpu(h->magic) != LZ4F_MAGIC || h->version != 1)
  82                        return -EPROTONOSUPPORT;        /* unknown format */
  83                if (h->reserved0 || h->reserved1 || h->reserved2)
  84                        return -EINVAL; /* reserved must be zero */
  85                if (!h->independent_blocks)
  86                        return -EPROTONOSUPPORT; /* we can't support this yet */
  87                has_block_checksum = h->has_block_checksum;
  88
  89                in += sizeof(*h);
  90                if (h->has_content_size)
  91                        in += sizeof(u64);
  92                in += sizeof(u8);
  93        }
  94
  95        while (1) {
  96                struct lz4_block_header b;
  97
  98                b.raw = le32_to_cpu(*(u32 *)in);
  99                in += sizeof(struct lz4_block_header);
 100
 101                if (in - src + b.size > srcn) {
 102                        ret = -EINVAL;          /* input overrun */
 103                        break;
 104                }
 105
 106                if (!b.size) {
 107                        ret = 0;        /* decompression successful */
 108                        break;
 109                }
 110
 111                if (b.not_compressed) {
 112                        size_t size = min((ptrdiff_t)b.size, end - out);
 113                        memcpy(out, in, size);
 114                        out += size;
 115                        if (size < b.size) {
 116                                ret = -ENOBUFS; /* output overrun */
 117                                break;
 118                        }
 119                } else {
 120                        /* constant folding essential, do not touch params! */
 121                        ret = LZ4_decompress_generic(in, out, b.size,
 122                                        end - out, endOnInputSize,
 123                                        full, 0, noDict, out, NULL, 0);
 124                        if (ret < 0) {
 125                                ret = -EPROTO;  /* decompression error */
 126                                break;
 127                        }
 128                        out += ret;
 129                }
 130
 131                in += b.size;
 132                if (has_block_checksum)
 133                        in += sizeof(u32);
 134        }
 135
 136        *dstn = out - dst;
 137        return ret;
 138}
 139