blob: c2b523877e45fafe8c55a52c485a339e00572ea3 [file] [log] [blame] [edit]
// SPDX-License-Identifier: GPL 2.0+ OR BSD-3-Clause
/*
* Copyright 2015 Google Inc.
*/
#include <common.h>
#include <compiler.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include "lz4_wrapper.h"
#define LZ4F_MAGIC 0x184D2204
#define LZ4_MAX_BLOCK_SIZE_64K 4
#define LZ4_MAX_BLOCK_SIZE_256K 5
#define LZ4_MAX_BLOCK_SIZE_1M 6
#define LZ4_MAX_BLOCK_SIZE_4M 7
struct lz4_block_header {
union {
u32 raw;
struct {
u32 size : 31;
u32 not_compressed : 1;
};
};
/* + size bytes of data */
/* + u32 block_checksum iff has_block_checksum is set */
} __packed;
static u16 LZ4_readLE16(const void *src)
{
return le16_to_cpu(*(u16 *)src);
}
static void LZ4_copy4(void *dst, const void *src)
{
*(u32 *)dst = *(u32 *)src;
}
static void LZ4_copy8(void *dst, const void *src)
{
*(u64 *)dst = *(u64 *)src;
}
/* Unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */
#include "lz4.c" /* #include for inlining, do not link! */
bool is_data_lz4_compressed(const void *src, size_t srcn)
{
if (srcn < sizeof(struct lz4_frame_header)) {
return false;
}
struct lz4_frame_header h;
memcpy(&h, src, sizeof(h));
return le32_to_cpu(h.magic) == LZ4F_MAGIC;
}
int check_and_extract_lz4_frame_header(const void *src, size_t srcn,
struct lz4_frame_header *out,
size_t *data_offset)
{
const void *in = src;
const struct lz4_frame_header *h = in;
if (srcn < sizeof(*h) + sizeof(u64) + sizeof(u8))
return -EINVAL; /* input overrun */
/* We assume there's always only a single, standard frame. */
if (le32_to_cpu(h->magic) != LZ4F_MAGIC || h->version != 1) {
fprintf(stderr, "invalid magic %x, %d\n",
le32_to_cpu(h->magic) != LZ4F_MAGIC, h->version);
return -EPROTONOSUPPORT; /* unknown format */
}
if (h->reserved0 || h->reserved1 || h->reserved2)
return -EINVAL; /* reserved must be zero */
if (!h->independent_blocks) {
fprintf(stderr, "no support for independent block\n");
return -EPROTONOSUPPORT; /* we can't support this yet */
}
in += sizeof(*h);
if (h->has_content_size)
in += sizeof(u64);
in += sizeof(u8);
*data_offset = in - src;
*out = *h;
return 0;
}
/**
* Decompress one block of data from lz4 data.
*
* @param src The lz4 compressed data.
* @param srcn Size of |src|.
* @param dst Output pointer for storing the decompress block.
* @param dstn Size of |dst|.
* @param block_size Output pointer for size of current compressed block.
* @param decompressed_size Output pointer for the amount of data decompressed.
*/
int decompress_block(const void *src, size_t srcn, void *dst, int dstn,
size_t *block_size, size_t *decompressed_size)
{
const void *in = src;
void *out = dst;
const void *end = out + dstn;
*decompressed_size = 0;
struct lz4_block_header b;
b.raw = le32_to_cpu(*(u32 *)in);
*block_size = sizeof(struct lz4_block_header) + b.size;
in += sizeof(struct lz4_block_header);
if (in - src + b.size > srcn) {
fprintf(stderr, "input overrun\n");
return -EINVAL; /* input overrun */
}
if (!b.size) {
return 0; /* decompression successful */
}
if (b.not_compressed) {
size_t size = min((ptrdiff_t)b.size, end - out);
memcpy(out, in, size);
out += size;
if (size < b.size) {
fprintf(stderr, "output overrun\n");
return -ENOBUFS; /* output overrun */
}
} else {
/* constant folding essential, do not touch params! */
int ret = LZ4_decompress_generic(in, out, b.size, end - out,
endOnInputSize, full, 0,
noDict, out, NULL, 0);
if (ret < 0) {
fprintf(stderr, "LZ4_decompress_generic error %d\n",
ret);
return -EPROTO; /* decompression error */
}
out += ret;
}
*decompressed_size = out - dst;
return 0;
}
int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn)
{
const void *src_end = src + srcn;
const void *dst_end = dst + *dstn;
struct lz4_frame_header h;
size_t data_offset = 0;
int ret =
check_and_extract_lz4_frame_header(src, srcn, &h, &data_offset);
if (ret) {
return ret;
}
const void *data = (uint8_t *)src + data_offset;
void *out = dst;
size_t decompressed_size = 0, block_size;
do {
if ((ret = decompress_block(data, src_end - data, out,
dst_end - out, &block_size,
&decompressed_size))) {
return ret;
}
out += decompressed_size;
data += block_size + (h.has_block_checksum ? sizeof(u32) : 0);
} while (decompressed_size);
*dstn = out - dst;
return 0;
}
int get_lz4_max_block_size(const struct lz4_frame_header *h, size_t *out)
{
switch (h->max_block_size) {
case LZ4_MAX_BLOCK_SIZE_64K:
*out = 64 * 1024;
break;
case LZ4_MAX_BLOCK_SIZE_256K:
*out = 256 * 1024;
break;
case LZ4_MAX_BLOCK_SIZE_1M:
*out = 1024 * 1024;
break;
case LZ4_MAX_BLOCK_SIZE_4M:
*out = 4 * 1024 * 1024;
break;
default:
printf("Invalid block max size code");
return -1;
}
return 0;
}
int lz4_decompress(const struct lz4_frame_header *h, const uint8_t *src,
size_t *srcn, uint8_t *dst, size_t *dstn,
bool *has_more_data)
{
int ret = 0;
size_t max_block_size = 0;
if ((ret = get_lz4_max_block_size(h, &max_block_size))) {
return ret;
}
const uint8_t *in_curr = src;
const uint8_t *in_end = src + *srcn;
uint8_t *out_curr = dst;
uint8_t *out_end = dst + *dstn;
*dstn = 0;
*srcn = 0;
*has_more_data = true;
while (out_curr + max_block_size <= out_end) {
size_t compressed_size = 0, decompressed_size = 0;
if ((ret = decompress_block(in_curr, in_end - in_curr, out_curr,
out_end - out_curr,
&compressed_size,
&decompressed_size))) {
return ret;
}
in_curr += compressed_size +
(h->has_block_checksum ? sizeof(u32) : 0);
out_curr += decompressed_size;
// If no more data can be decompressed, exit the loop
if (!decompressed_size) {
*has_more_data = false;
break;
}
}
*dstn = out_curr - dst;
*srcn = in_curr - src;
return 0;
}