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// SPDX-License-Identifier: GPL 2.0+ OR BSD-3-Clause
/*
* Copyright 2015 Google Inc.
*/
#include <compiler.h>
#include <image.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <asm/unaligned.h>
#include <u-boot/lz4.h>
/* lz4.c is unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */
#include "lz4.c" /* #include for inlining, do not link! */
#define LZ4F_BLOCKUNCOMPRESSED_FLAG 0x80000000U
int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn)
{
const void *end = dst + *dstn;
const void *in = src;
void *out = dst;
int has_block_checksum;
int ret;
*dstn = 0;
{ /* With in-place decompression the header may become invalid later. */
u32 magic;
u8 flags, version, independent_blocks, has_content_size;
u8 block_desc;
if (srcn < sizeof(u32) + 3*sizeof(u8))
return -EINVAL; /* input overrun */
magic = get_unaligned_le32(in);
in += sizeof(u32);
flags = *(u8 *)in;
in += sizeof(u8);
block_desc = *(u8 *)in;
in += sizeof(u8);
version = (flags >> 6) & 0x3;
independent_blocks = (flags >> 5) & 0x1;
has_block_checksum = (flags >> 4) & 0x1;
has_content_size = (flags >> 3) & 0x1;
/* We assume there's always only a single, standard frame. */
if (magic != LZ4F_MAGIC || version != 1)
return -EPROTONOSUPPORT; /* unknown format */
if ((flags & 0x03) || (block_desc & 0x8f))
return -EINVAL; /* reserved bits must be zero */
if (!independent_blocks)
return -EPROTONOSUPPORT; /* we can't support this yet */
if (has_content_size) {
if (srcn < sizeof(u32) + 3*sizeof(u8) + sizeof(u64))
return -EINVAL; /* input overrun */
in += sizeof(u64);
}
/* Header checksum byte */
in += sizeof(u8);
}
while (1) {
u32 block_header, block_size;
block_header = get_unaligned_le32(in);
in += sizeof(u32);
block_size = block_header & ~LZ4F_BLOCKUNCOMPRESSED_FLAG;
if (in - src + block_size > srcn) {
ret = -EINVAL; /* input overrun */
break;
}
if (!block_size) {
ret = 0; /* decompression successful */
break;
}
if (block_header & LZ4F_BLOCKUNCOMPRESSED_FLAG) {
size_t size = min((ptrdiff_t)block_size, (ptrdiff_t)(end - out));
memcpy(out, in, size);
out += size;
if (size < block_size) {
ret = -ENOBUFS; /* output overrun */
break;
}
} else {
/* constant folding essential, do not touch params! */
ret = LZ4_decompress_generic(in, out, block_size,
end - out, endOnInputSize,
decode_full_block, noDict, out, NULL, 0);
if (ret < 0) {
ret = -EPROTO; /* decompression error */
break;
}
out += ret;
}
in += block_size;
if (has_block_checksum)
in += sizeof(u32);
}
*dstn = out - dst;
return ret;
}
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