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/*
* Copyright 2015 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <assert.h>
#include <endian.h>
#include <libpayload.h>
#include <lz4.h>
/* LZ4 comes with its own supposedly portable memory access functions, but they
* seem to be very inefficient in practice (at least on ARM64). Since libpayload
* knows about endinaness and allows some basic assumptions (such as unaligned
* access support), we can easily write the ones we need ourselves. */
static u16 LZ4_readLE16(const void *src) { return le16toh(*(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; }
typedef uint8_t BYTE;
typedef uint16_t U16;
typedef uint32_t U32;
typedef int32_t S32;
typedef uint64_t U64;
#define FORCE_INLINE static inline __attribute__((always_inline))
#define likely(expr) __builtin_expect((expr) != 0, 1)
#define unlikely(expr) __builtin_expect((expr) != 0, 0)
/* Unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */
#include "lz4.c" /* #include for inlining, do not link! */
#define LZ4F_MAGICNUMBER 0x184D2204
struct lz4_frame_header {
u32 magic;
union {
u8 flags;
struct {
u8 reserved0 : 2;
u8 has_content_checksum : 1;
u8 has_content_size : 1;
u8 has_block_checksum : 1;
u8 independent_blocks : 1;
u8 version : 2;
};
};
union {
u8 block_descriptor;
struct {
u8 reserved1 : 4;
u8 max_block_size : 3;
u8 reserved2 : 1;
};
};
/* + u64 content_size iff has_content_size is set */
/* + u8 header_checksum */
} __attribute__((packed));
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 */
} __attribute__((packed));
size_t ulz4fn(const void *src, size_t srcn, void *dst, size_t dstn)
{
const void *in = src;
void *out = dst;
int has_block_checksum;
{ /* With in-place decompression the header may become invalid later. */
const struct lz4_frame_header *h = in;
if (srcn < sizeof(*h) + sizeof(u64) + sizeof(u8))
return 0; /* input overrun */
/* We assume there's always only a single, standard frame. */
if (le32toh(h->magic) != LZ4F_MAGICNUMBER || h->version != 1)
return 0; /* unknown format */
if (h->reserved0 || h->reserved1 || h->reserved2)
return 0; /* reserved must be zero */
if (!h->independent_blocks)
return 0; /* we don't support block dependency */
has_block_checksum = h->has_block_checksum;
in += sizeof(*h);
if (h->has_content_size)
in += sizeof(u64);
in += sizeof(u8);
}
while (1) {
struct lz4_block_header b = { .raw = le32toh(*(u32 *)in) };
in += sizeof(struct lz4_block_header);
if (in - src + b.size > srcn)
return 0; /* input overrun */
if (!b.size)
return out - dst; /* decompression successful */
if (b.not_compressed) {
size_t size = MIN((u32)b.size, dst + dstn - out);
memcpy(out, in, size);
if (size < b.size)
return 0; /* output overrun */
else
out += size;
} else {
/* constant folding essential, do not touch params! */
int ret = LZ4_decompress_generic(in, out, b.size,
dst + dstn - out, endOnInputSize,
full, 0, noDict, out, NULL, 0);
if (ret < 0)
return 0; /* decompression error */
else
out += ret;
}
in += b.size;
if (has_block_checksum)
in += sizeof(u32);
}
}
size_t ulz4f(const void *src, void *dst)
{
/* LZ4 uses signed size parameters, so can't just use ((u32)-1) here. */
return ulz4fn(src, 1*GiB, dst, 1*GiB);
}
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