lib/lzma/LzmaTools.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Usefuls routines based on the LzmaTest.c file from LZMA SDK 4.65
 *
 * Copyright (C) 2007-2009 Industrie Dial Face S.p.A.
 * Luigi 'Comio' Mantellini (luigi.mantellini@idf-hit.com)
 *
 * Copyright (C) 1999-2005 Igor Pavlov
 */

/*
 * LZMA_Alone stream format:
 *
 * uchar   Properties[5]
 * uint64  Uncompressed size
 * uchar   data[*]
 *
 */

#include <config.h>
#include <log.h>
#include <watchdog.h>

#ifdef CONFIG_LZMA

#define LZMA_PROPERTIES_OFFSET 0
#define LZMA_SIZE_OFFSET       LZMA_PROPS_SIZE
#define LZMA_DATA_OFFSET       LZMA_SIZE_OFFSET+sizeof(uint64_t)

#include "LzmaTools.h"
#include "LzmaDec.h"

#include <linux/string.h>
#include <malloc.h>

static void *SzAlloc(void *p, size_t size) { return malloc(size); }
static void SzFree(void *p, void *address) { free(address); }

int lzmaBuffToBuffDecompress(unsigned char *outStream, SizeT *uncompressedSize,
			     const unsigned char *inStream, SizeT length)
{
    int res = SZ_ERROR_DATA;
    int i;
    ISzAlloc g_Alloc;

    SizeT outSizeFull = 0xFFFFFFFF; /* 4GBytes limit */
    SizeT outProcessed;
    SizeT outSize;
    SizeT outSizeHigh;
    ELzmaStatus state;
    SizeT compressedSize = (SizeT)(length - LZMA_PROPS_SIZE);

    debug ("LZMA: Image address............... 0x%p\n", inStream);
    debug ("LZMA: Properties address.......... 0x%p\n", inStream + LZMA_PROPERTIES_OFFSET);
    debug ("LZMA: Uncompressed size address... 0x%p\n", inStream + LZMA_SIZE_OFFSET);
    debug ("LZMA: Compressed data address..... 0x%p\n", inStream + LZMA_DATA_OFFSET);
    debug ("LZMA: Destination address......... 0x%p\n", outStream);

    memset(&state, 0, sizeof(state));

    outSize = 0;
    outSizeHigh = 0;
    /* Read the uncompressed size */
    for (i = 0; i < 8; i++) {
        unsigned char b = inStream[LZMA_SIZE_OFFSET + i];
            if (i < 4) {
                outSize     += (UInt32)(b) << (i * 8);
        } else {
                outSizeHigh += (UInt32)(b) << ((i - 4) * 8);
        }
    }

    outSizeFull = (SizeT)outSize;
    if (sizeof(SizeT) >= 8) {
        /*
         * SizeT is a 64 bit uint => We can manage files larger than 4GB!
         *
         */
            outSizeFull |= (((SizeT)outSizeHigh << 16) << 16);
    } else if (outSizeHigh != 0 || (UInt32)(SizeT)outSize != outSize) {
        /*
         * SizeT is a 32 bit uint => We cannot manage files larger than
         * 4GB!  Assume however that all 0xf values is "unknown size" and
         * not actually a file of 2^64 bits.
         *
         */
        if (outSizeHigh != (SizeT)-1 || outSize != (SizeT)-1) {
            debug ("LZMA: 64bit support not enabled.\n");
            return SZ_ERROR_DATA;
        }
    }

    debug("LZMA: Uncompresed size............ 0x%zx\n", outSizeFull);
    debug("LZMA: Compresed size.............. 0x%zx\n", compressedSize);

    g_Alloc.Alloc = SzAlloc;
    g_Alloc.Free = SzFree;

    /* Short-circuit early if we know the buffer can't hold the results. */
    if (outSizeFull != (SizeT)-1 && *uncompressedSize < outSizeFull)
        return SZ_ERROR_OUTPUT_EOF;

    /* Decompress */
    outProcessed = min(outSizeFull, *uncompressedSize);

    schedule();

    res = LzmaDecode(
        outStream, &outProcessed,
        inStream + LZMA_DATA_OFFSET, &compressedSize,
        inStream, LZMA_PROPS_SIZE, LZMA_FINISH_END, &state, &g_Alloc);
    *uncompressedSize = outProcessed;

    debug("LZMA: Uncompressed ............... 0x%zx\n", outProcessed);

    if (res != SZ_OK)  {
        return res;
    }

    return res;
}

#endif