packer.cpp

UPX 源代码

/* packer.cpp --

   This file is part of the UPX executable compressor.

   Copyright (C) 1996-2007 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 1996-2007 Laszlo Molnar
   All Rights Reserved.

   UPX and the UCL library are free software; you can redistribute them
   and/or modify them under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of
   the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; see the file COPYING.
   If not, write to the Free Software Foundation, Inc.,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

   Markus F.X.J. Oberhumer   Laszlo Molnar
   [e-mail]      [e-mail]
 */


//#define WANT_STL
#include "conf.h"
#include "file.h"
#include "packer.h"
#include "filter.h"
#include "linker.h"
#include "ui.h"


/*************************************************************************
//
**************************************************************************/

Packer::Packer(InputFile *f) :
    bele(NULL),
    fi(f), file_size(-1), ph_format(-1), ph_version(-1),
    uip(NULL), linker(NULL),
    last_patch(NULL), last_patch_len(0), last_patch_off(0)
{
    if (fi != NULL)
        file_size = fi->st_size();
    uip = new UiPacker(this);
    memset(&ph, 0, sizeof(ph));
}


Packer::~Packer()
{
    delete uip; uip = NULL;
    delete linker; linker = NULL;
}


// for PackMaster
void Packer::assertPacker() const
{
    assert(getFormat() > 0);
    assert(getFormat() <= 255);
    assert(getVersion() >= 11);
    assert(getVersion() <= 14);
    assert(strlen(getName()) <= 13);
    // info: 32 is limit for show_all_packers() in help.cpp
    assert(strlen(getFullName(opt)) <= 28);
    assert(strlen(getFullName(NULL)) <= 28);
    if (bele == NULL) fprintf(stderr, "%s\n", getName());
    assert(bele != NULL);
#if 1
    Linker *l = newLinker();
    if (bele != l->bele) fprintf(stderr, "%s\n", getName());
    assert(bele == l->bele);
    delete l;
#endif
}


/*************************************************************************
// public entries called from class PackMaster
**************************************************************************/

void Packer::doPack(OutputFile *fo)
{
    uip->uiPackStart(fo);
    pack(fo);
    uip->uiPackEnd(fo);
}

void Packer::doUnpack(OutputFile *fo)
{
    uip->uiUnpackStart(fo);
    unpack(fo);
    uip->uiUnpackEnd(fo);
}

void Packer::doTest()
{
    uip->uiTestStart();
    test();
    uip->uiTestEnd();
}

void Packer::doList()
{
    uip->uiListStart();
    list();
    uip->uiListEnd();
}

void Packer::doFileInfo()
{
    uip->uiFileInfoStart();
    fileInfo();
    uip->uiFileInfoEnd();
}


/*************************************************************************
// default actions
**************************************************************************/

void Packer::test()
{
    unpack(NULL);
}


void Packer::list()
{
    uip->uiList();
}


void Packer::fileInfo()
{
    // FIXME: subclasses should list their sections here
    // We also should try to get a nice layout...
}


bool Packer::testUnpackVersion(int version) const
{
    if (version != ph_version && ph_version != -1)
        throwCantUnpack("program has been modified; run a virus checker!");
    if (!canUnpackVersion(version))
        throwCantUnpack("I am not compatible with older versions of UPX");
    return true;
}


bool Packer::testUnpackFormat(int format) const
{
    if (format != ph_format && ph_format != -1)
        throwCantUnpack("program has been modified; run a virus checker!");
    return canUnpackFormat(format);
}


bool ph_skipVerify(const PackHeader &ph)
{
    if (M_IS_DEFLATE(ph.method))
        return false;
    if (M_IS_LZMA(ph.method))
        return false;
    if (ph.level > 1)
        return false;
    return true;
}


/*************************************************************************
// compress - wrap call to low-level upx_compress()
**************************************************************************/

bool Packer::compress(upx_bytep i_ptr, unsigned i_len, upx_bytep o_ptr,
                      const upx_compress_config_t *cconf_parm)
{
    ph.u_len = i_len;
    ph.c_len = 0;
    assert(ph.level >= 1); assert(ph.level <= 10);

    // Avoid too many progress bar updates. 64 is s->bar_len in ui.cpp.
    unsigned step = (ph.u_len < 64*1024) ? 0 : ph.u_len / 64;

    // save current checksums
    ph.saved_u_adler = ph.u_adler;
    ph.saved_c_adler = ph.c_adler;
    // update checksum of uncompressed data
    ph.u_adler = upx_adler32(i_ptr, ph.u_len, ph.u_adler);

    // set compression paramters
    upx_compress_config_t cconf; cconf.reset();
    if (cconf_parm)
        cconf = *cconf_parm;
    // cconf options
    if (M_IS_NRV2B(ph.method) || M_IS_NRV2D(ph.method) || M_IS_NRV2E(ph.method))
    {
        if (opt->crp.crp_ucl.c_flags != -1)
            cconf.conf_ucl.c_flags = opt->crp.crp_ucl.c_flags;
        if (opt->crp.crp_ucl.p_level != -1)
            cconf.conf_ucl.p_level = opt->crp.crp_ucl.p_level;
        if (opt->crp.crp_ucl.h_level != -1)
            cconf.conf_ucl.h_level = opt->crp.crp_ucl.h_level;
        if (opt->crp.crp_ucl.max_offset != UINT_MAX && opt->crp.crp_ucl.max_offset < cconf.conf_ucl.max_offset)
            cconf.conf_ucl.max_offset = opt->crp.crp_ucl.max_offset;
        if (opt->crp.crp_ucl.max_match != UINT_MAX && opt->crp.crp_ucl.max_match < cconf.conf_ucl.max_match)
            cconf.conf_ucl.max_match = opt->crp.crp_ucl.max_match;
#if defined(WITH_NRV)
        if (ph.level >= 7 || (ph.level >= 4 && ph.u_len >= 512*1024))
            step = 0;
#endif
    }
    if (M_IS_LZMA(ph.method))
    {
        oassign(cconf.conf_lzma.pos_bits, opt->crp.crp_lzma.pos_bits);
        oassign(cconf.conf_lzma.lit_pos_bits, opt->crp.crp_lzma.lit_pos_bits);
        oassign(cconf.conf_lzma.lit_context_bits, opt->crp.crp_lzma.lit_context_bits);
        oassign(cconf.conf_lzma.dict_size, opt->crp.crp_lzma.dict_size);
        oassign(cconf.conf_lzma.num_fast_bytes, opt->crp.crp_lzma.num_fast_bytes);
    }
    if (M_IS_DEFLATE(ph.method))
    {
        oassign(cconf.conf_zlib.mem_level, opt->crp.crp_zlib.mem_level);
        oassign(cconf.conf_zlib.window_bits, opt->crp.crp_zlib.window_bits);
        oassign(cconf.conf_zlib.strategy, opt->crp.crp_zlib.strategy);
    }
    if (uip->ui_pass >= 0)
        uip->ui_pass++;
    uip->startCallback(ph.u_len, step, uip->ui_pass, uip->ui_total_passes);
    uip->firstCallback();

    //OutputFile::dump("data.raw", in, ph.u_len);

    // compress
    int r = upx_compress(i_ptr, ph.u_len, o_ptr, &ph.c_len,
                         uip->getCallback(),
                         ph.method, ph.level, &cconf, &ph.compress_result);

    //uip->finalCallback(ph.u_len, ph.c_len);
    uip->endCallback();

    if (r == UPX_E_OUT_OF_MEMORY)
        throwOutOfMemoryException();
    if (r != UPX_E_OK)
        throwInternalError("compression failed");

    if (M_IS_NRV2B(ph.method) || M_IS_NRV2D(ph.method) || M_IS_NRV2E(ph.method))
    {
        const ucl_uint *res = ph.compress_result.result_ucl.result;
        //ph.min_offset_found = res[0];
        ph.max_offset_found = res[1];
        //ph.min_match_found = res[2];
        ph.max_match_found = res[3];
        //ph.min_run_found = res[4];
        ph.max_run_found = res[5];
        ph.first_offset_found = res[6];
        //ph.same_match_offsets_found = res[7];
        if (cconf_parm)
        {
            assert(cconf.conf_ucl.max_offset == 0 || cconf.conf_ucl.max_offset >= ph.max_offset_found);
            assert(cconf.conf_ucl.max_match == 0 || cconf.conf_ucl.max_match >= ph.max_match_found);
        }
    }

    //printf("\nPacker::compress: %d/%d: %7d -> %7d\n", ph.method, ph.level, ph.u_len, ph.c_len);
    if (!checkCompressionRatio(ph.u_len, ph.c_len))
        return false;
    // return in any case if not compressible
    if (ph.c_len >= ph.u_len)
        return false;

    // update checksum of compressed data
    ph.c_adler = upx_adler32(o_ptr, ph.c_len, ph.c_adler);
    // Decompress and verify. Skip this when using the fastest level.
    if (!ph_skipVerify(ph))
    {
        // decompress
        unsigned new_len = ph.u_len;
        r = upx_decompress(o_ptr, ph.c_len, i_ptr, &new_len, ph.method, &ph.compress_result);
        if (r == UPX_E_OUT_OF_MEMORY)
            throwOutOfMemoryException();
        //printf("%d %d: %d %d %d\n", ph.method, r, ph.c_len, ph.u_len, new_len);
        if (r != UPX_E_OK)
            throwInternalError("decompression failed");
        if (new_len != ph.u_len)
            throwInternalError("decompression failed (size error)");

        // verify decompression
        if (ph.u_adler != upx_adler32(i_ptr, ph.u_len, ph.saved_u_adler))
            throwInternalError("decompression failed (checksum error)");
    }
    return true;
}


#if 0
bool Packer::compress(upx_bytep in, upx_bytep out,
                      const upx_compress_config_t *cconf)
{
    return ph_compress(ph, in, out, cconf);
}
#endif


bool Packer::checkDefaultCompressionRatio(unsigned u_len, unsigned c_len) const
{
    assert((int)u_len > 0);
    assert((int)c_len > 0);
    if (c_len >= u_len)
        return false;
    unsigned gain = u_len - c_len;

    if (gain < 512)             // need at least 512 bytes gain
        return false;
#if 1
    if (gain >= 4096)           // ok if we have 4096 bytes gain
        return true;
    if (gain >= u_len / 16)     // ok if we have 6.25% gain
        return true;
    return false;
#else
    return true;
#endif
}


bool Packer::checkCompressionRatio(unsigned u_len, unsigned c_len) const
{
    return checkDefaultCompressionRatio(u_len, c_len);
}

bool Packer::checkFinalCompressionRatio(const OutputFile *fo) const
{
    const unsigned u_len = file_size;
    const unsigned c_len = fo->getBytesWritten();
    return checkDefaultCompressionRatio(u_len, c_len);
}


/*************************************************************************
// decompress
**************************************************************************/

void ph_decompress(PackHeader &ph, const upx_bytep in, upx_bytep out,
                   bool verify_checksum, Filter *ft)
{
    unsigned adler;

    // verify checksum of compressed data
    if (verify_checksum)
    {
        adler = upx_adler32(in, ph.c_len, ph.saved_c_adler);
        if (adler != ph.c_adler)
            throwChecksumError();
    }

    // decompress
    unsigned new_len = ph.u_len;
    int r = upx_decompress(in, ph.c_len, out, &new_len, ph.method, &ph.compress_result);
    if (r == UPX_E_OUT_OF_MEMORY)
        throwOutOfMemoryException();
    if (r != UPX_E_OK || new_len != ph.u_len)
        throwCompressedDataViolation();

    // verify checksum of decompressed data
    if (verify_checksum)
    {
        if (ft)
            ft->unfilter(out, ph.u_len);
        adler = upx_adler32(out, ph.u_len, ph.saved_u_adler);
        if (adler != ph.u_adler)
            throwChecksumError();
    }
}


void Packer::decompress(const upx_bytep in, upx_bytep out,
                        bool verify_checksum, Filter *ft)
{
    ph_decompress(ph, in, out, verify_checksum, ft);
}