/* p_unix.h --

   This file is part of the UPX executable compressor.

   Copyright (C) 1996-2025 Markus Franz Xaver Johannes Oberhumer

   Copyright (C) 1996-2025 Laszlo Molnar

   Copyright (C) 2000-2025 John F. Reiser

   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

   <markus@oberhumer.com>               <ezerotven+github@gmail.com>

   John F. Reiser

   <jreiser@users.sourceforge.net>

 */

#pragma once

#ifndef __UPX_P_UNIX_H

#define __UPX_P_UNIX_H 1

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

// Abstract class for all Unix-type packers.

// Already provides most of the functionality.

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

class PackUnix : public Packer

{

public:

    ~PackUnix();

    typedef Packer super;

protected:

    PackUnix(InputFile *f);

public:

    virtual int getVersion() const override { return 13; }

    virtual const int *getFilters() const override { return nullptr; }

    virtual int getStrategy(Filter &);

    virtual void pack(OutputFile *fo) override;

    virtual void unpack(OutputFile *fo) override;

    virtual tribool canPack() override;

    virtual tribool canUnpack() override; // bool, except -1: format known, but not packed

    int find_overlay_offset(MemBuffer const &buf);

protected:

    // called by the generic pack()

    virtual void pack1(OutputFile *, Filter &);  // generate executable header

    virtual int  pack2(OutputFile *, Filter &);  // append compressed data

    virtual off_t pack3(OutputFile *, Filter &);  // append loader

    virtual void pack4(OutputFile *, Filter &);  // append PackHeader

    virtual void patchLoader() = 0;

    virtual void patchLoaderChecksum();

    virtual void updateLoader(OutputFile *) = 0;

    virtual void writePackHeader(OutputFile *fo);

    virtual bool checkCompressionRatio(unsigned, unsigned) const override;

protected:

    struct Extent {

        upx_off_t offset;

        upx_off_t size;

    };

    virtual void packExtent(const Extent &x,

        Filter *, OutputFile *,

        unsigned hdr_len = 0, unsigned b_extra = 0 ,

        bool inhibit_compression_check = false);

    virtual unsigned unpackExtent(unsigned wanted, OutputFile *fo,

        unsigned &c_adler, unsigned &u_adler,

        bool first_PF_X,

        int is_rewrite = false  // 0(false): write; 1(true): rewrite; -1: no write

        );

    unsigned total_in, total_out;  // unpack

    int exetype;  // 0: unknown; 1: ELF; 2: pre-ELF; -1: /bin/sh; -2: Java

    unsigned blocksize;

    unsigned progid;              // program id

    unsigned overlay_offset;      // used when decompressing

    MemBuffer loader;

    int lsize;

    MemBuffer pt_dynamic;

    int sz_dynamic;

    unsigned b_len;  // total length of b_info blocks  FIXME: unused

    unsigned methods_used;  // bitmask of compression methods

    unsigned szb_info;  // 3*4 (sizeof b_info); or 2*4 if ancient

    unsigned saved_opt_android_shlib;

    // must agree with stub/linux.hh

    packed_struct(b_info) { // 12-byte header before each compressed block

        NE32 sz_unc;  // uncompressed_size

        NE32 sz_cpr;  //   compressed_size

        unsigned char b_method;  // compression algorithm

        unsigned char b_ftid;  // filter id

        unsigned char b_cto8;  // filter parameter

        unsigned char b_extra;

    };

    packed_struct(l_info) { // 12-byte trailer in header for loader

        LE32 l_checksum;

        LE32 l_magic;

        LE16 l_lsize;

        unsigned char l_version;

        unsigned char l_format;

    };

    packed_struct(p_info) { // 12-byte packed program header

        NE32 p_progid;

        NE32 p_filesize;

        NE32 p_blocksize;

    };

    struct l_info linfo;

    // do not change !!!

    enum { OVERHEAD = 2048 };

};

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

// abstract classes encapsulating endian issues

// note: UPX_MAGIC is always stored in le32 format

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

class PackUnixBe32 : public PackUnix

{

    typedef PackUnix super;

protected:

    PackUnixBe32(InputFile *f) : super(f) { bele = &N_BELE_RTP::be_policy; }

    // must agree with stub/linux.hh

    packed_struct(b_info) { // 12-byte header before each compressed block

        BE32 sz_unc;  // uncompressed_size

        BE32 sz_cpr;  //   compressed_size

        unsigned char b_method;  // compression algorithm

        unsigned char b_ftid;  // filter id

        unsigned char b_cto8;  // filter parameter

        unsigned char b_extra;

    };

    packed_struct(l_info) { // 12-byte trailer in header for loader

        BE32 l_checksum;

        BE32 l_magic;

        BE16 l_lsize;

        unsigned char l_version;

        unsigned char l_format;

    };

    packed_struct(p_info)  {// 12-byte packed program header

        BE32 p_progid;

        BE32 p_filesize;

        BE32 p_blocksize;

    };

};

class PackUnixLe32 : public PackUnix

{

    typedef PackUnix super;

protected:

    PackUnixLe32(InputFile *f) : super(f) { bele = &N_BELE_RTP::le_policy; }

    // must agree with stub/linux.hh

    packed_struct(b_info) { // 12-byte header before each compressed block

        LE32 sz_unc;  // uncompressed_size

        LE32 sz_cpr;  //   compressed_size

        unsigned char b_method;  // compression algorithm

        unsigned char b_ftid;  // filter id

        unsigned char b_cto8;  // filter parameter

        unsigned char b_extra;

    };

    packed_struct(l_info) { // 12-byte trailer in header for loader

        LE32 l_checksum;

        LE32 l_magic;

        LE16 l_lsize;

        unsigned char l_version;

        unsigned char l_format;

    };

    packed_struct(p_info) { // 12-byte packed program header

        LE32 p_progid;

        LE32 p_filesize;

        LE32 p_blocksize;

    };

};

#endif /* already included */

/* vim:set ts=4 sw=4 et: */