mirror of
https://github.com/upx/upx
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133 lines
4.0 KiB
C++
133 lines
4.0 KiB
C++
/* p_sys.cpp --
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This file is part of the UPX executable compressor.
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Copyright (C) 1996-2000 Markus Franz Xaver Johannes Oberhumer
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Copyright (C) 1996-2000 Laszlo Molnar
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UPX and the UCL library are free software; you can redistribute them
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and/or modify them under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of
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the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; see the file COPYING.
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If not, write to the Free Software Foundation, Inc.,
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59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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Markus F.X.J. Oberhumer Laszlo Molnar
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markus.oberhumer@jk.uni-linz.ac.at ml1050@cdata.tvnet.hu
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*/
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#include "conf.h"
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#include "file.h"
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#include "filter.h"
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#include "packer.h"
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#include "p_com.h"
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#include "p_sys.h"
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static const
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#include "stub/l_sys.h"
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/*************************************************************************
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//
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**************************************************************************/
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bool PackSys::canPack()
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{
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unsigned char buf[128];
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fi->readx(buf,128);
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if (memcmp (buf,"\xff\xff\xff\xff",4) != 0)
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return false;
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if (!fn_has_ext(fi->getName(),"sys"))
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return false;
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if (find_le32(buf,128,UPX_MAGIC_LE32))
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throwAlreadyPacked();
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if (file_size < 1024)
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throwCantPack("file is too small");
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if (file_size > 0x10000)
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throwCantPack("file is too big for dos/sys");
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return true;
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}
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/*************************************************************************
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//
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**************************************************************************/
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void PackSys::patchLoader(OutputFile *fo,
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upx_byte *loader, int lsize,
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unsigned calls, unsigned overlapoh)
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{
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const int filter_id = ph.filter;
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const int e_len = getLoaderSection("SYSCUTPO");
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const int d_len = lsize - e_len;
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assert(e_len > 0 && e_len < 256);
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assert(d_len > 0 && d_len < 256);
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if (ph.u_len + d_len + overlapoh > 0xfffe)
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throwNotCompressible();
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memcpy(loader,ibuf,6); // copy from orig. header
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memcpy(loader+8,ibuf+8,2); // opendos wants this word too
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unsigned copy_to = ph.u_len + d_len + overlapoh;
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patch_le16(loader,lsize,"JO",get_le16(ibuf+6)-copy_to-1);
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if (filter_id)
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{
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assert(calls > 0);
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patch_le16(loader,lsize,"CT",calls);
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}
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unsigned jmp_pos;
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jmp_pos = find_le16(loader,e_len,get_le16("JM")) - loader;
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patch_le16(loader,e_len,"JM",ph.u_len+overlapoh+2-jmp_pos-2);
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loader[getLoaderSection("SYSSUBSI") - 1] = (upx_byte) -e_len;
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patch_le16(loader,e_len,"DI",copy_to);
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patch_le16(loader,e_len,"SI",ph.c_len+e_len+d_len-1);
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// write loader + compressed file
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fo->write(loader,e_len); // entry
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fo->write(obuf,ph.c_len);
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fo->write(loader+e_len,d_len); // decompressor
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}
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int PackSys::buildLoader(const Filter *ft)
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{
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const int filter_id = ft->id;
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initLoader(nrv2b_loader,sizeof(nrv2b_loader));
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addLoader("SYSMAIN1",
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opt->cpu == opt->CPU_8086 ? "SYSI0861" : "SYSI2861",
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"SYSMAIN2""SYSSUBSI",
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filter_id ? "SYSCALLT" : "",
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"SYSMAIN3""UPX1HEAD""SYSCUTPO""NRV2B160""NRVDDONE""NRVDECO1",
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ph.max_offset_found <= 0xd00 ? "NRVLED00" : "NRVGTD00",
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"NRVDECO2""NRV2B169",
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NULL
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);
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if (filter_id)
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addFilter16(filter_id);
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addLoader("SYSMAIN5",
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opt->cpu == opt->CPU_8086 ? "SYSI0862" : "SYSI2862",
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"SYSJUMP1",
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NULL
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);
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return getLoaderSize();
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}
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/*
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vi:ts=4:et
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*/
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