src: refactoring: create packhead.h and move some methods

2023-08-11 03:57:20 +02:00
parent c65c882ecc
commit 777d4f5279
7 changed files with 217 additions and 174 deletions
@@ -0,0 +1,99 @@
+/* packhead.h --
+
+   This file is part of the UPX executable compressor.
+
+   Copyright (C) 1996-2023 Markus Franz Xaver Johannes Oberhumer
+   Copyright (C) 1996-2023 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
+   <markus@oberhumer.com>               <ezerotven+github@gmail.com>
+ */
+
+#pragma once
+
+class Filter;
+
+/*************************************************************************
+// PackHeader
+// also see stub/src/include/header.S
+**************************************************************************/
+
+class PackHeader final {
+public:
+    explicit PackHeader() noexcept;
+    ~PackHeader() noexcept = default;
+
+    void putPackHeader(SPAN_S(byte) p) const;
+    bool decodePackHeaderFromBuf(SPAN_S(const byte) b, int blen);
+
+    int getPackHeaderSize() const;
+
+    // fields stored in compressed file => see header.S
+    // enum { magic = UPX_MAGIC_LE32 };
+    int version;
+    int format; // executable format
+    int method; // compresison method
+    int level;  // compresison level 1..10
+    unsigned u_len;
+    unsigned c_len;
+    unsigned u_adler;
+    unsigned c_adler;
+    unsigned u_file_size;
+    int filter;
+    int filter_cto;
+    int n_mru; // FIXME: rename to filter_misc
+    int header_checksum;
+
+    // support fields for verifying decompression
+    unsigned saved_u_adler;
+    unsigned saved_c_adler;
+
+    // info fields set by decodePackHeaderFromBuf()
+    unsigned buf_offset;
+
+    // info fields set by Packer::compress()
+    upx_compress_result_t compress_result;
+    // unsigned min_offset_found;
+    unsigned max_offset_found;
+    // unsigned min_match_found;
+    unsigned max_match_found;
+    // unsigned min_run_found;
+    unsigned max_run_found;
+    unsigned first_offset_found;
+    // unsigned same_match_offsets_found;
+
+    // info fields set by Packer::compressWithFilters()
+    unsigned overlap_overhead;
+};
+
+/*************************************************************************
+// ph default util functions
+**************************************************************************/
+
+bool ph_is_forced_method(int method) noexcept; // predicate
+int ph_force_method(int method) noexcept;      // (0x80ul<<24)|method
+int ph_forced_method(int method) noexcept;     // (0x80ul<<24)|method ==> method
+
+bool ph_skipVerify(const PackHeader &ph) noexcept;
+
+void ph_decompress(PackHeader &ph, SPAN_P(const byte) in, SPAN_P(byte) out, bool verify_checksum,
+                   Filter *ft);
+
+bool ph_testOverlappingDecompression(const PackHeader &ph, const byte *buf, const byte *tbuf,
+                                     unsigned overlap_overhead);