mirror of
https://github.com/FirebirdSQL/firebird.git
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143 lines
4.4 KiB
C++
143 lines
4.4 KiB
C++
/*
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* PROGRAM: Client/Server Common Code
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* MODULE: ClumpletReader.h
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* DESCRIPTION: Secure handling of clumplet buffers
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*
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* The contents of this file are subject to the Initial
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* Developer's Public License Version 1.0 (the "License");
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* you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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* http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_idpl.
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*
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* Software distributed under the License is distributed AS IS,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied.
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* See the License for the specific language governing rights
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* and limitations under the License.
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*
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* The Original Code was created by Nickolay Samofatov
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* for the Firebird Open Source RDBMS project.
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*
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* Copyright (c) 2004 Nickolay Samofatov <nickolay@broadviewsoftware.com>
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* and all contributors signed below.
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*
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* All Rights Reserved.
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* Contributor(s): ______________________________________.
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*
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*
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*/
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#ifndef CLUMPLETREADER_H
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#define CLUMPLETREADER_H
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#include "../common/classes/alloc.h"
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#include "../common/classes/array.h"
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#include "../common/classes/fb_string.h"
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#define DEBUG_CLUMPLETS
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#if defined(DEV_BUILD) && !defined(DEBUG_CLUMPLETS)
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#define DEBUG_CLUMPLETS
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#endif
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namespace Firebird {
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// This class provides read access for clumplet structure
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// Note: it doesn't make a copy of buffer it reads
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class ClumpletReader : protected AutoStorage
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{
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public:
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enum Kind {Tagged, UnTagged, SpbAttach, SpbStart, Tpb/*, SpbInfo*/, WideTagged, WideUnTagged, SpbItems};
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// Constructor prepares an object from plain PB
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ClumpletReader(Kind k, const UCHAR* buffer, size_t buffLen);
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ClumpletReader(MemoryPool& pool, Kind k, const UCHAR* buffer, size_t buffLen);
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virtual ~ClumpletReader() { }
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// Navigation in clumplet buffer
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bool isEof() const { return cur_offset >= getBufferLength(); }
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void moveNext();
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void rewind();
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bool find(UCHAR tag);
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// Methods which work with currently selected clumplet
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UCHAR getClumpTag() const;
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size_t getClumpLength() const;
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SLONG getInt() const;
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bool getBoolean() const;
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SINT64 getBigInt() const;
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string& getString(string& str) const;
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PathName& getPath(PathName& str) const;
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const UCHAR* getBytes() const;
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double getDouble() const;
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ISC_TIMESTAMP getTimeStamp() const;
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ISC_TIME getTime() const { return getInt(); }
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ISC_DATE getDate() const { return getInt(); }
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// Return the tag for buffer (usually structure version)
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UCHAR getBufferTag() const;
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size_t getBufferLength() const
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{
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size_t rc = getBufferEnd() - getBuffer();
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if (rc == 1 && kind != UnTagged && kind != SpbStart &&
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kind != WideUnTagged && kind != SpbItems)
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{
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rc = 0;
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}
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return rc;
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}
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size_t getCurOffset() const { return cur_offset; }
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void setCurOffset(size_t newOffset) { cur_offset = newOffset; }
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#ifdef DEBUG_CLUMPLETS
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// Sometimes it's really useful to have it in case of errors
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void dump() const;
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#endif
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// it is not exact comparison as clumplets may have same tags
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// but in different order
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bool simpleCompare(const ClumpletReader &other) const
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{
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const size_t len = getBufferLength();
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return (len == other.getBufferLength()) && (memcmp(getBuffer(), other.getBuffer(), len) == 0);
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}
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protected:
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enum ClumpletType {TraditionalDpb, SingleTpb, StringSpb, IntSpb, ByteSpb, Wide};
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ClumpletType getClumpletType(UCHAR tag) const;
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size_t getClumpletSize(bool wTag, bool wLength, bool wData) const;
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void adjustSpbState();
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size_t cur_offset;
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const Kind kind;
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UCHAR spbState; // Reflects state of spb parser/writer
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// Methods are virtual so writer can override 'em
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virtual const UCHAR* getBuffer() const { return static_buffer; }
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virtual const UCHAR* getBufferEnd() const { return static_buffer_end; }
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// These functions are called when error condition is detected by this class.
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// They may throw exceptions. If they don't reader tries to do something
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// sensible, certainly not overwrite memory or read past the end of buffer
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// This appears to be a programming error in buffer access pattern
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virtual void usage_mistake(const char* what) const;
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// This is called when passed buffer appears invalid
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virtual void invalid_structure(const char* what) const;
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private:
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// Assignment and copy constructor not implemented.
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ClumpletReader(const ClumpletReader& from);
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ClumpletReader& operator=(const ClumpletReader& from);
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const UCHAR* static_buffer;
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const UCHAR* static_buffer_end;
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static SINT64 fromVaxInteger(const UCHAR* ptr, size_t length);
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};
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} // namespace Firebird
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#endif // CLUMPLETREADER_H
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