53 lines
1.9 KiB
C++
53 lines
1.9 KiB
C++
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// BlitzSteam - Steam wrapper for Blitz
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// Copyright (C) 2015 Xaymar (Michael Fabian Dirks)
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as
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// published by the Free Software Foundation, either version 3 of the
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// License, or (at your option) any later version.
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//
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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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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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#include "BlitzPointer.h"
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DLL(intptr_t) BS_BlitzPointer_GetReturnAddress() {
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intptr_t BasePointer, ReturnAddress;
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__asm { //ASM. Do touch if suicidal.
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mov BasePointer, ebp; // Store current BasePointer
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}
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// Blitz uses X86 Call-Near (E8) instructions to call its own functions.
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// We can simply deduce the Return Address like this because of that.
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//-- Parent_EBP = *EBP
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//-- Parent_RP = Parent_EBP + 16
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ReturnAddress = *(intptr_t*)((*(intptr_t*)BasePointer) + 16);
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return ReturnAddress;
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}
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DLL(intptr_t) BS_BlitzPointer_GetFunctionPointer() {
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intptr_t BasePointer, ReturnAddress, FunctionPointer;
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__asm { //ASM. Do touch if suicidal.
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mov BasePointer, ebp; // Store current BasePointer
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}
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// Blitz uses X86 Call-Near (E8) instructions to call its own functions.
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// We can simply deduce the Return Address like this because of that.
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//-- Parent_EBP = *EBP
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//-- Parent_RP = Parent_EBP + 16
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ReturnAddress = *(intptr_t*)((*(intptr_t*)BasePointer) + 16);
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// And since it's a Call-Near, the call is offset to the return address.
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FunctionPointer = ReturnAddress + *(intptr_t*)(ReturnAddress - 4);
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return FunctionPointer;
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}
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