43 lines
927 B
C
43 lines
927 B
C
#ifdef WIN32
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#include <Windows.h>
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/**
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* 跳转指令结构
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*************************/
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#pragma pack(push, 1)
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struct jmpInstruct
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{
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unsigned char code;
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unsigned int offset;
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};
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#pragma pack(pop)
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//计算跳转偏移地址
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#define CalcJmpOffset(s, d) ((SIZE_T)(d) - ((SIZE_T)(s) + 5))
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int patchFunction(void *dest, void *src)
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{
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struct jmpInstruct* fn = (struct jmpInstruct*)src;
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DWORD dwOldProtect;
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MEMORY_BASIC_INFORMATION mbi;
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if ( VirtualQuery(fn, &mbi, sizeof(mbi)) != sizeof(mbi) )
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return GetLastError();
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//修改_output_l函数的内存保护模式，增加可读写保护
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if ( !VirtualProtect(fn, sizeof(*fn), PAGE_EXECUTE_READWRITE, &dwOldProtect) )
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return GetLastError();
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fn->code = 0xE9;
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fn->offset = (UINT)CalcJmpOffset(fn, dest);
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//还原_output_l函数的内存保护模式
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if ( !VirtualProtect(fn, sizeof(*fn), dwOldProtect, &dwOldProtect) )
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return GetLastError();
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return 0;
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}
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#endif
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