78 lines
1.4 KiB
C++
78 lines
1.4 KiB
C++
/*++
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Copyright (c) 2001 Microsoft Corporation
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Module Name:
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RCenter.cpp
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Abstract:
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RCenter attempts to compare file extensions from a CD's root against known media
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types. When they get the file's extension, they get ".txt" and then add one to the
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pointer to leave "txt".
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The trouble is that if a file has no extension they end up with a null pointer for
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the extension string, add one to it, and then pass it into lstrcmpiA. lstrcmpiA
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can handle null pointers, but not "1" pointers.
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This shim treats bad pointers as the shortest possible string:
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lstrcmpi(BAD_PTR, "Hello World") == LESS_THAN
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lstrcmpi("Hello World", BAD_PTR) == GREATER_THAN
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lstrcmpi(BAD_PTR, BAD_PTR) == EQUAL
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Notes:
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This is an app specific shim.
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History:
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11/13/2001 astritz Created
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--*/
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#include "precomp.h"
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IMPLEMENT_SHIM_BEGIN(RCenter)
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#include "ShimHookMacro.h"
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APIHOOK_ENUM_BEGIN
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APIHOOK_ENUM_ENTRY(lstrcmpiA)
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APIHOOK_ENUM_END
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/*++
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Hook lstrcmpiA to handle NULL pointers as above.
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--*/
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BOOL
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APIHOOK(lstrcmpiA)(
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LPCSTR lpString1,
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LPCSTR lpString2
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)
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{
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if (IsBadReadPtr(lpString1, 1)) {
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if (IsBadReadPtr(lpString2, 1)) {
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return 0;
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} else {
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return -1;
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}
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} else if (IsBadReadPtr(lpString2, 1)) {
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return 1;
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}
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return ORIGINAL_API(lstrcmpiA)(lpString1, lpString2);
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}
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/*++
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Register hooked functions
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--*/
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HOOK_BEGIN
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APIHOOK_ENTRY(KERNEL32.DLL, lstrcmpiA)
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HOOK_END
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IMPLEMENT_SHIM_END |