[ion] 52621: [NTDLL]: Cleanup and half-fix LdrpCheckForLoadedDll, including adding comments for where it's broken. This uses RtlImageNtHeaderEx with much stringent checks as well.
Author: ion Date: Mon Jul 11 00:12:33 2011 New Revision: 52621
URL: http://svn.reactos.org/svn/reactos?rev=52621&view=rev Log: [NTDLL]: Cleanup and half-fix LdrpCheckForLoadedDll, including adding comments for where it's broken. This uses RtlImageNtHeaderEx with much stringent checks as well.
Modified: trunk/reactos/dll/ntdll/ldr/ldrutils.c
Modified: trunk/reactos/dll/ntdll/ldr/ldrutils.c URL: http://svn.reactos.org/svn/reactos/trunk/reactos/dll/ntdll/ldr/ldrutils.c?re... ============================================================================== --- trunk/reactos/dll/ntdll/ldr/ldrutils.c [iso-8859-1] (original) +++ trunk/reactos/dll/ntdll/ldr/ldrutils.c [iso-8859-1] Mon Jul 11 00:12:33 2011 @@ -1394,6 +1394,7 @@ return FALSE; }
+/* NOTE: This function is b0rked and in the process of being slowly unf*cked */ BOOLEAN NTAPI LdrpCheckForLoadedDll(IN PWSTR DllPath, @@ -1417,12 +1418,14 @@ PVOID ViewBase = NULL; SIZE_T ViewSize = 0; PIMAGE_NT_HEADERS NtHeader, NtHeader2; - DPRINT("LdrpCheckForLoadedDll('%S' '%wZ' %d %d %p)\n", DllPath, DllName, Flag, RedirectedDll, LdrEntry);
/* Check if a dll name was provided */ - if (!DllName->Buffer || !DllName->Buffer[0]) return FALSE; - + if (!(DllName->Buffer) || !(DllName->Buffer[0])) return FALSE; + + /* FIXME: Warning, "Flag" is used as magic instead of "Static" */ + /* FIXME: Warning, code does not support redirection at all */ + /* Look in the hash table if flag was set */ lookinhash: if (Flag) @@ -1459,7 +1462,7 @@ while (*wc) { /* Check for a slash in the current position*/ - if (*wc == L'\' || *wc == L'/') + if ((*wc == L'\') || (*wc == L'/')) { /* Found the slash, so dll name contains path */ FullPath = TRUE; @@ -1467,6 +1470,7 @@ /* Setup full dll name string */ FullDllName.Buffer = NameBuf;
+ /* FIXME: This is from the Windows 2000 loader, not XP/2003, we should call LdrpSearchPath */ Length = RtlDosSearchPath_U(DllPath ? DllPath : LdrpDefaultPath.Buffer, DllName->Buffer, NULL, @@ -1475,7 +1479,7 @@ NULL);
/* Check if that was successful */ - if (!Length || Length > sizeof(NameBuf) - sizeof(UNICODE_NULL)) + if (!(Length) || (Length > (sizeof(NameBuf) - sizeof(UNICODE_NULL)))) { if (ShowSnaps) { @@ -1502,18 +1506,22 @@ Flag = TRUE; goto lookinhash; } - - /* Now go through the InLoadOrder module list */ + + /* FIXME: Warning, activation context missing */ + /* NOTE: From here on down, everything looks good */ + + /* Loop the module list */ ListHead = &NtCurrentPeb()->Ldr->InLoadOrderModuleList; ListEntry = ListHead->Flink; - while (ListEntry != ListHead) { - /* Get the containing record of the current entry and advance to the next one */ - CurEntry = CONTAINING_RECORD(ListEntry, LDR_DATA_TABLE_ENTRY, InLoadOrderLinks); + /* Get the current entry and advance to the next one */ + CurEntry = CONTAINING_RECORD(ListEntry, + LDR_DATA_TABLE_ENTRY, + InLoadOrderLinks); ListEntry = ListEntry->Flink;
- /* Check if it's already being unloaded */ + /* Check if it's being unloaded */ if (!CurEntry->InMemoryOrderModuleList.Flink) continue;
/* Check if name matches */ @@ -1523,17 +1531,9 @@ { /* Found it */ *LdrEntry = CurEntry; - - /* Find activation context */ - //Status = RtlFindActivationContextSectionString(0, NULL, ACTIVATION_CONTEXT_SECTION_DLL_REDIRECTION, DllName, NULL); - //if (!NT_SUCCESS(Status)) - // return FALSE; - //else return TRUE; } } - - /* The DLL was not found in the load order modules list. Perform a complex check */
/* Convert given path to NT path */ if (!RtlDosPathNameToNtPathName_U(FullDllName.Buffer, @@ -1551,7 +1551,6 @@ OBJ_CASE_INSENSITIVE, NULL, NULL); - Status = NtOpenFile(&FileHandle, SYNCHRONIZE | FILE_EXECUTE, &ObjectAttributes, @@ -1567,7 +1566,9 @@
/* Create a section for this file */ Status = NtCreateSection(&SectionHandle, - SECTION_MAP_READ | SECTION_MAP_EXECUTE | SECTION_MAP_WRITE, + SECTION_MAP_READ | + SECTION_MAP_EXECUTE | + SECTION_MAP_WRITE, NULL, NULL, PAGE_EXECUTE, @@ -1591,6 +1592,7 @@ ViewShare, 0, PAGE_EXECUTE); + /* Close section handle */ NtClose(SectionHandle);
@@ -1598,52 +1600,51 @@ if (!NT_SUCCESS(Status)) return FALSE;
/* Get pointer to the NT header of this section */ - NtHeader = RtlImageNtHeader(ViewBase); - if (!NtHeader) + Status = RtlImageNtHeaderEx(0, ViewBase, ViewSize, &NtHeader); + if (!(NT_SUCCESS(Status)) || !(NtHeader)) { /* Unmap the section and fail */ NtUnmapViewOfSection(NtCurrentProcess(), ViewBase); return FALSE; }
- /* Go through the list of modules */ + /* Go through the list of modules again */ ListHead = &NtCurrentPeb()->Ldr->InLoadOrderModuleList; ListEntry = ListHead->Flink; - while (ListEntry != ListHead) { - CurEntry = CONTAINING_RECORD(ListEntry, LDR_DATA_TABLE_ENTRY, InLoadOrderLinks); + /* Get the current entry and advance to the next one */ + CurEntry = CONTAINING_RECORD(ListEntry, + LDR_DATA_TABLE_ENTRY, + InLoadOrderLinks); ListEntry = ListEntry->Flink;
- /* Check if it's already being unloaded */ + /* Check if it's in the process of being unloaded */ if (!CurEntry->InMemoryOrderModuleList.Flink) continue; - + + /* The header is untrusted, use SEH */ _SEH2_TRY { /* Check if timedate stamp and sizes match */ - if (CurEntry->TimeDateStamp == NtHeader->FileHeader.TimeDateStamp && - CurEntry->SizeOfImage == NtHeader->OptionalHeader.SizeOfImage) + if ((CurEntry->TimeDateStamp == NtHeader->FileHeader.TimeDateStamp) && + (CurEntry->SizeOfImage == NtHeader->OptionalHeader.SizeOfImage)) { /* Time, date and size match. Let's compare their headers */ NtHeader2 = RtlImageNtHeader(CurEntry->DllBase); - if (RtlCompareMemory(NtHeader2, NtHeader, sizeof(IMAGE_NT_HEADERS))) { /* Headers match too! Finally ask the kernel to compare mapped files */ Status = ZwAreMappedFilesTheSame(CurEntry->DllBase, ViewBase); - if (!NT_SUCCESS(Status)) { + /* Almost identical, but not quite, keep trying */ _SEH2_YIELD(continue;) } else { - /* This is our entry! */ + /* This is our entry!, unmap and return success */ *LdrEntry = CurEntry; - - /* Unmap the section */ NtUnmapViewOfSection(NtCurrentProcess(), ViewBase); - _SEH2_YIELD(return TRUE;) } } @@ -1656,9 +1657,8 @@ _SEH2_END; }
- /* Unmap the section */ + /* Unmap the section and fail */ NtUnmapViewOfSection(NtCurrentProcess(), ViewBase); - return FALSE; }
-
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