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[NTDLL]: Cleanup and half-fix LdrpCheckForLoadedDll, including adding comments for where it's broken. This uses RtlImageNtHeaderEx with much stringent checks as well.

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svn path=/trunk/; revision=52621
This commit is contained in:
Alex Ionescu 2011-07-11 00:12:33 +00:00
parent f1c4df527e
commit 1b775b8d8a
1 changed files with 36 additions and 36 deletions
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70
reactos/dll/ntdll/ldr/ldrutils.c
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@ -1394,6 +1394,7 @@ LdrpCheckForLoadedDllHandle(IN PVOID Base,
return FALSE;
}
/* NOTE: This function is b0rked and in the process of being slowly unf*cked */
BOOLEAN
NTAPI
LdrpCheckForLoadedDll(IN PWSTR DllPath,
@ -1417,11 +1418,13 @@ LdrpCheckForLoadedDll(IN PWSTR DllPath,
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:
@ -1459,7 +1462,7 @@ lookinhash:
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 @@ lookinhash:
/* 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 @@ lookinhash:
NULL);
/* Check if that was successful */
if (!Length || Length > sizeof(NameBuf) - sizeof(UNICODE_NULL))
if (!(Length) || (Length > (sizeof(NameBuf) - sizeof(UNICODE_NULL))))
{
if (ShowSnaps)
{
@ -1503,17 +1507,21 @@ lookinhash:
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 */
@ -1523,18 +1531,10 @@ lookinhash:
{
/* 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,
&NtPathName,
@ -1551,7 +1551,6 @@ lookinhash:
OBJ_CASE_INSENSITIVE,
NULL,
NULL);
Status = NtOpenFile(&FileHandle,
SYNCHRONIZE | FILE_EXECUTE,
&ObjectAttributes,
@ -1567,7 +1566,9 @@ lookinhash:
/* 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 @@ lookinhash:
ViewShare,
0,
PAGE_EXECUTE);
/* Close section handle */
NtClose(SectionHandle);
@ -1598,52 +1600,51 @@ lookinhash:
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 @@ lookinhash:
_SEH2_END;
}
/* Unmap the section */
/* Unmap the section and fail */
NtUnmapViewOfSection(NtCurrentProcess(), ViewBase);
return FALSE;
}