reactos/base/services/svchost/svchost.c

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/*
* PROJECT: ReactOS Service Host
* LICENSE: BSD - See COPYING.ARM in the top level directory
* FILE: base/services/svchost/svchost.c
* PURPOSE: Main Service Host Implementation Routines
* PROGRAMMERS: ReactOS Portable Systems Group
*/
/* INCLUDES ******************************************************************/
#include "svchost.h"
#include <objidl.h>
/* GLOBALS *******************************************************************/
LIST_ENTRY DllList;
CRITICAL_SECTION ListLock;
DWORD ServiceCount;
LPCWSTR ServiceNames;
PSVCHOST_SERVICE ServiceArray;
/* FUNCTIONS *****************************************************************/
__callback
LONG
WINAPI
SvchostUnhandledExceptionFilter (
_In_ struct _EXCEPTION_POINTERS * ExceptionInfo
)
{
/* Call the default OS handler */
return RtlUnhandledExceptionFilter(ExceptionInfo);
}
VOID
WINAPI
DummySvchostCtrlHandler (
_In_ DWORD dwControl
)
{
/* This is just a stub while we abort loading */
return;
}
PSVCHOST_OPTIONS
WINAPI
BuildCommandOptions (
_In_ LPWSTR pszCmdLine
)
{
ULONG cbCmdLine;
PSVCHOST_OPTIONS pOptions;
LPWSTR pch, pGroupNameStart, lpServiceGroup;
LPWSTR *pGroupName = NULL;
/* Nothing to do without a command-line */
if (pszCmdLine == NULL) return ERROR_SUCCESS;
/* Get the length if the command line*/
cbCmdLine = sizeof(WCHAR) * lstrlenW(pszCmdLine) + sizeof(UNICODE_NULL);
/* Allocate a buffer for the parsed options */
pOptions = MemAlloc(HEAP_ZERO_MEMORY, cbCmdLine + sizeof(*pOptions));
if (pOptions == NULL) return ERROR_SUCCESS;
/* Copy the buffer into the parsed options block */
pOptions->CmdLineBuffer = (PWCHAR)(pOptions + 1);
memcpy(pOptions->CmdLineBuffer, pszCmdLine, cbCmdLine);
/* Set the command-line as being inside the block itself */
pch = pOptions->CmdLineBuffer;
ASSERT(pch);
pOptions->CmdLine = pch;
/* Now scan it */
while (*pch != UNICODE_NULL)
{
/* And look for the first space or TAB */
if ((*pch == ' ') || (*pch == '\t'))
{
/* Terminate the command-line there */
*pch++ = UNICODE_NULL;
break;
}
/* Keep searching */
pch++;
}
/* Lowercase the entire command line, but not the options */
SvchostCharLowerW(pOptions->CmdLine);
/* Loop over the command-line */
while (*pch != UNICODE_NULL)
{
/* Do an inner loop within it */
while (*pch != UNICODE_NULL)
{
/* And keep going until we find a space or TAB */
if ((*pch != ' ') && (*pch != '\t')) break;
pch++;
}
/* Did we reach the end? If so, bail out */
if (*pch == UNICODE_NULL) break;
/* We found the space -- is it followed by a dash or slash? */
if ((*pch == '-' || *pch == '/') && (*(pch + 1) != UNICODE_NULL))
{
/* Yep, and there's at least one character. Is it k or K? */
pch++;
if (*pch == 'k' || *pch == 'K')
{
/* Yep, we have a proper command line with a group! */
pOptions->HasServiceGroup = TRUE;
pGroupName = &pOptions->ServiceGroupName;
}
/* Keep going -- the name follows between spaces or quotes */
pch++;
}
else
{
/* Nope, so this might be the group being entered */
pGroupNameStart = pch;
/* Check if there's a quote */
if ((*pch == '"') && (*(pch + 1) != UNICODE_NULL))
{
/* There is, keep going until the quote is over with */
pGroupNameStart = ++pch;
while (*pch) if (*pch++ == '"') break;
}
else
{
/* No quote, so keep going until the next space or TAB */
while ((*pch) && ((*pch != ' ') && (*pch != '\t'))) pch++;
}
/* Now we have a space or quote delimited name, terminate it */
if (*pch) *pch++ = UNICODE_NULL;
/* Ok, so we have a string -- was it preceded by a -K or /K? */
if (pGroupName)
{
/* Yes it was, remember this, and don't overwrite it later */
*pGroupName = pGroupNameStart;
pGroupName = NULL;
}
}
}
/* Print out the service group for the debugger, and the command line */
DBG_TRACE("Command line : %ws\n", pszCmdLine);
lpServiceGroup = (pOptions->HasServiceGroup) ?
pOptions->ServiceGroupName : L"No";
DBG_TRACE("Service Group : %ws\n", lpServiceGroup);
/* Was a group specified? */
if (pOptions->HasServiceGroup == FALSE)
{
/* This isn't valid. Print out help on the debugger and fail */
DBG_TRACE("Generic Service Host\n\n"
"%ws [-k <key>] | [-r] | <service>\n\n"
" -k <key> Host all services whose ImagePath matches\n"
" %ws -k <key>.\n\n",
lpServiceGroup);
MemFree(pOptions);
pOptions = NULL;
}
/* Return the allocated option block, if valid*/
return pOptions;
}
DWORD
WINAPI
ReadPerInstanceRegistryParameters (
_In_ HKEY hKey,
_In_ PSVCHOST_OPTIONS pOptions
)
{
DWORD dwError, dwData;
HKEY hSubKey;
/* We should have a name for this service group... */
ASSERT(pOptions->ServiceGroupName);
/* Query the group to see what services are part of it */
dwError = RegQueryString(hKey,
pOptions->ServiceGroupName,
REG_MULTI_SZ,
(PBYTE*)&ServiceNames);
if ((dwError == ERROR_SUCCESS) &&
((ServiceNames == NULL) || (*ServiceNames == UNICODE_NULL)))
{
/* If the key exists but there's no data, fail */
return ERROR_INVALID_DATA;
}
/* Open the key for this group */
if (RegOpenKeyExW(hKey,
pOptions->ServiceGroupName,
0,
KEY_READ,
&hSubKey) != ERROR_SUCCESS)
{
/* If we couldn't, bail out */
return dwError;
}
/* Check if we should initialize COM */
if (RegQueryDword(hSubKey,
L"CoInitializeSecurityParam",
&dwData) == ERROR_SUCCESS)
{
/* Yes, remember the parameter to be sent when we do so */
pOptions->CoInitializeSecurityParam = dwData;
}
/* Also, if COM is requested, we must read a bunch more data... */
if (pOptions->CoInitializeSecurityParam)
{
/* First, read the authentication level, use a default if none is set */
if (RegQueryDword(hSubKey, L"AuthenticationLevel", &dwData))
{
pOptions->AuthenticationLevel = RPC_C_AUTHN_LEVEL_PKT;
}
else
{
pOptions->AuthenticationLevel = dwData;
}
/* Do the same for the impersonation level */
if (RegQueryDword(hSubKey, L"ImpersonationLevel", &dwData))
{
pOptions->ImpersonationLevel = RPC_C_IMP_LEVEL_IDENTIFY;
}
else
{
pOptions->ImpersonationLevel = dwData;
}
/* Do the same for the authentication capabilities */
if (RegQueryDword(hSubKey, L"AuthenticationCapabilities", &dwData))
{
pOptions->AuthenticationCapabilities = EOAC_NO_CUSTOM_MARSHAL |
EOAC_DISABLE_AAA;
}
else
{
pOptions->AuthenticationCapabilities = dwData;
}
}
/* Check if we need a specific RPC stack size, if not, we'll set it later */
if (!RegQueryDword(hSubKey, L"DefaultRpcStackSize", &dwData))
{
pOptions->DefaultRpcStackSize = dwData;
}
/* Finally, check if the services should be marked critical later on */
if (!RegQueryDword(hSubKey, L"SystemCritical", &dwData))
{
pOptions->SystemCritical = dwData;
}
/* All done reading the settings */
RegCloseKey(hSubKey);
return dwError;
}
VOID
WINAPI
BuildServiceArray (
_In_ PSVCHOST_OPTIONS lpOptions
)
{
DWORD dwError;
PSVCHOST_SERVICE pService;
LPCWSTR pszServiceName;
HKEY hKey;
/* Open the service host key */
dwError = RegOpenKeyExW(HKEY_LOCAL_MACHINE,
L"Software\\Microsoft\\Windows NT\\CurrentVersion\\Svchost",
0,
KEY_READ,
&hKey);
if (dwError != ERROR_SUCCESS) return;
/* Read all the parameters for this service group */
dwError = ReadPerInstanceRegistryParameters(hKey, lpOptions);
RegCloseKey(hKey);
if (dwError != ERROR_SUCCESS) return;
/* Acquire the database lock while we create the service group */
EnterCriticalSection(&ListLock);
/* Loop the array of services for this group */
pszServiceName = ServiceNames;
while (*pszServiceName != UNICODE_NULL)
{
/* For each one, increment the amount of services we'llhost */
ServiceCount++;
pszServiceName += lstrlenW(pszServiceName) + 1;
}
/* We should host at least one... */
ASSERT(ServiceCount);
/* Now allocate an array to hold all their pointers */
ServiceArray = MemAlloc(HEAP_ZERO_MEMORY, sizeof(*pService) * ServiceCount);
if (ServiceArray)
{
/* Start at the beginning of the array */
pService = ServiceArray;
/* Loop through all the services */
pszServiceName = ServiceNames;
while (*pszServiceName != UNICODE_NULL)
{
/* Save the service's name and move to the next entry */
pService++->pszServiceName = pszServiceName;
pszServiceName += lstrlenW(pszServiceName) + 1;
}
/* We should have gotten the same count as earlier! */
ASSERT(pService == ServiceArray + ServiceCount);
}
/* We're done, drop the lock */
LeaveCriticalSection(&ListLock);
}
BOOL
WINAPI
FDebugBreakForService (
_In_ LPCWSTR ServiceName
)
{
DWORD Data;
BOOL DebugBreakOn = FALSE;
HKEY hKey, hSubKey;
/* Open the key for Svchost itself */
if (RegOpenKeyExW(HKEY_LOCAL_MACHINE,
L"Software\\Microsoft\\Windows NT\\CurrentVersion\\Svchost",
0,
KEY_READ,
&hKey) == ERROR_SUCCESS)
{
/* That worked, now open the key for this service, if it exists */
if (RegOpenKeyExW(hKey, ServiceName, 0, KEY_READ, &hSubKey) == ERROR_SUCCESS)
{
/* It does -- is there a DebugBreak value set? */
if (RegQueryDword(hSubKey, L"DebugBreak", &Data) == ERROR_SUCCESS)
{
/* There is! Check if it's 0 or 1 */
DebugBreakOn = Data != 0;
}
/* Done, close the service key */
RegCloseKey(hSubKey);
}
/* Done, close the svchost key */
RegCloseKey(hKey);
}
/* Return if the value was set or not */
return DebugBreakOn;
}
DWORD
WINAPI
OpenServiceParametersKey (
_In_ LPCWSTR lpSubKey,
_Out_ PHKEY phKey
)
{
DWORD dwError;
HKEY hSubKey = NULL, hKey = NULL;
ASSERT(phKey);
/* Open the services key */
dwError = RegOpenKeyExW(HKEY_LOCAL_MACHINE,
L"System\\CurrentControlSet\\Services",
0,
KEY_READ,
&hKey);
if (dwError == ERROR_SUCCESS)
{
/* Now open the service specific key, returning its handle */
dwError = RegOpenKeyExW(hKey, lpSubKey, 0, KEY_READ, &hSubKey);
if (dwError == ERROR_SUCCESS)
{
/* And if that worked, return a handle to the parameters key */
dwError = RegOpenKeyExW(hSubKey,
L"Parameters",
0,
KEY_READ,
phKey);
}
}
/* Clean up any leftovers*/
if (hKey != NULL) RegCloseKey(hKey);
if (hSubKey != NULL) RegCloseKey(hSubKey);
return dwError;
}
VOID
WINAPI
UnloadServiceDll (
_In_ PSVCHOST_SERVICE pService
)
{
DWORD cbData;
DWORD Data;
DWORD dwType;
HKEY hKey = NULL;
cbData = 4;
Data = 0;
/* Grab the lock while we touch the thread count and potentially unload */
EnterCriticalSection(&ListLock);
/* There is one less active callout into the DLL, it may be unloadabl now */
ASSERT(pService->cServiceActiveThreadCount > 0);
pService->cServiceActiveThreadCount--;
/* Try to open the service registry key */
if (OpenServiceParametersKey(pService->pszServiceName, &hKey) == ERROR_SUCCESS)
{
/* It worked -- check if we should unload the service when stopped */
if (RegQueryValueExW(hKey,
L"ServiceDllUnloadOnStop",
0,
&dwType,
(LPBYTE)&Data,
&cbData) == ERROR_SUCCESS)
{
/* Make sure the data is correctly formatted */
if ((dwType == REG_DWORD) && (Data == 1))
{
/* Does the service still have active threads? */
if (pService->cServiceActiveThreadCount != 0)
{
/* Yep, so we can't kill it just yet */
DBG_TRACE("Skip Unload dll %ws for service %ws, "
"active threads %d\n",
pService->pDll->pszDllPath,
pService->pszServiceName,
pService->cServiceActiveThreadCount);
}
else
{
/* Nope, we're good to go */
DBG_TRACE("Unload dll %ws for service %ws\n",
pService->pDll->pszDllPath,
pService->pszServiceName);
/* Free the library and clear the module handle */
FreeLibrary(pService->pDll->hModule);
pService->pDll->hModule = NULL;
}
}
}
}
/* Drop the lock, unload is complete */
LeaveCriticalSection(&ListLock);
/* Close the parameters key if we had it */
if (hKey) RegCloseKey(hKey);
}
VOID
WINAPI
SvchostStopCallback (
_In_ PVOID Context,
_In_ BOOLEAN TimerOrWaitFired
)
{
PSVCHOST_CALLBACK_CONTEXT pSvcsStopCbContext = Context;
PSVCHOST_STOP_CALLBACK pfnStopCallback;
/* Hold the lock while we grab the callback */
EnterCriticalSection(&ListLock);
/* Grab the callback, then clear it */
ASSERT(pSvcsStopCbContext->pService != NULL);
pfnStopCallback = pSvcsStopCbContext->pService->pfnStopCallback;
ASSERT(pfnStopCallback != NULL);
pSvcsStopCbContext->pService->pfnStopCallback = NULL;
/* Now release the lock, making sure the above was atomic */
LeaveCriticalSection(&ListLock);
/* Now make the callout */
DBG_TRACE("Call stop callback for service %ws, active threads %d\n",
pSvcsStopCbContext->pService->pszServiceName,
pSvcsStopCbContext->pService->cServiceActiveThreadCount);
pfnStopCallback(pSvcsStopCbContext->pContext, TimerOrWaitFired);
/* Decrement the active threads -- maybe the DLL can unload now */
UnloadServiceDll(pSvcsStopCbContext->pService);
/* We no longer need the context */
MemFree(pSvcsStopCbContext);
}
DWORD
WINAPI
SvcRegisterStopCallback (
_In_ PHANDLE phNewWaitObject,
_In_ LPCWSTR ServiceName,
_In_ HANDLE hObject,
_In_ PSVCHOST_STOP_CALLBACK pfnStopCallback,
_In_ PVOID pContext,
_In_ ULONG dwFlags
)
{
ULONG i;
PSVCHOST_CALLBACK_CONTEXT pSvcsStopCbContext = NULL;
PSVCHOST_SERVICE pService = NULL;
DWORD dwError = ERROR_SUCCESS;
/* All parameters must be present */
if ((phNewWaitObject == NULL) ||
(ServiceName == NULL) ||
(hObject == NULL) ||
(pfnStopCallback == NULL))
{
/* Fail otherwise */
return ERROR_INVALID_PARAMETER;
}
/* Don't allow new DLLs while we send notifications */
EnterCriticalSection(&ListLock);
/* Scan all registered services */
for (i = 0; i < ServiceCount; i++)
{
/* Search for the service entry matching this service name */
if (lstrcmpiW(ServiceName, ServiceArray[i].pszServiceName) == 0)
{
/* Found it */
pService = &ServiceArray[i];
break;
}
}
/* Do we have a service? Does it already have a callback? */
if ((pService == NULL) || (pService->pfnStopCallback != NULL))
{
/* Affirmative, nothing for us to do */
dwError = ERROR_INVALID_DATA;
DBG_ERR("Service %ws missing or already registered for callback, "
"status %d\n",
ServiceName,
dwError);
goto Quickie;
}
/* Allocate our internal context */
pSvcsStopCbContext = MemAlloc(HEAP_ZERO_MEMORY, sizeof(*pSvcsStopCbContext));
if (pSvcsStopCbContext == NULL)
{
/* We failed, bail out */
dwError = ERROR_NOT_ENOUGH_MEMORY;
DBG_ERR("MemAlloc for context block for service %ws failed, status "
"%d\n",
ServiceName,
dwError);
goto Quickie;
}
/* Setup the context and register for the wait */
pSvcsStopCbContext->pContext = pContext;
pSvcsStopCbContext->pService = pService;
if (RegisterWaitForSingleObject(phNewWaitObject,
hObject,
SvchostStopCallback,
pSvcsStopCbContext,
INFINITE,
dwFlags))
{
/* We now have an active thread associated with this wait */
pService->cServiceActiveThreadCount++;
pService->pfnStopCallback = pfnStopCallback;
DBG_TRACE("Registered stop callback for service %ws, active threads %d\n",
ServiceName,
pService->cServiceActiveThreadCount);
}
else
{
/* Registration failed, bail out */
dwError = GetLastError();
DBG_ERR("Registration for stop callback for service %ws failed, "
"status %d\n",
ServiceName,
dwError);
}
Quickie:
/* Drop the lock, and free the context if we failed */
LeaveCriticalSection(&ListLock);
if (dwError != ERROR_SUCCESS) MemFree(pSvcsStopCbContext);
return dwError;
}
VOID
WINAPI
AbortSvchostService (
_In_ LPCWSTR lpServiceName,
_In_ DWORD dwExitCode
)
{
SERVICE_STATUS_HANDLE scHandle;
SERVICE_STATUS ServiceStatus;
/* Make us stopped and accept only query commands */
ServiceStatus.dwCheckPoint = 0;
ServiceStatus.dwWaitHint = 0;
ServiceStatus.dwServiceSpecificExitCode = 0;
ServiceStatus.dwCurrentState = SERVICE_STOPPED;
ServiceStatus.dwControlsAccepted = SERVICE_QUERY_CONFIG;
ServiceStatus.dwServiceType = SERVICE_WIN32;
ServiceStatus.dwWin32ExitCode = dwExitCode;
/* Register a handler that will do nothing while we are being stopped */
scHandle = RegisterServiceCtrlHandlerW(lpServiceName,
DummySvchostCtrlHandler);
if (scHandle)
{
/* Stop us */
if (!SetServiceStatus(scHandle, &ServiceStatus))
{
/* Tell the debugger if this didn't work */
DBG_ERR("AbortSvchostService: SetServiceStatus error %ld\n",
GetLastError());
}
}
else
{
/* Tell the debugger if we couldn't register the handler */
DBG_ERR("AbortSvchostService: RegisterServiceCtrlHandler failed %d\n",
GetLastError());
}
}
PVOID
WINAPI
GetServiceDllFunction (
_In_ PSVCHOST_DLL pDll,
_In_ LPCSTR lpProcName,
_Out_ PDWORD lpdwError
)
{
HMODULE hModule;
PVOID lpAddress = NULL;
ULONG_PTR ulCookie = 0;
/* Activate the context */
if (ActivateActCtx(pDll->hActCtx, &ulCookie) == FALSE)
{
/* We couldn't, bail out */
if (lpdwError) *lpdwError = GetLastError();
DBG_ERR("ActivateActCtx for %ws failed. Error %d.\n",
pDll->pszDllPath,
GetLastError());
return lpAddress;
}
/* Check if we already have a loaded module for this service */
hModule = pDll->hModule;
if (!hModule)
{
/* We don't -- load it */
hModule = LoadLibraryExW(pDll->pszDllPath,
NULL,
LOAD_WITH_ALTERED_SEARCH_PATH);
if (!hModule)
{
/* We failed to load it, bail out */
if (lpdwError) *lpdwError = GetLastError();
DBG_ERR("LoadLibrary (%ws) failed. Error %d.\n",
pDll->pszDllPath,
GetLastError());
DeactivateActCtx(0, ulCookie);
return lpAddress;
}
/* Loaded! */
pDll->hModule = hModule;
}
/* Next, get the address being looked up*/
lpAddress = GetProcAddress(hModule, lpProcName);
if (!lpAddress && lpdwError)
{
/* We couldn't find it, write the error code and a debug statement */
*lpdwError = GetLastError();
DBG_ERR("GetProcAddress (%s) failed on DLL %ws. Error %d.\n",
lpProcName,
pDll->pszDllPath,
GetLastError());
}
/* All done, get rid of the activation context */
DeactivateActCtx(0, ulCookie);
return lpAddress;
}
PSVCHOST_DLL
WINAPI
FindDll (
_In_ LPCWSTR pszManifestPath,
_In_ LPCWSTR pszDllPath,
_In_ PSVCHOST_SERVICE pService
)
{
PSVCHOST_DLL pDll, pFoundDll = NULL;
PLIST_ENTRY pNextEntry;
ASSERT(pszDllPath);
/* Lock the DLL database */
EnterCriticalSection(&ListLock);
/* Scan through the database */
pNextEntry = DllList.Flink;
while (pNextEntry != &DllList)
{
/* Search for an existing DLL with the same parameters */
pDll = CONTAINING_RECORD(pNextEntry, SVCHOST_DLL, DllList);
if ((lstrcmpW(pDll->pszDllPath, pszDllPath) == 0) &&
(lstrcmpW(pDll->pszManifestPath, pszManifestPath) == 0) &&
(lstrcmpW(pDll->pService->pszServiceName, pService->pszServiceName) == 0))
{
/* Found it! */
pFoundDll = pDll;
break;
}
/* Keep searching */
pNextEntry = pNextEntry->Flink;
}
/* All done, release the lock and return what we found, if anything */
LeaveCriticalSection(&ListLock);
return pFoundDll;
}
PSVCHOST_DLL
WINAPI
AddDll (
_In_ LPCWSTR pszManifestPath,
_In_ LPCWSTR pszDllPath,
_In_ PSVCHOST_SERVICE pService,
_Out_ PDWORD lpdwError
)
{
PSVCHOST_DLL pDll;
ULONG nDllPathLength, nManifestPathLength;
ASSERT(pszDllPath);
ASSERT(*pszDllPath);
/* Compute the length of the two paths */
nDllPathLength = lstrlenW(pszDllPath);
nManifestPathLength = lstrlenW(pszManifestPath);
/* Allocate the DLL entry for this service */
pDll = MemAlloc(HEAP_ZERO_MEMORY,
sizeof(*pDll) +
(nDllPathLength + nManifestPathLength) * sizeof(WCHAR) +
2 * sizeof(UNICODE_NULL));
if (pDll == NULL)
{
/* Bail out with failure */
*lpdwError = ERROR_NOT_ENOUGH_MEMORY;
return pDll;
}
/* Put the DLL path right after the DLL entry */
pDll->pszDllPath = (LPCWSTR)(pDll + 1);
/* Put the manifest path right past the DLL path (note the pointer math) */
pDll->pszManifestPath = pDll->pszDllPath + nDllPathLength + 1;
/* Now copy both paths */
CopyMemory((PVOID)pDll->pszDllPath,
pszDllPath,
sizeof(WCHAR) * nDllPathLength);
CopyMemory((PVOID)pDll->pszManifestPath,
pszManifestPath,
sizeof(WCHAR) * nManifestPathLength);
/* Now set the service, and make sure both paths are NULL-terminated */
pDll->pService = pService;
ASSERT(pDll->hActCtx == NULL);
ASSERT(pDll->pszDllPath[nDllPathLength] == UNICODE_NULL);
ASSERT(pDll->pszManifestPath[nManifestPathLength] == UNICODE_NULL);
/* Finally, add the entry to the DLL database, while holding the lock */
EnterCriticalSection(&ListLock);
InsertTailList(&DllList, &pDll->DllList);
LeaveCriticalSection(&ListLock);
/* And return it */
return pDll;
}
VOID
WINAPI
GetServiceMainFunctions (
_In_ PSVCHOST_SERVICE pService,
_Out_ PVOID *pServiceMain,
_Out_ PVOID *pPushServiceGlobals,
_Out_ PDWORD lpdwError
)
{
DWORD dwError, cbDllLength, cbData, dwType;
PSVCHOST_DLL pDll;
ACTCTXW actCtx;
LPCWSTR pszDllPath;
HKEY hKey;
HANDLE hActCtx;
LPWSTR lpData;
WCHAR szDllBuffer[MAX_PATH + 2], szManifestBuffer[MAX_PATH + 2];
/* Initialize the activation context we might need later */
RtlZeroMemory(&actCtx, sizeof(actCtx));
actCtx.cbSize = sizeof(actCtx);
/* We clean these up in our failure path so initialize them to NULL here */
hActCtx = NULL;
hKey = NULL;
lpData = NULL;
*lpdwError = ERROR_SUCCESS;
/* Null terminate the string buffers */
szDllBuffer[0] = UNICODE_NULL;
szManifestBuffer[0] = UNICODE_NULL;
/* Do we already have a DLL ready to go for this service? */
pDll = pService->pDll;
if (pDll != NULL) goto HaveDll;
/* Nope, we're starting from scratch. Open a handle to parameters key */
dwError = OpenServiceParametersKey(pService->pszServiceName, &hKey);
if (dwError)
{
*lpdwError = dwError;
ASSERT(*lpdwError != NO_ERROR);
goto Quickie;
}
/* Allocate enough space to hold a unicode path (NULL-terminated) */
cbData = MAX_PATH * sizeof(WCHAR) + sizeof(UNICODE_NULL);
lpData = MemAlloc(0, cbData);
if (lpData == NULL)
{
/* No memory, bail out */
*lpdwError = ERROR_NOT_ENOUGH_MEMORY;
goto Quickie;
}
/* Query the DLL path */
lpData[0] = UNICODE_NULL;
dwError = RegQueryValueExW(hKey,
L"ServiceDll",
0,
&dwType,
(LPBYTE)lpData,
&cbData);
if (dwError != ERROR_SUCCESS)
{
*lpdwError = dwError;
DBG_ERR("RegQueryValueEx for the ServiceDll parameter of the %ws "
"service returned %u\n",
pService->pszServiceName,
dwError);
goto Quickie;
}
/* Is the registry data valid and present? */
if ((dwType != REG_EXPAND_SZ) || (lpData[0] == UNICODE_NULL))
{
/* Nope, bail out */
*lpdwError = ERROR_FILE_NOT_FOUND;
DBG_ERR("The ServiceDll parameter for the %ws service is not of type "
"REG_EXPAND_SZ\n",
pService->pszServiceName);
goto Quickie;
}
/* Convert the expandable path into an absolute path */
ExpandEnvironmentStringsW(lpData, szDllBuffer, MAX_PATH);
SvchostCharLowerW(szDllBuffer);
/* Check if the service has a manifest file associated with it */
cbData = MAX_PATH * sizeof(WCHAR) + sizeof(UNICODE_NULL);
dwError = RegQueryValueExW(hKey,
L"ServiceManifest",
NULL,
&dwType,
(LPBYTE)lpData,
&cbData);
if (dwError != ERROR_SUCCESS)
{
/* Did we fail because one wasn't set? */
if ((dwError != ERROR_PATH_NOT_FOUND) &&
(dwError != ERROR_FILE_NOT_FOUND))
{
/* We failed for some other reason, bail out */
*lpdwError = dwError;
DBG_ERR("RegQueryValueEx for the ServiceManifest parameter of the "
"%ws service returned %u\n",
pService->pszServiceName,
dwError);
goto Quickie;
}
/* We have no manifest, make sure the buffer is empty */
szManifestBuffer[0] = UNICODE_NULL;
/* We're done with this buffer */
MemFree(lpData);
lpData = NULL;
/* Use the whole DLL path, since we don't have a manifest */
pszDllPath = szDllBuffer;
}
else
{
/* Do we have invalid registry data? */
if ((dwType != REG_EXPAND_SZ) || (*lpData == UNICODE_NULL))
{
/* Yes, pretend there's no manifest and bail out */
*lpdwError = ERROR_FILE_NOT_FOUND;
DBG_ERR("The ServiceManifest parameter for the %ws service is not "
"of type REG_EXPAND_SZ\n",
pService->pszServiceName);
goto Quickie;
}
/* Expand the string into our stack buffer */
ExpandEnvironmentStringsW(lpData, szManifestBuffer, MAX_PATH);
/* We no longer need the heap buffer*/
MemFree(lpData);
lpData = NULL;
/* Lowercase the manifest path */
SvchostCharLowerW(szManifestBuffer);
/* Now loop over the DLL path */
cbDllLength = lstrlenW(szDllBuffer);
while (cbDllLength)
{
/* From the end, until we find the first path separator */
if (szDllBuffer[cbDllLength] == '\\' || szDllBuffer[cbDllLength] == '/')
{
/* Use just a short name (cut out the rest of the path) */
pszDllPath = &szDllBuffer[cbDllLength + 1];
break;
}
/* Try the next character */
cbDllLength--;
}
}
/* See if we already have a matching DLL and manifest for this service */
pDll = FindDll(szManifestBuffer, pszDllPath, pService);
if (pDll == NULL)
{
/* We don't have it yet -- does this DLL have a manifest? */
if (szManifestBuffer[0] != UNICODE_NULL)
{
/* Create an activation context for it */
actCtx.lpSource = szManifestBuffer;
hActCtx = CreateActCtxW(&actCtx);
if (hActCtx == INVALID_HANDLE_VALUE)
{
/* We've failed to create one, bail out */
*lpdwError = GetLastError();
DBG_ERR("CreateActCtxW(%ws) for the %ws service returned %u\n",
szManifestBuffer,
pService->pszServiceName,
*lpdwError);
goto Quickie;
}
}
/* Add this new DLL into the database */
pDll = AddDll(szManifestBuffer, pszDllPath, pService, lpdwError);
if (pDll)
{
/* Save the activation context and zero it so we don't release later */
pDll->hActCtx = hActCtx;
hActCtx = NULL;
}
}
/* We either found, added, or failed to add, the DLL for this service */
ASSERT(!pService->pDll);
pService->pDll = pDll;
/* In all cases, we will query the ServiceMain function, however*/
RegQueryStringA(hKey,
L"ServiceMain",
REG_SZ,
&pService->pszServiceMain);
/* And now we'll check if we were able to create it earlier (or find it) */
if (!pService->pDll)
{
/* We were not, so there's no point in going on */
ASSERT(*lpdwError != NO_ERROR);
goto Quickie;
}
/* We do have a valid DLL, so now get the service main routine out of it */
HaveDll:
*pServiceMain = GetServiceDllFunction(pDll,
pService->pszServiceMain ?
pService->pszServiceMain :
"ServiceMain",
lpdwError);
/* And now get the globals routine out of it (this one is optional) */
*pPushServiceGlobals = GetServiceDllFunction(pDll,
"SvchostPushServiceGlobals",
NULL);
Quickie:
/* We're done, cleanup any resources we left behind */
if (hKey != NULL) RegCloseKey(hKey);
if (lpData != NULL) MemFree(lpData);
if ((hActCtx) && (hActCtx != INVALID_HANDLE_VALUE)) ReleaseActCtx(hActCtx);
}
VOID
WINAPI
ServiceStarter (
_In_ DWORD dwNumServicesArgs,
_In_ LPWSTR *lpServiceArgVectors
)
{
DWORD i, dwError = ERROR_FILE_NOT_FOUND;
PSVCHOST_SERVICE ServiceEntry;
LPCWSTR lpServiceName;
LPSERVICE_MAIN_FUNCTIONW ServiceMain = NULL;
PSVCHOST_INIT_GLOBALS ServiceInitGlobals = NULL;
/* Hold the lock while we start a service */
EnterCriticalSection(&ListLock);
/* Get this service's name, and loop the database */
lpServiceName = *lpServiceArgVectors;
for (i = 0; i < ServiceCount; i++)
{
/* Try to find a match by name */
if (!lstrcmpiW(lpServiceName, ServiceArray[i].pszServiceName)) break;
}
/* Check if we didn't find it */
if (i == ServiceCount)
{
/* This looks like a bogus attempt, bail out */
LeaveCriticalSection(&ListLock);
return;
}
/* We have it */
ServiceEntry = &ServiceArray[i];
/* Should we breakpoint before loading this service? */
if (FDebugBreakForService(lpServiceName) != FALSE)
{
/* Yep -- do it */
DBG_TRACE("Attaching debugger before getting ServiceMain for %ws...\n",
lpServiceName);
DebugBreak();
}
/* Get the callbacks for this service */
GetServiceMainFunctions(&ServiceArray[i],
(PVOID*)&ServiceMain,
(PVOID*)&ServiceInitGlobals,
&dwError);
/* If this service is valid and needs globals, but we don't have them... */
if ((ServiceMain != NULL) &&
(ServiceInitGlobals != NULL) &&
(g_pSvchostSharedGlobals == NULL))
{
/* Go and build them for the first time! */
SvchostBuildSharedGlobals();
}
/* We call a service if it has a main, or if wants globals and we have them */
if (((ServiceInitGlobals != NULL) && (g_pSvchostSharedGlobals != NULL)) ||
((ServiceMain != NULL) && (ServiceInitGlobals == NULL)))
{
/* Therefore, make sure it won't be unloaded as we drop the lock */
ServiceEntry->cServiceActiveThreadCount++;
}
/* Drop the lock while we call into the service DLL */
LeaveCriticalSection(&ListLock);
/* First: does this service want globals? */
if (ServiceInitGlobals != NULL)
{
/* Do we have any to give? */
if (g_pSvchostSharedGlobals != NULL)
{
/* Yes, push them to the service */
ServiceInitGlobals(g_pSvchostSharedGlobals);
/* Does the service NOT have an entrypoint? */
if (ServiceMain == NULL)
{
/* We're going to abort loading, it serves no use */
if (lpServiceName != NULL)
{
AbortSvchostService(lpServiceName, dwError);
}
/* And drop a reference count since it's not active anymore */
UnloadServiceDll(ServiceEntry);
}
}
else if (lpServiceName != NULL)
{
/* We have no globals to give, so don't even bother calling it */
AbortSvchostService(lpServiceName, dwError);
}
}
/* Next up, does it have an entrypoint? */
if (ServiceMain != NULL)
{
/* It does, so call it */
DBG_TRACE("Calling ServiceMain for %ws...\n", lpServiceName);
ServiceMain(dwNumServicesArgs, lpServiceArgVectors);
/* We're out of the service now, so we can drop a reference */
UnloadServiceDll(ServiceEntry);
}
else if (lpServiceName != NULL)
{
/* It has no entrypoint, so abort its launch */
AbortSvchostService(lpServiceName, dwError);
}
}
SERVICE_TABLE_ENTRYW*
WINAPI
BuildServiceTable (
VOID
)
{
SERVICE_TABLE_ENTRYW *pServiceTable;
ULONG i;
/* Acquire the database lock while we go over the services */
EnterCriticalSection(&ListLock);
/* Allocate space for a NULL entry at the end as well, Windows needs this */
pServiceTable = MemAlloc(HEAP_ZERO_MEMORY,
(ServiceCount + 1) * sizeof(*pServiceTable));
if (pServiceTable)
{
/* Go over all our registered services */
for (i = 0; i < ServiceCount; i++)
{
/* And set their parameters in the service table */
pServiceTable[i].lpServiceName = (LPWSTR)ServiceArray[i].pszServiceName;
pServiceTable[i].lpServiceProc = ServiceStarter;
DBG_TRACE("Added service table entry for %ws\n",
pServiceTable[i].lpServiceName);
}
}
/* All done, can release the lock now */
LeaveCriticalSection(&ListLock);
return pServiceTable;
}
BOOLEAN
WINAPI
CallPerInstanceInitFunctions (
_In_ PSVCHOST_OPTIONS pOptions
)
{
PIMAGE_NT_HEADERS pNtHeaders;
BOOLEAN bResult;
/* Is COM required for this host? */
if (pOptions->CoInitializeSecurityParam != 0)
{
/* Yes, initialize COM security and parameters */
bResult = InitializeSecurity(pOptions->CoInitializeSecurityParam,
pOptions->AuthenticationLevel,
pOptions->ImpersonationLevel,
pOptions->AuthenticationCapabilities);
if (bResult == FALSE) return FALSE;
}
/* Do we have a custom RPC stack size? */
if (pOptions->DefaultRpcStackSize != 0)
{
/* Yes, go set it */
RpcMgmtSetServerStackSize(pOptions->DefaultRpcStackSize << 10);
}
else
{
/* Nope, get the NT headers from the image */
pNtHeaders = RtlImageNtHeader(NtCurrentPeb()->ImageBaseAddress);
if (pNtHeaders)
{
/* And just use whatever the default thread stack is */
RpcMgmtSetServerStackSize(pNtHeaders->OptionalHeader.SizeOfStackCommit);
}
}
/* Is this host holding critical services? */
if (pOptions->SystemCritical != FALSE)
{
/* Mark the process as critical if so */
RtlSetProcessIsCritical(TRUE, NULL, TRUE);
}
/* All done */
return TRUE;
}
VOID
__cdecl
wmainCRTStartup (
VOID
)
{
PSVCHOST_OPTIONS lpOptions;
SERVICE_TABLE_ENTRYW *pServiceTable;
LPWSTR pszCmdLine;
/* Set a generic SEH filter and hard fail all critical errors */
SetUnhandledExceptionFilter(SvchostUnhandledExceptionFilter);
SetErrorMode(SEM_FAILCRITICALERRORS);
/* Initialize the heap allocator */
MemInit(GetProcessHeap());
/* Initialize the DLL database and lock */
InitializeListHead(&DllList);
InitializeCriticalSection(&ListLock);
/* Get the command-line and parse it to get the service group */
pszCmdLine = GetCommandLineW();
lpOptions = BuildCommandOptions(pszCmdLine);
if (lpOptions == NULL)
{
/* Without a valid command-line, there's nothing for us to do */
DBG_TRACE("Calling ExitProcess for %ws\n", pszCmdLine);
ExitProcess(0);
}
/* Now use the service group information to lookup all the services */
BuildServiceArray(lpOptions);
/* Convert the list of services in this group to the SCM format */
pServiceTable = BuildServiceTable();
if (pServiceTable == NULL)
{
/* This is critical, bail out without it */
MemFree(lpOptions);
return;
}
/* Initialize COM and RPC as needed for this service group */
if (CallPerInstanceInitFunctions(lpOptions) == FALSE)
{
/* Exit with a special code indicating COM/RPC setup has failed */
DBG_ERR("%s", "CallPerInstanceInitFunctions failed -- exiting!\n");
ExitProcess(1);
}
/* We're ready to go -- free the options buffer */
MemFree(lpOptions);
/* And call into ADVAPI32 to get our services going */
StartServiceCtrlDispatcherW(pServiceTable);
}