windows-nt/Source/XPSP1/NT/inetsrv/iis/svcs/ftp/server51/acptctxt.cxx
2020-09-26 16:20:57 +08:00

875 lines
22 KiB
C++

/**********************************************************************/
/** Microsoft Windows NT **/
/** Copyright(c) Microsoft Corp., 1998 **/
/**********************************************************************/
/*
acptctxt.cxx
This file contains the implementations of the PASV_ACCEPT_CONTEXT and ACCEPT_CONTEXT_ENTRY
classes used to deal with async PASV connections
*/
#include "ftpdp.hxx"
#include "auxctrs.h"
#include "acptctxt.hxx"
PASV_ACCEPT_CONTEXT::PASV_ACCEPT_CONTEXT() :
m_dwErr( ERROR_SUCCESS ),
m_dwNumEvents( 0 ),
m_hWatchThread( NULL ),
m_dwThreadId( 0 ),
m_dwSignature( ACCEPT_CONTEXT_GOOD_SIG )
/*++
Constructor
Arguments:
None
Returns:
Nothing
--*/
{
if ( ( m_ahEvents[NEEDUPDATE_INDEX] = WSACreateEvent() ) == WSA_INVALID_EVENT ||
( m_ahEvents[CANUPDATE_INDEX] = WSACreateEvent() ) == WSA_INVALID_EVENT ||
( m_ahEvents[HAVEUPDATED_INDEX] = WSACreateEvent() ) == WSA_INVALID_EVENT ||
( m_ahEvents[EXITTHREAD_INDEX] = WSACreateEvent() ) == WSA_INVALID_EVENT )
{
m_dwErr = WSAGetLastError();
DBGWARN((DBG_CONTEXT,
"WSACreateEvent failed : 0x%x\n",
m_dwErr));
return;
}
m_dwNumEvents = 4;
INITIALIZE_CRITICAL_SECTION( &m_csLock );
//
// Create the watching thread
//
m_hWatchThread = CreateThread( NULL,
0,
AcceptThreadFunc,
this,
0,
&m_dwThreadId );
if ( !m_hWatchThread )
{
m_dwErr = GetLastError();
DBGERROR((DBG_CONTEXT,
"Failed to create thread to watch for PASV accept events : 0x%x\n",
m_dwErr));
}
}
PASV_ACCEPT_CONTEXT::~PASV_ACCEPT_CONTEXT()
/*++
Destructor
Arguments:
None
Returns:
Nothing
--*/
{
DWORD dwRet = 0;
//
// Tell watch thread to shut down
//
if ( !WSASetEvent( m_ahEvents[EXITTHREAD_INDEX] ) )
{
DBGPRINTF((DBG_CONTEXT,
"WSASetEvent failed : 0x%x\n",
WSAGetLastError()));
}
//
// wait for thread to shut down
//
if ( WaitForSingleObject( m_hWatchThread,
INFINITE ) == WAIT_FAILED )
{
DBGWARN((DBG_CONTEXT,
"Waiting for thread shutdown failed : 0x%x\n",
GetLastError()));
}
CloseHandle( m_hWatchThread );
DeleteCriticalSection( &m_csLock );
m_dwSignature = ACCEPT_CONTEXT_BAD_SIG;
}
BOOL PASV_ACCEPT_CONTEXT::RemoveAcceptEvent( IN WSAEVENT hEvent,
IN USER_DATA *pUserData,
OUT PBOOL pfFound )
/*++
Removes the event to be signalled when a socket is accept()'able
Arguments:
hEvent - event to be removed
pUserData - USER_DATA attached to signalled event
pfFound - BOOL set to TRUE if event was found, FALSE if not
Returns:
BOOL indicating success or failure
--*/
{
*pfFound = FALSE;
DWORD dwIndex = 0;
DWORD dwRet = ERROR_SUCCESS;
DWORD dwWait = 0;
//
// Look for the wanted event
//
for ( DWORD i = LASTPREALLOC_INDEX; i < m_dwNumEvents; i++ )
{
if ( m_ahEvents[i] == hEvent )
{
DBG_ASSERT( m_apUserData[i] == pUserData );
*pfFound = TRUE;
dwIndex = i;
break;
}
}
//
// Didn't find the event, but function succeeded
//
if ( !*pfFound )
{
return TRUE;
}
//
// Signal that we want to update the list of events
//
if ( !WSASetEvent( m_ahEvents[NEEDUPDATE_INDEX] ) )
{
dwRet = WSAGetLastError();
DBGPRINTF((DBG_CONTEXT,
"WSASetEvent failed : 0x%x\n",
dwRet));
goto exit;
}
//
// Wait until we can update the list
//
dwWait = WSAWaitForMultipleEvents( 1,
&(m_ahEvents[CANUPDATE_INDEX]),
TRUE,
900000, // 15 minutes should do it....
FALSE );
switch (dwWait)
{
case WSA_WAIT_EVENT_0:
{
//
// Remove the data associated with the socket
//
//
// we're not going to use the context any more, so remove the reference we hold to it
//
m_apUserData[dwIndex]->DeReference();
memmove( (PVOID) (m_ahEvents + dwIndex),
(PVOID) (m_ahEvents + (dwIndex + 1) ),
sizeof(WSAEVENT) * (m_dwNumEvents - dwIndex - 1) );
memmove( (PVOID) ( m_apUserData + dwIndex ),
(PVOID) (m_apUserData + (dwIndex + 1) ),
sizeof(LPUSER_DATA) * (m_dwNumEvents - dwIndex - 1) );
memmove( (PVOID) (m_adwNumTimeouts + dwIndex),
(PVOID) (m_adwNumTimeouts + (dwIndex + 1) ),
sizeof(DWORD) * (m_dwNumEvents - dwIndex - 1) );
m_dwNumEvents--;
//
// reset to known state
//
if ( !WSAResetEvent( m_ahEvents[CANUPDATE_INDEX] ) )
{
dwRet = WSAGetLastError();
DBGWARN((DBG_CONTEXT,
"WSAResetEvent failed : 0x%x\n",
GetLastError()));
goto exit;
}
//
// signal that watch thread can start watching again
//
if ( !WSASetEvent( m_ahEvents[HAVEUPDATED_INDEX] ) )
{
dwRet = WSAGetLastError();
DBGPRINTF((DBG_CONTEXT,
"WSASetEvent failed : 0x%x\n",
GetLastError()));
goto exit;
}
}
break;
case WSA_WAIT_TIMEOUT:
{
IF_DEBUG( PASV )
{
DBGWARN((DBG_CONTEXT,
"Wait timed out ... \n"));
}
dwRet = ERROR_TIMEOUT;
goto exit;
}
break;
default:
{
DBGERROR((DBG_CONTEXT,
"Invalid return from WSAWaitForMultipleEvents : 0x%x\n",
dwWait));
dwRet = ERROR_INVALID_PARAMETER;
}
}
exit:
return ( dwRet == ERROR_SUCCESS ? TRUE : FALSE );
}
DWORD PASV_ACCEPT_CONTEXT::AddAcceptEvent( WSAEVENT hEvent,
LPUSER_DATA pUserData )
/*++
Adds an event to be signalled when a socket is accept()'able
Arguments:
hEvent - event that will be signalled
pUserData - USER_DATA context to attach to signalled event
Returns:
Error code
--*/
{
DWORD dwRet = 0;
DWORD dwWait = 0;
if ( m_dwNumEvents == WSA_MAXIMUM_WAIT_EVENTS )
{
return ERROR_INVALID_PARAMETER;
}
//
// Signal that we want to update the list of events
//
if ( !WSASetEvent( m_ahEvents[NEEDUPDATE_INDEX] ) )
{
dwRet = WSAGetLastError();
DBGWARN((DBG_CONTEXT,
"WSASetEvent failed : 0x%x\n",
dwRet));
goto exit;
}
//
// Wait until we can update the list
//
dwWait = WSAWaitForMultipleEvents( 1,
&(m_ahEvents[CANUPDATE_INDEX]),
TRUE,
10000, //10 secs seems like a reasonable time to wait
FALSE );
switch (dwWait)
{
case WSA_WAIT_EVENT_0:
{
//
// cool, we can update the list
//
m_ahEvents[m_dwNumEvents] = hEvent;
//
// add a reference to make sure nobody deletes the context out from under us
//
pUserData->Reference();
m_apUserData[m_dwNumEvents] = pUserData;
m_adwNumTimeouts[m_dwNumEvents] = 0;
m_dwNumEvents++;
//
// reset to known state
//
if ( !WSAResetEvent( m_ahEvents[CANUPDATE_INDEX] ) )
{
pUserData->DeReference();
m_dwNumEvents--; //make sure event isn't still seen as valid
dwRet = WSAGetLastError();
DBGWARN((DBG_CONTEXT,
"WSAResetEvent failed : 0x%x\n",
GetLastError()));
goto exit;
}
//
// signal that watch thread can start watching again
//
if ( !WSASetEvent( m_ahEvents[HAVEUPDATED_INDEX] ) )
{
pUserData->DeReference();
m_dwNumEvents--; //make sure event isn't still seen as valid
dwRet = WSAGetLastError();
DBGWARN((DBG_CONTEXT,
"WSASetEvent failed : 0x%x\n",
GetLastError()));
goto exit;
}
IF_DEBUG ( PASV )
{
DBGPRINTF((DBG_CONTEXT,
"Added event for context 0x%x at index %d\n",
pUserData, m_dwNumEvents - 1));
}
}
break;
case WSA_WAIT_TIMEOUT:
{
IF_DEBUG( PASV )
{
DBGWARN((DBG_CONTEXT,
"Timed out waiting for permission to update PASV event list ... \n"));
}
dwRet = ERROR_TIMEOUT;
goto exit;
}
break;
default:
{
DBGERROR((DBG_CONTEXT,
"Invalid return from WSAWaitForMultipleEvents : 0x%x\n",
dwWait));
dwRet = ERROR_INVALID_PARAMETER;
}
}
exit:
return dwRet;
}
ACCEPT_CONTEXT_ENTRY::ACCEPT_CONTEXT_ENTRY()
/*++
Constructor
Arguments:
None
Returns:
Nothing
--*/
{
m_pAcceptContext = new PASV_ACCEPT_CONTEXT();
if ( !m_pAcceptContext )
{
DBGERROR((DBG_CONTEXT,
"Failed to allocate new PASV_ACCEPT_CONTEXT !\n"));
}
}
ACCEPT_CONTEXT_ENTRY::~ACCEPT_CONTEXT_ENTRY()
/*++
Destructor
Arguments:
None
Returns:
Nothing
--*/
{
if ( m_pAcceptContext )
{
delete m_pAcceptContext;
}
}
DWORD CreateInitialAcceptContext()
/*++
Creates the first PASV_ACCEPT_CONTEXT object
Arguments:
None
Returns:
Error indicating success/failure
--*/
{
ACCEPT_CONTEXT_ENTRY *pEntry = NULL;
DWORD dwRet = ERROR_SUCCESS;
if ( !(pEntry = new ACCEPT_CONTEXT_ENTRY() ) )
{
DBGERROR((DBG_CONTEXT,
"Failed to allocate new ACCEPT_CONTEXT_ENTRY !\n"));
return ERROR_OUTOFMEMORY;
}
if ( NULL == pEntry->m_pAcceptContext )
{
DBGERROR((DBG_CONTEXT,
"Failed to allocate new ACCEPT_CONTEXT_ENTRY::m_pAcceptContext !\n"));
delete pEntry;
return ERROR_OUTOFMEMORY;
}
if ( ( dwRet = pEntry->m_pAcceptContext->ErrorStatus() ) != ERROR_SUCCESS )
{
DBGERROR((DBG_CONTEXT,
"Error occurred constructing PASV_ACCEPT_CONTEXT : 0x%x\n",
pEntry->m_pAcceptContext->ErrorStatus()));
delete pEntry;
return dwRet;
}
InsertHeadList( &g_AcceptContextList, &pEntry->ListEntry );
return dwRet;
}
VOID DeleteAcceptContexts()
/*++
Deletes all of the PASV_ACCEPT_CONTEXT objects
Arguments:
None
Returns:
Nothing
--*/
{
while ( !IsListEmpty( &g_AcceptContextList ) )
{
ACCEPT_CONTEXT_ENTRY *pEntry = CONTAINING_RECORD( g_AcceptContextList.Flink,
ACCEPT_CONTEXT_ENTRY,
ListEntry );
RemoveEntryList( &(pEntry->ListEntry) );
delete pEntry;
}
}
DWORD AddAcceptEvent( WSAEVENT hEvent,
LPUSER_DATA pUserData )
/*++
Adds an accept event to an available PASV_ACCEPT_CONTEXT
Arguments:
hEvent - handle to event to be added
pUserData - USER_DATA context to attach to event
Returns:
Error code indicating success/failure
--*/
{
LIST_ENTRY *pEntry = NULL;
PPASV_ACCEPT_CONTEXT pAcceptContext = NULL;
PACCEPT_CONTEXT_ENTRY pContextEntry = NULL;
DWORD dwRet = ERROR_SUCCESS;
BOOL fFoundOne = FALSE;
pUserData->FakeIOTimes = 0;
//
// Walk the list of contexts looking for one that can handle an additional
// event.
//
// NB : currently [9/20/98], that list contains only a -single- context, so we can handle
// up to a maximum of (WSA_MAXIMUM_WAIT_EVENTS - 4) events. If we want to get really
// fancy, we could add the necessary code to create a new PASV_ACCEPT_CONTEXT as necessary,
// but that also creates a new thread, and actually opens us up even more to a Denial Of
// Service attack, which is partly what this code is trying to avoid
//
for ( pEntry = g_AcceptContextList.Flink;
pEntry != &g_AcceptContextList;
pEntry = pEntry->Flink )
{
pContextEntry = CONTAINING_RECORD( pEntry, ACCEPT_CONTEXT_ENTRY , ListEntry );
pAcceptContext = pContextEntry->m_pAcceptContext;
pAcceptContext->Lock();
if ( pAcceptContext->QueryNumEvents() < WSA_MAXIMUM_WAIT_EVENTS )
{
dwRet = pAcceptContext->AddAcceptEvent( hEvent,
pUserData );
fFoundOne = TRUE;
}
pAcceptContext->Unlock();
if ( fFoundOne )
break;
}
if (!fFoundOne )
{
dwRet = ERROR_OUTOFMEMORY; //not quite the right error
}
return dwRet;
}
BOOL RemoveAcceptEvent( WSAEVENT hEvent,
LPUSER_DATA pUserData )
/*++
Removes an accept event from the appropriate PASV_ACCEPT_CONTEXT
Arguments:
hEvent - handle to event to be removed
pUserData - USER_DATA context attached to event
Returns:
BOOL indicating success/failure
--*/
{
LIST_ENTRY *pEntry = NULL;
PPASV_ACCEPT_CONTEXT pAcceptContext = NULL;
PACCEPT_CONTEXT_ENTRY pContextEntry = NULL;
DWORD dwRet = ERROR_SUCCESS;
BOOL fFound = FALSE;
BOOL fSuccess = FALSE;
//
// Walk the list of contexts looking for the one that holds the event
// event.
//
for ( pEntry = g_AcceptContextList.Flink;
pEntry != &g_AcceptContextList;
pEntry = pEntry->Flink )
{
pContextEntry = CONTAINING_RECORD( pEntry, ACCEPT_CONTEXT_ENTRY , ListEntry );
pAcceptContext = pContextEntry->m_pAcceptContext;
pAcceptContext->Lock();
fSuccess = pAcceptContext->RemoveAcceptEvent( hEvent,
pUserData,
&fFound );
if ( fFound )
{
pAcceptContext->Unlock();
return fSuccess;
}
pAcceptContext->Unlock();
}
return TRUE;
}
DWORD WINAPI PASV_ACCEPT_CONTEXT::AcceptThreadFunc( LPVOID pvContext )
/*++
Thread function for the thread that waits on the accept events
Arguments:
pvContext - context pointer (pointer to PASV_ACCEPT_CONTEXT object)
Returns:
Nothing useful
--*/
{
PPASV_ACCEPT_CONTEXT pAcceptContext = NULL;
WSAEVENT *phAcceptEvents = NULL;
DWORD dwNumEvents = 0;
DWORD dwRet = 0;
WSAEVENT *phNeedUpdate = NULL;
WSAEVENT *phCanUpdate = NULL;
WSAEVENT *phHaveUpdated = NULL;
WSAEVENT *phExitThread = NULL;
DBG_ASSERT( pvContext );
pAcceptContext = (PPASV_ACCEPT_CONTEXT) pvContext;
phAcceptEvents = pAcceptContext->m_ahEvents;
dwNumEvents = pAcceptContext->m_dwNumEvents;
phNeedUpdate = &phAcceptEvents[NEEDUPDATE_INDEX];
phCanUpdate = &phAcceptEvents[CANUPDATE_INDEX];
phHaveUpdated = &phAcceptEvents[HAVEUPDATED_INDEX];
phExitThread = &phAcceptEvents[EXITTHREAD_INDEX];
loop:
// wait timeout should be fairly small, so we can go through list and purge all
// sockets that have been inactive a given # of timeouts
dwRet = WSAWaitForMultipleEvents( dwNumEvents,
phAcceptEvents,
FALSE,
PASV_TIMEOUT_INTERVAL,
FALSE );
if ( dwRet <= (WSA_WAIT_EVENT_0 + dwNumEvents - 1) )
{
//
// One of the events was signalled
//
DWORD dwIndex = dwRet - WSA_WAIT_EVENT_0;
switch (dwIndex)
{
case (NEEDUPDATE_INDEX):
{
//
// Somebody wants to update the list of events to watch for, so signal that
// they can do so and wait for them to tell us they're done with the update
//
if ( !WSAResetEvent( *phNeedUpdate ) ) //back to known state
{
DBGWARN((DBG_CONTEXT,
"WSAResetEvent failed : 0x%x\n",
WSAGetLastError()));
}
if ( !WSASetEvent( *phCanUpdate ) )
{
DBGWARN((DBG_CONTEXT,
"WSASetEvent failed : 0x%x\n",
WSAGetLastError()));
}
if ( WSAWaitForMultipleEvents( 1,
phHaveUpdated,
TRUE,
INFINITE,
FALSE ) == WSA_WAIT_FAILED )
{
DBGERROR((DBG_CONTEXT,
"WSAWaitForMultipleEvents failed : 0x%x\n",
WSAGetLastError()));
}
if ( !WSAResetEvent( *phHaveUpdated ) ) //back to known state
{
DBGWARN((DBG_CONTEXT,
"WSAResetEvent failed : 0x%x\n",
WSAGetLastError()));
}
dwNumEvents = pAcceptContext->m_dwNumEvents;
goto loop;
}
break;
case (CANUPDATE_INDEX):
case (HAVEUPDATED_INDEX):
{
//
// Should never happen !
//
IF_DEBUG ( PASV )
{
DBGERROR((DBG_CONTEXT,
"Invalid event signalled !\n"));
}
}
break;
case (EXITTHREAD_INDEX):
{
//
// We're all done
//
IF_DEBUG ( PASV )
{
DBGPRINTF((DBG_CONTEXT,
"Exiting thread watching for PASV events....\n"));
}
return 0;
}
break;
default:
{
LPUSER_DATA pUserData = NULL;
//
// One of the sockets has become accept()'able.
//
IF_DEBUG ( PASV )
{
DBGPRINTF((DBG_CONTEXT,
"Got an acceptable socket, index : %i, context : 0x%x\n",
dwIndex, pAcceptContext->m_apUserData[dwIndex]));
}
pUserData = pAcceptContext->m_apUserData[dwIndex];
//
// Remove the data associated with the socket
//
memmove( (PVOID) (pAcceptContext->m_ahEvents + dwIndex),
(PVOID) (pAcceptContext->m_ahEvents + (dwIndex + 1) ),
sizeof(WSAEVENT) * (dwNumEvents - dwIndex - 1) );
memmove( (PVOID) ( pAcceptContext->m_apUserData + dwIndex ),
(PVOID) (pAcceptContext->m_apUserData + (dwIndex + 1) ),
sizeof(LPUSER_DATA) * (dwNumEvents - dwIndex - 1) );
memmove( (PVOID) (pAcceptContext->m_adwNumTimeouts + dwIndex),
(PVOID) (pAcceptContext->m_adwNumTimeouts + (dwIndex + 1) ),
sizeof(DWORD) * (dwNumEvents - dwIndex - 1) );
pAcceptContext->m_dwNumEvents--;
dwNumEvents = pAcceptContext->m_dwNumEvents;
//
// deal with restarting processing
//
SignalAcceptableSocket( pUserData );
goto loop;
}
}
}
else if ( dwRet == WSA_WAIT_TIMEOUT )
{
//
// wait timed out, so go through the list of events and remove those that have
// timed out too often
//
for ( DWORD i = LASTPREALLOC_INDEX;//skip the events that don't have a fixed # of timeouts
i < dwNumEvents;
i++ )
{
if ( pAcceptContext->m_adwNumTimeouts[i] == MAX_PASV_TIMEOUTS )
{
DBGPRINTF((DBG_CONTEXT,
"timing out socket at index %i, context 0x%x \n",
i,
pAcceptContext->m_apUserData[i]));
CleanupTimedOutSocketContext( pAcceptContext->m_apUserData[i] );
memmove( (PVOID) (pAcceptContext->m_ahEvents + i),
(PVOID) (pAcceptContext->m_ahEvents + (i+1) ),
sizeof(WSAEVENT) * (dwNumEvents - i - 1) );
memmove( (PVOID) ( pAcceptContext->m_apUserData + i ),
(PVOID) (pAcceptContext->m_apUserData + (i+1) ),
sizeof(LPUSER_DATA) * (dwNumEvents - i - 1) );
memmove( (PVOID) (pAcceptContext->m_adwNumTimeouts + i),
(PVOID) (pAcceptContext->m_adwNumTimeouts + (i+1) ),
sizeof(DWORD) * (dwNumEvents - i - 1) );
//
// need to readjust the index and number of items in the array
//
i--;
dwNumEvents--;
pAcceptContext->m_dwNumEvents--;
}
else
{
pAcceptContext->m_adwNumTimeouts[i]++;
}
}
dwNumEvents = pAcceptContext->m_dwNumEvents;
goto loop;
}
else if ( dwRet == WAIT_IO_COMPLETION )
{
DBGWARN((DBG_CONTEXT,
"Invalid value from WSAWaitForMultipleEvents !\n"));
goto loop;
}
else
{
DBGERROR((DBG_CONTEXT,
"WSAWaitForMultipleEvents returned 0x%x, error : 0x%x\n",
dwRet, WSAGetLastError()));
goto loop;
}
return 0;
}