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/*
* Copyright (c) Microsoft Corporation * * Module Name : * bridge.c * * This contains the main worker thread that passes information between the clients * the Com port. * * Sadagopan Rajaram -- Oct 15, 1999 * */
#include "tcsrv.h"
#include "tcsrvc.h"
#include "proto.h"
DWORD bridge( PCOM_PORT_INFO pComPortInfo ){ NTSTATUS Status; PCONNECTION_INFO pTemp; DWORD waitStatus; int SocketStatus;
Status = ReadFile(pComPortInfo->ComPortHandle, pComPortInfo->Buffer, MAX_QUEUE_SIZE, &(pComPortInfo->BytesRead), &(pComPortInfo->Overlapped) ); if (!NT_SUCCESS(Status)) { TCDebugPrint(("Could not read from Com Port %x\n",GetLastError())); goto end; }
while(1){ MutexLock(pComPortInfo); // Get the new sockets that have been added to the port since
// you were asleep. Send them the requested information and add
// them to the connections list so that they are primed to receive
// information.
while(pComPortInfo->Sockets != NULL){ pTemp = pComPortInfo->Sockets; SocketStatus = 1; if(pTemp->Flags){ SocketStatus=GetBufferInfo(pTemp, pComPortInfo); pTemp->Flags = 0; } TCDebugPrint(("Got conn\n")); pComPortInfo->Sockets = pTemp->Next; pTemp->Next = pComPortInfo->Connections; pComPortInfo->Connections = pTemp; if (SocketStatus == SOCKET_ERROR) { TCDebugPrint(("something wrong with socket %d\n", WSAGetLastError())); CleanupSocket(pTemp); continue; } SocketStatus = WSARecv(pTemp->Socket, &(pTemp->Buffer), 1 , &(pTemp->BytesRecvd), &(pTemp->Flags), &(pTemp->Overlapped), updateComPort ); if (SocketStatus == SOCKET_ERROR ) { SocketStatus = WSAGetLastError(); if (SocketStatus != WSA_IO_PENDING) { TCDebugPrint(("something wrong with socket %d\n", SocketStatus)); CleanupSocket(pTemp); } } } MutexRelease(pComPortInfo);wait: waitStatus=NtWaitForMultipleObjects(4, pComPortInfo->Events, WaitAny, TRUE, NULL ); if(waitStatus == WAIT_FAILED){ TCDebugPrint(("Fatal Error %x", waitStatus)); closesocket(MainSocket); goto end; } else{ if(waitStatus == WAIT_IO_COMPLETION){ goto wait; } waitStatus = waitStatus - WAIT_OBJECT_0; switch(waitStatus){ case 0: Status = STATUS_SUCCESS; goto end; break; case 1: ResetEvent(pComPortInfo->Events[1]); break; case 2: ResetEvent(pComPortInfo->Events[2]); updateClients(pComPortInfo); goto wait; break; case 3: Status = STATUS_SUCCESS; ResetEvent(pComPortInfo->Events[3]); goto end; break; default: goto wait; break; }
} }end:
// Cancel the pending IRPs and close all the sockets.
TCDebugPrint(("Cancelling all irps and shutting down the thread\n")); MutexLock(pComPortInfo); CancelIo(pComPortInfo->ComPortHandle); NtClose(pComPortInfo->ComPortHandle); while(pComPortInfo->Sockets != NULL){ pTemp = pComPortInfo->Sockets; closesocket(pTemp->Socket); pComPortInfo->Sockets = pTemp->Next; pTemp->Next = NULL; TCFree(pTemp); } pTemp = pComPortInfo->Connections; while(pTemp != NULL){ closesocket(pTemp->Socket); pTemp = pTemp->Next; } pComPortInfo->ShuttingDown = TRUE; if(pComPortInfo->Connections == NULL) SetEvent(pComPortInfo->TerminateEvent); MutexRelease(pComPortInfo);wait2: waitStatus=NtWaitForSingleObject(pComPortInfo->TerminateEvent,TRUE,NULL); if(waitStatus == WAIT_IO_COMPLETION){ goto wait2; } TCDebugPrint(("End of COM port\n")); return Status;}
VOID CALLBACKupdateComPort( IN DWORD dwError, IN DWORD cbTransferred, IN LPWSAOVERLAPPED lpOverlapped, IN DWORD dwFlags )
/*++
Writes the data that it has gotten from the socket to all the connection that it currently has and to the com port.--*/{
PCONNECTION_INFO pTemp = (PCONNECTION_INFO) lpOverlapped->hEvent; PCONNECTION_INFO pConn; PCOM_PORT_INFO pComPort; int Status;
pComPort = pTemp->pComPortInfo; MutexLock(pComPort); if((cbTransferred == 0) && (dwError == 0)) { // For byte stream socket, this indicates graceful closure
CleanupSocket(pTemp); MutexRelease(pComPort); return; } // If socket closed, remove it from the connection list.
if(pComPort->ShuttingDown){ CleanupSocket(pTemp); if(pComPort->Connections == NULL){ SetEvent(pComPort->TerminateEvent); MutexRelease(pComPort); return; } MutexRelease(pComPort); return; } if (dwError != 0) { // Something wrong with the connection. Close the socket and
// delete it from the listeners list.
CleanupSocket(pTemp); MutexRelease(pComPort); return; }
Status =WriteFile(pComPort->ComPortHandle, (pTemp->Buffer).buf, cbTransferred, &(pTemp->BytesRecvd), &(pComPort->WriteOverlapped) ); if(!Status){ if(GetLastError() != ERROR_IO_PENDING) TCDebugPrint(("Error writing to comport %d",GetLastError())); } Status = WSARecv(pTemp->Socket, &(pTemp->Buffer), 1 , &(pTemp->BytesRecvd), &(pTemp->Flags), &(pTemp->Overlapped), updateComPort ); if (Status == SOCKET_ERROR ) { Status = WSAGetLastError(); if (Status != WSA_IO_PENDING) { TCDebugPrint(("something wrong with socket %d\n", Status)); CleanupSocket(pTemp); } } MutexRelease(pComPort); return;}
VOIDupdateClients( PCOM_PORT_INFO pComPortInfo
)/*++
Writes the data that it has gotten from the com port to all the connection that it currently has--*/{ PCONNECTION_INFO pConn; BOOL Status; DWORD Error; NTSTATUS stat;
if((pComPortInfo->Overlapped.InternalHigh == 0)|| (!NT_SUCCESS(pComPortInfo->Overlapped.Internal))){ TCDebugPrint(("Problem with Com Port %x\n", pComPortInfo->Overlapped.Internal)); MutexLock(pComPortInfo); if(pComPortInfo->ShuttingDown){ // will never occur because this is a procedure called from
// the thread
MutexRelease(pComPortInfo); return; } if (pComPortInfo->Overlapped.Internal == STATUS_CANCELLED){ // something wrong, try reinitializing the com port
// this thing happens every time the m/c on the other end
// reboots. Pretty painful.Probably can improve this later.
// Why should the reboot cause this com port
// to go awry ??
stat = NtClose(pComPortInfo->ComPortHandle); if(!NT_SUCCESS(stat)){ TCDebugPrint(("Cannot close handle\n")); } stat = InitializeComPort(pComPortInfo); if(!NT_SUCCESS(stat)){ TCDebugPrint(("Cannot reinitialize com port\n")); MutexRelease(pComPortInfo); return; } } Status = ReadFile(pComPortInfo->ComPortHandle, pComPortInfo->Buffer, MAX_QUEUE_SIZE, &(pComPortInfo->BytesRead), &(pComPortInfo->Overlapped) ); if(Status == 0){ if ((Error = GetLastError()) != ERROR_IO_PENDING) { TCDebugPrint(("Error = %d\n", Error)); } } MutexRelease(pComPortInfo);
return; } MutexLock(pComPortInfo); Enqueue(pComPortInfo); pConn = pComPortInfo->Connections; while(pConn!=NULL){ send(pConn->Socket, pComPortInfo->Buffer, (int)pComPortInfo->Overlapped.InternalHigh, 0 ); pConn = pConn->Next; } Status = ReadFile(pComPortInfo->ComPortHandle, pComPortInfo->Buffer, MAX_QUEUE_SIZE, &(pComPortInfo->BytesRead), &(pComPortInfo->Overlapped) ); if (Status == 0) { if((Error=GetLastError())!= ERROR_IO_PENDING){ TCDebugPrint(("Problem with Com Port %x\n", Error)); } } MutexRelease(pComPortInfo); return;}
VOID CleanupSocket( PCONNECTION_INFO pConn ){ PCOM_PORT_INFO pTemp; PCONNECTION_INFO pPrevConn;
// Assume that the structure is locked earlier.
// the socket connection is closed when this occurs.
// We free the socket either if the TCP port on the
// client end has died or we are deleting this com port.
pTemp = pConn->pComPortInfo; if(pConn == pTemp->Connections) { pTemp->Connections = pConn->Next; } else{ pPrevConn = pTemp->Connections; while((pPrevConn !=NULL) &&(pPrevConn->Next != pConn)){ pPrevConn=pPrevConn->Next; } if(pPrevConn == NULL) return; pPrevConn->Next = pConn->Next; } pConn->Next = NULL; TCFree(pConn);
}
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