Leaked source code of windows server 2003
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/*==========================================================================
*
* Copyright (C) 1996-1997 Microsoft Corporation. All Rights Reserved.
*
* File: dpserial.c
* Content: Implementation of serial port service provider
* History:
* Date By Reason
* ==== == ======
* 4/10/96 kipo created it
* 4/12/96 kipo updated for new interfaces
* 4/15/96 kipo added msinternal
* 5/22/96 kipo updated for new interfaces
* 6/10/96 kipo updated for new interfaces
* 6/10/96 kipo added modem support
* 6/18/96 kipo use guid to choose serial/modem connection
* 6/20/96 kipo updated for new interfaces
* 6/21/96 kipo Bug #2078. Changed modem service provider GUID so it's not the
* same as the DPlay 1.0 GUID, so games that are checking won't
* put up their loopy modem-specific UI.
* 6/21/96 kipo updated for latest interfaces; return error if message size is too big.
* 6/22/96 kipo updated for latest interfaces; use connection data; return version
* 6/23/96 kipo updated for latest service provider interfaces.
* 6/24/96 kipo divide baud rate by 100 to conform to DPlay 1.0 usage.
* 6/25/96 kipo added WINAPI prototypes and updated for DPADDRESS
* 7/13/96 kipo added support for GetAddress() method.
* 7/13/96 kipo don't print as many errors for invalid messages.
* 8/10/96 kipo return DPERR_SESSIONLOST on write failures
* 8/13/96 kipo added CRC
* 8/21/96 kipo return a value for dwHeaderLength in caps
* 9/07/96 kip changed latency and timeout values
* 1/06/97 kipo updated for objects
* 2/11/97 kipo pass player flags to GetAddress()
* 2/11/97 kipo SPInit was needlessly clearing the dwFlags field of the
* callback table.
* 2/18/97 kipo allow multiple instances of service provider
* 3/04/97 kipo updated debug output; make sure we linke with dplayx.dll
* 4/08/97 kipo added support for separate modem and serial baud rates
* 5/07/97 kipo added support for modem choice list
* 5/23/97 kipo added support return status codes
* 5/15/98 a-peterz When Write fails, return DPERR_NOCONNECTION (#23745)
* 12/22/00 aarono #190380 - use process heap for memory allocation
***************************************************************************/
#define INITGUID
#include <windows.h>
#include <windowsx.h>
#include <objbase.h>
#include <initguid.h>
#include "dpf.h"
#include "dplaysp.h"
#include "comport.h"
#include "macros.h"
// macros
#ifdef DEBUG
#define DPF_ERRVAL(a, b) DPF( 0, DPF_MODNAME ": " a, b );
#else
#define DPF_ERRVAL(a, b)
#endif
// constants
#define SPMINORVERSION 0x0000 // service provider-specific version number
#define VERSIONNUMBER (DPSP_MAJORVERSION | SPMINORVERSION) // version number for service provider
#define MESSAGETOKEN 0x2BAD // token to signify start of message
#define MESSAGEHEADERLEN sizeof(MESSAGEHEADER) // size of message header
#define MESSAGEMAXSIZEINT 0x0000FFFF // maximum size of an internal message
#define MESSAGEMAXSIZEEXT (MESSAGEMAXSIZEINT - MESSAGEHEADERLEN) // maximum size of an external message
typedef enum {
NEWMESSAGESTATE = 0, // start reading a new message
READHEADERSTATE, // read the message header
READDATASTATE, // read the message data
SKIPDATASTATE // skip the message data
} MESSAGESTATE;
// structures
// message header
typedef struct {
WORD wToken; // message token
WORD wMessageSize; // length of message
WORD wMessageCRC; // CRC checksum value for message body
WORD wHeaderCRC; // CRC checksum value for header
} MESSAGEHEADER, *LPMESSAGEHEADER;
// service provider context
typedef struct {
LPDPCOMPORT lpComPort; // pointer to com port data structure
MESSAGESTATE msReadState; // current read state
BYTE lpReadHeader[MESSAGEHEADERLEN]; // buffer for message header
LPBYTE lpReadBuffer; // buffer for message data
DWORD dwReadBufferSize; // size of message buffer in bytes
DWORD dwReadCount; // no. bytes read into message buffer
DWORD dwReadTotal; // no. total bytes to read into message buffer
DWORD dwSkipCount; // no. bytes skipped to find message header
LPDIRECTPLAYSP lpDPlay; // pointer to IDirectPlaySP needed to call back into DPlay
} SPCONTEXT, *LPSPCONTEXT;
// {0F1D6860-88D9-11cf-9C4E-00A0C905425E}
DEFINE_GUID(DPSERIAL_GUID, // GUID for serial service provider
0xf1d6860, 0x88d9, 0x11cf, 0x9c, 0x4e, 0x0, 0xa0, 0xc9, 0x5, 0x42, 0x5e);
// {44EAA760-CB68-11cf-9C4E-00A0C905425E}
DEFINE_GUID(DPMODEM_GUID, // GUID for modem service provider
0x44eaa760, 0xcb68, 0x11cf, 0x9c, 0x4e, 0x0, 0xa0, 0xc9, 0x5, 0x42, 0x5e);
CRITICAL_SECTION csMem;
/*
* GetSPContext
*
* Get service provider context from DirectPlay.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "GetSPContext"
LPSPCONTEXT GetSPContext(LPDIRECTPLAYSP lpDPlay)
{
LPSPCONTEXT lpContext = NULL;
DWORD dwContextSize = 0;
HRESULT hr;
// no dplay interface?
if (lpDPlay == NULL)
{
DPF_ERR("DPlaySP interface is NULL!");
goto FAILURE;
}
// get pointer to context from DPlay
hr = lpDPlay->lpVtbl->GetSPData(lpDPlay, &lpContext, &dwContextSize, DPGET_LOCAL);
if FAILED(hr)
{
DPF_ERRVAL("could not get context: 0x%08X", hr);
goto FAILURE;
}
// make sure size is correct
if (dwContextSize != sizeof(SPCONTEXT))
{
DPF_ERR("invalid context size!");
goto FAILURE;
}
return (lpContext);
FAILURE:
return (NULL);
}
/*
* SetupMessageHeader
*
* Initialize the service provider-specific header put
* in front of every message.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SetupMessageHeader"
HRESULT SetupMessageHeader(LPVOID pvMessage, DWORD dwMessageSize)
{
LPMESSAGEHEADER pMessageHeader = (LPMESSAGEHEADER) pvMessage;
// make sure message will fit in header
if (dwMessageSize > MESSAGEMAXSIZEINT)
return (DPERR_SENDTOOBIG);
// set message header
pMessageHeader->wToken = (WORD) MESSAGETOKEN;
// set message size
pMessageHeader->wMessageSize = (WORD) dwMessageSize;
// generate CRC for message body
pMessageHeader->wMessageCRC = (WORD) GenerateCRC(((LPBYTE) pvMessage) + MESSAGEHEADERLEN,
dwMessageSize - MESSAGEHEADERLEN);
// generate CRC for message header
pMessageHeader->wHeaderCRC = (WORD) GenerateCRC(pvMessage, MESSAGEHEADERLEN - sizeof(pMessageHeader->wHeaderCRC));
return (DP_OK);
}
/*
* GetMessageLength
*
* Check for valid message header and return length of message.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "GetMessageLength"
DWORD GetMessageLength(LPBYTE header)
{
LPMESSAGEHEADER pMessageHeader = (LPMESSAGEHEADER) header;
DWORD byteCount;
// check for token we put in front of every message
if (pMessageHeader->wToken != MESSAGETOKEN)
goto FAILURE;
// check CRC for message header
if (pMessageHeader->wHeaderCRC != (WORD) GenerateCRC(header, MESSAGEHEADERLEN - sizeof(pMessageHeader->wHeaderCRC)))
goto FAILURE;
// get length of message
byteCount = pMessageHeader->wMessageSize;
if (byteCount <= MESSAGEHEADERLEN)
{
DPF_ERRVAL("bad message size: %d", byteCount);
goto FAILURE;
}
return (byteCount);
FAILURE:
return (0);
}
/*
* SetupToReadMessage
*
* Create/resize buffer to fit length of message and initialize header.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SetupToReadMessage"
BOOL SetupToReadMessage(LPSPCONTEXT lpContext)
{
// no buffer, so create one
if (lpContext->lpReadBuffer == NULL)
{
lpContext->lpReadBuffer = SP_MemAlloc(lpContext->dwReadTotal);
if (lpContext->lpReadBuffer == NULL)
{
DPF_ERRVAL("could not create message buffer: %d", GetLastError());
goto FAILURE;
}
lpContext->dwReadBufferSize = lpContext->dwReadTotal;
}
// existing buffer not big enough, so resize
else if (lpContext->dwReadBufferSize < lpContext->dwReadTotal)
{
HANDLE h;
h = SP_MemReAlloc(lpContext->lpReadBuffer, lpContext->dwReadTotal);
if (h == NULL)
{
DPF_ERRVAL("could not reallocate message buffer: %d", GetLastError());
goto FAILURE;
}
lpContext->lpReadBuffer = h;
lpContext->dwReadBufferSize = lpContext->dwReadTotal;
}
// copy message header to buffer
CopyMemory(lpContext->lpReadBuffer, lpContext->lpReadHeader, lpContext->dwReadCount);
return (TRUE);
FAILURE:
return (FALSE);
}
/*
* ReadRoutine
*
* Read bytes from COM port using a state machine to assemble a message.
* When message is assembled, call back to DirectPlay to deliver it.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "ReadRoutine"
void ReadRoutine(LPDIRECTPLAYSP lpDPlay)
{
LPSPCONTEXT lpContext;
DWORD byteCount;
// get service provider context
lpContext = GetSPContext(lpDPlay);
if (lpContext == NULL)
{
DPF_ERR("invalid context!");
return;
}
while (1)
{
switch (lpContext->msReadState)
{
// start reading a new message
case NEWMESSAGESTATE:
lpContext->dwReadCount = 0;
lpContext->dwReadTotal = MESSAGEHEADERLEN;
lpContext->msReadState = READHEADERSTATE;
lpContext->dwSkipCount = 0;
break;
// read message header
case READHEADERSTATE:
byteCount = lpContext->lpComPort->Read(lpContext->lpComPort,
&lpContext->lpReadHeader[lpContext->dwReadCount],
lpContext->dwReadTotal - lpContext->dwReadCount);
if (byteCount == 0)
return;
lpContext->dwReadCount += byteCount;
if (lpContext->dwReadCount == lpContext->dwReadTotal) // got enough for a header
{
lpContext->dwReadTotal = GetMessageLength(lpContext->lpReadHeader); // see if it's real
if (lpContext->dwReadTotal)
{
if (lpContext->dwSkipCount)
DPF_ERRVAL("%d bytes skipped", lpContext->dwSkipCount);
if (SetupToReadMessage(lpContext)) // prepare to read message
lpContext->msReadState = READDATASTATE;
else
lpContext->msReadState = SKIPDATASTATE;
}
else // bad message header - reset
{
DWORD i;
if (lpContext->dwSkipCount == 0)
DPF_ERR("invalid message header - skipping bytes");
lpContext->dwReadCount = MESSAGEHEADERLEN - 1; // throw away first byte and try again
lpContext->dwReadTotal = MESSAGEHEADERLEN;
lpContext->dwSkipCount += 1;
for (i = 0; i < lpContext->dwReadCount; i++) // shuffle down one byte
lpContext->lpReadHeader[i] = lpContext->lpReadHeader[i + 1];
}
}
break;
// read message data
case READDATASTATE:
byteCount = lpContext->lpComPort->Read(lpContext->lpComPort,
&lpContext->lpReadBuffer[lpContext->dwReadCount],
lpContext->dwReadTotal - lpContext->dwReadCount);
if (byteCount == 0)
return;
lpContext->dwReadCount += byteCount;
if (lpContext->dwReadCount == lpContext->dwReadTotal) // have read entire message
{
LPMESSAGEHEADER pMessageHeader;
// check for CRC errors
pMessageHeader = (LPMESSAGEHEADER) lpContext->lpReadBuffer;
if (pMessageHeader->wMessageCRC != (WORD) GenerateCRC(lpContext->lpReadBuffer + MESSAGEHEADERLEN, lpContext->dwReadTotal - MESSAGEHEADERLEN))
{
DPF_ERR("Message dropped - CRC did not match!");
}
else
{
DPF(5, "%d byte message received", lpContext->dwReadTotal);
// deliver message to DirectPlay
lpContext->lpDPlay->lpVtbl->HandleMessage(lpContext->lpDPlay, // DirectPlay instance
lpContext->lpReadBuffer + MESSAGEHEADERLEN, // pointer to message data
lpContext->dwReadTotal - MESSAGEHEADERLEN, // length of message data
NULL); // pointer to header (unused here)
}
lpContext->msReadState = NEWMESSAGESTATE; // go read next message
}
break;
// skip message data
case SKIPDATASTATE:
DPF_ERR("Skipping data!");
while (lpContext->lpComPort->Read(lpContext->lpComPort, &lpContext->lpReadHeader[0], 1)) // spin until entire message discarded
{
lpContext->dwReadCount += 1;
if (lpContext->dwReadCount == lpContext->dwReadTotal)
{
lpContext->msReadState = NEWMESSAGESTATE;
break;
}
}
break;
default:
DPF_ERRVAL("bad read state: %d", lpContext->msReadState);
break;
}
}
}
/*
* SP_EnumSessions
*
* Broadcast a message to the network.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SP_EnumSessions"
HRESULT WINAPI SP_EnumSessions(LPDPSP_ENUMSESSIONSDATA ped)
{
LPSPCONTEXT lpContext;
DWORD byteCount;
HRESULT hr;
DPF(5,"entering SP_EnumSessions");
// get service provider context
lpContext = GetSPContext(ped->lpISP);
if (lpContext == NULL)
{
DPF_ERR("invalid context!");
hr = DPERR_NOINTERFACE;
goto FAILURE;
}
// make connection
hr = lpContext->lpComPort->Connect(lpContext->lpComPort, FALSE, ped->bReturnStatus);
if FAILED(hr)
{
if (hr != DPERR_CONNECTING)
DPF_ERRVAL("error making connection: 0x%08X", hr);
goto FAILURE;
}
// see if connection has been lost
if (lpContext->lpComPort->GetHandle(lpContext->lpComPort) == NULL)
{
DPF_ERR("connection lost!");
hr = DPERR_SESSIONLOST;
goto FAILURE;
}
// setup the message
hr = SetupMessageHeader(ped->lpMessage, ped->dwMessageSize);
if FAILED(hr)
{
DPF_ERR("message too large!");
goto FAILURE;
}
// send message
byteCount = lpContext->lpComPort->Write(lpContext->lpComPort, ped->lpMessage, ped->dwMessageSize, TRUE);
if (byteCount != ped->dwMessageSize)
{
DPF(0, "error writing message: %d requested, %d actual", ped->dwMessageSize, byteCount);
hr = DPERR_CONNECTIONLOST;
goto FAILURE;
}
DPF(5, "%d byte enum sessions message sent", byteCount);
return (DP_OK);
FAILURE:
return (hr);
} // EnumSessions
/*
* SP_Send
*
* Send a message to a particular player or group.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SP_Send"
HRESULT WINAPI SP_Send(LPDPSP_SENDDATA psd)
{
LPSPCONTEXT lpContext;
DWORD byteCount;
HRESULT hr;
DPF(5,"entering SP_Send");
// get service provider context
lpContext = GetSPContext(psd->lpISP);
if (lpContext == NULL)
{
DPF_ERR("invalid context!");
hr = DPERR_NOINTERFACE;
goto FAILURE;
}
// see if connection has been lost
if (lpContext->lpComPort->GetHandle(lpContext->lpComPort) == NULL)
{
DPF_ERR("connection lost!");
hr = DPERR_SESSIONLOST;
goto FAILURE;
}
// setup the message
hr = SetupMessageHeader(psd->lpMessage, psd->dwMessageSize);
if FAILED(hr)
{
DPF_ERR("message too large!");
goto FAILURE;
}
// send message
byteCount = lpContext->lpComPort->Write(lpContext->lpComPort, psd->lpMessage, psd->dwMessageSize, TRUE);
if (byteCount != psd->dwMessageSize)
{
DPF(0, "error writing message: %d requested, %d actual", psd->dwMessageSize, byteCount);
hr = DPERR_CONNECTIONLOST;
goto FAILURE;
}
DPF(5, "%d byte message sent", byteCount);
return (DP_OK);
FAILURE:
return (hr);
} // Send
/*
* SP_Reply
*
* Send a reply to a message.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SP_Reply"
HRESULT WINAPI SP_Reply(LPDPSP_REPLYDATA prd)
{
LPSPCONTEXT lpContext;
DWORD byteCount;
HRESULT hr;
DPF(5,"entering Reply");
// get service provider context
lpContext = GetSPContext(prd->lpISP);
if (lpContext == NULL)
{
DPF_ERR("invalid context!");
hr = DPERR_NOINTERFACE;
goto FAILURE;
}
// see if connection has been lost
if (lpContext->lpComPort->GetHandle(lpContext->lpComPort) == NULL)
{
DPF_ERR("connection lost!");
hr = DPERR_SESSIONLOST;
goto FAILURE;
}
// setup the message
hr = SetupMessageHeader(prd->lpMessage, prd->dwMessageSize);
if FAILED(hr)
{
DPF_ERR("message too large!");
goto FAILURE;
}
// send message
byteCount = lpContext->lpComPort->Write(lpContext->lpComPort, prd->lpMessage, prd->dwMessageSize, TRUE);
if (byteCount != prd->dwMessageSize)
{
DPF(0, "error writing message: %d requested, %d actual", prd->dwMessageSize, byteCount);
hr = DPERR_CONNECTIONLOST;
goto FAILURE;
}
DPF(5, "%d byte reply message sent", byteCount);
return (DP_OK);
FAILURE:
return (hr);
} // Reply
/*
* SP_Open
*
* Open the service provider.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SP_Open"
HRESULT WINAPI SP_Open(LPDPSP_OPENDATA pod)
{
LPSPCONTEXT lpContext;
HRESULT hr;
DPF(5,"entering Open");
// get service provider context
lpContext = GetSPContext(pod->lpISP);
if (lpContext == NULL)
{
DPF_ERR("invalid context!");
hr = DPERR_NOINTERFACE;
goto FAILURE;
}
// make connection
hr = lpContext->lpComPort->Connect(lpContext->lpComPort, pod->bCreate, pod->bReturnStatus);
if FAILED(hr)
{
DPF_ERRVAL("error making connection: 0x%08X", hr);
goto FAILURE;
}
return (DP_OK);
FAILURE:
return (hr);
} // Open
/*
* SP_GetCaps
*
* Return capabilities of service provider.
*
* Only the fields that matter to this service provider have
* to be set here, since all the fields are preset to
* default values.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SP_GetCaps"
HRESULT WINAPI SP_GetCaps(LPDPSP_GETCAPSDATA pcd)
{
LPSPCONTEXT lpContext;
LPDPCAPS lpCaps;
HRESULT hr;
DPF(5,"entering GetCaps");
// get service provider context
lpContext = GetSPContext(pcd->lpISP);
if (lpContext == NULL)
{
DPF_ERR("invalid context!");
hr = DPERR_NOINTERFACE;
goto FAILURE;
}
// make sure caps buffer is large enough
lpCaps = pcd->lpCaps;
if (lpCaps->dwSize < sizeof(DPCAPS))
{
DPF_ERR("caps buffer too small");
hr = DPERR_BUFFERTOOSMALL;
goto FAILURE;
}
// don't zero out caps as DPlay has pre-initialized some default caps for us
lpCaps->dwSize = sizeof(DPCAPS);
lpCaps->dwMaxBufferSize = MESSAGEMAXSIZEEXT; // return maximum external message size
lpCaps->dwHeaderLength = MESSAGEHEADERLEN; // return size of message header
lpCaps->dwFlags = 0; // have DPlay do the keep-alives
lpCaps->dwLatency = 250; // todo - base these on baud rate ACK!!!
lpCaps->dwTimeout = 2500;
// if we have connected we can get the baud rate
if (lpContext->lpComPort->GetHandle(lpContext->lpComPort))
{
DWORD dwBaudRate;
// try to get baud rate
hr = lpContext->lpComPort->GetBaudRate(lpContext->lpComPort, &dwBaudRate);
if SUCCEEDED(hr)
{
lpCaps->dwHundredBaud = dwBaudRate / 100; // return baud rate in hundreds of baud
}
}
return (DP_OK);
FAILURE:
return (hr);
} // GetCaps
/*
* SP_GetAddress
*
* Return network address of a given player.
*
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SP_GetAddress"
HRESULT WINAPI SP_GetAddress(LPDPSP_GETADDRESSDATA pga)
{
LPSPCONTEXT lpContext;
HRESULT hr;
DPF(5,"entering GetAddress");
// get service provider context
lpContext = GetSPContext(pga->lpISP);
if (lpContext == NULL)
{
DPF_ERR("invalid context!");
hr = DPERR_NOINTERFACE;
goto FAILURE;
}
hr = lpContext->lpComPort->GetAddress(lpContext->lpComPort, pga->dwFlags, pga->lpAddress, pga->lpdwAddressSize);
FAILURE:
return (hr);
} // GetAddress
/*
* SP_GetAddressChoices
*
* Return address choices for this service provider
*
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SP_GetAddressChoices"
HRESULT WINAPI SP_GetAddressChoices(LPDPSP_GETADDRESSCHOICESDATA pga)
{
LPSPCONTEXT lpContext;
HRESULT hr;
DPF(5,"entering GetAddressChoices");
// get service provider context
lpContext = GetSPContext(pga->lpISP);
if (lpContext == NULL)
{
DPF_ERR("invalid context!");
hr = DPERR_NOINTERFACE;
goto FAILURE;
}
hr = lpContext->lpComPort->GetAddressChoices(lpContext->lpComPort, pga->lpAddress, pga->lpdwAddressSize);
FAILURE:
return (hr);
} // GetAddressChoices
/*
* SP_Shutdown
*
* Turn off all I/O on service provider and release all allocated
* memory and resources.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SP_Shutdown"
HRESULT WINAPI SP_ShutdownEx(LPDPSP_SHUTDOWNDATA psd)
{
LPSPCONTEXT lpContext;
HRESULT hr;
DPF(5,"entering Shutdown");
// get service provider context
lpContext = GetSPContext(psd->lpISP);
if (lpContext == NULL)
{
DPF_ERR("invalid context!");
hr = DPERR_NOINTERFACE;
goto FAILURE;
}
if (lpContext->lpComPort)
{
lpContext->lpComPort->Dispose(lpContext->lpComPort);
lpContext->lpComPort = NULL;
}
if (lpContext->lpReadBuffer)
{
SP_MemFree(lpContext->lpReadBuffer);
lpContext->lpReadBuffer = NULL;
}
lpContext->lpDPlay = NULL;
// OK to release DPLAYX.DLL
gdwDPlaySPRefCount++;
return (DP_OK);
FAILURE:
return (hr);
} // Shutdown
/*
* SPInit
*
* This is the main entry point for the service provider. This should be
* the only entry point exported from the DLL.
*
* Allocate any needed resources and return the supported callbacks.
*/
#undef DPF_MODNAME
#define DPF_MODNAME "SPInit"
HRESULT WINAPI SPInit(LPSPINITDATA pid)
{
SPCONTEXT context;
LPSPCONTEXT lpContext;
LPDPSP_SPCALLBACKS lpcbTable;
HRESULT hr;
DPF(5,"entering SPInit");
// check to make sure table is big enough
lpcbTable = pid->lpCB;
if (lpcbTable->dwSize < sizeof(DPSP_SPCALLBACKS)) // table not big enough
{
DPF_ERR("callback table too small");
hr = DPERR_BUFFERTOOSMALL;
goto FAILURE;
}
// initialize context
ZeroMemory(&context, sizeof(SPCONTEXT));
lpContext = &context;
lpContext->msReadState = NEWMESSAGESTATE;
lpContext->lpDPlay = pid->lpISP; // save pointer to IDPlaySP so we can pass it back later
// check for correct GUID
if (IsEqualGUID(pid->lpGuid, &DPSERIAL_GUID))
{
hr = NewSerial(pid->lpAddress, pid->dwAddressSize,
lpContext->lpDPlay, ReadRoutine,
&lpContext->lpComPort);
}
else if (IsEqualGUID(pid->lpGuid, &DPMODEM_GUID))
{
hr = NewModem(pid->lpAddress, pid->dwAddressSize,
lpContext->lpDPlay, ReadRoutine,
&lpContext->lpComPort);
}
else
{
DPF_ERR("unknown service provider GUID");
hr = DPERR_INVALIDPARAM;
}
if FAILED(hr)
{
DPF_ERRVAL("error opening com port: 0x%08X", hr);
goto FAILURE;
}
// return size of header we need on every message so
// DirectPlay will leave room for it.
pid->dwSPHeaderSize = MESSAGEHEADERLEN;
// return version number so DirectPlay will treat us with respect
pid->dwSPVersion = VERSIONNUMBER;
// set up callbacks
lpcbTable->dwSize = sizeof(DPSP_SPCALLBACKS); // MUST set the return size of the table
lpcbTable->Send = SP_Send;
lpcbTable->EnumSessions = SP_EnumSessions;
lpcbTable->Reply = SP_Reply;
lpcbTable->GetCaps = SP_GetCaps;
lpcbTable->GetAddress = SP_GetAddress;
lpcbTable->GetAddressChoices = SP_GetAddressChoices;
lpcbTable->Open = SP_Open;
lpcbTable->ShutdownEx = SP_ShutdownEx;
// save context with DPlay so we can get it later
hr = lpContext->lpDPlay->lpVtbl->SetSPData(lpContext->lpDPlay, lpContext, sizeof(SPCONTEXT), DPSET_LOCAL);
if FAILED(hr)
{
DPF_ERRVAL("could not store context: 0x%08X", hr);
goto FAILURE;
}
// make sure DPLAYX.DLL sticks around
gdwDPlaySPRefCount++;
return (DP_OK);
FAILURE:
return (hr);
} // SPInit