Source code of Windows XP (NT5)
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9.8 KiB

/*++
Copyright (c) 1997 Microsoft Corporation
Module Name:
version.c
Abstract:
TAPI Service Provider functions related to negotiating version.
TSPI_lineNegotiateTSPIVersion
Environment:
User Mode - Win32
--*/
///////////////////////////////////////////////////////////////////////////////
// //
// Include files //
// //
///////////////////////////////////////////////////////////////////////////////
#include "globals.h"
#include "provider.h"
#include "version.h"
#include "line.h"
///////////////////////////////////////////////////////////////////////////////
// //
// Private procedures //
// //
///////////////////////////////////////////////////////////////////////////////
BOOL
H323NegotiateTSPIVersion(
DWORD dwLowVersion,
DWORD dwHighVersion,
PDWORD pdwTSPIVersion
)
/*++
Routine Description:
This function determines whether or not specified TSPI version is
supported by the service provider.
Arguments:
dwLowVersion - Specifies the lowest TSPI version number under which the
TAPI DLL is willing to operate. The most-significant WORD is the
major version number and the least-significant WORD is the minor
version number.
dwHighVersion - Specifies the highest TSPI version number under which
the TAPI DLL is willing to operate. The most-significant WORD is the
major version number and the least-significant WORD is the minor
version number.
pdwTSPIVersion - Specifies a far pointer to a DWORD. The service
provider fills this location with the highest TSPI version number,
within the range requested by the caller, under which the service
provider is willing to operate. The most-significant WORD is the
major version number and the least-significant WORD is the minor
version number.
Return Values:
Returns true if successful.
--*/
{
// validate extension version range
if ((TSPI_VERSION_HI <= dwHighVersion) &&
(TSPI_VERSION_HI >= dwLowVersion)) {
// save negotiated version
*pdwTSPIVersion = TSPI_VERSION_HI;
// success
return TRUE;
} else if ((dwHighVersion <= TSPI_VERSION_HI) &&
(dwHighVersion >= TSPI_VERSION_LO)) {
// save negotiated version
*pdwTSPIVersion = dwHighVersion;
// success
return TRUE;
}
H323DBG((
DEBUG_LEVEL_ERROR,
"failed to negotiate version.\n"
));
// failure
return FALSE;
}
///////////////////////////////////////////////////////////////////////////////
// //
// Public procedures //
// //
///////////////////////////////////////////////////////////////////////////////
BOOL
H323ValidateTSPIVersion(
DWORD dwTSPIVersion
)
/*++
Routine Description:
This function determines whether or not specified TSPI version is
supported by the service provider.
Arguments:
dwTSPIVersion - Specifies the TSPI version to validate.
Return Values:
Returns true if successful.
--*/
{
// see if specified version is supported
if ((dwTSPIVersion >= TSPI_VERSION_LO) &&
(dwTSPIVersion <= TSPI_VERSION_HI)) {
// success
return TRUE;
}
H323DBG((
DEBUG_LEVEL_ERROR,
"do not support TSPI version %d.%d.\n",
HIWORD(dwTSPIVersion),
LOWORD(dwTSPIVersion)
));
// failure
return FALSE;
}
BOOL
H323ValidateExtVersion(
DWORD dwExtVersion
)
/*++
Routine Description:
This function determines whether or not specified extension version is
supported by the service provider.
Arguments:
dwExtVersion - Specifies the extension version to validate.
Return Values:
Returns true if successful.
--*/
{
// see if specified version is supported
if ((dwExtVersion >= H323_VERSION_LO) &&
(dwExtVersion <= H323_VERSION_HI)) {
// success
return TRUE;
}
H323DBG((
DEBUG_LEVEL_ERROR,
"do not support extension version %d.%d.\n",
HIWORD(dwExtVersion),
LOWORD(dwExtVersion)
));
// failure
return FALSE;
}
///////////////////////////////////////////////////////////////////////////////
// //
// TSPI procedures //
// //
///////////////////////////////////////////////////////////////////////////////
LONG
TSPIAPI
TSPI_lineNegotiateTSPIVersion(
DWORD dwDeviceID,
DWORD dwLowVersion,
DWORD dwHighVersion,
PDWORD pdwTSPIVersion
)
/*++
Routine Description:
This function returns the highest SPI version the Service Provider is
willing to operate under for this device given the range of possible
SPI versions.
The TAPI DLL typically calls this function early in the initialization
sequence for each line device. In addition, it calls this with the
value INITIALIZE_NEGOTIATION for dwDeviceID to negotiate an interface
version for calling early initialization functions.
Note that when dwDeviceID is INITIALIZE_NEGOTIATION, this function must
not return LINEERR_OPERATIONUNAVAIL, since this function (with that value)
is mandatory for negotiating the overall interface version even if the
service provider supports no line devices.
Negotiation of an Extension version is done through the separate
procedure TSPI_lineNegotiateExtVersion.
Arguments:
dwDeviceID - Identifies the line device for which interface version
negotiation is to be performed. In addition to device IDs within
the range the Service Provider supports, this may be the value:
INITIALIZE_NEGOTIATION - This value is used to signify that an overall
interface version is to be negotiated. Such an interface version
is required for functions that can be called early in the
initialization sequence, i.e., before the device ID range has
been set.
dwLowVersion - Specifies the lowest TSPI version number under which the
TAPI DLL is willing to operate. The most-significant WORD is the
major version number and the least-significant WORD is the minor
version number.
dwHighVersion - Specifies the highest TSPI version number under which
the TAPI DLL is willing to operate. The most-significant WORD is the
major version number and the least-significant WORD is the minor
version number.
pdwTSPIVersion - Specifies a far pointer to a DWORD. The service
provider fills this location with the highest TSPI version number,
within the range requested by the caller, under which the service
provider is willing to operate. The most-significant WORD is the
major version number and the least-significant WORD is the minor
version number. If the requested range does not overlap the range
supported by the service provider, the function returns
LINEERR_INCOMPATIBLEAPIVERSION.
Return Values:
Returns zero if the function is successful, or a negative error number
if an error has occurred. Possible return values are as follows:
LINEERR_BADDEVICEID - The specified device identifier or line device
identifier (such as in a dwDeviceID parameter) is invalid or
out of range.
LINEERR_INCOMPATIBLEAPIVERSION - The application requested an API
version or version range that is either incompatible or cannot
be supported by the Telephony API implementation and/or
corresponding service provider.
LINEERR_OPERATIONFAILED - The operation failed for an unspecified
or unknown reason.
--*/
{
DWORD dwTSPIVersion = UNINITIALIZED;
PH323_LINE pLine = NULL;
// see if this is a init line device
if ((DWORD_PTR)dwDeviceID == INITIALIZE_NEGOTIATION) {
H323DBG((
DEBUG_LEVEL_VERBOSE,
"tapisrv supports tspi version %d.%d through %d.%d.\n",
HIWORD(dwLowVersion),
LOWORD(dwLowVersion),
HIWORD(dwHighVersion),
LOWORD(dwHighVersion)
));
// perform version negotiation
if (!H323NegotiateTSPIVersion(
dwLowVersion,
dwHighVersion,
&dwTSPIVersion)) {
// negotiated version not agreed upon
return LINEERR_INCOMPATIBLEAPIVERSION;
}
// see if this is a valid line device
} else if (H323GetLineFromIDAndLock(&pLine, (DWORD)dwDeviceID)) {
// perform version negotiation
if (!H323NegotiateTSPIVersion(
dwLowVersion,
dwHighVersion,
&dwTSPIVersion)) {
// release line device
H323UnlockLine(pLine);
// negotiated version not agreed upon
return LINEERR_INCOMPATIBLEAPIVERSION;
}
// release line device
H323UnlockLine(pLine);
} else {
// do not recognize device
return LINEERR_BADDEVICEID;
}
// return negotiated version
*pdwTSPIVersion = dwTSPIVersion;
// success
return NOERROR;
}