/*++
Copyright (c) 1989-1993 Microsoft Corporation
Module Name:
nbfmac.c
Abstract:
This module contains code which implements Mac type dependent code for
the ST transport.
Environment:
Kernel mode (Actually, unimportant)
Revision History:
--*/
#include "st.h"
UCHAR SingleRouteSourceRouting[] = { 0xc2, 0x70 };
UCHAR GeneralRouteSourceRouting[] = { 0x82, 0x70 };
ULONG DefaultSourceRoutingLength = 2;
VOID
MacInitializeMacInfo(
IN NDIS_MEDIUM MacType,
OUT PST_NDIS_IDENTIFICATION MacInfo
);
//
// This is the interpretation of the length bits in
// the 802.5 source-routing information.
//
ULONG SR802_5Lengths[8] = { 516, 1500, 2052, 4472,
8144, 11407, 17800, 17800 };
#ifdef ALLOC_PRAGMA
#pragma alloc_text(INIT,MacInitializeMacInfo)
#pragma alloc_text(INIT,MacSetMulticastAddress)
#endif
VOID
MacInitializeMacInfo(
IN NDIS_MEDIUM MacType,
OUT PST_NDIS_IDENTIFICATION MacInfo
)
/*++
Routine Description:
Fills in the MacInfo table based on MacType.
Arguments:
MacType - The MAC type we wish to decode.
MacInfo - The MacInfo structure to fill in.
Return Value:
None.
--*/
{
switch (MacType) {
case NdisMedium802_3:
MacInfo->DestinationOffset = 0;
MacInfo->SourceOffset = 6;
MacInfo->SourceRouting = FALSE;
MacInfo->AddressLength = 6;
MacInfo->MaxHeaderLength = 14;
MacInfo->MediumType = NdisMedium802_3;
break;
case NdisMedium802_5:
MacInfo->DestinationOffset = 2;
MacInfo->SourceOffset = 8;
MacInfo->SourceRouting = TRUE;
MacInfo->AddressLength = 6;
MacInfo->MaxHeaderLength = 32;
MacInfo->MediumType = NdisMedium802_5;
break;
case NdisMediumFddi:
MacInfo->DestinationOffset = 1;
MacInfo->SourceOffset = 7;
MacInfo->SourceRouting = FALSE;
MacInfo->AddressLength = 6;
MacInfo->MaxHeaderLength = 13;
MacInfo->MediumType = NdisMediumFddi;
break;
default:
ASSERT(FALSE);
}
}
VOID
MacConstructHeader (
IN PST_NDIS_IDENTIFICATION MacInfo,
IN PUCHAR Buffer,
IN PUCHAR DestinationAddress,
IN PUCHAR SourceAddress,
IN UINT PacketLength,
IN PUCHAR SourceRouting,
IN UINT SourceRoutingLength,
OUT PUINT HeaderLength
)
/*++
Routine Description:
This routine is called to construct the Mac header for the particular
network type we're talking to.
Arguments:
MacInfo - Describes the mac we wish to build a header for.
Buffer - Where to build the header.
DestinationAddress - the address this packet is to be sent to.
SourceAddress - Our address. Passing it in as a parameter allows us to play
games with source if we need to.
PacketLength - The length of this packet. Note that this does not
includes the Mac header.
SourceRouting - Optional source routing information.
SourceRoutingLength - The length of SourceRouting.
HeaderLength - Returns the length of the constructed header.
Return Value:
None.
--*/
{
//
// Note network order of bytes.
//
switch (MacInfo->MediumType) {
case NdisMedium802_3:
*(ULONG UNALIGNED *)&Buffer[6] = *(ULONG UNALIGNED *)&SourceAddress[0];
Buffer[10] = SourceAddress[4];
Buffer[11] = SourceAddress[5];
*(ULONG UNALIGNED *)&Buffer[0] = *(ULONG UNALIGNED *)&DestinationAddress[0];
Buffer[4] = DestinationAddress[4];
Buffer[5] = DestinationAddress[5];
Buffer[12] = (UCHAR)(PacketLength >> 8);
Buffer[13] = (UCHAR)PacketLength;
*HeaderLength = 14;
break;
case NdisMedium802_5:
Buffer[0] = TR_HEADER_BYTE_0;
Buffer[1] = TR_HEADER_BYTE_1;
ASSERT (TR_ADDRESS_LENGTH == 6);
*(ULONG UNALIGNED *)&Buffer[8] = *(ULONG UNALIGNED *)&SourceAddress[0];
Buffer[12] = SourceAddress[4];
Buffer[13] = SourceAddress[5];
*(ULONG UNALIGNED *)&Buffer[2] = *(ULONG UNALIGNED *)&DestinationAddress[0];
Buffer[6] = DestinationAddress[4];
Buffer[7] = DestinationAddress[5];
*HeaderLength = 14;
if (SourceRouting != NULL) {
RtlCopyMemory (&Buffer[14], SourceRouting, SourceRoutingLength);
Buffer[8] |= 0x80; // add SR bit in source address
*HeaderLength = 14 + SourceRoutingLength;
}
break;
case NdisMediumFddi:
Buffer[0] = FDDI_HEADER_BYTE;
*(ULONG UNALIGNED *)&Buffer[7] = *(ULONG UNALIGNED *)&SourceAddress[0];
Buffer[11] = SourceAddress[4];
Buffer[12] = SourceAddress[5];
*(ULONG UNALIGNED *)&Buffer[1] = *(ULONG UNALIGNED *)&DestinationAddress[0];
Buffer[5] = DestinationAddress[4];
Buffer[6] = DestinationAddress[5];
*HeaderLength = 13;
break;
default:
PANIC ("MacConstructHeader: PANIC! called with unsupported Mac type.\n");
}
}
VOID
MacReturnMaxDataSize(
IN PST_NDIS_IDENTIFICATION MacInfo,
IN PUCHAR SourceRouting,
IN UINT SourceRoutingLength,
IN UINT DeviceMaxFrameSize,
OUT PUINT MaxFrameSize
)
/*++
Routine Description:
This routine returns the space available for user data in a MAC packet.
This will be the available space after the MAC header; all headers
headers will be included in this space.
Arguments:
MacInfo - Describes the MAC we wish to decode.
SourceRouting - If we are concerned about a reply to a specific
frame, then this information is used.
SourceRouting - The length of SourceRouting.
MaxFrameSize - The maximum frame size as returned by the adapter.
MaxDataSize - The maximum data size computed.
Return Value:
None.
--*/
{
switch (MacInfo->MediumType) {
case NdisMedium802_3:
//
// For 802.3, we always have a 14-byte MAC header.
//
*MaxFrameSize = DeviceMaxFrameSize - 14;
break;
case NdisMedium802_5:
//
// For 802.5, if we have source routing information then
// use that, otherwise assume the worst.
//
if (SourceRouting && SourceRoutingLength >= 2) {
UINT SRLength;
SRLength = SR802_5Lengths[(SourceRouting[1] & 0x70) >> 4];
DeviceMaxFrameSize -= (SourceRoutingLength + 14);
if (DeviceMaxFrameSize < SRLength) {
*MaxFrameSize = DeviceMaxFrameSize;
} else {
*MaxFrameSize = SRLength;
}
} else {
if (DeviceMaxFrameSize < 548) {
*MaxFrameSize = DeviceMaxFrameSize - 32;
} else {
*MaxFrameSize = 516;
}
}
break;
case NdisMediumFddi:
//
// For FDDI, we always have a 13-byte MAC header.
//
*MaxFrameSize = DeviceMaxFrameSize - 13;
break;
}
}
VOID
MacSetMulticastAddress (
IN NDIS_MEDIUM Type,
IN PUCHAR Buffer
)
/*++
Routine Description:
This routine sets the multicast address into a buffer provided
by the user.
Arguments:
Type the Mac Medium type.
Buffer the buffer to put the multicast address in.
Return Value:
none.
--*/
{
switch (Type) {
case NdisMedium802_3:
case NdisMediumFddi:
Buffer[0] = 0x03;
Buffer[1] = 0x07;
Buffer[2] = 0x03;
Buffer[3] = 0x07;
Buffer[4] = 0x03;
Buffer[5] = 0x07;
break;
case NdisMedium802_5:
Buffer[0] = 0xc0;
Buffer[3] = 0x20;
break;
default:
PANIC ("MacSetMulticastAddress: PANIC! called with unsupported Mac type.\n");
}
}
