ZealOS/src/Home/Net/Protocols/Ethernet.ZC
2024-03-07 00:05:39 -05:00

69 lines
1.8 KiB
HolyC
Executable File

class CEthernetFrame
{
U8 source_address[MAC_ADDRESS_LENGTH];
U8 padding[2];
U8 destination_address[MAC_ADDRESS_LENGTH];
U16 ethertype;
U8 *data;
I64 length;
};
class CEthernetGlobals
{
U8 ethernet_null[MAC_ADDRESS_LENGTH];
U8 ethernet_broadcast[MAC_ADDRESS_LENGTH];
} ethernet_globals;
U0 EthernetGlobalsInit()
{
I64 i;
for (i = 0; i < MAC_ADDRESS_LENGTH; i++)
{
ethernet_globals.ethernet_null[i] = 0;
ethernet_globals.ethernet_broadcast[i] = 0xFF;
}
}
U0 EthernetFrameParse(CEthernetFrame *frame_out, U8 *frame, U16 length)
{
// length is assumed to NOT include the FCS.
// Shrine says MemCopy has a high overhead.
// Almost tempted to say that means that a lot
// of the current system should be done with
// less extra allocation altogether, more passing.
// In practice, MemCopy causes the most slowdown on bare-metal.
NetLog("ETHERNET FRAME PARSE: Parsing frame, copying out to frame_out param.");
MemCopy(frame_out->destination_address, frame, MAC_ADDRESS_LENGTH);
MemCopy(frame_out->source_address, frame + MAC_ADDRESS_LENGTH, MAC_ADDRESS_LENGTH);
frame_out->ethertype = frame[ETHERNET_ETHERTYPE_OFFSET + 1] | frame[ETHERNET_ETHERTYPE_OFFSET] << 8;
frame_out->data = frame + ETHERNET_DATA_OFFSET;
frame_out->length = length - ETHERNET_MAC_HEADER_LENGTH;
}
U0 EthernetFrameFinish(I64 de_index)
{//Alias for generic driver Finish TX function.
U8 *data = NetDriverPacketBufferGet(de_index);
I64 length = NetDriverPacketLengthGet(de_index);
U8 *mac = EthernetMACGet();
Bool is_loopback = !MemCompare(mac, data, MAC_ADDRESS_LENGTH); // check the TX packet MAC against local MAC
// software loopback the TX packet to RX NetQueue if it's loopback
if (is_loopback)
NetQueueLazyPush(data, length);
NetDriverTransmitPacketFinish(de_index);
}
EthernetGlobalsInit;