// === CONSTANTS ===
#define MAX_PACKET_SIZE 2048
+// === PROTOTYPES ===
+void Link_RegisterType(Uint16 Type, tPacketCallback Callback);
+void Link_InitCRC();
+Uint32 Link_CalculateCRC(void *Data, int Length);
+void Link_SendPacket(tAdapter *Adapter, Uint16 Type, tMacAddr To, int Length, void *Buffer);
+void Link_WatchDevice(tAdapter *Adapter);
+
// === GLOBALS ===
int giRegisteredTypes = 0;
struct {
Uint16 Type;
tPacketCallback Callback;
} *gaRegisteredTypes;
+ int gbLink_CRCTableGenerated = 0;
+Uint32 gaiLink_CRCTable[256];
// === CODE ===
/**
{
int i;
void *tmp;
+
+ Type = htons(Type); // Set to network order
+
for( i = giRegisteredTypes; i -- ; )
{
if(gaRegisteredTypes[i].Type == Type) {
- Warning("[NET ] Attempt to register 0x%x twice", Type);
+ Log_Warning("NET", "Attempt to register 0x%x twice", Type);
return ;
}
// Ooh! Free slot!
if(i == -1)
{
tmp = realloc(gaRegisteredTypes, (giRegisteredTypes+1)*sizeof(*gaRegisteredTypes));
- if(!tmp) Panic("[NET ] Out of heap space!");
+ if(!tmp) {
+ Log_Warning("NET", "Out of heap space!");
+ return ;
+ }
i = giRegisteredTypes;
giRegisteredTypes ++;
gaRegisteredTypes = tmp;
*/
void Link_SendPacket(tAdapter *Adapter, Uint16 Type, tMacAddr To, int Length, void *Buffer)
{
- int bufSize = sizeof(tEthernetHeader) + Length;
- Uint8 buf[bufSize];
+ int bufSize = sizeof(tEthernetHeader) + ((Length+3)&~3) + 4;
+ Uint8 buf[bufSize]; // dynamic stack arrays ftw!
tEthernetHeader *hdr = (void*)buf;
+ Log_Log("NET", "Sending %i bytes to %02x:%02x:%02x:%02x:%02x:%02x (Type 0x%x)",
+ Length, To.B[0], To.B[1], To.B[2], To.B[3], To.B[4], To.B[5], Type);
+
hdr->Dest = To;
hdr->Src = Adapter->MacAddr;
hdr->Type = htons(Type);
memcpy(hdr->Data, Buffer, Length);
+ *(Uint32*) &hdr->Data[bufSize-4] = 0;
+ *(Uint32*) &hdr->Data[bufSize-4] = htonl( Link_CalculateCRC(buf, bufSize) );
+
VFS_Write(Adapter->DeviceFD, bufSize, buf);
}
int tid = Proc_SpawnWorker(); // Create a new worker thread
if(tid < 0) {
- Panic("[NET ] Unable to create watcher thread for '%s'", Adapter->Device);
+ Log_Warning("NET", "Unable to create watcher thread for '%s'", Adapter->Device);
+ return ;
}
if(tid > 0) {
- Log("[NET ] Watching '%s' using tid %i", Adapter->Device, tid);
+ Log_Log("NET", "Watching '%s' using tid %i", Adapter->Device, tid);
return ;
}
+ if( !gbLink_CRCTableGenerated )
+ Link_InitCRC();
+
// Child Thread
while(Adapter->DeviceFD != -1)
{
Uint8 buf[MAX_PACKET_SIZE];
tEthernetHeader *hdr = (void*)buf;
int ret, i;
+ Uint32 checksum;
// Wait for a packet (Read on a network device is blocking)
ret = VFS_Read(Adapter->DeviceFD, MAX_PACKET_SIZE, buf);
if(ret == -1) break;
if(ret <= sizeof(tEthernetHeader)) {
- Log("[NET ] Recieved an undersized packet");
+ Log_Log("NET", "Recieved an undersized packet");
continue;
}
+ Log_Log("NET", "Packet from %02x:%02x:%02x:%02x:%02x:%02x",
+ hdr->Src.B[0], hdr->Src.B[1], hdr->Src.B[2],
+ hdr->Src.B[3], hdr->Src.B[4], hdr->Src.B[5]
+ );
+ Log_Log("NET", "to %02x:%02x:%02x:%02x:%02x:%02x",
+ hdr->Dest.B[0], hdr->Dest.B[1], hdr->Dest.B[2],
+ hdr->Dest.B[3], hdr->Dest.B[4], hdr->Dest.B[5]
+ );
+ checksum = *(Uint32*)&hdr->Data[ret-sizeof(tEthernetHeader)-4];
+ Log_Log("NET", "Checksum 0x%08x", checksum);
+
// Check if there is a registered callback for this packet type
for( i = giRegisteredTypes; i--; )
{
- if(gaRegisteredTypes[i].Type == hdr->Type) continue;
+ if(gaRegisteredTypes[i].Type == hdr->Type) break;
}
// No? Ignore it
- if( i == -1 ) continue;
+ if( i == -1 ) {
+ Log_Log("NET", "Unregistered type 0x%x", ntohs(hdr->Type));
+ continue;
+ }
// Call the callback
gaRegisteredTypes[i].Callback(
);
}
- Log("[NET ] Watcher terminated (file closed)");
+ Log_Log("NET", "Watcher terminated (file closed)");
+}
+
+// From http://www.cl.cam.ac.uk/research/srg/bluebook/21/crc/node6.html
+#define QUOTIENT 0x04c11db7
+void Link_InitCRC(void)
+{
+ int i, j;
+ Uint32 crc;
+
+ for (i = 0; i < 256; i++)
+ {
+ crc = i << 24;
+ for (j = 0; j < 8; j++)
+ {
+ if (crc & 0x80000000)
+ crc = (crc << 1) ^ QUOTIENT;
+ else
+ crc = crc << 1;
+ }
+ gaiLink_CRCTable[i] = crc;
+ }
+
+ gbLink_CRCTableGenerated = 1;
+}
+
+Uint32 Link_CalculateCRC(void *Data, int Length)
+{
+ // x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1
+ Uint32 result;
+ int i;
+ Uint32 *data = Data;
+
+ if(Length < 4) return 0;
+
+ result = *data++ << 24;
+ result |= *data++ << 16;
+ result |= *data++ << 8;
+ result |= *data++;
+ result = ~ result;
+ Length -= 4;
+
+ for( i = 0; i < Length; i++ )
+ {
+ result = (result << 8 | *data++) ^ gaiLink_CRCTable[result >> 24];
+ }
+
+ return ~result;
}