/*
- * Acess2 IP Stack
- * - Link/Media Layer Interface
+ * Acess2 Networking Stack
+ * - By John Hodge (thePowersGang)
+ *
+ * link.c
+ * - Ethernet/802.3 Handling code
+ * TODO: Rename file
*/
#include "ipstack.h"
#include "link.h"
+#include "include/buffer.h"
+#include "include/adapters_int.h"
// === 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);
+void Link_SendPacket(tAdapter *Adapter, Uint16 Type, tMacAddr To, tIPStackBuffer *Buffer);
+ int Link_HandlePacket(tAdapter *Adapter, tIPStackBuffer *Buffer);
+// --- CRC ---
+void Link_InitCRC(void);
+Uint32 Link_CalculateCRC(tIPStackBuffer *Buffer);
+Uint32 Link_CalculatePartialCRC(Uint32 CRC, const void *Data, int Length);
// === GLOBALS ===
int giRegisteredTypes = 0;
* \fn void Link_SendPacket(tAdapter *Adapter, Uint16 Type, tMacAddr To, int Length, void *Buffer)
* \brief Formats and sends a packet on the specified interface
*/
-void Link_SendPacket(tAdapter *Adapter, Uint16 Type, tMacAddr To, int Length, void *Buffer)
+void Link_SendPacket(tAdapter *Adapter, Uint16 Type, tMacAddr To, tIPStackBuffer *Buffer)
{
- int bufSize = sizeof(tEthernetHeader) + ((Length+3)&~3) + 4;
- Uint8 buf[bufSize]; // dynamic stack arrays ftw!
+ int length = IPStack_Buffer_GetLength(Buffer);
+ int ofs = 4 - (length & 3);
+ Uint8 buf[sizeof(tEthernetHeader) + ofs + 4];
tEthernetHeader *hdr = (void*)buf;
-
+
+ if( ofs == 4 ) ofs = 0;
+
Log_Log("Net Link", "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);
-
+ 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;
+ memcpy(&hdr->Src, Adapter->HWAddr, 6); // TODO: Remove hard coded 6
hdr->Type = htons(Type);
+ *(Uint32*)(buf + sizeof(tEthernetHeader) + ofs) = 0;
+
+ IPStack_Buffer_AppendSubBuffer(Buffer, sizeof(tEthernetHeader), ofs + 4, hdr, NULL, NULL);
- 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);
+ *(Uint32*)(buf + sizeof(tEthernetHeader) + ofs) = htonl( Link_CalculateCRC(Buffer) );
+
+ Log_Log("Net Link", " 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]
+ );
+
+ Adapter_SendPacket(Adapter, Buffer);
}
-void Link_WorkerThread(void *Ptr)
+int Link_HandlePacket(tAdapter *Adapter, tIPStackBuffer *Buffer)
{
- tAdapter *Adapter = Ptr;
+ size_t len = 0;
+ void *data = IPStack_Buffer_CompactBuffer(Buffer, &len);
- Threads_SetName(Adapter->Device);
- Log_Log("Net Link", "Thread %i watching '%s'", Threads_GetTID(), Adapter->Device);
+ tEthernetHeader *hdr = (void*)data;
+ int i;
+ Uint32 checksum;
- // 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)
- //Log_Debug("NET", "Waiting on adapter FD#0x%x", Adapter->DeviceFD);
- ret = VFS_Read(Adapter->DeviceFD, MAX_PACKET_SIZE, buf);
- if(ret == -1) break;
-
- if(ret < sizeof(tEthernetHeader)) {
- Log_Log("Net Link", "Recieved an undersized packet (%i < %i)",
- ret, sizeof(tEthernetHeader));
- continue;
- }
-
- Log_Log("Net Link",
- "Packet from %02x:%02x:%02x:%02x:%02x:%02x"
- " to %02x:%02x:%02x:%02x:%02x:%02x (Type=%04x)",
- hdr->Src.B[0], hdr->Src.B[1], hdr->Src.B[2],
- hdr->Src.B[3], hdr->Src.B[4], hdr->Src.B[5],
- hdr->Dest.B[0], hdr->Dest.B[1], hdr->Dest.B[2],
- hdr->Dest.B[3], hdr->Dest.B[4], hdr->Dest.B[5],
- ntohs(hdr->Type)
- );
- checksum = *(Uint32*)&hdr->Data[ret-sizeof(tEthernetHeader)-4];
- //Log_Log("NET", "Checksum 0x%08x", checksum);
- // TODO: Check checksum
+ if(len < sizeof(tEthernetHeader)) {
+ Log_Log("Net Link", "Recieved an undersized packet (%i < %i)",
+ len, sizeof(tEthernetHeader));
+ free(data);
+ return 1;
+ }
- // Check if there is a registered callback for this packet type
- for( i = giRegisteredTypes; i--; )
- {
- if(gaRegisteredTypes[i].Type == ntohs(hdr->Type)) break;
- }
- // No? Ignore it
- if( i == -1 ) {
- Log_Log("Net Link", "Unregistered type 0x%x", ntohs(hdr->Type));
- continue;
- }
+ Log_Log("Net Link",
+ "Packet from %02x:%02x:%02x:%02x:%02x:%02x"
+ " to %02x:%02x:%02x:%02x:%02x:%02x (Type=%04x)",
+ hdr->Src.B[0], hdr->Src.B[1], hdr->Src.B[2],
+ hdr->Src.B[3], hdr->Src.B[4], hdr->Src.B[5],
+ hdr->Dest.B[0], hdr->Dest.B[1], hdr->Dest.B[2],
+ hdr->Dest.B[3], hdr->Dest.B[4], hdr->Dest.B[5],
+ ntohs(hdr->Type)
+ );
+ checksum = *(Uint32*)&hdr->Data[len-sizeof(tEthernetHeader)-4];
+ //Log_Log("NET", "Checksum 0x%08x", checksum);
+ // TODO: Check checksum
+
+ // Check if there is a registered callback for this packet type
+ for( i = giRegisteredTypes; i--; )
+ {
+ if(gaRegisteredTypes[i].Type == ntohs(hdr->Type)) break;
+ }
+ // No? Ignore it
+ if( i == -1 ) {
+ Log_Log("Net Link", "Unregistered type 0x%x", ntohs(hdr->Type));
- // Call the callback
- gaRegisteredTypes[i].Callback(
- Adapter,
- hdr->Src,
- ret - sizeof(tEthernetHeader),
- hdr->Data
- );
+ free(data);
+ return 1;
}
- Log_Log("Net Link", "Watcher terminated (file closed)");
-
- Threads_Exit(0, 0);
-}
-
-/**
- * \fn void Link_WatchDevice(tAdapter *Adapter)
- * \brief Spawns a worker thread to watch the specified adapter
- */
-void Link_WatchDevice(tAdapter *Adapter)
-{
- int tid;
-
- if( !gbLink_CRCTableGenerated )
- Link_InitCRC();
+ // Call the callback
+ gaRegisteredTypes[i].Callback(
+ Adapter,
+ hdr->Src,
+ len - sizeof(tEthernetHeader),
+ hdr->Data
+ );
- tid = Proc_SpawnWorker(Link_WorkerThread, Adapter); // Create a new worker thread
+ free(data);
- if(tid < 0) {
- Log_Warning("Net Link", "Unable to create watcher thread for '%s'", Adapter->Device);
- return ;
- }
-
- Log_Log("Net Link", "Watching '%s' using tid %i", Adapter->Device, tid);
+ return 0;
}
// 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;
- }
+ 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)
+Uint32 Link_CalculateCRC(tIPStackBuffer *Buffer)
+{
+ Uint32 ret = 0xFFFFFFFF;
+ const void *data;
+ size_t length;
+
+ int id = -1;
+ while( (id = IPStack_Buffer_GetBuffer(Buffer, id, &length, &data)) != -1 )
+ {
+ ret = Link_CalculatePartialCRC(ret, data, length);
+ }
+
+ return ~ret;
+}
+
+Uint32 Link_CalculatePartialCRC(Uint32 CRC, const 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;
+ const Uint32 *data = Data;
+
+ for( int i = 0; i < Length/4; i++ )
+ {
+ CRC = (CRC << 8 | *data++) ^ gaiLink_CRCTable[CRC >> 24];
+ }
+
+ return CRC;
}