+++ /dev/null
-/*
- * Acess2 IP Stack
- * - Link/Media Layer Interface
- */
-#include "ipstack.h"
-#include "link.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);
-
-// === GLOBALS ===
- int giRegisteredTypes = 0;
- int giRegisteredTypeSpace = 0;
-struct {
- Uint16 Type;
- tPacketCallback Callback;
-} *gaRegisteredTypes;
- int gbLink_CRCTableGenerated = 0;
-Uint32 gaiLink_CRCTable[256];
-
-// === CODE ===
-/**
- * \fn void Link_RegisterType(Uint16 Type, tPacketCallback Callback)
- * \brief Registers a callback for a specific packet type
- *
- * \todo Make thread safe (place a mutex on the list)
- */
-void Link_RegisterType(Uint16 Type, tPacketCallback Callback)
-{
- int i;
- void *tmp;
-
- for( i = giRegisteredTypes; i -- ; )
- {
- if(gaRegisteredTypes[i].Type == Type) {
- Log_Warning("Net Link", "Attempt to register 0x%x twice", Type);
- return ;
- }
- // Ooh! Free slot!
- if(gaRegisteredTypes[i].Callback == NULL) break;
- }
-
- if(i == -1)
- {
- giRegisteredTypeSpace += 5;
- tmp = realloc(gaRegisteredTypes, giRegisteredTypeSpace*sizeof(*gaRegisteredTypes));
- if(!tmp) {
- Log_Warning("Net Link",
- "Out of heap space! (Attempted to allocate %i)",
- giRegisteredTypeSpace*sizeof(*gaRegisteredTypes)
- );
- return ;
- }
- gaRegisteredTypes = tmp;
- i = giRegisteredTypes;
- giRegisteredTypes ++;
- }
-
- gaRegisteredTypes[i].Callback = Callback;
- gaRegisteredTypes[i].Type = Type;
-}
-
-/**
- * \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)
-{
- int bufSize = sizeof(tEthernetHeader) + ((Length+3)&~3) + 4;
- Uint8 buf[bufSize]; // dynamic stack arrays ftw!
- tEthernetHeader *hdr = (void*)buf;
-
- 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);
-
- 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);
-}
-
-/**
- * \fn void Link_WatchDevice(tAdapter *Adapter)
- * \brief Spawns a worker thread to watch the specified adapter
- */
-void Link_WatchDevice(tAdapter *Adapter)
-{
- int tid = Proc_SpawnWorker(); // Create a new worker thread
-
- if(tid < 0) {
- Log_Warning("Net Link", "Unable to create watcher thread for '%s'", Adapter->Device);
- return ;
- }
-
- if(tid > 0) {
- Log_Log("Net Link", "Watching '%s' using tid %i", Adapter->Device, tid);
- return ;
- }
-
- if( !gbLink_CRCTableGenerated )
- Link_InitCRC();
-
- Threads_SetName(Adapter->Device);
- Log_Log("Net Link", "Thread %i watching '%s'", Threads_GetTID(), Adapter->Device);
-
- // 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
-
- // 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;
- }
-
- // Call the callback
- gaRegisteredTypes[i].Callback(
- Adapter,
- hdr->Src,
- ret - sizeof(tEthernetHeader),
- hdr->Data
- );
- }
-
- Log_Log("Net Link", "Watcher terminated (file closed)");
-
- Threads_Exit(0, 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;
- }
-
- 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;
-}
git.ucc.asn.au / tpg / acess2.git / blobdiff
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