* Acess2 IP Stack
* - TCP Handling
*/
-#define DEBUG 0
+#define DEBUG 1
#include "ipstack.h"
#include "ipv4.h"
#include "ipv6.h"
void TCP_Client_Close(tVFS_Node *Node);
// --- Helpers
int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue);
+Uint32 GetRelative(Uint32 Base, Uint32 Value);
// === TEMPLATES ===
tSocketFile gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
LOG("Sending %i+%i to %s:%i", sizeof(*Header), Length,
IPStack_PrintAddress(Interface->Type, Dest),
- ntohs(Header->RemotePort)
+ ntohs(Header->DestPort)
);
Header->Checksum = 0;
conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
conn->HighestSequenceRcvd = conn->NextSequenceRcv;
conn->NextSequenceSend = rand();
+ conn->LastACKSequence = ntohl( hdr->SequenceNumber );
conn->Node.ImplInt = srv->NextID ++;
#if 1
// - Only send an ACK if we've had a burst
- if( Connection->NextSequenceRcv > (Uint32)(TCP_DACK_THRESHOLD + Connection->LastACKSequence) )
+ Uint32 bytes_since_last_ack = Connection->NextSequenceRcv - Connection->LastACKSequence;
+ LOG("bytes_since_last_ack = 0x%x", bytes_since_last_ack);
+ if( bytes_since_last_ack > TCP_DACK_THRESHOLD )
{
TCP_INT_SendACK(Connection, "DACK Burst");
// - Extend TCP deferred ACK timer
#endif
}
// Check if the packet is in window
- else if( WrapBetween(Connection->NextSequenceRcv, sequence_num,
- Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
+ else if( sequence_num - Connection->NextSequenceRcv < TCP_WINDOW_SIZE )
{
Uint8 *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
- #if CACHE_FUTURE_PACKETS_IN_BYTES
- Uint32 index;
-
- index = sequence_num % TCP_WINDOW_SIZE;
+ Uint32 index = sequence_num % TCP_WINDOW_SIZE;
+ Uint32 max = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
+ if( !(Connection->FuturePacketValidBytes[index/8] & (1 << (index%8))) )
+ TCP_INT_SendACK(Connection, "Lost packet");
for( int i = 0; i < dataLen; i ++ )
{
Connection->FuturePacketValidBytes[index/8] |= 1 << (index%8);
// Do a wrap increment
index ++;
if(index == TCP_WINDOW_SIZE) index = 0;
+ if(index == max) break;
}
- #else
- tTCPStoredPacket *pkt, *tmp, *prev = NULL;
-
- // Allocate and fill cached packet
- pkt = malloc( sizeof(tTCPStoredPacket) + dataLen );
- pkt->Next = NULL;
- pkt->Sequence = ntohl(Header->SequenceNumber);
- pkt->Length = dataLen;
- memcpy(pkt->Data, dataptr, dataLen);
-
- Log_Log("TCP", "We missed a packet, caching",
- pkt->Sequence, Connection->NextSequenceRcv);
-
- // No? Well, let's cache it and look at it later
- SHORTLOCK( &Connection->lFuturePackets );
- for(tmp = Connection->FuturePackets;
- tmp;
- prev = tmp, tmp = tmp->Next)
- {
- if(tmp->Sequence >= pkt->Sequence) break;
- }
-
- // Add if before first, or sequences don't match
- if( !tmp || tmp->Sequence != pkt->Sequence )
- {
- if(prev)
- prev->Next = pkt;
- else
- Connection->FuturePackets = pkt;
- pkt->Next = tmp;
- }
- // Replace if larger
- else if(pkt->Length > tmp->Length)
- {
- if(prev)
- prev->Next = pkt;
- pkt->Next = tmp->Next;
- free(tmp);
- }
- else
+ Uint32 rel_highest = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
+ Uint32 rel_this = index - Connection->NextSequenceRcv;
+ LOG("Updating highest this(0x%x) > highest(%x)", rel_this, rel_highest);
+ if( rel_this > rel_highest )
{
- free(pkt); // TODO: Find some way to remove this
+ Connection->HighestSequenceRcvd = index;
}
- SHORTREL( &Connection->lFuturePackets );
- #endif
}
// Badly out of sequence packet
else
*/
void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
{
- #if CACHE_FUTURE_PACKETS_IN_BYTES
// Calculate length of contiguous bytes
- int length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
+ const int length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
Uint32 index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
- LOG("length=%i, index=%i", length, index);
+ size_t runlength = length;
+ LOG("length=%i, index=0x%x", length, index);
for( int i = 0; i < length; i ++ )
{
int bit = index % 8;
Uint8 bitfield_byte = Connection->FuturePacketValidBytes[index / 8];
if( (bitfield_byte & (1 << bit)) == 0 ) {
- length = i;
+ runlength = i;
+ LOG("Hit missing, break");
break;
}
}
index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
+ Connection->NextSequenceRcv += runlength;
// Write data to to the ring buffer
- if( TCP_WINDOW_SIZE - index > length )
+ if( TCP_WINDOW_SIZE - index > runlength )
{
// Simple case
- RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, length );
+ RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, runlength );
}
else
{
int endLen = TCP_WINDOW_SIZE - index;
// 2-part case
RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
- RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - length );
+ RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - runlength );
}
// Mark (now saved) bytes as invalid
// - Align index
- while(index % 8 && length > 0)
+ while(index % 8 && runlength > 0)
{
Connection->FuturePacketData[index] = 0;
Connection->FuturePacketValidBytes[index/8] &= ~(1 << (index%8));
index ++;
if(index > TCP_WINDOW_SIZE)
index -= TCP_WINDOW_SIZE;
- length --;
+ runlength --;
}
- while( length > 7 )
+ while( runlength > 7 )
{
Connection->FuturePacketData[index] = 0;
Connection->FuturePacketValidBytes[index/8] = 0;
- length -= 8;
+ runlength -= 8;
index += 8;
if(index > TCP_WINDOW_SIZE)
index -= TCP_WINDOW_SIZE;
}
- while(length)
+ while( runlength > 0)
{
Connection->FuturePacketData[index] = 0;
Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
index ++;
if(index > TCP_WINDOW_SIZE)
index -= TCP_WINDOW_SIZE;
- length --;
- }
-
- #else
- tTCPStoredPacket *pkt;
- for(;;)
- {
- SHORTLOCK( &Connection->lFuturePackets );
-
- // Clear out duplicates from cache
- // - If a packet has just been recieved, and it is expected, then
- // (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
- // packets in cache that are smaller than the next expected
- // are now defunct.
- pkt = Connection->FuturePackets;
- while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
- {
- tTCPStoredPacket *next = pkt->Next;
- free(pkt);
- pkt = next;
- }
-
- // If there's no packets left in cache, stop looking
- if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
- SHORTREL( &Connection->lFuturePackets );
- return;
- }
-
- // Delete packet from future list
- Connection->FuturePackets = pkt->Next;
-
- // Release list
- SHORTREL( &Connection->lFuturePackets );
-
- // Looks like we found one
- TCP_INT_AppendRecieved(Connection, pkt->Data, pkt->Length);
- if( Connection->HighestSequenceRcvd == Connection->NextSequenceRcv )
- Connection->HighestSequenceRcvd += pkt->Length;
- Connection->NextSequenceRcv += pkt->Length;
- free(pkt);
+ runlength --;
}
- #endif
}
void TCP_int_SendDelayedACK(void *ConnPtr)
// - Stop Delayed ACK timer (as this data packet ACKs)
Time_RemoveTimer(Connection->DeferredACKTimer);
+
+ // TODO: Don't exceed window size
packet->SourcePort = htons(Connection->LocalPort);
packet->DestPort = htons(Connection->RemotePort);
return 0;
}
+Uint32 GetRelative(Uint32 Base, Uint32 Value)
+{
+ if( Value < Base )
+ return Value - Base + 0xFFFFFFFF;
+ else
+ return Value - Base;
+}
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