From 641862e3d1cf499b4265c90241f897f62645718a Mon Sep 17 00:00:00 2001
From: David Doan <daviddoan@Davids-MacBook-Pro-70.local>
Date: Thu, 9 Nov 2023 12:19:38 -0500
Subject: sending changes

---
 pkg/ipstack/ipstack.go |  78 +++++++++++++++++++++++++++----------------------
 vhost                  | Bin 3191006 -> 3179481 bytes
 vrouter                | Bin 3182993 -> 3146532 bytes
 3 files changed, 43 insertions(+), 35 deletions(-)

diff --git a/pkg/ipstack/ipstack.go b/pkg/ipstack/ipstack.go
index 9ffe34f..afe3bc5 100644
--- a/pkg/ipstack/ipstack.go
+++ b/pkg/ipstack/ipstack.go
@@ -891,37 +891,6 @@ func HandleTCP(src *Interface, message []byte, hdr *ipv4header.IPv4Header) error
 		// if the SYN flag is set, then send a SYNACK
 		available := false
 
-		socketEntry, in := VHostSocketMaps[SocketKey{hdr.Dst.String(), tcpHdr.DstPort, hdr.Src.String(), tcpHdr.SrcPort}]
-		if !in {
-			fmt.Println("no socket entry found")
-		} else if socketEntry.State == Established {
-			fmt.Println("socket entry found")
-
-			// make ack header
-			tcpHdr := &header.TCPFields{
-				SrcPort:       tcpHdr.DstPort,
-				DstPort:       tcpHdr.SrcPort,
-				SeqNum:        tcpHdr.SeqNum,
-				AckNum:        tcpHdr.SeqNum + 1,
-				DataOffset:    20,
-				Flags:         0x10,
-				WindowSize:    MAX_WINDOW_SIZE,
-				Checksum:      0,
-				UrgentPointer: 0,
-			}
-			// make the payload
-			err := SendTCP(tcpHdr, message, hdr.Dst, hdr.Src)
-			if err != nil {
-				fmt.Println(err)
-			}
-			ptr := socketEntry.Conn.RecvBuffer.recvNext
-			l := uint32(len(tcpPayload))
-			copy(socketEntry.Conn.RecvBuffer.buffer[ptr:ptr+l], tcpPayload)
-			socketEntry.Conn.RecvBuffer.recvNext += l
-			fmt.Println("recvNext: ", socketEntry.Conn.RecvBuffer.recvNext)
-			fmt.Println("recvBuffer: ", socketEntry.Conn.RecvBuffer.buffer)
-			break
-		}
 		// add to table if available
 		mapMutex.Lock()
 		for _, socketEntry := range VHostSocketMaps {
@@ -1007,17 +976,56 @@ func HandleTCP(src *Interface, message []byte, hdr *ipv4header.IPv4Header) error
 		fmt.Println("I see an ACK flag")
 		// lookup for socket entry and update its state
 		// set synChan to true (TODO)
-		key := SocketKey{hdr.Dst.String(), tcpHdr.DstPort, hdr.Src.String(), tcpHdr.SrcPort}
-		socketEntry, in := VHostSocketMaps[key]
+		// key := SocketKey{hdr.Dst.String(), tcpHdr.DstPort, hdr.Src.String(), tcpHdr.SrcPort}
+		// socketEntry, in := VHostSocketMaps[key]
+		// if !in {
+		// 	fmt.Println("no socket entry found")
+		// } else if socketEntry.State == Established {
+		// 	fmt.Println("socket entry found")
+		// 	// socketEntry.Conn.RecvBuffer.buffer = append(socketEntry.Conn.RecvBuffer.buffer, tcpPayload...)
+		// 	socketEntry.Conn.SendBuffer.una += uint32(len(tcpPayload))
+		// 	break
+		// }
+		socketEntry, in := VHostSocketMaps[SocketKey{hdr.Dst.String(), tcpHdr.DstPort, hdr.Src.String(), tcpHdr.SrcPort}]
 		if !in {
 			fmt.Println("no socket entry found")
 		} else if socketEntry.State == Established {
+			if (len(tcpPayload) == 0) {
+				break
+			}
 			fmt.Println("socket entry found")
-			// socketEntry.Conn.RecvBuffer.buffer = append(socketEntry.Conn.RecvBuffer.buffer, tcpPayload...)
+			// infinite loop is created here
+			// make ack header
+			tcpHdr := &header.TCPFields{
+				SrcPort:       tcpHdr.DstPort,
+				DstPort:       tcpHdr.SrcPort,
+				SeqNum:        tcpHdr.AckNum,
+				AckNum:        tcpHdr.SeqNum + uint32(len(tcpPayload)),
+				DataOffset:    20,
+				Flags:         0x10,
+				WindowSize:    MAX_WINDOW_SIZE,
+				Checksum:      0,
+				UrgentPointer: 0,
+			}
+			// make the payload
+			payloadToSend := []byte{}
+			err := SendTCP(tcpHdr, payloadToSend, hdr.Dst, hdr.Src)
+			if err != nil {
+				fmt.Println(err)
+			}
+
 			socketEntry.Conn.SendBuffer.una += uint32(len(tcpPayload))
+
+			ptr := socketEntry.Conn.RecvBuffer.recvNext
+			l := uint32(len(tcpPayload))
+			copy(socketEntry.Conn.RecvBuffer.buffer[ptr:ptr+l], tcpPayload)
+			socketEntry.Conn.RecvBuffer.recvNext += l
+			fmt.Println("recvNext: ", socketEntry.Conn.RecvBuffer.recvNext)
+			fmt.Println("recvBuffer: ", socketEntry.Conn.RecvBuffer.buffer)
 			break
 		}
 
+
 		mapMutex.Lock()
 		for _, socketEntry := range VHostSocketMaps {
 			if socketEntry.LocalPort == tcpHdr.DstPort && socketEntry.LocalIP == hdr.Dst.String() && socketEntry.State == SYNRECIEVED {
@@ -1513,7 +1521,7 @@ func (c *VTCPConn) VWrite(payload []byte) (int, error) {
 		SeqNum:        c.SendBuffer.nxt,
 		AckNum:        c.SendBuffer.una,
 		DataOffset:    20,
-		Flags:         header.TCPFlagSyn,
+		Flags:         header.TCPFlagAck,
 		WindowSize:    uint16(advertisedWindow),
 		Checksum:      0,
 		UrgentPointer: 0,
diff --git a/vhost b/vhost
index 71946eb..82caaa7 100755
Binary files a/vhost and b/vhost differ
diff --git a/vrouter b/vrouter
index 707d2d0..e0eee04 100755
Binary files a/vrouter and b/vrouter differ
-- 
cgit v1.2.3-70-g09d2