server updates

server/utils/file_transfer.go

@@ -0,0 +1,39 @@
+package utils
+
+import (
+	"log"
+	"github.com/google/gopacket"
+
+	"saprusserver/structs"
+)
+
+func (c* SocketCall) FileTransferPacket(message string) gopacket.SerializeBuffer {
+        eth, ip, udp := basePacket(c)
+
+        sapFile := structs.SaprusFileTransfer {
+                Flag:           [1]byte{0x11},
+                Sequence:       [2]byte{0x22, 0x33},
+                Checksum:       [2]byte{0x44, 0x44},
+                Payload:        []byte(message),
+        }
+
+        sapHeader := structs.SaprusHeaderFrame {
+                PacketType:     [2]byte{0x88, 0x88},
+                Length:         c.saprusPayloadLength(sapFile.Bytes()),
+                Payload:        sapFile.Bytes(),
+        }
+
+        buf := gopacket.NewSerializeBuffer()
+        opts := gopacket.SerializeOptions {
+                ComputeChecksums:       true,
+                FixLengths:             true,
+        }
+
+        udp.SetNetworkLayerForChecksum(&ip)
+        err := gopacket.SerializeLayers(buf, opts, &eth, &ip, &udp, gopacket.Payload(sapHeader.Bytes()))
+        if err != nil {
+                log.Panic(err)
+        }
+        return buf
+}
+

server/utils/packet_helper.go

@@ -0,0 +1,27 @@
+package utils
+
+import (
+	"github.com/google/gopacket/layers"
+)
+
+func basePacket(c* SocketCall) (layers.Ethernet, layers.IPv4, layers.UDP) {
+        eth := layers.Ethernet {
+                EthernetType:   layers.EthernetTypeIPv4,
+                SrcMAC:         c.Iface.HardwareAddr,
+                DstMAC:         layers.EthernetBroadcast,
+        }
+        ip := layers.IPv4 {
+                Version:        4,
+                TTL:            64,
+                SrcIP:          []byte{0, 0, 0, 0},
+                DstIP:          []byte{255, 255, 255, 255},
+                Protocol:       layers.IPProtocolUDP,
+        }
+        udp := layers.UDP {
+                SrcPort:        6868,
+                DstPort:        6767,
+        }
+
+        return eth, ip, udp
+}
+

server/utils/raw_packet_send.go

@@ -1,8 +1,8 @@
 package utils
 
 import (
-	//"bytes"
-	//"encoding/binary"
+	"encoding/binary"
+	"fmt"
 	"log"
 	"net"
 	"unicode/utf8"
@@ -21,10 +21,12 @@ type SocketCall struct {
 
 func splitData(message string) []string {
         data := []string{}
+	maxPacketLength := 8
+	//maxPacketLength := 1458
 
         var i, j int
 
-        for i, j = 0, 1458; j < len(message); i, j = j, j+1458 {
+        for i, j = 0, maxPacketLength; j < len(message); i, j = j, j+maxPacketLength {
                 for !utf8.RuneStart(message[j]) {
                         j--
                 }
@@ -35,15 +37,38 @@ func splitData(message string) []string {
         return data
 }
 
+func (c* SocketCall) SendPackage(buf gopacket.SerializeBuffer) error {
+	_, err := c.conn.WriteTo(buf.Bytes(), &packet.Addr{HardwareAddr: layers.EthernetBroadcast})
+	return err
+}
+
 func (c* SocketCall)SendData(message string) {
+	iface, _ := net.InterfaceByName("virbr0")
+	c.Iface = iface
+
+        conn, _ := packet.Listen(iface, packet.Raw, int(layers.EthernetTypeIPv4), nil)
+	c.conn = conn
+
         splitMessage := splitData(message)
 
         for i := 0; i < len(splitMessage); i++ {
-                c.init(splitMessage[i])
+		c.SendPackage(c.FileTransferPacket(splitMessage[i]))
         }
         return
 }
 
+func (c* SocketCall) saprusPayloadLength(pkt []byte) [2]byte{
+	payloadLength := make([]byte, 2)
+	var length [2]byte
+	binary.BigEndian.PutUint16(payloadLength, uint16(len(pkt)))
+
+	length[0] = payloadLength[0]
+	length[1] = payloadLength[1]
+
+	return length
+}
+
+/*
 func (c* SocketCall)init(data string) {
         iface, _ := net.InterfaceByName("virbr0")
         conn, err := packet.Listen(iface, packet.Raw, int(layers.EthernetTypeIPv4), nil)
@@ -71,9 +96,16 @@ func (c* SocketCall)init(data string) {
                 SrcPort: 6868,
                 DstPort: 6767,
         }
+
+	saprusPayloadLength := make([]byte, 2)
+	binary.BigEndian.PutUint16(saprusPayloadLength, uint16(len(data)))
+	var saprusPayloadLengthTwo [2]byte
+	saprusPayloadLengthTwo[0] = saprusPayloadLength[0]
+	saprusPayloadLengthTwo[1] = saprusPayloadLength[1]
+
 	saprus := structs.SaprusHeaderFrame{
-		PacketType:	10,
-		Length:		uint16(len(data)),
+		PacketType:	[2]byte{0, 10},
+		Length:		saprusPayloadLengthTwo,
 		Payload:	[]byte(data),
 	}
 
@@ -96,4 +128,4 @@ func (c* SocketCall)init(data string) {
 
         return
 }
-
+*/