WIP GRE tunnel

1 files changed, 140 insertions, 5 deletions

diff --git a/pkg/tcpip/sample/tun_tcp_connect/main.go b/pkg/tcpip/sample/tun_tcp_connect/main.go
index a7da9dcd9..f44237295 100644
--- a/pkg/tcpip/sample/tun_tcp_connect/main.go
+++ b/pkg/tcpip/sample/tun_tcp_connect/main.go
@@ -41,6 +41,7 @@
 package main
 
 import (
+        "context"
 	"bufio"
 	"fmt"
 	"log"
@@ -54,12 +55,16 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
+	"gvisor.dev/gvisor/pkg/tcpip/link/channel"
 	"gvisor.dev/gvisor/pkg/tcpip/link/fdbased"
+	grelink "gvisor.dev/gvisor/pkg/tcpip/link/gre"
 	"gvisor.dev/gvisor/pkg/tcpip/link/rawfile"
 	"gvisor.dev/gvisor/pkg/tcpip/link/sniffer"
 	"gvisor.dev/gvisor/pkg/tcpip/link/tun"
 	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/gre"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/raw"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
@@ -93,9 +98,75 @@ func writer(ch chan struct{}, ep tcpip.Endpoint) {
 	}
 }
 
+type GrePacketInfo struct {
+        pi *channel.PacketInfo
+}
+
+func (g GrePacketInfo) FullPayload() ([]byte, *tcpip.Error){
+        log.Println("FullPayload")
+        pkt := g.pi.Pkt
+        size := pkt.Size()
+        vv := buffer.NewVectorisedView(size, pkt.Views())
+        var buf = make([]byte, size, size)
+        pos := 0
+        for {
+                copied, err := vv.Read(buf[pos:])
+                log.Printf("VectorisedView Read: %d %d %d %v", size, pos, copied, err)
+                if err != nil {
+                        return nil, tcpip.ErrBadBuffer
+                }
+                pos = pos + copied
+                if pos == size {
+                        break
+                }
+        }
+                
+        log.Printf("FullPayload return: %d %v", len(buf), buf)
+        return buf, nil
+}
+
+func (g GrePacketInfo) Payload(size int) ([]byte, *tcpip.Error){
+        log.Println("Payload")
+        return nil, tcpip.ErrNotSupported
+}
+
+type GreHandlerInfo struct {
+        ChEp *channel.Endpoint
+        Raw tcpip.Endpoint
+        Raddr tcpip.FullAddress
+}
+
+func (info *GreHandlerInfo) greHandler(req *gre.ForwarderRequest) {
+        pkt := req.Pkt
+        log.Println("greHandler: ", req.Pkt.Size(), req.Pkt.Views())
+        views := pkt.Data.Views()
+        size := pkt.Data.Size()
+        data := buffer.NewVectorisedView(size, views)
+	newPkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
+		Data: data,
+	})
+        log.Println("greHandler cloned: ", newPkt.Views())
+
+        info.ChEp.InjectInbound(header.IPv4ProtocolNumber, newPkt)
+}
+
+func (info *GreHandlerInfo) greRead(ep *channel.Endpoint) {
+        for {
+                pi, err := ep.ReadContext(context.Background());
+                linkHdr := pi.Pkt.LinkHeader()
+                greHdr := header.GRE(linkHdr.Push(4)) //header.IPv4MinimumSize + 4)
+                greHdr.SetProtocolType(header.IPv4ProtocolNumber)
+                log.Printf("greRead %d %v %v %v", pi.Proto, pi, err, greHdr)
+                opts := tcpip.WriteOptions{
+                        //To: &info.Raddr
+                }
+                info.Raw.Write(GrePacketInfo{&pi}, opts)
+        }
+}
+
 func main() {
-	if len(os.Args) != 6 {
-		log.Fatal("Usage: ", os.Args[0], " <tun-device> <local-ipv4-address> <local-port> <remote-ipv4-address> <remote-port>")
+	if len(os.Args) != 8 {
+		log.Fatal("Usage: ", os.Args[0], " <tun-device> <local-ipv4-address> <local-port> <remote-ipv4-address> <remote-port> <local-gre-address> <remote-gre-address>")
 	}
 
 	tunName := os.Args[1]
@@ -103,15 +174,21 @@ func main() {
 	portName := os.Args[3]
 	remoteAddrName := os.Args[4]
 	remotePortName := os.Args[5]
+        greAddrName := os.Args[6]
+        greRemoteAddrName := os.Args[7]
 
 	rand.Seed(time.Now().UnixNano())
 
 	addr := tcpip.Address(net.ParseIP(addrName).To4())
+	greAddr := tcpip.Address(net.ParseIP(greAddrName).To4())
+	greRemoteAddr := tcpip.Address(net.ParseIP(greRemoteAddrName).To4())
 	remote := tcpip.FullAddress{
-		NIC:  1,
+		NIC:  0,
 		Addr: tcpip.Address(net.ParseIP(remoteAddrName).To4()),
 	}
 
+        log.Printf("local:%v remote:%v", addr, remote)
+
 	var localPort uint16
 	if v, err := strconv.Atoi(portName); err != nil {
 		log.Fatalf("Unable to convert port %v: %v", portName, err)
@@ -129,7 +206,7 @@ func main() {
 	// NIC and ipv4 address.
 	s := stack.New(stack.Options{
 		NetworkProtocols:   []stack.NetworkProtocolFactory{ipv4.NewProtocol},
-		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol},
+		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol, gre.NewProtocol},
 	})
 
 	mtu, err := rawfile.GetMTU(tunName)
@@ -150,17 +227,73 @@ func main() {
 		log.Fatal(err)
 	}
 
-	if err := s.AddAddress(1, ipv4.ProtocolNumber, addr); err != nil {
+	if err := s.AddAddress(1, ipv4.ProtocolNumber, greAddr); err != nil {
+		log.Fatal(err)
+	}
+
+	// Create TCP endpoint.
+	var rawWq waiter.Queue
+	rawEp, tcperr := raw.NewEndpoint(s, ipv4.ProtocolNumber, 47, &rawWq)
+	if tcperr != nil {
+		log.Fatal(tcperr)
+	}
+        log.Println("EP: %s", rawEp)
+
+        raddr := greRemoteAddr
+        fraddr := tcpip.FullAddress{NIC: 1, Addr: raddr}
+        fgreAddr := tcpip.FullAddress{NIC: 1, Addr: greAddr}
+        tcperr = rawEp.Bind(fgreAddr)
+        if tcperr != nil {
+                log.Fatal(tcperr)
+        }
+        log.Printf("Remote: %v %v", raddr, fraddr)
+
+        // Create GRE
+        greEP := grelink.New(mtu - 24)
+        chEP := greEP.GetChannel()
+        greEP.NMaxHeaderLength = 4 + 20
+
+        greInfo := GreHandlerInfo{
+//                Ep: loEP,
+                ChEp: chEP,
+                Raw: rawEp,
+                Raddr: fraddr,
+        }
+        greFwd := gre.NewForwarder(s, greInfo.greHandler)
+        s.SetTransportProtocolHandler(47, greFwd.HandlePacket)
+
+        go greInfo.greRead(chEP)
+        //greEP.Bind(s, greIP)
+	if err := s.CreateNIC(2, sniffer.New(greEP)); err != nil {
+	 	log.Fatal(err)
+        }
+	if err := s.AddAddress(2, ipv4.ProtocolNumber, addr); err != nil {
 		log.Fatal(err)
 	}
 
 	// Add default route.
+        subnet, err := tcpip.NewSubnet(
+                tcpip.Address(net.ParseIP("10.0.1.0").To4()),
+                tcpip.AddressMask(net.ParseIP("255.255.255.0").To4()))
+        if err != nil {
+                panic(err)
+        }
 	s.SetRouteTable([]tcpip.Route{
 		{
+			Destination: subnet,
+			NIC:         2,
+		},
+		{
 			Destination: header.IPv4EmptySubnet,
 			NIC:         1,
 		},
 	})
+        log.Printf("Nics enabled 1:%v 2:%v 3:%v", s.CheckNIC(1), s.CheckNIC(2), s.CheckNIC(3))
+
+        tcperr = rawEp.Connect(fraddr)
+        if tcperr != nil {
+                log.Fatal(tcperr)
+        }
 
 	// Create TCP endpoint.
 	var wq waiter.Queue
@@ -179,7 +312,9 @@ func main() {
 	// Issue connect request and wait for it to complete.
 	waitEntry, notifyCh := waiter.NewChannelEntry(nil)
 	wq.EventRegister(&waitEntry, waiter.EventOut)
+	fmt.Println("Connect")
 	terr := ep.Connect(remote)
+	fmt.Println("Connect called")
 	if terr == tcpip.ErrConnectStarted {
 		fmt.Println("Connect is pending...")
 		<-notifyCh