added TestVirtioSocketListener

go.mod

@@ -2,7 +2,6 @@ module github.com/Code-Hex/vz/v2
 
 go 1.17
 
-require (
-	golang.org/x/crypto v0.1.0
-	golang.org/x/sys v0.1.0
-)
+require golang.org/x/crypto v0.1.0
+
+require golang.org/x/sys v0.1.0 // indirect

socket.go

@@ -7,15 +7,12 @@ package vz
 */
 import "C"
 import (
-	"fmt"
 	"net"
 	"os"
 	"runtime"
 	"runtime/cgo"
 	"time"
 	"unsafe"
-
-	"golang.org/x/sys/unix"
 )
 
 // SocketDeviceConfiguration for a socket device configuration.
@@ -176,17 +173,26 @@ func shouldAcceptNewConnectionHandler(listenerPtr, connPtr, devicePtr unsafe.Poi
 // You don’t create connection objects directly. When the guest operating system initiates a connection, the virtual machine creates
 // the connection object and passes it to the appropriate VirtioSocketListener struct, which forwards the object to its delegate.
 //
-// This is implemented net.Conn interface.
+// This is implemented net.Conn interface. This is generated from duplicated a file descriptor which is returned
+// from virtualization.framework. macOS cannot connect directly to the Guest operating system using vsock. The　vsock
+// connection must always be made via virtualization.framework. The diagram looks like this.
+//
+// ┌─────────┐                     ┌────────────────────────────┐               ┌────────────┐
+// │  macOS  │<─── unix socket ───>│  virtualization.framework  │<─── vsock ───>│  Guest OS  │
+// └─────────┘                     └────────────────────────────┘               └────────────┘
+//
+// You will notice that this is not vsock in using this library. However, all data this connection goes through to the vsock
+// connection to which the Guest OS is connected.
 //
 // This struct does not have any pointers for objects of the Objective-C. Because the various values
 // of the VZVirtioSocketConnection object handled by Objective-C are no longer needed after the conversion
 // to the Go struct.
 //
 // see: https://developer.apple.com/documentation/virtualization/vzvirtiosocketconnection?language=objc
 type VirtioSocketConnection struct {
-	rawConn net.Conn
-	laddr   *Addr // local
-	raddr   *Addr // remote
+	rawConn         net.Conn
+	destinationPort uint32
+	sourcePort      uint32
 }
 
 var _ net.Conn = (*VirtioSocketConnection)(nil)
@@ -200,15 +206,9 @@ func newVirtioSocketConnection(ptr unsafe.Pointer) (*VirtioSocketConnection, err
 		return nil, err
 	}
 	conn := &VirtioSocketConnection{
-		rawConn: rawConn,
-		laddr: &Addr{
-			CID:  unix.VMADDR_CID_HOST,
-			Port: (uint32)(vzVirtioSocketConnection.destinationPort),
-		},
-		raddr: &Addr{
-			CID:  unix.VMADDR_CID_HYPERVISOR,
-			Port: (uint32)(vzVirtioSocketConnection.sourcePort),
-		},
+		rawConn:         rawConn,
+		destinationPort: (uint32)(vzVirtioSocketConnection.destinationPort),
+		sourcePort:      (uint32)(vzVirtioSocketConnection.sourcePort),
 	}
 	return conn, nil
 }
@@ -225,10 +225,10 @@ func (v *VirtioSocketConnection) Close() error {
 }
 
 // LocalAddr returns the local network address.
-func (v *VirtioSocketConnection) LocalAddr() net.Addr { return v.laddr }
+func (v *VirtioSocketConnection) LocalAddr() net.Addr { return v.rawConn.LocalAddr() }
 
 // RemoteAddr returns the remote network address.
-func (v *VirtioSocketConnection) RemoteAddr() net.Addr { return v.raddr }
+func (v *VirtioSocketConnection) RemoteAddr() net.Addr { return v.rawConn.RemoteAddr() }
 
 // SetDeadline sets the read and write deadlines associated
 // with the connection. It is equivalent to calling both
@@ -253,24 +253,10 @@ func (v *VirtioSocketConnection) SetWriteDeadline(t time.Time) error {
 
 // DestinationPort returns the destination port number of the connection.
 func (v *VirtioSocketConnection) DestinationPort() uint32 {
-	return v.laddr.Port
+	return v.destinationPort
 }
 
 // SourcePort returns the source port number of the connection.
 func (v *VirtioSocketConnection) SourcePort() uint32 {
-	return v.raddr.Port
+	return v.sourcePort
 }
-
-// Addr represents a network end point address for the vsock protocol.
-type Addr struct {
-	CID  uint32
-	Port uint32
-}
-
-var _ net.Addr = (*Addr)(nil)
-
-// Network returns "vsock".
-func (a *Addr) Network() string { return "vsock" }
-
-// String returns string of "<cid>:<port>"
-func (a *Addr) String() string { return fmt.Sprintf("%d:%d", a.CID, a.Port) }

socket_test.go

@@ -0,0 +1,74 @@
+package vz_test
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"testing"
+	"time"
+
+	"github.com/Code-Hex/vz/v2"
+)
+
+func TestVirtioSocketListener(t *testing.T) {
+	container := newVirtualizationMachine(t)
+	defer container.Close()
+
+	vm := container.VirtualMachine
+
+	socketDevice := vm.SocketDevices()[0] // already tested in newVirtualizationMachine
+
+	port := 43218
+	wantData := "hello"
+	done := make(chan struct{})
+
+	listener, err := vz.NewVirtioSocketListener(func(conn *vz.VirtioSocketConnection, err error) {
+		defer close(done)
+
+		if err != nil {
+			t.Errorf("failed to accept connection: %v", err)
+			return
+		}
+		defer conn.Close()
+
+		destPort := conn.DestinationPort()
+		if port != int(destPort) {
+			t.Errorf("want destination port %d but got %d", destPort, port)
+			return
+		}
+
+		buf := make([]byte, len(wantData))
+		n, err := conn.Read(buf)
+		if err != nil && err != io.EOF {
+			t.Errorf("failed to read data: %v", err)
+			return
+		}
+		got := string(buf[:n])
+
+		if wantData != got {
+			t.Errorf("want %q but got %q", wantData, got)
+		}
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	socketDevice.SetSocketListenerForPort(listener, uint32(port))
+
+	session := container.NewSession(t)
+	var buf bytes.Buffer
+	session.Stderr = &buf
+	cmd := fmt.Sprintf("echo %s | socat - VSOCK-CONNECT:2:%d", wantData, port)
+	if err := session.Run(cmd); err != nil {
+		t.Fatalf("failed to write data to vsock: %v\nstderr: %q", err, buf)
+	}
+	session.Close()
+
+	select {
+	case <-done:
+	case <-time.After(3 * time.Second):
+		t.Fatalf("timeout connection handling after accepted")
+	}
+
+	socketDevice.RemoveSocketListenerForPort(listener, uint32(port))
+}