Disable tx and rx offloading on VXLAN interfaces

backend/vxlan/device.go

@@ -118,6 +118,11 @@ func (dev *vxlanDevice) Configure(ipn ip.IP4Net) error {
 		return fmt.Errorf("failed to set interface %s to UP state: %s", dev.link.Attrs().Name, err)
 	}
 
+	// TODO: Workaround to fix #1282
+	if err := ip.SetChecksumOffloading(dev.link.Attrs().Name, false, false); err != nil {
+		return fmt.Errorf("failed to disable interface %s tx and rx offloading: %s", dev.link.Attrs().Name, err)
+	}
+
 	return nil
 }
 

pkg/ip/iface.go

@@ -22,10 +22,77 @@ import (
 	"fmt"
 	"net"
 	"syscall"
+	"unsafe"
 
 	"github.com/vishvananda/netlink"
 )
 
+const (
+	siocEthtool = 0x8946 // linux/sockios.h
+
+	// #define ETHTOOL_SRXCSUM		0x00000015 /* Set RX hw csum enable (ethtool_value) */
+	ethtoolSRxCsum = 0x00000015 // linux/ethtool.h
+	// #define ETHTOOL_STXCSUM		0x00000017 /* Set TX hw csum enable (ethtool_value) */
+	ethtoolSTxCsum = 0x00000017 // linux/ethtool.h
+
+	maxIfNameSize = 16 // linux/if.h
+)
+
+// linux/if.h 'struct ifreq'
+type ifreq struct {
+	Name [maxIfNameSize]byte
+	Data uintptr
+}
+
+// linux/ethtool.h 'struct ethtool_value'
+type ethtoolValue struct {
+	Cmd  uint32
+	Data uint32
+}
+
+// ethtool executes Linux ethtool syscall.
+func ethtool(iface string, cmd, val uint32) (retval uint32, err error) {
+	if len(iface)+1 > maxIfNameSize {
+		return 0, fmt.Errorf("interface name is too long")
+	}
+	socket, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, 0)
+	if err != nil {
+		return 0, err
+	}
+	defer syscall.Close(socket)
+
+	// prepare ethtool request
+	value := ethtoolValue{cmd, val}
+	request := ifreq{Data: uintptr(unsafe.Pointer(&value))}
+	copy(request.Name[:], iface)
+
+	// ioctl system call
+	_, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(socket), uintptr(siocEthtool),
+		uintptr(unsafe.Pointer(&request)))
+	if errno != 0 {
+		return 0, errno
+	}
+	return value.Data, nil
+}
+
+// SetChecksumOffloading enables/disables Rx/Tx checksum offloading
+// for the given interface.
+func SetChecksumOffloading(ifName string, rxOn, txOn bool) error {
+	var rxVal, txVal uint32
+	if rxOn {
+		rxVal = 1
+	}
+	if txOn {
+		txVal = 1
+	}
+	_, err := ethtool(ifName, ethtoolSRxCsum, rxVal)
+	if err != nil {
+		return err
+	}
+	_, err = ethtool(ifName, ethtoolSTxCsum, txVal)
+	return err
+}
+
 func getIfaceAddrs(iface *net.Interface) ([]netlink.Addr, error) {
 	link := &netlink.Device{
 		netlink.LinkAttrs{