Allow to set/get netlink socket timeout for default handle

Ref: #613

Signed-off-by: arthurchiao <arthurchiao@hotmail.com>

handle_linux.go

@@ -21,6 +21,22 @@ type Handle struct {
 	lookupByDump bool
 }
 
+// SetSocketTimeout configures timeout for default netlink sockets
+func SetSocketTimeout(to time.Duration) error {
+	if to < time.Microsecond {
+		return fmt.Errorf("invalid timeout, minimul value is %s", time.Microsecond)
+	}
+
+	nl.SocketTimeoutTv = unix.NsecToTimeval(to.Nanoseconds())
+	return nil
+}
+
+// GetSocketTimeout returns the timeout value used by default netlink sockets
+func GetSocketTimeout() time.Duration {
+	nsec := unix.TimevalToNsec(nl.SocketTimeoutTv)
+	return time.Duration(nsec) * time.Nanosecond
+}
+
 // SupportsNetlinkFamily reports whether the passed netlink family is supported by this Handle
 func (h *Handle) SupportsNetlinkFamily(nlFamily int) bool {
 	_, ok := h.sockets[nlFamily]

handle_linux_test.go

@@ -0,0 +1,17 @@
+package netlink
+
+import (
+	"testing"
+	"time"
+)
+
+func TestSetGetSocketTimeout(t *testing.T) {
+	timeout := 10 * time.Second
+	if err := SetSocketTimeout(10 * time.Second); err != nil {
+		t.Fatalf("Set socket timeout for default handle failed: %v", err)
+	}
+
+	if val := GetSocketTimeout(); val != timeout {
+		t.Fatalf("Unexpcted socket timeout value: got=%v, expected=%v", val, timeout)
+	}
+}

nl/nl_linux.go

@@ -35,6 +35,9 @@ var SupportedNlFamilies = []int{unix.NETLINK_ROUTE, unix.NETLINK_XFRM, unix.NETL
 
 var nextSeqNr uint32
 
+// Default netlink socket timeout, 60s
+var SocketTimeoutTv = unix.Timeval{Sec: 60, Usec: 0}
+
 // GetIPFamily returns the family type of a net.IP.
 func GetIPFamily(ip net.IP) int {
 	if len(ip) <= net.IPv4len {
@@ -426,6 +429,14 @@ func (req *NetlinkRequest) Execute(sockType int, resType uint16) ([][]byte, erro
 		if err != nil {
 			return nil, err
 		}
+
+		if err := s.SetSendTimeout(&SocketTimeoutTv); err != nil {
+			return nil, err
+		}
+		if err := s.SetReceiveTimeout(&SocketTimeoutTv); err != nil {
+			return nil, err
+		}
+
 		defer s.Close()
 	} else {
 		s.Lock()