initial commit

pkg/vip/vip.go

@@ -0,0 +1,96 @@
+package vip
+
+import (
+	"errors"
+	"github.com/vishvananda/netlink"
+	"net"
+)
+
+var ErrNoDefaultInterface = errors.New("no default interface found")
+
+func DefaultInterface() (iface string, err error) {
+	routes, err := netlink.RouteGet(net.IPv4bcast)
+	if err != nil {
+		return
+	}
+	if len(routes) >= 1 {
+		link, err := netlink.LinkByIndex(routes[0].LinkIndex)
+		if err != nil {
+			return "", err
+		}
+		return link.Attrs().Name, nil
+	}
+	err = ErrNoDefaultInterface
+	return
+}
+
+type Network struct {
+	iface string
+	label string
+	link  netlink.Link
+}
+
+func NewNetwork(iface string) (n *Network, err error) {
+	return NewNetworkWithLabel(iface, "")
+}
+
+func NewNetworkWithLabel(iface, label string) (n *Network, err error) {
+	if iface == "" {
+		iface, err = DefaultInterface()
+		if err != nil {
+			return
+		}
+	}
+	link, err := netlink.LinkByName(iface)
+	if err != nil {
+		return
+	}
+	n = &Network{iface, label, link}
+	return
+}
+
+func (n *Network) Interface() string {
+	return n.iface
+}
+
+func (n *Network) HasIP(a *netlink.Addr) bool {
+	addrs, err := netlink.AddrList(n.link, 0)
+	if err != nil {
+		return false
+	}
+	for _, addr := range addrs {
+		if addr.Equal(*a) {
+			return true
+		}
+	}
+	return false
+}
+
+func (n *Network) AddIP(cidr string) error {
+	addr, err := netlink.ParseAddr(cidr)
+	if err != nil {
+		return err
+	}
+	if n.HasIP(addr) {
+		return nil
+	}
+	if n.label != "" {
+		addr.Label = n.iface + ":" + n.label
+	}
+	err = netlink.AddrReplace(n.link, addr)
+	if err != nil {
+		return err
+	}
+	return ARPSendGratuitous(cidr, n.iface)
+}
+
+func (n *Network) DeleteIP(cidr string) error {
+	addr, err := netlink.ParseAddr(cidr)
+	if err != nil {
+		return err
+	}
+	if !n.HasIP(addr) {
+		return nil
+	}
+	return netlink.AddrDel(n.link, addr)
+}