Moves to official vendoring solution

vendor/github.com/vishvananda/netlink/route_linux.go

@@ -0,0 +1,249 @@
+package netlink
+
+import (
+	"fmt"
+	"net"
+	"syscall"
+
+	"github.com/vishvananda/netlink/nl"
+)
+
+// RtAttr is shared so it is in netlink_linux.go
+
+// RouteAdd will add a route to the system.
+// Equivalent to: `ip route add $route`
+func RouteAdd(route *Route) error {
+	req := nl.NewNetlinkRequest(syscall.RTM_NEWROUTE, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
+	return routeHandle(route, req, nl.NewRtMsg())
+}
+
+// RouteDel will delete a route from the system.
+// Equivalent to: `ip route del $route`
+func RouteDel(route *Route) error {
+	req := nl.NewNetlinkRequest(syscall.RTM_DELROUTE, syscall.NLM_F_ACK)
+	return routeHandle(route, req, nl.NewRtDelMsg())
+}
+
+func routeHandle(route *Route, req *nl.NetlinkRequest, msg *nl.RtMsg) error {
+	if (route.Dst == nil || route.Dst.IP == nil) && route.Src == nil && route.Gw == nil {
+		return fmt.Errorf("one of Dst.IP, Src, or Gw must not be nil")
+	}
+
+	msg.Scope = uint8(route.Scope)
+	family := -1
+	var rtAttrs []*nl.RtAttr
+
+	if route.Dst != nil && route.Dst.IP != nil {
+		dstLen, _ := route.Dst.Mask.Size()
+		msg.Dst_len = uint8(dstLen)
+		dstFamily := nl.GetIPFamily(route.Dst.IP)
+		family = dstFamily
+		var dstData []byte
+		if dstFamily == FAMILY_V4 {
+			dstData = route.Dst.IP.To4()
+		} else {
+			dstData = route.Dst.IP.To16()
+		}
+		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_DST, dstData))
+	}
+
+	if route.Src != nil {
+		srcFamily := nl.GetIPFamily(route.Src)
+		if family != -1 && family != srcFamily {
+			return fmt.Errorf("source and destination ip are not the same IP family")
+		}
+		family = srcFamily
+		var srcData []byte
+		if srcFamily == FAMILY_V4 {
+			srcData = route.Src.To4()
+		} else {
+			srcData = route.Src.To16()
+		}
+		// The commonly used src ip for routes is actually PREFSRC
+		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_PREFSRC, srcData))
+	}
+
+	if route.Gw != nil {
+		gwFamily := nl.GetIPFamily(route.Gw)
+		if family != -1 && family != gwFamily {
+			return fmt.Errorf("gateway, source, and destination ip are not the same IP family")
+		}
+		family = gwFamily
+		var gwData []byte
+		if gwFamily == FAMILY_V4 {
+			gwData = route.Gw.To4()
+		} else {
+			gwData = route.Gw.To16()
+		}
+		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_GATEWAY, gwData))
+	}
+
+	msg.Family = uint8(family)
+
+	req.AddData(msg)
+	for _, attr := range rtAttrs {
+		req.AddData(attr)
+	}
+
+	var (
+		b      = make([]byte, 4)
+		native = nl.NativeEndian()
+	)
+	native.PutUint32(b, uint32(route.LinkIndex))
+
+	req.AddData(nl.NewRtAttr(syscall.RTA_OIF, b))
+
+	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
+	return err
+}
+
+// RouteList gets a list of routes in the system.
+// Equivalent to: `ip route show`.
+// The list can be filtered by link and ip family.
+func RouteList(link Link, family int) ([]Route, error) {
+	req := nl.NewNetlinkRequest(syscall.RTM_GETROUTE, syscall.NLM_F_DUMP)
+	msg := nl.NewIfInfomsg(family)
+	req.AddData(msg)
+
+	msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWROUTE)
+	if err != nil {
+		return nil, err
+	}
+
+	index := 0
+	if link != nil {
+		base := link.Attrs()
+		ensureIndex(base)
+		index = base.Index
+	}
+
+	var res []Route
+	for _, m := range msgs {
+		msg := nl.DeserializeRtMsg(m)
+
+		if msg.Flags&syscall.RTM_F_CLONED != 0 {
+			// Ignore cloned routes
+			continue
+		}
+
+		if msg.Table != syscall.RT_TABLE_MAIN {
+			// Ignore non-main tables
+			continue
+		}
+
+		route, err := deserializeRoute(m)
+		if err != nil {
+			return nil, err
+		}
+
+		if link != nil && route.LinkIndex != index {
+			// Ignore routes from other interfaces
+			continue
+		}
+		res = append(res, route)
+	}
+
+	return res, nil
+}
+
+// deserializeRoute decodes a binary netlink message into a Route struct
+func deserializeRoute(m []byte) (Route, error) {
+	route := Route{}
+	msg := nl.DeserializeRtMsg(m)
+	attrs, err := nl.ParseRouteAttr(m[msg.Len():])
+	if err != nil {
+		return route, err
+	}
+	route.Scope = Scope(msg.Scope)
+
+	native := nl.NativeEndian()
+	for _, attr := range attrs {
+		switch attr.Attr.Type {
+		case syscall.RTA_GATEWAY:
+			route.Gw = net.IP(attr.Value)
+		case syscall.RTA_PREFSRC:
+			route.Src = net.IP(attr.Value)
+		case syscall.RTA_DST:
+			route.Dst = &net.IPNet{
+				IP:   attr.Value,
+				Mask: net.CIDRMask(int(msg.Dst_len), 8*len(attr.Value)),
+			}
+		case syscall.RTA_OIF:
+			routeIndex := int(native.Uint32(attr.Value[0:4]))
+			route.LinkIndex = routeIndex
+		}
+	}
+	return route, nil
+}
+
+// RouteGet gets a route to a specific destination from the host system.
+// Equivalent to: 'ip route get'.
+func RouteGet(destination net.IP) ([]Route, error) {
+	req := nl.NewNetlinkRequest(syscall.RTM_GETROUTE, syscall.NLM_F_REQUEST)
+	family := nl.GetIPFamily(destination)
+	var destinationData []byte
+	var bitlen uint8
+	if family == FAMILY_V4 {
+		destinationData = destination.To4()
+		bitlen = 32
+	} else {
+		destinationData = destination.To16()
+		bitlen = 128
+	}
+	msg := &nl.RtMsg{}
+	msg.Family = uint8(family)
+	msg.Dst_len = bitlen
+	req.AddData(msg)
+
+	rtaDst := nl.NewRtAttr(syscall.RTA_DST, destinationData)
+	req.AddData(rtaDst)
+
+	msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWROUTE)
+	if err != nil {
+		return nil, err
+	}
+
+	var res []Route
+	for _, m := range msgs {
+		route, err := deserializeRoute(m)
+		if err != nil {
+			return nil, err
+		}
+		res = append(res, route)
+	}
+	return res, nil
+
+}
+
+// RouteSubscribe takes a chan down which notifications will be sent
+// when routes are added or deleted. Close the 'done' chan to stop subscription.
+func RouteSubscribe(ch chan<- RouteUpdate, done <-chan struct{}) error {
+	s, err := nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_IPV4_ROUTE, syscall.RTNLGRP_IPV6_ROUTE)
+	if err != nil {
+		return err
+	}
+	if done != nil {
+		go func() {
+			<-done
+			s.Close()
+		}()
+	}
+	go func() {
+		defer close(ch)
+		for {
+			msgs, err := s.Receive()
+			if err != nil {
+				return
+			}
+			for _, m := range msgs {
+				route, err := deserializeRoute(m.Data)
+				if err != nil {
+					return
+				}
+				ch <- RouteUpdate{Type: m.Header.Type, Route: route}
+			}
+		}
+	}()
+
+	return nil
+}