示例#1
0
// 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)
	route.Flags = int(msg.Flags)

	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
}
示例#2
0
// 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
}