Method localRoute

pkg/sentry/socket/netstack/stack.go:953–1050

localRoute constructs a local route from the netlink message.

(msg *nlmsg.Message)

// localRoute constructs a local route from the netlink message.
func (s *Stack) localRoute(msg *nlmsg.Message) (tcpip.Route, *syserr.Error) {
	var rtMsg linux.RouteMessage
	attrs, ok := msg.GetData(&rtMsg)
	if !ok {
		return tcpip.Route{}, syserr.ErrInvalidArgument
	}

	route := inet.Route{
		Family:   rtMsg.Family,
		DstLen:   rtMsg.DstLen,
		SrcLen:   rtMsg.SrcLen,
		TOS:      rtMsg.TOS,
		Table:    rtMsg.Table,
		Protocol: rtMsg.Protocol,
		Scope:    rtMsg.Scope,
		Type:     rtMsg.Type,
		Flags:    rtMsg.Flags,
	}

	for !attrs.Empty() {
		ahdr, value, rest, ok := attrs.ParseFirst()
		if !ok {
			return tcpip.Route{}, syserr.ErrInvalidArgument
		}
		attrs = rest

		switch ahdr.Type {
		case linux.RTA_DST:
			if len(value) < 1 {
				return tcpip.Route{}, syserr.ErrInvalidArgument
			}
			route.DstAddr = value
		case linux.RTA_SRC:
			if len(value) < 1 {
				return tcpip.Route{}, syserr.ErrInvalidArgument
			}
			route.SrcAddr = value
		case linux.RTA_OIF:
			oif := nlmsg.BytesView(value)
			outputInterface, ok := oif.Int32()
			if !ok {
				return tcpip.Route{}, syserr.ErrInvalidArgument
			}
			if _, exist := s.Interfaces()[outputInterface]; !exist {
				return tcpip.Route{}, syserr.ErrNoDevice
			}
			route.OutputInterface = outputInterface
		case linux.RTA_GATEWAY:
			if len(value) < 1 {
				return tcpip.Route{}, syserr.ErrInvalidArgument
			}
			route.GatewayAddr = value
		case linux.RTA_PRIORITY:
		default:
			log.Warningf("Unknown attribute: %v", ahdr.Type)
			return tcpip.Route{}, syserr.ErrNotSupported
		}
	}