Beispiel #1
0
func cmdAdd(args *skel.CmdArgs) error {
	n, err := loadNetConf(args.StdinData)
	if err != nil {
		return err
	}

	br, err := setupBridge(n)
	if err != nil {
		return err
	}

	if err = setupVeth(args.Netns, br, args.IfName, n.MTU); err != nil {
		return err
	}

	// run the IPAM plugin and get back the config to apply
	result, err := ipam.ExecAdd(n.IPAM.Type, args.StdinData)
	if err != nil {
		return err
	}

	if result.IP4 == nil {
		return errors.New("IPAM plugin returned missing IPv4 config")
	}

	if result.IP4.Gateway == nil && n.IsGW {
		result.IP4.Gateway = calcGatewayIP(&result.IP4.IP)
	}

	err = ns.WithNetNSPath(args.Netns, false, func(hostNS *os.File) error {
		return ipam.ConfigureIface(args.IfName, result)
	})
	if err != nil {
		return err
	}

	if n.IsGW {
		gwn := &net.IPNet{
			IP:   result.IP4.Gateway,
			Mask: result.IP4.IP.Mask,
		}

		if err = ensureBridgeAddr(br, gwn); err != nil {
			return err
		}

		if err := ip.EnableIP4Forward(); err != nil {
			return fmt.Errorf("failed to enable forwarding: %v", err)
		}
	}

	if n.IPMasq {
		chain := "CNI-" + n.Name
		if err = ip.SetupIPMasq(ip.Network(&result.IP4.IP), chain); err != nil {
			return err
		}
	}

	return result.Print()
}
Beispiel #2
0
func cmdAdd(args *skel.CmdArgs) error {
	n, err := loadConf(args.StdinData)
	if err != nil {
		return err
	}

	netns, err := os.Open(args.Netns)
	if err != nil {
		return fmt.Errorf("failed to open netns %q: %v", netns, err)
	}
	defer netns.Close()

	if err = createIpvlan(n, args.IfName, netns); err != nil {
		return err
	}

	// run the IPAM plugin and get back the config to apply
	result, err := ipam.ExecAdd(n.IPAM.Type, args.StdinData)
	if err != nil {
		return err
	}
	if result.IP4 == nil {
		return errors.New("IPAM plugin returned missing IPv4 config")
	}

	err = ns.WithNetNS(netns, false, func(_ *os.File) error {
		return ipam.ConfigureIface(args.IfName, result)
	})
	if err != nil {
		return err
	}

	return result.Print()
}
Beispiel #3
0
func setupContainerVeth(netns, ifName string, mtu int, pr *types.Result) (string, error) {
	// The IPAM result will be something like IP=192.168.3.5/24, GW=192.168.3.1.
	// What we want is really a point-to-point link but veth does not support IFF_POINTOPONT.
	// Next best thing would be to let it ARP but set interface to 192.168.3.5/32 and
	// add a route like "192.168.3.0/24 via 192.168.3.1 dev $ifName".
	// Unfortunately that won't work as the GW will be outside the interface's subnet.

	// Our solution is to configure the interface with 192.168.3.5/24, then delete the
	// "192.168.3.0/24 dev $ifName" route that was automatically added. Then we add
	// "192.168.3.1/32 dev $ifName" and "192.168.3.0/24 via 192.168.3.1 dev $ifName".
	// In other words we force all traffic to ARP via the gateway except for GW itself.

	var hostVethName string
	err := ns.WithNetNSPath(netns, false, func(hostNS *os.File) error {
		hostVeth, _, err := ip.SetupVeth(ifName, mtu, hostNS)
		if err != nil {
			return err
		}

		if err = ipam.ConfigureIface(ifName, pr); err != nil {
			return err
		}

		contVeth, err := netlink.LinkByName(ifName)
		if err != nil {
			return fmt.Errorf("failed to look up %q: %v", ifName, err)
		}

		// Delete the route that was automatically added
		route := netlink.Route{
			LinkIndex: contVeth.Attrs().Index,
			Dst: &net.IPNet{
				IP:   pr.IP4.IP.IP.Mask(pr.IP4.IP.Mask),
				Mask: pr.IP4.IP.Mask,
			},
			Scope: netlink.SCOPE_NOWHERE,
		}

		if err := netlink.RouteDel(&route); err != nil {
			return fmt.Errorf("failed to delete route %v: %v", route, err)
		}

		for _, r := range []netlink.Route{
			netlink.Route{
				LinkIndex: contVeth.Attrs().Index,
				Dst: &net.IPNet{
					IP:   pr.IP4.Gateway,
					Mask: net.CIDRMask(32, 32),
				},
				Scope: netlink.SCOPE_LINK,
				Src:   pr.IP4.IP.IP,
			},
			netlink.Route{
				LinkIndex: contVeth.Attrs().Index,
				Dst: &net.IPNet{
					IP:   pr.IP4.IP.IP.Mask(pr.IP4.IP.Mask),
					Mask: pr.IP4.IP.Mask,
				},
				Scope: netlink.SCOPE_UNIVERSE,
				Gw:    pr.IP4.Gateway,
				Src:   pr.IP4.IP.IP,
			},
		} {
			if err := netlink.RouteAdd(&r); err != nil {
				return fmt.Errorf("failed to add route %v: %v", r, err)
			}
		}

		hostVethName = hostVeth.Attrs().Name

		return nil
	})
	return hostVethName, err
}