dualStack-changes.patch

From a8eab5d86a7e3fe08636aba6d53f9be6d8dd4c4c Mon Sep 17 00:00:00 2001
From: manuelbuil <mbuil@suse.com>
Date: Tue, 11 Jan 2022 11:37:19 +0100
Subject: [PATCH] Dual-stack patch

Signed-off-by: manuelbuil <mbuil@suse.com>
---
 internal/pkg/utils/utils.go | 57 +++++++++++++++++++++++++------------
 pkg/k8s/k8s.go              | 55 +++++++++++++++++++++++++++--------
 2 files changed, 82 insertions(+), 30 deletions(-)

diff --git a/internal/pkg/utils/utils.go b/internal/pkg/utils/utils.go
index faa8720..e87c61e 100644
--- a/internal/pkg/utils/utils.go
+++ b/internal/pkg/utils/utils.go
@@ -202,16 +202,18 @@ func DeleteIPAM(conf types.NetConf, args *skel.CmdArgs, logger *logrus.Entry) er
 		// We need to replace "usePodCidr" with a valid, but dummy podCidr string with "host-local" IPAM.
 		// host-local IPAM releases the IP by ContainerID, so podCidr isn't really used to release the IP.
 		// It just needs a valid CIDR, but it doesn't have to be the CIDR associated with the host.
-		const dummyPodCidr = "0.0.0.0/0"
+		dummyPodCidrv4 := "0.0.0.0/0"
+		dummyPodCidrv6 := "::/0"
 		var stdinData map[string]interface{}
 		err := json.Unmarshal(args.StdinData, &stdinData)
 		if err != nil {
 			return err
 		}
 
-		logger.WithField("podCidr", dummyPodCidr).Info("Using a dummy podCidr to release the IP")
-		getDummyPodCIDR := func() (string, error) {
-			return dummyPodCidr, nil
+		logger.WithFields(logrus.Fields{"podCidrv4": dummyPodCidrv4,
+			"podCidrv6": dummyPodCidrv6}).Info("Using dummy podCidrs to release the IPs")
+		getDummyPodCIDR := func() (string, string, error) {
+			return dummyPodCidrv4, dummyPodCidrv6, nil
 		}
 		err = ReplaceHostLocalIPAMPodCIDRs(logger, stdinData, getDummyPodCIDR)
 		if err != nil {
@@ -286,13 +288,13 @@ func DeleteIPAM(conf types.NetConf, args *skel.CmdArgs, logger *logrus.Entry) er
 //      }
 //      ...
 //    }
-func ReplaceHostLocalIPAMPodCIDRs(logger *logrus.Entry, stdinData map[string]interface{}, getPodCIDR func() (string, error)) error {
+func ReplaceHostLocalIPAMPodCIDRs(logger *logrus.Entry, stdinData map[string]interface{}, getPodCIDRs func() (string, string, error)) error {
 	ipamData, ok := stdinData["ipam"].(map[string]interface{})
 	if !ok {
 		return fmt.Errorf("failed to parse host-local IPAM data; was expecting a dict, not: %v", stdinData["ipam"])
 	}
 	// Older versions of host-local IPAM store a single subnet in the top-level IPAM dict.
-	err := replaceHostLocalIPAMPodCIDR(logger, ipamData, getPodCIDR)
+	err := replaceHostLocalIPAMPodCIDR(logger, ipamData, getPodCIDRs)
 	if err != nil {
 		return err
 	}
@@ -310,7 +312,7 @@ func ReplaceHostLocalIPAMPodCIDRs(logger *logrus.Entry, stdinData map[string]int
 				return fmt.Errorf("failed to parse host-local IPAM range set; was expecting a list, not: %v", rs)
 			}
 			for _, r := range rs {
-				err := replaceHostLocalIPAMPodCIDR(logger, r, getPodCIDR)
+				err := replaceHostLocalIPAMPodCIDR(logger, r, getPodCIDRs)
 				if err != nil {
 					return err
 				}
@@ -320,29 +322,47 @@ func ReplaceHostLocalIPAMPodCIDRs(logger *logrus.Entry, stdinData map[string]int
 	return nil
 }
 
-func replaceHostLocalIPAMPodCIDR(logger *logrus.Entry, rawIpamData interface{}, getPodCidr func() (string, error)) error {
+func replaceHostLocalIPAMPodCIDR(logger *logrus.Entry, rawIpamData interface{}, getPodCidrs func() (string, string, error)) error {
 	logrus.WithField("ipamData", rawIpamData).Debug("Examining IPAM data for usePodCidr")
 	ipamData, ok := rawIpamData.(map[string]interface{})
 	if !ok {
 		return fmt.Errorf("failed to parse host-local IPAM data; was expecting a dict, not: %v", rawIpamData)
 	}
 	subnet, _ := ipamData["subnet"].(string)
+
 	if strings.EqualFold(subnet, "usePodCidr") {
-		logger.Info("Calico CNI fetching podCidr from Kubernetes")
-		podCidr, err := getPodCidr()
+		ipv4Cidr, _, err := getPodCidrs()
+		if err != nil {
+			logger.Errorf("Failed to getPodCidrs")
+			return err
+		}
+		if ipv4Cidr == "" {
+			return errors.New("usePodCidr found but there is no IPv4 CIDR configured")
+		}
+
+		ipamData["subnet"] = ipv4Cidr
+		subnet = ipv4Cidr
+		logger.Infof("Calico CNI passing podCidr to host-local IPAM: %s", ipv4Cidr)
+
+		// updateHostLocalIPAMDataForOS is only required for Windows and only ipv4 is supported
+		err = updateHostLocalIPAMDataForOS(subnet, ipamData)
 		if err != nil {
-			logger.Info("Failed to getPodCidr")
 			return err
 		}
-		logger.WithField("podCidr", podCidr).Info("Fetched podCidr")
-		ipamData["subnet"] = podCidr
-		subnet = podCidr
-		logger.Infof("Calico CNI passing podCidr to host-local IPAM: %s", podCidr)
 	}
 
-	err := updateHostLocalIPAMDataForOS(subnet, ipamData)
-	if err != nil {
-		return err
+	if strings.EqualFold(subnet, "usePodCidrIPv6") {
+		_, ipv6Cidr, err := getPodCidrs()
+		if err != nil {
+			logger.Errorf("Failed to ipv6 getPodCidrs")
+			return err
+		}
+		if ipv6Cidr == "" {
+			return errors.New("usePodCidrIPv6 found but there is no IPv6 CIDR configured")
+		}
+
+		ipamData["subnet"] = ipv6Cidr
+		logger.Infof("Calico CNI passing podCidrv6 to host-local IPAM: %s", ipv6Cidr)
 	}
 
 	return nil
@@ -360,6 +380,7 @@ func UpdateHostLocalIPAMDataForWindows(subnet string, ipamData map[string]interf
 		return err
 	}
 	//process only if we have ipv4 subnet
+	//VXLAN networks on Windows do not support dual-stack https://kubernetes.io/docs/setup/production-environment/windows/intro-windows-in-kubernetes/#ipv6-networking
 	if ip.To4() != nil {
 		//get Expected start and end range for given CIDR
 		expStartRange, expEndRange := getIPRanges(ip, ipnet)
diff --git a/pkg/k8s/k8s.go b/pkg/k8s/k8s.go
index ca11f90..e4170df 100644
--- a/pkg/k8s/k8s.go
+++ b/pkg/k8s/k8s.go
@@ -106,18 +106,24 @@ func CmdAddK8s(ctx context.Context, args *skel.CmdArgs, conf types.NetConf, epID
 		}
 
 		// Defer to ReplaceHostLocalIPAMPodCIDRs to swap the "usePodCidr" value out.
-		var cachedPodCidr string
-		getRealPodCIDR := func() (string, error) {
-			if cachedPodCidr == "" {
+		var cachedPodCidrs []string
+		var cachedIpv4Cidr, cachedIpv6Cidr string
+		getRealPodCIDRs := func() (string, string, error) {
+			if len(cachedPodCidrs) == 0 {
 				var err error
-				cachedPodCidr, err = getPodCidr(client, conf, epIDs.Node)
+				var emptyResult string
+				cachedPodCidrs, err = getPodCidrs(client, conf, epIDs.Node)
 				if err != nil {
-					return "", err
+					return emptyResult, emptyResult, err
+				}
+				cachedIpv4Cidr, cachedIpv6Cidr, err = getIPsByFamily(cachedPodCidrs)
+				if err != nil {
+					return emptyResult, emptyResult, err
 				}
 			}
-			return cachedPodCidr, nil
+			return cachedIpv4Cidr, cachedIpv6Cidr, nil
 		}
-		err = utils.ReplaceHostLocalIPAMPodCIDRs(logger, stdinData, getRealPodCIDR)
+		err = utils.ReplaceHostLocalIPAMPodCIDRs(logger, stdinData, getRealPodCIDRs)
 		if err != nil {
 			return nil, err
 		}
@@ -892,7 +898,9 @@ func getK8sPodInfo(client *kubernetes.Clientset, podName, podNamespace string) (
 	return labels, pod.Annotations, ports, profiles, generateName, serviceAccount, nil
 }
 
-func getPodCidr(client *kubernetes.Clientset, conf types.NetConf, nodename string) (string, error) {
+// getPodCidrs returns the podCidrs included in the node manifest
+func getPodCidrs(client *kubernetes.Clientset, conf types.NetConf, nodename string) ([]string, error) {
+	var emptyString []string
 	// Pull the node name out of the config if it's set. Defaults to nodename
 	if conf.Kubernetes.NodeName != "" {
 		nodename = conf.Kubernetes.NodeName
@@ -900,11 +908,34 @@ func getPodCidr(client *kubernetes.Clientset, conf types.NetConf, nodename strin
 
 	node, err := client.CoreV1().Nodes().Get(context.Background(), nodename, metav1.GetOptions{})
 	if err != nil {
-		return "", err
+		return emptyString, err
+	}
+	if len(node.Spec.PodCIDRs) == 0 {
+		return emptyString, fmt.Errorf("no podCidr for node %s", nodename)
+	}
+	return node.Spec.PodCIDRs, nil
+}
+
+// getIPsByFamily returns the IPv4 and IPv6 CIDRs
+func getIPsByFamily(cidrs []string) (string, string, error) {
+	var ipv4Cidr, ipv6Cidr string
+	for _, cidr := range cidrs {
+		_, ipNet, err := cnet.ParseCIDR(cidr)
+		if err != nil {
+			return "", "", err
+		}
+		if ipNet.Version() == 4 {
+			ipv4Cidr = cidr
+		}
+
+		if ipNet.Version() == 6 {
+			ipv6Cidr = cidr
+		}
 	}
 
-	if node.Spec.PodCIDR == "" {
-		return "", fmt.Errorf("no podCidr for node %s", nodename)
+	if (len(cidrs) > 1) && (ipv4Cidr == "" || ipv6Cidr == "") {
+		return "", "", errors.New("ClusterCIDR contains two ranges of the same type")
 	}
-	return node.Spec.PodCIDR, nil
+
+	return ipv4Cidr, ipv6Cidr, nil
 }
-- 
2.26.2