podman network create

initial implementation of network create.  we only support bridging
networks with this first pass.

Signed-off-by: baude <bbaude@redhat.com>

1 files changed, 135 insertions, 11 deletions

diff --git a/pkg/network/network.go b/pkg/network/network.go
index 9d04340a3..b241a66c0 100644
--- a/pkg/network/network.go
+++ b/pkg/network/network.go
@@ -1,26 +1,150 @@
 package network
 
 import (
-	"sort"
+	"github.com/containers/libpod/pkg/util"
+	"net"
 
-	"github.com/containernetworking/cni/libcni"
+	"github.com/containernetworking/cni/pkg/types"
+	"github.com/containernetworking/plugins/plugins/ipam/host-local/backend/allocator"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 )
 
-// LoadCNIConfsFromDir loads all the CNI configurations from a dir
-func LoadCNIConfsFromDir(dir string) ([]*libcni.NetworkConfigList, error) {
-	var configs []*libcni.NetworkConfigList
-	files, err := libcni.ConfFiles(dir, []string{".conflist"})
+// SupportedNetworkDrivers describes the list of supported drivers
+var SupportedNetworkDrivers = []string{"bridge"}
+
+// IsSupportedDriver checks if the user provided driver is supported
+func IsSupportedDriver(driver string) error {
+	if util.StringInSlice(driver, SupportedNetworkDrivers) {
+		return nil
+	}
+	return errors.Errorf("driver '%s' is not supported", driver)
+}
+
+// GetLiveNetworks returns a slice of networks representing what the system
+// has defined as network interfaces
+func GetLiveNetworks() ([]*net.IPNet, error) {
+	var nets []*net.IPNet
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return nil, err
+	}
+	for _, address := range addrs {
+		_, n, err := net.ParseCIDR(address.String())
+		if err != nil {
+			return nil, err
+		}
+		nets = append(nets, n)
+	}
+	return nets, nil
+}
+
+// GetLiveNetworkNames returns a list of network interfaces on the system
+func GetLiveNetworkNames() ([]string, error) {
+	var interfaceNames []string
+	liveInterfaces, err := net.Interfaces()
 	if err != nil {
 		return nil, err
 	}
-	sort.Strings(files)
+	for _, i := range liveInterfaces {
+		interfaceNames = append(interfaceNames, i.Name)
+	}
+	return interfaceNames, nil
+}
 
-	for _, confFile := range files {
-		conf, err := libcni.ConfListFromFile(confFile)
+// GetFreeNetwork looks for a free network according to existing cni configuration
+// files and network interfaces.
+func GetFreeNetwork() (*net.IPNet, error) {
+	networks, err := GetNetworksFromFilesystem()
+	if err != nil {
+		return nil, err
+	}
+	liveNetworks, err := GetLiveNetworks()
+	if err != nil {
+		return nil, err
+	}
+	nextNetwork, err := GetDefaultPodmanNetwork()
+	if err != nil {
+		return nil, err
+	}
+	logrus.Debugf("default network is %s", nextNetwork.String())
+	for {
+		newNetwork, err := NextSubnet(nextNetwork)
 		if err != nil {
 			return nil, err
 		}
-		configs = append(configs, conf)
+		logrus.Debugf("checking if network %s intersects with other cni networks", nextNetwork.String())
+		if intersectsConfig, _ := networkIntersectsWithNetworks(newNetwork, allocatorToIPNets(networks)); intersectsConfig {
+			logrus.Debugf("network %s is already being used by a cni configuration", nextNetwork.String())
+			nextNetwork = newNetwork
+			continue
+		}
+		logrus.Debugf("checking if network %s intersects with any network interfaces", nextNetwork.String())
+		if intersectsLive, _ := networkIntersectsWithNetworks(newNetwork, liveNetworks); !intersectsLive {
+			break
+		}
+		logrus.Debugf("network %s is being used by a network interface", nextNetwork.String())
+		nextNetwork = newNetwork
+	}
+	return nextNetwork, nil
+}
+
+func allocatorToIPNets(networks []*allocator.Net) []*net.IPNet {
+	var nets []*net.IPNet
+	for _, network := range networks {
+		if len(network.IPAM.Ranges) > 0 {
+			// this is the new IPAM range style
+			// append each subnet from ipam the rangeset
+			for _, r := range network.IPAM.Ranges[0] {
+				nets = append(nets, newIPNetFromSubnet(r.Subnet))
+			}
+		} else {
+			//	 looks like the old, deprecated style
+			nets = append(nets, newIPNetFromSubnet(network.IPAM.Subnet))
+		}
+	}
+	return nets
+}
+
+func newIPNetFromSubnet(subnet types.IPNet) *net.IPNet {
+	n := net.IPNet{
+		IP:   subnet.IP,
+		Mask: subnet.Mask,
+	}
+	return &n
+}
+
+func networkIntersectsWithNetworks(n *net.IPNet, networklist []*net.IPNet) (bool, *net.IPNet) {
+	for _, nw := range networklist {
+		if networkIntersect(n, nw) {
+			return true, nw
+		}
+	}
+	return false, nil
+}
+
+func networkIntersect(n1, n2 *net.IPNet) bool {
+	return n2.Contains(n1.IP) || n1.Contains(n2.IP)
+}
+
+// ValidateUserNetworkIsAvailable returns via an error if a network is available
+// to be used
+func ValidateUserNetworkIsAvailable(userNet *net.IPNet) error {
+	networks, err := GetNetworksFromFilesystem()
+	if err != nil {
+		return err
+	}
+	liveNetworks, err := GetLiveNetworks()
+	if err != nil {
+		return err
+	}
+	logrus.Debugf("checking if network %s exists in cni networks", userNet.String())
+	if intersectsConfig, _ := networkIntersectsWithNetworks(userNet, allocatorToIPNets(networks)); intersectsConfig {
+		return errors.Errorf("network %s is already being used by a cni configuration", userNet.String())
+	}
+	logrus.Debugf("checking if network %s exists in any network interfaces", userNet.String())
+	if intersectsLive, _ := networkIntersectsWithNetworks(userNet, liveNetworks); intersectsLive {
+		return errors.Errorf("network %s is being used by a network interface", userNet.String())
 	}
-	return configs, nil
+	return nil
 }