Make networking code reusable

To prevent code duplication when creating new network backends move
reusable code into a separate internal package.

This allows all network backends to use the same code as long as they
implement the new NetUtil interface.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/libpod/network/internal/util/bridge.go b/libpod/network/internal/util/bridge.go
new file mode 100644
index 000000000..c054c7d4e
--- /dev/null
+++ b/libpod/network/internal/util/bridge.go
@@ -0,0 +1,67 @@
+package util
+
+import (
+	"net"
+
+	"github.com/containers/podman/v3/libpod/define"
+	"github.com/containers/podman/v3/libpod/network/types"
+	"github.com/containers/podman/v3/libpod/network/util"
+	pkgutil "github.com/containers/podman/v3/pkg/util"
+	"github.com/pkg/errors"
+)
+
+func CreateBridge(n NetUtil, network *types.Network, usedNetworks []*net.IPNet) error {
+	if network.NetworkInterface != "" {
+		bridges := GetBridgeInterfaceNames(n)
+		if pkgutil.StringInSlice(network.NetworkInterface, bridges) {
+			return errors.Errorf("bridge name %s already in use", network.NetworkInterface)
+		}
+		if !define.NameRegex.MatchString(network.NetworkInterface) {
+			return errors.Wrapf(define.RegexError, "bridge name %s invalid", network.NetworkInterface)
+		}
+	} else {
+		var err error
+		network.NetworkInterface, err = GetFreeDeviceName(n)
+		if err != nil {
+			return err
+		}
+	}
+
+	if len(network.Subnets) == 0 {
+		freeSubnet, err := GetFreeIPv4NetworkSubnet(usedNetworks)
+		if err != nil {
+			return err
+		}
+		network.Subnets = append(network.Subnets, *freeSubnet)
+	}
+	// ipv6 enabled means dual stack, check if we already have
+	// a ipv4 or ipv6 subnet and add one if not.
+	if network.IPv6Enabled {
+		ipv4 := false
+		ipv6 := false
+		for _, subnet := range network.Subnets {
+			if util.IsIPv6(subnet.Subnet.IP) {
+				ipv6 = true
+			}
+			if util.IsIPv4(subnet.Subnet.IP) {
+				ipv4 = true
+			}
+		}
+		if !ipv4 {
+			freeSubnet, err := GetFreeIPv4NetworkSubnet(usedNetworks)
+			if err != nil {
+				return err
+			}
+			network.Subnets = append(network.Subnets, *freeSubnet)
+		}
+		if !ipv6 {
+			freeSubnet, err := GetFreeIPv6NetworkSubnet(usedNetworks)
+			if err != nil {
+				return err
+			}
+			network.Subnets = append(network.Subnets, *freeSubnet)
+		}
+	}
+	network.IPAMOptions["driver"] = types.HostLocalIPAMDriver
+	return nil
+}