Add containers-common spec and command to podman

Since containers-common package is tied to specific versions
of Podman, add tools to build the package into the contrib directory
This should help other distributions to figure out which commont
package to ship.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/github.com/containers/common/libnetwork/internal/util/bridge.go

@@ -5,11 +5,12 @@ import (
 
 	"github.com/containers/common/libnetwork/types"
 	"github.com/containers/common/libnetwork/util"
+	"github.com/containers/common/pkg/config"
 	pkgutil "github.com/containers/common/pkg/util"
 	"github.com/pkg/errors"
 )
 
-func CreateBridge(n NetUtil, network *types.Network, usedNetworks []*net.IPNet) error {
+func CreateBridge(n NetUtil, network *types.Network, usedNetworks []*net.IPNet, subnetPools []config.SubnetPool) error {
 	if network.NetworkInterface != "" {
 		bridges := GetBridgeInterfaceNames(n)
 		if pkgutil.StringInSlice(network.NetworkInterface, bridges) {
@@ -28,7 +29,7 @@ func CreateBridge(n NetUtil, network *types.Network, usedNetworks []*net.IPNet)
 
 	if network.IPAMOptions["driver"] != types.DHCPIPAMDriver {
 		if len(network.Subnets) == 0 {
-			freeSubnet, err := GetFreeIPv4NetworkSubnet(usedNetworks)
+			freeSubnet, err := GetFreeIPv4NetworkSubnet(usedNetworks, subnetPools)
 			if err != nil {
 				return err
 			}
@@ -48,7 +49,7 @@ func CreateBridge(n NetUtil, network *types.Network, usedNetworks []*net.IPNet)
 				}
 			}
 			if !ipv4 {
-				freeSubnet, err := GetFreeIPv4NetworkSubnet(usedNetworks)
+				freeSubnet, err := GetFreeIPv4NetworkSubnet(usedNetworks, subnetPools)
 				if err != nil {
 					return err
 				}

vendor/github.com/containers/common/libnetwork/internal/util/ip.go

@@ -11,11 +11,15 @@ func incByte(subnet *net.IPNet, idx int, shift uint) error {
 	if idx < 0 {
 		return errors.New("no more subnets left")
 	}
-	if subnet.IP[idx] == 255 {
-		subnet.IP[idx] = 0
-		return incByte(subnet, idx-1, 0)
+
+	var val byte = 1 << shift
+	// if overflow we have to inc the previous byte
+	if uint(subnet.IP[idx])+uint(val) > 255 {
+		if err := incByte(subnet, idx-1, 0); err != nil {
+			return err
+		}
 	}
-	subnet.IP[idx] += 1 << shift
+	subnet.IP[idx] += val
 	return nil
 }
 
@@ -31,10 +35,7 @@ func NextSubnet(subnet *net.IPNet) (*net.IPNet, error) {
 	}
 	zeroes := uint(bits - ones)
 	shift := zeroes % 8
-	idx := ones/8 - 1
-	if idx < 0 {
-		idx = 0
-	}
+	idx := (ones - 1) / 8
 	if err := incByte(newSubnet, idx, shift); err != nil {
 		return nil, err
 	}

vendor/github.com/containers/common/libnetwork/internal/util/util.go

@@ -6,6 +6,7 @@ import (
 	"net"
 
 	"github.com/containers/common/libnetwork/types"
+	"github.com/containers/common/pkg/config"
 	"github.com/containers/common/pkg/util"
 	"github.com/sirupsen/logrus"
 )
@@ -79,28 +80,36 @@ func GetUsedSubnets(n NetUtil) ([]*net.IPNet, error) {
 }
 
 // GetFreeIPv4NetworkSubnet returns a unused ipv4 subnet
-func GetFreeIPv4NetworkSubnet(usedNetworks []*net.IPNet) (*types.Subnet, error) {
-	// the default podman network is 10.88.0.0/16
-	// start locking for free /24 networks
-	network := &net.IPNet{
-		IP:   net.IP{10, 89, 0, 0},
-		Mask: net.IPMask{255, 255, 255, 0},
+func GetFreeIPv4NetworkSubnet(usedNetworks []*net.IPNet, subnetPools []config.SubnetPool) (*types.Subnet, error) {
+	var err error
+	for _, pool := range subnetPools {
+		// make sure to copy the netip to prevent overwriting the subnet pool
+		netIP := make(net.IP, net.IPv4len)
+		copy(netIP, pool.Base.IP)
+		network := &net.IPNet{
+			IP:   netIP,
+			Mask: net.CIDRMask(pool.Size, 32),
+		}
+		for pool.Base.Contains(network.IP) {
+			if !NetworkIntersectsWithNetworks(network, usedNetworks) {
+				logrus.Debugf("found free ipv4 network subnet %s", network.String())
+				return &types.Subnet{
+					Subnet: types.IPNet{IPNet: *network},
+				}, nil
+			}
+			network, err = NextSubnet(network)
+			if err != nil {
+				// when error go to next pool, we return the error only when all pools are done
+				break
+			}
+		}
 	}
 
-	// TODO: make sure to not use public subnets
-	for {
-		if intersectsConfig := NetworkIntersectsWithNetworks(network, usedNetworks); !intersectsConfig {
-			logrus.Debugf("found free ipv4 network subnet %s", network.String())
-			return &types.Subnet{
-				Subnet: types.IPNet{IPNet: *network},
-			}, nil
-		}
-		var err error
-		network, err = NextSubnet(network)
-		if err != nil {
-			return nil, err
-		}
+	if err != nil {
+		return nil, err
 	}
+	return nil, errors.New("could not find free subnet from subnet pools")
+
 }
 
 // GetFreeIPv6NetworkSubnet returns a unused ipv6 subnet