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, 97 insertions, 0 deletions

diff --git a/libpod/network/internal/util/validate.go b/libpod/network/internal/util/validate.go
new file mode 100644
index 000000000..03a985043
--- /dev/null
+++ b/libpod/network/internal/util/validate.go
@@ -0,0 +1,97 @@
+package util
+
+import (
+	"net"
+
+	"github.com/containers/podman/v3/libpod/network/types"
+	"github.com/containers/podman/v3/libpod/network/util"
+	"github.com/pkg/errors"
+)
+
+// ValidateSubnet will validate a given Subnet. It checks if the
+// given gateway and lease range are part of this subnet. If the
+// gateway is empty and addGateway is true it will get the first
+// available ip in the subnet assigned.
+func ValidateSubnet(s *types.Subnet, addGateway bool, usedNetworks []*net.IPNet) error {
+	if s == nil {
+		return errors.New("subnet is nil")
+	}
+	if s.Subnet.IP == nil {
+		return errors.New("subnet ip is nil")
+	}
+
+	// Reparse to ensure subnet is valid.
+	// Do not use types.ParseCIDR() because we want the ip to be
+	// the network address and not a random ip in the subnet.
+	_, net, err := net.ParseCIDR(s.Subnet.String())
+	if err != nil {
+		return errors.Wrap(err, "subnet invalid")
+	}
+
+	// check that the new subnet does not conflict with existing ones
+	if NetworkIntersectsWithNetworks(net, usedNetworks) {
+		return errors.Errorf("subnet %s is already used on the host or by another config", net.String())
+	}
+
+	s.Subnet = types.IPNet{IPNet: *net}
+	if s.Gateway != nil {
+		if !s.Subnet.Contains(s.Gateway) {
+			return errors.Errorf("gateway %s not in subnet %s", s.Gateway, &s.Subnet)
+		}
+	} else if addGateway {
+		ip, err := util.FirstIPInSubnet(net)
+		if err != nil {
+			return err
+		}
+		s.Gateway = ip
+	}
+	if s.LeaseRange != nil {
+		if s.LeaseRange.StartIP != nil && !s.Subnet.Contains(s.LeaseRange.StartIP) {
+			return errors.Errorf("lease range start ip %s not in subnet %s", s.LeaseRange.StartIP, &s.Subnet)
+		}
+		if s.LeaseRange.EndIP != nil && !s.Subnet.Contains(s.LeaseRange.EndIP) {
+			return errors.Errorf("lease range end ip %s not in subnet %s", s.LeaseRange.EndIP, &s.Subnet)
+		}
+	}
+	return nil
+}
+
+func ValidateSetupOptions(n NetUtil, namespacePath string, options types.SetupOptions) error {
+	if namespacePath == "" {
+		return errors.New("namespacePath is empty")
+	}
+	if options.ContainerID == "" {
+		return errors.New("ContainerID is empty")
+	}
+	if len(options.Networks) == 0 {
+		return errors.New("must specify at least one network")
+	}
+	for name, netOpts := range options.Networks {
+		network, err := n.Network(name)
+		if err != nil {
+			return err
+		}
+		err = validatePerNetworkOpts(network, netOpts)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// validatePerNetworkOpts checks that all given static ips are in a subnet on this network
+func validatePerNetworkOpts(network *types.Network, netOpts types.PerNetworkOptions) error {
+	if netOpts.InterfaceName == "" {
+		return errors.Errorf("interface name on network %s is empty", network.Name)
+	}
+outer:
+	for _, ip := range netOpts.StaticIPs {
+		for _, s := range network.Subnets {
+			if s.Subnet.Contains(ip) {
+				continue outer
+			}
+		}
+		return errors.Errorf("requested static ip %s not in any subnet on network %s", ip.String(), network.Name)
+	}
+	return nil
+}