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>

3 files changed, 1 insertions, 154 deletions

diff --git a/libpod/network/util/interfaces.go b/libpod/network/util/interfaces.go
deleted file mode 100644
index dc2bd601d..000000000
--- a/libpod/network/util/interfaces.go
+++ /dev/null
@@ -1,34 +0,0 @@
-package util
-
-import "net"
-
-// GetLiveNetworkSubnets returns a slice of subnets representing what the system
-// has defined as network interfaces
-func GetLiveNetworkSubnets() ([]*net.IPNet, error) {
-	addrs, err := net.InterfaceAddrs()
-	if err != nil {
-		return nil, err
-	}
-	nets := make([]*net.IPNet, 0, len(addrs))
-	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 interface names on the system
-func GetLiveNetworkNames() ([]string, error) {
-	liveInterfaces, err := net.Interfaces()
-	if err != nil {
-		return nil, err
-	}
-	interfaceNames := make([]string, 0, len(liveInterfaces))
-	for _, i := range liveInterfaces {
-		interfaceNames = append(interfaceNames, i.Name)
-	}
-	return interfaceNames, nil
-}
diff --git a/libpod/network/util/ip.go b/libpod/network/util/ip.go
index b2ba92735..e75107a1c 100644
--- a/libpod/network/util/ip.go
+++ b/libpod/network/util/ip.go
@@ -1,11 +1,6 @@
 package util
 
-import (
-	"crypto/rand"
-	"net"
-
-	"github.com/pkg/errors"
-)
+import "net"
 
 // IsIPv6 returns true if netIP is IPv6.
 func IsIPv6(netIP net.IP) bool {
@@ -17,40 +12,6 @@ func IsIPv4(netIP net.IP) bool {
 	return netIP != nil && netIP.To4() != nil
 }
 
-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)
-	}
-	subnet.IP[idx] += 1 << shift
-	return nil
-}
-
-// NextSubnet returns subnet incremented by 1
-func NextSubnet(subnet *net.IPNet) (*net.IPNet, error) {
-	newSubnet := &net.IPNet{
-		IP:   subnet.IP,
-		Mask: subnet.Mask,
-	}
-	ones, bits := newSubnet.Mask.Size()
-	if ones == 0 {
-		return nil, errors.Errorf("%s has only one subnet", subnet.String())
-	}
-	zeroes := uint(bits - ones)
-	shift := zeroes % 8
-	idx := ones/8 - 1
-	if idx < 0 {
-		idx = 0
-	}
-	if err := incByte(newSubnet, idx, shift); err != nil {
-		return nil, err
-	}
-	return newSubnet, nil
-}
-
 // LastIPInSubnet gets the last IP in a subnet
 func LastIPInSubnet(addr *net.IPNet) (net.IP, error) { //nolint:interfacer
 	// re-parse to ensure clean network address
@@ -83,31 +44,3 @@ func FirstIPInSubnet(addr *net.IPNet) (net.IP, error) { //nolint:interfacer
 	cidr.IP[len(cidr.IP)-1]++
 	return cidr.IP, nil
 }
-
-func NetworkIntersectsWithNetworks(n *net.IPNet, networklist []*net.IPNet) bool {
-	for _, nw := range networklist {
-		if networkIntersect(n, nw) {
-			return true
-		}
-	}
-	return false
-}
-
-func networkIntersect(n1, n2 *net.IPNet) bool {
-	return n2.Contains(n1.IP) || n1.Contains(n2.IP)
-}
-
-// GetRandomIPv6Subnet returns a random internal ipv6 subnet as described in RFC3879.
-func GetRandomIPv6Subnet() (net.IPNet, error) {
-	ip := make(net.IP, 8, net.IPv6len)
-	// read 8 random bytes
-	_, err := rand.Read(ip)
-	if err != nil {
-		return net.IPNet{}, nil
-	}
-	// first byte must be FD as per RFC3879
-	ip[0] = 0xfd
-	// add 8 zero bytes
-	ip = append(ip, make([]byte, 8)...)
-	return net.IPNet{IP: ip, Mask: net.CIDRMask(64, 128)}, nil
-}
diff --git a/libpod/network/util/ip_test.go b/libpod/network/util/ip_test.go
index c26ad140a..63ac555f0 100644
--- a/libpod/network/util/ip_test.go
+++ b/libpod/network/util/ip_test.go
@@ -1,9 +1,7 @@
 package util
 
 import (
-	"fmt"
 	"net"
-	"reflect"
 	"testing"
 )
 
@@ -12,34 +10,6 @@ func parseCIDR(n string) *net.IPNet {
 	return parsedNet
 }
 
-func TestNextSubnet(t *testing.T) {
-	type args struct {
-		subnet *net.IPNet
-	}
-	tests := []struct {
-		name    string
-		args    args
-		want    *net.IPNet
-		wantErr bool
-	}{
-		{"class b", args{subnet: parseCIDR("192.168.0.0/16")}, parseCIDR("192.169.0.0/16"), false},
-		{"class c", args{subnet: parseCIDR("192.168.1.0/24")}, parseCIDR("192.168.2.0/24"), false},
-	}
-	for _, tt := range tests {
-		test := tt
-		t.Run(test.name, func(t *testing.T) {
-			got, err := NextSubnet(test.args.subnet)
-			if (err != nil) != test.wantErr {
-				t.Errorf("NextSubnet() error = %v, wantErr %v", err, test.wantErr)
-				return
-			}
-			if !reflect.DeepEqual(got, test.want) {
-				t.Errorf("NextSubnet() got = %v, want %v", got, test.want)
-			}
-		})
-	}
-}
-
 func TestFirstIPInSubnet(t *testing.T) {
 	tests := []struct {
 		name    string
@@ -101,25 +71,3 @@ func TestLastIPInSubnet(t *testing.T) {
 		})
 	}
 }
-
-func TestGetRandomIPv6Subnet(t *testing.T) {
-	for i := 0; i < 1000; i++ {
-		t.Run(fmt.Sprintf("GetRandomIPv6Subnet %d", i), func(t *testing.T) {
-			sub, err := GetRandomIPv6Subnet()
-			if err != nil {
-				t.Errorf("GetRandomIPv6Subnet() error should be nil: %v", err)
-				return
-			}
-			if sub.IP.To4() != nil {
-				t.Errorf("ip %s is not an ipv6 address", sub.IP)
-			}
-			if sub.IP[0] != 0xfd {
-				t.Errorf("ipv6 %s does not start with fd", sub.IP)
-			}
-			ones, bytes := sub.Mask.Size()
-			if ones != 64 || bytes != 128 {
-				t.Errorf("wrong network mask %v, it should be /64", sub.Mask)
-			}
-		})
-	}
-}