5 files changed, 87 insertions, 7 deletions
diff --git a/libpod/network/config.go b/libpod/network/config.go
index ce8a4446c..ce351129e 100644
--- a/libpod/network/config.go
+++ b/libpod/network/config.go
@@ -129,6 +129,16 @@ func (f FirewallConfig) Bytes() ([]byte, error) {
 	return json.MarshalIndent(f, "", "\t")
 }
 
+// TuningConfig describes the tuning plugin
+type TuningConfig struct {
+	PluginType string `json:"type"`
+}
+
+// Bytes outputs the configuration as []byte
+func (f TuningConfig) Bytes() ([]byte, error) {
+	return json.MarshalIndent(f, "", "\t")
+}
+
 // DNSNameConfig describes the dns container name resolution plugin config
 type DNSNameConfig struct {
 	PluginType   string          `json:"type"`
diff --git a/libpod/network/create.go b/libpod/network/create.go
index 387f4fcd3..7e4fc574a 100644
--- a/libpod/network/create.go
+++ b/libpod/network/create.go
@@ -176,6 +176,7 @@ func createBridge(name string, options entities.NetworkCreateOptions, runtimeCon
 	plugins = append(plugins, bridge)
 	plugins = append(plugins, NewPortMapPlugin())
 	plugins = append(plugins, NewFirewallPlugin())
+	plugins = append(plugins, NewTuningPlugin())
 	// if we find the dnsname plugin or are rootless, we add configuration for it
 	// the rootless-cni-infra container has the dnsname plugin always installed
 	if (HasDNSNamePlugin(runtimeConfig.Network.CNIPluginDirs) || rootless.IsRootless()) && !options.DisableDNS {
diff --git a/libpod/network/netconflist.go b/libpod/network/netconflist.go
index 111f1715c..ee9adce14 100644
--- a/libpod/network/netconflist.go
+++ b/libpod/network/netconflist.go
@@ -119,6 +119,13 @@ func NewFirewallPlugin() FirewallConfig {
 	}
 }
 
+// NewTuningPlugin creates a generic tuning section
+func NewTuningPlugin() TuningConfig {
+	return TuningConfig{
+		PluginType: "tuning",
+	}
+}
+
 // NewDNSNamePlugin creates the dnsname config with a given
 // domainname
 func NewDNSNamePlugin(domainName string) DNSNameConfig {
diff --git a/libpod/network/subnet.go b/libpod/network/subnet.go
index 90f0cdfce..120038e57 100644
--- a/libpod/network/subnet.go
+++ b/libpod/network/subnet.go
@@ -54,14 +54,10 @@ func LastIPInSubnet(addr *net.IPNet) (net.IP, error) { //nolint:interfacer
 
 	ones, bits := cidr.Mask.Size()
 	if ones == bits {
-		return FirstIPInSubnet(cidr)
+		return cidr.IP, nil
 	}
-	hostStart := ones / 8
-	// Handle the first host byte
-	cidr.IP[hostStart] |= 0xff & cidr.Mask[hostStart]
-	// Fill the rest with ones
-	for i := hostStart; i < len(cidr.IP); i++ {
-		cidr.IP[i] = 0xff
+	for i := range cidr.IP {
+		cidr.IP[i] = cidr.IP[i] | ^cidr.Mask[i]
 	}
 	return cidr.IP, nil
 }
@@ -73,6 +69,10 @@ func FirstIPInSubnet(addr *net.IPNet) (net.IP, error) { //nolint:interfacer
 	if err != nil {
 		return nil, err
 	}
+	ones, bits := cidr.Mask.Size()
+	if ones == bits {
+		return cidr.IP, nil
+	}
 	cidr.IP[len(cidr.IP)-1]++
 	return cidr.IP, nil
 }
diff --git a/libpod/network/subnet_test.go b/libpod/network/subnet_test.go
index 917c3be88..55b2443bd 100644
--- a/libpod/network/subnet_test.go
+++ b/libpod/network/subnet_test.go
@@ -33,3 +33,65 @@ func TestNextSubnet(t *testing.T) {
 		})
 	}
 }
+
+func TestFirstIPInSubnet(t *testing.T) {
+	tests := []struct {
+		name    string
+		args    *net.IPNet
+		want    net.IP
+		wantErr bool
+	}{
+		{"class b", parseCIDR("192.168.0.0/16"), net.ParseIP("192.168.0.1"), false},
+		{"class c", parseCIDR("192.168.1.0/24"), net.ParseIP("192.168.1.1"), false},
+		{"cidr /23", parseCIDR("192.168.0.0/23"), net.ParseIP("192.168.0.1"), false},
+		{"cidr /25", parseCIDR("192.168.1.0/25"), net.ParseIP("192.168.1.1"), false},
+		{"cidr /26", parseCIDR("172.16.1.128/26"), net.ParseIP("172.16.1.129"), false},
+		{"class a", parseCIDR("10.0.0.0/8"), net.ParseIP("10.0.0.1"), false},
+		{"cidr /32", parseCIDR("192.168.255.4/32"), net.ParseIP("192.168.255.4"), false},
+		{"cidr /31", parseCIDR("192.168.255.4/31"), net.ParseIP("192.168.255.5"), false},
+	}
+	for _, tt := range tests {
+		test := tt
+		t.Run(test.name, func(t *testing.T) {
+			got, err := FirstIPInSubnet(test.args)
+			if (err != nil) != test.wantErr {
+				t.Errorf("FirstIPInSubnet() error = %v, wantErr %v", err, test.wantErr)
+				return
+			}
+			if !got.Equal(test.want) {
+				t.Errorf("FirstIPInSubnet() got = %v, want %v", got, test.want)
+			}
+		})
+	}
+}
+
+func TestLastIPInSubnet(t *testing.T) {
+	tests := []struct {
+		name    string
+		args    *net.IPNet
+		want    net.IP
+		wantErr bool
+	}{
+		{"class b", parseCIDR("192.168.0.0/16"), net.ParseIP("192.168.255.255"), false},
+		{"class c", parseCIDR("192.168.1.0/24"), net.ParseIP("192.168.1.255"), false},
+		{"cidr /23", parseCIDR("192.168.0.0/23"), net.ParseIP("192.168.1.255"), false},
+		{"cidr /25", parseCIDR("192.168.1.0/25"), net.ParseIP("192.168.1.127"), false},
+		{"cidr /26", parseCIDR("172.16.1.128/26"), net.ParseIP("172.16.1.191"), false},
+		{"class a", parseCIDR("10.0.0.0/8"), net.ParseIP("10.255.255.255"), false},
+		{"cidr /32", parseCIDR("192.168.255.4/32"), net.ParseIP("192.168.255.4"), false},
+		{"cidr /31", parseCIDR("192.168.255.4/31"), net.ParseIP("192.168.255.5"), false},
+	}
+	for _, tt := range tests {
+		test := tt
+		t.Run(test.name, func(t *testing.T) {
+			got, err := LastIPInSubnet(test.args)
+			if (err != nil) != test.wantErr {
+				t.Errorf("LastIPInSubnet() error = %v, wantErr %v", err, test.wantErr)
+				return
+			}
+			if !got.Equal(test.want) {
+				t.Errorf("LastIPInSubnet() got = %v, want %v", got, test.want)
+			}
+		})
+	}
+}