MTU fix for cmd-forwarder-vpp#557 (#554)

Signed-off-by: Ed Warnicke <hagbard@gmail.com>
networkservicemesh · Apr 11, 2022 · dc652f0 · dc652f0
1 parent c508e18
commit dc652f0
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Showing 5 changed files with 58 additions and 78 deletions.
diff --git a/pkg/networkservice/connectioncontext/mtu/client.go b/pkg/networkservice/connectioncontext/mtu/client.go
@@ -28,7 +28,6 @@ import (
 
 	"github.com/networkservicemesh/api/pkg/api/networkservice"
 	"github.com/networkservicemesh/api/pkg/api/networkservice/mechanisms/vlan"
-	"github.com/networkservicemesh/api/pkg/api/networkservice/payload"
 	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
 	"github.com/networkservicemesh/sdk/pkg/networkservice/utils/metadata"
 	"github.com/networkservicemesh/sdk/pkg/tools/postpone"
@@ -81,22 +80,11 @@ func (m *mtuClient) Request(ctx context.Context, request *networkservice.Network
 		return conn, nil
 	}
 
-	if conn.GetPayload() == payload.Ethernet {
-		if err := setVPPL2MTU(ctx, conn, m.vppConn, metadata.IsClient(m)); err != nil {
-			if closeErr := m.closeOnFailure(postponeCtxFunc, conn, opts); closeErr != nil {
-				err = errors.Wrapf(err, "connection closed with error: %s", closeErr.Error())
-			}
-			return nil, err
-		}
-	}
-
-	if conn.GetPayload() == payload.IP {
-		if err := setVPPL3MTU(ctx, conn, m.vppConn, metadata.IsClient(m)); err != nil {
-			if closeErr := m.closeOnFailure(postponeCtxFunc, conn, opts); closeErr != nil {
-				err = errors.Wrapf(err, "connection closed with error: %s", closeErr.Error())
-			}
-			return nil, err
+	if err := setVPPMTU(ctx, conn, m.vppConn, metadata.IsClient(m)); err != nil {
+		if closeErr := m.closeOnFailure(postponeCtxFunc, conn, opts); closeErr != nil {
+			err = errors.Wrapf(err, "connection closed with error: %s", closeErr.Error())
 		}
+		return nil, err
 	}
 
 	return conn, nil

diff --git a/pkg/networkservice/connectioncontext/mtu/common.go b/pkg/networkservice/connectioncontext/mtu/common.go
@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Cisco and/or its affiliates.
+// Copyright (c) 2021-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -34,36 +34,7 @@ const (
 	jumboFrameSize = 9000
 )
 
-func setVPPL2MTU(ctx context.Context, conn *networkservice.Connection, vppConn api.Connection, isClient bool) error {
-	now := time.Now()
-	swIfIndex, ok := ifindex.Load(ctx, isClient)
-	if !ok || conn.GetContext().GetMTU() == 0 {
-		return nil
-	}
-	setMTU := &interfaces.HwInterfaceSetMtu{
-		SwIfIndex: swIfIndex,
-		Mtu:       uint16(conn.GetContext().GetMTU()),
-	}
-	_, err := interfaces.NewServiceClient(vppConn).HwInterfaceSetMtu(ctx, setMTU)
-	if err != nil {
-		err = errors.WithStack(err)
-		log.FromContext(ctx).
-			WithField("SwIfIndex", setMTU.SwIfIndex).
-			WithField("MTU", setMTU.Mtu).
-			WithField("duration", time.Since(now)).
-			WithField("error", err).
-			WithField("vppapi", "HwInterfaceSetMtu").Debug("error")
-		return err
-	}
-	log.FromContext(ctx).
-		WithField("SwIfIndex", setMTU.SwIfIndex).
-		WithField("MTU", setMTU.Mtu).
-		WithField("duration", time.Since(now)).
-		WithField("vppapi", "HwInterfaceSetMtu").Debug("completed")
-	return nil
-}
-
-func setVPPL3MTU(ctx context.Context, conn *networkservice.Connection, vppConn api.Connection, isClient bool) error {
+func setVPPMTU(ctx context.Context, conn *networkservice.Connection, vppConn api.Connection, isClient bool) error {
 	now := time.Now()
 	swIfIndex, ok := ifindex.Load(ctx, isClient)
 	if !ok || conn.GetContext().GetMTU() == 0 {

diff --git a/pkg/networkservice/connectioncontext/mtu/server.go b/pkg/networkservice/connectioncontext/mtu/server.go
@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Cisco and/or its affiliates.
+// Copyright (c) 2021-2022 Cisco and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -24,7 +24,6 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/networkservicemesh/api/pkg/api/networkservice"
-	"github.com/networkservicemesh/api/pkg/api/networkservice/payload"
 	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
 	"github.com/networkservicemesh/sdk/pkg/networkservice/utils/metadata"
 	"github.com/networkservicemesh/sdk/pkg/tools/postpone"
@@ -72,22 +71,11 @@ func (m *mtuServer) Request(ctx context.Context, request *networkservice.Network
 		return nil, err
 	}
 
-	if conn.GetPayload() == payload.Ethernet {
-		if err := setVPPL2MTU(ctx, conn, m.vppConn, metadata.IsClient(m)); err != nil {
-			if closeErr := m.closeOnFailure(postponeCtxFunc, conn); closeErr != nil {
-				err = errors.Wrapf(err, "connection closed with error: %s", closeErr.Error())
-			}
-			return nil, err
-		}
-	}
-
-	if conn.GetPayload() == payload.IP {
-		if err := setVPPL3MTU(ctx, conn, m.vppConn, metadata.IsClient(m)); err != nil {
-			if closeErr := m.closeOnFailure(postponeCtxFunc, conn); closeErr != nil {
-				err = errors.Wrapf(err, "connection closed with error: %s", closeErr.Error())
-			}
-			return nil, err
+	if err := setVPPMTU(ctx, conn, m.vppConn, metadata.IsClient(m)); err != nil {
+		if closeErr := m.closeOnFailure(postponeCtxFunc, conn); closeErr != nil {
+			err = errors.Wrapf(err, "connection closed with error: %s", closeErr.Error())
 		}
+		return nil, err
 	}
 
 	return conn, nil

diff --git a/pkg/networkservice/mechanisms/vxlan/mtu/common.go b/pkg/networkservice/mechanisms/vxlan/mtu/common.go
@@ -30,10 +30,6 @@ import (
 	"github.com/networkservicemesh/sdk-vpp/pkg/tools/types"
 )
 
-const (
-	overhead = 50
-)
-
 func getMTU(ctx context.Context, vppConn api.Connection, tunnelIP net.IP) (uint32, error) {
 	client, err := interfaces.NewServiceClient(vppConn).SwInterfaceDump(ctx, &interfaces.SwInterfaceDump{})
 	if err != nil {
@@ -67,10 +63,29 @@ func getMTU(ctx context.Context, vppConn api.Connection, tunnelIP net.IP) (uint3
 			if err != nil {
 				return 0, errors.Wrapf(err, "error attempting to get interface ip address for %q (swIfIndex: %q) to determine MTU for tunnelIP %q", details.InterfaceName, details.SwIfIndex, tunnelIP)
 			}
-			if types.FromVppAddressWithPrefix(ipAddressDetails.Prefix).IP.Equal(tunnelIP) {
-				return (uint32(details.LinkMtu) - overhead), nil
+			if types.FromVppAddressWithPrefix(ipAddressDetails.Prefix).IP.Equal(tunnelIP) && details.Mtu[0] != 0 {
+				return (details.Mtu[0] - overhead(tunnelIP.To4() == nil)), nil
 			}
 		}
 	}
-	return 0, errors.Errorf("unable to find interface in vpp with tunnelIP: %q", tunnelIP)
+	return 0, errors.Errorf("unable to find interface in vpp with tunnelIP: %q or interface IP MTU is zero", tunnelIP)
+}
+
+func overhead(isV6 bool) uint32 {
+	if !isV6 {
+		// outer ipv4 header - 20 bytes
+		// outer udp header - 8 bytes
+		// vxlan header - 8 bytes
+		// inner ethernet header - 14 bytes
+		// optional overhead for 802.1q vlan tags - 4 bytes
+		// total - 54 bytes
+		return 54
+	}
+	// outer ipv6 header - 40 bytes
+	// outer udp header - 8 bytes
+	// vxlan header - 8 bytes
+	// inner ethernet header - 14 bytes
+	// optional overhead for 802.1q vlan tags - 4 bytes
+	// total - 74 bytes
+	return 74
 }
diff --git a/pkg/networkservice/mechanisms/wireguard/mtu/common.go b/pkg/networkservice/mechanisms/wireguard/mtu/common.go
@@ -30,10 +30,6 @@ import (
 	"github.com/networkservicemesh/sdk-vpp/pkg/tools/types"
 )
 
-const (
-	overhead = 80
-)
-
 func getMTU(ctx context.Context, vppConn api.Connection, tunnelIP net.IP) (uint32, error) {
 	client, err := interfaces.NewServiceClient(vppConn).SwInterfaceDump(ctx, &interfaces.SwInterfaceDump{})
 	if err != nil {
@@ -67,10 +63,32 @@ func getMTU(ctx context.Context, vppConn api.Connection, tunnelIP net.IP) (uint3
 			if err != nil {
 				return 0, errors.Wrapf(err, "error attempting to get interface ip address for %q (swIfIndex: %q) to determine MTU for tunnelIP %q", details.InterfaceName, details.SwIfIndex, tunnelIP)
 			}
-			if types.FromVppAddressWithPrefix(ipAddressDetails.Prefix).IP.Equal(tunnelIP) {
-				return (uint32(details.LinkMtu) - overhead), nil
+			if types.FromVppAddressWithPrefix(ipAddressDetails.Prefix).IP.Equal(tunnelIP) && details.Mtu[0] != 0 {
+				return (details.Mtu[0] - overhead(tunnelIP.To4() == nil)), nil
 			}
 		}
 	}
-	return 0, errors.Errorf("unable to find interface in vpp with tunnelIP: %q", tunnelIP)
+	return 0, errors.Errorf("unable to find interface in vpp with tunnelIP: %q or interface IP MTU is zero", tunnelIP)
+}
+
+func overhead(isV6 bool) uint32 {
+	// https://lists.zx2c4.com/pipermail/wireguard/2017-December/002201.html
+	if !isV6 {
+		//  20-byte outer IPv4 header
+		//  8-byte outer UDP header
+		//  4-byte type
+		//  4-byte key index
+		//  8-byte nonce
+		// 16-byte authentication tag
+		// 60 byte total
+		return 60
+	}
+	//  40-byte outer IPv4 header
+	//  8-byte outer UDP header
+	//  4-byte type
+	//  4-byte key index
+	//  8-byte nonce
+	// 16-byte authentication tag
+	// 80 bytes total
+	return 80
 }