From f44416cdc6cb6ca5ad631cdae29844dd05c3c23c Mon Sep 17 00:00:00 2001
From: Lionel Jouin <lionel.jouin@est.tech>
Date: Fri, 21 Oct 2022 18:17:38 +0200
Subject: [PATCH] Add MTU property as parameter of the Service

Makes the MTU configurable in addition to the vlan ID and the base
interface.

Signed-off-by: Lionel Jouin <lionel.jouin@est.tech>
---
 internal/pkg/config/config.go                  | 18 +++++++++++++-----
 internal/pkg/config/config_test.go             |  4 +++-
 .../pkg/networkservice/vlanmapserver/server.go |  9 ++++++---
 3 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/internal/pkg/config/config.go b/internal/pkg/config/config.go
index 77594cf..9c55a65 100644
--- a/internal/pkg/config/config.go
+++ b/internal/pkg/config/config.go
@@ -32,6 +32,7 @@ const (
 	labelsPrefix = "labels:"
 	viaPrefix    = "via:"
 	domainPrefix = "domain:"
+	mtuPrefix    = "mtu:"
 
 	tcpSchema = "tcp"
 )
@@ -74,8 +75,9 @@ type ServiceConfig struct {
 	Name    string
 	Domain  string
 	Via     string
-	VLANTag int32
+	VLANTag uint32
 	Labels  map[string]string
+	MTU     uint32
 }
 
 // InitValues set initial values for ServiceConfig
@@ -83,6 +85,7 @@ func (s *ServiceConfig) InitValues() {
 	s.Domain = ""
 	s.VLANTag = 0
 	s.Via = ""
+	s.MTU = 0
 }
 
 // UnmarshalBinary expects string(bytes) to be in format:
@@ -102,13 +105,15 @@ func (s *ServiceConfig) UnmarshalBinary(bytes []byte) (err error) {
 		part = strings.TrimSpace(part)
 		switch {
 		case strings.HasPrefix(part, vlanPrefix):
-			s.VLANTag, err = parseInt32(trimPrefix(part, vlanPrefix))
+			s.VLANTag, err = parseUInt32(trimPrefix(part, vlanPrefix))
 		case strings.HasPrefix(part, labelsPrefix):
 			s.Labels, err = parseMap(trimPrefix(part, labelsPrefix))
 		case strings.HasPrefix(part, viaPrefix):
 			s.Via = trimPrefix(part, viaPrefix)
 		case strings.HasPrefix(part, domainPrefix):
 			s.Domain = trimPrefix(part, domainPrefix)
+		case strings.HasPrefix(part, mtuPrefix):
+			s.MTU, err = parseUInt32(trimPrefix(part, mtuPrefix))
 		default:
 			err = errors.Errorf("invalid format: %s", text)
 		}
@@ -124,12 +129,12 @@ func trimPrefix(s, prefix string) string {
 	return strings.TrimSpace(s)
 }
 
-func parseInt32(s string) (int32, error) {
-	i, err := strconv.ParseInt(s, 0, 32)
+func parseUInt32(s string) (uint32, error) {
+	i, err := strconv.ParseUint(s, 0, 32)
 	if err != nil {
 		return 0, err
 	}
-	return int32(i), nil
+	return uint32(i), nil
 }
 
 func parseMap(s string) (map[string]string, error) {
@@ -154,5 +159,8 @@ func (s *ServiceConfig) validate() error {
 	if s.VLANTag < 0 || s.VLANTag > 4095 {
 		return errors.New("Invalid VLAN ID")
 	}
+	if s.MTU > 0 && (s.MTU < 68 || s.MTU > 65535) {
+		return errors.New("Invalid MTU")
+	}
 	return nil
 }
diff --git a/internal/pkg/config/config_test.go b/internal/pkg/config/config_test.go
index c2024e2..e872b42 100644
--- a/internal/pkg/config/config_test.go
+++ b/internal/pkg/config/config_test.go
@@ -27,7 +27,7 @@ import (
 func TestServiceConfig_UnmarshalBinary(t *testing.T) {
 	cfg := new(config.ServiceConfig)
 
-	err := cfg.UnmarshalBinary([]byte("finance-bridge { domain: service-domain.2; vlan: 100; via: gw-1 }"))
+	err := cfg.UnmarshalBinary([]byte("finance-bridge { domain: service-domain.2; vlan: 100; via: gw-1 ; mtu: 1450 }"))
 	require.NoError(t, err)
 
 	require.Equal(t, &config.ServiceConfig{
@@ -35,6 +35,7 @@ func TestServiceConfig_UnmarshalBinary(t *testing.T) {
 		Domain:  "service-domain.2",
 		Via:     "gw-1",
 		VLANTag: 100,
+		MTU:     1450,
 	}, cfg)
 
 	err = cfg.UnmarshalBinary([]byte("finance-bridge { vlan: 200; via: service-domain.1 }"))
@@ -44,5 +45,6 @@ func TestServiceConfig_UnmarshalBinary(t *testing.T) {
 		Name:    "finance-bridge",
 		Via:     "service-domain.1",
 		VLANTag: 200,
+		MTU:     0,
 	}, cfg)
 }
diff --git a/internal/pkg/networkservice/vlanmapserver/server.go b/internal/pkg/networkservice/vlanmapserver/server.go
index 3279664..df720a4 100644
--- a/internal/pkg/networkservice/vlanmapserver/server.go
+++ b/internal/pkg/networkservice/vlanmapserver/server.go
@@ -39,8 +39,9 @@ type vlanMapServer struct {
 	entries map[string]*entry
 }
 type entry struct {
-	vlanTag int32
+	vlanTag uint32
 	via     string
+	mtu     uint32
 }
 
 // NewServer - creates a NetworkServiceServer that requests a vlan interface and populates the netns inode
@@ -54,6 +55,7 @@ func NewServer(cfg *config.Config) networkservice.NetworkServiceServer {
 		v.entries[service.Name] = &entry{
 			vlanTag: service.VLANTag,
 			via:     service.Via,
+			mtu:     service.MTU,
 		}
 	}
 	return v
@@ -68,7 +70,7 @@ func (v *vlanMapServer) Request(ctx context.Context, request *networkservice.Net
 	}
 
 	if mechanism := vlan.ToMechanism(conn.GetMechanism()); mechanism != nil {
-		mechanism.SetVlanID(uint32(entry.vlanTag))
+		mechanism.SetVlanID(entry.vlanTag)
 
 		conn.Labels = make(map[string]string, 1)
 		conn.Labels[viaLabel] = entry.via
@@ -76,7 +78,8 @@ func (v *vlanMapServer) Request(ctx context.Context, request *networkservice.Net
 	if request.GetConnection().GetContext() == nil {
 		request.GetConnection().Context = &networkservice.ConnectionContext{}
 	}
-	request.GetConnection().GetContext().MTU = 0
+	request.GetConnection().GetContext().MTU = entry.mtu
+
 	return next.Server(ctx).Request(ctx, request)
 }