feature/wgcf/custom-mtu-generation

README.md

@@ -43,6 +43,13 @@ This adds `PersistentKeepalive` to the profile's `[Peer]` section. The setting i
 #### Maximum transmission unit (MTU)
 To ensure maximum compatibility, the generated profile will have a MTU of 1280, just like the official Android app. If you are experiencing performance issues, you may be able to improve your speed by increasing this value. For more information, please check [#40](https://github.com/ViRb3/wgcf/issues/40).
 
+You can override the default MTU or omit it from the generated profile:
+
+```bash
+wgcf generate --mtu 1420    # sets a custom MTU
+wgcf generate --no-mtu      # omits the MTU setting
+```
+
 ### Add a license key
 
 If you have an existing Warp+ subscription, for example on your phone, you can bind the account generated by this tool to your phone's account, sharing its Warp+ status. Please note that there is a limit of 5 maximum devices linked at a time. You can remove linked devices from the 1.1.1.1 app on your phone.

cmd/generate/generate.go

@@ -14,9 +14,14 @@ import (
 
 var profileFile string
 var keepalive int
+var mtu int
+var noMTU bool
 var shortMsg = "Generates a WireGuard profile from the current Cloudflare Warp account"
 
-const maxKeepalive = 65535
+const (
+	maxKeepalive = 65535
+	defaultMTU   = 1280
+)
 
 var Cmd = &cobra.Command{
 	Use:   "generate",
@@ -31,17 +36,29 @@ func init() {
 	Cmd.PersistentFlags().StringVarP(&profileFile, "profile", "p", "wgcf-profile.conf", "WireGuard profile file")
 	Cmd.PersistentFlags().IntVarP(&keepalive, "keepalive", "k", 0, "Persistent keepalive interval in seconds (default 25)")
 	Cmd.PersistentFlags().Lookup("keepalive").NoOptDefVal = "25"
+	Cmd.PersistentFlags().IntVarP(&mtu, "mtu", "m", defaultMTU, "WireGuard interface MTU")
+	Cmd.PersistentFlags().BoolVar(&noMTU, "no-mtu", false, "Omit MTU from the generated profile")
+	Cmd.MarkFlagsMutuallyExclusive("mtu", "no-mtu")
 }
 
 func generateProfile() error {
 	if err := validateKeepalive(keepalive); err != nil {
 		return err
 	}
 
+	if err := validateMTU(mtu); err != nil {
+		return err
+	}
+
 	if err := EnsureConfigValidAccount(); err != nil {
 		return errors.WithStack(err)
 	}
 
+	profileMTU := mtu
+	if noMTU {
+		profileMTU = 0
+	}
+
 	ctx := CreateContext()
 	thisDevice, err := cloudflare.GetSourceDevice(ctx)
 	if err != nil {
@@ -64,6 +81,7 @@ func generateProfile() error {
 		PublicKey:  peer.PublicKey,
 		Endpoint:   endpoint,
 		Keepalive:  keepalive,
+		MTU:        profileMTU,
 	})
 	if err != nil {
 		return errors.WithStack(err)
@@ -82,3 +100,10 @@ func validateKeepalive(interval int) error {
 	}
 	return nil
 }
+
+func validateMTU(mtuValue int) error {
+	if mtuValue <= 0 {
+		return errors.Errorf("mtu value must be greater than 0, got %d", mtuValue)
+	}
+	return nil
+}

cmd/generate/generate_test.go

@@ -25,6 +25,29 @@ func TestValidateKeepalive(t *testing.T) {
 	}
 }
 
+func TestValidateMTU(t *testing.T) {
+	tests := []struct {
+		name    string
+		mtu     int
+		wantErr bool
+	}{
+		{name: "negative", mtu: -1, wantErr: true},
+		{name: "zero", mtu: 0, wantErr: true},
+		{name: "minimum accepted", mtu: 1},
+		{name: "default", mtu: 1280},
+		{name: "custom", mtu: 1500},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			err := validateMTU(test.mtu)
+			if (err != nil) != test.wantErr {
+				t.Fatalf("validateMTU(%d) error = %v, wantErr %v", test.mtu, err, test.wantErr)
+			}
+		})
+	}
+}
+
 func TestKeepaliveFlag(t *testing.T) {
 	flags := Cmd.PersistentFlags()
 	flag := flags.Lookup("keepalive")
@@ -57,3 +80,69 @@ func TestKeepaliveFlag(t *testing.T) {
 		t.Error()
 	}
 }
+
+func TestMTUFlags(t *testing.T) {
+	tests := []struct {
+		name         string
+		args         []string
+		wantMTU      int
+		wantNoMTU    bool
+		wantParseErr bool
+		wantGroupErr bool
+	}{
+		{name: "omitted", wantMTU: 1280},
+		{name: "custom", args: []string{"--mtu=1500"}, wantMTU: 1500},
+		{name: "short", args: []string{"-m", "1400"}, wantMTU: 1400},
+		{name: "no MTU", args: []string{"--no-mtu"}, wantMTU: 1280, wantNoMTU: true},
+		{name: "no MTU explicitly false", args: []string{"--no-mtu=false"}, wantMTU: 1280},
+		{name: "missing MTU value", args: []string{"--mtu"}, wantParseErr: true},
+		{name: "invalid MTU value", args: []string{"--mtu=invalid"}, wantParseErr: true},
+		{name: "conflicting flags", args: []string{"--mtu=1500", "--no-mtu"}, wantMTU: 1500, wantNoMTU: true, wantGroupErr: true},
+		{name: "conflicting flags reversed", args: []string{"--no-mtu", "--mtu=1500"}, wantMTU: 1500, wantNoMTU: true, wantGroupErr: true},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			resetFlag(t, "mtu")
+			resetFlag(t, "no-mtu")
+
+			err := Cmd.ParseFlags(test.args)
+			if (err != nil) != test.wantParseErr {
+				t.Fatalf("ParseFlags(%q) error = %v, wantParseErr %v", test.args, err, test.wantParseErr)
+			}
+			if test.wantParseErr {
+				return
+			}
+
+			err = Cmd.ValidateFlagGroups()
+			if (err != nil) != test.wantGroupErr {
+				t.Fatalf("ValidateFlagGroups() error = %v, wantGroupErr %v", err, test.wantGroupErr)
+			}
+			if mtu != test.wantMTU {
+				t.Errorf("mtu = %d, want %d", mtu, test.wantMTU)
+			}
+			if noMTU != test.wantNoMTU {
+				t.Errorf("noMTU = %t, want %t", noMTU, test.wantNoMTU)
+			}
+		})
+	}
+}
+
+func resetFlag(t *testing.T, name string) {
+	t.Helper()
+	flag := Cmd.PersistentFlags().Lookup(name)
+	if flag == nil {
+		t.Fatalf("flag %q not found", name)
+	}
+	value, changed := flag.Value.String(), flag.Changed
+	t.Cleanup(func() {
+		if err := flag.Value.Set(value); err != nil {
+			t.Errorf("restore flag %q: %v", name, err)
+		}
+		flag.Changed = changed
+	})
+	if err := flag.Value.Set(flag.DefValue); err != nil {
+		t.Fatalf("reset flag %q: %v", name, err)
+	}
+	flag.Changed = false
+}

wireguard/profile.go

@@ -12,7 +12,9 @@ var profileTemplate = `[Interface]
 PrivateKey = {{ .PrivateKey }}
 Address = {{ .Address1 }}/32, {{ .Address2 }}/128
 DNS = 1.1.1.1, 1.0.0.1, 2606:4700:4700::1111, 2606:4700:4700::1001
-MTU = 1280
+{{- if .MTU }}
+MTU = {{ .MTU }}
+{{- end }}
 [Peer]
 PublicKey = {{ .PublicKey }}
 AllowedIPs = 0.0.0.0/0, ::/0
@@ -33,6 +35,7 @@ type ProfileData struct {
 	PublicKey  string
 	Endpoint   string
 	Keepalive  int
+	MTU        int
 }
 
 func NewProfile(data *ProfileData) (*Profile, error) {

wireguard/profile_test.go

@@ -23,6 +23,7 @@ Endpoint = 5
 		Address2:   "3",
 		PublicKey:  "4",
 		Endpoint:   "5",
+		MTU:        1280,
 	})
 	if err != nil {
 		t.Error(err)
@@ -53,6 +54,7 @@ PersistentKeepalive = 25
 		PublicKey:  "4",
 		Endpoint:   "5",
 		Keepalive:  25,
+		MTU:        1280,
 	})
 	if err != nil {
 		t.Fatal(err)
@@ -81,3 +83,60 @@ func TestGenerateProfileWithCustomKeepalive(t *testing.T) {
 		t.Errorf("expected profile to end with %q, got:\n%s", expected, result)
 	}
 }
+
+func TestGenerateProfileWithoutMTU(t *testing.T) {
+	var expectedResult = `[Interface]
+PrivateKey = 1
+Address = 2/32, 3/128
+DNS = 1.1.1.1, 1.0.0.1, 2606:4700:4700::1111, 2606:4700:4700::1001
+[Peer]
+PublicKey = 4
+AllowedIPs = 0.0.0.0/0, ::/0
+Endpoint = 5
+`
+
+	result, err := generateProfile(&ProfileData{
+		PrivateKey: "1",
+		Address1:   "2",
+		Address2:   "3",
+		PublicKey:  "4",
+		Endpoint:   "5",
+		MTU:        0,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if expectedResult != result {
+		t.Errorf("unexpected profile:\n%s", result)
+	}
+}
+
+func TestGenerateProfileWithCustomMTU(t *testing.T) {
+	var expectedResult = `[Interface]
+PrivateKey = 1
+Address = 2/32, 3/128
+DNS = 1.1.1.1, 1.0.0.1, 2606:4700:4700::1111, 2606:4700:4700::1001
+MTU = 1500
+[Peer]
+PublicKey = 4
+AllowedIPs = 0.0.0.0/0, ::/0
+Endpoint = 5
+`
+
+	result, err := generateProfile(&ProfileData{
+		PrivateKey: "1",
+		Address1:   "2",
+		Address2:   "3",
+		PublicKey:  "4",
+		Endpoint:   "5",
+		MTU:        1500,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if expectedResult != result {
+		t.Errorf("unexpected profile:\n%s", result)
+	}
+}