net/udprelay: change ServerEndpoint time.Duration fields to tstime.GoDuration (#15725)

tstime.GoDuration JSON serializes with time.Duration.String(), which is
more human-friendly than nanoseconds.

ServerEndpoint is currently experimental, therefore breaking changes
are tolerable.

Updates tailscale/corp#27502

Signed-off-by: Jordan Whited <jordan@tailscale.com>

net/udprelay/server.go

@@ -21,6 +21,7 @@ import (
 	"go4.org/mem"
 	"tailscale.com/disco"
 	"tailscale.com/net/packet"
+	"tailscale.com/tstime"
 	"tailscale.com/types/key"
 )
 
@@ -114,12 +115,12 @@ type ServerEndpoint struct {
 	// BindLifetime is amount of time post-allocation the Server will consider
 	// the endpoint active while it has yet to be bound via 3-way bind handshake
 	// from both client parties.
-	BindLifetime time.Duration
+	BindLifetime tstime.GoDuration
 
 	// SteadyStateLifetime is the amount of time post 3-way bind handshake from
 	// both client parties the Server will consider the endpoint active lacking
 	// bidirectional data flow.
-	SteadyStateLifetime time.Duration
+	SteadyStateLifetime tstime.GoDuration
 }
 
 // serverEndpoint contains Server-internal ServerEndpoint state. serverEndpoint
@@ -489,8 +490,8 @@ func (s *Server) AllocateEndpoint(discoA, discoB key.DiscoPublic) (ServerEndpoin
 				AddrPorts:           s.addrPorts,
 				VNI:                 e.vni,
 				LamportID:           e.lamportID,
-				BindLifetime:        s.bindLifetime,
+				BindLifetime:        tstime.GoDuration{Duration: s.bindLifetime},
-				SteadyStateLifetime: s.steadyStateLifetime,
+				SteadyStateLifetime: tstime.GoDuration{Duration: s.steadyStateLifetime},
 			}, nil
 		}
 		// If an endpoint exists for the pair of key.DiscoPublic's, and is
@@ -526,7 +527,7 @@ func (s *Server) AllocateEndpoint(discoA, discoB key.DiscoPublic) (ServerEndpoin
 		AddrPorts:           s.addrPorts,
 		VNI:                 e.vni,
 		LamportID:           e.lamportID,
-		BindLifetime:        s.bindLifetime,
+		BindLifetime:        tstime.GoDuration{Duration: s.bindLifetime},
-		SteadyStateLifetime: s.steadyStateLifetime,
+		SteadyStateLifetime: tstime.GoDuration{Duration: s.steadyStateLifetime},
 	}, nil
 }

net/udprelay/server_test.go

@@ -5,6 +5,8 @@ package udprelay
 
 import (
 	"bytes"
+	"encoding/json"
+	"math"
 	"net"
 	"net/netip"
 	"testing"
@@ -15,6 +17,7 @@ import (
 	"go4.org/mem"
 	"tailscale.com/disco"
 	"tailscale.com/net/packet"
+	"tailscale.com/tstime"
 	"tailscale.com/types/key"
 )
 
@@ -202,3 +205,96 @@ func TestServer(t *testing.T) {
 		t.Fatal("unexpected msg B->A")
 	}
 }
+
+func TestServerEndpointJSONUnmarshal(t *testing.T) {
+	tests := []struct {
+		name    string
+		json    []byte
+		wantErr bool
+	}{
+		{
+			name:    "valid",
+			json:    []byte(`{"ServerDisco":"discokey:003cd7453e04a653eb0e7a18f206fc353180efadb2facfd05ebd6982a1392c7f","LamportID":18446744073709551615,"AddrPorts":["127.0.0.1:1","127.0.0.2:2"],"VNI":16777215,"BindLifetime":"30s","SteadyStateLifetime":"5m0s"}`),
+			wantErr: false,
+		},
+		{
+			name:    "invalid ServerDisco",
+			json:    []byte(`{"ServerDisco":"1","LamportID":18446744073709551615,"AddrPorts":["127.0.0.1:1","127.0.0.2:2"],"VNI":16777215,"BindLifetime":"30s","SteadyStateLifetime":"5m0s"}`),
+			wantErr: true,
+		},
+		{
+			name:    "invalid LamportID",
+			json:    []byte(`{"ServerDisco":"discokey:003cd7453e04a653eb0e7a18f206fc353180efadb2facfd05ebd6982a1392c7f","LamportID":1.1,"AddrPorts":["127.0.0.1:1","127.0.0.2:2"],"VNI":16777215,"BindLifetime":"30s","SteadyStateLifetime":"5m0s"}`),
+			wantErr: true,
+		},
+		{
+			name:    "invalid AddrPorts",
+			json:    []byte(`{"ServerDisco":"discokey:003cd7453e04a653eb0e7a18f206fc353180efadb2facfd05ebd6982a1392c7f","LamportID":18446744073709551615,"AddrPorts":["127.0.0.1.1:1","127.0.0.2:2"],"VNI":16777215,"BindLifetime":"30s","SteadyStateLifetime":"5m0s"}`),
+			wantErr: true,
+		},
+		{
+			name:    "invalid VNI",
+			json:    []byte(`{"ServerDisco":"discokey:003cd7453e04a653eb0e7a18f206fc353180efadb2facfd05ebd6982a1392c7f","LamportID":18446744073709551615,"AddrPorts":["127.0.0.1:1","127.0.0.2:2"],"VNI":18446744073709551615,"BindLifetime":"30s","SteadyStateLifetime":"5m0s"}`),
+			wantErr: true,
+		},
+		{
+			name:    "invalid BindLifetime",
+			json:    []byte(`{"ServerDisco":"discokey:003cd7453e04a653eb0e7a18f206fc353180efadb2facfd05ebd6982a1392c7f","LamportID":18446744073709551615,"AddrPorts":["127.0.0.1:1","127.0.0.2:2"],"VNI":16777215,"BindLifetime":"5","SteadyStateLifetime":"5m0s"}`),
+			wantErr: true,
+		},
+		{
+			name:    "invalid SteadyStateLifetime",
+			json:    []byte(`{"ServerDisco":"discokey:003cd7453e04a653eb0e7a18f206fc353180efadb2facfd05ebd6982a1392c7f","LamportID":18446744073709551615,"AddrPorts":["127.0.0.1:1","127.0.0.2:2"],"VNI":16777215,"BindLifetime":"30s","SteadyStateLifetime":"5"}`),
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var out ServerEndpoint
+			err := json.Unmarshal(tt.json, &out)
+			if tt.wantErr != (err != nil) {
+				t.Fatalf("wantErr: %v (err == nil): %v", tt.wantErr, err == nil)
+			}
+			if tt.wantErr {
+				return
+			}
+		})
+	}
+}
+
+func TestServerEndpointJSONMarshal(t *testing.T) {
+	tests := []struct {
+		name           string
+		serverEndpoint ServerEndpoint
+	}{
+		{
+			name: "valid roundtrip",
+			serverEndpoint: ServerEndpoint{
+				ServerDisco:         key.NewDisco().Public(),
+				LamportID:           uint64(math.MaxUint64),
+				AddrPorts:           []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:1"), netip.MustParseAddrPort("127.0.0.2:2")},
+				VNI:                 1<<24 - 1,
+				BindLifetime:        tstime.GoDuration{Duration: defaultBindLifetime},
+				SteadyStateLifetime: tstime.GoDuration{Duration: defaultSteadyStateLifetime},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			b, err := json.Marshal(&tt.serverEndpoint)
+			if err != nil {
+				t.Fatal(err)
+			}
+			var got ServerEndpoint
+			err = json.Unmarshal(b, &got)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if diff := cmp.Diff(got, tt.serverEndpoint, cmpopts.EquateComparable(netip.AddrPort{}, key.DiscoPublic{})); diff != "" {
+				t.Fatalf("ServerEndpoint unequal (-got +want)\n%s", diff)
+			}
+		})
+	}
+}