snapshot of https://github.com/nats-io/nats-server.git (main, 2026-09-15; blobs > 131072B omitted)

test/maxpayload_test.go

@@ -0,0 +1,158 @@
+// Copyright 2015-2026 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package test
+
+import (
+	"fmt"
+	"net"
+	"runtime"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/nats-io/jwt/v2"
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nkeys"
+)
+
+func TestMaxPayload(t *testing.T) {
+	srv, opts := RunServerWithConfig("./configs/override.conf")
+	defer srv.Shutdown()
+
+	endpoint := net.JoinHostPort(opts.Host, fmt.Sprintf("%d", opts.Port))
+	nc, err := nats.Connect(fmt.Sprintf("nats://%s/", endpoint))
+	if err != nil {
+		t.Fatalf("Could not connect to server: %v", err)
+	}
+	defer nc.Close()
+
+	size := 4 * 1024 * 1024
+	big := sizedBytes(size)
+	err = nc.Publish("foo", big)
+
+	if err != nats.ErrMaxPayload {
+		t.Fatalf("Expected a Max Payload error")
+	}
+
+	conn, err := net.DialTimeout("tcp", endpoint, nc.Opts.Timeout)
+	if err != nil {
+		t.Fatalf("Could not make a raw connection to the server: %v", err)
+	}
+	defer conn.Close()
+	info := make([]byte, 512)
+	_, err = conn.Read(info)
+	if err != nil {
+		t.Fatalf("Expected an info message to be sent by the server: %s", err)
+	}
+	pub := fmt.Sprintf("PUB bar %d\r\n", size)
+	_, err = conn.Write([]byte(pub))
+	if err != nil {
+		t.Fatalf("Could not publish event to the server: %s", err)
+	}
+
+	errMsg := make([]byte, 35)
+	_, err = conn.Read(errMsg)
+	if err != nil {
+		t.Fatalf("Expected an error message to be sent by the server: %s", err)
+	}
+
+	if !strings.Contains(string(errMsg), "Maximum Payload Violation") {
+		t.Errorf("Received wrong error message (%v)\n", string(errMsg))
+	}
+
+	// Client proactively omits sending the message so server
+	// does not close the connection.
+	if nc.IsClosed() {
+		t.Errorf("Expected connection to not be closed.")
+	}
+
+	// On the other hand client which did not proactively omitted
+	// publishing the bytes following what is suggested by server
+	// in the info message has its connection closed.
+	_, err = conn.Write(big)
+	if err == nil && runtime.GOOS != "windows" {
+		t.Errorf("Expected error due to maximum payload transgression.")
+	}
+
+	// On windows, the previous write will not fail because the connection
+	// is not fully closed at this stage.
+	if runtime.GOOS == "windows" {
+		// Issuing a PING and not expecting the PONG.
+		_, err = conn.Write([]byte("PING\r\n"))
+		if err == nil {
+			conn.SetReadDeadline(time.Now().Add(500 * time.Millisecond))
+			_, err = conn.Read(big)
+			if err == nil {
+				t.Errorf("Expected closed connection due to maximum payload transgression.")
+			}
+		}
+	}
+}
+
+func TestMaxPayloadOverrun(t *testing.T) {
+	opts := DefaultTestOptions
+	opts.Port = -1
+	opts.MaxPayload = 10000
+	s := RunServer(&opts)
+	defer s.Shutdown()
+
+	// Overrun a int32
+	c := createClientConn(t, "127.0.0.1", opts.Port)
+	defer c.Close()
+
+	send, expect := setupConn(t, c)
+	send("PUB foo 199380988\r\n")
+	expect(errRe)
+
+	// Now overrun an int64, parseSize will have returned -1,
+	// so we get disconnected.
+	c = createClientConn(t, "127.0.0.1", opts.Port)
+	defer c.Close()
+
+	send, _ = setupConn(t, c)
+	send("PUB foo 18446744073709551615123\r\n")
+	expectDisconnect(t, c)
+}
+
+func TestAsyncInfoWithSmallerMaxPayload(t *testing.T) {
+	s, opts := runOperatorServer(t)
+	defer s.Shutdown()
+
+	const testMaxPayload = 522
+
+	okp, _ := nkeys.FromSeed(oSeed)
+	akp, _ := nkeys.CreateAccount()
+	apub, _ := akp.PublicKey()
+	nac := jwt.NewAccountClaims(apub)
+	nac.Limits.Payload = testMaxPayload
+	ajwt, err := nac.Encode(okp)
+	if err != nil {
+		t.Fatalf("Error generating account JWT: %v", err)
+	}
+	if err := s.AccountResolver().Store(apub, ajwt); err != nil {
+		t.Fatalf("Account Resolver returned an error: %v", err)
+	}
+
+	url := fmt.Sprintf("nats://%s:%d", opts.Host, opts.Port)
+	nc, err := nats.Connect(url, createUserCreds(t, s, akp))
+	if err != nil {
+		t.Fatalf("Error on connect: %v", err)
+	}
+	nc.Flush()
+	defer nc.Close()
+
+	if mp := nc.MaxPayload(); mp != testMaxPayload {
+		t.Fatalf("Expected MaxPayload of %d, got %d", testMaxPayload, mp)
+	}
+}