Netty + Protocol Buffers Java <-> C 通信问题
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【中文标题】Netty + Protocol Buffers Java <-> C 通信问题【英文标题】：Netty + Protocol Buffers Java <-> C communication issue 【发布时间】：2017-09-04 16:27:51 【问题描述】：我正在尝试使用 Netty 和协议缓冲区（以及加密，但这不会影响此问题）。服务器使用 Netty 用 Java 编写，客户端应该用 C 和 Java 编写。这是Java服务器端代码。
应用类：
@SpringBootApplication
public class Application
public static void main(String[] args) throws InterruptedException
ConfigurableApplicationContext context = SpringApplication.run(Application.class, args);
TcpServer tcpServer = context.getBean(TcpServer.class);
tcpServer.start();
@Autowired
private SomethingChannelInitializer somethingChannelInitializer;
@SuppressWarnings( "unchecked", "rawtypes" )
@Bean
public ServerBootstrap bootstrap()
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup(), workerGroup()).channel(NioserverSocketChannel.class)
.handler(new LoggingHandler(LogLevel.DEBUG)).childHandler(somethingChannelInitializer);
Map<ChannelOption<?>, Object> tcpChannelOptions = tcpChannelOptions();
Set<ChannelOption<?>> keySet = tcpChannelOptions.keySet();
for (ChannelOption option : keySet)
b.option(option, tcpChannelOptions.get(option));
return b;
@Bean(name = "tcpChannelOptions")
public Map<ChannelOption<?>, Object> tcpChannelOptions()
Map<ChannelOption<?>, Object> options = new HashMap<ChannelOption<?>, Object>();
options.put(ChannelOption.SO_KEEPALIVE, true);
options.put(ChannelOption.SO_BACKLOG, 3);
return options;
@Bean(destroyMethod = "shutdownGracefully")
public NioEventLoopGroup bossGroup()
return new NioEventLoopGroup(2);
@Bean(destroyMethod = "shutdownGracefully")
public NioEventLoopGroup workerGroup()
return new NioEventLoopGroup(2);
@Bean
public InetSocketAddress tcpPort()
return new InetSocketAddress(12888);
SomethingChannelInitializer 类：
@Component
public class SomethingChannelInitializer extends ChannelInitializer<SocketChannel>
@Autowired
private ChannelInboundHandlerAdapter somethingServerHandler;
@Override
protected void initChannel(SocketChannel socketChannel) throws Exception
ChannelPipeline pipeline = socketChannel.pipeline();
// SSL stuff
pipeline.addLast(new ProtobufVarint32FrameDecoder());
pipeline.addLast(new ProtobufDecoder(ProtocolMessage.OneRequest.getDefaultInstance()));
pipeline.addLast(new ProtobufVarint32LengthFieldPrepender());
pipeline.addLast(new ProtobufEncoder());
pipeline.addLast(somethingServerHandler);
SomethingServerHandler 类：
@Component
@Sharable
public class SomethingServerHandler extends ChannelInboundHandlerAdapter
private static Logger logger = LoggerFactory.getLogger(SomethingServerHandler.class);
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
logger.debug("read ...");
ProtocolMessage.OneRequest req = (ProtocolMessage.OneRequest) msg;
switch (req.getType())
case LOGIN:
logger.debug(", ", req.getLoginRequest().getLogin(), req.getLoginRequest().getPassword());
break;
case REGISTER:
logger.debug(", ", req.getRegistrationRequest().getEmail(), req.getRegistrationRequest().getPassword());
break;
default:
break;
ProtocolMessage.RegistrationResponse registrationResponse = ProtocolMessage.RegistrationResponse.newBuilder().setStatus("got it").build();
ProtocolMessage.OneResponse rsp = ProtocolMessage.OneResponse.newBuilder().setRegistrationResponse(registrationResponse).build();
ctx.writeAndFlush(rsp);
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception
logger.error(cause.getMessage(), cause);
//ctx.close();
@Override
public void channelInactive(ChannelHandlerContext ctx)
ProtocolMessage.proto：
package com.company.model;
message LoginRequest
required string login = 1;
required string password = 2;
message RegistrationRequest
required string login = 1;
required string email = 2;
required string password = 3;
message RegistrationResponse
required string status = 1;
message OneRequest
enum Type LOGIN = 1; REGISTER = 2;
required Type type = 1;
oneof request
LoginRequest loginRequest = 2;
RegistrationRequest registrationRequest = 3;
message OneResponse
oneof response
RegistrationResponse registrationResponse = 1;
C 客户端：
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <unistd.h>
#include <string.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include "ProtocolMessage.pb-c.h"
#define HERR(source) (fprintf(stderr,"%s(%d) at %s:%d\n",source,h_errno,__FILE__,__LINE__),\
exit(EXIT_FAILURE))
int main(int argc, char **argv)
// SSL initialization, making new connection etc.
Com__Company__Model__LoginRequest login = COM__COMPANY__MODEL__LOGIN_REQUEST__INIT;
login.login="sample_login";
login.password="secret_password";
Com__Company__Model__OneRequest req = COM__COMPANY__MODEL__ONE_REQUEST__INIT;
req.loginrequest=&login;
req.type=COM__COMPANY__MODEL__ONE_REQUEST__TYPE__LOGIN;
unsigned len = com__company__model__one_request__get_packed_size(&req);
void *buf = malloc(len);
com__company__model__one_request__pack(&req, buf);
SSL_write(clientssl, buf, len);
printf("SSL server sent %d\n", len);
SSL_shutdown(clientssl);
close(clientsocketfd);
SSL_free(clientssl);
SSL_CTX_free(ssl_client_ctx);
return 0;
服务器日志：
2017-09-04 18:14:37.209 DEBUG 63166 --- [ntLoopGroup-3-1] io.netty.handler.ssl.SslHandler : [id: 0x445a7c98, L:/127.0.0.1:12888 - R:/127.0.0.1:50688] HANDSHAKEN: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
2017-09-04 18:14:37.218 ERROR 63166 --- [ntLoopGroup-3-1] p.o.g.handlers.SomethingServerHandler : com.google.protobuf.InvalidProtocolBufferException: Protocol message contained an invalid tag (zero).
io.netty.handler.codec.DecoderException: com.google.protobuf.InvalidProtocolBufferException: Protocol message contained an invalid tag (zero).
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:98) ~[netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:297) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:413) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1273) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1084) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:134) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:644) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:579) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:496) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:458) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138) [netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_91]
Caused by: com.google.protobuf.InvalidProtocolBufferException: Protocol message contained an invalid tag (zero).
at com.google.protobuf.InvalidProtocolBufferException.invalidTag(InvalidProtocolBufferException.java:89) ~[protobuf-java-2.6.1.jar!/:na]
at com.google.protobuf.CodedInputStream.readTag(CodedInputStream.java:158) ~[protobuf-java-2.6.1.jar!/:na]
at com.company.model.ProtocolMessage$OneRequest.<init>(ProtocolMessage.java:2037) ~[classes!/:0.0.1-SNAPSHOT]
at com.company.model.ProtocolMessage$OneRequest.<init>(ProtocolMessage.java:2000) ~[classes!/:0.0.1-SNAPSHOT]
at com.company.model.ProtocolMessage$OneRequest$1.parsePartialFrom(ProtocolMessage.java:2116) ~[classes!/:0.0.1-SNAPSHOT]
at com.company.model.ProtocolMessage$OneRequest$1.parsePartialFrom(ProtocolMessage.java:2111) ~[classes!/:0.0.1-SNAPSHOT]
at com.google.protobuf.AbstractParser.parsePartialFrom(AbstractParser.java:137) ~[protobuf-java-2.6.1.jar!/:na]
at com.google.protobuf.AbstractParser.parseFrom(AbstractParser.java:168) ~[protobuf-java-2.6.1.jar!/:na]
at com.google.protobuf.AbstractParser.parseFrom(AbstractParser.java:174) ~[protobuf-java-2.6.1.jar!/:na]
at com.google.protobuf.AbstractParser.parseFrom(AbstractParser.java:49) ~[protobuf-java-2.6.1.jar!/:na]
at io.netty.handler.codec.protobuf.ProtobufDecoder.decode(ProtobufDecoder.java:121) ~[netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.codec.protobuf.ProtobufDecoder.decode(ProtobufDecoder.java:64) ~[netty-all-4.1.13.Final.jar!/:4.1.13.Final]
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:88) ~[netty-all-4.1.13.Final.jar!/:4.1.13.Final]
... 30 common frames omitted
protobuf-java 2.6.1 protobuf-c 1.0.2 libprotoc 2.6.1
基本上这是一些从网上获取并稍作修改的示例代码。不要查看硬编码值或其他缺陷。这仅用于学习目的。我可以使用 Java 客户端与服务器通信，没有任何问题。但是，当我尝试从 C 客户端发送相同的消息时，服务器会立即引发异常。我读过一些关于定界的东西，但我不知道如何处理。我也尝试过首先将消息的长度作为 int 发送，然后是来自 C 客户端的实际消息，但这也无济于事。加密在这里不是问题。如果我禁用它，我会得到相同的结果。
我在这里缺少什么？这是否可能与 C 客户端进行通信？
【问题讨论】：
你分析网络流量了吗？使用wireshark 之类的工具？只是为了得到一个提示，在哪一边搜索问题。
【参考方案1】：
尝试使用 LengthFieldBasedFrameDecoder 代替 ProtobufVarint32FrameDecoder， 并先发送包裹长度：
void *buf = malloc(len);
// send package len
buf[0] = (len >> 24) & 0xFF;
buf[1] = (len >> 16) & 0xFF;
buf[2] = (len >> 8) & 0xFF;
buf[3] = len & 0xFF;
SSL_write(clientssl, buf, 4);
// send package
com__company__model__one_request__pack(&req, buf);
SSL_write(clientssl, buf, len);
您需要根据需要指定字节顺序 BIG_ENDIAN 或 LITTLE_ENDIAN。
【讨论】：
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