Raspberry Pi通讯挂在accept（）上

Question

我有2个树莓pi，我想在它们之间发送一些数据以同时在两者上启动功能，两者之间的连接是一条以太网电缆，并且都没有连接到Internet。

我遇到一个问题，即服务器代码一经接受就会挂起。我已经包含了服务器和客户端代码。我正在使用在客户端代码中运行服务器代码的Pi的IP。我认为这是客户端没有将连接发送到正确位置的问题，还是服务器没有被告知正确的接收位置的问题。

该代码基于此处的示例代码http://www.cs.rpi.edu/~moorthy/Courses/os98/Pgms/socket.html。

服务器：

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>
//#include <opencv2/opencv.hpp>
#include <iostream>
#include <chrono>
#include <iomanip>
#include <sstream>
#include <algorithm>
#include <iterator>

using namespace std;

int main(int argc, char *argv[]){
     int sockfd, newsockfd, portno;
     printf("Sock \n");
     socklen_t clilen;
     printf("clilen \n");
     char buffer[256];
     printf("buffer \n");
     struct sockaddr_in serv_addr, cli_addr;
     printf("struct \n");
     int n;
     printf("n \n");

     sockfd = socket(AF_INET, SOCK_STREAM, 0);
     printf("Sockfd \n");

     bzero((char *) &serv_addr, sizeof(serv_addr));
     printf("bzero \n");
     portno = 6666;
     printf("port \n");
     serv_addr.sin_family = AF_INET;
     printf("afinet \n");
     serv_addr.sin_addr.s_addr = INADDR_ANY;
     printf("inadder any \n");
     serv_addr.sin_port = htons(portno);
     printf("htons \n");

     printf("listen \n");
     cout << listen(sockfd,5) << "\n";
     listen(sockfd,5);
     clilen = sizeof(cli_addr);
     cout << "&clilen: " << &clilen << "\n";
     cout << "clilen: " << clilen << "\n";

     newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
     printf("newsock \n");

     bzero(buffer,256);
     printf("bezero 2 \n");
     n = read(newsockfd,buffer,255);
     printf("read \n");
     printf("Here is the message: %s\n",buffer);


     n = write(newsockfd,"I got your message",18);
     printf("write \n");

     return 0;
}

服务器输出：

Sock
clilen
buffer
struct
n
Sockfd
bzero
port
afinet
inadder any
htons
listen
0
&clilen: 0x7eeaaf0c
clilen: 16

客户代码：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>
//#include <opencv2/opencv.hpp>
#include <iostream>
#include <chrono>
#include <iomanip>
#include <sstream>
#include <algorithm>
#include <iterator>

using namespace std;

int main(int argc, char *argv[]){
    int sockfd, portno, n;
    printf("sock \n");

    struct sockaddr_in serv_addr;
    printf("sockaddr \n");
    struct in_addr ipv4addr;
    printf("ipv4 \n");
    struct hostent *server;
    printf("hostent \n");

    char buffer[256];
    printf("buffer \n");

    portno = 6666;
    printf("port \n");
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    printf("sockfd \n");
    if (sockfd < 0)
        printf("ERROR opening socket");
    inet_pton(AF_INET, "169.254.59.109", &ipv4addr);
    printf("inet \n");
    server = gethostbyaddr(&ipv4addr, sizeof ipv4addr, AF_INET);
    cout << "server: " << server << "\n";
    printf("server \n");
    //if (server == NULL) {
        //fprintf(stderr,"ERROR, no such host\n");
        //exit(0);
    //}
    bzero((char *) &serv_addr, sizeof(serv_addr));
    printf("bzero \n");
    serv_addr.sin_family = AF_INET;
    printf("af \n");
    bcopy((char *)server->h_addr,(char*)&serv_addr.sin_addr.s_addr,server->h_length);
    printf("bcopy \n");
    serv_addr.sin_port = htons(portno);
    printf("htons \n");
    cout << "connect: " << (connect(sockfd,(struct sockaddr*)&serv_addr,sizeof(serv_addr))) << "\n";
    cout << "sockfd: " << sockfd << "\n";
    cout << "struct: " << (struct sockaddr *)&serv_addr << "\n";
    cout << "serv: " << sizeof(serv_addr) << "\n";
    if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
        printf("ERROR connecting\n");


    printf("Please enter the message: ");
    bzero(buffer,256);
    fgets(buffer,255,stdin);
    n = write(sockfd,buffer,strlen(buffer));
    printf("write \n");
    if (n < 0)
         printf("ERROR writing to socket");
    bzero(buffer,256);
    n = read(sockfd,buffer,255);
    printf("read \n");
    if (n < 0)
         printf("ERROR reading from socket");
    printf("%s\n",buffer);
    return 0;
}

客户端输出：

sock
sockaddr
ipv4
hostent
buffer
port
sockfd
inet
server: 0x76d3c5a4
server
bzero
af
bcopy
htons
connect: -1
sockfd: 3
struct: 0x7ea32ef0
serv: 16
ERROR connecting
Please enter the message: hello