个人中心
gpt4 book ai didi

c++ - 为什么显示 "Received a connection from 0.0.0.0, port 0"？

转载 作者：行者123 更新时间：2023-11-28 02:22:04 25 4
gpt4 key购买 nike

<分区>

这是我的简单服务器和客户端。

server.cc

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>

#include <iostream>

struct TcpConnection {
    int client_id;
    struct sockaddr_in client_addr;
    socklen_t  addr_len;

    ~TcpConnection() {
        shutdown(client_id, SHUT_RDWR);
    }
};

int main()
{
    // Creates an endpoint for communication
    int server_id = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (server_id < 0) {
        perror("socket");
        exit(errno);
    }

    // Assigning a name to a socket
    struct sockaddr_in addr;
    addr.sin_family = AF_INET;
    // address to accept any incoming messages
    addr.sin_addr.s_addr = INADDR_ANY;
    addr.sin_port = htons(9219);

    int yes = 1;
    setsockopt(server_id, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));

    if (bind(server_id, (struct sockaddr *)(&addr), sizeof(addr)) < 0) {
        perror("bind");
        exit(errno);
    }

    if (listen(server_id, 5) < 0) {
        perror("listen");
        exit(errno);
    }

    while (1) {
        // Accept a connection on a socket
        TcpConnection * conn = new TcpConnection;
        conn->client_id = accept(server_id, 
                (struct sockaddr *)(&conn->client_addr), &(conn->addr_len));

        if (conn->client_id < 0) {
                perror("accept");
                exit(errno);
        } else {
            char ip[16];
            inet_ntop(AF_INET, &(conn->client_addr.sin_addr), ip, 16);
            std::cout << " Received a connection from " << ip << ", port " << conn->client_addr.sin_port << std::endl;

        }

        delete conn;
    }
    return 0;
}

客户端.cc

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>

#include <iostream>

std::string get_ip_addr(struct addrinfo* host)
{
    struct sockaddr_in* addr = (struct sockaddr_in *)host->ai_addr;
    char ip[16];
    inet_ntop(AF_INET, &addr->sin_addr, ip, 16);
    return std::string(ip);
}


int main(int argc, char* argv[])
{
    if (argc != 3) {
        std::cout << "Usage: "<< argv[0] << " <server name> <port>\n";
        exit(errno);
    }

    // Create an endpoint for communication
    int client_id = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

    // Get the information of server to be connected
    struct addrinfo * server_ai;

    int rv = getaddrinfo(argv[1], argv[2], 0, &server_ai);
    if ( rv < 0 ) {
        std::cout << gai_strerror(rv) << std::endl;
        exit(errno);
    }

    std::cout << "Connecting to " << argv[1] << 
        "|" << get_ip_addr(server_ai) << "|:" << argv[2] << "... ";
    std::cout.flush();

    // Connect to server
    if ( connect(client_id, server_ai->ai_addr, sizeof(struct sockaddr)) < 0 ) { 
        perror("connect");
        exit(errno);
    }

    std::cout << "connected" << std::endl;

    freeaddrinfo(server_ai);
}

启动服务器程序后，我启动客户端进行连接这个服务器。服务器输出:

Received a connection from 0.0.0.0, port 0

太乱了!然后我再次启动客户端，服务器输出:

Received a connection from 127.0.0.1, port 15566

这次我得到了预期的结果。那么如何解释第一个输出呢？

25 4 0
文章推荐： c++ - OpenGL 变换反馈不返回任何东西
文章推荐： c++ - 我的文件里什么都没写
文章推荐： c++ - 使用指向成员和宏的指针
文章推荐： c++ - alignof运算符有什么用？
行者123
个人简介

我是一名优秀的程序员,十分优秀！

滴滴打车优惠券免费领取
滴滴打车优惠券
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com