[网络协议]通过C++封装UdpSocketl类 实现简单的服务端-客户端通信

?一.封装UDP实现简单通信

#include <iostream>
#include <stdio.h>
#include <string>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>
using namespace std;

class UdpSocket{
public:
    UdpSocket()
        :_sockfd(-1)
    {}
    //
    bool Socket(){
        _sockfd = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
        if(_sockfd < 0){
            perror("socket error");
            return false;
        }
        return true;
    }
    bool Bind(const string& ip,uint16_t port){
        struct sockaddr_in addr;
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        addr.sin_addr.s_addr = inet_addr(ip.c_str());
        socklen_t len = sizeof(struct sockaddr_in);
        int ret = bind(_sockfd,(struct sockaddr*)&addr,len);
        if(ret < 0){
            perror("bind error");
            return false;
        }
        return true;
    }
   bool Send(string& data,string& ip,uint16_t port){
        struct sockaddr_in addr;
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        addr.sin_addr.s_addr = inet_addr(ip.c_str());
        socklen_t len = sizeof(struct sockaddr_in);
        int ret = sendto(_sockfd,data.c_str(),data.size(),0,(struct sockaddr*)&addr,len);
        if(ret < 0){
            perror("sendto error");
            return false;
        }
        return true;
    }
    bool Recv(string* buf,string* ip = NULL,uint16_t* port = NULL){
        struct sockaddr_in peer_addr;
        socklen_t len = sizeof(struct sockaddr_in);
        char tmp[4096] = {0};
        int ret = recvfrom(_sockfd,tmp,4096,0,(struct sockaddr*)&peer_addr,&len);
        if(ret < 0){
            perror("recvfrom error");
            return false;
        }
        buf->assign(tmp,ret);
        if(port != NULL){
            *port = ntohs(peer_addr.sin_port);
        }
        if(ip != NULL){
            *ip = inet_ntoa(peer_addr.sin_addr);
        }
        return true;
    }
    bool Close(){
        if(_sockfd > 0){
            close(_sockfd);
            _sockfd = -1;
        }
    }

private:
    int _sockfd;
};

二.服务端

#include <iostream>
#include <string>
#include <cstdlib>
#include "udpsocket.hpp"

#define CHECK_RET(q) if(q==false){return false;}
int main(int argc,char* argv[]){
    if(argc != 3){
        cout << "Usage: ./server ip port" << endl;
        return -1;
    }
    uint16_t port = atoi(argv[2]);
    string ip = argv[1];
    UdpSocket srv_sock;
    CHECK_RET(srv_sock.Socket()); //套接字初始化
    CHECK_RET(srv_sock.Bind(ip,port)); //绑定地址信息

    while(1){
        string buf;
        string peer_ip;
        uint16_t peer_port;
        CHECK_RET(srv_sock.Recv(&buf,&peer_ip,&peer_port));
        cout << "client[" << peer_ip << ":" << peer_port <<"]say: " << buf << endl;

        buf.clear();
        cout << "server say:";
        cin >> buf;
        CHECK_RET(srv_sock.Send(buf,peer_ip,peer_port));
    }
    CHECK_RET(srv_sock.Close());
    return 0;
}

三.客户端

#include <iostream>
#include <cstdlib>
#include <string>
#include "udpsocket.hpp"

#define CHECK_RET(q) if(q==false){return false;}

int main(int argc,char* argv[]){
    if(argc != 3){
        cout << "Usage: ./client ip port" << endl;
        return -1;
    }
    string srv_ip = argv[1];
    uint16_t srv_port = atoi(argv[2]);
    UdpSocket cli_sock;

    CHECK_RET(cli_sock.Socket());
    while(1){
        //fasongshuju
        cout << "client say:";
        string buf;
        cin >> buf;
        CHECK_RET(cli_sock.Send(buf,srv_ip,srv_port));
        //jieshoushuju
        buf.clear();
        CHECK_RET(cli_sock.Recv(&buf));
        cout << "server say:" << buf << endl;
    }
    CHECK_RET(cli_sock.Close());
    return 0;
}