Webserver(4.8)UDP、广播、组播

目录

• UDP通信
• 广播
• 组播

UDP通信

server.c

#include<arpa/inet.h>
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
int main(){

    //1.创建一个通信的socket
    int fd=socket(PF_INET,SOCK_DGRAM,0);
    if(fd==-1){
        perror("socket");
        exit(-1);
    }


    struct sockaddr_in addr;
    addr.sin_family=AF_INET;
    addr.sin_port=htons(9999);
    addr.sin_addr.s_addr=INADDR_ANY;
    //2.绑定
    int ret=bind(fd,(struct sockaddr *)&addr,sizeof(addr));
    if(ret==-1){
        perror("bind");
        exit(-1);
    }

    //3.通信
    while(1){
        char recvbuf[128];
        char ipbuf[16];
        struct sockaddr_in cliaddr;
        int len=sizeof(cliaddr);
        //接收数据
        int num=recvfrom(fd,recvbuf,sizeof(recvbuf),0,(struct sockaddr *)&cliaddr,&len);
        printf("client IP:%s,Port:%d\n",
            inet_ntop(AF_INET,&cliaddr.sin_addr.s_addr,ipbuf,sizeof(ipbuf)),
            ntohs(cliaddr.sin_port));
        printf("client say:%s\n",recvbuf);

        //发送数据
        sendto(fd,recvbuf,strlen(recvbuf)+1,0,(struct sockaddr *)&cliaddr,sizeof(cliaddr));

    }
    close(fd);
    return 0;
}

client.c

#include<arpa/inet.h>
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
int main(){

    //1.创建一个通信的socket
    int fd=socket(PF_INET,SOCK_DGRAM,0);
    if(fd==-1){
        perror("socket");
        exit(-1);
    }

    //服务器的地址信息
    struct sockaddr_in saddr;
    saddr.sin_family=AF_INET;
    saddr.sin_port=htons(9999);
    inet_pton(AF_INET,"127.0.0.1",&saddr.sin_addr.s_addr);

    int num=0;
    //3.通信
    while(1){
        
        char sendBuf[128];
        sprintf(sendBuf,"hello,i am client%d\n",num++);
        //发送数据
        sendto(fd,sendBuf,strlen(sendBuf)+1,0,(struct sockaddr *)&saddr,sizeof(saddr));
        //接收数据
        int num=recvfrom(fd,sendBuf,sizeof(sendBuf),0,NULL,NULL);

        printf("server say:%s\n",sendBuf);
        sleep(1);

        

    }
    close(fd);
    return 0;
}

广播

向子网中多台计算机发送消息，只能向局域网发送。
每个广播消息都包含一个特殊的IP地址，这个IP中子网内主机标志部分的二进制全部为1。
192.168.10.最后一位255可以发给所有人
客户端需要绑定服务器广播使用的端口

客户端从部分数据才开始接收

client.c

#include<arpa/inet.h>
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
int main(){

    //1.创建一个通信的socket
    int fd=socket(PF_INET,SOCK_DGRAM,0);
    if(fd==-1){
        perror("socket");
        exit(-1);
    }

    //客户端绑定本地的IP和端口
    struct sockaddr_in addr;
    addr.sin_family=AF_INET;
    addr.sin_port=htons(9999);
    addr.sin_addr.s_addr=INADDR_ANY;

    int ret=bind(fd,(struct sockaddr *)&addr,sizeof(addr));
    if(ret==-1){
        perror("bind");
        exit(-1);
    }

    int num=0;
    //3.通信
    while(1){
        
        char buf[128];
        //接收数据
        int num=recvfrom(fd,buf,sizeof(buf),0,NULL,NULL);

        printf("server say:%s\n",buf);
        sleep(1);

        

    }
    close(fd);
    return 0;
}

server.c

#include<arpa/inet.h>
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
int main(){

    //1.创建一个通信的socket
    int fd=socket(PF_INET,SOCK_DGRAM,0);
    if(fd==-1){
        perror("socket");
        exit(-1);
    }

    //2.设置广播属性
    int op=1;
    setsockopt(fd,SOL_SOCKET,SO_BROADCAST,&op,sizeof(op));
    //3.创建一个广播的地址
    struct sockaddr_in cliaddr;
    cliaddr.sin_family=AF_INET;
    cliaddr.sin_port=htons(9999);
    inet_pton(AF_INET,"192.168.227.255",&cliaddr.sin_addr.s_addr);
    
    //3.通信
    int num=0;
    while(1){

        char sendBuf[128];
        sprintf(sendBuf,"hello,client...%d\n",num++);

        //发送数据
        sendto(fd,sendBuf,strlen(sendBuf)+1,0,(struct sockaddr *)&cliaddr,sizeof(cliaddr));
        printf("广播的数据：%s\n",sendBuf);
        sleep(1);

    }
    close(fd);
    return 0;
}

组播

组播既可以用于局域网，也可以用于广域网
客户端需要加入多播组，才能接收到多播的数据

client.c

#include<arpa/inet.h>
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
int main(){

    //1.创建一个通信的socket
    int fd=socket(PF_INET,SOCK_DGRAM,0);
    if(fd==-1){
        perror("socket");
        exit(-1);
    }

    //客户端绑定本地的IP和端口
    struct sockaddr_in addr;
    addr.sin_family=AF_INET;
    addr.sin_port=htons(9999);
    addr.sin_addr.s_addr=INADDR_ANY;

    int ret=bind(fd,(struct sockaddr *)&addr,sizeof(addr));
    if(ret==-1){
        perror("bind");
        exit(-1);
    }

    struct ip_mreq op;
    inet_pton(AF_INET,"239.0.0.10",&op.imr_multiaddr.s_addr);
    op.imr_interface.s_addr=INADDR_ANY;
    //加入到多播组
    setsockopt(fd,IPPROTO_IP,IP_ADD_MEMBERSHIP,&op,sizeof(op));

    
    int num=0;
    //3.通信
    while(1){
        
        char buf[128];
        //接收数据
        int num=recvfrom(fd,buf,sizeof(buf),0,NULL,NULL);

        printf("server say:%s\n",buf);
        sleep(1);

        

    }
    close(fd);
    return 0;
}

server.c

#include<arpa/inet.h>
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
int main(){

    //1.创建一个通信的socket
    int fd=socket(PF_INET,SOCK_DGRAM,0);
    if(fd==-1){
        perror("socket");
        exit(-1);
    }

    //2.设置多播属性，设置外出接口
    struct in_addr imr_multiaddr;
    //初始化多播地址
    inet_pton(AF_INET,"239.0.0.10",&imr_multiaddr.s_addr);
    setsockopt(fd,IPPROTO_IP,IP_MULTICAST_IF,&imr_multiaddr,sizeof(imr_multiaddr));
    //3.初始化客户端的地址信息
    struct sockaddr_in cliaddr;
    cliaddr.sin_family=AF_INET;
    cliaddr.sin_port=htons(9999);
    inet_pton(AF_INET,"239.0.0.10",&cliaddr.sin_addr.s_addr);
    
    //3.通信
    int num=0;
    while(1){

        char sendBuf[128];
        sprintf(sendBuf,"hello,client...%d\n",num++);

        //发送数据
        sendto(fd,sendBuf,strlen(sendBuf)+1,0,(struct sockaddr *)&cliaddr,sizeof(cliaddr));
        printf("组播的数据：%s\n",sendBuf);
        sleep(1);

    }
    close(fd);
    return 0;
}