Webserver(4.8)UDP、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socketint 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socketint 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socketint 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socketint 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socketint 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socketint 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;
}