广播服务器

在这#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
//#include <stdio.h>
#define ERR(msg) do{\
	fprintf(stderr,"%d",__LINE__);\
	perror("msg");\
}while(0);
int main(int argc, const char *argv[])
{
	int sfd=socket(AF_INET,SOCK_DGRAM,0);
		if(sfd<0){
			ERR("socket");
			return 0;
			}
		//绑定
		struct sockaddr_in md;
		md.sin_family=AF_INET;
		md.sin_port=htons(8888);
		md.sin_addr.s_addr=inet_addr("192.168.43.255");
		int asd=bind(sfd,(struct sockaddr*)&md,sizeof(md));
			if(asd<0){
				ERR("bind");
				return 0;
			}
		//接收
		char c[128]="";
		struct sockaddr_in sd;
		ssize_t rad;
		socklen_t arrlen=sizeof(sd);
		while(1){
			bzero(c,sizeof(c));
		 rad=recvfrom(sfd,c,sizeof(c),0,(struct sockaddr*)&sd,&arrlen);
		if(rad<0){
			ERR("recvfrom");
			return 0;
		}else if(0==rad){
			printf("对端关闭\n");
			break;
		}
		printf("[%s:%d] %s\n",inet_ntoa(sd.sin_addr),ntohs(sd.sin_port),c);
		
				}
		close(sfd);
	return 0;
}
里插入代码片

广播客户端

在这#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
//#include <stdio.h>
#define ERR(msg) do{\
	fprintf(stderr,"%d",__LINE__);\
	perror("msg");\
}while(0);
int main(int argc, const char *argv[])
{
	int sfd=socket(AF_INET,SOCK_DGRAM,0);
		if(sfd<0){
			ERR("socket");
			return 0;
			}
//允许广播
		int num=1;
		if(setsockopt(sfd,SOL_SOCKET,SO_BROADCAST,&num,sizeof(num))<0){
			ERR("setsockcpt");
			return 0;
		}
		struct sockaddr_in md;
          md.sin_family=AF_INET;
          md.sin_port=htons(8888);
          md.sin_addr.s_addr=inet_addr("192.168.43.255");

		char c[128]="";
		ssize_t rad;
		socklen_t arrlen=sizeof(md);
		while(1){
			printf("请输入>>>");
			bzero(c,sizeof(c));
			//发送
			fgets(c,sizeof(c),stdin);
			c[strlen(c)-1]='\0';
		 rad=sendto(sfd,c,sizeof(c),0,(struct sockaddr*)&md,arrlen);
		if(rad<0){
			ERR("recvfrom");
			return 0;
		}else if(0==rad){
			printf("对端关闭\n");
			break;
		}			
		}
		close(sfd);
	return 0;
}
里插入代码片

组播服务器

在这#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <net/if.h>
#define ERR(msg) do{\
	fprintf(stderr,"%d",__LINE__);\
	perror("msg");\
}while(0);
int main(int argc, const char *argv[])
{
	int sfd=socket(AF_INET,SOCK_DGRAM,0);
		if(sfd<0){
			ERR("socket");
			return 0;
			}
		int reuse = 1;
  if(setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &reuse ,sizeof(reuse)) < 0)
  {
  ERR("setsockopt");
  return -1;
  }
  printf("允许端口快速重用\n");

		struct ip_mreqn sp;
		sp.imr_multiaddr.s_addr=inet_addr("224.6.6.6");
		sp.imr_address.s_addr=inet_addr("192.168.43.9");
		sp.imr_ifindex=if_nametoindex("ens33");

		if(setsockopt(sfd,IPPROTO_IP,IP_ADD_MEMBERSHIP,&sp,sizeof(sp))<0){
			ERR("setsockopt");
			return 0;

		}
			struct sockaddr_in md;
          md.sin_family=AF_INET;
          md.sin_port=htons(8888);
          md.sin_addr.s_addr=inet_addr("224.6.6.6");
		if(bind(sfd,(struct sockaddr*)&md,sizeof(md))<0){
			ERR("bind");
			return 0;
		}
		char c[128]="";
		ssize_t rad;
		socklen_t arrlen=sizeof(md);
		while(1){
			//接收
		bzero(c,sizeof(c));
		 rad=recvfrom(sfd,c,sizeof(c),0,(struct sockaddr*)&md,&arrlen);
		if(rad<0){
			ERR("recvfrom");
			return 0;
		}else if(0==rad){
			printf("对端关闭\n");
			break;
		}
		printf("%s\n",c);
				}
		close(sfd);
	return 0;
}
里插入代码片

组播客户端

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
//#include <stdio.h>
#define ERR(msg) do{\
	fprintf(stderr,"%d",__LINE__);\
	perror("msg");\
}while(0);
int main(int argc, const char *argv[])
{
	int sfd=socket(AF_INET,SOCK_DGRAM,0);
		if(sfd<0){
			ERR("socket");
			return 0;
			}
		//绑定
		struct sockaddr_in md;
		md.sin_family=AF_INET;
		md.sin_port=htons(8888);
		md.sin_addr.s_addr=inet_addr("224.6.6.6");

				//接收
		char c[128]="";
		struct sockaddr_in sd;
		ssize_t rad;
		socklen_t arrlen=sizeof(md);
		while(1){
		 		//发送
			printf("请输入>>>");
			bzero(c,sizeof(c));
			fgets(c,sizeof(c),stdin);
			c[strlen(c)-1]='\0';
			rad=sendto(sfd,c,sizeof(c),0,(struct sockaddr*)&md,arrlen);
		if(rad<0){
			ERR("sendto");
			return 0;
		}else if(0==rad){
			printf("对端关闭\n");
			break;
		}
		}
		close(sfd);
	return 0;
}