（TCP IP网络编程）实验三 广播和多播编程

一．实验目的

(1) 在掌握IP多播的基本概念和工作原理的基础上，进行多播编程，实现多播通信；
(2) 在掌握广播的基本概念和工作原理的基础上，进行广播播编程，实现广播通信；

二．实验内容

（1）编写一对用于发送和接收信息的IP多播程序，其中：
发送端可向该多播组广播文件中保存的新闻信息，接收端可接收传递到该多播组的新闻信息。
（2）编写一对用于发送和接收信息的IP多播程序，其中：
发送端可向该多播组广播使用者从键盘输入的即时消息，接收端可接收传递到该多播组的即时消息。
（3）编写一对用于发送和接收信息的广播程序，其中：
发送端可向特定网络广播文件中保存的新闻信息，接收端可接收传递到该网络的新闻信息。
（4）编写一对用于发送和接收信息的广播程序，其中：
发送端可向特定网络广播使用者从键盘输入的即时消息，接收端可接收传递到该网络的即时消息。

三．实验过程

（1）多播接收发送文件：

News_sender.c:#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <arpa/inet.h>#include <sys/socket.h>#define TTL 64#define BUF_SIZE 30void error_handling(char *message);int main(int argc, char *argv[]){int send_sock;struct sockaddr_in mul_adr;int time_live=TTL;FILE *fp;char buf[BUF_SIZE];if(argc!=3){printf(\"Usage : %s <GroupIP> <PORT>\\n\", argv[0]);exit(1);}send_sock=socket(PF_INET, SOCK_DGRAM, 0);memset(&mul_adr, 0, sizeof(mul_adr));mul_adr.sin_family=AF_INET;mul_adr.sin_addr.s_addr=inet_addr(argv[1]);  // Multicast IPmul_adr.sin_port=htons(atoi(argv[2]));       // Multicast Portsetsockopt(send_sock, IPPROTO_IP,IP_MULTICAST_TTL, (void*)&time_live, sizeof(time_live));if((fp=fopen(\"news.txt\", \"r\"))==NULL)error_handling(\"fopen() error\");while(!feof(fp))   /* Broadcasting */{fgets(buf, BUF_SIZE, fp);sendto(send_sock, buf, strlen(buf),0, (struct sockaddr*)&mul_adr, sizeof(mul_adr));sleep(2);}fclose(fp);close(send_sock);return 0;}void error_handling(char *message){fputs(message, stderr);fputc(\'\\n\', stderr);exit(1);}News_receiver.c:#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <arpa/inet.h>#include <sys/socket.h>#define BUF_SIZE 30void error_handling(char *message);int main(int argc, char *argv[]){int recv_sock;int str_len;char buf[BUF_SIZE];struct sockaddr_in adr;struct ip_mreq join_adr;if(argc!=3) {printf(\"Usage : %s <GroupIP> <PORT>\\n\", argv[0]);exit(1);}recv_sock=socket(PF_INET, SOCK_DGRAM, 0);memset(&adr, 0, sizeof(adr));adr.sin_family=AF_INET;adr.sin_addr.s_addr=htonl(INADDR_ANY);adr.sin_port=htons(atoi(argv[2]));if(bind(recv_sock, (struct sockaddr*) &adr, sizeof(adr))==-1)error_handling(\"bind() error\");join_adr.imr_multiaddr.s_addr=inet_addr(argv[1]);join_adr.imr_interface.s_addr=htonl(INADDR_ANY);setsockopt(recv_sock, IPPROTO_IP,IP_ADD_MEMBERSHIP, (void*)&join_adr, sizeof(join_adr));while(1){str_len=recvfrom(recv_sock, buf, BUF_SIZE-1, 0, NULL, 0);if(str_len<0)break;buf[str_len]=0;fputs(buf, stdout);}close(recv_sock);return 0;}void error_handling(char *message){fputs(message, stderr);fputc(\'\\n\', stderr);exit(1);}

结果：

（2）多播实现接收发送消息;

Sender.c:#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <arpa/inet.h>#include <sys/socket.h>#define TTL 64#define BUF_SIZE 30void error_handling(char *message);int main(int argc, char *argv[]){int send_sock;struct sockaddr_in mul_adr;int time_live=TTL;char buf[BUF_SIZE];if(argc!=3){printf(\"Usage : %s <GroupIP> <PORT>\\n\", argv[0]);exit(1);}send_sock=socket(PF_INET, SOCK_DGRAM, 0);memset(&mul_adr, 0, sizeof(mul_adr));mul_adr.sin_family=AF_INET;mul_adr.sin_addr.s_addr=inet_addr(argv[1]);  // Multicast IPmul_adr.sin_port=htons(atoi(argv[2]));       // Multicast Portsetsockopt(send_sock, IPPROTO_IP,IP_MULTICAST_TTL, (void*)&time_live, sizeof(time_live));while(1)   /* Broadcasting */{fputs(\"请输入：\",stdout);fgets(buf, sizeof(buf), stdin);sendto(send_sock, buf, strlen(buf),0, (struct sockaddr*)&mul_adr, sizeof(mul_adr));}close(send_sock);return 0;}void error_handling(char *message){fputs(message, stderr);fputc(\'\\n\', stderr);exit(1);}Receiver.c:#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <arpa/inet.h>#include <sys/socket.h>#define BUF_SIZE 30void error_handling(char *message);int main(int argc, char *argv[]){int recv_sock;int str_len;char buf[BUF_SIZE];struct sockaddr_in adr;struct ip_mreq join_adr;if(argc!=3) {printf(\"Usage : %s <GroupIP> <PORT>\\n\", argv[0]);exit(1);}recv_sock=socket(PF_INET, SOCK_DGRAM, 0);memset(&adr, 0, sizeof(adr));adr.sin_family=AF_INET;adr.sin_addr.s_addr=htonl(INADDR_ANY);adr.sin_port=htons(atoi(argv[2]));if(bind(recv_sock, (struct sockaddr*) &adr, sizeof(adr))==-1)error_handling(\"bind() error\");join_adr.imr_multiaddr.s_addr=inet_addr(argv[1]);join_adr.imr_interface.s_addr=htonl(INADDR_ANY);setsockopt(recv_sock, IPPROTO_IP,IP_ADD_MEMBERSHIP, (void*)&join_adr, sizeof(join_adr));while(1){str_len=recvfrom(recv_sock, buf, BUF_SIZE-1, 0, NULL, 0);if(str_len<0)break;buf[str_len]=0;fputs(buf, stdout);}close(recv_sock);return 0;}void error_handling(char *message){fputs(message, stderr);fputc(\'\\n\', stderr);exit(1);}

结果：

（3）广播接收发送文件：

Sender_brd.c:#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <arpa/inet.h>#include <sys/socket.h>#define BUF_SIZE 30void error_handling(char *message);int main(int argc, char *argv[]){int send_sock;struct sockaddr_in broad_adr;FILE *fp;char buf[BUF_SIZE];int so_brd=1;if(argc!=3) {printf(\"Usage : %s <Boradcast IP> <PORT>\\n\", argv[0]);exit(1);}send_sock=socket(PF_INET, SOCK_DGRAM, 0);memset(&broad_adr, 0, sizeof(broad_adr));broad_adr.sin_family=AF_INET;broad_adr.sin_addr.s_addr=inet_addr(argv[1]);broad_adr.sin_port=htons(atoi(argv[2]));setsockopt(send_sock, SOL_SOCKET,SO_BROADCAST, (void*)&so_brd, sizeof(so_brd));if((fp=fopen(\"news.txt\", \"r\"))==NULL)error_handling(\"fopen() error\");while(!feof(fp)){fgets(buf, BUF_SIZE, fp);sendto(send_sock, buf, strlen(buf),0, (struct sockaddr*)&broad_adr, sizeof(broad_adr));sleep(2);}close(send_sock);return 0;}void error_handling(char *message){fputs(message, stderr);fputc(\'\\n\', stderr);exit(1);}Receiver_brd.c:#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <arpa/inet.h>#include <sys/socket.h>#define BUF_SIZE 30void error_handling(char *message);int main(int argc, char *argv[]){int recv_sock;struct sockaddr_in adr;int str_len;char buf[BUF_SIZE];if(argc!=2) {printf(\"Usage : %s  <PORT>\\n\", argv[0]);exit(1);}recv_sock=socket(PF_INET, SOCK_DGRAM, 0);memset(&adr, 0, sizeof(adr));adr.sin_family=AF_INET;adr.sin_addr.s_addr=htonl(INADDR_ANY);adr.sin_port=htons(atoi(argv[1]));if(bind(recv_sock, (struct sockaddr*)&adr, sizeof(adr))==-1)error_handling(\"bind() error\");while(1){str_len=recvfrom(recv_sock, buf, BUF_SIZE-1, 0, NULL, 0);if(str_len<0)break;buf[str_len]=0;fputs(buf, stdout);}close(recv_sock);return 0;}void error_handling(char *message){fputs(message, stderr);fputc(\'\\n\', stderr);exit(1);}

结果：

（4）广播实现接收发送消息：

Sender_brd.c:#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <arpa/inet.h>#include <sys/socket.h>#define BUF_SIZE 30void error_handling(char *message);int main(int argc, char *argv[]){int send_sock;struct sockaddr_in broad_adr;char buf[BUF_SIZE];int so_brd=1;if(argc!=3) {printf(\"Usage : %s <Boradcast IP> <PORT>\\n\", argv[0]);exit(1);}send_sock=socket(PF_INET, SOCK_DGRAM, 0);memset(&broad_adr, 0, sizeof(broad_adr));broad_adr.sin_family=AF_INET;broad_adr.sin_addr.s_addr=inet_addr(argv[1]);broad_adr.sin_port=htons(atoi(argv[2]));setsockopt(send_sock, SOL_SOCKET,SO_BROADCAST, (void*)&so_brd, sizeof(so_brd));while(1){fputs(\"请输入：\",stdout);fgets(buf, sizeof(buf), stdin);sendto(send_sock, buf, strlen(buf),0, (struct sockaddr*)&broad_adr, sizeof(broad_adr));}close(send_sock);return 0;}void error_handling(char *message){fputs(message, stderr);fputc(\'\\n\', stderr);exit(1);}Receiver.c:#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <arpa/inet.h>#include <sys/socket.h>#define BUF_SIZE 30void error_handling(char *message);int main(int argc, char *argv[]){int recv_sock;struct sockaddr_in adr;int str_len;char buf[BUF_SIZE];if(argc!=2) {printf(\"Usage : %s  <PORT>\\n\", argv[0]);exit(1);}recv_sock=socket(PF_INET, SOCK_DGRAM, 0);memset(&adr, 0, sizeof(adr));adr.sin_family=AF_INET;adr.sin_addr.s_addr=htonl(INADDR_ANY);adr.sin_port=htons(atoi(argv[1]));if(bind(recv_sock, (struct sockaddr*)&adr, sizeof(adr))==-1)error_handling(\"bind() error\");while(1){str_len=recvfrom(recv_sock, buf, BUF_SIZE-1, 0, NULL, 0);if(str_len<0)break;buf[str_len]=0;fputs(buf, stdout);}close(recv_sock);return 0;}void error_handling(char *message){fputs(message, stderr);fputc(\'\\n\', stderr);exit(1);}

结果：