Linux下TCP、UDP、UDP广播通信代码及运行

一、网络环境配置

网络通信方式可选择一台主机里的两个虚拟机，也可以两台主机里的两个虚拟机，本文采用方式二。

主机一IP地址为192.168.1.109

主机二IP地址为192.168.1.24

必须使两台主机在一个网段内，并且可以ping通才可进行以下 *** 作。

二、TCP连接

客户端（主机一）代码

TCP_client.c

#include 
#include 
#include 
#include 
#include 
#include 
#include 
int main(int argc, char *argv[])
{
	unsigned short port = 8000; 
	char *server_ip = "192.168.1.24";   //设置第二个主机ip地址为服务器地址，进行TCP通信
	char send_buf[512] = "hello every!"; //设置发送的内容
	char recv_buf[512] = "";
	int sockfd = 0;
	int err_log = 0;
	struct sockaddr_in server_addr;
	if( argc > 1 ) 
		server_ip = argv[1];
	if( argc > 2 ) 
		port = atoi(argv[2]);
	bzero(&server_addr,sizeof(server_addr)); 
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(port);
	inet_pton(AF_INET, server_ip, &server_addr.sin_addr);
	sockfd = socket(AF_INET, SOCK_STREAM, 0); 
	if(sockfd < 0)
	{
		perror("socket");
		exit(-1);
	}
	err_log = connect(sockfd, (struct sockaddr*)&server_addr, sizeof(server_addr));
	if(err_log != 0)
	{
		perror("connect");
		close(sockfd);
		exit(-1);
	}
	send(sockfd, send_buf, strlen(send_buf), 0); 
	recv(sockfd, recv_buf, sizeof(recv_buf), 0); 
	printf("%s\n", recv_buf);
	close(sockfd);
	return 0;
}

服务器端（主机二）代码

TCP_server.c

#include 
#include 
#include 
#include 
#include 
#include 
#include 
int main(int argc, char *argv[])
{
	char recv_buf[2048] = ""; 
	int sockfd = 0; 
	int connfd = 0;
	int err_log = 0;
	struct sockaddr_in my_addr; 
	unsigned short port = 8000; 
	if(argc > 1) 
		port = atoi(argv[1]);
	printf("TCP Server Started at port %d!\n", port);
	sockfd = socket(AF_INET, SOCK_STREAM, 0); 
	if(sockfd < 0)
	{
		perror("socket");
		exit(-1);
	}
	bzero(&my_addr, sizeof(my_addr)); 
	my_addr.sin_family = AF_INET;
	my_addr.sin_port = htons(port);
	my_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	printf("Binding server to port %d\n", port);
	err_log = bind(sockfd, (struct sockaddr*)&my_addr, sizeof(my_addr));
	if( err_log != 0)
	{
		perror("binding");
		close(sockfd);
		exit(-1);
	}
	err_log = listen(sockfd, 10);
	if(err_log != 0)
	{
		perror("listen");
		close(sockfd);
		exit(-1);
	}
	printf("Waiting client...\n");
	while(1)
	{
		size_t recv_len = 0;
		struct sockaddr_in client_addr; 
		char cli_ip[INET_ADDRSTRLEN] = ""; 
		socklen_t cliaddr_len = sizeof(client_addr); 
		connfd = accept(sockfd, (struct sockaddr*)&client_addr, &cliaddr_len); 
		if(connfd < 0)
		{
			perror("accept");
			continue;
		}
		inet_ntop(AF_INET, &client_addr.sin_addr, cli_ip, INET_ADDRSTRLEN);
		printf("client ip = %s\n", cli_ip);
		
		while((recv_len = recv(connfd, recv_buf, sizeof(recv_buf), 0)) > 0)
			send(connfd, recv_buf, recv_len, 0);
			printf("%s\n",recv_buf);
		close(connfd); 
		printf("client closed!\n");
	}
	close(sockfd); 
	return 0;
}

客户端输入代码

gcc TCP_client.c -o TCP_client
./TCP_clent

服务器端输入代码

gcc TCP_server.c -o TCP_server
./TCP_server

 三、UDP连接

 客户端（主机一）代码

UDP_client.c

#include 
#include 
#include 
#include 
#include 
#include 
#include 

int main (int argc, char *argv[])
{
	int sockfd = 0;
	struct sockaddr_in server_addr;
	unsigned short port = 8000;
	char *ser_ip = "192.168.1.24";

	if(argc >1)
		ser_ip = argv[1];
	if(argc >2)
		port = atoi(argv[2]);
    
	sockfd = socket (AF_INET, SOCK_DGRAM, 0);
	if(sockfd < 0)
	{
		perror("socket error!");
		exit(-1);
	}

	bzero (&server_addr, sizeof(server_addr));
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(port);
	inet_pton(AF_INET, ser_ip,&server_addr.sin_addr);

	printf("ready send data to UDP server %s:%d!\n",ser_ip,port);
	while (1)
	{
		char send_buf[2048] = "";
		int len = 0;

		fgets(send_buf, sizeof(send_buf),stdin);
		send_buf[strlen(send_buf)-1] ='

'; sendto(sockfd, send_buf, strlen(send_buf),0,(struct sockaddr*)&server_addr,sizeof(server_addr)); len = recvfrom(sockfd, send_buf, sizeof(send_buf),0,NULL,NULL); printf("%s\n",send_buf); } close(sockfd); return 0; }

服务器端（主机二）代码

UDP_server.c

 
#include 
#include 
#include 
#include 
#include 
#include < 0)
	{
		perror("socket error");
		exit(-1);
	}

	bzero(&bind_addr, sizeof(bind_addr));
	bind_addr.sin_family = AF_INET;
	bind_addr.sin_port = htons(port);
	bind_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	
	printf("Binding server to port %d\n", port);
	error_log = bind(sockfd, (struct  sockaddr *)&bind_addr, sizeof(bind_addr));
  	if (error_log  != 0)
	{
		perror("bind error");
		close(sockfd);
		exit(-1);
	}

	printf("waiting data from other client...\n");
	while(1)
	{
		char recv_buf[1024] = "";
		char cli_ip[INET_ADDRSTRLEN] = "";
		int recv_len =0;
		struct sockaddr_in client_addr;
		socklen_t client_addr_len = sizeof(client_addr);

		recv_len = recvfrom(sockfd, recv_buf,sizeof(recv_buf), 0 ,(struct sockaddr*)&client_addr,&client_addr_len);

		inet_ntop(AF_INET, &client_addr.sin_addr,cli_ip,INET_ADDRSTRLEN);
		printf("clinet ip = %s\n", cli_ip);
		printf("recver message :%s\n",recv_buf);
		sendto(sockfd, recv_buf,recv_len,0,(struct sockaddr*)&client_addr,&client_addr_len);
	}
	close(sockfd);
  	return 0;
  
}
#include 

int main(int argc, char *argv[])
{
	int sockfd = 0;
	int error_log = 0;
	struct sockaddr_in bind_addr;
	unsigned short port = 8000;
    
	if (argc > 1)
		port = atoi(argv[1]);
	printf("UDP server Started!\n");

	sockfd = socket(AF_INET, SOCK_DGRAM,0);
	if (sockfd 

客户端输入代码

gcc UDP_client.c -o UDP_client ./UDP_client hello

 服务器端输入代码

gcc UDP_server.c -o UDP_server ./UDP_server

 四、UDP广播

发送端（主机一）代码

send.c

 
#include 
#include 
#include 
#include 
#include 
#include 
#include < 0){
		perror("socket create error");
		exit(1);
	}
	int flag = 1;
	setsockopt(lfd, SOL_SOCKET, SO_BROADCAST | SO_REUSEADDR, &flag, sizeof(flag) );

	caddr.sin_family = AF_INET;
	caddr.sin_port = htons(4001);
	caddr.sin_addr.s_addr = inet_addr("192.168.1.255");
	clen = sizeof(caddr);
	
		int n = sendto(lfd, msg, strlen(msg), 0, (struct sockaddr *)&caddr, clen);
		if(n  < 0){
			perror("sendto Error:");
			exit(1);
		}
		close(lfd);
	return 0;
}

#include 

int main(){
	char msg[128] = "I am broadCast message from server!";
	
	struct sockaddr_in saddr, caddr;
	socklen_t slen, clen;
	int lfd, ret;

	lfd = socket(AF_INET, SOCK_DGRAM, 0);
	if(lfd 

接收端（主机二）代码

recv.c

 
#include
#include
#include
#include
#include
#include
#include
#include
#include
int main(){
	int sockListen;
	if((sockListen = socket(AF_INET, SOCK_DGRAM, 0)) == -1){
		printf("socket fail\n");
		return -1;
	}
	int set = 1;
	setsockopt(sockListen, SOL_SOCKET, SO_REUSEADDR, &set, sizeof(int));
	struct sockaddr_in recvAddr;
	memset(&recvAddr, 0, sizeof(struct sockaddr_in));
	recvAddr.sin_family = AF_INET;
	recvAddr.sin_port = htons(4001);
	recvAddr.sin_addr.s_addr = INADDR_ANY;
	
	if(bind(sockListen, (struct sockaddr *)&recvAddr, sizeof(struct sockaddr)) == -1){
		printf("bind fail\n");
		return -1;
	}
	int recvbytes;
	char recvbuf[128];
	int addrLen = sizeof(struct sockaddr_in);
	if((recvbytes = recvfrom(sockListen, recvbuf, 128, 0,
		(struct sockaddr *)&recvAddr, &addrLen)) != -1){
		recvbuf[recvbytes] = '\0';
		printf("receive a broadCast messgse:%s\n", recvbuf);
	}else{
		printf("recvfrom fail\n");
	}
	close(sockListen);
	return 0;
}

发送端输入代码

gcc send.c -o send ./send

接收端输入代码

gcc recv.c -o recv ./recv