C语言 LINUX 环境下 socket UDP 服务器客户端发送信息

服务器

#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>

#define MAXLINE 1024
#define SERV_PORT 8000

struct MSG_PACK
{
char cmd;
char status;
short int len;
};

struct host
{
char UserName[20];
char Host[20];
char IP[20];
char PassWord [20];
char SubNet[512];
char Mode;
char ConState;
char Pin[20];
char ConTrol;
char RandPassword[10];
};

int main(void)
{
int sockfd;
struct sockaddr_in servaddr, cliaddr;

sockfd = socket(AF_INET, SOCK_DGRAM, 0); /* create a socket */

/* init servaddr */
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = htons(SERV_PORT);

/* bind address and port to socket */
if(bind(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) == -1)
{
perror("bind error");
exit(1);
}

do_echo(sockfd, (struct sockaddr *)&cliaddr, sizeof(cliaddr));

close(sockfd);
return 0;
}

void do_echo(int sockfd, struct sockaddr *pcliaddr, socklen_t clilen)
{

int n;
socklen_t len;
char mesg[MAXLINE];

for(;;)
{
len = clilen;

/* waiting for receive data */
n = recvfrom(sockfd, mesg, MAXLINE, 0, pcliaddr, &len);
//mesg
='/0';

printf ("^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^n:%d len=%d/n",n,len);
struct MSG_PACK pocket;

memcpy(&pocket,mesg,sizeof(struct MSG_PACK));

printf("$$$$$$$$$$$$$$/n-----pocket1------->%d/n",pocket.cmd);

printf("-----pocket2------->%d/n",pocket.status);

printf("-----pocket3------->%d/n$$$$$$$$$$$$$$$/n",pocket.len);

struct host sHost2 ;
memcpy(&sHost2 , mesg + sizeof(struct MSG_PACK) , sizeof(struct host));
printf("&&&&&&&&&&&&&&&&&&&&/n-----sHost1------->%s/n",sHost2.UserName);
printf("-----sHost2------->%s/n",sHost2.Host);
printf("-----sHost3------->%s/n",sHost2.IP);
printf("-----sHost4------->%s/n",sHost2.PassWord);
printf("-----sHost5------->%s/n",sHost2.SubNet);
printf("-----sHost6------->%d/n",sHost2.Mode);
printf("-----sHost7------->%d/n",sHost2.ConState);
printf("-----sHost8------->%s/n",sHost2.Pin);
printf("-----sHost9------->%d/n",sHost2.ConTrol);
printf("-----sHost10------->%s/n&&&&&&&&&&&&&&&&&&&&/n",sHost2.RandPassword);

/* sent data back to client */
n = sendto(sockfd, mesg, n, 0, pcliaddr, len);

}

}

客户端：


#include <stdio.h>


#include <stdlib.h>


#include <string.h>


#include <sys/types.h>


#include <netinet/in.h>


#include <sys/socket.h>


#include <arpa/inet.h>


#include <unistd.h>




#define minornode 0 //从节点向主节点发送连接请求


#define hostnode_return 1 //主节点响应从节点的请求


#define minornode_change 2 //从节点向主节点发送更新请求


#define hostnode_returnchange 3 //主节点响应更新请求




//包头的定义


struct MSG_PACK




...{


char cmd;


char status;


short int len;


};








//定义host


struct host




...{


char UserName[20];


char Host[20];


char IP[20];


char PassWord [20];


char SubNet[512];


char Mode;


char ConState;


char Pin[20];


char ConTrol;


char RandPassword[10];


};




int main()




...{


char sentbuf[1024];




struct host newhost;




memset(&newhost,0,sizeof(struct host));




strcpy(newhost.UserName,"aaaa");


strcpy(newhost.Host,"www");


strcpy(newhost.IP,"192.168.8.103");


strcpy(newhost.PassWord,"1111");


strcpy(newhost.SubNet,"255.255.255.0");


newhost.Mode=0;


newhost.ConState=1;


strcpy(newhost.Pin,"20");


newhost.ConTrol=0;


strcpy(newhost.RandPassword,"122122");


//printf("@@@@@@@@@@@@@@@@@@@@@@@@@@@@ %s %s %s %s %s %d %d %s %d %s @@@@@@@@@@@@@@@@@@@@@@@@@@@@ ",newhost.UserName,newhost.Host,newhost.IP,newhost.PassWord,newhost.SubNet,newhost.Mode,newhost.ConState,newhost.Pin,newhost.ConTrol,newhost.RandPassword);




struct MSG_PACK newpack;


newpack.cmd=1;


newpack.status=1;


newpack.len=sizeof(newhost);


//printf("@@@@@@@@@@@@@@@@@@@@@@@@@@@@ %d %d %d @@@@@@@@@@@@@@@@@@@@@@@@@@@ ",newpack.cmd,newpack.status,newpack.len);


memcpy(sentbuf,&newpack,sizeof(struct MSG_PACK));


memcpy(sentbuf+sizeof(struct MSG_PACK),&newhost,sizeof(struct host));


int iLen = sizeof(struct MSG_PACK)+ sizeof(struct host);


printf("-=-=-=-=-=-=-=-=-=-=-=-=%d ",iLen);


int sock;


//sendto中使用的对方地址


struct sockaddr_in servaddr;


//在recvfrom中使用的对方主机地址


struct sockaddr_in fromAddr;






unsigned int fromLen;


char recvBuffer[1024];


sock = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);


memset(&servaddr,0,sizeof(servaddr));


servaddr.sin_family=AF_INET;


servaddr.sin_addr.s_addr=inet_addr("192.168.8.200");


servaddr.sin_port = htons(8000);


if(sendto(sock,sentbuf,iLen,0,(struct sockaddr*)&servaddr,sizeof(servaddr)) != iLen)




...{


perror("sendto error");


close(sock);


exit(1);


}


fromLen = sizeof(fromAddr);


if(recvfrom(sock,recvBuffer,1024,0,(struct sockaddr*)&fromAddr,&fromLen)<0)




...{


perror("recvfrom error");


close(sock);


exit(1);


}


struct MSG_PACK pocket;


memcpy(&pocket , recvBuffer , sizeof(struct MSG_PACK));




printf("-----pocket1------->%d ",pocket.cmd);


printf("-----pocket2------->%d ",pocket.status);


printf("-----pocket3------->%d ",pocket.len);




struct host sHost2 ;


memcpy(&sHost2 , recvBuffer + sizeof(struct MSG_PACK) , sizeof(struct host));


printf("&&&&&&&&&&&&&&&&&&&& -----sHost1------->%s ",sHost2.UserName);


printf("-----sHost2------->%s ",sHost2.Host);


printf("-----sHost3------->%s ",sHost2.IP);


printf("-----sHost4------->%s ",sHost2.PassWord);


printf("-----sHost5------->%s ",sHost2.SubNet);


printf("-----sHost6------->%d ",sHost2.Mode);


printf("-----sHost7------->%d ",sHost2.ConState);


printf("-----sHost8------->%s ",sHost2.Pin);


printf("-----sHost9------->%d ",sHost2.ConTrol);


printf("-----sHost10------->%s &&&&&&&&&&&&&&&&&&&& ",sHost2.RandPassword);




close(sock);


return 0;


}