peer.c

一个简单的p2p共享文件的程序

{
	int pong_sockfd;
	struct sockaddr_in pong_addr, recv_addr;
	int recv_addr_len;
	
	struct Message snd;//the package rcv & snd
	struct Message rcv;
	unsigned char *buf; //snd buffer
	buf=(unsigned char *)malloc(BUFMAX); //dynamic alloc mem!!!!so fucking!
	unsigned char buf2[BUFMAX];//rcv buffer


	
	//create socket
	if ((pong_sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
       		perror("create socket error!");
	}
	//set my listen port !
    	bzero((char *) &pong_addr, sizeof(pong_addr));
	pong_addr.sin_family = AF_INET;
	pong_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	pong_addr.sin_port = htons(atoi(port));  //7000 is very important!
	//bind
	if (bind(pong_sockfd, (struct sockaddr *)&pong_addr, sizeof(pong_addr)) < 0) {
        	perror("bind service socket error!");
	}
	//listen ping
	for(;;) {
		printf("In pong service...\n");
        	bzero((char *) &recv_addr, sizeof(recv_addr));//get the sender's ip
		memset(buf2,'\0', BUFMAX);
		memset(&rcv,'\0',BUFMAX);
		recvfrom(pong_sockfd, buf2, BUFMAX, 0, (struct sockaddr *) &recv_addr, &recv_addr_len);
		rcv=*(struct Message *)buf2;
		if(rcv.head==PING && strcmp(inet_ntoa(recv_addr.sin_addr),"0.0.0.0")!=0){
			printf("got, recv_ip : %s, recv_port : %d\n", inet_ntoa(recv_addr.sin_addr), ntohs(recv_addr.sin_port));
           		//send pong!
			snd.head=PRES;
			strcpy(snd.content,"\n");
			buf=(unsigned char *)&snd;
            		if (sendto(pong_sockfd, buf, BUFMAX, 0, (struct sockaddr *) &recv_addr, sizeof(recv_addr)) < 0) {
    				perror("sendto error\n");
    			}//end send
		}//end if
		//if quit then close sock
	//	printf("fuc\n");
		//printf("now is %d\n",isQuit);

	}//end for
	//printf("close pong service\n");
	//close(pong_sockfd);
	return;
};
int doPING(struct Message msg)
{
	char *peerip;
	char *peerport;
	
	//get ip port
	strtok(msg.content,"#");
	strtok(NULL,"#");
	peerip=strtok(NULL,"#");
	peerport=strtok(NULL,"\n");

	struct sockaddr_in send_addr, bcast_addr;
    	int ping_sockfd;
    	int recv_addr_len;
    	struct sockaddr_in recv_addr;
    	
	struct Message snd;//the package rcv & snd
	struct Message rcv;
	unsigned char *buf; //snd buffer
	buf=(unsigned char *)malloc(BUFMAX); //dynamic alloc mem!!!!so fucking!
	unsigned char buf2[BUFMAX];//rcv buffer

    	//create sock
    	if ((ping_sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
        	perror("create socket error");
    	}
	//set source addr
	bzero((char *) &send_addr, sizeof(send_addr));
	send_addr.sin_family = AF_INET;
	send_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	send_addr.sin_port = htons(0); //
	//bind
	if (bind(ping_sockfd, (struct sockaddr *) &send_addr, sizeof(send_addr)) < 0) {
		perror("bind socket error");
	}
	//set destinate addr
    	bzero((char *) &recv_addr, sizeof(recv_addr));
    	recv_addr.sin_family = AF_INET;
    	recv_addr.sin_addr.s_addr = inet_addr(peerip);
    	recv_addr.sin_port = htons(atoi(peerport));//change to int
	//build send buffer
	snd.head=PING;
	strcpy(snd.content,"\n");
	buf=(unsigned char *)&snd;
 	//send
    	if (sendto(ping_sockfd, buf, BUFMAX, 0, (struct sockaddr *) &recv_addr, sizeof(recv_addr)) < 0) {
        	perror("sendto error");
    	}
	//recv
	signal(SIGALRM, alarm_handler);
	alarm(5); // after 5s ,alert
 	for (;;) {
       		if (setjmp(env_alrm) != 0) {
            		break;
        	}
       		bzero((char *) &recv_addr, sizeof(recv_addr));
        	recvfrom(ping_sockfd, buf2, BUFMAX, 0, (struct sockaddr *) &recv_addr, &recv_addr_len);
        	rcv=*(struct Message *)buf2;
        	if(rcv.head==PRES){
			printf("got ping!\n");
			close(ping_sockfd);
			return 1;
		}
    	}
	printf("time out:%s\n",msg.content);
	close(ping_sockfd);
	return 0;

};
void doQUIT(int sockfd)
{
	struct Message snd;//the package rcv & snd
	unsigned char *buf; //snd buffer
	buf=(unsigned char *)malloc(BUFMAX); //dynamic alloc mem!!!!so fucking!
	
	snd.head=QUIT;
	strcpy(snd.content,"\n");
	buf=(unsigned char *)&snd;
        printf("send %d bytes\n",write(sockfd, buf, BUFMAX));
};
void doSRCH(int sockfd)
{
	struct Message snd;//the package rcv & snd
	unsigned char *buf; //snd buffer
	buf=(unsigned char *)malloc(BUFMAX); //dynamic alloc mem!!!!so fucking!
	
	char filename[20];
	
	snd.head=SRCH;
	printf("search file:");
	gets(filename);
	strcpy(snd.content,filename);
	strcat(snd.content,"\n");
	printf("look content:%s",snd.content);//test
	buf=(unsigned char *)&snd;
        printf("send %d bytes\n",write(sockfd, buf, BUFMAX));
	
};
void doSRES(struct Message msg)
{
	char *temp;
	temp=strtok(msg.content,"#");
	printf("ENTER doSRES:%s\n");
	printf("file:%s",temp);
	temp=strtok(NULL,"#");
	printf(" user:%s",temp);
	temp=strtok(NULL,"#");
	printf(" ip:%s",temp);
	temp=strtok(NULL,"#");
	printf(" port:%s\n",temp);

	
	
};
void doSHRE(int sockfd)
{
	struct Message snd;//the package rcv & snd
	unsigned char *buf; //snd buffer
	buf=(unsigned char *)malloc(BUFMAX); //dynamic alloc mem!!!!so fucking!
	
	char filename[20];
//	char port[10]="7001";

	FILE *file;
	if((file=fopen(nowusername,"a+"))==NULL)
		printf("can not open file\n");
	
	snd.head=SHRE;
	//printf("your port number:");
	//gets(port);
	strcpy(snd.content,port);
	printf("your filename:");
	gets(filename);
	while(filename[0]!='\0'){
		printf("your filename:");
		strcat(snd.content,"#");
		strcat(snd.content,filename);	
		//share list add
		fwrite(filename,1,strlen(filename),file);//copy to file
		fwrite("\n",1,strlen("\n"),file);

		gets(filename);	
	}
	fclose(file);//close file!
	strcat(snd.content,"\n");
	printf("content:%s",snd.content);//test
	buf=(unsigned char *)&snd;
        printf("send %d bytes\n",write(sockfd, buf, BUFMAX));
	
};
void doLGIN(int sockfd)
{
	struct Message snd;//the package rcv & snd
	unsigned char *buf; //snd buffer
	buf=(unsigned char *)malloc(BUFMAX); //dynamic alloc mem!!!!so fucking!


	char password[20];
	char usrpwd[50];
	char *splits="#";//temp
	int i;
	int seed;
	char *charseed;
	charseed=(char *)malloc(1);

	//ini the encrypt seed
	srand((unsigned)time(NULL));
	seed=rand()%9+1;
	charseed[0]=seed+'0';
	
	//log in!
 	memset(&snd,'\0', BUFMAX);
	memset(buf,'\0', BUFMAX);
	snd.head=LGIN;
	//get the username+password;
	printf("Login:");
	gets(nowusername);
	printf("Password:");
	gets(password);
	//scrype the password
	strcpy(snd.content,nowusername);
	strcat(snd.content,splits);
	strcat(snd.content,charseed);
	for(i=0;i<strlen(password);i++)
		password[i]-=seed;
	strcat(snd.content,password);
	printf("content:%s\n",snd.content);//test
	buf=(unsigned char *)&snd;
        printf("send %d bytes\n",write(sockfd, buf, BUFMAX));
};
int main()
{
	/////////do ipc//////////////////////

	//////////////////////////////////////
    	int sockfd;
	struct sockaddr_in target_addr;
	unsigned char buf2[BUFMAX];
	pid_t pid;//for one ping
	pid_t pid2;//for ping pong listen service!
	pid_t pid3;//for file service!

	struct Message msg;//the package rcv & snd

	int flag=0;//log on success flag;
	char input[100];  //choice of menu!
	char choice[10];// weather to download file!
 
	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < -1) {
		perror("create socket error");
	}
	//set the server addr
	bzero(&target_addr, sizeof(target_addr));
	target_addr.sin_family = AF_INET;
	target_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
	target_addr.sin_port = htons(8092);
	
	printf("Welcome, hello!\n");

	if (connect(sockfd, (struct sockaddr *)&target_addr, sizeof(target_addr)) < -1) {
		perror("connect error");
	}

	doLGIN(sockfd);
	// read
   	for (;;) {
		memset(&msg,'\0', sizeof(&msg));
		memset(buf2,'\0', sizeof(buf2));
		printf("read %d bytes\n",read(sockfd, buf2, BUFMAX));
		msg=*(struct Message *)buf2;
		if(msg.head==ERROR){
			printf("%d,%s\n",msg.head,msg.content);
			break;
		}else if(msg.head==LRES){
			printf("%d,%s\n",msg.head,msg.content);	
			flag=1;
			break;
		}
   	}
	//if lgin sucuss
	if(flag){
	    //build up ping pong service!
	     printf("input your listen port number:");
	     gets(port);
	    /////////fork///////////////
	    pid2=fork();
	    if(pid2>0){}
	    else if(pid2==0){
		//isQuit=0;
	    	doPRES();
	    }else {perror("fork error");}
	    ///////end fork/////////////////////
	    /////////fork///to file////////////
	    pid3=fork();
	    if(pid3>0){}
	    else if(pid3==0){
	    	doFILE();
	    }else {perror("fork error");}
	    ///////end fork/////////////////////
	    while(1){
		printf("Log in sucuss,please input your order(1=share,2=search,3=quit):");
		gets(input);
		if(input[0]=='1') //share
			doSHRE(sockfd);
		else if(input[0]=='2')//search
			doSRCH(sockfd);
		else if(input[0]=='3'){//quit
			doQUIT(sockfd);
			//isQuit=1;
			kill(pid2,9);
			kill(pid3,9);
			break;
		}//end if
		//read respose
		while(1){
			memset(&msg,'\0', sizeof(&msg));
			memset(buf2,'\0', sizeof(buf2));
			printf("read %d bytes\n",read(sockfd, buf2, BUFMAX));
			msg=*(struct Message *)buf2;
			if(msg.head==ERROR){
				printf("%d,%s\n",msg.head,msg.content);
				break;
			}else if(msg.head==SHOK){
				printf("%d,%s\n",msg.head,"Share file sucuss");	
				break;
			}else if(msg.head==SRES){
			//	printf("%d,%s\n",msg.head,msg.content);	
				if(strncmp("\n",msg.content,strlen("\n"))==0)
					break;
				doSRES(msg);
				//ping
				if(doPING(msg)==1){
					printf("ping yes:%s\n",msg.content);
					//download
					printf("do you want to download ?(y/n):");
					gets(choice);
					if(choice[0]=='y')	
						doGETF(msg);
				}

			}
		//	if(msg.head!=0)
		//		printf("head is %d",msg.head);
		}//end while read
	    }//end while get order		
	}//end if flag
	close(sockfd);
    return 0;
}