[Anet-checkins] CVS: ANet/ANet_Daemon/Linux/Samples AsyncTCPServer.c,NONE,1.1 AsyncUDPServer.c,NONE,1.1 SyncTCPServer.c,NONE,1.1 SyncUDPServer.c,NONE,1.1 TCPClient.c,NONE,1.1 UDPClient.c,NONE,1.1

[Prasanna G. <gpr...@us...>]

Update of /cvsroot/anet/ANet/ANet_Daemon/Linux/Samples
In directory usw-pr-cvs1:/tmp/cvs-serv31581

Added Files:
	AsyncTCPServer.c AsyncUDPServer.c SyncTCPServer.c 
	SyncUDPServer.c TCPClient.c UDPClient.c 
Log Message:
""

--- NEW FILE: AsyncTCPServer.c ---
#include <stdio.h>      /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket(), bind(), and connect() */
#include <arpa/inet.h>  /* for sockaddr_in and inet_ntoa() */
#include <stdlib.h>     /* for atoi() */
#include <string.h>     /* for memset() */
#include <unistd.h>     /* for close() */

#define MAXPENDING 5    /* Maximum outstanding connection requests */
#define RCVBUFSIZE 11   /* Size of receive buffer */

void DieWithError(char *errorMessage) {	/* Error handling function */
    perror(errorMessage);
    exit(1);
}


int main(int argc, char *argv[]) {

    int servSock;                    /* Socket descriptor for server */
    int clntSock;                    /* Socket descriptor for client */
    struct sockaddr_in servAddr; /* Local address */
    struct sockaddr_in clntAddr; /* Client address */
	fd_set rset,wset;				/* File Descriptor for read and write */
    unsigned short servPort;     /* Server port */
    unsigned int clntLen;            /* Length of client address data structure */
	struct timeval tv = {0,0};		/* Timeout value for select */
	
	char sendBuffer[RCVBUFSIZE];        /* Buffer for send string */
    int recvMsgSize;                    /* Size of received message */
	int noOfPacktoSend;					/* No of Packet to send */
	char recvBuffer[RCVBUFSIZE];        /* Buffer for receving string */

    if (argc != 2)     /* Test for correct number of arguments */
    {
        fprintf(stderr, "Usage:  %s <Server Port>\n", argv[0]);
        exit(1);
    }

    servPort = atoi(argv[1]);  /* First arg:  local port */

    /* Create socket for incoming connections */
    if ((servSock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
        DieWithError("socket() failed");
      
    /* Construct local address structure */
    memset(&servAddr, 0, sizeof(servAddr));   /* Zero out structure */
    servAddr.sin_family = AF_INET;                /* Internet address family */
    servAddr.sin_addr.s_addr = htonl(INADDR_ANY); /* Any incoming interface */
    servAddr.sin_port = htons(servPort);      /* Local port */

    /* Bind to the local address */
    if (bind(servSock, (struct sockaddr *) &servAddr, sizeof(servAddr)) < 0)
        DieWithError("bind() failed");

    /* Mark the socket so it will listen for incoming connections */
    if (listen(servSock, MAXPENDING) < 0)
        DieWithError("listen() failed");
	
	/* Set the size of the in-out parameter */
    clntLen = sizeof(clntAddr);

    /* Wait for a client to connect */
    if ((clntSock = accept(servSock, (struct sockaddr *) &clntAddr, 
                               &clntLen)) < 0)
       DieWithError("accept() failed");

    /* clntSock is connected to a client! */
	
	/* Receive message from client */
    if ((recvMsgSize = recv(clntSock, recvBuffer, RCVBUFSIZE, 0)) < 0)
        DieWithError("recv() failed");
	
	noOfPacktoSend = (int) atoi(recvBuffer);
	printf("No of Packets to send = %d\n",noOfPacktoSend);

    /* Send received string and receive again until end of transmission */
	
	while(1) {
		FD_ZERO(&rset);
		FD_ZERO(&wset);
		FD_SET(clntSock,&rset);
		FD_SET(clntSock,&wset);
		select(clntSock+1,&rset,&wset,NULL,&tv);
		if (FD_ISSET(clntSock,&rset)) {
			/* See if there is more data to receive */
			if ((recvMsgSize = recv(clntSock, recvBuffer, RCVBUFSIZE,0)) < 0)
				 DieWithError("recv() failed");
			recvBuffer[recvMsgSize] ='\0';
			sleep(5);
			printf("receiving : %s\n",recvBuffer);
			if (!strcmp(recvBuffer,"Closed") || recvMsgSize > 3)
				break;
		}
		if (FD_ISSET(clntSock,&wset)) {
			if (noOfPacktoSend >= 0) {
				memset(sendBuffer,0,RCVBUFSIZE);
				if (!noOfPacktoSend) {
					strcpy(sendBuffer,"Disconnect");
				} else {
					sprintf(sendBuffer,"%10d",rand() % 1000);
				}
				if (send(clntSock, sendBuffer, strlen(sendBuffer), 0) != strlen(sendBuffer))
					DieWithError("send() failed");
				noOfPacktoSend--;
				printf("Sending : %s\n",sendBuffer);
			}
		}
	}
	close(clntSock);
}


--- NEW FILE: AsyncUDPServer.c ---
#include <stdio.h>      /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket() and bind() */
#include <arpa/inet.h>  /* for sockaddr_in and inet_ntoa() */
#include <stdlib.h>     /* for atoi() */
#include <string.h>     /* for memset() */
#include <unistd.h>     /* for close() */

#define STRMAX 10     /* Longest string to send or receive */

void DieWithError(char *errorMessage)	 /* External error handling function */
{
    perror(errorMessage);
    exit(1);
} 

int main(int argc, char *argv[])
{
    int sock;                        /* Socket */
    struct sockaddr_in servAddr;	 /* Local address */
    struct sockaddr_in clntAddr;	 /* Client address */
	fd_set rset,wset;				/* File Descriptor for read and write */
    unsigned int cliAddrLen;         /* Length of incoming message */
    char sendBuffer[STRMAX];         /* Buffer for send and receiving string */
    unsigned short servPort; 	     /* Server port */
    int recvMsgSize;                 /* Size of received message */
	int noOfPacktoSend;				 /* No of Pack to be send */
	struct timeval tv = {0,0};		/* Timeout value for select */
	

    if (argc != 2)         /* Test for correct number of parameters */
    {
        fprintf(stderr,"Usage:  %s <UDP SERVER PORT>\n", argv[0]);
        exit(1);
    }

    servPort = atoi(argv[1]);  /* First arg:  local port */

    /* Create socket for sending/receiving datagrams */
    if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
        DieWithError("socket() failed");

    /* Construct local address structure */
    memset(&servAddr, 0, sizeof(servAddr));   /* Zero out structure */
    servAddr.sin_family = AF_INET;                /* Internet address family */
    servAddr.sin_addr.s_addr = htonl(INADDR_ANY); /* Any incoming interface */
    servAddr.sin_port = htons(servPort);      /* Local port */

    /* Bind to the local address */
    if (bind(sock, (struct sockaddr *) &servAddr, sizeof(servAddr)) < 0)
        DieWithError("bind() failed");
  
    /* Set the size of the in-out parameter */
    cliAddrLen = sizeof(clntAddr);

    /* Block until receive message from a client */
    if ((recvMsgSize = recvfrom(sock, sendBuffer, STRMAX, 0,
            (struct sockaddr *) &clntAddr, &cliAddrLen)) < 0)
        DieWithError("recvfrom() failed");

    printf("Handling client %s\n", inet_ntoa(clntAddr.sin_addr));

	noOfPacktoSend = (int) atoi(sendBuffer);
	printf("No of UDP Packets to send = %d\n",noOfPacktoSend);

	while(1) {
		FD_ZERO(&rset);
		FD_ZERO(&wset);
		FD_SET(sock,&rset);
		FD_SET(sock,&wset);
		select(sock+1,&rset,&wset,NULL,&tv);
		if (FD_ISSET(sock,&wset)) {
			if (noOfPacktoSend >= 0) {
				if (!noOfPacktoSend) {
					strcpy(sendBuffer,"Disconnect");
				} else {
					sprintf(sendBuffer,"%9d",rand() % 1000);
				}
					/* Send received datagram back to the client */
				if (sendto(sock, sendBuffer, strlen(sendBuffer), 0, 
						(struct sockaddr *) &clntAddr, sizeof(clntAddr)) != strlen(sendBuffer))
					DieWithError("sendto() sent a different number of bytes than expected");
				printf("Sending : %s\n",sendBuffer);
				noOfPacktoSend--;
			}
		}
		if (FD_ISSET(sock,&rset)) {
			if ((recvMsgSize = recvfrom(sock, sendBuffer, STRMAX, 0,
					(struct sockaddr *) &clntAddr, &cliAddrLen)) < 0)
				DieWithError("recvfrom() failed");
			sendBuffer[recvMsgSize] = '\0';
			printf("Receiving : %s\n",sendBuffer);
			if (!strcmp(sendBuffer,"Closed"))
				break;
		}
    }
	close(sock);
    /* NOT REACHED */
}

--- NEW FILE: SyncTCPServer.c ---
#include <stdio.h>      /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket(), bind(), and connect() */
#include <arpa/inet.h>  /* for sockaddr_in and inet_ntoa() */
#include <stdlib.h>     /* for atoi() */
#include <string.h>     /* for memset() */
#include <unistd.h>     /* for close() */

#define MAXPENDING 5    /* Maximum outstanding connection requests */
#define RCVBUFSIZE 11   /* Size of receive buffer */

void DieWithError(char *errorMessage) {	/* Error handling function */
    perror(errorMessage);
    exit(1);
}


int HandleTCPClient(int clntSocket) {  /* TCP client handling function */
    char sendBuffer[RCVBUFSIZE];        /* Buffer for send string */
    int recvMsgSize;                    /* Size of received message */
	int noOfPacktoSend;					/* No of Packet to send */
	char recvBuffer[RCVBUFSIZE];        /* Buffer for receving string */

    /* Receive message from client */
    if ((recvMsgSize = recv(clntSocket, recvBuffer, RCVBUFSIZE, 0)) < 0)
        DieWithError("recv() failed");
	
	noOfPacktoSend = (int) atoi(recvBuffer);
	printf("No of Packets to send = %d\n",noOfPacktoSend);

    /* Send received string and receive again until end of transmission */
    while (1)      /* zero indicates end of transmission */
    {
		memset(sendBuffer,0,RCVBUFSIZE);
		if (!noOfPacktoSend) {
			strcpy(sendBuffer,"Disconnect");
		} else {
			sprintf(sendBuffer,"%5d",rand() % 1000 );
		}
		
		if (send(clntSocket, sendBuffer, strlen(sendBuffer), 0) != strlen(sendBuffer))
			DieWithError("send() failed");
			
		    /* See if there is more data to receive */
		if ((recvMsgSize = recv(clntSocket, recvBuffer, RCVBUFSIZE,0)) < 0)
			 DieWithError("recv() failed");
		recvBuffer[recvMsgSize] ='\0';
		
		printf("Sending : %s\tReceiving : %s\n",sendBuffer,recvBuffer);
			
		if (!strcmp(recvBuffer,"Closed"))
			break;
		
		noOfPacktoSend--;
		
    }

    close(clntSocket);    /* Close client socket */
	return 1;
}

int main(int argc, char *argv[]) {
    int servSock;                    /* Socket descriptor for server */
    int clntSock;                    /* Socket descriptor for client */
    struct sockaddr_in servAddr; /* Local address */
    struct sockaddr_in clntAddr; /* Client address */
    unsigned short servPort;     /* Server port */
    unsigned int clntLen;            /* Length of client address data structure */

    if (argc != 2)     /* Test for correct number of arguments */
    {
        fprintf(stderr, "Usage:  %s <Server Port>\n", argv[0]);
        exit(1);
    }

    servPort = atoi(argv[1]);  /* First arg:  local port */

    /* Create socket for incoming connections */
    if ((servSock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
        DieWithError("socket() failed");
      
    /* Construct local address structure */
    memset(&servAddr, 0, sizeof(servAddr));   /* Zero out structure */
    servAddr.sin_family = AF_INET;                /* Internet address family */
    servAddr.sin_addr.s_addr = htonl(INADDR_ANY); /* Any incoming interface */
    servAddr.sin_port = htons(servPort);      /* Local port */

    /* Bind to the local address */
    if (bind(servSock, (struct sockaddr *) &servAddr, sizeof(servAddr)) < 0)
        DieWithError("bind() failed");

    /* Mark the socket so it will listen for incoming connections */
    if (listen(servSock, MAXPENDING) < 0)
        DieWithError("listen() failed");

    for (;;) /* Run forever */
    {
        /* Set the size of the in-out parameter */
        clntLen = sizeof(clntAddr);

        /* Wait for a client to connect */
        if ((clntSock = accept(servSock, (struct sockaddr *) &clntAddr, 
                               &clntLen)) < 0)
            DieWithError("accept() failed");

        /* clntSock is connected to a client! */

        printf("Handling client %s\n", inet_ntoa(clntAddr.sin_addr));

        if (HandleTCPClient(clntSock))
			break;
    }
    /* NOT REACHED */
}

--- NEW FILE: SyncUDPServer.c ---
#include <stdio.h>      /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket() and bind() */
#include <arpa/inet.h>  /* for sockaddr_in and inet_ntoa() */
#include <stdlib.h>     /* for atoi() */
#include <string.h>     /* for memset() */
#include <unistd.h>     /* for close() */

#define STRMAX 255     /* Longest string to send or receive */

void DieWithError(char *errorMessage)	 /* External error handling function */
{
    perror(errorMessage);
    exit(1);
} 

int main(int argc, char *argv[])
{
    int sock;                        /* Socket */
    struct sockaddr_in servAddr;	 /* Local address */
    struct sockaddr_in clntAddr;	 /* Client address */
    unsigned int cliAddrLen;         /* Length of incoming message */
    char sendBuffer[STRMAX];         /* Buffer for send and receiving string */
    unsigned short servPort; 	     /* Server port */
    int recvMsgSize;                 /* Size of received message */
	int noOfPacktoSend;				 /* No of Pack to be send */
	

    if (argc != 2)         /* Test for correct number of parameters */
    {
        fprintf(stderr,"Usage:  %s <UDP SERVER PORT>\n", argv[0]);
        exit(1);
    }

    servPort = atoi(argv[1]);  /* First arg:  local port */

    /* Create socket for sending/receiving datagrams */
    if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
        DieWithError("socket() failed");

    /* Construct local address structure */
    memset(&servAddr, 0, sizeof(servAddr));   /* Zero out structure */
    servAddr.sin_family = AF_INET;                /* Internet address family */
    servAddr.sin_addr.s_addr = htonl(INADDR_ANY); /* Any incoming interface */
    servAddr.sin_port = htons(servPort);      /* Local port */

    /* Bind to the local address */
    if (bind(sock, (struct sockaddr *) &servAddr, sizeof(servAddr)) < 0)
        DieWithError("bind() failed");
  
    for (;;) /* Run forever */
    {
        /* Set the size of the in-out parameter */
        cliAddrLen = sizeof(clntAddr);

        /* Block until receive message from a client */
        if ((recvMsgSize = recvfrom(sock, sendBuffer, STRMAX, 0,
            (struct sockaddr *) &clntAddr, &cliAddrLen)) < 0)
            DieWithError("recvfrom() failed");

        printf("Handling client %s\n", inet_ntoa(clntAddr.sin_addr));

		noOfPacktoSend = (int) atoi(sendBuffer);
		printf("No of UDP Packets to send = %d\n",noOfPacktoSend);

		while(1) {
			if (!noOfPacktoSend) {
				strcpy(sendBuffer,"Disconnect");
				if (sendto(sock, sendBuffer, strlen(sendBuffer), 0, 
						(struct sockaddr *) &clntAddr, sizeof(clntAddr)) != strlen(sendBuffer))
					DieWithError("sendto() sent a different number of bytes than expected");
			} else {
				sprintf(sendBuffer,"%d",rand());
				
				/* Send received datagram back to the client */
				if (sendto(sock, sendBuffer, strlen(sendBuffer), 0, 
						(struct sockaddr *) &clntAddr, sizeof(clntAddr)) != strlen(sendBuffer))
					DieWithError("sendto() sent a different number of bytes than expected");
				printf("Sending : %s\t",sendBuffer);
				noOfPacktoSend--;
			}
			if ((recvMsgSize = recvfrom(sock, sendBuffer, STRMAX, 0,
					(struct sockaddr *) &clntAddr, &cliAddrLen)) < 0)
				DieWithError("recvfrom() failed");
			sendBuffer[recvMsgSize] = '\0';
			printf("Receiving : %s\n",sendBuffer);
			if (!strcmp(sendBuffer,"Closed"))
				exit(0);	
		}
    }
    /* NOT REACHED */
}

--- NEW FILE: TCPClient.c ---
#include <stdio.h>      /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket(), connect(), send(), and recv() */
#include <arpa/inet.h>  /* for sockaddr_in and inet_addr() */
#include <stdlib.h>     /* for atoi() */
#include <string.h>     /* for memset() */
#include <unistd.h>     /* for close() */

#define RCVBUFSIZE 11   /* Size of receive buffer */
 
void DieWithError(char *errorMessage) {	/* Error handling function */
    perror(errorMessage);
    exit(1);
}


int main(int argc, char *argv[]) {
    int sock;                        /* Socket descriptor */
    struct sockaddr_in servAddr; /* Server address */
    unsigned short servPort;     /* Server port */
    char *servIP;                    /* Server IP address (dotted quad) */
    char *sendString;                /* String to send to server */
    char recvString[RCVBUFSIZE];     /* Buffer for recv string */
    unsigned int sendStringLen;      /* Length of send string */
    int bytesRcvd, totalBytesRcvd;   /* Bytes read in single recv() 
                                        and total bytes read */

    if ((argc < 3) || (argc > 4))    /* Test for correct number of arguments */
    {
       fprintf(stderr, "Usage: %s <Server IP> <No Packet to Send> [<Echo Port>]\n",
               argv[0]);
       exit(1);
    }

    servIP = argv[1];             /* First arg: server IP address (dotted quad) */
    sendString = argv[2];         /* Second arg: Number of Packet to send and receive */

    if (argc == 4)
        servPort = atoi(argv[3]); /* Use given port, if any */
    else
        servPort = 7;  /* 7 is the well-known port for the echo service */

    /* Create a reliable, stream socket using TCP */
    if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
        DieWithError("socket() failed");

    /* Construct the server address structure */
    memset(&servAddr, 0, sizeof(servAddr));     /* Zero out structure */
    servAddr.sin_family      = AF_INET;             /* Internet address family */
    servAddr.sin_addr.s_addr = inet_addr(servIP);   /* Server IP address */
    servAddr.sin_port        = htons(servPort); /* Server port */

    /* Establish the connection to the echo server */
    if (connect(sock, (struct sockaddr *) &servAddr, sizeof(servAddr)) < 0)
        DieWithError("connect() failed");

	// strcpy(sendString,"5");
    sendStringLen = strlen(sendString);          /* Determine input length */

    /* Send the string to the server */
    if (send(sock, sendString, sendStringLen, 0) != sendStringLen)
        DieWithError("send() sent a different number of bytes than expected");

    /* Receive the same string back from the server */
    totalBytesRcvd = 0;
    strcpy(sendString,"Ok");
	sendStringLen = strlen(sendString);          /* Determine input length */
    while (1)
    {
		memset(recvString,0,RCVBUFSIZE);	  /* Set the Buffer with 0 */
        /* Receive up to the buffer size (minus 1 to leave space for
           a null terminator) bytes from the sender */
        if ((bytesRcvd = recv(sock, recvString, RCVBUFSIZE - 1, 0)) <= 0)
            DieWithError("recv() failed or connection closed prematurely");
		if (!strcmp(recvString,"Disconnect")) {
			strcpy(sendString,"Closed");
			sendStringLen = strlen(sendString);          /* Determine input length */
			if (send(sock, sendString, sendStringLen, 0) != sendStringLen)
				DieWithError("send() sent a different number of bytes than expected");
			printf("Reveiving: %s\tSending: %s\n",recvString,sendString);
			break;
		}
		sleep(5);
		if (send(sock, sendString, sendStringLen, 0) != sendStringLen)
			DieWithError("send() sent a different number of bytes than expected");
        totalBytesRcvd += bytesRcvd;   /* Keep tally of total bytes */
        recvString[bytesRcvd] = '\0';  /* Terminate the string! */
		printf("Reveiving: %s\tSending: %s\n",recvString,sendString);
        
    }

    close(sock);
    exit(0);
}

--- NEW FILE: UDPClient.c ---
#include <stdio.h>      /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket(), connect(), sendto(), and recvfrom() */
#include <arpa/inet.h>  /* for sockaddr_in and inet_addr() */
#include <stdlib.h>     /* for atoi() */
#include <string.h>     /* for memset() */
#include <unistd.h>     /* for close() */

#define STRMAX 255     /* Longest string to handled */

void DieWithError(char *errorMessage)
{
    perror(errorMessage);
    exit(1);
}

int main(int argc, char *argv[])
{
    int sock;                        /* Socket descriptor */
    struct sockaddr_in servAddr; /* Server address */
    struct sockaddr_in fromAddr;     /* Source address of echo */
    unsigned short servPort;     /* server port */
    unsigned int fromSize;           /* In-out of address size for recvfrom() */
    char *servIP;                    /* IP address of server */
    char *sendString;                /* String to send to server */
    char recvBuffer[STRMAX+1];      /* Buffer for receiving string */
    int sendStringLen;               /* Length of send string*/
    int respStringLen;               /* Length of received response */

    if ((argc < 3) || (argc > 4))    /* Test for correct number of arguments */
    {
        fprintf(stderr,"Usage: %s <Server IP> <Num packet Recv> [<Echo Port>]\n", argv[0]);
        exit(1);
    }

    servIP = argv[1];           /* First arg: server IP address (dotted quad) */
    sendString = argv[2];       /* Second arg: No of Packets to Receive */

    if ((sendStringLen = strlen(sendString)) > STRMAX)  /* Check input length */
        DieWithError("Echo word too long");

    if (argc == 4)
        servPort = atoi(argv[3]);  /* Use given port, if any */
    else
        servPort = 7;  /* 7 is the well-known port for the echo service */

    /* Create a datagram/UDP socket */
    if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
        DieWithError("socket() failed");

    /* Construct the server address structure */
    memset(&servAddr, 0, sizeof(servAddr));    /* Zero out structure */
    servAddr.sin_family = AF_INET;                 /* Internet addr family */
    servAddr.sin_addr.s_addr = inet_addr(servIP);  /* Server IP address */
    servAddr.sin_port   = htons(servPort);     /* Server port */

   // strcpy(sendString,"5");
    sendStringLen = strlen(sendString);          /* Determine input length */

    /* Send the string to the server */
    if (sendto(sock, sendString, sendStringLen, 0, (struct sockaddr *)
               &servAddr, sizeof(servAddr)) != sendStringLen)
        DieWithError("sendto() sent a different number of bytes than expected");

	strcpy(sendString,"Ok");
	sendStringLen = strlen(sendString);          /* Determine input length */

	while (1) {
		memset(recvBuffer,0,STRMAX);	  /* Set the Buffer with 0 */
		/* Recv a response */
		fromSize = sizeof(fromAddr);
		if ((respStringLen = recvfrom(sock, recvBuffer, STRMAX, 0, 
			(struct sockaddr *) &fromAddr, &fromSize)) != strlen(recvBuffer)) {
			printf("Recived %s\n",recvBuffer);
			DieWithError("recvfrom() failed");
		}

		if (!strcmp(recvBuffer,"Disconnect")) {
			strcpy(sendString,"Closed");
			sendStringLen = strlen(sendString);          /* Determine input length */
			if (sendto(sock, sendString, sendStringLen, 0, (struct sockaddr *)
				   &servAddr, sizeof(servAddr)) != sendStringLen)
				DieWithError("sendto() sent a different number of bytes than expected");
			break;
		}

		if (servAddr.sin_addr.s_addr != fromAddr.sin_addr.s_addr)
		{
	        fprintf(stderr,"Error: received a packet from unknown source.\n");
			exit(1);
		}
		sleep(5);
		/* Send the string to the server */
		if (sendto(sock, sendString, sendStringLen, 0, (struct sockaddr *)
               &servAddr, sizeof(servAddr)) != sendStringLen)
			DieWithError("sendto() sent a different number of bytes than expected");
		/* null-terminate the received data */
		recvBuffer[respStringLen] = '\0';
		printf("Received: %s\tSending : %s\n", recvBuffer,sendString);    /* Print the echoed arg */
       
		
	}
    
    close(sock);
    exit(0);
}