int main(int argc, char** argv){
if (argc!=3) {
printf("Usage: %s <Server IP> <PortNumer>\n",argv[0]);
exit(1);
}
struct sockaddr_in serverAddr;
socklen_t serverAddrLen;
serverAddr.sin_family = PF_INET;
serverAddr.sin_port = htons(atoi(argv[2]));
inet_pton(AF_INET,argv[1],&serverAddr.sin_addr);
serverAddrLen = sizeof(serverAddr);
newSocket* server;
server = connectUDP(&serverAddr,serverAddrLen);
char buffer[1000] = "P r a s e e m";
buffer[13] = '\0';
char recv[1000];
sendToUDP(server,buffer);
recvFromUDP(server,recv);
printf("Received %s\n",recv);
return 0;
}
/*
* This function should pass messages to client, collect ack
* and calculate the latency as per given formula.
*/
int
UDPLatency(const char *host, const char *service, int msg_len) {
char *buf;
int sock, nchars;
char msg_count = 0;
struct timeval client_start_time, client_end_time;
long int cst_usecs, cet_usecs;
/* Create msg buffer of specified length here */
buf = (char *) malloc(sizeof(char) * msg_len);
memset(buf, 'M', msg_len);
/* Allocate a socket */
sock = connectUDP(host, service);
/* Note time before sending the messages */
gettimeofday(&client_start_time, NULL);
cst_usecs = (client_start_time.tv_sec * MICROSECS + client_start_time.tv_usec);
while(msg_count < MSGCOUNT) {
msg_count++;
buf[0] = msg_count;
nchars = strlen(buf);
(void *)write(sock, buf, msg_len);
fprintf(stderr, "The size of buffer is %d \n", strlen(buf));
/* Read the ack back from server */
if(read(sock, buf, sizeof(buf)) < 0) {
errexit("Socket read failed %s \n", strerror(errno));
}
}
/* Note time after all messages are received */
gettimeofday(&client_end_time, NULL);
cet_usecs = (client_end_time.tv_sec * MICROSECS + client_end_time.tv_usec);
/* Calculate throughput number */
long int total_time_msecs = (cet_usecs - cst_usecs)/1000;
long int throughput = (MSGCOUNT * msg_len * 1000)/total_time_msecs;
fprintf(stdout, "\nTotal time spent is: %ld ms, Throughtput of client with msg size : %d is %ld \n", total_time_msecs, msg_len, throughput);
free(buf);
close(sock);
}
/*------------------------------------------------------------------------
* UDPecho - send input to ECHO service on specified host and print reply
*------------------------------------------------------------------------
*/
int
UDPecho(const char *host, const char *service)
{
char buf[LINELEN+1]; /* buffer for one line of text */
int s, nchars; /* socket descriptor, read count*/
s = connectUDP(host, service);
while (fgets(buf, sizeof(buf), stdin)) {
buf[LINELEN] = '\0'; /* insure null-terminated */
nchars = strlen(buf);
(void) write(s, buf, nchars);
if (read(s, buf, nchars) < 0)
errexit("socket read failed: %s\n",
strerror(errno));
fputs(buf, stdout);
}
}
/*------------------------------------------------------------------------
* main - UDP client for TIME service that prints the resulting time
*------------------------------------------------------------------------
*/
int
main(int argc, char *argv[])
{
char *host = "localhost"; /* host to use if none supplied */
char *service = "time"; /* default service name */
time_t now; /* 32-bit integer to hold time */
int s, n; /* socket descriptor, read count*/
switch (argc) {
case 1:
host = "localhost";
break;
case 3:
service = argv[2];
/* FALL THROUGH */
case 2:
host = argv[1];
break;
default:
fprintf(stderr, "usage: UDPtime [host [port]]\n");
exit(1);
}
s = connectUDP(host, service);
(void) write(s, MSG, strlen(MSG));
/* Read the time */
n = read(s, (char *)&now, sizeof(now));
if (n < 0)
errexit("read failed: %s\n", strerror(errno));
now = ntohl((unsigned long)now); /* put in host order */
now -= UNIXEPOCH; /* convert UCT to UNIX epoch */
printf("%s", ctime(&now));
exit(0);
}
