Finding maximum queue length
Hey all,
Basically this hacked up version of a tcp/ip tutorial is supposed to make as many connections as possible, then report how many it was able to make. This will tell you how many active TCP connections can exist.
:( But it doesn't work. :(
Basically when I run it agaisnt linux or solaris boxes, I get 188 as the result, and it just sits their afterwards. Now, I know that the number should be a lot higher than 188, and also that the numbers are different for solaris and linux.
Here's the code:
Code:
#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() and exit() */
#include <string.h> /* for memset() */
#include <unistd.h> /* for close() */
#define MAXCONN 1024 /* Max number of connections */
int main(int argc, char *argv[])
{
int sock[MAXCONN]; /* Socket descriptor */
struct sockaddr_in echoServAddr; /* Echo server address */
unsigned short echoServPort; /* Echo server port */
char *servIP; /* Server IP address (dotted quad) */
char *echoString; /* String to send to echo server */
int i=0,s=0,numconn;
if (argc < 2) /* Test for correct number of arguments */
{
fprintf(stderr, "Usage: %s <IP> <Port>\n",
argv[0]);
exit(1);
}
servIP = argv[1]; /* First arg: server IP address (dotted quad) */
echoServPort = atoi(argv[2]); /* Use given port, if any */
/* Create a reliable, stream socket using TCP */
printf("Creating %d sockets for the test...",MAXCONN);
i=0;
while (i<MAXCONN) {
if ((sock[i] = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
s=1;
i++;
}
printf("Done.\n");
printf("Currently opening connection number:\n");
/* Construct the server address structure */
memset(&echoServAddr, 0, sizeof(echoServAddr)); /* Zero out structure */
echoServAddr.sin_family = AF_INET; /* Internet address family */
echoServAddr.sin_addr.s_addr = inet_addr(servIP); /* Server IP address */
echoServAddr.sin_port = htons(echoServPort); /* Server port */
/* Establish the connection to the echo server */
s=0;
i=0;
while (s!=1) {
if (connect(sock[i], (struct sockaddr *) &echoServAddr, sizeof(echoServAddr)) < 0)
s=1;
printf("\b\b\b%d",i);
i++;
if (i>MAXCONN) {
printf("\nReached max number of connections. Recompile? ;-)\n");
s=1;
}
sleep(0.2);
}
close(sock[0]); //havent gotten around to closing them all, but i will
exit(0);
}
Ideas?
