Creating a TCP Ping Echo on User-Defined Protocols

Environment: Internet, networking

TCP Ping is necessary when measuring server functionality from different IP networks (mirror sites). As you see, it uses a TCP transport protocl instead of ICMP. To ping the remote (or local) server, it should be able to provide "NOOP" command (NO OPeration) followed by CRLF.

Such user-defined protocols can be:

  • SMTP/25;
  • FTP/21;
  • POP3/110;
  • and so forth (NOOP implemented).

Options included in demo project are the following:

  • -cv: Connective ping (default)
  • -ct: Continuous ping
  • -n: Specify NOOP command
  • -crlf: Append CRLF to NOOP
  • -t<t>: Specify timeout

Hence, you can specify NOOP command yourself, of course, if it differs from the default.

The reasonable question: How do you ping the HTTP server? To ping the HTTP server, you should specify a NOOP-command (because it's not implelemented in HTTP/1.x) as the implemented method. This time, a connective ping is better than a continuous ping. Let's see the connective ping source:

unsigned int CPing::PingConnective(char* szHost,
                                   unsigned int iPort,
                                   unsigned int iPackets)
{
  struct hostent* host = NULL;
  struct sockaddr_in saddr;
  unsigned int s = 0;
  unsigned int dw1, dw2, dw3;
  char szBuffer[256];

  if (iPackets>MAX_SENDS) return (0);
  free (Res);
  Res = (pingstore*)malloc (sizeof(pingstore)*iPackets);
  memset (Res, 0, sizeof(pingstore)*iPackets);
  if (!iBytesToRecv) iBytesToRecv = strlen(szNoop);

  host = gethostbyname (szHost);
  if (host==NULL) return (0);
  saddr.sin_family = AF_INET;
  saddr.sin_port = htons(iPort);
  saddr.sin_addr = *((struct in_addr*)host->h_addr);

  for (int i=0;i< iPackets;i++)
  {
    s = socket(AF_INET, SOCK_STREAM, 0);
    if (!s) return ((iTotalRes)?1:0);
    setsockopt(s, SOL_SOCKET, SO_RCVTIMEO,
              (char*)&iTimeOut, sizeof(iTimeOut));
    setsockopt(s, SOL_SOCKET, SO_SNDTIMEO,
              (char*)&iTimeOut, sizeof(iTimeOut));
    if (connect (s,(struct sockaddr*)&saddr, sizeof(saddr))
        == -1) return ((iTotalRes)?1:0);

    iTotalRes++;
    sprintf (szBuffer, "%s\r\n", szNoop);

    dw1 = GetTickCount();
    int iSent = send (s, szBuffer, strlen(szBuffer), 0);
    dw2 = GetTickCount();
    int iRecv = recv (s, szBuffer, iBytesToRecv, 0);
    dw3 = GetTickCount();

    Res[i].iPort       = iPort;
    Res[i].iTimeSend   = dw2-dw1;
    Res[i].iTimeRecv   = dw3-dw2;
    Res[i].iTotalSent  = ((iSent==SOCKET_ERROR)?0:iSent);
    Res[i].iTotalRecvd = ((iRecv==SOCKET_ERROR)?0:iRecv);

    closesocket (s);
  }
  return (1);
}

You can use a simple Perl script for it:

#!/usr/local/bin/perl
# ################################
# Connective ping to http-server
# ################################

die("httpping.pl <host> <packets> [-p<port>]\n")
     unless (scalar(@ARGV)>=2);
$host    = $ARGV[0];
$port    = 80;    # default, but you can change it
$packets = $ARGV[1];
$noop    = "GET / HTTP/1.0";

for ($i=2; $i< scalar(@ARGV);$i++)
{
  if ($ARGV[$i] =~ /^(\x2D\x70)/)
  {
    $port = substr ($ARGV[$i],2,length($ARGV[$i])-2);
  }
}

open (PING, "|ping.exe $host $port $packets -n -cv -crlf") ||
              die ("Error: ping executable not found\n");
print PING "$noop\n";
close (PING);

Example of Usage

> ping localhost 8080 10 -n -crlf -cv    # connective ping
Enter valid NOOP command: GET / HTTP/1.0
...

In conclusion, note that you can also modify the timeout value to extend or lower the "live time" of requests. I hope this will be very helpful for system administrators to audit their systems on "request-response" ability.

Downloads

Download demo program - 24 Kb
Download source - 2 Kb


Comments

  • Error in the code

    Posted by Ulfen on 05/21/2004 10:25am

    There is a small error in the code:

    s = socket(AF_INET, SOCK_STREAM, 0); if (!s) ...

    s == 0 could be a valid socket, so the check should be:

    if (s == SOCKET_ERROR) ...

    Reply
  • How can i messure the signal of the current interfaces xxx b/s ?

    Posted by Legacy on 12/19/2003 12:00am

    Originally posted by: mathabu

    best regards

    Reply
Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: November 20, 2014 @ 2:00 p.m. ET / 11:00 a.m. PT Are you wanting to target two or more platforms such as iOS, Android, and/or Windows? You are not alone. 90% of enterprises today are targeting two or more platforms. Attend this eSeminar to discover how mobile app developers can rely on one IDE to create applications across platforms and approaches (web, native, and/or hybrid), saving time, money, and effort and introducing apps to market faster. You'll learn the trade-offs for gaining long …

  • IBM Worklight is a mobile application development platform that lets you extend your business to mobile devices. It is designed to provide an open, comprehensive platform to build, run and manage HTML5, hybrid and native mobile apps.

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds