Avoiding perl, UDP QOTD (Re: QOTD server (Re: Help with socket 'select'))

[Bart Massey]

In article <13937 at orstcs.CS.ORST.EDU> pvo3366 at sapphire.OCE.ORST.EDU (Paul O'Neill) writes:
> 
> Only a few hosts in the NIC host tables advertise supporting QOTD service.
> (Quote of the day.)  This should change that!!

Note that for Berkeley-derived systems, at least, the above-referenced
perl code is unnecessary -- inetd will do exactly the right thing.  Try
putting the following line in /etc/inetd.conf (or wherever you hide your
inetd config).

quote	stream	tcp	nowait	nobody	/usr/games/fortune	fortune -a

This works great on my 4.3-Tahoe box.

FTP Software's PC TCP/IP stuff includes a client known as "cookie", which
uses the UDP version of the quote service.  Since we have a bunch of those
boxes here, I spent 15 minutes whacking together a UDP quote server which
runs under inetd...

cookie	dgram	udp	wait	nobody	/usr/local/cookied	cookied

The following line should also be added to /etc/services.

cookie		17/udp				# FTP software's cookie server

And here's the C code for the server.  Yes, I know this isn't production
quality, but I typed it in *really fast* :-).  Please send patches with any
bug reports, and be aware that I'm not really very interested in making it
run on anything but 4BSD boxes...

					Bart Massey
					..tektronix!videovax.tv.tek.com!bart
					..tektronix!reed.bitnet!bart

/*
--- cut here -----
/*
 * cookied.c -- UDP fortune server
 * Bart Massey 11/27/89
 */

#include <stdio.h>
#include <syslog.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define FORTUNEBUFSIZE	(64 * 1024)
#define FORTUNEPROG	"/usr/bin/fortune -a"

main(argc, argv)
int argc;
char **argv;
  {
    char *fortunebuf, *fbp;
    FILE *pfile;
    int nextchar, fromlen;
    struct sockaddr_in from;
    extern char *malloc();

    openlog( argv[0], LOG_PID|LOG_NOWAIT, LOG_DAEMON );
    fortunebuf = malloc( FORTUNEBUFSIZE  );
    if( !fortunebuf )
      {
        syslog( LOG_ERR, "out of memory" );
	exit( 1 );
      }
    fromlen = sizeof( from );
    if( recvfrom( 0, fortunebuf, FORTUNEBUFSIZE, 0, (struct sockaddr *) &from, &fromlen ) == -1 )
      {
        syslog( LOG_ERR,  "recvfrom: %m" );
	exit( 1 );
      }
    pfile = popen( FORTUNEPROG, "r" );
    if( !pfile )
      {
        syslog( LOG_ERR, "popen \"%s\": %m", FORTUNEPROG );
	exit( 1 );
      }
    for( fbp = fortunebuf; fbp < fortunebuf + FORTUNEBUFSIZE; fbp++ )
      {
        nextchar = getc( pfile );
	if( nextchar == EOF )
	  {
	    *fbp = '\0';  /* we don't *send* this, but... */
	    break;
	  }
        *fbp = nextchar;
      }
    if( nextchar != EOF )
      {
        syslog( LOG_ERR, "buffer too small" );
	exit( 1 );
      }
    pclose( pfile );
    if( sendto( 0, fortunebuf, fbp - fortunebuf, 0, &from, fromlen ) == -1 )
      {
        syslog( LOG_ERR, "send: %m" );
	exit( 1 );
      }
    syslog( LOG_DEBUG, "sent fortune to %s (%d)",
      inet_ntoa( * (long *) (&from.sin_addr) ), ntohs( from.sin_port ) );
    exit( 0 );
  }