/******************************************************************************
* Function: main
*
* Description:
* Set up a PIT server and handle network requests. This server
* handles both TCP and UDP requests.
*
* Parameters:
* The usual argc and argv parameters to a main() function.
*
* Return Value:
* This is a daemon program and never returns. However, in the degenerate
* case where no sockets are created, the function returns zero.
******************************************************************************/
int main( int argc,
char *argv[ ] )
{
int opt;
int tSckt[ MAXTCPSCKTS ]; /* Array of TCP socket descriptors. */
size_t tScktSize = MAXTCPSCKTS; /* Size of uSckt (# of elements). */
int uSckt[ MAXUDPSCKTS ]; /* Array of UDP socket descriptors. */
size_t uScktSize = MAXUDPSCKTS; /* Size of uSckt (# of elements). */
strcpy(service_name,DFLT_SERVICE);
/*
** Set the program name (w/o directory prefix).
*/
pgmName = strrchr( argv[ 0 ], '/' );
pgmName = pgmName == NULL ? argv[ 0 ] : pgmName + 1;
/*
** Process command options.
*/
opterr = 0; /* Turns off "invalid option" error messages. */
while ( ( opt = getopt( argc, argv, VALIDOPTS ) ) >= 0 )
{
switch ( opt )
{
case 'v': /* Verbose mode. */
{
verbose = true;
break;
}
case 'p': /* Get the port number */
{
strcpy(service_name,optarg);
need++;
break;
}
default:
{
USAGE;
}
} /* End SWITCH on command option. */
} /* End WHILE processing options. */
if(need < 1)
{
USAGE;
exit;
}
/*
** Open both a TCP and UDP socket, for both IPv4 & IPv6, on which to receive
** service requests.
*/
if ( ( openSckt( service_name, "tcp", tSckt, &tScktSize ) < 0 ) ||
( openSckt( service_name, "udp", uSckt, &uScktSize ) < 0 ) )
{
exit( 1 );
}
/*
** Run the Programmable Interdimensional Timer server.
*/
if ( ( tScktSize > 0 ) || ( uScktSize > 0 ) )
{
pit( tSckt, /* pit() never returns. */
tScktSize,
uSckt,
uScktSize );
}
/*
** Since pit() never returns, execution only gets here if no sockets were
** created.
*/
if ( verbose )
{
fprintf( stderr,
"%s: No sockets opened... terminating.\n",
pgmName );
}
return 0;
} /* End main() */
/******************************************************************************
* Function: main
*
* Description:
* Connect to a remote time-of-day service and write the remote host's TOD to
* stdout.
*
* Parameters:
* The usual argc & argv parameters to a main() program.
*
* Return Value:
* This function always returns zero.
******************************************************************************/
int main( int argc,
char *argv[ ] )
{
const char *host = DFLT_HOST;
int opt;
int sckt;
unsigned int scopeId = if_nametoindex( DFLT_SCOPE_ID );
const char *service = DFLT_SERVICE;
init_performance();
/*
** Determine the program name (w/o directory prefix).
*/
pgmName = (const char*) strrchr( argv[ 0 ], '/' );
pgmName = pgmName == NULL ? argv[ 0 ] : pgmName+1;
/*
** Process command line options.
*/
opterr = 0; /* Turns off "invalid option" error messages. */
while ( ( opt = getopt( argc, argv, VALIDOPTS ) ) != -1 )
{
switch ( opt )
{
case 's': /* Scope identifier (IPv6 kluge). */
{
scopeId = if_nametoindex( optarg );
if ( scopeId == 0 )
{
fprintf( stderr,
"%s: Unknown network interface (%s).\n",
pgmName,
optarg );
USAGE;
}
break;
}
case 'v': /* Verbose mode. */
{
verbose = true;
break;
}
default:
{
USAGE;
}
} /* End SWITCH on command option. */
} /* End WHILE processing command options. */
/*
** Process command arguments. At the end of the above loop, optind is the
** index of the first NON-option argv element.
*/
switch ( argc - optind )
{
case 2: /* Both host & service are specified on the command line. */
{
service = argv[ optind + 1 ];
/***** Fall through *****/
}
case 1: /* Host is specified on the command line. */
{
host = argv[ optind ];
/***** Fall through *****/
}
case 0: /* Use default host & service. */
{
break;
}
default:
{
USAGE;
}
} /* End SWITCH on number of command arguments. */
/*
** Open a connection to the indicated host/service.
**
** Note that if all three of the following conditions are met, then the
** scope identifier remains unresolved at this point.
** 1) The default network interface is unknown for some reason.
** 2) The -s option was not used on the command line.
** 3) An IPv6 "scoped address" was not specified for the hostname on the
** command line.
** If the above three conditions are met, then only an IPv4 socket can be
** opened (connect(2) fails without the scope ID properly set for IPv6
** sockets).
*/
if ( ( sckt = openSckt( host,
service,
scopeId ) ) == INVALID_DESC )
{
fprintf( stderr,
"%s: Sorry... a connection could not be established.\n",
pgmName );
exit( 1 );
}
/*
** Get the remote time-of-day.
*/
tod( sckt );
/*
** Close the connection and terminate.
*/
(void) SYSCALL( "close",
__LINE__,
close( sckt ) );
return 0;
} /* End main() */