#!/usr/local/bin/perl

$Snoophosts   = "/usr/lib/snoophosts";
$Snoopresult  = "/usr/lib/snoopresult";

#$Snoophosts   = "/user2/lindner/snoop/snoophosts";
#$Snoopresult  = "/user2/lindner/snoop/snoopresult";

$Humans       = "gopher@your.site.here";
$BeeperNo     = "xxx-xxxx";


push(@message, "\n");
sub OpenSock { 
    local($them,$port,$query) = @_;
    $them = 'localhost' unless them;
    $port = 43 unless $port;

    $AF_INET = 2;
    $SOCK_STREAM = 1;

    $SIG{'INT'} = 'dokill';

    $sockaddr = 'S n a4 x8';

    chop($hostname = `hostname`);

    ($name,$aliases,$proto) = getprotobyname('tcp');
    ($name,$aliases,$port) = getservbyname($port,'tcp')
        unless $port =~ /^\d+$/;;
    ($name,$aliases,$type,$len,$thisaddr) = gethostbyname($hostname);
    ($name,$aliases,$type,$len,$thataddr) = gethostbyname($them);

    $this = pack($sockaddr, $AF_INET, 0, $thisaddr);
    $that = pack($sockaddr, $AF_INET, $port, $thataddr);

    # Make the socket filehandle.
    socket(SOCK, $AF_INET, $SOCK_STREAM, $proto) || return $!;

    # Give the socket an address.
    bind(SOCK, $this) || return $!;

    # Call up the server.
    connect(SOCK,$that) || return $!;

    # Set socket to be command buffered.
    select(SOCK); $| = 1; select(STDOUT);

    # send the whois query
    print SOCK "$query\r\n";
    return "is up";
}

open(Snoophosts, "<$Snoophosts") || die "No hosts to snoop on\n";

$SeverityLevel = 0;

while (<Snoophosts>) {
	chop;
	next if /^#/;

	($Host, $Port, $Importance) = split;

        $key = "$Host $Port";

	$Importance{$key} = $Importance;
}

#
# Read the old status.
#

system("touch $Snoopresult");
open(Snoopresult, "+<$Snoopresult");
chop($OldSeverity = <Snoopresult>);

while (<Snoopresult>) {
	chop;
	m/^(\S* \S*) (.*)$/;
	$key = $1;
	$status = $2;

	$OldStatus{$key} = $status;
}	
#
# Test each host/port
#

foreach (keys(%Importance)) {
	$key = $_;

	$Host = $_;   $Host =~ s/ .*$//;
	$Port = $_;   $Port =~ s/^.* //;

	
	$result = &OpenSock($Host, $Port, "");
	if ($result ne "is up") {
		$SeverityLevel += $Importance{$_};
        }
	if ($result ne $OldStatus{$key}) {
		if ($result eq "is up") {
			push(@message, "$Host, port $Port came back up\n");
		} else {
			push(@message, "** $Host, port $Port went down: $result\n");
		}
	}

	$Newstatus{$key} = $result;
}

#
# Write out the new results file
#
seek(Snoopresult, 0, 0);
truncate(Snoopresult,0);

print Snoopresult $SeverityLevel . "\n";
foreach $key (keys(%Importance)) {
	print Snoopresult "$key $Newstatus{$key}\n";
}
		

#
# Okay, now lets inform the humans
#

if ($SeverityLevel == 0 && $OldSeverity != 0) {	
	push(@message, "All machines are up again\n");
	&DialBeeper(0);
} else {
        if ($#message > 0) {
            push(@message, "Some machines are still down\n");
        }
}

#
# Mail to the humans a status report at the end of the day.
#

($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);

if ($hour == 16 && $min < 15) {
	open(Mail,"|mail $Humans");
	print Mail "Subject: Gopher is alive\n\n";
	foreach $key (keys(%Importance)) {
       	 	print Mail "$key $Newstatus{$key}\n";
	}
}

if ($#message > 0) {
	open(Mail, "|mail $Humans");
	print Mail "Subject: *** Gopher Trouble Update ***\n";
	print Mail "Priority: Urgent\n\n";
	print Mail @message;

	print Mail "\nCurrently down Machines\n";
	print Mail "-----------------------\n\n";
	foreach $key (keys(%Importance)) {
		if (!($Newstatus{$key} =~ /is up/)) {
			print Mail "$key $Newstatus{$key}\n";
		}
	}
}

#
# Ring the beeper
#

if ($SeverityLevel > 0 && $OldSeverity != $SeverityLevel) {
	$severe = $SeverityLevel/10;
	$severe = 1 if ($severe == 1);
	$severe = 9 if ($severe > 9);	

	$severe =~ s/\..*$//;
	&DialBeeper($severe);
}

#
#  Procedure to dial the beeper
#

sub DialBeeper {
	local($Severity) = @_;
 	
	($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
	if ($hour < 10) { $hour = "0" . $hour;}
	local($Num)= "$hour$min";

	while ($i <5) {
		$Num = $Num . $Severity;
		$i ++;
  	}

#
# fixed this to explicitly use the ATDT command because cu has been
# intermittently pulse dialing (ATD rather than ATDT)
#				-mpm
#	open(BeeperCmd, "|cu -s 1200 $BeeperNo,,,,,$Num,>/dev/null  2>&1");
	open(BeeperCmd, "|cu -s 1200 -l tty0 dir > /dev/null	2>&1");
	print BeeperCmd "ATDT $BeeperNo,,,,,$Num,,\r";
#
#
# end of patch (-mpm)
#
	print BeeperCmd "\r~.\r\r";
	close BeeperCmd;
}