#!/usr/bin/perl

# Quick & Dirty Debug Script for changing Scanaddr routine

$logfile = "/var/log/maillog";		# POP3 daemon log.
$pidfile = "/var/run/poprelayd.pid";	# Where we put our PID.
$dbfile = "/etc/mail/popauth.db";	# Sendmail map to update.
$dbtype = "DB_HASH";
$timeout_minutes = 240;			# Minutes an entry lasts.
$log_wait_interval = 5;			# Number of seconds between checks

#
#  Modules
#

use Getopt::Std;
use Fcntl;
use DB_File;
use POSIX;

# You may need to uncomment this if your fcntl.ph doesn't export it.
sub O_EXLOCK { 0x20 };

#
#  Variables
#

undef $pid;				# Process ID.
undef %db;				# Hash into database file.
undef $lffd;				# $logfile file descriptor.
undef $lfino;				# Inode of $logfile when we opened it.
undef $lfbuf;				# Buffer for data from $lffd.
undef @addrs;				# List of IP addresses to add.
undef $lasttimeout;			# Last time we did a timeout.

#
#  Subroutines
#

# timeoutdb(secs)
#
# Remove all entries from %db more than secs seconds old.
#
sub timeoutdb {
    # Convert timeout in secs to a time_t before which we delete.
    my $to = time - $_[0];

    foreach $key (sort(keys(%db))) {
	if ($db{$key} < $to)  {
	    delete $db{$key};
	}
    }
}

# getlogline()
#
# Return the next line from $logfile, or undef if one isn't currently ready.
#
# XXX Note that there's a bug in this routine that causes it to ignore
# blank lines. I kinda like this behaviour, so I've not fixed it.
#
sub getlogline {
    my $junk;
    my $ino;
    my $foundeof = 0;
    my $buf;
    my $count;

    # The first time we're called; open the logfile, skip to the end,
    # and remember the inode we opened.
    if (!defined($lffd))  {
	$lffd = POSIX::open($logfile, O_RDONLY|O_NONBLOCK, 0);
	if (!defined($lffd))  {
	    die "Can't open $logfile\n";
	}
	if (POSIX::lseek($lffd, 0, &POSIX::SEEK_END) == -1)  {
	    die "Can't seek to end of $logfile\n";
	}
	($junk, $lfino, $junk) = POSIX::fstat($lffd);
    }

    # Append new data, if available, to our buffer.
    $count = POSIX::read($lffd, $buf, 1024);
    if ($count)  {
	$lfbuf = $lfbuf . $buf;
    }

    # Return a line, if we have one.
    if ($lfbuf =~ m/\n/m)  {
	($buf, $lfbuf) = split(/\n/m, $lfbuf, 2);
	return $buf;
    }

    # Check the inode number of $logfile; if it's not the saved one,
    # the logfile has been rotated and we need to reopen.
    ($junk, $ino, $junk) = POSIX::stat($logfile);
    if ($ino != $lfino)  {
	POSIX::close($lf_fd);
	undef($lf_fd);
	$lffd = POSIX::open($logfile, O_RDONLY|O_NONBLOCK, 0);
	if (!defined($lffd))  {
	    die "Can't open $logfile\n";
	}
	($junk, $lfino, $junk) = POSIX::fstat($lffd);
    }

    return undef;
}

# scanaddr($line)
#
# Scan $line to see if it's a log of a successful POP3 authentication.
# Return an array of the addresses that authenticated.
#
sub scanaddr ($) {
    my $s = $_[0];
    my @paddrs;		# Packed IP addresses.
    my @addrs;		# ASCII addresses.
    my $junk;

    if ($s =~ m/i(pop2|pop3|map)d\[[0-9]+\]: (Login|Auth) user=/)  {

        # DEBUG ENTRY -- HOST NAME NO IP 
        #$s = "Mar  7 01:48:42 intel1 imapd[1653]: Login user=kam host=intel2.peregrinehw.com";
        # DEBUG ENTRY -- NO HOST NAME 
        #$s = "Mar  7 08:18:01 intel1 ipop3d[6265]: Login user=nscainc host=[64.67.148.177] nmsgs=1/1";
        # DEBUG ENTRY -- HOST NAME & IP
        #$s = "Mar  7 10:59:12 intel1 ipop3d[7851]: Login user=slothy host=1Cust199.tnt10.tco2.da.uu.net [63.39.89.199] nmsgs=1/1"; 

        print "Line to clean -- $s\n";

	if ($s =~ /\[\d+\.\d+\.\d+\.\d+\]/) {
          # IP Address with NO Host Name
          if ($s =~ /host=\[\d+\.\d+\.\d+\.\d+\]/) {
            $s =~ s/.*host=\[(.*)\].*/$1/;
            if ($s ne "127.0.0.1") {
              push (@addrs,$s);
              #print "IP Added to Return Stack\n";
            }

          # Host Name with IP Address
          } else {
            $s =~ s/.*host=\S+ \[(.*)\].*/$1/;
            if ($s ne "127.0.0.1") {
              push (@addrs,$s);
              #print "IP Added to Return Stack\n";
            }
          }
          print "IP Cleaned -- $s\n";

        # Host Name with No IP Address
        } else {
  	  $s =~ s/.*host=(\S+).*/$1/;
          #print "Address Found -- $s\n";
	  ($junk, $junk, $junk, $junk, @paddrs) = gethostbyname($s);
	  while (@paddrs)  {
            $s = join('.', unpack('C4', shift(@paddrs)));

            if ($s ne "127.0.0.1") {
	      push(@addrs, $s);
              #print "IP Added to Return Stack\n";
            }
  	  }
          #print "Address Resolved -- $addrs[0]\n";
        }
	return @addrs;
    }
    return ();
}

#  cleanup
#
#  Clean up and exit; executed on receipt of a sighup.
#
sub cleanup {
    unlink $pidfile;
    exit 0;
}


#
#  Main Program
#

$countopts = 0;

    # Check to see we can read/write the files we need.
    die "Can't read $logfile: $!\n" if ! -r $logfile;
    die "Can't write $dbfile: $!\n" if ! -w $dbfile;

    # Main loop.
    $lasttimeout = 0;
    while (1)  {
	# Build list of addresses of recent authentications.
	while ($line = getlogline)  {
	    undef @ret;
	    if (@ret = scanaddr($line))  {
		push(@addrs, @ret);
	    }
	}
	sleep $log_wait_interval;
    }