#!/usr/bin/perl -w
# -*-CPerl-*-
# Script to configure Postfix.
# Based on code by Colin Walters <walters@cis.ohio-state.edu>,
# and John Goerzen <jgoerzen@progenylinux.com>.

use strict;
use warnings;

use Debconf::Client::ConfModule qw(:all);
use Fcntl;

my $version = version(2.0);
capb("backup");
title("Postfix Configuration");

# begin configuration script

my $topstate;
my $back;
my $noninteractive;
my $skiprelayhost;

# Regexps for checking domain names, blatantly stolen from exim config
my $rfc1035_label_re= '[0-9A-Za-z]([-0-9A-Za-z]*[0-9A-Za-z])?';
my $rfc1035_domain_re= "$rfc1035_label_re(\\.$rfc1035_label_re)*";
my $network_re= '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}/[0-9]{1,2}';

$topstate = "start";

my $distribution = lc(`lsb_release -is 2>/dev/null`);
$distribution = 'debian' if $distribution eq '';

while ($topstate ne "done") {
 TOPSTATE: {
    if ($topstate eq "start") {
      if (fget("postfix/main_mailer_type", "isdefault") eq "true") {
	if (-f "/etc/postfix/main.cf") {
	    set("postfix/main_mailer_type", "No configuration");
	}
      }
      my $pri = "high";
      $pri = "medium" if ($ARGV[1] ne "" && $distribution eq "ubuntu");
      $noninteractive = (((input($pri, "postfix/main_mailer_type"))[0]) == 30);
      if ($noninteractive) {
	my $mailertype = get("postfix/main_mailer_type");
	if ($mailertype eq "No configuration") {
	  # We can't display a note here, because it could send mail,
	  # which isn't configured...
	  #$noninteractive = ((input("critical", "postfix/not_configured"))[0] == 30);
	  #go();
          fset("postfix/newaliases", "run", "false");
	  $topstate="ending-setup";
	} else {
	  $topstate="mailname";
	}
      } else {
	go();
	$back = (((go())[0]) == 30);
	my $mailertype = get("postfix/main_mailer_type");
	if ($mailertype eq "No configuration") {
	  $topstate="ending-setup";
	} else {
	  fset("postfix/main_mailer_type", "changed", "true");
          fset("postfix/newaliases", "run", "true");
	  if ($back) {
	    fset("postfix/main_mailer_type", "isdefault", "true");
	  } else {
	    fset("postfix/main_mailer_type", "changed", "true");
	    $topstate = "mailname";
	    if (!(($mailertype eq "Internet with smarthost") ||
		  ($mailertype eq "Satellite system") ||
		  ($mailertype eq "HP"))) {
	      set("postfix/relayhost", "");
	      fset("postfix/relayhost", "changed", "true");
	    }
	  }
	}
      }
    }

    if ($topstate eq "mailname") {
      my $mailname;
      if (-f "/etc/mailname") {
	if (open my $fh, '<', "/etc/mailname") {
	  $mailname = <$fh>;
	  close $fh;
	  chomp $mailname;
	}
      }
      if (!defined($mailname) || $mailname eq "") {
	$mailname = `hostname --fqdn 2>/dev/null` || "localdomain";
	chomp $mailname;
      }
      # broken mailname, change it to the default, and prompt.
      if (lc($mailname) eq "ubuntu.com" || lc($mailname) eq "debian.org") {
	fset("postfix/mailname", "isdefault", "true");
	$mailname = `hostname --fqdn 2>/dev/null` || "localdomain";
	chomp $mailname;
      }
      if (fget("postfix/mailname", "isdefault") eq "true") {
	set("postfix/mailname", $mailname);
      }
      $noninteractive = (((input("high", "postfix/mailname"))[0]) == 30);
      if ($noninteractive) {
	$topstate = "relayhost";
      } else {
	$back = (((go())[0]) == 30);
	if ($back) {
	  fset("postfix/main_mailer_type", "isdefault", "true");
	  fset("postfix/mailname", "isdefault", "true");
	  $topstate = "start";
	} else {
	  # error checking
	  my $mailname = lc(get("postfix/mailname"));
	  fset("postfix/mailname", "changed", "true");
	  if ($mailname eq "ubuntu.com" || $mailname eq "debian.org") {
	    fset("postfix/mailname", "isdefault", "true");
	  } elsif ($mailname =~ /$rfc1035_domain_re/ || $mailname eq "==default==") {
	    # their mailname passed error checking, go on
	    $topstate = "relayhost";
	  } else {
	    set("postfix/rfc1035_violation", "false");
	    fset("postfix/rfc1035_violation", "isdefault", "true");
	    subst("postfix/rfc1035_violation", "enteredstring", $mailname);
	    $noninteractive = (((input("high", "postfix/rfc1035_violation"))[0]) == 30);
	    $back = (((go())[0]) == 30);
	    if ($back) {
	      fset("postfix/mailname", "isdefault", "true");
	      # and back around to ask mailname again.
	    }
	    if (get("postfix/rfc1035_violation") eq "true") {
	      # they wanted to continue despite the error
	      $topstate = "relayhost";
	    } else {
	      fset("postfix/mailname", "isdefault", "true");
	      # and back around to ask mailname again.
	    }
	  }
	}
      }
    }

    if ($topstate eq "relayhost") {
      my $mailertype = get("postfix/main_mailer_type");
      if (($mailertype eq "Internet with smarthost") || ($mailertype eq "Satellite system")) {
	if (fget("postfix/relayhost", "isdefault") eq "true") {
	  my $hostname = `hostname --domain 2>/dev/null` || "localdomain";
	  chomp $hostname;
	  my $relayname = "smtp." . $hostname;
	  set("postfix/relayhost", $relayname);
	}
	$noninteractive = (((input("high", "postfix/relayhost"))[0]) == 30);
	$skiprelayhost=0;
      } else {
	# skip relayhost if we're an "Internet site" or a "Local only"
	$topstate = "root";
	$noninteractive=1;
	$skiprelayhost=1;
      }
      if ($noninteractive) {
	$topstate = "root";
      } else {
	$back = (((go())[0]) == 30);
	if ($back) {
	  fset("postfix/mailname", "isdefault", "true");
	  fset("postfix/relayhost", "isdefault", "true");
	  $topstate = "mailname"; # we skip back to the last question of equal or higher priority
	} else {
	  my $host = get("postfix/relayhost");
	  if ($host =~ /[\s,]/) {
	    fset("postfix/relayhost", "isdefault", "true");
	  } else {
	    fset("postfix/relayhost", "changed", "true");
	    $topstate = "root";
	  }
	}
      }
    }

    if ($topstate eq "root") {
      if (fget("postfix/root_address", "isdefault") eq "true") {
        my @l = ();
        if (open my $fh, '-|', "getent passwd 1000") {
          @l=<$fh>;
          close $fh;
        }
        if ($#l > 0) {
          $l[0] =~ s/:.*$//;
          set("postfix/root_address",$l[0]);
          fset("postfix/root_address", "changed", "true");
        }
      }
      $noninteractive = (((input("medium", "postfix/root_address"))[0]) == 30);
      if ($noninteractive) {
	$topstate="destinations";
      } else {
	$back = (((go())[0]) == 30);
	if ($back) {
	  fset("postfix/relayhost", "isdefault", "true");
	  fset("postfix/root_address", "isdefault", "true");
	  if ($skiprelayhost) {
	    fset("postfix/mailname", "isdefault", "true");
	    $topstate = "mailname";
	  } else {
	    $topstate = "relayhost";
	  }
	} else {
	  fset("postfix/root_address", "changed", "true");
	  $topstate="destinations";
	}
      }
    }

    if ($topstate eq "destinations") {
      my $mailertype = get("postfix/main_mailer_type");
      my $hostname = `hostname --fqdn 2>/dev/null` || "localhost";
      chomp $hostname;
      my $domain = `hostname --domain 2>/dev/null` || "localdomain";
      chomp $domain;
      my $mailname = get("postfix/mailname") || "localhost";
      my $destinations;
      my $priority="medium";
      if (fget("postfix/destinations", "set") eq "true") {
	if ((-x "/usr/sbin/postconf") && (-f "/etc/postfix/main.cf")) {
	  if (open my $fh, '-|', "postconf -hx mydestination") {
	    $destinations=<$fh>;
	    close $fh;
	    chomp $destinations;
	    set("postfix/destinations", $destinations);
	  }
	}
      } else {
	if ($mailertype eq "Internet Site") {
	  if ($mailname eq $hostname) {
	    $destinations = join ", ",("\$myhostname", $mailname, "localhost." . $domain, ", localhost");
	  } else {
	    $destinations = join ", ",("\$myhostname", $mailname, $hostname, "localhost." . $domain . ", localhost");
	  }
	} else {
	  # don't accept mail for $mailname by default if we have a relayhost or local only mail,
	  # unless the mailname bears no resemblance to $myorigin.
	  $destinations = join ", ",("\$myhostname", $hostname, "localhost." . $domain . ", localhost" );
	  unless ( $hostname =~ m/(^|[\.])$mailname$/  ) {
	    $destinations = $mailname . ", " . $destinations;
	  }
	}
	set("postfix/destinations", $destinations);
	fset("postfix/destinations","set","true");
      }
      if ($mailertype eq "Local only") {
	$priority="low";
      }
      $noninteractive = (((input($priority, "postfix/destinations"))[0]) == 30);
      if ($noninteractive) {
	$topstate = "mynetworks";
      } else {
	$back = (((go())[0]) == 30);
	if ($back) {
	  fset("postfix/relayhost", "isdefault", "true");
	  fset("postfix/destinations", "isdefault", "true");
	  $topstate = "relayhost";
	} else {
	  fset("postfix/destinations", "changed", "true");
	  $topstate = "mynetworks";
	}
      }
    }

    if ($topstate eq "mynetworks") {
      if ((-x "/usr/sbin/postconf") && (-f "/etc/postfix/main.cf")) {
	my $mynetworks;
	if (open my $fh, '-|', "postconf -hx mynetworks") {
	  $mynetworks=<$fh>;
	  close $fh;
	  chomp $mynetworks;
	  set("postfix/mynetworks", $mynetworks);
	}
      }
      $noninteractive = (((input("low", "postfix/mynetworks"))[0]) == 30);
      if ($noninteractive) {
	$topstate = "procmail";
      } else {
	$back = (((go())[0]) == 30);
	if ($back) {
	  fset("postfix/destinations", "isdefault", "true");
	  fset("postfix/mynetworks", "isdefault", "true");
	  $topstate = "destinations";
	} else {
	  fset("postfix/mynetworks", "changed", "true");
	  $topstate = "procmail";
	}
      }
    }

    if ($topstate eq "procmail") {
      if (fget("postfix/procmail", "isdefault") eq "true") {
	my $pmdefault="false";
	if (-x "/usr/bin/procmail") {
	  $pmdefault="true";
	}
	set("postfix/procmail", $pmdefault);
      }
      if (-x "/usr/bin/procmail") {
	$noninteractive = (((input("low", "postfix/procmail"))[0]) == 30);
      } else {
	$noninteractive = 1;
      }
      if ($noninteractive) {
	$topstate = "mailbox_limit";
      } else {
	$back = (((go())[0]) == 30);
	if ($back) {
	  fset("postfix/mynetworks", "isdefault", "true");
	  fset("postfix/procmail", "isdefault", "true");
	  $topstate = "mynetworks";
	} else {
	  fset("postfix/procmail", "changed", "true");
	  $topstate = "mailbox_limit";
	}
      }
    }

    if ($topstate eq "mailbox_limit") {
      $noninteractive = (((input("low", "postfix/mailbox_limit"))[0]) == 30);
      if ($noninteractive) {
	$topstate = "recipient_delim";
      } else {
	$back = (((go())[0]) == 30);
	if ($back) {
	  fset("postfix/procmail", "isdefault", "true");
	  fset("postfix/mailbox_limit", "isdefault", "true");
	  if (-x "/usr/bin/procmail") {
	    $topstate = "procmail";
	  } else {
	    fset("postfix/mynetworks", "isdefault", "true");
	    $topstate = "mynetworks";
	  }
	} else {
	  fset("postfix/mailbox_limit", "changed", "true");
	  $topstate = "recipient_delim";
	}
      }
    }

    if ($topstate eq "recipient_delim") {
      $noninteractive = (((input("low", "postfix/recipient_delim"))[0]) == 30);
      if ($noninteractive) {
	$topstate = "protocols";
      } else {
	$back = (((go())[0]) == 30);
	if ($back) {
	  fset("postfix/mailbox_limit", "isdefault", "true");
	  fset("postfix/recipient_delim", "isdefault", "true");
	  $topstate = "mailbox_limit";
	} else {
	  my $delim = get("postfix/recipient_delim");
	  if (length($delim) > 1) {
	    fset("postfix/bad_recipient_delimiter","isdefault","true");
	    subst("postfix/bad_recipient_delimiter", "enteredstring", $delim);
	    $noninteractive = (((input("low", "postfix/bad_recipient_delimiter"))[0]) == 30);
	    fset("postfix/recipient_delim","isdefault","true");
	    # and do it again...
	  } else {
	    fset("postfix/recipient_delim", "changed", "true");
	    $topstate = "protocols";
	  }
	}
      }
    }

    if ($topstate eq "protocols") {
      if ((-x "/usr/sbin/postconf") && (-f "/etc/postfix/main.cf")) {
	my $protos;
	if (open my $fh, '-|', "postconf -hx inet_protocols") {
	  $protos=<$fh>;
	  close $fh;
	  chomp $protos;
	  set("postfix/protocols", $protos);
	}
      } elsif (fget("postfix/protocols", "isdefault") eq "true") {
	my $protos;
	if (-d "/proc/sys/net/ipv6" && -d "/proc/sys/net/ipv4") {
	  $protos="all";
	} elsif (-d "/proc/sys/net/ipv6") {
	  $protos="ipv6";
	} elsif (-d "/proc/sys/net/ipv4") {
	  $protos="ipv4";
	}
	set("postfix/protocols", $protos) if $protos;
      }

      $noninteractive = (((input("low", "postfix/protocols"))[0]) == 30);
      if ($noninteractive) {
	$topstate = "ending-setup";
      } else {
	$back = (((go())[0]) == 30);
	if ($back) {
	  fset("postfix/recipient_delim", "isdefault", "true");
	  fset("postfix/protocols", "isdefault", "true");
	  $topstate = "recipient_delim";
	} else {
	  fset("postfix/protocols", "changed", "true");
	  $topstate = "ending-setup";
	}
      }
    }

    if ($topstate eq "ending-setup") {
      if ($ARGV[0] eq "reconfigure") {
	# touch /var/lib/postfix/reload
	if (sysopen my $fh, "/var/spool/postfix/reload", O_CREAT) {
	  close $fh;
	}
      } else {
	# touch /var/lib/postfix/restart
	if (sysopen my $fh, "/var/spool/postfix/restart", O_CREAT) {
	  close $fh;
	}
      }
      $topstate = "done";
    }
  }				# end TOPSTATE
}				# end while ($topstate ne q(done))