#!perl -w
#############################################################################
#
#          Scandinavian Mail eXchange - ScanMailX.com
#
# qpsmtpd module build to support https://www.invaluement.com/serviceproviderdnsbl/
#
##############################################################################

use Data::Validate::Domain qw(is_domain);
use LWP::UserAgent;

my @SPBL_IDs = ();
my @SPBL_Domains = ();

sub register {
  my ($self, $qp, @args) = @_;

  $self->{spbl_lastreload} = 0;
}

sub hook_connect {
  my ($self, $transaction) = @_;

  $self->reload_spbl();

  return (DECLINED);
}

sub reload_spbl {
  my ($self) = @_;

  # reload every hours
  if (time() > $self->{spbl_lastreload} + 60*10) {
    $self->{spbl_lastreload} = time();
  } else {
    return;
  }

  Qpsmtpd->varlog(LOGINFO, "init", "spbl", "Reloading SPBL...");

  @SPBL_IDs = ();
  @SPBL_Domains = ();

  my $max_entries = 2000;
  my $count = 0;

  my $Dest = $self->spool_dir();

  my $URL_IDs = 'http://www.invaluement.com/spdata/sendgrid-id-dnsbl.txt';
  my $File_IDs = 'sendgrid-id-dnsbl.txt';

  my $URL_Domains = 'http://www.invaluement.com/spdata/sendgrid-envelopefromdomain-dnsbl.txt';
  my $File_Domains = 'sendgrid-envelopefromdomain-dnsbl.txt';

  my $browser = LWP::UserAgent->new();

  $browser->timeout(10);

  my $response = $browser->get($URL_IDs,
                               ':content_file' => "$Dest/$File_IDs"
      );

  if ($response->is_success) {
    if (open (READ, "< $Dest/$File_IDs")) {
      foreach my $item (<READ>) {
	chomp($item);
	next if ($item =~ /^#/);
	if ( $item =~ /^[0-9]+$/ ) {   
#	  Qpsmtpd->varlog(LOGINFO, "init", "spbl", "Adding SendGrid ID: \"$item\"");

          if (++$count > $max_entries) {
            Qpsmtpd->varlog(LOGINFO, "init", "spbl", "Reached limit of $max_entries SendGrid IDs");
            last;
          }

	  push (@SPBL_IDs,$item);
	}
      }
    }
    unlink "$Dest/$File_IDs";
  }


  $count = 0;

  $response = $browser->get($URL_Domains,
			    ':content_file' => "$Dest/$File_Domains"
      );
  
  if ($response->is_success) {
    if (open (READ, "< $Dest/$File_Domains")) {
      foreach my $item (<READ>) {
        chomp($item);
        next if ($item =~ /^#/);
        if ( is_domain($item)) {
#	  Qpsmtpd->varlog(LOGINFO, "init", "spbl", "Adding SendGrid Domain: \"$item\"");
	  
	  if (++$count > $max_entries) {
	    Qpsmtpd->varlog(LOGINFO, "init", "spbl", "Reached limit of $max_entries SendGrid Domains");
	    last;
	  }
	  
          push (@SPBL_Domains,$item);
        }
      }
    }
    unlink "$Dest/$File_Domains";
  }
  
  
  return 1;
}

sub hook_mail {
  my ($self,$transaction, $sender) = @_;

  my $from;

  if ($sender->host and $sender->user) {
    $from = lc($sender->user) . '@' . lc($sender->host);
  } else {
    return DECLINED;
  }

  return DECLINED if ($from eq '');

  my ($id,$rest) = $from =~ /^bounces\+([^-]+)-(.*)\@sendgrid\.net$/;

  if (defined($id)) {
    
#    $self->log(LOGINFO, "SendGrid Mail \"$from\" with ID \"$id\"");
    
    if (grep (/$id/,@SPBL_IDs)) {
      
      $self->log(LOGINFO, "SendGrid Match ID \"$id\" on \"$from\"");
      return (DENY,"Message was sent from a known SendGrid spammer");
    }
  }

  # Custom Sendgrid domain

  if ($from =~ /^bounces\+/) {
    foreach my $Domain (@SPBL_Domains) {
      if ($from =~ /^bounces\+(.*).$Domain$/) {
	$self->log(LOGINFO, "SendGrid Match Domain \"$Domain\" on \"$from\"");
	return (DENY,"Message was sent from a known SendGrid spammer");
      }
    }
  }
  return DECLINED;
}