1 files changed, 116 insertions, 0 deletions
diff --git a/dmarc_milter.pl b/dmarc_milter.pl
new file mode 100755
index 0000000..bdb6e0b
--- /dev/null
+++ b/dmarc_milter.pl
@@ -0,0 +1,116 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+use lib '.';
+
+use Sendmail::Milter;
+use Spline::DMARC qw(check_addresses);
+use Spline::Log qw(set_verbose debug info);
+use Spline::Data;
+
+use Data::Dumper;
+
+my %milter_callbacks = (
+    'envfrom' => \&from_callback,
+    'envrcpt' => \&rcpt_callback,
+    'header' => \&header_callback,
+    'eoh' => \&eom_callback,
+    'abort' => \&abort_callback,
+    'close' => \&close_callback,
+);
+
+sub from_callback($$@) {
+    my $ctx = shift;
+    my $from = shift;
+
+    my $data = Spline::Data->new($ctx);
+    $data->set('counter', 0);
+
+    debug "MAIL FROM: $from";
+    return SMFIS_CONTINUE;
+}
+
+sub rcpt_callback($$@) {
+    my $ctx = shift;
+    my $rcpt_to = shift;
+
+    my $data = Spline::Data->load($ctx);
+    debug "RCPT TO: $rcpt_to";
+
+    my $next_hop = $ctx->getsymval('{rcpt_host}');
+    if ($next_hop eq '[lists.spline.inf.fu-berlin.de]') {
+        info "Mailinglist address: $rcpt_to";
+        $data->set('counter', 1);
+    }
+
+    return SMFIS_CONTINUE;
+}
+
+sub header_callback($$$) {
+    my $ctx = shift;
+    my ($field, $value) = @_;
+ 
+    my $data = Spline::Data->load($ctx);
+    debug "HEADER '$field': $value";
+
+    if (lc($field) eq 'from') {
+        return SMFIS_CONTINUE if $data->get('counter') == 0;
+
+        my $reject = check_addresses($value);
+        if ($reject) {
+            info 'Rejecting mail';
+            $ctx->setreply('550', '5.7.2', 'Your provider does not permit sending to mailing lists (DMARC policy)');
+            return SMFIS_REJECT;
+        }
+    }
+
+    # We cannot SMFIS_ACCEPT here, because there could
+    # be multiple From headers.
+    return SMFIS_CONTINUE; 
+}
+
+sub eoh_callback($) {
+    my $ctx = shift;
+
+    my $data = Spline::Data->load($ctx);
+    $data->set('counter', 0);
+
+    debug 'END OF HEADER';
+    return SMFIS_ACCEPT;
+}
+
+sub abort_callback($) {
+    my $ctx = shift;
+
+    my $data = Spline::Data->load($ctx);
+    $data->set('counter', 0);
+
+    debug 'ABORT';
+    return SMFIS_CONTINUE;
+}
+
+sub close_callback($) {
+    my $ctx = shift;
+    
+    Spline::Data->load($ctx);
+    $ctx->setpriv(undef);
+
+    debug 'CLOSE';
+    return SMFIS_CONTINUE;
+}
+
+sub main($) {
+    my $listen = shift;
+
+    Sendmail::Milter::setconn($listen);
+    Sendmail::Milter::register("dmarc_lists_filter",
+        \%milter_callbacks, SMFI_CURR_ACTS);
+    Sendmail::Milter::main();
+}
+
+main('inet:12345@localhost');
+
+# vim: set et tabstop=4 tw=70: