[pmg-devel] [PATCH pmg-api v2 1/4] smtputf8: keep smtputf8 from incoming postfix, detect for local mail

[Stoiko Ivanov]

This patch changes the detection if smtputf8 is needed as option to
the 'MAIL' command:
* for mail arriving through postfix it is only added if the mail
  originally was received with it (Accept and BCC actions)
* for locally generated mail (Notify, reports, quarantine-link and
  ndrs) it is decided based on utf8 characters in the mail-addresses
  or headers - this is done by `reinject_local_mail`, as a new helper

This should match postfix own behavior in those cases quite
closely:
https://www.postfix.org/SMTPUTF8_README.html#using

Notable difference is that we check the complete e-mail address and
not only the domain part, but I assume non-ascii local-parts to be a
very fringe edge-case in environments where smtputf8 is not supported.

Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
---
 src/PMG/API2/Quarantine.pm |  2 +-
 src/PMG/RuleDB/Notify.pm   |  2 +-
 src/PMG/SMTP.pm            |  3 ++-
 src/PMG/Utils.pm           | 28 ++++++++++++++++++++--------
 4 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/src/PMG/API2/Quarantine.pm b/src/PMG/API2/Quarantine.pm
index fbb302a..6318082 100644
--- a/src/PMG/API2/Quarantine.pm
+++ b/src/PMG/API2/Quarantine.pm
@@ -1239,7 +1239,7 @@ my sub send_link_mail {
     );
 
     # we use an empty envelope sender (we don't want to receive NDRs)
-    PMG::Utils::reinject_mail ($mail, '', [$receiver], undef, $fqdn);
+    PMG::Utils::reinject_local_mail ($mail, '', [$receiver], undef, $fqdn);
 }
 
 __PACKAGE__->register_method ({
diff --git a/src/PMG/RuleDB/Notify.pm b/src/PMG/RuleDB/Notify.pm
index 68f9b4e..c024840 100644
--- a/src/PMG/RuleDB/Notify.pm
+++ b/src/PMG/RuleDB/Notify.pm
@@ -256,7 +256,7 @@ sub execute {
 	print $fh "notify end\n";
     } else {
 	my @targets = split(/\s*,\s*/, $to);
-	my $qid = PMG::Utils::reinject_mail(
+	my $qid = PMG::Utils::reinject_local_mail(
 	    $top, $from, \@targets, undef, $msginfo->{fqdn});
 	foreach (@targets) {
 	    my $target = encode('UTF-8', $_);
diff --git a/src/PMG/SMTP.pm b/src/PMG/SMTP.pm
index fbf5c95..b7bc5d3 100644
--- a/src/PMG/SMTP.pm
+++ b/src/PMG/SMTP.pm
@@ -111,6 +111,7 @@ sub loop {
 			$self->{param}->{mail}->{$1} = $2;
 		    } elsif ($opt =~ m/smtputf8/i) {
 			$self->{smtputf8} = 1;
+			$self->{param}->{mail}->{smtputf8} = 1;
 			$from = decode('UTF-8', $from);
 		    } else {
 			#ignore everything else
@@ -314,7 +315,7 @@ EOF
 	Encoding => '7bit',
 	Description => 'Delivery report');
 
-    my $qid = PMG::Utils::reinject_mail($ndr, '', [$sender], undef, $hostname);
+    my $qid = PMG::Utils::reinject_local_mail($ndr, '', [$sender], undef, $hostname);
     if ($qid) {
 	syslog('info', "sent NDR for rejecting recipients - $qid");
     } else {
diff --git a/src/PMG/Utils.pm b/src/PMG/Utils.pm
index 9c6f841..49939c4 100644
--- a/src/PMG/Utils.pm
+++ b/src/PMG/Utils.pm
@@ -221,18 +221,28 @@ sub subst_values_for_header {
     return $res;
 }
 
-sub mail_needs_smtputf8 {
-    my ($entity, $sender, $targets) = @_;
+# detects the need for setting smtputf8 based on addresses and headers
+sub reinject_local_mail {
+    my ($entity, $sender, $targets, $xforward, $me, $params) = @_;
+
+    my $needs_smtputf8 = 0;
 
-    return 1 if ($sender =~ /[^\p{PosixPrint}]/);
+    $needs_smtputf8 = 1 if ($sender =~ /[^\p{PosixPrint}]/);
 
     foreach my $target (@$targets) {
 	if ($target =~ /[^\p{PosixPrint}]/) {
-	    return 1;
+	    $needs_smtputf8 = 1;
+	    last;
 	}
     }
 
-    return 0;
+    if (!$needs_smtputf8 && $entity->head()->as_string() =~ /([^\p{PosixPrint}\n\r\t])/) {
+	$needs_smtputf8 = 1;
+    }
+
+    $params->{mail}->{smtputf8} = $needs_smtputf8;
+
+    return reinject_mail($entity, $sender, $targets, $xforward, $me, $params);
 }
 
 sub reinject_mail {
@@ -260,10 +270,12 @@ sub reinject_mail {
 	}
 
 	my $mail_opts = " BODY=8BITMIME";
-	$mail_opts .= " SMTPUTF8" if mail_needs_smtputf8($entity, $sender, $targets);
 	my $sender_addr = encode('UTF-8', $smtp->_addr($sender));
-
 	if (defined($params->{mail})) {
+	    if (delete $params->{mail}->{smtputf8}) {
+		$mail_opts .= " SMTPUTF8";
+	    }
+
 	    my $mailparams = $params->{mail};
 	    for my $p (keys %$mailparams) {
 		$mail_opts .= " $p=$mailparams->{$p}";
@@ -1258,7 +1270,7 @@ sub finalize_report {
 	return;
     }
     # we use an empty envelope sender (we don't want to receive NDRs)
-    PMG::Utils::reinject_mail ($top, '', [$receiver], undef, $data->{fqdn});
+    PMG::Utils::reinject_local_mail ($top, '', [$receiver], undef, $data->{fqdn});
 }
 
 sub lookup_timespan {
-- 
2.30.2