[pmg-devel] [PATCH pmg-api 2/2] smtputf8: keep smtputf8 from incoming postfix, detect for local mail

[Stoiko Ivanov <s.ivanov@proxmox.com>]

This patch changes the detection if smtputf8 is needed as option to
the 'MAIL' command:
* for mail passing 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 should approximate 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.
If this occurs in the wild we would also need to adapt the
unconditional encoding of the envelope addresses in reinject_mail

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
 src/PMG/API2/Quarantine.pm |  7 ++++++-
 src/PMG/RuleDB/Notify.pm   |  6 +++++-
 src/PMG/SMTP.pm            |  7 ++++++-
 src/PMG/Utils.pm           | 16 +++++++++++++---
 4 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/src/PMG/API2/Quarantine.pm b/src/PMG/API2/Quarantine.pm
index fbb302a..352f6b6 100644
--- a/src/PMG/API2/Quarantine.pm
+++ b/src/PMG/API2/Quarantine.pm
@@ -1239,7 +1239,12 @@ 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);
+
+    my $params;
+    if (PMG::Utils::mail_needs_smtputf8($mail, '', [$receiver])) {
+	$params->{mail}->{smtputf8} = 1;
+    }
+    PMG::Utils::reinject_mail ($mail, '', [$receiver], undef, $fqdn, $params);
 }
 
 __PACKAGE__->register_method ({
diff --git a/src/PMG/RuleDB/Notify.pm b/src/PMG/RuleDB/Notify.pm
index 68f9b4e..7887195 100644
--- a/src/PMG/RuleDB/Notify.pm
+++ b/src/PMG/RuleDB/Notify.pm
@@ -256,8 +256,12 @@ sub execute {
 	print $fh "notify end\n";
     } else {
 	my @targets = split(/\s*,\s*/, $to);
+	my $params;
+	if (PMG::Utils::mail_needs_smtputf8($top, $from, \@targets)) {
+	    $params->{mail}->{smtputf8} = 1;
+	}
 	my $qid = PMG::Utils::reinject_mail(
-	    $top, $from, \@targets, undef, $msginfo->{fqdn});
+	    $top, $from, \@targets, undef, $msginfo->{fqdn}, $params);
 	foreach (@targets) {
 	    my $target = encode('UTF-8', $_);
 	    if ($qid) {
diff --git a/src/PMG/SMTP.pm b/src/PMG/SMTP.pm
index fbf5c95..35ed9c4 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 +315,11 @@ EOF
 	Encoding => '7bit',
 	Description => 'Delivery report');
 
-    my $qid = PMG::Utils::reinject_mail($ndr, '', [$sender], undef, $hostname);
+    my $params;
+    if (PMG::Utils::mail_needs_smtputf8($ndr, '', [$sender])) {
+	$params->{mail}->{smtputf8} = 1;
+    }
+    my $qid = PMG::Utils::reinject_mail($ndr, '', [$sender], undef, $hostname, $params);
     if ($qid) {
 	syslog('info', "sent NDR for rejecting recipients - $qid");
     } else {
diff --git a/src/PMG/Utils.pm b/src/PMG/Utils.pm
index 9c6f841..1ccd7d2 100644
--- a/src/PMG/Utils.pm
+++ b/src/PMG/Utils.pm
@@ -232,6 +232,10 @@ sub mail_needs_smtputf8 {
 	}
     }
 
+    if ($entity->head()->as_string() =~ /([^\p{PosixPrint}\n\r\t])/) {
+	return 1;
+    }
+
     return 0;
 }
 
@@ -260,10 +264,12 @@ 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->{$p}";
@@ -1258,7 +1264,11 @@ sub finalize_report {
 	return;
     }
     # we use an empty envelope sender (we don't want to receive NDRs)
-    PMG::Utils::reinject_mail ($top, '', [$receiver], undef, $data->{fqdn});
+    my $params;
+    if (PMG::Utils::mail_needs_smtputf8($top, '', [$receiver])) {
+	$params->{mail}->{smtputf8} = 1;
+    }
+    PMG::Utils::reinject_mail ($top, '', [$receiver], undef, $data->{fqdn}, $params);
 }
 
 sub lookup_timespan {
-- 
2.30.2