From: Eric Wong <e@80x24.org>
Date: Wed, 2 Jul 2025 20:43:21 +0000 (+0000)
Subject: nntpd|imapd|pop3d: wait on writability, first
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=HEAD;p=thirdparty%2Fpublic-inbox.git

nntpd|imapd|pop3d: wait on writability, first

While instances of the first write(2) failing with EAGAIN
immediately after being returned by accept(2) is highly
unlikely, it still seems like a theoretical possibility.  So out
of an abundance of caution, we'll just wait on writability to
reduce branches in our code.
---

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 9706d520e..0da84b250 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -334,18 +334,13 @@ retry:
 # for IMAP, NNTP, and POP3 which greet clients upon connect
 sub greet {
 	my ($self, $sock) = @_;
-	my $ev = EPOLLIN;
-	my $wbuf;
+	my $ev = EPOLLOUT;
 	if ($sock->can('accept_SSL') && !$sock->accept_SSL) {
 		return if $! != EAGAIN || !($ev = PublicInbox::TLS::epollbit());
-		$wbuf = [ \&accept_tls_step, $self->can('do_greet')];
+		$self->{wbuf} = [ \&accept_tls_step ];
 	}
+	push @{$self->{wbuf}}, $self->can('do_greet');
 	new($self, $sock, $ev | EPOLLONESHOT);
-	if ($wbuf) {
-		$self->{wbuf} = $wbuf;
-	} else {
-		$self->do_greet;
-	}
 	$self;
 }