daemon: set TCP_DEFER_ACCEPT on everything but NNTP

This Linux-specific option can save us some wakeups during
the TLS negotiation phase, and it can help with ordinary HTTP,
too.

Plain NNTP (and in the future, POP3) are the only things which
require the server send messages, first.

1 files changed, 10 insertions, 1 deletions

diff --git a/t/nntpd-tls.t b/t/nntpd-tls.t
index e8fb63b4..ef683cab 100644
--- a/t/nntpd-tls.t
+++ b/t/nntpd-tls.t
@@ -4,7 +4,7 @@ use strict;
 use warnings;
 use Test::More;
 use File::Temp qw(tempdir);
-use Socket qw(SOCK_STREAM);
+use Socket qw(SOCK_STREAM IPPROTO_TCP);
 # IO::Poll and Net::NNTP are part of the standard library, but
 # distros may split them off...
 foreach my $mod (qw(DBD::SQLite IO::Socket::SSL Net::NNTP IO::Poll)) {
@@ -182,6 +182,15 @@ for my $args (
         is(sysread($slow, my $eof, 4096), 0, 'got EOF');
         $slow = undef;
 
+        SKIP: {
+                skip 'TCP_DEFER_ACCEPT is Linux-only', 2 if $^O ne 'linux';
+                my $var = Socket::TCP_DEFER_ACCEPT();
+                defined(my $x = getsockopt($nntps, IPPROTO_TCP, $var)) or die;
+                ok(unpack('i', $x) > 0, 'TCP_DEFER_ACCEPT set on NNTPS');
+                defined($x = getsockopt($starttls, IPPROTO_TCP, $var)) or die;
+                is(unpack('i', $x), 0, 'TCP_DEFER_ACCEPT is 0 on plain NNTP');
+        };
+
         $c = undef;
         kill('TERM', $pid);
         is($pid, waitpid($pid, 0), 'nntpd exited successfully');