{ "dane_require_tls_ciphers", opt_stringptr, LOFF(dane_require_tls_ciphers) },
# endif
{ "data_timeout", opt_time, LOFF(data_timeout) },
- { "delay_after_cutoff", opt_bool, LOFF(delay_after_cutoff) },
+ { "delay_after_cutoff", opt_bool, LOFF(delay_after_cutoff) },
#ifndef DISABLE_DKIM
{ "dkim_canon", opt_stringptr, LOFF(dkim.dkim_canon) },
{ "dkim_domain", opt_stringptr, LOFF(dkim.dkim_domain) },
static BOOL
smtp_reap_banner(smtp_context * sx)
{
-BOOL good_response = smtp_read_response(sx, sx->buffer, sizeof(sx->buffer),
+BOOL good_response;
+#if defined(__linux__) && defined(TCP_QUICKACK)
+ { /* Hack to get QUICKACK disabled; has to be right after 3whs, and has to on->off */
+ int sock = sx->cctx.sock;
+ struct pollfd p = {.fd = sock, .events = POLLOUT};
+ int rc = poll(&p, 1, 1000);
+ (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &on, sizeof(on));
+ (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
+ }
+#endif
+good_response = smtp_read_response(sx, sx->buffer, sizeof(sx->buffer),
'2', (SOB sx->conn_args.ob)->command_timeout);
#ifdef EXPERIMENTAL_DSN_INFO
sx->smtp_greeting = string_copy(sx->buffer);
uschar * ehlo_resp_key = ehlo_cache_key(sx);
dbdata_ehlo_resp * er;
- if (!(er = dbfn_read(dbm_file, ehlo_resp_key)))
+ if (!(er = dbfn_read_enforce_length(dbm_file, ehlo_resp_key, sizeof(dbdata_ehlo_resp))))
{ DEBUG(D_transport) debug_printf("no ehlo-resp record\n"); }
else if (time(NULL) - er->time_stamp > retry_data_expire)
{
else
#endif
{
- if ((sx->cctx.sock = smtp_connect(&sx->conn_args, NULL)) < 0)
+ blob lazy_conn = {.data = NULL};
+ /* For TLS-connect, a TFO lazy-connect is useful since the Client Hello
+ can go on the TCP SYN. */
+
+ if ((sx->cctx.sock = smtp_connect(&sx->conn_args,
+ sx->smtps ? &lazy_conn : NULL)) < 0)
{
set_errno_nohost(sx->addrlist,
errno == ETIMEDOUT ? ERRNO_CONNECTTIMEOUT : errno,
sx->send_quit = FALSE;
return DEFER;
}
+#ifdef TCP_QUICKACK
+ (void) setsockopt(sx->cctx.sock, IPPROTO_TCP, TCP_QUICKACK, US &off,
+ sizeof(off));
+#endif
}
/* Expand the greeting message while waiting for the initial response. (Makes
sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is
else
#endif
{
-#ifdef TCP_QUICKACK
- (void) setsockopt(sx->cctx.sock, IPPROTO_TCP, TCP_QUICKACK, US &off,
- sizeof(off));
-#endif
if (!smtp_reap_banner(sx))
goto RESPONSE_FAILED;
}
*message_defer = TRUE;
}
+#ifdef TIOCOUTQ
+ DEBUG(D_transport) if (sx->cctx.sock >= 0)
+ {
+ int n;
+ if (ioctl(sx->cctx.sock, TIOCOUTQ, &n) == 0)
+ debug_printf("%d bytes remain in socket output buffer\n", n);
+ }
+#endif
}
-
/* Otherwise, we have an I/O error or a timeout other than after MAIL or
".", or some other transportation error. We defer all addresses and yield
DEFER, except for the case of failed add_headers expansion, or a transport
}
/* End off tidily with QUIT unless the connection has died or the socket has
-been passed to another process. There has been discussion on the net about what
-to do after sending QUIT. The wording of the RFC suggests that it is necessary
-to wait for a response, but on the other hand, there isn't anything one can do
-with an error response, other than log it. Exim used to do that. However,
-further discussion suggested that it is positively advantageous not to wait for
-the response, but to close the session immediately. This is supposed to move
-the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
-load from the server. (Hosts that are both servers and clients may not see much
-difference, of course.) Further discussion indicated that this was safe to do
-on Unix systems which have decent implementations of TCP/IP that leave the
-connection around for a while (TIME_WAIT) after the application has gone away.
-This enables the response sent by the server to be properly ACKed rather than
-timed out, as can happen on broken TCP/IP implementations on other OS.
-
-This change is being made on 31-Jul-98. After over a year of trouble-free
-operation, the old commented-out code was removed on 17-Sep-99. */
+been passed to another process. */
SEND_QUIT:
-#ifdef TCP_CORK
-(void) setsockopt(sx->cctx.sock, IPPROTO_TCP, TCP_CORK, US &on, sizeof(on));
-#endif
-if (sx->send_quit) (void)smtp_write_command(sx, SCMD_FLUSH, "QUIT\r\n");
+if (sx->send_quit)
+ /* Use _MORE to get QUIT in FIN segment */
+ (void)smtp_write_command(sx, SCMD_MORE, "QUIT\r\n");
END_OFF:
#ifndef DISABLE_TLS
+# ifdef EXIM_TCP_CORK
+if (sx->cctx.tls_ctx) /* Use _CORK to get TLS Close Notify in FIN segment */
+ (void) setsockopt(sx->cctx.sock, IPPROTO_TCP, EXIM_TCP_CORK, US &on, sizeof(on));
+# endif
+
tls_close(sx->cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
sx->cctx.tls_ctx = NULL;
#endif
HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
if (sx->send_quit)
{
+ /* This flushes data queued in the socket, being the QUIT and any TLS Close,
+ sending them along with the client FIN flag. Us (we hope) sending FIN first
+ means we (client) take the TIME_WAIT state, so the server (which likely has a
+ higher connection rate) does no have to. */
+
shutdown(sx->cctx.sock, SHUT_WR);
+
+ /* Wait for (we hope) ack of our QUIT, and a server FIN. Discard any data
+ received, then discard the socket. Any packet received after then, or receive
+ data still in the socket, will get a RST - hence the pause/drain. */
+
millisleep(20);
testharness_pause_ms(200);
if (fcntl(sx->cctx.sock, F_SETFL, O_NONBLOCK) == 0)