X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fsrc%2Fsmtp_out.c;h=2a4497488bc1468c483a16cf8f3b712e94d71203;hb=20586bdc24045da63928cbdaace2f036e3c80bd5;hp=bb7a0e3b30e120b240a2caf98f3fc64bdcd86207;hpb=996a98d33f790a1e6af927c02318649feec6061b;p=user%2Fhenk%2Fcode%2Fexim.git

diff --git a/src/src/smtp_out.c b/src/src/smtp_out.c
index bb7a0e3b3..2a4497488 100644
--- a/src/src/smtp_out.c
+++ b/src/src/smtp_out.c
@@ -246,9 +246,18 @@ switch (tcp_out_fastopen)
 #endif
 
 
-/* Arguments as for smtp_connect(), plus
-  early_data	if non-NULL, idenmpotent data to be sent -
+/* Arguments:
+  host        host item containing name and address and port
+  host_af     AF_INET or AF_INET6
+  port	      TCP port number
+  interface   outgoing interface address or NULL
+  tb          transport
+  timeout     timeout value or 0
+  early_data	if non-NULL, idempotent data to be sent -
 		preferably in the TCP SYN segment
+	      Special case: non-NULL but with NULL blob.data - caller is
+	      client-data-first (eg. TLS-on-connect) and a lazy-TCP-connect is
+	      acceptable.
 
 Returns:      connected socket number, or -1 with errno set
 */
@@ -318,23 +327,45 @@ early-data but no TFO support, send it after connecting. */
 else
   {
 #ifdef TCP_FASTOPEN
+  /* See if TCP Fast Open usable.  Default is a traditional 3WHS connect */
   if (verify_check_given_host(CUSS &ob->hosts_try_fastopen, host) == OK)
-    fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata;
+    {
+    if (!early_data)
+      fastopen_blob = &tcp_fastopen_nodata;	/* TFO, with no data */
+    else if (early_data->data)
+      fastopen_blob = early_data;		/* TFO, with data */
+# ifdef TCP_FASTOPEN_CONNECT
+    else
+      {						/* expecting client data */
+      debug_printf(" set up lazy-connect\n");
+      setsockopt(sock, IPPROTO_TCP, TCP_FASTOPEN_CONNECT, US &on, sizeof(on));
+      /* fastopen_blob = NULL;		 lazy TFO, triggered by data write */
+      }
+# endif
+    }
 #endif
 
   if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0)
     save_errno = errno;
   else if (early_data && !fastopen_blob && early_data->data && early_data->len)
     {
+    /* We had some early-data to send, but couldn't do TFO */
     HDEBUG(D_transport|D_acl|D_v)
       debug_printf("sending %ld nonTFO early-data\n", (long)early_data->len);
 
-#ifdef TCP_QUICKACK
+#ifdef TCP_QUICKACK_notdef
     (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
 #endif
     if (send(sock, early_data->data, early_data->len, 0) < 0)
       save_errno = errno;
     }
+#ifdef TCP_QUICKACK_notdef
+  /* Under TFO (with openssl & pipe-conn; testcase 4069, as of
+  5.10.8-100.fc32.x86_64) this seems to be inop.
+  Perhaps overwritten when we (client) go -> ESTABLISHED on seeing the 3rd-ACK?
+  For that case, added at smtp_reap_banner(). */
+  (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
+#endif
   }
 
 /* Either bind() or connect() failed */
@@ -409,6 +440,9 @@ host->address will always be an IPv4 address.
 Arguments:
   sc	      details for making connection: host, af, interface, transport
   early_data  if non-NULL, data to be sent - preferably in the TCP SYN segment
+	      Special case: non-NULL but with NULL blob.data - caller is
+	      client-data-first (eg. TLS-on-connect) and a lazy-TCP-connect is
+	      acceptable.
 
 Returns:      connected socket number, or -1 with errno set
 */
@@ -625,7 +659,9 @@ if (format)
     while (*p) *p++ = '*';
     }
 
-  HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("  SMTP>> %s\n", big_buffer);
+  HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("  SMTP%c> %s\n",
+    mode == SCMD_BUFFER ? '|' : mode == SCMD_MORE ? '+' : '>',
+    big_buffer);
   }
 
 if (mode != SCMD_BUFFER)