TFO: change the default for hosts_try_fastopen, enabling use by default

[exim.git] / src / src / transports / smtp.c

diff --git a/src/src/transports/smtp.c b/src/src/transports/smtp.c
index 5f610821981d1cb5a08065e46552b80242a74c7e..3ed2166ce591a1544b5f35f59f741473964e90ee 100644 (file)
--- a/src/src/transports/smtp.c
+++ b/src/src/transports/smtp.c
@@ -244,7 +244,7 @@ smtp_transport_options_block smtp_transport_option_defaults = {
   .hosts_require_dane =                NULL,
   .dane_require_tls_ciphers =  NULL,
 #endif
-  .hosts_try_fastopen =                NULL,
+  .hosts_try_fastopen =                US"*",
 #ifndef DISABLE_PRDR
   .hosts_try_prdr =            US"*",
 #endif
@@ -2125,16 +2125,9 @@ if (!continue_hostname)
     {
     if ((sx->cctx.sock = smtp_connect(&sx->conn_args, NULL)) < 0)
       {
-      uschar * msg = NULL;
-      if (sx->verify)
-       {
-       msg = US strerror(errno);
-       HDEBUG(D_verify) debug_printf("connect: %s\n", msg);
-       }
       set_errno_nohost(sx->addrlist,
        errno == ETIMEDOUT ? ERRNO_CONNECTTIMEOUT : errno,
-       sx->verify ? string_sprintf("could not connect: %s", msg)
-              : NULL,
+       sx->verify ? US strerror(errno) : NULL,
        DEFER, FALSE);
       sx->send_quit = FALSE;
       return DEFER;
@@ -2847,6 +2840,29 @@ return OK;
   int code;
 
   RESPONSE_FAILED:
+    if (errno == ECONNREFUSED) /* first-read error on a TFO conn */
+      {
+      /* There is a testing facility for simulating a connection timeout, as I
+      can't think of any other way of doing this. It converts a connection
+      refused into a timeout if the timeout is set to 999999.  This is done for
+      a 3whs connection in ip_connect(), but a TFO connection does not error
+      there - instead it gets ECONNREFUSED on the first data read.  Tracking
+      that a TFO really was done is too hard, or we would set a
+      sx->pending_conn_done bit and test that in smtp_reap_banner() and
+      smtp_reap_ehlo().  That would let us also add the conn-timeout to the
+      cmd-timeout. */
+
+      if (f.running_in_test_harness && ob->connect_timeout == 999999)
+       errno = ETIMEDOUT;
+      set_errno_nohost(sx->addrlist,
+       errno == ETIMEDOUT ? ERRNO_CONNECTTIMEOUT : errno,
+       sx->verify ? US strerror(errno) : NULL,
+       DEFER, FALSE);
+      sx->send_quit = FALSE;
+      return DEFER;
+      }
+
+    /* really an error on an SMTP read */
     message = NULL;
     sx->send_quit = check_response(sx->conn_args.host, &errno, sx->addrlist->more_errno,
       sx->buffer, &code, &message, &pass_message);
@@ -2904,7 +2920,8 @@ FAILED:
                        || errno == ERRNO_UTF8_FWD
 #endif
            ? FAIL : DEFER,
-           pass_message, sx->conn_args.host
+           pass_message,
+           errno == ECONNREFUSED ? NULL : sx->conn_args.host
 #ifdef EXPERIMENTAL_DSN_INFO
            , sx->smtp_greeting, sx->helo_response
 #endif