upstream: Reset last-seen time when sending a keepalive. Prevents

sending two keepalives successively and prematurely terminating connection
when ClientAliveCount=1.  While there, collapse two similar tests into one.
ok markus@

OpenBSD-Commit-ID: 043670d201dfe222537a2a4bed16ce1087de5ddd

diff --git a/serverloop.c b/serverloop.c
index 9602e050de5384f66682e47438a85277916a5489..f86f832b6f8af6bd691429cd31002acce896b4ee 100644 (file)
--- a/serverloop.c
+++ b/serverloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: serverloop.c,v 1.213 2019/01/19 22:30:52 djm Exp $ */
+/* $OpenBSD: serverloop.c,v 1.214 2019/03/06 21:06:59 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -225,6 +225,7 @@ wait_until_can_do_something(struct ssh *ssh,
        int ret;
        time_t minwait_secs = 0;
        int client_alive_scheduled = 0;
+       /* time we last heard from the client OR sent a keepalive */
        static time_t last_client_time;
 
        /* Allocate and update select() masks for channel descriptors. */
@@ -293,13 +294,15 @@ wait_until_can_do_something(struct ssh *ssh,
        } else if (client_alive_scheduled) {
                time_t now = monotime();
 
-               if (ret == 0) { /* timeout */
+               /*
+                * If the select timed out, or returned for some other reason
+                * but we haven't heard from the client in time, send keepalive.
+                */
+               if (ret == 0 || (last_client_time != 0 && last_client_time +
+                   options.client_alive_interval <= now)) {
                        client_alive_check(ssh);
-               } else if (FD_ISSET(connection_in, *readsetp)) {
                        last_client_time = now;
-               } else if (last_client_time != 0 && last_client_time +
-                   options.client_alive_interval <= now) {
-                       client_alive_check(ssh);
+               } else if (FD_ISSET(connection_in, *readsetp)) {
                        last_client_time = now;
                }
        }