From: djm <djm@openbsd.org>
Date: Wed, 20 Apr 2022 04:19:11 +0000 (+0000)
Subject: Try to continue running local I/O for channels in state OPEN during
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=bb597569f5b494b0ac7de51895ba7cbfa92a6150;p=openbsd

Try to continue running local I/O for channels in state OPEN during
SSH transport rekeying. The most visible benefit is that it should make
~-escapes work in the client (e.g. to exit) if the connection happened
to have stalled during a rekey event. Based work by and ok dtucker@
---

diff --git a/usr.bin/ssh/channels.c b/usr.bin/ssh/channels.c
index 97d7178eef6..f2f6267cec9 100644
--- a/usr.bin/ssh/channels.c
+++ b/usr.bin/ssh/channels.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.c,v 1.416 2022/04/11 22:52:08 djm Exp $ */
+/* $OpenBSD: channels.c,v 1.417 2022/04/20 04:19:11 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2378,6 +2378,9 @@ channel_handler(struct ssh *ssh, int table, time_t *unpause_secs)
 		c = sc->channels[i];
 		if (c == NULL)
 			continue;
+		/* Try to keep IO going while rekeying */
+		if (ssh_packet_is_rekeying(ssh) && c->type != SSH_CHANNEL_OPEN)
+			continue;
 		if (c->delayed) {
 			if (table == CHAN_PRE)
 				c->delayed = 0;
@@ -2568,17 +2571,13 @@ channel_prepare_poll(struct ssh *ssh, struct pollfd **pfdp, u_int *npfd_allocp,
 	/* Allocate 4x pollfd for each channel (rfd, wfd, efd, sock) */
 	if (sc->channels_alloc >= (INT_MAX / 4) - npfd_reserved)
 		fatal_f("too many channels"); /* shouldn't happen */
-	if (!ssh_packet_is_rekeying(ssh))
-		npfd += sc->channels_alloc * 4;
+	npfd += sc->channels_alloc * 4;
 	if (npfd > *npfd_allocp) {
 		*pfdp = xrecallocarray(*pfdp, *npfd_allocp,
 		    npfd, sizeof(**pfdp));
 		*npfd_allocp = npfd;
 	}
 	*npfd_activep = npfd_reserved;
-	if (ssh_packet_is_rekeying(ssh))
-		return;
-
 	oalloc = sc->channels_alloc;
 
 	channel_handler(ssh, CHAN_PRE, minwait_secs);
diff --git a/usr.bin/ssh/clientloop.c b/usr.bin/ssh/clientloop.c
index 6e799daa0d0..8807d230621 100644
--- a/usr.bin/ssh/clientloop.c
+++ b/usr.bin/ssh/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.378 2022/01/22 00:49:34 djm Exp $ */
+/* $OpenBSD: clientloop.c,v 1.379 2022/04/20 04:19:11 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1339,9 +1339,8 @@ client_loop(struct ssh *ssh, int have_pty, int escape_char_arg,
 		if (quit_pending)
 			break;
 
-		/* Do channel operations unless rekeying in progress. */
-		if (!ssh_packet_is_rekeying(ssh))
-			channel_after_poll(ssh, pfd, npfd_active);
+		/* Do channel operations. */
+		channel_after_poll(ssh, pfd, npfd_active);
 
 		/* Buffer input from the connection.  */
 		if (conn_in_ready)
diff --git a/usr.bin/ssh/serverloop.c b/usr.bin/ssh/serverloop.c
index 3b49719824b..221043617d2 100644
--- a/usr.bin/ssh/serverloop.c
+++ b/usr.bin/ssh/serverloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: serverloop.c,v 1.231 2022/01/22 00:49:34 djm Exp $ */
+/* $OpenBSD: serverloop.c,v 1.232 2022/04/20 04:19:11 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -386,8 +386,7 @@ server_loop2(struct ssh *ssh, Authctxt *authctxt)
 			cleanup_exit(255);
 		}
 
-		if (!ssh_packet_is_rekeying(ssh))
-			channel_after_poll(ssh, pfd, npfd_active);
+		channel_after_poll(ssh, pfd, npfd_active);
 		if (conn_in_ready &&
 		    process_input(ssh, connection_in) < 0)
 			break;