From e014fd79423129b7913d71b48a5f40ccab030edb Mon Sep 17 00:00:00 2001
From: Christoph Klaffl <christoph@phreaker.eu>
Date: Wed, 20 Feb 2019 18:06:04 +0100
Subject: [PATCH] check if ssh connection works

---
 syncoid | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/syncoid b/syncoid
index 3f6f9ba..6c98ff8 100755
--- a/syncoid
+++ b/syncoid
@@ -1247,6 +1247,13 @@ sub getssh {
 		$socket = "/tmp/syncoid-$remoteuser-$rhost-" . time();
 		open FH, "$sshcmd -M -S $socket -o ControlPersist=1m $args{'sshport'} $rhost exit |";
 		close FH;
+
+		system("$sshcmd -S $socket $rhost echo -n") == 0 or do {
+			my $code = $? >> 8;
+			warn "CRITICAL ERROR: ssh connection echo test failed for $rhost with exit code $code";
+			exit(2);
+		};
+
 		$rhost = "-S $socket $rhost";
 	} else {
 		my $localuid = $<;