From fb6608bf47a9508fb3b661a364e597b94b517e5f Mon Sep 17 00:00:00 2001
From: Christoph Klaffl <christoph@phreaker.eu>
Date: Tue, 16 Oct 2018 10:48:04 +0200
Subject: [PATCH] implemented timeout for pre/post script execution and made
 sure environment is cleaned up after script failure

---
 sanoid | 50 ++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 42 insertions(+), 8 deletions(-)

diff --git a/sanoid b/sanoid
index 73efd5e..c12dff8 100755
--- a/sanoid
+++ b/sanoid
@@ -458,17 +458,21 @@ sub take_snapshots {
 			my $dataset = (split '@', $snap)[0];
 			my $snapname = (split '@', $snap)[1];
 			my $presnapshotfailure = 0;
+			my $timeout = 5;
 			if ($config{$dataset}{'pre_snapshot_script'} and !$args{'readonly'}) {
 				$ENV{'SANOID_TARGET'} = $dataset;
 				$ENV{'SANOID_SNAPNAME'} = $snapname;
 				if ($args{'verbose'}) { print "executing pre_snapshot_script '".$config{$dataset}{'pre_snapshot_script'}."' on dataset '$dataset'\n"; }
-				if (system($config{$dataset}{'pre_snapshot_script'}) != 0) {
-					warn "WARN: pre_snapshot_script failed, $?";
+				my $ret = runscript('pre_snapshot_script',$dataset,$timeout);
+
+				delete $ENV{'SANOID_TARGET'};
+				delete $ENV{'SANOID_SNAPNAME'};
+
+				if ($ret != 0) {
+					# warning was already thrown by runscript function
 					$config{$dataset}{'no_inconsistent_snapshot'} and next;
 					$presnapshotfailure = 1;
 				}
-				delete $ENV{'SANOID_TARGET'};
-				delete $ENV{'SANOID_SNAPNAME'};
 			}
 			if ($args{'verbose'}) { print "taking snapshot $snap\n"; }
 			if (!$args{'readonly'}) {
@@ -482,10 +486,8 @@ sub take_snapshots {
 					$ENV{'SANOID_TARGET'} = $dataset;
 					$ENV{'SANOID_SNAPNAME'} = $snapname;
 					if ($args{'verbose'}) { print "executing post_snapshot_script '".$config{$dataset}{'post_snapshot_script'}."' on dataset '$dataset'\n"; }
-					if (system($config{$dataset}{'post_snapshot_script'}) != 0) {
-						warn "WARN: post_snapshot_script failed, $?";
-						$config{$dataset}{'no_inconsistent_snapshot'} and next;
-					}
+					runscript('post_snapshot_script',$dataset,$timeout);
+
 					delete $ENV{'SANOID_TARGET'};
 					delete $ENV{'SANOID_SNAPNAME'};
 				}
@@ -1337,6 +1339,38 @@ sub removecachedsnapshots {
 	undef %pruned;
 }
 
+#######################################################################################################################3
+#######################################################################################################################3
+#######################################################################################################################3
+
+sub runscript {
+	my $key=shift;
+	my $dataset=shift;
+	my $timeout=shift;
+
+	my $ret;
+	eval {
+		local $SIG{ALRM} = sub { die "alarm\n" };
+		alarm $timeout;
+		$ret = system($config{$dataset}{$key});
+		alarm 0;
+	};
+	if ($@) {
+		if ($@ eq "alarm\n") {
+			warn "WARN: $key didn't finish in the allowed time!";
+		} else {
+			warn "CRITICAL ERROR: $@";
+		}
+		return -1;
+	} else {
+		if ($ret != 0) {
+			warn "WARN: $key failed, $?";
+		}
+	}
+
+	return $ret;
+}
+
 __END__
 
 =head1 NAME