blockcheck: do not require root if SKIP_PKTWS=1. preserve vars during elevation

common/elevate.sh

@@ -1,13 +1,28 @@
 require_root()
 {
-	local exe
+	local exe preserve_env
 	echo \* checking privileges
 	[ $(id -u) -ne "0" ] && {
 		echo root is required
 		exe="$EXEDIR/$(basename "$0")"
-		exists sudo && exec sudo sh "$exe"
-		exists su && exec su root -c "sh \"$exe\""
+		exists sudo && {
+			echo elevating with sudo
+			exec sudo -E sh "$exe"
+		}
+		exists su && {
+			echo elevating with su
+			case "$UNAME" in
+				Linux)
+					preserve_env="--preserve-environment"
+					;;
+				FreeBSD|OpenBSD|Darwin)
+					preserve_env="-m"
+					;;
+			esac
+			exec su $preserve_env root -c "sh \"$exe\""
+		}
 		echo su or sudo not found
 		exitp 2
 	}
+	HAVE_ROOT=1
 }