1 files changed, 31 insertions, 28 deletions

diff --git a/plugins/check_swap.c b/plugins/check_swap.c
index 499a8d2..56c5f42 100644
--- a/plugins/check_swap.c
+++ b/plugins/check_swap.c
@@ -399,28 +399,30 @@ check_swap(float free_swap_mb, float total_swap_mb)
         if (!total_swap_mb) return no_swap_state;
 
         uint64_t free_swap = free_swap_mb * (1024 * 1024);              /* Convert back to bytes as warn and crit specified in bytes */
-
-        if (!crit.is_percentage && crit.value >= free_swap) return STATE_CRITICAL;
-        if (!warn.is_percentage && warn.value >= free_swap) return STATE_WARNING;
-
-
         uint64_t usage_percentage = ((total_swap_mb - free_swap_mb) / total_swap_mb) * 100;
 
-        if (crit.is_percentage &&
-                        crit.value != 0 &&
-                        usage_percentage >= (100 - crit.value))
-        {
-                        return STATE_CRITICAL;
-        }
-
-        if (warn.is_percentage &&
-                        warn.value != 0 &&
-                        usage_percentage >= (100 - warn.value))
-        {
-                        return STATE_WARNING;
-        }
-
-        return STATE_OK;
+        if (warn.value && crit.value) {                                 /* Thresholds defined */
+                if (!crit.is_percentage && crit.value >= free_swap) return STATE_CRITICAL;
+                if (!warn.is_percentage && warn.value >= free_swap) return STATE_WARNING;
+
+                if (crit.is_percentage &&
+                                crit.value != 0 &&
+                                usage_percentage >= (100 - crit.value))
+                {
+                                return STATE_CRITICAL;
+                }
+
+                if (warn.is_percentage &&
+                                warn.value != 0 &&
+                                usage_percentage >= (100 - warn.value))
+                {
+                                return STATE_WARNING;
+                }
+
+                return STATE_OK;
+        } else {                                                        /* Without thresholds */
+                return STATE_OK;
+        }
 }
 
 
@@ -443,9 +445,6 @@ process_arguments (int argc, char **argv)
                 {0, 0, 0, 0}
         };
 
-        if (argc < 2)
-                return ERROR;
-
         while (1) {
                 c = getopt_long (argc, argv, "+?Vvhac:w:n:", longopts, &option);
 
@@ -547,9 +546,12 @@ process_arguments (int argc, char **argv)
 int
 validate_arguments (void)
 {
-        if (warn.value == 0 && crit.value == 0) {
-                return ERROR;
-        }
+        if (warn.value && !crit.value) {
+                usage4(_("Must define both warning and critical thresholds"));
+        }
+        else if (crit.value && !warn.value) {
+                usage4(_("Must define both warning and critical thresholds"));
+        }
         else if ((warn.is_percentage == crit.is_percentage) && (warn.value < crit.value)) {
                 /* This is NOT triggered if warn and crit are different units, e.g warn is percentage
                  * and crit is absolute. We cannot determine the condition at this point since we
@@ -595,6 +597,7 @@ print_help (void)
         printf ("\n");
         printf ("%s\n", _("Notes:"));
         printf (" %s\n", _("Both INTEGER and PERCENT thresholds can be specified, they are all checked."));
+        printf (" %s\n", _("Without thresholds, the plugin shows free swap space and performance data, but always returns OK."));
         printf (" %s\n", _("On AIX, if -a is specified, uses lsps -a, otherwise uses lsps -s."));
 
         printf (UT_SUPPORT);
@@ -605,6 +608,6 @@ void
 print_usage (void)
 {
         printf ("%s\n", _("Usage:"));
-        printf (" %s [-av] -w <percent_free>%% -c <percent_free>%%\n",progname);
-        printf ("  -w <bytes_free> -c <bytes_free> [-n <state>]\n");
+        printf (" %s [-av] [-w <percent_free>%%] [-c <percent_free>%%]\n",progname);
+        printf ("  [-w <bytes_free>] [-c <bytes_free>] [-n <state>]\n");
 }