1 files changed, 42 insertions, 45 deletions

diff --git a/plugins/check_swap.c b/plugins/check_swap.c
index cd965e31..e7ee785d 100644
--- a/plugins/check_swap.c
+++ b/plugins/check_swap.c
@@ -4,7 +4,7 @@
 *
 * License: GPL
 * Copyright (c) 2000 Karl DeBisschop (kdebisschop@users.sourceforge.net)
-* Copyright (c) 2000-2007 Monitoring Plugins Development Team
+* Copyright (c) 2000-2024 Monitoring Plugins Development Team
 *
 * Description:
 *
@@ -28,7 +28,7 @@
 *****************************************************************************/
 
 const char *progname = "check_swap";
-const char *copyright = "2000-2007";
+const char *copyright = "2000-2024";
 const char *email = "devel@monitoring-plugins.org";
 
 #include "common.h"
@@ -52,9 +52,9 @@ const char *email = "devel@monitoring-plugins.org";
 #endif
 
 typedef struct {
-        int is_percentage;
+        bool is_percentage;
         uint64_t value;
-} threshold_t;
+} threshold;
 
 int check_swap (float free_swap_mb, float total_swap_mb);
 int process_arguments (int argc, char **argv);
@@ -62,10 +62,10 @@ int validate_arguments (void);
 void print_usage (void);
 void print_help (void);
 
-threshold_t warn;
-threshold_t crit;
+threshold warn;
+threshold crit;
 int verbose;
-int allswaps;
+bool allswaps = false;
 int no_swap_state = STATE_CRITICAL;
 
 int
@@ -383,10 +383,10 @@ main (int argc, char **argv)
         if (crit.is_percentage) crit_print = crit.value * (total_swap_mb *1024 *1024/100);
 
         puts (perfdata_uint64 ("swap", free_swap_mb *1024 *1024, "B",
-                        TRUE, warn_print,
-                        TRUE, crit_print,
-                        TRUE, 0,
-                        TRUE, (long) total_swap_mb * 1024 * 1024));
+                        true, warn_print,
+                        true, crit_print,
+                        true, 0,
+                        true, (long) total_swap_mb * 1024 * 1024));
 
         return result;
 }
@@ -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);
 
@@ -465,7 +464,7 @@ process_arguments (int argc, char **argv)
 
                                 if (optarg[length - 1] == '%') {
                                         /* It's percentage */
-                                        warn.is_percentage = 1;
+                                        warn.is_percentage = true;
                                         optarg[length - 1] = '\0';
                                         if (is_uint64(optarg, &warn.value)) {
                                                 if (warn.value > 100) {
@@ -475,7 +474,7 @@ process_arguments (int argc, char **argv)
                                         break;
                                 } else {
                                         /* It's Bytes */
-                                        warn.is_percentage = 0;
+                                        warn.is_percentage = false;
                                         if (is_uint64(optarg, &warn.value)) {
                                                 break;
                                         } else {
@@ -495,7 +494,7 @@ process_arguments (int argc, char **argv)
 
                                 if (optarg[length - 1] == '%') {
                                         /* It's percentage */
-                                        crit.is_percentage = 1;
+                                        crit.is_percentage = true;
                                         optarg[length - 1] = '\0';
                                         if (is_uint64(optarg, &crit.value)) {
                                                 if (crit.value> 100) {
@@ -505,7 +504,7 @@ process_arguments (int argc, char **argv)
                                         break;
                                 } else {
                                         /* It's Bytes */
-                                        crit.is_percentage = 0;
+                                        crit.is_percentage = false;
                                         if (is_uint64(optarg, &crit.value)) {
                                                 break;
                                         } else {
@@ -514,7 +513,7 @@ process_arguments (int argc, char **argv)
                                 }
                           }
                 case 'a':                                                                       /* all swap */
-                        allswaps = TRUE;
+                        allswaps = true;
                         break;
                 case 'n':
                         if ((no_swap_state = mp_translate_state(optarg)) == ERROR) {
@@ -547,10 +546,7 @@ process_arguments (int argc, char **argv)
 int
 validate_arguments (void)
 {
-        if (warn.value == 0 && crit.value == 0) {
-                return ERROR;
-        }
-        else if ((warn.is_percentage == crit.is_percentage) && (warn.value < crit.value)) {
+        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
                  * dont know the value of total swap yet
@@ -595,6 +591,7 @@ 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 +602,6 @@ 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");
 }