[monitoring-plugins] check_swap: Fix perfdata und thresholds for big ...
rincewind
git at monitoring-plugins.org
Sun Oct 3 13:40:11 CEST 2021
Module: monitoring-plugins
Branch: master
Commit: 4621427ba8cbfab4815e65d35a728ad51ad8c391
Author: rincewind <rincewind at example.com>
Date: Sat Sep 25 23:24:45 2021 +0200
URL: https://www.monitoring-plugins.org/repositories/monitoring-plugins/commit/?id=4621427
check_swap: Fix perfdata und thresholds for big values and simplify code
The original problem was https://github.com/monitoring-plugins/monitoring-plugins/pull/1705
where the performance data output of check_swap did not conform to
the parser logic of a monitoring system (which decided to go for
"correct" SI or IEC units.
The PR was accompanied by a change to byte values in the performance
data which broke the _perfdata_ helper function which could not handle
values of this size.
The fix for this, was to use _fperfdata_ which could, but would
use float values.
I didn't like that (since all values here are discreet) and this
is my proposal for a fix for the problem.
It introduces some helper functions which do now explicitely work
with (u)int64_t, including a special version of the _perfdata_ helper.
In the process of introducing this to check_swap, I stumbled over
several sections of the check_swap code which I found problematic.
Therefore I tried to simplify the code and make it more readable
and less redundant.
I am kinda sorry about this, but sincerely hope my changes can
be helpful.
---
plugins/check_swap.c | 239 +++++++++++++++++++++++++++++----------------------
1 file changed, 137 insertions(+), 102 deletions(-)
diff --git a/plugins/check_swap.c b/plugins/check_swap.c
index 0ff0c77..25bcb3d 100644
--- a/plugins/check_swap.c
+++ b/plugins/check_swap.c
@@ -34,6 +34,10 @@ const char *email = "devel at monitoring-plugins.org";
#include "common.h"
#include "popen.h"
#include "utils.h"
+#include <string.h>
+#include <math.h>
+#include <libintl.h>
+#include <stdbool.h>
#ifdef HAVE_DECL_SWAPCTL
# ifdef HAVE_SYS_PARAM_H
@@ -51,26 +55,30 @@ const char *email = "devel at monitoring-plugins.org";
# define SWAP_CONVERSION 1
#endif
-int check_swap (int usp, float free_swap_mb, float total_swap_mb);
+typedef struct {
+ bool is_percentage;
+ uint64_t value;
+} threshold_t;
+
+int check_swap (float free_swap_mb, float total_swap_mb);
int process_arguments (int argc, char **argv);
int validate_arguments (void);
void print_usage (void);
void print_help (void);
-int warn_percent = 0;
-int crit_percent = 0;
-float warn_size_bytes = 0;
-float crit_size_bytes = 0;
+threshold_t warn;
+threshold_t crit;
int verbose;
-int allswaps;
+bool allswaps;
int no_swap_state = STATE_CRITICAL;
int
main (int argc, char **argv)
{
- int percent_used, percent;
- float total_swap_mb = 0, used_swap_mb = 0, free_swap_mb = 0;
- float dsktotal_mb = 0, dskused_mb = 0, dskfree_mb = 0, tmp_mb = 0;
+ unsigned int percent_used, percent;
+ uint64_t total_swap_mb = 0, used_swap_mb = 0, free_swap_mb = 0;
+ uint64_t dsktotal_mb = 0, dskused_mb = 0, dskfree_mb = 0;
+ uint64_t tmp_KB = 0;
int result = STATE_UNKNOWN;
char input_buffer[MAX_INPUT_BUFFER];
#ifdef HAVE_PROC_MEMINFO
@@ -116,10 +124,15 @@ main (int argc, char **argv)
}
fp = fopen (PROC_MEMINFO, "r");
while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, fp)) {
- if (sscanf (input_buffer, "%*[S]%*[w]%*[a]%*[p]%*[:] %f %f %f", &dsktotal_mb, &dskused_mb, &dskfree_mb) == 3) {
- dsktotal_mb = dsktotal_mb / 1048576; /* Apply conversion */
- dskused_mb = dskused_mb / 1048576;
- dskfree_mb = dskfree_mb / 1048576;
+ /*
+ * The following sscanf call looks for a line looking like: "Swap: 123 123 123"
+ * On which kind of system this format exists, I can not say, but I wanted to
+ * document this for people who are not adapt with sscanf anymore, like me
+ */
+ if (sscanf (input_buffer, "%*[S]%*[w]%*[a]%*[p]%*[:] %lu %lu %lu", &dsktotal_mb, &dskused_mb, &dskfree_mb) == 3) {
+ dsktotal_mb = dsktotal_mb / (1024 * 1024); /* Apply conversion */
+ dskused_mb = dskused_mb / (1024 * 1024);
+ dskfree_mb = dskfree_mb / (1024 * 1024);
total_swap_mb += dsktotal_mb;
used_swap_mb += dskused_mb;
free_swap_mb += dskfree_mb;
@@ -128,21 +141,25 @@ main (int argc, char **argv)
percent=100.0;
else
percent = 100 * (((double) dskused_mb) / ((double) dsktotal_mb));
- result = max_state (result, check_swap (percent, dskfree_mb, dsktotal_mb));
+ result = max_state (result, check_swap (dskfree_mb, dsktotal_mb));
if (verbose)
xasprintf (&status, "%s [%.0f (%d%%)]", status, dskfree_mb, 100 - percent);
}
}
- else if (sscanf (input_buffer, "%*[S]%*[w]%*[a]%*[p]%[TotalFre]%*[:] %f %*[k]%*[B]", str, &tmp_mb)) {
+ /*
+ * The following sscanf call looks for lines looking like: "SwapTotal: 123" and "SwapFree: 123"
+ * This format exists at least on Debian Linux with a 5.* kernel
+ */
+ else if (sscanf (input_buffer, "%*[S]%*[w]%*[a]%*[p]%[TotalFre]%*[:] %lu %*[k]%*[B]", str, &tmp_KB)) {
if (verbose >= 3) {
- printf("Got %s with %f\n", str, tmp_mb);
+ printf("Got %s with %lu\n", str, tmp_KB);
}
/* I think this part is always in Kb, so convert to mb */
if (strcmp ("Total", str) == 0) {
- dsktotal_mb = tmp_mb / 1024;
+ dsktotal_mb = tmp_KB / 1024;
}
else if (strcmp ("Free", str) == 0) {
- dskfree_mb = tmp_mb / 1024;
+ dskfree_mb = tmp_KB / 1024;
}
}
}
@@ -227,7 +244,7 @@ main (int argc, char **argv)
free_swap_mb += dskfree_mb;
if (allswaps) {
percent = 100 * (((double) dskused_mb) / ((double) dsktotal_mb));
- result = max_state (result, check_swap (percent, dskfree_mb, dsktotal_mb));
+ result = max_state (result, check_swap (dskfree_mb, dsktotal_mb));
if (verbose)
xasprintf (&status, "%s [%.0f (%d%%)]", status, dskfree_mb, 100 - percent);
}
@@ -289,7 +306,7 @@ main (int argc, char **argv)
if(allswaps && dsktotal_mb > 0){
percent = 100 * (((double) dskused_mb) / ((double) dsktotal_mb));
- result = max_state (result, check_swap (percent, dskfree_mb, dsktotal_mb));
+ result = max_state (result, check_swap (dskfree_mb, dsktotal_mb));
if (verbose) {
xasprintf (&status, "%s [%.0f (%d%%)]", status, dskfree_mb, 100 - percent);
}
@@ -328,7 +345,7 @@ main (int argc, char **argv)
if(allswaps && dsktotal_mb > 0){
percent = 100 * (((double) dskused_mb) / ((double) dsktotal_mb));
- result = max_state (result, check_swap (percent, dskfree_mb, dsktotal_mb));
+ result = max_state (result, check_swap(dskfree_mb, dsktotal_mb));
if (verbose) {
xasprintf (&status, "%s [%.0f (%d%%)]", status, dskfree_mb, 100 - percent);
}
@@ -355,14 +372,19 @@ main (int argc, char **argv)
status = "- Swap is either disabled, not present, or of zero size. ";
}
- result = max_state (result, check_swap (percent_used, free_swap_mb, total_swap_mb));
- printf (_("SWAP %s - %d%% free (%d MB out of %d MB) %s|"),
+ result = max_state (result, check_swap(free_swap_mb, total_swap_mb));
+ printf (_("SWAP %s - %d%% free (%dMB out of %dMB) %s|"),
state_text (result),
(100 - percent_used), (int) free_swap_mb, (int) total_swap_mb, status);
- puts (perfdata ("swap", (long) free_swap_mb, "MB",
- TRUE, (long) max (warn_size_bytes/(1024 * 1024), warn_percent/100.0*total_swap_mb),
- TRUE, (long) max (crit_size_bytes/(1024 * 1024), crit_percent/100.0*total_swap_mb),
+ uint64_t warn_print = warn.value;
+ if (warn.is_percentage) warn_print = warn.value * (total_swap_mb *1024 *1024/100);
+ uint64_t crit_print = crit.value;
+ 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));
@@ -370,26 +392,37 @@ main (int argc, char **argv)
}
-
int
-check_swap (int usp, float free_swap_mb, float total_swap_mb)
+check_swap(float free_swap_mb, float total_swap_mb)
{
if (!total_swap_mb) return no_swap_state;
- int result = STATE_UNKNOWN;
- float free_swap = free_swap_mb * (1024 * 1024); /* Convert back to bytes as warn and crit specified in bytes */
- if (usp >= 0 && crit_percent != 0 && usp >= (100.0 - crit_percent))
- result = STATE_CRITICAL;
- else if (crit_size_bytes > 0 && free_swap <= crit_size_bytes)
- result = STATE_CRITICAL;
- else if (usp >= 0 && warn_percent != 0 && usp >= (100.0 - warn_percent))
- result = STATE_WARNING;
- else if (warn_size_bytes > 0 && free_swap <= warn_size_bytes)
- result = STATE_WARNING;
- else if (usp >= 0.0)
- result = STATE_OK;
- return result;
+ 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 &&
+ usage_percentage >= 0 &&
+ crit.value != 0 &&
+ usage_percentage >= (100 - crit.value))
+ {
+ return STATE_CRITICAL;
+ }
+
+ if (warn.is_percentage &&
+ usage_percentage >= 0 &&
+ warn.value != 0 &&
+ usage_percentage >= (100 - warn.value))
+ {
+ return STATE_WARNING;
+ }
+
+ return STATE_OK;
}
@@ -422,42 +455,67 @@ process_arguments (int argc, char **argv)
break;
switch (c) {
- case 'w': /* warning size threshold */
- if (is_intnonneg (optarg)) {
- warn_size_bytes = (float) atoi (optarg);
- break;
- }
- else if (strstr (optarg, ",") &&
- strstr (optarg, "%") &&
- sscanf (optarg, "%f,%d%%", &warn_size_bytes, &warn_percent) == 2) {
- warn_size_bytes = floorf(warn_size_bytes);
- break;
- }
- else if (strstr (optarg, "%") &&
- sscanf (optarg, "%d%%", &warn_percent) == 1) {
- break;
- }
- else {
- usage4 (_("Warning threshold must be integer or percentage!"));
- }
- case 'c': /* critical size threshold */
- if (is_intnonneg (optarg)) {
- crit_size_bytes = (float) atoi (optarg);
- break;
- }
- else if (strstr (optarg, ",") &&
- strstr (optarg, "%") &&
- sscanf (optarg, "%f,%d%%", &crit_size_bytes, &crit_percent) == 2) {
- crit_size_bytes = floorf(crit_size_bytes);
- break;
- }
- else if (strstr (optarg, "%") &&
- sscanf (optarg, "%d%%", &crit_percent) == 1) {
- break;
- }
- else {
- usage4 (_("Critical threshold must be integer or percentage!"));
+ case 'w': /* warning size threshold */
+ {
+ /*
+ * We expect either a positive integer value without a unit, which means
+ * the unit is Bytes or a positive integer value and a percentage sign (%),
+ * which means the value must be with 0 and 100 and is relative to the total swap
+ */
+ size_t length;
+ length = strlen(optarg);
+
+ if (optarg[length - 1] == '%') {
+ // It's percentage!
+ warn.is_percentage = true;
+ optarg[length - 1] = '\0';
+ if (is_uint64(optarg, &warn.value)) {
+ if (warn.value > 100) {
+ usage4 (_("Warning threshold percentage must be <= 100!"));
+ } else {
+ break;
+ }
+ }
+ } else {
+ // It's Bytes
+ warn.is_percentage = false;
+ if (is_uint64(optarg, &warn.value)) {
+ break;
+ } else {
+ usage4 (_("Warning threshold be positive integer or percentage!"));
+ }
+ }
}
+ case 'c': /* critical size threshold */
+ {
+ /*
+ * We expect either a positive integer value without a unit, which means
+ * the unit is Bytes or a positive integer value and a percentage sign (%),
+ * which means the value must be with 0 and 100 and is relative to the total swap
+ */
+ size_t length;
+ length = strlen(optarg);
+
+ if (optarg[length - 1] == '%') {
+ // It's percentage!
+ crit.is_percentage = true;
+ optarg[length - 1] = '\0';
+ if (is_uint64(optarg, &crit.value)) {
+ if (crit.value> 100) {
+ usage4 (_("Critical threshold percentage must be <= 100!"));
+ } else {
+ break;
+ }
+ }
+ } else {
+ crit.is_percentage = false;
+ if (is_uint64(optarg, &crit.value)) {
+ break;
+ } else {
+ usage4 (_("Critical threshold be positive integer or percentage!"));
+ }
+ }
+ }
case 'a': /* all swap */
allswaps = TRUE;
break;
@@ -482,23 +540,6 @@ process_arguments (int argc, char **argv)
c = optind;
if (c == argc)
return validate_arguments ();
- if (warn_percent == 0 && is_intnonneg (argv[c]))
- warn_percent = atoi (argv[c++]);
-
- if (c == argc)
- return validate_arguments ();
- if (crit_percent == 0 && is_intnonneg (argv[c]))
- crit_percent = atoi (argv[c++]);
-
- if (c == argc)
- return validate_arguments ();
- if (warn_size_bytes == 0 && is_intnonneg (argv[c]))
- warn_size_bytes = (float) atoi (argv[c++]);
-
- if (c == argc)
- return validate_arguments ();
- if (crit_size_bytes == 0 && is_intnonneg (argv[c]))
- crit_size_bytes = (float) atoi (argv[c++]);
return validate_arguments ();
}
@@ -508,17 +549,12 @@ process_arguments (int argc, char **argv)
int
validate_arguments (void)
{
- if (warn_percent == 0 && crit_percent == 0 && warn_size_bytes == 0
- && crit_size_bytes == 0) {
+ if (warn.value == 0 && crit.value == 0) {
return ERROR;
}
- else if (warn_percent < crit_percent) {
- usage4
- (_("Warning percentage should be more than critical percentage"));
- }
- else if (warn_size_bytes < crit_size_bytes) {
+ else if (warn.value < crit.value) {
usage4
- (_("Warning free space should be more than critical free space"));
+ (_("Warning should be more than critical"));
}
return OK;
}
@@ -564,7 +600,6 @@ print_help (void)
}
-
void
print_usage (void)
{
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