check_swap: add supports for a configurable state when there is no swap

Check_swap used to allow no swap when thresholds were only specified in
percent. This is no longer the case and the state now must be specified
explicitly. The default is to always return CRITICAL when the swap is
absent regardless of thresholds.

NEWS

@@ -4,6 +4,7 @@ This file documents the major additions and syntax changes between releases.
 	ENHANCEMENTS
 	check_ide_smart now defaults to plugin output, original output appended with -v
 	Extra-Opts are now enabled by default
+	check_swap now supports a configurable state when there is no swap
 
 	FIXES
 	Don't let e.g. check_http's -C option reset SSL version if e.g. -S 1 -C 5 is specified
@@ -20,6 +21,8 @@ This file documents the major additions and syntax changes between releases.
 	  been disabled because they were broken
 	State retention: the NAGIOS_PLUGIN_STATE_DIRECTORY environment variable has been
 	  renamed MP_STATE_DIRECTORY. The old variable will continue to work in v1.6.x
+	check_swap used to allow returning OK on a system without swap when only percent thresholds
+	  were used. This is no longer the case and one must now use -n/--no-swap=<state>
 
 1.5 2nd October 2013
 	ENHANCEMENTS

plugins/check_swap.c

@@ -60,9 +60,10 @@ void print_help (void);
 int warn_percent = 0;
 int crit_percent = 0;
 float warn_size_bytes = 0;
-float crit_size_bytes= 0;
+float crit_size_bytes = 0;
 int verbose;
 int allswaps;
+int no_swap_state = STATE_CRITICAL;
 
 int
 main (int argc, char **argv)
@@ -372,6 +373,9 @@ main (int argc, char **argv)
 int
 check_swap (int usp, float free_swap_mb)
 {
+
+	if (!free_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))
@@ -400,6 +404,7 @@ process_arguments (int argc, char **argv)
 		{"warning", required_argument, 0, 'w'},
 		{"critical", required_argument, 0, 'c'},
 		{"allswaps", no_argument, 0, 'a'},
+		{"no-swap", required_argument, 0, 'n'},
 		{"verbose", no_argument, 0, 'v'},
 		{"version", no_argument, 0, 'V'},
 		{"help", no_argument, 0, 'h'},
@@ -410,7 +415,7 @@ process_arguments (int argc, char **argv)
 		return ERROR;
 
 	while (1) {
-		c = getopt_long (argc, argv, "+?Vvhac:w:", longopts, &option);
+		c = getopt_long (argc, argv, "+?Vvhac:w:n:", longopts, &option);
 
 		if (c == -1 || c == EOF)
 			break;
@@ -455,6 +460,10 @@ process_arguments (int argc, char **argv)
 		case 'a':									/* all swap */
 			allswaps = TRUE;
 			break;
+		case 'n':
+			if ((no_swap_state = mp_translate_state(optarg)) == ERROR) {
+				usage4 (_("no-swap result must be a valid state name (OK, WARNING, CRITICAL, UNKNOWN) or integer (0-3)."));
+			}
 		case 'v':									/* verbose */
 			verbose++;
 			break;
@@ -541,6 +550,8 @@ print_help (void)
   printf ("    %s\n", _("Exit with CRITCAL status if less than PERCENT of swap space is free"));
   printf (" %s\n", "-a, --allswaps");
   printf ("    %s\n", _("Conduct comparisons for all swap partitions, one by one"));
+  printf (" %s\n", "-n, --no-swap=<ok|warning|critical|unknown>");
+  printf ("    %s %s\n", _("Resulting state when there is no swap regardless of thresholds. Default:"), state_text(no_swap_state));
 	printf (UT_VERBOSE);
 
 	printf ("\n");