add --snet-alarms option to suppress excess range alarms

Some users may not want to have alarms about ranges that are part of a
shared-network, so allow them to suppress such.

Requested-by: Frank Bulk <fbulk@mypremieronline.com>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>

man/dhcpd-pools.1.in

@@ -161,6 +161,12 @@ is
 If critical percentage is not specified it defaults to
 .BR @ALARM_CRIT@ .
 .TP
+\fB\-\-snet\-alarms
+Suppress range alarms that are part of shared networks.  Use of this option
+will keep alarm criteria applied to ranges that are not part of shared-net
+along with shared-net alarms.  This option may help reducing alarm noise for
+configurations that has lots of small ranges in big shared-networks.
+.TP
 \fB\-\-minsize\fR=\fIsize\fR
 Ignore ranges and shared networks that are smaller or equal to the
 defined size.  This option is meaningful only in context of alarming, and

src/dhcpd-pools.c

@@ -94,7 +94,8 @@ int main(int argc, char **argv)
 	char const *tmp;
 	struct range_t *tmp_ranges;
 	enum {
-		OPT_WARN = CHAR_MAX + 1,
+		OPT_SNET_ALARMS = CHAR_MAX + 1,
+		OPT_WARN,
 		OPT_CRIT,
 		OPT_MINSIZE
 	};
@@ -110,6 +111,7 @@ int main(int argc, char **argv)
 		{"limit", required_argument, NULL, 'L'},
 		{"version", no_argument, NULL, 'v'},
 		{"help", no_argument, NULL, 'h'},
+		{"snet-alarms", no_argument, NULL, OPT_SNET_ALARMS},
 		{"warning", required_argument, NULL, OPT_WARN},
 		{"critical", required_argument, NULL, OPT_CRIT},
 		{"minsize", required_argument, NULL, OPT_MINSIZE},
@@ -127,6 +129,7 @@ int main(int argc, char **argv)
 	 * command line option */
 	config.output_file[0] = '\0';
 	/* Alarming defaults. */
+	config.snet_alarms = false;
 	config.warning = ALARM_WARN;
 	config.critical = ALARM_CRIT;
 	/* File location defaults */
@@ -194,6 +197,9 @@ int main(int argc, char **argv)
 				}
 			}
 			break;
+		case OPT_SNET_ALARMS:
+			config.snet_alarms = true;
+			break;
 		case OPT_WARN:
 			strcpy(config.output_format, "a");
 			config.warning = strtod_or_err(optarg, "illegal argument");

src/dhcpd-pools.h

@@ -130,6 +130,7 @@ struct configuration_t {
 	char *output_file;
 	int output_limit[2];
 	bool backups_found;
+	bool snet_alarms;
 	double warning;
 	double critical;
 	double minsize;

src/output.c

@@ -1000,6 +1000,9 @@ int output_alarming(void)
 
 	if (config.output_limit[1] & BIT1) {
 		for (i = 0; i < num_ranges; i++) {
+			if (config.snet_alarms && range_p->shared_net != shared_networks) {
+				continue;
+			}
 			if (config.minsize < range_size) {
 				perc = (float)(100 * range_p->count) / range_size;
 				if (config.critical < perc)