[PATCH 07/11] batctl: ping: reject invalid packet count argument

The -c option parsed its argument with strtol and only mapped the result to
the internal "endless" value when it was smaller than 1. But it ignores any
invalid parameter silently. The manpage also only documented the "missing
-c" as valid selection of the endless loop and not an invalid or smaller
than 1 value.

Use the same strto* validation as the rest of batctl and print a user
readable error in case of an parsing error.

Fixes: 87ade2869cf3 ("add interval and loop count options")
Signed-off-by: Sven Eckelmann <[email protected]>
---
 ping.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/ping.c b/ping.c
index c875c38..5551cd4 100644
--- a/ping.c
+++ b/ping.c
@@ -8,6 +8,7 @@
 
 #include <netinet/in.h>
 #include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -90,15 +91,23 @@ static int ping(struct state *state, int argc, char **argv)
 	char *endptr;
 	int optchar;
 	int rr = 0;
+	long tmp;
 	int res;
 	int i;
 
 	while ((optchar = getopt(argc, argv, "hc:i:t:RT")) != -1) {
 		switch (optchar) {
 		case 'c':
-			loop_count = strtol(optarg, NULL, 10);
-			if (loop_count < 1)
-				loop_count = -1;
+			tmp = strtol(optarg, &endptr, 10);
+			if (!endptr || *endptr != '\0' || endptr == optarg ||
+			    tmp < 1 || tmp > INT_MAX) {
+				fprintf(stderr,
+					"Error - the supplied packet count is invalid: %s\n",
+					optarg);
+				ping_usage();
+				return EXIT_FAILURE;
+			}
+			loop_count = tmp;
 			break;
 		case 'h':
 			ping_usage();

-- 
2.47.3