From 6830ddad67e245b7aed7ef0c3dfcf775d68a4841 Mon Sep 17 00:00:00 2001
From: "Tristan B. Velloza Kildaire" <deavmi@redxen.eu>
Date: Thu, 19 Dec 2024 08:44:00 +0200
Subject: [PATCH] tncattach

- WHen parsing the `prefixPart_s` (the prefix length), only continue if
the text is a number, if not then bail out with an error
---
 tncattach.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tncattach.c b/tncattach.c
index ab5772c..04041eb 100644
--- a/tncattach.c
+++ b/tncattach.c
@@ -504,6 +504,10 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state) {
 
             long prefixLen_l = strtol(prefixPart_s, NULL, 10); // TODO: Add handling here for errors (using errno)
 
+						if(prefixLen_l == 0) {
+								printf("Prefix length '%s' is not numeric\n", prefixPart_s);
+								exit(EXIT_FAILURE);
+						}
 
             arguments->ipv6 = ipPart_s;