Sanity check that the requested fd is greater than zero in arrindex().

1 files changed, 6 insertions, 0 deletions

diff --git a/functions.c b/functions.c
index 31282ed..377f1af 100644
--- a/functions.c
+++ b/functions.c
@@ -438,6 +438,12 @@ void updategreetings(char *greeting001, char *greeting002, char *greeting003, ch
 // TODO - Use this wherever we are calculating the position (various places) instead of
 // duplicating code.
 int arrindex(struct client *clients, int clientfd) {
+  // Make sure the client fd requested is >0 (less than 0 is nonsense, 0 is almost certainly standard input)
+  if (clientfd < 1) {
+    debugprint(DEBUG_CRIT, "arrindex(): error: requested client fd '%d' is less than 1, returning -1.\n", clientfd);
+    return -1;
+  }
+
   // Find the client in the clients array
   for (int i = 0; i < MAXCLIENTS; i++) {
     if (clients[i].fd == clientfd) {