From 3749c0431005c29b83597dc4d6b33bed2a5f9fda Mon Sep 17 00:00:00 2001
From: dmiller <dmiller@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Mon, 7 Mar 2016 16:44:52 +0000
Subject: [PATCH] Sanity check in pcap_recieve to avoid crash. Fixes #313

---
 nse_nsock.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/nse_nsock.cc b/nse_nsock.cc
index 717ab54e6..094aa3790 100644
--- a/nse_nsock.cc
+++ b/nse_nsock.cc
@@ -1043,6 +1043,9 @@ static int l_pcap_receive (lua_State *L)
 {
   nsock_pool nsp = get_pool(L);
   nse_nsock_udata *nu = check_nsock_udata(L, 1, true);
+  if (!nu->is_pcap) {
+    return nseU_safeerror(L, "not a pcap socket");
+  }
   NSOCK_UDATA_ENSURE_OPEN(L, nu);
   nu->nseid = nsock_pcap_read_packet(nsp, nu->nsiod, pcap_receive_handler,
       nu->timeout, nu);