From a16dd6550385cca9faf3f315db4608d4520f9c19 Mon Sep 17 00:00:00 2001
From: david <david@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Thu, 5 Sep 2013 20:35:49 +0000
Subject: [PATCH] Get rid of static lua-exec state.

Have lua_setup return the state it creates. Store the state created from
--lua-exec in the global options table. Use a temporary local for
--lua-exec-internal.
---
 ncat/ncat_core.c  |  4 ++++
 ncat/ncat_core.h  |  8 ++++++++
 ncat/ncat_lua.c   | 16 +++++++++-------
 ncat/ncat_lua.h   |  4 ++--
 ncat/ncat_main.c  |  9 ++++++---
 ncat/ncat_posix.c |  2 +-
 6 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/ncat/ncat_core.c b/ncat/ncat_core.c
index 006386f36..b7177d193 100644
--- a/ncat/ncat_core.c
+++ b/ncat/ncat_core.c
@@ -204,6 +204,10 @@ void options_init(void)
     o.proxy_auth = NULL;
     o.proxytype = NULL;
 
+#ifdef HAVE_LUA
+    o.lua_exec_state = NULL;
+#endif
+
 #ifdef HAVE_OPENSSL
     o.ssl = 0;
     o.sslcert = NULL;
diff --git a/ncat/ncat_core.h b/ncat/ncat_core.h
index 0dca7ef8c..f86fa5b58 100644
--- a/ncat/ncat_core.h
+++ b/ncat/ncat_core.h
@@ -126,6 +126,10 @@
 #include "util.h"
 #include "sockaddr_u.h"
 
+#ifdef HAVE_LUA
+#include "ncat_lua.h"
+#endif
+
 /* Maximum size of the srcaddrs array. In this case two because we can only have
    a IPV4 INADDR_ANY and a IPV6 in6addr_any at most or a user defined address */
 #define NUM_LISTEN_ADDRS 2
@@ -198,6 +202,10 @@ struct options {
     char *proxy_auth;
     char *proxytype;
 
+#ifdef HAVE_LUA
+    lua_State *lua_exec_state;
+#endif
+
     int ssl;
     char *sslcert;
     char *sslkey;
diff --git a/ncat/ncat_lua.c b/ncat/ncat_lua.c
index 4bfa5d12b..56895cadb 100644
--- a/ncat/ncat_lua.c
+++ b/ncat/ncat_lua.c
@@ -124,9 +124,7 @@
 #include "ncat.h"
 #include "ncat_lua.h"
 
-static lua_State *L;
-
-static void report(char *prefix)
+static void report(lua_State *L, char *prefix)
 {
     const char *errormsg;
     errormsg = lua_tostring(L, -1);
@@ -150,25 +148,29 @@ static int traceback (lua_State *L)
     return 1;
 }
 
-void lua_setup(void)
+lua_State *lua_setup(void)
 {
+    lua_State *L;
+
     ncat_assert(o.cmdexec != NULL);
 
     L = luaL_newstate();
     luaL_openlibs(L);
 
     if (luaL_loadfile(L, o.cmdexec) != 0)
-        report("Error loading the Lua script");
+        report(L, "Error loading the Lua script");
+
+    return L;
 }
 
-void lua_run(void)
+void lua_run(lua_State *L)
 {
     /* The chunk as read from lua_setup is on top of the stack. Put the
        traceback function before it and run it. */
     lua_pushcfunction(L, traceback);
     lua_insert(L, -2);
     if (lua_pcall(L, 0, 0, -2) != LUA_OK && !lua_isnil(L, -1)) {
-        report("Error running the Lua script");
+        report(L, "Error running the Lua script");
     } else {
         if (o.debug)
             logdebug("%s returned successfully.\n", o.cmdexec);
diff --git a/ncat/ncat_lua.h b/ncat/ncat_lua.h
index b2e80ce2a..7404b6b8c 100644
--- a/ncat/ncat_lua.h
+++ b/ncat/ncat_lua.h
@@ -138,7 +138,7 @@ extern "C" {
 }
 #endif
 
-void lua_setup(void);
-void lua_run(void);
+lua_State *lua_setup(void);
+void lua_run(lua_State *L);
 
 #endif
diff --git a/ncat/ncat_main.c b/ncat/ncat_main.c
index d6c2bdbe7..6ba38312a 100644
--- a/ncat/ncat_main.c
+++ b/ncat/ncat_main.c
@@ -535,6 +535,8 @@ int main(int argc, char *argv[])
                    forking in POSIX builds, Windows does not have the fork() system
                    call and thus requires this workaround. More info here:
                    http://seclists.org/nmap-dev/2013/q2/492 */
+                lua_State *L;
+
 #ifdef WIN32
                 if (o.debug)
                     logdebug("Enabling binary stdout for the Lua output.\n");
@@ -544,8 +546,9 @@ int main(int argc, char *argv[])
 #endif
                 ncat_assert(argc == 3);
                 o.cmdexec = argv[2];
-                lua_setup();
-                lua_run();
+                L = lua_setup();
+                ncat_assert(L != NULL);
+                lua_run(L);
             }
 #endif
             break;
@@ -869,7 +872,7 @@ connection brokering should work.");
 
 #ifdef HAVE_LUA
     if (o.execmode == EXEC_LUA)
-        lua_setup();
+        o.lua_exec_state = lua_setup();
 #endif
 
     if (o.listen)
diff --git a/ncat/ncat_posix.c b/ncat/ncat_posix.c
index 9946b20b6..16ddb271b 100644
--- a/ncat/ncat_posix.c
+++ b/ncat/ncat_posix.c
@@ -234,7 +234,7 @@ void netexec(struct fdinfo *info, char *cmdexec)
             break;
 #ifdef HAVE_LUA
         case EXEC_LUA:
-            lua_run();
+            lua_run(o.lua_exec_state);
             break;
 #endif
         default: