Add the stdnse.sleep function.

nse_init.cc

@@ -252,6 +252,7 @@ int init_lua (lua_State *L)
 #ifdef HAVE_OPENSSL
     {OPENSSLLIBNAME, luaopen_openssl}, // openssl bindings
 #endif
+    {"stdnse.c", luaopen_stdnse_c},
   };
 
   luaL_openlibs(L); // opens all standard libraries

nse_nmaplib.cc

@@ -562,3 +562,17 @@ int luaopen_nmap (lua_State *L)
 
   return 1;
 }
+
+/* Register C functions that belong in the stdnse namespace. They are loaded
+   from here in stdnse.lua. */
+int luaopen_stdnse_c (lua_State *L)
+{
+  static const luaL_reg stdnse_clib [] = {
+    {"sleep", l_nsock_sleep},
+    {NULL, NULL}
+  };
+
+  luaL_register(L, "stdnse.c", stdnse_clib);
+
+  return 1;
+}

nse_nmaplib.h

@@ -11,6 +11,7 @@ class Target;
 class Port;
 
 int luaopen_nmap(lua_State* l);
+int luaopen_stdnse_c (lua_State *L);
 void set_hostinfo(lua_State* l, Target* currenths);
 void set_portinfo(lua_State* l, Port* port);
 

nse_nsock.cc

@@ -950,6 +950,25 @@ void l_nsock_clear_buf(lua_State *L, l_nsock_udata* udata){
 	udata->bufused=0;
 }
 
+static void l_nsock_sleep_handler(nsock_pool nsp, nsock_event nse, void *udata) {
+  lua_State *L = (lua_State*) udata;
+  assert(nse_status(nse) == NSE_STATUS_SUCCESS);
+  process_waiting2running(L, 0);
+}
+
+int l_nsock_sleep(lua_State *L) {
+  double secs = luaL_checknumber(L, 1);
+  int msecs;
+
+  if (secs < 0)
+    luaL_error(L, "Argument to sleep (%f) must not be negative\n", secs);
+  /* Convert to milliseconds for nsock_timer_create. */
+  msecs = (int) (secs * 1000 + 0.5);
+  nsock_timer_create(nsp, l_nsock_sleep_handler, msecs, L);
+
+  return lua_yield(L, 0);
+}
+
 /****************** NCAP_SOCKET ***********************************************/ 
 #ifdef WIN32
 /* From tcpip.cc. Gets pcap device name from dnet name. */

nse_nsock.h

@@ -10,6 +10,7 @@ extern "C" {
 int luaopen_nsock(lua_State *);
 int l_nsock_new(lua_State *);
 int l_nsock_loop(int tout);
+int l_nsock_sleep(lua_State *L);
 
 int l_dnet_new(lua_State *);
 int l_dnet_open(lua_State *);

nselib/stdnse.lua

@@ -17,10 +17,31 @@ local concat = table.concat;
 
 local nmap = require "nmap";
 
+local c_funcs = require "stdnse.c";
+
 local EMPTY = {}; -- Empty constant table
 
 module(... or "stdnse");
 
+-- Load C functions from stdnse.c into this namespace.
+for k, v in pairs(c_funcs) do
+  _M[k] = v
+end
+-- Remove visibility of the stdnse.c table.
+c = nil
+
+--- Sleeps for a given amount of time.
+--
+-- This causes the program to yield control and not regain it until the time
+-- period has elapsed. The time may have a fractional part. Internally, the
+-- timer provides millisecond resolution.
+-- @name sleep
+-- @class function
+-- @param t Time to sleep, in seconds.
+-- @usage stdnse.sleep(1.5)
+
+-- sleep is a C function defined in nse_nmaplib.cc.
+
 --- Prints a formatted debug message if the current verbosity level is greater
 -- than or equal to a given level.
 --