added net.dns.setdnsserver('ip',[index]), net.dns.getdnsserver([index]), net.dns.resolve('domain.com', function cb('ip' or nil if fail) )

modified:   app/modules/net.c

app/modules/net.c

@@ -204,13 +204,12 @@ static void net_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
     NODE_DBG("self_ref null.\n");
     return;
   }
-
+/* original
   if(ipaddr == NULL)
   {
     NODE_ERR( "DNS Fail!\n" );
     goto end;
   }
-
   // ipaddr->addr is a uint32_t ip
   char ip_str[20];
   c_memset(ip_str, 0, sizeof(ip_str));
@@ -220,9 +219,30 @@ static void net_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
   }
 
   lua_rawgeti(gL, LUA_REGISTRYINDEX, nud->cb_dns_found_ref);    // the callback function
-  lua_rawgeti(gL, LUA_REGISTRYINDEX, nud->self_ref);  // pass the userdata(conn) to callback func in lua
+  //lua_rawgeti(gL, LUA_REGISTRYINDEX, nud->self_ref);  // pass the userdata(conn) to callback func in lua
   lua_pushstring(gL, ip_str);   // the ip para
-  lua_call(gL, 2, 0);
+*/
+
+  // "enhanced"
+  lua_rawgeti(gL, LUA_REGISTRYINDEX, nud->cb_dns_found_ref);    // the callback function
+
+  if(ipaddr == NULL)
+  {
+    NODE_DBG( "DNS Fail!\n" );
+    lua_pushnil(gL);
+  }else{
+    // ipaddr->addr is a uint32_t ip
+    char ip_str[20];
+    c_memset(ip_str, 0, sizeof(ip_str));
+    if(host_ip.addr == 0 && ipaddr->addr != 0)
+    {
+      c_sprintf(ip_str, IPSTR, IP2STR(&(ipaddr->addr)));
+    }
+    lua_pushstring(gL, ip_str);   // the ip para
+  }
+  // "enhanced" end
+
+  lua_call(gL, 1, 0);
 
 end:
   if((pesp_conn->type == ESPCONN_TCP && pesp_conn->proto.tcp->remote_port == 0)
@@ -1331,6 +1351,112 @@ static int net_multicastLeave( lua_State* L )
 	return net_multicastJoinLeave(L,0);
 }
 
+// Lua: s = net.dns.setdnsserver(ip_addr, [index])
+static int net_setdnsserver( lua_State* L )
+{
+  size_t l;
+  u32_t ip32;
+
+  const char *server = luaL_checklstring( L, 1, &l );
+  if (l>16 || server == NULL || (ip32 = ipaddr_addr(server)) == IPADDR_NONE || ip32 == IPADDR_ANY)
+    return luaL_error( L, "invalid dns server ip" );
+
+  int numdns = luaL_optint(L, 2, 0);
+  if (numdns >= DNS_MAX_SERVERS)
+    return luaL_error( L, "server index out of range [0-%d]", DNS_MAX_SERVERS - 1);
+
+  ip_addr_t ipaddr;
+  ip4_addr_set_u32(&ipaddr, ip32);
+  dns_setserver(numdns,&ipaddr);
+
+  return 0;
+}
+
+// Lua: s = net.dns.getdnsserver([index])
+static int net_getdnsserver( lua_State* L )
+{
+  int numdns = luaL_optint(L, 1, 0);
+  if (numdns >= DNS_MAX_SERVERS)
+    return luaL_error( L, "server index out of range [0-%d]", DNS_MAX_SERVERS - 1);
+
+  ip_addr_t ipaddr;
+  dns_getserver(numdns,&ipaddr);
+
+  if ( ip_addr_isany(&ipaddr) ) {
+    lua_pushnil( L );
+  } else {
+    char temp[20] = {0};
+    c_sprintf(temp, IPSTR, IP2STR( &ipaddr ) );
+    lua_pushstring( L, temp );
+  }
+
+  return 1;
+}
+
+// Lua: net.dns.resolve( domain, function(ip) )
+static int net_dns_static( lua_State* L )
+{
+  const char *mt = "net.socket";
+  if (!lua_isstring( L, 1 ))
+    return luaL_error( L, "wrong parameter type (domain)" );
+  
+  int rfunc = LUA_NOREF; //save reference to func
+  if (lua_type(L, 2) == LUA_TFUNCTION || lua_type(L, 2) == LUA_TLIGHTFUNCTION){
+    rfunc = luaL_ref(L, LUA_REGISTRYINDEX);
+  }
+  int rdom = luaL_ref(L, LUA_REGISTRYINDEX); //save reference to domain
+
+  lua_settop(L,0); //empty stack
+  lua_getfield(L, LUA_GLOBALSINDEX, "net");
+  lua_getfield(L, -1, "createConnection");
+  lua_remove(L, -2); //remove "net" from stack
+  lua_pushinteger(L, UDP); // we are going to create a new dummy UDP socket
+  lua_call(L,1,1);// after this the stack should have a socket
+
+  lua_rawgeti(gL, LUA_REGISTRYINDEX, rdom);    // load domain back to the stack
+  lua_rawgeti(gL, LUA_REGISTRYINDEX, rfunc);    // load the callback function back to the stack
+
+  luaL_unref(L, LUA_REGISTRYINDEX, rdom); //free reference
+  luaL_unref(L, LUA_REGISTRYINDEX, rfunc); //free reference
+
+  bool isserver = false;
+  struct espconn *pesp_conn = NULL;
+  lnet_userdata *nud;
+  size_t l;
+  
+  nud = (lnet_userdata *)luaL_checkudata(L, 1, mt);
+  luaL_argcheck(L, nud, 1, "Server/Socket expected");
+  if(nud==NULL){
+    NODE_DBG("userdata is nil.\n");
+    return 0;
+  }
+  if(nud->pesp_conn == NULL){
+    NODE_DBG("nud->pesp_conn is NULL.\n");
+    return 0;
+  }
+  pesp_conn = nud->pesp_conn;
+
+  lua_pushvalue(L, 1);  // copy to the top of stack
+  if(nud->self_ref != LUA_NOREF)
+    luaL_unref(L, LUA_REGISTRYINDEX, nud->self_ref);
+  nud->self_ref = luaL_ref(L, LUA_REGISTRYINDEX);
+
+  const char *domain = luaL_checklstring( L, 2, &l );
+  if (l>128 || domain == NULL)
+    return luaL_error( L, "need <128 domain" );
+
+  if (lua_type(L, 3) == LUA_TFUNCTION || lua_type(L, 3) == LUA_TLIGHTFUNCTION){
+    lua_pushvalue(L, 3);  // copy argument (func) to the top of stack
+    if(nud->cb_dns_found_ref != LUA_NOREF)
+      luaL_unref(L, LUA_REGISTRYINDEX, nud->cb_dns_found_ref);
+    nud->cb_dns_found_ref = luaL_ref(L, LUA_REGISTRYINDEX);
+  }
+
+  host_ip.addr = 0;
+  espconn_gethostbyname(pesp_conn, domain, &host_ip, net_dns_found);
+
+  return 0;
+}
 
 #if 0
 static int net_array_index( lua_State* L )
@@ -1402,6 +1528,15 @@ static const LUA_REG_TYPE net_array_map[] =
   { LNILKEY, LNILVAL }
 };
 #endif
+
+static const LUA_REG_TYPE net_dns_map[] =
+{
+  { LSTRKEY( "setdnsserver" ), LFUNCVAL ( net_setdnsserver ) },  
+  { LSTRKEY( "getdnsserver" ), LFUNCVAL ( net_getdnsserver ) }, 
+  { LSTRKEY( "resolve" ), LFUNCVAL ( net_dns_static ) },  
+  { LNILKEY, LNILVAL }
+};
+
 const LUA_REG_TYPE net_map[] = 
 {
   { LSTRKEY( "createServer" ), LFUNCVAL ( net_createServer ) },
@@ -1409,6 +1544,7 @@ const LUA_REG_TYPE net_map[] =
   { LSTRKEY( "multicastJoin"), LFUNCVAL( net_multicastJoin ) },
   { LSTRKEY( "multicastLeave"), LFUNCVAL( net_multicastLeave ) },
 #if LUA_OPTIMIZE_MEMORY > 0
+  { LSTRKEY( "dns" ), LROVAL( net_dns_map ) },
   { LSTRKEY( "TCP" ), LNUMVAL( TCP ) },
   { LSTRKEY( "UDP" ), LNUMVAL( UDP ) },
 
@@ -1471,6 +1607,10 @@ LUALIB_API int luaopen_net( lua_State *L )
   // Setup the methods inside metatable
   luaL_register( L, NULL, net_array_map );
 #endif
+  lua_settop(L, n);
+  lua_newtable( L );
+  luaL_register( L, NULL, net_dns_map );
+  lua_setfield( L, -2, "dns" );
   return 1;
 #endif // #if LUA_OPTIMIZE_MEMORY > 0  
 }