lua/ubus.c

   1 /*
   2  * Copyright (C) 2012 Jo-Philipp Wich <jow@openwrt.org>
   3  * Copyright (C) 2012 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <unistd.h>
  16 #include <libubus.h>
  17 #include <libubox/blobmsg.h>
  18 #include <libubox/blobmsg_json.h>
  19 #include <lauxlib.h>
  20 #include <lua.h>
  21
  22 #define MODNAME         "ubus"
  23 #define METANAME        MODNAME ".meta"
  24
  25 static lua_State *state;
  26
  27 struct ubus_lua_connection {
  28         int timeout;
  29         struct blob_buf buf;
  30         struct ubus_context *ctx;
  31 };
  32
  33 struct ubus_lua_object {
  34         struct ubus_object o;
  35         int r;
  36 };
  37
  38 struct ubus_lua_event {
  39         struct ubus_event_handler e;
  40         int r;
  41 };
  42
  43 static int
  44 ubus_lua_parse_blob(lua_State *L, struct blob_attr *attr, bool table);
  45
  46 static int
  47 ubus_lua_parse_blob_array(lua_State *L, struct blob_attr *attr, int len, bool table)
  48 {
  49         int rv;
  50         int idx = 1;
  51         int rem = len;
  52         struct blob_attr *pos;
  53
  54         lua_newtable(L);
  55
  56         __blob_for_each_attr(pos, attr, rem)
  57         {
  58                 rv = ubus_lua_parse_blob(L, pos, table);
  59
  60                 if (rv > 1)
  61                         lua_rawset(L, -3);
  62                 else if (rv > 0)
  63                         lua_rawseti(L, -2, idx++);
  64         }
  65
  66         return 1;
  67 }
  68
  69 static int
  70 ubus_lua_parse_blob(lua_State *L, struct blob_attr *attr, bool table)
  71 {
  72         int len;
  73         int off = 0;
  74         void *data;
  75
  76         if (!blobmsg_check_attr(attr, false))
  77                 return 0;
  78
  79         if (table && blobmsg_name(attr)[0])
  80         {
  81                 lua_pushstring(L, blobmsg_name(attr));
  82                 off++;
  83         }
  84
  85         data = blobmsg_data(attr);
  86         len = blobmsg_data_len(attr);
  87
  88         switch (blob_id(attr))
  89         {
  90         case BLOBMSG_TYPE_BOOL:
  91                 lua_pushboolean(L, *(uint8_t *)data);
  92                 break;
  93
  94         case BLOBMSG_TYPE_INT16:
  95                 lua_pushinteger(L, be16_to_cpu(*(uint16_t *)data));
  96                 break;
  97
  98         case BLOBMSG_TYPE_INT32:
  99                 lua_pushinteger(L, be32_to_cpu(*(uint32_t *)data));
 100                 break;
 101
 102         case BLOBMSG_TYPE_INT64:
 103                 lua_pushnumber(L, (double) be64_to_cpu(*(uint64_t *)data));
 104                 break;
 105
 106         case BLOBMSG_TYPE_STRING:
 107                 lua_pushstring(L, data);
 108                 break;
 109
 110         case BLOBMSG_TYPE_ARRAY:
 111                 ubus_lua_parse_blob_array(L, data, len, false);
 112                 break;
 113
 114         case BLOBMSG_TYPE_TABLE:
 115                 ubus_lua_parse_blob_array(L, data, len, true);
 116                 break;
 117
 118         default:
 119                 lua_pushnil(L);
 120                 break;
 121         }
 122
 123         return off + 1;
 124 }
 125
 126
 127 static bool
 128 ubus_lua_format_blob_is_array(lua_State *L)
 129 {
 130         lua_Integer prv = 0;
 131         lua_Integer cur = 0;
 132
 133         /* Find out whether table is array-like */
 134         for (lua_pushnil(L); lua_next(L, -2); lua_pop(L, 1))
 135         {
 136 #ifdef LUA_TINT
 137                 if (lua_type(L, -2) != LUA_TNUMBER && lua_type(L, -2) != LUA_TINT)
 138 #else
 139                 if (lua_type(L, -2) != LUA_TNUMBER)
 140 #endif
 141                 {
 142                         lua_pop(L, 2);
 143                         return false;
 144                 }
 145
 146                 cur = lua_tointeger(L, -2);
 147
 148                 if ((cur - 1) != prv)
 149                 {
 150                         lua_pop(L, 2);
 151                         return false;
 152                 }
 153
 154                 prv = cur;
 155         }
 156
 157         return true;
 158 }
 159
 160 static int
 161 ubus_lua_format_blob_array(lua_State *L, struct blob_buf *b, bool table);
 162
 163 static int
 164 ubus_lua_format_blob(lua_State *L, struct blob_buf *b, bool table)
 165 {
 166         void *c;
 167         bool rv = true;
 168         const char *key = table ? lua_tostring(L, -2) : NULL;
 169
 170         switch (lua_type(L, -1))
 171         {
 172         case LUA_TBOOLEAN:
 173                 blobmsg_add_u8(b, key, (uint8_t)lua_toboolean(L, -1));
 174                 break;
 175
 176 #ifdef LUA_TINT
 177         case LUA_TINT:
 178 #endif
 179         case LUA_TNUMBER:
 180                 blobmsg_add_u32(b, key, (uint32_t)lua_tointeger(L, -1));
 181                 break;
 182
 183         case LUA_TSTRING:
 184         case LUA_TUSERDATA:
 185         case LUA_TLIGHTUSERDATA:
 186                 blobmsg_add_string(b, key, lua_tostring(L, -1));
 187                 break;
 188
 189         case LUA_TTABLE:
 190                 if (ubus_lua_format_blob_is_array(L))
 191                 {
 192                         c = blobmsg_open_array(b, key);
 193                         rv = ubus_lua_format_blob_array(L, b, false);
 194                         blobmsg_close_array(b, c);
 195                 }
 196                 else
 197                 {
 198                         c = blobmsg_open_table(b, key);
 199                         rv = ubus_lua_format_blob_array(L, b, true);
 200                         blobmsg_close_table(b, c);
 201                 }
 202                 break;
 203
 204         default:
 205                 rv = false;
 206                 break;
 207         }
 208
 209         return rv;
 210 }
 211
 212 static int
 213 ubus_lua_format_blob_array(lua_State *L, struct blob_buf *b, bool table)
 214 {
 215         for (lua_pushnil(L); lua_next(L, -2); lua_pop(L, 1))
 216         {
 217                 if (!ubus_lua_format_blob(L, b, table))
 218                 {
 219                         lua_pop(L, 1);
 220                         return false;
 221                 }
 222         }
 223
 224         return true;
 225 }
 226
 227
 228 static int
 229 ubus_lua_connect(lua_State *L)
 230 {
 231         struct ubus_lua_connection *c;
 232         const char *sockpath = luaL_optstring(L, 1, NULL);
 233         int timeout = luaL_optint(L, 2, 30);
 234
 235         if ((c = lua_newuserdata(L, sizeof(*c))) != NULL &&
 236                 (c->ctx = ubus_connect(sockpath)) != NULL)
 237         {
 238                 ubus_add_uloop(c->ctx);
 239                 c->timeout = timeout;
 240                 memset(&c->buf, 0, sizeof(c->buf));
 241                 luaL_getmetatable(L, METANAME);
 242                 lua_setmetatable(L, -2);
 243                 return 1;
 244         }
 245
 246         /* NB: no errors from ubus_connect() yet */
 247         lua_pushnil(L);
 248         lua_pushinteger(L, UBUS_STATUS_UNKNOWN_ERROR);
 249         return 2;
 250 }
 251
 252
 253 static void
 254 ubus_lua_objects_cb(struct ubus_context *c, struct ubus_object_data *o, void *p)
 255 {
 256         lua_State *L = (lua_State *)p;
 257
 258         lua_pushstring(L, o->path);
 259         lua_rawseti(L, -2, lua_objlen(L, -2) + 1);
 260 }
 261
 262 static int
 263 ubus_lua_objects(lua_State *L)
 264 {
 265         int rv;
 266         struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
 267
 268         lua_newtable(L);
 269         rv = ubus_lookup(c->ctx, NULL, ubus_lua_objects_cb, L);
 270
 271         if (rv != UBUS_STATUS_OK)
 272         {
 273                 lua_pop(L, 1);
 274                 lua_pushnil(L);
 275                 lua_pushinteger(L, rv);
 276                 return 2;
 277         }
 278
 279         return 1;
 280 }
 281
 282 static int
 283 ubus_method_handler(struct ubus_context *ctx, struct ubus_object *obj,
 284                 struct ubus_request_data *req, const char *method,
 285                 struct blob_attr *msg)
 286 {
 287         struct ubus_lua_object *o = container_of(obj, struct ubus_lua_object, o);
 288         int rv = 0;
 289
 290         lua_getglobal(state, "__ubus_cb");
 291         lua_rawgeti(state, -1, o->r);
 292         lua_getfield(state, -1, method);
 293         lua_remove(state, -2);
 294         lua_remove(state, -2);
 295
 296         if (lua_isfunction(state, -1)) {
 297                 lua_pushlightuserdata(state, req);
 298                 if (!msg)
 299                         lua_pushnil(state);
 300                 else
 301                         ubus_lua_parse_blob_array(state, blob_data(msg), blob_len(msg), true);
 302                 lua_call(state, 2, 1);
 303                 if (lua_isnumber(state, -1))
 304                         rv = lua_tonumber(state, -1);
 305         } else
 306                 lua_pop(state, 1);
 307
 308         return rv;
 309 }
 310
 311 static int lua_gettablelen(lua_State *L, int index)
 312 {
 313         int cnt = 0;
 314
 315         lua_pushnil(L);
 316         index -= 1;
 317         while (lua_next(L, index) != 0) {
 318                 cnt++;
 319                 lua_pop(L, 1);
 320         }
 321
 322         return cnt;
 323 }
 324
 325 static int ubus_lua_reply(lua_State *L)
 326 {
 327         struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
 328         struct ubus_request_data *req;
 329
 330         luaL_checktype(L, 3, LUA_TTABLE);
 331         blob_buf_init(&c->buf, 0);
 332
 333         if (!ubus_lua_format_blob_array(L, &c->buf, true))
 334         {
 335                 lua_pushnil(L);
 336                 lua_pushinteger(L, UBUS_STATUS_INVALID_ARGUMENT);
 337                 return 2;
 338         }
 339
 340         req = lua_touserdata(L, 2);
 341         ubus_send_reply(c->ctx, req, c->buf.head);
 342
 343         return 0;
 344 }
 345
 346 static int ubus_lua_load_methods(lua_State *L, struct ubus_method *m)
 347 {
 348         struct blobmsg_policy *p;
 349         int plen;
 350         int pidx = 0;
 351
 352         /* get the function pointer */
 353         lua_pushinteger(L, 1);
 354         lua_gettable(L, -2);
 355
 356         /* get the policy table */
 357         lua_pushinteger(L, 2);
 358         lua_gettable(L, -3);
 359
 360         /* check if the method table is valid */
 361         if ((lua_type(L, -2) != LUA_TFUNCTION) ||
 362                         (lua_type(L, -1) != LUA_TTABLE) ||
 363                         lua_objlen(L, -1)) {
 364                 lua_pop(L, 2);
 365                 return 1;
 366         }
 367
 368         /* store function pointer */
 369         lua_pushvalue(L, -2);
 370         lua_setfield(L, -6, lua_tostring(L, -5));
 371
 372         m->name = lua_tostring(L, -4);
 373         m->handler = ubus_method_handler;
 374
 375         plen = lua_gettablelen(L, -1);
 376
 377         /* exit if policy table is empty */
 378         if (!plen) {
 379                 lua_pop(L, 2);
 380                 return 0;
 381         }
 382
 383         /* setup the policy pointers */
 384         p = malloc(sizeof(struct blobmsg_policy) * plen);
 385         memset(p, 0, sizeof(struct blobmsg_policy) * plen);
 386         m->policy = p;
 387         lua_pushnil(L);
 388         while (lua_next(L, -2) != 0) {
 389                 int val = lua_tointeger(L, -1);
 390
 391                 /* check if the policy is valid */
 392                 if ((lua_type(L, -2) != LUA_TSTRING) ||
 393                                 (lua_type(L, -1) != LUA_TNUMBER) ||
 394                                 (val < 0) ||
 395                                 (val > BLOBMSG_TYPE_LAST)) {
 396                         lua_pop(L, 1);
 397                         continue;
 398                 }
 399                 p[pidx].name = lua_tostring(L, -2);
 400                 p[pidx].type = val;
 401                 lua_pop(L, 1);
 402                 pidx++;
 403         }
 404
 405         m->n_policy = pidx;
 406         lua_pop(L, 2);
 407
 408         return 0;
 409 }
 410
 411 static struct ubus_object* ubus_lua_load_object(lua_State *L)
 412 {
 413         struct ubus_lua_object *obj = NULL;
 414         int mlen = lua_gettablelen(L, -1);
 415         struct ubus_method *m;
 416         int midx = 0;
 417
 418         /* setup object pointers */
 419         obj = malloc(sizeof(struct ubus_lua_object));
 420         memset(obj, 0, sizeof(struct ubus_lua_object));
 421         obj->o.name = lua_tostring(L, -2);
 422
 423         /* setup method pointers */
 424         m = malloc(sizeof(struct ubus_method) * mlen);
 425         memset(m, 0, sizeof(struct ubus_method) * mlen);
 426         obj->o.methods = m;
 427
 428         /* setup type pointers */
 429         obj->o.type = malloc(sizeof(struct ubus_object_type));
 430         memset(obj->o.type, 0, sizeof(struct ubus_object_type));
 431         obj->o.type->name = lua_tostring(L, -2);
 432         obj->o.type->id = 0;
 433         obj->o.type->methods = obj->o.methods;
 434
 435         /* create the callback lookup table */
 436         lua_createtable(L, 1, 0);
 437         lua_getglobal(L, "__ubus_cb");
 438         lua_pushvalue(L, -2);
 439         obj->r = luaL_ref(L, -2);
 440         lua_pop(L, 1);
 441
 442         /* scan each method */
 443         lua_pushnil(L);
 444         while (lua_next(L, -3) != 0) {
 445                 /* check if it looks like a method */
 446                 if ((lua_type(L, -2) != LUA_TSTRING) ||
 447                                 (lua_type(L, -1) != LUA_TTABLE) ||
 448                                 !lua_objlen(L, -1)) {
 449                         lua_pop(L, 1);
 450                         continue;
 451                 }
 452
 453                 if (!ubus_lua_load_methods(L, &m[midx]))
 454                         midx++;
 455                 lua_pop(L, 1);
 456         }
 457
 458         obj->o.type->n_methods = obj->o.n_methods = midx;
 459
 460         /* pop the callback table */
 461         lua_pop(L, 1);
 462
 463         return &obj->o;
 464 }
 465
 466 static int ubus_lua_add(lua_State *L)
 467 {
 468         struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
 469
 470         /* verify top level object */
 471         if (lua_istable(L, 1)) {
 472                 lua_pushstring(L, "you need to pass a table");
 473                 lua_error(L);
 474                 return 0;
 475         }
 476
 477         /* scan each object */
 478         lua_pushnil(L);
 479         while (lua_next(L, -2) != 0) {
 480                 struct ubus_object *obj = NULL;
 481
 482                 /* check if the object has a table of methods */
 483                 if ((lua_type(L, -2) == LUA_TSTRING) && (lua_type(L, -1) == LUA_TTABLE)) {
 484                         obj = ubus_lua_load_object(L);
 485
 486                         if (obj)
 487                                 ubus_add_object(c->ctx, obj);
 488                 }
 489                 lua_pop(L, 1);
 490         }
 491
 492         return 0;
 493 }
 494
 495 static void
 496 ubus_lua_signatures_cb(struct ubus_context *c, struct ubus_object_data *o, void *p)
 497 {
 498         lua_State *L = (lua_State *)p;
 499
 500         if (!o->signature)
 501                 return;
 502
 503         ubus_lua_parse_blob_array(L, blob_data(o->signature), blob_len(o->signature), true);
 504 }
 505
 506 static int
 507 ubus_lua_signatures(lua_State *L)
 508 {
 509         int rv;
 510         struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
 511         const char *path = luaL_checkstring(L, 2);
 512
 513         rv = ubus_lookup(c->ctx, path, ubus_lua_signatures_cb, L);
 514
 515         if (rv != UBUS_STATUS_OK)
 516         {
 517                 lua_pop(L, 1);
 518                 lua_pushnil(L);
 519                 lua_pushinteger(L, rv);
 520                 return 2;
 521         }
 522
 523         return 1;
 524 }
 525
 526
 527 static void
 528 ubus_lua_call_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 529 {
 530         lua_State *L = (lua_State *)req->priv;
 531
 532         if (!msg)
 533                 lua_pushnil(L);
 534
 535         ubus_lua_parse_blob_array(L, blob_data(msg), blob_len(msg), true);
 536 }
 537
 538 static int
 539 ubus_lua_call(lua_State *L)
 540 {
 541         int rv, top;
 542         uint32_t id;
 543         struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
 544         const char *path = luaL_checkstring(L, 2);
 545         const char *func = luaL_checkstring(L, 3);
 546
 547         luaL_checktype(L, 4, LUA_TTABLE);
 548         blob_buf_init(&c->buf, 0);
 549
 550         if (!ubus_lua_format_blob_array(L, &c->buf, true))
 551         {
 552                 lua_pushnil(L);
 553                 lua_pushinteger(L, UBUS_STATUS_INVALID_ARGUMENT);
 554                 return 2;
 555         }
 556
 557         rv = ubus_lookup_id(c->ctx, path, &id);
 558
 559         if (rv)
 560         {
 561                 lua_pushnil(L);
 562                 lua_pushinteger(L, rv);
 563                 return 2;
 564         }
 565
 566         top = lua_gettop(L);
 567         rv = ubus_invoke(c->ctx, id, func, c->buf.head, ubus_lua_call_cb, L, c->timeout * 1000);
 568
 569         if (rv != UBUS_STATUS_OK)
 570         {
 571                 lua_pop(L, 1);
 572                 lua_pushnil(L);
 573                 lua_pushinteger(L, rv);
 574                 return 2;
 575         }
 576
 577         return lua_gettop(L) - top;
 578 }
 579
 580 static void
 581 ubus_event_handler(struct ubus_context *ctx, struct ubus_event_handler *ev,
 582                         const char *type, struct blob_attr *msg)
 583 {
 584         struct ubus_lua_event *listener = container_of(ev, struct ubus_lua_event, e);
 585
 586         lua_getglobal(state, "__ubus_cb_event");
 587         lua_rawgeti(state, -1, listener->r);
 588
 589         if (lua_isfunction(state, -1)) {
 590                 ubus_lua_parse_blob_array(state, blob_data(msg), blob_len(msg), true);
 591                 lua_call(state, 1, 0);
 592         }
 593 }
 594
 595 static struct ubus_event_handler*
 596 ubus_lua_load_event(lua_State *L)
 597 {
 598         struct ubus_lua_event* event = NULL;
 599
 600         event = malloc(sizeof(struct ubus_lua_event));
 601         memset(event, 0, sizeof(struct ubus_lua_event));
 602         event->e.cb = ubus_event_handler;
 603
 604         /* update the he callback lookup table */
 605         lua_getglobal(L, "__ubus_cb_event");
 606         lua_pushvalue(L, -2);
 607         event->r = luaL_ref(L, -2);
 608         lua_setfield(L, -1, lua_tostring(L, -3));
 609
 610         return &event->e;
 611 }
 612
 613 static int
 614 ubus_lua_listen(lua_State *L) {
 615         struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
 616
 617         /* verify top level object */
 618         luaL_checktype(L, 2, LUA_TTABLE);
 619
 620         /* scan each object */
 621         lua_pushnil(L);
 622         while (lua_next(L, -2) != 0) {
 623                 struct ubus_event_handler *listener;
 624
 625                 /* check if the key is a string and the value is a method */
 626                 if ((lua_type(L, -2) == LUA_TSTRING) && (lua_type(L, -1) == LUA_TFUNCTION)) {
 627                         listener = ubus_lua_load_event(L);
 628                         if(listener != NULL) {
 629                                 ubus_register_event_handler(c->ctx, listener, lua_tostring(L, -2));
 630                         }
 631                 }
 632                 lua_pop(L, 1);
 633         }
 634         return 0;
 635 }
 636
 637 static int
 638 ubus_lua_send(lua_State *L)
 639 {
 640         struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
 641         const char *event = luaL_checkstring(L, 2);
 642
 643         if (*event == 0)
 644                 return luaL_argerror(L, 2, "no event name");
 645
 646         // Event content convert to ubus form
 647         luaL_checktype(L, 3, LUA_TTABLE);
 648         blob_buf_init(&c->buf, 0);
 649
 650         if (!ubus_lua_format_blob_array(L, &c->buf, true)) {
 651                 lua_pushnil(L);
 652                 lua_pushinteger(L, UBUS_STATUS_INVALID_ARGUMENT);
 653                 return 2;
 654         }
 655
 656         // Send the event
 657         ubus_send_event(c->ctx, event, c->buf.head);
 658
 659         return 0;
 660 }
 661
 662
 663
 664 static int
 665 ubus_lua__gc(lua_State *L)
 666 {
 667         struct ubus_lua_connection *c = luaL_checkudata(L, 1, METANAME);
 668
 669         if (c->ctx != NULL)
 670         {
 671                 ubus_free(c->ctx);
 672                 memset(c, 0, sizeof(*c));
 673         }
 674
 675         return 0;
 676 }
 677
 678 static const luaL_Reg ubus[] = {
 679         { "connect", ubus_lua_connect },
 680         { "objects", ubus_lua_objects },
 681         { "add", ubus_lua_add },
 682         { "reply", ubus_lua_reply },
 683         { "signatures", ubus_lua_signatures },
 684         { "call", ubus_lua_call },
 685         { "close", ubus_lua__gc },
 686         { "listen", ubus_lua_listen },
 687         { "send", ubus_lua_send },
 688         { "__gc", ubus_lua__gc },
 689         { NULL, NULL },
 690 };
 691
 692 /* avoid missing prototype warning */
 693 int luaopen_ubus(lua_State *L);
 694
 695 int
 696 luaopen_ubus(lua_State *L)
 697 {
 698         /* create metatable */
 699         luaL_newmetatable(L, METANAME);
 700
 701         /* metatable.__index = metatable */
 702         lua_pushvalue(L, -1);
 703         lua_setfield(L, -2, "__index");
 704
 705         /* fill metatable */
 706         luaL_register(L, NULL, ubus);
 707         lua_pop(L, 1);
 708
 709         /* create module */
 710         luaL_register(L, MODNAME, ubus);
 711
 712         /* set some enum defines */
 713         lua_pushinteger(L, BLOBMSG_TYPE_ARRAY);
 714         lua_setfield(L, -2, "ARRAY");
 715         lua_pushinteger(L, BLOBMSG_TYPE_TABLE);
 716         lua_setfield(L, -2, "TABLE");
 717         lua_pushinteger(L, BLOBMSG_TYPE_STRING);
 718         lua_setfield(L, -2, "STRING");
 719         lua_pushinteger(L, BLOBMSG_TYPE_INT64);
 720         lua_setfield(L, -2, "INT64");
 721         lua_pushinteger(L, BLOBMSG_TYPE_INT32);
 722         lua_setfield(L, -2, "INT32");
 723         lua_pushinteger(L, BLOBMSG_TYPE_INT16);
 724         lua_setfield(L, -2, "INT16");
 725         lua_pushinteger(L, BLOBMSG_TYPE_INT8);
 726         lua_setfield(L, -2, "INT8");
 727         lua_pushinteger(L, BLOBMSG_TYPE_BOOL);
 728         lua_setfield(L, -2, "BOOLEAN");
 729
 730         /* used in our callbacks */
 731         state = L;
 732
 733         /* create the callback table */
 734         lua_createtable(L, 1, 0);
 735         lua_setglobal(L, "__ubus_cb");
 736
 737         /* create the event table */
 738         lua_createtable(L, 1, 0);
 739         lua_setglobal(L, "__ubus_cb_event");
 740
 741         return 0;
 742 }