lua/uci.c

   1 /*
   2  * libuci plugin for Lua
   3  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2
   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 <sys/types.h>
  16 #include <sys/time.h>
  17 #include <stdbool.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <unistd.h>
  21 #include <stdio.h>
  22 #include <errno.h>
  23
  24 #include <lauxlib.h>
  25 #include <uci.h>
  26
  27 #define MODNAME        "uci"
  28 #define METANAME       MODNAME ".meta"
  29 //#define DEBUG 1
  30
  31 #ifdef DEBUG
  32 #define DPRINTF(...) fprintf(stderr, __VA_ARGS__)
  33 #else
  34 #define DPRINTF(...) do {} while (0)
  35 #endif
  36
  37 static struct uci_context *global_ctx = NULL;
  38
  39 static struct uci_context *
  40 find_context(lua_State *L, int *offset)
  41 {
  42         struct uci_context **ctx;
  43         if (!lua_isuserdata(L, 1)) {
  44                 if (!global_ctx) {
  45                         global_ctx = uci_alloc_context();
  46                         if (!global_ctx)
  47                                 luaL_error(L, "failed to allocate UCI context");
  48                 }
  49                 if (offset)
  50                         *offset = 0;
  51                 return global_ctx;
  52         }
  53         if (offset)
  54                 *offset = 1;
  55         ctx = luaL_checkudata(L, 1, METANAME);
  56         if (!ctx || !*ctx)
  57                 luaL_error(L, "failed to get UCI context");
  58
  59         return *ctx;
  60 }
  61
  62 static struct uci_package *
  63 find_package(lua_State *L, struct uci_context *ctx, const char *str, bool al)
  64 {
  65         struct uci_package *p = NULL;
  66         struct uci_element *e;
  67         char *sep;
  68         char *name;
  69
  70         sep = strchr(str, '.');
  71         if (sep) {
  72                 name = malloc(1 + sep - str);
  73                 if (!name)
  74                         luaL_error(L, "out of memory");
  75                 strncpy(name, str, sep - str);
  76                 name[sep - str] = 0;
  77         } else
  78                 name = (char *) str;
  79
  80         uci_foreach_element(&ctx->root, e) {
  81                 if (strcmp(e->name, name) != 0)
  82                         continue;
  83
  84                 p = uci_to_package(e);
  85                 goto done;
  86         }
  87
  88         if (al == true)
  89                 uci_load(ctx, name, &p);
  90         else if (al) {
  91                 uci_load(ctx, name, &p);
  92         }
  93
  94 done:
  95         if (name != str)
  96                 free(name);
  97         return p;
  98 }
  99
 100 static int
 101 lookup_args(lua_State *L, struct uci_context *ctx, int offset, struct uci_ptr *ptr, char **buf)
 102 {
 103         char *s = NULL;
 104         int n;
 105
 106         n = lua_gettop(L);
 107         luaL_checkstring(L, 1 + offset);
 108         s = strdup(lua_tostring(L, 1 + offset));
 109         if (!s)
 110                 goto error;
 111
 112         memset(ptr, 0, sizeof(struct uci_ptr));
 113         if (!find_package(L, ctx, s, true))
 114                 goto error;
 115
 116         switch (n - offset) {
 117         case 4:
 118         case 3:
 119                 ptr->option = luaL_checkstring(L, 3 + offset);
 120                 /* fall through */
 121         case 2:
 122                 ptr->section = luaL_checkstring(L, 2 + offset);
 123                 ptr->package = luaL_checkstring(L, 1 + offset);
 124                 if (uci_lookup_ptr(ctx, ptr, NULL, true) != UCI_OK)
 125                         goto error;
 126                 break;
 127         case 1:
 128                 if (uci_lookup_ptr(ctx, ptr, s, true) != UCI_OK)
 129                         goto error;
 130                 break;
 131         default:
 132                 luaL_error(L, "invalid argument count");
 133                 goto error;
 134         }
 135
 136         *buf = s;
 137         return 0;
 138
 139 error:
 140         if (s)
 141                 free(s);
 142         return 1;
 143 }
 144
 145 static int
 146 uci_push_status(lua_State *L, struct uci_context *ctx, bool hasarg)
 147 {
 148         char *str = NULL;
 149
 150         if (!hasarg)
 151                 lua_pushboolean(L, (ctx->err == UCI_OK));
 152         if (ctx->err) {
 153                 uci_get_errorstr(ctx, &str, MODNAME);
 154                 if (str) {
 155                         lua_pushstring(L, str);
 156                         free(str);
 157                         return 2;
 158                 }
 159         }
 160         return 1;
 161 }
 162
 163 static void
 164 uci_push_option(lua_State *L, struct uci_option *o)
 165 {
 166         struct uci_element *e;
 167         int i = 0;
 168
 169         switch(o->type) {
 170         case UCI_TYPE_STRING:
 171                 lua_pushstring(L, o->v.string);
 172                 break;
 173         case UCI_TYPE_LIST:
 174                 lua_newtable(L);
 175                 uci_foreach_element(&o->v.list, e) {
 176                         i++;
 177                         lua_pushstring(L, e->name);
 178                         lua_rawseti(L, -2, i);
 179                 }
 180                 break;
 181         default:
 182                 lua_pushnil(L);
 183                 break;
 184         }
 185 }
 186
 187 static void
 188 uci_push_section(lua_State *L, struct uci_section *s, int index)
 189 {
 190         struct uci_element *e;
 191
 192         lua_newtable(L);
 193         lua_pushboolean(L, s->anonymous);
 194         lua_setfield(L, -2, ".anonymous");
 195         lua_pushstring(L, s->type);
 196         lua_setfield(L, -2, ".type");
 197         lua_pushstring(L, s->e.name);
 198         lua_setfield(L, -2, ".name");
 199         if (index >= 0) {
 200                 lua_pushinteger(L, index);
 201                 lua_setfield(L, -2, ".index");
 202         }
 203
 204         uci_foreach_element(&s->options, e) {
 205                 struct uci_option *o = uci_to_option(e);
 206                 uci_push_option(L, o);
 207                 lua_setfield(L, -2, o->e.name);
 208         }
 209 }
 210
 211 static void
 212 uci_push_package(lua_State *L, struct uci_package *p)
 213 {
 214         struct uci_element *e;
 215         int i = 0;
 216
 217         lua_newtable(L);
 218         uci_foreach_element(&p->sections, e) {
 219                 uci_push_section(L, uci_to_section(e), i);
 220                 lua_setfield(L, -2, e->name);
 221                 i++;
 222         }
 223 }
 224
 225 static int
 226 uci_lua_unload(lua_State *L)
 227 {
 228         struct uci_context *ctx;
 229         struct uci_package *p;
 230         const char *s;
 231         int offset = 0;
 232
 233         ctx = find_context(L, &offset);
 234         luaL_checkstring(L, 1 + offset);
 235         s = lua_tostring(L, 1 + offset);
 236         p = find_package(L, ctx, s, false);
 237         if (p) {
 238                 uci_unload(ctx, p);
 239                 return uci_push_status(L, ctx, false);
 240         } else {
 241                 lua_pushboolean(L, 0);
 242         }
 243         return 1;
 244 }
 245
 246 static int
 247 uci_lua_load(lua_State *L)
 248 {
 249         struct uci_context *ctx;
 250         struct uci_package *p = NULL;
 251         const char *s;
 252         int offset = 0;
 253
 254         ctx = find_context(L, &offset);
 255         uci_lua_unload(L);
 256         lua_pop(L, 1); /* bool ret value of unload */
 257         s = lua_tostring(L, -1);
 258
 259         uci_load(ctx, s, &p);
 260         return uci_push_status(L, ctx, false);
 261 }
 262
 263
 264 static int
 265 uci_lua_foreach(lua_State *L)
 266 {
 267         struct uci_context *ctx;
 268         struct uci_package *p;
 269         struct uci_element *e, *tmp;
 270         const char *package, *type;
 271         bool ret = false;
 272         int offset = 0;
 273         int i = 0;
 274
 275         ctx = find_context(L, &offset);
 276         package = luaL_checkstring(L, 1 + offset);
 277
 278         if (lua_isnil(L, 2))
 279                 type = NULL;
 280         else
 281                 type = luaL_checkstring(L, 2 + offset);
 282
 283         if (!lua_isfunction(L, 3 + offset) || !package)
 284                 luaL_error(L, "Invalid argument");
 285
 286         p = find_package(L, ctx, package, true);
 287         if (!p)
 288                 goto done;
 289
 290         uci_foreach_element_safe(&p->sections, tmp, e) {
 291                 struct uci_section *s = uci_to_section(e);
 292
 293                 i++;
 294
 295                 if (type && (strcmp(s->type, type) != 0))
 296                         continue;
 297
 298                 lua_pushvalue(L, 3 + offset); /* iterator function */
 299                 uci_push_section(L, s, i - 1);
 300                 if (lua_pcall(L, 1, 1, 0) == 0) {
 301                         ret = true;
 302                         if (lua_isboolean(L, -1) && !lua_toboolean(L, -1))
 303                                 break;
 304                 }
 305                 else
 306                 {
 307                         lua_error(L);
 308                         break;
 309                 }
 310         }
 311
 312 done:
 313         lua_pushboolean(L, ret);
 314         return 1;
 315 }
 316
 317 static int
 318 uci_lua_get_any(lua_State *L, bool all)
 319 {
 320         struct uci_context *ctx;
 321         struct uci_element *e = NULL;
 322         struct uci_ptr ptr;
 323         int offset = 0;
 324         char *s = NULL;
 325         int err = UCI_ERR_NOTFOUND;
 326
 327         ctx = find_context(L, &offset);
 328
 329         if (lookup_args(L, ctx, offset, &ptr, &s))
 330                 goto error;
 331
 332         uci_lookup_ptr(ctx, &ptr, NULL, true);
 333         if (!all && !ptr.s) {
 334                 err = UCI_ERR_INVAL;
 335                 goto error;
 336         }
 337         if (!(ptr.flags & UCI_LOOKUP_COMPLETE)) {
 338                 err = UCI_ERR_NOTFOUND;
 339                 goto error;
 340         }
 341
 342         err = UCI_OK;
 343         e = ptr.last;
 344         switch(e->type) {
 345                 case UCI_TYPE_PACKAGE:
 346                         uci_push_package(L, ptr.p);
 347                         break;
 348                 case UCI_TYPE_SECTION:
 349                         if (all)
 350                                 uci_push_section(L, ptr.s, -1);
 351                         else
 352                                 lua_pushstring(L, ptr.s->type);
 353                         break;
 354                 case UCI_TYPE_OPTION:
 355                         uci_push_option(L, ptr.o);
 356                         break;
 357                 default:
 358                         err = UCI_ERR_INVAL;
 359                         goto error;
 360         }
 361         if (!err)
 362                 return 1;
 363
 364 error:
 365         if (s)
 366                 free(s);
 367
 368         lua_pushnil(L);
 369         return uci_push_status(L, ctx, true);
 370 }
 371
 372 static int
 373 uci_lua_get(lua_State *L)
 374 {
 375         return uci_lua_get_any(L, false);
 376 }
 377
 378 static int
 379 uci_lua_get_all(lua_State *L)
 380 {
 381         return uci_lua_get_any(L, true);
 382 }
 383
 384 static int
 385 uci_lua_add(lua_State *L)
 386 {
 387         struct uci_context *ctx;
 388         struct uci_section *s = NULL;
 389         struct uci_package *p;
 390         const char *package;
 391         const char *type;
 392         const char *name = NULL;
 393         int offset = 0;
 394
 395         ctx = find_context(L, &offset);
 396         package = luaL_checkstring(L, 1 + offset);
 397         type = luaL_checkstring(L, 2 + offset);
 398         p = find_package(L, ctx, package, true);
 399         if (!p)
 400                 goto fail;
 401
 402         if (uci_add_section(ctx, p, type, &s) || !s)
 403                 goto fail;
 404
 405         name = s->e.name;
 406         lua_pushstring(L, name);
 407         return 1;
 408
 409 fail:
 410         lua_pushnil(L);
 411         return uci_push_status(L, ctx, true);
 412 }
 413
 414 static int
 415 uci_lua_delete(lua_State *L)
 416 {
 417         struct uci_context *ctx;
 418         struct uci_ptr ptr;
 419         int offset = 0;
 420         char *s = NULL;
 421
 422         ctx = find_context(L, &offset);
 423
 424         if (lookup_args(L, ctx, offset, &ptr, &s))
 425                 goto error;
 426
 427         uci_delete(ctx, &ptr);
 428
 429 error:
 430         if (s)
 431                 free(s);
 432         return uci_push_status(L, ctx, false);
 433 }
 434
 435 static int
 436 uci_lua_rename(lua_State *L)
 437 {
 438         struct uci_context *ctx;
 439         struct uci_ptr ptr;
 440         int err = UCI_ERR_MEM;
 441         char *s = NULL;
 442         int nargs, offset = 0;
 443
 444         ctx = find_context(L, &offset);
 445         nargs = lua_gettop(L);
 446         if (lookup_args(L, ctx, offset, &ptr, &s))
 447                 goto error;
 448
 449         switch(nargs - offset) {
 450         case 1:
 451                 /* Format: uci.set("p.s.o=v") or uci.set("p.s=v") */
 452                 break;
 453         case 4:
 454                 /* Format: uci.set("p", "s", "o", "v") */
 455                 ptr.value = luaL_checkstring(L, nargs);
 456                 break;
 457         case 3:
 458                 /* Format: uci.set("p", "s", "v") */
 459                 ptr.value = ptr.option;
 460                 ptr.option = NULL;
 461                 break;
 462         default:
 463                 err = UCI_ERR_INVAL;
 464                 goto error;
 465         }
 466
 467         err = uci_lookup_ptr(ctx, &ptr, NULL, true);
 468         if (err)
 469                 goto error;
 470
 471         if (((ptr.s == NULL) && (ptr.option != NULL)) || (ptr.value == NULL)) {
 472                 err = UCI_ERR_INVAL;
 473                 goto error;
 474         }
 475
 476         err = uci_rename(ctx, &ptr);
 477         if (err)
 478                 goto error;
 479
 480 error:
 481         return uci_push_status(L, ctx, false);
 482 }
 483
 484 static int
 485 uci_lua_reorder(lua_State *L)
 486 {
 487         struct uci_context *ctx;
 488         struct uci_ptr ptr;
 489         int err = UCI_ERR_MEM;
 490         char *s = NULL;
 491         int nargs, offset = 0;
 492
 493         ctx = find_context(L, &offset);
 494         nargs = lua_gettop(L);
 495         if (lookup_args(L, ctx, offset, &ptr, &s))
 496                 goto error;
 497
 498         switch(nargs - offset) {
 499         case 1:
 500                 /* Format: uci.set("p.s=v") or uci.set("p.s=v") */
 501                 if (ptr.option) {
 502                         err = UCI_ERR_INVAL;
 503                         goto error;
 504                 }
 505                 break;
 506         case 3:
 507                 /* Format: uci.set("p", "s", "v") */
 508                 ptr.value = ptr.option;
 509                 ptr.option = NULL;
 510                 break;
 511         default:
 512                 err = UCI_ERR_INVAL;
 513                 goto error;
 514         }
 515
 516         err = uci_lookup_ptr(ctx, &ptr, NULL, true);
 517         if (err)
 518                 goto error;
 519
 520         if ((ptr.s == NULL) || (ptr.value == NULL)) {
 521                 err = UCI_ERR_INVAL;
 522                 goto error;
 523         }
 524
 525         err = uci_reorder_section(ctx, ptr.s, strtoul(ptr.value, NULL, 10));
 526         if (err)
 527                 goto error;
 528
 529 error:
 530         return uci_push_status(L, ctx, false);
 531 }
 532
 533
 534 static int
 535 uci_lua_set(lua_State *L)
 536 {
 537         struct uci_context *ctx;
 538         struct uci_ptr ptr;
 539         bool istable = false;
 540         int err = UCI_ERR_MEM;
 541         char *s = NULL;
 542         int i, nargs, offset = 0;
 543
 544         ctx = find_context(L, &offset);
 545         nargs = lua_gettop(L);
 546         if (lookup_args(L, ctx, offset, &ptr, &s))
 547                 goto error;
 548
 549         switch(nargs - offset) {
 550         case 1:
 551                 /* Format: uci.set("p.s.o=v") or uci.set("p.s=v") */
 552                 break;
 553         case 4:
 554                 /* Format: uci.set("p", "s", "o", "v") */
 555                 if (lua_istable(L, nargs)) {
 556                         if (lua_objlen(L, nargs) < 1)
 557                                 luaL_error(L, "Cannot set an uci option to an empty table value");
 558                         lua_rawgeti(L, nargs, 1);
 559                         ptr.value = luaL_checkstring(L, -1);
 560                         lua_pop(L, 1);
 561                         istable = true;
 562                 } else {
 563                         ptr.value = luaL_checkstring(L, nargs);
 564                 }
 565                 break;
 566         case 3:
 567                 /* Format: uci.set("p", "s", "v") */
 568                 ptr.value = ptr.option;
 569                 ptr.option = NULL;
 570                 break;
 571         default:
 572                 err = UCI_ERR_INVAL;
 573                 goto error;
 574         }
 575
 576         err = uci_lookup_ptr(ctx, &ptr, NULL, true);
 577         if (err)
 578                 goto error;
 579
 580         if (((ptr.s == NULL) && (ptr.option != NULL)) || (ptr.value == NULL)) {
 581                 err = UCI_ERR_INVAL;
 582                 goto error;
 583         }
 584
 585         if (istable) {
 586                 if (lua_objlen(L, nargs) == 1) {
 587                         i = 1;
 588                         if (ptr.o)
 589                                 err = uci_delete(ctx, &ptr);
 590                 } else {
 591                         i = 2;
 592                         err = uci_set(ctx, &ptr);
 593                         if (err)
 594                                 goto error;
 595                 }
 596
 597                 for (; i <= lua_objlen(L, nargs); i++) {
 598                         lua_rawgeti(L, nargs, i);
 599                         ptr.value = luaL_checkstring(L, -1);
 600                         err = uci_add_list(ctx, &ptr);
 601                         lua_pop(L, 1);
 602                         if (err)
 603                                 goto error;
 604                 }
 605         } else {
 606                 err = uci_set(ctx, &ptr);
 607                 if (err)
 608                         goto error;
 609         }
 610
 611
 612 error:
 613         return uci_push_status(L, ctx, false);
 614 }
 615
 616 enum pkg_cmd {
 617         CMD_SAVE,
 618         CMD_COMMIT,
 619         CMD_REVERT
 620 };
 621
 622 static int
 623 uci_lua_package_cmd(lua_State *L, enum pkg_cmd cmd)
 624 {
 625         struct uci_context *ctx;
 626         struct uci_element *e, *tmp;
 627         struct uci_ptr ptr;
 628         char *s = NULL;
 629         int nargs, offset = 0;
 630
 631         ctx = find_context(L, &offset);
 632         nargs = lua_gettop(L);
 633         if ((cmd != CMD_REVERT) && (nargs - offset > 1))
 634                 goto err;
 635
 636         if (lookup_args(L, ctx, offset, &ptr, &s))
 637                 goto err;
 638
 639         uci_lookup_ptr(ctx, &ptr, NULL, true);
 640
 641         uci_foreach_element_safe(&ctx->root, tmp, e) {
 642                 struct uci_package *p = uci_to_package(e);
 643                 int ret = UCI_ERR_INVAL;
 644
 645                 if (ptr.p && (ptr.p != p))
 646                         continue;
 647
 648                 ptr.p = p;
 649                 switch(cmd) {
 650                 case CMD_COMMIT:
 651                         ret = uci_commit(ctx, &p, false);
 652                         break;
 653                 case CMD_SAVE:
 654                         ret = uci_save(ctx, p);
 655                         break;
 656                 case CMD_REVERT:
 657                         ret = uci_revert(ctx, &ptr);
 658                         break;
 659                 }
 660         }
 661
 662 err:
 663         return uci_push_status(L, ctx, false);
 664 }
 665
 666 static int
 667 uci_lua_save(lua_State *L)
 668 {
 669         return uci_lua_package_cmd(L, CMD_SAVE);
 670 }
 671
 672 static int
 673 uci_lua_commit(lua_State *L)
 674 {
 675         return uci_lua_package_cmd(L, CMD_COMMIT);
 676 }
 677
 678 static int
 679 uci_lua_revert(lua_State *L)
 680 {
 681         return uci_lua_package_cmd(L, CMD_REVERT);
 682 }
 683
 684 static void
 685 uci_lua_add_change(lua_State *L, struct uci_element *e)
 686 {
 687         struct uci_delta *h;
 688         const char *name;
 689
 690         h = uci_to_delta(e);
 691         if (!h->section)
 692                 return;
 693
 694         lua_getfield(L, -1, h->section);
 695         if (lua_isnil(L, -1)) {
 696                 lua_pop(L, 1);
 697                 lua_newtable(L);
 698                 lua_pushvalue(L, -1); /* copy for setfield */
 699                 lua_setfield(L, -3, h->section);
 700         }
 701
 702         name = (h->e.name ? h->e.name : ".type");
 703         if (h->value)
 704                 lua_pushstring(L, h->value);
 705         else
 706                 lua_pushstring(L, "");
 707         lua_setfield(L, -2, name);
 708         lua_pop(L, 1);
 709 }
 710
 711 static void
 712 uci_lua_changes_pkg(lua_State *L, struct uci_context *ctx, const char *package)
 713 {
 714         struct uci_package *p = NULL;
 715         struct uci_element *e;
 716         bool autoload = false;
 717
 718         p = find_package(L, ctx, package, false);
 719         if (!p) {
 720                 autoload = true;
 721                 p = find_package(L, ctx, package, true);
 722                 if (!p)
 723                         return;
 724         }
 725
 726         if (uci_list_empty(&p->delta) && uci_list_empty(&p->saved_delta))
 727                 goto done;
 728
 729         lua_newtable(L);
 730         uci_foreach_element(&p->saved_delta, e) {
 731                 uci_lua_add_change(L, e);
 732         }
 733         uci_foreach_element(&p->delta, e) {
 734                 uci_lua_add_change(L, e);
 735         }
 736         lua_setfield(L, -2, p->e.name);
 737
 738 done:
 739         if (autoload)
 740                 uci_unload(ctx, p);
 741 }
 742
 743 static int
 744 uci_lua_changes(lua_State *L)
 745 {
 746         struct uci_context *ctx;
 747         const char *package = NULL;
 748         char **config = NULL;
 749         int nargs;
 750         int i, offset = 0;
 751
 752         ctx = find_context(L, &offset);
 753         nargs = lua_gettop(L);
 754         switch(nargs - offset) {
 755         case 1:
 756                 package = luaL_checkstring(L, 1 + offset);
 757         case 0:
 758                 break;
 759         default:
 760                 luaL_error(L, "invalid argument count");
 761         }
 762
 763         lua_newtable(L);
 764         if (package) {
 765                 uci_lua_changes_pkg(L, ctx, package);
 766         } else {
 767                 if (uci_list_configs(ctx, &config) != 0)
 768                         goto done;
 769
 770                 for(i = 0; config[i] != NULL; i++) {
 771                         uci_lua_changes_pkg(L, ctx, config[i]);
 772                 }
 773         }
 774
 775 done:
 776         return 1;
 777 }
 778
 779 static int
 780 uci_lua_get_confdir(lua_State *L)
 781 {
 782         struct uci_context *ctx = find_context(L, NULL);
 783         lua_pushstring(L, ctx->confdir);
 784         return 1;
 785 }
 786
 787 static int
 788 uci_lua_set_confdir(lua_State *L)
 789 {
 790         struct uci_context *ctx;
 791         int offset = 0;
 792
 793         ctx = find_context(L, &offset);
 794         luaL_checkstring(L, 1 + offset);
 795         uci_set_confdir(ctx, lua_tostring(L, -1));
 796         return uci_push_status(L, ctx, false);
 797 }
 798
 799 static int
 800 uci_lua_get_savedir(lua_State *L)
 801 {
 802         struct uci_context *ctx = find_context(L, NULL);
 803         lua_pushstring(L, ctx->savedir);
 804         return 1;
 805 }
 806
 807 static int
 808 uci_lua_add_delta(lua_State *L)
 809 {
 810         struct uci_context *ctx;
 811         int offset = 0;
 812
 813         ctx = find_context(L, &offset);
 814         luaL_checkstring(L, 1 + offset);
 815         uci_add_delta_path(ctx, lua_tostring(L, -1));
 816         return uci_push_status(L, ctx, false);
 817 }
 818
 819 static int
 820 uci_lua_load_plugins(lua_State *L)
 821 {
 822         struct uci_context *ctx;
 823         int offset = 0;
 824         const char *str = NULL;
 825
 826         ctx = find_context(L, &offset);
 827         if (lua_isstring(L, -1))
 828                 str = lua_tostring(L, -1);
 829         uci_load_plugins(ctx, str);
 830         return uci_push_status(L, ctx, false);
 831 }
 832
 833 static int
 834 uci_lua_set_savedir(lua_State *L)
 835 {
 836         struct uci_context *ctx;
 837         int offset = 0;
 838
 839         ctx = find_context(L, &offset);
 840         luaL_checkstring(L, 1 + offset);
 841         uci_set_savedir(ctx, lua_tostring(L, -1));
 842         return uci_push_status(L, ctx, false);
 843 }
 844
 845 static int
 846 uci_lua_gc(lua_State *L)
 847 {
 848         struct uci_context *ctx = find_context(L, NULL);
 849         uci_free_context(ctx);
 850         return 0;
 851 }
 852
 853 static int
 854 uci_lua_cursor(lua_State *L)
 855 {
 856         struct uci_context **u;
 857         int argc = lua_gettop(L);
 858
 859         u = lua_newuserdata(L, sizeof(struct uci_context *));
 860         luaL_getmetatable(L, METANAME);
 861         lua_setmetatable(L, -2);
 862
 863         *u = uci_alloc_context();
 864         if (!*u)
 865                 luaL_error(L, "Cannot allocate UCI context");
 866         switch (argc) {
 867                 case 2:
 868                         if (lua_isstring(L, 2) &&
 869                                 (uci_set_savedir(*u, luaL_checkstring(L, 2)) != UCI_OK))
 870                                 luaL_error(L, "Unable to set savedir");
 871                         /* fall through */
 872                 case 1:
 873                         if (lua_isstring(L, 1) &&
 874                                 (uci_set_confdir(*u, luaL_checkstring(L, 1)) != UCI_OK))
 875                                 luaL_error(L, "Unable to set savedir");
 876                         break;
 877                 default:
 878                         break;
 879         }
 880         return 1;
 881 }
 882
 883 static const luaL_Reg uci[] = {
 884         { "__gc", uci_lua_gc },
 885         { "cursor", uci_lua_cursor },
 886         { "load", uci_lua_load },
 887         { "unload", uci_lua_unload },
 888         { "get", uci_lua_get },
 889         { "get_all", uci_lua_get_all },
 890         { "add", uci_lua_add },
 891         { "set", uci_lua_set },
 892         { "rename", uci_lua_rename },
 893         { "save", uci_lua_save },
 894         { "delete", uci_lua_delete },
 895         { "commit", uci_lua_commit },
 896         { "revert", uci_lua_revert },
 897         { "reorder", uci_lua_reorder },
 898         { "changes", uci_lua_changes },
 899         { "foreach", uci_lua_foreach },
 900         { "add_history", uci_lua_add_delta },
 901         { "add_delta", uci_lua_add_delta },
 902         { "load_plugins", uci_lua_load_plugins },
 903         { "get_confdir", uci_lua_get_confdir },
 904         { "set_confdir", uci_lua_set_confdir },
 905         { "get_savedir", uci_lua_get_savedir },
 906         { "set_savedir", uci_lua_set_savedir },
 907         { NULL, NULL },
 908 };
 909
 910
 911 int
 912 luaopen_uci(lua_State *L)
 913 {
 914         /* create metatable */
 915         luaL_newmetatable(L, METANAME);
 916
 917         /* metatable.__index = metatable */
 918         lua_pushvalue(L, -1);
 919         lua_setfield(L, -2, "__index");
 920
 921         /* fill metatable */
 922         luaL_register(L, NULL, uci);
 923         lua_pop(L, 1);
 924
 925         /* create module */
 926         luaL_register(L, MODNAME, uci);
 927
 928         return 0;
 929 }