package/libnl-tiny/src/cache.c

   1 /*
   2  * lib/cache.c          Caching Module
   3  *
   4  *      This library is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU Lesser General Public
   6  *      License as published by the Free Software Foundation version 2.1
   7  *      of the License.
   8  *
   9  * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
  10  */
  11
  12 /**
  13  * @ingroup cache_mngt
  14  * @defgroup cache Cache
  15  *
  16  * @code
  17  *   Cache Management             |    | Type Specific Cache Operations
  18  *
  19  *                                |    | +----------------+ +------------+
  20  *                                       | request update | | msg_parser |
  21  *                                |    | +----------------+ +------------+
  22  *                                     +- - - - -^- - - - - - - -^- -|- - - -
  23  *    nl_cache_update:            |              |               |   |
  24  *          1) --------- co_request_update ------+               |   |
  25  *                                |                              |   |
  26  *          2) destroy old cache     +----------- pp_cb ---------|---+
  27  *                                |  |                           |
  28  *          3) ---------- nl_recvmsgs ----------+   +- cb_valid -+
  29  *             +--------------+   |  |          |   |
  30  *             | nl_cache_add |<-----+   + - - -v- -|- - - - - - - - - - -
  31  *             +--------------+   |      | +-------------+
  32  *                                         | nl_recvmsgs |
  33  *                                |      | +-----|-^-----+
  34  *                                           +---v-|---+
  35  *                                |      |   | nl_recv |
  36  *                                           +---------+
  37  *                                |      |                 Core Netlink
  38  * @endcode
  39  *
  40  * @{
  41  */
  42
  43 #include <netlink-local.h>
  44 #include <netlink/netlink.h>
  45 #include <netlink/cache.h>
  46 #include <netlink/object.h>
  47 #include <netlink/utils.h>
  48
  49 /**
  50  * @name Access Functions
  51  * @{
  52  */
  53
  54 #ifdef disabled
  55 /**
  56  * Return the number of items in the cache
  57  * @arg cache           cache handle
  58  */
  59 int nl_cache_nitems(struct nl_cache *cache)
  60 {
  61         return cache->c_nitems;
  62 }
  63
  64 /**
  65  * Return the number of items matching a filter in the cache
  66  * @arg cache           Cache object.
  67  * @arg filter          Filter object.
  68  */
  69 int nl_cache_nitems_filter(struct nl_cache *cache, struct nl_object *filter)
  70 {
  71         struct nl_object_ops *ops;
  72         struct nl_object *obj;
  73         int nitems = 0;
  74
  75         if (cache->c_ops == NULL)
  76                 BUG();
  77
  78         ops = cache->c_ops->co_obj_ops;
  79
  80         nl_list_for_each_entry(obj, &cache->c_items, ce_list) {
  81                 if (filter && !nl_object_match_filter(obj, filter))
  82                         continue;
  83
  84                 nitems++;
  85         }
  86
  87         return nitems;
  88 }
  89
  90 /**
  91  * Returns \b true if the cache is empty.
  92  * @arg cache           Cache to check
  93  * @return \a true if the cache is empty, otherwise \b false is returned.
  94  */
  95 int nl_cache_is_empty(struct nl_cache *cache)
  96 {
  97         return nl_list_empty(&cache->c_items);
  98 }
  99
 100 /**
 101  * Return the operations set of the cache
 102  * @arg cache           cache handle
 103  */
 104 struct nl_cache_ops *nl_cache_get_ops(struct nl_cache *cache)
 105 {
 106         return cache->c_ops;
 107 }
 108
 109 /**
 110  * Return the first element in the cache
 111  * @arg cache           cache handle
 112  */
 113 struct nl_object *nl_cache_get_first(struct nl_cache *cache)
 114 {
 115         if (nl_list_empty(&cache->c_items))
 116                 return NULL;
 117
 118         return nl_list_entry(cache->c_items.next,
 119                              struct nl_object, ce_list);
 120 }
 121
 122 /**
 123  * Return the last element in the cache
 124  * @arg cache           cache handle
 125  */
 126 struct nl_object *nl_cache_get_last(struct nl_cache *cache)
 127 {
 128         if (nl_list_empty(&cache->c_items))
 129                 return NULL;
 130
 131         return nl_list_entry(cache->c_items.prev,
 132                              struct nl_object, ce_list);
 133 }
 134
 135 /**
 136  * Return the next element in the cache
 137  * @arg obj             current object
 138  */
 139 struct nl_object *nl_cache_get_next(struct nl_object *obj)
 140 {
 141         if (nl_list_at_tail(obj, &obj->ce_cache->c_items, ce_list))
 142                 return NULL;
 143         else
 144                 return nl_list_entry(obj->ce_list.next,
 145                                      struct nl_object, ce_list);
 146 }
 147
 148 /**
 149  * Return the previous element in the cache
 150  * @arg obj             current object
 151  */
 152 struct nl_object *nl_cache_get_prev(struct nl_object *obj)
 153 {
 154         if (nl_list_at_head(obj, &obj->ce_cache->c_items, ce_list))
 155                 return NULL;
 156         else
 157                 return nl_list_entry(obj->ce_list.prev,
 158                                      struct nl_object, ce_list);
 159 }
 160 #endif
 161
 162 /** @} */
 163
 164 /**
 165  * @name Cache Creation/Deletion
 166  * @{
 167  */
 168
 169 /**
 170  * Allocate an empty cache
 171  * @arg ops             cache operations to base the cache on
 172  *
 173  * @return A newly allocated and initialized cache.
 174  */
 175 struct nl_cache *nl_cache_alloc(struct nl_cache_ops *ops)
 176 {
 177         struct nl_cache *cache;
 178
 179         cache = calloc(1, sizeof(*cache));
 180         if (!cache)
 181                 return NULL;
 182
 183         nl_init_list_head(&cache->c_items);
 184         cache->c_ops = ops;
 185
 186         NL_DBG(2, "Allocated cache %p <%s>.\n", cache, nl_cache_name(cache));
 187
 188         return cache;
 189 }
 190
 191 int nl_cache_alloc_and_fill(struct nl_cache_ops *ops, struct nl_sock *sock,
 192                             struct nl_cache **result)
 193 {
 194         struct nl_cache *cache;
 195         int err;
 196
 197         if (!(cache = nl_cache_alloc(ops)))
 198                 return -NLE_NOMEM;
 199
 200         if (sock && (err = nl_cache_refill(sock, cache)) < 0) {
 201                 nl_cache_free(cache);
 202                 return err;
 203         }
 204
 205         *result = cache;
 206         return 0;
 207 }
 208
 209 #ifdef disabled
 210 /**
 211  * Allocate an empty cache based on type name
 212  * @arg kind            Name of cache type
 213  * @return A newly allocated and initialized cache.
 214  */
 215 int nl_cache_alloc_name(const char *kind, struct nl_cache **result)
 216 {
 217         struct nl_cache_ops *ops;
 218         struct nl_cache *cache;
 219
 220         ops = nl_cache_ops_lookup(kind);
 221         if (!ops)
 222                 return -NLE_NOCACHE;
 223
 224         if (!(cache = nl_cache_alloc(ops)))
 225                 return -NLE_NOMEM;
 226
 227         *result = cache;
 228         return 0;
 229 }
 230
 231 /**
 232  * Allocate a new cache containing a subset of a cache
 233  * @arg orig            Original cache to be based on
 234  * @arg filter          Filter defining the subset to be filled into new cache
 235  * @return A newly allocated cache or NULL.
 236  */
 237 struct nl_cache *nl_cache_subset(struct nl_cache *orig,
 238                                  struct nl_object *filter)
 239 {
 240         struct nl_cache *cache;
 241         struct nl_object_ops *ops;
 242         struct nl_object *obj;
 243
 244         if (!filter)
 245                 BUG();
 246
 247         cache = nl_cache_alloc(orig->c_ops);
 248         if (!cache)
 249                 return NULL;
 250
 251         ops = orig->c_ops->co_obj_ops;
 252
 253         nl_list_for_each_entry(obj, &orig->c_items, ce_list) {
 254                 if (!nl_object_match_filter(obj, filter))
 255                         continue;
 256
 257                 nl_cache_add(cache, obj);
 258         }
 259
 260         return cache;
 261 }
 262 #endif
 263
 264 /**
 265  * Clear a cache.
 266  * @arg cache           cache to clear
 267  *
 268  * Removes all elements of a cache.
 269  */
 270 void nl_cache_clear(struct nl_cache *cache)
 271 {
 272         struct nl_object *obj, *tmp;
 273
 274         NL_DBG(1, "Clearing cache %p <%s>...\n", cache, nl_cache_name(cache));
 275
 276         nl_list_for_each_entry_safe(obj, tmp, &cache->c_items, ce_list)
 277                 nl_cache_remove(obj);
 278 }
 279
 280 /**
 281  * Free a cache.
 282  * @arg cache           Cache to free.
 283  *
 284  * Removes all elements of a cache and frees all memory.
 285  *
 286  * @note Use this function if you are working with allocated caches.
 287  */
 288 void nl_cache_free(struct nl_cache *cache)
 289 {
 290         if (!cache)
 291                 return;
 292
 293         nl_cache_clear(cache);
 294         NL_DBG(1, "Freeing cache %p <%s>...\n", cache, nl_cache_name(cache));
 295         free(cache);
 296 }
 297
 298 /** @} */
 299
 300 /**
 301  * @name Cache Modifications
 302  * @{
 303  */
 304
 305 static int __cache_add(struct nl_cache *cache, struct nl_object *obj)
 306 {
 307         obj->ce_cache = cache;
 308
 309         nl_list_add_tail(&obj->ce_list, &cache->c_items);
 310         cache->c_nitems++;
 311
 312         NL_DBG(1, "Added %p to cache %p <%s>.\n",
 313                obj, cache, nl_cache_name(cache));
 314
 315         return 0;
 316 }
 317
 318 /**
 319  * Add object to a cache.
 320  * @arg cache           Cache to add object to
 321  * @arg obj             Object to be added to the cache
 322  *
 323  * Adds the given object to the specified cache. The object is cloned
 324  * if it has been added to another cache already.
 325  *
 326  * @return 0 or a negative error code.
 327  */
 328 int nl_cache_add(struct nl_cache *cache, struct nl_object *obj)
 329 {
 330         struct nl_object *new;
 331
 332         if (cache->c_ops->co_obj_ops != obj->ce_ops)
 333                 return -NLE_OBJ_MISMATCH;
 334
 335         if (!nl_list_empty(&obj->ce_list)) {
 336                 new = nl_object_clone(obj);
 337                 if (!new)
 338                         return -NLE_NOMEM;
 339         } else {
 340                 nl_object_get(obj);
 341                 new = obj;
 342         }
 343
 344         return __cache_add(cache, new);
 345 }
 346
 347 #ifdef disabled
 348 /**
 349  * Move object from one cache to another
 350  * @arg cache           Cache to move object to.
 351  * @arg obj             Object subject to be moved
 352  *
 353  * Removes the given object from its associated cache if needed
 354  * and adds it to the new cache.
 355  *
 356  * @return 0 on success or a negative error code.
 357  */
 358 int nl_cache_move(struct nl_cache *cache, struct nl_object *obj)
 359 {
 360         if (cache->c_ops->co_obj_ops != obj->ce_ops)
 361                 return -NLE_OBJ_MISMATCH;
 362
 363         NL_DBG(3, "Moving object %p to cache %p\n", obj, cache);
 364
 365         /* Acquire reference, if already in a cache this will be
 366          * reverted during removal */
 367         nl_object_get(obj);
 368
 369         if (!nl_list_empty(&obj->ce_list))
 370                 nl_cache_remove(obj);
 371
 372         return __cache_add(cache, obj);
 373 }
 374 #endif
 375
 376 /**
 377  * Removes an object from a cache.
 378  * @arg obj             Object to remove from its cache
 379  *
 380  * Removes the object \c obj from the cache it is assigned to, since
 381  * an object can only be assigned to one cache at a time, the cache
 382  * must ne be passed along with it.
 383  */
 384 void nl_cache_remove(struct nl_object *obj)
 385 {
 386         struct nl_cache *cache = obj->ce_cache;
 387
 388         if (cache == NULL)
 389                 return;
 390
 391         nl_list_del(&obj->ce_list);
 392         obj->ce_cache = NULL;
 393         nl_object_put(obj);
 394         cache->c_nitems--;
 395
 396         NL_DBG(1, "Deleted %p from cache %p <%s>.\n",
 397                obj, cache, nl_cache_name(cache));
 398 }
 399
 400 #ifdef disabled
 401 /**
 402  * Search for an object in a cache
 403  * @arg cache           Cache to search in.
 404  * @arg needle          Object to look for.
 405  *
 406  * Iterates over the cache and looks for an object with identical
 407  * identifiers as the needle.
 408  *
 409  * @return Reference to object or NULL if not found.
 410  * @note The returned object must be returned via nl_object_put().
 411  */
 412 struct nl_object *nl_cache_search(struct nl_cache *cache,
 413                                   struct nl_object *needle)
 414 {
 415         struct nl_object *obj;
 416
 417         nl_list_for_each_entry(obj, &cache->c_items, ce_list) {
 418                 if (nl_object_identical(obj, needle)) {
 419                         nl_object_get(obj);
 420                         return obj;
 421                 }
 422         }
 423
 424         return NULL;
 425 }
 426 #endif
 427
 428 /** @} */
 429
 430 /**
 431  * @name Synchronization
 432  * @{
 433  */
 434
 435 /**
 436  * Request a full dump from the kernel to fill a cache
 437  * @arg sk              Netlink socket.
 438  * @arg cache           Cache subjected to be filled.
 439  *
 440  * Send a dumping request to the kernel causing it to dump all objects
 441  * related to the specified cache to the netlink socket.
 442  *
 443  * Use nl_cache_pickup() to read the objects from the socket and fill them
 444  * into a cache.
 445  */
 446 int nl_cache_request_full_dump(struct nl_sock *sk, struct nl_cache *cache)
 447 {
 448         NL_DBG(2, "Requesting dump from kernel for cache %p <%s>...\n",
 449                   cache, nl_cache_name(cache));
 450
 451         if (cache->c_ops->co_request_update == NULL)
 452                 return -NLE_OPNOTSUPP;
 453
 454         return cache->c_ops->co_request_update(cache, sk);
 455 }
 456
 457 /** @cond SKIP */
 458 struct update_xdata {
 459         struct nl_cache_ops *ops;
 460         struct nl_parser_param *params;
 461 };
 462
 463 static int update_msg_parser(struct nl_msg *msg, void *arg)
 464 {
 465         struct update_xdata *x = arg;
 466
 467         return nl_cache_parse(x->ops, &msg->nm_src, msg->nm_nlh, x->params);
 468 }
 469 /** @endcond */
 470
 471 int __cache_pickup(struct nl_sock *sk, struct nl_cache *cache,
 472                    struct nl_parser_param *param)
 473 {
 474         int err;
 475         struct nl_cb *cb;
 476         struct update_xdata x = {
 477                 .ops = cache->c_ops,
 478                 .params = param,
 479         };
 480
 481         NL_DBG(1, "Picking up answer for cache %p <%s>...\n",
 482                   cache, nl_cache_name(cache));
 483
 484         cb = nl_cb_clone(sk->s_cb);
 485         if (cb == NULL)
 486                 return -NLE_NOMEM;
 487
 488         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, update_msg_parser, &x);
 489
 490         err = nl_recvmsgs(sk, cb);
 491         if (err < 0)
 492                 NL_DBG(2, "While picking up for %p <%s>, recvmsgs() returned " \
 493                        "%d: %s", cache, nl_cache_name(cache),
 494                        err, nl_geterror(err));
 495
 496         nl_cb_put(cb);
 497
 498         return err;
 499 }
 500
 501 static int pickup_cb(struct nl_object *c, struct nl_parser_param *p)
 502 {
 503         return nl_cache_add((struct nl_cache *) p->pp_arg, c);
 504 }
 505
 506 /**
 507  * Pickup a netlink dump response and put it into a cache.
 508  * @arg sk              Netlink socket.
 509  * @arg cache           Cache to put items into.
 510  *
 511  * Waits for netlink messages to arrive, parses them and puts them into
 512  * the specified cache.
 513  *
 514  * @return 0 on success or a negative error code.
 515  */
 516 int nl_cache_pickup(struct nl_sock *sk, struct nl_cache *cache)
 517 {
 518         struct nl_parser_param p = {
 519                 .pp_cb = pickup_cb,
 520                 .pp_arg = cache,
 521         };
 522
 523         return __cache_pickup(sk, cache, &p);
 524 }
 525
 526 #ifdef disabled
 527 static int cache_include(struct nl_cache *cache, struct nl_object *obj,
 528                          struct nl_msgtype *type, change_func_t cb)
 529 {
 530         struct nl_object *old;
 531
 532         switch (type->mt_act) {
 533         case NL_ACT_NEW:
 534         case NL_ACT_DEL:
 535                 old = nl_cache_search(cache, obj);
 536                 if (old) {
 537                         nl_cache_remove(old);
 538                         if (type->mt_act == NL_ACT_DEL) {
 539                                 if (cb)
 540                                         cb(cache, old, NL_ACT_DEL);
 541                                 nl_object_put(old);
 542                         }
 543                 }
 544
 545                 if (type->mt_act == NL_ACT_NEW) {
 546                         nl_cache_move(cache, obj);
 547                         if (old == NULL && cb)
 548                                 cb(cache, obj, NL_ACT_NEW);
 549                         else if (old) {
 550                                 if (nl_object_diff(old, obj) && cb)
 551                                         cb(cache, obj, NL_ACT_CHANGE);
 552
 553                                 nl_object_put(old);
 554                         }
 555                 }
 556                 break;
 557         default:
 558                 NL_DBG(2, "Unknown action associated to object %p\n", obj);
 559                 return 0;
 560         }
 561
 562         return 0;
 563 }
 564
 565 int nl_cache_include(struct nl_cache *cache, struct nl_object *obj,
 566                      change_func_t change_cb)
 567 {
 568         struct nl_cache_ops *ops = cache->c_ops;
 569         int i;
 570
 571         if (ops->co_obj_ops != obj->ce_ops)
 572                 return -NLE_OBJ_MISMATCH;
 573
 574         for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++)
 575                 if (ops->co_msgtypes[i].mt_id == obj->ce_msgtype)
 576                         return cache_include(cache, obj, &ops->co_msgtypes[i],
 577                                              change_cb);
 578
 579         return -NLE_MSGTYPE_NOSUPPORT;
 580 }
 581
 582 static int resync_cb(struct nl_object *c, struct nl_parser_param *p)
 583 {
 584         struct nl_cache_assoc *ca = p->pp_arg;
 585
 586         return nl_cache_include(ca->ca_cache, c, ca->ca_change);
 587 }
 588
 589 int nl_cache_resync(struct nl_sock *sk, struct nl_cache *cache,
 590                     change_func_t change_cb)
 591 {
 592         struct nl_object *obj, *next;
 593         struct nl_cache_assoc ca = {
 594                 .ca_cache = cache,
 595                 .ca_change = change_cb,
 596         };
 597         struct nl_parser_param p = {
 598                 .pp_cb = resync_cb,
 599                 .pp_arg = &ca,
 600         };
 601         int err;
 602
 603         NL_DBG(1, "Resyncing cache %p <%s>...\n", cache, nl_cache_name(cache));
 604
 605         /* Mark all objects so we can see if some of them are obsolete */
 606         nl_cache_mark_all(cache);
 607
 608         err = nl_cache_request_full_dump(sk, cache);
 609         if (err < 0)
 610                 goto errout;
 611
 612         err = __cache_pickup(sk, cache, &p);
 613         if (err < 0)
 614                 goto errout;
 615
 616         nl_list_for_each_entry_safe(obj, next, &cache->c_items, ce_list)
 617                 if (nl_object_is_marked(obj))
 618                         nl_cache_remove(obj);
 619
 620         NL_DBG(1, "Finished resyncing %p <%s>\n", cache, nl_cache_name(cache));
 621
 622         err = 0;
 623 errout:
 624         return err;
 625 }
 626 #endif
 627
 628 /** @} */
 629
 630 /**
 631  * @name Parsing
 632  * @{
 633  */
 634
 635 /** @cond SKIP */
 636 int nl_cache_parse(struct nl_cache_ops *ops, struct sockaddr_nl *who,
 637                    struct nlmsghdr *nlh, struct nl_parser_param *params)
 638 {
 639         int i, err;
 640
 641         if (!nlmsg_valid_hdr(nlh, ops->co_hdrsize))
 642                 return -NLE_MSG_TOOSHORT;
 643
 644         for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++) {
 645                 if (ops->co_msgtypes[i].mt_id == nlh->nlmsg_type) {
 646                         err = ops->co_msg_parser(ops, who, nlh, params);
 647                         if (err != -NLE_OPNOTSUPP)
 648                                 goto errout;
 649                 }
 650         }
 651
 652
 653         err = -NLE_MSGTYPE_NOSUPPORT;
 654 errout:
 655         return err;
 656 }
 657 /** @endcond */
 658
 659 /**
 660  * Parse a netlink message and add it to the cache.
 661  * @arg cache           cache to add element to
 662  * @arg msg             netlink message
 663  *
 664  * Parses a netlink message by calling the cache specific message parser
 665  * and adds the new element to the cache.
 666  *
 667  * @return 0 or a negative error code.
 668  */
 669 int nl_cache_parse_and_add(struct nl_cache *cache, struct nl_msg *msg)
 670 {
 671         struct nl_parser_param p = {
 672                 .pp_cb = pickup_cb,
 673                 .pp_arg = cache,
 674         };
 675
 676         return nl_cache_parse(cache->c_ops, NULL, nlmsg_hdr(msg), &p);
 677 }
 678
 679 /**
 680  * (Re)fill a cache with the contents in the kernel.
 681  * @arg sk              Netlink socket.
 682  * @arg cache           cache to update
 683  *
 684  * Clears the specified cache and fills it with the current state in
 685  * the kernel.
 686  *
 687  * @return 0 or a negative error code.
 688  */
 689 int nl_cache_refill(struct nl_sock *sk, struct nl_cache *cache)
 690 {
 691         int err;
 692
 693         err = nl_cache_request_full_dump(sk, cache);
 694         if (err < 0)
 695                 return err;
 696
 697         NL_DBG(2, "Upading cache %p <%s>, request sent, waiting for dump...\n",
 698                cache, nl_cache_name(cache));
 699         nl_cache_clear(cache);
 700
 701         return nl_cache_pickup(sk, cache);
 702 }
 703
 704 /** @} */
 705 #ifdef disabled
 706
 707 /**
 708  * @name Utillities
 709  * @{
 710  */
 711
 712 /**
 713  * Mark all objects in a cache
 714  * @arg cache           Cache to mark all objects in
 715  */
 716 void nl_cache_mark_all(struct nl_cache *cache)
 717 {
 718         struct nl_object *obj;
 719
 720         NL_DBG(2, "Marking all objects in cache %p <%s>...\n",
 721                   cache, nl_cache_name(cache));
 722
 723         nl_list_for_each_entry(obj, &cache->c_items, ce_list)
 724                 nl_object_mark(obj);
 725 }
 726
 727 /** @} */
 728
 729 /**
 730  * @name Dumping
 731  * @{
 732  */
 733 /**
 734  * Dump all elements of a cache.
 735  * @arg cache           cache to dump
 736  * @arg params          dumping parameters
 737  *
 738  * Dumps all elements of the \a cache to the file descriptor \a fd.
 739  */
 740 void nl_cache_dump(struct nl_cache *cache, struct nl_dump_params *params)
 741 {
 742         nl_cache_dump_filter(cache, params, NULL);
 743 }
 744
 745 /**
 746  * Dump all elements of a cache (filtered).
 747  * @arg cache           cache to dump
 748  * @arg params          dumping parameters (optional)
 749  * @arg filter          filter object
 750  *
 751  * Dumps all elements of the \a cache to the file descriptor \a fd
 752  * given they match the given filter \a filter.
 753  */
 754 void nl_cache_dump_filter(struct nl_cache *cache,
 755                           struct nl_dump_params *params,
 756                           struct nl_object *filter)
 757 {
 758         int type = params ? params->dp_type : NL_DUMP_DETAILS;
 759         struct nl_object_ops *ops;
 760         struct nl_object *obj;
 761
 762         NL_DBG(2, "Dumping cache %p <%s> filter %p\n",
 763                cache, nl_cache_name(cache), filter);
 764
 765         if (type > NL_DUMP_MAX || type < 0)
 766                 BUG();
 767
 768         if (cache->c_ops == NULL)
 769                 BUG();
 770
 771         ops = cache->c_ops->co_obj_ops;
 772         if (!ops->oo_dump[type])
 773                 return;
 774
 775         nl_list_for_each_entry(obj, &cache->c_items, ce_list) {
 776                 if (filter && !nl_object_match_filter(obj, filter))
 777                         continue;
 778
 779                 NL_DBG(4, "Dumping object %p...\n", obj);
 780                 dump_from_ops(obj, params);
 781         }
 782 }
 783
 784 /** @} */
 785
 786 /**
 787  * @name Iterators
 788  * @{
 789  */
 790
 791 /**
 792  * Call a callback on each element of the cache.
 793  * @arg cache           cache to iterate on
 794  * @arg cb              callback function
 795  * @arg arg             argument passed to callback function
 796  *
 797  * Calls a callback function \a cb on each element of the \a cache.
 798  * The argument \a arg is passed on the callback function.
 799  */
 800 void nl_cache_foreach(struct nl_cache *cache,
 801                       void (*cb)(struct nl_object *, void *), void *arg)
 802 {
 803         nl_cache_foreach_filter(cache, NULL, cb, arg);
 804 }
 805
 806 /**
 807  * Call a callback on each element of the cache (filtered).
 808  * @arg cache           cache to iterate on
 809  * @arg filter          filter object
 810  * @arg cb              callback function
 811  * @arg arg             argument passed to callback function
 812  *
 813  * Calls a callback function \a cb on each element of the \a cache
 814  * that matches the \a filter. The argument \a arg is passed on
 815  * to the callback function.
 816  */
 817 void nl_cache_foreach_filter(struct nl_cache *cache, struct nl_object *filter,
 818                              void (*cb)(struct nl_object *, void *), void *arg)
 819 {
 820         struct nl_object *obj, *tmp;
 821         struct nl_object_ops *ops;
 822
 823         if (cache->c_ops == NULL)
 824                 BUG();
 825
 826         ops = cache->c_ops->co_obj_ops;
 827
 828         nl_list_for_each_entry_safe(obj, tmp, &cache->c_items, ce_list) {
 829                 if (filter && !nl_object_match_filter(obj, filter))
 830                         continue;
 831
 832                 cb(obj, arg);
 833         }
 834 }
 835
 836 /** @} */
 837 #endif
 838
 839 /** @} */