net/sched/cls_api.c

   1 /*
   2  * net/sched/cls_api.c  Packet classifier API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  11  * Changes:
  12  *
  13  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
  14  *
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/string.h>
  21 #include <linux/errno.h>
  22 #include <linux/err.h>
  23 #include <linux/skbuff.h>
  24 #include <linux/init.h>
  25 #include <linux/kmod.h>
  26 #include <linux/slab.h>
  27 #include <net/net_namespace.h>
  28 #include <net/sock.h>
  29 #include <net/netlink.h>
  30 #include <net/pkt_sched.h>
  31 #include <net/pkt_cls.h>
  32
  33 /* The list of all installed classifier types */
  34 static LIST_HEAD(tcf_proto_base);
  35
  36 /* Protects list of registered TC modules. It is pure SMP lock. */
  37 static DEFINE_RWLOCK(cls_mod_lock);
  38
  39 /* Find classifier type by string name */
  40
  41 static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind)
  42 {
  43         const struct tcf_proto_ops *t, *res = NULL;
  44
  45         if (kind) {
  46                 read_lock(&cls_mod_lock);
  47                 list_for_each_entry(t, &tcf_proto_base, head) {
  48                         if (strcmp(kind, t->kind) == 0) {
  49                                 if (try_module_get(t->owner))
  50                                         res = t;
  51                                 break;
  52                         }
  53                 }
  54                 read_unlock(&cls_mod_lock);
  55         }
  56         return res;
  57 }
  58
  59 /* Register(unregister) new classifier type */
  60
  61 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
  62 {
  63         struct tcf_proto_ops *t;
  64         int rc = -EEXIST;
  65
  66         write_lock(&cls_mod_lock);
  67         list_for_each_entry(t, &tcf_proto_base, head)
  68                 if (!strcmp(ops->kind, t->kind))
  69                         goto out;
  70
  71         list_add_tail(&ops->head, &tcf_proto_base);
  72         rc = 0;
  73 out:
  74         write_unlock(&cls_mod_lock);
  75         return rc;
  76 }
  77 EXPORT_SYMBOL(register_tcf_proto_ops);
  78
  79 static struct workqueue_struct *tc_filter_wq;
  80
  81 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
  82 {
  83         struct tcf_proto_ops *t;
  84         int rc = -ENOENT;
  85
  86         /* Wait for outstanding call_rcu()s, if any, from a
  87          * tcf_proto_ops's destroy() handler.
  88          */
  89         rcu_barrier();
  90         flush_workqueue(tc_filter_wq);
  91
  92         write_lock(&cls_mod_lock);
  93         list_for_each_entry(t, &tcf_proto_base, head) {
  94                 if (t == ops) {
  95                         list_del(&t->head);
  96                         rc = 0;
  97                         break;
  98                 }
  99         }
 100         write_unlock(&cls_mod_lock);
 101         return rc;
 102 }
 103 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 104
 105 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 106 {
 107         INIT_RCU_WORK(rwork, func);
 108         return queue_rcu_work(tc_filter_wq, rwork);
 109 }
 110 EXPORT_SYMBOL(tcf_queue_work);
 111
 112 /* Select new prio value from the range, managed by kernel. */
 113
 114 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 115 {
 116         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 117
 118         if (tp)
 119                 first = tp->prio - 1;
 120
 121         return TC_H_MAJ(first);
 122 }
 123
 124 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 125                                           u32 prio, u32 parent, struct Qdisc *q,
 126                                           struct tcf_chain *chain)
 127 {
 128         struct tcf_proto *tp;
 129         int err;
 130
 131         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 132         if (!tp)
 133                 return ERR_PTR(-ENOBUFS);
 134
 135         err = -ENOENT;
 136         tp->ops = tcf_proto_lookup_ops(kind);
 137         if (!tp->ops) {
 138 #ifdef CONFIG_MODULES
 139                 rtnl_unlock();
 140                 request_module("cls_%s", kind);
 141                 rtnl_lock();
 142                 tp->ops = tcf_proto_lookup_ops(kind);
 143                 /* We dropped the RTNL semaphore in order to perform
 144                  * the module load. So, even if we succeeded in loading
 145                  * the module we have to replay the request. We indicate
 146                  * this using -EAGAIN.
 147                  */
 148                 if (tp->ops) {
 149                         module_put(tp->ops->owner);
 150                         err = -EAGAIN;
 151                 } else {
 152                         err = -ENOENT;
 153                 }
 154 #endif
 155                 goto errout;
 156         }
 157         tp->classify = tp->ops->classify;
 158         tp->protocol = protocol;
 159         tp->prio = prio;
 160         tp->classid = parent;
 161         tp->q = q;
 162         tp->chain = chain;
 163
 164         err = tp->ops->init(tp);
 165         if (err) {
 166                 module_put(tp->ops->owner);
 167                 goto errout;
 168         }
 169         return tp;
 170
 171 errout:
 172         kfree(tp);
 173         return ERR_PTR(err);
 174 }
 175
 176 static void tcf_proto_destroy(struct tcf_proto *tp)
 177 {
 178         tp->ops->destroy(tp);
 179         module_put(tp->ops->owner);
 180         kfree_rcu(tp, rcu);
 181 }
 182
 183 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 184                                           u32 chain_index)
 185 {
 186         struct tcf_chain *chain;
 187
 188         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 189         if (!chain)
 190                 return NULL;
 191         list_add_tail(&chain->list, &block->chain_list);
 192         chain->block = block;
 193         chain->index = chain_index;
 194         chain->refcnt = 1;
 195         return chain;
 196 }
 197
 198 static void tcf_chain_head_change(struct tcf_chain *chain,
 199                                   struct tcf_proto *tp_head)
 200 {
 201         if (chain->chain_head_change)
 202                 chain->chain_head_change(tp_head,
 203                                          chain->chain_head_change_priv);
 204 }
 205
 206 static void tcf_chain_flush(struct tcf_chain *chain)
 207 {
 208         struct tcf_proto *tp = rtnl_dereference(chain->filter_chain);
 209
 210         tcf_chain_head_change(chain, NULL);
 211         while (tp) {
 212                 RCU_INIT_POINTER(chain->filter_chain, tp->next);
 213                 tcf_proto_destroy(tp);
 214                 tp = rtnl_dereference(chain->filter_chain);
 215                 tcf_chain_put(chain);
 216         }
 217 }
 218
 219 static void tcf_chain_destroy(struct tcf_chain *chain)
 220 {
 221         struct tcf_block *block = chain->block;
 222
 223         list_del(&chain->list);
 224         kfree(chain);
 225         if (list_empty(&block->chain_list))
 226                 kfree(block);
 227 }
 228
 229 static void tcf_chain_hold(struct tcf_chain *chain)
 230 {
 231         ++chain->refcnt;
 232 }
 233
 234 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 235                                 bool create)
 236 {
 237         struct tcf_chain *chain;
 238
 239         list_for_each_entry(chain, &block->chain_list, list) {
 240                 if (chain->index == chain_index) {
 241                         tcf_chain_hold(chain);
 242                         return chain;
 243                 }
 244         }
 245
 246         return create ? tcf_chain_create(block, chain_index) : NULL;
 247 }
 248 EXPORT_SYMBOL(tcf_chain_get);
 249
 250 void tcf_chain_put(struct tcf_chain *chain)
 251 {
 252         if (--chain->refcnt == 0)
 253                 tcf_chain_destroy(chain);
 254 }
 255 EXPORT_SYMBOL(tcf_chain_put);
 256
 257 static void tcf_block_offload_cmd(struct tcf_block *block, struct Qdisc *q,
 258                                   struct tcf_block_ext_info *ei,
 259                                   enum tc_block_command command)
 260 {
 261         struct net_device *dev = q->dev_queue->dev;
 262         struct tc_block_offload bo = {};
 263
 264         if (!dev->netdev_ops->ndo_setup_tc)
 265                 return;
 266         bo.command = command;
 267         bo.binder_type = ei->binder_type;
 268         bo.block = block;
 269         dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 270 }
 271
 272 static void tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 273                                    struct tcf_block_ext_info *ei)
 274 {
 275         tcf_block_offload_cmd(block, q, ei, TC_BLOCK_BIND);
 276 }
 277
 278 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 279                                      struct tcf_block_ext_info *ei)
 280 {
 281         tcf_block_offload_cmd(block, q, ei, TC_BLOCK_UNBIND);
 282 }
 283
 284 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
 285                       struct tcf_block_ext_info *ei)
 286 {
 287         struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
 288         struct tcf_chain *chain;
 289         int err;
 290
 291         if (!block)
 292                 return -ENOMEM;
 293         INIT_LIST_HEAD(&block->chain_list);
 294         INIT_LIST_HEAD(&block->cb_list);
 295
 296         /* Create chain 0 by default, it has to be always present. */
 297         chain = tcf_chain_create(block, 0);
 298         if (!chain) {
 299                 err = -ENOMEM;
 300                 goto err_chain_create;
 301         }
 302         WARN_ON(!ei->chain_head_change);
 303         chain->chain_head_change = ei->chain_head_change;
 304         chain->chain_head_change_priv = ei->chain_head_change_priv;
 305         block->net = qdisc_net(q);
 306         block->q = q;
 307         tcf_block_offload_bind(block, q, ei);
 308         *p_block = block;
 309         return 0;
 310
 311 err_chain_create:
 312         kfree(block);
 313         return err;
 314 }
 315 EXPORT_SYMBOL(tcf_block_get_ext);
 316
 317 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
 318 {
 319         struct tcf_proto __rcu **p_filter_chain = priv;
 320
 321         rcu_assign_pointer(*p_filter_chain, tp_head);
 322 }
 323
 324 int tcf_block_get(struct tcf_block **p_block,
 325                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q)
 326 {
 327         struct tcf_block_ext_info ei = {
 328                 .chain_head_change = tcf_chain_head_change_dflt,
 329                 .chain_head_change_priv = p_filter_chain,
 330         };
 331
 332         WARN_ON(!p_filter_chain);
 333         return tcf_block_get_ext(p_block, q, &ei);
 334 }
 335 EXPORT_SYMBOL(tcf_block_get);
 336
 337 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
 338  * actions should be all removed after flushing.
 339  */
 340 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 341                        struct tcf_block_ext_info *ei)
 342 {
 343         struct tcf_chain *chain, *tmp;
 344
 345         if (!block)
 346                 return;
 347         /* Hold a refcnt for all chains, so that they don't disappear
 348          * while we are iterating.
 349          */
 350         list_for_each_entry(chain, &block->chain_list, list)
 351                 tcf_chain_hold(chain);
 352
 353         list_for_each_entry(chain, &block->chain_list, list)
 354                 tcf_chain_flush(chain);
 355
 356         tcf_block_offload_unbind(block, q, ei);
 357
 358         /* At this point, all the chains should have refcnt >= 1. */
 359         list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
 360                 tcf_chain_put(chain);
 361
 362         /* Finally, put chain 0 and allow block to be freed. */
 363         chain = list_first_entry(&block->chain_list, struct tcf_chain, list);
 364         tcf_chain_put(chain);
 365 }
 366 EXPORT_SYMBOL(tcf_block_put_ext);
 367
 368 void tcf_block_put(struct tcf_block *block)
 369 {
 370         struct tcf_block_ext_info ei = {0, };
 371
 372         if (!block)
 373                 return;
 374         tcf_block_put_ext(block, block->q, &ei);
 375 }
 376
 377 EXPORT_SYMBOL(tcf_block_put);
 378
 379 struct tcf_block_cb {
 380         struct list_head list;
 381         tc_setup_cb_t *cb;
 382         void *cb_ident;
 383         void *cb_priv;
 384         unsigned int refcnt;
 385 };
 386
 387 void *tcf_block_cb_priv(struct tcf_block_cb *block_cb)
 388 {
 389         return block_cb->cb_priv;
 390 }
 391 EXPORT_SYMBOL(tcf_block_cb_priv);
 392
 393 struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block,
 394                                          tc_setup_cb_t *cb, void *cb_ident)
 395 {       struct tcf_block_cb *block_cb;
 396
 397         list_for_each_entry(block_cb, &block->cb_list, list)
 398                 if (block_cb->cb == cb && block_cb->cb_ident == cb_ident)
 399                         return block_cb;
 400         return NULL;
 401 }
 402 EXPORT_SYMBOL(tcf_block_cb_lookup);
 403
 404 void tcf_block_cb_incref(struct tcf_block_cb *block_cb)
 405 {
 406         block_cb->refcnt++;
 407 }
 408 EXPORT_SYMBOL(tcf_block_cb_incref);
 409
 410 unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb)
 411 {
 412         return --block_cb->refcnt;
 413 }
 414 EXPORT_SYMBOL(tcf_block_cb_decref);
 415
 416 struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block,
 417                                              tc_setup_cb_t *cb, void *cb_ident,
 418                                              void *cb_priv)
 419 {
 420         struct tcf_block_cb *block_cb;
 421
 422         block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL);
 423         if (!block_cb)
 424                 return NULL;
 425         block_cb->cb = cb;
 426         block_cb->cb_ident = cb_ident;
 427         block_cb->cb_priv = cb_priv;
 428         list_add(&block_cb->list, &block->cb_list);
 429         return block_cb;
 430 }
 431 EXPORT_SYMBOL(__tcf_block_cb_register);
 432
 433 int tcf_block_cb_register(struct tcf_block *block,
 434                           tc_setup_cb_t *cb, void *cb_ident,
 435                           void *cb_priv)
 436 {
 437         struct tcf_block_cb *block_cb;
 438
 439         block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv);
 440         return block_cb ? 0 : -ENOMEM;
 441 }
 442 EXPORT_SYMBOL(tcf_block_cb_register);
 443
 444 void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb)
 445 {
 446         list_del(&block_cb->list);
 447         kfree(block_cb);
 448 }
 449 EXPORT_SYMBOL(__tcf_block_cb_unregister);
 450
 451 void tcf_block_cb_unregister(struct tcf_block *block,
 452                              tc_setup_cb_t *cb, void *cb_ident)
 453 {
 454         struct tcf_block_cb *block_cb;
 455
 456         block_cb = tcf_block_cb_lookup(block, cb, cb_ident);
 457         if (!block_cb)
 458                 return;
 459         __tcf_block_cb_unregister(block_cb);
 460 }
 461 EXPORT_SYMBOL(tcf_block_cb_unregister);
 462
 463 static int tcf_block_cb_call(struct tcf_block *block, enum tc_setup_type type,
 464                              void *type_data, bool err_stop)
 465 {
 466         struct tcf_block_cb *block_cb;
 467         int ok_count = 0;
 468         int err;
 469
 470         list_for_each_entry(block_cb, &block->cb_list, list) {
 471                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
 472                 if (err) {
 473                         if (err_stop)
 474                                 return err;
 475                 } else {
 476                         ok_count++;
 477                 }
 478         }
 479         return ok_count;
 480 }
 481
 482 /* Main classifier routine: scans classifier chain attached
 483  * to this qdisc, (optionally) tests for protocol and asks
 484  * specific classifiers.
 485  */
 486 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 487                  struct tcf_result *res, bool compat_mode)
 488 {
 489         __be16 protocol = tc_skb_protocol(skb);
 490 #ifdef CONFIG_NET_CLS_ACT
 491         const int max_reclassify_loop = 4;
 492         const struct tcf_proto *orig_tp = tp;
 493         const struct tcf_proto *first_tp;
 494         int limit = 0;
 495
 496 reclassify:
 497 #endif
 498         for (; tp; tp = rcu_dereference_bh(tp->next)) {
 499                 int err;
 500
 501                 if (tp->protocol != protocol &&
 502                     tp->protocol != htons(ETH_P_ALL))
 503                         continue;
 504
 505                 err = tp->classify(skb, tp, res);
 506 #ifdef CONFIG_NET_CLS_ACT
 507                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
 508                         first_tp = orig_tp;
 509                         goto reset;
 510                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
 511                         first_tp = res->goto_tp;
 512                         goto reset;
 513                 }
 514 #endif
 515                 if (err >= 0)
 516                         return err;
 517         }
 518
 519         return TC_ACT_UNSPEC; /* signal: continue lookup */
 520 #ifdef CONFIG_NET_CLS_ACT
 521 reset:
 522         if (unlikely(limit++ >= max_reclassify_loop)) {
 523                 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
 524                                        tp->q->ops->id, tp->prio & 0xffff,
 525                                        ntohs(tp->protocol));
 526                 return TC_ACT_SHOT;
 527         }
 528
 529         tp = first_tp;
 530         protocol = tc_skb_protocol(skb);
 531         goto reclassify;
 532 #endif
 533 }
 534 EXPORT_SYMBOL(tcf_classify);
 535
 536 struct tcf_chain_info {
 537         struct tcf_proto __rcu **pprev;
 538         struct tcf_proto __rcu *next;
 539 };
 540
 541 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)
 542 {
 543         return rtnl_dereference(*chain_info->pprev);
 544 }
 545
 546 static void tcf_chain_tp_insert(struct tcf_chain *chain,
 547                                 struct tcf_chain_info *chain_info,
 548                                 struct tcf_proto *tp)
 549 {
 550         if (*chain_info->pprev == chain->filter_chain)
 551                 tcf_chain_head_change(chain, tp);
 552         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));
 553         rcu_assign_pointer(*chain_info->pprev, tp);
 554         tcf_chain_hold(chain);
 555 }
 556
 557 static void tcf_chain_tp_remove(struct tcf_chain *chain,
 558                                 struct tcf_chain_info *chain_info,
 559                                 struct tcf_proto *tp)
 560 {
 561         struct tcf_proto *next = rtnl_dereference(chain_info->next);
 562
 563         if (tp == chain->filter_chain)
 564                 tcf_chain_head_change(chain, next);
 565         RCU_INIT_POINTER(*chain_info->pprev, next);
 566         tcf_chain_put(chain);
 567 }
 568
 569 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 570                                            struct tcf_chain_info *chain_info,
 571                                            u32 protocol, u32 prio,
 572                                            bool prio_allocate)
 573 {
 574         struct tcf_proto **pprev;
 575         struct tcf_proto *tp;
 576
 577         /* Check the chain for existence of proto-tcf with this priority */
 578         for (pprev = &chain->filter_chain;
 579              (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {
 580                 if (tp->prio >= prio) {
 581                         if (tp->prio == prio) {
 582                                 if (prio_allocate ||
 583                                     (tp->protocol != protocol && protocol))
 584                                         return ERR_PTR(-EINVAL);
 585                         } else {
 586                                 tp = NULL;
 587                         }
 588                         break;
 589                 }
 590         }
 591         chain_info->pprev = pprev;
 592         chain_info->next = tp ? tp->next : NULL;
 593         return tp;
 594 }
 595
 596 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 597                          struct tcf_proto *tp, struct Qdisc *q, u32 parent,
 598                          void *fh, u32 portid, u32 seq, u16 flags, int event)
 599 {
 600         struct tcmsg *tcm;
 601         struct nlmsghdr  *nlh;
 602         unsigned char *b = skb_tail_pointer(skb);
 603
 604         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 605         if (!nlh)
 606                 goto out_nlmsg_trim;
 607         tcm = nlmsg_data(nlh);
 608         tcm->tcm_family = AF_UNSPEC;
 609         tcm->tcm__pad1 = 0;
 610         tcm->tcm__pad2 = 0;
 611         tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
 612         tcm->tcm_parent = parent;
 613         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
 614         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
 615                 goto nla_put_failure;
 616         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
 617                 goto nla_put_failure;
 618         if (!fh) {
 619                 tcm->tcm_handle = 0;
 620         } else {
 621                 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
 622                         goto nla_put_failure;
 623         }
 624         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 625         return skb->len;
 626
 627 out_nlmsg_trim:
 628 nla_put_failure:
 629         nlmsg_trim(skb, b);
 630         return -1;
 631 }
 632
 633 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 634                           struct nlmsghdr *n, struct tcf_proto *tp,
 635                           struct Qdisc *q, u32 parent,
 636                           void *fh, int event, bool unicast)
 637 {
 638         struct sk_buff *skb;
 639         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 640
 641         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 642         if (!skb)
 643                 return -ENOBUFS;
 644
 645         if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq,
 646                           n->nlmsg_flags, event) <= 0) {
 647                 kfree_skb(skb);
 648                 return -EINVAL;
 649         }
 650
 651         if (unicast)
 652                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 653
 654         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 655                               n->nlmsg_flags & NLM_F_ECHO);
 656 }
 657
 658 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 659                               struct nlmsghdr *n, struct tcf_proto *tp,
 660                               struct Qdisc *q, u32 parent,
 661                               void *fh, bool unicast, bool *last)
 662 {
 663         struct sk_buff *skb;
 664         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 665         int err;
 666
 667         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 668         if (!skb)
 669                 return -ENOBUFS;
 670
 671         if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq,
 672                           n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
 673                 kfree_skb(skb);
 674                 return -EINVAL;
 675         }
 676
 677         err = tp->ops->delete(tp, fh, last);
 678         if (err) {
 679                 kfree_skb(skb);
 680                 return err;
 681         }
 682
 683         if (unicast)
 684                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 685
 686         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 687                               n->nlmsg_flags & NLM_F_ECHO);
 688 }
 689
 690 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
 691                                  struct Qdisc *q, u32 parent,
 692                                  struct nlmsghdr *n,
 693                                  struct tcf_chain *chain, int event)
 694 {
 695         struct tcf_proto *tp;
 696
 697         for (tp = rtnl_dereference(chain->filter_chain);
 698              tp; tp = rtnl_dereference(tp->next))
 699                 tfilter_notify(net, oskb, n, tp, q, parent, 0, event, false);
 700 }
 701
 702 /* Add/change/delete/get a filter node */
 703
 704 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 705                           struct netlink_ext_ack *extack)
 706 {
 707         struct net *net = sock_net(skb->sk);
 708         struct nlattr *tca[TCA_MAX + 1];
 709         struct tcmsg *t;
 710         u32 protocol;
 711         u32 prio;
 712         bool prio_allocate;
 713         u32 parent;
 714         u32 chain_index;
 715         struct net_device *dev;
 716         struct Qdisc  *q;
 717         struct tcf_chain_info chain_info;
 718         struct tcf_chain *chain = NULL;
 719         struct tcf_block *block;
 720         struct tcf_proto *tp;
 721         const struct Qdisc_class_ops *cops;
 722         unsigned long cl;
 723         void *fh;
 724         int err;
 725         int tp_created;
 726
 727         if ((n->nlmsg_type != RTM_GETTFILTER) &&
 728             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 729                 return -EPERM;
 730
 731 replay:
 732         tp_created = 0;
 733
 734         err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack);
 735         if (err < 0)
 736                 return err;
 737
 738         t = nlmsg_data(n);
 739         protocol = TC_H_MIN(t->tcm_info);
 740         prio = TC_H_MAJ(t->tcm_info);
 741         prio_allocate = false;
 742         parent = t->tcm_parent;
 743         cl = 0;
 744
 745         if (prio == 0) {
 746                 switch (n->nlmsg_type) {
 747                 case RTM_DELTFILTER:
 748                         if (protocol || t->tcm_handle || tca[TCA_KIND])
 749                                 return -ENOENT;
 750                         break;
 751                 case RTM_NEWTFILTER:
 752                         /* If no priority is provided by the user,
 753                          * we allocate one.
 754                          */
 755                         if (n->nlmsg_flags & NLM_F_CREATE) {
 756                                 prio = TC_H_MAKE(0x80000000U, 0U);
 757                                 prio_allocate = true;
 758                                 break;
 759                         }
 760                         /* fall-through */
 761                 default:
 762                         return -ENOENT;
 763                 }
 764         }
 765
 766         /* Find head of filter chain. */
 767
 768         /* Find link */
 769         dev = __dev_get_by_index(net, t->tcm_ifindex);
 770         if (dev == NULL)
 771                 return -ENODEV;
 772
 773         /* Find qdisc */
 774         if (!parent) {
 775                 q = dev->qdisc;
 776                 parent = q->handle;
 777         } else {
 778                 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
 779                 if (q == NULL)
 780                         return -EINVAL;
 781         }
 782
 783         /* Is it classful? */
 784         cops = q->ops->cl_ops;
 785         if (!cops)
 786                 return -EINVAL;
 787
 788         if (!cops->tcf_block)
 789                 return -EOPNOTSUPP;
 790
 791         /* Do we search for filter, attached to class? */
 792         if (TC_H_MIN(parent)) {
 793                 cl = cops->find(q, parent);
 794                 if (cl == 0)
 795                         return -ENOENT;
 796         }
 797
 798         /* And the last stroke */
 799         block = cops->tcf_block(q, cl);
 800         if (!block) {
 801                 err = -EINVAL;
 802                 goto errout;
 803         }
 804
 805         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
 806         if (chain_index > TC_ACT_EXT_VAL_MASK) {
 807                 err = -EINVAL;
 808                 goto errout;
 809         }
 810         chain = tcf_chain_get(block, chain_index,
 811                               n->nlmsg_type == RTM_NEWTFILTER);
 812         if (!chain) {
 813                 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL;
 814                 goto errout;
 815         }
 816
 817         if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
 818                 tfilter_notify_chain(net, skb, q, parent, n,
 819                                      chain, RTM_DELTFILTER);
 820                 tcf_chain_flush(chain);
 821                 err = 0;
 822                 goto errout;
 823         }
 824
 825         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 826                                prio, prio_allocate);
 827         if (IS_ERR(tp)) {
 828                 err = PTR_ERR(tp);
 829                 goto errout;
 830         }
 831
 832         if (tp == NULL) {
 833                 /* Proto-tcf does not exist, create new one */
 834
 835                 if (tca[TCA_KIND] == NULL || !protocol) {
 836                         err = -EINVAL;
 837                         goto errout;
 838                 }
 839
 840                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 841                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 842                         err = -ENOENT;
 843                         goto errout;
 844                 }
 845
 846                 if (prio_allocate)
 847                         prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
 848
 849                 tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
 850                                       protocol, prio, parent, q, chain);
 851                 if (IS_ERR(tp)) {
 852                         err = PTR_ERR(tp);
 853                         goto errout;
 854                 }
 855                 tp_created = 1;
 856         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
 857                 err = -EINVAL;
 858                 goto errout;
 859         }
 860
 861         fh = tp->ops->get(tp, t->tcm_handle);
 862
 863         if (!fh) {
 864                 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
 865                         tcf_chain_tp_remove(chain, &chain_info, tp);
 866                         tfilter_notify(net, skb, n, tp, q, parent, fh,
 867                                        RTM_DELTFILTER, false);
 868                         tcf_proto_destroy(tp);
 869                         err = 0;
 870                         goto errout;
 871                 }
 872
 873                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 874                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 875                         err = -ENOENT;
 876                         goto errout;
 877                 }
 878         } else {
 879                 bool last;
 880
 881                 switch (n->nlmsg_type) {
 882                 case RTM_NEWTFILTER:
 883                         if (n->nlmsg_flags & NLM_F_EXCL) {
 884                                 if (tp_created)
 885                                         tcf_proto_destroy(tp);
 886                                 err = -EEXIST;
 887                                 goto errout;
 888                         }
 889                         break;
 890                 case RTM_DELTFILTER:
 891                         err = tfilter_del_notify(net, skb, n, tp, q, parent,
 892                                                  fh, false, &last);
 893                         if (err)
 894                                 goto errout;
 895                         if (last) {
 896                                 tcf_chain_tp_remove(chain, &chain_info, tp);
 897                                 tcf_proto_destroy(tp);
 898                         }
 899                         goto errout;
 900                 case RTM_GETTFILTER:
 901                         err = tfilter_notify(net, skb, n, tp, q, parent, fh,
 902                                              RTM_NEWTFILTER, true);
 903                         goto errout;
 904                 default:
 905                         err = -EINVAL;
 906                         goto errout;
 907                 }
 908         }
 909
 910         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 911                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
 912         if (err == 0) {
 913                 if (tp_created)
 914                         tcf_chain_tp_insert(chain, &chain_info, tp);
 915                 tfilter_notify(net, skb, n, tp, q, parent, fh,
 916                                RTM_NEWTFILTER, false);
 917         } else {
 918                 if (tp_created)
 919                         tcf_proto_destroy(tp);
 920         }
 921
 922 errout:
 923         if (chain)
 924                 tcf_chain_put(chain);
 925         if (err == -EAGAIN)
 926                 /* Replay the request. */
 927                 goto replay;
 928         return err;
 929 }
 930
 931 struct tcf_dump_args {
 932         struct tcf_walker w;
 933         struct sk_buff *skb;
 934         struct netlink_callback *cb;
 935         struct Qdisc *q;
 936         u32 parent;
 937 };
 938
 939 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
 940 {
 941         struct tcf_dump_args *a = (void *)arg;
 942         struct net *net = sock_net(a->skb->sk);
 943
 944         return tcf_fill_node(net, a->skb, tp, a->q, a->parent,
 945                              n, NETLINK_CB(a->cb->skb).portid,
 946                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
 947                              RTM_NEWTFILTER);
 948 }
 949
 950 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 951                            struct sk_buff *skb, struct netlink_callback *cb,
 952                            long index_start, long *p_index)
 953 {
 954         struct net *net = sock_net(skb->sk);
 955         struct tcmsg *tcm = nlmsg_data(cb->nlh);
 956         struct tcf_dump_args arg;
 957         struct tcf_proto *tp;
 958
 959         for (tp = rtnl_dereference(chain->filter_chain);
 960              tp; tp = rtnl_dereference(tp->next), (*p_index)++) {
 961                 if (*p_index < index_start)
 962                         continue;
 963                 if (TC_H_MAJ(tcm->tcm_info) &&
 964                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
 965                         continue;
 966                 if (TC_H_MIN(tcm->tcm_info) &&
 967                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
 968                         continue;
 969                 if (*p_index > index_start)
 970                         memset(&cb->args[1], 0,
 971                                sizeof(cb->args) - sizeof(cb->args[0]));
 972                 if (cb->args[1] == 0) {
 973                         if (tcf_fill_node(net, skb, tp, q, parent, 0,
 974                                           NETLINK_CB(cb->skb).portid,
 975                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
 976                                           RTM_NEWTFILTER) <= 0)
 977                                 return false;
 978
 979                         cb->args[1] = 1;
 980                 }
 981                 if (!tp->ops->walk)
 982                         continue;
 983                 arg.w.fn = tcf_node_dump;
 984                 arg.skb = skb;
 985                 arg.cb = cb;
 986                 arg.q = q;
 987                 arg.parent = parent;
 988                 arg.w.stop = 0;
 989                 arg.w.skip = cb->args[1] - 1;
 990                 arg.w.count = 0;
 991                 tp->ops->walk(tp, &arg.w);
 992                 cb->args[1] = arg.w.count + 1;
 993                 if (arg.w.stop)
 994                         return false;
 995         }
 996         return true;
 997 }
 998
 999 /* called with RTNL */
1000 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
1001 {
1002         struct net *net = sock_net(skb->sk);
1003         struct nlattr *tca[TCA_MAX + 1];
1004         struct net_device *dev;
1005         struct Qdisc *q;
1006         struct tcf_block *block;
1007         struct tcf_chain *chain;
1008         struct tcmsg *tcm = nlmsg_data(cb->nlh);
1009         unsigned long cl = 0;
1010         const struct Qdisc_class_ops *cops;
1011         long index_start;
1012         long index;
1013         u32 parent;
1014         int err;
1015
1016         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1017                 return skb->len;
1018
1019         err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL);
1020         if (err)
1021                 return err;
1022
1023         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1024         if (!dev)
1025                 return skb->len;
1026
1027         parent = tcm->tcm_parent;
1028         if (!parent) {
1029                 q = dev->qdisc;
1030                 parent = q->handle;
1031         } else {
1032                 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
1033         }
1034         if (!q)
1035                 goto out;
1036         cops = q->ops->cl_ops;
1037         if (!cops)
1038                 goto out;
1039         if (!cops->tcf_block)
1040                 goto out;
1041         if (TC_H_MIN(tcm->tcm_parent)) {
1042                 cl = cops->find(q, tcm->tcm_parent);
1043                 if (cl == 0)
1044                         goto out;
1045         }
1046         block = cops->tcf_block(q, cl);
1047         if (!block)
1048                 goto out;
1049
1050         index_start = cb->args[0];
1051         index = 0;
1052
1053         list_for_each_entry(chain, &block->chain_list, list) {
1054                 if (tca[TCA_CHAIN] &&
1055                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
1056                         continue;
1057                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
1058                                     index_start, &index)) {
1059                         err = -EMSGSIZE;
1060                         break;
1061                 }
1062         }
1063
1064         cb->args[0] = index;
1065
1066 out:
1067         /* If we did no progress, the error (EMSGSIZE) is real */
1068         if (skb->len == 0 && err)
1069                 return err;
1070         return skb->len;
1071 }
1072
1073 void tcf_exts_destroy(struct tcf_exts *exts)
1074 {
1075 #ifdef CONFIG_NET_CLS_ACT
1076         LIST_HEAD(actions);
1077
1078         ASSERT_RTNL();
1079         tcf_exts_to_list(exts, &actions);
1080         tcf_action_destroy(&actions, TCA_ACT_UNBIND);
1081         kfree(exts->actions);
1082         exts->nr_actions = 0;
1083 #endif
1084 }
1085 EXPORT_SYMBOL(tcf_exts_destroy);
1086
1087 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
1088                       struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)
1089 {
1090 #ifdef CONFIG_NET_CLS_ACT
1091         {
1092                 struct tc_action *act;
1093
1094                 if (exts->police && tb[exts->police]) {
1095                         act = tcf_action_init_1(net, tp, tb[exts->police],
1096                                                 rate_tlv, "police", ovr,
1097                                                 TCA_ACT_BIND);
1098                         if (IS_ERR(act))
1099                                 return PTR_ERR(act);
1100
1101                         act->type = exts->type = TCA_OLD_COMPAT;
1102                         exts->actions[0] = act;
1103                         exts->nr_actions = 1;
1104                 } else if (exts->action && tb[exts->action]) {
1105                         LIST_HEAD(actions);
1106                         int err, i = 0;
1107
1108                         err = tcf_action_init(net, tp, tb[exts->action],
1109                                               rate_tlv, NULL, ovr, TCA_ACT_BIND,
1110                                               &actions);
1111                         if (err)
1112                                 return err;
1113                         list_for_each_entry(act, &actions, list)
1114                                 exts->actions[i++] = act;
1115                         exts->nr_actions = i;
1116                 }
1117         }
1118 #else
1119         if ((exts->action && tb[exts->action]) ||
1120             (exts->police && tb[exts->police]))
1121                 return -EOPNOTSUPP;
1122 #endif
1123
1124         return 0;
1125 }
1126 EXPORT_SYMBOL(tcf_exts_validate);
1127
1128 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
1129 {
1130 #ifdef CONFIG_NET_CLS_ACT
1131         struct tcf_exts old = *dst;
1132
1133         *dst = *src;
1134         tcf_exts_destroy(&old);
1135 #endif
1136 }
1137 EXPORT_SYMBOL(tcf_exts_change);
1138
1139 #ifdef CONFIG_NET_CLS_ACT
1140 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
1141 {
1142         if (exts->nr_actions == 0)
1143                 return NULL;
1144         else
1145                 return exts->actions[0];
1146 }
1147 #endif
1148
1149 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
1150 {
1151 #ifdef CONFIG_NET_CLS_ACT
1152         struct nlattr *nest;
1153
1154         if (exts->action && tcf_exts_has_actions(exts)) {
1155                 /*
1156                  * again for backward compatible mode - we want
1157                  * to work with both old and new modes of entering
1158                  * tc data even if iproute2  was newer - jhs
1159                  */
1160                 if (exts->type != TCA_OLD_COMPAT) {
1161                         LIST_HEAD(actions);
1162
1163                         nest = nla_nest_start(skb, exts->action);
1164                         if (nest == NULL)
1165                                 goto nla_put_failure;
1166
1167                         tcf_exts_to_list(exts, &actions);
1168                         if (tcf_action_dump(skb, &actions, 0, 0) < 0)
1169                                 goto nla_put_failure;
1170                         nla_nest_end(skb, nest);
1171                 } else if (exts->police) {
1172                         struct tc_action *act = tcf_exts_first_act(exts);
1173                         nest = nla_nest_start(skb, exts->police);
1174                         if (nest == NULL || !act)
1175                                 goto nla_put_failure;
1176                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
1177                                 goto nla_put_failure;
1178                         nla_nest_end(skb, nest);
1179                 }
1180         }
1181         return 0;
1182
1183 nla_put_failure:
1184         nla_nest_cancel(skb, nest);
1185         return -1;
1186 #else
1187         return 0;
1188 #endif
1189 }
1190 EXPORT_SYMBOL(tcf_exts_dump);
1191
1192
1193 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
1194 {
1195 #ifdef CONFIG_NET_CLS_ACT
1196         struct tc_action *a = tcf_exts_first_act(exts);
1197         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
1198                 return -1;
1199 #endif
1200         return 0;
1201 }
1202 EXPORT_SYMBOL(tcf_exts_dump_stats);
1203
1204 static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts,
1205                                        enum tc_setup_type type,
1206                                        void *type_data, bool err_stop)
1207 {
1208         int ok_count = 0;
1209 #ifdef CONFIG_NET_CLS_ACT
1210         const struct tc_action *a;
1211         struct net_device *dev;
1212         int i, ret;
1213
1214         if (!tcf_exts_has_actions(exts))
1215                 return 0;
1216
1217         for (i = 0; i < exts->nr_actions; i++) {
1218                 a = exts->actions[i];
1219                 if (!a->ops->get_dev)
1220                         continue;
1221                 dev = a->ops->get_dev(a);
1222                 if (!dev)
1223                         continue;
1224                 ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop);
1225                 if (ret < 0)
1226                         return ret;
1227                 ok_count += ret;
1228         }
1229 #endif
1230         return ok_count;
1231 }
1232
1233 int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts,
1234                      enum tc_setup_type type, void *type_data, bool err_stop)
1235 {
1236         int ok_count;
1237         int ret;
1238
1239         ret = tcf_block_cb_call(block, type, type_data, err_stop);
1240         if (ret < 0)
1241                 return ret;
1242         ok_count = ret;
1243
1244         if (!exts || ok_count)
1245                 return ok_count;
1246         ret = tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop);
1247         if (ret < 0)
1248                 return ret;
1249         ok_count += ret;
1250
1251         return ok_count;
1252 }
1253 EXPORT_SYMBOL(tc_setup_cb_call);
1254
1255 static int __init tc_filter_init(void)
1256 {
1257         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
1258         if (!tc_filter_wq)
1259                 return -ENOMEM;
1260
1261         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0);
1262         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0);
1263         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
1264                       tc_dump_tfilter, 0);
1265
1266         return 0;
1267 }
1268
1269 subsys_initcall(tc_filter_init);