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 extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
  34
  35 /* The list of all installed classifier types */
  36 static LIST_HEAD(tcf_proto_base);
  37
  38 /* Protects list of registered TC modules. It is pure SMP lock. */
  39 static DEFINE_RWLOCK(cls_mod_lock);
  40
  41 /* Find classifier type by string name */
  42
  43 static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind)
  44 {
  45         const struct tcf_proto_ops *t, *res = NULL;
  46
  47         if (kind) {
  48                 read_lock(&cls_mod_lock);
  49                 list_for_each_entry(t, &tcf_proto_base, head) {
  50                         if (strcmp(kind, t->kind) == 0) {
  51                                 if (try_module_get(t->owner))
  52                                         res = t;
  53                                 break;
  54                         }
  55                 }
  56                 read_unlock(&cls_mod_lock);
  57         }
  58         return res;
  59 }
  60
  61 /* Register(unregister) new classifier type */
  62
  63 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
  64 {
  65         struct tcf_proto_ops *t;
  66         int rc = -EEXIST;
  67
  68         write_lock(&cls_mod_lock);
  69         list_for_each_entry(t, &tcf_proto_base, head)
  70                 if (!strcmp(ops->kind, t->kind))
  71                         goto out;
  72
  73         list_add_tail(&ops->head, &tcf_proto_base);
  74         rc = 0;
  75 out:
  76         write_unlock(&cls_mod_lock);
  77         return rc;
  78 }
  79 EXPORT_SYMBOL(register_tcf_proto_ops);
  80
  81 static struct workqueue_struct *tc_filter_wq;
  82
  83 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
  84 {
  85         struct tcf_proto_ops *t;
  86         int rc = -ENOENT;
  87
  88         /* Wait for outstanding call_rcu()s, if any, from a
  89          * tcf_proto_ops's destroy() handler.
  90          */
  91         rcu_barrier();
  92         flush_workqueue(tc_filter_wq);
  93
  94         write_lock(&cls_mod_lock);
  95         list_for_each_entry(t, &tcf_proto_base, head) {
  96                 if (t == ops) {
  97                         list_del(&t->head);
  98                         rc = 0;
  99                         break;
 100                 }
 101         }
 102         write_unlock(&cls_mod_lock);
 103         return rc;
 104 }
 105 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 106
 107 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 108 {
 109         INIT_RCU_WORK(rwork, func);
 110         return queue_rcu_work(tc_filter_wq, rwork);
 111 }
 112 EXPORT_SYMBOL(tcf_queue_work);
 113
 114 /* Select new prio value from the range, managed by kernel. */
 115
 116 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 117 {
 118         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 119
 120         if (tp)
 121                 first = tp->prio - 1;
 122
 123         return TC_H_MAJ(first);
 124 }
 125
 126 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 127                                           u32 prio, u32 parent, struct Qdisc *q,
 128                                           struct tcf_chain *chain)
 129 {
 130         struct tcf_proto *tp;
 131         int err;
 132
 133         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 134         if (!tp)
 135                 return ERR_PTR(-ENOBUFS);
 136
 137         err = -ENOENT;
 138         tp->ops = tcf_proto_lookup_ops(kind);
 139         if (!tp->ops) {
 140 #ifdef CONFIG_MODULES
 141                 rtnl_unlock();
 142                 request_module("cls_%s", kind);
 143                 rtnl_lock();
 144                 tp->ops = tcf_proto_lookup_ops(kind);
 145                 /* We dropped the RTNL semaphore in order to perform
 146                  * the module load. So, even if we succeeded in loading
 147                  * the module we have to replay the request. We indicate
 148                  * this using -EAGAIN.
 149                  */
 150                 if (tp->ops) {
 151                         module_put(tp->ops->owner);
 152                         err = -EAGAIN;
 153                 } else {
 154                         err = -ENOENT;
 155                 }
 156 #endif
 157                 goto errout;
 158         }
 159         tp->classify = tp->ops->classify;
 160         tp->protocol = protocol;
 161         tp->prio = prio;
 162         tp->classid = parent;
 163         tp->q = q;
 164         tp->chain = chain;
 165
 166         err = tp->ops->init(tp);
 167         if (err) {
 168                 module_put(tp->ops->owner);
 169                 goto errout;
 170         }
 171         return tp;
 172
 173 errout:
 174         kfree(tp);
 175         return ERR_PTR(err);
 176 }
 177
 178 static void tcf_proto_destroy(struct tcf_proto *tp)
 179 {
 180         tp->ops->destroy(tp);
 181         module_put(tp->ops->owner);
 182         kfree_rcu(tp, rcu);
 183 }
 184
 185 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 186                                           u32 chain_index)
 187 {
 188         struct tcf_chain *chain;
 189
 190         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 191         if (!chain)
 192                 return NULL;
 193         list_add_tail(&chain->list, &block->chain_list);
 194         chain->block = block;
 195         chain->index = chain_index;
 196         chain->refcnt = 1;
 197         return chain;
 198 }
 199
 200 static void tcf_chain_head_change(struct tcf_chain *chain,
 201                                   struct tcf_proto *tp_head)
 202 {
 203         if (chain->chain_head_change)
 204                 chain->chain_head_change(tp_head,
 205                                          chain->chain_head_change_priv);
 206 }
 207
 208 static void tcf_chain_flush(struct tcf_chain *chain)
 209 {
 210         struct tcf_proto *tp = rtnl_dereference(chain->filter_chain);
 211
 212         tcf_chain_head_change(chain, NULL);
 213         while (tp) {
 214                 RCU_INIT_POINTER(chain->filter_chain, tp->next);
 215                 tcf_proto_destroy(tp);
 216                 tp = rtnl_dereference(chain->filter_chain);
 217                 tcf_chain_put(chain);
 218         }
 219 }
 220
 221 static void tcf_chain_destroy(struct tcf_chain *chain)
 222 {
 223         struct tcf_block *block = chain->block;
 224
 225         list_del(&chain->list);
 226         kfree(chain);
 227         if (list_empty(&block->chain_list))
 228                 kfree(block);
 229 }
 230
 231 static void tcf_chain_hold(struct tcf_chain *chain)
 232 {
 233         ++chain->refcnt;
 234 }
 235
 236 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 237                                 bool create)
 238 {
 239         struct tcf_chain *chain;
 240
 241         list_for_each_entry(chain, &block->chain_list, list) {
 242                 if (chain->index == chain_index) {
 243                         tcf_chain_hold(chain);
 244                         return chain;
 245                 }
 246         }
 247
 248         return create ? tcf_chain_create(block, chain_index) : NULL;
 249 }
 250 EXPORT_SYMBOL(tcf_chain_get);
 251
 252 void tcf_chain_put(struct tcf_chain *chain)
 253 {
 254         if (--chain->refcnt == 0)
 255                 tcf_chain_destroy(chain);
 256 }
 257 EXPORT_SYMBOL(tcf_chain_put);
 258
 259 static void tcf_block_offload_cmd(struct tcf_block *block, struct Qdisc *q,
 260                                   struct tcf_block_ext_info *ei,
 261                                   enum tc_block_command command)
 262 {
 263         struct net_device *dev = q->dev_queue->dev;
 264         struct tc_block_offload bo = {};
 265
 266         if (!dev->netdev_ops->ndo_setup_tc)
 267                 return;
 268         bo.command = command;
 269         bo.binder_type = ei->binder_type;
 270         bo.block = block;
 271         dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 272 }
 273
 274 static void tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 275                                    struct tcf_block_ext_info *ei)
 276 {
 277         tcf_block_offload_cmd(block, q, ei, TC_BLOCK_BIND);
 278 }
 279
 280 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 281                                      struct tcf_block_ext_info *ei)
 282 {
 283         tcf_block_offload_cmd(block, q, ei, TC_BLOCK_UNBIND);
 284 }
 285
 286 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
 287                       struct tcf_block_ext_info *ei)
 288 {
 289         struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
 290         struct tcf_chain *chain;
 291         int err;
 292
 293         if (!block)
 294                 return -ENOMEM;
 295         INIT_LIST_HEAD(&block->chain_list);
 296         INIT_LIST_HEAD(&block->cb_list);
 297
 298         /* Create chain 0 by default, it has to be always present. */
 299         chain = tcf_chain_create(block, 0);
 300         if (!chain) {
 301                 err = -ENOMEM;
 302                 goto err_chain_create;
 303         }
 304         WARN_ON(!ei->chain_head_change);
 305         chain->chain_head_change = ei->chain_head_change;
 306         chain->chain_head_change_priv = ei->chain_head_change_priv;
 307         block->net = qdisc_net(q);
 308         block->q = q;
 309         tcf_block_offload_bind(block, q, ei);
 310         *p_block = block;
 311         return 0;
 312
 313 err_chain_create:
 314         kfree(block);
 315         return err;
 316 }
 317 EXPORT_SYMBOL(tcf_block_get_ext);
 318
 319 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
 320 {
 321         struct tcf_proto __rcu **p_filter_chain = priv;
 322
 323         rcu_assign_pointer(*p_filter_chain, tp_head);
 324 }
 325
 326 int tcf_block_get(struct tcf_block **p_block,
 327                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q)
 328 {
 329         struct tcf_block_ext_info ei = {
 330                 .chain_head_change = tcf_chain_head_change_dflt,
 331                 .chain_head_change_priv = p_filter_chain,
 332         };
 333
 334         WARN_ON(!p_filter_chain);
 335         return tcf_block_get_ext(p_block, q, &ei);
 336 }
 337 EXPORT_SYMBOL(tcf_block_get);
 338
 339 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
 340  * actions should be all removed after flushing.
 341  */
 342 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 343                        struct tcf_block_ext_info *ei)
 344 {
 345         struct tcf_chain *chain, *tmp;
 346
 347         if (!block)
 348                 return;
 349         /* Hold a refcnt for all chains, so that they don't disappear
 350          * while we are iterating.
 351          */
 352         list_for_each_entry(chain, &block->chain_list, list)
 353                 tcf_chain_hold(chain);
 354
 355         list_for_each_entry(chain, &block->chain_list, list)
 356                 tcf_chain_flush(chain);
 357
 358         tcf_block_offload_unbind(block, q, ei);
 359
 360         /* At this point, all the chains should have refcnt >= 1. */
 361         list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
 362                 tcf_chain_put(chain);
 363
 364         /* Finally, put chain 0 and allow block to be freed. */
 365         chain = list_first_entry(&block->chain_list, struct tcf_chain, list);
 366         tcf_chain_put(chain);
 367 }
 368 EXPORT_SYMBOL(tcf_block_put_ext);
 369
 370 void tcf_block_put(struct tcf_block *block)
 371 {
 372         struct tcf_block_ext_info ei = {0, };
 373
 374         if (!block)
 375                 return;
 376         tcf_block_put_ext(block, block->q, &ei);
 377 }
 378
 379 EXPORT_SYMBOL(tcf_block_put);
 380
 381 struct tcf_block_cb {
 382         struct list_head list;
 383         tc_setup_cb_t *cb;
 384         void *cb_ident;
 385         void *cb_priv;
 386         unsigned int refcnt;
 387 };
 388
 389 void *tcf_block_cb_priv(struct tcf_block_cb *block_cb)
 390 {
 391         return block_cb->cb_priv;
 392 }
 393 EXPORT_SYMBOL(tcf_block_cb_priv);
 394
 395 struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block,
 396                                          tc_setup_cb_t *cb, void *cb_ident)
 397 {       struct tcf_block_cb *block_cb;
 398
 399         list_for_each_entry(block_cb, &block->cb_list, list)
 400                 if (block_cb->cb == cb && block_cb->cb_ident == cb_ident)
 401                         return block_cb;
 402         return NULL;
 403 }
 404 EXPORT_SYMBOL(tcf_block_cb_lookup);
 405
 406 void tcf_block_cb_incref(struct tcf_block_cb *block_cb)
 407 {
 408         block_cb->refcnt++;
 409 }
 410 EXPORT_SYMBOL(tcf_block_cb_incref);
 411
 412 unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb)
 413 {
 414         return --block_cb->refcnt;
 415 }
 416 EXPORT_SYMBOL(tcf_block_cb_decref);
 417
 418 struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block,
 419                                              tc_setup_cb_t *cb, void *cb_ident,
 420                                              void *cb_priv)
 421 {
 422         struct tcf_block_cb *block_cb;
 423
 424         block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL);
 425         if (!block_cb)
 426                 return NULL;
 427         block_cb->cb = cb;
 428         block_cb->cb_ident = cb_ident;
 429         block_cb->cb_priv = cb_priv;
 430         list_add(&block_cb->list, &block->cb_list);
 431         return block_cb;
 432 }
 433 EXPORT_SYMBOL(__tcf_block_cb_register);
 434
 435 int tcf_block_cb_register(struct tcf_block *block,
 436                           tc_setup_cb_t *cb, void *cb_ident,
 437                           void *cb_priv)
 438 {
 439         struct tcf_block_cb *block_cb;
 440
 441         block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv);
 442         return block_cb ? 0 : -ENOMEM;
 443 }
 444 EXPORT_SYMBOL(tcf_block_cb_register);
 445
 446 void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb)
 447 {
 448         list_del(&block_cb->list);
 449         kfree(block_cb);
 450 }
 451 EXPORT_SYMBOL(__tcf_block_cb_unregister);
 452
 453 void tcf_block_cb_unregister(struct tcf_block *block,
 454                              tc_setup_cb_t *cb, void *cb_ident)
 455 {
 456         struct tcf_block_cb *block_cb;
 457
 458         block_cb = tcf_block_cb_lookup(block, cb, cb_ident);
 459         if (!block_cb)
 460                 return;
 461         __tcf_block_cb_unregister(block_cb);
 462 }
 463 EXPORT_SYMBOL(tcf_block_cb_unregister);
 464
 465 static int tcf_block_cb_call(struct tcf_block *block, enum tc_setup_type type,
 466                              void *type_data, bool err_stop)
 467 {
 468         struct tcf_block_cb *block_cb;
 469         int ok_count = 0;
 470         int err;
 471
 472         list_for_each_entry(block_cb, &block->cb_list, list) {
 473                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
 474                 if (err) {
 475                         if (err_stop)
 476                                 return err;
 477                 } else {
 478                         ok_count++;
 479                 }
 480         }
 481         return ok_count;
 482 }
 483
 484 /* Main classifier routine: scans classifier chain attached
 485  * to this qdisc, (optionally) tests for protocol and asks
 486  * specific classifiers.
 487  */
 488 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 489                  struct tcf_result *res, bool compat_mode)
 490 {
 491 #ifdef CONFIG_NET_CLS_ACT
 492         const int max_reclassify_loop = 4;
 493         const struct tcf_proto *orig_tp = tp;
 494         const struct tcf_proto *first_tp;
 495         int limit = 0;
 496
 497 reclassify:
 498 #endif
 499         for (; tp; tp = rcu_dereference_bh(tp->next)) {
 500                 __be16 protocol = tc_skb_protocol(skb);
 501                 int err;
 502
 503                 if (tp->protocol != protocol &&
 504                     tp->protocol != htons(ETH_P_ALL))
 505                         continue;
 506
 507                 err = tp->classify(skb, tp, res);
 508 #ifdef CONFIG_NET_CLS_ACT
 509                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
 510                         first_tp = orig_tp;
 511                         goto reset;
 512                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
 513                         first_tp = res->goto_tp;
 514                         goto reset;
 515                 }
 516 #endif
 517                 if (err >= 0)
 518                         return err;
 519         }
 520
 521         return TC_ACT_UNSPEC; /* signal: continue lookup */
 522 #ifdef CONFIG_NET_CLS_ACT
 523 reset:
 524         if (unlikely(limit++ >= max_reclassify_loop)) {
 525                 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
 526                                        tp->q->ops->id, tp->prio & 0xffff,
 527                                        ntohs(tp->protocol));
 528                 return TC_ACT_SHOT;
 529         }
 530
 531         tp = first_tp;
 532         goto reclassify;
 533 #endif
 534 }
 535 EXPORT_SYMBOL(tcf_classify);
 536
 537 struct tcf_chain_info {
 538         struct tcf_proto __rcu **pprev;
 539         struct tcf_proto __rcu *next;
 540 };
 541
 542 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)
 543 {
 544         return rtnl_dereference(*chain_info->pprev);
 545 }
 546
 547 static void tcf_chain_tp_insert(struct tcf_chain *chain,
 548                                 struct tcf_chain_info *chain_info,
 549                                 struct tcf_proto *tp)
 550 {
 551         if (*chain_info->pprev == chain->filter_chain)
 552                 tcf_chain_head_change(chain, tp);
 553         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));
 554         rcu_assign_pointer(*chain_info->pprev, tp);
 555         tcf_chain_hold(chain);
 556 }
 557
 558 static void tcf_chain_tp_remove(struct tcf_chain *chain,
 559                                 struct tcf_chain_info *chain_info,
 560                                 struct tcf_proto *tp)
 561 {
 562         struct tcf_proto *next = rtnl_dereference(chain_info->next);
 563
 564         if (tp == chain->filter_chain)
 565                 tcf_chain_head_change(chain, next);
 566         RCU_INIT_POINTER(*chain_info->pprev, next);
 567         tcf_chain_put(chain);
 568 }
 569
 570 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 571                                            struct tcf_chain_info *chain_info,
 572                                            u32 protocol, u32 prio,
 573                                            bool prio_allocate)
 574 {
 575         struct tcf_proto **pprev;
 576         struct tcf_proto *tp;
 577
 578         /* Check the chain for existence of proto-tcf with this priority */
 579         for (pprev = &chain->filter_chain;
 580              (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {
 581                 if (tp->prio >= prio) {
 582                         if (tp->prio == prio) {
 583                                 if (prio_allocate ||
 584                                     (tp->protocol != protocol && protocol))
 585                                         return ERR_PTR(-EINVAL);
 586                         } else {
 587                                 tp = NULL;
 588                         }
 589                         break;
 590                 }
 591         }
 592         chain_info->pprev = pprev;
 593         chain_info->next = tp ? tp->next : NULL;
 594         return tp;
 595 }
 596
 597 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 598                          struct tcf_proto *tp, struct Qdisc *q, u32 parent,
 599                          void *fh, u32 portid, u32 seq, u16 flags, int event)
 600 {
 601         struct tcmsg *tcm;
 602         struct nlmsghdr  *nlh;
 603         unsigned char *b = skb_tail_pointer(skb);
 604
 605         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 606         if (!nlh)
 607                 goto out_nlmsg_trim;
 608         tcm = nlmsg_data(nlh);
 609         tcm->tcm_family = AF_UNSPEC;
 610         tcm->tcm__pad1 = 0;
 611         tcm->tcm__pad2 = 0;
 612         tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
 613         tcm->tcm_parent = parent;
 614         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
 615         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
 616                 goto nla_put_failure;
 617         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
 618                 goto nla_put_failure;
 619         if (!fh) {
 620                 tcm->tcm_handle = 0;
 621         } else {
 622                 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
 623                         goto nla_put_failure;
 624         }
 625         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 626         return skb->len;
 627
 628 out_nlmsg_trim:
 629 nla_put_failure:
 630         nlmsg_trim(skb, b);
 631         return -1;
 632 }
 633
 634 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 635                           struct nlmsghdr *n, struct tcf_proto *tp,
 636                           struct Qdisc *q, u32 parent,
 637                           void *fh, int event, bool unicast)
 638 {
 639         struct sk_buff *skb;
 640         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 641
 642         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 643         if (!skb)
 644                 return -ENOBUFS;
 645
 646         if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq,
 647                           n->nlmsg_flags, event) <= 0) {
 648                 kfree_skb(skb);
 649                 return -EINVAL;
 650         }
 651
 652         if (unicast)
 653                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 654
 655         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 656                               n->nlmsg_flags & NLM_F_ECHO);
 657 }
 658
 659 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 660                               struct nlmsghdr *n, struct tcf_proto *tp,
 661                               struct Qdisc *q, u32 parent,
 662                               void *fh, bool unicast, bool *last)
 663 {
 664         struct sk_buff *skb;
 665         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 666         int err;
 667
 668         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 669         if (!skb)
 670                 return -ENOBUFS;
 671
 672         if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq,
 673                           n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
 674                 kfree_skb(skb);
 675                 return -EINVAL;
 676         }
 677
 678         err = tp->ops->delete(tp, fh, last);
 679         if (err) {
 680                 kfree_skb(skb);
 681                 return err;
 682         }
 683
 684         if (unicast)
 685                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 686
 687         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 688                               n->nlmsg_flags & NLM_F_ECHO);
 689 }
 690
 691 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
 692                                  struct Qdisc *q, u32 parent,
 693                                  struct nlmsghdr *n,
 694                                  struct tcf_chain *chain, int event)
 695 {
 696         struct tcf_proto *tp;
 697
 698         for (tp = rtnl_dereference(chain->filter_chain);
 699              tp; tp = rtnl_dereference(tp->next))
 700                 tfilter_notify(net, oskb, n, tp, q, parent, 0, event, false);
 701 }
 702
 703 /* Add/change/delete/get a filter node */
 704
 705 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 706                           struct netlink_ext_ack *extack)
 707 {
 708         struct net *net = sock_net(skb->sk);
 709         struct nlattr *tca[TCA_MAX + 1];
 710         struct tcmsg *t;
 711         u32 protocol;
 712         u32 prio;
 713         bool prio_allocate;
 714         u32 parent;
 715         u32 chain_index;
 716         struct net_device *dev;
 717         struct Qdisc  *q;
 718         struct tcf_chain_info chain_info;
 719         struct tcf_chain *chain = NULL;
 720         struct tcf_block *block;
 721         struct tcf_proto *tp;
 722         const struct Qdisc_class_ops *cops;
 723         unsigned long cl;
 724         void *fh;
 725         int err;
 726         int tp_created;
 727
 728         if ((n->nlmsg_type != RTM_GETTFILTER) &&
 729             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 730                 return -EPERM;
 731
 732 replay:
 733         tp_created = 0;
 734
 735         err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, rtm_tca_policy, extack);
 736         if (err < 0)
 737                 return err;
 738
 739         t = nlmsg_data(n);
 740         protocol = TC_H_MIN(t->tcm_info);
 741         prio = TC_H_MAJ(t->tcm_info);
 742         prio_allocate = false;
 743         parent = t->tcm_parent;
 744         cl = 0;
 745
 746         if (prio == 0) {
 747                 switch (n->nlmsg_type) {
 748                 case RTM_DELTFILTER:
 749                         if (protocol || t->tcm_handle || tca[TCA_KIND])
 750                                 return -ENOENT;
 751                         break;
 752                 case RTM_NEWTFILTER:
 753                         /* If no priority is provided by the user,
 754                          * we allocate one.
 755                          */
 756                         if (n->nlmsg_flags & NLM_F_CREATE) {
 757                                 prio = TC_H_MAKE(0x80000000U, 0U);
 758                                 prio_allocate = true;
 759                                 break;
 760                         }
 761                         /* fall-through */
 762                 default:
 763                         return -ENOENT;
 764                 }
 765         }
 766
 767         /* Find head of filter chain. */
 768
 769         /* Find link */
 770         dev = __dev_get_by_index(net, t->tcm_ifindex);
 771         if (dev == NULL)
 772                 return -ENODEV;
 773
 774         /* Find qdisc */
 775         if (!parent) {
 776                 q = dev->qdisc;
 777                 parent = q->handle;
 778         } else {
 779                 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
 780                 if (q == NULL)
 781                         return -EINVAL;
 782         }
 783
 784         /* Is it classful? */
 785         cops = q->ops->cl_ops;
 786         if (!cops)
 787                 return -EINVAL;
 788
 789         if (!cops->tcf_block)
 790                 return -EOPNOTSUPP;
 791
 792         /* Do we search for filter, attached to class? */
 793         if (TC_H_MIN(parent)) {
 794                 cl = cops->find(q, parent);
 795                 if (cl == 0)
 796                         return -ENOENT;
 797         }
 798
 799         /* And the last stroke */
 800         block = cops->tcf_block(q, cl);
 801         if (!block) {
 802                 err = -EINVAL;
 803                 goto errout;
 804         }
 805
 806         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
 807         if (chain_index > TC_ACT_EXT_VAL_MASK) {
 808                 err = -EINVAL;
 809                 goto errout;
 810         }
 811         chain = tcf_chain_get(block, chain_index,
 812                               n->nlmsg_type == RTM_NEWTFILTER);
 813         if (!chain) {
 814                 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL;
 815                 goto errout;
 816         }
 817
 818         if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
 819                 tfilter_notify_chain(net, skb, q, parent, n,
 820                                      chain, RTM_DELTFILTER);
 821                 tcf_chain_flush(chain);
 822                 err = 0;
 823                 goto errout;
 824         }
 825
 826         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 827                                prio, prio_allocate);
 828         if (IS_ERR(tp)) {
 829                 err = PTR_ERR(tp);
 830                 goto errout;
 831         }
 832
 833         if (tp == NULL) {
 834                 /* Proto-tcf does not exist, create new one */
 835
 836                 if (tca[TCA_KIND] == NULL || !protocol) {
 837                         err = -EINVAL;
 838                         goto errout;
 839                 }
 840
 841                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 842                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 843                         err = -ENOENT;
 844                         goto errout;
 845                 }
 846
 847                 if (prio_allocate)
 848                         prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
 849
 850                 tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
 851                                       protocol, prio, parent, q, chain);
 852                 if (IS_ERR(tp)) {
 853                         err = PTR_ERR(tp);
 854                         goto errout;
 855                 }
 856                 tp_created = 1;
 857         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
 858                 err = -EINVAL;
 859                 goto errout;
 860         }
 861
 862         fh = tp->ops->get(tp, t->tcm_handle);
 863
 864         if (!fh) {
 865                 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
 866                         tcf_chain_tp_remove(chain, &chain_info, tp);
 867                         tfilter_notify(net, skb, n, tp, q, parent, fh,
 868                                        RTM_DELTFILTER, false);
 869                         tcf_proto_destroy(tp);
 870                         err = 0;
 871                         goto errout;
 872                 }
 873
 874                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 875                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 876                         err = -ENOENT;
 877                         goto errout;
 878                 }
 879         } else {
 880                 bool last;
 881
 882                 switch (n->nlmsg_type) {
 883                 case RTM_NEWTFILTER:
 884                         if (n->nlmsg_flags & NLM_F_EXCL) {
 885                                 if (tp_created)
 886                                         tcf_proto_destroy(tp);
 887                                 err = -EEXIST;
 888                                 goto errout;
 889                         }
 890                         break;
 891                 case RTM_DELTFILTER:
 892                         err = tfilter_del_notify(net, skb, n, tp, q, parent,
 893                                                  fh, false, &last);
 894                         if (err)
 895                                 goto errout;
 896                         if (last) {
 897                                 tcf_chain_tp_remove(chain, &chain_info, tp);
 898                                 tcf_proto_destroy(tp);
 899                         }
 900                         goto errout;
 901                 case RTM_GETTFILTER:
 902                         err = tfilter_notify(net, skb, n, tp, q, parent, fh,
 903                                              RTM_NEWTFILTER, true);
 904                         goto errout;
 905                 default:
 906                         err = -EINVAL;
 907                         goto errout;
 908                 }
 909         }
 910
 911         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 912                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
 913         if (err == 0) {
 914                 if (tp_created)
 915                         tcf_chain_tp_insert(chain, &chain_info, tp);
 916                 tfilter_notify(net, skb, n, tp, q, parent, fh,
 917                                RTM_NEWTFILTER, false);
 918                 /* q pointer is NULL for shared blocks */
 919                 if (q)
 920                         q->flags &= ~TCQ_F_CAN_BYPASS;
 921         } else {
 922                 if (tp_created)
 923                         tcf_proto_destroy(tp);
 924         }
 925
 926 errout:
 927         if (chain)
 928                 tcf_chain_put(chain);
 929         if (err == -EAGAIN)
 930                 /* Replay the request. */
 931                 goto replay;
 932         return err;
 933 }
 934
 935 struct tcf_dump_args {
 936         struct tcf_walker w;
 937         struct sk_buff *skb;
 938         struct netlink_callback *cb;
 939         struct Qdisc *q;
 940         u32 parent;
 941 };
 942
 943 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
 944 {
 945         struct tcf_dump_args *a = (void *)arg;
 946         struct net *net = sock_net(a->skb->sk);
 947
 948         return tcf_fill_node(net, a->skb, tp, a->q, a->parent,
 949                              n, NETLINK_CB(a->cb->skb).portid,
 950                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
 951                              RTM_NEWTFILTER);
 952 }
 953
 954 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 955                            struct sk_buff *skb, struct netlink_callback *cb,
 956                            long index_start, long *p_index)
 957 {
 958         struct net *net = sock_net(skb->sk);
 959         struct tcmsg *tcm = nlmsg_data(cb->nlh);
 960         struct tcf_dump_args arg;
 961         struct tcf_proto *tp;
 962
 963         for (tp = rtnl_dereference(chain->filter_chain);
 964              tp; tp = rtnl_dereference(tp->next), (*p_index)++) {
 965                 if (*p_index < index_start)
 966                         continue;
 967                 if (TC_H_MAJ(tcm->tcm_info) &&
 968                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
 969                         continue;
 970                 if (TC_H_MIN(tcm->tcm_info) &&
 971                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
 972                         continue;
 973                 if (*p_index > index_start)
 974                         memset(&cb->args[1], 0,
 975                                sizeof(cb->args) - sizeof(cb->args[0]));
 976                 if (cb->args[1] == 0) {
 977                         if (tcf_fill_node(net, skb, tp, q, parent, 0,
 978                                           NETLINK_CB(cb->skb).portid,
 979                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
 980                                           RTM_NEWTFILTER) <= 0)
 981                                 return false;
 982
 983                         cb->args[1] = 1;
 984                 }
 985                 if (!tp->ops->walk)
 986                         continue;
 987                 arg.w.fn = tcf_node_dump;
 988                 arg.skb = skb;
 989                 arg.cb = cb;
 990                 arg.q = q;
 991                 arg.parent = parent;
 992                 arg.w.stop = 0;
 993                 arg.w.skip = cb->args[1] - 1;
 994                 arg.w.count = 0;
 995                 tp->ops->walk(tp, &arg.w);
 996                 cb->args[1] = arg.w.count + 1;
 997                 if (arg.w.stop)
 998                         return false;
 999         }
1000         return true;
1001 }
1002
1003 /* called with RTNL */
1004 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
1005 {
1006         struct net *net = sock_net(skb->sk);
1007         struct nlattr *tca[TCA_MAX + 1];
1008         struct net_device *dev;
1009         struct Qdisc *q;
1010         struct tcf_block *block;
1011         struct tcf_chain *chain;
1012         struct tcmsg *tcm = nlmsg_data(cb->nlh);
1013         unsigned long cl = 0;
1014         const struct Qdisc_class_ops *cops;
1015         long index_start;
1016         long index;
1017         u32 parent;
1018         int err;
1019
1020         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1021                 return skb->len;
1022
1023         err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy,
1024                           NULL);
1025         if (err)
1026                 return err;
1027
1028         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1029         if (!dev)
1030                 return skb->len;
1031
1032         parent = tcm->tcm_parent;
1033         if (!parent) {
1034                 q = dev->qdisc;
1035                 parent = q->handle;
1036         } else {
1037                 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
1038         }
1039         if (!q)
1040                 goto out;
1041         cops = q->ops->cl_ops;
1042         if (!cops)
1043                 goto out;
1044         if (!cops->tcf_block)
1045                 goto out;
1046         if (TC_H_MIN(tcm->tcm_parent)) {
1047                 cl = cops->find(q, tcm->tcm_parent);
1048                 if (cl == 0)
1049                         goto out;
1050         }
1051         block = cops->tcf_block(q, cl);
1052         if (!block)
1053                 goto out;
1054
1055         index_start = cb->args[0];
1056         index = 0;
1057
1058         list_for_each_entry(chain, &block->chain_list, list) {
1059                 if (tca[TCA_CHAIN] &&
1060                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
1061                         continue;
1062                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
1063                                     index_start, &index)) {
1064                         err = -EMSGSIZE;
1065                         break;
1066                 }
1067         }
1068
1069         cb->args[0] = index;
1070
1071 out:
1072         /* If we did no progress, the error (EMSGSIZE) is real */
1073         if (skb->len == 0 && err)
1074                 return err;
1075         return skb->len;
1076 }
1077
1078 void tcf_exts_destroy(struct tcf_exts *exts)
1079 {
1080 #ifdef CONFIG_NET_CLS_ACT
1081         LIST_HEAD(actions);
1082
1083         ASSERT_RTNL();
1084         tcf_exts_to_list(exts, &actions);
1085         tcf_action_destroy(&actions, TCA_ACT_UNBIND);
1086         kfree(exts->actions);
1087         exts->nr_actions = 0;
1088 #endif
1089 }
1090 EXPORT_SYMBOL(tcf_exts_destroy);
1091
1092 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
1093                       struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)
1094 {
1095 #ifdef CONFIG_NET_CLS_ACT
1096         {
1097                 struct tc_action *act;
1098
1099                 if (exts->police && tb[exts->police]) {
1100                         act = tcf_action_init_1(net, tp, tb[exts->police],
1101                                                 rate_tlv, "police", ovr,
1102                                                 TCA_ACT_BIND);
1103                         if (IS_ERR(act))
1104                                 return PTR_ERR(act);
1105
1106                         act->type = exts->type = TCA_OLD_COMPAT;
1107                         exts->actions[0] = act;
1108                         exts->nr_actions = 1;
1109                 } else if (exts->action && tb[exts->action]) {
1110                         LIST_HEAD(actions);
1111                         int err, i = 0;
1112
1113                         err = tcf_action_init(net, tp, tb[exts->action],
1114                                               rate_tlv, NULL, ovr, TCA_ACT_BIND,
1115                                               &actions);
1116                         if (err)
1117                                 return err;
1118                         list_for_each_entry(act, &actions, list)
1119                                 exts->actions[i++] = act;
1120                         exts->nr_actions = i;
1121                 }
1122         }
1123 #else
1124         if ((exts->action && tb[exts->action]) ||
1125             (exts->police && tb[exts->police]))
1126                 return -EOPNOTSUPP;
1127 #endif
1128
1129         return 0;
1130 }
1131 EXPORT_SYMBOL(tcf_exts_validate);
1132
1133 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
1134 {
1135 #ifdef CONFIG_NET_CLS_ACT
1136         struct tcf_exts old = *dst;
1137
1138         *dst = *src;
1139         tcf_exts_destroy(&old);
1140 #endif
1141 }
1142 EXPORT_SYMBOL(tcf_exts_change);
1143
1144 #ifdef CONFIG_NET_CLS_ACT
1145 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
1146 {
1147         if (exts->nr_actions == 0)
1148                 return NULL;
1149         else
1150                 return exts->actions[0];
1151 }
1152 #endif
1153
1154 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
1155 {
1156 #ifdef CONFIG_NET_CLS_ACT
1157         struct nlattr *nest;
1158
1159         if (exts->action && tcf_exts_has_actions(exts)) {
1160                 /*
1161                  * again for backward compatible mode - we want
1162                  * to work with both old and new modes of entering
1163                  * tc data even if iproute2  was newer - jhs
1164                  */
1165                 if (exts->type != TCA_OLD_COMPAT) {
1166                         LIST_HEAD(actions);
1167
1168                         nest = nla_nest_start(skb, exts->action);
1169                         if (nest == NULL)
1170                                 goto nla_put_failure;
1171
1172                         tcf_exts_to_list(exts, &actions);
1173                         if (tcf_action_dump(skb, &actions, 0, 0) < 0)
1174                                 goto nla_put_failure;
1175                         nla_nest_end(skb, nest);
1176                 } else if (exts->police) {
1177                         struct tc_action *act = tcf_exts_first_act(exts);
1178                         nest = nla_nest_start(skb, exts->police);
1179                         if (nest == NULL || !act)
1180                                 goto nla_put_failure;
1181                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
1182                                 goto nla_put_failure;
1183                         nla_nest_end(skb, nest);
1184                 }
1185         }
1186         return 0;
1187
1188 nla_put_failure:
1189         nla_nest_cancel(skb, nest);
1190         return -1;
1191 #else
1192         return 0;
1193 #endif
1194 }
1195 EXPORT_SYMBOL(tcf_exts_dump);
1196
1197
1198 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
1199 {
1200 #ifdef CONFIG_NET_CLS_ACT
1201         struct tc_action *a = tcf_exts_first_act(exts);
1202         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
1203                 return -1;
1204 #endif
1205         return 0;
1206 }
1207 EXPORT_SYMBOL(tcf_exts_dump_stats);
1208
1209 static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts,
1210                                        enum tc_setup_type type,
1211                                        void *type_data, bool err_stop)
1212 {
1213         int ok_count = 0;
1214 #ifdef CONFIG_NET_CLS_ACT
1215         const struct tc_action *a;
1216         struct net_device *dev;
1217         int i, ret;
1218
1219         if (!tcf_exts_has_actions(exts))
1220                 return 0;
1221
1222         for (i = 0; i < exts->nr_actions; i++) {
1223                 a = exts->actions[i];
1224                 if (!a->ops->get_dev)
1225                         continue;
1226                 dev = a->ops->get_dev(a);
1227                 if (!dev)
1228                         continue;
1229                 ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop);
1230                 if (ret < 0)
1231                         return ret;
1232                 ok_count += ret;
1233         }
1234 #endif
1235         return ok_count;
1236 }
1237
1238 int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts,
1239                      enum tc_setup_type type, void *type_data, bool err_stop)
1240 {
1241         int ok_count;
1242         int ret;
1243
1244         ret = tcf_block_cb_call(block, type, type_data, err_stop);
1245         if (ret < 0)
1246                 return ret;
1247         ok_count = ret;
1248
1249         if (!exts || ok_count)
1250                 return ok_count;
1251         ret = tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop);
1252         if (ret < 0)
1253                 return ret;
1254         ok_count += ret;
1255
1256         return ok_count;
1257 }
1258 EXPORT_SYMBOL(tc_setup_cb_call);
1259
1260 static int __init tc_filter_init(void)
1261 {
1262         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
1263         if (!tc_filter_wq)
1264                 return -ENOMEM;
1265
1266         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0);
1267         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0);
1268         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
1269                       tc_dump_tfilter, 0);
1270
1271         return 0;
1272 }
1273
1274 subsys_initcall(tc_filter_init);