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         __be16 protocol = tc_skb_protocol(skb);
 492 #ifdef CONFIG_NET_CLS_ACT
 493         const int max_reclassify_loop = 4;
 494         const struct tcf_proto *orig_tp = tp;
 495         const struct tcf_proto *first_tp;
 496         int limit = 0;
 497
 498 reclassify:
 499 #endif
 500         for (; tp; tp = rcu_dereference_bh(tp->next)) {
 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         protocol = tc_skb_protocol(skb);
 533         goto reclassify;
 534 #endif
 535 }
 536 EXPORT_SYMBOL(tcf_classify);
 537
 538 struct tcf_chain_info {
 539         struct tcf_proto __rcu **pprev;
 540         struct tcf_proto __rcu *next;
 541 };
 542
 543 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)
 544 {
 545         return rtnl_dereference(*chain_info->pprev);
 546 }
 547
 548 static void tcf_chain_tp_insert(struct tcf_chain *chain,
 549                                 struct tcf_chain_info *chain_info,
 550                                 struct tcf_proto *tp)
 551 {
 552         if (*chain_info->pprev == chain->filter_chain)
 553                 tcf_chain_head_change(chain, tp);
 554         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));
 555         rcu_assign_pointer(*chain_info->pprev, tp);
 556         tcf_chain_hold(chain);
 557 }
 558
 559 static void tcf_chain_tp_remove(struct tcf_chain *chain,
 560                                 struct tcf_chain_info *chain_info,
 561                                 struct tcf_proto *tp)
 562 {
 563         struct tcf_proto *next = rtnl_dereference(chain_info->next);
 564
 565         if (tp == chain->filter_chain)
 566                 tcf_chain_head_change(chain, next);
 567         RCU_INIT_POINTER(*chain_info->pprev, next);
 568         tcf_chain_put(chain);
 569 }
 570
 571 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 572                                            struct tcf_chain_info *chain_info,
 573                                            u32 protocol, u32 prio,
 574                                            bool prio_allocate)
 575 {
 576         struct tcf_proto **pprev;
 577         struct tcf_proto *tp;
 578
 579         /* Check the chain for existence of proto-tcf with this priority */
 580         for (pprev = &chain->filter_chain;
 581              (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {
 582                 if (tp->prio >= prio) {
 583                         if (tp->prio == prio) {
 584                                 if (prio_allocate ||
 585                                     (tp->protocol != protocol && protocol))
 586                                         return ERR_PTR(-EINVAL);
 587                         } else {
 588                                 tp = NULL;
 589                         }
 590                         break;
 591                 }
 592         }
 593         chain_info->pprev = pprev;
 594         chain_info->next = tp ? tp->next : NULL;
 595         return tp;
 596 }
 597
 598 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 599                          struct tcf_proto *tp, struct Qdisc *q, u32 parent,
 600                          void *fh, u32 portid, u32 seq, u16 flags, int event)
 601 {
 602         struct tcmsg *tcm;
 603         struct nlmsghdr  *nlh;
 604         unsigned char *b = skb_tail_pointer(skb);
 605
 606         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 607         if (!nlh)
 608                 goto out_nlmsg_trim;
 609         tcm = nlmsg_data(nlh);
 610         tcm->tcm_family = AF_UNSPEC;
 611         tcm->tcm__pad1 = 0;
 612         tcm->tcm__pad2 = 0;
 613         tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
 614         tcm->tcm_parent = parent;
 615         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
 616         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
 617                 goto nla_put_failure;
 618         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
 619                 goto nla_put_failure;
 620         if (!fh) {
 621                 tcm->tcm_handle = 0;
 622         } else {
 623                 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
 624                         goto nla_put_failure;
 625         }
 626         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 627         return skb->len;
 628
 629 out_nlmsg_trim:
 630 nla_put_failure:
 631         nlmsg_trim(skb, b);
 632         return -1;
 633 }
 634
 635 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 636                           struct nlmsghdr *n, struct tcf_proto *tp,
 637                           struct Qdisc *q, u32 parent,
 638                           void *fh, int event, bool unicast)
 639 {
 640         struct sk_buff *skb;
 641         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 642
 643         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 644         if (!skb)
 645                 return -ENOBUFS;
 646
 647         if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq,
 648                           n->nlmsg_flags, event) <= 0) {
 649                 kfree_skb(skb);
 650                 return -EINVAL;
 651         }
 652
 653         if (unicast)
 654                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 655
 656         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 657                               n->nlmsg_flags & NLM_F_ECHO);
 658 }
 659
 660 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 661                               struct nlmsghdr *n, struct tcf_proto *tp,
 662                               struct Qdisc *q, u32 parent,
 663                               void *fh, bool unicast, bool *last)
 664 {
 665         struct sk_buff *skb;
 666         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 667         int err;
 668
 669         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 670         if (!skb)
 671                 return -ENOBUFS;
 672
 673         if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq,
 674                           n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
 675                 kfree_skb(skb);
 676                 return -EINVAL;
 677         }
 678
 679         err = tp->ops->delete(tp, fh, last);
 680         if (err) {
 681                 kfree_skb(skb);
 682                 return err;
 683         }
 684
 685         if (unicast)
 686                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 687
 688         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 689                               n->nlmsg_flags & NLM_F_ECHO);
 690 }
 691
 692 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
 693                                  struct Qdisc *q, u32 parent,
 694                                  struct nlmsghdr *n,
 695                                  struct tcf_chain *chain, int event)
 696 {
 697         struct tcf_proto *tp;
 698
 699         for (tp = rtnl_dereference(chain->filter_chain);
 700              tp; tp = rtnl_dereference(tp->next))
 701                 tfilter_notify(net, oskb, n, tp, q, parent, 0, event, false);
 702 }
 703
 704 /* Add/change/delete/get a filter node */
 705
 706 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 707                           struct netlink_ext_ack *extack)
 708 {
 709         struct net *net = sock_net(skb->sk);
 710         struct nlattr *tca[TCA_MAX + 1];
 711         struct tcmsg *t;
 712         u32 protocol;
 713         u32 prio;
 714         bool prio_allocate;
 715         u32 parent;
 716         u32 chain_index;
 717         struct net_device *dev;
 718         struct Qdisc  *q;
 719         struct tcf_chain_info chain_info;
 720         struct tcf_chain *chain = NULL;
 721         struct tcf_block *block;
 722         struct tcf_proto *tp;
 723         const struct Qdisc_class_ops *cops;
 724         unsigned long cl;
 725         void *fh;
 726         int err;
 727         int tp_created;
 728
 729         if ((n->nlmsg_type != RTM_GETTFILTER) &&
 730             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 731                 return -EPERM;
 732
 733 replay:
 734         tp_created = 0;
 735
 736         err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, rtm_tca_policy, extack);
 737         if (err < 0)
 738                 return err;
 739
 740         t = nlmsg_data(n);
 741         protocol = TC_H_MIN(t->tcm_info);
 742         prio = TC_H_MAJ(t->tcm_info);
 743         prio_allocate = false;
 744         parent = t->tcm_parent;
 745         cl = 0;
 746
 747         if (prio == 0) {
 748                 switch (n->nlmsg_type) {
 749                 case RTM_DELTFILTER:
 750                         if (protocol || t->tcm_handle || tca[TCA_KIND])
 751                                 return -ENOENT;
 752                         break;
 753                 case RTM_NEWTFILTER:
 754                         /* If no priority is provided by the user,
 755                          * we allocate one.
 756                          */
 757                         if (n->nlmsg_flags & NLM_F_CREATE) {
 758                                 prio = TC_H_MAKE(0x80000000U, 0U);
 759                                 prio_allocate = true;
 760                                 break;
 761                         }
 762                         /* fall-through */
 763                 default:
 764                         return -ENOENT;
 765                 }
 766         }
 767
 768         /* Find head of filter chain. */
 769
 770         /* Find link */
 771         dev = __dev_get_by_index(net, t->tcm_ifindex);
 772         if (dev == NULL)
 773                 return -ENODEV;
 774
 775         /* Find qdisc */
 776         if (!parent) {
 777                 q = dev->qdisc;
 778                 parent = q->handle;
 779         } else {
 780                 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
 781                 if (q == NULL)
 782                         return -EINVAL;
 783         }
 784
 785         /* Is it classful? */
 786         cops = q->ops->cl_ops;
 787         if (!cops)
 788                 return -EINVAL;
 789
 790         if (!cops->tcf_block)
 791                 return -EOPNOTSUPP;
 792
 793         /* Do we search for filter, attached to class? */
 794         if (TC_H_MIN(parent)) {
 795                 cl = cops->find(q, parent);
 796                 if (cl == 0)
 797                         return -ENOENT;
 798         }
 799
 800         /* And the last stroke */
 801         block = cops->tcf_block(q, cl);
 802         if (!block) {
 803                 err = -EINVAL;
 804                 goto errout;
 805         }
 806
 807         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
 808         if (chain_index > TC_ACT_EXT_VAL_MASK) {
 809                 err = -EINVAL;
 810                 goto errout;
 811         }
 812         chain = tcf_chain_get(block, chain_index,
 813                               n->nlmsg_type == RTM_NEWTFILTER);
 814         if (!chain) {
 815                 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL;
 816                 goto errout;
 817         }
 818
 819         if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
 820                 tfilter_notify_chain(net, skb, q, parent, n,
 821                                      chain, RTM_DELTFILTER);
 822                 tcf_chain_flush(chain);
 823                 err = 0;
 824                 goto errout;
 825         }
 826
 827         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 828                                prio, prio_allocate);
 829         if (IS_ERR(tp)) {
 830                 err = PTR_ERR(tp);
 831                 goto errout;
 832         }
 833
 834         if (tp == NULL) {
 835                 /* Proto-tcf does not exist, create new one */
 836
 837                 if (tca[TCA_KIND] == NULL || !protocol) {
 838                         err = -EINVAL;
 839                         goto errout;
 840                 }
 841
 842                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 843                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 844                         err = -ENOENT;
 845                         goto errout;
 846                 }
 847
 848                 if (prio_allocate)
 849                         prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
 850
 851                 tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
 852                                       protocol, prio, parent, q, chain);
 853                 if (IS_ERR(tp)) {
 854                         err = PTR_ERR(tp);
 855                         goto errout;
 856                 }
 857                 tp_created = 1;
 858         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
 859                 err = -EINVAL;
 860                 goto errout;
 861         }
 862
 863         fh = tp->ops->get(tp, t->tcm_handle);
 864
 865         if (!fh) {
 866                 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
 867                         tcf_chain_tp_remove(chain, &chain_info, tp);
 868                         tfilter_notify(net, skb, n, tp, q, parent, fh,
 869                                        RTM_DELTFILTER, false);
 870                         tcf_proto_destroy(tp);
 871                         err = 0;
 872                         goto errout;
 873                 }
 874
 875                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 876                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 877                         err = -ENOENT;
 878                         goto errout;
 879                 }
 880         } else {
 881                 bool last;
 882
 883                 switch (n->nlmsg_type) {
 884                 case RTM_NEWTFILTER:
 885                         if (n->nlmsg_flags & NLM_F_EXCL) {
 886                                 if (tp_created)
 887                                         tcf_proto_destroy(tp);
 888                                 err = -EEXIST;
 889                                 goto errout;
 890                         }
 891                         break;
 892                 case RTM_DELTFILTER:
 893                         err = tfilter_del_notify(net, skb, n, tp, q, parent,
 894                                                  fh, false, &last);
 895                         if (err)
 896                                 goto errout;
 897                         if (last) {
 898                                 tcf_chain_tp_remove(chain, &chain_info, tp);
 899                                 tcf_proto_destroy(tp);
 900                         }
 901                         goto errout;
 902                 case RTM_GETTFILTER:
 903                         err = tfilter_notify(net, skb, n, tp, q, parent, fh,
 904                                              RTM_NEWTFILTER, true);
 905                         goto errout;
 906                 default:
 907                         err = -EINVAL;
 908                         goto errout;
 909                 }
 910         }
 911
 912         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 913                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
 914         if (err == 0) {
 915                 if (tp_created)
 916                         tcf_chain_tp_insert(chain, &chain_info, tp);
 917                 tfilter_notify(net, skb, n, tp, q, parent, fh,
 918                                RTM_NEWTFILTER, false);
 919         } else {
 920                 if (tp_created)
 921                         tcf_proto_destroy(tp);
 922         }
 923
 924 errout:
 925         if (chain)
 926                 tcf_chain_put(chain);
 927         if (err == -EAGAIN)
 928                 /* Replay the request. */
 929                 goto replay;
 930         return err;
 931 }
 932
 933 struct tcf_dump_args {
 934         struct tcf_walker w;
 935         struct sk_buff *skb;
 936         struct netlink_callback *cb;
 937         struct Qdisc *q;
 938         u32 parent;
 939 };
 940
 941 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
 942 {
 943         struct tcf_dump_args *a = (void *)arg;
 944         struct net *net = sock_net(a->skb->sk);
 945
 946         return tcf_fill_node(net, a->skb, tp, a->q, a->parent,
 947                              n, NETLINK_CB(a->cb->skb).portid,
 948                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
 949                              RTM_NEWTFILTER);
 950 }
 951
 952 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 953                            struct sk_buff *skb, struct netlink_callback *cb,
 954                            long index_start, long *p_index)
 955 {
 956         struct net *net = sock_net(skb->sk);
 957         struct tcmsg *tcm = nlmsg_data(cb->nlh);
 958         struct tcf_dump_args arg;
 959         struct tcf_proto *tp;
 960
 961         for (tp = rtnl_dereference(chain->filter_chain);
 962              tp; tp = rtnl_dereference(tp->next), (*p_index)++) {
 963                 if (*p_index < index_start)
 964                         continue;
 965                 if (TC_H_MAJ(tcm->tcm_info) &&
 966                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
 967                         continue;
 968                 if (TC_H_MIN(tcm->tcm_info) &&
 969                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
 970                         continue;
 971                 if (*p_index > index_start)
 972                         memset(&cb->args[1], 0,
 973                                sizeof(cb->args) - sizeof(cb->args[0]));
 974                 if (cb->args[1] == 0) {
 975                         if (tcf_fill_node(net, skb, tp, q, parent, 0,
 976                                           NETLINK_CB(cb->skb).portid,
 977                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
 978                                           RTM_NEWTFILTER) <= 0)
 979                                 return false;
 980
 981                         cb->args[1] = 1;
 982                 }
 983                 if (!tp->ops->walk)
 984                         continue;
 985                 arg.w.fn = tcf_node_dump;
 986                 arg.skb = skb;
 987                 arg.cb = cb;
 988                 arg.q = q;
 989                 arg.parent = parent;
 990                 arg.w.stop = 0;
 991                 arg.w.skip = cb->args[1] - 1;
 992                 arg.w.count = 0;
 993                 tp->ops->walk(tp, &arg.w);
 994                 cb->args[1] = arg.w.count + 1;
 995                 if (arg.w.stop)
 996                         return false;
 997         }
 998         return true;
 999 }
1000
1001 /* called with RTNL */
1002 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
1003 {
1004         struct net *net = sock_net(skb->sk);
1005         struct nlattr *tca[TCA_MAX + 1];
1006         struct net_device *dev;
1007         struct Qdisc *q;
1008         struct tcf_block *block;
1009         struct tcf_chain *chain;
1010         struct tcmsg *tcm = nlmsg_data(cb->nlh);
1011         unsigned long cl = 0;
1012         const struct Qdisc_class_ops *cops;
1013         long index_start;
1014         long index;
1015         u32 parent;
1016         int err;
1017
1018         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1019                 return skb->len;
1020
1021         err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy,
1022                           NULL);
1023         if (err)
1024                 return err;
1025
1026         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1027         if (!dev)
1028                 return skb->len;
1029
1030         parent = tcm->tcm_parent;
1031         if (!parent) {
1032                 q = dev->qdisc;
1033                 parent = q->handle;
1034         } else {
1035                 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
1036         }
1037         if (!q)
1038                 goto out;
1039         cops = q->ops->cl_ops;
1040         if (!cops)
1041                 goto out;
1042         if (!cops->tcf_block)
1043                 goto out;
1044         if (TC_H_MIN(tcm->tcm_parent)) {
1045                 cl = cops->find(q, tcm->tcm_parent);
1046                 if (cl == 0)
1047                         goto out;
1048         }
1049         block = cops->tcf_block(q, cl);
1050         if (!block)
1051                 goto out;
1052
1053         index_start = cb->args[0];
1054         index = 0;
1055
1056         list_for_each_entry(chain, &block->chain_list, list) {
1057                 if (tca[TCA_CHAIN] &&
1058                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
1059                         continue;
1060                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
1061                                     index_start, &index)) {
1062                         err = -EMSGSIZE;
1063                         break;
1064                 }
1065         }
1066
1067         cb->args[0] = index;
1068
1069 out:
1070         /* If we did no progress, the error (EMSGSIZE) is real */
1071         if (skb->len == 0 && err)
1072                 return err;
1073         return skb->len;
1074 }
1075
1076 void tcf_exts_destroy(struct tcf_exts *exts)
1077 {
1078 #ifdef CONFIG_NET_CLS_ACT
1079         LIST_HEAD(actions);
1080
1081         ASSERT_RTNL();
1082         tcf_exts_to_list(exts, &actions);
1083         tcf_action_destroy(&actions, TCA_ACT_UNBIND);
1084         kfree(exts->actions);
1085         exts->nr_actions = 0;
1086 #endif
1087 }
1088 EXPORT_SYMBOL(tcf_exts_destroy);
1089
1090 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
1091                       struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)
1092 {
1093 #ifdef CONFIG_NET_CLS_ACT
1094         {
1095                 struct tc_action *act;
1096
1097                 if (exts->police && tb[exts->police]) {
1098                         act = tcf_action_init_1(net, tp, tb[exts->police],
1099                                                 rate_tlv, "police", ovr,
1100                                                 TCA_ACT_BIND);
1101                         if (IS_ERR(act))
1102                                 return PTR_ERR(act);
1103
1104                         act->type = exts->type = TCA_OLD_COMPAT;
1105                         exts->actions[0] = act;
1106                         exts->nr_actions = 1;
1107                 } else if (exts->action && tb[exts->action]) {
1108                         LIST_HEAD(actions);
1109                         int err, i = 0;
1110
1111                         err = tcf_action_init(net, tp, tb[exts->action],
1112                                               rate_tlv, NULL, ovr, TCA_ACT_BIND,
1113                                               &actions);
1114                         if (err)
1115                                 return err;
1116                         list_for_each_entry(act, &actions, list)
1117                                 exts->actions[i++] = act;
1118                         exts->nr_actions = i;
1119                 }
1120         }
1121 #else
1122         if ((exts->action && tb[exts->action]) ||
1123             (exts->police && tb[exts->police]))
1124                 return -EOPNOTSUPP;
1125 #endif
1126
1127         return 0;
1128 }
1129 EXPORT_SYMBOL(tcf_exts_validate);
1130
1131 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
1132 {
1133 #ifdef CONFIG_NET_CLS_ACT
1134         struct tcf_exts old = *dst;
1135
1136         *dst = *src;
1137         tcf_exts_destroy(&old);
1138 #endif
1139 }
1140 EXPORT_SYMBOL(tcf_exts_change);
1141
1142 #ifdef CONFIG_NET_CLS_ACT
1143 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
1144 {
1145         if (exts->nr_actions == 0)
1146                 return NULL;
1147         else
1148                 return exts->actions[0];
1149 }
1150 #endif
1151
1152 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
1153 {
1154 #ifdef CONFIG_NET_CLS_ACT
1155         struct nlattr *nest;
1156
1157         if (exts->action && tcf_exts_has_actions(exts)) {
1158                 /*
1159                  * again for backward compatible mode - we want
1160                  * to work with both old and new modes of entering
1161                  * tc data even if iproute2  was newer - jhs
1162                  */
1163                 if (exts->type != TCA_OLD_COMPAT) {
1164                         LIST_HEAD(actions);
1165
1166                         nest = nla_nest_start(skb, exts->action);
1167                         if (nest == NULL)
1168                                 goto nla_put_failure;
1169
1170                         tcf_exts_to_list(exts, &actions);
1171                         if (tcf_action_dump(skb, &actions, 0, 0) < 0)
1172                                 goto nla_put_failure;
1173                         nla_nest_end(skb, nest);
1174                 } else if (exts->police) {
1175                         struct tc_action *act = tcf_exts_first_act(exts);
1176                         nest = nla_nest_start(skb, exts->police);
1177                         if (nest == NULL || !act)
1178                                 goto nla_put_failure;
1179                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
1180                                 goto nla_put_failure;
1181                         nla_nest_end(skb, nest);
1182                 }
1183         }
1184         return 0;
1185
1186 nla_put_failure:
1187         nla_nest_cancel(skb, nest);
1188         return -1;
1189 #else
1190         return 0;
1191 #endif
1192 }
1193 EXPORT_SYMBOL(tcf_exts_dump);
1194
1195
1196 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
1197 {
1198 #ifdef CONFIG_NET_CLS_ACT
1199         struct tc_action *a = tcf_exts_first_act(exts);
1200         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
1201                 return -1;
1202 #endif
1203         return 0;
1204 }
1205 EXPORT_SYMBOL(tcf_exts_dump_stats);
1206
1207 static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts,
1208                                        enum tc_setup_type type,
1209                                        void *type_data, bool err_stop)
1210 {
1211         int ok_count = 0;
1212 #ifdef CONFIG_NET_CLS_ACT
1213         const struct tc_action *a;
1214         struct net_device *dev;
1215         int i, ret;
1216
1217         if (!tcf_exts_has_actions(exts))
1218                 return 0;
1219
1220         for (i = 0; i < exts->nr_actions; i++) {
1221                 a = exts->actions[i];
1222                 if (!a->ops->get_dev)
1223                         continue;
1224                 dev = a->ops->get_dev(a);
1225                 if (!dev)
1226                         continue;
1227                 ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop);
1228                 if (ret < 0)
1229                         return ret;
1230                 ok_count += ret;
1231         }
1232 #endif
1233         return ok_count;
1234 }
1235
1236 int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts,
1237                      enum tc_setup_type type, void *type_data, bool err_stop)
1238 {
1239         int ok_count;
1240         int ret;
1241
1242         ret = tcf_block_cb_call(block, type, type_data, err_stop);
1243         if (ret < 0)
1244                 return ret;
1245         ok_count = ret;
1246
1247         if (!exts || ok_count)
1248                 return ok_count;
1249         ret = tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop);
1250         if (ret < 0)
1251                 return ret;
1252         ok_count += ret;
1253
1254         return ok_count;
1255 }
1256 EXPORT_SYMBOL(tc_setup_cb_call);
1257
1258 static int __init tc_filter_init(void)
1259 {
1260         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
1261         if (!tc_filter_wq)
1262                 return -ENOMEM;
1263
1264         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0);
1265         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0);
1266         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
1267                       tc_dump_tfilter, 0);
1268
1269         return 0;
1270 }
1271
1272 subsys_initcall(tc_filter_init);