net/sched/cls_api.c

   1 /*
   2  * net/sched/cls_api.c  Packet classifier API.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  11  * Changes:
  12  *
  13  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
  14  *
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/string.h>
  21 #include <linux/errno.h>
  22 #include <linux/err.h>
  23 #include <linux/skbuff.h>
  24 #include <linux/init.h>
  25 #include <linux/kmod.h>
  26 #include <linux/slab.h>
  27 #include <net/net_namespace.h>
  28 #include <net/sock.h>
  29 #include <net/netlink.h>
  30 #include <net/pkt_sched.h>
  31 #include <net/pkt_cls.h>
  32
  33 /* The list of all installed classifier types */
  34 static LIST_HEAD(tcf_proto_base);
  35
  36 /* Protects list of registered TC modules. It is pure SMP lock. */
  37 static DEFINE_RWLOCK(cls_mod_lock);
  38
  39 /* Find classifier type by string name */
  40
  41 static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind)
  42 {
  43         const struct tcf_proto_ops *t, *res = NULL;
  44
  45         if (kind) {
  46                 read_lock(&cls_mod_lock);
  47                 list_for_each_entry(t, &tcf_proto_base, head) {
  48                         if (strcmp(kind, t->kind) == 0) {
  49                                 if (try_module_get(t->owner))
  50                                         res = t;
  51                                 break;
  52                         }
  53                 }
  54                 read_unlock(&cls_mod_lock);
  55         }
  56         return res;
  57 }
  58
  59 /* Register(unregister) new classifier type */
  60
  61 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
  62 {
  63         struct tcf_proto_ops *t;
  64         int rc = -EEXIST;
  65
  66         write_lock(&cls_mod_lock);
  67         list_for_each_entry(t, &tcf_proto_base, head)
  68                 if (!strcmp(ops->kind, t->kind))
  69                         goto out;
  70
  71         list_add_tail(&ops->head, &tcf_proto_base);
  72         rc = 0;
  73 out:
  74         write_unlock(&cls_mod_lock);
  75         return rc;
  76 }
  77 EXPORT_SYMBOL(register_tcf_proto_ops);
  78
  79 static struct workqueue_struct *tc_filter_wq;
  80
  81 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
  82 {
  83         struct tcf_proto_ops *t;
  84         int rc = -ENOENT;
  85
  86         /* Wait for outstanding call_rcu()s, if any, from a
  87          * tcf_proto_ops's destroy() handler.
  88          */
  89         rcu_barrier();
  90         flush_workqueue(tc_filter_wq);
  91
  92         write_lock(&cls_mod_lock);
  93         list_for_each_entry(t, &tcf_proto_base, head) {
  94                 if (t == ops) {
  95                         list_del(&t->head);
  96                         rc = 0;
  97                         break;
  98                 }
  99         }
 100         write_unlock(&cls_mod_lock);
 101         return rc;
 102 }
 103 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 104
 105 bool tcf_queue_work(struct work_struct *work)
 106 {
 107         return queue_work(tc_filter_wq, work);
 108 }
 109 EXPORT_SYMBOL(tcf_queue_work);
 110
 111 /* Select new prio value from the range, managed by kernel. */
 112
 113 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 114 {
 115         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 116
 117         if (tp)
 118                 first = tp->prio - 1;
 119
 120         return TC_H_MAJ(first);
 121 }
 122
 123 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 124                                           u32 prio, u32 parent, struct Qdisc *q,
 125                                           struct tcf_chain *chain)
 126 {
 127         struct tcf_proto *tp;
 128         int err;
 129
 130         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 131         if (!tp)
 132                 return ERR_PTR(-ENOBUFS);
 133
 134         err = -ENOENT;
 135         tp->ops = tcf_proto_lookup_ops(kind);
 136         if (!tp->ops) {
 137 #ifdef CONFIG_MODULES
 138                 rtnl_unlock();
 139                 request_module("cls_%s", kind);
 140                 rtnl_lock();
 141                 tp->ops = tcf_proto_lookup_ops(kind);
 142                 /* We dropped the RTNL semaphore in order to perform
 143                  * the module load. So, even if we succeeded in loading
 144                  * the module we have to replay the request. We indicate
 145                  * this using -EAGAIN.
 146                  */
 147                 if (tp->ops) {
 148                         module_put(tp->ops->owner);
 149                         err = -EAGAIN;
 150                 } else {
 151                         err = -ENOENT;
 152                 }
 153                 goto errout;
 154 #endif
 155         }
 156         tp->classify = tp->ops->classify;
 157         tp->protocol = protocol;
 158         tp->prio = prio;
 159         tp->classid = parent;
 160         tp->q = q;
 161         tp->chain = chain;
 162
 163         err = tp->ops->init(tp);
 164         if (err) {
 165                 module_put(tp->ops->owner);
 166                 goto errout;
 167         }
 168         return tp;
 169
 170 errout:
 171         kfree(tp);
 172         return ERR_PTR(err);
 173 }
 174
 175 static void tcf_proto_destroy(struct tcf_proto *tp)
 176 {
 177         tp->ops->destroy(tp);
 178         module_put(tp->ops->owner);
 179         kfree_rcu(tp, rcu);
 180 }
 181
 182 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 183                                           u32 chain_index)
 184 {
 185         struct tcf_chain *chain;
 186
 187         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 188         if (!chain)
 189                 return NULL;
 190         list_add_tail(&chain->list, &block->chain_list);
 191         chain->block = block;
 192         chain->index = chain_index;
 193         chain->refcnt = 1;
 194         return chain;
 195 }
 196
 197 static void tcf_chain_head_change(struct tcf_chain *chain,
 198                                   struct tcf_proto *tp_head)
 199 {
 200         if (chain->chain_head_change)
 201                 chain->chain_head_change(tp_head,
 202                                          chain->chain_head_change_priv);
 203 }
 204
 205 static void tcf_chain_flush(struct tcf_chain *chain)
 206 {
 207         struct tcf_proto *tp = rtnl_dereference(chain->filter_chain);
 208
 209         tcf_chain_head_change(chain, NULL);
 210         while (tp) {
 211                 RCU_INIT_POINTER(chain->filter_chain, tp->next);
 212                 tcf_proto_destroy(tp);
 213                 tp = rtnl_dereference(chain->filter_chain);
 214                 tcf_chain_put(chain);
 215         }
 216 }
 217
 218 static void tcf_chain_destroy(struct tcf_chain *chain)
 219 {
 220         list_del(&chain->list);
 221         kfree(chain);
 222 }
 223
 224 static void tcf_chain_hold(struct tcf_chain *chain)
 225 {
 226         ++chain->refcnt;
 227 }
 228
 229 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 230                                 bool create)
 231 {
 232         struct tcf_chain *chain;
 233
 234         list_for_each_entry(chain, &block->chain_list, list) {
 235                 if (chain->index == chain_index) {
 236                         tcf_chain_hold(chain);
 237                         return chain;
 238                 }
 239         }
 240
 241         return create ? tcf_chain_create(block, chain_index) : NULL;
 242 }
 243 EXPORT_SYMBOL(tcf_chain_get);
 244
 245 void tcf_chain_put(struct tcf_chain *chain)
 246 {
 247         if (--chain->refcnt == 0)
 248                 tcf_chain_destroy(chain);
 249 }
 250 EXPORT_SYMBOL(tcf_chain_put);
 251
 252 static void tcf_block_offload_cmd(struct tcf_block *block, struct Qdisc *q,
 253                                   struct tcf_block_ext_info *ei,
 254                                   enum tc_block_command command)
 255 {
 256         struct net_device *dev = q->dev_queue->dev;
 257         struct tc_block_offload bo = {};
 258
 259         if (!dev->netdev_ops->ndo_setup_tc)
 260                 return;
 261         bo.command = command;
 262         bo.binder_type = ei->binder_type;
 263         bo.block = block;
 264         dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
 265 }
 266
 267 static void tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
 268                                    struct tcf_block_ext_info *ei)
 269 {
 270         tcf_block_offload_cmd(block, q, ei, TC_BLOCK_BIND);
 271 }
 272
 273 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
 274                                      struct tcf_block_ext_info *ei)
 275 {
 276         tcf_block_offload_cmd(block, q, ei, TC_BLOCK_UNBIND);
 277 }
 278
 279 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
 280                       struct tcf_block_ext_info *ei)
 281 {
 282         struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
 283         struct tcf_chain *chain;
 284         int err;
 285
 286         if (!block)
 287                 return -ENOMEM;
 288         INIT_LIST_HEAD(&block->chain_list);
 289         INIT_LIST_HEAD(&block->cb_list);
 290
 291         /* Create chain 0 by default, it has to be always present. */
 292         chain = tcf_chain_create(block, 0);
 293         if (!chain) {
 294                 err = -ENOMEM;
 295                 goto err_chain_create;
 296         }
 297         WARN_ON(!ei->chain_head_change);
 298         chain->chain_head_change = ei->chain_head_change;
 299         chain->chain_head_change_priv = ei->chain_head_change_priv;
 300         block->net = qdisc_net(q);
 301         block->q = q;
 302         tcf_block_offload_bind(block, q, ei);
 303         *p_block = block;
 304         return 0;
 305
 306 err_chain_create:
 307         kfree(block);
 308         return err;
 309 }
 310 EXPORT_SYMBOL(tcf_block_get_ext);
 311
 312 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
 313 {
 314         struct tcf_proto __rcu **p_filter_chain = priv;
 315
 316         rcu_assign_pointer(*p_filter_chain, tp_head);
 317 }
 318
 319 int tcf_block_get(struct tcf_block **p_block,
 320                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q)
 321 {
 322         struct tcf_block_ext_info ei = {
 323                 .chain_head_change = tcf_chain_head_change_dflt,
 324                 .chain_head_change_priv = p_filter_chain,
 325         };
 326
 327         WARN_ON(!p_filter_chain);
 328         return tcf_block_get_ext(p_block, q, &ei);
 329 }
 330 EXPORT_SYMBOL(tcf_block_get);
 331
 332 static void tcf_block_put_final(struct work_struct *work)
 333 {
 334         struct tcf_block *block = container_of(work, struct tcf_block, work);
 335         struct tcf_chain *chain, *tmp;
 336
 337         rtnl_lock();
 338
 339         /* At this point, all the chains should have refcnt == 1. */
 340         list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
 341                 tcf_chain_put(chain);
 342         rtnl_unlock();
 343         kfree(block);
 344 }
 345
 346 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
 347  * actions should be all removed after flushing.
 348  */
 349 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 350                        struct tcf_block_ext_info *ei)
 351 {
 352         struct tcf_chain *chain;
 353
 354         /* Hold a refcnt for all chains, except 0, so that they don't disappear
 355          * while we are iterating.
 356          */
 357         list_for_each_entry(chain, &block->chain_list, list)
 358                 if (chain->index)
 359                         tcf_chain_hold(chain);
 360
 361         list_for_each_entry(chain, &block->chain_list, list)
 362                 tcf_chain_flush(chain);
 363
 364         tcf_block_offload_unbind(block, q, ei);
 365
 366         INIT_WORK(&block->work, tcf_block_put_final);
 367         /* Wait for existing RCU callbacks to cool down, make sure their works
 368          * have been queued before this. We can not flush pending works here
 369          * because we are holding the RTNL lock.
 370          */
 371         rcu_barrier();
 372         tcf_queue_work(&block->work);
 373 }
 374 EXPORT_SYMBOL(tcf_block_put_ext);
 375
 376 void tcf_block_put(struct tcf_block *block)
 377 {
 378         struct tcf_block_ext_info ei = {0, };
 379
 380         if (!block)
 381                 return;
 382         tcf_block_put_ext(block, block->q, &ei);
 383 }
 384
 385 EXPORT_SYMBOL(tcf_block_put);
 386
 387 struct tcf_block_cb {
 388         struct list_head list;
 389         tc_setup_cb_t *cb;
 390         void *cb_ident;
 391         void *cb_priv;
 392         unsigned int refcnt;
 393 };
 394
 395 void *tcf_block_cb_priv(struct tcf_block_cb *block_cb)
 396 {
 397         return block_cb->cb_priv;
 398 }
 399 EXPORT_SYMBOL(tcf_block_cb_priv);
 400
 401 struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block,
 402                                          tc_setup_cb_t *cb, void *cb_ident)
 403 {       struct tcf_block_cb *block_cb;
 404
 405         list_for_each_entry(block_cb, &block->cb_list, list)
 406                 if (block_cb->cb == cb && block_cb->cb_ident == cb_ident)
 407                         return block_cb;
 408         return NULL;
 409 }
 410 EXPORT_SYMBOL(tcf_block_cb_lookup);
 411
 412 void tcf_block_cb_incref(struct tcf_block_cb *block_cb)
 413 {
 414         block_cb->refcnt++;
 415 }
 416 EXPORT_SYMBOL(tcf_block_cb_incref);
 417
 418 unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb)
 419 {
 420         return --block_cb->refcnt;
 421 }
 422 EXPORT_SYMBOL(tcf_block_cb_decref);
 423
 424 struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block,
 425                                              tc_setup_cb_t *cb, void *cb_ident,
 426                                              void *cb_priv)
 427 {
 428         struct tcf_block_cb *block_cb;
 429
 430         block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL);
 431         if (!block_cb)
 432                 return NULL;
 433         block_cb->cb = cb;
 434         block_cb->cb_ident = cb_ident;
 435         block_cb->cb_priv = cb_priv;
 436         list_add(&block_cb->list, &block->cb_list);
 437         return block_cb;
 438 }
 439 EXPORT_SYMBOL(__tcf_block_cb_register);
 440
 441 int tcf_block_cb_register(struct tcf_block *block,
 442                           tc_setup_cb_t *cb, void *cb_ident,
 443                           void *cb_priv)
 444 {
 445         struct tcf_block_cb *block_cb;
 446
 447         block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv);
 448         return block_cb ? 0 : -ENOMEM;
 449 }
 450 EXPORT_SYMBOL(tcf_block_cb_register);
 451
 452 void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb)
 453 {
 454         list_del(&block_cb->list);
 455         kfree(block_cb);
 456 }
 457 EXPORT_SYMBOL(__tcf_block_cb_unregister);
 458
 459 void tcf_block_cb_unregister(struct tcf_block *block,
 460                              tc_setup_cb_t *cb, void *cb_ident)
 461 {
 462         struct tcf_block_cb *block_cb;
 463
 464         block_cb = tcf_block_cb_lookup(block, cb, cb_ident);
 465         if (!block_cb)
 466                 return;
 467         __tcf_block_cb_unregister(block_cb);
 468 }
 469 EXPORT_SYMBOL(tcf_block_cb_unregister);
 470
 471 static int tcf_block_cb_call(struct tcf_block *block, enum tc_setup_type type,
 472                              void *type_data, bool err_stop)
 473 {
 474         struct tcf_block_cb *block_cb;
 475         int ok_count = 0;
 476         int err;
 477
 478         list_for_each_entry(block_cb, &block->cb_list, list) {
 479                 err = block_cb->cb(type, type_data, block_cb->cb_priv);
 480                 if (err) {
 481                         if (err_stop)
 482                                 return err;
 483                 } else {
 484                         ok_count++;
 485                 }
 486         }
 487         return ok_count;
 488 }
 489
 490 /* Main classifier routine: scans classifier chain attached
 491  * to this qdisc, (optionally) tests for protocol and asks
 492  * specific classifiers.
 493  */
 494 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 495                  struct tcf_result *res, bool compat_mode)
 496 {
 497         __be16 protocol = tc_skb_protocol(skb);
 498 #ifdef CONFIG_NET_CLS_ACT
 499         const int max_reclassify_loop = 4;
 500         const struct tcf_proto *orig_tp = tp;
 501         const struct tcf_proto *first_tp;
 502         int limit = 0;
 503
 504 reclassify:
 505 #endif
 506         for (; tp; tp = rcu_dereference_bh(tp->next)) {
 507                 int err;
 508
 509                 if (tp->protocol != protocol &&
 510                     tp->protocol != htons(ETH_P_ALL))
 511                         continue;
 512
 513                 err = tp->classify(skb, tp, res);
 514 #ifdef CONFIG_NET_CLS_ACT
 515                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
 516                         first_tp = orig_tp;
 517                         goto reset;
 518                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
 519                         first_tp = res->goto_tp;
 520                         goto reset;
 521                 }
 522 #endif
 523                 if (err >= 0)
 524                         return err;
 525         }
 526
 527         return TC_ACT_UNSPEC; /* signal: continue lookup */
 528 #ifdef CONFIG_NET_CLS_ACT
 529 reset:
 530         if (unlikely(limit++ >= max_reclassify_loop)) {
 531                 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
 532                                        tp->q->ops->id, tp->prio & 0xffff,
 533                                        ntohs(tp->protocol));
 534                 return TC_ACT_SHOT;
 535         }
 536
 537         tp = first_tp;
 538         protocol = tc_skb_protocol(skb);
 539         goto reclassify;
 540 #endif
 541 }
 542 EXPORT_SYMBOL(tcf_classify);
 543
 544 struct tcf_chain_info {
 545         struct tcf_proto __rcu **pprev;
 546         struct tcf_proto __rcu *next;
 547 };
 548
 549 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)
 550 {
 551         return rtnl_dereference(*chain_info->pprev);
 552 }
 553
 554 static void tcf_chain_tp_insert(struct tcf_chain *chain,
 555                                 struct tcf_chain_info *chain_info,
 556                                 struct tcf_proto *tp)
 557 {
 558         if (*chain_info->pprev == chain->filter_chain)
 559                 tcf_chain_head_change(chain, tp);
 560         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));
 561         rcu_assign_pointer(*chain_info->pprev, tp);
 562         tcf_chain_hold(chain);
 563 }
 564
 565 static void tcf_chain_tp_remove(struct tcf_chain *chain,
 566                                 struct tcf_chain_info *chain_info,
 567                                 struct tcf_proto *tp)
 568 {
 569         struct tcf_proto *next = rtnl_dereference(chain_info->next);
 570
 571         if (tp == chain->filter_chain)
 572                 tcf_chain_head_change(chain, next);
 573         RCU_INIT_POINTER(*chain_info->pprev, next);
 574         tcf_chain_put(chain);
 575 }
 576
 577 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 578                                            struct tcf_chain_info *chain_info,
 579                                            u32 protocol, u32 prio,
 580                                            bool prio_allocate)
 581 {
 582         struct tcf_proto **pprev;
 583         struct tcf_proto *tp;
 584
 585         /* Check the chain for existence of proto-tcf with this priority */
 586         for (pprev = &chain->filter_chain;
 587              (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {
 588                 if (tp->prio >= prio) {
 589                         if (tp->prio == prio) {
 590                                 if (prio_allocate ||
 591                                     (tp->protocol != protocol && protocol))
 592                                         return ERR_PTR(-EINVAL);
 593                         } else {
 594                                 tp = NULL;
 595                         }
 596                         break;
 597                 }
 598         }
 599         chain_info->pprev = pprev;
 600         chain_info->next = tp ? tp->next : NULL;
 601         return tp;
 602 }
 603
 604 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 605                          struct tcf_proto *tp, struct Qdisc *q, u32 parent,
 606                          void *fh, u32 portid, u32 seq, u16 flags, int event)
 607 {
 608         struct tcmsg *tcm;
 609         struct nlmsghdr  *nlh;
 610         unsigned char *b = skb_tail_pointer(skb);
 611
 612         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 613         if (!nlh)
 614                 goto out_nlmsg_trim;
 615         tcm = nlmsg_data(nlh);
 616         tcm->tcm_family = AF_UNSPEC;
 617         tcm->tcm__pad1 = 0;
 618         tcm->tcm__pad2 = 0;
 619         tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
 620         tcm->tcm_parent = parent;
 621         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
 622         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
 623                 goto nla_put_failure;
 624         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
 625                 goto nla_put_failure;
 626         if (!fh) {
 627                 tcm->tcm_handle = 0;
 628         } else {
 629                 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
 630                         goto nla_put_failure;
 631         }
 632         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 633         return skb->len;
 634
 635 out_nlmsg_trim:
 636 nla_put_failure:
 637         nlmsg_trim(skb, b);
 638         return -1;
 639 }
 640
 641 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 642                           struct nlmsghdr *n, struct tcf_proto *tp,
 643                           struct Qdisc *q, u32 parent,
 644                           void *fh, int event, bool unicast)
 645 {
 646         struct sk_buff *skb;
 647         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 648
 649         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 650         if (!skb)
 651                 return -ENOBUFS;
 652
 653         if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq,
 654                           n->nlmsg_flags, event) <= 0) {
 655                 kfree_skb(skb);
 656                 return -EINVAL;
 657         }
 658
 659         if (unicast)
 660                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 661
 662         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 663                               n->nlmsg_flags & NLM_F_ECHO);
 664 }
 665
 666 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 667                               struct nlmsghdr *n, struct tcf_proto *tp,
 668                               struct Qdisc *q, u32 parent,
 669                               void *fh, bool unicast, bool *last)
 670 {
 671         struct sk_buff *skb;
 672         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 673         int err;
 674
 675         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 676         if (!skb)
 677                 return -ENOBUFS;
 678
 679         if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq,
 680                           n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
 681                 kfree_skb(skb);
 682                 return -EINVAL;
 683         }
 684
 685         err = tp->ops->delete(tp, fh, last);
 686         if (err) {
 687                 kfree_skb(skb);
 688                 return err;
 689         }
 690
 691         if (unicast)
 692                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 693
 694         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 695                               n->nlmsg_flags & NLM_F_ECHO);
 696 }
 697
 698 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
 699                                  struct Qdisc *q, u32 parent,
 700                                  struct nlmsghdr *n,
 701                                  struct tcf_chain *chain, int event)
 702 {
 703         struct tcf_proto *tp;
 704
 705         for (tp = rtnl_dereference(chain->filter_chain);
 706              tp; tp = rtnl_dereference(tp->next))
 707                 tfilter_notify(net, oskb, n, tp, q, parent, 0, event, false);
 708 }
 709
 710 /* Add/change/delete/get a filter node */
 711
 712 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 713                           struct netlink_ext_ack *extack)
 714 {
 715         struct net *net = sock_net(skb->sk);
 716         struct nlattr *tca[TCA_MAX + 1];
 717         struct tcmsg *t;
 718         u32 protocol;
 719         u32 prio;
 720         bool prio_allocate;
 721         u32 parent;
 722         u32 chain_index;
 723         struct net_device *dev;
 724         struct Qdisc  *q;
 725         struct tcf_chain_info chain_info;
 726         struct tcf_chain *chain = NULL;
 727         struct tcf_block *block;
 728         struct tcf_proto *tp;
 729         const struct Qdisc_class_ops *cops;
 730         unsigned long cl;
 731         void *fh;
 732         int err;
 733         int tp_created;
 734
 735         if ((n->nlmsg_type != RTM_GETTFILTER) &&
 736             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 737                 return -EPERM;
 738
 739 replay:
 740         tp_created = 0;
 741
 742         err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack);
 743         if (err < 0)
 744                 return err;
 745
 746         t = nlmsg_data(n);
 747         protocol = TC_H_MIN(t->tcm_info);
 748         prio = TC_H_MAJ(t->tcm_info);
 749         prio_allocate = false;
 750         parent = t->tcm_parent;
 751         cl = 0;
 752
 753         if (prio == 0) {
 754                 switch (n->nlmsg_type) {
 755                 case RTM_DELTFILTER:
 756                         if (protocol || t->tcm_handle || tca[TCA_KIND])
 757                                 return -ENOENT;
 758                         break;
 759                 case RTM_NEWTFILTER:
 760                         /* If no priority is provided by the user,
 761                          * we allocate one.
 762                          */
 763                         if (n->nlmsg_flags & NLM_F_CREATE) {
 764                                 prio = TC_H_MAKE(0x80000000U, 0U);
 765                                 prio_allocate = true;
 766                                 break;
 767                         }
 768                         /* fall-through */
 769                 default:
 770                         return -ENOENT;
 771                 }
 772         }
 773
 774         /* Find head of filter chain. */
 775
 776         /* Find link */
 777         dev = __dev_get_by_index(net, t->tcm_ifindex);
 778         if (dev == NULL)
 779                 return -ENODEV;
 780
 781         /* Find qdisc */
 782         if (!parent) {
 783                 q = dev->qdisc;
 784                 parent = q->handle;
 785         } else {
 786                 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
 787                 if (q == NULL)
 788                         return -EINVAL;
 789         }
 790
 791         /* Is it classful? */
 792         cops = q->ops->cl_ops;
 793         if (!cops)
 794                 return -EINVAL;
 795
 796         if (!cops->tcf_block)
 797                 return -EOPNOTSUPP;
 798
 799         /* Do we search for filter, attached to class? */
 800         if (TC_H_MIN(parent)) {
 801                 cl = cops->find(q, parent);
 802                 if (cl == 0)
 803                         return -ENOENT;
 804         }
 805
 806         /* And the last stroke */
 807         block = cops->tcf_block(q, cl);
 808         if (!block) {
 809                 err = -EINVAL;
 810                 goto errout;
 811         }
 812
 813         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
 814         if (chain_index > TC_ACT_EXT_VAL_MASK) {
 815                 err = -EINVAL;
 816                 goto errout;
 817         }
 818         chain = tcf_chain_get(block, chain_index,
 819                               n->nlmsg_type == RTM_NEWTFILTER);
 820         if (!chain) {
 821                 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL;
 822                 goto errout;
 823         }
 824
 825         if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
 826                 tfilter_notify_chain(net, skb, q, parent, n,
 827                                      chain, RTM_DELTFILTER);
 828                 tcf_chain_flush(chain);
 829                 err = 0;
 830                 goto errout;
 831         }
 832
 833         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 834                                prio, prio_allocate);
 835         if (IS_ERR(tp)) {
 836                 err = PTR_ERR(tp);
 837                 goto errout;
 838         }
 839
 840         if (tp == NULL) {
 841                 /* Proto-tcf does not exist, create new one */
 842
 843                 if (tca[TCA_KIND] == NULL || !protocol) {
 844                         err = -EINVAL;
 845                         goto errout;
 846                 }
 847
 848                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 849                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 850                         err = -ENOENT;
 851                         goto errout;
 852                 }
 853
 854                 if (prio_allocate)
 855                         prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
 856
 857                 tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
 858                                       protocol, prio, parent, q, chain);
 859                 if (IS_ERR(tp)) {
 860                         err = PTR_ERR(tp);
 861                         goto errout;
 862                 }
 863                 tp_created = 1;
 864         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
 865                 err = -EINVAL;
 866                 goto errout;
 867         }
 868
 869         fh = tp->ops->get(tp, t->tcm_handle);
 870
 871         if (!fh) {
 872                 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
 873                         tcf_chain_tp_remove(chain, &chain_info, tp);
 874                         tfilter_notify(net, skb, n, tp, q, parent, fh,
 875                                        RTM_DELTFILTER, false);
 876                         tcf_proto_destroy(tp);
 877                         err = 0;
 878                         goto errout;
 879                 }
 880
 881                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 882                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 883                         err = -ENOENT;
 884                         goto errout;
 885                 }
 886         } else {
 887                 bool last;
 888
 889                 switch (n->nlmsg_type) {
 890                 case RTM_NEWTFILTER:
 891                         if (n->nlmsg_flags & NLM_F_EXCL) {
 892                                 if (tp_created)
 893                                         tcf_proto_destroy(tp);
 894                                 err = -EEXIST;
 895                                 goto errout;
 896                         }
 897                         break;
 898                 case RTM_DELTFILTER:
 899                         err = tfilter_del_notify(net, skb, n, tp, q, parent,
 900                                                  fh, false, &last);
 901                         if (err)
 902                                 goto errout;
 903                         if (last) {
 904                                 tcf_chain_tp_remove(chain, &chain_info, tp);
 905                                 tcf_proto_destroy(tp);
 906                         }
 907                         goto errout;
 908                 case RTM_GETTFILTER:
 909                         err = tfilter_notify(net, skb, n, tp, q, parent, fh,
 910                                              RTM_NEWTFILTER, true);
 911                         goto errout;
 912                 default:
 913                         err = -EINVAL;
 914                         goto errout;
 915                 }
 916         }
 917
 918         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 919                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
 920         if (err == 0) {
 921                 if (tp_created)
 922                         tcf_chain_tp_insert(chain, &chain_info, tp);
 923                 tfilter_notify(net, skb, n, tp, q, parent, fh,
 924                                RTM_NEWTFILTER, false);
 925         } else {
 926                 if (tp_created)
 927                         tcf_proto_destroy(tp);
 928         }
 929
 930 errout:
 931         if (chain)
 932                 tcf_chain_put(chain);
 933         if (err == -EAGAIN)
 934                 /* Replay the request. */
 935                 goto replay;
 936         return err;
 937 }
 938
 939 struct tcf_dump_args {
 940         struct tcf_walker w;
 941         struct sk_buff *skb;
 942         struct netlink_callback *cb;
 943         struct Qdisc *q;
 944         u32 parent;
 945 };
 946
 947 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
 948 {
 949         struct tcf_dump_args *a = (void *)arg;
 950         struct net *net = sock_net(a->skb->sk);
 951
 952         return tcf_fill_node(net, a->skb, tp, a->q, a->parent,
 953                              n, NETLINK_CB(a->cb->skb).portid,
 954                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
 955                              RTM_NEWTFILTER);
 956 }
 957
 958 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 959                            struct sk_buff *skb, struct netlink_callback *cb,
 960                            long index_start, long *p_index)
 961 {
 962         struct net *net = sock_net(skb->sk);
 963         struct tcmsg *tcm = nlmsg_data(cb->nlh);
 964         struct tcf_dump_args arg;
 965         struct tcf_proto *tp;
 966
 967         for (tp = rtnl_dereference(chain->filter_chain);
 968              tp; tp = rtnl_dereference(tp->next), (*p_index)++) {
 969                 if (*p_index < index_start)
 970                         continue;
 971                 if (TC_H_MAJ(tcm->tcm_info) &&
 972                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
 973                         continue;
 974                 if (TC_H_MIN(tcm->tcm_info) &&
 975                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
 976                         continue;
 977                 if (*p_index > index_start)
 978                         memset(&cb->args[1], 0,
 979                                sizeof(cb->args) - sizeof(cb->args[0]));
 980                 if (cb->args[1] == 0) {
 981                         if (tcf_fill_node(net, skb, tp, q, parent, 0,
 982                                           NETLINK_CB(cb->skb).portid,
 983                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
 984                                           RTM_NEWTFILTER) <= 0)
 985                                 return false;
 986
 987                         cb->args[1] = 1;
 988                 }
 989                 if (!tp->ops->walk)
 990                         continue;
 991                 arg.w.fn = tcf_node_dump;
 992                 arg.skb = skb;
 993                 arg.cb = cb;
 994                 arg.q = q;
 995                 arg.parent = parent;
 996                 arg.w.stop = 0;
 997                 arg.w.skip = cb->args[1] - 1;
 998                 arg.w.count = 0;
 999                 tp->ops->walk(tp, &arg.w);
1000                 cb->args[1] = arg.w.count + 1;
1001                 if (arg.w.stop)
1002                         return false;
1003         }
1004         return true;
1005 }
1006
1007 /* called with RTNL */
1008 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
1009 {
1010         struct net *net = sock_net(skb->sk);
1011         struct nlattr *tca[TCA_MAX + 1];
1012         struct net_device *dev;
1013         struct Qdisc *q;
1014         struct tcf_block *block;
1015         struct tcf_chain *chain;
1016         struct tcmsg *tcm = nlmsg_data(cb->nlh);
1017         unsigned long cl = 0;
1018         const struct Qdisc_class_ops *cops;
1019         long index_start;
1020         long index;
1021         u32 parent;
1022         int err;
1023
1024         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
1025                 return skb->len;
1026
1027         err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL);
1028         if (err)
1029                 return err;
1030
1031         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
1032         if (!dev)
1033                 return skb->len;
1034
1035         parent = tcm->tcm_parent;
1036         if (!parent) {
1037                 q = dev->qdisc;
1038                 parent = q->handle;
1039         } else {
1040                 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
1041         }
1042         if (!q)
1043                 goto out;
1044         cops = q->ops->cl_ops;
1045         if (!cops)
1046                 goto out;
1047         if (!cops->tcf_block)
1048                 goto out;
1049         if (TC_H_MIN(tcm->tcm_parent)) {
1050                 cl = cops->find(q, tcm->tcm_parent);
1051                 if (cl == 0)
1052                         goto out;
1053         }
1054         block = cops->tcf_block(q, cl);
1055         if (!block)
1056                 goto out;
1057
1058         index_start = cb->args[0];
1059         index = 0;
1060
1061         list_for_each_entry(chain, &block->chain_list, list) {
1062                 if (tca[TCA_CHAIN] &&
1063                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
1064                         continue;
1065                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
1066                                     index_start, &index))
1067                         break;
1068         }
1069
1070         cb->args[0] = index;
1071
1072 out:
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                 exts->net = net;
1121         }
1122 #else
1123         if ((exts->action && tb[exts->action]) ||
1124             (exts->police && tb[exts->police]))
1125                 return -EOPNOTSUPP;
1126 #endif
1127
1128         return 0;
1129 }
1130 EXPORT_SYMBOL(tcf_exts_validate);
1131
1132 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
1133 {
1134 #ifdef CONFIG_NET_CLS_ACT
1135         struct tcf_exts old = *dst;
1136
1137         *dst = *src;
1138         tcf_exts_destroy(&old);
1139 #endif
1140 }
1141 EXPORT_SYMBOL(tcf_exts_change);
1142
1143 #ifdef CONFIG_NET_CLS_ACT
1144 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
1145 {
1146         if (exts->nr_actions == 0)
1147                 return NULL;
1148         else
1149                 return exts->actions[0];
1150 }
1151 #endif
1152
1153 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
1154 {
1155 #ifdef CONFIG_NET_CLS_ACT
1156         struct nlattr *nest;
1157
1158         if (exts->action && tcf_exts_has_actions(exts)) {
1159                 /*
1160                  * again for backward compatible mode - we want
1161                  * to work with both old and new modes of entering
1162                  * tc data even if iproute2  was newer - jhs
1163                  */
1164                 if (exts->type != TCA_OLD_COMPAT) {
1165                         LIST_HEAD(actions);
1166
1167                         nest = nla_nest_start(skb, exts->action);
1168                         if (nest == NULL)
1169                                 goto nla_put_failure;
1170
1171                         tcf_exts_to_list(exts, &actions);
1172                         if (tcf_action_dump(skb, &actions, 0, 0) < 0)
1173                                 goto nla_put_failure;
1174                         nla_nest_end(skb, nest);
1175                 } else if (exts->police) {
1176                         struct tc_action *act = tcf_exts_first_act(exts);
1177                         nest = nla_nest_start(skb, exts->police);
1178                         if (nest == NULL || !act)
1179                                 goto nla_put_failure;
1180                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
1181                                 goto nla_put_failure;
1182                         nla_nest_end(skb, nest);
1183                 }
1184         }
1185         return 0;
1186
1187 nla_put_failure:
1188         nla_nest_cancel(skb, nest);
1189         return -1;
1190 #else
1191         return 0;
1192 #endif
1193 }
1194 EXPORT_SYMBOL(tcf_exts_dump);
1195
1196
1197 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
1198 {
1199 #ifdef CONFIG_NET_CLS_ACT
1200         struct tc_action *a = tcf_exts_first_act(exts);
1201         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
1202                 return -1;
1203 #endif
1204         return 0;
1205 }
1206 EXPORT_SYMBOL(tcf_exts_dump_stats);
1207
1208 static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts,
1209                                        enum tc_setup_type type,
1210                                        void *type_data, bool err_stop)
1211 {
1212         int ok_count = 0;
1213 #ifdef CONFIG_NET_CLS_ACT
1214         const struct tc_action *a;
1215         struct net_device *dev;
1216         int i, ret;
1217
1218         if (!tcf_exts_has_actions(exts))
1219                 return 0;
1220
1221         for (i = 0; i < exts->nr_actions; i++) {
1222                 a = exts->actions[i];
1223                 if (!a->ops->get_dev)
1224                         continue;
1225                 dev = a->ops->get_dev(a);
1226                 if (!dev)
1227                         continue;
1228                 ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop);
1229                 if (ret < 0)
1230                         return ret;
1231                 ok_count += ret;
1232         }
1233 #endif
1234         return ok_count;
1235 }
1236
1237 int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts,
1238                      enum tc_setup_type type, void *type_data, bool err_stop)
1239 {
1240         int ok_count;
1241         int ret;
1242
1243         ret = tcf_block_cb_call(block, type, type_data, err_stop);
1244         if (ret < 0)
1245                 return ret;
1246         ok_count = ret;
1247
1248         if (!exts)
1249                 return ok_count;
1250         ret = tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop);
1251         if (ret < 0)
1252                 return ret;
1253         ok_count += ret;
1254
1255         return ok_count;
1256 }
1257 EXPORT_SYMBOL(tc_setup_cb_call);
1258
1259 static int __init tc_filter_init(void)
1260 {
1261         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
1262         if (!tc_filter_wq)
1263                 return -ENOMEM;
1264
1265         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0);
1266         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0);
1267         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
1268                       tc_dump_tfilter, 0);
1269
1270         return 0;
1271 }
1272
1273 subsys_initcall(tc_filter_init);