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/err.h>
  27 #include <linux/slab.h>
  28 #include <net/net_namespace.h>
  29 #include <net/sock.h>
  30 #include <net/netlink.h>
  31 #include <net/pkt_sched.h>
  32 #include <net/pkt_cls.h>
  33
  34 /* The list of all installed classifier types */
  35 static LIST_HEAD(tcf_proto_base);
  36
  37 /* Protects list of registered TC modules. It is pure SMP lock. */
  38 static DEFINE_RWLOCK(cls_mod_lock);
  39
  40 /* Find classifier type by string name */
  41
  42 static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind)
  43 {
  44         const struct tcf_proto_ops *t, *res = NULL;
  45
  46         if (kind) {
  47                 read_lock(&cls_mod_lock);
  48                 list_for_each_entry(t, &tcf_proto_base, head) {
  49                         if (strcmp(kind, t->kind) == 0) {
  50                                 if (try_module_get(t->owner))
  51                                         res = t;
  52                                 break;
  53                         }
  54                 }
  55                 read_unlock(&cls_mod_lock);
  56         }
  57         return res;
  58 }
  59
  60 /* Register(unregister) new classifier type */
  61
  62 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
  63 {
  64         struct tcf_proto_ops *t;
  65         int rc = -EEXIST;
  66
  67         write_lock(&cls_mod_lock);
  68         list_for_each_entry(t, &tcf_proto_base, head)
  69                 if (!strcmp(ops->kind, t->kind))
  70                         goto out;
  71
  72         list_add_tail(&ops->head, &tcf_proto_base);
  73         rc = 0;
  74 out:
  75         write_unlock(&cls_mod_lock);
  76         return rc;
  77 }
  78 EXPORT_SYMBOL(register_tcf_proto_ops);
  79
  80 static struct workqueue_struct *tc_filter_wq;
  81
  82 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
  83 {
  84         struct tcf_proto_ops *t;
  85         int rc = -ENOENT;
  86
  87         /* Wait for outstanding call_rcu()s, if any, from a
  88          * tcf_proto_ops's destroy() handler.
  89          */
  90         rcu_barrier();
  91         flush_workqueue(tc_filter_wq);
  92
  93         write_lock(&cls_mod_lock);
  94         list_for_each_entry(t, &tcf_proto_base, head) {
  95                 if (t == ops) {
  96                         list_del(&t->head);
  97                         rc = 0;
  98                         break;
  99                 }
 100         }
 101         write_unlock(&cls_mod_lock);
 102         return rc;
 103 }
 104 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 105
 106 bool tcf_queue_work(struct work_struct *work)
 107 {
 108         return queue_work(tc_filter_wq, work);
 109 }
 110 EXPORT_SYMBOL(tcf_queue_work);
 111
 112 /* Select new prio value from the range, managed by kernel. */
 113
 114 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 115 {
 116         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 117
 118         if (tp)
 119                 first = tp->prio - 1;
 120
 121         return TC_H_MAJ(first);
 122 }
 123
 124 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 125                                           u32 prio, u32 parent, struct Qdisc *q,
 126                                           struct tcf_chain *chain)
 127 {
 128         struct tcf_proto *tp;
 129         int err;
 130
 131         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 132         if (!tp)
 133                 return ERR_PTR(-ENOBUFS);
 134
 135         err = -ENOENT;
 136         tp->ops = tcf_proto_lookup_ops(kind);
 137         if (!tp->ops) {
 138 #ifdef CONFIG_MODULES
 139                 rtnl_unlock();
 140                 request_module("cls_%s", kind);
 141                 rtnl_lock();
 142                 tp->ops = tcf_proto_lookup_ops(kind);
 143                 /* We dropped the RTNL semaphore in order to perform
 144                  * the module load. So, even if we succeeded in loading
 145                  * the module we have to replay the request. We indicate
 146                  * this using -EAGAIN.
 147                  */
 148                 if (tp->ops) {
 149                         module_put(tp->ops->owner);
 150                         err = -EAGAIN;
 151                 } else {
 152                         err = -ENOENT;
 153                 }
 154                 goto errout;
 155 #endif
 156         }
 157         tp->classify = tp->ops->classify;
 158         tp->protocol = protocol;
 159         tp->prio = prio;
 160         tp->classid = parent;
 161         tp->q = q;
 162         tp->chain = chain;
 163
 164         err = tp->ops->init(tp);
 165         if (err) {
 166                 module_put(tp->ops->owner);
 167                 goto errout;
 168         }
 169         return tp;
 170
 171 errout:
 172         kfree(tp);
 173         return ERR_PTR(err);
 174 }
 175
 176 static void tcf_proto_destroy(struct tcf_proto *tp)
 177 {
 178         tp->ops->destroy(tp);
 179         module_put(tp->ops->owner);
 180         kfree_rcu(tp, rcu);
 181 }
 182
 183 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 184                                           u32 chain_index)
 185 {
 186         struct tcf_chain *chain;
 187
 188         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 189         if (!chain)
 190                 return NULL;
 191         list_add_tail(&chain->list, &block->chain_list);
 192         chain->block = block;
 193         chain->index = chain_index;
 194         chain->refcnt = 1;
 195         return chain;
 196 }
 197
 198 static void tcf_chain_flush(struct tcf_chain *chain)
 199 {
 200         struct tcf_proto *tp;
 201
 202         if (chain->p_filter_chain)
 203                 RCU_INIT_POINTER(*chain->p_filter_chain, NULL);
 204         while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) {
 205                 RCU_INIT_POINTER(chain->filter_chain, tp->next);
 206                 tcf_chain_put(chain);
 207                 tcf_proto_destroy(tp);
 208         }
 209 }
 210
 211 static void tcf_chain_destroy(struct tcf_chain *chain)
 212 {
 213         list_del(&chain->list);
 214         kfree(chain);
 215 }
 216
 217 static void tcf_chain_hold(struct tcf_chain *chain)
 218 {
 219         ++chain->refcnt;
 220 }
 221
 222 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 223                                 bool create)
 224 {
 225         struct tcf_chain *chain;
 226
 227         list_for_each_entry(chain, &block->chain_list, list) {
 228                 if (chain->index == chain_index) {
 229                         tcf_chain_hold(chain);
 230                         return chain;
 231                 }
 232         }
 233
 234         return create ? tcf_chain_create(block, chain_index) : NULL;
 235 }
 236 EXPORT_SYMBOL(tcf_chain_get);
 237
 238 void tcf_chain_put(struct tcf_chain *chain)
 239 {
 240         if (--chain->refcnt == 0)
 241                 tcf_chain_destroy(chain);
 242 }
 243 EXPORT_SYMBOL(tcf_chain_put);
 244
 245 static void
 246 tcf_chain_filter_chain_ptr_set(struct tcf_chain *chain,
 247                                struct tcf_proto __rcu **p_filter_chain)
 248 {
 249         chain->p_filter_chain = p_filter_chain;
 250 }
 251
 252 int tcf_block_get(struct tcf_block **p_block,
 253                   struct tcf_proto __rcu **p_filter_chain)
 254 {
 255         struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
 256         struct tcf_chain *chain;
 257         int err;
 258
 259         if (!block)
 260                 return -ENOMEM;
 261         INIT_LIST_HEAD(&block->chain_list);
 262         /* Create chain 0 by default, it has to be always present. */
 263         chain = tcf_chain_create(block, 0);
 264         if (!chain) {
 265                 err = -ENOMEM;
 266                 goto err_chain_create;
 267         }
 268         tcf_chain_filter_chain_ptr_set(chain, p_filter_chain);
 269         *p_block = block;
 270         return 0;
 271
 272 err_chain_create:
 273         kfree(block);
 274         return err;
 275 }
 276 EXPORT_SYMBOL(tcf_block_get);
 277
 278 static void tcf_block_put_final(struct work_struct *work)
 279 {
 280         struct tcf_block *block = container_of(work, struct tcf_block, work);
 281         struct tcf_chain *chain, *tmp;
 282
 283         rtnl_lock();
 284         /* Only chain 0 should be still here. */
 285         list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
 286                 tcf_chain_put(chain);
 287         rtnl_unlock();
 288         kfree(block);
 289 }
 290
 291 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
 292  * actions should be all removed after flushing. However, filters are now
 293  * destroyed in tc filter workqueue with RTNL lock, they can not race here.
 294  */
 295 void tcf_block_put(struct tcf_block *block)
 296 {
 297         struct tcf_chain *chain, *tmp;
 298
 299         if (!block)
 300                 return;
 301
 302         list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
 303                 tcf_chain_flush(chain);
 304
 305         INIT_WORK(&block->work, tcf_block_put_final);
 306         /* Wait for RCU callbacks to release the reference count and make
 307          * sure their works have been queued before this.
 308          */
 309         rcu_barrier();
 310         tcf_queue_work(&block->work);
 311 }
 312 EXPORT_SYMBOL(tcf_block_put);
 313
 314 /* Main classifier routine: scans classifier chain attached
 315  * to this qdisc, (optionally) tests for protocol and asks
 316  * specific classifiers.
 317  */
 318 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 319                  struct tcf_result *res, bool compat_mode)
 320 {
 321         __be16 protocol = tc_skb_protocol(skb);
 322 #ifdef CONFIG_NET_CLS_ACT
 323         const int max_reclassify_loop = 4;
 324         const struct tcf_proto *orig_tp = tp;
 325         const struct tcf_proto *first_tp;
 326         int limit = 0;
 327
 328 reclassify:
 329 #endif
 330         for (; tp; tp = rcu_dereference_bh(tp->next)) {
 331                 int err;
 332
 333                 if (tp->protocol != protocol &&
 334                     tp->protocol != htons(ETH_P_ALL))
 335                         continue;
 336
 337                 err = tp->classify(skb, tp, res);
 338 #ifdef CONFIG_NET_CLS_ACT
 339                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
 340                         first_tp = orig_tp;
 341                         goto reset;
 342                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
 343                         first_tp = res->goto_tp;
 344                         goto reset;
 345                 }
 346 #endif
 347                 if (err >= 0)
 348                         return err;
 349         }
 350
 351         return TC_ACT_UNSPEC; /* signal: continue lookup */
 352 #ifdef CONFIG_NET_CLS_ACT
 353 reset:
 354         if (unlikely(limit++ >= max_reclassify_loop)) {
 355                 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
 356                                        tp->q->ops->id, tp->prio & 0xffff,
 357                                        ntohs(tp->protocol));
 358                 return TC_ACT_SHOT;
 359         }
 360
 361         tp = first_tp;
 362         protocol = tc_skb_protocol(skb);
 363         goto reclassify;
 364 #endif
 365 }
 366 EXPORT_SYMBOL(tcf_classify);
 367
 368 struct tcf_chain_info {
 369         struct tcf_proto __rcu **pprev;
 370         struct tcf_proto __rcu *next;
 371 };
 372
 373 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)
 374 {
 375         return rtnl_dereference(*chain_info->pprev);
 376 }
 377
 378 static void tcf_chain_tp_insert(struct tcf_chain *chain,
 379                                 struct tcf_chain_info *chain_info,
 380                                 struct tcf_proto *tp)
 381 {
 382         if (chain->p_filter_chain &&
 383             *chain_info->pprev == chain->filter_chain)
 384                 rcu_assign_pointer(*chain->p_filter_chain, tp);
 385         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));
 386         rcu_assign_pointer(*chain_info->pprev, tp);
 387         tcf_chain_hold(chain);
 388 }
 389
 390 static void tcf_chain_tp_remove(struct tcf_chain *chain,
 391                                 struct tcf_chain_info *chain_info,
 392                                 struct tcf_proto *tp)
 393 {
 394         struct tcf_proto *next = rtnl_dereference(chain_info->next);
 395
 396         if (chain->p_filter_chain && tp == chain->filter_chain)
 397                 RCU_INIT_POINTER(*chain->p_filter_chain, next);
 398         RCU_INIT_POINTER(*chain_info->pprev, next);
 399         tcf_chain_put(chain);
 400 }
 401
 402 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 403                                            struct tcf_chain_info *chain_info,
 404                                            u32 protocol, u32 prio,
 405                                            bool prio_allocate)
 406 {
 407         struct tcf_proto **pprev;
 408         struct tcf_proto *tp;
 409
 410         /* Check the chain for existence of proto-tcf with this priority */
 411         for (pprev = &chain->filter_chain;
 412              (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {
 413                 if (tp->prio >= prio) {
 414                         if (tp->prio == prio) {
 415                                 if (prio_allocate ||
 416                                     (tp->protocol != protocol && protocol))
 417                                         return ERR_PTR(-EINVAL);
 418                         } else {
 419                                 tp = NULL;
 420                         }
 421                         break;
 422                 }
 423         }
 424         chain_info->pprev = pprev;
 425         chain_info->next = tp ? tp->next : NULL;
 426         return tp;
 427 }
 428
 429 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 430                          struct tcf_proto *tp, void *fh, u32 portid,
 431                          u32 seq, u16 flags, int event)
 432 {
 433         struct tcmsg *tcm;
 434         struct nlmsghdr  *nlh;
 435         unsigned char *b = skb_tail_pointer(skb);
 436
 437         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 438         if (!nlh)
 439                 goto out_nlmsg_trim;
 440         tcm = nlmsg_data(nlh);
 441         tcm->tcm_family = AF_UNSPEC;
 442         tcm->tcm__pad1 = 0;
 443         tcm->tcm__pad2 = 0;
 444         tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex;
 445         tcm->tcm_parent = tp->classid;
 446         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
 447         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
 448                 goto nla_put_failure;
 449         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
 450                 goto nla_put_failure;
 451         if (!fh) {
 452                 tcm->tcm_handle = 0;
 453         } else {
 454                 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
 455                         goto nla_put_failure;
 456         }
 457         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 458         return skb->len;
 459
 460 out_nlmsg_trim:
 461 nla_put_failure:
 462         nlmsg_trim(skb, b);
 463         return -1;
 464 }
 465
 466 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 467                           struct nlmsghdr *n, struct tcf_proto *tp,
 468                           void *fh, int event, bool unicast)
 469 {
 470         struct sk_buff *skb;
 471         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 472
 473         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 474         if (!skb)
 475                 return -ENOBUFS;
 476
 477         if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq,
 478                           n->nlmsg_flags, event) <= 0) {
 479                 kfree_skb(skb);
 480                 return -EINVAL;
 481         }
 482
 483         if (unicast)
 484                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 485
 486         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 487                               n->nlmsg_flags & NLM_F_ECHO);
 488 }
 489
 490 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 491                               struct nlmsghdr *n, struct tcf_proto *tp,
 492                               void *fh, bool unicast, bool *last)
 493 {
 494         struct sk_buff *skb;
 495         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 496         int err;
 497
 498         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 499         if (!skb)
 500                 return -ENOBUFS;
 501
 502         if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq,
 503                           n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
 504                 kfree_skb(skb);
 505                 return -EINVAL;
 506         }
 507
 508         err = tp->ops->delete(tp, fh, last);
 509         if (err) {
 510                 kfree_skb(skb);
 511                 return err;
 512         }
 513
 514         if (unicast)
 515                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 516
 517         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 518                               n->nlmsg_flags & NLM_F_ECHO);
 519 }
 520
 521 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
 522                                  struct nlmsghdr *n,
 523                                  struct tcf_chain *chain, int event)
 524 {
 525         struct tcf_proto *tp;
 526
 527         for (tp = rtnl_dereference(chain->filter_chain);
 528              tp; tp = rtnl_dereference(tp->next))
 529                 tfilter_notify(net, oskb, n, tp, 0, event, false);
 530 }
 531
 532 /* Add/change/delete/get a filter node */
 533
 534 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 535                           struct netlink_ext_ack *extack)
 536 {
 537         struct net *net = sock_net(skb->sk);
 538         struct nlattr *tca[TCA_MAX + 1];
 539         struct tcmsg *t;
 540         u32 protocol;
 541         u32 prio;
 542         bool prio_allocate;
 543         u32 parent;
 544         u32 chain_index;
 545         struct net_device *dev;
 546         struct Qdisc  *q;
 547         struct tcf_chain_info chain_info;
 548         struct tcf_chain *chain = NULL;
 549         struct tcf_block *block;
 550         struct tcf_proto *tp;
 551         const struct Qdisc_class_ops *cops;
 552         unsigned long cl;
 553         void *fh;
 554         int err;
 555         int tp_created;
 556
 557         if ((n->nlmsg_type != RTM_GETTFILTER) &&
 558             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 559                 return -EPERM;
 560
 561 replay:
 562         tp_created = 0;
 563
 564         err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack);
 565         if (err < 0)
 566                 return err;
 567
 568         t = nlmsg_data(n);
 569         protocol = TC_H_MIN(t->tcm_info);
 570         prio = TC_H_MAJ(t->tcm_info);
 571         prio_allocate = false;
 572         parent = t->tcm_parent;
 573         cl = 0;
 574
 575         if (prio == 0) {
 576                 switch (n->nlmsg_type) {
 577                 case RTM_DELTFILTER:
 578                         if (protocol || t->tcm_handle || tca[TCA_KIND])
 579                                 return -ENOENT;
 580                         break;
 581                 case RTM_NEWTFILTER:
 582                         /* If no priority is provided by the user,
 583                          * we allocate one.
 584                          */
 585                         if (n->nlmsg_flags & NLM_F_CREATE) {
 586                                 prio = TC_H_MAKE(0x80000000U, 0U);
 587                                 prio_allocate = true;
 588                                 break;
 589                         }
 590                         /* fall-through */
 591                 default:
 592                         return -ENOENT;
 593                 }
 594         }
 595
 596         /* Find head of filter chain. */
 597
 598         /* Find link */
 599         dev = __dev_get_by_index(net, t->tcm_ifindex);
 600         if (dev == NULL)
 601                 return -ENODEV;
 602
 603         /* Find qdisc */
 604         if (!parent) {
 605                 q = dev->qdisc;
 606                 parent = q->handle;
 607         } else {
 608                 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
 609                 if (q == NULL)
 610                         return -EINVAL;
 611         }
 612
 613         /* Is it classful? */
 614         cops = q->ops->cl_ops;
 615         if (!cops)
 616                 return -EINVAL;
 617
 618         if (!cops->tcf_block)
 619                 return -EOPNOTSUPP;
 620
 621         /* Do we search for filter, attached to class? */
 622         if (TC_H_MIN(parent)) {
 623                 cl = cops->find(q, parent);
 624                 if (cl == 0)
 625                         return -ENOENT;
 626         }
 627
 628         /* And the last stroke */
 629         block = cops->tcf_block(q, cl);
 630         if (!block) {
 631                 err = -EINVAL;
 632                 goto errout;
 633         }
 634
 635         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
 636         if (chain_index > TC_ACT_EXT_VAL_MASK) {
 637                 err = -EINVAL;
 638                 goto errout;
 639         }
 640         chain = tcf_chain_get(block, chain_index,
 641                               n->nlmsg_type == RTM_NEWTFILTER);
 642         if (!chain) {
 643                 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL;
 644                 goto errout;
 645         }
 646
 647         if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
 648                 tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER);
 649                 tcf_chain_flush(chain);
 650                 err = 0;
 651                 goto errout;
 652         }
 653
 654         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 655                                prio, prio_allocate);
 656         if (IS_ERR(tp)) {
 657                 err = PTR_ERR(tp);
 658                 goto errout;
 659         }
 660
 661         if (tp == NULL) {
 662                 /* Proto-tcf does not exist, create new one */
 663
 664                 if (tca[TCA_KIND] == NULL || !protocol) {
 665                         err = -EINVAL;
 666                         goto errout;
 667                 }
 668
 669                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 670                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 671                         err = -ENOENT;
 672                         goto errout;
 673                 }
 674
 675                 if (prio_allocate)
 676                         prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
 677
 678                 tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
 679                                       protocol, prio, parent, q, chain);
 680                 if (IS_ERR(tp)) {
 681                         err = PTR_ERR(tp);
 682                         goto errout;
 683                 }
 684                 tp_created = 1;
 685         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
 686                 err = -EINVAL;
 687                 goto errout;
 688         }
 689
 690         fh = tp->ops->get(tp, t->tcm_handle);
 691
 692         if (!fh) {
 693                 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
 694                         tcf_chain_tp_remove(chain, &chain_info, tp);
 695                         tfilter_notify(net, skb, n, tp, fh,
 696                                        RTM_DELTFILTER, false);
 697                         tcf_proto_destroy(tp);
 698                         err = 0;
 699                         goto errout;
 700                 }
 701
 702                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 703                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 704                         err = -ENOENT;
 705                         goto errout;
 706                 }
 707         } else {
 708                 bool last;
 709
 710                 switch (n->nlmsg_type) {
 711                 case RTM_NEWTFILTER:
 712                         if (n->nlmsg_flags & NLM_F_EXCL) {
 713                                 if (tp_created)
 714                                         tcf_proto_destroy(tp);
 715                                 err = -EEXIST;
 716                                 goto errout;
 717                         }
 718                         break;
 719                 case RTM_DELTFILTER:
 720                         err = tfilter_del_notify(net, skb, n, tp, fh, false,
 721                                                  &last);
 722                         if (err)
 723                                 goto errout;
 724                         if (last) {
 725                                 tcf_chain_tp_remove(chain, &chain_info, tp);
 726                                 tcf_proto_destroy(tp);
 727                         }
 728                         goto errout;
 729                 case RTM_GETTFILTER:
 730                         err = tfilter_notify(net, skb, n, tp, fh,
 731                                              RTM_NEWTFILTER, true);
 732                         goto errout;
 733                 default:
 734                         err = -EINVAL;
 735                         goto errout;
 736                 }
 737         }
 738
 739         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 740                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
 741         if (err == 0) {
 742                 if (tp_created)
 743                         tcf_chain_tp_insert(chain, &chain_info, tp);
 744                 tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER, false);
 745         } else {
 746                 if (tp_created)
 747                         tcf_proto_destroy(tp);
 748         }
 749
 750 errout:
 751         if (chain)
 752                 tcf_chain_put(chain);
 753         if (err == -EAGAIN)
 754                 /* Replay the request. */
 755                 goto replay;
 756         return err;
 757 }
 758
 759 struct tcf_dump_args {
 760         struct tcf_walker w;
 761         struct sk_buff *skb;
 762         struct netlink_callback *cb;
 763 };
 764
 765 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
 766 {
 767         struct tcf_dump_args *a = (void *)arg;
 768         struct net *net = sock_net(a->skb->sk);
 769
 770         return tcf_fill_node(net, a->skb, tp, n, NETLINK_CB(a->cb->skb).portid,
 771                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
 772                              RTM_NEWTFILTER);
 773 }
 774
 775 static bool tcf_chain_dump(struct tcf_chain *chain, struct sk_buff *skb,
 776                            struct netlink_callback *cb,
 777                            long index_start, long *p_index)
 778 {
 779         struct net *net = sock_net(skb->sk);
 780         struct tcmsg *tcm = nlmsg_data(cb->nlh);
 781         struct tcf_dump_args arg;
 782         struct tcf_proto *tp;
 783
 784         for (tp = rtnl_dereference(chain->filter_chain);
 785              tp; tp = rtnl_dereference(tp->next), (*p_index)++) {
 786                 if (*p_index < index_start)
 787                         continue;
 788                 if (TC_H_MAJ(tcm->tcm_info) &&
 789                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
 790                         continue;
 791                 if (TC_H_MIN(tcm->tcm_info) &&
 792                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
 793                         continue;
 794                 if (*p_index > index_start)
 795                         memset(&cb->args[1], 0,
 796                                sizeof(cb->args) - sizeof(cb->args[0]));
 797                 if (cb->args[1] == 0) {
 798                         if (tcf_fill_node(net, skb, tp, 0,
 799                                           NETLINK_CB(cb->skb).portid,
 800                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
 801                                           RTM_NEWTFILTER) <= 0)
 802                                 return false;
 803
 804                         cb->args[1] = 1;
 805                 }
 806                 if (!tp->ops->walk)
 807                         continue;
 808                 arg.w.fn = tcf_node_dump;
 809                 arg.skb = skb;
 810                 arg.cb = cb;
 811                 arg.w.stop = 0;
 812                 arg.w.skip = cb->args[1] - 1;
 813                 arg.w.count = 0;
 814                 tp->ops->walk(tp, &arg.w);
 815                 cb->args[1] = arg.w.count + 1;
 816                 if (arg.w.stop)
 817                         return false;
 818         }
 819         return true;
 820 }
 821
 822 /* called with RTNL */
 823 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 824 {
 825         struct net *net = sock_net(skb->sk);
 826         struct nlattr *tca[TCA_MAX + 1];
 827         struct net_device *dev;
 828         struct Qdisc *q;
 829         struct tcf_block *block;
 830         struct tcf_chain *chain;
 831         struct tcmsg *tcm = nlmsg_data(cb->nlh);
 832         unsigned long cl = 0;
 833         const struct Qdisc_class_ops *cops;
 834         long index_start;
 835         long index;
 836         int err;
 837
 838         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
 839                 return skb->len;
 840
 841         err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL);
 842         if (err)
 843                 return err;
 844
 845         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
 846         if (!dev)
 847                 return skb->len;
 848
 849         if (!tcm->tcm_parent)
 850                 q = dev->qdisc;
 851         else
 852                 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
 853         if (!q)
 854                 goto out;
 855         cops = q->ops->cl_ops;
 856         if (!cops)
 857                 goto out;
 858         if (!cops->tcf_block)
 859                 goto out;
 860         if (TC_H_MIN(tcm->tcm_parent)) {
 861                 cl = cops->find(q, tcm->tcm_parent);
 862                 if (cl == 0)
 863                         goto out;
 864         }
 865         block = cops->tcf_block(q, cl);
 866         if (!block)
 867                 goto out;
 868
 869         index_start = cb->args[0];
 870         index = 0;
 871
 872         list_for_each_entry(chain, &block->chain_list, list) {
 873                 if (tca[TCA_CHAIN] &&
 874                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
 875                         continue;
 876                 if (!tcf_chain_dump(chain, skb, cb, index_start, &index))
 877                         break;
 878         }
 879
 880         cb->args[0] = index;
 881
 882 out:
 883         return skb->len;
 884 }
 885
 886 void tcf_exts_destroy(struct tcf_exts *exts)
 887 {
 888 #ifdef CONFIG_NET_CLS_ACT
 889         LIST_HEAD(actions);
 890
 891         ASSERT_RTNL();
 892         tcf_exts_to_list(exts, &actions);
 893         tcf_action_destroy(&actions, TCA_ACT_UNBIND);
 894         kfree(exts->actions);
 895         exts->nr_actions = 0;
 896 #endif
 897 }
 898 EXPORT_SYMBOL(tcf_exts_destroy);
 899
 900 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 901                       struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)
 902 {
 903 #ifdef CONFIG_NET_CLS_ACT
 904         {
 905                 struct tc_action *act;
 906
 907                 if (exts->police && tb[exts->police]) {
 908                         act = tcf_action_init_1(net, tp, tb[exts->police],
 909                                                 rate_tlv, "police", ovr,
 910                                                 TCA_ACT_BIND);
 911                         if (IS_ERR(act))
 912                                 return PTR_ERR(act);
 913
 914                         act->type = exts->type = TCA_OLD_COMPAT;
 915                         exts->actions[0] = act;
 916                         exts->nr_actions = 1;
 917                 } else if (exts->action && tb[exts->action]) {
 918                         LIST_HEAD(actions);
 919                         int err, i = 0;
 920
 921                         err = tcf_action_init(net, tp, tb[exts->action],
 922                                               rate_tlv, NULL, ovr, TCA_ACT_BIND,
 923                                               &actions);
 924                         if (err)
 925                                 return err;
 926                         list_for_each_entry(act, &actions, list)
 927                                 exts->actions[i++] = act;
 928                         exts->nr_actions = i;
 929                 }
 930         }
 931 #else
 932         if ((exts->action && tb[exts->action]) ||
 933             (exts->police && tb[exts->police]))
 934                 return -EOPNOTSUPP;
 935 #endif
 936
 937         return 0;
 938 }
 939 EXPORT_SYMBOL(tcf_exts_validate);
 940
 941 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
 942 {
 943 #ifdef CONFIG_NET_CLS_ACT
 944         struct tcf_exts old = *dst;
 945
 946         *dst = *src;
 947         tcf_exts_destroy(&old);
 948 #endif
 949 }
 950 EXPORT_SYMBOL(tcf_exts_change);
 951
 952 #ifdef CONFIG_NET_CLS_ACT
 953 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
 954 {
 955         if (exts->nr_actions == 0)
 956                 return NULL;
 957         else
 958                 return exts->actions[0];
 959 }
 960 #endif
 961
 962 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
 963 {
 964 #ifdef CONFIG_NET_CLS_ACT
 965         struct nlattr *nest;
 966
 967         if (exts->action && tcf_exts_has_actions(exts)) {
 968                 /*
 969                  * again for backward compatible mode - we want
 970                  * to work with both old and new modes of entering
 971                  * tc data even if iproute2  was newer - jhs
 972                  */
 973                 if (exts->type != TCA_OLD_COMPAT) {
 974                         LIST_HEAD(actions);
 975
 976                         nest = nla_nest_start(skb, exts->action);
 977                         if (nest == NULL)
 978                                 goto nla_put_failure;
 979
 980                         tcf_exts_to_list(exts, &actions);
 981                         if (tcf_action_dump(skb, &actions, 0, 0) < 0)
 982                                 goto nla_put_failure;
 983                         nla_nest_end(skb, nest);
 984                 } else if (exts->police) {
 985                         struct tc_action *act = tcf_exts_first_act(exts);
 986                         nest = nla_nest_start(skb, exts->police);
 987                         if (nest == NULL || !act)
 988                                 goto nla_put_failure;
 989                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
 990                                 goto nla_put_failure;
 991                         nla_nest_end(skb, nest);
 992                 }
 993         }
 994         return 0;
 995
 996 nla_put_failure:
 997         nla_nest_cancel(skb, nest);
 998         return -1;
 999 #else
1000         return 0;
1001 #endif
1002 }
1003 EXPORT_SYMBOL(tcf_exts_dump);
1004
1005
1006 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
1007 {
1008 #ifdef CONFIG_NET_CLS_ACT
1009         struct tc_action *a = tcf_exts_first_act(exts);
1010         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
1011                 return -1;
1012 #endif
1013         return 0;
1014 }
1015 EXPORT_SYMBOL(tcf_exts_dump_stats);
1016
1017 int tcf_exts_get_dev(struct net_device *dev, struct tcf_exts *exts,
1018                      struct net_device **hw_dev)
1019 {
1020 #ifdef CONFIG_NET_CLS_ACT
1021         const struct tc_action *a;
1022         LIST_HEAD(actions);
1023
1024         if (!tcf_exts_has_actions(exts))
1025                 return -EINVAL;
1026
1027         tcf_exts_to_list(exts, &actions);
1028         list_for_each_entry(a, &actions, list) {
1029                 if (a->ops->get_dev) {
1030                         a->ops->get_dev(a, dev_net(dev), hw_dev);
1031                         break;
1032                 }
1033         }
1034         if (*hw_dev)
1035                 return 0;
1036 #endif
1037         return -EOPNOTSUPP;
1038 }
1039 EXPORT_SYMBOL(tcf_exts_get_dev);
1040
1041 static int __init tc_filter_init(void)
1042 {
1043         tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
1044         if (!tc_filter_wq)
1045                 return -ENOMEM;
1046
1047         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0);
1048         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0);
1049         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
1050                       tc_dump_tfilter, 0);
1051
1052         return 0;
1053 }
1054
1055 subsys_initcall(tc_filter_init);