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 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
  81 {
  82         struct tcf_proto_ops *t;
  83         int rc = -ENOENT;
  84
  85         /* Wait for outstanding call_rcu()s, if any, from a
  86          * tcf_proto_ops's destroy() handler.
  87          */
  88         rcu_barrier();
  89
  90         write_lock(&cls_mod_lock);
  91         list_for_each_entry(t, &tcf_proto_base, head) {
  92                 if (t == ops) {
  93                         list_del(&t->head);
  94                         rc = 0;
  95                         break;
  96                 }
  97         }
  98         write_unlock(&cls_mod_lock);
  99         return rc;
 100 }
 101 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 102
 103 /* Select new prio value from the range, managed by kernel. */
 104
 105 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 106 {
 107         u32 first = TC_H_MAKE(0xC0000000U, 0U);
 108
 109         if (tp)
 110                 first = tp->prio - 1;
 111
 112         return TC_H_MAJ(first);
 113 }
 114
 115 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 116                                           u32 prio, u32 parent, struct Qdisc *q,
 117                                           struct tcf_chain *chain)
 118 {
 119         struct tcf_proto *tp;
 120         int err;
 121
 122         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 123         if (!tp)
 124                 return ERR_PTR(-ENOBUFS);
 125
 126         err = -ENOENT;
 127         tp->ops = tcf_proto_lookup_ops(kind);
 128         if (!tp->ops) {
 129 #ifdef CONFIG_MODULES
 130                 rtnl_unlock();
 131                 request_module("cls_%s", kind);
 132                 rtnl_lock();
 133                 tp->ops = tcf_proto_lookup_ops(kind);
 134                 /* We dropped the RTNL semaphore in order to perform
 135                  * the module load. So, even if we succeeded in loading
 136                  * the module we have to replay the request. We indicate
 137                  * this using -EAGAIN.
 138                  */
 139                 if (tp->ops) {
 140                         module_put(tp->ops->owner);
 141                         err = -EAGAIN;
 142                 } else {
 143                         err = -ENOENT;
 144                 }
 145                 goto errout;
 146 #endif
 147         }
 148         tp->classify = tp->ops->classify;
 149         tp->protocol = protocol;
 150         tp->prio = prio;
 151         tp->classid = parent;
 152         tp->q = q;
 153         tp->chain = chain;
 154
 155         err = tp->ops->init(tp);
 156         if (err) {
 157                 module_put(tp->ops->owner);
 158                 goto errout;
 159         }
 160         return tp;
 161
 162 errout:
 163         kfree(tp);
 164         return ERR_PTR(err);
 165 }
 166
 167 static void tcf_proto_destroy(struct tcf_proto *tp)
 168 {
 169         tp->ops->destroy(tp);
 170         module_put(tp->ops->owner);
 171         kfree_rcu(tp, rcu);
 172 }
 173
 174 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 175                                           u32 chain_index)
 176 {
 177         struct tcf_chain *chain;
 178
 179         chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 180         if (!chain)
 181                 return NULL;
 182         list_add_tail(&chain->list, &block->chain_list);
 183         chain->block = block;
 184         chain->index = chain_index;
 185         chain->refcnt = 1;
 186         return chain;
 187 }
 188
 189 static void tcf_chain_flush(struct tcf_chain *chain)
 190 {
 191         struct tcf_proto *tp;
 192
 193         if (chain->p_filter_chain)
 194                 RCU_INIT_POINTER(*chain->p_filter_chain, NULL);
 195         while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) {
 196                 RCU_INIT_POINTER(chain->filter_chain, tp->next);
 197                 tcf_chain_put(chain);
 198                 tcf_proto_destroy(tp);
 199         }
 200 }
 201
 202 static void tcf_chain_destroy(struct tcf_chain *chain)
 203 {
 204         list_del(&chain->list);
 205         kfree(chain);
 206 }
 207
 208 static void tcf_chain_hold(struct tcf_chain *chain)
 209 {
 210         ++chain->refcnt;
 211 }
 212
 213 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 214                                 bool create)
 215 {
 216         struct tcf_chain *chain;
 217
 218         list_for_each_entry(chain, &block->chain_list, list) {
 219                 if (chain->index == chain_index) {
 220                         tcf_chain_hold(chain);
 221                         return chain;
 222                 }
 223         }
 224
 225         return create ? tcf_chain_create(block, chain_index) : NULL;
 226 }
 227 EXPORT_SYMBOL(tcf_chain_get);
 228
 229 void tcf_chain_put(struct tcf_chain *chain)
 230 {
 231         if (--chain->refcnt == 0)
 232                 tcf_chain_destroy(chain);
 233 }
 234 EXPORT_SYMBOL(tcf_chain_put);
 235
 236 static void
 237 tcf_chain_filter_chain_ptr_set(struct tcf_chain *chain,
 238                                struct tcf_proto __rcu **p_filter_chain)
 239 {
 240         chain->p_filter_chain = p_filter_chain;
 241 }
 242
 243 int tcf_block_get(struct tcf_block **p_block,
 244                   struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q)
 245 {
 246         struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
 247         struct tcf_chain *chain;
 248         int err;
 249
 250         if (!block)
 251                 return -ENOMEM;
 252         INIT_LIST_HEAD(&block->chain_list);
 253         /* Create chain 0 by default, it has to be always present. */
 254         chain = tcf_chain_create(block, 0);
 255         if (!chain) {
 256                 err = -ENOMEM;
 257                 goto err_chain_create;
 258         }
 259         tcf_chain_filter_chain_ptr_set(chain, p_filter_chain);
 260         block->net = qdisc_net(q);
 261         block->q = q;
 262         *p_block = block;
 263         return 0;
 264
 265 err_chain_create:
 266         kfree(block);
 267         return err;
 268 }
 269 EXPORT_SYMBOL(tcf_block_get);
 270
 271 void tcf_block_put(struct tcf_block *block)
 272 {
 273         struct tcf_chain *chain, *tmp;
 274
 275         if (!block)
 276                 return;
 277
 278         /* XXX: Standalone actions are not allowed to jump to any chain, and
 279          * bound actions should be all removed after flushing. However,
 280          * filters are destroyed in RCU callbacks, we have to hold the chains
 281          * first, otherwise we would always race with RCU callbacks on this list
 282          * without proper locking.
 283          */
 284
 285         /* Wait for existing RCU callbacks to cool down. */
 286         rcu_barrier();
 287
 288         /* Hold a refcnt for all chains, except 0, in case they are gone. */
 289         list_for_each_entry(chain, &block->chain_list, list)
 290                 if (chain->index)
 291                         tcf_chain_hold(chain);
 292
 293         /* No race on the list, because no chain could be destroyed. */
 294         list_for_each_entry(chain, &block->chain_list, list)
 295                 tcf_chain_flush(chain);
 296
 297         /* Wait for RCU callbacks to release the reference count. */
 298         rcu_barrier();
 299
 300         /* At this point, all the chains should have refcnt == 1. */
 301         list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
 302                 tcf_chain_put(chain);
 303         kfree(block);
 304 }
 305 EXPORT_SYMBOL(tcf_block_put);
 306
 307 /* Main classifier routine: scans classifier chain attached
 308  * to this qdisc, (optionally) tests for protocol and asks
 309  * specific classifiers.
 310  */
 311 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 312                  struct tcf_result *res, bool compat_mode)
 313 {
 314         __be16 protocol = tc_skb_protocol(skb);
 315 #ifdef CONFIG_NET_CLS_ACT
 316         const int max_reclassify_loop = 4;
 317         const struct tcf_proto *orig_tp = tp;
 318         const struct tcf_proto *first_tp;
 319         int limit = 0;
 320
 321 reclassify:
 322 #endif
 323         for (; tp; tp = rcu_dereference_bh(tp->next)) {
 324                 int err;
 325
 326                 if (tp->protocol != protocol &&
 327                     tp->protocol != htons(ETH_P_ALL))
 328                         continue;
 329
 330                 err = tp->classify(skb, tp, res);
 331 #ifdef CONFIG_NET_CLS_ACT
 332                 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
 333                         first_tp = orig_tp;
 334                         goto reset;
 335                 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
 336                         first_tp = res->goto_tp;
 337                         goto reset;
 338                 }
 339 #endif
 340                 if (err >= 0)
 341                         return err;
 342         }
 343
 344         return TC_ACT_UNSPEC; /* signal: continue lookup */
 345 #ifdef CONFIG_NET_CLS_ACT
 346 reset:
 347         if (unlikely(limit++ >= max_reclassify_loop)) {
 348                 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n",
 349                                        tp->q->ops->id, tp->prio & 0xffff,
 350                                        ntohs(tp->protocol));
 351                 return TC_ACT_SHOT;
 352         }
 353
 354         tp = first_tp;
 355         protocol = tc_skb_protocol(skb);
 356         goto reclassify;
 357 #endif
 358 }
 359 EXPORT_SYMBOL(tcf_classify);
 360
 361 struct tcf_chain_info {
 362         struct tcf_proto __rcu **pprev;
 363         struct tcf_proto __rcu *next;
 364 };
 365
 366 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)
 367 {
 368         return rtnl_dereference(*chain_info->pprev);
 369 }
 370
 371 static void tcf_chain_tp_insert(struct tcf_chain *chain,
 372                                 struct tcf_chain_info *chain_info,
 373                                 struct tcf_proto *tp)
 374 {
 375         if (chain->p_filter_chain &&
 376             *chain_info->pprev == chain->filter_chain)
 377                 rcu_assign_pointer(*chain->p_filter_chain, tp);
 378         RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));
 379         rcu_assign_pointer(*chain_info->pprev, tp);
 380         tcf_chain_hold(chain);
 381 }
 382
 383 static void tcf_chain_tp_remove(struct tcf_chain *chain,
 384                                 struct tcf_chain_info *chain_info,
 385                                 struct tcf_proto *tp)
 386 {
 387         struct tcf_proto *next = rtnl_dereference(chain_info->next);
 388
 389         if (chain->p_filter_chain && tp == chain->filter_chain)
 390                 RCU_INIT_POINTER(*chain->p_filter_chain, next);
 391         RCU_INIT_POINTER(*chain_info->pprev, next);
 392         tcf_chain_put(chain);
 393 }
 394
 395 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 396                                            struct tcf_chain_info *chain_info,
 397                                            u32 protocol, u32 prio,
 398                                            bool prio_allocate)
 399 {
 400         struct tcf_proto **pprev;
 401         struct tcf_proto *tp;
 402
 403         /* Check the chain for existence of proto-tcf with this priority */
 404         for (pprev = &chain->filter_chain;
 405              (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {
 406                 if (tp->prio >= prio) {
 407                         if (tp->prio == prio) {
 408                                 if (prio_allocate ||
 409                                     (tp->protocol != protocol && protocol))
 410                                         return ERR_PTR(-EINVAL);
 411                         } else {
 412                                 tp = NULL;
 413                         }
 414                         break;
 415                 }
 416         }
 417         chain_info->pprev = pprev;
 418         chain_info->next = tp ? tp->next : NULL;
 419         return tp;
 420 }
 421
 422 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 423                          struct tcf_proto *tp, void *fh, u32 portid,
 424                          u32 seq, u16 flags, int event)
 425 {
 426         struct tcmsg *tcm;
 427         struct nlmsghdr  *nlh;
 428         unsigned char *b = skb_tail_pointer(skb);
 429
 430         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 431         if (!nlh)
 432                 goto out_nlmsg_trim;
 433         tcm = nlmsg_data(nlh);
 434         tcm->tcm_family = AF_UNSPEC;
 435         tcm->tcm__pad1 = 0;
 436         tcm->tcm__pad2 = 0;
 437         tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex;
 438         tcm->tcm_parent = tp->classid;
 439         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
 440         if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
 441                 goto nla_put_failure;
 442         if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
 443                 goto nla_put_failure;
 444         if (!fh) {
 445                 tcm->tcm_handle = 0;
 446         } else {
 447                 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
 448                         goto nla_put_failure;
 449         }
 450         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 451         return skb->len;
 452
 453 out_nlmsg_trim:
 454 nla_put_failure:
 455         nlmsg_trim(skb, b);
 456         return -1;
 457 }
 458
 459 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 460                           struct nlmsghdr *n, struct tcf_proto *tp,
 461                           void *fh, int event, bool unicast)
 462 {
 463         struct sk_buff *skb;
 464         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 465
 466         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 467         if (!skb)
 468                 return -ENOBUFS;
 469
 470         if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq,
 471                           n->nlmsg_flags, event) <= 0) {
 472                 kfree_skb(skb);
 473                 return -EINVAL;
 474         }
 475
 476         if (unicast)
 477                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 478
 479         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 480                               n->nlmsg_flags & NLM_F_ECHO);
 481 }
 482
 483 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 484                               struct nlmsghdr *n, struct tcf_proto *tp,
 485                               void *fh, bool unicast, bool *last)
 486 {
 487         struct sk_buff *skb;
 488         u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
 489         int err;
 490
 491         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 492         if (!skb)
 493                 return -ENOBUFS;
 494
 495         if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq,
 496                           n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
 497                 kfree_skb(skb);
 498                 return -EINVAL;
 499         }
 500
 501         err = tp->ops->delete(tp, fh, last);
 502         if (err) {
 503                 kfree_skb(skb);
 504                 return err;
 505         }
 506
 507         if (unicast)
 508                 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 509
 510         return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 511                               n->nlmsg_flags & NLM_F_ECHO);
 512 }
 513
 514 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
 515                                  struct nlmsghdr *n,
 516                                  struct tcf_chain *chain, int event)
 517 {
 518         struct tcf_proto *tp;
 519
 520         for (tp = rtnl_dereference(chain->filter_chain);
 521              tp; tp = rtnl_dereference(tp->next))
 522                 tfilter_notify(net, oskb, n, tp, 0, event, false);
 523 }
 524
 525 /* Add/change/delete/get a filter node */
 526
 527 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 528                           struct netlink_ext_ack *extack)
 529 {
 530         struct net *net = sock_net(skb->sk);
 531         struct nlattr *tca[TCA_MAX + 1];
 532         struct tcmsg *t;
 533         u32 protocol;
 534         u32 prio;
 535         bool prio_allocate;
 536         u32 parent;
 537         u32 chain_index;
 538         struct net_device *dev;
 539         struct Qdisc  *q;
 540         struct tcf_chain_info chain_info;
 541         struct tcf_chain *chain = NULL;
 542         struct tcf_block *block;
 543         struct tcf_proto *tp;
 544         const struct Qdisc_class_ops *cops;
 545         unsigned long cl;
 546         void *fh;
 547         int err;
 548         int tp_created;
 549
 550         if ((n->nlmsg_type != RTM_GETTFILTER) &&
 551             !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 552                 return -EPERM;
 553
 554 replay:
 555         tp_created = 0;
 556
 557         err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack);
 558         if (err < 0)
 559                 return err;
 560
 561         t = nlmsg_data(n);
 562         protocol = TC_H_MIN(t->tcm_info);
 563         prio = TC_H_MAJ(t->tcm_info);
 564         prio_allocate = false;
 565         parent = t->tcm_parent;
 566         cl = 0;
 567
 568         if (prio == 0) {
 569                 switch (n->nlmsg_type) {
 570                 case RTM_DELTFILTER:
 571                         if (protocol || t->tcm_handle || tca[TCA_KIND])
 572                                 return -ENOENT;
 573                         break;
 574                 case RTM_NEWTFILTER:
 575                         /* If no priority is provided by the user,
 576                          * we allocate one.
 577                          */
 578                         if (n->nlmsg_flags & NLM_F_CREATE) {
 579                                 prio = TC_H_MAKE(0x80000000U, 0U);
 580                                 prio_allocate = true;
 581                                 break;
 582                         }
 583                         /* fall-through */
 584                 default:
 585                         return -ENOENT;
 586                 }
 587         }
 588
 589         /* Find head of filter chain. */
 590
 591         /* Find link */
 592         dev = __dev_get_by_index(net, t->tcm_ifindex);
 593         if (dev == NULL)
 594                 return -ENODEV;
 595
 596         /* Find qdisc */
 597         if (!parent) {
 598                 q = dev->qdisc;
 599                 parent = q->handle;
 600         } else {
 601                 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
 602                 if (q == NULL)
 603                         return -EINVAL;
 604         }
 605
 606         /* Is it classful? */
 607         cops = q->ops->cl_ops;
 608         if (!cops)
 609                 return -EINVAL;
 610
 611         if (!cops->tcf_block)
 612                 return -EOPNOTSUPP;
 613
 614         /* Do we search for filter, attached to class? */
 615         if (TC_H_MIN(parent)) {
 616                 cl = cops->find(q, parent);
 617                 if (cl == 0)
 618                         return -ENOENT;
 619         }
 620
 621         /* And the last stroke */
 622         block = cops->tcf_block(q, cl);
 623         if (!block) {
 624                 err = -EINVAL;
 625                 goto errout;
 626         }
 627
 628         chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
 629         if (chain_index > TC_ACT_EXT_VAL_MASK) {
 630                 err = -EINVAL;
 631                 goto errout;
 632         }
 633         chain = tcf_chain_get(block, chain_index,
 634                               n->nlmsg_type == RTM_NEWTFILTER);
 635         if (!chain) {
 636                 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL;
 637                 goto errout;
 638         }
 639
 640         if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
 641                 tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER);
 642                 tcf_chain_flush(chain);
 643                 err = 0;
 644                 goto errout;
 645         }
 646
 647         tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 648                                prio, prio_allocate);
 649         if (IS_ERR(tp)) {
 650                 err = PTR_ERR(tp);
 651                 goto errout;
 652         }
 653
 654         if (tp == NULL) {
 655                 /* Proto-tcf does not exist, create new one */
 656
 657                 if (tca[TCA_KIND] == NULL || !protocol) {
 658                         err = -EINVAL;
 659                         goto errout;
 660                 }
 661
 662                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 663                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 664                         err = -ENOENT;
 665                         goto errout;
 666                 }
 667
 668                 if (prio_allocate)
 669                         prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
 670
 671                 tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
 672                                       protocol, prio, parent, q, chain);
 673                 if (IS_ERR(tp)) {
 674                         err = PTR_ERR(tp);
 675                         goto errout;
 676                 }
 677                 tp_created = 1;
 678         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
 679                 err = -EINVAL;
 680                 goto errout;
 681         }
 682
 683         fh = tp->ops->get(tp, t->tcm_handle);
 684
 685         if (!fh) {
 686                 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
 687                         tcf_chain_tp_remove(chain, &chain_info, tp);
 688                         tfilter_notify(net, skb, n, tp, fh,
 689                                        RTM_DELTFILTER, false);
 690                         tcf_proto_destroy(tp);
 691                         err = 0;
 692                         goto errout;
 693                 }
 694
 695                 if (n->nlmsg_type != RTM_NEWTFILTER ||
 696                     !(n->nlmsg_flags & NLM_F_CREATE)) {
 697                         err = -ENOENT;
 698                         goto errout;
 699                 }
 700         } else {
 701                 bool last;
 702
 703                 switch (n->nlmsg_type) {
 704                 case RTM_NEWTFILTER:
 705                         if (n->nlmsg_flags & NLM_F_EXCL) {
 706                                 if (tp_created)
 707                                         tcf_proto_destroy(tp);
 708                                 err = -EEXIST;
 709                                 goto errout;
 710                         }
 711                         break;
 712                 case RTM_DELTFILTER:
 713                         err = tfilter_del_notify(net, skb, n, tp, fh, false,
 714                                                  &last);
 715                         if (err)
 716                                 goto errout;
 717                         if (last) {
 718                                 tcf_chain_tp_remove(chain, &chain_info, tp);
 719                                 tcf_proto_destroy(tp);
 720                         }
 721                         goto errout;
 722                 case RTM_GETTFILTER:
 723                         err = tfilter_notify(net, skb, n, tp, fh,
 724                                              RTM_NEWTFILTER, true);
 725                         goto errout;
 726                 default:
 727                         err = -EINVAL;
 728                         goto errout;
 729                 }
 730         }
 731
 732         err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 733                               n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
 734         if (err == 0) {
 735                 if (tp_created)
 736                         tcf_chain_tp_insert(chain, &chain_info, tp);
 737                 tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER, false);
 738         } else {
 739                 if (tp_created)
 740                         tcf_proto_destroy(tp);
 741         }
 742
 743 errout:
 744         if (chain)
 745                 tcf_chain_put(chain);
 746         if (err == -EAGAIN)
 747                 /* Replay the request. */
 748                 goto replay;
 749         return err;
 750 }
 751
 752 struct tcf_dump_args {
 753         struct tcf_walker w;
 754         struct sk_buff *skb;
 755         struct netlink_callback *cb;
 756 };
 757
 758 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
 759 {
 760         struct tcf_dump_args *a = (void *)arg;
 761         struct net *net = sock_net(a->skb->sk);
 762
 763         return tcf_fill_node(net, a->skb, tp, n, NETLINK_CB(a->cb->skb).portid,
 764                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
 765                              RTM_NEWTFILTER);
 766 }
 767
 768 static bool tcf_chain_dump(struct tcf_chain *chain, struct sk_buff *skb,
 769                            struct netlink_callback *cb,
 770                            long index_start, long *p_index)
 771 {
 772         struct net *net = sock_net(skb->sk);
 773         struct tcmsg *tcm = nlmsg_data(cb->nlh);
 774         struct tcf_dump_args arg;
 775         struct tcf_proto *tp;
 776
 777         for (tp = rtnl_dereference(chain->filter_chain);
 778              tp; tp = rtnl_dereference(tp->next), (*p_index)++) {
 779                 if (*p_index < index_start)
 780                         continue;
 781                 if (TC_H_MAJ(tcm->tcm_info) &&
 782                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
 783                         continue;
 784                 if (TC_H_MIN(tcm->tcm_info) &&
 785                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
 786                         continue;
 787                 if (*p_index > index_start)
 788                         memset(&cb->args[1], 0,
 789                                sizeof(cb->args) - sizeof(cb->args[0]));
 790                 if (cb->args[1] == 0) {
 791                         if (tcf_fill_node(net, skb, tp, 0,
 792                                           NETLINK_CB(cb->skb).portid,
 793                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
 794                                           RTM_NEWTFILTER) <= 0)
 795                                 return false;
 796
 797                         cb->args[1] = 1;
 798                 }
 799                 if (!tp->ops->walk)
 800                         continue;
 801                 arg.w.fn = tcf_node_dump;
 802                 arg.skb = skb;
 803                 arg.cb = cb;
 804                 arg.w.stop = 0;
 805                 arg.w.skip = cb->args[1] - 1;
 806                 arg.w.count = 0;
 807                 tp->ops->walk(tp, &arg.w);
 808                 cb->args[1] = arg.w.count + 1;
 809                 if (arg.w.stop)
 810                         return false;
 811         }
 812         return true;
 813 }
 814
 815 /* called with RTNL */
 816 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 817 {
 818         struct net *net = sock_net(skb->sk);
 819         struct nlattr *tca[TCA_MAX + 1];
 820         struct net_device *dev;
 821         struct Qdisc *q;
 822         struct tcf_block *block;
 823         struct tcf_chain *chain;
 824         struct tcmsg *tcm = nlmsg_data(cb->nlh);
 825         unsigned long cl = 0;
 826         const struct Qdisc_class_ops *cops;
 827         long index_start;
 828         long index;
 829         int err;
 830
 831         if (nlmsg_len(cb->nlh) < sizeof(*tcm))
 832                 return skb->len;
 833
 834         err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL);
 835         if (err)
 836                 return err;
 837
 838         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
 839         if (!dev)
 840                 return skb->len;
 841
 842         if (!tcm->tcm_parent)
 843                 q = dev->qdisc;
 844         else
 845                 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
 846         if (!q)
 847                 goto out;
 848         cops = q->ops->cl_ops;
 849         if (!cops)
 850                 goto out;
 851         if (!cops->tcf_block)
 852                 goto out;
 853         if (TC_H_MIN(tcm->tcm_parent)) {
 854                 cl = cops->find(q, tcm->tcm_parent);
 855                 if (cl == 0)
 856                         goto out;
 857         }
 858         block = cops->tcf_block(q, cl);
 859         if (!block)
 860                 goto out;
 861
 862         index_start = cb->args[0];
 863         index = 0;
 864
 865         list_for_each_entry(chain, &block->chain_list, list) {
 866                 if (tca[TCA_CHAIN] &&
 867                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
 868                         continue;
 869                 if (!tcf_chain_dump(chain, skb, cb, index_start, &index))
 870                         break;
 871         }
 872
 873         cb->args[0] = index;
 874
 875 out:
 876         return skb->len;
 877 }
 878
 879 void tcf_exts_destroy(struct tcf_exts *exts)
 880 {
 881 #ifdef CONFIG_NET_CLS_ACT
 882         LIST_HEAD(actions);
 883
 884         tcf_exts_to_list(exts, &actions);
 885         tcf_action_destroy(&actions, TCA_ACT_UNBIND);
 886         kfree(exts->actions);
 887         exts->nr_actions = 0;
 888 #endif
 889 }
 890 EXPORT_SYMBOL(tcf_exts_destroy);
 891
 892 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 893                       struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)
 894 {
 895 #ifdef CONFIG_NET_CLS_ACT
 896         {
 897                 struct tc_action *act;
 898
 899                 if (exts->police && tb[exts->police]) {
 900                         act = tcf_action_init_1(net, tp, tb[exts->police],
 901                                                 rate_tlv, "police", ovr,
 902                                                 TCA_ACT_BIND);
 903                         if (IS_ERR(act))
 904                                 return PTR_ERR(act);
 905
 906                         act->type = exts->type = TCA_OLD_COMPAT;
 907                         exts->actions[0] = act;
 908                         exts->nr_actions = 1;
 909                 } else if (exts->action && tb[exts->action]) {
 910                         LIST_HEAD(actions);
 911                         int err, i = 0;
 912
 913                         err = tcf_action_init(net, tp, tb[exts->action],
 914                                               rate_tlv, NULL, ovr, TCA_ACT_BIND,
 915                                               &actions);
 916                         if (err)
 917                                 return err;
 918                         list_for_each_entry(act, &actions, list)
 919                                 exts->actions[i++] = act;
 920                         exts->nr_actions = i;
 921                 }
 922         }
 923 #else
 924         if ((exts->action && tb[exts->action]) ||
 925             (exts->police && tb[exts->police]))
 926                 return -EOPNOTSUPP;
 927 #endif
 928
 929         return 0;
 930 }
 931 EXPORT_SYMBOL(tcf_exts_validate);
 932
 933 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
 934 {
 935 #ifdef CONFIG_NET_CLS_ACT
 936         struct tcf_exts old = *dst;
 937
 938         *dst = *src;
 939         tcf_exts_destroy(&old);
 940 #endif
 941 }
 942 EXPORT_SYMBOL(tcf_exts_change);
 943
 944 #ifdef CONFIG_NET_CLS_ACT
 945 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
 946 {
 947         if (exts->nr_actions == 0)
 948                 return NULL;
 949         else
 950                 return exts->actions[0];
 951 }
 952 #endif
 953
 954 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
 955 {
 956 #ifdef CONFIG_NET_CLS_ACT
 957         struct nlattr *nest;
 958
 959         if (exts->action && tcf_exts_has_actions(exts)) {
 960                 /*
 961                  * again for backward compatible mode - we want
 962                  * to work with both old and new modes of entering
 963                  * tc data even if iproute2  was newer - jhs
 964                  */
 965                 if (exts->type != TCA_OLD_COMPAT) {
 966                         LIST_HEAD(actions);
 967
 968                         nest = nla_nest_start(skb, exts->action);
 969                         if (nest == NULL)
 970                                 goto nla_put_failure;
 971
 972                         tcf_exts_to_list(exts, &actions);
 973                         if (tcf_action_dump(skb, &actions, 0, 0) < 0)
 974                                 goto nla_put_failure;
 975                         nla_nest_end(skb, nest);
 976                 } else if (exts->police) {
 977                         struct tc_action *act = tcf_exts_first_act(exts);
 978                         nest = nla_nest_start(skb, exts->police);
 979                         if (nest == NULL || !act)
 980                                 goto nla_put_failure;
 981                         if (tcf_action_dump_old(skb, act, 0, 0) < 0)
 982                                 goto nla_put_failure;
 983                         nla_nest_end(skb, nest);
 984                 }
 985         }
 986         return 0;
 987
 988 nla_put_failure:
 989         nla_nest_cancel(skb, nest);
 990         return -1;
 991 #else
 992         return 0;
 993 #endif
 994 }
 995 EXPORT_SYMBOL(tcf_exts_dump);
 996
 997
 998 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
 999 {
1000 #ifdef CONFIG_NET_CLS_ACT
1001         struct tc_action *a = tcf_exts_first_act(exts);
1002         if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
1003                 return -1;
1004 #endif
1005         return 0;
1006 }
1007 EXPORT_SYMBOL(tcf_exts_dump_stats);
1008
1009 static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts,
1010                                        enum tc_setup_type type,
1011                                        void *type_data, bool err_stop)
1012 {
1013         int ok_count = 0;
1014 #ifdef CONFIG_NET_CLS_ACT
1015         const struct tc_action *a;
1016         struct net_device *dev;
1017         LIST_HEAD(actions);
1018         int ret;
1019
1020         if (!tcf_exts_has_actions(exts))
1021                 return 0;
1022
1023         tcf_exts_to_list(exts, &actions);
1024         list_for_each_entry(a, &actions, list) {
1025                 if (!a->ops->get_dev)
1026                         continue;
1027                 dev = a->ops->get_dev(a);
1028                 if (!dev || !tc_can_offload(dev))
1029                         continue;
1030                 ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop);
1031                 if (ret < 0)
1032                         return ret;
1033                 ok_count += ret;
1034         }
1035 #endif
1036         return ok_count;
1037 }
1038
1039 int tc_setup_cb_call(struct tcf_exts *exts, enum tc_setup_type type,
1040                      void *type_data, bool err_stop)
1041 {
1042         return tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop);
1043 }
1044 EXPORT_SYMBOL(tc_setup_cb_call);
1045
1046 static int __init tc_filter_init(void)
1047 {
1048         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0);
1049         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0);
1050         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
1051                       tc_dump_tfilter, 0);
1052
1053         return 0;
1054 }
1055
1056 subsys_initcall(tc_filter_init);