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