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