1 /* 2 * net/sched/cls_api.c Packet classifier API. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 * 11 * Changes: 12 * 13 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support 14 * 15 */ 16 17 #include <linux/module.h> 18 #include <linux/types.h> 19 #include <linux/kernel.h> 20 #include <linux/string.h> 21 #include <linux/errno.h> 22 #include <linux/err.h> 23 #include <linux/skbuff.h> 24 #include <linux/init.h> 25 #include <linux/kmod.h> 26 #include <linux/err.h> 27 #include <linux/slab.h> 28 #include <net/net_namespace.h> 29 #include <net/sock.h> 30 #include <net/netlink.h> 31 #include <net/pkt_sched.h> 32 #include <net/pkt_cls.h> 33 34 /* The list of all installed classifier types */ 35 static LIST_HEAD(tcf_proto_base); 36 37 /* Protects list of registered TC modules. It is pure SMP lock. */ 38 static DEFINE_RWLOCK(cls_mod_lock); 39 40 /* Find classifier type by string name */ 41 42 static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind) 43 { 44 const struct tcf_proto_ops *t, *res = NULL; 45 46 if (kind) { 47 read_lock(&cls_mod_lock); 48 list_for_each_entry(t, &tcf_proto_base, head) { 49 if (strcmp(kind, t->kind) == 0) { 50 if (try_module_get(t->owner)) 51 res = t; 52 break; 53 } 54 } 55 read_unlock(&cls_mod_lock); 56 } 57 return res; 58 } 59 60 /* Register(unregister) new classifier type */ 61 62 int register_tcf_proto_ops(struct tcf_proto_ops *ops) 63 { 64 struct tcf_proto_ops *t; 65 int rc = -EEXIST; 66 67 write_lock(&cls_mod_lock); 68 list_for_each_entry(t, &tcf_proto_base, head) 69 if (!strcmp(ops->kind, t->kind)) 70 goto out; 71 72 list_add_tail(&ops->head, &tcf_proto_base); 73 rc = 0; 74 out: 75 write_unlock(&cls_mod_lock); 76 return rc; 77 } 78 EXPORT_SYMBOL(register_tcf_proto_ops); 79 80 static struct workqueue_struct *tc_filter_wq; 81 82 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops) 83 { 84 struct tcf_proto_ops *t; 85 int rc = -ENOENT; 86 87 /* Wait for outstanding call_rcu()s, if any, from a 88 * tcf_proto_ops's destroy() handler. 89 */ 90 rcu_barrier(); 91 flush_workqueue(tc_filter_wq); 92 93 write_lock(&cls_mod_lock); 94 list_for_each_entry(t, &tcf_proto_base, head) { 95 if (t == ops) { 96 list_del(&t->head); 97 rc = 0; 98 break; 99 } 100 } 101 write_unlock(&cls_mod_lock); 102 return rc; 103 } 104 EXPORT_SYMBOL(unregister_tcf_proto_ops); 105 106 bool tcf_queue_work(struct work_struct *work) 107 { 108 return queue_work(tc_filter_wq, work); 109 } 110 EXPORT_SYMBOL(tcf_queue_work); 111 112 /* Select new prio value from the range, managed by kernel. */ 113 114 static inline u32 tcf_auto_prio(struct tcf_proto *tp) 115 { 116 u32 first = TC_H_MAKE(0xC0000000U, 0U); 117 118 if (tp) 119 first = tp->prio - 1; 120 121 return TC_H_MAJ(first); 122 } 123 124 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol, 125 u32 prio, u32 parent, struct Qdisc *q, 126 struct tcf_chain *chain) 127 { 128 struct tcf_proto *tp; 129 int err; 130 131 tp = kzalloc(sizeof(*tp), GFP_KERNEL); 132 if (!tp) 133 return ERR_PTR(-ENOBUFS); 134 135 err = -ENOENT; 136 tp->ops = tcf_proto_lookup_ops(kind); 137 if (!tp->ops) { 138 #ifdef CONFIG_MODULES 139 rtnl_unlock(); 140 request_module("cls_%s", kind); 141 rtnl_lock(); 142 tp->ops = tcf_proto_lookup_ops(kind); 143 /* We dropped the RTNL semaphore in order to perform 144 * the module load. So, even if we succeeded in loading 145 * the module we have to replay the request. We indicate 146 * this using -EAGAIN. 147 */ 148 if (tp->ops) { 149 module_put(tp->ops->owner); 150 err = -EAGAIN; 151 } else { 152 err = -ENOENT; 153 } 154 goto errout; 155 #endif 156 } 157 tp->classify = tp->ops->classify; 158 tp->protocol = protocol; 159 tp->prio = prio; 160 tp->classid = parent; 161 tp->q = q; 162 tp->chain = chain; 163 164 err = tp->ops->init(tp); 165 if (err) { 166 module_put(tp->ops->owner); 167 goto errout; 168 } 169 return tp; 170 171 errout: 172 kfree(tp); 173 return ERR_PTR(err); 174 } 175 176 static void tcf_proto_destroy(struct tcf_proto *tp) 177 { 178 tp->ops->destroy(tp); 179 module_put(tp->ops->owner); 180 kfree_rcu(tp, rcu); 181 } 182 183 static struct tcf_chain *tcf_chain_create(struct tcf_block *block, 184 u32 chain_index) 185 { 186 struct tcf_chain *chain; 187 188 chain = kzalloc(sizeof(*chain), GFP_KERNEL); 189 if (!chain) 190 return NULL; 191 list_add_tail(&chain->list, &block->chain_list); 192 chain->block = block; 193 chain->index = chain_index; 194 chain->refcnt = 1; 195 return chain; 196 } 197 198 static void tcf_chain_flush(struct tcf_chain *chain) 199 { 200 struct tcf_proto *tp; 201 202 if (chain->p_filter_chain) 203 RCU_INIT_POINTER(*chain->p_filter_chain, NULL); 204 while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) { 205 RCU_INIT_POINTER(chain->filter_chain, tp->next); 206 tcf_chain_put(chain); 207 tcf_proto_destroy(tp); 208 } 209 } 210 211 static void tcf_chain_destroy(struct tcf_chain *chain) 212 { 213 list_del(&chain->list); 214 kfree(chain); 215 } 216 217 static void tcf_chain_hold(struct tcf_chain *chain) 218 { 219 ++chain->refcnt; 220 } 221 222 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index, 223 bool create) 224 { 225 struct tcf_chain *chain; 226 227 list_for_each_entry(chain, &block->chain_list, list) { 228 if (chain->index == chain_index) { 229 tcf_chain_hold(chain); 230 return chain; 231 } 232 } 233 234 return create ? tcf_chain_create(block, chain_index) : NULL; 235 } 236 EXPORT_SYMBOL(tcf_chain_get); 237 238 void tcf_chain_put(struct tcf_chain *chain) 239 { 240 if (--chain->refcnt == 0) 241 tcf_chain_destroy(chain); 242 } 243 EXPORT_SYMBOL(tcf_chain_put); 244 245 static void 246 tcf_chain_filter_chain_ptr_set(struct tcf_chain *chain, 247 struct tcf_proto __rcu **p_filter_chain) 248 { 249 chain->p_filter_chain = p_filter_chain; 250 } 251 252 int tcf_block_get(struct tcf_block **p_block, 253 struct tcf_proto __rcu **p_filter_chain) 254 { 255 struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL); 256 struct tcf_chain *chain; 257 int err; 258 259 if (!block) 260 return -ENOMEM; 261 INIT_LIST_HEAD(&block->chain_list); 262 /* Create chain 0 by default, it has to be always present. */ 263 chain = tcf_chain_create(block, 0); 264 if (!chain) { 265 err = -ENOMEM; 266 goto err_chain_create; 267 } 268 tcf_chain_filter_chain_ptr_set(chain, p_filter_chain); 269 *p_block = block; 270 return 0; 271 272 err_chain_create: 273 kfree(block); 274 return err; 275 } 276 EXPORT_SYMBOL(tcf_block_get); 277 278 static void tcf_block_put_final(struct work_struct *work) 279 { 280 struct tcf_block *block = container_of(work, struct tcf_block, work); 281 struct tcf_chain *chain, *tmp; 282 283 rtnl_lock(); 284 /* Only chain 0 should be still here. */ 285 list_for_each_entry_safe(chain, tmp, &block->chain_list, list) 286 tcf_chain_put(chain); 287 rtnl_unlock(); 288 kfree(block); 289 } 290 291 /* XXX: Standalone actions are not allowed to jump to any chain, and bound 292 * actions should be all removed after flushing. However, filters are now 293 * destroyed in tc filter workqueue with RTNL lock, they can not race here. 294 */ 295 void tcf_block_put(struct tcf_block *block) 296 { 297 struct tcf_chain *chain, *tmp; 298 299 if (!block) 300 return; 301 302 list_for_each_entry_safe(chain, tmp, &block->chain_list, list) 303 tcf_chain_flush(chain); 304 305 INIT_WORK(&block->work, tcf_block_put_final); 306 /* Wait for RCU callbacks to release the reference count and make 307 * sure their works have been queued before this. 308 */ 309 rcu_barrier(); 310 tcf_queue_work(&block->work); 311 } 312 EXPORT_SYMBOL(tcf_block_put); 313 314 /* Main classifier routine: scans classifier chain attached 315 * to this qdisc, (optionally) tests for protocol and asks 316 * specific classifiers. 317 */ 318 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, 319 struct tcf_result *res, bool compat_mode) 320 { 321 __be16 protocol = tc_skb_protocol(skb); 322 #ifdef CONFIG_NET_CLS_ACT 323 const int max_reclassify_loop = 4; 324 const struct tcf_proto *orig_tp = tp; 325 const struct tcf_proto *first_tp; 326 int limit = 0; 327 328 reclassify: 329 #endif 330 for (; tp; tp = rcu_dereference_bh(tp->next)) { 331 int err; 332 333 if (tp->protocol != protocol && 334 tp->protocol != htons(ETH_P_ALL)) 335 continue; 336 337 err = tp->classify(skb, tp, res); 338 #ifdef CONFIG_NET_CLS_ACT 339 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) { 340 first_tp = orig_tp; 341 goto reset; 342 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) { 343 first_tp = res->goto_tp; 344 goto reset; 345 } 346 #endif 347 if (err >= 0) 348 return err; 349 } 350 351 return TC_ACT_UNSPEC; /* signal: continue lookup */ 352 #ifdef CONFIG_NET_CLS_ACT 353 reset: 354 if (unlikely(limit++ >= max_reclassify_loop)) { 355 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n", 356 tp->q->ops->id, tp->prio & 0xffff, 357 ntohs(tp->protocol)); 358 return TC_ACT_SHOT; 359 } 360 361 tp = first_tp; 362 protocol = tc_skb_protocol(skb); 363 goto reclassify; 364 #endif 365 } 366 EXPORT_SYMBOL(tcf_classify); 367 368 struct tcf_chain_info { 369 struct tcf_proto __rcu **pprev; 370 struct tcf_proto __rcu *next; 371 }; 372 373 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info) 374 { 375 return rtnl_dereference(*chain_info->pprev); 376 } 377 378 static void tcf_chain_tp_insert(struct tcf_chain *chain, 379 struct tcf_chain_info *chain_info, 380 struct tcf_proto *tp) 381 { 382 if (chain->p_filter_chain && 383 *chain_info->pprev == chain->filter_chain) 384 rcu_assign_pointer(*chain->p_filter_chain, tp); 385 RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info)); 386 rcu_assign_pointer(*chain_info->pprev, tp); 387 tcf_chain_hold(chain); 388 } 389 390 static void tcf_chain_tp_remove(struct tcf_chain *chain, 391 struct tcf_chain_info *chain_info, 392 struct tcf_proto *tp) 393 { 394 struct tcf_proto *next = rtnl_dereference(chain_info->next); 395 396 if (chain->p_filter_chain && tp == chain->filter_chain) 397 RCU_INIT_POINTER(*chain->p_filter_chain, next); 398 RCU_INIT_POINTER(*chain_info->pprev, next); 399 tcf_chain_put(chain); 400 } 401 402 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain, 403 struct tcf_chain_info *chain_info, 404 u32 protocol, u32 prio, 405 bool prio_allocate) 406 { 407 struct tcf_proto **pprev; 408 struct tcf_proto *tp; 409 410 /* Check the chain for existence of proto-tcf with this priority */ 411 for (pprev = &chain->filter_chain; 412 (tp = rtnl_dereference(*pprev)); pprev = &tp->next) { 413 if (tp->prio >= prio) { 414 if (tp->prio == prio) { 415 if (prio_allocate || 416 (tp->protocol != protocol && protocol)) 417 return ERR_PTR(-EINVAL); 418 } else { 419 tp = NULL; 420 } 421 break; 422 } 423 } 424 chain_info->pprev = pprev; 425 chain_info->next = tp ? tp->next : NULL; 426 return tp; 427 } 428 429 static int tcf_fill_node(struct net *net, struct sk_buff *skb, 430 struct tcf_proto *tp, void *fh, u32 portid, 431 u32 seq, u16 flags, int event) 432 { 433 struct tcmsg *tcm; 434 struct nlmsghdr *nlh; 435 unsigned char *b = skb_tail_pointer(skb); 436 437 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 438 if (!nlh) 439 goto out_nlmsg_trim; 440 tcm = nlmsg_data(nlh); 441 tcm->tcm_family = AF_UNSPEC; 442 tcm->tcm__pad1 = 0; 443 tcm->tcm__pad2 = 0; 444 tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex; 445 tcm->tcm_parent = tp->classid; 446 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol); 447 if (nla_put_string(skb, TCA_KIND, tp->ops->kind)) 448 goto nla_put_failure; 449 if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index)) 450 goto nla_put_failure; 451 if (!fh) { 452 tcm->tcm_handle = 0; 453 } else { 454 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0) 455 goto nla_put_failure; 456 } 457 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 458 return skb->len; 459 460 out_nlmsg_trim: 461 nla_put_failure: 462 nlmsg_trim(skb, b); 463 return -1; 464 } 465 466 static int tfilter_notify(struct net *net, struct sk_buff *oskb, 467 struct nlmsghdr *n, struct tcf_proto *tp, 468 void *fh, int event, bool unicast) 469 { 470 struct sk_buff *skb; 471 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 472 473 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 474 if (!skb) 475 return -ENOBUFS; 476 477 if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq, 478 n->nlmsg_flags, event) <= 0) { 479 kfree_skb(skb); 480 return -EINVAL; 481 } 482 483 if (unicast) 484 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 485 486 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 487 n->nlmsg_flags & NLM_F_ECHO); 488 } 489 490 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb, 491 struct nlmsghdr *n, struct tcf_proto *tp, 492 void *fh, bool unicast, bool *last) 493 { 494 struct sk_buff *skb; 495 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 496 int err; 497 498 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 499 if (!skb) 500 return -ENOBUFS; 501 502 if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq, 503 n->nlmsg_flags, RTM_DELTFILTER) <= 0) { 504 kfree_skb(skb); 505 return -EINVAL; 506 } 507 508 err = tp->ops->delete(tp, fh, last); 509 if (err) { 510 kfree_skb(skb); 511 return err; 512 } 513 514 if (unicast) 515 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 516 517 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 518 n->nlmsg_flags & NLM_F_ECHO); 519 } 520 521 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb, 522 struct nlmsghdr *n, 523 struct tcf_chain *chain, int event) 524 { 525 struct tcf_proto *tp; 526 527 for (tp = rtnl_dereference(chain->filter_chain); 528 tp; tp = rtnl_dereference(tp->next)) 529 tfilter_notify(net, oskb, n, tp, 0, event, false); 530 } 531 532 /* Add/change/delete/get a filter node */ 533 534 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 535 struct netlink_ext_ack *extack) 536 { 537 struct net *net = sock_net(skb->sk); 538 struct nlattr *tca[TCA_MAX + 1]; 539 struct tcmsg *t; 540 u32 protocol; 541 u32 prio; 542 bool prio_allocate; 543 u32 parent; 544 u32 chain_index; 545 struct net_device *dev; 546 struct Qdisc *q; 547 struct tcf_chain_info chain_info; 548 struct tcf_chain *chain = NULL; 549 struct tcf_block *block; 550 struct tcf_proto *tp; 551 const struct Qdisc_class_ops *cops; 552 unsigned long cl; 553 void *fh; 554 int err; 555 int tp_created; 556 557 if ((n->nlmsg_type != RTM_GETTFILTER) && 558 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) 559 return -EPERM; 560 561 replay: 562 tp_created = 0; 563 564 err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack); 565 if (err < 0) 566 return err; 567 568 t = nlmsg_data(n); 569 protocol = TC_H_MIN(t->tcm_info); 570 prio = TC_H_MAJ(t->tcm_info); 571 prio_allocate = false; 572 parent = t->tcm_parent; 573 cl = 0; 574 575 if (prio == 0) { 576 switch (n->nlmsg_type) { 577 case RTM_DELTFILTER: 578 if (protocol || t->tcm_handle || tca[TCA_KIND]) 579 return -ENOENT; 580 break; 581 case RTM_NEWTFILTER: 582 /* If no priority is provided by the user, 583 * we allocate one. 584 */ 585 if (n->nlmsg_flags & NLM_F_CREATE) { 586 prio = TC_H_MAKE(0x80000000U, 0U); 587 prio_allocate = true; 588 break; 589 } 590 /* fall-through */ 591 default: 592 return -ENOENT; 593 } 594 } 595 596 /* Find head of filter chain. */ 597 598 /* Find link */ 599 dev = __dev_get_by_index(net, t->tcm_ifindex); 600 if (dev == NULL) 601 return -ENODEV; 602 603 /* Find qdisc */ 604 if (!parent) { 605 q = dev->qdisc; 606 parent = q->handle; 607 } else { 608 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent)); 609 if (q == NULL) 610 return -EINVAL; 611 } 612 613 /* Is it classful? */ 614 cops = q->ops->cl_ops; 615 if (!cops) 616 return -EINVAL; 617 618 if (!cops->tcf_block) 619 return -EOPNOTSUPP; 620 621 /* Do we search for filter, attached to class? */ 622 if (TC_H_MIN(parent)) { 623 cl = cops->find(q, parent); 624 if (cl == 0) 625 return -ENOENT; 626 } 627 628 /* And the last stroke */ 629 block = cops->tcf_block(q, cl); 630 if (!block) { 631 err = -EINVAL; 632 goto errout; 633 } 634 635 chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0; 636 if (chain_index > TC_ACT_EXT_VAL_MASK) { 637 err = -EINVAL; 638 goto errout; 639 } 640 chain = tcf_chain_get(block, chain_index, 641 n->nlmsg_type == RTM_NEWTFILTER); 642 if (!chain) { 643 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL; 644 goto errout; 645 } 646 647 if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) { 648 tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER); 649 tcf_chain_flush(chain); 650 err = 0; 651 goto errout; 652 } 653 654 tp = tcf_chain_tp_find(chain, &chain_info, protocol, 655 prio, prio_allocate); 656 if (IS_ERR(tp)) { 657 err = PTR_ERR(tp); 658 goto errout; 659 } 660 661 if (tp == NULL) { 662 /* Proto-tcf does not exist, create new one */ 663 664 if (tca[TCA_KIND] == NULL || !protocol) { 665 err = -EINVAL; 666 goto errout; 667 } 668 669 if (n->nlmsg_type != RTM_NEWTFILTER || 670 !(n->nlmsg_flags & NLM_F_CREATE)) { 671 err = -ENOENT; 672 goto errout; 673 } 674 675 if (prio_allocate) 676 prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info)); 677 678 tp = tcf_proto_create(nla_data(tca[TCA_KIND]), 679 protocol, prio, parent, q, chain); 680 if (IS_ERR(tp)) { 681 err = PTR_ERR(tp); 682 goto errout; 683 } 684 tp_created = 1; 685 } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) { 686 err = -EINVAL; 687 goto errout; 688 } 689 690 fh = tp->ops->get(tp, t->tcm_handle); 691 692 if (!fh) { 693 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { 694 tcf_chain_tp_remove(chain, &chain_info, tp); 695 tfilter_notify(net, skb, n, tp, fh, 696 RTM_DELTFILTER, false); 697 tcf_proto_destroy(tp); 698 err = 0; 699 goto errout; 700 } 701 702 if (n->nlmsg_type != RTM_NEWTFILTER || 703 !(n->nlmsg_flags & NLM_F_CREATE)) { 704 err = -ENOENT; 705 goto errout; 706 } 707 } else { 708 bool last; 709 710 switch (n->nlmsg_type) { 711 case RTM_NEWTFILTER: 712 if (n->nlmsg_flags & NLM_F_EXCL) { 713 if (tp_created) 714 tcf_proto_destroy(tp); 715 err = -EEXIST; 716 goto errout; 717 } 718 break; 719 case RTM_DELTFILTER: 720 err = tfilter_del_notify(net, skb, n, tp, fh, false, 721 &last); 722 if (err) 723 goto errout; 724 if (last) { 725 tcf_chain_tp_remove(chain, &chain_info, tp); 726 tcf_proto_destroy(tp); 727 } 728 goto errout; 729 case RTM_GETTFILTER: 730 err = tfilter_notify(net, skb, n, tp, fh, 731 RTM_NEWTFILTER, true); 732 goto errout; 733 default: 734 err = -EINVAL; 735 goto errout; 736 } 737 } 738 739 err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh, 740 n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE); 741 if (err == 0) { 742 if (tp_created) 743 tcf_chain_tp_insert(chain, &chain_info, tp); 744 tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER, false); 745 } else { 746 if (tp_created) 747 tcf_proto_destroy(tp); 748 } 749 750 errout: 751 if (chain) 752 tcf_chain_put(chain); 753 if (err == -EAGAIN) 754 /* Replay the request. */ 755 goto replay; 756 return err; 757 } 758 759 struct tcf_dump_args { 760 struct tcf_walker w; 761 struct sk_buff *skb; 762 struct netlink_callback *cb; 763 }; 764 765 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 766 { 767 struct tcf_dump_args *a = (void *)arg; 768 struct net *net = sock_net(a->skb->sk); 769 770 return tcf_fill_node(net, a->skb, tp, n, NETLINK_CB(a->cb->skb).portid, 771 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 772 RTM_NEWTFILTER); 773 } 774 775 static bool tcf_chain_dump(struct tcf_chain *chain, struct sk_buff *skb, 776 struct netlink_callback *cb, 777 long index_start, long *p_index) 778 { 779 struct net *net = sock_net(skb->sk); 780 struct tcmsg *tcm = nlmsg_data(cb->nlh); 781 struct tcf_dump_args arg; 782 struct tcf_proto *tp; 783 784 for (tp = rtnl_dereference(chain->filter_chain); 785 tp; tp = rtnl_dereference(tp->next), (*p_index)++) { 786 if (*p_index < index_start) 787 continue; 788 if (TC_H_MAJ(tcm->tcm_info) && 789 TC_H_MAJ(tcm->tcm_info) != tp->prio) 790 continue; 791 if (TC_H_MIN(tcm->tcm_info) && 792 TC_H_MIN(tcm->tcm_info) != tp->protocol) 793 continue; 794 if (*p_index > index_start) 795 memset(&cb->args[1], 0, 796 sizeof(cb->args) - sizeof(cb->args[0])); 797 if (cb->args[1] == 0) { 798 if (tcf_fill_node(net, skb, tp, 0, 799 NETLINK_CB(cb->skb).portid, 800 cb->nlh->nlmsg_seq, NLM_F_MULTI, 801 RTM_NEWTFILTER) <= 0) 802 return false; 803 804 cb->args[1] = 1; 805 } 806 if (!tp->ops->walk) 807 continue; 808 arg.w.fn = tcf_node_dump; 809 arg.skb = skb; 810 arg.cb = cb; 811 arg.w.stop = 0; 812 arg.w.skip = cb->args[1] - 1; 813 arg.w.count = 0; 814 tp->ops->walk(tp, &arg.w); 815 cb->args[1] = arg.w.count + 1; 816 if (arg.w.stop) 817 return false; 818 } 819 return true; 820 } 821 822 /* called with RTNL */ 823 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) 824 { 825 struct net *net = sock_net(skb->sk); 826 struct nlattr *tca[TCA_MAX + 1]; 827 struct net_device *dev; 828 struct Qdisc *q; 829 struct tcf_block *block; 830 struct tcf_chain *chain; 831 struct tcmsg *tcm = nlmsg_data(cb->nlh); 832 unsigned long cl = 0; 833 const struct Qdisc_class_ops *cops; 834 long index_start; 835 long index; 836 int err; 837 838 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 839 return skb->len; 840 841 err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL); 842 if (err) 843 return err; 844 845 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 846 if (!dev) 847 return skb->len; 848 849 if (!tcm->tcm_parent) 850 q = dev->qdisc; 851 else 852 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); 853 if (!q) 854 goto out; 855 cops = q->ops->cl_ops; 856 if (!cops) 857 goto out; 858 if (!cops->tcf_block) 859 goto out; 860 if (TC_H_MIN(tcm->tcm_parent)) { 861 cl = cops->find(q, tcm->tcm_parent); 862 if (cl == 0) 863 goto out; 864 } 865 block = cops->tcf_block(q, cl); 866 if (!block) 867 goto out; 868 869 index_start = cb->args[0]; 870 index = 0; 871 872 list_for_each_entry(chain, &block->chain_list, list) { 873 if (tca[TCA_CHAIN] && 874 nla_get_u32(tca[TCA_CHAIN]) != chain->index) 875 continue; 876 if (!tcf_chain_dump(chain, skb, cb, index_start, &index)) 877 break; 878 } 879 880 cb->args[0] = index; 881 882 out: 883 return skb->len; 884 } 885 886 void tcf_exts_destroy(struct tcf_exts *exts) 887 { 888 #ifdef CONFIG_NET_CLS_ACT 889 LIST_HEAD(actions); 890 891 ASSERT_RTNL(); 892 tcf_exts_to_list(exts, &actions); 893 tcf_action_destroy(&actions, TCA_ACT_UNBIND); 894 kfree(exts->actions); 895 exts->nr_actions = 0; 896 #endif 897 } 898 EXPORT_SYMBOL(tcf_exts_destroy); 899 900 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, 901 struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr) 902 { 903 #ifdef CONFIG_NET_CLS_ACT 904 { 905 struct tc_action *act; 906 907 if (exts->police && tb[exts->police]) { 908 act = tcf_action_init_1(net, tp, tb[exts->police], 909 rate_tlv, "police", ovr, 910 TCA_ACT_BIND); 911 if (IS_ERR(act)) 912 return PTR_ERR(act); 913 914 act->type = exts->type = TCA_OLD_COMPAT; 915 exts->actions[0] = act; 916 exts->nr_actions = 1; 917 } else if (exts->action && tb[exts->action]) { 918 LIST_HEAD(actions); 919 int err, i = 0; 920 921 err = tcf_action_init(net, tp, tb[exts->action], 922 rate_tlv, NULL, ovr, TCA_ACT_BIND, 923 &actions); 924 if (err) 925 return err; 926 list_for_each_entry(act, &actions, list) 927 exts->actions[i++] = act; 928 exts->nr_actions = i; 929 } 930 } 931 #else 932 if ((exts->action && tb[exts->action]) || 933 (exts->police && tb[exts->police])) 934 return -EOPNOTSUPP; 935 #endif 936 937 return 0; 938 } 939 EXPORT_SYMBOL(tcf_exts_validate); 940 941 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src) 942 { 943 #ifdef CONFIG_NET_CLS_ACT 944 struct tcf_exts old = *dst; 945 946 *dst = *src; 947 tcf_exts_destroy(&old); 948 #endif 949 } 950 EXPORT_SYMBOL(tcf_exts_change); 951 952 #ifdef CONFIG_NET_CLS_ACT 953 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts) 954 { 955 if (exts->nr_actions == 0) 956 return NULL; 957 else 958 return exts->actions[0]; 959 } 960 #endif 961 962 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts) 963 { 964 #ifdef CONFIG_NET_CLS_ACT 965 struct nlattr *nest; 966 967 if (exts->action && tcf_exts_has_actions(exts)) { 968 /* 969 * again for backward compatible mode - we want 970 * to work with both old and new modes of entering 971 * tc data even if iproute2 was newer - jhs 972 */ 973 if (exts->type != TCA_OLD_COMPAT) { 974 LIST_HEAD(actions); 975 976 nest = nla_nest_start(skb, exts->action); 977 if (nest == NULL) 978 goto nla_put_failure; 979 980 tcf_exts_to_list(exts, &actions); 981 if (tcf_action_dump(skb, &actions, 0, 0) < 0) 982 goto nla_put_failure; 983 nla_nest_end(skb, nest); 984 } else if (exts->police) { 985 struct tc_action *act = tcf_exts_first_act(exts); 986 nest = nla_nest_start(skb, exts->police); 987 if (nest == NULL || !act) 988 goto nla_put_failure; 989 if (tcf_action_dump_old(skb, act, 0, 0) < 0) 990 goto nla_put_failure; 991 nla_nest_end(skb, nest); 992 } 993 } 994 return 0; 995 996 nla_put_failure: 997 nla_nest_cancel(skb, nest); 998 return -1; 999 #else 1000 return 0; 1001 #endif 1002 } 1003 EXPORT_SYMBOL(tcf_exts_dump); 1004 1005 1006 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts) 1007 { 1008 #ifdef CONFIG_NET_CLS_ACT 1009 struct tc_action *a = tcf_exts_first_act(exts); 1010 if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0) 1011 return -1; 1012 #endif 1013 return 0; 1014 } 1015 EXPORT_SYMBOL(tcf_exts_dump_stats); 1016 1017 int tcf_exts_get_dev(struct net_device *dev, struct tcf_exts *exts, 1018 struct net_device **hw_dev) 1019 { 1020 #ifdef CONFIG_NET_CLS_ACT 1021 const struct tc_action *a; 1022 LIST_HEAD(actions); 1023 1024 if (!tcf_exts_has_actions(exts)) 1025 return -EINVAL; 1026 1027 tcf_exts_to_list(exts, &actions); 1028 list_for_each_entry(a, &actions, list) { 1029 if (a->ops->get_dev) { 1030 a->ops->get_dev(a, dev_net(dev), hw_dev); 1031 break; 1032 } 1033 } 1034 if (*hw_dev) 1035 return 0; 1036 #endif 1037 return -EOPNOTSUPP; 1038 } 1039 EXPORT_SYMBOL(tcf_exts_get_dev); 1040 1041 static int __init tc_filter_init(void) 1042 { 1043 tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0); 1044 if (!tc_filter_wq) 1045 return -ENOMEM; 1046 1047 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0); 1048 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0); 1049 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter, 1050 tc_dump_tfilter, 0); 1051 1052 return 0; 1053 } 1054 1055 subsys_initcall(tc_filter_init); 1056