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 static void tcf_block_offload_cmd(struct tcf_block *block, struct Qdisc *q, 253 struct tcf_block_ext_info *ei, 254 enum tc_block_command command) 255 { 256 struct net_device *dev = q->dev_queue->dev; 257 struct tc_block_offload bo = {}; 258 259 if (!tc_can_offload(dev)) 260 return; 261 bo.command = command; 262 bo.binder_type = ei->binder_type; 263 bo.block = block; 264 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo); 265 } 266 267 static void tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q, 268 struct tcf_block_ext_info *ei) 269 { 270 tcf_block_offload_cmd(block, q, ei, TC_BLOCK_BIND); 271 } 272 273 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q, 274 struct tcf_block_ext_info *ei) 275 { 276 tcf_block_offload_cmd(block, q, ei, TC_BLOCK_UNBIND); 277 } 278 279 int tcf_block_get_ext(struct tcf_block **p_block, 280 struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q, 281 struct tcf_block_ext_info *ei) 282 { 283 struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL); 284 struct tcf_chain *chain; 285 int err; 286 287 if (!block) 288 return -ENOMEM; 289 INIT_LIST_HEAD(&block->chain_list); 290 INIT_LIST_HEAD(&block->cb_list); 291 292 /* Create chain 0 by default, it has to be always present. */ 293 chain = tcf_chain_create(block, 0); 294 if (!chain) { 295 err = -ENOMEM; 296 goto err_chain_create; 297 } 298 tcf_chain_filter_chain_ptr_set(chain, p_filter_chain); 299 block->net = qdisc_net(q); 300 block->q = q; 301 tcf_block_offload_bind(block, q, ei); 302 *p_block = block; 303 return 0; 304 305 err_chain_create: 306 kfree(block); 307 return err; 308 } 309 EXPORT_SYMBOL(tcf_block_get_ext); 310 311 int tcf_block_get(struct tcf_block **p_block, 312 struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q) 313 { 314 struct tcf_block_ext_info ei = {0, }; 315 316 return tcf_block_get_ext(p_block, p_filter_chain, q, &ei); 317 } 318 EXPORT_SYMBOL(tcf_block_get); 319 320 static void tcf_block_put_final(struct work_struct *work) 321 { 322 struct tcf_block *block = container_of(work, struct tcf_block, work); 323 struct tcf_chain *chain, *tmp; 324 325 /* At this point, all the chains should have refcnt == 1. */ 326 rtnl_lock(); 327 list_for_each_entry_safe(chain, tmp, &block->chain_list, list) 328 tcf_chain_put(chain); 329 rtnl_unlock(); 330 kfree(block); 331 } 332 333 /* XXX: Standalone actions are not allowed to jump to any chain, and bound 334 * actions should be all removed after flushing. However, filters are destroyed 335 * in RCU callbacks, we have to hold the chains first, otherwise we would 336 * always race with RCU callbacks on this list without proper locking. 337 */ 338 static void tcf_block_put_deferred(struct work_struct *work) 339 { 340 struct tcf_block *block = container_of(work, struct tcf_block, work); 341 struct tcf_chain *chain; 342 343 rtnl_lock(); 344 /* Hold a refcnt for all chains, except 0, in case they are gone. */ 345 list_for_each_entry(chain, &block->chain_list, list) 346 if (chain->index) 347 tcf_chain_hold(chain); 348 349 /* No race on the list, because no chain could be destroyed. */ 350 list_for_each_entry(chain, &block->chain_list, list) 351 tcf_chain_flush(chain); 352 353 INIT_WORK(&block->work, tcf_block_put_final); 354 /* Wait for RCU callbacks to release the reference count and make 355 * sure their works have been queued before this. 356 */ 357 rcu_barrier(); 358 tcf_queue_work(&block->work); 359 rtnl_unlock(); 360 } 361 362 void tcf_block_put_ext(struct tcf_block *block, 363 struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q, 364 struct tcf_block_ext_info *ei) 365 { 366 if (!block) 367 return; 368 369 tcf_block_offload_unbind(block, q, ei); 370 371 INIT_WORK(&block->work, tcf_block_put_deferred); 372 /* Wait for existing RCU callbacks to cool down, make sure their works 373 * have been queued before this. We can not flush pending works here 374 * because we are holding the RTNL lock. 375 */ 376 rcu_barrier(); 377 tcf_queue_work(&block->work); 378 } 379 EXPORT_SYMBOL(tcf_block_put_ext); 380 381 void tcf_block_put(struct tcf_block *block) 382 { 383 struct tcf_block_ext_info ei = {0, }; 384 385 tcf_block_put_ext(block, NULL, block->q, &ei); 386 } 387 388 EXPORT_SYMBOL(tcf_block_put); 389 390 struct tcf_block_cb { 391 struct list_head list; 392 tc_setup_cb_t *cb; 393 void *cb_ident; 394 void *cb_priv; 395 unsigned int refcnt; 396 }; 397 398 void *tcf_block_cb_priv(struct tcf_block_cb *block_cb) 399 { 400 return block_cb->cb_priv; 401 } 402 EXPORT_SYMBOL(tcf_block_cb_priv); 403 404 struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block, 405 tc_setup_cb_t *cb, void *cb_ident) 406 { struct tcf_block_cb *block_cb; 407 408 list_for_each_entry(block_cb, &block->cb_list, list) 409 if (block_cb->cb == cb && block_cb->cb_ident == cb_ident) 410 return block_cb; 411 return NULL; 412 } 413 EXPORT_SYMBOL(tcf_block_cb_lookup); 414 415 void tcf_block_cb_incref(struct tcf_block_cb *block_cb) 416 { 417 block_cb->refcnt++; 418 } 419 EXPORT_SYMBOL(tcf_block_cb_incref); 420 421 unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb) 422 { 423 return --block_cb->refcnt; 424 } 425 EXPORT_SYMBOL(tcf_block_cb_decref); 426 427 struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block, 428 tc_setup_cb_t *cb, void *cb_ident, 429 void *cb_priv) 430 { 431 struct tcf_block_cb *block_cb; 432 433 block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL); 434 if (!block_cb) 435 return NULL; 436 block_cb->cb = cb; 437 block_cb->cb_ident = cb_ident; 438 block_cb->cb_priv = cb_priv; 439 list_add(&block_cb->list, &block->cb_list); 440 return block_cb; 441 } 442 EXPORT_SYMBOL(__tcf_block_cb_register); 443 444 int tcf_block_cb_register(struct tcf_block *block, 445 tc_setup_cb_t *cb, void *cb_ident, 446 void *cb_priv) 447 { 448 struct tcf_block_cb *block_cb; 449 450 block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv); 451 return block_cb ? 0 : -ENOMEM; 452 } 453 EXPORT_SYMBOL(tcf_block_cb_register); 454 455 void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb) 456 { 457 list_del(&block_cb->list); 458 kfree(block_cb); 459 } 460 EXPORT_SYMBOL(__tcf_block_cb_unregister); 461 462 void tcf_block_cb_unregister(struct tcf_block *block, 463 tc_setup_cb_t *cb, void *cb_ident) 464 { 465 struct tcf_block_cb *block_cb; 466 467 block_cb = tcf_block_cb_lookup(block, cb, cb_ident); 468 if (!block_cb) 469 return; 470 __tcf_block_cb_unregister(block_cb); 471 } 472 EXPORT_SYMBOL(tcf_block_cb_unregister); 473 474 static int tcf_block_cb_call(struct tcf_block *block, enum tc_setup_type type, 475 void *type_data, bool err_stop) 476 { 477 struct tcf_block_cb *block_cb; 478 int ok_count = 0; 479 int err; 480 481 list_for_each_entry(block_cb, &block->cb_list, list) { 482 err = block_cb->cb(type, type_data, block_cb->cb_priv); 483 if (err) { 484 if (err_stop) 485 return err; 486 } else { 487 ok_count++; 488 } 489 } 490 return ok_count; 491 } 492 493 /* Main classifier routine: scans classifier chain attached 494 * to this qdisc, (optionally) tests for protocol and asks 495 * specific classifiers. 496 */ 497 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, 498 struct tcf_result *res, bool compat_mode) 499 { 500 __be16 protocol = tc_skb_protocol(skb); 501 #ifdef CONFIG_NET_CLS_ACT 502 const int max_reclassify_loop = 4; 503 const struct tcf_proto *orig_tp = tp; 504 const struct tcf_proto *first_tp; 505 int limit = 0; 506 507 reclassify: 508 #endif 509 for (; tp; tp = rcu_dereference_bh(tp->next)) { 510 int err; 511 512 if (tp->protocol != protocol && 513 tp->protocol != htons(ETH_P_ALL)) 514 continue; 515 516 err = tp->classify(skb, tp, res); 517 #ifdef CONFIG_NET_CLS_ACT 518 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) { 519 first_tp = orig_tp; 520 goto reset; 521 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) { 522 first_tp = res->goto_tp; 523 goto reset; 524 } 525 #endif 526 if (err >= 0) 527 return err; 528 } 529 530 return TC_ACT_UNSPEC; /* signal: continue lookup */ 531 #ifdef CONFIG_NET_CLS_ACT 532 reset: 533 if (unlikely(limit++ >= max_reclassify_loop)) { 534 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n", 535 tp->q->ops->id, tp->prio & 0xffff, 536 ntohs(tp->protocol)); 537 return TC_ACT_SHOT; 538 } 539 540 tp = first_tp; 541 protocol = tc_skb_protocol(skb); 542 goto reclassify; 543 #endif 544 } 545 EXPORT_SYMBOL(tcf_classify); 546 547 struct tcf_chain_info { 548 struct tcf_proto __rcu **pprev; 549 struct tcf_proto __rcu *next; 550 }; 551 552 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info) 553 { 554 return rtnl_dereference(*chain_info->pprev); 555 } 556 557 static void tcf_chain_tp_insert(struct tcf_chain *chain, 558 struct tcf_chain_info *chain_info, 559 struct tcf_proto *tp) 560 { 561 if (chain->p_filter_chain && 562 *chain_info->pprev == chain->filter_chain) 563 rcu_assign_pointer(*chain->p_filter_chain, tp); 564 RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info)); 565 rcu_assign_pointer(*chain_info->pprev, tp); 566 tcf_chain_hold(chain); 567 } 568 569 static void tcf_chain_tp_remove(struct tcf_chain *chain, 570 struct tcf_chain_info *chain_info, 571 struct tcf_proto *tp) 572 { 573 struct tcf_proto *next = rtnl_dereference(chain_info->next); 574 575 if (chain->p_filter_chain && tp == chain->filter_chain) 576 RCU_INIT_POINTER(*chain->p_filter_chain, next); 577 RCU_INIT_POINTER(*chain_info->pprev, next); 578 tcf_chain_put(chain); 579 } 580 581 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain, 582 struct tcf_chain_info *chain_info, 583 u32 protocol, u32 prio, 584 bool prio_allocate) 585 { 586 struct tcf_proto **pprev; 587 struct tcf_proto *tp; 588 589 /* Check the chain for existence of proto-tcf with this priority */ 590 for (pprev = &chain->filter_chain; 591 (tp = rtnl_dereference(*pprev)); pprev = &tp->next) { 592 if (tp->prio >= prio) { 593 if (tp->prio == prio) { 594 if (prio_allocate || 595 (tp->protocol != protocol && protocol)) 596 return ERR_PTR(-EINVAL); 597 } else { 598 tp = NULL; 599 } 600 break; 601 } 602 } 603 chain_info->pprev = pprev; 604 chain_info->next = tp ? tp->next : NULL; 605 return tp; 606 } 607 608 static int tcf_fill_node(struct net *net, struct sk_buff *skb, 609 struct tcf_proto *tp, struct Qdisc *q, u32 parent, 610 void *fh, u32 portid, u32 seq, u16 flags, int event) 611 { 612 struct tcmsg *tcm; 613 struct nlmsghdr *nlh; 614 unsigned char *b = skb_tail_pointer(skb); 615 616 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 617 if (!nlh) 618 goto out_nlmsg_trim; 619 tcm = nlmsg_data(nlh); 620 tcm->tcm_family = AF_UNSPEC; 621 tcm->tcm__pad1 = 0; 622 tcm->tcm__pad2 = 0; 623 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 624 tcm->tcm_parent = parent; 625 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol); 626 if (nla_put_string(skb, TCA_KIND, tp->ops->kind)) 627 goto nla_put_failure; 628 if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index)) 629 goto nla_put_failure; 630 if (!fh) { 631 tcm->tcm_handle = 0; 632 } else { 633 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0) 634 goto nla_put_failure; 635 } 636 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 637 return skb->len; 638 639 out_nlmsg_trim: 640 nla_put_failure: 641 nlmsg_trim(skb, b); 642 return -1; 643 } 644 645 static int tfilter_notify(struct net *net, struct sk_buff *oskb, 646 struct nlmsghdr *n, struct tcf_proto *tp, 647 struct Qdisc *q, u32 parent, 648 void *fh, int event, bool unicast) 649 { 650 struct sk_buff *skb; 651 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 652 653 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 654 if (!skb) 655 return -ENOBUFS; 656 657 if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq, 658 n->nlmsg_flags, event) <= 0) { 659 kfree_skb(skb); 660 return -EINVAL; 661 } 662 663 if (unicast) 664 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 665 666 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 667 n->nlmsg_flags & NLM_F_ECHO); 668 } 669 670 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb, 671 struct nlmsghdr *n, struct tcf_proto *tp, 672 struct Qdisc *q, u32 parent, 673 void *fh, bool unicast, bool *last) 674 { 675 struct sk_buff *skb; 676 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 677 int err; 678 679 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 680 if (!skb) 681 return -ENOBUFS; 682 683 if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq, 684 n->nlmsg_flags, RTM_DELTFILTER) <= 0) { 685 kfree_skb(skb); 686 return -EINVAL; 687 } 688 689 err = tp->ops->delete(tp, fh, last); 690 if (err) { 691 kfree_skb(skb); 692 return err; 693 } 694 695 if (unicast) 696 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 697 698 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 699 n->nlmsg_flags & NLM_F_ECHO); 700 } 701 702 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb, 703 struct Qdisc *q, u32 parent, 704 struct nlmsghdr *n, 705 struct tcf_chain *chain, int event) 706 { 707 struct tcf_proto *tp; 708 709 for (tp = rtnl_dereference(chain->filter_chain); 710 tp; tp = rtnl_dereference(tp->next)) 711 tfilter_notify(net, oskb, n, tp, q, parent, 0, event, false); 712 } 713 714 /* Add/change/delete/get a filter node */ 715 716 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 717 struct netlink_ext_ack *extack) 718 { 719 struct net *net = sock_net(skb->sk); 720 struct nlattr *tca[TCA_MAX + 1]; 721 struct tcmsg *t; 722 u32 protocol; 723 u32 prio; 724 bool prio_allocate; 725 u32 parent; 726 u32 chain_index; 727 struct net_device *dev; 728 struct Qdisc *q; 729 struct tcf_chain_info chain_info; 730 struct tcf_chain *chain = NULL; 731 struct tcf_block *block; 732 struct tcf_proto *tp; 733 const struct Qdisc_class_ops *cops; 734 unsigned long cl; 735 void *fh; 736 int err; 737 int tp_created; 738 739 if ((n->nlmsg_type != RTM_GETTFILTER) && 740 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) 741 return -EPERM; 742 743 replay: 744 tp_created = 0; 745 746 err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack); 747 if (err < 0) 748 return err; 749 750 t = nlmsg_data(n); 751 protocol = TC_H_MIN(t->tcm_info); 752 prio = TC_H_MAJ(t->tcm_info); 753 prio_allocate = false; 754 parent = t->tcm_parent; 755 cl = 0; 756 757 if (prio == 0) { 758 switch (n->nlmsg_type) { 759 case RTM_DELTFILTER: 760 if (protocol || t->tcm_handle || tca[TCA_KIND]) 761 return -ENOENT; 762 break; 763 case RTM_NEWTFILTER: 764 /* If no priority is provided by the user, 765 * we allocate one. 766 */ 767 if (n->nlmsg_flags & NLM_F_CREATE) { 768 prio = TC_H_MAKE(0x80000000U, 0U); 769 prio_allocate = true; 770 break; 771 } 772 /* fall-through */ 773 default: 774 return -ENOENT; 775 } 776 } 777 778 /* Find head of filter chain. */ 779 780 /* Find link */ 781 dev = __dev_get_by_index(net, t->tcm_ifindex); 782 if (dev == NULL) 783 return -ENODEV; 784 785 /* Find qdisc */ 786 if (!parent) { 787 q = dev->qdisc; 788 parent = q->handle; 789 } else { 790 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent)); 791 if (q == NULL) 792 return -EINVAL; 793 } 794 795 /* Is it classful? */ 796 cops = q->ops->cl_ops; 797 if (!cops) 798 return -EINVAL; 799 800 if (!cops->tcf_block) 801 return -EOPNOTSUPP; 802 803 /* Do we search for filter, attached to class? */ 804 if (TC_H_MIN(parent)) { 805 cl = cops->find(q, parent); 806 if (cl == 0) 807 return -ENOENT; 808 } 809 810 /* And the last stroke */ 811 block = cops->tcf_block(q, cl); 812 if (!block) { 813 err = -EINVAL; 814 goto errout; 815 } 816 817 chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0; 818 if (chain_index > TC_ACT_EXT_VAL_MASK) { 819 err = -EINVAL; 820 goto errout; 821 } 822 chain = tcf_chain_get(block, chain_index, 823 n->nlmsg_type == RTM_NEWTFILTER); 824 if (!chain) { 825 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL; 826 goto errout; 827 } 828 829 if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) { 830 tfilter_notify_chain(net, skb, q, parent, n, 831 chain, RTM_DELTFILTER); 832 tcf_chain_flush(chain); 833 err = 0; 834 goto errout; 835 } 836 837 tp = tcf_chain_tp_find(chain, &chain_info, protocol, 838 prio, prio_allocate); 839 if (IS_ERR(tp)) { 840 err = PTR_ERR(tp); 841 goto errout; 842 } 843 844 if (tp == NULL) { 845 /* Proto-tcf does not exist, create new one */ 846 847 if (tca[TCA_KIND] == NULL || !protocol) { 848 err = -EINVAL; 849 goto errout; 850 } 851 852 if (n->nlmsg_type != RTM_NEWTFILTER || 853 !(n->nlmsg_flags & NLM_F_CREATE)) { 854 err = -ENOENT; 855 goto errout; 856 } 857 858 if (prio_allocate) 859 prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info)); 860 861 tp = tcf_proto_create(nla_data(tca[TCA_KIND]), 862 protocol, prio, parent, q, chain); 863 if (IS_ERR(tp)) { 864 err = PTR_ERR(tp); 865 goto errout; 866 } 867 tp_created = 1; 868 } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) { 869 err = -EINVAL; 870 goto errout; 871 } 872 873 fh = tp->ops->get(tp, t->tcm_handle); 874 875 if (!fh) { 876 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { 877 tcf_chain_tp_remove(chain, &chain_info, tp); 878 tfilter_notify(net, skb, n, tp, q, parent, fh, 879 RTM_DELTFILTER, false); 880 tcf_proto_destroy(tp); 881 err = 0; 882 goto errout; 883 } 884 885 if (n->nlmsg_type != RTM_NEWTFILTER || 886 !(n->nlmsg_flags & NLM_F_CREATE)) { 887 err = -ENOENT; 888 goto errout; 889 } 890 } else { 891 bool last; 892 893 switch (n->nlmsg_type) { 894 case RTM_NEWTFILTER: 895 if (n->nlmsg_flags & NLM_F_EXCL) { 896 if (tp_created) 897 tcf_proto_destroy(tp); 898 err = -EEXIST; 899 goto errout; 900 } 901 break; 902 case RTM_DELTFILTER: 903 err = tfilter_del_notify(net, skb, n, tp, q, parent, 904 fh, false, &last); 905 if (err) 906 goto errout; 907 if (last) { 908 tcf_chain_tp_remove(chain, &chain_info, tp); 909 tcf_proto_destroy(tp); 910 } 911 goto errout; 912 case RTM_GETTFILTER: 913 err = tfilter_notify(net, skb, n, tp, q, parent, fh, 914 RTM_NEWTFILTER, true); 915 goto errout; 916 default: 917 err = -EINVAL; 918 goto errout; 919 } 920 } 921 922 err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh, 923 n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE); 924 if (err == 0) { 925 if (tp_created) 926 tcf_chain_tp_insert(chain, &chain_info, tp); 927 tfilter_notify(net, skb, n, tp, q, parent, fh, 928 RTM_NEWTFILTER, false); 929 } else { 930 if (tp_created) 931 tcf_proto_destroy(tp); 932 } 933 934 errout: 935 if (chain) 936 tcf_chain_put(chain); 937 if (err == -EAGAIN) 938 /* Replay the request. */ 939 goto replay; 940 return err; 941 } 942 943 struct tcf_dump_args { 944 struct tcf_walker w; 945 struct sk_buff *skb; 946 struct netlink_callback *cb; 947 struct Qdisc *q; 948 u32 parent; 949 }; 950 951 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 952 { 953 struct tcf_dump_args *a = (void *)arg; 954 struct net *net = sock_net(a->skb->sk); 955 956 return tcf_fill_node(net, a->skb, tp, a->q, a->parent, 957 n, NETLINK_CB(a->cb->skb).portid, 958 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 959 RTM_NEWTFILTER); 960 } 961 962 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent, 963 struct sk_buff *skb, struct netlink_callback *cb, 964 long index_start, long *p_index) 965 { 966 struct net *net = sock_net(skb->sk); 967 struct tcmsg *tcm = nlmsg_data(cb->nlh); 968 struct tcf_dump_args arg; 969 struct tcf_proto *tp; 970 971 for (tp = rtnl_dereference(chain->filter_chain); 972 tp; tp = rtnl_dereference(tp->next), (*p_index)++) { 973 if (*p_index < index_start) 974 continue; 975 if (TC_H_MAJ(tcm->tcm_info) && 976 TC_H_MAJ(tcm->tcm_info) != tp->prio) 977 continue; 978 if (TC_H_MIN(tcm->tcm_info) && 979 TC_H_MIN(tcm->tcm_info) != tp->protocol) 980 continue; 981 if (*p_index > index_start) 982 memset(&cb->args[1], 0, 983 sizeof(cb->args) - sizeof(cb->args[0])); 984 if (cb->args[1] == 0) { 985 if (tcf_fill_node(net, skb, tp, q, parent, 0, 986 NETLINK_CB(cb->skb).portid, 987 cb->nlh->nlmsg_seq, NLM_F_MULTI, 988 RTM_NEWTFILTER) <= 0) 989 return false; 990 991 cb->args[1] = 1; 992 } 993 if (!tp->ops->walk) 994 continue; 995 arg.w.fn = tcf_node_dump; 996 arg.skb = skb; 997 arg.cb = cb; 998 arg.q = q; 999 arg.parent = parent; 1000 arg.w.stop = 0; 1001 arg.w.skip = cb->args[1] - 1; 1002 arg.w.count = 0; 1003 tp->ops->walk(tp, &arg.w); 1004 cb->args[1] = arg.w.count + 1; 1005 if (arg.w.stop) 1006 return false; 1007 } 1008 return true; 1009 } 1010 1011 /* called with RTNL */ 1012 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) 1013 { 1014 struct net *net = sock_net(skb->sk); 1015 struct nlattr *tca[TCA_MAX + 1]; 1016 struct net_device *dev; 1017 struct Qdisc *q; 1018 struct tcf_block *block; 1019 struct tcf_chain *chain; 1020 struct tcmsg *tcm = nlmsg_data(cb->nlh); 1021 unsigned long cl = 0; 1022 const struct Qdisc_class_ops *cops; 1023 long index_start; 1024 long index; 1025 u32 parent; 1026 int err; 1027 1028 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 1029 return skb->len; 1030 1031 err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL); 1032 if (err) 1033 return err; 1034 1035 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1036 if (!dev) 1037 return skb->len; 1038 1039 parent = tcm->tcm_parent; 1040 if (!parent) { 1041 q = dev->qdisc; 1042 parent = q->handle; 1043 } else { 1044 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); 1045 } 1046 if (!q) 1047 goto out; 1048 cops = q->ops->cl_ops; 1049 if (!cops) 1050 goto out; 1051 if (!cops->tcf_block) 1052 goto out; 1053 if (TC_H_MIN(tcm->tcm_parent)) { 1054 cl = cops->find(q, tcm->tcm_parent); 1055 if (cl == 0) 1056 goto out; 1057 } 1058 block = cops->tcf_block(q, cl); 1059 if (!block) 1060 goto out; 1061 1062 index_start = cb->args[0]; 1063 index = 0; 1064 1065 list_for_each_entry(chain, &block->chain_list, list) { 1066 if (tca[TCA_CHAIN] && 1067 nla_get_u32(tca[TCA_CHAIN]) != chain->index) 1068 continue; 1069 if (!tcf_chain_dump(chain, q, parent, skb, cb, 1070 index_start, &index)) 1071 break; 1072 } 1073 1074 cb->args[0] = index; 1075 1076 out: 1077 return skb->len; 1078 } 1079 1080 void tcf_exts_destroy(struct tcf_exts *exts) 1081 { 1082 #ifdef CONFIG_NET_CLS_ACT 1083 LIST_HEAD(actions); 1084 1085 ASSERT_RTNL(); 1086 tcf_exts_to_list(exts, &actions); 1087 tcf_action_destroy(&actions, TCA_ACT_UNBIND); 1088 kfree(exts->actions); 1089 exts->nr_actions = 0; 1090 #endif 1091 } 1092 EXPORT_SYMBOL(tcf_exts_destroy); 1093 1094 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, 1095 struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr) 1096 { 1097 #ifdef CONFIG_NET_CLS_ACT 1098 { 1099 struct tc_action *act; 1100 1101 if (exts->police && tb[exts->police]) { 1102 act = tcf_action_init_1(net, tp, tb[exts->police], 1103 rate_tlv, "police", ovr, 1104 TCA_ACT_BIND); 1105 if (IS_ERR(act)) 1106 return PTR_ERR(act); 1107 1108 act->type = exts->type = TCA_OLD_COMPAT; 1109 exts->actions[0] = act; 1110 exts->nr_actions = 1; 1111 } else if (exts->action && tb[exts->action]) { 1112 LIST_HEAD(actions); 1113 int err, i = 0; 1114 1115 err = tcf_action_init(net, tp, tb[exts->action], 1116 rate_tlv, NULL, ovr, TCA_ACT_BIND, 1117 &actions); 1118 if (err) 1119 return err; 1120 list_for_each_entry(act, &actions, list) 1121 exts->actions[i++] = act; 1122 exts->nr_actions = i; 1123 } 1124 } 1125 #else 1126 if ((exts->action && tb[exts->action]) || 1127 (exts->police && tb[exts->police])) 1128 return -EOPNOTSUPP; 1129 #endif 1130 1131 return 0; 1132 } 1133 EXPORT_SYMBOL(tcf_exts_validate); 1134 1135 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src) 1136 { 1137 #ifdef CONFIG_NET_CLS_ACT 1138 struct tcf_exts old = *dst; 1139 1140 *dst = *src; 1141 tcf_exts_destroy(&old); 1142 #endif 1143 } 1144 EXPORT_SYMBOL(tcf_exts_change); 1145 1146 #ifdef CONFIG_NET_CLS_ACT 1147 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts) 1148 { 1149 if (exts->nr_actions == 0) 1150 return NULL; 1151 else 1152 return exts->actions[0]; 1153 } 1154 #endif 1155 1156 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts) 1157 { 1158 #ifdef CONFIG_NET_CLS_ACT 1159 struct nlattr *nest; 1160 1161 if (exts->action && tcf_exts_has_actions(exts)) { 1162 /* 1163 * again for backward compatible mode - we want 1164 * to work with both old and new modes of entering 1165 * tc data even if iproute2 was newer - jhs 1166 */ 1167 if (exts->type != TCA_OLD_COMPAT) { 1168 LIST_HEAD(actions); 1169 1170 nest = nla_nest_start(skb, exts->action); 1171 if (nest == NULL) 1172 goto nla_put_failure; 1173 1174 tcf_exts_to_list(exts, &actions); 1175 if (tcf_action_dump(skb, &actions, 0, 0) < 0) 1176 goto nla_put_failure; 1177 nla_nest_end(skb, nest); 1178 } else if (exts->police) { 1179 struct tc_action *act = tcf_exts_first_act(exts); 1180 nest = nla_nest_start(skb, exts->police); 1181 if (nest == NULL || !act) 1182 goto nla_put_failure; 1183 if (tcf_action_dump_old(skb, act, 0, 0) < 0) 1184 goto nla_put_failure; 1185 nla_nest_end(skb, nest); 1186 } 1187 } 1188 return 0; 1189 1190 nla_put_failure: 1191 nla_nest_cancel(skb, nest); 1192 return -1; 1193 #else 1194 return 0; 1195 #endif 1196 } 1197 EXPORT_SYMBOL(tcf_exts_dump); 1198 1199 1200 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts) 1201 { 1202 #ifdef CONFIG_NET_CLS_ACT 1203 struct tc_action *a = tcf_exts_first_act(exts); 1204 if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0) 1205 return -1; 1206 #endif 1207 return 0; 1208 } 1209 EXPORT_SYMBOL(tcf_exts_dump_stats); 1210 1211 static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts, 1212 enum tc_setup_type type, 1213 void *type_data, bool err_stop) 1214 { 1215 int ok_count = 0; 1216 #ifdef CONFIG_NET_CLS_ACT 1217 const struct tc_action *a; 1218 struct net_device *dev; 1219 int i, ret; 1220 1221 if (!tcf_exts_has_actions(exts)) 1222 return 0; 1223 1224 for (i = 0; i < exts->nr_actions; i++) { 1225 a = exts->actions[i]; 1226 if (!a->ops->get_dev) 1227 continue; 1228 dev = a->ops->get_dev(a); 1229 if (!dev || !tc_can_offload(dev)) 1230 continue; 1231 ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop); 1232 if (ret < 0) 1233 return ret; 1234 ok_count += ret; 1235 } 1236 #endif 1237 return ok_count; 1238 } 1239 1240 int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts, 1241 enum tc_setup_type type, void *type_data, bool err_stop) 1242 { 1243 int ok_count; 1244 int ret; 1245 1246 ret = tcf_block_cb_call(block, type, type_data, err_stop); 1247 if (ret < 0) 1248 return ret; 1249 ok_count = ret; 1250 1251 if (!exts) 1252 return ok_count; 1253 ret = tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop); 1254 if (ret < 0) 1255 return ret; 1256 ok_count += ret; 1257 1258 return ok_count; 1259 } 1260 EXPORT_SYMBOL(tc_setup_cb_call); 1261 1262 static int __init tc_filter_init(void) 1263 { 1264 tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0); 1265 if (!tc_filter_wq) 1266 return -ENOMEM; 1267 1268 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0); 1269 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0); 1270 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter, 1271 tc_dump_tfilter, 0); 1272 1273 return 0; 1274 } 1275 1276 subsys_initcall(tc_filter_init); 1277