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/slab.h> 27 #include <net/net_namespace.h> 28 #include <net/sock.h> 29 #include <net/netlink.h> 30 #include <net/pkt_sched.h> 31 #include <net/pkt_cls.h> 32 33 /* The list of all installed classifier types */ 34 static LIST_HEAD(tcf_proto_base); 35 36 /* Protects list of registered TC modules. It is pure SMP lock. */ 37 static DEFINE_RWLOCK(cls_mod_lock); 38 39 /* Find classifier type by string name */ 40 41 static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind) 42 { 43 const struct tcf_proto_ops *t, *res = NULL; 44 45 if (kind) { 46 read_lock(&cls_mod_lock); 47 list_for_each_entry(t, &tcf_proto_base, head) { 48 if (strcmp(kind, t->kind) == 0) { 49 if (try_module_get(t->owner)) 50 res = t; 51 break; 52 } 53 } 54 read_unlock(&cls_mod_lock); 55 } 56 return res; 57 } 58 59 /* Register(unregister) new classifier type */ 60 61 int register_tcf_proto_ops(struct tcf_proto_ops *ops) 62 { 63 struct tcf_proto_ops *t; 64 int rc = -EEXIST; 65 66 write_lock(&cls_mod_lock); 67 list_for_each_entry(t, &tcf_proto_base, head) 68 if (!strcmp(ops->kind, t->kind)) 69 goto out; 70 71 list_add_tail(&ops->head, &tcf_proto_base); 72 rc = 0; 73 out: 74 write_unlock(&cls_mod_lock); 75 return rc; 76 } 77 EXPORT_SYMBOL(register_tcf_proto_ops); 78 79 static struct workqueue_struct *tc_filter_wq; 80 81 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops) 82 { 83 struct tcf_proto_ops *t; 84 int rc = -ENOENT; 85 86 /* Wait for outstanding call_rcu()s, if any, from a 87 * tcf_proto_ops's destroy() handler. 88 */ 89 rcu_barrier(); 90 flush_workqueue(tc_filter_wq); 91 92 write_lock(&cls_mod_lock); 93 list_for_each_entry(t, &tcf_proto_base, head) { 94 if (t == ops) { 95 list_del(&t->head); 96 rc = 0; 97 break; 98 } 99 } 100 write_unlock(&cls_mod_lock); 101 return rc; 102 } 103 EXPORT_SYMBOL(unregister_tcf_proto_ops); 104 105 bool tcf_queue_work(struct work_struct *work) 106 { 107 return queue_work(tc_filter_wq, work); 108 } 109 EXPORT_SYMBOL(tcf_queue_work); 110 111 /* Select new prio value from the range, managed by kernel. */ 112 113 static inline u32 tcf_auto_prio(struct tcf_proto *tp) 114 { 115 u32 first = TC_H_MAKE(0xC0000000U, 0U); 116 117 if (tp) 118 first = tp->prio - 1; 119 120 return TC_H_MAJ(first); 121 } 122 123 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol, 124 u32 prio, u32 parent, struct Qdisc *q, 125 struct tcf_chain *chain) 126 { 127 struct tcf_proto *tp; 128 int err; 129 130 tp = kzalloc(sizeof(*tp), GFP_KERNEL); 131 if (!tp) 132 return ERR_PTR(-ENOBUFS); 133 134 err = -ENOENT; 135 tp->ops = tcf_proto_lookup_ops(kind); 136 if (!tp->ops) { 137 #ifdef CONFIG_MODULES 138 rtnl_unlock(); 139 request_module("cls_%s", kind); 140 rtnl_lock(); 141 tp->ops = tcf_proto_lookup_ops(kind); 142 /* We dropped the RTNL semaphore in order to perform 143 * the module load. So, even if we succeeded in loading 144 * the module we have to replay the request. We indicate 145 * this using -EAGAIN. 146 */ 147 if (tp->ops) { 148 module_put(tp->ops->owner); 149 err = -EAGAIN; 150 } else { 151 err = -ENOENT; 152 } 153 goto errout; 154 #endif 155 } 156 tp->classify = tp->ops->classify; 157 tp->protocol = protocol; 158 tp->prio = prio; 159 tp->classid = parent; 160 tp->q = q; 161 tp->chain = chain; 162 163 err = tp->ops->init(tp); 164 if (err) { 165 module_put(tp->ops->owner); 166 goto errout; 167 } 168 return tp; 169 170 errout: 171 kfree(tp); 172 return ERR_PTR(err); 173 } 174 175 static void tcf_proto_destroy(struct tcf_proto *tp) 176 { 177 tp->ops->destroy(tp); 178 module_put(tp->ops->owner); 179 kfree_rcu(tp, rcu); 180 } 181 182 static struct tcf_chain *tcf_chain_create(struct tcf_block *block, 183 u32 chain_index) 184 { 185 struct tcf_chain *chain; 186 187 chain = kzalloc(sizeof(*chain), GFP_KERNEL); 188 if (!chain) 189 return NULL; 190 list_add_tail(&chain->list, &block->chain_list); 191 chain->block = block; 192 chain->index = chain_index; 193 chain->refcnt = 1; 194 return chain; 195 } 196 197 static void tcf_chain_head_change(struct tcf_chain *chain, 198 struct tcf_proto *tp_head) 199 { 200 if (chain->chain_head_change) 201 chain->chain_head_change(tp_head, 202 chain->chain_head_change_priv); 203 } 204 205 static void tcf_chain_flush(struct tcf_chain *chain) 206 { 207 struct tcf_proto *tp = rtnl_dereference(chain->filter_chain); 208 209 tcf_chain_head_change(chain, NULL); 210 while (tp) { 211 RCU_INIT_POINTER(chain->filter_chain, tp->next); 212 tcf_proto_destroy(tp); 213 tp = rtnl_dereference(chain->filter_chain); 214 tcf_chain_put(chain); 215 } 216 } 217 218 static void tcf_chain_destroy(struct tcf_chain *chain) 219 { 220 list_del(&chain->list); 221 kfree(chain); 222 } 223 224 static void tcf_chain_hold(struct tcf_chain *chain) 225 { 226 ++chain->refcnt; 227 } 228 229 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index, 230 bool create) 231 { 232 struct tcf_chain *chain; 233 234 list_for_each_entry(chain, &block->chain_list, list) { 235 if (chain->index == chain_index) { 236 tcf_chain_hold(chain); 237 return chain; 238 } 239 } 240 241 return create ? tcf_chain_create(block, chain_index) : NULL; 242 } 243 EXPORT_SYMBOL(tcf_chain_get); 244 245 void tcf_chain_put(struct tcf_chain *chain) 246 { 247 if (--chain->refcnt == 0) 248 tcf_chain_destroy(chain); 249 } 250 EXPORT_SYMBOL(tcf_chain_put); 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 (!dev->netdev_ops->ndo_setup_tc) 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, struct Qdisc *q, 280 struct tcf_block_ext_info *ei) 281 { 282 struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL); 283 struct tcf_chain *chain; 284 int err; 285 286 if (!block) 287 return -ENOMEM; 288 INIT_LIST_HEAD(&block->chain_list); 289 INIT_LIST_HEAD(&block->cb_list); 290 291 /* Create chain 0 by default, it has to be always present. */ 292 chain = tcf_chain_create(block, 0); 293 if (!chain) { 294 err = -ENOMEM; 295 goto err_chain_create; 296 } 297 WARN_ON(!ei->chain_head_change); 298 chain->chain_head_change = ei->chain_head_change; 299 chain->chain_head_change_priv = ei->chain_head_change_priv; 300 block->net = qdisc_net(q); 301 block->q = q; 302 tcf_block_offload_bind(block, q, ei); 303 *p_block = block; 304 return 0; 305 306 err_chain_create: 307 kfree(block); 308 return err; 309 } 310 EXPORT_SYMBOL(tcf_block_get_ext); 311 312 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv) 313 { 314 struct tcf_proto __rcu **p_filter_chain = priv; 315 316 rcu_assign_pointer(*p_filter_chain, tp_head); 317 } 318 319 int tcf_block_get(struct tcf_block **p_block, 320 struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q) 321 { 322 struct tcf_block_ext_info ei = { 323 .chain_head_change = tcf_chain_head_change_dflt, 324 .chain_head_change_priv = p_filter_chain, 325 }; 326 327 WARN_ON(!p_filter_chain); 328 return tcf_block_get_ext(p_block, q, &ei); 329 } 330 EXPORT_SYMBOL(tcf_block_get); 331 332 static void tcf_block_put_final(struct work_struct *work) 333 { 334 struct tcf_block *block = container_of(work, struct tcf_block, work); 335 struct tcf_chain *chain, *tmp; 336 337 rtnl_lock(); 338 339 /* At this point, all the chains should have refcnt == 1. */ 340 list_for_each_entry_safe(chain, tmp, &block->chain_list, list) 341 tcf_chain_put(chain); 342 rtnl_unlock(); 343 kfree(block); 344 } 345 346 /* XXX: Standalone actions are not allowed to jump to any chain, and bound 347 * actions should be all removed after flushing. 348 */ 349 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q, 350 struct tcf_block_ext_info *ei) 351 { 352 struct tcf_chain *chain; 353 354 if (!block) 355 return; 356 /* Hold a refcnt for all chains, except 0, so that they don't disappear 357 * while we are iterating. 358 */ 359 list_for_each_entry(chain, &block->chain_list, list) 360 if (chain->index) 361 tcf_chain_hold(chain); 362 363 list_for_each_entry(chain, &block->chain_list, list) 364 tcf_chain_flush(chain); 365 366 tcf_block_offload_unbind(block, q, ei); 367 368 INIT_WORK(&block->work, tcf_block_put_final); 369 /* Wait for existing RCU callbacks to cool down, make sure their works 370 * have been queued before this. We can not flush pending works here 371 * because we are holding the RTNL lock. 372 */ 373 rcu_barrier(); 374 tcf_queue_work(&block->work); 375 } 376 EXPORT_SYMBOL(tcf_block_put_ext); 377 378 void tcf_block_put(struct tcf_block *block) 379 { 380 struct tcf_block_ext_info ei = {0, }; 381 382 tcf_block_put_ext(block, block->q, &ei); 383 } 384 385 EXPORT_SYMBOL(tcf_block_put); 386 387 struct tcf_block_cb { 388 struct list_head list; 389 tc_setup_cb_t *cb; 390 void *cb_ident; 391 void *cb_priv; 392 unsigned int refcnt; 393 }; 394 395 void *tcf_block_cb_priv(struct tcf_block_cb *block_cb) 396 { 397 return block_cb->cb_priv; 398 } 399 EXPORT_SYMBOL(tcf_block_cb_priv); 400 401 struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block, 402 tc_setup_cb_t *cb, void *cb_ident) 403 { struct tcf_block_cb *block_cb; 404 405 list_for_each_entry(block_cb, &block->cb_list, list) 406 if (block_cb->cb == cb && block_cb->cb_ident == cb_ident) 407 return block_cb; 408 return NULL; 409 } 410 EXPORT_SYMBOL(tcf_block_cb_lookup); 411 412 void tcf_block_cb_incref(struct tcf_block_cb *block_cb) 413 { 414 block_cb->refcnt++; 415 } 416 EXPORT_SYMBOL(tcf_block_cb_incref); 417 418 unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb) 419 { 420 return --block_cb->refcnt; 421 } 422 EXPORT_SYMBOL(tcf_block_cb_decref); 423 424 struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block, 425 tc_setup_cb_t *cb, void *cb_ident, 426 void *cb_priv) 427 { 428 struct tcf_block_cb *block_cb; 429 430 block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL); 431 if (!block_cb) 432 return NULL; 433 block_cb->cb = cb; 434 block_cb->cb_ident = cb_ident; 435 block_cb->cb_priv = cb_priv; 436 list_add(&block_cb->list, &block->cb_list); 437 return block_cb; 438 } 439 EXPORT_SYMBOL(__tcf_block_cb_register); 440 441 int tcf_block_cb_register(struct tcf_block *block, 442 tc_setup_cb_t *cb, void *cb_ident, 443 void *cb_priv) 444 { 445 struct tcf_block_cb *block_cb; 446 447 block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv); 448 return block_cb ? 0 : -ENOMEM; 449 } 450 EXPORT_SYMBOL(tcf_block_cb_register); 451 452 void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb) 453 { 454 list_del(&block_cb->list); 455 kfree(block_cb); 456 } 457 EXPORT_SYMBOL(__tcf_block_cb_unregister); 458 459 void tcf_block_cb_unregister(struct tcf_block *block, 460 tc_setup_cb_t *cb, void *cb_ident) 461 { 462 struct tcf_block_cb *block_cb; 463 464 block_cb = tcf_block_cb_lookup(block, cb, cb_ident); 465 if (!block_cb) 466 return; 467 __tcf_block_cb_unregister(block_cb); 468 } 469 EXPORT_SYMBOL(tcf_block_cb_unregister); 470 471 static int tcf_block_cb_call(struct tcf_block *block, enum tc_setup_type type, 472 void *type_data, bool err_stop) 473 { 474 struct tcf_block_cb *block_cb; 475 int ok_count = 0; 476 int err; 477 478 list_for_each_entry(block_cb, &block->cb_list, list) { 479 err = block_cb->cb(type, type_data, block_cb->cb_priv); 480 if (err) { 481 if (err_stop) 482 return err; 483 } else { 484 ok_count++; 485 } 486 } 487 return ok_count; 488 } 489 490 /* Main classifier routine: scans classifier chain attached 491 * to this qdisc, (optionally) tests for protocol and asks 492 * specific classifiers. 493 */ 494 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, 495 struct tcf_result *res, bool compat_mode) 496 { 497 __be16 protocol = tc_skb_protocol(skb); 498 #ifdef CONFIG_NET_CLS_ACT 499 const int max_reclassify_loop = 4; 500 const struct tcf_proto *orig_tp = tp; 501 const struct tcf_proto *first_tp; 502 int limit = 0; 503 504 reclassify: 505 #endif 506 for (; tp; tp = rcu_dereference_bh(tp->next)) { 507 int err; 508 509 if (tp->protocol != protocol && 510 tp->protocol != htons(ETH_P_ALL)) 511 continue; 512 513 err = tp->classify(skb, tp, res); 514 #ifdef CONFIG_NET_CLS_ACT 515 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) { 516 first_tp = orig_tp; 517 goto reset; 518 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) { 519 first_tp = res->goto_tp; 520 goto reset; 521 } 522 #endif 523 if (err >= 0) 524 return err; 525 } 526 527 return TC_ACT_UNSPEC; /* signal: continue lookup */ 528 #ifdef CONFIG_NET_CLS_ACT 529 reset: 530 if (unlikely(limit++ >= max_reclassify_loop)) { 531 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n", 532 tp->q->ops->id, tp->prio & 0xffff, 533 ntohs(tp->protocol)); 534 return TC_ACT_SHOT; 535 } 536 537 tp = first_tp; 538 protocol = tc_skb_protocol(skb); 539 goto reclassify; 540 #endif 541 } 542 EXPORT_SYMBOL(tcf_classify); 543 544 struct tcf_chain_info { 545 struct tcf_proto __rcu **pprev; 546 struct tcf_proto __rcu *next; 547 }; 548 549 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info) 550 { 551 return rtnl_dereference(*chain_info->pprev); 552 } 553 554 static void tcf_chain_tp_insert(struct tcf_chain *chain, 555 struct tcf_chain_info *chain_info, 556 struct tcf_proto *tp) 557 { 558 if (*chain_info->pprev == chain->filter_chain) 559 tcf_chain_head_change(chain, tp); 560 RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info)); 561 rcu_assign_pointer(*chain_info->pprev, tp); 562 tcf_chain_hold(chain); 563 } 564 565 static void tcf_chain_tp_remove(struct tcf_chain *chain, 566 struct tcf_chain_info *chain_info, 567 struct tcf_proto *tp) 568 { 569 struct tcf_proto *next = rtnl_dereference(chain_info->next); 570 571 if (tp == chain->filter_chain) 572 tcf_chain_head_change(chain, next); 573 RCU_INIT_POINTER(*chain_info->pprev, next); 574 tcf_chain_put(chain); 575 } 576 577 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain, 578 struct tcf_chain_info *chain_info, 579 u32 protocol, u32 prio, 580 bool prio_allocate) 581 { 582 struct tcf_proto **pprev; 583 struct tcf_proto *tp; 584 585 /* Check the chain for existence of proto-tcf with this priority */ 586 for (pprev = &chain->filter_chain; 587 (tp = rtnl_dereference(*pprev)); pprev = &tp->next) { 588 if (tp->prio >= prio) { 589 if (tp->prio == prio) { 590 if (prio_allocate || 591 (tp->protocol != protocol && protocol)) 592 return ERR_PTR(-EINVAL); 593 } else { 594 tp = NULL; 595 } 596 break; 597 } 598 } 599 chain_info->pprev = pprev; 600 chain_info->next = tp ? tp->next : NULL; 601 return tp; 602 } 603 604 static int tcf_fill_node(struct net *net, struct sk_buff *skb, 605 struct tcf_proto *tp, struct Qdisc *q, u32 parent, 606 void *fh, u32 portid, u32 seq, u16 flags, int event) 607 { 608 struct tcmsg *tcm; 609 struct nlmsghdr *nlh; 610 unsigned char *b = skb_tail_pointer(skb); 611 612 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 613 if (!nlh) 614 goto out_nlmsg_trim; 615 tcm = nlmsg_data(nlh); 616 tcm->tcm_family = AF_UNSPEC; 617 tcm->tcm__pad1 = 0; 618 tcm->tcm__pad2 = 0; 619 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 620 tcm->tcm_parent = parent; 621 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol); 622 if (nla_put_string(skb, TCA_KIND, tp->ops->kind)) 623 goto nla_put_failure; 624 if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index)) 625 goto nla_put_failure; 626 if (!fh) { 627 tcm->tcm_handle = 0; 628 } else { 629 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0) 630 goto nla_put_failure; 631 } 632 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 633 return skb->len; 634 635 out_nlmsg_trim: 636 nla_put_failure: 637 nlmsg_trim(skb, b); 638 return -1; 639 } 640 641 static int tfilter_notify(struct net *net, struct sk_buff *oskb, 642 struct nlmsghdr *n, struct tcf_proto *tp, 643 struct Qdisc *q, u32 parent, 644 void *fh, int event, bool unicast) 645 { 646 struct sk_buff *skb; 647 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 648 649 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 650 if (!skb) 651 return -ENOBUFS; 652 653 if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq, 654 n->nlmsg_flags, event) <= 0) { 655 kfree_skb(skb); 656 return -EINVAL; 657 } 658 659 if (unicast) 660 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 661 662 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 663 n->nlmsg_flags & NLM_F_ECHO); 664 } 665 666 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb, 667 struct nlmsghdr *n, struct tcf_proto *tp, 668 struct Qdisc *q, u32 parent, 669 void *fh, bool unicast, bool *last) 670 { 671 struct sk_buff *skb; 672 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 673 int err; 674 675 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 676 if (!skb) 677 return -ENOBUFS; 678 679 if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq, 680 n->nlmsg_flags, RTM_DELTFILTER) <= 0) { 681 kfree_skb(skb); 682 return -EINVAL; 683 } 684 685 err = tp->ops->delete(tp, fh, last); 686 if (err) { 687 kfree_skb(skb); 688 return err; 689 } 690 691 if (unicast) 692 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 693 694 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 695 n->nlmsg_flags & NLM_F_ECHO); 696 } 697 698 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb, 699 struct Qdisc *q, u32 parent, 700 struct nlmsghdr *n, 701 struct tcf_chain *chain, int event) 702 { 703 struct tcf_proto *tp; 704 705 for (tp = rtnl_dereference(chain->filter_chain); 706 tp; tp = rtnl_dereference(tp->next)) 707 tfilter_notify(net, oskb, n, tp, q, parent, 0, event, false); 708 } 709 710 /* Add/change/delete/get a filter node */ 711 712 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 713 struct netlink_ext_ack *extack) 714 { 715 struct net *net = sock_net(skb->sk); 716 struct nlattr *tca[TCA_MAX + 1]; 717 struct tcmsg *t; 718 u32 protocol; 719 u32 prio; 720 bool prio_allocate; 721 u32 parent; 722 u32 chain_index; 723 struct net_device *dev; 724 struct Qdisc *q; 725 struct tcf_chain_info chain_info; 726 struct tcf_chain *chain = NULL; 727 struct tcf_block *block; 728 struct tcf_proto *tp; 729 const struct Qdisc_class_ops *cops; 730 unsigned long cl; 731 void *fh; 732 int err; 733 int tp_created; 734 735 if ((n->nlmsg_type != RTM_GETTFILTER) && 736 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) 737 return -EPERM; 738 739 replay: 740 tp_created = 0; 741 742 err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack); 743 if (err < 0) 744 return err; 745 746 t = nlmsg_data(n); 747 protocol = TC_H_MIN(t->tcm_info); 748 prio = TC_H_MAJ(t->tcm_info); 749 prio_allocate = false; 750 parent = t->tcm_parent; 751 cl = 0; 752 753 if (prio == 0) { 754 switch (n->nlmsg_type) { 755 case RTM_DELTFILTER: 756 if (protocol || t->tcm_handle || tca[TCA_KIND]) 757 return -ENOENT; 758 break; 759 case RTM_NEWTFILTER: 760 /* If no priority is provided by the user, 761 * we allocate one. 762 */ 763 if (n->nlmsg_flags & NLM_F_CREATE) { 764 prio = TC_H_MAKE(0x80000000U, 0U); 765 prio_allocate = true; 766 break; 767 } 768 /* fall-through */ 769 default: 770 return -ENOENT; 771 } 772 } 773 774 /* Find head of filter chain. */ 775 776 /* Find link */ 777 dev = __dev_get_by_index(net, t->tcm_ifindex); 778 if (dev == NULL) 779 return -ENODEV; 780 781 /* Find qdisc */ 782 if (!parent) { 783 q = dev->qdisc; 784 parent = q->handle; 785 } else { 786 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent)); 787 if (q == NULL) 788 return -EINVAL; 789 } 790 791 /* Is it classful? */ 792 cops = q->ops->cl_ops; 793 if (!cops) 794 return -EINVAL; 795 796 if (!cops->tcf_block) 797 return -EOPNOTSUPP; 798 799 /* Do we search for filter, attached to class? */ 800 if (TC_H_MIN(parent)) { 801 cl = cops->find(q, parent); 802 if (cl == 0) 803 return -ENOENT; 804 } 805 806 /* And the last stroke */ 807 block = cops->tcf_block(q, cl); 808 if (!block) { 809 err = -EINVAL; 810 goto errout; 811 } 812 813 chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0; 814 if (chain_index > TC_ACT_EXT_VAL_MASK) { 815 err = -EINVAL; 816 goto errout; 817 } 818 chain = tcf_chain_get(block, chain_index, 819 n->nlmsg_type == RTM_NEWTFILTER); 820 if (!chain) { 821 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL; 822 goto errout; 823 } 824 825 if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) { 826 tfilter_notify_chain(net, skb, q, parent, n, 827 chain, RTM_DELTFILTER); 828 tcf_chain_flush(chain); 829 err = 0; 830 goto errout; 831 } 832 833 tp = tcf_chain_tp_find(chain, &chain_info, protocol, 834 prio, prio_allocate); 835 if (IS_ERR(tp)) { 836 err = PTR_ERR(tp); 837 goto errout; 838 } 839 840 if (tp == NULL) { 841 /* Proto-tcf does not exist, create new one */ 842 843 if (tca[TCA_KIND] == NULL || !protocol) { 844 err = -EINVAL; 845 goto errout; 846 } 847 848 if (n->nlmsg_type != RTM_NEWTFILTER || 849 !(n->nlmsg_flags & NLM_F_CREATE)) { 850 err = -ENOENT; 851 goto errout; 852 } 853 854 if (prio_allocate) 855 prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info)); 856 857 tp = tcf_proto_create(nla_data(tca[TCA_KIND]), 858 protocol, prio, parent, q, chain); 859 if (IS_ERR(tp)) { 860 err = PTR_ERR(tp); 861 goto errout; 862 } 863 tp_created = 1; 864 } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) { 865 err = -EINVAL; 866 goto errout; 867 } 868 869 fh = tp->ops->get(tp, t->tcm_handle); 870 871 if (!fh) { 872 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { 873 tcf_chain_tp_remove(chain, &chain_info, tp); 874 tfilter_notify(net, skb, n, tp, q, parent, fh, 875 RTM_DELTFILTER, false); 876 tcf_proto_destroy(tp); 877 err = 0; 878 goto errout; 879 } 880 881 if (n->nlmsg_type != RTM_NEWTFILTER || 882 !(n->nlmsg_flags & NLM_F_CREATE)) { 883 err = -ENOENT; 884 goto errout; 885 } 886 } else { 887 bool last; 888 889 switch (n->nlmsg_type) { 890 case RTM_NEWTFILTER: 891 if (n->nlmsg_flags & NLM_F_EXCL) { 892 if (tp_created) 893 tcf_proto_destroy(tp); 894 err = -EEXIST; 895 goto errout; 896 } 897 break; 898 case RTM_DELTFILTER: 899 err = tfilter_del_notify(net, skb, n, tp, q, parent, 900 fh, false, &last); 901 if (err) 902 goto errout; 903 if (last) { 904 tcf_chain_tp_remove(chain, &chain_info, tp); 905 tcf_proto_destroy(tp); 906 } 907 goto errout; 908 case RTM_GETTFILTER: 909 err = tfilter_notify(net, skb, n, tp, q, parent, fh, 910 RTM_NEWTFILTER, true); 911 goto errout; 912 default: 913 err = -EINVAL; 914 goto errout; 915 } 916 } 917 918 err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh, 919 n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE); 920 if (err == 0) { 921 if (tp_created) 922 tcf_chain_tp_insert(chain, &chain_info, tp); 923 tfilter_notify(net, skb, n, tp, q, parent, fh, 924 RTM_NEWTFILTER, false); 925 } else { 926 if (tp_created) 927 tcf_proto_destroy(tp); 928 } 929 930 errout: 931 if (chain) 932 tcf_chain_put(chain); 933 if (err == -EAGAIN) 934 /* Replay the request. */ 935 goto replay; 936 return err; 937 } 938 939 struct tcf_dump_args { 940 struct tcf_walker w; 941 struct sk_buff *skb; 942 struct netlink_callback *cb; 943 struct Qdisc *q; 944 u32 parent; 945 }; 946 947 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 948 { 949 struct tcf_dump_args *a = (void *)arg; 950 struct net *net = sock_net(a->skb->sk); 951 952 return tcf_fill_node(net, a->skb, tp, a->q, a->parent, 953 n, NETLINK_CB(a->cb->skb).portid, 954 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 955 RTM_NEWTFILTER); 956 } 957 958 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent, 959 struct sk_buff *skb, struct netlink_callback *cb, 960 long index_start, long *p_index) 961 { 962 struct net *net = sock_net(skb->sk); 963 struct tcmsg *tcm = nlmsg_data(cb->nlh); 964 struct tcf_dump_args arg; 965 struct tcf_proto *tp; 966 967 for (tp = rtnl_dereference(chain->filter_chain); 968 tp; tp = rtnl_dereference(tp->next), (*p_index)++) { 969 if (*p_index < index_start) 970 continue; 971 if (TC_H_MAJ(tcm->tcm_info) && 972 TC_H_MAJ(tcm->tcm_info) != tp->prio) 973 continue; 974 if (TC_H_MIN(tcm->tcm_info) && 975 TC_H_MIN(tcm->tcm_info) != tp->protocol) 976 continue; 977 if (*p_index > index_start) 978 memset(&cb->args[1], 0, 979 sizeof(cb->args) - sizeof(cb->args[0])); 980 if (cb->args[1] == 0) { 981 if (tcf_fill_node(net, skb, tp, q, parent, 0, 982 NETLINK_CB(cb->skb).portid, 983 cb->nlh->nlmsg_seq, NLM_F_MULTI, 984 RTM_NEWTFILTER) <= 0) 985 return false; 986 987 cb->args[1] = 1; 988 } 989 if (!tp->ops->walk) 990 continue; 991 arg.w.fn = tcf_node_dump; 992 arg.skb = skb; 993 arg.cb = cb; 994 arg.q = q; 995 arg.parent = parent; 996 arg.w.stop = 0; 997 arg.w.skip = cb->args[1] - 1; 998 arg.w.count = 0; 999 tp->ops->walk(tp, &arg.w); 1000 cb->args[1] = arg.w.count + 1; 1001 if (arg.w.stop) 1002 return false; 1003 } 1004 return true; 1005 } 1006 1007 /* called with RTNL */ 1008 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) 1009 { 1010 struct net *net = sock_net(skb->sk); 1011 struct nlattr *tca[TCA_MAX + 1]; 1012 struct net_device *dev; 1013 struct Qdisc *q; 1014 struct tcf_block *block; 1015 struct tcf_chain *chain; 1016 struct tcmsg *tcm = nlmsg_data(cb->nlh); 1017 unsigned long cl = 0; 1018 const struct Qdisc_class_ops *cops; 1019 long index_start; 1020 long index; 1021 u32 parent; 1022 int err; 1023 1024 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 1025 return skb->len; 1026 1027 err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL); 1028 if (err) 1029 return err; 1030 1031 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1032 if (!dev) 1033 return skb->len; 1034 1035 parent = tcm->tcm_parent; 1036 if (!parent) { 1037 q = dev->qdisc; 1038 parent = q->handle; 1039 } else { 1040 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); 1041 } 1042 if (!q) 1043 goto out; 1044 cops = q->ops->cl_ops; 1045 if (!cops) 1046 goto out; 1047 if (!cops->tcf_block) 1048 goto out; 1049 if (TC_H_MIN(tcm->tcm_parent)) { 1050 cl = cops->find(q, tcm->tcm_parent); 1051 if (cl == 0) 1052 goto out; 1053 } 1054 block = cops->tcf_block(q, cl); 1055 if (!block) 1056 goto out; 1057 1058 index_start = cb->args[0]; 1059 index = 0; 1060 1061 list_for_each_entry(chain, &block->chain_list, list) { 1062 if (tca[TCA_CHAIN] && 1063 nla_get_u32(tca[TCA_CHAIN]) != chain->index) 1064 continue; 1065 if (!tcf_chain_dump(chain, q, parent, skb, cb, 1066 index_start, &index)) 1067 break; 1068 } 1069 1070 cb->args[0] = index; 1071 1072 out: 1073 return skb->len; 1074 } 1075 1076 void tcf_exts_destroy(struct tcf_exts *exts) 1077 { 1078 #ifdef CONFIG_NET_CLS_ACT 1079 LIST_HEAD(actions); 1080 1081 ASSERT_RTNL(); 1082 tcf_exts_to_list(exts, &actions); 1083 tcf_action_destroy(&actions, TCA_ACT_UNBIND); 1084 kfree(exts->actions); 1085 exts->nr_actions = 0; 1086 #endif 1087 } 1088 EXPORT_SYMBOL(tcf_exts_destroy); 1089 1090 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, 1091 struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr) 1092 { 1093 #ifdef CONFIG_NET_CLS_ACT 1094 { 1095 struct tc_action *act; 1096 1097 if (exts->police && tb[exts->police]) { 1098 act = tcf_action_init_1(net, tp, tb[exts->police], 1099 rate_tlv, "police", ovr, 1100 TCA_ACT_BIND); 1101 if (IS_ERR(act)) 1102 return PTR_ERR(act); 1103 1104 act->type = exts->type = TCA_OLD_COMPAT; 1105 exts->actions[0] = act; 1106 exts->nr_actions = 1; 1107 } else if (exts->action && tb[exts->action]) { 1108 LIST_HEAD(actions); 1109 int err, i = 0; 1110 1111 err = tcf_action_init(net, tp, tb[exts->action], 1112 rate_tlv, NULL, ovr, TCA_ACT_BIND, 1113 &actions); 1114 if (err) 1115 return err; 1116 list_for_each_entry(act, &actions, list) 1117 exts->actions[i++] = act; 1118 exts->nr_actions = i; 1119 } 1120 exts->net = net; 1121 } 1122 #else 1123 if ((exts->action && tb[exts->action]) || 1124 (exts->police && tb[exts->police])) 1125 return -EOPNOTSUPP; 1126 #endif 1127 1128 return 0; 1129 } 1130 EXPORT_SYMBOL(tcf_exts_validate); 1131 1132 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src) 1133 { 1134 #ifdef CONFIG_NET_CLS_ACT 1135 struct tcf_exts old = *dst; 1136 1137 *dst = *src; 1138 tcf_exts_destroy(&old); 1139 #endif 1140 } 1141 EXPORT_SYMBOL(tcf_exts_change); 1142 1143 #ifdef CONFIG_NET_CLS_ACT 1144 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts) 1145 { 1146 if (exts->nr_actions == 0) 1147 return NULL; 1148 else 1149 return exts->actions[0]; 1150 } 1151 #endif 1152 1153 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts) 1154 { 1155 #ifdef CONFIG_NET_CLS_ACT 1156 struct nlattr *nest; 1157 1158 if (exts->action && tcf_exts_has_actions(exts)) { 1159 /* 1160 * again for backward compatible mode - we want 1161 * to work with both old and new modes of entering 1162 * tc data even if iproute2 was newer - jhs 1163 */ 1164 if (exts->type != TCA_OLD_COMPAT) { 1165 LIST_HEAD(actions); 1166 1167 nest = nla_nest_start(skb, exts->action); 1168 if (nest == NULL) 1169 goto nla_put_failure; 1170 1171 tcf_exts_to_list(exts, &actions); 1172 if (tcf_action_dump(skb, &actions, 0, 0) < 0) 1173 goto nla_put_failure; 1174 nla_nest_end(skb, nest); 1175 } else if (exts->police) { 1176 struct tc_action *act = tcf_exts_first_act(exts); 1177 nest = nla_nest_start(skb, exts->police); 1178 if (nest == NULL || !act) 1179 goto nla_put_failure; 1180 if (tcf_action_dump_old(skb, act, 0, 0) < 0) 1181 goto nla_put_failure; 1182 nla_nest_end(skb, nest); 1183 } 1184 } 1185 return 0; 1186 1187 nla_put_failure: 1188 nla_nest_cancel(skb, nest); 1189 return -1; 1190 #else 1191 return 0; 1192 #endif 1193 } 1194 EXPORT_SYMBOL(tcf_exts_dump); 1195 1196 1197 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts) 1198 { 1199 #ifdef CONFIG_NET_CLS_ACT 1200 struct tc_action *a = tcf_exts_first_act(exts); 1201 if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0) 1202 return -1; 1203 #endif 1204 return 0; 1205 } 1206 EXPORT_SYMBOL(tcf_exts_dump_stats); 1207 1208 static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts, 1209 enum tc_setup_type type, 1210 void *type_data, bool err_stop) 1211 { 1212 int ok_count = 0; 1213 #ifdef CONFIG_NET_CLS_ACT 1214 const struct tc_action *a; 1215 struct net_device *dev; 1216 int i, ret; 1217 1218 if (!tcf_exts_has_actions(exts)) 1219 return 0; 1220 1221 for (i = 0; i < exts->nr_actions; i++) { 1222 a = exts->actions[i]; 1223 if (!a->ops->get_dev) 1224 continue; 1225 dev = a->ops->get_dev(a); 1226 if (!dev) 1227 continue; 1228 ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop); 1229 if (ret < 0) 1230 return ret; 1231 ok_count += ret; 1232 } 1233 #endif 1234 return ok_count; 1235 } 1236 1237 int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts, 1238 enum tc_setup_type type, void *type_data, bool err_stop) 1239 { 1240 int ok_count; 1241 int ret; 1242 1243 ret = tcf_block_cb_call(block, type, type_data, err_stop); 1244 if (ret < 0) 1245 return ret; 1246 ok_count = ret; 1247 1248 if (!exts) 1249 return ok_count; 1250 ret = tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop); 1251 if (ret < 0) 1252 return ret; 1253 ok_count += ret; 1254 1255 return ok_count; 1256 } 1257 EXPORT_SYMBOL(tc_setup_cb_call); 1258 1259 static int __init tc_filter_init(void) 1260 { 1261 tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0); 1262 if (!tc_filter_wq) 1263 return -ENOMEM; 1264 1265 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0); 1266 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0); 1267 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter, 1268 tc_dump_tfilter, 0); 1269 1270 return 0; 1271 } 1272 1273 subsys_initcall(tc_filter_init); 1274