1 /* 2 * net/sched/cls_api.c Packet classifier API. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 * 11 * Changes: 12 * 13 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support 14 * 15 */ 16 17 #include <linux/module.h> 18 #include <linux/types.h> 19 #include <linux/kernel.h> 20 #include <linux/string.h> 21 #include <linux/errno.h> 22 #include <linux/err.h> 23 #include <linux/skbuff.h> 24 #include <linux/init.h> 25 #include <linux/kmod.h> 26 #include <linux/err.h> 27 #include <linux/slab.h> 28 #include <net/net_namespace.h> 29 #include <net/sock.h> 30 #include <net/netlink.h> 31 #include <net/pkt_sched.h> 32 #include <net/pkt_cls.h> 33 34 /* The list of all installed classifier types */ 35 static LIST_HEAD(tcf_proto_base); 36 37 /* Protects list of registered TC modules. It is pure SMP lock. */ 38 static DEFINE_RWLOCK(cls_mod_lock); 39 40 /* Find classifier type by string name */ 41 42 static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind) 43 { 44 const struct tcf_proto_ops *t, *res = NULL; 45 46 if (kind) { 47 read_lock(&cls_mod_lock); 48 list_for_each_entry(t, &tcf_proto_base, head) { 49 if (strcmp(kind, t->kind) == 0) { 50 if (try_module_get(t->owner)) 51 res = t; 52 break; 53 } 54 } 55 read_unlock(&cls_mod_lock); 56 } 57 return res; 58 } 59 60 /* Register(unregister) new classifier type */ 61 62 int register_tcf_proto_ops(struct tcf_proto_ops *ops) 63 { 64 struct tcf_proto_ops *t; 65 int rc = -EEXIST; 66 67 write_lock(&cls_mod_lock); 68 list_for_each_entry(t, &tcf_proto_base, head) 69 if (!strcmp(ops->kind, t->kind)) 70 goto out; 71 72 list_add_tail(&ops->head, &tcf_proto_base); 73 rc = 0; 74 out: 75 write_unlock(&cls_mod_lock); 76 return rc; 77 } 78 EXPORT_SYMBOL(register_tcf_proto_ops); 79 80 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops) 81 { 82 struct tcf_proto_ops *t; 83 int rc = -ENOENT; 84 85 /* Wait for outstanding call_rcu()s, if any, from a 86 * tcf_proto_ops's destroy() handler. 87 */ 88 rcu_barrier(); 89 90 write_lock(&cls_mod_lock); 91 list_for_each_entry(t, &tcf_proto_base, head) { 92 if (t == ops) { 93 list_del(&t->head); 94 rc = 0; 95 break; 96 } 97 } 98 write_unlock(&cls_mod_lock); 99 return rc; 100 } 101 EXPORT_SYMBOL(unregister_tcf_proto_ops); 102 103 /* Select new prio value from the range, managed by kernel. */ 104 105 static inline u32 tcf_auto_prio(struct tcf_proto *tp) 106 { 107 u32 first = TC_H_MAKE(0xC0000000U, 0U); 108 109 if (tp) 110 first = tp->prio - 1; 111 112 return TC_H_MAJ(first); 113 } 114 115 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol, 116 u32 prio, u32 parent, struct Qdisc *q, 117 struct tcf_chain *chain) 118 { 119 struct tcf_proto *tp; 120 int err; 121 122 tp = kzalloc(sizeof(*tp), GFP_KERNEL); 123 if (!tp) 124 return ERR_PTR(-ENOBUFS); 125 126 err = -ENOENT; 127 tp->ops = tcf_proto_lookup_ops(kind); 128 if (!tp->ops) { 129 #ifdef CONFIG_MODULES 130 rtnl_unlock(); 131 request_module("cls_%s", kind); 132 rtnl_lock(); 133 tp->ops = tcf_proto_lookup_ops(kind); 134 /* We dropped the RTNL semaphore in order to perform 135 * the module load. So, even if we succeeded in loading 136 * the module we have to replay the request. We indicate 137 * this using -EAGAIN. 138 */ 139 if (tp->ops) { 140 module_put(tp->ops->owner); 141 err = -EAGAIN; 142 } else { 143 err = -ENOENT; 144 } 145 goto errout; 146 #endif 147 } 148 tp->classify = tp->ops->classify; 149 tp->protocol = protocol; 150 tp->prio = prio; 151 tp->classid = parent; 152 tp->q = q; 153 tp->chain = chain; 154 155 err = tp->ops->init(tp); 156 if (err) { 157 module_put(tp->ops->owner); 158 goto errout; 159 } 160 return tp; 161 162 errout: 163 kfree(tp); 164 return ERR_PTR(err); 165 } 166 167 static void tcf_proto_destroy(struct tcf_proto *tp) 168 { 169 tp->ops->destroy(tp); 170 module_put(tp->ops->owner); 171 kfree_rcu(tp, rcu); 172 } 173 174 static struct tcf_chain *tcf_chain_create(struct tcf_block *block, 175 u32 chain_index) 176 { 177 struct tcf_chain *chain; 178 179 chain = kzalloc(sizeof(*chain), GFP_KERNEL); 180 if (!chain) 181 return NULL; 182 list_add_tail(&chain->list, &block->chain_list); 183 chain->block = block; 184 chain->index = chain_index; 185 chain->refcnt = 1; 186 return chain; 187 } 188 189 static void tcf_chain_flush(struct tcf_chain *chain) 190 { 191 struct tcf_proto *tp; 192 193 if (chain->p_filter_chain) 194 RCU_INIT_POINTER(*chain->p_filter_chain, NULL); 195 while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) { 196 RCU_INIT_POINTER(chain->filter_chain, tp->next); 197 tcf_chain_put(chain); 198 tcf_proto_destroy(tp); 199 } 200 } 201 202 static void tcf_chain_destroy(struct tcf_chain *chain) 203 { 204 list_del(&chain->list); 205 kfree(chain); 206 } 207 208 static void tcf_chain_hold(struct tcf_chain *chain) 209 { 210 ++chain->refcnt; 211 } 212 213 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index, 214 bool create) 215 { 216 struct tcf_chain *chain; 217 218 list_for_each_entry(chain, &block->chain_list, list) { 219 if (chain->index == chain_index) { 220 tcf_chain_hold(chain); 221 return chain; 222 } 223 } 224 225 return create ? tcf_chain_create(block, chain_index) : NULL; 226 } 227 EXPORT_SYMBOL(tcf_chain_get); 228 229 void tcf_chain_put(struct tcf_chain *chain) 230 { 231 if (--chain->refcnt == 0) 232 tcf_chain_destroy(chain); 233 } 234 EXPORT_SYMBOL(tcf_chain_put); 235 236 static void 237 tcf_chain_filter_chain_ptr_set(struct tcf_chain *chain, 238 struct tcf_proto __rcu **p_filter_chain) 239 { 240 chain->p_filter_chain = p_filter_chain; 241 } 242 243 int tcf_block_get(struct tcf_block **p_block, 244 struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q) 245 { 246 struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL); 247 struct tcf_chain *chain; 248 int err; 249 250 if (!block) 251 return -ENOMEM; 252 INIT_LIST_HEAD(&block->chain_list); 253 /* Create chain 0 by default, it has to be always present. */ 254 chain = tcf_chain_create(block, 0); 255 if (!chain) { 256 err = -ENOMEM; 257 goto err_chain_create; 258 } 259 tcf_chain_filter_chain_ptr_set(chain, p_filter_chain); 260 block->net = qdisc_net(q); 261 block->q = q; 262 *p_block = block; 263 return 0; 264 265 err_chain_create: 266 kfree(block); 267 return err; 268 } 269 EXPORT_SYMBOL(tcf_block_get); 270 271 void tcf_block_put(struct tcf_block *block) 272 { 273 struct tcf_chain *chain, *tmp; 274 275 if (!block) 276 return; 277 278 /* XXX: Standalone actions are not allowed to jump to any chain, and 279 * bound actions should be all removed after flushing. However, 280 * filters are destroyed in RCU callbacks, we have to hold the chains 281 * first, otherwise we would always race with RCU callbacks on this list 282 * without proper locking. 283 */ 284 285 /* Wait for existing RCU callbacks to cool down. */ 286 rcu_barrier(); 287 288 /* Hold a refcnt for all chains, except 0, in case they are gone. */ 289 list_for_each_entry(chain, &block->chain_list, list) 290 if (chain->index) 291 tcf_chain_hold(chain); 292 293 /* No race on the list, because no chain could be destroyed. */ 294 list_for_each_entry(chain, &block->chain_list, list) 295 tcf_chain_flush(chain); 296 297 /* Wait for RCU callbacks to release the reference count. */ 298 rcu_barrier(); 299 300 /* At this point, all the chains should have refcnt == 1. */ 301 list_for_each_entry_safe(chain, tmp, &block->chain_list, list) 302 tcf_chain_put(chain); 303 kfree(block); 304 } 305 EXPORT_SYMBOL(tcf_block_put); 306 307 /* Main classifier routine: scans classifier chain attached 308 * to this qdisc, (optionally) tests for protocol and asks 309 * specific classifiers. 310 */ 311 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, 312 struct tcf_result *res, bool compat_mode) 313 { 314 __be16 protocol = tc_skb_protocol(skb); 315 #ifdef CONFIG_NET_CLS_ACT 316 const int max_reclassify_loop = 4; 317 const struct tcf_proto *orig_tp = tp; 318 const struct tcf_proto *first_tp; 319 int limit = 0; 320 321 reclassify: 322 #endif 323 for (; tp; tp = rcu_dereference_bh(tp->next)) { 324 int err; 325 326 if (tp->protocol != protocol && 327 tp->protocol != htons(ETH_P_ALL)) 328 continue; 329 330 err = tp->classify(skb, tp, res); 331 #ifdef CONFIG_NET_CLS_ACT 332 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) { 333 first_tp = orig_tp; 334 goto reset; 335 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) { 336 first_tp = res->goto_tp; 337 goto reset; 338 } 339 #endif 340 if (err >= 0) 341 return err; 342 } 343 344 return TC_ACT_UNSPEC; /* signal: continue lookup */ 345 #ifdef CONFIG_NET_CLS_ACT 346 reset: 347 if (unlikely(limit++ >= max_reclassify_loop)) { 348 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n", 349 tp->q->ops->id, tp->prio & 0xffff, 350 ntohs(tp->protocol)); 351 return TC_ACT_SHOT; 352 } 353 354 tp = first_tp; 355 protocol = tc_skb_protocol(skb); 356 goto reclassify; 357 #endif 358 } 359 EXPORT_SYMBOL(tcf_classify); 360 361 struct tcf_chain_info { 362 struct tcf_proto __rcu **pprev; 363 struct tcf_proto __rcu *next; 364 }; 365 366 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info) 367 { 368 return rtnl_dereference(*chain_info->pprev); 369 } 370 371 static void tcf_chain_tp_insert(struct tcf_chain *chain, 372 struct tcf_chain_info *chain_info, 373 struct tcf_proto *tp) 374 { 375 if (chain->p_filter_chain && 376 *chain_info->pprev == chain->filter_chain) 377 rcu_assign_pointer(*chain->p_filter_chain, tp); 378 RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info)); 379 rcu_assign_pointer(*chain_info->pprev, tp); 380 tcf_chain_hold(chain); 381 } 382 383 static void tcf_chain_tp_remove(struct tcf_chain *chain, 384 struct tcf_chain_info *chain_info, 385 struct tcf_proto *tp) 386 { 387 struct tcf_proto *next = rtnl_dereference(chain_info->next); 388 389 if (chain->p_filter_chain && tp == chain->filter_chain) 390 RCU_INIT_POINTER(*chain->p_filter_chain, next); 391 RCU_INIT_POINTER(*chain_info->pprev, next); 392 tcf_chain_put(chain); 393 } 394 395 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain, 396 struct tcf_chain_info *chain_info, 397 u32 protocol, u32 prio, 398 bool prio_allocate) 399 { 400 struct tcf_proto **pprev; 401 struct tcf_proto *tp; 402 403 /* Check the chain for existence of proto-tcf with this priority */ 404 for (pprev = &chain->filter_chain; 405 (tp = rtnl_dereference(*pprev)); pprev = &tp->next) { 406 if (tp->prio >= prio) { 407 if (tp->prio == prio) { 408 if (prio_allocate || 409 (tp->protocol != protocol && protocol)) 410 return ERR_PTR(-EINVAL); 411 } else { 412 tp = NULL; 413 } 414 break; 415 } 416 } 417 chain_info->pprev = pprev; 418 chain_info->next = tp ? tp->next : NULL; 419 return tp; 420 } 421 422 static int tcf_fill_node(struct net *net, struct sk_buff *skb, 423 struct tcf_proto *tp, struct Qdisc *q, u32 parent, 424 void *fh, u32 portid, u32 seq, u16 flags, int event) 425 { 426 struct tcmsg *tcm; 427 struct nlmsghdr *nlh; 428 unsigned char *b = skb_tail_pointer(skb); 429 430 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 431 if (!nlh) 432 goto out_nlmsg_trim; 433 tcm = nlmsg_data(nlh); 434 tcm->tcm_family = AF_UNSPEC; 435 tcm->tcm__pad1 = 0; 436 tcm->tcm__pad2 = 0; 437 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 438 tcm->tcm_parent = parent; 439 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol); 440 if (nla_put_string(skb, TCA_KIND, tp->ops->kind)) 441 goto nla_put_failure; 442 if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index)) 443 goto nla_put_failure; 444 if (!fh) { 445 tcm->tcm_handle = 0; 446 } else { 447 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0) 448 goto nla_put_failure; 449 } 450 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 451 return skb->len; 452 453 out_nlmsg_trim: 454 nla_put_failure: 455 nlmsg_trim(skb, b); 456 return -1; 457 } 458 459 static int tfilter_notify(struct net *net, struct sk_buff *oskb, 460 struct nlmsghdr *n, struct tcf_proto *tp, 461 struct Qdisc *q, u32 parent, 462 void *fh, int event, bool unicast) 463 { 464 struct sk_buff *skb; 465 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 466 467 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 468 if (!skb) 469 return -ENOBUFS; 470 471 if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq, 472 n->nlmsg_flags, event) <= 0) { 473 kfree_skb(skb); 474 return -EINVAL; 475 } 476 477 if (unicast) 478 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 479 480 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 481 n->nlmsg_flags & NLM_F_ECHO); 482 } 483 484 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb, 485 struct nlmsghdr *n, struct tcf_proto *tp, 486 struct Qdisc *q, u32 parent, 487 void *fh, bool unicast, bool *last) 488 { 489 struct sk_buff *skb; 490 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 491 int err; 492 493 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 494 if (!skb) 495 return -ENOBUFS; 496 497 if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq, 498 n->nlmsg_flags, RTM_DELTFILTER) <= 0) { 499 kfree_skb(skb); 500 return -EINVAL; 501 } 502 503 err = tp->ops->delete(tp, fh, last); 504 if (err) { 505 kfree_skb(skb); 506 return err; 507 } 508 509 if (unicast) 510 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 511 512 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 513 n->nlmsg_flags & NLM_F_ECHO); 514 } 515 516 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb, 517 struct Qdisc *q, u32 parent, 518 struct nlmsghdr *n, 519 struct tcf_chain *chain, int event) 520 { 521 struct tcf_proto *tp; 522 523 for (tp = rtnl_dereference(chain->filter_chain); 524 tp; tp = rtnl_dereference(tp->next)) 525 tfilter_notify(net, oskb, n, tp, q, parent, 0, event, false); 526 } 527 528 /* Add/change/delete/get a filter node */ 529 530 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 531 struct netlink_ext_ack *extack) 532 { 533 struct net *net = sock_net(skb->sk); 534 struct nlattr *tca[TCA_MAX + 1]; 535 struct tcmsg *t; 536 u32 protocol; 537 u32 prio; 538 bool prio_allocate; 539 u32 parent; 540 u32 chain_index; 541 struct net_device *dev; 542 struct Qdisc *q; 543 struct tcf_chain_info chain_info; 544 struct tcf_chain *chain = NULL; 545 struct tcf_block *block; 546 struct tcf_proto *tp; 547 const struct Qdisc_class_ops *cops; 548 unsigned long cl; 549 void *fh; 550 int err; 551 int tp_created; 552 553 if ((n->nlmsg_type != RTM_GETTFILTER) && 554 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) 555 return -EPERM; 556 557 replay: 558 tp_created = 0; 559 560 err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack); 561 if (err < 0) 562 return err; 563 564 t = nlmsg_data(n); 565 protocol = TC_H_MIN(t->tcm_info); 566 prio = TC_H_MAJ(t->tcm_info); 567 prio_allocate = false; 568 parent = t->tcm_parent; 569 cl = 0; 570 571 if (prio == 0) { 572 switch (n->nlmsg_type) { 573 case RTM_DELTFILTER: 574 if (protocol || t->tcm_handle || tca[TCA_KIND]) 575 return -ENOENT; 576 break; 577 case RTM_NEWTFILTER: 578 /* If no priority is provided by the user, 579 * we allocate one. 580 */ 581 if (n->nlmsg_flags & NLM_F_CREATE) { 582 prio = TC_H_MAKE(0x80000000U, 0U); 583 prio_allocate = true; 584 break; 585 } 586 /* fall-through */ 587 default: 588 return -ENOENT; 589 } 590 } 591 592 /* Find head of filter chain. */ 593 594 /* Find link */ 595 dev = __dev_get_by_index(net, t->tcm_ifindex); 596 if (dev == NULL) 597 return -ENODEV; 598 599 /* Find qdisc */ 600 if (!parent) { 601 q = dev->qdisc; 602 parent = q->handle; 603 } else { 604 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent)); 605 if (q == NULL) 606 return -EINVAL; 607 } 608 609 /* Is it classful? */ 610 cops = q->ops->cl_ops; 611 if (!cops) 612 return -EINVAL; 613 614 if (!cops->tcf_block) 615 return -EOPNOTSUPP; 616 617 /* Do we search for filter, attached to class? */ 618 if (TC_H_MIN(parent)) { 619 cl = cops->find(q, parent); 620 if (cl == 0) 621 return -ENOENT; 622 } 623 624 /* And the last stroke */ 625 block = cops->tcf_block(q, cl); 626 if (!block) { 627 err = -EINVAL; 628 goto errout; 629 } 630 631 chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0; 632 if (chain_index > TC_ACT_EXT_VAL_MASK) { 633 err = -EINVAL; 634 goto errout; 635 } 636 chain = tcf_chain_get(block, chain_index, 637 n->nlmsg_type == RTM_NEWTFILTER); 638 if (!chain) { 639 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL; 640 goto errout; 641 } 642 643 if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) { 644 tfilter_notify_chain(net, skb, q, parent, n, 645 chain, RTM_DELTFILTER); 646 tcf_chain_flush(chain); 647 err = 0; 648 goto errout; 649 } 650 651 tp = tcf_chain_tp_find(chain, &chain_info, protocol, 652 prio, prio_allocate); 653 if (IS_ERR(tp)) { 654 err = PTR_ERR(tp); 655 goto errout; 656 } 657 658 if (tp == NULL) { 659 /* Proto-tcf does not exist, create new one */ 660 661 if (tca[TCA_KIND] == NULL || !protocol) { 662 err = -EINVAL; 663 goto errout; 664 } 665 666 if (n->nlmsg_type != RTM_NEWTFILTER || 667 !(n->nlmsg_flags & NLM_F_CREATE)) { 668 err = -ENOENT; 669 goto errout; 670 } 671 672 if (prio_allocate) 673 prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info)); 674 675 tp = tcf_proto_create(nla_data(tca[TCA_KIND]), 676 protocol, prio, parent, q, chain); 677 if (IS_ERR(tp)) { 678 err = PTR_ERR(tp); 679 goto errout; 680 } 681 tp_created = 1; 682 } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) { 683 err = -EINVAL; 684 goto errout; 685 } 686 687 fh = tp->ops->get(tp, t->tcm_handle); 688 689 if (!fh) { 690 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { 691 tcf_chain_tp_remove(chain, &chain_info, tp); 692 tfilter_notify(net, skb, n, tp, q, parent, fh, 693 RTM_DELTFILTER, false); 694 tcf_proto_destroy(tp); 695 err = 0; 696 goto errout; 697 } 698 699 if (n->nlmsg_type != RTM_NEWTFILTER || 700 !(n->nlmsg_flags & NLM_F_CREATE)) { 701 err = -ENOENT; 702 goto errout; 703 } 704 } else { 705 bool last; 706 707 switch (n->nlmsg_type) { 708 case RTM_NEWTFILTER: 709 if (n->nlmsg_flags & NLM_F_EXCL) { 710 if (tp_created) 711 tcf_proto_destroy(tp); 712 err = -EEXIST; 713 goto errout; 714 } 715 break; 716 case RTM_DELTFILTER: 717 err = tfilter_del_notify(net, skb, n, tp, q, parent, 718 fh, false, &last); 719 if (err) 720 goto errout; 721 if (last) { 722 tcf_chain_tp_remove(chain, &chain_info, tp); 723 tcf_proto_destroy(tp); 724 } 725 goto errout; 726 case RTM_GETTFILTER: 727 err = tfilter_notify(net, skb, n, tp, q, parent, fh, 728 RTM_NEWTFILTER, true); 729 goto errout; 730 default: 731 err = -EINVAL; 732 goto errout; 733 } 734 } 735 736 err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh, 737 n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE); 738 if (err == 0) { 739 if (tp_created) 740 tcf_chain_tp_insert(chain, &chain_info, tp); 741 tfilter_notify(net, skb, n, tp, q, parent, fh, 742 RTM_NEWTFILTER, false); 743 } else { 744 if (tp_created) 745 tcf_proto_destroy(tp); 746 } 747 748 errout: 749 if (chain) 750 tcf_chain_put(chain); 751 if (err == -EAGAIN) 752 /* Replay the request. */ 753 goto replay; 754 return err; 755 } 756 757 struct tcf_dump_args { 758 struct tcf_walker w; 759 struct sk_buff *skb; 760 struct netlink_callback *cb; 761 struct Qdisc *q; 762 u32 parent; 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, a->q, a->parent, 771 n, NETLINK_CB(a->cb->skb).portid, 772 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 773 RTM_NEWTFILTER); 774 } 775 776 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent, 777 struct sk_buff *skb, struct netlink_callback *cb, 778 long index_start, long *p_index) 779 { 780 struct net *net = sock_net(skb->sk); 781 struct tcmsg *tcm = nlmsg_data(cb->nlh); 782 struct tcf_dump_args arg; 783 struct tcf_proto *tp; 784 785 for (tp = rtnl_dereference(chain->filter_chain); 786 tp; tp = rtnl_dereference(tp->next), (*p_index)++) { 787 if (*p_index < index_start) 788 continue; 789 if (TC_H_MAJ(tcm->tcm_info) && 790 TC_H_MAJ(tcm->tcm_info) != tp->prio) 791 continue; 792 if (TC_H_MIN(tcm->tcm_info) && 793 TC_H_MIN(tcm->tcm_info) != tp->protocol) 794 continue; 795 if (*p_index > index_start) 796 memset(&cb->args[1], 0, 797 sizeof(cb->args) - sizeof(cb->args[0])); 798 if (cb->args[1] == 0) { 799 if (tcf_fill_node(net, skb, tp, q, parent, 0, 800 NETLINK_CB(cb->skb).portid, 801 cb->nlh->nlmsg_seq, NLM_F_MULTI, 802 RTM_NEWTFILTER) <= 0) 803 return false; 804 805 cb->args[1] = 1; 806 } 807 if (!tp->ops->walk) 808 continue; 809 arg.w.fn = tcf_node_dump; 810 arg.skb = skb; 811 arg.cb = cb; 812 arg.q = q; 813 arg.parent = parent; 814 arg.w.stop = 0; 815 arg.w.skip = cb->args[1] - 1; 816 arg.w.count = 0; 817 tp->ops->walk(tp, &arg.w); 818 cb->args[1] = arg.w.count + 1; 819 if (arg.w.stop) 820 return false; 821 } 822 return true; 823 } 824 825 /* called with RTNL */ 826 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) 827 { 828 struct net *net = sock_net(skb->sk); 829 struct nlattr *tca[TCA_MAX + 1]; 830 struct net_device *dev; 831 struct Qdisc *q; 832 struct tcf_block *block; 833 struct tcf_chain *chain; 834 struct tcmsg *tcm = nlmsg_data(cb->nlh); 835 unsigned long cl = 0; 836 const struct Qdisc_class_ops *cops; 837 long index_start; 838 long index; 839 u32 parent; 840 int err; 841 842 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 843 return skb->len; 844 845 err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL); 846 if (err) 847 return err; 848 849 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 850 if (!dev) 851 return skb->len; 852 853 parent = tcm->tcm_parent; 854 if (!parent) { 855 q = dev->qdisc; 856 parent = q->handle; 857 } else { 858 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); 859 } 860 if (!q) 861 goto out; 862 cops = q->ops->cl_ops; 863 if (!cops) 864 goto out; 865 if (!cops->tcf_block) 866 goto out; 867 if (TC_H_MIN(tcm->tcm_parent)) { 868 cl = cops->find(q, tcm->tcm_parent); 869 if (cl == 0) 870 goto out; 871 } 872 block = cops->tcf_block(q, cl); 873 if (!block) 874 goto out; 875 876 index_start = cb->args[0]; 877 index = 0; 878 879 list_for_each_entry(chain, &block->chain_list, list) { 880 if (tca[TCA_CHAIN] && 881 nla_get_u32(tca[TCA_CHAIN]) != chain->index) 882 continue; 883 if (!tcf_chain_dump(chain, q, parent, skb, cb, 884 index_start, &index)) 885 break; 886 } 887 888 cb->args[0] = index; 889 890 out: 891 return skb->len; 892 } 893 894 void tcf_exts_destroy(struct tcf_exts *exts) 895 { 896 #ifdef CONFIG_NET_CLS_ACT 897 LIST_HEAD(actions); 898 899 tcf_exts_to_list(exts, &actions); 900 tcf_action_destroy(&actions, TCA_ACT_UNBIND); 901 kfree(exts->actions); 902 exts->nr_actions = 0; 903 #endif 904 } 905 EXPORT_SYMBOL(tcf_exts_destroy); 906 907 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, 908 struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr) 909 { 910 #ifdef CONFIG_NET_CLS_ACT 911 { 912 struct tc_action *act; 913 914 if (exts->police && tb[exts->police]) { 915 act = tcf_action_init_1(net, tp, tb[exts->police], 916 rate_tlv, "police", ovr, 917 TCA_ACT_BIND); 918 if (IS_ERR(act)) 919 return PTR_ERR(act); 920 921 act->type = exts->type = TCA_OLD_COMPAT; 922 exts->actions[0] = act; 923 exts->nr_actions = 1; 924 } else if (exts->action && tb[exts->action]) { 925 LIST_HEAD(actions); 926 int err, i = 0; 927 928 err = tcf_action_init(net, tp, tb[exts->action], 929 rate_tlv, NULL, ovr, TCA_ACT_BIND, 930 &actions); 931 if (err) 932 return err; 933 list_for_each_entry(act, &actions, list) 934 exts->actions[i++] = act; 935 exts->nr_actions = i; 936 } 937 } 938 #else 939 if ((exts->action && tb[exts->action]) || 940 (exts->police && tb[exts->police])) 941 return -EOPNOTSUPP; 942 #endif 943 944 return 0; 945 } 946 EXPORT_SYMBOL(tcf_exts_validate); 947 948 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src) 949 { 950 #ifdef CONFIG_NET_CLS_ACT 951 struct tcf_exts old = *dst; 952 953 *dst = *src; 954 tcf_exts_destroy(&old); 955 #endif 956 } 957 EXPORT_SYMBOL(tcf_exts_change); 958 959 #ifdef CONFIG_NET_CLS_ACT 960 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts) 961 { 962 if (exts->nr_actions == 0) 963 return NULL; 964 else 965 return exts->actions[0]; 966 } 967 #endif 968 969 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts) 970 { 971 #ifdef CONFIG_NET_CLS_ACT 972 struct nlattr *nest; 973 974 if (exts->action && tcf_exts_has_actions(exts)) { 975 /* 976 * again for backward compatible mode - we want 977 * to work with both old and new modes of entering 978 * tc data even if iproute2 was newer - jhs 979 */ 980 if (exts->type != TCA_OLD_COMPAT) { 981 LIST_HEAD(actions); 982 983 nest = nla_nest_start(skb, exts->action); 984 if (nest == NULL) 985 goto nla_put_failure; 986 987 tcf_exts_to_list(exts, &actions); 988 if (tcf_action_dump(skb, &actions, 0, 0) < 0) 989 goto nla_put_failure; 990 nla_nest_end(skb, nest); 991 } else if (exts->police) { 992 struct tc_action *act = tcf_exts_first_act(exts); 993 nest = nla_nest_start(skb, exts->police); 994 if (nest == NULL || !act) 995 goto nla_put_failure; 996 if (tcf_action_dump_old(skb, act, 0, 0) < 0) 997 goto nla_put_failure; 998 nla_nest_end(skb, nest); 999 } 1000 } 1001 return 0; 1002 1003 nla_put_failure: 1004 nla_nest_cancel(skb, nest); 1005 return -1; 1006 #else 1007 return 0; 1008 #endif 1009 } 1010 EXPORT_SYMBOL(tcf_exts_dump); 1011 1012 1013 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts) 1014 { 1015 #ifdef CONFIG_NET_CLS_ACT 1016 struct tc_action *a = tcf_exts_first_act(exts); 1017 if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0) 1018 return -1; 1019 #endif 1020 return 0; 1021 } 1022 EXPORT_SYMBOL(tcf_exts_dump_stats); 1023 1024 static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts, 1025 enum tc_setup_type type, 1026 void *type_data, bool err_stop) 1027 { 1028 int ok_count = 0; 1029 #ifdef CONFIG_NET_CLS_ACT 1030 const struct tc_action *a; 1031 struct net_device *dev; 1032 LIST_HEAD(actions); 1033 int ret; 1034 1035 if (!tcf_exts_has_actions(exts)) 1036 return 0; 1037 1038 tcf_exts_to_list(exts, &actions); 1039 list_for_each_entry(a, &actions, list) { 1040 if (!a->ops->get_dev) 1041 continue; 1042 dev = a->ops->get_dev(a); 1043 if (!dev || !tc_can_offload(dev)) 1044 continue; 1045 ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop); 1046 if (ret < 0) 1047 return ret; 1048 ok_count += ret; 1049 } 1050 #endif 1051 return ok_count; 1052 } 1053 1054 int tc_setup_cb_call(struct tcf_exts *exts, enum tc_setup_type type, 1055 void *type_data, bool err_stop) 1056 { 1057 return tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop); 1058 } 1059 EXPORT_SYMBOL(tc_setup_cb_call); 1060 1061 static int __init tc_filter_init(void) 1062 { 1063 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0); 1064 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0); 1065 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter, 1066 tc_dump_tfilter, 0); 1067 1068 return 0; 1069 } 1070 1071 subsys_initcall(tc_filter_init); 1072