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 struct tcf_block *block = chain->block; 221 222 list_del(&chain->list); 223 kfree(chain); 224 if (list_empty(&block->chain_list)) 225 kfree(block); 226 } 227 228 static void tcf_chain_hold(struct tcf_chain *chain) 229 { 230 ++chain->refcnt; 231 } 232 233 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index, 234 bool create) 235 { 236 struct tcf_chain *chain; 237 238 list_for_each_entry(chain, &block->chain_list, list) { 239 if (chain->index == chain_index) { 240 tcf_chain_hold(chain); 241 return chain; 242 } 243 } 244 245 return create ? tcf_chain_create(block, chain_index) : NULL; 246 } 247 EXPORT_SYMBOL(tcf_chain_get); 248 249 void tcf_chain_put(struct tcf_chain *chain) 250 { 251 if (--chain->refcnt == 0) 252 tcf_chain_destroy(chain); 253 } 254 EXPORT_SYMBOL(tcf_chain_put); 255 256 static void tcf_block_offload_cmd(struct tcf_block *block, struct Qdisc *q, 257 struct tcf_block_ext_info *ei, 258 enum tc_block_command command) 259 { 260 struct net_device *dev = q->dev_queue->dev; 261 struct tc_block_offload bo = {}; 262 263 if (!dev->netdev_ops->ndo_setup_tc) 264 return; 265 bo.command = command; 266 bo.binder_type = ei->binder_type; 267 bo.block = block; 268 dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo); 269 } 270 271 static void tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q, 272 struct tcf_block_ext_info *ei) 273 { 274 tcf_block_offload_cmd(block, q, ei, TC_BLOCK_BIND); 275 } 276 277 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q, 278 struct tcf_block_ext_info *ei) 279 { 280 tcf_block_offload_cmd(block, q, ei, TC_BLOCK_UNBIND); 281 } 282 283 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q, 284 struct tcf_block_ext_info *ei, 285 struct netlink_ext_ack *extack) 286 { 287 struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL); 288 struct tcf_chain *chain; 289 int err; 290 291 if (!block) { 292 NL_SET_ERR_MSG(extack, "Memory allocation for block failed"); 293 return -ENOMEM; 294 } 295 INIT_LIST_HEAD(&block->chain_list); 296 INIT_LIST_HEAD(&block->cb_list); 297 298 /* Create chain 0 by default, it has to be always present. */ 299 chain = tcf_chain_create(block, 0); 300 if (!chain) { 301 NL_SET_ERR_MSG(extack, "Failed to create new tcf chain"); 302 err = -ENOMEM; 303 goto err_chain_create; 304 } 305 WARN_ON(!ei->chain_head_change); 306 chain->chain_head_change = ei->chain_head_change; 307 chain->chain_head_change_priv = ei->chain_head_change_priv; 308 block->net = qdisc_net(q); 309 block->q = q; 310 tcf_block_offload_bind(block, q, ei); 311 *p_block = block; 312 return 0; 313 314 err_chain_create: 315 kfree(block); 316 return err; 317 } 318 EXPORT_SYMBOL(tcf_block_get_ext); 319 320 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv) 321 { 322 struct tcf_proto __rcu **p_filter_chain = priv; 323 324 rcu_assign_pointer(*p_filter_chain, tp_head); 325 } 326 327 int tcf_block_get(struct tcf_block **p_block, 328 struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q, 329 struct netlink_ext_ack *extack) 330 { 331 struct tcf_block_ext_info ei = { 332 .chain_head_change = tcf_chain_head_change_dflt, 333 .chain_head_change_priv = p_filter_chain, 334 }; 335 336 WARN_ON(!p_filter_chain); 337 return tcf_block_get_ext(p_block, q, &ei, extack); 338 } 339 EXPORT_SYMBOL(tcf_block_get); 340 341 /* XXX: Standalone actions are not allowed to jump to any chain, and bound 342 * actions should be all removed after flushing. 343 */ 344 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q, 345 struct tcf_block_ext_info *ei) 346 { 347 struct tcf_chain *chain, *tmp; 348 349 /* Hold a refcnt for all chains, so that they don't disappear 350 * while we are iterating. 351 */ 352 if (!block) 353 return; 354 list_for_each_entry(chain, &block->chain_list, list) 355 tcf_chain_hold(chain); 356 357 list_for_each_entry(chain, &block->chain_list, list) 358 tcf_chain_flush(chain); 359 360 tcf_block_offload_unbind(block, q, ei); 361 362 /* At this point, all the chains should have refcnt >= 1. */ 363 list_for_each_entry_safe(chain, tmp, &block->chain_list, list) 364 tcf_chain_put(chain); 365 366 /* Finally, put chain 0 and allow block to be freed. */ 367 chain = list_first_entry(&block->chain_list, struct tcf_chain, list); 368 tcf_chain_put(chain); 369 } 370 EXPORT_SYMBOL(tcf_block_put_ext); 371 372 void tcf_block_put(struct tcf_block *block) 373 { 374 struct tcf_block_ext_info ei = {0, }; 375 376 if (!block) 377 return; 378 tcf_block_put_ext(block, block->q, &ei); 379 } 380 381 EXPORT_SYMBOL(tcf_block_put); 382 383 struct tcf_block_cb { 384 struct list_head list; 385 tc_setup_cb_t *cb; 386 void *cb_ident; 387 void *cb_priv; 388 unsigned int refcnt; 389 }; 390 391 void *tcf_block_cb_priv(struct tcf_block_cb *block_cb) 392 { 393 return block_cb->cb_priv; 394 } 395 EXPORT_SYMBOL(tcf_block_cb_priv); 396 397 struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block, 398 tc_setup_cb_t *cb, void *cb_ident) 399 { struct tcf_block_cb *block_cb; 400 401 list_for_each_entry(block_cb, &block->cb_list, list) 402 if (block_cb->cb == cb && block_cb->cb_ident == cb_ident) 403 return block_cb; 404 return NULL; 405 } 406 EXPORT_SYMBOL(tcf_block_cb_lookup); 407 408 void tcf_block_cb_incref(struct tcf_block_cb *block_cb) 409 { 410 block_cb->refcnt++; 411 } 412 EXPORT_SYMBOL(tcf_block_cb_incref); 413 414 unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb) 415 { 416 return --block_cb->refcnt; 417 } 418 EXPORT_SYMBOL(tcf_block_cb_decref); 419 420 struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block, 421 tc_setup_cb_t *cb, void *cb_ident, 422 void *cb_priv) 423 { 424 struct tcf_block_cb *block_cb; 425 426 block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL); 427 if (!block_cb) 428 return NULL; 429 block_cb->cb = cb; 430 block_cb->cb_ident = cb_ident; 431 block_cb->cb_priv = cb_priv; 432 list_add(&block_cb->list, &block->cb_list); 433 return block_cb; 434 } 435 EXPORT_SYMBOL(__tcf_block_cb_register); 436 437 int tcf_block_cb_register(struct tcf_block *block, 438 tc_setup_cb_t *cb, void *cb_ident, 439 void *cb_priv) 440 { 441 struct tcf_block_cb *block_cb; 442 443 block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv); 444 return block_cb ? 0 : -ENOMEM; 445 } 446 EXPORT_SYMBOL(tcf_block_cb_register); 447 448 void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb) 449 { 450 list_del(&block_cb->list); 451 kfree(block_cb); 452 } 453 EXPORT_SYMBOL(__tcf_block_cb_unregister); 454 455 void tcf_block_cb_unregister(struct tcf_block *block, 456 tc_setup_cb_t *cb, void *cb_ident) 457 { 458 struct tcf_block_cb *block_cb; 459 460 block_cb = tcf_block_cb_lookup(block, cb, cb_ident); 461 if (!block_cb) 462 return; 463 __tcf_block_cb_unregister(block_cb); 464 } 465 EXPORT_SYMBOL(tcf_block_cb_unregister); 466 467 static int tcf_block_cb_call(struct tcf_block *block, enum tc_setup_type type, 468 void *type_data, bool err_stop) 469 { 470 struct tcf_block_cb *block_cb; 471 int ok_count = 0; 472 int err; 473 474 list_for_each_entry(block_cb, &block->cb_list, list) { 475 err = block_cb->cb(type, type_data, block_cb->cb_priv); 476 if (err) { 477 if (err_stop) 478 return err; 479 } else { 480 ok_count++; 481 } 482 } 483 return ok_count; 484 } 485 486 /* Main classifier routine: scans classifier chain attached 487 * to this qdisc, (optionally) tests for protocol and asks 488 * specific classifiers. 489 */ 490 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, 491 struct tcf_result *res, bool compat_mode) 492 { 493 __be16 protocol = tc_skb_protocol(skb); 494 #ifdef CONFIG_NET_CLS_ACT 495 const int max_reclassify_loop = 4; 496 const struct tcf_proto *orig_tp = tp; 497 const struct tcf_proto *first_tp; 498 int limit = 0; 499 500 reclassify: 501 #endif 502 for (; tp; tp = rcu_dereference_bh(tp->next)) { 503 int err; 504 505 if (tp->protocol != protocol && 506 tp->protocol != htons(ETH_P_ALL)) 507 continue; 508 509 err = tp->classify(skb, tp, res); 510 #ifdef CONFIG_NET_CLS_ACT 511 if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) { 512 first_tp = orig_tp; 513 goto reset; 514 } else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) { 515 first_tp = res->goto_tp; 516 goto reset; 517 } 518 #endif 519 if (err >= 0) 520 return err; 521 } 522 523 return TC_ACT_UNSPEC; /* signal: continue lookup */ 524 #ifdef CONFIG_NET_CLS_ACT 525 reset: 526 if (unlikely(limit++ >= max_reclassify_loop)) { 527 net_notice_ratelimited("%s: reclassify loop, rule prio %u, protocol %02x\n", 528 tp->q->ops->id, tp->prio & 0xffff, 529 ntohs(tp->protocol)); 530 return TC_ACT_SHOT; 531 } 532 533 tp = first_tp; 534 protocol = tc_skb_protocol(skb); 535 goto reclassify; 536 #endif 537 } 538 EXPORT_SYMBOL(tcf_classify); 539 540 struct tcf_chain_info { 541 struct tcf_proto __rcu **pprev; 542 struct tcf_proto __rcu *next; 543 }; 544 545 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info) 546 { 547 return rtnl_dereference(*chain_info->pprev); 548 } 549 550 static void tcf_chain_tp_insert(struct tcf_chain *chain, 551 struct tcf_chain_info *chain_info, 552 struct tcf_proto *tp) 553 { 554 if (*chain_info->pprev == chain->filter_chain) 555 tcf_chain_head_change(chain, tp); 556 RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info)); 557 rcu_assign_pointer(*chain_info->pprev, tp); 558 tcf_chain_hold(chain); 559 } 560 561 static void tcf_chain_tp_remove(struct tcf_chain *chain, 562 struct tcf_chain_info *chain_info, 563 struct tcf_proto *tp) 564 { 565 struct tcf_proto *next = rtnl_dereference(chain_info->next); 566 567 if (tp == chain->filter_chain) 568 tcf_chain_head_change(chain, next); 569 RCU_INIT_POINTER(*chain_info->pprev, next); 570 tcf_chain_put(chain); 571 } 572 573 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain, 574 struct tcf_chain_info *chain_info, 575 u32 protocol, u32 prio, 576 bool prio_allocate) 577 { 578 struct tcf_proto **pprev; 579 struct tcf_proto *tp; 580 581 /* Check the chain for existence of proto-tcf with this priority */ 582 for (pprev = &chain->filter_chain; 583 (tp = rtnl_dereference(*pprev)); pprev = &tp->next) { 584 if (tp->prio >= prio) { 585 if (tp->prio == prio) { 586 if (prio_allocate || 587 (tp->protocol != protocol && protocol)) 588 return ERR_PTR(-EINVAL); 589 } else { 590 tp = NULL; 591 } 592 break; 593 } 594 } 595 chain_info->pprev = pprev; 596 chain_info->next = tp ? tp->next : NULL; 597 return tp; 598 } 599 600 static int tcf_fill_node(struct net *net, struct sk_buff *skb, 601 struct tcf_proto *tp, struct Qdisc *q, u32 parent, 602 void *fh, u32 portid, u32 seq, u16 flags, int event) 603 { 604 struct tcmsg *tcm; 605 struct nlmsghdr *nlh; 606 unsigned char *b = skb_tail_pointer(skb); 607 608 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 609 if (!nlh) 610 goto out_nlmsg_trim; 611 tcm = nlmsg_data(nlh); 612 tcm->tcm_family = AF_UNSPEC; 613 tcm->tcm__pad1 = 0; 614 tcm->tcm__pad2 = 0; 615 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 616 tcm->tcm_parent = parent; 617 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol); 618 if (nla_put_string(skb, TCA_KIND, tp->ops->kind)) 619 goto nla_put_failure; 620 if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index)) 621 goto nla_put_failure; 622 if (!fh) { 623 tcm->tcm_handle = 0; 624 } else { 625 if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0) 626 goto nla_put_failure; 627 } 628 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 629 return skb->len; 630 631 out_nlmsg_trim: 632 nla_put_failure: 633 nlmsg_trim(skb, b); 634 return -1; 635 } 636 637 static int tfilter_notify(struct net *net, struct sk_buff *oskb, 638 struct nlmsghdr *n, struct tcf_proto *tp, 639 struct Qdisc *q, u32 parent, 640 void *fh, int event, bool unicast) 641 { 642 struct sk_buff *skb; 643 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 644 645 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 646 if (!skb) 647 return -ENOBUFS; 648 649 if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq, 650 n->nlmsg_flags, event) <= 0) { 651 kfree_skb(skb); 652 return -EINVAL; 653 } 654 655 if (unicast) 656 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 657 658 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 659 n->nlmsg_flags & NLM_F_ECHO); 660 } 661 662 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb, 663 struct nlmsghdr *n, struct tcf_proto *tp, 664 struct Qdisc *q, u32 parent, 665 void *fh, bool unicast, bool *last) 666 { 667 struct sk_buff *skb; 668 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 669 int err; 670 671 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 672 if (!skb) 673 return -ENOBUFS; 674 675 if (tcf_fill_node(net, skb, tp, q, parent, fh, portid, n->nlmsg_seq, 676 n->nlmsg_flags, RTM_DELTFILTER) <= 0) { 677 kfree_skb(skb); 678 return -EINVAL; 679 } 680 681 err = tp->ops->delete(tp, fh, last); 682 if (err) { 683 kfree_skb(skb); 684 return err; 685 } 686 687 if (unicast) 688 return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT); 689 690 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 691 n->nlmsg_flags & NLM_F_ECHO); 692 } 693 694 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb, 695 struct Qdisc *q, u32 parent, 696 struct nlmsghdr *n, 697 struct tcf_chain *chain, int event) 698 { 699 struct tcf_proto *tp; 700 701 for (tp = rtnl_dereference(chain->filter_chain); 702 tp; tp = rtnl_dereference(tp->next)) 703 tfilter_notify(net, oskb, n, tp, q, parent, 0, event, false); 704 } 705 706 /* Add/change/delete/get a filter node */ 707 708 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 709 struct netlink_ext_ack *extack) 710 { 711 struct net *net = sock_net(skb->sk); 712 struct nlattr *tca[TCA_MAX + 1]; 713 struct tcmsg *t; 714 u32 protocol; 715 u32 prio; 716 bool prio_allocate; 717 u32 parent; 718 u32 chain_index; 719 struct net_device *dev; 720 struct Qdisc *q; 721 struct tcf_chain_info chain_info; 722 struct tcf_chain *chain = NULL; 723 struct tcf_block *block; 724 struct tcf_proto *tp; 725 const struct Qdisc_class_ops *cops; 726 unsigned long cl; 727 void *fh; 728 int err; 729 int tp_created; 730 731 if ((n->nlmsg_type != RTM_GETTFILTER) && 732 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) 733 return -EPERM; 734 735 replay: 736 tp_created = 0; 737 738 err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL, extack); 739 if (err < 0) 740 return err; 741 742 t = nlmsg_data(n); 743 protocol = TC_H_MIN(t->tcm_info); 744 prio = TC_H_MAJ(t->tcm_info); 745 prio_allocate = false; 746 parent = t->tcm_parent; 747 cl = 0; 748 749 if (prio == 0) { 750 switch (n->nlmsg_type) { 751 case RTM_DELTFILTER: 752 if (protocol || t->tcm_handle || tca[TCA_KIND]) 753 return -ENOENT; 754 break; 755 case RTM_NEWTFILTER: 756 /* If no priority is provided by the user, 757 * we allocate one. 758 */ 759 if (n->nlmsg_flags & NLM_F_CREATE) { 760 prio = TC_H_MAKE(0x80000000U, 0U); 761 prio_allocate = true; 762 break; 763 } 764 /* fall-through */ 765 default: 766 return -ENOENT; 767 } 768 } 769 770 /* Find head of filter chain. */ 771 772 /* Find link */ 773 dev = __dev_get_by_index(net, t->tcm_ifindex); 774 if (dev == NULL) 775 return -ENODEV; 776 777 /* Find qdisc */ 778 if (!parent) { 779 q = dev->qdisc; 780 parent = q->handle; 781 } else { 782 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent)); 783 if (q == NULL) 784 return -EINVAL; 785 } 786 787 /* Is it classful? */ 788 cops = q->ops->cl_ops; 789 if (!cops) 790 return -EINVAL; 791 792 if (!cops->tcf_block) 793 return -EOPNOTSUPP; 794 795 /* Do we search for filter, attached to class? */ 796 if (TC_H_MIN(parent)) { 797 cl = cops->find(q, parent); 798 if (cl == 0) 799 return -ENOENT; 800 } 801 802 /* And the last stroke */ 803 block = cops->tcf_block(q, cl, extack); 804 if (!block) { 805 err = -EINVAL; 806 goto errout; 807 } 808 809 chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0; 810 if (chain_index > TC_ACT_EXT_VAL_MASK) { 811 err = -EINVAL; 812 goto errout; 813 } 814 chain = tcf_chain_get(block, chain_index, 815 n->nlmsg_type == RTM_NEWTFILTER); 816 if (!chain) { 817 err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL; 818 goto errout; 819 } 820 821 if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) { 822 tfilter_notify_chain(net, skb, q, parent, n, 823 chain, RTM_DELTFILTER); 824 tcf_chain_flush(chain); 825 err = 0; 826 goto errout; 827 } 828 829 tp = tcf_chain_tp_find(chain, &chain_info, protocol, 830 prio, prio_allocate); 831 if (IS_ERR(tp)) { 832 err = PTR_ERR(tp); 833 goto errout; 834 } 835 836 if (tp == NULL) { 837 /* Proto-tcf does not exist, create new one */ 838 839 if (tca[TCA_KIND] == NULL || !protocol) { 840 err = -EINVAL; 841 goto errout; 842 } 843 844 if (n->nlmsg_type != RTM_NEWTFILTER || 845 !(n->nlmsg_flags & NLM_F_CREATE)) { 846 err = -ENOENT; 847 goto errout; 848 } 849 850 if (prio_allocate) 851 prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info)); 852 853 tp = tcf_proto_create(nla_data(tca[TCA_KIND]), 854 protocol, prio, parent, q, chain); 855 if (IS_ERR(tp)) { 856 err = PTR_ERR(tp); 857 goto errout; 858 } 859 tp_created = 1; 860 } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) { 861 err = -EINVAL; 862 goto errout; 863 } 864 865 fh = tp->ops->get(tp, t->tcm_handle); 866 867 if (!fh) { 868 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { 869 tcf_chain_tp_remove(chain, &chain_info, tp); 870 tfilter_notify(net, skb, n, tp, q, parent, fh, 871 RTM_DELTFILTER, false); 872 tcf_proto_destroy(tp); 873 err = 0; 874 goto errout; 875 } 876 877 if (n->nlmsg_type != RTM_NEWTFILTER || 878 !(n->nlmsg_flags & NLM_F_CREATE)) { 879 err = -ENOENT; 880 goto errout; 881 } 882 } else { 883 bool last; 884 885 switch (n->nlmsg_type) { 886 case RTM_NEWTFILTER: 887 if (n->nlmsg_flags & NLM_F_EXCL) { 888 if (tp_created) 889 tcf_proto_destroy(tp); 890 err = -EEXIST; 891 goto errout; 892 } 893 break; 894 case RTM_DELTFILTER: 895 err = tfilter_del_notify(net, skb, n, tp, q, parent, 896 fh, false, &last); 897 if (err) 898 goto errout; 899 if (last) { 900 tcf_chain_tp_remove(chain, &chain_info, tp); 901 tcf_proto_destroy(tp); 902 } 903 goto errout; 904 case RTM_GETTFILTER: 905 err = tfilter_notify(net, skb, n, tp, q, parent, fh, 906 RTM_NEWTFILTER, true); 907 goto errout; 908 default: 909 err = -EINVAL; 910 goto errout; 911 } 912 } 913 914 err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh, 915 n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE); 916 if (err == 0) { 917 if (tp_created) 918 tcf_chain_tp_insert(chain, &chain_info, tp); 919 tfilter_notify(net, skb, n, tp, q, parent, fh, 920 RTM_NEWTFILTER, false); 921 } else { 922 if (tp_created) 923 tcf_proto_destroy(tp); 924 } 925 926 errout: 927 if (chain) 928 tcf_chain_put(chain); 929 if (err == -EAGAIN) 930 /* Replay the request. */ 931 goto replay; 932 return err; 933 } 934 935 struct tcf_dump_args { 936 struct tcf_walker w; 937 struct sk_buff *skb; 938 struct netlink_callback *cb; 939 struct Qdisc *q; 940 u32 parent; 941 }; 942 943 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 944 { 945 struct tcf_dump_args *a = (void *)arg; 946 struct net *net = sock_net(a->skb->sk); 947 948 return tcf_fill_node(net, a->skb, tp, a->q, a->parent, 949 n, NETLINK_CB(a->cb->skb).portid, 950 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 951 RTM_NEWTFILTER); 952 } 953 954 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent, 955 struct sk_buff *skb, struct netlink_callback *cb, 956 long index_start, long *p_index) 957 { 958 struct net *net = sock_net(skb->sk); 959 struct tcmsg *tcm = nlmsg_data(cb->nlh); 960 struct tcf_dump_args arg; 961 struct tcf_proto *tp; 962 963 for (tp = rtnl_dereference(chain->filter_chain); 964 tp; tp = rtnl_dereference(tp->next), (*p_index)++) { 965 if (*p_index < index_start) 966 continue; 967 if (TC_H_MAJ(tcm->tcm_info) && 968 TC_H_MAJ(tcm->tcm_info) != tp->prio) 969 continue; 970 if (TC_H_MIN(tcm->tcm_info) && 971 TC_H_MIN(tcm->tcm_info) != tp->protocol) 972 continue; 973 if (*p_index > index_start) 974 memset(&cb->args[1], 0, 975 sizeof(cb->args) - sizeof(cb->args[0])); 976 if (cb->args[1] == 0) { 977 if (tcf_fill_node(net, skb, tp, q, parent, 0, 978 NETLINK_CB(cb->skb).portid, 979 cb->nlh->nlmsg_seq, NLM_F_MULTI, 980 RTM_NEWTFILTER) <= 0) 981 return false; 982 983 cb->args[1] = 1; 984 } 985 if (!tp->ops->walk) 986 continue; 987 arg.w.fn = tcf_node_dump; 988 arg.skb = skb; 989 arg.cb = cb; 990 arg.q = q; 991 arg.parent = parent; 992 arg.w.stop = 0; 993 arg.w.skip = cb->args[1] - 1; 994 arg.w.count = 0; 995 tp->ops->walk(tp, &arg.w); 996 cb->args[1] = arg.w.count + 1; 997 if (arg.w.stop) 998 return false; 999 } 1000 return true; 1001 } 1002 1003 /* called with RTNL */ 1004 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) 1005 { 1006 struct net *net = sock_net(skb->sk); 1007 struct nlattr *tca[TCA_MAX + 1]; 1008 struct net_device *dev; 1009 struct Qdisc *q; 1010 struct tcf_block *block; 1011 struct tcf_chain *chain; 1012 struct tcmsg *tcm = nlmsg_data(cb->nlh); 1013 unsigned long cl = 0; 1014 const struct Qdisc_class_ops *cops; 1015 long index_start; 1016 long index; 1017 u32 parent; 1018 int err; 1019 1020 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 1021 return skb->len; 1022 1023 err = nlmsg_parse(cb->nlh, sizeof(*tcm), tca, TCA_MAX, NULL, NULL); 1024 if (err) 1025 return err; 1026 1027 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1028 if (!dev) 1029 return skb->len; 1030 1031 parent = tcm->tcm_parent; 1032 if (!parent) { 1033 q = dev->qdisc; 1034 parent = q->handle; 1035 } else { 1036 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); 1037 } 1038 if (!q) 1039 goto out; 1040 cops = q->ops->cl_ops; 1041 if (!cops) 1042 goto out; 1043 if (!cops->tcf_block) 1044 goto out; 1045 if (TC_H_MIN(tcm->tcm_parent)) { 1046 cl = cops->find(q, tcm->tcm_parent); 1047 if (cl == 0) 1048 goto out; 1049 } 1050 block = cops->tcf_block(q, cl, NULL); 1051 if (!block) 1052 goto out; 1053 1054 index_start = cb->args[0]; 1055 index = 0; 1056 1057 list_for_each_entry(chain, &block->chain_list, list) { 1058 if (tca[TCA_CHAIN] && 1059 nla_get_u32(tca[TCA_CHAIN]) != chain->index) 1060 continue; 1061 if (!tcf_chain_dump(chain, q, parent, skb, cb, 1062 index_start, &index)) 1063 break; 1064 } 1065 1066 cb->args[0] = index; 1067 1068 out: 1069 return skb->len; 1070 } 1071 1072 void tcf_exts_destroy(struct tcf_exts *exts) 1073 { 1074 #ifdef CONFIG_NET_CLS_ACT 1075 LIST_HEAD(actions); 1076 1077 ASSERT_RTNL(); 1078 tcf_exts_to_list(exts, &actions); 1079 tcf_action_destroy(&actions, TCA_ACT_UNBIND); 1080 kfree(exts->actions); 1081 exts->nr_actions = 0; 1082 #endif 1083 } 1084 EXPORT_SYMBOL(tcf_exts_destroy); 1085 1086 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, 1087 struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr) 1088 { 1089 #ifdef CONFIG_NET_CLS_ACT 1090 { 1091 struct tc_action *act; 1092 1093 if (exts->police && tb[exts->police]) { 1094 act = tcf_action_init_1(net, tp, tb[exts->police], 1095 rate_tlv, "police", ovr, 1096 TCA_ACT_BIND); 1097 if (IS_ERR(act)) 1098 return PTR_ERR(act); 1099 1100 act->type = exts->type = TCA_OLD_COMPAT; 1101 exts->actions[0] = act; 1102 exts->nr_actions = 1; 1103 } else if (exts->action && tb[exts->action]) { 1104 LIST_HEAD(actions); 1105 int err, i = 0; 1106 1107 err = tcf_action_init(net, tp, tb[exts->action], 1108 rate_tlv, NULL, ovr, TCA_ACT_BIND, 1109 &actions); 1110 if (err) 1111 return err; 1112 list_for_each_entry(act, &actions, list) 1113 exts->actions[i++] = act; 1114 exts->nr_actions = i; 1115 } 1116 exts->net = net; 1117 } 1118 #else 1119 if ((exts->action && tb[exts->action]) || 1120 (exts->police && tb[exts->police])) 1121 return -EOPNOTSUPP; 1122 #endif 1123 1124 return 0; 1125 } 1126 EXPORT_SYMBOL(tcf_exts_validate); 1127 1128 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src) 1129 { 1130 #ifdef CONFIG_NET_CLS_ACT 1131 struct tcf_exts old = *dst; 1132 1133 *dst = *src; 1134 tcf_exts_destroy(&old); 1135 #endif 1136 } 1137 EXPORT_SYMBOL(tcf_exts_change); 1138 1139 #ifdef CONFIG_NET_CLS_ACT 1140 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts) 1141 { 1142 if (exts->nr_actions == 0) 1143 return NULL; 1144 else 1145 return exts->actions[0]; 1146 } 1147 #endif 1148 1149 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts) 1150 { 1151 #ifdef CONFIG_NET_CLS_ACT 1152 struct nlattr *nest; 1153 1154 if (exts->action && tcf_exts_has_actions(exts)) { 1155 /* 1156 * again for backward compatible mode - we want 1157 * to work with both old and new modes of entering 1158 * tc data even if iproute2 was newer - jhs 1159 */ 1160 if (exts->type != TCA_OLD_COMPAT) { 1161 LIST_HEAD(actions); 1162 1163 nest = nla_nest_start(skb, exts->action); 1164 if (nest == NULL) 1165 goto nla_put_failure; 1166 1167 tcf_exts_to_list(exts, &actions); 1168 if (tcf_action_dump(skb, &actions, 0, 0) < 0) 1169 goto nla_put_failure; 1170 nla_nest_end(skb, nest); 1171 } else if (exts->police) { 1172 struct tc_action *act = tcf_exts_first_act(exts); 1173 nest = nla_nest_start(skb, exts->police); 1174 if (nest == NULL || !act) 1175 goto nla_put_failure; 1176 if (tcf_action_dump_old(skb, act, 0, 0) < 0) 1177 goto nla_put_failure; 1178 nla_nest_end(skb, nest); 1179 } 1180 } 1181 return 0; 1182 1183 nla_put_failure: 1184 nla_nest_cancel(skb, nest); 1185 return -1; 1186 #else 1187 return 0; 1188 #endif 1189 } 1190 EXPORT_SYMBOL(tcf_exts_dump); 1191 1192 1193 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts) 1194 { 1195 #ifdef CONFIG_NET_CLS_ACT 1196 struct tc_action *a = tcf_exts_first_act(exts); 1197 if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0) 1198 return -1; 1199 #endif 1200 return 0; 1201 } 1202 EXPORT_SYMBOL(tcf_exts_dump_stats); 1203 1204 static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts, 1205 enum tc_setup_type type, 1206 void *type_data, bool err_stop) 1207 { 1208 int ok_count = 0; 1209 #ifdef CONFIG_NET_CLS_ACT 1210 const struct tc_action *a; 1211 struct net_device *dev; 1212 int i, ret; 1213 1214 if (!tcf_exts_has_actions(exts)) 1215 return 0; 1216 1217 for (i = 0; i < exts->nr_actions; i++) { 1218 a = exts->actions[i]; 1219 if (!a->ops->get_dev) 1220 continue; 1221 dev = a->ops->get_dev(a); 1222 if (!dev) 1223 continue; 1224 ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop); 1225 if (ret < 0) 1226 return ret; 1227 ok_count += ret; 1228 } 1229 #endif 1230 return ok_count; 1231 } 1232 1233 int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts, 1234 enum tc_setup_type type, void *type_data, bool err_stop) 1235 { 1236 int ok_count; 1237 int ret; 1238 1239 ret = tcf_block_cb_call(block, type, type_data, err_stop); 1240 if (ret < 0) 1241 return ret; 1242 ok_count = ret; 1243 1244 if (!exts) 1245 return ok_count; 1246 ret = tc_exts_setup_cb_egdev_call(exts, type, type_data, err_stop); 1247 if (ret < 0) 1248 return ret; 1249 ok_count += ret; 1250 1251 return ok_count; 1252 } 1253 EXPORT_SYMBOL(tc_setup_cb_call); 1254 1255 static int __init tc_filter_init(void) 1256 { 1257 tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0); 1258 if (!tc_filter_wq) 1259 return -ENOMEM; 1260 1261 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0); 1262 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0); 1263 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter, 1264 tc_dump_tfilter, 0); 1265 1266 return 0; 1267 } 1268 1269 subsys_initcall(tc_filter_init); 1270