1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/sched/cls_flow.c Generic flow classifier 4 * 5 * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net> 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/init.h> 10 #include <linux/list.h> 11 #include <linux/jhash.h> 12 #include <linux/random.h> 13 #include <linux/pkt_cls.h> 14 #include <linux/skbuff.h> 15 #include <linux/in.h> 16 #include <linux/ip.h> 17 #include <linux/ipv6.h> 18 #include <linux/if_vlan.h> 19 #include <linux/slab.h> 20 #include <linux/module.h> 21 #include <net/inet_sock.h> 22 23 #include <net/pkt_cls.h> 24 #include <net/ip.h> 25 #include <net/route.h> 26 #include <net/flow_dissector.h> 27 28 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 29 #include <net/netfilter/nf_conntrack.h> 30 #endif 31 32 struct flow_head { 33 struct list_head filters; 34 struct rcu_head rcu; 35 }; 36 37 struct flow_filter { 38 struct list_head list; 39 struct tcf_exts exts; 40 struct tcf_ematch_tree ematches; 41 struct tcf_proto *tp; 42 struct timer_list perturb_timer; 43 u32 perturb_period; 44 u32 handle; 45 46 u32 nkeys; 47 u32 keymask; 48 u32 mode; 49 u32 mask; 50 u32 xor; 51 u32 rshift; 52 u32 addend; 53 u32 divisor; 54 u32 baseclass; 55 u32 hashrnd; 56 struct rcu_work rwork; 57 }; 58 59 static inline u32 addr_fold(void *addr) 60 { 61 unsigned long a = (unsigned long)addr; 62 63 return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0); 64 } 65 66 static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow) 67 { 68 __be32 src = flow_get_u32_src(flow); 69 70 if (src) 71 return ntohl(src); 72 73 return addr_fold(skb->sk); 74 } 75 76 static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow) 77 { 78 __be32 dst = flow_get_u32_dst(flow); 79 80 if (dst) 81 return ntohl(dst); 82 83 return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb); 84 } 85 86 static u32 flow_get_proto(const struct sk_buff *skb, 87 const struct flow_keys *flow) 88 { 89 return flow->basic.ip_proto; 90 } 91 92 static u32 flow_get_proto_src(const struct sk_buff *skb, 93 const struct flow_keys *flow) 94 { 95 if (flow->ports.ports) 96 return ntohs(flow->ports.src); 97 98 return addr_fold(skb->sk); 99 } 100 101 static u32 flow_get_proto_dst(const struct sk_buff *skb, 102 const struct flow_keys *flow) 103 { 104 if (flow->ports.ports) 105 return ntohs(flow->ports.dst); 106 107 return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb); 108 } 109 110 static u32 flow_get_iif(const struct sk_buff *skb) 111 { 112 return skb->skb_iif; 113 } 114 115 static u32 flow_get_priority(const struct sk_buff *skb) 116 { 117 return skb->priority; 118 } 119 120 static u32 flow_get_mark(const struct sk_buff *skb) 121 { 122 return skb->mark; 123 } 124 125 static u32 flow_get_nfct(const struct sk_buff *skb) 126 { 127 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 128 return addr_fold(skb_nfct(skb)); 129 #else 130 return 0; 131 #endif 132 } 133 134 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 135 #define CTTUPLE(skb, member) \ 136 ({ \ 137 enum ip_conntrack_info ctinfo; \ 138 const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \ 139 if (ct == NULL) \ 140 goto fallback; \ 141 ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \ 142 }) 143 #else 144 #define CTTUPLE(skb, member) \ 145 ({ \ 146 goto fallback; \ 147 0; \ 148 }) 149 #endif 150 151 static u32 flow_get_nfct_src(const struct sk_buff *skb, 152 const struct flow_keys *flow) 153 { 154 switch (tc_skb_protocol(skb)) { 155 case htons(ETH_P_IP): 156 return ntohl(CTTUPLE(skb, src.u3.ip)); 157 case htons(ETH_P_IPV6): 158 return ntohl(CTTUPLE(skb, src.u3.ip6[3])); 159 } 160 fallback: 161 return flow_get_src(skb, flow); 162 } 163 164 static u32 flow_get_nfct_dst(const struct sk_buff *skb, 165 const struct flow_keys *flow) 166 { 167 switch (tc_skb_protocol(skb)) { 168 case htons(ETH_P_IP): 169 return ntohl(CTTUPLE(skb, dst.u3.ip)); 170 case htons(ETH_P_IPV6): 171 return ntohl(CTTUPLE(skb, dst.u3.ip6[3])); 172 } 173 fallback: 174 return flow_get_dst(skb, flow); 175 } 176 177 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, 178 const struct flow_keys *flow) 179 { 180 return ntohs(CTTUPLE(skb, src.u.all)); 181 fallback: 182 return flow_get_proto_src(skb, flow); 183 } 184 185 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, 186 const struct flow_keys *flow) 187 { 188 return ntohs(CTTUPLE(skb, dst.u.all)); 189 fallback: 190 return flow_get_proto_dst(skb, flow); 191 } 192 193 static u32 flow_get_rtclassid(const struct sk_buff *skb) 194 { 195 #ifdef CONFIG_IP_ROUTE_CLASSID 196 if (skb_dst(skb)) 197 return skb_dst(skb)->tclassid; 198 #endif 199 return 0; 200 } 201 202 static u32 flow_get_skuid(const struct sk_buff *skb) 203 { 204 struct sock *sk = skb_to_full_sk(skb); 205 206 if (sk && sk->sk_socket && sk->sk_socket->file) { 207 kuid_t skuid = sk->sk_socket->file->f_cred->fsuid; 208 209 return from_kuid(&init_user_ns, skuid); 210 } 211 return 0; 212 } 213 214 static u32 flow_get_skgid(const struct sk_buff *skb) 215 { 216 struct sock *sk = skb_to_full_sk(skb); 217 218 if (sk && sk->sk_socket && sk->sk_socket->file) { 219 kgid_t skgid = sk->sk_socket->file->f_cred->fsgid; 220 221 return from_kgid(&init_user_ns, skgid); 222 } 223 return 0; 224 } 225 226 static u32 flow_get_vlan_tag(const struct sk_buff *skb) 227 { 228 u16 uninitialized_var(tag); 229 230 if (vlan_get_tag(skb, &tag) < 0) 231 return 0; 232 return tag & VLAN_VID_MASK; 233 } 234 235 static u32 flow_get_rxhash(struct sk_buff *skb) 236 { 237 return skb_get_hash(skb); 238 } 239 240 static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow) 241 { 242 switch (key) { 243 case FLOW_KEY_SRC: 244 return flow_get_src(skb, flow); 245 case FLOW_KEY_DST: 246 return flow_get_dst(skb, flow); 247 case FLOW_KEY_PROTO: 248 return flow_get_proto(skb, flow); 249 case FLOW_KEY_PROTO_SRC: 250 return flow_get_proto_src(skb, flow); 251 case FLOW_KEY_PROTO_DST: 252 return flow_get_proto_dst(skb, flow); 253 case FLOW_KEY_IIF: 254 return flow_get_iif(skb); 255 case FLOW_KEY_PRIORITY: 256 return flow_get_priority(skb); 257 case FLOW_KEY_MARK: 258 return flow_get_mark(skb); 259 case FLOW_KEY_NFCT: 260 return flow_get_nfct(skb); 261 case FLOW_KEY_NFCT_SRC: 262 return flow_get_nfct_src(skb, flow); 263 case FLOW_KEY_NFCT_DST: 264 return flow_get_nfct_dst(skb, flow); 265 case FLOW_KEY_NFCT_PROTO_SRC: 266 return flow_get_nfct_proto_src(skb, flow); 267 case FLOW_KEY_NFCT_PROTO_DST: 268 return flow_get_nfct_proto_dst(skb, flow); 269 case FLOW_KEY_RTCLASSID: 270 return flow_get_rtclassid(skb); 271 case FLOW_KEY_SKUID: 272 return flow_get_skuid(skb); 273 case FLOW_KEY_SKGID: 274 return flow_get_skgid(skb); 275 case FLOW_KEY_VLAN_TAG: 276 return flow_get_vlan_tag(skb); 277 case FLOW_KEY_RXHASH: 278 return flow_get_rxhash(skb); 279 default: 280 WARN_ON(1); 281 return 0; 282 } 283 } 284 285 #define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | \ 286 (1 << FLOW_KEY_DST) | \ 287 (1 << FLOW_KEY_PROTO) | \ 288 (1 << FLOW_KEY_PROTO_SRC) | \ 289 (1 << FLOW_KEY_PROTO_DST) | \ 290 (1 << FLOW_KEY_NFCT_SRC) | \ 291 (1 << FLOW_KEY_NFCT_DST) | \ 292 (1 << FLOW_KEY_NFCT_PROTO_SRC) | \ 293 (1 << FLOW_KEY_NFCT_PROTO_DST)) 294 295 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp, 296 struct tcf_result *res) 297 { 298 struct flow_head *head = rcu_dereference_bh(tp->root); 299 struct flow_filter *f; 300 u32 keymask; 301 u32 classid; 302 unsigned int n, key; 303 int r; 304 305 list_for_each_entry_rcu(f, &head->filters, list) { 306 u32 keys[FLOW_KEY_MAX + 1]; 307 struct flow_keys flow_keys; 308 309 if (!tcf_em_tree_match(skb, &f->ematches, NULL)) 310 continue; 311 312 keymask = f->keymask; 313 if (keymask & FLOW_KEYS_NEEDED) 314 skb_flow_dissect_flow_keys(skb, &flow_keys, 0); 315 316 for (n = 0; n < f->nkeys; n++) { 317 key = ffs(keymask) - 1; 318 keymask &= ~(1 << key); 319 keys[n] = flow_key_get(skb, key, &flow_keys); 320 } 321 322 if (f->mode == FLOW_MODE_HASH) 323 classid = jhash2(keys, f->nkeys, f->hashrnd); 324 else { 325 classid = keys[0]; 326 classid = (classid & f->mask) ^ f->xor; 327 classid = (classid >> f->rshift) + f->addend; 328 } 329 330 if (f->divisor) 331 classid %= f->divisor; 332 333 res->class = 0; 334 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid); 335 336 r = tcf_exts_exec(skb, &f->exts, res); 337 if (r < 0) 338 continue; 339 return r; 340 } 341 return -1; 342 } 343 344 static void flow_perturbation(struct timer_list *t) 345 { 346 struct flow_filter *f = from_timer(f, t, perturb_timer); 347 348 get_random_bytes(&f->hashrnd, 4); 349 if (f->perturb_period) 350 mod_timer(&f->perturb_timer, jiffies + f->perturb_period); 351 } 352 353 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = { 354 [TCA_FLOW_KEYS] = { .type = NLA_U32 }, 355 [TCA_FLOW_MODE] = { .type = NLA_U32 }, 356 [TCA_FLOW_BASECLASS] = { .type = NLA_U32 }, 357 [TCA_FLOW_RSHIFT] = { .type = NLA_U32 }, 358 [TCA_FLOW_ADDEND] = { .type = NLA_U32 }, 359 [TCA_FLOW_MASK] = { .type = NLA_U32 }, 360 [TCA_FLOW_XOR] = { .type = NLA_U32 }, 361 [TCA_FLOW_DIVISOR] = { .type = NLA_U32 }, 362 [TCA_FLOW_ACT] = { .type = NLA_NESTED }, 363 [TCA_FLOW_POLICE] = { .type = NLA_NESTED }, 364 [TCA_FLOW_EMATCHES] = { .type = NLA_NESTED }, 365 [TCA_FLOW_PERTURB] = { .type = NLA_U32 }, 366 }; 367 368 static void __flow_destroy_filter(struct flow_filter *f) 369 { 370 del_timer_sync(&f->perturb_timer); 371 tcf_exts_destroy(&f->exts); 372 tcf_em_tree_destroy(&f->ematches); 373 tcf_exts_put_net(&f->exts); 374 kfree(f); 375 } 376 377 static void flow_destroy_filter_work(struct work_struct *work) 378 { 379 struct flow_filter *f = container_of(to_rcu_work(work), 380 struct flow_filter, 381 rwork); 382 rtnl_lock(); 383 __flow_destroy_filter(f); 384 rtnl_unlock(); 385 } 386 387 static int flow_change(struct net *net, struct sk_buff *in_skb, 388 struct tcf_proto *tp, unsigned long base, 389 u32 handle, struct nlattr **tca, 390 void **arg, bool ovr, bool rtnl_held, 391 struct netlink_ext_ack *extack) 392 { 393 struct flow_head *head = rtnl_dereference(tp->root); 394 struct flow_filter *fold, *fnew; 395 struct nlattr *opt = tca[TCA_OPTIONS]; 396 struct nlattr *tb[TCA_FLOW_MAX + 1]; 397 unsigned int nkeys = 0; 398 unsigned int perturb_period = 0; 399 u32 baseclass = 0; 400 u32 keymask = 0; 401 u32 mode; 402 int err; 403 404 if (opt == NULL) 405 return -EINVAL; 406 407 err = nla_parse_nested_deprecated(tb, TCA_FLOW_MAX, opt, flow_policy, 408 NULL); 409 if (err < 0) 410 return err; 411 412 if (tb[TCA_FLOW_BASECLASS]) { 413 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]); 414 if (TC_H_MIN(baseclass) == 0) 415 return -EINVAL; 416 } 417 418 if (tb[TCA_FLOW_KEYS]) { 419 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]); 420 421 nkeys = hweight32(keymask); 422 if (nkeys == 0) 423 return -EINVAL; 424 425 if (fls(keymask) - 1 > FLOW_KEY_MAX) 426 return -EOPNOTSUPP; 427 428 if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) && 429 sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns) 430 return -EOPNOTSUPP; 431 } 432 433 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); 434 if (!fnew) 435 return -ENOBUFS; 436 437 err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &fnew->ematches); 438 if (err < 0) 439 goto err1; 440 441 err = tcf_exts_init(&fnew->exts, net, TCA_FLOW_ACT, TCA_FLOW_POLICE); 442 if (err < 0) 443 goto err2; 444 445 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, ovr, 446 true, extack); 447 if (err < 0) 448 goto err2; 449 450 fold = *arg; 451 if (fold) { 452 err = -EINVAL; 453 if (fold->handle != handle && handle) 454 goto err2; 455 456 /* Copy fold into fnew */ 457 fnew->tp = fold->tp; 458 fnew->handle = fold->handle; 459 fnew->nkeys = fold->nkeys; 460 fnew->keymask = fold->keymask; 461 fnew->mode = fold->mode; 462 fnew->mask = fold->mask; 463 fnew->xor = fold->xor; 464 fnew->rshift = fold->rshift; 465 fnew->addend = fold->addend; 466 fnew->divisor = fold->divisor; 467 fnew->baseclass = fold->baseclass; 468 fnew->hashrnd = fold->hashrnd; 469 470 mode = fold->mode; 471 if (tb[TCA_FLOW_MODE]) 472 mode = nla_get_u32(tb[TCA_FLOW_MODE]); 473 if (mode != FLOW_MODE_HASH && nkeys > 1) 474 goto err2; 475 476 if (mode == FLOW_MODE_HASH) 477 perturb_period = fold->perturb_period; 478 if (tb[TCA_FLOW_PERTURB]) { 479 if (mode != FLOW_MODE_HASH) 480 goto err2; 481 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ; 482 } 483 } else { 484 err = -EINVAL; 485 if (!handle) 486 goto err2; 487 if (!tb[TCA_FLOW_KEYS]) 488 goto err2; 489 490 mode = FLOW_MODE_MAP; 491 if (tb[TCA_FLOW_MODE]) 492 mode = nla_get_u32(tb[TCA_FLOW_MODE]); 493 if (mode != FLOW_MODE_HASH && nkeys > 1) 494 goto err2; 495 496 if (tb[TCA_FLOW_PERTURB]) { 497 if (mode != FLOW_MODE_HASH) 498 goto err2; 499 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ; 500 } 501 502 if (TC_H_MAJ(baseclass) == 0) { 503 struct Qdisc *q = tcf_block_q(tp->chain->block); 504 505 baseclass = TC_H_MAKE(q->handle, baseclass); 506 } 507 if (TC_H_MIN(baseclass) == 0) 508 baseclass = TC_H_MAKE(baseclass, 1); 509 510 fnew->handle = handle; 511 fnew->mask = ~0U; 512 fnew->tp = tp; 513 get_random_bytes(&fnew->hashrnd, 4); 514 } 515 516 timer_setup(&fnew->perturb_timer, flow_perturbation, TIMER_DEFERRABLE); 517 518 tcf_block_netif_keep_dst(tp->chain->block); 519 520 if (tb[TCA_FLOW_KEYS]) { 521 fnew->keymask = keymask; 522 fnew->nkeys = nkeys; 523 } 524 525 fnew->mode = mode; 526 527 if (tb[TCA_FLOW_MASK]) 528 fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]); 529 if (tb[TCA_FLOW_XOR]) 530 fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]); 531 if (tb[TCA_FLOW_RSHIFT]) 532 fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]); 533 if (tb[TCA_FLOW_ADDEND]) 534 fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]); 535 536 if (tb[TCA_FLOW_DIVISOR]) 537 fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]); 538 if (baseclass) 539 fnew->baseclass = baseclass; 540 541 fnew->perturb_period = perturb_period; 542 if (perturb_period) 543 mod_timer(&fnew->perturb_timer, jiffies + perturb_period); 544 545 if (!*arg) 546 list_add_tail_rcu(&fnew->list, &head->filters); 547 else 548 list_replace_rcu(&fold->list, &fnew->list); 549 550 *arg = fnew; 551 552 if (fold) { 553 tcf_exts_get_net(&fold->exts); 554 tcf_queue_work(&fold->rwork, flow_destroy_filter_work); 555 } 556 return 0; 557 558 err2: 559 tcf_exts_destroy(&fnew->exts); 560 tcf_em_tree_destroy(&fnew->ematches); 561 err1: 562 kfree(fnew); 563 return err; 564 } 565 566 static int flow_delete(struct tcf_proto *tp, void *arg, bool *last, 567 bool rtnl_held, struct netlink_ext_ack *extack) 568 { 569 struct flow_head *head = rtnl_dereference(tp->root); 570 struct flow_filter *f = arg; 571 572 list_del_rcu(&f->list); 573 tcf_exts_get_net(&f->exts); 574 tcf_queue_work(&f->rwork, flow_destroy_filter_work); 575 *last = list_empty(&head->filters); 576 return 0; 577 } 578 579 static int flow_init(struct tcf_proto *tp) 580 { 581 struct flow_head *head; 582 583 head = kzalloc(sizeof(*head), GFP_KERNEL); 584 if (head == NULL) 585 return -ENOBUFS; 586 INIT_LIST_HEAD(&head->filters); 587 rcu_assign_pointer(tp->root, head); 588 return 0; 589 } 590 591 static void flow_destroy(struct tcf_proto *tp, bool rtnl_held, 592 struct netlink_ext_ack *extack) 593 { 594 struct flow_head *head = rtnl_dereference(tp->root); 595 struct flow_filter *f, *next; 596 597 list_for_each_entry_safe(f, next, &head->filters, list) { 598 list_del_rcu(&f->list); 599 if (tcf_exts_get_net(&f->exts)) 600 tcf_queue_work(&f->rwork, flow_destroy_filter_work); 601 else 602 __flow_destroy_filter(f); 603 } 604 kfree_rcu(head, rcu); 605 } 606 607 static void *flow_get(struct tcf_proto *tp, u32 handle) 608 { 609 struct flow_head *head = rtnl_dereference(tp->root); 610 struct flow_filter *f; 611 612 list_for_each_entry(f, &head->filters, list) 613 if (f->handle == handle) 614 return f; 615 return NULL; 616 } 617 618 static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh, 619 struct sk_buff *skb, struct tcmsg *t, bool rtnl_held) 620 { 621 struct flow_filter *f = fh; 622 struct nlattr *nest; 623 624 if (f == NULL) 625 return skb->len; 626 627 t->tcm_handle = f->handle; 628 629 nest = nla_nest_start_noflag(skb, TCA_OPTIONS); 630 if (nest == NULL) 631 goto nla_put_failure; 632 633 if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) || 634 nla_put_u32(skb, TCA_FLOW_MODE, f->mode)) 635 goto nla_put_failure; 636 637 if (f->mask != ~0 || f->xor != 0) { 638 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) || 639 nla_put_u32(skb, TCA_FLOW_XOR, f->xor)) 640 goto nla_put_failure; 641 } 642 if (f->rshift && 643 nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift)) 644 goto nla_put_failure; 645 if (f->addend && 646 nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend)) 647 goto nla_put_failure; 648 649 if (f->divisor && 650 nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor)) 651 goto nla_put_failure; 652 if (f->baseclass && 653 nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass)) 654 goto nla_put_failure; 655 656 if (f->perturb_period && 657 nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ)) 658 goto nla_put_failure; 659 660 if (tcf_exts_dump(skb, &f->exts) < 0) 661 goto nla_put_failure; 662 #ifdef CONFIG_NET_EMATCH 663 if (f->ematches.hdr.nmatches && 664 tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0) 665 goto nla_put_failure; 666 #endif 667 nla_nest_end(skb, nest); 668 669 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 670 goto nla_put_failure; 671 672 return skb->len; 673 674 nla_put_failure: 675 nla_nest_cancel(skb, nest); 676 return -1; 677 } 678 679 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg, 680 bool rtnl_held) 681 { 682 struct flow_head *head = rtnl_dereference(tp->root); 683 struct flow_filter *f; 684 685 list_for_each_entry(f, &head->filters, list) { 686 if (arg->count < arg->skip) 687 goto skip; 688 if (arg->fn(tp, f, arg) < 0) { 689 arg->stop = 1; 690 break; 691 } 692 skip: 693 arg->count++; 694 } 695 } 696 697 static struct tcf_proto_ops cls_flow_ops __read_mostly = { 698 .kind = "flow", 699 .classify = flow_classify, 700 .init = flow_init, 701 .destroy = flow_destroy, 702 .change = flow_change, 703 .delete = flow_delete, 704 .get = flow_get, 705 .dump = flow_dump, 706 .walk = flow_walk, 707 .owner = THIS_MODULE, 708 }; 709 710 static int __init cls_flow_init(void) 711 { 712 return register_tcf_proto_ops(&cls_flow_ops); 713 } 714 715 static void __exit cls_flow_exit(void) 716 { 717 unregister_tcf_proto_ops(&cls_flow_ops); 718 } 719 720 module_init(cls_flow_init); 721 module_exit(cls_flow_exit); 722 723 MODULE_LICENSE("GPL"); 724 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); 725 MODULE_DESCRIPTION("TC flow classifier"); 726