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