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_work rwork; 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(struct timer_list *t) 349 { 350 struct flow_filter *f = from_timer(f, t, perturb_timer); 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 flow_filter *f) 373 { 374 del_timer_sync(&f->perturb_timer); 375 tcf_exts_destroy(&f->exts); 376 tcf_em_tree_destroy(&f->ematches); 377 tcf_exts_put_net(&f->exts); 378 kfree(f); 379 } 380 381 static void flow_destroy_filter_work(struct work_struct *work) 382 { 383 struct flow_filter *f = container_of(to_rcu_work(work), 384 struct flow_filter, 385 rwork); 386 rtnl_lock(); 387 __flow_destroy_filter(f); 388 rtnl_unlock(); 389 } 390 391 static int flow_change(struct net *net, struct sk_buff *in_skb, 392 struct tcf_proto *tp, unsigned long base, 393 u32 handle, struct nlattr **tca, 394 void **arg, bool ovr, struct netlink_ext_ack *extack) 395 { 396 struct flow_head *head = rtnl_dereference(tp->root); 397 struct flow_filter *fold, *fnew; 398 struct nlattr *opt = tca[TCA_OPTIONS]; 399 struct nlattr *tb[TCA_FLOW_MAX + 1]; 400 unsigned int nkeys = 0; 401 unsigned int perturb_period = 0; 402 u32 baseclass = 0; 403 u32 keymask = 0; 404 u32 mode; 405 int err; 406 407 if (opt == NULL) 408 return -EINVAL; 409 410 err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy, NULL); 411 if (err < 0) 412 return err; 413 414 if (tb[TCA_FLOW_BASECLASS]) { 415 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]); 416 if (TC_H_MIN(baseclass) == 0) 417 return -EINVAL; 418 } 419 420 if (tb[TCA_FLOW_KEYS]) { 421 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]); 422 423 nkeys = hweight32(keymask); 424 if (nkeys == 0) 425 return -EINVAL; 426 427 if (fls(keymask) - 1 > FLOW_KEY_MAX) 428 return -EOPNOTSUPP; 429 430 if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) && 431 sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns) 432 return -EOPNOTSUPP; 433 } 434 435 fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); 436 if (!fnew) 437 return -ENOBUFS; 438 439 err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &fnew->ematches); 440 if (err < 0) 441 goto err1; 442 443 err = tcf_exts_init(&fnew->exts, TCA_FLOW_ACT, TCA_FLOW_POLICE); 444 if (err < 0) 445 goto err2; 446 447 err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, ovr, 448 extack); 449 if (err < 0) 450 goto err2; 451 452 fold = *arg; 453 if (fold) { 454 err = -EINVAL; 455 if (fold->handle != handle && handle) 456 goto err2; 457 458 /* Copy fold into fnew */ 459 fnew->tp = fold->tp; 460 fnew->handle = fold->handle; 461 fnew->nkeys = fold->nkeys; 462 fnew->keymask = fold->keymask; 463 fnew->mode = fold->mode; 464 fnew->mask = fold->mask; 465 fnew->xor = fold->xor; 466 fnew->rshift = fold->rshift; 467 fnew->addend = fold->addend; 468 fnew->divisor = fold->divisor; 469 fnew->baseclass = fold->baseclass; 470 fnew->hashrnd = fold->hashrnd; 471 472 mode = fold->mode; 473 if (tb[TCA_FLOW_MODE]) 474 mode = nla_get_u32(tb[TCA_FLOW_MODE]); 475 if (mode != FLOW_MODE_HASH && nkeys > 1) 476 goto err2; 477 478 if (mode == FLOW_MODE_HASH) 479 perturb_period = fold->perturb_period; 480 if (tb[TCA_FLOW_PERTURB]) { 481 if (mode != FLOW_MODE_HASH) 482 goto err2; 483 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ; 484 } 485 } else { 486 err = -EINVAL; 487 if (!handle) 488 goto err2; 489 if (!tb[TCA_FLOW_KEYS]) 490 goto err2; 491 492 mode = FLOW_MODE_MAP; 493 if (tb[TCA_FLOW_MODE]) 494 mode = nla_get_u32(tb[TCA_FLOW_MODE]); 495 if (mode != FLOW_MODE_HASH && nkeys > 1) 496 goto err2; 497 498 if (tb[TCA_FLOW_PERTURB]) { 499 if (mode != FLOW_MODE_HASH) 500 goto err2; 501 perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ; 502 } 503 504 if (TC_H_MAJ(baseclass) == 0) { 505 struct Qdisc *q = tcf_block_q(tp->chain->block); 506 507 baseclass = TC_H_MAKE(q->handle, baseclass); 508 } 509 if (TC_H_MIN(baseclass) == 0) 510 baseclass = TC_H_MAKE(baseclass, 1); 511 512 fnew->handle = handle; 513 fnew->mask = ~0U; 514 fnew->tp = tp; 515 get_random_bytes(&fnew->hashrnd, 4); 516 } 517 518 timer_setup(&fnew->perturb_timer, flow_perturbation, TIMER_DEFERRABLE); 519 520 tcf_block_netif_keep_dst(tp->chain->block); 521 522 if (tb[TCA_FLOW_KEYS]) { 523 fnew->keymask = keymask; 524 fnew->nkeys = nkeys; 525 } 526 527 fnew->mode = mode; 528 529 if (tb[TCA_FLOW_MASK]) 530 fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]); 531 if (tb[TCA_FLOW_XOR]) 532 fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]); 533 if (tb[TCA_FLOW_RSHIFT]) 534 fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]); 535 if (tb[TCA_FLOW_ADDEND]) 536 fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]); 537 538 if (tb[TCA_FLOW_DIVISOR]) 539 fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]); 540 if (baseclass) 541 fnew->baseclass = baseclass; 542 543 fnew->perturb_period = perturb_period; 544 if (perturb_period) 545 mod_timer(&fnew->perturb_timer, jiffies + perturb_period); 546 547 if (!*arg) 548 list_add_tail_rcu(&fnew->list, &head->filters); 549 else 550 list_replace_rcu(&fold->list, &fnew->list); 551 552 *arg = fnew; 553 554 if (fold) { 555 tcf_exts_get_net(&fold->exts); 556 tcf_queue_work(&fold->rwork, flow_destroy_filter_work); 557 } 558 return 0; 559 560 err2: 561 tcf_exts_destroy(&fnew->exts); 562 tcf_em_tree_destroy(&fnew->ematches); 563 err1: 564 kfree(fnew); 565 return err; 566 } 567 568 static int flow_delete(struct tcf_proto *tp, void *arg, bool *last, 569 struct netlink_ext_ack *extack) 570 { 571 struct flow_head *head = rtnl_dereference(tp->root); 572 struct flow_filter *f = arg; 573 574 list_del_rcu(&f->list); 575 tcf_exts_get_net(&f->exts); 576 tcf_queue_work(&f->rwork, flow_destroy_filter_work); 577 *last = list_empty(&head->filters); 578 return 0; 579 } 580 581 static int flow_init(struct tcf_proto *tp) 582 { 583 struct flow_head *head; 584 585 head = kzalloc(sizeof(*head), GFP_KERNEL); 586 if (head == NULL) 587 return -ENOBUFS; 588 INIT_LIST_HEAD(&head->filters); 589 rcu_assign_pointer(tp->root, head); 590 return 0; 591 } 592 593 static void flow_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack) 594 { 595 struct flow_head *head = rtnl_dereference(tp->root); 596 struct flow_filter *f, *next; 597 598 list_for_each_entry_safe(f, next, &head->filters, list) { 599 list_del_rcu(&f->list); 600 if (tcf_exts_get_net(&f->exts)) 601 tcf_queue_work(&f->rwork, flow_destroy_filter_work); 602 else 603 __flow_destroy_filter(f); 604 } 605 kfree_rcu(head, rcu); 606 } 607 608 static void *flow_get(struct tcf_proto *tp, u32 handle) 609 { 610 struct flow_head *head = rtnl_dereference(tp->root); 611 struct flow_filter *f; 612 613 list_for_each_entry(f, &head->filters, list) 614 if (f->handle == handle) 615 return f; 616 return NULL; 617 } 618 619 static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh, 620 struct sk_buff *skb, struct tcmsg *t) 621 { 622 struct flow_filter *f = fh; 623 struct nlattr *nest; 624 625 if (f == NULL) 626 return skb->len; 627 628 t->tcm_handle = f->handle; 629 630 nest = nla_nest_start(skb, TCA_OPTIONS); 631 if (nest == NULL) 632 goto nla_put_failure; 633 634 if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) || 635 nla_put_u32(skb, TCA_FLOW_MODE, f->mode)) 636 goto nla_put_failure; 637 638 if (f->mask != ~0 || f->xor != 0) { 639 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) || 640 nla_put_u32(skb, TCA_FLOW_XOR, f->xor)) 641 goto nla_put_failure; 642 } 643 if (f->rshift && 644 nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift)) 645 goto nla_put_failure; 646 if (f->addend && 647 nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend)) 648 goto nla_put_failure; 649 650 if (f->divisor && 651 nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor)) 652 goto nla_put_failure; 653 if (f->baseclass && 654 nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass)) 655 goto nla_put_failure; 656 657 if (f->perturb_period && 658 nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ)) 659 goto nla_put_failure; 660 661 if (tcf_exts_dump(skb, &f->exts) < 0) 662 goto nla_put_failure; 663 #ifdef CONFIG_NET_EMATCH 664 if (f->ematches.hdr.nmatches && 665 tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0) 666 goto nla_put_failure; 667 #endif 668 nla_nest_end(skb, nest); 669 670 if (tcf_exts_dump_stats(skb, &f->exts) < 0) 671 goto nla_put_failure; 672 673 return skb->len; 674 675 nla_put_failure: 676 nla_nest_cancel(skb, nest); 677 return -1; 678 } 679 680 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg) 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