net/sched/cls_flow.c

   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
  26 #include <net/pkt_cls.h>
  27 #include <net/ip.h>
  28 #include <net/route.h>
  29 #include <net/flow_keys.h>
  30
  31 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  32 #include <net/netfilter/nf_conntrack.h>
  33 #endif
  34
  35 struct flow_head {
  36         struct list_head        filters;
  37 };
  38
  39 struct flow_filter {
  40         struct list_head        list;
  41         struct tcf_exts         exts;
  42         struct tcf_ematch_tree  ematches;
  43         struct timer_list       perturb_timer;
  44         u32                     perturb_period;
  45         u32                     handle;
  46
  47         u32                     nkeys;
  48         u32                     keymask;
  49         u32                     mode;
  50         u32                     mask;
  51         u32                     xor;
  52         u32                     rshift;
  53         u32                     addend;
  54         u32                     divisor;
  55         u32                     baseclass;
  56         u32                     hashrnd;
  57 };
  58
  59 static const struct tcf_ext_map flow_ext_map = {
  60         .action = TCA_FLOW_ACT,
  61         .police = TCA_FLOW_POLICE,
  62 };
  63
  64 static inline u32 addr_fold(void *addr)
  65 {
  66         unsigned long a = (unsigned long)addr;
  67
  68         return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
  69 }
  70
  71 static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
  72 {
  73         if (flow->src)
  74                 return ntohl(flow->src);
  75         return addr_fold(skb->sk);
  76 }
  77
  78 static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
  79 {
  80         if (flow->dst)
  81                 return ntohl(flow->dst);
  82         return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
  83 }
  84
  85 static u32 flow_get_proto(const struct sk_buff *skb, const struct flow_keys *flow)
  86 {
  87         return flow->ip_proto;
  88 }
  89
  90 static u32 flow_get_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
  91 {
  92         if (flow->ports)
  93                 return ntohs(flow->port16[0]);
  94
  95         return addr_fold(skb->sk);
  96 }
  97
  98 static u32 flow_get_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
  99 {
 100         if (flow->ports)
 101                 return ntohs(flow->port16[1]);
 102
 103         return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
 104 }
 105
 106 static u32 flow_get_iif(const struct sk_buff *skb)
 107 {
 108         return skb->skb_iif;
 109 }
 110
 111 static u32 flow_get_priority(const struct sk_buff *skb)
 112 {
 113         return skb->priority;
 114 }
 115
 116 static u32 flow_get_mark(const struct sk_buff *skb)
 117 {
 118         return skb->mark;
 119 }
 120
 121 static u32 flow_get_nfct(const struct sk_buff *skb)
 122 {
 123 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 124         return addr_fold(skb->nfct);
 125 #else
 126         return 0;
 127 #endif
 128 }
 129
 130 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 131 #define CTTUPLE(skb, member)                                            \
 132 ({                                                                      \
 133         enum ip_conntrack_info ctinfo;                                  \
 134         const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);             \
 135         if (ct == NULL)                                                 \
 136                 goto fallback;                                          \
 137         ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;                 \
 138 })
 139 #else
 140 #define CTTUPLE(skb, member)                                            \
 141 ({                                                                      \
 142         goto fallback;                                                  \
 143         0;                                                              \
 144 })
 145 #endif
 146
 147 static u32 flow_get_nfct_src(const struct sk_buff *skb, const struct flow_keys *flow)
 148 {
 149         switch (skb->protocol) {
 150         case htons(ETH_P_IP):
 151                 return ntohl(CTTUPLE(skb, src.u3.ip));
 152         case htons(ETH_P_IPV6):
 153                 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
 154         }
 155 fallback:
 156         return flow_get_src(skb, flow);
 157 }
 158
 159 static u32 flow_get_nfct_dst(const struct sk_buff *skb, const struct flow_keys *flow)
 160 {
 161         switch (skb->protocol) {
 162         case htons(ETH_P_IP):
 163                 return ntohl(CTTUPLE(skb, dst.u3.ip));
 164         case htons(ETH_P_IPV6):
 165                 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
 166         }
 167 fallback:
 168         return flow_get_dst(skb, flow);
 169 }
 170
 171 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
 172 {
 173         return ntohs(CTTUPLE(skb, src.u.all));
 174 fallback:
 175         return flow_get_proto_src(skb, flow);
 176 }
 177
 178 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
 179 {
 180         return ntohs(CTTUPLE(skb, dst.u.all));
 181 fallback:
 182         return flow_get_proto_dst(skb, flow);
 183 }
 184
 185 static u32 flow_get_rtclassid(const struct sk_buff *skb)
 186 {
 187 #ifdef CONFIG_IP_ROUTE_CLASSID
 188         if (skb_dst(skb))
 189                 return skb_dst(skb)->tclassid;
 190 #endif
 191         return 0;
 192 }
 193
 194 static u32 flow_get_skuid(const struct sk_buff *skb)
 195 {
 196         if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
 197                 return skb->sk->sk_socket->file->f_cred->fsuid;
 198         return 0;
 199 }
 200
 201 static u32 flow_get_skgid(const struct sk_buff *skb)
 202 {
 203         if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
 204                 return skb->sk->sk_socket->file->f_cred->fsgid;
 205         return 0;
 206 }
 207
 208 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
 209 {
 210         u16 uninitialized_var(tag);
 211
 212         if (vlan_get_tag(skb, &tag) < 0)
 213                 return 0;
 214         return tag & VLAN_VID_MASK;
 215 }
 216
 217 static u32 flow_get_rxhash(struct sk_buff *skb)
 218 {
 219         return skb_get_rxhash(skb);
 220 }
 221
 222 static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
 223 {
 224         switch (key) {
 225         case FLOW_KEY_SRC:
 226                 return flow_get_src(skb, flow);
 227         case FLOW_KEY_DST:
 228                 return flow_get_dst(skb, flow);
 229         case FLOW_KEY_PROTO:
 230                 return flow_get_proto(skb, flow);
 231         case FLOW_KEY_PROTO_SRC:
 232                 return flow_get_proto_src(skb, flow);
 233         case FLOW_KEY_PROTO_DST:
 234                 return flow_get_proto_dst(skb, flow);
 235         case FLOW_KEY_IIF:
 236                 return flow_get_iif(skb);
 237         case FLOW_KEY_PRIORITY:
 238                 return flow_get_priority(skb);
 239         case FLOW_KEY_MARK:
 240                 return flow_get_mark(skb);
 241         case FLOW_KEY_NFCT:
 242                 return flow_get_nfct(skb);
 243         case FLOW_KEY_NFCT_SRC:
 244                 return flow_get_nfct_src(skb, flow);
 245         case FLOW_KEY_NFCT_DST:
 246                 return flow_get_nfct_dst(skb, flow);
 247         case FLOW_KEY_NFCT_PROTO_SRC:
 248                 return flow_get_nfct_proto_src(skb, flow);
 249         case FLOW_KEY_NFCT_PROTO_DST:
 250                 return flow_get_nfct_proto_dst(skb, flow);
 251         case FLOW_KEY_RTCLASSID:
 252                 return flow_get_rtclassid(skb);
 253         case FLOW_KEY_SKUID:
 254                 return flow_get_skuid(skb);
 255         case FLOW_KEY_SKGID:
 256                 return flow_get_skgid(skb);
 257         case FLOW_KEY_VLAN_TAG:
 258                 return flow_get_vlan_tag(skb);
 259         case FLOW_KEY_RXHASH:
 260                 return flow_get_rxhash(skb);
 261         default:
 262                 WARN_ON(1);
 263                 return 0;
 264         }
 265 }
 266
 267 #define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) |                 \
 268                           (1 << FLOW_KEY_DST) |                 \
 269                           (1 << FLOW_KEY_PROTO) |               \
 270                           (1 << FLOW_KEY_PROTO_SRC) |           \
 271                           (1 << FLOW_KEY_PROTO_DST) |           \
 272                           (1 << FLOW_KEY_NFCT_SRC) |            \
 273                           (1 << FLOW_KEY_NFCT_DST) |            \
 274                           (1 << FLOW_KEY_NFCT_PROTO_SRC) |      \
 275                           (1 << FLOW_KEY_NFCT_PROTO_DST))
 276
 277 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 278                          struct tcf_result *res)
 279 {
 280         struct flow_head *head = tp->root;
 281         struct flow_filter *f;
 282         u32 keymask;
 283         u32 classid;
 284         unsigned int n, key;
 285         int r;
 286
 287         list_for_each_entry(f, &head->filters, list) {
 288                 u32 keys[FLOW_KEY_MAX + 1];
 289                 struct flow_keys flow_keys;
 290
 291                 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
 292                         continue;
 293
 294                 keymask = f->keymask;
 295                 if (keymask & FLOW_KEYS_NEEDED)
 296                         skb_flow_dissect(skb, &flow_keys);
 297
 298                 for (n = 0; n < f->nkeys; n++) {
 299                         key = ffs(keymask) - 1;
 300                         keymask &= ~(1 << key);
 301                         keys[n] = flow_key_get(skb, key, &flow_keys);
 302                 }
 303
 304                 if (f->mode == FLOW_MODE_HASH)
 305                         classid = jhash2(keys, f->nkeys, f->hashrnd);
 306                 else {
 307                         classid = keys[0];
 308                         classid = (classid & f->mask) ^ f->xor;
 309                         classid = (classid >> f->rshift) + f->addend;
 310                 }
 311
 312                 if (f->divisor)
 313                         classid %= f->divisor;
 314
 315                 res->class   = 0;
 316                 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
 317
 318                 r = tcf_exts_exec(skb, &f->exts, res);
 319                 if (r < 0)
 320                         continue;
 321                 return r;
 322         }
 323         return -1;
 324 }
 325
 326 static void flow_perturbation(unsigned long arg)
 327 {
 328         struct flow_filter *f = (struct flow_filter *)arg;
 329
 330         get_random_bytes(&f->hashrnd, 4);
 331         if (f->perturb_period)
 332                 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
 333 }
 334
 335 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
 336         [TCA_FLOW_KEYS]         = { .type = NLA_U32 },
 337         [TCA_FLOW_MODE]         = { .type = NLA_U32 },
 338         [TCA_FLOW_BASECLASS]    = { .type = NLA_U32 },
 339         [TCA_FLOW_RSHIFT]       = { .type = NLA_U32 },
 340         [TCA_FLOW_ADDEND]       = { .type = NLA_U32 },
 341         [TCA_FLOW_MASK]         = { .type = NLA_U32 },
 342         [TCA_FLOW_XOR]          = { .type = NLA_U32 },
 343         [TCA_FLOW_DIVISOR]      = { .type = NLA_U32 },
 344         [TCA_FLOW_ACT]          = { .type = NLA_NESTED },
 345         [TCA_FLOW_POLICE]       = { .type = NLA_NESTED },
 346         [TCA_FLOW_EMATCHES]     = { .type = NLA_NESTED },
 347         [TCA_FLOW_PERTURB]      = { .type = NLA_U32 },
 348 };
 349
 350 static int flow_change(struct tcf_proto *tp, unsigned long base,
 351                        u32 handle, struct nlattr **tca,
 352                        unsigned long *arg)
 353 {
 354         struct flow_head *head = tp->root;
 355         struct flow_filter *f;
 356         struct nlattr *opt = tca[TCA_OPTIONS];
 357         struct nlattr *tb[TCA_FLOW_MAX + 1];
 358         struct tcf_exts e;
 359         struct tcf_ematch_tree t;
 360         unsigned int nkeys = 0;
 361         unsigned int perturb_period = 0;
 362         u32 baseclass = 0;
 363         u32 keymask = 0;
 364         u32 mode;
 365         int err;
 366
 367         if (opt == NULL)
 368                 return -EINVAL;
 369
 370         err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
 371         if (err < 0)
 372                 return err;
 373
 374         if (tb[TCA_FLOW_BASECLASS]) {
 375                 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
 376                 if (TC_H_MIN(baseclass) == 0)
 377                         return -EINVAL;
 378         }
 379
 380         if (tb[TCA_FLOW_KEYS]) {
 381                 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
 382
 383                 nkeys = hweight32(keymask);
 384                 if (nkeys == 0)
 385                         return -EINVAL;
 386
 387                 if (fls(keymask) - 1 > FLOW_KEY_MAX)
 388                         return -EOPNOTSUPP;
 389         }
 390
 391         err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
 392         if (err < 0)
 393                 return err;
 394
 395         err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
 396         if (err < 0)
 397                 goto err1;
 398
 399         f = (struct flow_filter *)*arg;
 400         if (f != NULL) {
 401                 err = -EINVAL;
 402                 if (f->handle != handle && handle)
 403                         goto err2;
 404
 405                 mode = f->mode;
 406                 if (tb[TCA_FLOW_MODE])
 407                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 408                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 409                         goto err2;
 410
 411                 if (mode == FLOW_MODE_HASH)
 412                         perturb_period = f->perturb_period;
 413                 if (tb[TCA_FLOW_PERTURB]) {
 414                         if (mode != FLOW_MODE_HASH)
 415                                 goto err2;
 416                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 417                 }
 418         } else {
 419                 err = -EINVAL;
 420                 if (!handle)
 421                         goto err2;
 422                 if (!tb[TCA_FLOW_KEYS])
 423                         goto err2;
 424
 425                 mode = FLOW_MODE_MAP;
 426                 if (tb[TCA_FLOW_MODE])
 427                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 428                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 429                         goto err2;
 430
 431                 if (tb[TCA_FLOW_PERTURB]) {
 432                         if (mode != FLOW_MODE_HASH)
 433                                 goto err2;
 434                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 435                 }
 436
 437                 if (TC_H_MAJ(baseclass) == 0)
 438                         baseclass = TC_H_MAKE(tp->q->handle, baseclass);
 439                 if (TC_H_MIN(baseclass) == 0)
 440                         baseclass = TC_H_MAKE(baseclass, 1);
 441
 442                 err = -ENOBUFS;
 443                 f = kzalloc(sizeof(*f), GFP_KERNEL);
 444                 if (f == NULL)
 445                         goto err2;
 446
 447                 f->handle = handle;
 448                 f->mask   = ~0U;
 449
 450                 get_random_bytes(&f->hashrnd, 4);
 451                 f->perturb_timer.function = flow_perturbation;
 452                 f->perturb_timer.data = (unsigned long)f;
 453                 init_timer_deferrable(&f->perturb_timer);
 454         }
 455
 456         tcf_exts_change(tp, &f->exts, &e);
 457         tcf_em_tree_change(tp, &f->ematches, &t);
 458
 459         tcf_tree_lock(tp);
 460
 461         if (tb[TCA_FLOW_KEYS]) {
 462                 f->keymask = keymask;
 463                 f->nkeys   = nkeys;
 464         }
 465
 466         f->mode = mode;
 467
 468         if (tb[TCA_FLOW_MASK])
 469                 f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
 470         if (tb[TCA_FLOW_XOR])
 471                 f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
 472         if (tb[TCA_FLOW_RSHIFT])
 473                 f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
 474         if (tb[TCA_FLOW_ADDEND])
 475                 f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
 476
 477         if (tb[TCA_FLOW_DIVISOR])
 478                 f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
 479         if (baseclass)
 480                 f->baseclass = baseclass;
 481
 482         f->perturb_period = perturb_period;
 483         del_timer(&f->perturb_timer);
 484         if (perturb_period)
 485                 mod_timer(&f->perturb_timer, jiffies + perturb_period);
 486
 487         if (*arg == 0)
 488                 list_add_tail(&f->list, &head->filters);
 489
 490         tcf_tree_unlock(tp);
 491
 492         *arg = (unsigned long)f;
 493         return 0;
 494
 495 err2:
 496         tcf_em_tree_destroy(tp, &t);
 497 err1:
 498         tcf_exts_destroy(tp, &e);
 499         return err;
 500 }
 501
 502 static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
 503 {
 504         del_timer_sync(&f->perturb_timer);
 505         tcf_exts_destroy(tp, &f->exts);
 506         tcf_em_tree_destroy(tp, &f->ematches);
 507         kfree(f);
 508 }
 509
 510 static int flow_delete(struct tcf_proto *tp, unsigned long arg)
 511 {
 512         struct flow_filter *f = (struct flow_filter *)arg;
 513
 514         tcf_tree_lock(tp);
 515         list_del(&f->list);
 516         tcf_tree_unlock(tp);
 517         flow_destroy_filter(tp, f);
 518         return 0;
 519 }
 520
 521 static int flow_init(struct tcf_proto *tp)
 522 {
 523         struct flow_head *head;
 524
 525         head = kzalloc(sizeof(*head), GFP_KERNEL);
 526         if (head == NULL)
 527                 return -ENOBUFS;
 528         INIT_LIST_HEAD(&head->filters);
 529         tp->root = head;
 530         return 0;
 531 }
 532
 533 static void flow_destroy(struct tcf_proto *tp)
 534 {
 535         struct flow_head *head = tp->root;
 536         struct flow_filter *f, *next;
 537
 538         list_for_each_entry_safe(f, next, &head->filters, list) {
 539                 list_del(&f->list);
 540                 flow_destroy_filter(tp, f);
 541         }
 542         kfree(head);
 543 }
 544
 545 static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
 546 {
 547         struct flow_head *head = tp->root;
 548         struct flow_filter *f;
 549
 550         list_for_each_entry(f, &head->filters, list)
 551                 if (f->handle == handle)
 552                         return (unsigned long)f;
 553         return 0;
 554 }
 555
 556 static void flow_put(struct tcf_proto *tp, unsigned long f)
 557 {
 558 }
 559
 560 static int flow_dump(struct tcf_proto *tp, unsigned long fh,
 561                      struct sk_buff *skb, struct tcmsg *t)
 562 {
 563         struct flow_filter *f = (struct flow_filter *)fh;
 564         struct nlattr *nest;
 565
 566         if (f == NULL)
 567                 return skb->len;
 568
 569         t->tcm_handle = f->handle;
 570
 571         nest = nla_nest_start(skb, TCA_OPTIONS);
 572         if (nest == NULL)
 573                 goto nla_put_failure;
 574
 575         if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
 576             nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
 577                 goto nla_put_failure;
 578
 579         if (f->mask != ~0 || f->xor != 0) {
 580                 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
 581                     nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
 582                         goto nla_put_failure;
 583         }
 584         if (f->rshift &&
 585             nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
 586                 goto nla_put_failure;
 587         if (f->addend &&
 588             nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
 589                 goto nla_put_failure;
 590
 591         if (f->divisor &&
 592             nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
 593                 goto nla_put_failure;
 594         if (f->baseclass &&
 595             nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
 596                 goto nla_put_failure;
 597
 598         if (f->perturb_period &&
 599             nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
 600                 goto nla_put_failure;
 601
 602         if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
 603                 goto nla_put_failure;
 604 #ifdef CONFIG_NET_EMATCH
 605         if (f->ematches.hdr.nmatches &&
 606             tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
 607                 goto nla_put_failure;
 608 #endif
 609         nla_nest_end(skb, nest);
 610
 611         if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
 612                 goto nla_put_failure;
 613
 614         return skb->len;
 615
 616 nla_put_failure:
 617         nlmsg_trim(skb, nest);
 618         return -1;
 619 }
 620
 621 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 622 {
 623         struct flow_head *head = tp->root;
 624         struct flow_filter *f;
 625
 626         list_for_each_entry(f, &head->filters, list) {
 627                 if (arg->count < arg->skip)
 628                         goto skip;
 629                 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 630                         arg->stop = 1;
 631                         break;
 632                 }
 633 skip:
 634                 arg->count++;
 635         }
 636 }
 637
 638 static struct tcf_proto_ops cls_flow_ops __read_mostly = {
 639         .kind           = "flow",
 640         .classify       = flow_classify,
 641         .init           = flow_init,
 642         .destroy        = flow_destroy,
 643         .change         = flow_change,
 644         .delete         = flow_delete,
 645         .get            = flow_get,
 646         .put            = flow_put,
 647         .dump           = flow_dump,
 648         .walk           = flow_walk,
 649         .owner          = THIS_MODULE,
 650 };
 651
 652 static int __init cls_flow_init(void)
 653 {
 654         return register_tcf_proto_ops(&cls_flow_ops);
 655 }
 656
 657 static void __exit cls_flow_exit(void)
 658 {
 659         unregister_tcf_proto_ops(&cls_flow_ops);
 660 }
 661
 662 module_init(cls_flow_init);
 663 module_exit(cls_flow_exit);
 664
 665 MODULE_LICENSE("GPL");
 666 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 667 MODULE_DESCRIPTION("TC flow classifier");