net/sched/cls_bpf.c

   1 /*
   2  * Berkeley Packet Filter based traffic classifier
   3  *
   4  * Might be used to classify traffic through flexible, user-defined and
   5  * possibly JIT-ed BPF filters for traffic control as an alternative to
   6  * ematches.
   7  *
   8  * (C) 2013 Daniel Borkmann <dborkman@redhat.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/types.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/filter.h>
  19 #include <linux/bpf.h>
  20
  21 #include <net/rtnetlink.h>
  22 #include <net/pkt_cls.h>
  23 #include <net/sock.h>
  24
  25 MODULE_LICENSE("GPL");
  26 MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
  27 MODULE_DESCRIPTION("TC BPF based classifier");
  28
  29 #define CLS_BPF_NAME_LEN        256
  30 #define CLS_BPF_SUPPORTED_GEN_FLAGS             \
  31         (TCA_CLS_FLAGS_SKIP_HW | TCA_CLS_FLAGS_SKIP_SW)
  32
  33 struct cls_bpf_head {
  34         struct list_head plist;
  35         u32 hgen;
  36         struct rcu_head rcu;
  37 };
  38
  39 struct cls_bpf_prog {
  40         struct bpf_prog *filter;
  41         struct list_head link;
  42         struct tcf_result res;
  43         bool exts_integrated;
  44         bool offloaded;
  45         u32 gen_flags;
  46         struct tcf_exts exts;
  47         u32 handle;
  48         u16 bpf_num_ops;
  49         struct sock_filter *bpf_ops;
  50         const char *bpf_name;
  51         struct tcf_proto *tp;
  52         struct rcu_head rcu;
  53 };
  54
  55 static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
  56         [TCA_BPF_CLASSID]       = { .type = NLA_U32 },
  57         [TCA_BPF_FLAGS]         = { .type = NLA_U32 },
  58         [TCA_BPF_FLAGS_GEN]     = { .type = NLA_U32 },
  59         [TCA_BPF_FD]            = { .type = NLA_U32 },
  60         [TCA_BPF_NAME]          = { .type = NLA_NUL_STRING,
  61                                     .len = CLS_BPF_NAME_LEN },
  62         [TCA_BPF_OPS_LEN]       = { .type = NLA_U16 },
  63         [TCA_BPF_OPS]           = { .type = NLA_BINARY,
  64                                     .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
  65 };
  66
  67 static int cls_bpf_exec_opcode(int code)
  68 {
  69         switch (code) {
  70         case TC_ACT_OK:
  71         case TC_ACT_SHOT:
  72         case TC_ACT_STOLEN:
  73         case TC_ACT_TRAP:
  74         case TC_ACT_REDIRECT:
  75         case TC_ACT_UNSPEC:
  76                 return code;
  77         default:
  78                 return TC_ACT_UNSPEC;
  79         }
  80 }
  81
  82 static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  83                             struct tcf_result *res)
  84 {
  85         struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
  86         bool at_ingress = skb_at_tc_ingress(skb);
  87         struct cls_bpf_prog *prog;
  88         int ret = -1;
  89
  90         /* Needed here for accessing maps. */
  91         rcu_read_lock();
  92         list_for_each_entry_rcu(prog, &head->plist, link) {
  93                 int filter_res;
  94
  95                 qdisc_skb_cb(skb)->tc_classid = prog->res.classid;
  96
  97                 if (tc_skip_sw(prog->gen_flags)) {
  98                         filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0;
  99                 } else if (at_ingress) {
 100                         /* It is safe to push/pull even if skb_shared() */
 101                         __skb_push(skb, skb->mac_len);
 102                         bpf_compute_data_end(skb);
 103                         filter_res = BPF_PROG_RUN(prog->filter, skb);
 104                         __skb_pull(skb, skb->mac_len);
 105                 } else {
 106                         bpf_compute_data_end(skb);
 107                         filter_res = BPF_PROG_RUN(prog->filter, skb);
 108                 }
 109
 110                 if (prog->exts_integrated) {
 111                         res->class   = 0;
 112                         res->classid = TC_H_MAJ(prog->res.classid) |
 113                                        qdisc_skb_cb(skb)->tc_classid;
 114
 115                         ret = cls_bpf_exec_opcode(filter_res);
 116                         if (ret == TC_ACT_UNSPEC)
 117                                 continue;
 118                         break;
 119                 }
 120
 121                 if (filter_res == 0)
 122                         continue;
 123                 if (filter_res != -1) {
 124                         res->class   = 0;
 125                         res->classid = filter_res;
 126                 } else {
 127                         *res = prog->res;
 128                 }
 129
 130                 ret = tcf_exts_exec(skb, &prog->exts, res);
 131                 if (ret < 0)
 132                         continue;
 133
 134                 break;
 135         }
 136         rcu_read_unlock();
 137
 138         return ret;
 139 }
 140
 141 static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
 142 {
 143         return !prog->bpf_ops;
 144 }
 145
 146 static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 147                                enum tc_clsbpf_command cmd)
 148 {
 149         struct net_device *dev = tp->q->dev_queue->dev;
 150         struct tc_cls_bpf_offload bpf_offload = {};
 151         struct tc_to_netdev offload;
 152         int err;
 153
 154         offload.type = TC_SETUP_CLSBPF;
 155         offload.cls_bpf = &bpf_offload;
 156
 157         bpf_offload.command = cmd;
 158         bpf_offload.exts = &prog->exts;
 159         bpf_offload.prog = prog->filter;
 160         bpf_offload.name = prog->bpf_name;
 161         bpf_offload.exts_integrated = prog->exts_integrated;
 162         bpf_offload.gen_flags = prog->gen_flags;
 163
 164         err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 165                                             tp->chain->index,
 166                                             tp->protocol, &offload);
 167
 168         if (!err && (cmd == TC_CLSBPF_ADD || cmd == TC_CLSBPF_REPLACE))
 169                 prog->gen_flags |= TCA_CLS_FLAGS_IN_HW;
 170
 171         return err;
 172 }
 173
 174 static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 175                            struct cls_bpf_prog *oldprog)
 176 {
 177         struct net_device *dev = tp->q->dev_queue->dev;
 178         struct cls_bpf_prog *obj = prog;
 179         enum tc_clsbpf_command cmd;
 180         bool skip_sw;
 181         int ret;
 182
 183         skip_sw = tc_skip_sw(prog->gen_flags) ||
 184                 (oldprog && tc_skip_sw(oldprog->gen_flags));
 185
 186         if (oldprog && oldprog->offloaded) {
 187                 if (tc_should_offload(dev, tp, prog->gen_flags)) {
 188                         cmd = TC_CLSBPF_REPLACE;
 189                 } else if (!tc_skip_sw(prog->gen_flags)) {
 190                         obj = oldprog;
 191                         cmd = TC_CLSBPF_DESTROY;
 192                 } else {
 193                         return -EINVAL;
 194                 }
 195         } else {
 196                 if (!tc_should_offload(dev, tp, prog->gen_flags))
 197                         return skip_sw ? -EINVAL : 0;
 198                 cmd = TC_CLSBPF_ADD;
 199         }
 200
 201         ret = cls_bpf_offload_cmd(tp, obj, cmd);
 202         if (ret)
 203                 return skip_sw ? ret : 0;
 204
 205         obj->offloaded = true;
 206         if (oldprog)
 207                 oldprog->offloaded = false;
 208
 209         return 0;
 210 }
 211
 212 static void cls_bpf_stop_offload(struct tcf_proto *tp,
 213                                  struct cls_bpf_prog *prog)
 214 {
 215         int err;
 216
 217         if (!prog->offloaded)
 218                 return;
 219
 220         err = cls_bpf_offload_cmd(tp, prog, TC_CLSBPF_DESTROY);
 221         if (err) {
 222                 pr_err("Stopping hardware offload failed: %d\n", err);
 223                 return;
 224         }
 225
 226         prog->offloaded = false;
 227 }
 228
 229 static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
 230                                          struct cls_bpf_prog *prog)
 231 {
 232         if (!prog->offloaded)
 233                 return;
 234
 235         cls_bpf_offload_cmd(tp, prog, TC_CLSBPF_STATS);
 236 }
 237
 238 static int cls_bpf_init(struct tcf_proto *tp)
 239 {
 240         struct cls_bpf_head *head;
 241
 242         head = kzalloc(sizeof(*head), GFP_KERNEL);
 243         if (head == NULL)
 244                 return -ENOBUFS;
 245
 246         INIT_LIST_HEAD_RCU(&head->plist);
 247         rcu_assign_pointer(tp->root, head);
 248
 249         return 0;
 250 }
 251
 252 static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
 253 {
 254         tcf_exts_destroy(&prog->exts);
 255
 256         if (cls_bpf_is_ebpf(prog))
 257                 bpf_prog_put(prog->filter);
 258         else
 259                 bpf_prog_destroy(prog->filter);
 260
 261         kfree(prog->bpf_name);
 262         kfree(prog->bpf_ops);
 263         kfree(prog);
 264 }
 265
 266 static void cls_bpf_delete_prog_rcu(struct rcu_head *rcu)
 267 {
 268         __cls_bpf_delete_prog(container_of(rcu, struct cls_bpf_prog, rcu));
 269 }
 270
 271 static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog)
 272 {
 273         cls_bpf_stop_offload(tp, prog);
 274         list_del_rcu(&prog->link);
 275         tcf_unbind_filter(tp, &prog->res);
 276         call_rcu(&prog->rcu, cls_bpf_delete_prog_rcu);
 277 }
 278
 279 static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg, bool *last)
 280 {
 281         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 282
 283         __cls_bpf_delete(tp, (struct cls_bpf_prog *) arg);
 284         *last = list_empty(&head->plist);
 285         return 0;
 286 }
 287
 288 static void cls_bpf_destroy(struct tcf_proto *tp)
 289 {
 290         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 291         struct cls_bpf_prog *prog, *tmp;
 292
 293         list_for_each_entry_safe(prog, tmp, &head->plist, link)
 294                 __cls_bpf_delete(tp, prog);
 295
 296         kfree_rcu(head, rcu);
 297 }
 298
 299 static unsigned long cls_bpf_get(struct tcf_proto *tp, u32 handle)
 300 {
 301         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 302         struct cls_bpf_prog *prog;
 303         unsigned long ret = 0UL;
 304
 305         list_for_each_entry(prog, &head->plist, link) {
 306                 if (prog->handle == handle) {
 307                         ret = (unsigned long) prog;
 308                         break;
 309                 }
 310         }
 311
 312         return ret;
 313 }
 314
 315 static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
 316 {
 317         struct sock_filter *bpf_ops;
 318         struct sock_fprog_kern fprog_tmp;
 319         struct bpf_prog *fp;
 320         u16 bpf_size, bpf_num_ops;
 321         int ret;
 322
 323         bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
 324         if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
 325                 return -EINVAL;
 326
 327         bpf_size = bpf_num_ops * sizeof(*bpf_ops);
 328         if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
 329                 return -EINVAL;
 330
 331         bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
 332         if (bpf_ops == NULL)
 333                 return -ENOMEM;
 334
 335         memcpy(bpf_ops, nla_data(tb[TCA_BPF_OPS]), bpf_size);
 336
 337         fprog_tmp.len = bpf_num_ops;
 338         fprog_tmp.filter = bpf_ops;
 339
 340         ret = bpf_prog_create(&fp, &fprog_tmp);
 341         if (ret < 0) {
 342                 kfree(bpf_ops);
 343                 return ret;
 344         }
 345
 346         prog->bpf_ops = bpf_ops;
 347         prog->bpf_num_ops = bpf_num_ops;
 348         prog->bpf_name = NULL;
 349         prog->filter = fp;
 350
 351         return 0;
 352 }
 353
 354 static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
 355                                  const struct tcf_proto *tp)
 356 {
 357         struct bpf_prog *fp;
 358         char *name = NULL;
 359         u32 bpf_fd;
 360
 361         bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
 362
 363         fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_CLS);
 364         if (IS_ERR(fp))
 365                 return PTR_ERR(fp);
 366
 367         if (tb[TCA_BPF_NAME]) {
 368                 name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
 369                 if (!name) {
 370                         bpf_prog_put(fp);
 371                         return -ENOMEM;
 372                 }
 373         }
 374
 375         prog->bpf_ops = NULL;
 376         prog->bpf_name = name;
 377         prog->filter = fp;
 378
 379         if (fp->dst_needed && !(tp->q->flags & TCQ_F_INGRESS))
 380                 netif_keep_dst(qdisc_dev(tp->q));
 381
 382         return 0;
 383 }
 384
 385 static int cls_bpf_modify_existing(struct net *net, struct tcf_proto *tp,
 386                                    struct cls_bpf_prog *prog,
 387                                    unsigned long base, struct nlattr **tb,
 388                                    struct nlattr *est, bool ovr)
 389 {
 390         bool is_bpf, is_ebpf, have_exts = false;
 391         struct tcf_exts exts;
 392         u32 gen_flags = 0;
 393         int ret;
 394
 395         is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
 396         is_ebpf = tb[TCA_BPF_FD];
 397         if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
 398                 return -EINVAL;
 399
 400         ret = tcf_exts_init(&exts, TCA_BPF_ACT, TCA_BPF_POLICE);
 401         if (ret < 0)
 402                 return ret;
 403         ret = tcf_exts_validate(net, tp, tb, est, &exts, ovr);
 404         if (ret < 0)
 405                 goto errout;
 406
 407         if (tb[TCA_BPF_FLAGS]) {
 408                 u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
 409
 410                 if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) {
 411                         ret = -EINVAL;
 412                         goto errout;
 413                 }
 414
 415                 have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
 416         }
 417         if (tb[TCA_BPF_FLAGS_GEN]) {
 418                 gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
 419                 if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
 420                     !tc_flags_valid(gen_flags)) {
 421                         ret = -EINVAL;
 422                         goto errout;
 423                 }
 424         }
 425
 426         prog->exts_integrated = have_exts;
 427         prog->gen_flags = gen_flags;
 428
 429         ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
 430                        cls_bpf_prog_from_efd(tb, prog, tp);
 431         if (ret < 0)
 432                 goto errout;
 433
 434         if (tb[TCA_BPF_CLASSID]) {
 435                 prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
 436                 tcf_bind_filter(tp, &prog->res, base);
 437         }
 438
 439         tcf_exts_change(tp, &prog->exts, &exts);
 440         return 0;
 441
 442 errout:
 443         tcf_exts_destroy(&exts);
 444         return ret;
 445 }
 446
 447 static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
 448                                    struct cls_bpf_head *head)
 449 {
 450         unsigned int i = 0x80000000;
 451         u32 handle;
 452
 453         do {
 454                 if (++head->hgen == 0x7FFFFFFF)
 455                         head->hgen = 1;
 456         } while (--i > 0 && cls_bpf_get(tp, head->hgen));
 457
 458         if (unlikely(i == 0)) {
 459                 pr_err("Insufficient number of handles\n");
 460                 handle = 0;
 461         } else {
 462                 handle = head->hgen;
 463         }
 464
 465         return handle;
 466 }
 467
 468 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 469                           struct tcf_proto *tp, unsigned long base,
 470                           u32 handle, struct nlattr **tca,
 471                           unsigned long *arg, bool ovr)
 472 {
 473         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 474         struct cls_bpf_prog *oldprog = (struct cls_bpf_prog *) *arg;
 475         struct nlattr *tb[TCA_BPF_MAX + 1];
 476         struct cls_bpf_prog *prog;
 477         int ret;
 478
 479         if (tca[TCA_OPTIONS] == NULL)
 480                 return -EINVAL;
 481
 482         ret = nla_parse_nested(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], bpf_policy,
 483                                NULL);
 484         if (ret < 0)
 485                 return ret;
 486
 487         prog = kzalloc(sizeof(*prog), GFP_KERNEL);
 488         if (!prog)
 489                 return -ENOBUFS;
 490
 491         ret = tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
 492         if (ret < 0)
 493                 goto errout;
 494
 495         if (oldprog) {
 496                 if (handle && oldprog->handle != handle) {
 497                         ret = -EINVAL;
 498                         goto errout;
 499                 }
 500         }
 501
 502         if (handle == 0)
 503                 prog->handle = cls_bpf_grab_new_handle(tp, head);
 504         else
 505                 prog->handle = handle;
 506         if (prog->handle == 0) {
 507                 ret = -EINVAL;
 508                 goto errout;
 509         }
 510
 511         ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE],
 512                                       ovr);
 513         if (ret < 0)
 514                 goto errout;
 515
 516         ret = cls_bpf_offload(tp, prog, oldprog);
 517         if (ret) {
 518                 __cls_bpf_delete_prog(prog);
 519                 return ret;
 520         }
 521
 522         if (!tc_in_hw(prog->gen_flags))
 523                 prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 524
 525         if (oldprog) {
 526                 list_replace_rcu(&oldprog->link, &prog->link);
 527                 tcf_unbind_filter(tp, &oldprog->res);
 528                 call_rcu(&oldprog->rcu, cls_bpf_delete_prog_rcu);
 529         } else {
 530                 list_add_rcu(&prog->link, &head->plist);
 531         }
 532
 533         *arg = (unsigned long) prog;
 534         return 0;
 535
 536 errout:
 537         tcf_exts_destroy(&prog->exts);
 538         kfree(prog);
 539         return ret;
 540 }
 541
 542 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
 543                                  struct sk_buff *skb)
 544 {
 545         struct nlattr *nla;
 546
 547         if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
 548                 return -EMSGSIZE;
 549
 550         nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
 551                           sizeof(struct sock_filter));
 552         if (nla == NULL)
 553                 return -EMSGSIZE;
 554
 555         memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
 556
 557         return 0;
 558 }
 559
 560 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 561                                   struct sk_buff *skb)
 562 {
 563         struct nlattr *nla;
 564
 565         if (prog->bpf_name &&
 566             nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
 567                 return -EMSGSIZE;
 568
 569         if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
 570                 return -EMSGSIZE;
 571
 572         nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
 573         if (nla == NULL)
 574                 return -EMSGSIZE;
 575
 576         memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
 577
 578         return 0;
 579 }
 580
 581 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
 582                         struct sk_buff *skb, struct tcmsg *tm)
 583 {
 584         struct cls_bpf_prog *prog = (struct cls_bpf_prog *) fh;
 585         struct nlattr *nest;
 586         u32 bpf_flags = 0;
 587         int ret;
 588
 589         if (prog == NULL)
 590                 return skb->len;
 591
 592         tm->tcm_handle = prog->handle;
 593
 594         cls_bpf_offload_update_stats(tp, prog);
 595
 596         nest = nla_nest_start(skb, TCA_OPTIONS);
 597         if (nest == NULL)
 598                 goto nla_put_failure;
 599
 600         if (prog->res.classid &&
 601             nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
 602                 goto nla_put_failure;
 603
 604         if (cls_bpf_is_ebpf(prog))
 605                 ret = cls_bpf_dump_ebpf_info(prog, skb);
 606         else
 607                 ret = cls_bpf_dump_bpf_info(prog, skb);
 608         if (ret)
 609                 goto nla_put_failure;
 610
 611         if (tcf_exts_dump(skb, &prog->exts) < 0)
 612                 goto nla_put_failure;
 613
 614         if (prog->exts_integrated)
 615                 bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
 616         if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
 617                 goto nla_put_failure;
 618         if (prog->gen_flags &&
 619             nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
 620                 goto nla_put_failure;
 621
 622         nla_nest_end(skb, nest);
 623
 624         if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
 625                 goto nla_put_failure;
 626
 627         return skb->len;
 628
 629 nla_put_failure:
 630         nla_nest_cancel(skb, nest);
 631         return -1;
 632 }
 633
 634 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 635 {
 636         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 637         struct cls_bpf_prog *prog;
 638
 639         list_for_each_entry(prog, &head->plist, link) {
 640                 if (arg->count < arg->skip)
 641                         goto skip;
 642                 if (arg->fn(tp, (unsigned long) prog, arg) < 0) {
 643                         arg->stop = 1;
 644                         break;
 645                 }
 646 skip:
 647                 arg->count++;
 648         }
 649 }
 650
 651 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
 652         .kind           =       "bpf",
 653         .owner          =       THIS_MODULE,
 654         .classify       =       cls_bpf_classify,
 655         .init           =       cls_bpf_init,
 656         .destroy        =       cls_bpf_destroy,
 657         .get            =       cls_bpf_get,
 658         .change         =       cls_bpf_change,
 659         .delete         =       cls_bpf_delete,
 660         .walk           =       cls_bpf_walk,
 661         .dump           =       cls_bpf_dump,
 662 };
 663
 664 static int __init cls_bpf_init_mod(void)
 665 {
 666         return register_tcf_proto_ops(&cls_bpf_ops);
 667 }
 668
 669 static void __exit cls_bpf_exit_mod(void)
 670 {
 671         unregister_tcf_proto_ops(&cls_bpf_ops);
 672 }
 673
 674 module_init(cls_bpf_init_mod);
 675 module_exit(cls_bpf_exit_mod);