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         union {
  49                 u32 bpf_fd;
  50                 u16 bpf_num_ops;
  51         };
  52         struct sock_filter *bpf_ops;
  53         const char *bpf_name;
  54         struct tcf_proto *tp;
  55         struct rcu_head rcu;
  56 };
  57
  58 static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
  59         [TCA_BPF_CLASSID]       = { .type = NLA_U32 },
  60         [TCA_BPF_FLAGS]         = { .type = NLA_U32 },
  61         [TCA_BPF_FLAGS_GEN]     = { .type = NLA_U32 },
  62         [TCA_BPF_FD]            = { .type = NLA_U32 },
  63         [TCA_BPF_NAME]          = { .type = NLA_NUL_STRING,
  64                                     .len = CLS_BPF_NAME_LEN },
  65         [TCA_BPF_OPS_LEN]       = { .type = NLA_U16 },
  66         [TCA_BPF_OPS]           = { .type = NLA_BINARY,
  67                                     .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
  68 };
  69
  70 static int cls_bpf_exec_opcode(int code)
  71 {
  72         switch (code) {
  73         case TC_ACT_OK:
  74         case TC_ACT_SHOT:
  75         case TC_ACT_STOLEN:
  76         case TC_ACT_REDIRECT:
  77         case TC_ACT_UNSPEC:
  78                 return code;
  79         default:
  80                 return TC_ACT_UNSPEC;
  81         }
  82 }
  83
  84 static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  85                             struct tcf_result *res)
  86 {
  87         struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
  88         bool at_ingress = skb_at_tc_ingress(skb);
  89         struct cls_bpf_prog *prog;
  90         int ret = -1;
  91
  92         /* Needed here for accessing maps. */
  93         rcu_read_lock();
  94         list_for_each_entry_rcu(prog, &head->plist, link) {
  95                 int filter_res;
  96
  97                 qdisc_skb_cb(skb)->tc_classid = prog->res.classid;
  98
  99                 if (tc_skip_sw(prog->gen_flags)) {
 100                         filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0;
 101                 } else if (at_ingress) {
 102                         /* It is safe to push/pull even if skb_shared() */
 103                         __skb_push(skb, skb->mac_len);
 104                         bpf_compute_data_end(skb);
 105                         filter_res = BPF_PROG_RUN(prog->filter, skb);
 106                         __skb_pull(skb, skb->mac_len);
 107                 } else {
 108                         bpf_compute_data_end(skb);
 109                         filter_res = BPF_PROG_RUN(prog->filter, skb);
 110                 }
 111
 112                 if (prog->exts_integrated) {
 113                         res->class   = 0;
 114                         res->classid = TC_H_MAJ(prog->res.classid) |
 115                                        qdisc_skb_cb(skb)->tc_classid;
 116
 117                         ret = cls_bpf_exec_opcode(filter_res);
 118                         if (ret == TC_ACT_UNSPEC)
 119                                 continue;
 120                         break;
 121                 }
 122
 123                 if (filter_res == 0)
 124                         continue;
 125                 if (filter_res != -1) {
 126                         res->class   = 0;
 127                         res->classid = filter_res;
 128                 } else {
 129                         *res = prog->res;
 130                 }
 131
 132                 ret = tcf_exts_exec(skb, &prog->exts, res);
 133                 if (ret < 0)
 134                         continue;
 135
 136                 break;
 137         }
 138         rcu_read_unlock();
 139
 140         return ret;
 141 }
 142
 143 static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
 144 {
 145         return !prog->bpf_ops;
 146 }
 147
 148 static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 149                                enum tc_clsbpf_command cmd)
 150 {
 151         struct net_device *dev = tp->q->dev_queue->dev;
 152         struct tc_cls_bpf_offload bpf_offload = {};
 153         struct tc_to_netdev offload;
 154
 155         offload.type = TC_SETUP_CLSBPF;
 156         offload.cls_bpf = &bpf_offload;
 157
 158         bpf_offload.command = cmd;
 159         bpf_offload.exts = &prog->exts;
 160         bpf_offload.prog = prog->filter;
 161         bpf_offload.name = prog->bpf_name;
 162         bpf_offload.exts_integrated = prog->exts_integrated;
 163         bpf_offload.gen_flags = prog->gen_flags;
 164
 165         return dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
 166                                              tp->protocol, &offload);
 167 }
 168
 169 static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 170                            struct cls_bpf_prog *oldprog)
 171 {
 172         struct net_device *dev = tp->q->dev_queue->dev;
 173         struct cls_bpf_prog *obj = prog;
 174         enum tc_clsbpf_command cmd;
 175         bool skip_sw;
 176         int ret;
 177
 178         skip_sw = tc_skip_sw(prog->gen_flags) ||
 179                 (oldprog && tc_skip_sw(oldprog->gen_flags));
 180
 181         if (oldprog && oldprog->offloaded) {
 182                 if (tc_should_offload(dev, tp, prog->gen_flags)) {
 183                         cmd = TC_CLSBPF_REPLACE;
 184                 } else if (!tc_skip_sw(prog->gen_flags)) {
 185                         obj = oldprog;
 186                         cmd = TC_CLSBPF_DESTROY;
 187                 } else {
 188                         return -EINVAL;
 189                 }
 190         } else {
 191                 if (!tc_should_offload(dev, tp, prog->gen_flags))
 192                         return skip_sw ? -EINVAL : 0;
 193                 cmd = TC_CLSBPF_ADD;
 194         }
 195
 196         ret = cls_bpf_offload_cmd(tp, obj, cmd);
 197         if (ret)
 198                 return skip_sw ? ret : 0;
 199
 200         obj->offloaded = true;
 201         if (oldprog)
 202                 oldprog->offloaded = false;
 203
 204         return 0;
 205 }
 206
 207 static void cls_bpf_stop_offload(struct tcf_proto *tp,
 208                                  struct cls_bpf_prog *prog)
 209 {
 210         int err;
 211
 212         if (!prog->offloaded)
 213                 return;
 214
 215         err = cls_bpf_offload_cmd(tp, prog, TC_CLSBPF_DESTROY);
 216         if (err) {
 217                 pr_err("Stopping hardware offload failed: %d\n", err);
 218                 return;
 219         }
 220
 221         prog->offloaded = false;
 222 }
 223
 224 static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
 225                                          struct cls_bpf_prog *prog)
 226 {
 227         if (!prog->offloaded)
 228                 return;
 229
 230         cls_bpf_offload_cmd(tp, prog, TC_CLSBPF_STATS);
 231 }
 232
 233 static int cls_bpf_init(struct tcf_proto *tp)
 234 {
 235         struct cls_bpf_head *head;
 236
 237         head = kzalloc(sizeof(*head), GFP_KERNEL);
 238         if (head == NULL)
 239                 return -ENOBUFS;
 240
 241         INIT_LIST_HEAD_RCU(&head->plist);
 242         rcu_assign_pointer(tp->root, head);
 243
 244         return 0;
 245 }
 246
 247 static void cls_bpf_delete_prog(struct tcf_proto *tp, struct cls_bpf_prog *prog)
 248 {
 249         tcf_exts_destroy(&prog->exts);
 250
 251         if (cls_bpf_is_ebpf(prog))
 252                 bpf_prog_put(prog->filter);
 253         else
 254                 bpf_prog_destroy(prog->filter);
 255
 256         kfree(prog->bpf_name);
 257         kfree(prog->bpf_ops);
 258         kfree(prog);
 259 }
 260
 261 static void __cls_bpf_delete_prog(struct rcu_head *rcu)
 262 {
 263         struct cls_bpf_prog *prog = container_of(rcu, struct cls_bpf_prog, rcu);
 264
 265         cls_bpf_delete_prog(prog->tp, prog);
 266 }
 267
 268 static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
 269 {
 270         struct cls_bpf_prog *prog = (struct cls_bpf_prog *) arg;
 271
 272         cls_bpf_stop_offload(tp, prog);
 273         list_del_rcu(&prog->link);
 274         tcf_unbind_filter(tp, &prog->res);
 275         call_rcu(&prog->rcu, __cls_bpf_delete_prog);
 276
 277         return 0;
 278 }
 279
 280 static bool cls_bpf_destroy(struct tcf_proto *tp, bool force)
 281 {
 282         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 283         struct cls_bpf_prog *prog, *tmp;
 284
 285         if (!force && !list_empty(&head->plist))
 286                 return false;
 287
 288         list_for_each_entry_safe(prog, tmp, &head->plist, link) {
 289                 cls_bpf_stop_offload(tp, prog);
 290                 list_del_rcu(&prog->link);
 291                 tcf_unbind_filter(tp, &prog->res);
 292                 call_rcu(&prog->rcu, __cls_bpf_delete_prog);
 293         }
 294
 295         kfree_rcu(head, rcu);
 296         return true;
 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 = kmemdup(nla_data(tb[TCA_BPF_NAME]),
 369                                nla_len(tb[TCA_BPF_NAME]),
 370                                GFP_KERNEL);
 371                 if (!name) {
 372                         bpf_prog_put(fp);
 373                         return -ENOMEM;
 374                 }
 375         }
 376
 377         prog->bpf_ops = NULL;
 378         prog->bpf_fd = bpf_fd;
 379         prog->bpf_name = name;
 380         prog->filter = fp;
 381
 382         if (fp->dst_needed && !(tp->q->flags & TCQ_F_INGRESS))
 383                 netif_keep_dst(qdisc_dev(tp->q));
 384
 385         return 0;
 386 }
 387
 388 static int cls_bpf_modify_existing(struct net *net, struct tcf_proto *tp,
 389                                    struct cls_bpf_prog *prog,
 390                                    unsigned long base, struct nlattr **tb,
 391                                    struct nlattr *est, bool ovr)
 392 {
 393         bool is_bpf, is_ebpf, have_exts = false;
 394         struct tcf_exts exts;
 395         u32 gen_flags = 0;
 396         int ret;
 397
 398         is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
 399         is_ebpf = tb[TCA_BPF_FD];
 400         if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
 401                 return -EINVAL;
 402
 403         ret = tcf_exts_init(&exts, TCA_BPF_ACT, TCA_BPF_POLICE);
 404         if (ret < 0)
 405                 return ret;
 406         ret = tcf_exts_validate(net, tp, tb, est, &exts, ovr);
 407         if (ret < 0)
 408                 goto errout;
 409
 410         if (tb[TCA_BPF_FLAGS]) {
 411                 u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
 412
 413                 if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) {
 414                         ret = -EINVAL;
 415                         goto errout;
 416                 }
 417
 418                 have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
 419         }
 420         if (tb[TCA_BPF_FLAGS_GEN]) {
 421                 gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
 422                 if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
 423                     !tc_flags_valid(gen_flags)) {
 424                         ret = -EINVAL;
 425                         goto errout;
 426                 }
 427         }
 428
 429         prog->exts_integrated = have_exts;
 430         prog->gen_flags = gen_flags;
 431
 432         ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
 433                        cls_bpf_prog_from_efd(tb, prog, tp);
 434         if (ret < 0)
 435                 goto errout;
 436
 437         if (tb[TCA_BPF_CLASSID]) {
 438                 prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
 439                 tcf_bind_filter(tp, &prog->res, base);
 440         }
 441
 442         tcf_exts_change(tp, &prog->exts, &exts);
 443         return 0;
 444
 445 errout:
 446         tcf_exts_destroy(&exts);
 447         return ret;
 448 }
 449
 450 static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
 451                                    struct cls_bpf_head *head)
 452 {
 453         unsigned int i = 0x80000000;
 454         u32 handle;
 455
 456         do {
 457                 if (++head->hgen == 0x7FFFFFFF)
 458                         head->hgen = 1;
 459         } while (--i > 0 && cls_bpf_get(tp, head->hgen));
 460
 461         if (unlikely(i == 0)) {
 462                 pr_err("Insufficient number of handles\n");
 463                 handle = 0;
 464         } else {
 465                 handle = head->hgen;
 466         }
 467
 468         return handle;
 469 }
 470
 471 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 472                           struct tcf_proto *tp, unsigned long base,
 473                           u32 handle, struct nlattr **tca,
 474                           unsigned long *arg, bool ovr)
 475 {
 476         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 477         struct cls_bpf_prog *oldprog = (struct cls_bpf_prog *) *arg;
 478         struct nlattr *tb[TCA_BPF_MAX + 1];
 479         struct cls_bpf_prog *prog;
 480         int ret;
 481
 482         if (tca[TCA_OPTIONS] == NULL)
 483                 return -EINVAL;
 484
 485         ret = nla_parse_nested(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], bpf_policy);
 486         if (ret < 0)
 487                 return ret;
 488
 489         prog = kzalloc(sizeof(*prog), GFP_KERNEL);
 490         if (!prog)
 491                 return -ENOBUFS;
 492
 493         ret = tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
 494         if (ret < 0)
 495                 goto errout;
 496
 497         if (oldprog) {
 498                 if (handle && oldprog->handle != handle) {
 499                         ret = -EINVAL;
 500                         goto errout;
 501                 }
 502         }
 503
 504         if (handle == 0)
 505                 prog->handle = cls_bpf_grab_new_handle(tp, head);
 506         else
 507                 prog->handle = handle;
 508         if (prog->handle == 0) {
 509                 ret = -EINVAL;
 510                 goto errout;
 511         }
 512
 513         ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE],
 514                                       ovr);
 515         if (ret < 0)
 516                 goto errout;
 517
 518         ret = cls_bpf_offload(tp, prog, oldprog);
 519         if (ret) {
 520                 cls_bpf_delete_prog(tp, prog);
 521                 return ret;
 522         }
 523
 524         if (oldprog) {
 525                 list_replace_rcu(&oldprog->link, &prog->link);
 526                 tcf_unbind_filter(tp, &oldprog->res);
 527                 call_rcu(&oldprog->rcu, __cls_bpf_delete_prog);
 528         } else {
 529                 list_add_rcu(&prog->link, &head->plist);
 530         }
 531
 532         *arg = (unsigned long) prog;
 533         return 0;
 534
 535 errout:
 536         tcf_exts_destroy(&prog->exts);
 537         kfree(prog);
 538         return ret;
 539 }
 540
 541 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
 542                                  struct sk_buff *skb)
 543 {
 544         struct nlattr *nla;
 545
 546         if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
 547                 return -EMSGSIZE;
 548
 549         nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
 550                           sizeof(struct sock_filter));
 551         if (nla == NULL)
 552                 return -EMSGSIZE;
 553
 554         memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
 555
 556         return 0;
 557 }
 558
 559 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 560                                   struct sk_buff *skb)
 561 {
 562         if (nla_put_u32(skb, TCA_BPF_FD, prog->bpf_fd))
 563                 return -EMSGSIZE;
 564
 565         if (prog->bpf_name &&
 566             nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
 567                 return -EMSGSIZE;
 568
 569         return 0;
 570 }
 571
 572 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
 573                         struct sk_buff *skb, struct tcmsg *tm)
 574 {
 575         struct cls_bpf_prog *prog = (struct cls_bpf_prog *) fh;
 576         struct nlattr *nest;
 577         u32 bpf_flags = 0;
 578         int ret;
 579
 580         if (prog == NULL)
 581                 return skb->len;
 582
 583         tm->tcm_handle = prog->handle;
 584
 585         cls_bpf_offload_update_stats(tp, prog);
 586
 587         nest = nla_nest_start(skb, TCA_OPTIONS);
 588         if (nest == NULL)
 589                 goto nla_put_failure;
 590
 591         if (prog->res.classid &&
 592             nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
 593                 goto nla_put_failure;
 594
 595         if (cls_bpf_is_ebpf(prog))
 596                 ret = cls_bpf_dump_ebpf_info(prog, skb);
 597         else
 598                 ret = cls_bpf_dump_bpf_info(prog, skb);
 599         if (ret)
 600                 goto nla_put_failure;
 601
 602         if (tcf_exts_dump(skb, &prog->exts) < 0)
 603                 goto nla_put_failure;
 604
 605         if (prog->exts_integrated)
 606                 bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
 607         if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
 608                 goto nla_put_failure;
 609         if (prog->gen_flags &&
 610             nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
 611                 goto nla_put_failure;
 612
 613         nla_nest_end(skb, nest);
 614
 615         if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
 616                 goto nla_put_failure;
 617
 618         return skb->len;
 619
 620 nla_put_failure:
 621         nla_nest_cancel(skb, nest);
 622         return -1;
 623 }
 624
 625 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 626 {
 627         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 628         struct cls_bpf_prog *prog;
 629
 630         list_for_each_entry(prog, &head->plist, link) {
 631                 if (arg->count < arg->skip)
 632                         goto skip;
 633                 if (arg->fn(tp, (unsigned long) prog, arg) < 0) {
 634                         arg->stop = 1;
 635                         break;
 636                 }
 637 skip:
 638                 arg->count++;
 639         }
 640 }
 641
 642 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
 643         .kind           =       "bpf",
 644         .owner          =       THIS_MODULE,
 645         .classify       =       cls_bpf_classify,
 646         .init           =       cls_bpf_init,
 647         .destroy        =       cls_bpf_destroy,
 648         .get            =       cls_bpf_get,
 649         .change         =       cls_bpf_change,
 650         .delete         =       cls_bpf_delete,
 651         .walk           =       cls_bpf_walk,
 652         .dump           =       cls_bpf_dump,
 653 };
 654
 655 static int __init cls_bpf_init_mod(void)
 656 {
 657         return register_tcf_proto_ops(&cls_bpf_ops);
 658 }
 659
 660 static void __exit cls_bpf_exit_mod(void)
 661 {
 662         unregister_tcf_proto_ops(&cls_bpf_ops);
 663 }
 664
 665 module_init(cls_bpf_init_mod);
 666 module_exit(cls_bpf_exit_mod);