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