sched/cls_bpf.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Berkeley Packet Filter based traffic classifier
   4  *
   5  * Might be used to classify traffic through flexible, user-defined and
   6  * possibly JIT-ed BPF filters for traffic control as an alternative to
   7  * ematches.
   8  *
   9  * (C) 2013 Daniel Borkmann <dborkman@redhat.com>
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/filter.h>
  16 #include <linux/bpf.h>
  17 #include <linux/idr.h>
  18
  19 #include <net/rtnetlink.h>
  20 #include <net/pkt_cls.h>
  21 #include <net/sock.h>
  22
  23 MODULE_LICENSE("GPL");
  24 MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
  25 MODULE_DESCRIPTION("TC BPF based classifier");
  26
  27 #define CLS_BPF_NAME_LEN        256
  28 #define CLS_BPF_SUPPORTED_GEN_FLAGS             \
  29         (TCA_CLS_FLAGS_SKIP_HW | TCA_CLS_FLAGS_SKIP_SW)
  30
  31 struct cls_bpf_head {
  32         struct list_head plist;
  33         struct idr handle_idr;
  34         struct rcu_head rcu;
  35 };
  36
  37 struct cls_bpf_prog {
  38         struct bpf_prog *filter;
  39         struct list_head link;
  40         struct tcf_result res;
  41         bool exts_integrated;
  42         u32 gen_flags;
  43         unsigned int in_hw_count;
  44         struct tcf_exts exts;
  45         u32 handle;
  46         u16 bpf_num_ops;
  47         struct sock_filter *bpf_ops;
  48         const char *bpf_name;
  49         struct tcf_proto *tp;
  50         struct rcu_work rwork;
  51 };
  52
  53 static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
  54         [TCA_BPF_CLASSID]       = { .type = NLA_U32 },
  55         [TCA_BPF_FLAGS]         = { .type = NLA_U32 },
  56         [TCA_BPF_FLAGS_GEN]     = { .type = NLA_U32 },
  57         [TCA_BPF_FD]            = { .type = NLA_U32 },
  58         [TCA_BPF_NAME]          = { .type = NLA_NUL_STRING,
  59                                     .len = CLS_BPF_NAME_LEN },
  60         [TCA_BPF_OPS_LEN]       = { .type = NLA_U16 },
  61         [TCA_BPF_OPS]           = { .type = NLA_BINARY,
  62                                     .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
  63 };
  64
  65 static int cls_bpf_exec_opcode(int code)
  66 {
  67         switch (code) {
  68         case TC_ACT_OK:
  69         case TC_ACT_SHOT:
  70         case TC_ACT_STOLEN:
  71         case TC_ACT_TRAP:
  72         case TC_ACT_REDIRECT:
  73         case TC_ACT_UNSPEC:
  74                 return code;
  75         default:
  76                 return TC_ACT_UNSPEC;
  77         }
  78 }
  79
  80 static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  81                             struct tcf_result *res)
  82 {
  83         struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
  84         bool at_ingress = skb_at_tc_ingress(skb);
  85         struct cls_bpf_prog *prog;
  86         int ret = -1;
  87
  88         list_for_each_entry_rcu(prog, &head->plist, link) {
  89                 int filter_res;
  90
  91                 qdisc_skb_cb(skb)->tc_classid = prog->res.classid;
  92
  93                 if (tc_skip_sw(prog->gen_flags)) {
  94                         filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0;
  95                 } else if (at_ingress) {
  96                         /* It is safe to push/pull even if skb_shared() */
  97                         __skb_push(skb, skb->mac_len);
  98                         bpf_compute_data_pointers(skb);
  99                         filter_res = bpf_prog_run(prog->filter, skb);
 100                         __skb_pull(skb, skb->mac_len);
 101                 } else {
 102                         bpf_compute_data_pointers(skb);
 103                         filter_res = bpf_prog_run(prog->filter, skb);
 104                 }
 105                 if (unlikely(!skb->tstamp && skb->mono_delivery_time))
 106                         skb->mono_delivery_time = 0;
 107
 108                 if (prog->exts_integrated) {
 109                         res->class   = 0;
 110                         res->classid = TC_H_MAJ(prog->res.classid) |
 111                                        qdisc_skb_cb(skb)->tc_classid;
 112
 113                         ret = cls_bpf_exec_opcode(filter_res);
 114                         if (ret == TC_ACT_UNSPEC)
 115                                 continue;
 116                         break;
 117                 }
 118
 119                 if (filter_res == 0)
 120                         continue;
 121                 if (filter_res != -1) {
 122                         res->class   = 0;
 123                         res->classid = filter_res;
 124                 } else {
 125                         *res = prog->res;
 126                 }
 127
 128                 ret = tcf_exts_exec(skb, &prog->exts, res);
 129                 if (ret < 0)
 130                         continue;
 131
 132                 break;
 133         }
 134
 135         return ret;
 136 }
 137
 138 static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
 139 {
 140         return !prog->bpf_ops;
 141 }
 142
 143 static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 144                                struct cls_bpf_prog *oldprog,
 145                                struct netlink_ext_ack *extack)
 146 {
 147         struct tcf_block *block = tp->chain->block;
 148         struct tc_cls_bpf_offload cls_bpf = {};
 149         struct cls_bpf_prog *obj;
 150         bool skip_sw;
 151         int err;
 152
 153         skip_sw = prog && tc_skip_sw(prog->gen_flags);
 154         obj = prog ?: oldprog;
 155
 156         tc_cls_common_offload_init(&cls_bpf.common, tp, obj->gen_flags, extack);
 157         cls_bpf.command = TC_CLSBPF_OFFLOAD;
 158         cls_bpf.exts = &obj->exts;
 159         cls_bpf.prog = prog ? prog->filter : NULL;
 160         cls_bpf.oldprog = oldprog ? oldprog->filter : NULL;
 161         cls_bpf.name = obj->bpf_name;
 162         cls_bpf.exts_integrated = obj->exts_integrated;
 163
 164         if (oldprog && prog)
 165                 err = tc_setup_cb_replace(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 166                                           skip_sw, &oldprog->gen_flags,
 167                                           &oldprog->in_hw_count,
 168                                           &prog->gen_flags, &prog->in_hw_count,
 169                                           true);
 170         else if (prog)
 171                 err = tc_setup_cb_add(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 172                                       skip_sw, &prog->gen_flags,
 173                                       &prog->in_hw_count, true);
 174         else
 175                 err = tc_setup_cb_destroy(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 176                                           skip_sw, &oldprog->gen_flags,
 177                                           &oldprog->in_hw_count, true);
 178
 179         if (prog && err) {
 180                 cls_bpf_offload_cmd(tp, oldprog, prog, extack);
 181                 return err;
 182         }
 183
 184         if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW))
 185                 return -EINVAL;
 186
 187         return 0;
 188 }
 189
 190 static u32 cls_bpf_flags(u32 flags)
 191 {
 192         return flags & CLS_BPF_SUPPORTED_GEN_FLAGS;
 193 }
 194
 195 static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 196                            struct cls_bpf_prog *oldprog,
 197                            struct netlink_ext_ack *extack)
 198 {
 199         if (prog && oldprog &&
 200             cls_bpf_flags(prog->gen_flags) !=
 201             cls_bpf_flags(oldprog->gen_flags))
 202                 return -EINVAL;
 203
 204         if (prog && tc_skip_hw(prog->gen_flags))
 205                 prog = NULL;
 206         if (oldprog && tc_skip_hw(oldprog->gen_flags))
 207                 oldprog = NULL;
 208         if (!prog && !oldprog)
 209                 return 0;
 210
 211         return cls_bpf_offload_cmd(tp, prog, oldprog, extack);
 212 }
 213
 214 static void cls_bpf_stop_offload(struct tcf_proto *tp,
 215                                  struct cls_bpf_prog *prog,
 216                                  struct netlink_ext_ack *extack)
 217 {
 218         int err;
 219
 220         err = cls_bpf_offload_cmd(tp, NULL, prog, extack);
 221         if (err)
 222                 pr_err("Stopping hardware offload failed: %d\n", err);
 223 }
 224
 225 static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
 226                                          struct cls_bpf_prog *prog)
 227 {
 228         struct tcf_block *block = tp->chain->block;
 229         struct tc_cls_bpf_offload cls_bpf = {};
 230
 231         tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, NULL);
 232         cls_bpf.command = TC_CLSBPF_STATS;
 233         cls_bpf.exts = &prog->exts;
 234         cls_bpf.prog = prog->filter;
 235         cls_bpf.name = prog->bpf_name;
 236         cls_bpf.exts_integrated = prog->exts_integrated;
 237
 238         tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false, true);
 239 }
 240
 241 static int cls_bpf_init(struct tcf_proto *tp)
 242 {
 243         struct cls_bpf_head *head;
 244
 245         head = kzalloc(sizeof(*head), GFP_KERNEL);
 246         if (head == NULL)
 247                 return -ENOBUFS;
 248
 249         INIT_LIST_HEAD_RCU(&head->plist);
 250         idr_init(&head->handle_idr);
 251         rcu_assign_pointer(tp->root, head);
 252
 253         return 0;
 254 }
 255
 256 static void cls_bpf_free_parms(struct cls_bpf_prog *prog)
 257 {
 258         if (cls_bpf_is_ebpf(prog))
 259                 bpf_prog_put(prog->filter);
 260         else
 261                 bpf_prog_destroy(prog->filter);
 262
 263         kfree(prog->bpf_name);
 264         kfree(prog->bpf_ops);
 265 }
 266
 267 static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
 268 {
 269         tcf_exts_destroy(&prog->exts);
 270         tcf_exts_put_net(&prog->exts);
 271
 272         cls_bpf_free_parms(prog);
 273         kfree(prog);
 274 }
 275
 276 static void cls_bpf_delete_prog_work(struct work_struct *work)
 277 {
 278         struct cls_bpf_prog *prog = container_of(to_rcu_work(work),
 279                                                  struct cls_bpf_prog,
 280                                                  rwork);
 281         rtnl_lock();
 282         __cls_bpf_delete_prog(prog);
 283         rtnl_unlock();
 284 }
 285
 286 static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 287                              struct netlink_ext_ack *extack)
 288 {
 289         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 290
 291         idr_remove(&head->handle_idr, prog->handle);
 292         cls_bpf_stop_offload(tp, prog, extack);
 293         list_del_rcu(&prog->link);
 294         tcf_unbind_filter(tp, &prog->res);
 295         if (tcf_exts_get_net(&prog->exts))
 296                 tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work);
 297         else
 298                 __cls_bpf_delete_prog(prog);
 299 }
 300
 301 static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
 302                           bool rtnl_held, struct netlink_ext_ack *extack)
 303 {
 304         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 305
 306         __cls_bpf_delete(tp, arg, extack);
 307         *last = list_empty(&head->plist);
 308         return 0;
 309 }
 310
 311 static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held,
 312                             struct netlink_ext_ack *extack)
 313 {
 314         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 315         struct cls_bpf_prog *prog, *tmp;
 316
 317         list_for_each_entry_safe(prog, tmp, &head->plist, link)
 318                 __cls_bpf_delete(tp, prog, extack);
 319
 320         idr_destroy(&head->handle_idr);
 321         kfree_rcu(head, rcu);
 322 }
 323
 324 static void *cls_bpf_get(struct tcf_proto *tp, u32 handle)
 325 {
 326         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 327         struct cls_bpf_prog *prog;
 328
 329         list_for_each_entry(prog, &head->plist, link) {
 330                 if (prog->handle == handle)
 331                         return prog;
 332         }
 333
 334         return NULL;
 335 }
 336
 337 static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
 338 {
 339         struct sock_filter *bpf_ops;
 340         struct sock_fprog_kern fprog_tmp;
 341         struct bpf_prog *fp;
 342         u16 bpf_size, bpf_num_ops;
 343         int ret;
 344
 345         bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
 346         if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
 347                 return -EINVAL;
 348
 349         bpf_size = bpf_num_ops * sizeof(*bpf_ops);
 350         if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
 351                 return -EINVAL;
 352
 353         bpf_ops = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL);
 354         if (bpf_ops == NULL)
 355                 return -ENOMEM;
 356
 357         fprog_tmp.len = bpf_num_ops;
 358         fprog_tmp.filter = bpf_ops;
 359
 360         ret = bpf_prog_create(&fp, &fprog_tmp);
 361         if (ret < 0) {
 362                 kfree(bpf_ops);
 363                 return ret;
 364         }
 365
 366         prog->bpf_ops = bpf_ops;
 367         prog->bpf_num_ops = bpf_num_ops;
 368         prog->bpf_name = NULL;
 369         prog->filter = fp;
 370
 371         return 0;
 372 }
 373
 374 static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
 375                                  u32 gen_flags, const struct tcf_proto *tp)
 376 {
 377         struct bpf_prog *fp;
 378         char *name = NULL;
 379         bool skip_sw;
 380         u32 bpf_fd;
 381
 382         bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
 383         skip_sw = gen_flags & TCA_CLS_FLAGS_SKIP_SW;
 384
 385         fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS, skip_sw);
 386         if (IS_ERR(fp))
 387                 return PTR_ERR(fp);
 388
 389         if (tb[TCA_BPF_NAME]) {
 390                 name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
 391                 if (!name) {
 392                         bpf_prog_put(fp);
 393                         return -ENOMEM;
 394                 }
 395         }
 396
 397         prog->bpf_ops = NULL;
 398         prog->bpf_name = name;
 399         prog->filter = fp;
 400
 401         if (fp->dst_needed)
 402                 tcf_block_netif_keep_dst(tp->chain->block);
 403
 404         return 0;
 405 }
 406
 407 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 408                           struct tcf_proto *tp, unsigned long base,
 409                           u32 handle, struct nlattr **tca,
 410                           void **arg, u32 flags,
 411                           struct netlink_ext_ack *extack)
 412 {
 413         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 414         bool is_bpf, is_ebpf, have_exts = false;
 415         struct cls_bpf_prog *oldprog = *arg;
 416         struct nlattr *tb[TCA_BPF_MAX + 1];
 417         bool bound_to_filter = false;
 418         struct cls_bpf_prog *prog;
 419         u32 gen_flags = 0;
 420         int ret;
 421
 422         if (tca[TCA_OPTIONS] == NULL)
 423                 return -EINVAL;
 424
 425         ret = nla_parse_nested_deprecated(tb, TCA_BPF_MAX, tca[TCA_OPTIONS],
 426                                           bpf_policy, NULL);
 427         if (ret < 0)
 428                 return ret;
 429
 430         prog = kzalloc(sizeof(*prog), GFP_KERNEL);
 431         if (!prog)
 432                 return -ENOBUFS;
 433
 434         ret = tcf_exts_init(&prog->exts, net, TCA_BPF_ACT, TCA_BPF_POLICE);
 435         if (ret < 0)
 436                 goto errout;
 437
 438         if (oldprog) {
 439                 if (handle && oldprog->handle != handle) {
 440                         ret = -EINVAL;
 441                         goto errout;
 442                 }
 443         }
 444
 445         if (handle == 0) {
 446                 handle = 1;
 447                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 448                                     INT_MAX, GFP_KERNEL);
 449         } else if (!oldprog) {
 450                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 451                                     handle, GFP_KERNEL);
 452         }
 453
 454         if (ret)
 455                 goto errout;
 456         prog->handle = handle;
 457
 458         is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
 459         is_ebpf = tb[TCA_BPF_FD];
 460         if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf)) {
 461                 ret = -EINVAL;
 462                 goto errout_idr;
 463         }
 464
 465         ret = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &prog->exts,
 466                                 flags, extack);
 467         if (ret < 0)
 468                 goto errout_idr;
 469
 470         if (tb[TCA_BPF_FLAGS]) {
 471                 u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
 472
 473                 if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) {
 474                         ret = -EINVAL;
 475                         goto errout_idr;
 476                 }
 477
 478                 have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
 479         }
 480         if (tb[TCA_BPF_FLAGS_GEN]) {
 481                 gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
 482                 if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
 483                     !tc_flags_valid(gen_flags)) {
 484                         ret = -EINVAL;
 485                         goto errout_idr;
 486                 }
 487         }
 488
 489         prog->exts_integrated = have_exts;
 490         prog->gen_flags = gen_flags;
 491
 492         ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
 493                 cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
 494         if (ret < 0)
 495                 goto errout_idr;
 496
 497         if (tb[TCA_BPF_CLASSID]) {
 498                 prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
 499                 tcf_bind_filter(tp, &prog->res, base);
 500                 bound_to_filter = true;
 501         }
 502
 503         ret = cls_bpf_offload(tp, prog, oldprog, extack);
 504         if (ret)
 505                 goto errout_parms;
 506
 507         if (!tc_in_hw(prog->gen_flags))
 508                 prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 509
 510         if (oldprog) {
 511                 idr_replace(&head->handle_idr, prog, handle);
 512                 list_replace_rcu(&oldprog->link, &prog->link);
 513                 tcf_unbind_filter(tp, &oldprog->res);
 514                 tcf_exts_get_net(&oldprog->exts);
 515                 tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
 516         } else {
 517                 list_add_rcu(&prog->link, &head->plist);
 518         }
 519
 520         *arg = prog;
 521         return 0;
 522
 523 errout_parms:
 524         if (bound_to_filter)
 525                 tcf_unbind_filter(tp, &prog->res);
 526         cls_bpf_free_parms(prog);
 527 errout_idr:
 528         if (!oldprog)
 529                 idr_remove(&head->handle_idr, prog->handle);
 530 errout:
 531         tcf_exts_destroy(&prog->exts);
 532         kfree(prog);
 533         return ret;
 534 }
 535
 536 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
 537                                  struct sk_buff *skb)
 538 {
 539         struct nlattr *nla;
 540
 541         if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
 542                 return -EMSGSIZE;
 543
 544         nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
 545                           sizeof(struct sock_filter));
 546         if (nla == NULL)
 547                 return -EMSGSIZE;
 548
 549         memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
 550
 551         return 0;
 552 }
 553
 554 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 555                                   struct sk_buff *skb)
 556 {
 557         struct nlattr *nla;
 558
 559         if (prog->bpf_name &&
 560             nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
 561                 return -EMSGSIZE;
 562
 563         if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
 564                 return -EMSGSIZE;
 565
 566         nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
 567         if (nla == NULL)
 568                 return -EMSGSIZE;
 569
 570         memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
 571
 572         return 0;
 573 }
 574
 575 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
 576                         struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
 577 {
 578         struct cls_bpf_prog *prog = fh;
 579         struct nlattr *nest;
 580         u32 bpf_flags = 0;
 581         int ret;
 582
 583         if (prog == NULL)
 584                 return skb->len;
 585
 586         tm->tcm_handle = prog->handle;
 587
 588         cls_bpf_offload_update_stats(tp, prog);
 589
 590         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 591         if (nest == NULL)
 592                 goto nla_put_failure;
 593
 594         if (prog->res.classid &&
 595             nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
 596                 goto nla_put_failure;
 597
 598         if (cls_bpf_is_ebpf(prog))
 599                 ret = cls_bpf_dump_ebpf_info(prog, skb);
 600         else
 601                 ret = cls_bpf_dump_bpf_info(prog, skb);
 602         if (ret)
 603                 goto nla_put_failure;
 604
 605         if (tcf_exts_dump(skb, &prog->exts) < 0)
 606                 goto nla_put_failure;
 607
 608         if (prog->exts_integrated)
 609                 bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
 610         if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
 611                 goto nla_put_failure;
 612         if (prog->gen_flags &&
 613             nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
 614                 goto nla_put_failure;
 615
 616         nla_nest_end(skb, nest);
 617
 618         if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
 619                 goto nla_put_failure;
 620
 621         return skb->len;
 622
 623 nla_put_failure:
 624         nla_nest_cancel(skb, nest);
 625         return -1;
 626 }
 627
 628 static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl,
 629                                void *q, unsigned long base)
 630 {
 631         struct cls_bpf_prog *prog = fh;
 632
 633         tc_cls_bind_class(classid, cl, q, &prog->res, base);
 634 }
 635
 636 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
 637                          bool rtnl_held)
 638 {
 639         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 640         struct cls_bpf_prog *prog;
 641
 642         list_for_each_entry(prog, &head->plist, link) {
 643                 if (!tc_cls_stats_dump(tp, arg, prog))
 644                         break;
 645         }
 646 }
 647
 648 static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
 649                              void *cb_priv, struct netlink_ext_ack *extack)
 650 {
 651         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 652         struct tcf_block *block = tp->chain->block;
 653         struct tc_cls_bpf_offload cls_bpf = {};
 654         struct cls_bpf_prog *prog;
 655         int err;
 656
 657         list_for_each_entry(prog, &head->plist, link) {
 658                 if (tc_skip_hw(prog->gen_flags))
 659                         continue;
 660
 661                 tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
 662                                            extack);
 663                 cls_bpf.command = TC_CLSBPF_OFFLOAD;
 664                 cls_bpf.exts = &prog->exts;
 665                 cls_bpf.prog = add ? prog->filter : NULL;
 666                 cls_bpf.oldprog = add ? NULL : prog->filter;
 667                 cls_bpf.name = prog->bpf_name;
 668                 cls_bpf.exts_integrated = prog->exts_integrated;
 669
 670                 err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF,
 671                                             &cls_bpf, cb_priv, &prog->gen_flags,
 672                                             &prog->in_hw_count);
 673                 if (err)
 674                         return err;
 675         }
 676
 677         return 0;
 678 }
 679
 680 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
 681         .kind           =       "bpf",
 682         .owner          =       THIS_MODULE,
 683         .classify       =       cls_bpf_classify,
 684         .init           =       cls_bpf_init,
 685         .destroy        =       cls_bpf_destroy,
 686         .get            =       cls_bpf_get,
 687         .change         =       cls_bpf_change,
 688         .delete         =       cls_bpf_delete,
 689         .walk           =       cls_bpf_walk,
 690         .reoffload      =       cls_bpf_reoffload,
 691         .dump           =       cls_bpf_dump,
 692         .bind_class     =       cls_bpf_bind_class,
 693 };
 694
 695 static int __init cls_bpf_init_mod(void)
 696 {
 697         return register_tcf_proto_ops(&cls_bpf_ops);
 698 }
 699
 700 static void __exit cls_bpf_exit_mod(void)
 701 {
 702         unregister_tcf_proto_ops(&cls_bpf_ops);
 703 }
 704
 705 module_init(cls_bpf_init_mod);
 706 module_exit(cls_bpf_exit_mod);