net/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
 106                 if (prog->exts_integrated) {
 107                         res->class   = 0;
 108                         res->classid = TC_H_MAJ(prog->res.classid) |
 109                                        qdisc_skb_cb(skb)->tc_classid;
 110
 111                         ret = cls_bpf_exec_opcode(filter_res);
 112                         if (ret == TC_ACT_UNSPEC)
 113                                 continue;
 114                         break;
 115                 }
 116
 117                 if (filter_res == 0)
 118                         continue;
 119                 if (filter_res != -1) {
 120                         res->class   = 0;
 121                         res->classid = filter_res;
 122                 } else {
 123                         *res = prog->res;
 124                 }
 125
 126                 ret = tcf_exts_exec(skb, &prog->exts, res);
 127                 if (ret < 0)
 128                         continue;
 129
 130                 break;
 131         }
 132
 133         return ret;
 134 }
 135
 136 static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
 137 {
 138         return !prog->bpf_ops;
 139 }
 140
 141 static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 142                                struct cls_bpf_prog *oldprog,
 143                                struct netlink_ext_ack *extack)
 144 {
 145         struct tcf_block *block = tp->chain->block;
 146         struct tc_cls_bpf_offload cls_bpf = {};
 147         struct cls_bpf_prog *obj;
 148         bool skip_sw;
 149         int err;
 150
 151         skip_sw = prog && tc_skip_sw(prog->gen_flags);
 152         obj = prog ?: oldprog;
 153
 154         tc_cls_common_offload_init(&cls_bpf.common, tp, obj->gen_flags, extack);
 155         cls_bpf.command = TC_CLSBPF_OFFLOAD;
 156         cls_bpf.exts = &obj->exts;
 157         cls_bpf.prog = prog ? prog->filter : NULL;
 158         cls_bpf.oldprog = oldprog ? oldprog->filter : NULL;
 159         cls_bpf.name = obj->bpf_name;
 160         cls_bpf.exts_integrated = obj->exts_integrated;
 161
 162         if (oldprog && prog)
 163                 err = tc_setup_cb_replace(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 164                                           skip_sw, &oldprog->gen_flags,
 165                                           &oldprog->in_hw_count,
 166                                           &prog->gen_flags, &prog->in_hw_count,
 167                                           true);
 168         else if (prog)
 169                 err = tc_setup_cb_add(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 170                                       skip_sw, &prog->gen_flags,
 171                                       &prog->in_hw_count, true);
 172         else
 173                 err = tc_setup_cb_destroy(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 174                                           skip_sw, &oldprog->gen_flags,
 175                                           &oldprog->in_hw_count, true);
 176
 177         if (prog && err) {
 178                 cls_bpf_offload_cmd(tp, oldprog, prog, extack);
 179                 return err;
 180         }
 181
 182         if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW))
 183                 return -EINVAL;
 184
 185         return 0;
 186 }
 187
 188 static u32 cls_bpf_flags(u32 flags)
 189 {
 190         return flags & CLS_BPF_SUPPORTED_GEN_FLAGS;
 191 }
 192
 193 static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 194                            struct cls_bpf_prog *oldprog,
 195                            struct netlink_ext_ack *extack)
 196 {
 197         if (prog && oldprog &&
 198             cls_bpf_flags(prog->gen_flags) !=
 199             cls_bpf_flags(oldprog->gen_flags))
 200                 return -EINVAL;
 201
 202         if (prog && tc_skip_hw(prog->gen_flags))
 203                 prog = NULL;
 204         if (oldprog && tc_skip_hw(oldprog->gen_flags))
 205                 oldprog = NULL;
 206         if (!prog && !oldprog)
 207                 return 0;
 208
 209         return cls_bpf_offload_cmd(tp, prog, oldprog, extack);
 210 }
 211
 212 static void cls_bpf_stop_offload(struct tcf_proto *tp,
 213                                  struct cls_bpf_prog *prog,
 214                                  struct netlink_ext_ack *extack)
 215 {
 216         int err;
 217
 218         err = cls_bpf_offload_cmd(tp, NULL, prog, extack);
 219         if (err)
 220                 pr_err("Stopping hardware offload failed: %d\n", err);
 221 }
 222
 223 static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
 224                                          struct cls_bpf_prog *prog)
 225 {
 226         struct tcf_block *block = tp->chain->block;
 227         struct tc_cls_bpf_offload cls_bpf = {};
 228
 229         tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, NULL);
 230         cls_bpf.command = TC_CLSBPF_STATS;
 231         cls_bpf.exts = &prog->exts;
 232         cls_bpf.prog = prog->filter;
 233         cls_bpf.name = prog->bpf_name;
 234         cls_bpf.exts_integrated = prog->exts_integrated;
 235
 236         tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false, true);
 237 }
 238
 239 static int cls_bpf_init(struct tcf_proto *tp)
 240 {
 241         struct cls_bpf_head *head;
 242
 243         head = kzalloc(sizeof(*head), GFP_KERNEL);
 244         if (head == NULL)
 245                 return -ENOBUFS;
 246
 247         INIT_LIST_HEAD_RCU(&head->plist);
 248         idr_init(&head->handle_idr);
 249         rcu_assign_pointer(tp->root, head);
 250
 251         return 0;
 252 }
 253
 254 static void cls_bpf_free_parms(struct cls_bpf_prog *prog)
 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 }
 264
 265 static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
 266 {
 267         tcf_exts_destroy(&prog->exts);
 268         tcf_exts_put_net(&prog->exts);
 269
 270         cls_bpf_free_parms(prog);
 271         kfree(prog);
 272 }
 273
 274 static void cls_bpf_delete_prog_work(struct work_struct *work)
 275 {
 276         struct cls_bpf_prog *prog = container_of(to_rcu_work(work),
 277                                                  struct cls_bpf_prog,
 278                                                  rwork);
 279         rtnl_lock();
 280         __cls_bpf_delete_prog(prog);
 281         rtnl_unlock();
 282 }
 283
 284 static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 285                              struct netlink_ext_ack *extack)
 286 {
 287         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 288
 289         idr_remove(&head->handle_idr, prog->handle);
 290         cls_bpf_stop_offload(tp, prog, extack);
 291         list_del_rcu(&prog->link);
 292         tcf_unbind_filter(tp, &prog->res);
 293         if (tcf_exts_get_net(&prog->exts))
 294                 tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work);
 295         else
 296                 __cls_bpf_delete_prog(prog);
 297 }
 298
 299 static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
 300                           bool rtnl_held, struct netlink_ext_ack *extack)
 301 {
 302         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 303
 304         __cls_bpf_delete(tp, arg, extack);
 305         *last = list_empty(&head->plist);
 306         return 0;
 307 }
 308
 309 static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held,
 310                             struct netlink_ext_ack *extack)
 311 {
 312         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 313         struct cls_bpf_prog *prog, *tmp;
 314
 315         list_for_each_entry_safe(prog, tmp, &head->plist, link)
 316                 __cls_bpf_delete(tp, prog, extack);
 317
 318         idr_destroy(&head->handle_idr);
 319         kfree_rcu(head, rcu);
 320 }
 321
 322 static void *cls_bpf_get(struct tcf_proto *tp, u32 handle)
 323 {
 324         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 325         struct cls_bpf_prog *prog;
 326
 327         list_for_each_entry(prog, &head->plist, link) {
 328                 if (prog->handle == handle)
 329                         return prog;
 330         }
 331
 332         return NULL;
 333 }
 334
 335 static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
 336 {
 337         struct sock_filter *bpf_ops;
 338         struct sock_fprog_kern fprog_tmp;
 339         struct bpf_prog *fp;
 340         u16 bpf_size, bpf_num_ops;
 341         int ret;
 342
 343         bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
 344         if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
 345                 return -EINVAL;
 346
 347         bpf_size = bpf_num_ops * sizeof(*bpf_ops);
 348         if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
 349                 return -EINVAL;
 350
 351         bpf_ops = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL);
 352         if (bpf_ops == NULL)
 353                 return -ENOMEM;
 354
 355         fprog_tmp.len = bpf_num_ops;
 356         fprog_tmp.filter = bpf_ops;
 357
 358         ret = bpf_prog_create(&fp, &fprog_tmp);
 359         if (ret < 0) {
 360                 kfree(bpf_ops);
 361                 return ret;
 362         }
 363
 364         prog->bpf_ops = bpf_ops;
 365         prog->bpf_num_ops = bpf_num_ops;
 366         prog->bpf_name = NULL;
 367         prog->filter = fp;
 368
 369         return 0;
 370 }
 371
 372 static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
 373                                  u32 gen_flags, const struct tcf_proto *tp)
 374 {
 375         struct bpf_prog *fp;
 376         char *name = NULL;
 377         bool skip_sw;
 378         u32 bpf_fd;
 379
 380         bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
 381         skip_sw = gen_flags & TCA_CLS_FLAGS_SKIP_SW;
 382
 383         fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS, skip_sw);
 384         if (IS_ERR(fp))
 385                 return PTR_ERR(fp);
 386
 387         if (tb[TCA_BPF_NAME]) {
 388                 name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
 389                 if (!name) {
 390                         bpf_prog_put(fp);
 391                         return -ENOMEM;
 392                 }
 393         }
 394
 395         prog->bpf_ops = NULL;
 396         prog->bpf_name = name;
 397         prog->filter = fp;
 398
 399         if (fp->dst_needed)
 400                 tcf_block_netif_keep_dst(tp->chain->block);
 401
 402         return 0;
 403 }
 404
 405 static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 406                              struct cls_bpf_prog *prog, unsigned long base,
 407                              struct nlattr **tb, struct nlattr *est, bool ovr,
 408                              struct netlink_ext_ack *extack)
 409 {
 410         bool is_bpf, is_ebpf, have_exts = false;
 411         u32 gen_flags = 0;
 412         int ret;
 413
 414         is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
 415         is_ebpf = tb[TCA_BPF_FD];
 416         if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
 417                 return -EINVAL;
 418
 419         ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr, true,
 420                                 extack);
 421         if (ret < 0)
 422                 return ret;
 423
 424         if (tb[TCA_BPF_FLAGS]) {
 425                 u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
 426
 427                 if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT)
 428                         return -EINVAL;
 429
 430                 have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
 431         }
 432         if (tb[TCA_BPF_FLAGS_GEN]) {
 433                 gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
 434                 if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
 435                     !tc_flags_valid(gen_flags))
 436                         return -EINVAL;
 437         }
 438
 439         prog->exts_integrated = have_exts;
 440         prog->gen_flags = gen_flags;
 441
 442         ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
 443                        cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
 444         if (ret < 0)
 445                 return ret;
 446
 447         if (tb[TCA_BPF_CLASSID]) {
 448                 prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
 449                 tcf_bind_filter(tp, &prog->res, base);
 450         }
 451
 452         return 0;
 453 }
 454
 455 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 456                           struct tcf_proto *tp, unsigned long base,
 457                           u32 handle, struct nlattr **tca,
 458                           void **arg, bool ovr, bool rtnl_held,
 459                           struct netlink_ext_ack *extack)
 460 {
 461         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 462         struct cls_bpf_prog *oldprog = *arg;
 463         struct nlattr *tb[TCA_BPF_MAX + 1];
 464         struct cls_bpf_prog *prog;
 465         int ret;
 466
 467         if (tca[TCA_OPTIONS] == NULL)
 468                 return -EINVAL;
 469
 470         ret = nla_parse_nested_deprecated(tb, TCA_BPF_MAX, tca[TCA_OPTIONS],
 471                                           bpf_policy, NULL);
 472         if (ret < 0)
 473                 return ret;
 474
 475         prog = kzalloc(sizeof(*prog), GFP_KERNEL);
 476         if (!prog)
 477                 return -ENOBUFS;
 478
 479         ret = tcf_exts_init(&prog->exts, net, TCA_BPF_ACT, TCA_BPF_POLICE);
 480         if (ret < 0)
 481                 goto errout;
 482
 483         if (oldprog) {
 484                 if (handle && oldprog->handle != handle) {
 485                         ret = -EINVAL;
 486                         goto errout;
 487                 }
 488         }
 489
 490         if (handle == 0) {
 491                 handle = 1;
 492                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 493                                     INT_MAX, GFP_KERNEL);
 494         } else if (!oldprog) {
 495                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 496                                     handle, GFP_KERNEL);
 497         }
 498
 499         if (ret)
 500                 goto errout;
 501         prog->handle = handle;
 502
 503         ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr,
 504                                 extack);
 505         if (ret < 0)
 506                 goto errout_idr;
 507
 508         ret = cls_bpf_offload(tp, prog, oldprog, extack);
 509         if (ret)
 510                 goto errout_parms;
 511
 512         if (!tc_in_hw(prog->gen_flags))
 513                 prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 514
 515         if (oldprog) {
 516                 idr_replace(&head->handle_idr, prog, handle);
 517                 list_replace_rcu(&oldprog->link, &prog->link);
 518                 tcf_unbind_filter(tp, &oldprog->res);
 519                 tcf_exts_get_net(&oldprog->exts);
 520                 tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
 521         } else {
 522                 list_add_rcu(&prog->link, &head->plist);
 523         }
 524
 525         *arg = prog;
 526         return 0;
 527
 528 errout_parms:
 529         cls_bpf_free_parms(prog);
 530 errout_idr:
 531         if (!oldprog)
 532                 idr_remove(&head->handle_idr, prog->handle);
 533 errout:
 534         tcf_exts_destroy(&prog->exts);
 535         kfree(prog);
 536         return ret;
 537 }
 538
 539 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
 540                                  struct sk_buff *skb)
 541 {
 542         struct nlattr *nla;
 543
 544         if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
 545                 return -EMSGSIZE;
 546
 547         nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
 548                           sizeof(struct sock_filter));
 549         if (nla == NULL)
 550                 return -EMSGSIZE;
 551
 552         memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
 553
 554         return 0;
 555 }
 556
 557 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 558                                   struct sk_buff *skb)
 559 {
 560         struct nlattr *nla;
 561
 562         if (prog->bpf_name &&
 563             nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
 564                 return -EMSGSIZE;
 565
 566         if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
 567                 return -EMSGSIZE;
 568
 569         nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
 570         if (nla == NULL)
 571                 return -EMSGSIZE;
 572
 573         memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
 574
 575         return 0;
 576 }
 577
 578 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
 579                         struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
 580 {
 581         struct cls_bpf_prog *prog = fh;
 582         struct nlattr *nest;
 583         u32 bpf_flags = 0;
 584         int ret;
 585
 586         if (prog == NULL)
 587                 return skb->len;
 588
 589         tm->tcm_handle = prog->handle;
 590
 591         cls_bpf_offload_update_stats(tp, prog);
 592
 593         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 594         if (nest == NULL)
 595                 goto nla_put_failure;
 596
 597         if (prog->res.classid &&
 598             nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
 599                 goto nla_put_failure;
 600
 601         if (cls_bpf_is_ebpf(prog))
 602                 ret = cls_bpf_dump_ebpf_info(prog, skb);
 603         else
 604                 ret = cls_bpf_dump_bpf_info(prog, skb);
 605         if (ret)
 606                 goto nla_put_failure;
 607
 608         if (tcf_exts_dump(skb, &prog->exts) < 0)
 609                 goto nla_put_failure;
 610
 611         if (prog->exts_integrated)
 612                 bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
 613         if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
 614                 goto nla_put_failure;
 615         if (prog->gen_flags &&
 616             nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
 617                 goto nla_put_failure;
 618
 619         nla_nest_end(skb, nest);
 620
 621         if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
 622                 goto nla_put_failure;
 623
 624         return skb->len;
 625
 626 nla_put_failure:
 627         nla_nest_cancel(skb, nest);
 628         return -1;
 629 }
 630
 631 static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl,
 632                                void *q, unsigned long base)
 633 {
 634         struct cls_bpf_prog *prog = fh;
 635
 636         if (prog && prog->res.classid == classid) {
 637                 if (cl)
 638                         __tcf_bind_filter(q, &prog->res, base);
 639                 else
 640                         __tcf_unbind_filter(q, &prog->res);
 641         }
 642 }
 643
 644 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
 645                          bool rtnl_held)
 646 {
 647         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 648         struct cls_bpf_prog *prog;
 649
 650         list_for_each_entry(prog, &head->plist, link) {
 651                 if (arg->count < arg->skip)
 652                         goto skip;
 653                 if (arg->fn(tp, prog, arg) < 0) {
 654                         arg->stop = 1;
 655                         break;
 656                 }
 657 skip:
 658                 arg->count++;
 659         }
 660 }
 661
 662 static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
 663                              void *cb_priv, struct netlink_ext_ack *extack)
 664 {
 665         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 666         struct tcf_block *block = tp->chain->block;
 667         struct tc_cls_bpf_offload cls_bpf = {};
 668         struct cls_bpf_prog *prog;
 669         int err;
 670
 671         list_for_each_entry(prog, &head->plist, link) {
 672                 if (tc_skip_hw(prog->gen_flags))
 673                         continue;
 674
 675                 tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
 676                                            extack);
 677                 cls_bpf.command = TC_CLSBPF_OFFLOAD;
 678                 cls_bpf.exts = &prog->exts;
 679                 cls_bpf.prog = add ? prog->filter : NULL;
 680                 cls_bpf.oldprog = add ? NULL : prog->filter;
 681                 cls_bpf.name = prog->bpf_name;
 682                 cls_bpf.exts_integrated = prog->exts_integrated;
 683
 684                 err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF,
 685                                             &cls_bpf, cb_priv, &prog->gen_flags,
 686                                             &prog->in_hw_count);
 687                 if (err)
 688                         return err;
 689         }
 690
 691         return 0;
 692 }
 693
 694 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
 695         .kind           =       "bpf",
 696         .owner          =       THIS_MODULE,
 697         .classify       =       cls_bpf_classify,
 698         .init           =       cls_bpf_init,
 699         .destroy        =       cls_bpf_destroy,
 700         .get            =       cls_bpf_get,
 701         .change         =       cls_bpf_change,
 702         .delete         =       cls_bpf_delete,
 703         .walk           =       cls_bpf_walk,
 704         .reoffload      =       cls_bpf_reoffload,
 705         .dump           =       cls_bpf_dump,
 706         .bind_class     =       cls_bpf_bind_class,
 707 };
 708
 709 static int __init cls_bpf_init_mod(void)
 710 {
 711         return register_tcf_proto_ops(&cls_bpf_ops);
 712 }
 713
 714 static void __exit cls_bpf_exit_mod(void)
 715 {
 716         unregister_tcf_proto_ops(&cls_bpf_ops);
 717 }
 718
 719 module_init(cls_bpf_init_mod);
 720 module_exit(cls_bpf_exit_mod);