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 <[email protected]>
  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 <[email protected]>");
  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         /* Needed here for accessing maps. */
  89         rcu_read_lock();
  90         list_for_each_entry_rcu(prog, &head->plist, link) {
  91                 int filter_res;
  92
  93                 qdisc_skb_cb(skb)->tc_classid = prog->res.classid;
  94
  95                 if (tc_skip_sw(prog->gen_flags)) {
  96                         filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0;
  97                 } else if (at_ingress) {
  98                         /* It is safe to push/pull even if skb_shared() */
  99                         __skb_push(skb, skb->mac_len);
 100                         bpf_compute_data_pointers(skb);
 101                         filter_res = BPF_PROG_RUN(prog->filter, skb);
 102                         __skb_pull(skb, skb->mac_len);
 103                 } else {
 104                         bpf_compute_data_pointers(skb);
 105                         filter_res = BPF_PROG_RUN(prog->filter, skb);
 106                 }
 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         rcu_read_unlock();
 135
 136         return ret;
 137 }
 138
 139 static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
 140 {
 141         return !prog->bpf_ops;
 142 }
 143
 144 static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 145                                struct cls_bpf_prog *oldprog,
 146                                struct netlink_ext_ack *extack)
 147 {
 148         struct tcf_block *block = tp->chain->block;
 149         struct tc_cls_bpf_offload cls_bpf = {};
 150         struct cls_bpf_prog *obj;
 151         bool skip_sw;
 152         int err;
 153
 154         skip_sw = prog && tc_skip_sw(prog->gen_flags);
 155         obj = prog ?: oldprog;
 156
 157         tc_cls_common_offload_init(&cls_bpf.common, tp, obj->gen_flags, extack);
 158         cls_bpf.command = TC_CLSBPF_OFFLOAD;
 159         cls_bpf.exts = &obj->exts;
 160         cls_bpf.prog = prog ? prog->filter : NULL;
 161         cls_bpf.oldprog = oldprog ? oldprog->filter : NULL;
 162         cls_bpf.name = obj->bpf_name;
 163         cls_bpf.exts_integrated = obj->exts_integrated;
 164
 165         if (oldprog && prog)
 166                 err = tc_setup_cb_replace(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 167                                           skip_sw, &oldprog->gen_flags,
 168                                           &oldprog->in_hw_count,
 169                                           &prog->gen_flags, &prog->in_hw_count,
 170                                           true);
 171         else if (prog)
 172                 err = tc_setup_cb_add(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 173                                       skip_sw, &prog->gen_flags,
 174                                       &prog->in_hw_count, true);
 175         else
 176                 err = tc_setup_cb_destroy(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 177                                           skip_sw, &oldprog->gen_flags,
 178                                           &oldprog->in_hw_count, true);
 179
 180         if (prog && err) {
 181                 cls_bpf_offload_cmd(tp, oldprog, prog, extack);
 182                 return err;
 183         }
 184
 185         if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW))
 186                 return -EINVAL;
 187
 188         return 0;
 189 }
 190
 191 static u32 cls_bpf_flags(u32 flags)
 192 {
 193         return flags & CLS_BPF_SUPPORTED_GEN_FLAGS;
 194 }
 195
 196 static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 197                            struct cls_bpf_prog *oldprog,
 198                            struct netlink_ext_ack *extack)
 199 {
 200         if (prog && oldprog &&
 201             cls_bpf_flags(prog->gen_flags) !=
 202             cls_bpf_flags(oldprog->gen_flags))
 203                 return -EINVAL;
 204
 205         if (prog && tc_skip_hw(prog->gen_flags))
 206                 prog = NULL;
 207         if (oldprog && tc_skip_hw(oldprog->gen_flags))
 208                 oldprog = NULL;
 209         if (!prog && !oldprog)
 210                 return 0;
 211
 212         return cls_bpf_offload_cmd(tp, prog, oldprog, extack);
 213 }
 214
 215 static void cls_bpf_stop_offload(struct tcf_proto *tp,
 216                                  struct cls_bpf_prog *prog,
 217                                  struct netlink_ext_ack *extack)
 218 {
 219         int err;
 220
 221         err = cls_bpf_offload_cmd(tp, NULL, prog, extack);
 222         if (err)
 223                 pr_err("Stopping hardware offload failed: %d\n", err);
 224 }
 225
 226 static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
 227                                          struct cls_bpf_prog *prog)
 228 {
 229         struct tcf_block *block = tp->chain->block;
 230         struct tc_cls_bpf_offload cls_bpf = {};
 231
 232         tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, NULL);
 233         cls_bpf.command = TC_CLSBPF_STATS;
 234         cls_bpf.exts = &prog->exts;
 235         cls_bpf.prog = prog->filter;
 236         cls_bpf.name = prog->bpf_name;
 237         cls_bpf.exts_integrated = prog->exts_integrated;
 238
 239         tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false, true);
 240 }
 241
 242 static int cls_bpf_init(struct tcf_proto *tp)
 243 {
 244         struct cls_bpf_head *head;
 245
 246         head = kzalloc(sizeof(*head), GFP_KERNEL);
 247         if (head == NULL)
 248                 return -ENOBUFS;
 249
 250         INIT_LIST_HEAD_RCU(&head->plist);
 251         idr_init(&head->handle_idr);
 252         rcu_assign_pointer(tp->root, head);
 253
 254         return 0;
 255 }
 256
 257 static void cls_bpf_free_parms(struct cls_bpf_prog *prog)
 258 {
 259         if (cls_bpf_is_ebpf(prog))
 260                 bpf_prog_put(prog->filter);
 261         else
 262                 bpf_prog_destroy(prog->filter);
 263
 264         kfree(prog->bpf_name);
 265         kfree(prog->bpf_ops);
 266 }
 267
 268 static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
 269 {
 270         tcf_exts_destroy(&prog->exts);
 271         tcf_exts_put_net(&prog->exts);
 272
 273         cls_bpf_free_parms(prog);
 274         kfree(prog);
 275 }
 276
 277 static void cls_bpf_delete_prog_work(struct work_struct *work)
 278 {
 279         struct cls_bpf_prog *prog = container_of(to_rcu_work(work),
 280                                                  struct cls_bpf_prog,
 281                                                  rwork);
 282         rtnl_lock();
 283         __cls_bpf_delete_prog(prog);
 284         rtnl_unlock();
 285 }
 286
 287 static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 288                              struct netlink_ext_ack *extack)
 289 {
 290         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 291
 292         idr_remove(&head->handle_idr, prog->handle);
 293         cls_bpf_stop_offload(tp, prog, extack);
 294         list_del_rcu(&prog->link);
 295         tcf_unbind_filter(tp, &prog->res);
 296         if (tcf_exts_get_net(&prog->exts))
 297                 tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work);
 298         else
 299                 __cls_bpf_delete_prog(prog);
 300 }
 301
 302 static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
 303                           bool rtnl_held, struct netlink_ext_ack *extack)
 304 {
 305         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 306
 307         __cls_bpf_delete(tp, arg, extack);
 308         *last = list_empty(&head->plist);
 309         return 0;
 310 }
 311
 312 static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held,
 313                             struct netlink_ext_ack *extack)
 314 {
 315         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 316         struct cls_bpf_prog *prog, *tmp;
 317
 318         list_for_each_entry_safe(prog, tmp, &head->plist, link)
 319                 __cls_bpf_delete(tp, prog, extack);
 320
 321         idr_destroy(&head->handle_idr);
 322         kfree_rcu(head, rcu);
 323 }
 324
 325 static void *cls_bpf_get(struct tcf_proto *tp, u32 handle)
 326 {
 327         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 328         struct cls_bpf_prog *prog;
 329
 330         list_for_each_entry(prog, &head->plist, link) {
 331                 if (prog->handle == handle)
 332                         return prog;
 333         }
 334
 335         return NULL;
 336 }
 337
 338 static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
 339 {
 340         struct sock_filter *bpf_ops;
 341         struct sock_fprog_kern fprog_tmp;
 342         struct bpf_prog *fp;
 343         u16 bpf_size, bpf_num_ops;
 344         int ret;
 345
 346         bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
 347         if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
 348                 return -EINVAL;
 349
 350         bpf_size = bpf_num_ops * sizeof(*bpf_ops);
 351         if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
 352                 return -EINVAL;
 353
 354         bpf_ops = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL);
 355         if (bpf_ops == NULL)
 356                 return -ENOMEM;
 357
 358         fprog_tmp.len = bpf_num_ops;
 359         fprog_tmp.filter = bpf_ops;
 360
 361         ret = bpf_prog_create(&fp, &fprog_tmp);
 362         if (ret < 0) {
 363                 kfree(bpf_ops);
 364                 return ret;
 365         }
 366
 367         prog->bpf_ops = bpf_ops;
 368         prog->bpf_num_ops = bpf_num_ops;
 369         prog->bpf_name = NULL;
 370         prog->filter = fp;
 371
 372         return 0;
 373 }
 374
 375 static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
 376                                  u32 gen_flags, const struct tcf_proto *tp)
 377 {
 378         struct bpf_prog *fp;
 379         char *name = NULL;
 380         bool skip_sw;
 381         u32 bpf_fd;
 382
 383         bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
 384         skip_sw = gen_flags & TCA_CLS_FLAGS_SKIP_SW;
 385
 386         fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS, skip_sw);
 387         if (IS_ERR(fp))
 388                 return PTR_ERR(fp);
 389
 390         if (tb[TCA_BPF_NAME]) {
 391                 name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
 392                 if (!name) {
 393                         bpf_prog_put(fp);
 394                         return -ENOMEM;
 395                 }
 396         }
 397
 398         prog->bpf_ops = NULL;
 399         prog->bpf_name = name;
 400         prog->filter = fp;
 401
 402         if (fp->dst_needed)
 403                 tcf_block_netif_keep_dst(tp->chain->block);
 404
 405         return 0;
 406 }
 407
 408 static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 409                              struct cls_bpf_prog *prog, unsigned long base,
 410                              struct nlattr **tb, struct nlattr *est, bool ovr,
 411                              struct netlink_ext_ack *extack)
 412 {
 413         bool is_bpf, is_ebpf, have_exts = false;
 414         u32 gen_flags = 0;
 415         int ret;
 416
 417         is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
 418         is_ebpf = tb[TCA_BPF_FD];
 419         if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
 420                 return -EINVAL;
 421
 422         ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr, true,
 423                                 extack);
 424         if (ret < 0)
 425                 return ret;
 426
 427         if (tb[TCA_BPF_FLAGS]) {
 428                 u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
 429
 430                 if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT)
 431                         return -EINVAL;
 432
 433                 have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
 434         }
 435         if (tb[TCA_BPF_FLAGS_GEN]) {
 436                 gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
 437                 if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
 438                     !tc_flags_valid(gen_flags))
 439                         return -EINVAL;
 440         }
 441
 442         prog->exts_integrated = have_exts;
 443         prog->gen_flags = gen_flags;
 444
 445         ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
 446                        cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
 447         if (ret < 0)
 448                 return ret;
 449
 450         if (tb[TCA_BPF_CLASSID]) {
 451                 prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
 452                 tcf_bind_filter(tp, &prog->res, base);
 453         }
 454
 455         return 0;
 456 }
 457
 458 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 459                           struct tcf_proto *tp, unsigned long base,
 460                           u32 handle, struct nlattr **tca,
 461                           void **arg, bool ovr, bool rtnl_held,
 462                           struct netlink_ext_ack *extack)
 463 {
 464         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 465         struct cls_bpf_prog *oldprog = *arg;
 466         struct nlattr *tb[TCA_BPF_MAX + 1];
 467         struct cls_bpf_prog *prog;
 468         int ret;
 469
 470         if (tca[TCA_OPTIONS] == NULL)
 471                 return -EINVAL;
 472
 473         ret = nla_parse_nested_deprecated(tb, TCA_BPF_MAX, tca[TCA_OPTIONS],
 474                                           bpf_policy, NULL);
 475         if (ret < 0)
 476                 return ret;
 477
 478         prog = kzalloc(sizeof(*prog), GFP_KERNEL);
 479         if (!prog)
 480                 return -ENOBUFS;
 481
 482         ret = tcf_exts_init(&prog->exts, net, TCA_BPF_ACT, TCA_BPF_POLICE);
 483         if (ret < 0)
 484                 goto errout;
 485
 486         if (oldprog) {
 487                 if (handle && oldprog->handle != handle) {
 488                         ret = -EINVAL;
 489                         goto errout;
 490                 }
 491         }
 492
 493         if (handle == 0) {
 494                 handle = 1;
 495                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 496                                     INT_MAX, GFP_KERNEL);
 497         } else if (!oldprog) {
 498                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 499                                     handle, GFP_KERNEL);
 500         }
 501
 502         if (ret)
 503                 goto errout;
 504         prog->handle = handle;
 505
 506         ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr,
 507                                 extack);
 508         if (ret < 0)
 509                 goto errout_idr;
 510
 511         ret = cls_bpf_offload(tp, prog, oldprog, extack);
 512         if (ret)
 513                 goto errout_parms;
 514
 515         if (!tc_in_hw(prog->gen_flags))
 516                 prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 517
 518         if (oldprog) {
 519                 idr_replace(&head->handle_idr, prog, handle);
 520                 list_replace_rcu(&oldprog->link, &prog->link);
 521                 tcf_unbind_filter(tp, &oldprog->res);
 522                 tcf_exts_get_net(&oldprog->exts);
 523                 tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
 524         } else {
 525                 list_add_rcu(&prog->link, &head->plist);
 526         }
 527
 528         *arg = prog;
 529         return 0;
 530
 531 errout_parms:
 532         cls_bpf_free_parms(prog);
 533 errout_idr:
 534         if (!oldprog)
 535                 idr_remove(&head->handle_idr, prog->handle);
 536 errout:
 537         tcf_exts_destroy(&prog->exts);
 538         kfree(prog);
 539         return ret;
 540 }
 541
 542 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
 543                                  struct sk_buff *skb)
 544 {
 545         struct nlattr *nla;
 546
 547         if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
 548                 return -EMSGSIZE;
 549
 550         nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
 551                           sizeof(struct sock_filter));
 552         if (nla == NULL)
 553                 return -EMSGSIZE;
 554
 555         memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
 556
 557         return 0;
 558 }
 559
 560 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 561                                   struct sk_buff *skb)
 562 {
 563         struct nlattr *nla;
 564
 565         if (prog->bpf_name &&
 566             nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
 567                 return -EMSGSIZE;
 568
 569         if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
 570                 return -EMSGSIZE;
 571
 572         nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
 573         if (nla == NULL)
 574                 return -EMSGSIZE;
 575
 576         memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
 577
 578         return 0;
 579 }
 580
 581 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
 582                         struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
 583 {
 584         struct cls_bpf_prog *prog = fh;
 585         struct nlattr *nest;
 586         u32 bpf_flags = 0;
 587         int ret;
 588
 589         if (prog == NULL)
 590                 return skb->len;
 591
 592         tm->tcm_handle = prog->handle;
 593
 594         cls_bpf_offload_update_stats(tp, prog);
 595
 596         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 597         if (nest == NULL)
 598                 goto nla_put_failure;
 599
 600         if (prog->res.classid &&
 601             nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
 602                 goto nla_put_failure;
 603
 604         if (cls_bpf_is_ebpf(prog))
 605                 ret = cls_bpf_dump_ebpf_info(prog, skb);
 606         else
 607                 ret = cls_bpf_dump_bpf_info(prog, skb);
 608         if (ret)
 609                 goto nla_put_failure;
 610
 611         if (tcf_exts_dump(skb, &prog->exts) < 0)
 612                 goto nla_put_failure;
 613
 614         if (prog->exts_integrated)
 615                 bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
 616         if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
 617                 goto nla_put_failure;
 618         if (prog->gen_flags &&
 619             nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
 620                 goto nla_put_failure;
 621
 622         nla_nest_end(skb, nest);
 623
 624         if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
 625                 goto nla_put_failure;
 626
 627         return skb->len;
 628
 629 nla_put_failure:
 630         nla_nest_cancel(skb, nest);
 631         return -1;
 632 }
 633
 634 static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl,
 635                                void *q, unsigned long base)
 636 {
 637         struct cls_bpf_prog *prog = fh;
 638
 639         if (prog && prog->res.classid == classid) {
 640                 if (cl)
 641                         __tcf_bind_filter(q, &prog->res, base);
 642                 else
 643                         __tcf_unbind_filter(q, &prog->res);
 644         }
 645 }
 646
 647 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
 648                          bool rtnl_held)
 649 {
 650         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 651         struct cls_bpf_prog *prog;
 652
 653         list_for_each_entry(prog, &head->plist, link) {
 654                 if (arg->count < arg->skip)
 655                         goto skip;
 656                 if (arg->fn(tp, prog, arg) < 0) {
 657                         arg->stop = 1;
 658                         break;
 659                 }
 660 skip:
 661                 arg->count++;
 662         }
 663 }
 664
 665 static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
 666                              void *cb_priv, struct netlink_ext_ack *extack)
 667 {
 668         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 669         struct tcf_block *block = tp->chain->block;
 670         struct tc_cls_bpf_offload cls_bpf = {};
 671         struct cls_bpf_prog *prog;
 672         int err;
 673
 674         list_for_each_entry(prog, &head->plist, link) {
 675                 if (tc_skip_hw(prog->gen_flags))
 676                         continue;
 677
 678                 tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
 679                                            extack);
 680                 cls_bpf.command = TC_CLSBPF_OFFLOAD;
 681                 cls_bpf.exts = &prog->exts;
 682                 cls_bpf.prog = add ? prog->filter : NULL;
 683                 cls_bpf.oldprog = add ? NULL : prog->filter;
 684                 cls_bpf.name = prog->bpf_name;
 685                 cls_bpf.exts_integrated = prog->exts_integrated;
 686
 687                 err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF,
 688                                             &cls_bpf, cb_priv, &prog->gen_flags,
 689                                             &prog->in_hw_count);
 690                 if (err)
 691                         return err;
 692         }
 693
 694         return 0;
 695 }
 696
 697 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
 698         .kind           =       "bpf",
 699         .owner          =       THIS_MODULE,
 700         .classify       =       cls_bpf_classify,
 701         .init           =       cls_bpf_init,
 702         .destroy        =       cls_bpf_destroy,
 703         .get            =       cls_bpf_get,
 704         .change         =       cls_bpf_change,
 705         .delete         =       cls_bpf_delete,
 706         .walk           =       cls_bpf_walk,
 707         .reoffload      =       cls_bpf_reoffload,
 708         .dump           =       cls_bpf_dump,
 709         .bind_class     =       cls_bpf_bind_class,
 710 };
 711
 712 static int __init cls_bpf_init_mod(void)
 713 {
 714         return register_tcf_proto_ops(&cls_bpf_ops);
 715 }
 716
 717 static void __exit cls_bpf_exit_mod(void)
 718 {
 719         unregister_tcf_proto_ops(&cls_bpf_ops);
 720 }
 721
 722 module_init(cls_bpf_init_mod);
 723 module_exit(cls_bpf_exit_mod);