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 #include <linux/idr.h>
  21
  22 #include <net/rtnetlink.h>
  23 #include <net/pkt_cls.h>
  24 #include <net/sock.h>
  25
  26 MODULE_LICENSE("GPL");
  27 MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
  28 MODULE_DESCRIPTION("TC BPF based classifier");
  29
  30 #define CLS_BPF_NAME_LEN        256
  31 #define CLS_BPF_SUPPORTED_GEN_FLAGS             \
  32         (TCA_CLS_FLAGS_SKIP_HW | TCA_CLS_FLAGS_SKIP_SW)
  33
  34 struct cls_bpf_head {
  35         struct list_head plist;
  36         struct idr handle_idr;
  37         struct rcu_head rcu;
  38 };
  39
  40 struct cls_bpf_prog {
  41         struct bpf_prog *filter;
  42         struct list_head link;
  43         struct tcf_result res;
  44         bool exts_integrated;
  45         u32 gen_flags;
  46         unsigned int in_hw_count;
  47         struct tcf_exts exts;
  48         u32 handle;
  49         u16 bpf_num_ops;
  50         struct sock_filter *bpf_ops;
  51         const char *bpf_name;
  52         struct tcf_proto *tp;
  53         struct rcu_work rwork;
  54 };
  55
  56 static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
  57         [TCA_BPF_CLASSID]       = { .type = NLA_U32 },
  58         [TCA_BPF_FLAGS]         = { .type = NLA_U32 },
  59         [TCA_BPF_FLAGS_GEN]     = { .type = NLA_U32 },
  60         [TCA_BPF_FD]            = { .type = NLA_U32 },
  61         [TCA_BPF_NAME]          = { .type = NLA_NUL_STRING,
  62                                     .len = CLS_BPF_NAME_LEN },
  63         [TCA_BPF_OPS_LEN]       = { .type = NLA_U16 },
  64         [TCA_BPF_OPS]           = { .type = NLA_BINARY,
  65                                     .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
  66 };
  67
  68 static int cls_bpf_exec_opcode(int code)
  69 {
  70         switch (code) {
  71         case TC_ACT_OK:
  72         case TC_ACT_SHOT:
  73         case TC_ACT_STOLEN:
  74         case TC_ACT_TRAP:
  75         case TC_ACT_REDIRECT:
  76         case TC_ACT_UNSPEC:
  77                 return code;
  78         default:
  79                 return TC_ACT_UNSPEC;
  80         }
  81 }
  82
  83 static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  84                             struct tcf_result *res)
  85 {
  86         struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
  87         bool at_ingress = skb_at_tc_ingress(skb);
  88         struct cls_bpf_prog *prog;
  89         int ret = -1;
  90
  91         /* Needed here for accessing maps. */
  92         rcu_read_lock();
  93         list_for_each_entry_rcu(prog, &head->plist, link) {
  94                 int filter_res;
  95
  96                 qdisc_skb_cb(skb)->tc_classid = prog->res.classid;
  97
  98                 if (tc_skip_sw(prog->gen_flags)) {
  99                         filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0;
 100                 } else if (at_ingress) {
 101                         /* It is safe to push/pull even if skb_shared() */
 102                         __skb_push(skb, skb->mac_len);
 103                         bpf_compute_data_pointers(skb);
 104                         filter_res = BPF_PROG_RUN(prog->filter, skb);
 105                         __skb_pull(skb, skb->mac_len);
 106                 } else {
 107                         bpf_compute_data_pointers(skb);
 108                         filter_res = BPF_PROG_RUN(prog->filter, skb);
 109                 }
 110
 111                 if (prog->exts_integrated) {
 112                         res->class   = 0;
 113                         res->classid = TC_H_MAJ(prog->res.classid) |
 114                                        qdisc_skb_cb(skb)->tc_classid;
 115
 116                         ret = cls_bpf_exec_opcode(filter_res);
 117                         if (ret == TC_ACT_UNSPEC)
 118                                 continue;
 119                         break;
 120                 }
 121
 122                 if (filter_res == 0)
 123                         continue;
 124                 if (filter_res != -1) {
 125                         res->class   = 0;
 126                         res->classid = filter_res;
 127                 } else {
 128                         *res = prog->res;
 129                 }
 130
 131                 ret = tcf_exts_exec(skb, &prog->exts, res);
 132                 if (ret < 0)
 133                         continue;
 134
 135                 break;
 136         }
 137         rcu_read_unlock();
 138
 139         return ret;
 140 }
 141
 142 static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
 143 {
 144         return !prog->bpf_ops;
 145 }
 146
 147 static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 148                                struct cls_bpf_prog *oldprog,
 149                                struct netlink_ext_ack *extack)
 150 {
 151         struct tcf_block *block = tp->chain->block;
 152         struct tc_cls_bpf_offload cls_bpf = {};
 153         struct cls_bpf_prog *obj;
 154         bool skip_sw;
 155         int err;
 156
 157         skip_sw = prog && tc_skip_sw(prog->gen_flags);
 158         obj = prog ?: oldprog;
 159
 160         tc_cls_common_offload_init(&cls_bpf.common, tp, obj->gen_flags,
 161                                    extack);
 162         cls_bpf.command = TC_CLSBPF_OFFLOAD;
 163         cls_bpf.exts = &obj->exts;
 164         cls_bpf.prog = prog ? prog->filter : NULL;
 165         cls_bpf.oldprog = oldprog ? oldprog->filter : NULL;
 166         cls_bpf.name = obj->bpf_name;
 167         cls_bpf.exts_integrated = obj->exts_integrated;
 168
 169         if (oldprog)
 170                 tcf_block_offload_dec(block, &oldprog->gen_flags);
 171
 172         err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSBPF, &cls_bpf, skip_sw);
 173         if (prog) {
 174                 if (err < 0) {
 175                         cls_bpf_offload_cmd(tp, oldprog, prog, extack);
 176                         return err;
 177                 } else if (err > 0) {
 178                         prog->in_hw_count = err;
 179                         tcf_block_offload_inc(block, &prog->gen_flags);
 180                 }
 181         }
 182
 183         if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW))
 184                 return -EINVAL;
 185
 186         return 0;
 187 }
 188
 189 static u32 cls_bpf_flags(u32 flags)
 190 {
 191         return flags & CLS_BPF_SUPPORTED_GEN_FLAGS;
 192 }
 193
 194 static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 195                            struct cls_bpf_prog *oldprog,
 196                            struct netlink_ext_ack *extack)
 197 {
 198         if (prog && oldprog &&
 199             cls_bpf_flags(prog->gen_flags) !=
 200             cls_bpf_flags(oldprog->gen_flags))
 201                 return -EINVAL;
 202
 203         if (prog && tc_skip_hw(prog->gen_flags))
 204                 prog = NULL;
 205         if (oldprog && tc_skip_hw(oldprog->gen_flags))
 206                 oldprog = NULL;
 207         if (!prog && !oldprog)
 208                 return 0;
 209
 210         return cls_bpf_offload_cmd(tp, prog, oldprog, extack);
 211 }
 212
 213 static void cls_bpf_stop_offload(struct tcf_proto *tp,
 214                                  struct cls_bpf_prog *prog,
 215                                  struct netlink_ext_ack *extack)
 216 {
 217         int err;
 218
 219         err = cls_bpf_offload_cmd(tp, NULL, prog, extack);
 220         if (err)
 221                 pr_err("Stopping hardware offload failed: %d\n", err);
 222 }
 223
 224 static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
 225                                          struct cls_bpf_prog *prog)
 226 {
 227         struct tcf_block *block = tp->chain->block;
 228         struct tc_cls_bpf_offload cls_bpf = {};
 229
 230         tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, NULL);
 231         cls_bpf.command = TC_CLSBPF_STATS;
 232         cls_bpf.exts = &prog->exts;
 233         cls_bpf.prog = prog->filter;
 234         cls_bpf.name = prog->bpf_name;
 235         cls_bpf.exts_integrated = prog->exts_integrated;
 236
 237         tc_setup_cb_call(block, NULL, TC_SETUP_CLSBPF, &cls_bpf, false);
 238 }
 239
 240 static int cls_bpf_init(struct tcf_proto *tp)
 241 {
 242         struct cls_bpf_head *head;
 243
 244         head = kzalloc(sizeof(*head), GFP_KERNEL);
 245         if (head == NULL)
 246                 return -ENOBUFS;
 247
 248         INIT_LIST_HEAD_RCU(&head->plist);
 249         idr_init(&head->handle_idr);
 250         rcu_assign_pointer(tp->root, head);
 251
 252         return 0;
 253 }
 254
 255 static void cls_bpf_free_parms(struct cls_bpf_prog *prog)
 256 {
 257         if (cls_bpf_is_ebpf(prog))
 258                 bpf_prog_put(prog->filter);
 259         else
 260                 bpf_prog_destroy(prog->filter);
 261
 262         kfree(prog->bpf_name);
 263         kfree(prog->bpf_ops);
 264 }
 265
 266 static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
 267 {
 268         tcf_exts_destroy(&prog->exts);
 269         tcf_exts_put_net(&prog->exts);
 270
 271         cls_bpf_free_parms(prog);
 272         kfree(prog);
 273 }
 274
 275 static void cls_bpf_delete_prog_work(struct work_struct *work)
 276 {
 277         struct cls_bpf_prog *prog = container_of(to_rcu_work(work),
 278                                                  struct cls_bpf_prog,
 279                                                  rwork);
 280         rtnl_lock();
 281         __cls_bpf_delete_prog(prog);
 282         rtnl_unlock();
 283 }
 284
 285 static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 286                              struct netlink_ext_ack *extack)
 287 {
 288         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 289
 290         idr_remove(&head->handle_idr, prog->handle);
 291         cls_bpf_stop_offload(tp, prog, extack);
 292         list_del_rcu(&prog->link);
 293         tcf_unbind_filter(tp, &prog->res);
 294         if (tcf_exts_get_net(&prog->exts))
 295                 tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work);
 296         else
 297                 __cls_bpf_delete_prog(prog);
 298 }
 299
 300 static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
 301                           struct netlink_ext_ack *extack)
 302 {
 303         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 304
 305         __cls_bpf_delete(tp, arg, extack);
 306         *last = list_empty(&head->plist);
 307         return 0;
 308 }
 309
 310 static void cls_bpf_destroy(struct tcf_proto *tp,
 311                             struct netlink_ext_ack *extack)
 312 {
 313         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 314         struct cls_bpf_prog *prog, *tmp;
 315
 316         list_for_each_entry_safe(prog, tmp, &head->plist, link)
 317                 __cls_bpf_delete(tp, prog, extack);
 318
 319         idr_destroy(&head->handle_idr);
 320         kfree_rcu(head, rcu);
 321 }
 322
 323 static void *cls_bpf_get(struct tcf_proto *tp, u32 handle)
 324 {
 325         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 326         struct cls_bpf_prog *prog;
 327
 328         list_for_each_entry(prog, &head->plist, link) {
 329                 if (prog->handle == handle)
 330                         return prog;
 331         }
 332
 333         return NULL;
 334 }
 335
 336 static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
 337 {
 338         struct sock_filter *bpf_ops;
 339         struct sock_fprog_kern fprog_tmp;
 340         struct bpf_prog *fp;
 341         u16 bpf_size, bpf_num_ops;
 342         int ret;
 343
 344         bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
 345         if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
 346                 return -EINVAL;
 347
 348         bpf_size = bpf_num_ops * sizeof(*bpf_ops);
 349         if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
 350                 return -EINVAL;
 351
 352         bpf_ops = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL);
 353         if (bpf_ops == NULL)
 354                 return -ENOMEM;
 355
 356         fprog_tmp.len = bpf_num_ops;
 357         fprog_tmp.filter = bpf_ops;
 358
 359         ret = bpf_prog_create(&fp, &fprog_tmp);
 360         if (ret < 0) {
 361                 kfree(bpf_ops);
 362                 return ret;
 363         }
 364
 365         prog->bpf_ops = bpf_ops;
 366         prog->bpf_num_ops = bpf_num_ops;
 367         prog->bpf_name = NULL;
 368         prog->filter = fp;
 369
 370         return 0;
 371 }
 372
 373 static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
 374                                  u32 gen_flags, const struct tcf_proto *tp)
 375 {
 376         struct bpf_prog *fp;
 377         char *name = NULL;
 378         bool skip_sw;
 379         u32 bpf_fd;
 380
 381         bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
 382         skip_sw = gen_flags & TCA_CLS_FLAGS_SKIP_SW;
 383
 384         fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS, skip_sw);
 385         if (IS_ERR(fp))
 386                 return PTR_ERR(fp);
 387
 388         if (tb[TCA_BPF_NAME]) {
 389                 name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
 390                 if (!name) {
 391                         bpf_prog_put(fp);
 392                         return -ENOMEM;
 393                 }
 394         }
 395
 396         prog->bpf_ops = NULL;
 397         prog->bpf_name = name;
 398         prog->filter = fp;
 399
 400         if (fp->dst_needed)
 401                 tcf_block_netif_keep_dst(tp->chain->block);
 402
 403         return 0;
 404 }
 405
 406 static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 407                              struct cls_bpf_prog *prog, unsigned long base,
 408                              struct nlattr **tb, struct nlattr *est, bool ovr,
 409                              struct netlink_ext_ack *extack)
 410 {
 411         bool is_bpf, is_ebpf, have_exts = false;
 412         u32 gen_flags = 0;
 413         int ret;
 414
 415         is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
 416         is_ebpf = tb[TCA_BPF_FD];
 417         if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
 418                 return -EINVAL;
 419
 420         ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr, 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, struct netlink_ext_ack *extack)
 459 {
 460         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 461         struct cls_bpf_prog *oldprog = *arg;
 462         struct nlattr *tb[TCA_BPF_MAX + 1];
 463         struct cls_bpf_prog *prog;
 464         int ret;
 465
 466         if (tca[TCA_OPTIONS] == NULL)
 467                 return -EINVAL;
 468
 469         ret = nla_parse_nested(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], bpf_policy,
 470                                NULL);
 471         if (ret < 0)
 472                 return ret;
 473
 474         prog = kzalloc(sizeof(*prog), GFP_KERNEL);
 475         if (!prog)
 476                 return -ENOBUFS;
 477
 478         ret = tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
 479         if (ret < 0)
 480                 goto errout;
 481
 482         if (oldprog) {
 483                 if (handle && oldprog->handle != handle) {
 484                         ret = -EINVAL;
 485                         goto errout;
 486                 }
 487         }
 488
 489         if (handle == 0) {
 490                 handle = 1;
 491                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 492                                     INT_MAX, GFP_KERNEL);
 493         } else if (!oldprog) {
 494                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 495                                     handle, GFP_KERNEL);
 496         }
 497
 498         if (ret)
 499                 goto errout;
 500         prog->handle = handle;
 501
 502         ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr,
 503                                 extack);
 504         if (ret < 0)
 505                 goto errout_idr;
 506
 507         ret = cls_bpf_offload(tp, prog, oldprog, extack);
 508         if (ret)
 509                 goto errout_parms;
 510
 511         if (!tc_in_hw(prog->gen_flags))
 512                 prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 513
 514         if (oldprog) {
 515                 idr_replace(&head->handle_idr, prog, handle);
 516                 list_replace_rcu(&oldprog->link, &prog->link);
 517                 tcf_unbind_filter(tp, &oldprog->res);
 518                 tcf_exts_get_net(&oldprog->exts);
 519                 tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
 520         } else {
 521                 list_add_rcu(&prog->link, &head->plist);
 522         }
 523
 524         *arg = prog;
 525         return 0;
 526
 527 errout_parms:
 528         cls_bpf_free_parms(prog);
 529 errout_idr:
 530         if (!oldprog)
 531                 idr_remove(&head->handle_idr, prog->handle);
 532 errout:
 533         tcf_exts_destroy(&prog->exts);
 534         kfree(prog);
 535         return ret;
 536 }
 537
 538 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
 539                                  struct sk_buff *skb)
 540 {
 541         struct nlattr *nla;
 542
 543         if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
 544                 return -EMSGSIZE;
 545
 546         nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
 547                           sizeof(struct sock_filter));
 548         if (nla == NULL)
 549                 return -EMSGSIZE;
 550
 551         memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
 552
 553         return 0;
 554 }
 555
 556 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 557                                   struct sk_buff *skb)
 558 {
 559         struct nlattr *nla;
 560
 561         if (prog->bpf_name &&
 562             nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
 563                 return -EMSGSIZE;
 564
 565         if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
 566                 return -EMSGSIZE;
 567
 568         nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
 569         if (nla == NULL)
 570                 return -EMSGSIZE;
 571
 572         memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
 573
 574         return 0;
 575 }
 576
 577 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
 578                         struct sk_buff *skb, struct tcmsg *tm)
 579 {
 580         struct cls_bpf_prog *prog = fh;
 581         struct nlattr *nest;
 582         u32 bpf_flags = 0;
 583         int ret;
 584
 585         if (prog == NULL)
 586                 return skb->len;
 587
 588         tm->tcm_handle = prog->handle;
 589
 590         cls_bpf_offload_update_stats(tp, prog);
 591
 592         nest = nla_nest_start(skb, TCA_OPTIONS);
 593         if (nest == NULL)
 594                 goto nla_put_failure;
 595
 596         if (prog->res.classid &&
 597             nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
 598                 goto nla_put_failure;
 599
 600         if (cls_bpf_is_ebpf(prog))
 601                 ret = cls_bpf_dump_ebpf_info(prog, skb);
 602         else
 603                 ret = cls_bpf_dump_bpf_info(prog, skb);
 604         if (ret)
 605                 goto nla_put_failure;
 606
 607         if (tcf_exts_dump(skb, &prog->exts) < 0)
 608                 goto nla_put_failure;
 609
 610         if (prog->exts_integrated)
 611                 bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
 612         if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
 613                 goto nla_put_failure;
 614         if (prog->gen_flags &&
 615             nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
 616                 goto nla_put_failure;
 617
 618         nla_nest_end(skb, nest);
 619
 620         if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
 621                 goto nla_put_failure;
 622
 623         return skb->len;
 624
 625 nla_put_failure:
 626         nla_nest_cancel(skb, nest);
 627         return -1;
 628 }
 629
 630 static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl)
 631 {
 632         struct cls_bpf_prog *prog = fh;
 633
 634         if (prog && prog->res.classid == classid)
 635                 prog->res.class = cl;
 636 }
 637
 638 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 639 {
 640         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 641         struct cls_bpf_prog *prog;
 642
 643         list_for_each_entry(prog, &head->plist, link) {
 644                 if (arg->count < arg->skip)
 645                         goto skip;
 646                 if (arg->fn(tp, prog, arg) < 0) {
 647                         arg->stop = 1;
 648                         break;
 649                 }
 650 skip:
 651                 arg->count++;
 652         }
 653 }
 654
 655 static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, tc_setup_cb_t *cb,
 656                              void *cb_priv, struct netlink_ext_ack *extack)
 657 {
 658         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 659         struct tcf_block *block = tp->chain->block;
 660         struct tc_cls_bpf_offload cls_bpf = {};
 661         struct cls_bpf_prog *prog;
 662         int err;
 663
 664         list_for_each_entry(prog, &head->plist, link) {
 665                 if (tc_skip_hw(prog->gen_flags))
 666                         continue;
 667
 668                 tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
 669                                            extack);
 670                 cls_bpf.command = TC_CLSBPF_OFFLOAD;
 671                 cls_bpf.exts = &prog->exts;
 672                 cls_bpf.prog = add ? prog->filter : NULL;
 673                 cls_bpf.oldprog = add ? NULL : prog->filter;
 674                 cls_bpf.name = prog->bpf_name;
 675                 cls_bpf.exts_integrated = prog->exts_integrated;
 676
 677                 err = cb(TC_SETUP_CLSBPF, &cls_bpf, cb_priv);
 678                 if (err) {
 679                         if (add && tc_skip_sw(prog->gen_flags))
 680                                 return err;
 681                         continue;
 682                 }
 683
 684                 tc_cls_offload_cnt_update(block, &prog->in_hw_count,
 685                                           &prog->gen_flags, add);
 686         }
 687
 688         return 0;
 689 }
 690
 691 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
 692         .kind           =       "bpf",
 693         .owner          =       THIS_MODULE,
 694         .classify       =       cls_bpf_classify,
 695         .init           =       cls_bpf_init,
 696         .destroy        =       cls_bpf_destroy,
 697         .get            =       cls_bpf_get,
 698         .change         =       cls_bpf_change,
 699         .delete         =       cls_bpf_delete,
 700         .walk           =       cls_bpf_walk,
 701         .reoffload      =       cls_bpf_reoffload,
 702         .dump           =       cls_bpf_dump,
 703         .bind_class     =       cls_bpf_bind_class,
 704 };
 705
 706 static int __init cls_bpf_init_mod(void)
 707 {
 708         return register_tcf_proto_ops(&cls_bpf_ops);
 709 }
 710
 711 static void __exit cls_bpf_exit_mod(void)
 712 {
 713         unregister_tcf_proto_ops(&cls_bpf_ops);
 714 }
 715
 716 module_init(cls_bpf_init_mod);
 717 module_exit(cls_bpf_exit_mod);