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                 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_set_parms(struct net *net, struct tcf_proto *tp,
 408                              struct cls_bpf_prog *prog, unsigned long base,
 409                              struct nlattr **tb, struct nlattr *est, u32 flags,
 410                              struct netlink_ext_ack *extack)
 411 {
 412         bool is_bpf, is_ebpf, have_exts = false;
 413         u32 gen_flags = 0;
 414         int ret;
 415
 416         is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
 417         is_ebpf = tb[TCA_BPF_FD];
 418         if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
 419                 return -EINVAL;
 420
 421         ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, flags,
 422                                 extack);
 423         if (ret < 0)
 424                 return ret;
 425
 426         if (tb[TCA_BPF_FLAGS]) {
 427                 u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
 428
 429                 if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT)
 430                         return -EINVAL;
 431
 432                 have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
 433         }
 434         if (tb[TCA_BPF_FLAGS_GEN]) {
 435                 gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
 436                 if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
 437                     !tc_flags_valid(gen_flags))
 438                         return -EINVAL;
 439         }
 440
 441         prog->exts_integrated = have_exts;
 442         prog->gen_flags = gen_flags;
 443
 444         ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
 445                        cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
 446         if (ret < 0)
 447                 return ret;
 448
 449         if (tb[TCA_BPF_CLASSID]) {
 450                 prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
 451                 tcf_bind_filter(tp, &prog->res, base);
 452         }
 453
 454         return 0;
 455 }
 456
 457 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 458                           struct tcf_proto *tp, unsigned long base,
 459                           u32 handle, struct nlattr **tca,
 460                           void **arg, u32 flags,
 461                           struct netlink_ext_ack *extack)
 462 {
 463         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 464         struct cls_bpf_prog *oldprog = *arg;
 465         struct nlattr *tb[TCA_BPF_MAX + 1];
 466         struct cls_bpf_prog *prog;
 467         int ret;
 468
 469         if (tca[TCA_OPTIONS] == NULL)
 470                 return -EINVAL;
 471
 472         ret = nla_parse_nested_deprecated(tb, TCA_BPF_MAX, tca[TCA_OPTIONS],
 473                                           bpf_policy, NULL);
 474         if (ret < 0)
 475                 return ret;
 476
 477         prog = kzalloc(sizeof(*prog), GFP_KERNEL);
 478         if (!prog)
 479                 return -ENOBUFS;
 480
 481         ret = tcf_exts_init(&prog->exts, net, TCA_BPF_ACT, TCA_BPF_POLICE);
 482         if (ret < 0)
 483                 goto errout;
 484
 485         if (oldprog) {
 486                 if (handle && oldprog->handle != handle) {
 487                         ret = -EINVAL;
 488                         goto errout;
 489                 }
 490         }
 491
 492         if (handle == 0) {
 493                 handle = 1;
 494                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 495                                     INT_MAX, GFP_KERNEL);
 496         } else if (!oldprog) {
 497                 ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 498                                     handle, GFP_KERNEL);
 499         }
 500
 501         if (ret)
 502                 goto errout;
 503         prog->handle = handle;
 504
 505         ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], flags,
 506                                 extack);
 507         if (ret < 0)
 508                 goto errout_idr;
 509
 510         ret = cls_bpf_offload(tp, prog, oldprog, extack);
 511         if (ret)
 512                 goto errout_parms;
 513
 514         if (!tc_in_hw(prog->gen_flags))
 515                 prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 516
 517         if (oldprog) {
 518                 idr_replace(&head->handle_idr, prog, handle);
 519                 list_replace_rcu(&oldprog->link, &prog->link);
 520                 tcf_unbind_filter(tp, &oldprog->res);
 521                 tcf_exts_get_net(&oldprog->exts);
 522                 tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
 523         } else {
 524                 list_add_rcu(&prog->link, &head->plist);
 525         }
 526
 527         *arg = prog;
 528         return 0;
 529
 530 errout_parms:
 531         cls_bpf_free_parms(prog);
 532 errout_idr:
 533         if (!oldprog)
 534                 idr_remove(&head->handle_idr, prog->handle);
 535 errout:
 536         tcf_exts_destroy(&prog->exts);
 537         kfree(prog);
 538         return ret;
 539 }
 540
 541 static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
 542                                  struct sk_buff *skb)
 543 {
 544         struct nlattr *nla;
 545
 546         if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
 547                 return -EMSGSIZE;
 548
 549         nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
 550                           sizeof(struct sock_filter));
 551         if (nla == NULL)
 552                 return -EMSGSIZE;
 553
 554         memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
 555
 556         return 0;
 557 }
 558
 559 static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 560                                   struct sk_buff *skb)
 561 {
 562         struct nlattr *nla;
 563
 564         if (prog->bpf_name &&
 565             nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
 566                 return -EMSGSIZE;
 567
 568         if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
 569                 return -EMSGSIZE;
 570
 571         nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
 572         if (nla == NULL)
 573                 return -EMSGSIZE;
 574
 575         memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
 576
 577         return 0;
 578 }
 579
 580 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
 581                         struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
 582 {
 583         struct cls_bpf_prog *prog = fh;
 584         struct nlattr *nest;
 585         u32 bpf_flags = 0;
 586         int ret;
 587
 588         if (prog == NULL)
 589                 return skb->len;
 590
 591         tm->tcm_handle = prog->handle;
 592
 593         cls_bpf_offload_update_stats(tp, prog);
 594
 595         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 596         if (nest == NULL)
 597                 goto nla_put_failure;
 598
 599         if (prog->res.classid &&
 600             nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
 601                 goto nla_put_failure;
 602
 603         if (cls_bpf_is_ebpf(prog))
 604                 ret = cls_bpf_dump_ebpf_info(prog, skb);
 605         else
 606                 ret = cls_bpf_dump_bpf_info(prog, skb);
 607         if (ret)
 608                 goto nla_put_failure;
 609
 610         if (tcf_exts_dump(skb, &prog->exts) < 0)
 611                 goto nla_put_failure;
 612
 613         if (prog->exts_integrated)
 614                 bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
 615         if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
 616                 goto nla_put_failure;
 617         if (prog->gen_flags &&
 618             nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
 619                 goto nla_put_failure;
 620
 621         nla_nest_end(skb, nest);
 622
 623         if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
 624                 goto nla_put_failure;
 625
 626         return skb->len;
 627
 628 nla_put_failure:
 629         nla_nest_cancel(skb, nest);
 630         return -1;
 631 }
 632
 633 static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl,
 634                                void *q, unsigned long base)
 635 {
 636         struct cls_bpf_prog *prog = fh;
 637
 638         if (prog && prog->res.classid == classid) {
 639                 if (cl)
 640                         __tcf_bind_filter(q, &prog->res, base);
 641                 else
 642                         __tcf_unbind_filter(q, &prog->res);
 643         }
 644 }
 645
 646 static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
 647                          bool rtnl_held)
 648 {
 649         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 650         struct cls_bpf_prog *prog;
 651
 652         list_for_each_entry(prog, &head->plist, link) {
 653                 if (arg->count < arg->skip)
 654                         goto skip;
 655                 if (arg->fn(tp, prog, arg) < 0) {
 656                         arg->stop = 1;
 657                         break;
 658                 }
 659 skip:
 660                 arg->count++;
 661         }
 662 }
 663
 664 static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
 665                              void *cb_priv, struct netlink_ext_ack *extack)
 666 {
 667         struct cls_bpf_head *head = rtnl_dereference(tp->root);
 668         struct tcf_block *block = tp->chain->block;
 669         struct tc_cls_bpf_offload cls_bpf = {};
 670         struct cls_bpf_prog *prog;
 671         int err;
 672
 673         list_for_each_entry(prog, &head->plist, link) {
 674                 if (tc_skip_hw(prog->gen_flags))
 675                         continue;
 676
 677                 tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
 678                                            extack);
 679                 cls_bpf.command = TC_CLSBPF_OFFLOAD;
 680                 cls_bpf.exts = &prog->exts;
 681                 cls_bpf.prog = add ? prog->filter : NULL;
 682                 cls_bpf.oldprog = add ? NULL : prog->filter;
 683                 cls_bpf.name = prog->bpf_name;
 684                 cls_bpf.exts_integrated = prog->exts_integrated;
 685
 686                 err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF,
 687                                             &cls_bpf, cb_priv, &prog->gen_flags,
 688                                             &prog->in_hw_count);
 689                 if (err)
 690                         return err;
 691         }
 692
 693         return 0;
 694 }
 695
 696 static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
 697         .kind           =       "bpf",
 698         .owner          =       THIS_MODULE,
 699         .classify       =       cls_bpf_classify,
 700         .init           =       cls_bpf_init,
 701         .destroy        =       cls_bpf_destroy,
 702         .get            =       cls_bpf_get,
 703         .change         =       cls_bpf_change,
 704         .delete         =       cls_bpf_delete,
 705         .walk           =       cls_bpf_walk,
 706         .reoffload      =       cls_bpf_reoffload,
 707         .dump           =       cls_bpf_dump,
 708         .bind_class     =       cls_bpf_bind_class,
 709 };
 710
 711 static int __init cls_bpf_init_mod(void)
 712 {
 713         return register_tcf_proto_ops(&cls_bpf_ops);
 714 }
 715
 716 static void __exit cls_bpf_exit_mod(void)
 717 {
 718         unregister_tcf_proto_ops(&cls_bpf_ops);
 719 }
 720
 721 module_init(cls_bpf_init_mod);
 722 module_exit(cls_bpf_exit_mod);