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