linux/net/sched/cls_bpf.c
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   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
  23MODULE_LICENSE("GPL");
  24MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
  25MODULE_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
  31struct cls_bpf_head {
  32        struct list_head plist;
  33        struct idr handle_idr;
  34        struct rcu_head rcu;
  35};
  36
  37struct 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
  53static 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
  65static 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
  80static 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
 139static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
 140{
 141        return !prog->bpf_ops;
 142}
 143
 144static 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
 191static u32 cls_bpf_flags(u32 flags)
 192{
 193        return flags & CLS_BPF_SUPPORTED_GEN_FLAGS;
 194}
 195
 196static 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
 215static 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
 226static 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
 242static 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
 257static 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
 268static 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
 277static 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
 287static 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
 302static 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
 312static 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
 325static 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
 338static 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
 375static 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
 408static 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
 458static 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
 531errout_parms:
 532        cls_bpf_free_parms(prog);
 533errout_idr:
 534        if (!oldprog)
 535                idr_remove(&head->handle_idr, prog->handle);
 536errout:
 537        tcf_exts_destroy(&prog->exts);
 538        kfree(prog);
 539        return ret;
 540}
 541
 542static 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
 560static 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
 581static 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
 629nla_put_failure:
 630        nla_nest_cancel(skb, nest);
 631        return -1;
 632}
 633
 634static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl)
 635{
 636        struct cls_bpf_prog *prog = fh;
 637
 638        if (prog && prog->res.classid == classid)
 639                prog->res.class = cl;
 640}
 641
 642static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
 643                         bool rtnl_held)
 644{
 645        struct cls_bpf_head *head = rtnl_dereference(tp->root);
 646        struct cls_bpf_prog *prog;
 647
 648        list_for_each_entry(prog, &head->plist, link) {
 649                if (arg->count < arg->skip)
 650                        goto skip;
 651                if (arg->fn(tp, prog, arg) < 0) {
 652                        arg->stop = 1;
 653                        break;
 654                }
 655skip:
 656                arg->count++;
 657        }
 658}
 659
 660static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
 661                             void *cb_priv, struct netlink_ext_ack *extack)
 662{
 663        struct cls_bpf_head *head = rtnl_dereference(tp->root);
 664        struct tcf_block *block = tp->chain->block;
 665        struct tc_cls_bpf_offload cls_bpf = {};
 666        struct cls_bpf_prog *prog;
 667        int err;
 668
 669        list_for_each_entry(prog, &head->plist, link) {
 670                if (tc_skip_hw(prog->gen_flags))
 671                        continue;
 672
 673                tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
 674                                           extack);
 675                cls_bpf.command = TC_CLSBPF_OFFLOAD;
 676                cls_bpf.exts = &prog->exts;
 677                cls_bpf.prog = add ? prog->filter : NULL;
 678                cls_bpf.oldprog = add ? NULL : prog->filter;
 679                cls_bpf.name = prog->bpf_name;
 680                cls_bpf.exts_integrated = prog->exts_integrated;
 681
 682                err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF,
 683                                            &cls_bpf, cb_priv, &prog->gen_flags,
 684                                            &prog->in_hw_count);
 685                if (err)
 686                        return err;
 687        }
 688
 689        return 0;
 690}
 691
 692static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
 693        .kind           =       "bpf",
 694        .owner          =       THIS_MODULE,
 695        .classify       =       cls_bpf_classify,
 696        .init           =       cls_bpf_init,
 697        .destroy        =       cls_bpf_destroy,
 698        .get            =       cls_bpf_get,
 699        .change         =       cls_bpf_change,
 700        .delete         =       cls_bpf_delete,
 701        .walk           =       cls_bpf_walk,
 702        .reoffload      =       cls_bpf_reoffload,
 703        .dump           =       cls_bpf_dump,
 704        .bind_class     =       cls_bpf_bind_class,
 705};
 706
 707static int __init cls_bpf_init_mod(void)
 708{
 709        return register_tcf_proto_ops(&cls_bpf_ops);
 710}
 711
 712static void __exit cls_bpf_exit_mod(void)
 713{
 714        unregister_tcf_proto_ops(&cls_bpf_ops);
 715}
 716
 717module_init(cls_bpf_init_mod);
 718module_exit(cls_bpf_exit_mod);
 719