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        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
 106                if (prog->exts_integrated) {
 107                        res->class   = 0;
 108                        res->classid = TC_H_MAJ(prog->res.classid) |
 109                                       qdisc_skb_cb(skb)->tc_classid;
 110
 111                        ret = cls_bpf_exec_opcode(filter_res);
 112                        if (ret == TC_ACT_UNSPEC)
 113                                continue;
 114                        break;
 115                }
 116
 117                if (filter_res == 0)
 118                        continue;
 119                if (filter_res != -1) {
 120                        res->class   = 0;
 121                        res->classid = filter_res;
 122                } else {
 123                        *res = prog->res;
 124                }
 125
 126                ret = tcf_exts_exec(skb, &prog->exts, res);
 127                if (ret < 0)
 128                        continue;
 129
 130                break;
 131        }
 132
 133        return ret;
 134}
 135
 136static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
 137{
 138        return !prog->bpf_ops;
 139}
 140
 141static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 142                               struct cls_bpf_prog *oldprog,
 143                               struct netlink_ext_ack *extack)
 144{
 145        struct tcf_block *block = tp->chain->block;
 146        struct tc_cls_bpf_offload cls_bpf = {};
 147        struct cls_bpf_prog *obj;
 148        bool skip_sw;
 149        int err;
 150
 151        skip_sw = prog && tc_skip_sw(prog->gen_flags);
 152        obj = prog ?: oldprog;
 153
 154        tc_cls_common_offload_init(&cls_bpf.common, tp, obj->gen_flags, extack);
 155        cls_bpf.command = TC_CLSBPF_OFFLOAD;
 156        cls_bpf.exts = &obj->exts;
 157        cls_bpf.prog = prog ? prog->filter : NULL;
 158        cls_bpf.oldprog = oldprog ? oldprog->filter : NULL;
 159        cls_bpf.name = obj->bpf_name;
 160        cls_bpf.exts_integrated = obj->exts_integrated;
 161
 162        if (oldprog && prog)
 163                err = tc_setup_cb_replace(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 164                                          skip_sw, &oldprog->gen_flags,
 165                                          &oldprog->in_hw_count,
 166                                          &prog->gen_flags, &prog->in_hw_count,
 167                                          true);
 168        else if (prog)
 169                err = tc_setup_cb_add(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 170                                      skip_sw, &prog->gen_flags,
 171                                      &prog->in_hw_count, true);
 172        else
 173                err = tc_setup_cb_destroy(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 174                                          skip_sw, &oldprog->gen_flags,
 175                                          &oldprog->in_hw_count, true);
 176
 177        if (prog && err) {
 178                cls_bpf_offload_cmd(tp, oldprog, prog, extack);
 179                return err;
 180        }
 181
 182        if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW))
 183                return -EINVAL;
 184
 185        return 0;
 186}
 187
 188static u32 cls_bpf_flags(u32 flags)
 189{
 190        return flags & CLS_BPF_SUPPORTED_GEN_FLAGS;
 191}
 192
 193static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 194                           struct cls_bpf_prog *oldprog,
 195                           struct netlink_ext_ack *extack)
 196{
 197        if (prog && oldprog &&
 198            cls_bpf_flags(prog->gen_flags) !=
 199            cls_bpf_flags(oldprog->gen_flags))
 200                return -EINVAL;
 201
 202        if (prog && tc_skip_hw(prog->gen_flags))
 203                prog = NULL;
 204        if (oldprog && tc_skip_hw(oldprog->gen_flags))
 205                oldprog = NULL;
 206        if (!prog && !oldprog)
 207                return 0;
 208
 209        return cls_bpf_offload_cmd(tp, prog, oldprog, extack);
 210}
 211
 212static void cls_bpf_stop_offload(struct tcf_proto *tp,
 213                                 struct cls_bpf_prog *prog,
 214                                 struct netlink_ext_ack *extack)
 215{
 216        int err;
 217
 218        err = cls_bpf_offload_cmd(tp, NULL, prog, extack);
 219        if (err)
 220                pr_err("Stopping hardware offload failed: %d\n", err);
 221}
 222
 223static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
 224                                         struct cls_bpf_prog *prog)
 225{
 226        struct tcf_block *block = tp->chain->block;
 227        struct tc_cls_bpf_offload cls_bpf = {};
 228
 229        tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, NULL);
 230        cls_bpf.command = TC_CLSBPF_STATS;
 231        cls_bpf.exts = &prog->exts;
 232        cls_bpf.prog = prog->filter;
 233        cls_bpf.name = prog->bpf_name;
 234        cls_bpf.exts_integrated = prog->exts_integrated;
 235
 236        tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false, true);
 237}
 238
 239static int cls_bpf_init(struct tcf_proto *tp)
 240{
 241        struct cls_bpf_head *head;
 242
 243        head = kzalloc(sizeof(*head), GFP_KERNEL);
 244        if (head == NULL)
 245                return -ENOBUFS;
 246
 247        INIT_LIST_HEAD_RCU(&head->plist);
 248        idr_init(&head->handle_idr);
 249        rcu_assign_pointer(tp->root, head);
 250
 251        return 0;
 252}
 253
 254static void cls_bpf_free_parms(struct cls_bpf_prog *prog)
 255{
 256        if (cls_bpf_is_ebpf(prog))
 257                bpf_prog_put(prog->filter);
 258        else
 259                bpf_prog_destroy(prog->filter);
 260
 261        kfree(prog->bpf_name);
 262        kfree(prog->bpf_ops);
 263}
 264
 265static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
 266{
 267        tcf_exts_destroy(&prog->exts);
 268        tcf_exts_put_net(&prog->exts);
 269
 270        cls_bpf_free_parms(prog);
 271        kfree(prog);
 272}
 273
 274static void cls_bpf_delete_prog_work(struct work_struct *work)
 275{
 276        struct cls_bpf_prog *prog = container_of(to_rcu_work(work),
 277                                                 struct cls_bpf_prog,
 278                                                 rwork);
 279        rtnl_lock();
 280        __cls_bpf_delete_prog(prog);
 281        rtnl_unlock();
 282}
 283
 284static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 285                             struct netlink_ext_ack *extack)
 286{
 287        struct cls_bpf_head *head = rtnl_dereference(tp->root);
 288
 289        idr_remove(&head->handle_idr, prog->handle);
 290        cls_bpf_stop_offload(tp, prog, extack);
 291        list_del_rcu(&prog->link);
 292        tcf_unbind_filter(tp, &prog->res);
 293        if (tcf_exts_get_net(&prog->exts))
 294                tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work);
 295        else
 296                __cls_bpf_delete_prog(prog);
 297}
 298
 299static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
 300                          bool rtnl_held, struct netlink_ext_ack *extack)
 301{
 302        struct cls_bpf_head *head = rtnl_dereference(tp->root);
 303
 304        __cls_bpf_delete(tp, arg, extack);
 305        *last = list_empty(&head->plist);
 306        return 0;
 307}
 308
 309static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held,
 310                            struct netlink_ext_ack *extack)
 311{
 312        struct cls_bpf_head *head = rtnl_dereference(tp->root);
 313        struct cls_bpf_prog *prog, *tmp;
 314
 315        list_for_each_entry_safe(prog, tmp, &head->plist, link)
 316                __cls_bpf_delete(tp, prog, extack);
 317
 318        idr_destroy(&head->handle_idr);
 319        kfree_rcu(head, rcu);
 320}
 321
 322static void *cls_bpf_get(struct tcf_proto *tp, u32 handle)
 323{
 324        struct cls_bpf_head *head = rtnl_dereference(tp->root);
 325        struct cls_bpf_prog *prog;
 326
 327        list_for_each_entry(prog, &head->plist, link) {
 328                if (prog->handle == handle)
 329                        return prog;
 330        }
 331
 332        return NULL;
 333}
 334
 335static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
 336{
 337        struct sock_filter *bpf_ops;
 338        struct sock_fprog_kern fprog_tmp;
 339        struct bpf_prog *fp;
 340        u16 bpf_size, bpf_num_ops;
 341        int ret;
 342
 343        bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
 344        if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
 345                return -EINVAL;
 346
 347        bpf_size = bpf_num_ops * sizeof(*bpf_ops);
 348        if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
 349                return -EINVAL;
 350
 351        bpf_ops = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL);
 352        if (bpf_ops == NULL)
 353                return -ENOMEM;
 354
 355        fprog_tmp.len = bpf_num_ops;
 356        fprog_tmp.filter = bpf_ops;
 357
 358        ret = bpf_prog_create(&fp, &fprog_tmp);
 359        if (ret < 0) {
 360                kfree(bpf_ops);
 361                return ret;
 362        }
 363
 364        prog->bpf_ops = bpf_ops;
 365        prog->bpf_num_ops = bpf_num_ops;
 366        prog->bpf_name = NULL;
 367        prog->filter = fp;
 368
 369        return 0;
 370}
 371
 372static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
 373                                 u32 gen_flags, const struct tcf_proto *tp)
 374{
 375        struct bpf_prog *fp;
 376        char *name = NULL;
 377        bool skip_sw;
 378        u32 bpf_fd;
 379
 380        bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
 381        skip_sw = gen_flags & TCA_CLS_FLAGS_SKIP_SW;
 382
 383        fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS, skip_sw);
 384        if (IS_ERR(fp))
 385                return PTR_ERR(fp);
 386
 387        if (tb[TCA_BPF_NAME]) {
 388                name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
 389                if (!name) {
 390                        bpf_prog_put(fp);
 391                        return -ENOMEM;
 392                }
 393        }
 394
 395        prog->bpf_ops = NULL;
 396        prog->bpf_name = name;
 397        prog->filter = fp;
 398
 399        if (fp->dst_needed)
 400                tcf_block_netif_keep_dst(tp->chain->block);
 401
 402        return 0;
 403}
 404
 405static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 406                             struct cls_bpf_prog *prog, unsigned long base,
 407                             struct nlattr **tb, struct nlattr *est, bool ovr,
 408                             struct netlink_ext_ack *extack)
 409{
 410        bool is_bpf, is_ebpf, have_exts = false;
 411        u32 gen_flags = 0;
 412        int ret;
 413
 414        is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
 415        is_ebpf = tb[TCA_BPF_FD];
 416        if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
 417                return -EINVAL;
 418
 419        ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr, true,
 420                                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
 455static 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, bool rtnl_held,
 459                          struct netlink_ext_ack *extack)
 460{
 461        struct cls_bpf_head *head = rtnl_dereference(tp->root);
 462        struct cls_bpf_prog *oldprog = *arg;
 463        struct nlattr *tb[TCA_BPF_MAX + 1];
 464        struct cls_bpf_prog *prog;
 465        int ret;
 466
 467        if (tca[TCA_OPTIONS] == NULL)
 468                return -EINVAL;
 469
 470        ret = nla_parse_nested_deprecated(tb, TCA_BPF_MAX, tca[TCA_OPTIONS],
 471                                          bpf_policy, NULL);
 472        if (ret < 0)
 473                return ret;
 474
 475        prog = kzalloc(sizeof(*prog), GFP_KERNEL);
 476        if (!prog)
 477                return -ENOBUFS;
 478
 479        ret = tcf_exts_init(&prog->exts, net, TCA_BPF_ACT, TCA_BPF_POLICE);
 480        if (ret < 0)
 481                goto errout;
 482
 483        if (oldprog) {
 484                if (handle && oldprog->handle != handle) {
 485                        ret = -EINVAL;
 486                        goto errout;
 487                }
 488        }
 489
 490        if (handle == 0) {
 491                handle = 1;
 492                ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 493                                    INT_MAX, GFP_KERNEL);
 494        } else if (!oldprog) {
 495                ret = idr_alloc_u32(&head->handle_idr, prog, &handle,
 496                                    handle, GFP_KERNEL);
 497        }
 498
 499        if (ret)
 500                goto errout;
 501        prog->handle = handle;
 502
 503        ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr,
 504                                extack);
 505        if (ret < 0)
 506                goto errout_idr;
 507
 508        ret = cls_bpf_offload(tp, prog, oldprog, extack);
 509        if (ret)
 510                goto errout_parms;
 511
 512        if (!tc_in_hw(prog->gen_flags))
 513                prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 514
 515        if (oldprog) {
 516                idr_replace(&head->handle_idr, prog, handle);
 517                list_replace_rcu(&oldprog->link, &prog->link);
 518                tcf_unbind_filter(tp, &oldprog->res);
 519                tcf_exts_get_net(&oldprog->exts);
 520                tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
 521        } else {
 522                list_add_rcu(&prog->link, &head->plist);
 523        }
 524
 525        *arg = prog;
 526        return 0;
 527
 528errout_parms:
 529        cls_bpf_free_parms(prog);
 530errout_idr:
 531        if (!oldprog)
 532                idr_remove(&head->handle_idr, prog->handle);
 533errout:
 534        tcf_exts_destroy(&prog->exts);
 535        kfree(prog);
 536        return ret;
 537}
 538
 539static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
 540                                 struct sk_buff *skb)
 541{
 542        struct nlattr *nla;
 543
 544        if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
 545                return -EMSGSIZE;
 546
 547        nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
 548                          sizeof(struct sock_filter));
 549        if (nla == NULL)
 550                return -EMSGSIZE;
 551
 552        memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
 553
 554        return 0;
 555}
 556
 557static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 558                                  struct sk_buff *skb)
 559{
 560        struct nlattr *nla;
 561
 562        if (prog->bpf_name &&
 563            nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
 564                return -EMSGSIZE;
 565
 566        if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id))
 567                return -EMSGSIZE;
 568
 569        nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
 570        if (nla == NULL)
 571                return -EMSGSIZE;
 572
 573        memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
 574
 575        return 0;
 576}
 577
 578static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
 579                        struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
 580{
 581        struct cls_bpf_prog *prog = fh;
 582        struct nlattr *nest;
 583        u32 bpf_flags = 0;
 584        int ret;
 585
 586        if (prog == NULL)
 587                return skb->len;
 588
 589        tm->tcm_handle = prog->handle;
 590
 591        cls_bpf_offload_update_stats(tp, prog);
 592
 593        nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 594        if (nest == NULL)
 595                goto nla_put_failure;
 596
 597        if (prog->res.classid &&
 598            nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
 599                goto nla_put_failure;
 600
 601        if (cls_bpf_is_ebpf(prog))
 602                ret = cls_bpf_dump_ebpf_info(prog, skb);
 603        else
 604                ret = cls_bpf_dump_bpf_info(prog, skb);
 605        if (ret)
 606                goto nla_put_failure;
 607
 608        if (tcf_exts_dump(skb, &prog->exts) < 0)
 609                goto nla_put_failure;
 610
 611        if (prog->exts_integrated)
 612                bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
 613        if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
 614                goto nla_put_failure;
 615        if (prog->gen_flags &&
 616            nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
 617                goto nla_put_failure;
 618
 619        nla_nest_end(skb, nest);
 620
 621        if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
 622                goto nla_put_failure;
 623
 624        return skb->len;
 625
 626nla_put_failure:
 627        nla_nest_cancel(skb, nest);
 628        return -1;
 629}
 630
 631static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl,
 632                               void *q, unsigned long base)
 633{
 634        struct cls_bpf_prog *prog = fh;
 635
 636        if (prog && prog->res.classid == classid) {
 637                if (cl)
 638                        __tcf_bind_filter(q, &prog->res, base);
 639                else
 640                        __tcf_unbind_filter(q, &prog->res);
 641        }
 642}
 643
 644static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
 645                         bool rtnl_held)
 646{
 647        struct cls_bpf_head *head = rtnl_dereference(tp->root);
 648        struct cls_bpf_prog *prog;
 649
 650        list_for_each_entry(prog, &head->plist, link) {
 651                if (arg->count < arg->skip)
 652                        goto skip;
 653                if (arg->fn(tp, prog, arg) < 0) {
 654                        arg->stop = 1;
 655                        break;
 656                }
 657skip:
 658                arg->count++;
 659        }
 660}
 661
 662static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
 663                             void *cb_priv, struct netlink_ext_ack *extack)
 664{
 665        struct cls_bpf_head *head = rtnl_dereference(tp->root);
 666        struct tcf_block *block = tp->chain->block;
 667        struct tc_cls_bpf_offload cls_bpf = {};
 668        struct cls_bpf_prog *prog;
 669        int err;
 670
 671        list_for_each_entry(prog, &head->plist, link) {
 672                if (tc_skip_hw(prog->gen_flags))
 673                        continue;
 674
 675                tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags,
 676                                           extack);
 677                cls_bpf.command = TC_CLSBPF_OFFLOAD;
 678                cls_bpf.exts = &prog->exts;
 679                cls_bpf.prog = add ? prog->filter : NULL;
 680                cls_bpf.oldprog = add ? NULL : prog->filter;
 681                cls_bpf.name = prog->bpf_name;
 682                cls_bpf.exts_integrated = prog->exts_integrated;
 683
 684                err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF,
 685                                            &cls_bpf, cb_priv, &prog->gen_flags,
 686                                            &prog->in_hw_count);
 687                if (err)
 688                        return err;
 689        }
 690
 691        return 0;
 692}
 693
 694static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
 695        .kind           =       "bpf",
 696        .owner          =       THIS_MODULE,
 697        .classify       =       cls_bpf_classify,
 698        .init           =       cls_bpf_init,
 699        .destroy        =       cls_bpf_destroy,
 700        .get            =       cls_bpf_get,
 701        .change         =       cls_bpf_change,
 702        .delete         =       cls_bpf_delete,
 703        .walk           =       cls_bpf_walk,
 704        .reoffload      =       cls_bpf_reoffload,
 705        .dump           =       cls_bpf_dump,
 706        .bind_class     =       cls_bpf_bind_class,
 707};
 708
 709static int __init cls_bpf_init_mod(void)
 710{
 711        return register_tcf_proto_ops(&cls_bpf_ops);
 712}
 713
 714static void __exit cls_bpf_exit_mod(void)
 715{
 716        unregister_tcf_proto_ops(&cls_bpf_ops);
 717}
 718
 719module_init(cls_bpf_init_mod);
 720module_exit(cls_bpf_exit_mod);
 721