linux/net/sched/act_ife.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * net/sched/ife.c      Inter-FE action based on ForCES WG InterFE LFB
   4 *
   5 *              Refer to:
   6 *              draft-ietf-forces-interfelfb-03
   7 *              and
   8 *              netdev01 paper:
   9 *              "Distributing Linux Traffic Control Classifier-Action
  10 *              Subsystem"
  11 *              Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
  12 *
  13 * copyright Jamal Hadi Salim (2015)
  14*/
  15
  16#include <linux/types.h>
  17#include <linux/kernel.h>
  18#include <linux/string.h>
  19#include <linux/errno.h>
  20#include <linux/skbuff.h>
  21#include <linux/rtnetlink.h>
  22#include <linux/module.h>
  23#include <linux/init.h>
  24#include <net/net_namespace.h>
  25#include <net/netlink.h>
  26#include <net/pkt_sched.h>
  27#include <net/pkt_cls.h>
  28#include <uapi/linux/tc_act/tc_ife.h>
  29#include <net/tc_act/tc_ife.h>
  30#include <linux/etherdevice.h>
  31#include <net/ife.h>
  32
  33static unsigned int ife_net_id;
  34static int max_metacnt = IFE_META_MAX + 1;
  35static struct tc_action_ops act_ife_ops;
  36
  37static const struct nla_policy ife_policy[TCA_IFE_MAX + 1] = {
  38        [TCA_IFE_PARMS] = { .len = sizeof(struct tc_ife)},
  39        [TCA_IFE_DMAC] = { .len = ETH_ALEN},
  40        [TCA_IFE_SMAC] = { .len = ETH_ALEN},
  41        [TCA_IFE_TYPE] = { .type = NLA_U16},
  42};
  43
  44int ife_encode_meta_u16(u16 metaval, void *skbdata, struct tcf_meta_info *mi)
  45{
  46        u16 edata = 0;
  47
  48        if (mi->metaval)
  49                edata = *(u16 *)mi->metaval;
  50        else if (metaval)
  51                edata = metaval;
  52
  53        if (!edata) /* will not encode */
  54                return 0;
  55
  56        edata = htons(edata);
  57        return ife_tlv_meta_encode(skbdata, mi->metaid, 2, &edata);
  58}
  59EXPORT_SYMBOL_GPL(ife_encode_meta_u16);
  60
  61int ife_get_meta_u32(struct sk_buff *skb, struct tcf_meta_info *mi)
  62{
  63        if (mi->metaval)
  64                return nla_put_u32(skb, mi->metaid, *(u32 *)mi->metaval);
  65        else
  66                return nla_put(skb, mi->metaid, 0, NULL);
  67}
  68EXPORT_SYMBOL_GPL(ife_get_meta_u32);
  69
  70int ife_check_meta_u32(u32 metaval, struct tcf_meta_info *mi)
  71{
  72        if (metaval || mi->metaval)
  73                return 8; /* T+L+V == 2+2+4 */
  74
  75        return 0;
  76}
  77EXPORT_SYMBOL_GPL(ife_check_meta_u32);
  78
  79int ife_check_meta_u16(u16 metaval, struct tcf_meta_info *mi)
  80{
  81        if (metaval || mi->metaval)
  82                return 8; /* T+L+(V) == 2+2+(2+2bytepad) */
  83
  84        return 0;
  85}
  86EXPORT_SYMBOL_GPL(ife_check_meta_u16);
  87
  88int ife_encode_meta_u32(u32 metaval, void *skbdata, struct tcf_meta_info *mi)
  89{
  90        u32 edata = metaval;
  91
  92        if (mi->metaval)
  93                edata = *(u32 *)mi->metaval;
  94        else if (metaval)
  95                edata = metaval;
  96
  97        if (!edata) /* will not encode */
  98                return 0;
  99
 100        edata = htonl(edata);
 101        return ife_tlv_meta_encode(skbdata, mi->metaid, 4, &edata);
 102}
 103EXPORT_SYMBOL_GPL(ife_encode_meta_u32);
 104
 105int ife_get_meta_u16(struct sk_buff *skb, struct tcf_meta_info *mi)
 106{
 107        if (mi->metaval)
 108                return nla_put_u16(skb, mi->metaid, *(u16 *)mi->metaval);
 109        else
 110                return nla_put(skb, mi->metaid, 0, NULL);
 111}
 112EXPORT_SYMBOL_GPL(ife_get_meta_u16);
 113
 114int ife_alloc_meta_u32(struct tcf_meta_info *mi, void *metaval, gfp_t gfp)
 115{
 116        mi->metaval = kmemdup(metaval, sizeof(u32), gfp);
 117        if (!mi->metaval)
 118                return -ENOMEM;
 119
 120        return 0;
 121}
 122EXPORT_SYMBOL_GPL(ife_alloc_meta_u32);
 123
 124int ife_alloc_meta_u16(struct tcf_meta_info *mi, void *metaval, gfp_t gfp)
 125{
 126        mi->metaval = kmemdup(metaval, sizeof(u16), gfp);
 127        if (!mi->metaval)
 128                return -ENOMEM;
 129
 130        return 0;
 131}
 132EXPORT_SYMBOL_GPL(ife_alloc_meta_u16);
 133
 134void ife_release_meta_gen(struct tcf_meta_info *mi)
 135{
 136        kfree(mi->metaval);
 137}
 138EXPORT_SYMBOL_GPL(ife_release_meta_gen);
 139
 140int ife_validate_meta_u32(void *val, int len)
 141{
 142        if (len == sizeof(u32))
 143                return 0;
 144
 145        return -EINVAL;
 146}
 147EXPORT_SYMBOL_GPL(ife_validate_meta_u32);
 148
 149int ife_validate_meta_u16(void *val, int len)
 150{
 151        /* length will not include padding */
 152        if (len == sizeof(u16))
 153                return 0;
 154
 155        return -EINVAL;
 156}
 157EXPORT_SYMBOL_GPL(ife_validate_meta_u16);
 158
 159static LIST_HEAD(ifeoplist);
 160static DEFINE_RWLOCK(ife_mod_lock);
 161
 162static struct tcf_meta_ops *find_ife_oplist(u16 metaid)
 163{
 164        struct tcf_meta_ops *o;
 165
 166        read_lock(&ife_mod_lock);
 167        list_for_each_entry(o, &ifeoplist, list) {
 168                if (o->metaid == metaid) {
 169                        if (!try_module_get(o->owner))
 170                                o = NULL;
 171                        read_unlock(&ife_mod_lock);
 172                        return o;
 173                }
 174        }
 175        read_unlock(&ife_mod_lock);
 176
 177        return NULL;
 178}
 179
 180int register_ife_op(struct tcf_meta_ops *mops)
 181{
 182        struct tcf_meta_ops *m;
 183
 184        if (!mops->metaid || !mops->metatype || !mops->name ||
 185            !mops->check_presence || !mops->encode || !mops->decode ||
 186            !mops->get || !mops->alloc)
 187                return -EINVAL;
 188
 189        write_lock(&ife_mod_lock);
 190
 191        list_for_each_entry(m, &ifeoplist, list) {
 192                if (m->metaid == mops->metaid ||
 193                    (strcmp(mops->name, m->name) == 0)) {
 194                        write_unlock(&ife_mod_lock);
 195                        return -EEXIST;
 196                }
 197        }
 198
 199        if (!mops->release)
 200                mops->release = ife_release_meta_gen;
 201
 202        list_add_tail(&mops->list, &ifeoplist);
 203        write_unlock(&ife_mod_lock);
 204        return 0;
 205}
 206EXPORT_SYMBOL_GPL(unregister_ife_op);
 207
 208int unregister_ife_op(struct tcf_meta_ops *mops)
 209{
 210        struct tcf_meta_ops *m;
 211        int err = -ENOENT;
 212
 213        write_lock(&ife_mod_lock);
 214        list_for_each_entry(m, &ifeoplist, list) {
 215                if (m->metaid == mops->metaid) {
 216                        list_del(&mops->list);
 217                        err = 0;
 218                        break;
 219                }
 220        }
 221        write_unlock(&ife_mod_lock);
 222
 223        return err;
 224}
 225EXPORT_SYMBOL_GPL(register_ife_op);
 226
 227static int ife_validate_metatype(struct tcf_meta_ops *ops, void *val, int len)
 228{
 229        int ret = 0;
 230        /* XXX: unfortunately cant use nla_policy at this point
 231        * because a length of 0 is valid in the case of
 232        * "allow". "use" semantics do enforce for proper
 233        * length and i couldve use nla_policy but it makes it hard
 234        * to use it just for that..
 235        */
 236        if (ops->validate)
 237                return ops->validate(val, len);
 238
 239        if (ops->metatype == NLA_U32)
 240                ret = ife_validate_meta_u32(val, len);
 241        else if (ops->metatype == NLA_U16)
 242                ret = ife_validate_meta_u16(val, len);
 243
 244        return ret;
 245}
 246
 247#ifdef CONFIG_MODULES
 248static const char *ife_meta_id2name(u32 metaid)
 249{
 250        switch (metaid) {
 251        case IFE_META_SKBMARK:
 252                return "skbmark";
 253        case IFE_META_PRIO:
 254                return "skbprio";
 255        case IFE_META_TCINDEX:
 256                return "tcindex";
 257        default:
 258                return "unknown";
 259        }
 260}
 261#endif
 262
 263/* called when adding new meta information
 264*/
 265static int load_metaops_and_vet(u32 metaid, void *val, int len, bool rtnl_held)
 266{
 267        struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 268        int ret = 0;
 269
 270        if (!ops) {
 271                ret = -ENOENT;
 272#ifdef CONFIG_MODULES
 273                if (rtnl_held)
 274                        rtnl_unlock();
 275                request_module("ife-meta-%s", ife_meta_id2name(metaid));
 276                if (rtnl_held)
 277                        rtnl_lock();
 278                ops = find_ife_oplist(metaid);
 279#endif
 280        }
 281
 282        if (ops) {
 283                ret = 0;
 284                if (len)
 285                        ret = ife_validate_metatype(ops, val, len);
 286
 287                module_put(ops->owner);
 288        }
 289
 290        return ret;
 291}
 292
 293/* called when adding new meta information
 294*/
 295static int __add_metainfo(const struct tcf_meta_ops *ops,
 296                          struct tcf_ife_info *ife, u32 metaid, void *metaval,
 297                          int len, bool atomic, bool exists)
 298{
 299        struct tcf_meta_info *mi = NULL;
 300        int ret = 0;
 301
 302        mi = kzalloc(sizeof(*mi), atomic ? GFP_ATOMIC : GFP_KERNEL);
 303        if (!mi)
 304                return -ENOMEM;
 305
 306        mi->metaid = metaid;
 307        mi->ops = ops;
 308        if (len > 0) {
 309                ret = ops->alloc(mi, metaval, atomic ? GFP_ATOMIC : GFP_KERNEL);
 310                if (ret != 0) {
 311                        kfree(mi);
 312                        return ret;
 313                }
 314        }
 315
 316        if (exists)
 317                spin_lock_bh(&ife->tcf_lock);
 318        list_add_tail(&mi->metalist, &ife->metalist);
 319        if (exists)
 320                spin_unlock_bh(&ife->tcf_lock);
 321
 322        return ret;
 323}
 324
 325static int add_metainfo_and_get_ops(const struct tcf_meta_ops *ops,
 326                                    struct tcf_ife_info *ife, u32 metaid,
 327                                    bool exists)
 328{
 329        int ret;
 330
 331        if (!try_module_get(ops->owner))
 332                return -ENOENT;
 333        ret = __add_metainfo(ops, ife, metaid, NULL, 0, true, exists);
 334        if (ret)
 335                module_put(ops->owner);
 336        return ret;
 337}
 338
 339static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
 340                        int len, bool exists)
 341{
 342        const struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 343        int ret;
 344
 345        if (!ops)
 346                return -ENOENT;
 347        ret = __add_metainfo(ops, ife, metaid, metaval, len, false, exists);
 348        if (ret)
 349                /*put back what find_ife_oplist took */
 350                module_put(ops->owner);
 351        return ret;
 352}
 353
 354static int use_all_metadata(struct tcf_ife_info *ife, bool exists)
 355{
 356        struct tcf_meta_ops *o;
 357        int rc = 0;
 358        int installed = 0;
 359
 360        read_lock(&ife_mod_lock);
 361        list_for_each_entry(o, &ifeoplist, list) {
 362                rc = add_metainfo_and_get_ops(o, ife, o->metaid, exists);
 363                if (rc == 0)
 364                        installed += 1;
 365        }
 366        read_unlock(&ife_mod_lock);
 367
 368        if (installed)
 369                return 0;
 370        else
 371                return -EINVAL;
 372}
 373
 374static int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
 375{
 376        struct tcf_meta_info *e;
 377        struct nlattr *nest;
 378        unsigned char *b = skb_tail_pointer(skb);
 379        int total_encoded = 0;
 380
 381        /*can only happen on decode */
 382        if (list_empty(&ife->metalist))
 383                return 0;
 384
 385        nest = nla_nest_start_noflag(skb, TCA_IFE_METALST);
 386        if (!nest)
 387                goto out_nlmsg_trim;
 388
 389        list_for_each_entry(e, &ife->metalist, metalist) {
 390                if (!e->ops->get(skb, e))
 391                        total_encoded += 1;
 392        }
 393
 394        if (!total_encoded)
 395                goto out_nlmsg_trim;
 396
 397        nla_nest_end(skb, nest);
 398
 399        return 0;
 400
 401out_nlmsg_trim:
 402        nlmsg_trim(skb, b);
 403        return -1;
 404}
 405
 406/* under ife->tcf_lock */
 407static void _tcf_ife_cleanup(struct tc_action *a)
 408{
 409        struct tcf_ife_info *ife = to_ife(a);
 410        struct tcf_meta_info *e, *n;
 411
 412        list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 413                list_del(&e->metalist);
 414                if (e->metaval) {
 415                        if (e->ops->release)
 416                                e->ops->release(e);
 417                        else
 418                                kfree(e->metaval);
 419                }
 420                module_put(e->ops->owner);
 421                kfree(e);
 422        }
 423}
 424
 425static void tcf_ife_cleanup(struct tc_action *a)
 426{
 427        struct tcf_ife_info *ife = to_ife(a);
 428        struct tcf_ife_params *p;
 429
 430        spin_lock_bh(&ife->tcf_lock);
 431        _tcf_ife_cleanup(a);
 432        spin_unlock_bh(&ife->tcf_lock);
 433
 434        p = rcu_dereference_protected(ife->params, 1);
 435        if (p)
 436                kfree_rcu(p, rcu);
 437}
 438
 439static int load_metalist(struct nlattr **tb, bool rtnl_held)
 440{
 441        int i;
 442
 443        for (i = 1; i < max_metacnt; i++) {
 444                if (tb[i]) {
 445                        void *val = nla_data(tb[i]);
 446                        int len = nla_len(tb[i]);
 447                        int rc;
 448
 449                        rc = load_metaops_and_vet(i, val, len, rtnl_held);
 450                        if (rc != 0)
 451                                return rc;
 452                }
 453        }
 454
 455        return 0;
 456}
 457
 458static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
 459                             bool exists, bool rtnl_held)
 460{
 461        int len = 0;
 462        int rc = 0;
 463        int i = 0;
 464        void *val;
 465
 466        for (i = 1; i < max_metacnt; i++) {
 467                if (tb[i]) {
 468                        val = nla_data(tb[i]);
 469                        len = nla_len(tb[i]);
 470
 471                        rc = add_metainfo(ife, i, val, len, exists);
 472                        if (rc)
 473                                return rc;
 474                }
 475        }
 476
 477        return rc;
 478}
 479
 480static int tcf_ife_init(struct net *net, struct nlattr *nla,
 481                        struct nlattr *est, struct tc_action **a,
 482                        int ovr, int bind, bool rtnl_held,
 483                        struct tcf_proto *tp, u32 flags,
 484                        struct netlink_ext_ack *extack)
 485{
 486        struct tc_action_net *tn = net_generic(net, ife_net_id);
 487        struct nlattr *tb[TCA_IFE_MAX + 1];
 488        struct nlattr *tb2[IFE_META_MAX + 1];
 489        struct tcf_chain *goto_ch = NULL;
 490        struct tcf_ife_params *p;
 491        struct tcf_ife_info *ife;
 492        u16 ife_type = ETH_P_IFE;
 493        struct tc_ife *parm;
 494        u8 *daddr = NULL;
 495        u8 *saddr = NULL;
 496        bool exists = false;
 497        int ret = 0;
 498        u32 index;
 499        int err;
 500
 501        if (!nla) {
 502                NL_SET_ERR_MSG_MOD(extack, "IFE requires attributes to be passed");
 503                return -EINVAL;
 504        }
 505
 506        err = nla_parse_nested_deprecated(tb, TCA_IFE_MAX, nla, ife_policy,
 507                                          NULL);
 508        if (err < 0)
 509                return err;
 510
 511        if (!tb[TCA_IFE_PARMS])
 512                return -EINVAL;
 513
 514        parm = nla_data(tb[TCA_IFE_PARMS]);
 515
 516        /* IFE_DECODE is 0 and indicates the opposite of IFE_ENCODE because
 517         * they cannot run as the same time. Check on all other values which
 518         * are not supported right now.
 519         */
 520        if (parm->flags & ~IFE_ENCODE)
 521                return -EINVAL;
 522
 523        p = kzalloc(sizeof(*p), GFP_KERNEL);
 524        if (!p)
 525                return -ENOMEM;
 526
 527        if (tb[TCA_IFE_METALST]) {
 528                err = nla_parse_nested_deprecated(tb2, IFE_META_MAX,
 529                                                  tb[TCA_IFE_METALST], NULL,
 530                                                  NULL);
 531                if (err) {
 532                        kfree(p);
 533                        return err;
 534                }
 535                err = load_metalist(tb2, rtnl_held);
 536                if (err) {
 537                        kfree(p);
 538                        return err;
 539                }
 540        }
 541
 542        index = parm->index;
 543        err = tcf_idr_check_alloc(tn, &index, a, bind);
 544        if (err < 0) {
 545                kfree(p);
 546                return err;
 547        }
 548        exists = err;
 549        if (exists && bind) {
 550                kfree(p);
 551                return 0;
 552        }
 553
 554        if (!exists) {
 555                ret = tcf_idr_create(tn, index, est, a, &act_ife_ops,
 556                                     bind, true, 0);
 557                if (ret) {
 558                        tcf_idr_cleanup(tn, index);
 559                        kfree(p);
 560                        return ret;
 561                }
 562                ret = ACT_P_CREATED;
 563        } else if (!ovr) {
 564                tcf_idr_release(*a, bind);
 565                kfree(p);
 566                return -EEXIST;
 567        }
 568
 569        ife = to_ife(*a);
 570        if (ret == ACT_P_CREATED)
 571                INIT_LIST_HEAD(&ife->metalist);
 572
 573        err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 574        if (err < 0)
 575                goto release_idr;
 576
 577        p->flags = parm->flags;
 578
 579        if (parm->flags & IFE_ENCODE) {
 580                if (tb[TCA_IFE_TYPE])
 581                        ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
 582                if (tb[TCA_IFE_DMAC])
 583                        daddr = nla_data(tb[TCA_IFE_DMAC]);
 584                if (tb[TCA_IFE_SMAC])
 585                        saddr = nla_data(tb[TCA_IFE_SMAC]);
 586        }
 587
 588        if (parm->flags & IFE_ENCODE) {
 589                if (daddr)
 590                        ether_addr_copy(p->eth_dst, daddr);
 591                else
 592                        eth_zero_addr(p->eth_dst);
 593
 594                if (saddr)
 595                        ether_addr_copy(p->eth_src, saddr);
 596                else
 597                        eth_zero_addr(p->eth_src);
 598
 599                p->eth_type = ife_type;
 600        }
 601
 602        if (tb[TCA_IFE_METALST]) {
 603                err = populate_metalist(ife, tb2, exists, rtnl_held);
 604                if (err)
 605                        goto metadata_parse_err;
 606        } else {
 607                /* if no passed metadata allow list or passed allow-all
 608                 * then here we process by adding as many supported metadatum
 609                 * as we can. You better have at least one else we are
 610                 * going to bail out
 611                 */
 612                err = use_all_metadata(ife, exists);
 613                if (err)
 614                        goto metadata_parse_err;
 615        }
 616
 617        if (exists)
 618                spin_lock_bh(&ife->tcf_lock);
 619        /* protected by tcf_lock when modifying existing action */
 620        goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 621        p = rcu_replace_pointer(ife->params, p, 1);
 622
 623        if (exists)
 624                spin_unlock_bh(&ife->tcf_lock);
 625        if (goto_ch)
 626                tcf_chain_put_by_act(goto_ch);
 627        if (p)
 628                kfree_rcu(p, rcu);
 629
 630        return ret;
 631metadata_parse_err:
 632        if (goto_ch)
 633                tcf_chain_put_by_act(goto_ch);
 634release_idr:
 635        kfree(p);
 636        tcf_idr_release(*a, bind);
 637        return err;
 638}
 639
 640static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 641                        int ref)
 642{
 643        unsigned char *b = skb_tail_pointer(skb);
 644        struct tcf_ife_info *ife = to_ife(a);
 645        struct tcf_ife_params *p;
 646        struct tc_ife opt = {
 647                .index = ife->tcf_index,
 648                .refcnt = refcount_read(&ife->tcf_refcnt) - ref,
 649                .bindcnt = atomic_read(&ife->tcf_bindcnt) - bind,
 650        };
 651        struct tcf_t t;
 652
 653        spin_lock_bh(&ife->tcf_lock);
 654        opt.action = ife->tcf_action;
 655        p = rcu_dereference_protected(ife->params,
 656                                      lockdep_is_held(&ife->tcf_lock));
 657        opt.flags = p->flags;
 658
 659        if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
 660                goto nla_put_failure;
 661
 662        tcf_tm_dump(&t, &ife->tcf_tm);
 663        if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
 664                goto nla_put_failure;
 665
 666        if (!is_zero_ether_addr(p->eth_dst)) {
 667                if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
 668                        goto nla_put_failure;
 669        }
 670
 671        if (!is_zero_ether_addr(p->eth_src)) {
 672                if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
 673                        goto nla_put_failure;
 674        }
 675
 676        if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
 677                goto nla_put_failure;
 678
 679        if (dump_metalist(skb, ife)) {
 680                /*ignore failure to dump metalist */
 681                pr_info("Failed to dump metalist\n");
 682        }
 683
 684        spin_unlock_bh(&ife->tcf_lock);
 685        return skb->len;
 686
 687nla_put_failure:
 688        spin_unlock_bh(&ife->tcf_lock);
 689        nlmsg_trim(skb, b);
 690        return -1;
 691}
 692
 693static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
 694                              u16 metaid, u16 mlen, void *mdata)
 695{
 696        struct tcf_meta_info *e;
 697
 698        /* XXX: use hash to speed up */
 699        list_for_each_entry(e, &ife->metalist, metalist) {
 700                if (metaid == e->metaid) {
 701                        if (e->ops) {
 702                                /* We check for decode presence already */
 703                                return e->ops->decode(skb, mdata, mlen);
 704                        }
 705                }
 706        }
 707
 708        return -ENOENT;
 709}
 710
 711static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
 712                          struct tcf_result *res)
 713{
 714        struct tcf_ife_info *ife = to_ife(a);
 715        int action = ife->tcf_action;
 716        u8 *ifehdr_end;
 717        u8 *tlv_data;
 718        u16 metalen;
 719
 720        bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 721        tcf_lastuse_update(&ife->tcf_tm);
 722
 723        if (skb_at_tc_ingress(skb))
 724                skb_push(skb, skb->dev->hard_header_len);
 725
 726        tlv_data = ife_decode(skb, &metalen);
 727        if (unlikely(!tlv_data)) {
 728                qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 729                return TC_ACT_SHOT;
 730        }
 731
 732        ifehdr_end = tlv_data + metalen;
 733        for (; tlv_data < ifehdr_end; tlv_data = ife_tlv_meta_next(tlv_data)) {
 734                u8 *curr_data;
 735                u16 mtype;
 736                u16 dlen;
 737
 738                curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,
 739                                                &dlen, NULL);
 740                if (!curr_data) {
 741                        qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 742                        return TC_ACT_SHOT;
 743                }
 744
 745                if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {
 746                        /* abuse overlimits to count when we receive metadata
 747                         * but dont have an ops for it
 748                         */
 749                        pr_info_ratelimited("Unknown metaid %d dlen %d\n",
 750                                            mtype, dlen);
 751                        qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 752                }
 753        }
 754
 755        if (WARN_ON(tlv_data != ifehdr_end)) {
 756                qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 757                return TC_ACT_SHOT;
 758        }
 759
 760        skb->protocol = eth_type_trans(skb, skb->dev);
 761        skb_reset_network_header(skb);
 762
 763        return action;
 764}
 765
 766/*XXX: check if we can do this at install time instead of current
 767 * send data path
 768**/
 769static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
 770{
 771        struct tcf_meta_info *e, *n;
 772        int tot_run_sz = 0, run_sz = 0;
 773
 774        list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 775                if (e->ops->check_presence) {
 776                        run_sz = e->ops->check_presence(skb, e);
 777                        tot_run_sz += run_sz;
 778                }
 779        }
 780
 781        return tot_run_sz;
 782}
 783
 784static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
 785                          struct tcf_result *res, struct tcf_ife_params *p)
 786{
 787        struct tcf_ife_info *ife = to_ife(a);
 788        int action = ife->tcf_action;
 789        struct ethhdr *oethh;   /* outer ether header */
 790        struct tcf_meta_info *e;
 791        /*
 792           OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
 793           where ORIGDATA = original ethernet header ...
 794         */
 795        u16 metalen = ife_get_sz(skb, ife);
 796        int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
 797        unsigned int skboff = 0;
 798        int new_len = skb->len + hdrm;
 799        bool exceed_mtu = false;
 800        void *ife_meta;
 801        int err = 0;
 802
 803        if (!skb_at_tc_ingress(skb)) {
 804                if (new_len > skb->dev->mtu)
 805                        exceed_mtu = true;
 806        }
 807
 808        bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 809        tcf_lastuse_update(&ife->tcf_tm);
 810
 811        if (!metalen) {         /* no metadata to send */
 812                /* abuse overlimits to count when we allow packet
 813                 * with no metadata
 814                 */
 815                qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 816                return action;
 817        }
 818        /* could be stupid policy setup or mtu config
 819         * so lets be conservative.. */
 820        if ((action == TC_ACT_SHOT) || exceed_mtu) {
 821                qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 822                return TC_ACT_SHOT;
 823        }
 824
 825        if (skb_at_tc_ingress(skb))
 826                skb_push(skb, skb->dev->hard_header_len);
 827
 828        ife_meta = ife_encode(skb, metalen);
 829
 830        spin_lock(&ife->tcf_lock);
 831
 832        /* XXX: we dont have a clever way of telling encode to
 833         * not repeat some of the computations that are done by
 834         * ops->presence_check...
 835         */
 836        list_for_each_entry(e, &ife->metalist, metalist) {
 837                if (e->ops->encode) {
 838                        err = e->ops->encode(skb, (void *)(ife_meta + skboff),
 839                                             e);
 840                }
 841                if (err < 0) {
 842                        /* too corrupt to keep around if overwritten */
 843                        spin_unlock(&ife->tcf_lock);
 844                        qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 845                        return TC_ACT_SHOT;
 846                }
 847                skboff += err;
 848        }
 849        spin_unlock(&ife->tcf_lock);
 850        oethh = (struct ethhdr *)skb->data;
 851
 852        if (!is_zero_ether_addr(p->eth_src))
 853                ether_addr_copy(oethh->h_source, p->eth_src);
 854        if (!is_zero_ether_addr(p->eth_dst))
 855                ether_addr_copy(oethh->h_dest, p->eth_dst);
 856        oethh->h_proto = htons(p->eth_type);
 857
 858        if (skb_at_tc_ingress(skb))
 859                skb_pull(skb, skb->dev->hard_header_len);
 860
 861        return action;
 862}
 863
 864static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
 865                       struct tcf_result *res)
 866{
 867        struct tcf_ife_info *ife = to_ife(a);
 868        struct tcf_ife_params *p;
 869        int ret;
 870
 871        p = rcu_dereference_bh(ife->params);
 872        if (p->flags & IFE_ENCODE) {
 873                ret = tcf_ife_encode(skb, a, res, p);
 874                return ret;
 875        }
 876
 877        return tcf_ife_decode(skb, a, res);
 878}
 879
 880static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
 881                          struct netlink_callback *cb, int type,
 882                          const struct tc_action_ops *ops,
 883                          struct netlink_ext_ack *extack)
 884{
 885        struct tc_action_net *tn = net_generic(net, ife_net_id);
 886
 887        return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 888}
 889
 890static int tcf_ife_search(struct net *net, struct tc_action **a, u32 index)
 891{
 892        struct tc_action_net *tn = net_generic(net, ife_net_id);
 893
 894        return tcf_idr_search(tn, a, index);
 895}
 896
 897static struct tc_action_ops act_ife_ops = {
 898        .kind = "ife",
 899        .id = TCA_ID_IFE,
 900        .owner = THIS_MODULE,
 901        .act = tcf_ife_act,
 902        .dump = tcf_ife_dump,
 903        .cleanup = tcf_ife_cleanup,
 904        .init = tcf_ife_init,
 905        .walk = tcf_ife_walker,
 906        .lookup = tcf_ife_search,
 907        .size = sizeof(struct tcf_ife_info),
 908};
 909
 910static __net_init int ife_init_net(struct net *net)
 911{
 912        struct tc_action_net *tn = net_generic(net, ife_net_id);
 913
 914        return tc_action_net_init(net, tn, &act_ife_ops);
 915}
 916
 917static void __net_exit ife_exit_net(struct list_head *net_list)
 918{
 919        tc_action_net_exit(net_list, ife_net_id);
 920}
 921
 922static struct pernet_operations ife_net_ops = {
 923        .init = ife_init_net,
 924        .exit_batch = ife_exit_net,
 925        .id   = &ife_net_id,
 926        .size = sizeof(struct tc_action_net),
 927};
 928
 929static int __init ife_init_module(void)
 930{
 931        return tcf_register_action(&act_ife_ops, &ife_net_ops);
 932}
 933
 934static void __exit ife_cleanup_module(void)
 935{
 936        tcf_unregister_action(&act_ife_ops, &ife_net_ops);
 937}
 938
 939module_init(ife_init_module);
 940module_exit(ife_cleanup_module);
 941
 942MODULE_AUTHOR("Jamal Hadi Salim(2015)");
 943MODULE_DESCRIPTION("Inter-FE LFB action");
 944MODULE_LICENSE("GPL");
 945