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