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 * under ife->tcf_lock for existing action
 269*/
 270static int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
 271                                void *val, int len, bool exists)
 272{
 273        struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 274        int ret = 0;
 275
 276        if (!ops) {
 277                ret = -ENOENT;
 278#ifdef CONFIG_MODULES
 279                if (exists)
 280                        spin_unlock_bh(&ife->tcf_lock);
 281                rtnl_unlock();
 282                request_module("ife-meta-%s", ife_meta_id2name(metaid));
 283                rtnl_lock();
 284                if (exists)
 285                        spin_lock_bh(&ife->tcf_lock);
 286                ops = find_ife_oplist(metaid);
 287#endif
 288        }
 289
 290        if (ops) {
 291                ret = 0;
 292                if (len)
 293                        ret = ife_validate_metatype(ops, val, len);
 294
 295                module_put(ops->owner);
 296        }
 297
 298        return ret;
 299}
 300
 301/* called when adding new meta information
 302 * under ife->tcf_lock for existing action
 303*/
 304static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
 305                        int len, bool atomic)
 306{
 307        struct tcf_meta_info *mi = NULL;
 308        struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 309        int ret = 0;
 310
 311        if (!ops)
 312                return -ENOENT;
 313
 314        mi = kzalloc(sizeof(*mi), atomic ? GFP_ATOMIC : GFP_KERNEL);
 315        if (!mi) {
 316                /*put back what find_ife_oplist took */
 317                module_put(ops->owner);
 318                return -ENOMEM;
 319        }
 320
 321        mi->metaid = metaid;
 322        mi->ops = ops;
 323        if (len > 0) {
 324                ret = ops->alloc(mi, metaval, atomic ? GFP_ATOMIC : GFP_KERNEL);
 325                if (ret != 0) {
 326                        kfree(mi);
 327                        module_put(ops->owner);
 328                        return ret;
 329                }
 330        }
 331
 332        list_add_tail(&mi->metalist, &ife->metalist);
 333
 334        return ret;
 335}
 336
 337static int use_all_metadata(struct tcf_ife_info *ife)
 338{
 339        struct tcf_meta_ops *o;
 340        int rc = 0;
 341        int installed = 0;
 342
 343        read_lock(&ife_mod_lock);
 344        list_for_each_entry(o, &ifeoplist, list) {
 345                rc = add_metainfo(ife, o->metaid, NULL, 0, true);
 346                if (rc == 0)
 347                        installed += 1;
 348        }
 349        read_unlock(&ife_mod_lock);
 350
 351        if (installed)
 352                return 0;
 353        else
 354                return -EINVAL;
 355}
 356
 357static int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
 358{
 359        struct tcf_meta_info *e;
 360        struct nlattr *nest;
 361        unsigned char *b = skb_tail_pointer(skb);
 362        int total_encoded = 0;
 363
 364        /*can only happen on decode */
 365        if (list_empty(&ife->metalist))
 366                return 0;
 367
 368        nest = nla_nest_start(skb, TCA_IFE_METALST);
 369        if (!nest)
 370                goto out_nlmsg_trim;
 371
 372        list_for_each_entry(e, &ife->metalist, metalist) {
 373                if (!e->ops->get(skb, e))
 374                        total_encoded += 1;
 375        }
 376
 377        if (!total_encoded)
 378                goto out_nlmsg_trim;
 379
 380        nla_nest_end(skb, nest);
 381
 382        return 0;
 383
 384out_nlmsg_trim:
 385        nlmsg_trim(skb, b);
 386        return -1;
 387}
 388
 389/* under ife->tcf_lock */
 390static void _tcf_ife_cleanup(struct tc_action *a)
 391{
 392        struct tcf_ife_info *ife = to_ife(a);
 393        struct tcf_meta_info *e, *n;
 394
 395        list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 396                module_put(e->ops->owner);
 397                list_del(&e->metalist);
 398                if (e->metaval) {
 399                        if (e->ops->release)
 400                                e->ops->release(e);
 401                        else
 402                                kfree(e->metaval);
 403                }
 404                kfree(e);
 405        }
 406}
 407
 408static void tcf_ife_cleanup(struct tc_action *a)
 409{
 410        struct tcf_ife_info *ife = to_ife(a);
 411        struct tcf_ife_params *p;
 412
 413        spin_lock_bh(&ife->tcf_lock);
 414        _tcf_ife_cleanup(a);
 415        spin_unlock_bh(&ife->tcf_lock);
 416
 417        p = rcu_dereference_protected(ife->params, 1);
 418        kfree_rcu(p, rcu);
 419}
 420
 421/* under ife->tcf_lock for existing action */
 422static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
 423                             bool exists)
 424{
 425        int len = 0;
 426        int rc = 0;
 427        int i = 0;
 428        void *val;
 429
 430        for (i = 1; i < max_metacnt; i++) {
 431                if (tb[i]) {
 432                        val = nla_data(tb[i]);
 433                        len = nla_len(tb[i]);
 434
 435                        rc = load_metaops_and_vet(ife, i, val, len, exists);
 436                        if (rc != 0)
 437                                return rc;
 438
 439                        rc = add_metainfo(ife, i, val, len, exists);
 440                        if (rc)
 441                                return rc;
 442                }
 443        }
 444
 445        return rc;
 446}
 447
 448static int tcf_ife_init(struct net *net, struct nlattr *nla,
 449                        struct nlattr *est, struct tc_action **a,
 450                        int ovr, int bind, struct netlink_ext_ack *extack)
 451{
 452        struct tc_action_net *tn = net_generic(net, ife_net_id);
 453        struct nlattr *tb[TCA_IFE_MAX + 1];
 454        struct nlattr *tb2[IFE_META_MAX + 1];
 455        struct tcf_ife_params *p, *p_old;
 456        struct tcf_ife_info *ife;
 457        u16 ife_type = ETH_P_IFE;
 458        struct tc_ife *parm;
 459        u8 *daddr = NULL;
 460        u8 *saddr = NULL;
 461        bool exists = false;
 462        int ret = 0;
 463        int err;
 464
 465        err = nla_parse_nested(tb, TCA_IFE_MAX, nla, ife_policy, NULL);
 466        if (err < 0)
 467                return err;
 468
 469        if (!tb[TCA_IFE_PARMS])
 470                return -EINVAL;
 471
 472        parm = nla_data(tb[TCA_IFE_PARMS]);
 473
 474        /* IFE_DECODE is 0 and indicates the opposite of IFE_ENCODE because
 475         * they cannot run as the same time. Check on all other values which
 476         * are not supported right now.
 477         */
 478        if (parm->flags & ~IFE_ENCODE)
 479                return -EINVAL;
 480
 481        p = kzalloc(sizeof(*p), GFP_KERNEL);
 482        if (!p)
 483                return -ENOMEM;
 484
 485        exists = tcf_idr_check(tn, parm->index, a, bind);
 486        if (exists && bind) {
 487                kfree(p);
 488                return 0;
 489        }
 490
 491        if (!exists) {
 492                ret = tcf_idr_create(tn, parm->index, est, a, &act_ife_ops,
 493                                     bind, true);
 494                if (ret) {
 495                        kfree(p);
 496                        return ret;
 497                }
 498                ret = ACT_P_CREATED;
 499        } else {
 500                tcf_idr_release(*a, bind);
 501                if (!ovr) {
 502                        kfree(p);
 503                        return -EEXIST;
 504                }
 505        }
 506
 507        ife = to_ife(*a);
 508        p->flags = parm->flags;
 509
 510        if (parm->flags & IFE_ENCODE) {
 511                if (tb[TCA_IFE_TYPE])
 512                        ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
 513                if (tb[TCA_IFE_DMAC])
 514                        daddr = nla_data(tb[TCA_IFE_DMAC]);
 515                if (tb[TCA_IFE_SMAC])
 516                        saddr = nla_data(tb[TCA_IFE_SMAC]);
 517        }
 518
 519        ife->tcf_action = parm->action;
 520
 521        if (parm->flags & IFE_ENCODE) {
 522                if (daddr)
 523                        ether_addr_copy(p->eth_dst, daddr);
 524                else
 525                        eth_zero_addr(p->eth_dst);
 526
 527                if (saddr)
 528                        ether_addr_copy(p->eth_src, saddr);
 529                else
 530                        eth_zero_addr(p->eth_src);
 531
 532                p->eth_type = ife_type;
 533        }
 534
 535        if (exists)
 536                spin_lock_bh(&ife->tcf_lock);
 537
 538        if (ret == ACT_P_CREATED)
 539                INIT_LIST_HEAD(&ife->metalist);
 540
 541        if (tb[TCA_IFE_METALST]) {
 542                err = nla_parse_nested(tb2, IFE_META_MAX, tb[TCA_IFE_METALST],
 543                                       NULL, NULL);
 544                if (err) {
 545metadata_parse_err:
 546                        if (exists)
 547                                tcf_idr_release(*a, bind);
 548                        if (ret == ACT_P_CREATED)
 549                                _tcf_ife_cleanup(*a);
 550
 551                        if (exists)
 552                                spin_unlock_bh(&ife->tcf_lock);
 553                        kfree(p);
 554                        return err;
 555                }
 556
 557                err = populate_metalist(ife, tb2, exists);
 558                if (err)
 559                        goto metadata_parse_err;
 560
 561        } else {
 562                /* if no passed metadata allow list or passed allow-all
 563                 * then here we process by adding as many supported metadatum
 564                 * as we can. You better have at least one else we are
 565                 * going to bail out
 566                 */
 567                err = use_all_metadata(ife);
 568                if (err) {
 569                        if (ret == ACT_P_CREATED)
 570                                _tcf_ife_cleanup(*a);
 571
 572                        if (exists)
 573                                spin_unlock_bh(&ife->tcf_lock);
 574                        kfree(p);
 575                        return err;
 576                }
 577        }
 578
 579        if (exists)
 580                spin_unlock_bh(&ife->tcf_lock);
 581
 582        p_old = rtnl_dereference(ife->params);
 583        rcu_assign_pointer(ife->params, p);
 584        if (p_old)
 585                kfree_rcu(p_old, rcu);
 586
 587        if (ret == ACT_P_CREATED)
 588                tcf_idr_insert(tn, *a);
 589
 590        return ret;
 591}
 592
 593static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 594                        int ref)
 595{
 596        unsigned char *b = skb_tail_pointer(skb);
 597        struct tcf_ife_info *ife = to_ife(a);
 598        struct tcf_ife_params *p = rtnl_dereference(ife->params);
 599        struct tc_ife opt = {
 600                .index = ife->tcf_index,
 601                .refcnt = ife->tcf_refcnt - ref,
 602                .bindcnt = ife->tcf_bindcnt - bind,
 603                .action = ife->tcf_action,
 604                .flags = p->flags,
 605        };
 606        struct tcf_t t;
 607
 608        if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
 609                goto nla_put_failure;
 610
 611        tcf_tm_dump(&t, &ife->tcf_tm);
 612        if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
 613                goto nla_put_failure;
 614
 615        if (!is_zero_ether_addr(p->eth_dst)) {
 616                if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
 617                        goto nla_put_failure;
 618        }
 619
 620        if (!is_zero_ether_addr(p->eth_src)) {
 621                if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
 622                        goto nla_put_failure;
 623        }
 624
 625        if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
 626                goto nla_put_failure;
 627
 628        if (dump_metalist(skb, ife)) {
 629                /*ignore failure to dump metalist */
 630                pr_info("Failed to dump metalist\n");
 631        }
 632
 633        return skb->len;
 634
 635nla_put_failure:
 636        nlmsg_trim(skb, b);
 637        return -1;
 638}
 639
 640static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
 641                              u16 metaid, u16 mlen, void *mdata)
 642{
 643        struct tcf_meta_info *e;
 644
 645        /* XXX: use hash to speed up */
 646        list_for_each_entry(e, &ife->metalist, metalist) {
 647                if (metaid == e->metaid) {
 648                        if (e->ops) {
 649                                /* We check for decode presence already */
 650                                return e->ops->decode(skb, mdata, mlen);
 651                        }
 652                }
 653        }
 654
 655        return -ENOENT;
 656}
 657
 658static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
 659                          struct tcf_result *res)
 660{
 661        struct tcf_ife_info *ife = to_ife(a);
 662        int action = ife->tcf_action;
 663        u8 *ifehdr_end;
 664        u8 *tlv_data;
 665        u16 metalen;
 666
 667        bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 668        tcf_lastuse_update(&ife->tcf_tm);
 669
 670        if (skb_at_tc_ingress(skb))
 671                skb_push(skb, skb->dev->hard_header_len);
 672
 673        tlv_data = ife_decode(skb, &metalen);
 674        if (unlikely(!tlv_data)) {
 675                qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 676                return TC_ACT_SHOT;
 677        }
 678
 679        ifehdr_end = tlv_data + metalen;
 680        for (; tlv_data < ifehdr_end; tlv_data = ife_tlv_meta_next(tlv_data)) {
 681                u8 *curr_data;
 682                u16 mtype;
 683                u16 dlen;
 684
 685                curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,
 686                                                &dlen, NULL);
 687                if (!curr_data) {
 688                        qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 689                        return TC_ACT_SHOT;
 690                }
 691
 692                if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {
 693                        /* abuse overlimits to count when we receive metadata
 694                         * but dont have an ops for it
 695                         */
 696                        pr_info_ratelimited("Unknown metaid %d dlen %d\n",
 697                                            mtype, dlen);
 698                        qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 699                }
 700        }
 701
 702        if (WARN_ON(tlv_data != ifehdr_end)) {
 703                qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 704                return TC_ACT_SHOT;
 705        }
 706
 707        skb->protocol = eth_type_trans(skb, skb->dev);
 708        skb_reset_network_header(skb);
 709
 710        return action;
 711}
 712
 713/*XXX: check if we can do this at install time instead of current
 714 * send data path
 715**/
 716static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
 717{
 718        struct tcf_meta_info *e, *n;
 719        int tot_run_sz = 0, run_sz = 0;
 720
 721        list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 722                if (e->ops->check_presence) {
 723                        run_sz = e->ops->check_presence(skb, e);
 724                        tot_run_sz += run_sz;
 725                }
 726        }
 727
 728        return tot_run_sz;
 729}
 730
 731static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
 732                          struct tcf_result *res, struct tcf_ife_params *p)
 733{
 734        struct tcf_ife_info *ife = to_ife(a);
 735        int action = ife->tcf_action;
 736        struct ethhdr *oethh;   /* outer ether header */
 737        struct tcf_meta_info *e;
 738        /*
 739           OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
 740           where ORIGDATA = original ethernet header ...
 741         */
 742        u16 metalen = ife_get_sz(skb, ife);
 743        int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
 744        unsigned int skboff = 0;
 745        int new_len = skb->len + hdrm;
 746        bool exceed_mtu = false;
 747        void *ife_meta;
 748        int err = 0;
 749
 750        if (!skb_at_tc_ingress(skb)) {
 751                if (new_len > skb->dev->mtu)
 752                        exceed_mtu = true;
 753        }
 754
 755        bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 756        tcf_lastuse_update(&ife->tcf_tm);
 757
 758        if (!metalen) {         /* no metadata to send */
 759                /* abuse overlimits to count when we allow packet
 760                 * with no metadata
 761                 */
 762                qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 763                return action;
 764        }
 765        /* could be stupid policy setup or mtu config
 766         * so lets be conservative.. */
 767        if ((action == TC_ACT_SHOT) || exceed_mtu) {
 768                qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 769                return TC_ACT_SHOT;
 770        }
 771
 772        if (skb_at_tc_ingress(skb))
 773                skb_push(skb, skb->dev->hard_header_len);
 774
 775        ife_meta = ife_encode(skb, metalen);
 776
 777        spin_lock(&ife->tcf_lock);
 778
 779        /* XXX: we dont have a clever way of telling encode to
 780         * not repeat some of the computations that are done by
 781         * ops->presence_check...
 782         */
 783        list_for_each_entry(e, &ife->metalist, metalist) {
 784                if (e->ops->encode) {
 785                        err = e->ops->encode(skb, (void *)(ife_meta + skboff),
 786                                             e);
 787                }
 788                if (err < 0) {
 789                        /* too corrupt to keep around if overwritten */
 790                        spin_unlock(&ife->tcf_lock);
 791                        qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 792                        return TC_ACT_SHOT;
 793                }
 794                skboff += err;
 795        }
 796        spin_unlock(&ife->tcf_lock);
 797        oethh = (struct ethhdr *)skb->data;
 798
 799        if (!is_zero_ether_addr(p->eth_src))
 800                ether_addr_copy(oethh->h_source, p->eth_src);
 801        if (!is_zero_ether_addr(p->eth_dst))
 802                ether_addr_copy(oethh->h_dest, p->eth_dst);
 803        oethh->h_proto = htons(p->eth_type);
 804
 805        if (skb_at_tc_ingress(skb))
 806                skb_pull(skb, skb->dev->hard_header_len);
 807
 808        return action;
 809}
 810
 811static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
 812                       struct tcf_result *res)
 813{
 814        struct tcf_ife_info *ife = to_ife(a);
 815        struct tcf_ife_params *p;
 816        int ret;
 817
 818        rcu_read_lock();
 819        p = rcu_dereference(ife->params);
 820        if (p->flags & IFE_ENCODE) {
 821                ret = tcf_ife_encode(skb, a, res, p);
 822                rcu_read_unlock();
 823                return ret;
 824        }
 825        rcu_read_unlock();
 826
 827        return tcf_ife_decode(skb, a, res);
 828}
 829
 830static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
 831                          struct netlink_callback *cb, int type,
 832                          const struct tc_action_ops *ops,
 833                          struct netlink_ext_ack *extack)
 834{
 835        struct tc_action_net *tn = net_generic(net, ife_net_id);
 836
 837        return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 838}
 839
 840static int tcf_ife_search(struct net *net, struct tc_action **a, u32 index,
 841                          struct netlink_ext_ack *extack)
 842{
 843        struct tc_action_net *tn = net_generic(net, ife_net_id);
 844
 845        return tcf_idr_search(tn, a, index);
 846}
 847
 848static struct tc_action_ops act_ife_ops = {
 849        .kind = "ife",
 850        .type = TCA_ACT_IFE,
 851        .owner = THIS_MODULE,
 852        .act = tcf_ife_act,
 853        .dump = tcf_ife_dump,
 854        .cleanup = tcf_ife_cleanup,
 855        .init = tcf_ife_init,
 856        .walk = tcf_ife_walker,
 857        .lookup = tcf_ife_search,
 858        .size = sizeof(struct tcf_ife_info),
 859};
 860
 861static __net_init int ife_init_net(struct net *net)
 862{
 863        struct tc_action_net *tn = net_generic(net, ife_net_id);
 864
 865        return tc_action_net_init(tn, &act_ife_ops);
 866}
 867
 868static void __net_exit ife_exit_net(struct list_head *net_list)
 869{
 870        tc_action_net_exit(net_list, ife_net_id);
 871}
 872
 873static struct pernet_operations ife_net_ops = {
 874        .init = ife_init_net,
 875        .exit_batch = ife_exit_net,
 876        .id   = &ife_net_id,
 877        .size = sizeof(struct tc_action_net),
 878};
 879
 880static int __init ife_init_module(void)
 881{
 882        return tcf_register_action(&act_ife_ops, &ife_net_ops);
 883}
 884
 885static void __exit ife_cleanup_module(void)
 886{
 887        tcf_unregister_action(&act_ife_ops, &ife_net_ops);
 888}
 889
 890module_init(ife_init_module);
 891module_exit(ife_cleanup_module);
 892
 893MODULE_AUTHOR("Jamal Hadi Salim(2015)");
 894MODULE_DESCRIPTION("Inter-FE LFB action");
 895MODULE_LICENSE("GPL");
 896