net/sched/act_ife.c

   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
  37 static unsigned int ife_net_id;
  38 static int max_metacnt = IFE_META_MAX + 1;
  39 static struct tc_action_ops act_ife_ops;
  40
  41 static 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
  48 int 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 }
  63 EXPORT_SYMBOL_GPL(ife_encode_meta_u16);
  64
  65 int 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 }
  72 EXPORT_SYMBOL_GPL(ife_get_meta_u32);
  73
  74 int 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 }
  81 EXPORT_SYMBOL_GPL(ife_check_meta_u32);
  82
  83 int 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 }
  90 EXPORT_SYMBOL_GPL(ife_check_meta_u16);
  91
  92 int 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 }
 107 EXPORT_SYMBOL_GPL(ife_encode_meta_u32);
 108
 109 int 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 }
 116 EXPORT_SYMBOL_GPL(ife_get_meta_u16);
 117
 118 int 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 }
 126 EXPORT_SYMBOL_GPL(ife_alloc_meta_u32);
 127
 128 int 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 }
 136 EXPORT_SYMBOL_GPL(ife_alloc_meta_u16);
 137
 138 void ife_release_meta_gen(struct tcf_meta_info *mi)
 139 {
 140         kfree(mi->metaval);
 141 }
 142 EXPORT_SYMBOL_GPL(ife_release_meta_gen);
 143
 144 int ife_validate_meta_u32(void *val, int len)
 145 {
 146         if (len == sizeof(u32))
 147                 return 0;
 148
 149         return -EINVAL;
 150 }
 151 EXPORT_SYMBOL_GPL(ife_validate_meta_u32);
 152
 153 int 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 }
 161 EXPORT_SYMBOL_GPL(ife_validate_meta_u16);
 162
 163 static LIST_HEAD(ifeoplist);
 164 static DEFINE_RWLOCK(ife_mod_lock);
 165
 166 static struct tcf_meta_ops *find_ife_oplist(u16 metaid)
 167 {
 168         struct tcf_meta_ops *o;
 169
 170         read_lock_bh(&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_bh(&ife_mod_lock);
 176                         return o;
 177                 }
 178         }
 179         read_unlock_bh(&ife_mod_lock);
 180
 181         return NULL;
 182 }
 183
 184 int 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_bh(&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_bh(&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_bh(&ife_mod_lock);
 208         return 0;
 209 }
 210 EXPORT_SYMBOL_GPL(unregister_ife_op);
 211
 212 int unregister_ife_op(struct tcf_meta_ops *mops)
 213 {
 214         struct tcf_meta_ops *m;
 215         int err = -ENOENT;
 216
 217         write_lock_bh(&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_bh(&ife_mod_lock);
 226
 227         return err;
 228 }
 229 EXPORT_SYMBOL_GPL(register_ife_op);
 230
 231 static 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
 252 static 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 */
 270 static int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
 271                                 void *val, int len, bool exists,
 272                                 bool rtnl_held)
 273 {
 274         struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 275         int ret = 0;
 276
 277         if (!ops) {
 278                 ret = -ENOENT;
 279 #ifdef CONFIG_MODULES
 280                 if (exists)
 281                         spin_unlock_bh(&ife->tcf_lock);
 282                 if (rtnl_held)
 283                         rtnl_unlock();
 284                 request_module("ife-meta-%s", ife_meta_id2name(metaid));
 285                 if (rtnl_held)
 286                         rtnl_lock();
 287                 if (exists)
 288                         spin_lock_bh(&ife->tcf_lock);
 289                 ops = find_ife_oplist(metaid);
 290 #endif
 291         }
 292
 293         if (ops) {
 294                 ret = 0;
 295                 if (len)
 296                         ret = ife_validate_metatype(ops, val, len);
 297
 298                 module_put(ops->owner);
 299         }
 300
 301         return ret;
 302 }
 303
 304 /* called when adding new meta information
 305  * under ife->tcf_lock for existing action
 306 */
 307 static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
 308                         int len, bool atomic)
 309 {
 310         struct tcf_meta_info *mi = NULL;
 311         struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 312         int ret = 0;
 313
 314         if (!ops)
 315                 return -ENOENT;
 316
 317         mi = kzalloc(sizeof(*mi), atomic ? GFP_ATOMIC : GFP_KERNEL);
 318         if (!mi) {
 319                 /*put back what find_ife_oplist took */
 320                 module_put(ops->owner);
 321                 return -ENOMEM;
 322         }
 323
 324         mi->metaid = metaid;
 325         mi->ops = ops;
 326         if (len > 0) {
 327                 ret = ops->alloc(mi, metaval, atomic ? GFP_ATOMIC : GFP_KERNEL);
 328                 if (ret != 0) {
 329                         kfree(mi);
 330                         module_put(ops->owner);
 331                         return ret;
 332                 }
 333         }
 334
 335         list_add_tail(&mi->metalist, &ife->metalist);
 336
 337         return ret;
 338 }
 339
 340 static int use_all_metadata(struct tcf_ife_info *ife)
 341 {
 342         struct tcf_meta_ops *o;
 343         int rc = 0;
 344         int installed = 0;
 345
 346         read_lock_bh(&ife_mod_lock);
 347         list_for_each_entry(o, &ifeoplist, list) {
 348                 rc = add_metainfo(ife, o->metaid, NULL, 0, true);
 349                 if (rc == 0)
 350                         installed += 1;
 351         }
 352         read_unlock_bh(&ife_mod_lock);
 353
 354         if (installed)
 355                 return 0;
 356         else
 357                 return -EINVAL;
 358 }
 359
 360 static int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
 361 {
 362         struct tcf_meta_info *e;
 363         struct nlattr *nest;
 364         unsigned char *b = skb_tail_pointer(skb);
 365         int total_encoded = 0;
 366
 367         /*can only happen on decode */
 368         if (list_empty(&ife->metalist))
 369                 return 0;
 370
 371         nest = nla_nest_start(skb, TCA_IFE_METALST);
 372         if (!nest)
 373                 goto out_nlmsg_trim;
 374
 375         list_for_each_entry(e, &ife->metalist, metalist) {
 376                 if (!e->ops->get(skb, e))
 377                         total_encoded += 1;
 378         }
 379
 380         if (!total_encoded)
 381                 goto out_nlmsg_trim;
 382
 383         nla_nest_end(skb, nest);
 384
 385         return 0;
 386
 387 out_nlmsg_trim:
 388         nlmsg_trim(skb, b);
 389         return -1;
 390 }
 391
 392 /* under ife->tcf_lock */
 393 static void _tcf_ife_cleanup(struct tc_action *a)
 394 {
 395         struct tcf_ife_info *ife = to_ife(a);
 396         struct tcf_meta_info *e, *n;
 397
 398         list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 399                 module_put(e->ops->owner);
 400                 list_del(&e->metalist);
 401                 if (e->metaval) {
 402                         if (e->ops->release)
 403                                 e->ops->release(e);
 404                         else
 405                                 kfree(e->metaval);
 406                 }
 407                 kfree(e);
 408         }
 409 }
 410
 411 static void tcf_ife_cleanup(struct tc_action *a)
 412 {
 413         struct tcf_ife_info *ife = to_ife(a);
 414         struct tcf_ife_params *p;
 415
 416         spin_lock_bh(&ife->tcf_lock);
 417         _tcf_ife_cleanup(a);
 418         spin_unlock_bh(&ife->tcf_lock);
 419
 420         p = rcu_dereference_protected(ife->params, 1);
 421         if (p)
 422                 kfree_rcu(p, rcu);
 423 }
 424
 425 /* under ife->tcf_lock for existing action */
 426 static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
 427                              bool exists, bool rtnl_held)
 428 {
 429         int len = 0;
 430         int rc = 0;
 431         int i = 0;
 432         void *val;
 433
 434         for (i = 1; i < max_metacnt; i++) {
 435                 if (tb[i]) {
 436                         val = nla_data(tb[i]);
 437                         len = nla_len(tb[i]);
 438
 439                         rc = load_metaops_and_vet(ife, i, val, len, exists,
 440                                                   rtnl_held);
 441                         if (rc != 0)
 442                                 return rc;
 443
 444                         rc = add_metainfo(ife, i, val, len, exists);
 445                         if (rc)
 446                                 return rc;
 447                 }
 448         }
 449
 450         return rc;
 451 }
 452
 453 static int tcf_ife_init(struct net *net, struct nlattr *nla,
 454                         struct nlattr *est, struct tc_action **a,
 455                         int ovr, int bind, bool rtnl_held,
 456                         struct netlink_ext_ack *extack)
 457 {
 458         struct tc_action_net *tn = net_generic(net, ife_net_id);
 459         struct nlattr *tb[TCA_IFE_MAX + 1];
 460         struct nlattr *tb2[IFE_META_MAX + 1];
 461         struct tcf_ife_params *p;
 462         struct tcf_ife_info *ife;
 463         u16 ife_type = ETH_P_IFE;
 464         struct tc_ife *parm;
 465         u8 *daddr = NULL;
 466         u8 *saddr = NULL;
 467         bool exists = false;
 468         int ret = 0;
 469         int err;
 470
 471         err = nla_parse_nested(tb, TCA_IFE_MAX, nla, ife_policy, NULL);
 472         if (err < 0)
 473                 return err;
 474
 475         if (!tb[TCA_IFE_PARMS])
 476                 return -EINVAL;
 477
 478         parm = nla_data(tb[TCA_IFE_PARMS]);
 479
 480         /* IFE_DECODE is 0 and indicates the opposite of IFE_ENCODE because
 481          * they cannot run as the same time. Check on all other values which
 482          * are not supported right now.
 483          */
 484         if (parm->flags & ~IFE_ENCODE)
 485                 return -EINVAL;
 486
 487         p = kzalloc(sizeof(*p), GFP_KERNEL);
 488         if (!p)
 489                 return -ENOMEM;
 490
 491         err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
 492         if (err < 0) {
 493                 kfree(p);
 494                 return err;
 495         }
 496         exists = err;
 497         if (exists && bind) {
 498                 kfree(p);
 499                 return 0;
 500         }
 501
 502         if (!exists) {
 503                 ret = tcf_idr_create(tn, parm->index, est, a, &act_ife_ops,
 504                                      bind, true);
 505                 if (ret) {
 506                         tcf_idr_cleanup(tn, parm->index);
 507                         kfree(p);
 508                         return ret;
 509                 }
 510                 ret = ACT_P_CREATED;
 511         } else if (!ovr) {
 512                 tcf_idr_release(*a, bind);
 513                 kfree(p);
 514                 return -EEXIST;
 515         }
 516
 517         ife = to_ife(*a);
 518         p->flags = parm->flags;
 519
 520         if (parm->flags & IFE_ENCODE) {
 521                 if (tb[TCA_IFE_TYPE])
 522                         ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
 523                 if (tb[TCA_IFE_DMAC])
 524                         daddr = nla_data(tb[TCA_IFE_DMAC]);
 525                 if (tb[TCA_IFE_SMAC])
 526                         saddr = nla_data(tb[TCA_IFE_SMAC]);
 527         }
 528
 529         if (parm->flags & IFE_ENCODE) {
 530                 if (daddr)
 531                         ether_addr_copy(p->eth_dst, daddr);
 532                 else
 533                         eth_zero_addr(p->eth_dst);
 534
 535                 if (saddr)
 536                         ether_addr_copy(p->eth_src, saddr);
 537                 else
 538                         eth_zero_addr(p->eth_src);
 539
 540                 p->eth_type = ife_type;
 541         }
 542
 543         if (exists)
 544                 spin_lock_bh(&ife->tcf_lock);
 545
 546         if (ret == ACT_P_CREATED)
 547                 INIT_LIST_HEAD(&ife->metalist);
 548
 549         if (tb[TCA_IFE_METALST]) {
 550                 err = nla_parse_nested(tb2, IFE_META_MAX, tb[TCA_IFE_METALST],
 551                                        NULL, NULL);
 552                 if (err) {
 553 metadata_parse_err:
 554                         if (exists)
 555                                 spin_unlock_bh(&ife->tcf_lock);
 556                         tcf_idr_release(*a, bind);
 557
 558                         kfree(p);
 559                         return err;
 560                 }
 561
 562                 err = populate_metalist(ife, tb2, exists, rtnl_held);
 563                 if (err)
 564                         goto metadata_parse_err;
 565
 566         } else {
 567                 /* if no passed metadata allow list or passed allow-all
 568                  * then here we process by adding as many supported metadatum
 569                  * as we can. You better have at least one else we are
 570                  * going to bail out
 571                  */
 572                 err = use_all_metadata(ife);
 573                 if (err) {
 574                         if (exists)
 575                                 spin_unlock_bh(&ife->tcf_lock);
 576                         tcf_idr_release(*a, bind);
 577
 578                         kfree(p);
 579                         return err;
 580                 }
 581         }
 582
 583         ife->tcf_action = parm->action;
 584         /* protected by tcf_lock when modifying existing action */
 585         rcu_swap_protected(ife->params, p, 1);
 586
 587         if (exists)
 588                 spin_unlock_bh(&ife->tcf_lock);
 589         if (p)
 590                 kfree_rcu(p, rcu);
 591
 592         if (ret == ACT_P_CREATED)
 593                 tcf_idr_insert(tn, *a);
 594
 595         return ret;
 596 }
 597
 598 static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 599                         int ref)
 600 {
 601         unsigned char *b = skb_tail_pointer(skb);
 602         struct tcf_ife_info *ife = to_ife(a);
 603         struct tcf_ife_params *p;
 604         struct tc_ife opt = {
 605                 .index = ife->tcf_index,
 606                 .refcnt = refcount_read(&ife->tcf_refcnt) - ref,
 607                 .bindcnt = atomic_read(&ife->tcf_bindcnt) - bind,
 608         };
 609         struct tcf_t t;
 610
 611         spin_lock_bh(&ife->tcf_lock);
 612         opt.action = ife->tcf_action;
 613         p = rcu_dereference_protected(ife->params,
 614                                       lockdep_is_held(&ife->tcf_lock));
 615         opt.flags = p->flags;
 616
 617         if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
 618                 goto nla_put_failure;
 619
 620         tcf_tm_dump(&t, &ife->tcf_tm);
 621         if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
 622                 goto nla_put_failure;
 623
 624         if (!is_zero_ether_addr(p->eth_dst)) {
 625                 if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
 626                         goto nla_put_failure;
 627         }
 628
 629         if (!is_zero_ether_addr(p->eth_src)) {
 630                 if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
 631                         goto nla_put_failure;
 632         }
 633
 634         if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
 635                 goto nla_put_failure;
 636
 637         if (dump_metalist(skb, ife)) {
 638                 /*ignore failure to dump metalist */
 639                 pr_info("Failed to dump metalist\n");
 640         }
 641
 642         spin_unlock_bh(&ife->tcf_lock);
 643         return skb->len;
 644
 645 nla_put_failure:
 646         spin_unlock_bh(&ife->tcf_lock);
 647         nlmsg_trim(skb, b);
 648         return -1;
 649 }
 650
 651 static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
 652                               u16 metaid, u16 mlen, void *mdata)
 653 {
 654         struct tcf_meta_info *e;
 655
 656         /* XXX: use hash to speed up */
 657         list_for_each_entry(e, &ife->metalist, metalist) {
 658                 if (metaid == e->metaid) {
 659                         if (e->ops) {
 660                                 /* We check for decode presence already */
 661                                 return e->ops->decode(skb, mdata, mlen);
 662                         }
 663                 }
 664         }
 665
 666         return -ENOENT;
 667 }
 668
 669 static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
 670                           struct tcf_result *res)
 671 {
 672         struct tcf_ife_info *ife = to_ife(a);
 673         int action = ife->tcf_action;
 674         u8 *ifehdr_end;
 675         u8 *tlv_data;
 676         u16 metalen;
 677
 678         bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 679         tcf_lastuse_update(&ife->tcf_tm);
 680
 681         if (skb_at_tc_ingress(skb))
 682                 skb_push(skb, skb->dev->hard_header_len);
 683
 684         tlv_data = ife_decode(skb, &metalen);
 685         if (unlikely(!tlv_data)) {
 686                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 687                 return TC_ACT_SHOT;
 688         }
 689
 690         ifehdr_end = tlv_data + metalen;
 691         for (; tlv_data < ifehdr_end; tlv_data = ife_tlv_meta_next(tlv_data)) {
 692                 u8 *curr_data;
 693                 u16 mtype;
 694                 u16 dlen;
 695
 696                 curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,
 697                                                 &dlen, NULL);
 698                 if (!curr_data) {
 699                         qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 700                         return TC_ACT_SHOT;
 701                 }
 702
 703                 if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {
 704                         /* abuse overlimits to count when we receive metadata
 705                          * but dont have an ops for it
 706                          */
 707                         pr_info_ratelimited("Unknown metaid %d dlen %d\n",
 708                                             mtype, dlen);
 709                         qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 710                 }
 711         }
 712
 713         if (WARN_ON(tlv_data != ifehdr_end)) {
 714                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 715                 return TC_ACT_SHOT;
 716         }
 717
 718         skb->protocol = eth_type_trans(skb, skb->dev);
 719         skb_reset_network_header(skb);
 720
 721         return action;
 722 }
 723
 724 /*XXX: check if we can do this at install time instead of current
 725  * send data path
 726 **/
 727 static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
 728 {
 729         struct tcf_meta_info *e, *n;
 730         int tot_run_sz = 0, run_sz = 0;
 731
 732         list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 733                 if (e->ops->check_presence) {
 734                         run_sz = e->ops->check_presence(skb, e);
 735                         tot_run_sz += run_sz;
 736                 }
 737         }
 738
 739         return tot_run_sz;
 740 }
 741
 742 static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
 743                           struct tcf_result *res, struct tcf_ife_params *p)
 744 {
 745         struct tcf_ife_info *ife = to_ife(a);
 746         int action = ife->tcf_action;
 747         struct ethhdr *oethh;   /* outer ether header */
 748         struct tcf_meta_info *e;
 749         /*
 750            OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
 751            where ORIGDATA = original ethernet header ...
 752          */
 753         u16 metalen = ife_get_sz(skb, ife);
 754         int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
 755         unsigned int skboff = 0;
 756         int new_len = skb->len + hdrm;
 757         bool exceed_mtu = false;
 758         void *ife_meta;
 759         int err = 0;
 760
 761         if (!skb_at_tc_ingress(skb)) {
 762                 if (new_len > skb->dev->mtu)
 763                         exceed_mtu = true;
 764         }
 765
 766         bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 767         tcf_lastuse_update(&ife->tcf_tm);
 768
 769         if (!metalen) {         /* no metadata to send */
 770                 /* abuse overlimits to count when we allow packet
 771                  * with no metadata
 772                  */
 773                 qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 774                 return action;
 775         }
 776         /* could be stupid policy setup or mtu config
 777          * so lets be conservative.. */
 778         if ((action == TC_ACT_SHOT) || exceed_mtu) {
 779                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 780                 return TC_ACT_SHOT;
 781         }
 782
 783         if (skb_at_tc_ingress(skb))
 784                 skb_push(skb, skb->dev->hard_header_len);
 785
 786         ife_meta = ife_encode(skb, metalen);
 787
 788         spin_lock(&ife->tcf_lock);
 789
 790         /* XXX: we dont have a clever way of telling encode to
 791          * not repeat some of the computations that are done by
 792          * ops->presence_check...
 793          */
 794         list_for_each_entry(e, &ife->metalist, metalist) {
 795                 if (e->ops->encode) {
 796                         err = e->ops->encode(skb, (void *)(ife_meta + skboff),
 797                                              e);
 798                 }
 799                 if (err < 0) {
 800                         /* too corrupt to keep around if overwritten */
 801                         spin_unlock(&ife->tcf_lock);
 802                         qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 803                         return TC_ACT_SHOT;
 804                 }
 805                 skboff += err;
 806         }
 807         spin_unlock(&ife->tcf_lock);
 808         oethh = (struct ethhdr *)skb->data;
 809
 810         if (!is_zero_ether_addr(p->eth_src))
 811                 ether_addr_copy(oethh->h_source, p->eth_src);
 812         if (!is_zero_ether_addr(p->eth_dst))
 813                 ether_addr_copy(oethh->h_dest, p->eth_dst);
 814         oethh->h_proto = htons(p->eth_type);
 815
 816         if (skb_at_tc_ingress(skb))
 817                 skb_pull(skb, skb->dev->hard_header_len);
 818
 819         return action;
 820 }
 821
 822 static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
 823                        struct tcf_result *res)
 824 {
 825         struct tcf_ife_info *ife = to_ife(a);
 826         struct tcf_ife_params *p;
 827         int ret;
 828
 829         p = rcu_dereference_bh(ife->params);
 830         if (p->flags & IFE_ENCODE) {
 831                 ret = tcf_ife_encode(skb, a, res, p);
 832                 return ret;
 833         }
 834
 835         return tcf_ife_decode(skb, a, res);
 836 }
 837
 838 static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
 839                           struct netlink_callback *cb, int type,
 840                           const struct tc_action_ops *ops,
 841                           struct netlink_ext_ack *extack)
 842 {
 843         struct tc_action_net *tn = net_generic(net, ife_net_id);
 844
 845         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 846 }
 847
 848 static int tcf_ife_search(struct net *net, struct tc_action **a, u32 index,
 849                           struct netlink_ext_ack *extack)
 850 {
 851         struct tc_action_net *tn = net_generic(net, ife_net_id);
 852
 853         return tcf_idr_search(tn, a, index);
 854 }
 855
 856 static int tcf_ife_delete(struct net *net, u32 index)
 857 {
 858         struct tc_action_net *tn = net_generic(net, ife_net_id);
 859
 860         return tcf_idr_delete_index(tn, index);
 861 }
 862
 863 static struct tc_action_ops act_ife_ops = {
 864         .kind = "ife",
 865         .type = TCA_ACT_IFE,
 866         .owner = THIS_MODULE,
 867         .act = tcf_ife_act,
 868         .dump = tcf_ife_dump,
 869         .cleanup = tcf_ife_cleanup,
 870         .init = tcf_ife_init,
 871         .walk = tcf_ife_walker,
 872         .lookup = tcf_ife_search,
 873         .delete = tcf_ife_delete,
 874         .size = sizeof(struct tcf_ife_info),
 875 };
 876
 877 static __net_init int ife_init_net(struct net *net)
 878 {
 879         struct tc_action_net *tn = net_generic(net, ife_net_id);
 880
 881         return tc_action_net_init(tn, &act_ife_ops);
 882 }
 883
 884 static void __net_exit ife_exit_net(struct list_head *net_list)
 885 {
 886         tc_action_net_exit(net_list, ife_net_id);
 887 }
 888
 889 static struct pernet_operations ife_net_ops = {
 890         .init = ife_init_net,
 891         .exit_batch = ife_exit_net,
 892         .id   = &ife_net_id,
 893         .size = sizeof(struct tc_action_net),
 894 };
 895
 896 static int __init ife_init_module(void)
 897 {
 898         return tcf_register_action(&act_ife_ops, &ife_net_ops);
 899 }
 900
 901 static void __exit ife_cleanup_module(void)
 902 {
 903         tcf_unregister_action(&act_ife_ops, &ife_net_ops);
 904 }
 905
 906 module_init(ife_init_module);
 907 module_exit(ife_cleanup_module);
 908
 909 MODULE_AUTHOR("Jamal Hadi Salim(2015)");
 910 MODULE_DESCRIPTION("Inter-FE LFB action");
 911 MODULE_LICENSE("GPL");