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