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