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 /* called when adding new meta information
 252 */
 253 static int load_metaops_and_vet(u32 metaid, void *val, int len)
 254 {
 255         struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 256         int ret = 0;
 257
 258         if (!ops) {
 259                 ret = -ENOENT;
 260 #ifdef CONFIG_MODULES
 261                 rtnl_unlock();
 262                 request_module("ifemeta%u", metaid);
 263                 rtnl_lock();
 264                 ops = find_ife_oplist(metaid);
 265 #endif
 266         }
 267
 268         if (ops) {
 269                 ret = 0;
 270                 if (len)
 271                         ret = ife_validate_metatype(ops, val, len);
 272
 273                 module_put(ops->owner);
 274         }
 275
 276         return ret;
 277 }
 278
 279 /* called when adding new meta information
 280 */
 281 static int __add_metainfo(const struct tcf_meta_ops *ops,
 282                           struct tcf_ife_info *ife, u32 metaid, void *metaval,
 283                           int len, bool atomic, bool exists)
 284 {
 285         struct tcf_meta_info *mi = NULL;
 286         int ret = 0;
 287
 288         mi = kzalloc(sizeof(*mi), atomic ? GFP_ATOMIC : GFP_KERNEL);
 289         if (!mi)
 290                 return -ENOMEM;
 291
 292         mi->metaid = metaid;
 293         mi->ops = ops;
 294         if (len > 0) {
 295                 ret = ops->alloc(mi, metaval, atomic ? GFP_ATOMIC : GFP_KERNEL);
 296                 if (ret != 0) {
 297                         kfree(mi);
 298                         return ret;
 299                 }
 300         }
 301
 302         if (exists)
 303                 spin_lock_bh(&ife->tcf_lock);
 304         list_add_tail(&mi->metalist, &ife->metalist);
 305         if (exists)
 306                 spin_unlock_bh(&ife->tcf_lock);
 307
 308         return ret;
 309 }
 310
 311 static int add_metainfo_and_get_ops(const struct tcf_meta_ops *ops,
 312                                     struct tcf_ife_info *ife, u32 metaid,
 313                                     bool exists)
 314 {
 315         int ret;
 316
 317         if (!try_module_get(ops->owner))
 318                 return -ENOENT;
 319         ret = __add_metainfo(ops, ife, metaid, NULL, 0, true, exists);
 320         if (ret)
 321                 module_put(ops->owner);
 322         return ret;
 323 }
 324
 325 static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
 326                         int len, bool exists)
 327 {
 328         const struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 329         int ret;
 330
 331         if (!ops)
 332                 return -ENOENT;
 333         ret = __add_metainfo(ops, ife, metaid, metaval, len, false, exists);
 334         if (ret)
 335                 /*put back what find_ife_oplist took */
 336                 module_put(ops->owner);
 337         return ret;
 338 }
 339
 340 static int use_all_metadata(struct tcf_ife_info *ife, bool exists)
 341 {
 342         struct tcf_meta_ops *o;
 343         int rc = 0;
 344         int installed = 0;
 345
 346         read_lock(&ife_mod_lock);
 347         list_for_each_entry(o, &ifeoplist, list) {
 348                 rc = add_metainfo_and_get_ops(o, ife, o->metaid, exists);
 349                 if (rc == 0)
 350                         installed += 1;
 351         }
 352         read_unlock(&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, int bind)
 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                 list_del(&e->metalist);
 400                 if (e->metaval) {
 401                         if (e->ops->release)
 402                                 e->ops->release(e);
 403                         else
 404                                 kfree(e->metaval);
 405                 }
 406                 module_put(e->ops->owner);
 407                 kfree(e);
 408         }
 409 }
 410
 411 static void tcf_ife_cleanup(struct tc_action *a, int bind)
 412 {
 413         struct tcf_ife_info *ife = to_ife(a);
 414
 415         spin_lock_bh(&ife->tcf_lock);
 416         _tcf_ife_cleanup(a, bind);
 417         spin_unlock_bh(&ife->tcf_lock);
 418 }
 419
 420 static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
 421                              bool exists)
 422 {
 423         int len = 0;
 424         int rc = 0;
 425         int i = 0;
 426         void *val;
 427
 428         for (i = 1; i < max_metacnt; i++) {
 429                 if (tb[i]) {
 430                         val = nla_data(tb[i]);
 431                         len = nla_len(tb[i]);
 432
 433                         rc = load_metaops_and_vet(i, val, len);
 434                         if (rc != 0)
 435                                 return rc;
 436
 437                         rc = add_metainfo(ife, i, val, len, exists);
 438                         if (rc)
 439                                 return rc;
 440                 }
 441         }
 442
 443         return rc;
 444 }
 445
 446 static int tcf_ife_init(struct net *net, struct nlattr *nla,
 447                         struct nlattr *est, struct tc_action **a,
 448                         int ovr, int bind)
 449 {
 450         struct tc_action_net *tn = net_generic(net, ife_net_id);
 451         struct nlattr *tb[TCA_IFE_MAX + 1];
 452         struct nlattr *tb2[IFE_META_MAX + 1];
 453         struct tcf_ife_info *ife;
 454         u16 ife_type = ETH_P_IFE;
 455         struct tc_ife *parm;
 456         u8 *daddr = NULL;
 457         u8 *saddr = NULL;
 458         bool exists = false;
 459         int ret = 0;
 460         int err;
 461
 462         if (!nla)
 463                 return -EINVAL;
 464
 465         err = nla_parse_nested(tb, TCA_IFE_MAX, nla, ife_policy, NULL);
 466         if (err < 0)
 467                 return err;
 468
 469         if (!tb[TCA_IFE_PARMS])
 470                 return -EINVAL;
 471
 472         parm = nla_data(tb[TCA_IFE_PARMS]);
 473
 474         exists = tcf_idr_check(tn, parm->index, a, bind);
 475         if (exists && bind)
 476                 return 0;
 477
 478         if (!exists) {
 479                 ret = tcf_idr_create(tn, parm->index, est, a, &act_ife_ops,
 480                                      bind, false);
 481                 if (ret)
 482                         return ret;
 483                 ret = ACT_P_CREATED;
 484         } else {
 485                 tcf_idr_release(*a, bind);
 486                 if (!ovr)
 487                         return -EEXIST;
 488         }
 489
 490         ife = to_ife(*a);
 491         ife->flags = parm->flags;
 492
 493         if (parm->flags & IFE_ENCODE) {
 494                 if (tb[TCA_IFE_TYPE])
 495                         ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
 496                 if (tb[TCA_IFE_DMAC])
 497                         daddr = nla_data(tb[TCA_IFE_DMAC]);
 498                 if (tb[TCA_IFE_SMAC])
 499                         saddr = nla_data(tb[TCA_IFE_SMAC]);
 500         }
 501
 502         if (exists)
 503                 spin_lock_bh(&ife->tcf_lock);
 504         ife->tcf_action = parm->action;
 505         if (exists)
 506                 spin_unlock_bh(&ife->tcf_lock);
 507
 508         if (parm->flags & IFE_ENCODE) {
 509                 if (daddr)
 510                         ether_addr_copy(ife->eth_dst, daddr);
 511                 else
 512                         eth_zero_addr(ife->eth_dst);
 513
 514                 if (saddr)
 515                         ether_addr_copy(ife->eth_src, saddr);
 516                 else
 517                         eth_zero_addr(ife->eth_src);
 518
 519                 ife->eth_type = ife_type;
 520         }
 521
 522         if (ret == ACT_P_CREATED)
 523                 INIT_LIST_HEAD(&ife->metalist);
 524
 525         if (tb[TCA_IFE_METALST]) {
 526                 err = nla_parse_nested(tb2, IFE_META_MAX, tb[TCA_IFE_METALST],
 527                                        NULL, NULL);
 528                 if (err) {
 529 metadata_parse_err:
 530                         if (exists)
 531                                 tcf_idr_release(*a, bind);
 532                         if (ret == ACT_P_CREATED)
 533                                 _tcf_ife_cleanup(*a, bind);
 534                         return err;
 535                 }
 536
 537                 err = populate_metalist(ife, tb2, exists);
 538                 if (err)
 539                         goto metadata_parse_err;
 540
 541         } else {
 542                 /* if no passed metadata allow list or passed allow-all
 543                  * then here we process by adding as many supported metadatum
 544                  * as we can. You better have at least one else we are
 545                  * going to bail out
 546                  */
 547                 err = use_all_metadata(ife, exists);
 548                 if (err) {
 549                         if (ret == ACT_P_CREATED)
 550                                 _tcf_ife_cleanup(*a, bind);
 551                         return err;
 552                 }
 553         }
 554
 555         if (ret == ACT_P_CREATED)
 556                 tcf_idr_insert(tn, *a);
 557
 558         return ret;
 559 }
 560
 561 static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 562                         int ref)
 563 {
 564         unsigned char *b = skb_tail_pointer(skb);
 565         struct tcf_ife_info *ife = to_ife(a);
 566         struct tc_ife opt = {
 567                 .index = ife->tcf_index,
 568                 .refcnt = ife->tcf_refcnt - ref,
 569                 .bindcnt = ife->tcf_bindcnt - bind,
 570                 .action = ife->tcf_action,
 571                 .flags = ife->flags,
 572         };
 573         struct tcf_t t;
 574
 575         if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
 576                 goto nla_put_failure;
 577
 578         tcf_tm_dump(&t, &ife->tcf_tm);
 579         if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
 580                 goto nla_put_failure;
 581
 582         if (!is_zero_ether_addr(ife->eth_dst)) {
 583                 if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, ife->eth_dst))
 584                         goto nla_put_failure;
 585         }
 586
 587         if (!is_zero_ether_addr(ife->eth_src)) {
 588                 if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, ife->eth_src))
 589                         goto nla_put_failure;
 590         }
 591
 592         if (nla_put(skb, TCA_IFE_TYPE, 2, &ife->eth_type))
 593                 goto nla_put_failure;
 594
 595         if (dump_metalist(skb, ife)) {
 596                 /*ignore failure to dump metalist */
 597                 pr_info("Failed to dump metalist\n");
 598         }
 599
 600         return skb->len;
 601
 602 nla_put_failure:
 603         nlmsg_trim(skb, b);
 604         return -1;
 605 }
 606
 607 static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
 608                               u16 metaid, u16 mlen, void *mdata)
 609 {
 610         struct tcf_meta_info *e;
 611
 612         /* XXX: use hash to speed up */
 613         list_for_each_entry(e, &ife->metalist, metalist) {
 614                 if (metaid == e->metaid) {
 615                         if (e->ops) {
 616                                 /* We check for decode presence already */
 617                                 return e->ops->decode(skb, mdata, mlen);
 618                         }
 619                 }
 620         }
 621
 622         return -ENOENT;
 623 }
 624
 625 static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
 626                           struct tcf_result *res)
 627 {
 628         struct tcf_ife_info *ife = to_ife(a);
 629         int action = ife->tcf_action;
 630         u8 *ifehdr_end;
 631         u8 *tlv_data;
 632         u16 metalen;
 633
 634         spin_lock(&ife->tcf_lock);
 635         bstats_update(&ife->tcf_bstats, skb);
 636         tcf_lastuse_update(&ife->tcf_tm);
 637         spin_unlock(&ife->tcf_lock);
 638
 639         if (skb_at_tc_ingress(skb))
 640                 skb_push(skb, skb->dev->hard_header_len);
 641
 642         tlv_data = ife_decode(skb, &metalen);
 643         if (unlikely(!tlv_data)) {
 644                 spin_lock(&ife->tcf_lock);
 645                 ife->tcf_qstats.drops++;
 646                 spin_unlock(&ife->tcf_lock);
 647                 return TC_ACT_SHOT;
 648         }
 649
 650         ifehdr_end = tlv_data + metalen;
 651         for (; tlv_data < ifehdr_end; tlv_data = ife_tlv_meta_next(tlv_data)) {
 652                 u8 *curr_data;
 653                 u16 mtype;
 654                 u16 dlen;
 655
 656                 curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,
 657                                                 &dlen, NULL);
 658                 if (!curr_data) {
 659                         qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 660                         return TC_ACT_SHOT;
 661                 }
 662
 663                 if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {
 664                         /* abuse overlimits to count when we receive metadata
 665                          * but dont have an ops for it
 666                          */
 667                         pr_info_ratelimited("Unknown metaid %d dlen %d\n",
 668                                             mtype, dlen);
 669                         ife->tcf_qstats.overlimits++;
 670                 }
 671         }
 672
 673         if (WARN_ON(tlv_data != ifehdr_end)) {
 674                 spin_lock(&ife->tcf_lock);
 675                 ife->tcf_qstats.drops++;
 676                 spin_unlock(&ife->tcf_lock);
 677                 return TC_ACT_SHOT;
 678         }
 679
 680         skb->protocol = eth_type_trans(skb, skb->dev);
 681         skb_reset_network_header(skb);
 682
 683         return action;
 684 }
 685
 686 /*XXX: check if we can do this at install time instead of current
 687  * send data path
 688 **/
 689 static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
 690 {
 691         struct tcf_meta_info *e, *n;
 692         int tot_run_sz = 0, run_sz = 0;
 693
 694         list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 695                 if (e->ops->check_presence) {
 696                         run_sz = e->ops->check_presence(skb, e);
 697                         tot_run_sz += run_sz;
 698                 }
 699         }
 700
 701         return tot_run_sz;
 702 }
 703
 704 static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
 705                           struct tcf_result *res)
 706 {
 707         struct tcf_ife_info *ife = to_ife(a);
 708         int action = ife->tcf_action;
 709         struct ethhdr *oethh;   /* outer ether header */
 710         struct tcf_meta_info *e;
 711         /*
 712            OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
 713            where ORIGDATA = original ethernet header ...
 714          */
 715         u16 metalen = ife_get_sz(skb, ife);
 716         int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
 717         unsigned int skboff = 0;
 718         int new_len = skb->len + hdrm;
 719         bool exceed_mtu = false;
 720         void *ife_meta;
 721         int err = 0;
 722
 723         if (!skb_at_tc_ingress(skb)) {
 724                 if (new_len > skb->dev->mtu)
 725                         exceed_mtu = true;
 726         }
 727
 728         spin_lock(&ife->tcf_lock);
 729         bstats_update(&ife->tcf_bstats, skb);
 730         tcf_lastuse_update(&ife->tcf_tm);
 731
 732         if (!metalen) {         /* no metadata to send */
 733                 /* abuse overlimits to count when we allow packet
 734                  * with no metadata
 735                  */
 736                 ife->tcf_qstats.overlimits++;
 737                 spin_unlock(&ife->tcf_lock);
 738                 return action;
 739         }
 740         /* could be stupid policy setup or mtu config
 741          * so lets be conservative.. */
 742         if ((action == TC_ACT_SHOT) || exceed_mtu) {
 743                 ife->tcf_qstats.drops++;
 744                 spin_unlock(&ife->tcf_lock);
 745                 return TC_ACT_SHOT;
 746         }
 747
 748         if (skb_at_tc_ingress(skb))
 749                 skb_push(skb, skb->dev->hard_header_len);
 750
 751         ife_meta = ife_encode(skb, metalen);
 752
 753         /* XXX: we dont have a clever way of telling encode to
 754          * not repeat some of the computations that are done by
 755          * ops->presence_check...
 756          */
 757         list_for_each_entry(e, &ife->metalist, metalist) {
 758                 if (e->ops->encode) {
 759                         err = e->ops->encode(skb, (void *)(ife_meta + skboff),
 760                                              e);
 761                 }
 762                 if (err < 0) {
 763                         /* too corrupt to keep around if overwritten */
 764                         ife->tcf_qstats.drops++;
 765                         spin_unlock(&ife->tcf_lock);
 766                         return TC_ACT_SHOT;
 767                 }
 768                 skboff += err;
 769         }
 770         oethh = (struct ethhdr *)skb->data;
 771
 772         if (!is_zero_ether_addr(ife->eth_src))
 773                 ether_addr_copy(oethh->h_source, ife->eth_src);
 774         if (!is_zero_ether_addr(ife->eth_dst))
 775                 ether_addr_copy(oethh->h_dest, ife->eth_dst);
 776         oethh->h_proto = htons(ife->eth_type);
 777
 778         if (skb_at_tc_ingress(skb))
 779                 skb_pull(skb, skb->dev->hard_header_len);
 780
 781         spin_unlock(&ife->tcf_lock);
 782
 783         return action;
 784 }
 785
 786 static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
 787                        struct tcf_result *res)
 788 {
 789         struct tcf_ife_info *ife = to_ife(a);
 790
 791         if (ife->flags & IFE_ENCODE)
 792                 return tcf_ife_encode(skb, a, res);
 793
 794         if (!(ife->flags & IFE_ENCODE))
 795                 return tcf_ife_decode(skb, a, res);
 796
 797         pr_info_ratelimited("unknown failure(policy neither de/encode\n");
 798         spin_lock(&ife->tcf_lock);
 799         bstats_update(&ife->tcf_bstats, skb);
 800         tcf_lastuse_update(&ife->tcf_tm);
 801         ife->tcf_qstats.drops++;
 802         spin_unlock(&ife->tcf_lock);
 803
 804         return TC_ACT_SHOT;
 805 }
 806
 807 static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
 808                           struct netlink_callback *cb, int type,
 809                           const struct tc_action_ops *ops)
 810 {
 811         struct tc_action_net *tn = net_generic(net, ife_net_id);
 812
 813         return tcf_generic_walker(tn, skb, cb, type, ops);
 814 }
 815
 816 static int tcf_ife_search(struct net *net, struct tc_action **a, u32 index)
 817 {
 818         struct tc_action_net *tn = net_generic(net, ife_net_id);
 819
 820         return tcf_idr_search(tn, a, index);
 821 }
 822
 823 static struct tc_action_ops act_ife_ops = {
 824         .kind = "ife",
 825         .type = TCA_ACT_IFE,
 826         .owner = THIS_MODULE,
 827         .act = tcf_ife_act,
 828         .dump = tcf_ife_dump,
 829         .cleanup = tcf_ife_cleanup,
 830         .init = tcf_ife_init,
 831         .walk = tcf_ife_walker,
 832         .lookup = tcf_ife_search,
 833         .size = sizeof(struct tcf_ife_info),
 834 };
 835
 836 static __net_init int ife_init_net(struct net *net)
 837 {
 838         struct tc_action_net *tn = net_generic(net, ife_net_id);
 839
 840         return tc_action_net_init(net, tn, &act_ife_ops);
 841 }
 842
 843 static void __net_exit ife_exit_net(struct net *net)
 844 {
 845         struct tc_action_net *tn = net_generic(net, ife_net_id);
 846
 847         tc_action_net_exit(tn);
 848 }
 849
 850 static struct pernet_operations ife_net_ops = {
 851         .init = ife_init_net,
 852         .exit = ife_exit_net,
 853         .id   = &ife_net_id,
 854         .size = sizeof(struct tc_action_net),
 855 };
 856
 857 static int __init ife_init_module(void)
 858 {
 859         return tcf_register_action(&act_ife_ops, &ife_net_ops);
 860 }
 861
 862 static void __exit ife_cleanup_module(void)
 863 {
 864         tcf_unregister_action(&act_ife_ops, &ife_net_ops);
 865 }
 866
 867 module_init(ife_init_module);
 868 module_exit(ife_cleanup_module);
 869
 870 MODULE_AUTHOR("Jamal Hadi Salim(2015)");
 871 MODULE_DESCRIPTION("Inter-FE LFB action");
 872 MODULE_LICENSE("GPL");