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