net/sched/act_ife.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/ife.c      Inter-FE action based on ForCES WG InterFE LFB
   4  *
   5  *              Refer to:
   6  *              draft-ietf-forces-interfelfb-03
   7  *              and
   8  *              netdev01 paper:
   9  *              "Distributing Linux Traffic Control Classifier-Action
  10  *              Subsystem"
  11  *              Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
  12  *
  13  * copyright Jamal Hadi Salim (2015)
  14 */
  15
  16 #include <linux/types.h>
  17 #include <linux/kernel.h>
  18 #include <linux/string.h>
  19 #include <linux/errno.h>
  20 #include <linux/skbuff.h>
  21 #include <linux/rtnetlink.h>
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24 #include <net/net_namespace.h>
  25 #include <net/netlink.h>
  26 #include <net/pkt_sched.h>
  27 #include <net/pkt_cls.h>
  28 #include <uapi/linux/tc_act/tc_ife.h>
  29 #include <net/tc_act/tc_ife.h>
  30 #include <linux/etherdevice.h>
  31 #include <net/ife.h>
  32
  33 static unsigned int ife_net_id;
  34 static int max_metacnt = IFE_META_MAX + 1;
  35 static struct tc_action_ops act_ife_ops;
  36
  37 static const struct nla_policy ife_policy[TCA_IFE_MAX + 1] = {
  38         [TCA_IFE_PARMS] = { .len = sizeof(struct tc_ife)},
  39         [TCA_IFE_DMAC] = { .len = ETH_ALEN},
  40         [TCA_IFE_SMAC] = { .len = ETH_ALEN},
  41         [TCA_IFE_TYPE] = { .type = NLA_U16},
  42 };
  43
  44 int ife_encode_meta_u16(u16 metaval, void *skbdata, struct tcf_meta_info *mi)
  45 {
  46         u16 edata = 0;
  47
  48         if (mi->metaval)
  49                 edata = *(u16 *)mi->metaval;
  50         else if (metaval)
  51                 edata = metaval;
  52
  53         if (!edata) /* will not encode */
  54                 return 0;
  55
  56         edata = htons(edata);
  57         return ife_tlv_meta_encode(skbdata, mi->metaid, 2, &edata);
  58 }
  59 EXPORT_SYMBOL_GPL(ife_encode_meta_u16);
  60
  61 int ife_get_meta_u32(struct sk_buff *skb, struct tcf_meta_info *mi)
  62 {
  63         if (mi->metaval)
  64                 return nla_put_u32(skb, mi->metaid, *(u32 *)mi->metaval);
  65         else
  66                 return nla_put(skb, mi->metaid, 0, NULL);
  67 }
  68 EXPORT_SYMBOL_GPL(ife_get_meta_u32);
  69
  70 int ife_check_meta_u32(u32 metaval, struct tcf_meta_info *mi)
  71 {
  72         if (metaval || mi->metaval)
  73                 return 8; /* T+L+V == 2+2+4 */
  74
  75         return 0;
  76 }
  77 EXPORT_SYMBOL_GPL(ife_check_meta_u32);
  78
  79 int ife_check_meta_u16(u16 metaval, struct tcf_meta_info *mi)
  80 {
  81         if (metaval || mi->metaval)
  82                 return 8; /* T+L+(V) == 2+2+(2+2bytepad) */
  83
  84         return 0;
  85 }
  86 EXPORT_SYMBOL_GPL(ife_check_meta_u16);
  87
  88 int ife_encode_meta_u32(u32 metaval, void *skbdata, struct tcf_meta_info *mi)
  89 {
  90         u32 edata = metaval;
  91
  92         if (mi->metaval)
  93                 edata = *(u32 *)mi->metaval;
  94         else if (metaval)
  95                 edata = metaval;
  96
  97         if (!edata) /* will not encode */
  98                 return 0;
  99
 100         edata = htonl(edata);
 101         return ife_tlv_meta_encode(skbdata, mi->metaid, 4, &edata);
 102 }
 103 EXPORT_SYMBOL_GPL(ife_encode_meta_u32);
 104
 105 int ife_get_meta_u16(struct sk_buff *skb, struct tcf_meta_info *mi)
 106 {
 107         if (mi->metaval)
 108                 return nla_put_u16(skb, mi->metaid, *(u16 *)mi->metaval);
 109         else
 110                 return nla_put(skb, mi->metaid, 0, NULL);
 111 }
 112 EXPORT_SYMBOL_GPL(ife_get_meta_u16);
 113
 114 int ife_alloc_meta_u32(struct tcf_meta_info *mi, void *metaval, gfp_t gfp)
 115 {
 116         mi->metaval = kmemdup(metaval, sizeof(u32), gfp);
 117         if (!mi->metaval)
 118                 return -ENOMEM;
 119
 120         return 0;
 121 }
 122 EXPORT_SYMBOL_GPL(ife_alloc_meta_u32);
 123
 124 int ife_alloc_meta_u16(struct tcf_meta_info *mi, void *metaval, gfp_t gfp)
 125 {
 126         mi->metaval = kmemdup(metaval, sizeof(u16), gfp);
 127         if (!mi->metaval)
 128                 return -ENOMEM;
 129
 130         return 0;
 131 }
 132 EXPORT_SYMBOL_GPL(ife_alloc_meta_u16);
 133
 134 void ife_release_meta_gen(struct tcf_meta_info *mi)
 135 {
 136         kfree(mi->metaval);
 137 }
 138 EXPORT_SYMBOL_GPL(ife_release_meta_gen);
 139
 140 int ife_validate_meta_u32(void *val, int len)
 141 {
 142         if (len == sizeof(u32))
 143                 return 0;
 144
 145         return -EINVAL;
 146 }
 147 EXPORT_SYMBOL_GPL(ife_validate_meta_u32);
 148
 149 int ife_validate_meta_u16(void *val, int len)
 150 {
 151         /* length will not include padding */
 152         if (len == sizeof(u16))
 153                 return 0;
 154
 155         return -EINVAL;
 156 }
 157 EXPORT_SYMBOL_GPL(ife_validate_meta_u16);
 158
 159 static LIST_HEAD(ifeoplist);
 160 static DEFINE_RWLOCK(ife_mod_lock);
 161
 162 static struct tcf_meta_ops *find_ife_oplist(u16 metaid)
 163 {
 164         struct tcf_meta_ops *o;
 165
 166         read_lock(&ife_mod_lock);
 167         list_for_each_entry(o, &ifeoplist, list) {
 168                 if (o->metaid == metaid) {
 169                         if (!try_module_get(o->owner))
 170                                 o = NULL;
 171                         read_unlock(&ife_mod_lock);
 172                         return o;
 173                 }
 174         }
 175         read_unlock(&ife_mod_lock);
 176
 177         return NULL;
 178 }
 179
 180 int register_ife_op(struct tcf_meta_ops *mops)
 181 {
 182         struct tcf_meta_ops *m;
 183
 184         if (!mops->metaid || !mops->metatype || !mops->name ||
 185             !mops->check_presence || !mops->encode || !mops->decode ||
 186             !mops->get || !mops->alloc)
 187                 return -EINVAL;
 188
 189         write_lock(&ife_mod_lock);
 190
 191         list_for_each_entry(m, &ifeoplist, list) {
 192                 if (m->metaid == mops->metaid ||
 193                     (strcmp(mops->name, m->name) == 0)) {
 194                         write_unlock(&ife_mod_lock);
 195                         return -EEXIST;
 196                 }
 197         }
 198
 199         if (!mops->release)
 200                 mops->release = ife_release_meta_gen;
 201
 202         list_add_tail(&mops->list, &ifeoplist);
 203         write_unlock(&ife_mod_lock);
 204         return 0;
 205 }
 206 EXPORT_SYMBOL_GPL(unregister_ife_op);
 207
 208 int unregister_ife_op(struct tcf_meta_ops *mops)
 209 {
 210         struct tcf_meta_ops *m;
 211         int err = -ENOENT;
 212
 213         write_lock(&ife_mod_lock);
 214         list_for_each_entry(m, &ifeoplist, list) {
 215                 if (m->metaid == mops->metaid) {
 216                         list_del(&mops->list);
 217                         err = 0;
 218                         break;
 219                 }
 220         }
 221         write_unlock(&ife_mod_lock);
 222
 223         return err;
 224 }
 225 EXPORT_SYMBOL_GPL(register_ife_op);
 226
 227 static int ife_validate_metatype(struct tcf_meta_ops *ops, void *val, int len)
 228 {
 229         int ret = 0;
 230         /* XXX: unfortunately cant use nla_policy at this point
 231         * because a length of 0 is valid in the case of
 232         * "allow". "use" semantics do enforce for proper
 233         * length and i couldve use nla_policy but it makes it hard
 234         * to use it just for that..
 235         */
 236         if (ops->validate)
 237                 return ops->validate(val, len);
 238
 239         if (ops->metatype == NLA_U32)
 240                 ret = ife_validate_meta_u32(val, len);
 241         else if (ops->metatype == NLA_U16)
 242                 ret = ife_validate_meta_u16(val, len);
 243
 244         return ret;
 245 }
 246
 247 #ifdef CONFIG_MODULES
 248 static const char *ife_meta_id2name(u32 metaid)
 249 {
 250         switch (metaid) {
 251         case IFE_META_SKBMARK:
 252                 return "skbmark";
 253         case IFE_META_PRIO:
 254                 return "skbprio";
 255         case IFE_META_TCINDEX:
 256                 return "tcindex";
 257         default:
 258                 return "unknown";
 259         }
 260 }
 261 #endif
 262
 263 /* called when adding new meta information
 264 */
 265 static int load_metaops_and_vet(u32 metaid, void *val, int len, bool rtnl_held)
 266 {
 267         struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 268         int ret = 0;
 269
 270         if (!ops) {
 271                 ret = -ENOENT;
 272 #ifdef CONFIG_MODULES
 273                 if (rtnl_held)
 274                         rtnl_unlock();
 275                 request_module("ife-meta-%s", ife_meta_id2name(metaid));
 276                 if (rtnl_held)
 277                         rtnl_lock();
 278                 ops = find_ife_oplist(metaid);
 279 #endif
 280         }
 281
 282         if (ops) {
 283                 ret = 0;
 284                 if (len)
 285                         ret = ife_validate_metatype(ops, val, len);
 286
 287                 module_put(ops->owner);
 288         }
 289
 290         return ret;
 291 }
 292
 293 /* called when adding new meta information
 294 */
 295 static int __add_metainfo(const struct tcf_meta_ops *ops,
 296                           struct tcf_ife_info *ife, u32 metaid, void *metaval,
 297                           int len, bool atomic, bool exists)
 298 {
 299         struct tcf_meta_info *mi = NULL;
 300         int ret = 0;
 301
 302         mi = kzalloc(sizeof(*mi), atomic ? GFP_ATOMIC : GFP_KERNEL);
 303         if (!mi)
 304                 return -ENOMEM;
 305
 306         mi->metaid = metaid;
 307         mi->ops = ops;
 308         if (len > 0) {
 309                 ret = ops->alloc(mi, metaval, atomic ? GFP_ATOMIC : GFP_KERNEL);
 310                 if (ret != 0) {
 311                         kfree(mi);
 312                         return ret;
 313                 }
 314         }
 315
 316         if (exists)
 317                 spin_lock_bh(&ife->tcf_lock);
 318         list_add_tail(&mi->metalist, &ife->metalist);
 319         if (exists)
 320                 spin_unlock_bh(&ife->tcf_lock);
 321
 322         return ret;
 323 }
 324
 325 static int add_metainfo_and_get_ops(const struct tcf_meta_ops *ops,
 326                                     struct tcf_ife_info *ife, u32 metaid,
 327                                     bool exists)
 328 {
 329         int ret;
 330
 331         if (!try_module_get(ops->owner))
 332                 return -ENOENT;
 333         ret = __add_metainfo(ops, ife, metaid, NULL, 0, true, exists);
 334         if (ret)
 335                 module_put(ops->owner);
 336         return ret;
 337 }
 338
 339 static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
 340                         int len, bool exists)
 341 {
 342         const struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 343         int ret;
 344
 345         if (!ops)
 346                 return -ENOENT;
 347         ret = __add_metainfo(ops, ife, metaid, metaval, len, false, exists);
 348         if (ret)
 349                 /*put back what find_ife_oplist took */
 350                 module_put(ops->owner);
 351         return ret;
 352 }
 353
 354 static int use_all_metadata(struct tcf_ife_info *ife, bool exists)
 355 {
 356         struct tcf_meta_ops *o;
 357         int rc = 0;
 358         int installed = 0;
 359
 360         read_lock(&ife_mod_lock);
 361         list_for_each_entry(o, &ifeoplist, list) {
 362                 rc = add_metainfo_and_get_ops(o, ife, o->metaid, exists);
 363                 if (rc == 0)
 364                         installed += 1;
 365         }
 366         read_unlock(&ife_mod_lock);
 367
 368         if (installed)
 369                 return 0;
 370         else
 371                 return -EINVAL;
 372 }
 373
 374 static int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
 375 {
 376         struct tcf_meta_info *e;
 377         struct nlattr *nest;
 378         unsigned char *b = skb_tail_pointer(skb);
 379         int total_encoded = 0;
 380
 381         /*can only happen on decode */
 382         if (list_empty(&ife->metalist))
 383                 return 0;
 384
 385         nest = nla_nest_start_noflag(skb, TCA_IFE_METALST);
 386         if (!nest)
 387                 goto out_nlmsg_trim;
 388
 389         list_for_each_entry(e, &ife->metalist, metalist) {
 390                 if (!e->ops->get(skb, e))
 391                         total_encoded += 1;
 392         }
 393
 394         if (!total_encoded)
 395                 goto out_nlmsg_trim;
 396
 397         nla_nest_end(skb, nest);
 398
 399         return 0;
 400
 401 out_nlmsg_trim:
 402         nlmsg_trim(skb, b);
 403         return -1;
 404 }
 405
 406 /* under ife->tcf_lock */
 407 static void _tcf_ife_cleanup(struct tc_action *a)
 408 {
 409         struct tcf_ife_info *ife = to_ife(a);
 410         struct tcf_meta_info *e, *n;
 411
 412         list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 413                 list_del(&e->metalist);
 414                 if (e->metaval) {
 415                         if (e->ops->release)
 416                                 e->ops->release(e);
 417                         else
 418                                 kfree(e->metaval);
 419                 }
 420                 module_put(e->ops->owner);
 421                 kfree(e);
 422         }
 423 }
 424
 425 static void tcf_ife_cleanup(struct tc_action *a)
 426 {
 427         struct tcf_ife_info *ife = to_ife(a);
 428         struct tcf_ife_params *p;
 429
 430         spin_lock_bh(&ife->tcf_lock);
 431         _tcf_ife_cleanup(a);
 432         spin_unlock_bh(&ife->tcf_lock);
 433
 434         p = rcu_dereference_protected(ife->params, 1);
 435         if (p)
 436                 kfree_rcu(p, rcu);
 437 }
 438
 439 static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
 440                              bool exists, bool rtnl_held)
 441 {
 442         int len = 0;
 443         int rc = 0;
 444         int i = 0;
 445         void *val;
 446
 447         for (i = 1; i < max_metacnt; i++) {
 448                 if (tb[i]) {
 449                         val = nla_data(tb[i]);
 450                         len = nla_len(tb[i]);
 451
 452                         rc = load_metaops_and_vet(i, val, len, rtnl_held);
 453                         if (rc != 0)
 454                                 return rc;
 455
 456                         rc = add_metainfo(ife, i, val, len, exists);
 457                         if (rc)
 458                                 return rc;
 459                 }
 460         }
 461
 462         return rc;
 463 }
 464
 465 static int tcf_ife_init(struct net *net, struct nlattr *nla,
 466                         struct nlattr *est, struct tc_action **a,
 467                         int ovr, int bind, bool rtnl_held,
 468                         struct tcf_proto *tp, u32 flags,
 469                         struct netlink_ext_ack *extack)
 470 {
 471         struct tc_action_net *tn = net_generic(net, ife_net_id);
 472         struct nlattr *tb[TCA_IFE_MAX + 1];
 473         struct nlattr *tb2[IFE_META_MAX + 1];
 474         struct tcf_chain *goto_ch = NULL;
 475         struct tcf_ife_params *p;
 476         struct tcf_ife_info *ife;
 477         u16 ife_type = ETH_P_IFE;
 478         struct tc_ife *parm;
 479         u8 *daddr = NULL;
 480         u8 *saddr = NULL;
 481         bool exists = false;
 482         int ret = 0;
 483         u32 index;
 484         int err;
 485
 486         if (!nla) {
 487                 NL_SET_ERR_MSG_MOD(extack, "IFE requires attributes to be passed");
 488                 return -EINVAL;
 489         }
 490
 491         err = nla_parse_nested_deprecated(tb, TCA_IFE_MAX, nla, ife_policy,
 492                                           NULL);
 493         if (err < 0)
 494                 return err;
 495
 496         if (!tb[TCA_IFE_PARMS])
 497                 return -EINVAL;
 498
 499         parm = nla_data(tb[TCA_IFE_PARMS]);
 500
 501         /* IFE_DECODE is 0 and indicates the opposite of IFE_ENCODE because
 502          * they cannot run as the same time. Check on all other values which
 503          * are not supported right now.
 504          */
 505         if (parm->flags & ~IFE_ENCODE)
 506                 return -EINVAL;
 507
 508         p = kzalloc(sizeof(*p), GFP_KERNEL);
 509         if (!p)
 510                 return -ENOMEM;
 511
 512         index = parm->index;
 513         err = tcf_idr_check_alloc(tn, &index, a, bind);
 514         if (err < 0) {
 515                 kfree(p);
 516                 return err;
 517         }
 518         exists = err;
 519         if (exists && bind) {
 520                 kfree(p);
 521                 return 0;
 522         }
 523
 524         if (!exists) {
 525                 ret = tcf_idr_create(tn, index, est, a, &act_ife_ops,
 526                                      bind, true, 0);
 527                 if (ret) {
 528                         tcf_idr_cleanup(tn, index);
 529                         kfree(p);
 530                         return ret;
 531                 }
 532                 ret = ACT_P_CREATED;
 533         } else if (!ovr) {
 534                 tcf_idr_release(*a, bind);
 535                 kfree(p);
 536                 return -EEXIST;
 537         }
 538
 539         ife = to_ife(*a);
 540         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 541         if (err < 0)
 542                 goto release_idr;
 543
 544         p->flags = parm->flags;
 545
 546         if (parm->flags & IFE_ENCODE) {
 547                 if (tb[TCA_IFE_TYPE])
 548                         ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
 549                 if (tb[TCA_IFE_DMAC])
 550                         daddr = nla_data(tb[TCA_IFE_DMAC]);
 551                 if (tb[TCA_IFE_SMAC])
 552                         saddr = nla_data(tb[TCA_IFE_SMAC]);
 553         }
 554
 555         if (parm->flags & IFE_ENCODE) {
 556                 if (daddr)
 557                         ether_addr_copy(p->eth_dst, daddr);
 558                 else
 559                         eth_zero_addr(p->eth_dst);
 560
 561                 if (saddr)
 562                         ether_addr_copy(p->eth_src, saddr);
 563                 else
 564                         eth_zero_addr(p->eth_src);
 565
 566                 p->eth_type = ife_type;
 567         }
 568
 569
 570         if (ret == ACT_P_CREATED)
 571                 INIT_LIST_HEAD(&ife->metalist);
 572
 573         if (tb[TCA_IFE_METALST]) {
 574                 err = nla_parse_nested_deprecated(tb2, IFE_META_MAX,
 575                                                   tb[TCA_IFE_METALST], NULL,
 576                                                   NULL);
 577                 if (err)
 578                         goto metadata_parse_err;
 579                 err = populate_metalist(ife, tb2, exists, rtnl_held);
 580                 if (err)
 581                         goto metadata_parse_err;
 582
 583         } else {
 584                 /* if no passed metadata allow list or passed allow-all
 585                  * then here we process by adding as many supported metadatum
 586                  * as we can. You better have at least one else we are
 587                  * going to bail out
 588                  */
 589                 err = use_all_metadata(ife, exists);
 590                 if (err)
 591                         goto metadata_parse_err;
 592         }
 593
 594         if (exists)
 595                 spin_lock_bh(&ife->tcf_lock);
 596         /* protected by tcf_lock when modifying existing action */
 597         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 598         rcu_swap_protected(ife->params, p, 1);
 599
 600         if (exists)
 601                 spin_unlock_bh(&ife->tcf_lock);
 602         if (goto_ch)
 603                 tcf_chain_put_by_act(goto_ch);
 604         if (p)
 605                 kfree_rcu(p, rcu);
 606
 607         if (ret == ACT_P_CREATED)
 608                 tcf_idr_insert(tn, *a);
 609
 610         return ret;
 611 metadata_parse_err:
 612         if (goto_ch)
 613                 tcf_chain_put_by_act(goto_ch);
 614 release_idr:
 615         kfree(p);
 616         tcf_idr_release(*a, bind);
 617         return err;
 618 }
 619
 620 static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 621                         int ref)
 622 {
 623         unsigned char *b = skb_tail_pointer(skb);
 624         struct tcf_ife_info *ife = to_ife(a);
 625         struct tcf_ife_params *p;
 626         struct tc_ife opt = {
 627                 .index = ife->tcf_index,
 628                 .refcnt = refcount_read(&ife->tcf_refcnt) - ref,
 629                 .bindcnt = atomic_read(&ife->tcf_bindcnt) - bind,
 630         };
 631         struct tcf_t t;
 632
 633         spin_lock_bh(&ife->tcf_lock);
 634         opt.action = ife->tcf_action;
 635         p = rcu_dereference_protected(ife->params,
 636                                       lockdep_is_held(&ife->tcf_lock));
 637         opt.flags = p->flags;
 638
 639         if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
 640                 goto nla_put_failure;
 641
 642         tcf_tm_dump(&t, &ife->tcf_tm);
 643         if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
 644                 goto nla_put_failure;
 645
 646         if (!is_zero_ether_addr(p->eth_dst)) {
 647                 if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
 648                         goto nla_put_failure;
 649         }
 650
 651         if (!is_zero_ether_addr(p->eth_src)) {
 652                 if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
 653                         goto nla_put_failure;
 654         }
 655
 656         if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
 657                 goto nla_put_failure;
 658
 659         if (dump_metalist(skb, ife)) {
 660                 /*ignore failure to dump metalist */
 661                 pr_info("Failed to dump metalist\n");
 662         }
 663
 664         spin_unlock_bh(&ife->tcf_lock);
 665         return skb->len;
 666
 667 nla_put_failure:
 668         spin_unlock_bh(&ife->tcf_lock);
 669         nlmsg_trim(skb, b);
 670         return -1;
 671 }
 672
 673 static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
 674                               u16 metaid, u16 mlen, void *mdata)
 675 {
 676         struct tcf_meta_info *e;
 677
 678         /* XXX: use hash to speed up */
 679         list_for_each_entry(e, &ife->metalist, metalist) {
 680                 if (metaid == e->metaid) {
 681                         if (e->ops) {
 682                                 /* We check for decode presence already */
 683                                 return e->ops->decode(skb, mdata, mlen);
 684                         }
 685                 }
 686         }
 687
 688         return -ENOENT;
 689 }
 690
 691 static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
 692                           struct tcf_result *res)
 693 {
 694         struct tcf_ife_info *ife = to_ife(a);
 695         int action = ife->tcf_action;
 696         u8 *ifehdr_end;
 697         u8 *tlv_data;
 698         u16 metalen;
 699
 700         bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 701         tcf_lastuse_update(&ife->tcf_tm);
 702
 703         if (skb_at_tc_ingress(skb))
 704                 skb_push(skb, skb->dev->hard_header_len);
 705
 706         tlv_data = ife_decode(skb, &metalen);
 707         if (unlikely(!tlv_data)) {
 708                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 709                 return TC_ACT_SHOT;
 710         }
 711
 712         ifehdr_end = tlv_data + metalen;
 713         for (; tlv_data < ifehdr_end; tlv_data = ife_tlv_meta_next(tlv_data)) {
 714                 u8 *curr_data;
 715                 u16 mtype;
 716                 u16 dlen;
 717
 718                 curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,
 719                                                 &dlen, NULL);
 720                 if (!curr_data) {
 721                         qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 722                         return TC_ACT_SHOT;
 723                 }
 724
 725                 if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {
 726                         /* abuse overlimits to count when we receive metadata
 727                          * but dont have an ops for it
 728                          */
 729                         pr_info_ratelimited("Unknown metaid %d dlen %d\n",
 730                                             mtype, dlen);
 731                         qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 732                 }
 733         }
 734
 735         if (WARN_ON(tlv_data != ifehdr_end)) {
 736                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 737                 return TC_ACT_SHOT;
 738         }
 739
 740         skb->protocol = eth_type_trans(skb, skb->dev);
 741         skb_reset_network_header(skb);
 742
 743         return action;
 744 }
 745
 746 /*XXX: check if we can do this at install time instead of current
 747  * send data path
 748 **/
 749 static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
 750 {
 751         struct tcf_meta_info *e, *n;
 752         int tot_run_sz = 0, run_sz = 0;
 753
 754         list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 755                 if (e->ops->check_presence) {
 756                         run_sz = e->ops->check_presence(skb, e);
 757                         tot_run_sz += run_sz;
 758                 }
 759         }
 760
 761         return tot_run_sz;
 762 }
 763
 764 static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
 765                           struct tcf_result *res, struct tcf_ife_params *p)
 766 {
 767         struct tcf_ife_info *ife = to_ife(a);
 768         int action = ife->tcf_action;
 769         struct ethhdr *oethh;   /* outer ether header */
 770         struct tcf_meta_info *e;
 771         /*
 772            OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
 773            where ORIGDATA = original ethernet header ...
 774          */
 775         u16 metalen = ife_get_sz(skb, ife);
 776         int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
 777         unsigned int skboff = 0;
 778         int new_len = skb->len + hdrm;
 779         bool exceed_mtu = false;
 780         void *ife_meta;
 781         int err = 0;
 782
 783         if (!skb_at_tc_ingress(skb)) {
 784                 if (new_len > skb->dev->mtu)
 785                         exceed_mtu = true;
 786         }
 787
 788         bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 789         tcf_lastuse_update(&ife->tcf_tm);
 790
 791         if (!metalen) {         /* no metadata to send */
 792                 /* abuse overlimits to count when we allow packet
 793                  * with no metadata
 794                  */
 795                 qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 796                 return action;
 797         }
 798         /* could be stupid policy setup or mtu config
 799          * so lets be conservative.. */
 800         if ((action == TC_ACT_SHOT) || exceed_mtu) {
 801                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 802                 return TC_ACT_SHOT;
 803         }
 804
 805         if (skb_at_tc_ingress(skb))
 806                 skb_push(skb, skb->dev->hard_header_len);
 807
 808         ife_meta = ife_encode(skb, metalen);
 809
 810         spin_lock(&ife->tcf_lock);
 811
 812         /* XXX: we dont have a clever way of telling encode to
 813          * not repeat some of the computations that are done by
 814          * ops->presence_check...
 815          */
 816         list_for_each_entry(e, &ife->metalist, metalist) {
 817                 if (e->ops->encode) {
 818                         err = e->ops->encode(skb, (void *)(ife_meta + skboff),
 819                                              e);
 820                 }
 821                 if (err < 0) {
 822                         /* too corrupt to keep around if overwritten */
 823                         spin_unlock(&ife->tcf_lock);
 824                         qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 825                         return TC_ACT_SHOT;
 826                 }
 827                 skboff += err;
 828         }
 829         spin_unlock(&ife->tcf_lock);
 830         oethh = (struct ethhdr *)skb->data;
 831
 832         if (!is_zero_ether_addr(p->eth_src))
 833                 ether_addr_copy(oethh->h_source, p->eth_src);
 834         if (!is_zero_ether_addr(p->eth_dst))
 835                 ether_addr_copy(oethh->h_dest, p->eth_dst);
 836         oethh->h_proto = htons(p->eth_type);
 837
 838         if (skb_at_tc_ingress(skb))
 839                 skb_pull(skb, skb->dev->hard_header_len);
 840
 841         return action;
 842 }
 843
 844 static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
 845                        struct tcf_result *res)
 846 {
 847         struct tcf_ife_info *ife = to_ife(a);
 848         struct tcf_ife_params *p;
 849         int ret;
 850
 851         p = rcu_dereference_bh(ife->params);
 852         if (p->flags & IFE_ENCODE) {
 853                 ret = tcf_ife_encode(skb, a, res, p);
 854                 return ret;
 855         }
 856
 857         return tcf_ife_decode(skb, a, res);
 858 }
 859
 860 static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
 861                           struct netlink_callback *cb, int type,
 862                           const struct tc_action_ops *ops,
 863                           struct netlink_ext_ack *extack)
 864 {
 865         struct tc_action_net *tn = net_generic(net, ife_net_id);
 866
 867         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 868 }
 869
 870 static int tcf_ife_search(struct net *net, struct tc_action **a, u32 index)
 871 {
 872         struct tc_action_net *tn = net_generic(net, ife_net_id);
 873
 874         return tcf_idr_search(tn, a, index);
 875 }
 876
 877 static struct tc_action_ops act_ife_ops = {
 878         .kind = "ife",
 879         .id = TCA_ID_IFE,
 880         .owner = THIS_MODULE,
 881         .act = tcf_ife_act,
 882         .dump = tcf_ife_dump,
 883         .cleanup = tcf_ife_cleanup,
 884         .init = tcf_ife_init,
 885         .walk = tcf_ife_walker,
 886         .lookup = tcf_ife_search,
 887         .size = sizeof(struct tcf_ife_info),
 888 };
 889
 890 static __net_init int ife_init_net(struct net *net)
 891 {
 892         struct tc_action_net *tn = net_generic(net, ife_net_id);
 893
 894         return tc_action_net_init(net, tn, &act_ife_ops);
 895 }
 896
 897 static void __net_exit ife_exit_net(struct list_head *net_list)
 898 {
 899         tc_action_net_exit(net_list, ife_net_id);
 900 }
 901
 902 static struct pernet_operations ife_net_ops = {
 903         .init = ife_init_net,
 904         .exit_batch = ife_exit_net,
 905         .id   = &ife_net_id,
 906         .size = sizeof(struct tc_action_net),
 907 };
 908
 909 static int __init ife_init_module(void)
 910 {
 911         return tcf_register_action(&act_ife_ops, &ife_net_ops);
 912 }
 913
 914 static void __exit ife_cleanup_module(void)
 915 {
 916         tcf_unregister_action(&act_ife_ops, &ife_net_ops);
 917 }
 918
 919 module_init(ife_init_module);
 920 module_exit(ife_cleanup_module);
 921
 922 MODULE_AUTHOR("Jamal Hadi Salim(2015)");
 923 MODULE_DESCRIPTION("Inter-FE LFB action");
 924 MODULE_LICENSE("GPL");