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  * under ife->tcf_lock for existing action
 269 */
 270 static int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
 271                                 void *val, int len, bool exists)
 272 {
 273         struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 274         int ret = 0;
 275
 276         if (!ops) {
 277                 ret = -ENOENT;
 278 #ifdef CONFIG_MODULES
 279                 if (exists)
 280                         spin_unlock_bh(&ife->tcf_lock);
 281                 rtnl_unlock();
 282                 request_module("ife-meta-%s", ife_meta_id2name(metaid));
 283                 rtnl_lock();
 284                 if (exists)
 285                         spin_lock_bh(&ife->tcf_lock);
 286                 ops = find_ife_oplist(metaid);
 287 #endif
 288         }
 289
 290         if (ops) {
 291                 ret = 0;
 292                 if (len)
 293                         ret = ife_validate_metatype(ops, val, len);
 294
 295                 module_put(ops->owner);
 296         }
 297
 298         return ret;
 299 }
 300
 301 /* called when adding new meta information
 302  * under ife->tcf_lock for existing action
 303 */
 304 static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
 305                         int len, bool atomic)
 306 {
 307         struct tcf_meta_info *mi = NULL;
 308         struct tcf_meta_ops *ops = find_ife_oplist(metaid);
 309         int ret = 0;
 310
 311         if (!ops)
 312                 return -ENOENT;
 313
 314         mi = kzalloc(sizeof(*mi), atomic ? GFP_ATOMIC : GFP_KERNEL);
 315         if (!mi) {
 316                 /*put back what find_ife_oplist took */
 317                 module_put(ops->owner);
 318                 return -ENOMEM;
 319         }
 320
 321         mi->metaid = metaid;
 322         mi->ops = ops;
 323         if (len > 0) {
 324                 ret = ops->alloc(mi, metaval, atomic ? GFP_ATOMIC : GFP_KERNEL);
 325                 if (ret != 0) {
 326                         kfree(mi);
 327                         module_put(ops->owner);
 328                         return ret;
 329                 }
 330         }
 331
 332         list_add_tail(&mi->metalist, &ife->metalist);
 333
 334         return ret;
 335 }
 336
 337 static int use_all_metadata(struct tcf_ife_info *ife)
 338 {
 339         struct tcf_meta_ops *o;
 340         int rc = 0;
 341         int installed = 0;
 342
 343         read_lock(&ife_mod_lock);
 344         list_for_each_entry(o, &ifeoplist, list) {
 345                 rc = add_metainfo(ife, o->metaid, NULL, 0, true);
 346                 if (rc == 0)
 347                         installed += 1;
 348         }
 349         read_unlock(&ife_mod_lock);
 350
 351         if (installed)
 352                 return 0;
 353         else
 354                 return -EINVAL;
 355 }
 356
 357 static int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
 358 {
 359         struct tcf_meta_info *e;
 360         struct nlattr *nest;
 361         unsigned char *b = skb_tail_pointer(skb);
 362         int total_encoded = 0;
 363
 364         /*can only happen on decode */
 365         if (list_empty(&ife->metalist))
 366                 return 0;
 367
 368         nest = nla_nest_start(skb, TCA_IFE_METALST);
 369         if (!nest)
 370                 goto out_nlmsg_trim;
 371
 372         list_for_each_entry(e, &ife->metalist, metalist) {
 373                 if (!e->ops->get(skb, e))
 374                         total_encoded += 1;
 375         }
 376
 377         if (!total_encoded)
 378                 goto out_nlmsg_trim;
 379
 380         nla_nest_end(skb, nest);
 381
 382         return 0;
 383
 384 out_nlmsg_trim:
 385         nlmsg_trim(skb, b);
 386         return -1;
 387 }
 388
 389 /* under ife->tcf_lock */
 390 static void _tcf_ife_cleanup(struct tc_action *a)
 391 {
 392         struct tcf_ife_info *ife = to_ife(a);
 393         struct tcf_meta_info *e, *n;
 394
 395         list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 396                 module_put(e->ops->owner);
 397                 list_del(&e->metalist);
 398                 if (e->metaval) {
 399                         if (e->ops->release)
 400                                 e->ops->release(e);
 401                         else
 402                                 kfree(e->metaval);
 403                 }
 404                 kfree(e);
 405         }
 406 }
 407
 408 static void tcf_ife_cleanup(struct tc_action *a)
 409 {
 410         struct tcf_ife_info *ife = to_ife(a);
 411         struct tcf_ife_params *p;
 412
 413         spin_lock_bh(&ife->tcf_lock);
 414         _tcf_ife_cleanup(a);
 415         spin_unlock_bh(&ife->tcf_lock);
 416
 417         p = rcu_dereference_protected(ife->params, 1);
 418         kfree_rcu(p, rcu);
 419 }
 420
 421 /* under ife->tcf_lock for existing action */
 422 static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
 423                              bool exists)
 424 {
 425         int len = 0;
 426         int rc = 0;
 427         int i = 0;
 428         void *val;
 429
 430         for (i = 1; i < max_metacnt; i++) {
 431                 if (tb[i]) {
 432                         val = nla_data(tb[i]);
 433                         len = nla_len(tb[i]);
 434
 435                         rc = load_metaops_and_vet(ife, i, val, len, exists);
 436                         if (rc != 0)
 437                                 return rc;
 438
 439                         rc = add_metainfo(ife, i, val, len, exists);
 440                         if (rc)
 441                                 return rc;
 442                 }
 443         }
 444
 445         return rc;
 446 }
 447
 448 static int tcf_ife_init(struct net *net, struct nlattr *nla,
 449                         struct nlattr *est, struct tc_action **a,
 450                         int ovr, int bind, struct netlink_ext_ack *extack)
 451 {
 452         struct tc_action_net *tn = net_generic(net, ife_net_id);
 453         struct nlattr *tb[TCA_IFE_MAX + 1];
 454         struct nlattr *tb2[IFE_META_MAX + 1];
 455         struct tcf_ife_params *p, *p_old;
 456         struct tcf_ife_info *ife;
 457         u16 ife_type = ETH_P_IFE;
 458         struct tc_ife *parm;
 459         u8 *daddr = NULL;
 460         u8 *saddr = NULL;
 461         bool exists = false;
 462         int ret = 0;
 463         int err;
 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         /* IFE_DECODE is 0 and indicates the opposite of IFE_ENCODE because
 475          * they cannot run as the same time. Check on all other values which
 476          * are not supported right now.
 477          */
 478         if (parm->flags & ~IFE_ENCODE)
 479                 return -EINVAL;
 480
 481         p = kzalloc(sizeof(*p), GFP_KERNEL);
 482         if (!p)
 483                 return -ENOMEM;
 484
 485         exists = tcf_idr_check(tn, parm->index, a, bind);
 486         if (exists && bind) {
 487                 kfree(p);
 488                 return 0;
 489         }
 490
 491         if (!exists) {
 492                 ret = tcf_idr_create(tn, parm->index, est, a, &act_ife_ops,
 493                                      bind, true);
 494                 if (ret) {
 495                         kfree(p);
 496                         return ret;
 497                 }
 498                 ret = ACT_P_CREATED;
 499         } else {
 500                 tcf_idr_release(*a, bind);
 501                 if (!ovr) {
 502                         kfree(p);
 503                         return -EEXIST;
 504                 }
 505         }
 506
 507         ife = to_ife(*a);
 508         p->flags = parm->flags;
 509
 510         if (parm->flags & IFE_ENCODE) {
 511                 if (tb[TCA_IFE_TYPE])
 512                         ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
 513                 if (tb[TCA_IFE_DMAC])
 514                         daddr = nla_data(tb[TCA_IFE_DMAC]);
 515                 if (tb[TCA_IFE_SMAC])
 516                         saddr = nla_data(tb[TCA_IFE_SMAC]);
 517         }
 518
 519         ife->tcf_action = parm->action;
 520
 521         if (parm->flags & IFE_ENCODE) {
 522                 if (daddr)
 523                         ether_addr_copy(p->eth_dst, daddr);
 524                 else
 525                         eth_zero_addr(p->eth_dst);
 526
 527                 if (saddr)
 528                         ether_addr_copy(p->eth_src, saddr);
 529                 else
 530                         eth_zero_addr(p->eth_src);
 531
 532                 p->eth_type = ife_type;
 533         }
 534
 535         if (exists)
 536                 spin_lock_bh(&ife->tcf_lock);
 537
 538         if (ret == ACT_P_CREATED)
 539                 INIT_LIST_HEAD(&ife->metalist);
 540
 541         if (tb[TCA_IFE_METALST]) {
 542                 err = nla_parse_nested(tb2, IFE_META_MAX, tb[TCA_IFE_METALST],
 543                                        NULL, NULL);
 544                 if (err) {
 545 metadata_parse_err:
 546                         if (exists)
 547                                 tcf_idr_release(*a, bind);
 548                         if (ret == ACT_P_CREATED)
 549                                 _tcf_ife_cleanup(*a);
 550
 551                         if (exists)
 552                                 spin_unlock_bh(&ife->tcf_lock);
 553                         kfree(p);
 554                         return err;
 555                 }
 556
 557                 err = populate_metalist(ife, tb2, exists);
 558                 if (err)
 559                         goto metadata_parse_err;
 560
 561         } else {
 562                 /* if no passed metadata allow list or passed allow-all
 563                  * then here we process by adding as many supported metadatum
 564                  * as we can. You better have at least one else we are
 565                  * going to bail out
 566                  */
 567                 err = use_all_metadata(ife);
 568                 if (err) {
 569                         if (ret == ACT_P_CREATED)
 570                                 _tcf_ife_cleanup(*a);
 571
 572                         if (exists)
 573                                 spin_unlock_bh(&ife->tcf_lock);
 574                         kfree(p);
 575                         return err;
 576                 }
 577         }
 578
 579         if (exists)
 580                 spin_unlock_bh(&ife->tcf_lock);
 581
 582         p_old = rtnl_dereference(ife->params);
 583         rcu_assign_pointer(ife->params, p);
 584         if (p_old)
 585                 kfree_rcu(p_old, rcu);
 586
 587         if (ret == ACT_P_CREATED)
 588                 tcf_idr_insert(tn, *a);
 589
 590         return ret;
 591 }
 592
 593 static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
 594                         int ref)
 595 {
 596         unsigned char *b = skb_tail_pointer(skb);
 597         struct tcf_ife_info *ife = to_ife(a);
 598         struct tcf_ife_params *p = rtnl_dereference(ife->params);
 599         struct tc_ife opt = {
 600                 .index = ife->tcf_index,
 601                 .refcnt = ife->tcf_refcnt - ref,
 602                 .bindcnt = ife->tcf_bindcnt - bind,
 603                 .action = ife->tcf_action,
 604                 .flags = p->flags,
 605         };
 606         struct tcf_t t;
 607
 608         if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
 609                 goto nla_put_failure;
 610
 611         tcf_tm_dump(&t, &ife->tcf_tm);
 612         if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
 613                 goto nla_put_failure;
 614
 615         if (!is_zero_ether_addr(p->eth_dst)) {
 616                 if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
 617                         goto nla_put_failure;
 618         }
 619
 620         if (!is_zero_ether_addr(p->eth_src)) {
 621                 if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
 622                         goto nla_put_failure;
 623         }
 624
 625         if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
 626                 goto nla_put_failure;
 627
 628         if (dump_metalist(skb, ife)) {
 629                 /*ignore failure to dump metalist */
 630                 pr_info("Failed to dump metalist\n");
 631         }
 632
 633         return skb->len;
 634
 635 nla_put_failure:
 636         nlmsg_trim(skb, b);
 637         return -1;
 638 }
 639
 640 static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
 641                               u16 metaid, u16 mlen, void *mdata)
 642 {
 643         struct tcf_meta_info *e;
 644
 645         /* XXX: use hash to speed up */
 646         list_for_each_entry(e, &ife->metalist, metalist) {
 647                 if (metaid == e->metaid) {
 648                         if (e->ops) {
 649                                 /* We check for decode presence already */
 650                                 return e->ops->decode(skb, mdata, mlen);
 651                         }
 652                 }
 653         }
 654
 655         return -ENOENT;
 656 }
 657
 658 static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
 659                           struct tcf_result *res)
 660 {
 661         struct tcf_ife_info *ife = to_ife(a);
 662         int action = ife->tcf_action;
 663         u8 *ifehdr_end;
 664         u8 *tlv_data;
 665         u16 metalen;
 666
 667         bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 668         tcf_lastuse_update(&ife->tcf_tm);
 669
 670         if (skb_at_tc_ingress(skb))
 671                 skb_push(skb, skb->dev->hard_header_len);
 672
 673         tlv_data = ife_decode(skb, &metalen);
 674         if (unlikely(!tlv_data)) {
 675                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 676                 return TC_ACT_SHOT;
 677         }
 678
 679         ifehdr_end = tlv_data + metalen;
 680         for (; tlv_data < ifehdr_end; tlv_data = ife_tlv_meta_next(tlv_data)) {
 681                 u8 *curr_data;
 682                 u16 mtype;
 683                 u16 dlen;
 684
 685                 curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,
 686                                                 &dlen, NULL);
 687                 if (!curr_data) {
 688                         qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 689                         return TC_ACT_SHOT;
 690                 }
 691
 692                 if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {
 693                         /* abuse overlimits to count when we receive metadata
 694                          * but dont have an ops for it
 695                          */
 696                         pr_info_ratelimited("Unknown metaid %d dlen %d\n",
 697                                             mtype, dlen);
 698                         qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 699                 }
 700         }
 701
 702         if (WARN_ON(tlv_data != ifehdr_end)) {
 703                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 704                 return TC_ACT_SHOT;
 705         }
 706
 707         skb->protocol = eth_type_trans(skb, skb->dev);
 708         skb_reset_network_header(skb);
 709
 710         return action;
 711 }
 712
 713 /*XXX: check if we can do this at install time instead of current
 714  * send data path
 715 **/
 716 static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
 717 {
 718         struct tcf_meta_info *e, *n;
 719         int tot_run_sz = 0, run_sz = 0;
 720
 721         list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
 722                 if (e->ops->check_presence) {
 723                         run_sz = e->ops->check_presence(skb, e);
 724                         tot_run_sz += run_sz;
 725                 }
 726         }
 727
 728         return tot_run_sz;
 729 }
 730
 731 static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
 732                           struct tcf_result *res, struct tcf_ife_params *p)
 733 {
 734         struct tcf_ife_info *ife = to_ife(a);
 735         int action = ife->tcf_action;
 736         struct ethhdr *oethh;   /* outer ether header */
 737         struct tcf_meta_info *e;
 738         /*
 739            OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
 740            where ORIGDATA = original ethernet header ...
 741          */
 742         u16 metalen = ife_get_sz(skb, ife);
 743         int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
 744         unsigned int skboff = 0;
 745         int new_len = skb->len + hdrm;
 746         bool exceed_mtu = false;
 747         void *ife_meta;
 748         int err = 0;
 749
 750         if (!skb_at_tc_ingress(skb)) {
 751                 if (new_len > skb->dev->mtu)
 752                         exceed_mtu = true;
 753         }
 754
 755         bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
 756         tcf_lastuse_update(&ife->tcf_tm);
 757
 758         if (!metalen) {         /* no metadata to send */
 759                 /* abuse overlimits to count when we allow packet
 760                  * with no metadata
 761                  */
 762                 qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
 763                 return action;
 764         }
 765         /* could be stupid policy setup or mtu config
 766          * so lets be conservative.. */
 767         if ((action == TC_ACT_SHOT) || exceed_mtu) {
 768                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 769                 return TC_ACT_SHOT;
 770         }
 771
 772         if (skb_at_tc_ingress(skb))
 773                 skb_push(skb, skb->dev->hard_header_len);
 774
 775         ife_meta = ife_encode(skb, metalen);
 776
 777         spin_lock(&ife->tcf_lock);
 778
 779         /* XXX: we dont have a clever way of telling encode to
 780          * not repeat some of the computations that are done by
 781          * ops->presence_check...
 782          */
 783         list_for_each_entry(e, &ife->metalist, metalist) {
 784                 if (e->ops->encode) {
 785                         err = e->ops->encode(skb, (void *)(ife_meta + skboff),
 786                                              e);
 787                 }
 788                 if (err < 0) {
 789                         /* too corrupt to keep around if overwritten */
 790                         spin_unlock(&ife->tcf_lock);
 791                         qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
 792                         return TC_ACT_SHOT;
 793                 }
 794                 skboff += err;
 795         }
 796         spin_unlock(&ife->tcf_lock);
 797         oethh = (struct ethhdr *)skb->data;
 798
 799         if (!is_zero_ether_addr(p->eth_src))
 800                 ether_addr_copy(oethh->h_source, p->eth_src);
 801         if (!is_zero_ether_addr(p->eth_dst))
 802                 ether_addr_copy(oethh->h_dest, p->eth_dst);
 803         oethh->h_proto = htons(p->eth_type);
 804
 805         if (skb_at_tc_ingress(skb))
 806                 skb_pull(skb, skb->dev->hard_header_len);
 807
 808         return action;
 809 }
 810
 811 static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
 812                        struct tcf_result *res)
 813 {
 814         struct tcf_ife_info *ife = to_ife(a);
 815         struct tcf_ife_params *p;
 816         int ret;
 817
 818         rcu_read_lock();
 819         p = rcu_dereference(ife->params);
 820         if (p->flags & IFE_ENCODE) {
 821                 ret = tcf_ife_encode(skb, a, res, p);
 822                 rcu_read_unlock();
 823                 return ret;
 824         }
 825         rcu_read_unlock();
 826
 827         return tcf_ife_decode(skb, a, res);
 828 }
 829
 830 static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
 831                           struct netlink_callback *cb, int type,
 832                           const struct tc_action_ops *ops,
 833                           struct netlink_ext_ack *extack)
 834 {
 835         struct tc_action_net *tn = net_generic(net, ife_net_id);
 836
 837         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 838 }
 839
 840 static int tcf_ife_search(struct net *net, struct tc_action **a, u32 index,
 841                           struct netlink_ext_ack *extack)
 842 {
 843         struct tc_action_net *tn = net_generic(net, ife_net_id);
 844
 845         return tcf_idr_search(tn, a, index);
 846 }
 847
 848 static struct tc_action_ops act_ife_ops = {
 849         .kind = "ife",
 850         .type = TCA_ACT_IFE,
 851         .owner = THIS_MODULE,
 852         .act = tcf_ife_act,
 853         .dump = tcf_ife_dump,
 854         .cleanup = tcf_ife_cleanup,
 855         .init = tcf_ife_init,
 856         .walk = tcf_ife_walker,
 857         .lookup = tcf_ife_search,
 858         .size = sizeof(struct tcf_ife_info),
 859 };
 860
 861 static __net_init int ife_init_net(struct net *net)
 862 {
 863         struct tc_action_net *tn = net_generic(net, ife_net_id);
 864
 865         return tc_action_net_init(tn, &act_ife_ops);
 866 }
 867
 868 static void __net_exit ife_exit_net(struct list_head *net_list)
 869 {
 870         tc_action_net_exit(net_list, ife_net_id);
 871 }
 872
 873 static struct pernet_operations ife_net_ops = {
 874         .init = ife_init_net,
 875         .exit_batch = ife_exit_net,
 876         .id   = &ife_net_id,
 877         .size = sizeof(struct tc_action_net),
 878 };
 879
 880 static int __init ife_init_module(void)
 881 {
 882         return tcf_register_action(&act_ife_ops, &ife_net_ops);
 883 }
 884
 885 static void __exit ife_cleanup_module(void)
 886 {
 887         tcf_unregister_action(&act_ife_ops, &ife_net_ops);
 888 }
 889
 890 module_init(ife_init_module);
 891 module_exit(ife_cleanup_module);
 892
 893 MODULE_AUTHOR("Jamal Hadi Salim(2015)");
 894 MODULE_DESCRIPTION("Inter-FE LFB action");
 895 MODULE_LICENSE("GPL");