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