1 // SPDX-License-Identifier: GPL-2.0 2 /* Generic nexthop implementation 3 * 4 * Copyright (c) 2017-19 Cumulus Networks 5 * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com> 6 */ 7 8 #include <linux/nexthop.h> 9 #include <linux/rtnetlink.h> 10 #include <linux/slab.h> 11 #include <linux/vmalloc.h> 12 #include <net/arp.h> 13 #include <net/ipv6_stubs.h> 14 #include <net/lwtunnel.h> 15 #include <net/ndisc.h> 16 #include <net/nexthop.h> 17 #include <net/route.h> 18 #include <net/sock.h> 19 20 #define NH_RES_DEFAULT_IDLE_TIMER (120 * HZ) 21 #define NH_RES_DEFAULT_UNBALANCED_TIMER 0 /* No forced rebalancing. */ 22 23 static void remove_nexthop(struct net *net, struct nexthop *nh, 24 struct nl_info *nlinfo); 25 26 #define NH_DEV_HASHBITS 8 27 #define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS) 28 29 static const struct nla_policy rtm_nh_policy_new[] = { 30 [NHA_ID] = { .type = NLA_U32 }, 31 [NHA_GROUP] = { .type = NLA_BINARY }, 32 [NHA_GROUP_TYPE] = { .type = NLA_U16 }, 33 [NHA_BLACKHOLE] = { .type = NLA_FLAG }, 34 [NHA_OIF] = { .type = NLA_U32 }, 35 [NHA_GATEWAY] = { .type = NLA_BINARY }, 36 [NHA_ENCAP_TYPE] = { .type = NLA_U16 }, 37 [NHA_ENCAP] = { .type = NLA_NESTED }, 38 [NHA_FDB] = { .type = NLA_FLAG }, 39 [NHA_RES_GROUP] = { .type = NLA_NESTED }, 40 }; 41 42 static const struct nla_policy rtm_nh_policy_get[] = { 43 [NHA_ID] = { .type = NLA_U32 }, 44 }; 45 46 static const struct nla_policy rtm_nh_policy_dump[] = { 47 [NHA_OIF] = { .type = NLA_U32 }, 48 [NHA_GROUPS] = { .type = NLA_FLAG }, 49 [NHA_MASTER] = { .type = NLA_U32 }, 50 [NHA_FDB] = { .type = NLA_FLAG }, 51 }; 52 53 static const struct nla_policy rtm_nh_res_policy_new[] = { 54 [NHA_RES_GROUP_BUCKETS] = { .type = NLA_U16 }, 55 [NHA_RES_GROUP_IDLE_TIMER] = { .type = NLA_U32 }, 56 [NHA_RES_GROUP_UNBALANCED_TIMER] = { .type = NLA_U32 }, 57 }; 58 59 static const struct nla_policy rtm_nh_policy_dump_bucket[] = { 60 [NHA_ID] = { .type = NLA_U32 }, 61 [NHA_OIF] = { .type = NLA_U32 }, 62 [NHA_MASTER] = { .type = NLA_U32 }, 63 [NHA_RES_BUCKET] = { .type = NLA_NESTED }, 64 }; 65 66 static const struct nla_policy rtm_nh_res_bucket_policy_dump[] = { 67 [NHA_RES_BUCKET_NH_ID] = { .type = NLA_U32 }, 68 }; 69 70 static const struct nla_policy rtm_nh_policy_get_bucket[] = { 71 [NHA_ID] = { .type = NLA_U32 }, 72 [NHA_RES_BUCKET] = { .type = NLA_NESTED }, 73 }; 74 75 static const struct nla_policy rtm_nh_res_bucket_policy_get[] = { 76 [NHA_RES_BUCKET_INDEX] = { .type = NLA_U16 }, 77 }; 78 79 static bool nexthop_notifiers_is_empty(struct net *net) 80 { 81 return !net->nexthop.notifier_chain.head; 82 } 83 84 static void 85 __nh_notifier_single_info_init(struct nh_notifier_single_info *nh_info, 86 const struct nh_info *nhi) 87 { 88 nh_info->dev = nhi->fib_nhc.nhc_dev; 89 nh_info->gw_family = nhi->fib_nhc.nhc_gw_family; 90 if (nh_info->gw_family == AF_INET) 91 nh_info->ipv4 = nhi->fib_nhc.nhc_gw.ipv4; 92 else if (nh_info->gw_family == AF_INET6) 93 nh_info->ipv6 = nhi->fib_nhc.nhc_gw.ipv6; 94 95 nh_info->is_reject = nhi->reject_nh; 96 nh_info->is_fdb = nhi->fdb_nh; 97 nh_info->has_encap = !!nhi->fib_nhc.nhc_lwtstate; 98 } 99 100 static int nh_notifier_single_info_init(struct nh_notifier_info *info, 101 const struct nexthop *nh) 102 { 103 struct nh_info *nhi = rtnl_dereference(nh->nh_info); 104 105 info->type = NH_NOTIFIER_INFO_TYPE_SINGLE; 106 info->nh = kzalloc(sizeof(*info->nh), GFP_KERNEL); 107 if (!info->nh) 108 return -ENOMEM; 109 110 __nh_notifier_single_info_init(info->nh, nhi); 111 112 return 0; 113 } 114 115 static void nh_notifier_single_info_fini(struct nh_notifier_info *info) 116 { 117 kfree(info->nh); 118 } 119 120 static int nh_notifier_mpath_info_init(struct nh_notifier_info *info, 121 struct nh_group *nhg) 122 { 123 u16 num_nh = nhg->num_nh; 124 int i; 125 126 info->type = NH_NOTIFIER_INFO_TYPE_GRP; 127 info->nh_grp = kzalloc(struct_size(info->nh_grp, nh_entries, num_nh), 128 GFP_KERNEL); 129 if (!info->nh_grp) 130 return -ENOMEM; 131 132 info->nh_grp->num_nh = num_nh; 133 info->nh_grp->is_fdb = nhg->fdb_nh; 134 135 for (i = 0; i < num_nh; i++) { 136 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 137 struct nh_info *nhi; 138 139 nhi = rtnl_dereference(nhge->nh->nh_info); 140 info->nh_grp->nh_entries[i].id = nhge->nh->id; 141 info->nh_grp->nh_entries[i].weight = nhge->weight; 142 __nh_notifier_single_info_init(&info->nh_grp->nh_entries[i].nh, 143 nhi); 144 } 145 146 return 0; 147 } 148 149 static int nh_notifier_res_table_info_init(struct nh_notifier_info *info, 150 struct nh_group *nhg) 151 { 152 struct nh_res_table *res_table = rtnl_dereference(nhg->res_table); 153 u16 num_nh_buckets = res_table->num_nh_buckets; 154 unsigned long size; 155 u16 i; 156 157 info->type = NH_NOTIFIER_INFO_TYPE_RES_TABLE; 158 size = struct_size(info->nh_res_table, nhs, num_nh_buckets); 159 info->nh_res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO | 160 __GFP_NOWARN); 161 if (!info->nh_res_table) 162 return -ENOMEM; 163 164 info->nh_res_table->num_nh_buckets = num_nh_buckets; 165 166 for (i = 0; i < num_nh_buckets; i++) { 167 struct nh_res_bucket *bucket = &res_table->nh_buckets[i]; 168 struct nh_grp_entry *nhge; 169 struct nh_info *nhi; 170 171 nhge = rtnl_dereference(bucket->nh_entry); 172 nhi = rtnl_dereference(nhge->nh->nh_info); 173 __nh_notifier_single_info_init(&info->nh_res_table->nhs[i], 174 nhi); 175 } 176 177 return 0; 178 } 179 180 static int nh_notifier_grp_info_init(struct nh_notifier_info *info, 181 const struct nexthop *nh) 182 { 183 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 184 185 if (nhg->hash_threshold) 186 return nh_notifier_mpath_info_init(info, nhg); 187 else if (nhg->resilient) 188 return nh_notifier_res_table_info_init(info, nhg); 189 return -EINVAL; 190 } 191 192 static void nh_notifier_grp_info_fini(struct nh_notifier_info *info, 193 const struct nexthop *nh) 194 { 195 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 196 197 if (nhg->hash_threshold) 198 kfree(info->nh_grp); 199 else if (nhg->resilient) 200 vfree(info->nh_res_table); 201 } 202 203 static int nh_notifier_info_init(struct nh_notifier_info *info, 204 const struct nexthop *nh) 205 { 206 info->id = nh->id; 207 208 if (nh->is_group) 209 return nh_notifier_grp_info_init(info, nh); 210 else 211 return nh_notifier_single_info_init(info, nh); 212 } 213 214 static void nh_notifier_info_fini(struct nh_notifier_info *info, 215 const struct nexthop *nh) 216 { 217 if (nh->is_group) 218 nh_notifier_grp_info_fini(info, nh); 219 else 220 nh_notifier_single_info_fini(info); 221 } 222 223 static int call_nexthop_notifiers(struct net *net, 224 enum nexthop_event_type event_type, 225 struct nexthop *nh, 226 struct netlink_ext_ack *extack) 227 { 228 struct nh_notifier_info info = { 229 .net = net, 230 .extack = extack, 231 }; 232 int err; 233 234 ASSERT_RTNL(); 235 236 if (nexthop_notifiers_is_empty(net)) 237 return 0; 238 239 err = nh_notifier_info_init(&info, nh); 240 if (err) { 241 NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info"); 242 return err; 243 } 244 245 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain, 246 event_type, &info); 247 nh_notifier_info_fini(&info, nh); 248 249 return notifier_to_errno(err); 250 } 251 252 static int 253 nh_notifier_res_bucket_idle_timer_get(const struct nh_notifier_info *info, 254 bool force, unsigned int *p_idle_timer_ms) 255 { 256 struct nh_res_table *res_table; 257 struct nh_group *nhg; 258 struct nexthop *nh; 259 int err = 0; 260 261 /* When 'force' is false, nexthop bucket replacement is performed 262 * because the bucket was deemed to be idle. In this case, capable 263 * listeners can choose to perform an atomic replacement: The bucket is 264 * only replaced if it is inactive. However, if the idle timer interval 265 * is smaller than the interval in which a listener is querying 266 * buckets' activity from the device, then atomic replacement should 267 * not be tried. Pass the idle timer value to listeners, so that they 268 * could determine which type of replacement to perform. 269 */ 270 if (force) { 271 *p_idle_timer_ms = 0; 272 return 0; 273 } 274 275 rcu_read_lock(); 276 277 nh = nexthop_find_by_id(info->net, info->id); 278 if (!nh) { 279 err = -EINVAL; 280 goto out; 281 } 282 283 nhg = rcu_dereference(nh->nh_grp); 284 res_table = rcu_dereference(nhg->res_table); 285 *p_idle_timer_ms = jiffies_to_msecs(res_table->idle_timer); 286 287 out: 288 rcu_read_unlock(); 289 290 return err; 291 } 292 293 static int nh_notifier_res_bucket_info_init(struct nh_notifier_info *info, 294 u16 bucket_index, bool force, 295 struct nh_info *oldi, 296 struct nh_info *newi) 297 { 298 unsigned int idle_timer_ms; 299 int err; 300 301 err = nh_notifier_res_bucket_idle_timer_get(info, force, 302 &idle_timer_ms); 303 if (err) 304 return err; 305 306 info->type = NH_NOTIFIER_INFO_TYPE_RES_BUCKET; 307 info->nh_res_bucket = kzalloc(sizeof(*info->nh_res_bucket), 308 GFP_KERNEL); 309 if (!info->nh_res_bucket) 310 return -ENOMEM; 311 312 info->nh_res_bucket->bucket_index = bucket_index; 313 info->nh_res_bucket->idle_timer_ms = idle_timer_ms; 314 info->nh_res_bucket->force = force; 315 __nh_notifier_single_info_init(&info->nh_res_bucket->old_nh, oldi); 316 __nh_notifier_single_info_init(&info->nh_res_bucket->new_nh, newi); 317 return 0; 318 } 319 320 static void nh_notifier_res_bucket_info_fini(struct nh_notifier_info *info) 321 { 322 kfree(info->nh_res_bucket); 323 } 324 325 static int __call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id, 326 u16 bucket_index, bool force, 327 struct nh_info *oldi, 328 struct nh_info *newi, 329 struct netlink_ext_ack *extack) 330 { 331 struct nh_notifier_info info = { 332 .net = net, 333 .extack = extack, 334 .id = nhg_id, 335 }; 336 int err; 337 338 if (nexthop_notifiers_is_empty(net)) 339 return 0; 340 341 err = nh_notifier_res_bucket_info_init(&info, bucket_index, force, 342 oldi, newi); 343 if (err) 344 return err; 345 346 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain, 347 NEXTHOP_EVENT_BUCKET_REPLACE, &info); 348 nh_notifier_res_bucket_info_fini(&info); 349 350 return notifier_to_errno(err); 351 } 352 353 /* There are three users of RES_TABLE, and NHs etc. referenced from there: 354 * 355 * 1) a collection of callbacks for NH maintenance. This operates under 356 * RTNL, 357 * 2) the delayed work that gradually balances the resilient table, 358 * 3) and nexthop_select_path(), operating under RCU. 359 * 360 * Both the delayed work and the RTNL block are writers, and need to 361 * maintain mutual exclusion. Since there are only two and well-known 362 * writers for each table, the RTNL code can make sure it has exclusive 363 * access thus: 364 * 365 * - Have the DW operate without locking; 366 * - synchronously cancel the DW; 367 * - do the writing; 368 * - if the write was not actually a delete, call upkeep, which schedules 369 * DW again if necessary. 370 * 371 * The functions that are always called from the RTNL context use 372 * rtnl_dereference(). The functions that can also be called from the DW do 373 * a raw dereference and rely on the above mutual exclusion scheme. 374 */ 375 #define nh_res_dereference(p) (rcu_dereference_raw(p)) 376 377 static int call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id, 378 u16 bucket_index, bool force, 379 struct nexthop *old_nh, 380 struct nexthop *new_nh, 381 struct netlink_ext_ack *extack) 382 { 383 struct nh_info *oldi = nh_res_dereference(old_nh->nh_info); 384 struct nh_info *newi = nh_res_dereference(new_nh->nh_info); 385 386 return __call_nexthop_res_bucket_notifiers(net, nhg_id, bucket_index, 387 force, oldi, newi, extack); 388 } 389 390 static int call_nexthop_res_table_notifiers(struct net *net, struct nexthop *nh, 391 struct netlink_ext_ack *extack) 392 { 393 struct nh_notifier_info info = { 394 .net = net, 395 .extack = extack, 396 }; 397 struct nh_group *nhg; 398 int err; 399 400 ASSERT_RTNL(); 401 402 if (nexthop_notifiers_is_empty(net)) 403 return 0; 404 405 /* At this point, the nexthop buckets are still not populated. Only 406 * emit a notification with the logical nexthops, so that a listener 407 * could potentially veto it in case of unsupported configuration. 408 */ 409 nhg = rtnl_dereference(nh->nh_grp); 410 err = nh_notifier_mpath_info_init(&info, nhg); 411 if (err) { 412 NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info"); 413 return err; 414 } 415 416 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain, 417 NEXTHOP_EVENT_RES_TABLE_PRE_REPLACE, 418 &info); 419 kfree(info.nh_grp); 420 421 return notifier_to_errno(err); 422 } 423 424 static int call_nexthop_notifier(struct notifier_block *nb, struct net *net, 425 enum nexthop_event_type event_type, 426 struct nexthop *nh, 427 struct netlink_ext_ack *extack) 428 { 429 struct nh_notifier_info info = { 430 .net = net, 431 .extack = extack, 432 }; 433 int err; 434 435 err = nh_notifier_info_init(&info, nh); 436 if (err) 437 return err; 438 439 err = nb->notifier_call(nb, event_type, &info); 440 nh_notifier_info_fini(&info, nh); 441 442 return notifier_to_errno(err); 443 } 444 445 static unsigned int nh_dev_hashfn(unsigned int val) 446 { 447 unsigned int mask = NH_DEV_HASHSIZE - 1; 448 449 return (val ^ 450 (val >> NH_DEV_HASHBITS) ^ 451 (val >> (NH_DEV_HASHBITS * 2))) & mask; 452 } 453 454 static void nexthop_devhash_add(struct net *net, struct nh_info *nhi) 455 { 456 struct net_device *dev = nhi->fib_nhc.nhc_dev; 457 struct hlist_head *head; 458 unsigned int hash; 459 460 WARN_ON(!dev); 461 462 hash = nh_dev_hashfn(dev->ifindex); 463 head = &net->nexthop.devhash[hash]; 464 hlist_add_head(&nhi->dev_hash, head); 465 } 466 467 static void nexthop_free_group(struct nexthop *nh) 468 { 469 struct nh_group *nhg; 470 int i; 471 472 nhg = rcu_dereference_raw(nh->nh_grp); 473 for (i = 0; i < nhg->num_nh; ++i) { 474 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 475 476 WARN_ON(!list_empty(&nhge->nh_list)); 477 nexthop_put(nhge->nh); 478 } 479 480 WARN_ON(nhg->spare == nhg); 481 482 if (nhg->resilient) 483 vfree(rcu_dereference_raw(nhg->res_table)); 484 485 kfree(nhg->spare); 486 kfree(nhg); 487 } 488 489 static void nexthop_free_single(struct nexthop *nh) 490 { 491 struct nh_info *nhi; 492 493 nhi = rcu_dereference_raw(nh->nh_info); 494 switch (nhi->family) { 495 case AF_INET: 496 fib_nh_release(nh->net, &nhi->fib_nh); 497 break; 498 case AF_INET6: 499 ipv6_stub->fib6_nh_release(&nhi->fib6_nh); 500 break; 501 } 502 kfree(nhi); 503 } 504 505 void nexthop_free_rcu(struct rcu_head *head) 506 { 507 struct nexthop *nh = container_of(head, struct nexthop, rcu); 508 509 if (nh->is_group) 510 nexthop_free_group(nh); 511 else 512 nexthop_free_single(nh); 513 514 kfree(nh); 515 } 516 EXPORT_SYMBOL_GPL(nexthop_free_rcu); 517 518 static struct nexthop *nexthop_alloc(void) 519 { 520 struct nexthop *nh; 521 522 nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL); 523 if (nh) { 524 INIT_LIST_HEAD(&nh->fi_list); 525 INIT_LIST_HEAD(&nh->f6i_list); 526 INIT_LIST_HEAD(&nh->grp_list); 527 INIT_LIST_HEAD(&nh->fdb_list); 528 } 529 return nh; 530 } 531 532 static struct nh_group *nexthop_grp_alloc(u16 num_nh) 533 { 534 struct nh_group *nhg; 535 536 nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL); 537 if (nhg) 538 nhg->num_nh = num_nh; 539 540 return nhg; 541 } 542 543 static void nh_res_table_upkeep_dw(struct work_struct *work); 544 545 static struct nh_res_table * 546 nexthop_res_table_alloc(struct net *net, u32 nhg_id, struct nh_config *cfg) 547 { 548 const u16 num_nh_buckets = cfg->nh_grp_res_num_buckets; 549 struct nh_res_table *res_table; 550 unsigned long size; 551 552 size = struct_size(res_table, nh_buckets, num_nh_buckets); 553 res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN); 554 if (!res_table) 555 return NULL; 556 557 res_table->net = net; 558 res_table->nhg_id = nhg_id; 559 INIT_DELAYED_WORK(&res_table->upkeep_dw, &nh_res_table_upkeep_dw); 560 INIT_LIST_HEAD(&res_table->uw_nh_entries); 561 res_table->idle_timer = cfg->nh_grp_res_idle_timer; 562 res_table->unbalanced_timer = cfg->nh_grp_res_unbalanced_timer; 563 res_table->num_nh_buckets = num_nh_buckets; 564 return res_table; 565 } 566 567 static void nh_base_seq_inc(struct net *net) 568 { 569 while (++net->nexthop.seq == 0) 570 ; 571 } 572 573 /* no reference taken; rcu lock or rtnl must be held */ 574 struct nexthop *nexthop_find_by_id(struct net *net, u32 id) 575 { 576 struct rb_node **pp, *parent = NULL, *next; 577 578 pp = &net->nexthop.rb_root.rb_node; 579 while (1) { 580 struct nexthop *nh; 581 582 next = rcu_dereference_raw(*pp); 583 if (!next) 584 break; 585 parent = next; 586 587 nh = rb_entry(parent, struct nexthop, rb_node); 588 if (id < nh->id) 589 pp = &next->rb_left; 590 else if (id > nh->id) 591 pp = &next->rb_right; 592 else 593 return nh; 594 } 595 return NULL; 596 } 597 EXPORT_SYMBOL_GPL(nexthop_find_by_id); 598 599 /* used for auto id allocation; called with rtnl held */ 600 static u32 nh_find_unused_id(struct net *net) 601 { 602 u32 id_start = net->nexthop.last_id_allocated; 603 604 while (1) { 605 net->nexthop.last_id_allocated++; 606 if (net->nexthop.last_id_allocated == id_start) 607 break; 608 609 if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated)) 610 return net->nexthop.last_id_allocated; 611 } 612 return 0; 613 } 614 615 static void nh_res_time_set_deadline(unsigned long next_time, 616 unsigned long *deadline) 617 { 618 if (time_before(next_time, *deadline)) 619 *deadline = next_time; 620 } 621 622 static clock_t nh_res_table_unbalanced_time(struct nh_res_table *res_table) 623 { 624 if (list_empty(&res_table->uw_nh_entries)) 625 return 0; 626 return jiffies_delta_to_clock_t(jiffies - res_table->unbalanced_since); 627 } 628 629 static int nla_put_nh_group_res(struct sk_buff *skb, struct nh_group *nhg) 630 { 631 struct nh_res_table *res_table = rtnl_dereference(nhg->res_table); 632 struct nlattr *nest; 633 634 nest = nla_nest_start(skb, NHA_RES_GROUP); 635 if (!nest) 636 return -EMSGSIZE; 637 638 if (nla_put_u16(skb, NHA_RES_GROUP_BUCKETS, 639 res_table->num_nh_buckets) || 640 nla_put_u32(skb, NHA_RES_GROUP_IDLE_TIMER, 641 jiffies_to_clock_t(res_table->idle_timer)) || 642 nla_put_u32(skb, NHA_RES_GROUP_UNBALANCED_TIMER, 643 jiffies_to_clock_t(res_table->unbalanced_timer)) || 644 nla_put_u64_64bit(skb, NHA_RES_GROUP_UNBALANCED_TIME, 645 nh_res_table_unbalanced_time(res_table), 646 NHA_RES_GROUP_PAD)) 647 goto nla_put_failure; 648 649 nla_nest_end(skb, nest); 650 return 0; 651 652 nla_put_failure: 653 nla_nest_cancel(skb, nest); 654 return -EMSGSIZE; 655 } 656 657 static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg) 658 { 659 struct nexthop_grp *p; 660 size_t len = nhg->num_nh * sizeof(*p); 661 struct nlattr *nla; 662 u16 group_type = 0; 663 int i; 664 665 if (nhg->hash_threshold) 666 group_type = NEXTHOP_GRP_TYPE_MPATH; 667 else if (nhg->resilient) 668 group_type = NEXTHOP_GRP_TYPE_RES; 669 670 if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type)) 671 goto nla_put_failure; 672 673 nla = nla_reserve(skb, NHA_GROUP, len); 674 if (!nla) 675 goto nla_put_failure; 676 677 p = nla_data(nla); 678 for (i = 0; i < nhg->num_nh; ++i) { 679 p->id = nhg->nh_entries[i].nh->id; 680 p->weight = nhg->nh_entries[i].weight - 1; 681 p += 1; 682 } 683 684 if (nhg->resilient && nla_put_nh_group_res(skb, nhg)) 685 goto nla_put_failure; 686 687 return 0; 688 689 nla_put_failure: 690 return -EMSGSIZE; 691 } 692 693 static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh, 694 int event, u32 portid, u32 seq, unsigned int nlflags) 695 { 696 struct fib6_nh *fib6_nh; 697 struct fib_nh *fib_nh; 698 struct nlmsghdr *nlh; 699 struct nh_info *nhi; 700 struct nhmsg *nhm; 701 702 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags); 703 if (!nlh) 704 return -EMSGSIZE; 705 706 nhm = nlmsg_data(nlh); 707 nhm->nh_family = AF_UNSPEC; 708 nhm->nh_flags = nh->nh_flags; 709 nhm->nh_protocol = nh->protocol; 710 nhm->nh_scope = 0; 711 nhm->resvd = 0; 712 713 if (nla_put_u32(skb, NHA_ID, nh->id)) 714 goto nla_put_failure; 715 716 if (nh->is_group) { 717 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 718 719 if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB)) 720 goto nla_put_failure; 721 if (nla_put_nh_group(skb, nhg)) 722 goto nla_put_failure; 723 goto out; 724 } 725 726 nhi = rtnl_dereference(nh->nh_info); 727 nhm->nh_family = nhi->family; 728 if (nhi->reject_nh) { 729 if (nla_put_flag(skb, NHA_BLACKHOLE)) 730 goto nla_put_failure; 731 goto out; 732 } else if (nhi->fdb_nh) { 733 if (nla_put_flag(skb, NHA_FDB)) 734 goto nla_put_failure; 735 } else { 736 const struct net_device *dev; 737 738 dev = nhi->fib_nhc.nhc_dev; 739 if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex)) 740 goto nla_put_failure; 741 } 742 743 nhm->nh_scope = nhi->fib_nhc.nhc_scope; 744 switch (nhi->family) { 745 case AF_INET: 746 fib_nh = &nhi->fib_nh; 747 if (fib_nh->fib_nh_gw_family && 748 nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4)) 749 goto nla_put_failure; 750 break; 751 752 case AF_INET6: 753 fib6_nh = &nhi->fib6_nh; 754 if (fib6_nh->fib_nh_gw_family && 755 nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6)) 756 goto nla_put_failure; 757 break; 758 } 759 760 if (nhi->fib_nhc.nhc_lwtstate && 761 lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate, 762 NHA_ENCAP, NHA_ENCAP_TYPE) < 0) 763 goto nla_put_failure; 764 765 out: 766 nlmsg_end(skb, nlh); 767 return 0; 768 769 nla_put_failure: 770 nlmsg_cancel(skb, nlh); 771 return -EMSGSIZE; 772 } 773 774 static size_t nh_nlmsg_size_grp_res(struct nh_group *nhg) 775 { 776 return nla_total_size(0) + /* NHA_RES_GROUP */ 777 nla_total_size(2) + /* NHA_RES_GROUP_BUCKETS */ 778 nla_total_size(4) + /* NHA_RES_GROUP_IDLE_TIMER */ 779 nla_total_size(4) + /* NHA_RES_GROUP_UNBALANCED_TIMER */ 780 nla_total_size_64bit(8);/* NHA_RES_GROUP_UNBALANCED_TIME */ 781 } 782 783 static size_t nh_nlmsg_size_grp(struct nexthop *nh) 784 { 785 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 786 size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh; 787 size_t tot = nla_total_size(sz) + 788 nla_total_size(2); /* NHA_GROUP_TYPE */ 789 790 if (nhg->resilient) 791 tot += nh_nlmsg_size_grp_res(nhg); 792 793 return tot; 794 } 795 796 static size_t nh_nlmsg_size_single(struct nexthop *nh) 797 { 798 struct nh_info *nhi = rtnl_dereference(nh->nh_info); 799 size_t sz; 800 801 /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE 802 * are mutually exclusive 803 */ 804 sz = nla_total_size(4); /* NHA_OIF */ 805 806 switch (nhi->family) { 807 case AF_INET: 808 if (nhi->fib_nh.fib_nh_gw_family) 809 sz += nla_total_size(4); /* NHA_GATEWAY */ 810 break; 811 812 case AF_INET6: 813 /* NHA_GATEWAY */ 814 if (nhi->fib6_nh.fib_nh_gw_family) 815 sz += nla_total_size(sizeof(const struct in6_addr)); 816 break; 817 } 818 819 if (nhi->fib_nhc.nhc_lwtstate) { 820 sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate); 821 sz += nla_total_size(2); /* NHA_ENCAP_TYPE */ 822 } 823 824 return sz; 825 } 826 827 static size_t nh_nlmsg_size(struct nexthop *nh) 828 { 829 size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg)); 830 831 sz += nla_total_size(4); /* NHA_ID */ 832 833 if (nh->is_group) 834 sz += nh_nlmsg_size_grp(nh); 835 else 836 sz += nh_nlmsg_size_single(nh); 837 838 return sz; 839 } 840 841 static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info) 842 { 843 unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0; 844 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 845 struct sk_buff *skb; 846 int err = -ENOBUFS; 847 848 skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any()); 849 if (!skb) 850 goto errout; 851 852 err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags); 853 if (err < 0) { 854 /* -EMSGSIZE implies BUG in nh_nlmsg_size() */ 855 WARN_ON(err == -EMSGSIZE); 856 kfree_skb(skb); 857 goto errout; 858 } 859 860 rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP, 861 info->nlh, gfp_any()); 862 return; 863 errout: 864 if (err < 0) 865 rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err); 866 } 867 868 static unsigned long nh_res_bucket_used_time(const struct nh_res_bucket *bucket) 869 { 870 return (unsigned long)atomic_long_read(&bucket->used_time); 871 } 872 873 static unsigned long 874 nh_res_bucket_idle_point(const struct nh_res_table *res_table, 875 const struct nh_res_bucket *bucket, 876 unsigned long now) 877 { 878 unsigned long time = nh_res_bucket_used_time(bucket); 879 880 /* Bucket was not used since it was migrated. The idle time is now. */ 881 if (time == bucket->migrated_time) 882 return now; 883 884 return time + res_table->idle_timer; 885 } 886 887 static unsigned long 888 nh_res_table_unb_point(const struct nh_res_table *res_table) 889 { 890 return res_table->unbalanced_since + res_table->unbalanced_timer; 891 } 892 893 static void nh_res_bucket_set_idle(const struct nh_res_table *res_table, 894 struct nh_res_bucket *bucket) 895 { 896 unsigned long now = jiffies; 897 898 atomic_long_set(&bucket->used_time, (long)now); 899 bucket->migrated_time = now; 900 } 901 902 static void nh_res_bucket_set_busy(struct nh_res_bucket *bucket) 903 { 904 atomic_long_set(&bucket->used_time, (long)jiffies); 905 } 906 907 static clock_t nh_res_bucket_idle_time(const struct nh_res_bucket *bucket) 908 { 909 unsigned long used_time = nh_res_bucket_used_time(bucket); 910 911 return jiffies_delta_to_clock_t(jiffies - used_time); 912 } 913 914 static int nh_fill_res_bucket(struct sk_buff *skb, struct nexthop *nh, 915 struct nh_res_bucket *bucket, u16 bucket_index, 916 int event, u32 portid, u32 seq, 917 unsigned int nlflags, 918 struct netlink_ext_ack *extack) 919 { 920 struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry); 921 struct nlmsghdr *nlh; 922 struct nlattr *nest; 923 struct nhmsg *nhm; 924 925 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags); 926 if (!nlh) 927 return -EMSGSIZE; 928 929 nhm = nlmsg_data(nlh); 930 nhm->nh_family = AF_UNSPEC; 931 nhm->nh_flags = bucket->nh_flags; 932 nhm->nh_protocol = nh->protocol; 933 nhm->nh_scope = 0; 934 nhm->resvd = 0; 935 936 if (nla_put_u32(skb, NHA_ID, nh->id)) 937 goto nla_put_failure; 938 939 nest = nla_nest_start(skb, NHA_RES_BUCKET); 940 if (!nest) 941 goto nla_put_failure; 942 943 if (nla_put_u16(skb, NHA_RES_BUCKET_INDEX, bucket_index) || 944 nla_put_u32(skb, NHA_RES_BUCKET_NH_ID, nhge->nh->id) || 945 nla_put_u64_64bit(skb, NHA_RES_BUCKET_IDLE_TIME, 946 nh_res_bucket_idle_time(bucket), 947 NHA_RES_BUCKET_PAD)) 948 goto nla_put_failure_nest; 949 950 nla_nest_end(skb, nest); 951 nlmsg_end(skb, nlh); 952 return 0; 953 954 nla_put_failure_nest: 955 nla_nest_cancel(skb, nest); 956 nla_put_failure: 957 nlmsg_cancel(skb, nlh); 958 return -EMSGSIZE; 959 } 960 961 static void nexthop_bucket_notify(struct nh_res_table *res_table, 962 u16 bucket_index) 963 { 964 struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index]; 965 struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry); 966 struct nexthop *nh = nhge->nh_parent; 967 struct sk_buff *skb; 968 int err = -ENOBUFS; 969 970 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 971 if (!skb) 972 goto errout; 973 974 err = nh_fill_res_bucket(skb, nh, bucket, bucket_index, 975 RTM_NEWNEXTHOPBUCKET, 0, 0, NLM_F_REPLACE, 976 NULL); 977 if (err < 0) { 978 kfree_skb(skb); 979 goto errout; 980 } 981 982 rtnl_notify(skb, nh->net, 0, RTNLGRP_NEXTHOP, NULL, GFP_KERNEL); 983 return; 984 errout: 985 if (err < 0) 986 rtnl_set_sk_err(nh->net, RTNLGRP_NEXTHOP, err); 987 } 988 989 static bool valid_group_nh(struct nexthop *nh, unsigned int npaths, 990 bool *is_fdb, struct netlink_ext_ack *extack) 991 { 992 if (nh->is_group) { 993 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 994 995 /* Nesting groups within groups is not supported. */ 996 if (nhg->hash_threshold) { 997 NL_SET_ERR_MSG(extack, 998 "Hash-threshold group can not be a nexthop within a group"); 999 return false; 1000 } 1001 if (nhg->resilient) { 1002 NL_SET_ERR_MSG(extack, 1003 "Resilient group can not be a nexthop within a group"); 1004 return false; 1005 } 1006 *is_fdb = nhg->fdb_nh; 1007 } else { 1008 struct nh_info *nhi = rtnl_dereference(nh->nh_info); 1009 1010 if (nhi->reject_nh && npaths > 1) { 1011 NL_SET_ERR_MSG(extack, 1012 "Blackhole nexthop can not be used in a group with more than 1 path"); 1013 return false; 1014 } 1015 *is_fdb = nhi->fdb_nh; 1016 } 1017 1018 return true; 1019 } 1020 1021 static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family, 1022 struct netlink_ext_ack *extack) 1023 { 1024 struct nh_info *nhi; 1025 1026 nhi = rtnl_dereference(nh->nh_info); 1027 1028 if (!nhi->fdb_nh) { 1029 NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops"); 1030 return -EINVAL; 1031 } 1032 1033 if (*nh_family == AF_UNSPEC) { 1034 *nh_family = nhi->family; 1035 } else if (*nh_family != nhi->family) { 1036 NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops"); 1037 return -EINVAL; 1038 } 1039 1040 return 0; 1041 } 1042 1043 static int nh_check_attr_group(struct net *net, 1044 struct nlattr *tb[], size_t tb_size, 1045 u16 nh_grp_type, struct netlink_ext_ack *extack) 1046 { 1047 unsigned int len = nla_len(tb[NHA_GROUP]); 1048 u8 nh_family = AF_UNSPEC; 1049 struct nexthop_grp *nhg; 1050 unsigned int i, j; 1051 u8 nhg_fdb = 0; 1052 1053 if (!len || len & (sizeof(struct nexthop_grp) - 1)) { 1054 NL_SET_ERR_MSG(extack, 1055 "Invalid length for nexthop group attribute"); 1056 return -EINVAL; 1057 } 1058 1059 /* convert len to number of nexthop ids */ 1060 len /= sizeof(*nhg); 1061 1062 nhg = nla_data(tb[NHA_GROUP]); 1063 for (i = 0; i < len; ++i) { 1064 if (nhg[i].resvd1 || nhg[i].resvd2) { 1065 NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0"); 1066 return -EINVAL; 1067 } 1068 if (nhg[i].weight > 254) { 1069 NL_SET_ERR_MSG(extack, "Invalid value for weight"); 1070 return -EINVAL; 1071 } 1072 for (j = i + 1; j < len; ++j) { 1073 if (nhg[i].id == nhg[j].id) { 1074 NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group"); 1075 return -EINVAL; 1076 } 1077 } 1078 } 1079 1080 if (tb[NHA_FDB]) 1081 nhg_fdb = 1; 1082 nhg = nla_data(tb[NHA_GROUP]); 1083 for (i = 0; i < len; ++i) { 1084 struct nexthop *nh; 1085 bool is_fdb_nh; 1086 1087 nh = nexthop_find_by_id(net, nhg[i].id); 1088 if (!nh) { 1089 NL_SET_ERR_MSG(extack, "Invalid nexthop id"); 1090 return -EINVAL; 1091 } 1092 if (!valid_group_nh(nh, len, &is_fdb_nh, extack)) 1093 return -EINVAL; 1094 1095 if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack)) 1096 return -EINVAL; 1097 1098 if (!nhg_fdb && is_fdb_nh) { 1099 NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops"); 1100 return -EINVAL; 1101 } 1102 } 1103 for (i = NHA_GROUP_TYPE + 1; i < tb_size; ++i) { 1104 if (!tb[i]) 1105 continue; 1106 switch (i) { 1107 case NHA_FDB: 1108 continue; 1109 case NHA_RES_GROUP: 1110 if (nh_grp_type == NEXTHOP_GRP_TYPE_RES) 1111 continue; 1112 break; 1113 } 1114 NL_SET_ERR_MSG(extack, 1115 "No other attributes can be set in nexthop groups"); 1116 return -EINVAL; 1117 } 1118 1119 return 0; 1120 } 1121 1122 static bool ipv6_good_nh(const struct fib6_nh *nh) 1123 { 1124 int state = NUD_REACHABLE; 1125 struct neighbour *n; 1126 1127 rcu_read_lock_bh(); 1128 1129 n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6); 1130 if (n) 1131 state = n->nud_state; 1132 1133 rcu_read_unlock_bh(); 1134 1135 return !!(state & NUD_VALID); 1136 } 1137 1138 static bool ipv4_good_nh(const struct fib_nh *nh) 1139 { 1140 int state = NUD_REACHABLE; 1141 struct neighbour *n; 1142 1143 rcu_read_lock_bh(); 1144 1145 n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev, 1146 (__force u32)nh->fib_nh_gw4); 1147 if (n) 1148 state = n->nud_state; 1149 1150 rcu_read_unlock_bh(); 1151 1152 return !!(state & NUD_VALID); 1153 } 1154 1155 static struct nexthop *nexthop_select_path_hthr(struct nh_group *nhg, int hash) 1156 { 1157 struct nexthop *rc = NULL; 1158 int i; 1159 1160 for (i = 0; i < nhg->num_nh; ++i) { 1161 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 1162 struct nh_info *nhi; 1163 1164 if (hash > atomic_read(&nhge->hthr.upper_bound)) 1165 continue; 1166 1167 nhi = rcu_dereference(nhge->nh->nh_info); 1168 if (nhi->fdb_nh) 1169 return nhge->nh; 1170 1171 /* nexthops always check if it is good and does 1172 * not rely on a sysctl for this behavior 1173 */ 1174 switch (nhi->family) { 1175 case AF_INET: 1176 if (ipv4_good_nh(&nhi->fib_nh)) 1177 return nhge->nh; 1178 break; 1179 case AF_INET6: 1180 if (ipv6_good_nh(&nhi->fib6_nh)) 1181 return nhge->nh; 1182 break; 1183 } 1184 1185 if (!rc) 1186 rc = nhge->nh; 1187 } 1188 1189 return rc; 1190 } 1191 1192 static struct nexthop *nexthop_select_path_res(struct nh_group *nhg, int hash) 1193 { 1194 struct nh_res_table *res_table = rcu_dereference(nhg->res_table); 1195 u16 bucket_index = hash % res_table->num_nh_buckets; 1196 struct nh_res_bucket *bucket; 1197 struct nh_grp_entry *nhge; 1198 1199 /* nexthop_select_path() is expected to return a non-NULL value, so 1200 * skip protocol validation and just hand out whatever there is. 1201 */ 1202 bucket = &res_table->nh_buckets[bucket_index]; 1203 nh_res_bucket_set_busy(bucket); 1204 nhge = rcu_dereference(bucket->nh_entry); 1205 return nhge->nh; 1206 } 1207 1208 struct nexthop *nexthop_select_path(struct nexthop *nh, int hash) 1209 { 1210 struct nh_group *nhg; 1211 1212 if (!nh->is_group) 1213 return nh; 1214 1215 nhg = rcu_dereference(nh->nh_grp); 1216 if (nhg->hash_threshold) 1217 return nexthop_select_path_hthr(nhg, hash); 1218 else if (nhg->resilient) 1219 return nexthop_select_path_res(nhg, hash); 1220 1221 /* Unreachable. */ 1222 return NULL; 1223 } 1224 EXPORT_SYMBOL_GPL(nexthop_select_path); 1225 1226 int nexthop_for_each_fib6_nh(struct nexthop *nh, 1227 int (*cb)(struct fib6_nh *nh, void *arg), 1228 void *arg) 1229 { 1230 struct nh_info *nhi; 1231 int err; 1232 1233 if (nh->is_group) { 1234 struct nh_group *nhg; 1235 int i; 1236 1237 nhg = rcu_dereference_rtnl(nh->nh_grp); 1238 for (i = 0; i < nhg->num_nh; i++) { 1239 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 1240 1241 nhi = rcu_dereference_rtnl(nhge->nh->nh_info); 1242 err = cb(&nhi->fib6_nh, arg); 1243 if (err) 1244 return err; 1245 } 1246 } else { 1247 nhi = rcu_dereference_rtnl(nh->nh_info); 1248 err = cb(&nhi->fib6_nh, arg); 1249 if (err) 1250 return err; 1251 } 1252 1253 return 0; 1254 } 1255 EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh); 1256 1257 static int check_src_addr(const struct in6_addr *saddr, 1258 struct netlink_ext_ack *extack) 1259 { 1260 if (!ipv6_addr_any(saddr)) { 1261 NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects"); 1262 return -EINVAL; 1263 } 1264 return 0; 1265 } 1266 1267 int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg, 1268 struct netlink_ext_ack *extack) 1269 { 1270 struct nh_info *nhi; 1271 bool is_fdb_nh; 1272 1273 /* fib6_src is unique to a fib6_info and limits the ability to cache 1274 * routes in fib6_nh within a nexthop that is potentially shared 1275 * across multiple fib entries. If the config wants to use source 1276 * routing it can not use nexthop objects. mlxsw also does not allow 1277 * fib6_src on routes. 1278 */ 1279 if (cfg && check_src_addr(&cfg->fc_src, extack) < 0) 1280 return -EINVAL; 1281 1282 if (nh->is_group) { 1283 struct nh_group *nhg; 1284 1285 nhg = rtnl_dereference(nh->nh_grp); 1286 if (nhg->has_v4) 1287 goto no_v4_nh; 1288 is_fdb_nh = nhg->fdb_nh; 1289 } else { 1290 nhi = rtnl_dereference(nh->nh_info); 1291 if (nhi->family == AF_INET) 1292 goto no_v4_nh; 1293 is_fdb_nh = nhi->fdb_nh; 1294 } 1295 1296 if (is_fdb_nh) { 1297 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop"); 1298 return -EINVAL; 1299 } 1300 1301 return 0; 1302 no_v4_nh: 1303 NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop"); 1304 return -EINVAL; 1305 } 1306 EXPORT_SYMBOL_GPL(fib6_check_nexthop); 1307 1308 /* if existing nexthop has ipv6 routes linked to it, need 1309 * to verify this new spec works with ipv6 1310 */ 1311 static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new, 1312 struct netlink_ext_ack *extack) 1313 { 1314 struct fib6_info *f6i; 1315 1316 if (list_empty(&old->f6i_list)) 1317 return 0; 1318 1319 list_for_each_entry(f6i, &old->f6i_list, nh_list) { 1320 if (check_src_addr(&f6i->fib6_src.addr, extack) < 0) 1321 return -EINVAL; 1322 } 1323 1324 return fib6_check_nexthop(new, NULL, extack); 1325 } 1326 1327 static int nexthop_check_scope(struct nh_info *nhi, u8 scope, 1328 struct netlink_ext_ack *extack) 1329 { 1330 if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) { 1331 NL_SET_ERR_MSG(extack, 1332 "Route with host scope can not have a gateway"); 1333 return -EINVAL; 1334 } 1335 1336 if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) { 1337 NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop"); 1338 return -EINVAL; 1339 } 1340 1341 return 0; 1342 } 1343 1344 /* Invoked by fib add code to verify nexthop by id is ok with 1345 * config for prefix; parts of fib_check_nh not done when nexthop 1346 * object is used. 1347 */ 1348 int fib_check_nexthop(struct nexthop *nh, u8 scope, 1349 struct netlink_ext_ack *extack) 1350 { 1351 struct nh_info *nhi; 1352 int err = 0; 1353 1354 if (nh->is_group) { 1355 struct nh_group *nhg; 1356 1357 nhg = rtnl_dereference(nh->nh_grp); 1358 if (nhg->fdb_nh) { 1359 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop"); 1360 err = -EINVAL; 1361 goto out; 1362 } 1363 1364 if (scope == RT_SCOPE_HOST) { 1365 NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops"); 1366 err = -EINVAL; 1367 goto out; 1368 } 1369 1370 /* all nexthops in a group have the same scope */ 1371 nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info); 1372 err = nexthop_check_scope(nhi, scope, extack); 1373 } else { 1374 nhi = rtnl_dereference(nh->nh_info); 1375 if (nhi->fdb_nh) { 1376 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop"); 1377 err = -EINVAL; 1378 goto out; 1379 } 1380 err = nexthop_check_scope(nhi, scope, extack); 1381 } 1382 1383 out: 1384 return err; 1385 } 1386 1387 static int fib_check_nh_list(struct nexthop *old, struct nexthop *new, 1388 struct netlink_ext_ack *extack) 1389 { 1390 struct fib_info *fi; 1391 1392 list_for_each_entry(fi, &old->fi_list, nh_list) { 1393 int err; 1394 1395 err = fib_check_nexthop(new, fi->fib_scope, extack); 1396 if (err) 1397 return err; 1398 } 1399 return 0; 1400 } 1401 1402 static bool nh_res_nhge_is_balanced(const struct nh_grp_entry *nhge) 1403 { 1404 return nhge->res.count_buckets == nhge->res.wants_buckets; 1405 } 1406 1407 static bool nh_res_nhge_is_ow(const struct nh_grp_entry *nhge) 1408 { 1409 return nhge->res.count_buckets > nhge->res.wants_buckets; 1410 } 1411 1412 static bool nh_res_nhge_is_uw(const struct nh_grp_entry *nhge) 1413 { 1414 return nhge->res.count_buckets < nhge->res.wants_buckets; 1415 } 1416 1417 static bool nh_res_table_is_balanced(const struct nh_res_table *res_table) 1418 { 1419 return list_empty(&res_table->uw_nh_entries); 1420 } 1421 1422 static void nh_res_bucket_unset_nh(struct nh_res_bucket *bucket) 1423 { 1424 struct nh_grp_entry *nhge; 1425 1426 if (bucket->occupied) { 1427 nhge = nh_res_dereference(bucket->nh_entry); 1428 nhge->res.count_buckets--; 1429 bucket->occupied = false; 1430 } 1431 } 1432 1433 static void nh_res_bucket_set_nh(struct nh_res_bucket *bucket, 1434 struct nh_grp_entry *nhge) 1435 { 1436 nh_res_bucket_unset_nh(bucket); 1437 1438 bucket->occupied = true; 1439 rcu_assign_pointer(bucket->nh_entry, nhge); 1440 nhge->res.count_buckets++; 1441 } 1442 1443 static bool nh_res_bucket_should_migrate(struct nh_res_table *res_table, 1444 struct nh_res_bucket *bucket, 1445 unsigned long *deadline, bool *force) 1446 { 1447 unsigned long now = jiffies; 1448 struct nh_grp_entry *nhge; 1449 unsigned long idle_point; 1450 1451 if (!bucket->occupied) { 1452 /* The bucket is not occupied, its NHGE pointer is either 1453 * NULL or obsolete. We _have to_ migrate: set force. 1454 */ 1455 *force = true; 1456 return true; 1457 } 1458 1459 nhge = nh_res_dereference(bucket->nh_entry); 1460 1461 /* If the bucket is populated by an underweight or balanced 1462 * nexthop, do not migrate. 1463 */ 1464 if (!nh_res_nhge_is_ow(nhge)) 1465 return false; 1466 1467 /* At this point we know that the bucket is populated with an 1468 * overweight nexthop. It needs to be migrated to a new nexthop if 1469 * the idle timer of unbalanced timer expired. 1470 */ 1471 1472 idle_point = nh_res_bucket_idle_point(res_table, bucket, now); 1473 if (time_after_eq(now, idle_point)) { 1474 /* The bucket is idle. We _can_ migrate: unset force. */ 1475 *force = false; 1476 return true; 1477 } 1478 1479 /* Unbalanced timer of 0 means "never force". */ 1480 if (res_table->unbalanced_timer) { 1481 unsigned long unb_point; 1482 1483 unb_point = nh_res_table_unb_point(res_table); 1484 if (time_after(now, unb_point)) { 1485 /* The bucket is not idle, but the unbalanced timer 1486 * expired. We _can_ migrate, but set force anyway, 1487 * so that drivers know to ignore activity reports 1488 * from the HW. 1489 */ 1490 *force = true; 1491 return true; 1492 } 1493 1494 nh_res_time_set_deadline(unb_point, deadline); 1495 } 1496 1497 nh_res_time_set_deadline(idle_point, deadline); 1498 return false; 1499 } 1500 1501 static bool nh_res_bucket_migrate(struct nh_res_table *res_table, 1502 u16 bucket_index, bool notify, 1503 bool notify_nl, bool force) 1504 { 1505 struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index]; 1506 struct nh_grp_entry *new_nhge; 1507 struct netlink_ext_ack extack; 1508 int err; 1509 1510 new_nhge = list_first_entry_or_null(&res_table->uw_nh_entries, 1511 struct nh_grp_entry, 1512 res.uw_nh_entry); 1513 if (WARN_ON_ONCE(!new_nhge)) 1514 /* If this function is called, "bucket" is either not 1515 * occupied, or it belongs to a next hop that is 1516 * overweight. In either case, there ought to be a 1517 * corresponding underweight next hop. 1518 */ 1519 return false; 1520 1521 if (notify) { 1522 struct nh_grp_entry *old_nhge; 1523 1524 old_nhge = nh_res_dereference(bucket->nh_entry); 1525 err = call_nexthop_res_bucket_notifiers(res_table->net, 1526 res_table->nhg_id, 1527 bucket_index, force, 1528 old_nhge->nh, 1529 new_nhge->nh, &extack); 1530 if (err) { 1531 pr_err_ratelimited("%s\n", extack._msg); 1532 if (!force) 1533 return false; 1534 /* It is not possible to veto a forced replacement, so 1535 * just clear the hardware flags from the nexthop 1536 * bucket to indicate to user space that this bucket is 1537 * not correctly populated in hardware. 1538 */ 1539 bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP); 1540 } 1541 } 1542 1543 nh_res_bucket_set_nh(bucket, new_nhge); 1544 nh_res_bucket_set_idle(res_table, bucket); 1545 1546 if (notify_nl) 1547 nexthop_bucket_notify(res_table, bucket_index); 1548 1549 if (nh_res_nhge_is_balanced(new_nhge)) 1550 list_del(&new_nhge->res.uw_nh_entry); 1551 return true; 1552 } 1553 1554 #define NH_RES_UPKEEP_DW_MINIMUM_INTERVAL (HZ / 2) 1555 1556 static void nh_res_table_upkeep(struct nh_res_table *res_table, 1557 bool notify, bool notify_nl) 1558 { 1559 unsigned long now = jiffies; 1560 unsigned long deadline; 1561 u16 i; 1562 1563 /* Deadline is the next time that upkeep should be run. It is the 1564 * earliest time at which one of the buckets might be migrated. 1565 * Start at the most pessimistic estimate: either unbalanced_timer 1566 * from now, or if there is none, idle_timer from now. For each 1567 * encountered time point, call nh_res_time_set_deadline() to 1568 * refine the estimate. 1569 */ 1570 if (res_table->unbalanced_timer) 1571 deadline = now + res_table->unbalanced_timer; 1572 else 1573 deadline = now + res_table->idle_timer; 1574 1575 for (i = 0; i < res_table->num_nh_buckets; i++) { 1576 struct nh_res_bucket *bucket = &res_table->nh_buckets[i]; 1577 bool force; 1578 1579 if (nh_res_bucket_should_migrate(res_table, bucket, 1580 &deadline, &force)) { 1581 if (!nh_res_bucket_migrate(res_table, i, notify, 1582 notify_nl, force)) { 1583 unsigned long idle_point; 1584 1585 /* A driver can override the migration 1586 * decision if the HW reports that the 1587 * bucket is actually not idle. Therefore 1588 * remark the bucket as busy again and 1589 * update the deadline. 1590 */ 1591 nh_res_bucket_set_busy(bucket); 1592 idle_point = nh_res_bucket_idle_point(res_table, 1593 bucket, 1594 now); 1595 nh_res_time_set_deadline(idle_point, &deadline); 1596 } 1597 } 1598 } 1599 1600 /* If the group is still unbalanced, schedule the next upkeep to 1601 * either the deadline computed above, or the minimum deadline, 1602 * whichever comes later. 1603 */ 1604 if (!nh_res_table_is_balanced(res_table)) { 1605 unsigned long now = jiffies; 1606 unsigned long min_deadline; 1607 1608 min_deadline = now + NH_RES_UPKEEP_DW_MINIMUM_INTERVAL; 1609 if (time_before(deadline, min_deadline)) 1610 deadline = min_deadline; 1611 1612 queue_delayed_work(system_power_efficient_wq, 1613 &res_table->upkeep_dw, deadline - now); 1614 } 1615 } 1616 1617 static void nh_res_table_upkeep_dw(struct work_struct *work) 1618 { 1619 struct delayed_work *dw = to_delayed_work(work); 1620 struct nh_res_table *res_table; 1621 1622 res_table = container_of(dw, struct nh_res_table, upkeep_dw); 1623 nh_res_table_upkeep(res_table, true, true); 1624 } 1625 1626 static void nh_res_table_cancel_upkeep(struct nh_res_table *res_table) 1627 { 1628 cancel_delayed_work_sync(&res_table->upkeep_dw); 1629 } 1630 1631 static void nh_res_group_rebalance(struct nh_group *nhg, 1632 struct nh_res_table *res_table) 1633 { 1634 int prev_upper_bound = 0; 1635 int total = 0; 1636 int w = 0; 1637 int i; 1638 1639 INIT_LIST_HEAD(&res_table->uw_nh_entries); 1640 1641 for (i = 0; i < nhg->num_nh; ++i) 1642 total += nhg->nh_entries[i].weight; 1643 1644 for (i = 0; i < nhg->num_nh; ++i) { 1645 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 1646 int upper_bound; 1647 1648 w += nhge->weight; 1649 upper_bound = DIV_ROUND_CLOSEST(res_table->num_nh_buckets * w, 1650 total); 1651 nhge->res.wants_buckets = upper_bound - prev_upper_bound; 1652 prev_upper_bound = upper_bound; 1653 1654 if (nh_res_nhge_is_uw(nhge)) { 1655 if (list_empty(&res_table->uw_nh_entries)) 1656 res_table->unbalanced_since = jiffies; 1657 list_add(&nhge->res.uw_nh_entry, 1658 &res_table->uw_nh_entries); 1659 } 1660 } 1661 } 1662 1663 /* Migrate buckets in res_table so that they reference NHGE's from NHG with 1664 * the right NH ID. Set those buckets that do not have a corresponding NHGE 1665 * entry in NHG as not occupied. 1666 */ 1667 static void nh_res_table_migrate_buckets(struct nh_res_table *res_table, 1668 struct nh_group *nhg) 1669 { 1670 u16 i; 1671 1672 for (i = 0; i < res_table->num_nh_buckets; i++) { 1673 struct nh_res_bucket *bucket = &res_table->nh_buckets[i]; 1674 u32 id = rtnl_dereference(bucket->nh_entry)->nh->id; 1675 bool found = false; 1676 int j; 1677 1678 for (j = 0; j < nhg->num_nh; j++) { 1679 struct nh_grp_entry *nhge = &nhg->nh_entries[j]; 1680 1681 if (nhge->nh->id == id) { 1682 nh_res_bucket_set_nh(bucket, nhge); 1683 found = true; 1684 break; 1685 } 1686 } 1687 1688 if (!found) 1689 nh_res_bucket_unset_nh(bucket); 1690 } 1691 } 1692 1693 static void replace_nexthop_grp_res(struct nh_group *oldg, 1694 struct nh_group *newg) 1695 { 1696 /* For NH group replacement, the new NHG might only have a stub 1697 * hash table with 0 buckets, because the number of buckets was not 1698 * specified. For NH removal, oldg and newg both reference the same 1699 * res_table. So in any case, in the following, we want to work 1700 * with oldg->res_table. 1701 */ 1702 struct nh_res_table *old_res_table = rtnl_dereference(oldg->res_table); 1703 unsigned long prev_unbalanced_since = old_res_table->unbalanced_since; 1704 bool prev_has_uw = !list_empty(&old_res_table->uw_nh_entries); 1705 1706 nh_res_table_cancel_upkeep(old_res_table); 1707 nh_res_table_migrate_buckets(old_res_table, newg); 1708 nh_res_group_rebalance(newg, old_res_table); 1709 if (prev_has_uw && !list_empty(&old_res_table->uw_nh_entries)) 1710 old_res_table->unbalanced_since = prev_unbalanced_since; 1711 nh_res_table_upkeep(old_res_table, true, false); 1712 } 1713 1714 static void nh_hthr_group_rebalance(struct nh_group *nhg) 1715 { 1716 int total = 0; 1717 int w = 0; 1718 int i; 1719 1720 for (i = 0; i < nhg->num_nh; ++i) 1721 total += nhg->nh_entries[i].weight; 1722 1723 for (i = 0; i < nhg->num_nh; ++i) { 1724 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 1725 int upper_bound; 1726 1727 w += nhge->weight; 1728 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1; 1729 atomic_set(&nhge->hthr.upper_bound, upper_bound); 1730 } 1731 } 1732 1733 static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge, 1734 struct nl_info *nlinfo) 1735 { 1736 struct nh_grp_entry *nhges, *new_nhges; 1737 struct nexthop *nhp = nhge->nh_parent; 1738 struct netlink_ext_ack extack; 1739 struct nexthop *nh = nhge->nh; 1740 struct nh_group *nhg, *newg; 1741 int i, j, err; 1742 1743 WARN_ON(!nh); 1744 1745 nhg = rtnl_dereference(nhp->nh_grp); 1746 newg = nhg->spare; 1747 1748 /* last entry, keep it visible and remove the parent */ 1749 if (nhg->num_nh == 1) { 1750 remove_nexthop(net, nhp, nlinfo); 1751 return; 1752 } 1753 1754 newg->has_v4 = false; 1755 newg->is_multipath = nhg->is_multipath; 1756 newg->hash_threshold = nhg->hash_threshold; 1757 newg->resilient = nhg->resilient; 1758 newg->fdb_nh = nhg->fdb_nh; 1759 newg->num_nh = nhg->num_nh; 1760 1761 /* copy old entries to new except the one getting removed */ 1762 nhges = nhg->nh_entries; 1763 new_nhges = newg->nh_entries; 1764 for (i = 0, j = 0; i < nhg->num_nh; ++i) { 1765 struct nh_info *nhi; 1766 1767 /* current nexthop getting removed */ 1768 if (nhg->nh_entries[i].nh == nh) { 1769 newg->num_nh--; 1770 continue; 1771 } 1772 1773 nhi = rtnl_dereference(nhges[i].nh->nh_info); 1774 if (nhi->family == AF_INET) 1775 newg->has_v4 = true; 1776 1777 list_del(&nhges[i].nh_list); 1778 new_nhges[j].nh_parent = nhges[i].nh_parent; 1779 new_nhges[j].nh = nhges[i].nh; 1780 new_nhges[j].weight = nhges[i].weight; 1781 list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list); 1782 j++; 1783 } 1784 1785 if (newg->hash_threshold) 1786 nh_hthr_group_rebalance(newg); 1787 else if (newg->resilient) 1788 replace_nexthop_grp_res(nhg, newg); 1789 1790 rcu_assign_pointer(nhp->nh_grp, newg); 1791 1792 list_del(&nhge->nh_list); 1793 nexthop_put(nhge->nh); 1794 1795 /* Removal of a NH from a resilient group is notified through 1796 * bucket notifications. 1797 */ 1798 if (newg->hash_threshold) { 1799 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp, 1800 &extack); 1801 if (err) 1802 pr_err("%s\n", extack._msg); 1803 } 1804 1805 if (nlinfo) 1806 nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo); 1807 } 1808 1809 static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh, 1810 struct nl_info *nlinfo) 1811 { 1812 struct nh_grp_entry *nhge, *tmp; 1813 1814 list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list) 1815 remove_nh_grp_entry(net, nhge, nlinfo); 1816 1817 /* make sure all see the newly published array before releasing rtnl */ 1818 synchronize_net(); 1819 } 1820 1821 static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo) 1822 { 1823 struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp); 1824 struct nh_res_table *res_table; 1825 int i, num_nh = nhg->num_nh; 1826 1827 for (i = 0; i < num_nh; ++i) { 1828 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 1829 1830 if (WARN_ON(!nhge->nh)) 1831 continue; 1832 1833 list_del_init(&nhge->nh_list); 1834 } 1835 1836 if (nhg->resilient) { 1837 res_table = rtnl_dereference(nhg->res_table); 1838 nh_res_table_cancel_upkeep(res_table); 1839 } 1840 } 1841 1842 /* not called for nexthop replace */ 1843 static void __remove_nexthop_fib(struct net *net, struct nexthop *nh) 1844 { 1845 struct fib6_info *f6i, *tmp; 1846 bool do_flush = false; 1847 struct fib_info *fi; 1848 1849 list_for_each_entry(fi, &nh->fi_list, nh_list) { 1850 fi->fib_flags |= RTNH_F_DEAD; 1851 do_flush = true; 1852 } 1853 if (do_flush) 1854 fib_flush(net); 1855 1856 /* ip6_del_rt removes the entry from this list hence the _safe */ 1857 list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) { 1858 /* __ip6_del_rt does a release, so do a hold here */ 1859 fib6_info_hold(f6i); 1860 ipv6_stub->ip6_del_rt(net, f6i, 1861 !READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode)); 1862 } 1863 } 1864 1865 static void __remove_nexthop(struct net *net, struct nexthop *nh, 1866 struct nl_info *nlinfo) 1867 { 1868 __remove_nexthop_fib(net, nh); 1869 1870 if (nh->is_group) { 1871 remove_nexthop_group(nh, nlinfo); 1872 } else { 1873 struct nh_info *nhi; 1874 1875 nhi = rtnl_dereference(nh->nh_info); 1876 if (nhi->fib_nhc.nhc_dev) 1877 hlist_del(&nhi->dev_hash); 1878 1879 remove_nexthop_from_groups(net, nh, nlinfo); 1880 } 1881 } 1882 1883 static void remove_nexthop(struct net *net, struct nexthop *nh, 1884 struct nl_info *nlinfo) 1885 { 1886 call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh, NULL); 1887 1888 /* remove from the tree */ 1889 rb_erase(&nh->rb_node, &net->nexthop.rb_root); 1890 1891 if (nlinfo) 1892 nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo); 1893 1894 __remove_nexthop(net, nh, nlinfo); 1895 nh_base_seq_inc(net); 1896 1897 nexthop_put(nh); 1898 } 1899 1900 /* if any FIB entries reference this nexthop, any dst entries 1901 * need to be regenerated 1902 */ 1903 static void nh_rt_cache_flush(struct net *net, struct nexthop *nh, 1904 struct nexthop *replaced_nh) 1905 { 1906 struct fib6_info *f6i; 1907 struct nh_group *nhg; 1908 int i; 1909 1910 if (!list_empty(&nh->fi_list)) 1911 rt_cache_flush(net); 1912 1913 list_for_each_entry(f6i, &nh->f6i_list, nh_list) 1914 ipv6_stub->fib6_update_sernum(net, f6i); 1915 1916 /* if an IPv6 group was replaced, we have to release all old 1917 * dsts to make sure all refcounts are released 1918 */ 1919 if (!replaced_nh->is_group) 1920 return; 1921 1922 nhg = rtnl_dereference(replaced_nh->nh_grp); 1923 for (i = 0; i < nhg->num_nh; i++) { 1924 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 1925 struct nh_info *nhi = rtnl_dereference(nhge->nh->nh_info); 1926 1927 if (nhi->family == AF_INET6) 1928 ipv6_stub->fib6_nh_release_dsts(&nhi->fib6_nh); 1929 } 1930 } 1931 1932 static int replace_nexthop_grp(struct net *net, struct nexthop *old, 1933 struct nexthop *new, const struct nh_config *cfg, 1934 struct netlink_ext_ack *extack) 1935 { 1936 struct nh_res_table *tmp_table = NULL; 1937 struct nh_res_table *new_res_table; 1938 struct nh_res_table *old_res_table; 1939 struct nh_group *oldg, *newg; 1940 int i, err; 1941 1942 if (!new->is_group) { 1943 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop."); 1944 return -EINVAL; 1945 } 1946 1947 oldg = rtnl_dereference(old->nh_grp); 1948 newg = rtnl_dereference(new->nh_grp); 1949 1950 if (newg->hash_threshold != oldg->hash_threshold) { 1951 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with one of a different type."); 1952 return -EINVAL; 1953 } 1954 1955 if (newg->hash_threshold) { 1956 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, 1957 extack); 1958 if (err) 1959 return err; 1960 } else if (newg->resilient) { 1961 new_res_table = rtnl_dereference(newg->res_table); 1962 old_res_table = rtnl_dereference(oldg->res_table); 1963 1964 /* Accept if num_nh_buckets was not given, but if it was 1965 * given, demand that the value be correct. 1966 */ 1967 if (cfg->nh_grp_res_has_num_buckets && 1968 cfg->nh_grp_res_num_buckets != 1969 old_res_table->num_nh_buckets) { 1970 NL_SET_ERR_MSG(extack, "Can not change number of buckets of a resilient nexthop group."); 1971 return -EINVAL; 1972 } 1973 1974 /* Emit a pre-replace notification so that listeners could veto 1975 * a potentially unsupported configuration. Otherwise, 1976 * individual bucket replacement notifications would need to be 1977 * vetoed, which is something that should only happen if the 1978 * bucket is currently active. 1979 */ 1980 err = call_nexthop_res_table_notifiers(net, new, extack); 1981 if (err) 1982 return err; 1983 1984 if (cfg->nh_grp_res_has_idle_timer) 1985 old_res_table->idle_timer = cfg->nh_grp_res_idle_timer; 1986 if (cfg->nh_grp_res_has_unbalanced_timer) 1987 old_res_table->unbalanced_timer = 1988 cfg->nh_grp_res_unbalanced_timer; 1989 1990 replace_nexthop_grp_res(oldg, newg); 1991 1992 tmp_table = new_res_table; 1993 rcu_assign_pointer(newg->res_table, old_res_table); 1994 rcu_assign_pointer(newg->spare->res_table, old_res_table); 1995 } 1996 1997 /* update parents - used by nexthop code for cleanup */ 1998 for (i = 0; i < newg->num_nh; i++) 1999 newg->nh_entries[i].nh_parent = old; 2000 2001 rcu_assign_pointer(old->nh_grp, newg); 2002 2003 /* Make sure concurrent readers are not using 'oldg' anymore. */ 2004 synchronize_net(); 2005 2006 if (newg->resilient) { 2007 rcu_assign_pointer(oldg->res_table, tmp_table); 2008 rcu_assign_pointer(oldg->spare->res_table, tmp_table); 2009 } 2010 2011 for (i = 0; i < oldg->num_nh; i++) 2012 oldg->nh_entries[i].nh_parent = new; 2013 2014 rcu_assign_pointer(new->nh_grp, oldg); 2015 2016 return 0; 2017 } 2018 2019 static void nh_group_v4_update(struct nh_group *nhg) 2020 { 2021 struct nh_grp_entry *nhges; 2022 bool has_v4 = false; 2023 int i; 2024 2025 nhges = nhg->nh_entries; 2026 for (i = 0; i < nhg->num_nh; i++) { 2027 struct nh_info *nhi; 2028 2029 nhi = rtnl_dereference(nhges[i].nh->nh_info); 2030 if (nhi->family == AF_INET) 2031 has_v4 = true; 2032 } 2033 nhg->has_v4 = has_v4; 2034 } 2035 2036 static int replace_nexthop_single_notify_res(struct net *net, 2037 struct nh_res_table *res_table, 2038 struct nexthop *old, 2039 struct nh_info *oldi, 2040 struct nh_info *newi, 2041 struct netlink_ext_ack *extack) 2042 { 2043 u32 nhg_id = res_table->nhg_id; 2044 int err; 2045 u16 i; 2046 2047 for (i = 0; i < res_table->num_nh_buckets; i++) { 2048 struct nh_res_bucket *bucket = &res_table->nh_buckets[i]; 2049 struct nh_grp_entry *nhge; 2050 2051 nhge = rtnl_dereference(bucket->nh_entry); 2052 if (nhge->nh == old) { 2053 err = __call_nexthop_res_bucket_notifiers(net, nhg_id, 2054 i, true, 2055 oldi, newi, 2056 extack); 2057 if (err) 2058 goto err_notify; 2059 } 2060 } 2061 2062 return 0; 2063 2064 err_notify: 2065 while (i-- > 0) { 2066 struct nh_res_bucket *bucket = &res_table->nh_buckets[i]; 2067 struct nh_grp_entry *nhge; 2068 2069 nhge = rtnl_dereference(bucket->nh_entry); 2070 if (nhge->nh == old) 2071 __call_nexthop_res_bucket_notifiers(net, nhg_id, i, 2072 true, newi, oldi, 2073 extack); 2074 } 2075 return err; 2076 } 2077 2078 static int replace_nexthop_single_notify(struct net *net, 2079 struct nexthop *group_nh, 2080 struct nexthop *old, 2081 struct nh_info *oldi, 2082 struct nh_info *newi, 2083 struct netlink_ext_ack *extack) 2084 { 2085 struct nh_group *nhg = rtnl_dereference(group_nh->nh_grp); 2086 struct nh_res_table *res_table; 2087 2088 if (nhg->hash_threshold) { 2089 return call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, 2090 group_nh, extack); 2091 } else if (nhg->resilient) { 2092 res_table = rtnl_dereference(nhg->res_table); 2093 return replace_nexthop_single_notify_res(net, res_table, 2094 old, oldi, newi, 2095 extack); 2096 } 2097 2098 return -EINVAL; 2099 } 2100 2101 static int replace_nexthop_single(struct net *net, struct nexthop *old, 2102 struct nexthop *new, 2103 struct netlink_ext_ack *extack) 2104 { 2105 u8 old_protocol, old_nh_flags; 2106 struct nh_info *oldi, *newi; 2107 struct nh_grp_entry *nhge; 2108 int err; 2109 2110 if (new->is_group) { 2111 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group."); 2112 return -EINVAL; 2113 } 2114 2115 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack); 2116 if (err) 2117 return err; 2118 2119 /* Hardware flags were set on 'old' as 'new' is not in the red-black 2120 * tree. Therefore, inherit the flags from 'old' to 'new'. 2121 */ 2122 new->nh_flags |= old->nh_flags & (RTNH_F_OFFLOAD | RTNH_F_TRAP); 2123 2124 oldi = rtnl_dereference(old->nh_info); 2125 newi = rtnl_dereference(new->nh_info); 2126 2127 newi->nh_parent = old; 2128 oldi->nh_parent = new; 2129 2130 old_protocol = old->protocol; 2131 old_nh_flags = old->nh_flags; 2132 2133 old->protocol = new->protocol; 2134 old->nh_flags = new->nh_flags; 2135 2136 rcu_assign_pointer(old->nh_info, newi); 2137 rcu_assign_pointer(new->nh_info, oldi); 2138 2139 /* Send a replace notification for all the groups using the nexthop. */ 2140 list_for_each_entry(nhge, &old->grp_list, nh_list) { 2141 struct nexthop *nhp = nhge->nh_parent; 2142 2143 err = replace_nexthop_single_notify(net, nhp, old, oldi, newi, 2144 extack); 2145 if (err) 2146 goto err_notify; 2147 } 2148 2149 /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially 2150 * update IPv4 indication in all the groups using the nexthop. 2151 */ 2152 if (oldi->family == AF_INET && newi->family == AF_INET6) { 2153 list_for_each_entry(nhge, &old->grp_list, nh_list) { 2154 struct nexthop *nhp = nhge->nh_parent; 2155 struct nh_group *nhg; 2156 2157 nhg = rtnl_dereference(nhp->nh_grp); 2158 nh_group_v4_update(nhg); 2159 } 2160 } 2161 2162 return 0; 2163 2164 err_notify: 2165 rcu_assign_pointer(new->nh_info, newi); 2166 rcu_assign_pointer(old->nh_info, oldi); 2167 old->nh_flags = old_nh_flags; 2168 old->protocol = old_protocol; 2169 oldi->nh_parent = old; 2170 newi->nh_parent = new; 2171 list_for_each_entry_continue_reverse(nhge, &old->grp_list, nh_list) { 2172 struct nexthop *nhp = nhge->nh_parent; 2173 2174 replace_nexthop_single_notify(net, nhp, old, newi, oldi, NULL); 2175 } 2176 call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, old, extack); 2177 return err; 2178 } 2179 2180 static void __nexthop_replace_notify(struct net *net, struct nexthop *nh, 2181 struct nl_info *info) 2182 { 2183 struct fib6_info *f6i; 2184 2185 if (!list_empty(&nh->fi_list)) { 2186 struct fib_info *fi; 2187 2188 /* expectation is a few fib_info per nexthop and then 2189 * a lot of routes per fib_info. So mark the fib_info 2190 * and then walk the fib tables once 2191 */ 2192 list_for_each_entry(fi, &nh->fi_list, nh_list) 2193 fi->nh_updated = true; 2194 2195 fib_info_notify_update(net, info); 2196 2197 list_for_each_entry(fi, &nh->fi_list, nh_list) 2198 fi->nh_updated = false; 2199 } 2200 2201 list_for_each_entry(f6i, &nh->f6i_list, nh_list) 2202 ipv6_stub->fib6_rt_update(net, f6i, info); 2203 } 2204 2205 /* send RTM_NEWROUTE with REPLACE flag set for all FIB entries 2206 * linked to this nexthop and for all groups that the nexthop 2207 * is a member of 2208 */ 2209 static void nexthop_replace_notify(struct net *net, struct nexthop *nh, 2210 struct nl_info *info) 2211 { 2212 struct nh_grp_entry *nhge; 2213 2214 __nexthop_replace_notify(net, nh, info); 2215 2216 list_for_each_entry(nhge, &nh->grp_list, nh_list) 2217 __nexthop_replace_notify(net, nhge->nh_parent, info); 2218 } 2219 2220 static int replace_nexthop(struct net *net, struct nexthop *old, 2221 struct nexthop *new, const struct nh_config *cfg, 2222 struct netlink_ext_ack *extack) 2223 { 2224 bool new_is_reject = false; 2225 struct nh_grp_entry *nhge; 2226 int err; 2227 2228 /* check that existing FIB entries are ok with the 2229 * new nexthop definition 2230 */ 2231 err = fib_check_nh_list(old, new, extack); 2232 if (err) 2233 return err; 2234 2235 err = fib6_check_nh_list(old, new, extack); 2236 if (err) 2237 return err; 2238 2239 if (!new->is_group) { 2240 struct nh_info *nhi = rtnl_dereference(new->nh_info); 2241 2242 new_is_reject = nhi->reject_nh; 2243 } 2244 2245 list_for_each_entry(nhge, &old->grp_list, nh_list) { 2246 /* if new nexthop is a blackhole, any groups using this 2247 * nexthop cannot have more than 1 path 2248 */ 2249 if (new_is_reject && 2250 nexthop_num_path(nhge->nh_parent) > 1) { 2251 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path"); 2252 return -EINVAL; 2253 } 2254 2255 err = fib_check_nh_list(nhge->nh_parent, new, extack); 2256 if (err) 2257 return err; 2258 2259 err = fib6_check_nh_list(nhge->nh_parent, new, extack); 2260 if (err) 2261 return err; 2262 } 2263 2264 if (old->is_group) 2265 err = replace_nexthop_grp(net, old, new, cfg, extack); 2266 else 2267 err = replace_nexthop_single(net, old, new, extack); 2268 2269 if (!err) { 2270 nh_rt_cache_flush(net, old, new); 2271 2272 __remove_nexthop(net, new, NULL); 2273 nexthop_put(new); 2274 } 2275 2276 return err; 2277 } 2278 2279 /* called with rtnl_lock held */ 2280 static int insert_nexthop(struct net *net, struct nexthop *new_nh, 2281 struct nh_config *cfg, struct netlink_ext_ack *extack) 2282 { 2283 struct rb_node **pp, *parent = NULL, *next; 2284 struct rb_root *root = &net->nexthop.rb_root; 2285 bool replace = !!(cfg->nlflags & NLM_F_REPLACE); 2286 bool create = !!(cfg->nlflags & NLM_F_CREATE); 2287 u32 new_id = new_nh->id; 2288 int replace_notify = 0; 2289 int rc = -EEXIST; 2290 2291 pp = &root->rb_node; 2292 while (1) { 2293 struct nexthop *nh; 2294 2295 next = *pp; 2296 if (!next) 2297 break; 2298 2299 parent = next; 2300 2301 nh = rb_entry(parent, struct nexthop, rb_node); 2302 if (new_id < nh->id) { 2303 pp = &next->rb_left; 2304 } else if (new_id > nh->id) { 2305 pp = &next->rb_right; 2306 } else if (replace) { 2307 rc = replace_nexthop(net, nh, new_nh, cfg, extack); 2308 if (!rc) { 2309 new_nh = nh; /* send notification with old nh */ 2310 replace_notify = 1; 2311 } 2312 goto out; 2313 } else { 2314 /* id already exists and not a replace */ 2315 goto out; 2316 } 2317 } 2318 2319 if (replace && !create) { 2320 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists"); 2321 rc = -ENOENT; 2322 goto out; 2323 } 2324 2325 if (new_nh->is_group) { 2326 struct nh_group *nhg = rtnl_dereference(new_nh->nh_grp); 2327 struct nh_res_table *res_table; 2328 2329 if (nhg->resilient) { 2330 res_table = rtnl_dereference(nhg->res_table); 2331 2332 /* Not passing the number of buckets is OK when 2333 * replacing, but not when creating a new group. 2334 */ 2335 if (!cfg->nh_grp_res_has_num_buckets) { 2336 NL_SET_ERR_MSG(extack, "Number of buckets not specified for nexthop group insertion"); 2337 rc = -EINVAL; 2338 goto out; 2339 } 2340 2341 nh_res_group_rebalance(nhg, res_table); 2342 2343 /* Do not send bucket notifications, we do full 2344 * notification below. 2345 */ 2346 nh_res_table_upkeep(res_table, false, false); 2347 } 2348 } 2349 2350 rb_link_node_rcu(&new_nh->rb_node, parent, pp); 2351 rb_insert_color(&new_nh->rb_node, root); 2352 2353 /* The initial insertion is a full notification for hash-threshold as 2354 * well as resilient groups. 2355 */ 2356 rc = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new_nh, extack); 2357 if (rc) 2358 rb_erase(&new_nh->rb_node, &net->nexthop.rb_root); 2359 2360 out: 2361 if (!rc) { 2362 nh_base_seq_inc(net); 2363 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo); 2364 if (replace_notify && 2365 READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode)) 2366 nexthop_replace_notify(net, new_nh, &cfg->nlinfo); 2367 } 2368 2369 return rc; 2370 } 2371 2372 /* rtnl */ 2373 /* remove all nexthops tied to a device being deleted */ 2374 static void nexthop_flush_dev(struct net_device *dev, unsigned long event) 2375 { 2376 unsigned int hash = nh_dev_hashfn(dev->ifindex); 2377 struct net *net = dev_net(dev); 2378 struct hlist_head *head = &net->nexthop.devhash[hash]; 2379 struct hlist_node *n; 2380 struct nh_info *nhi; 2381 2382 hlist_for_each_entry_safe(nhi, n, head, dev_hash) { 2383 if (nhi->fib_nhc.nhc_dev != dev) 2384 continue; 2385 2386 if (nhi->reject_nh && 2387 (event == NETDEV_DOWN || event == NETDEV_CHANGE)) 2388 continue; 2389 2390 remove_nexthop(net, nhi->nh_parent, NULL); 2391 } 2392 } 2393 2394 /* rtnl; called when net namespace is deleted */ 2395 static void flush_all_nexthops(struct net *net) 2396 { 2397 struct rb_root *root = &net->nexthop.rb_root; 2398 struct rb_node *node; 2399 struct nexthop *nh; 2400 2401 while ((node = rb_first(root))) { 2402 nh = rb_entry(node, struct nexthop, rb_node); 2403 remove_nexthop(net, nh, NULL); 2404 cond_resched(); 2405 } 2406 } 2407 2408 static struct nexthop *nexthop_create_group(struct net *net, 2409 struct nh_config *cfg) 2410 { 2411 struct nlattr *grps_attr = cfg->nh_grp; 2412 struct nexthop_grp *entry = nla_data(grps_attr); 2413 u16 num_nh = nla_len(grps_attr) / sizeof(*entry); 2414 struct nh_group *nhg; 2415 struct nexthop *nh; 2416 int err; 2417 int i; 2418 2419 if (WARN_ON(!num_nh)) 2420 return ERR_PTR(-EINVAL); 2421 2422 nh = nexthop_alloc(); 2423 if (!nh) 2424 return ERR_PTR(-ENOMEM); 2425 2426 nh->is_group = 1; 2427 2428 nhg = nexthop_grp_alloc(num_nh); 2429 if (!nhg) { 2430 kfree(nh); 2431 return ERR_PTR(-ENOMEM); 2432 } 2433 2434 /* spare group used for removals */ 2435 nhg->spare = nexthop_grp_alloc(num_nh); 2436 if (!nhg->spare) { 2437 kfree(nhg); 2438 kfree(nh); 2439 return ERR_PTR(-ENOMEM); 2440 } 2441 nhg->spare->spare = nhg; 2442 2443 for (i = 0; i < nhg->num_nh; ++i) { 2444 struct nexthop *nhe; 2445 struct nh_info *nhi; 2446 2447 nhe = nexthop_find_by_id(net, entry[i].id); 2448 if (!nexthop_get(nhe)) { 2449 err = -ENOENT; 2450 goto out_no_nh; 2451 } 2452 2453 nhi = rtnl_dereference(nhe->nh_info); 2454 if (nhi->family == AF_INET) 2455 nhg->has_v4 = true; 2456 2457 nhg->nh_entries[i].nh = nhe; 2458 nhg->nh_entries[i].weight = entry[i].weight + 1; 2459 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list); 2460 nhg->nh_entries[i].nh_parent = nh; 2461 } 2462 2463 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) { 2464 nhg->hash_threshold = 1; 2465 nhg->is_multipath = true; 2466 } else if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) { 2467 struct nh_res_table *res_table; 2468 2469 res_table = nexthop_res_table_alloc(net, cfg->nh_id, cfg); 2470 if (!res_table) { 2471 err = -ENOMEM; 2472 goto out_no_nh; 2473 } 2474 2475 rcu_assign_pointer(nhg->spare->res_table, res_table); 2476 rcu_assign_pointer(nhg->res_table, res_table); 2477 nhg->resilient = true; 2478 nhg->is_multipath = true; 2479 } 2480 2481 WARN_ON_ONCE(nhg->hash_threshold + nhg->resilient != 1); 2482 2483 if (nhg->hash_threshold) 2484 nh_hthr_group_rebalance(nhg); 2485 2486 if (cfg->nh_fdb) 2487 nhg->fdb_nh = 1; 2488 2489 rcu_assign_pointer(nh->nh_grp, nhg); 2490 2491 return nh; 2492 2493 out_no_nh: 2494 for (i--; i >= 0; --i) { 2495 list_del(&nhg->nh_entries[i].nh_list); 2496 nexthop_put(nhg->nh_entries[i].nh); 2497 } 2498 2499 kfree(nhg->spare); 2500 kfree(nhg); 2501 kfree(nh); 2502 2503 return ERR_PTR(err); 2504 } 2505 2506 static int nh_create_ipv4(struct net *net, struct nexthop *nh, 2507 struct nh_info *nhi, struct nh_config *cfg, 2508 struct netlink_ext_ack *extack) 2509 { 2510 struct fib_nh *fib_nh = &nhi->fib_nh; 2511 struct fib_config fib_cfg = { 2512 .fc_oif = cfg->nh_ifindex, 2513 .fc_gw4 = cfg->gw.ipv4, 2514 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0, 2515 .fc_flags = cfg->nh_flags, 2516 .fc_nlinfo = cfg->nlinfo, 2517 .fc_encap = cfg->nh_encap, 2518 .fc_encap_type = cfg->nh_encap_type, 2519 }; 2520 u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN); 2521 int err; 2522 2523 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack); 2524 if (err) { 2525 fib_nh_release(net, fib_nh); 2526 goto out; 2527 } 2528 2529 if (nhi->fdb_nh) 2530 goto out; 2531 2532 /* sets nh_dev if successful */ 2533 err = fib_check_nh(net, fib_nh, tb_id, 0, extack); 2534 if (!err) { 2535 nh->nh_flags = fib_nh->fib_nh_flags; 2536 fib_info_update_nhc_saddr(net, &fib_nh->nh_common, 2537 !fib_nh->fib_nh_scope ? 0 : fib_nh->fib_nh_scope - 1); 2538 } else { 2539 fib_nh_release(net, fib_nh); 2540 } 2541 out: 2542 return err; 2543 } 2544 2545 static int nh_create_ipv6(struct net *net, struct nexthop *nh, 2546 struct nh_info *nhi, struct nh_config *cfg, 2547 struct netlink_ext_ack *extack) 2548 { 2549 struct fib6_nh *fib6_nh = &nhi->fib6_nh; 2550 struct fib6_config fib6_cfg = { 2551 .fc_table = l3mdev_fib_table(cfg->dev), 2552 .fc_ifindex = cfg->nh_ifindex, 2553 .fc_gateway = cfg->gw.ipv6, 2554 .fc_flags = cfg->nh_flags, 2555 .fc_nlinfo = cfg->nlinfo, 2556 .fc_encap = cfg->nh_encap, 2557 .fc_encap_type = cfg->nh_encap_type, 2558 .fc_is_fdb = cfg->nh_fdb, 2559 }; 2560 int err; 2561 2562 if (!ipv6_addr_any(&cfg->gw.ipv6)) 2563 fib6_cfg.fc_flags |= RTF_GATEWAY; 2564 2565 /* sets nh_dev if successful */ 2566 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL, 2567 extack); 2568 if (err) { 2569 /* IPv6 is not enabled, don't call fib6_nh_release */ 2570 if (err == -EAFNOSUPPORT) 2571 goto out; 2572 ipv6_stub->fib6_nh_release(fib6_nh); 2573 } else { 2574 nh->nh_flags = fib6_nh->fib_nh_flags; 2575 } 2576 out: 2577 return err; 2578 } 2579 2580 static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg, 2581 struct netlink_ext_ack *extack) 2582 { 2583 struct nh_info *nhi; 2584 struct nexthop *nh; 2585 int err = 0; 2586 2587 nh = nexthop_alloc(); 2588 if (!nh) 2589 return ERR_PTR(-ENOMEM); 2590 2591 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL); 2592 if (!nhi) { 2593 kfree(nh); 2594 return ERR_PTR(-ENOMEM); 2595 } 2596 2597 nh->nh_flags = cfg->nh_flags; 2598 nh->net = net; 2599 2600 nhi->nh_parent = nh; 2601 nhi->family = cfg->nh_family; 2602 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK; 2603 2604 if (cfg->nh_fdb) 2605 nhi->fdb_nh = 1; 2606 2607 if (cfg->nh_blackhole) { 2608 nhi->reject_nh = 1; 2609 cfg->nh_ifindex = net->loopback_dev->ifindex; 2610 } 2611 2612 switch (cfg->nh_family) { 2613 case AF_INET: 2614 err = nh_create_ipv4(net, nh, nhi, cfg, extack); 2615 break; 2616 case AF_INET6: 2617 err = nh_create_ipv6(net, nh, nhi, cfg, extack); 2618 break; 2619 } 2620 2621 if (err) { 2622 kfree(nhi); 2623 kfree(nh); 2624 return ERR_PTR(err); 2625 } 2626 2627 /* add the entry to the device based hash */ 2628 if (!nhi->fdb_nh) 2629 nexthop_devhash_add(net, nhi); 2630 2631 rcu_assign_pointer(nh->nh_info, nhi); 2632 2633 return nh; 2634 } 2635 2636 /* called with rtnl lock held */ 2637 static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg, 2638 struct netlink_ext_ack *extack) 2639 { 2640 struct nexthop *nh; 2641 int err; 2642 2643 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) { 2644 NL_SET_ERR_MSG(extack, "Replace requires nexthop id"); 2645 return ERR_PTR(-EINVAL); 2646 } 2647 2648 if (!cfg->nh_id) { 2649 cfg->nh_id = nh_find_unused_id(net); 2650 if (!cfg->nh_id) { 2651 NL_SET_ERR_MSG(extack, "No unused id"); 2652 return ERR_PTR(-EINVAL); 2653 } 2654 } 2655 2656 if (cfg->nh_grp) 2657 nh = nexthop_create_group(net, cfg); 2658 else 2659 nh = nexthop_create(net, cfg, extack); 2660 2661 if (IS_ERR(nh)) 2662 return nh; 2663 2664 refcount_set(&nh->refcnt, 1); 2665 nh->id = cfg->nh_id; 2666 nh->protocol = cfg->nh_protocol; 2667 nh->net = net; 2668 2669 err = insert_nexthop(net, nh, cfg, extack); 2670 if (err) { 2671 __remove_nexthop(net, nh, NULL); 2672 nexthop_put(nh); 2673 nh = ERR_PTR(err); 2674 } 2675 2676 return nh; 2677 } 2678 2679 static int rtm_nh_get_timer(struct nlattr *attr, unsigned long fallback, 2680 unsigned long *timer_p, bool *has_p, 2681 struct netlink_ext_ack *extack) 2682 { 2683 unsigned long timer; 2684 u32 value; 2685 2686 if (!attr) { 2687 *timer_p = fallback; 2688 *has_p = false; 2689 return 0; 2690 } 2691 2692 value = nla_get_u32(attr); 2693 timer = clock_t_to_jiffies(value); 2694 if (timer == ~0UL) { 2695 NL_SET_ERR_MSG(extack, "Timer value too large"); 2696 return -EINVAL; 2697 } 2698 2699 *timer_p = timer; 2700 *has_p = true; 2701 return 0; 2702 } 2703 2704 static int rtm_to_nh_config_grp_res(struct nlattr *res, struct nh_config *cfg, 2705 struct netlink_ext_ack *extack) 2706 { 2707 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_policy_new)] = {}; 2708 int err; 2709 2710 if (res) { 2711 err = nla_parse_nested(tb, 2712 ARRAY_SIZE(rtm_nh_res_policy_new) - 1, 2713 res, rtm_nh_res_policy_new, extack); 2714 if (err < 0) 2715 return err; 2716 } 2717 2718 if (tb[NHA_RES_GROUP_BUCKETS]) { 2719 cfg->nh_grp_res_num_buckets = 2720 nla_get_u16(tb[NHA_RES_GROUP_BUCKETS]); 2721 cfg->nh_grp_res_has_num_buckets = true; 2722 if (!cfg->nh_grp_res_num_buckets) { 2723 NL_SET_ERR_MSG(extack, "Number of buckets needs to be non-0"); 2724 return -EINVAL; 2725 } 2726 } 2727 2728 err = rtm_nh_get_timer(tb[NHA_RES_GROUP_IDLE_TIMER], 2729 NH_RES_DEFAULT_IDLE_TIMER, 2730 &cfg->nh_grp_res_idle_timer, 2731 &cfg->nh_grp_res_has_idle_timer, 2732 extack); 2733 if (err) 2734 return err; 2735 2736 return rtm_nh_get_timer(tb[NHA_RES_GROUP_UNBALANCED_TIMER], 2737 NH_RES_DEFAULT_UNBALANCED_TIMER, 2738 &cfg->nh_grp_res_unbalanced_timer, 2739 &cfg->nh_grp_res_has_unbalanced_timer, 2740 extack); 2741 } 2742 2743 static int rtm_to_nh_config(struct net *net, struct sk_buff *skb, 2744 struct nlmsghdr *nlh, struct nh_config *cfg, 2745 struct netlink_ext_ack *extack) 2746 { 2747 struct nhmsg *nhm = nlmsg_data(nlh); 2748 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)]; 2749 int err; 2750 2751 err = nlmsg_parse(nlh, sizeof(*nhm), tb, 2752 ARRAY_SIZE(rtm_nh_policy_new) - 1, 2753 rtm_nh_policy_new, extack); 2754 if (err < 0) 2755 return err; 2756 2757 err = -EINVAL; 2758 if (nhm->resvd || nhm->nh_scope) { 2759 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header"); 2760 goto out; 2761 } 2762 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) { 2763 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header"); 2764 goto out; 2765 } 2766 2767 switch (nhm->nh_family) { 2768 case AF_INET: 2769 case AF_INET6: 2770 break; 2771 case AF_UNSPEC: 2772 if (tb[NHA_GROUP]) 2773 break; 2774 fallthrough; 2775 default: 2776 NL_SET_ERR_MSG(extack, "Invalid address family"); 2777 goto out; 2778 } 2779 2780 memset(cfg, 0, sizeof(*cfg)); 2781 cfg->nlflags = nlh->nlmsg_flags; 2782 cfg->nlinfo.portid = NETLINK_CB(skb).portid; 2783 cfg->nlinfo.nlh = nlh; 2784 cfg->nlinfo.nl_net = net; 2785 2786 cfg->nh_family = nhm->nh_family; 2787 cfg->nh_protocol = nhm->nh_protocol; 2788 cfg->nh_flags = nhm->nh_flags; 2789 2790 if (tb[NHA_ID]) 2791 cfg->nh_id = nla_get_u32(tb[NHA_ID]); 2792 2793 if (tb[NHA_FDB]) { 2794 if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] || 2795 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) { 2796 NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole"); 2797 goto out; 2798 } 2799 if (nhm->nh_flags) { 2800 NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header"); 2801 goto out; 2802 } 2803 cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]); 2804 } 2805 2806 if (tb[NHA_GROUP]) { 2807 if (nhm->nh_family != AF_UNSPEC) { 2808 NL_SET_ERR_MSG(extack, "Invalid family for group"); 2809 goto out; 2810 } 2811 cfg->nh_grp = tb[NHA_GROUP]; 2812 2813 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH; 2814 if (tb[NHA_GROUP_TYPE]) 2815 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]); 2816 2817 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) { 2818 NL_SET_ERR_MSG(extack, "Invalid group type"); 2819 goto out; 2820 } 2821 err = nh_check_attr_group(net, tb, ARRAY_SIZE(tb), 2822 cfg->nh_grp_type, extack); 2823 if (err) 2824 goto out; 2825 2826 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) 2827 err = rtm_to_nh_config_grp_res(tb[NHA_RES_GROUP], 2828 cfg, extack); 2829 2830 /* no other attributes should be set */ 2831 goto out; 2832 } 2833 2834 if (tb[NHA_BLACKHOLE]) { 2835 if (tb[NHA_GATEWAY] || tb[NHA_OIF] || 2836 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) { 2837 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb"); 2838 goto out; 2839 } 2840 2841 cfg->nh_blackhole = 1; 2842 err = 0; 2843 goto out; 2844 } 2845 2846 if (!cfg->nh_fdb && !tb[NHA_OIF]) { 2847 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops"); 2848 goto out; 2849 } 2850 2851 if (!cfg->nh_fdb && tb[NHA_OIF]) { 2852 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]); 2853 if (cfg->nh_ifindex) 2854 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex); 2855 2856 if (!cfg->dev) { 2857 NL_SET_ERR_MSG(extack, "Invalid device index"); 2858 goto out; 2859 } else if (!(cfg->dev->flags & IFF_UP)) { 2860 NL_SET_ERR_MSG(extack, "Nexthop device is not up"); 2861 err = -ENETDOWN; 2862 goto out; 2863 } else if (!netif_carrier_ok(cfg->dev)) { 2864 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down"); 2865 err = -ENETDOWN; 2866 goto out; 2867 } 2868 } 2869 2870 err = -EINVAL; 2871 if (tb[NHA_GATEWAY]) { 2872 struct nlattr *gwa = tb[NHA_GATEWAY]; 2873 2874 switch (cfg->nh_family) { 2875 case AF_INET: 2876 if (nla_len(gwa) != sizeof(u32)) { 2877 NL_SET_ERR_MSG(extack, "Invalid gateway"); 2878 goto out; 2879 } 2880 cfg->gw.ipv4 = nla_get_be32(gwa); 2881 break; 2882 case AF_INET6: 2883 if (nla_len(gwa) != sizeof(struct in6_addr)) { 2884 NL_SET_ERR_MSG(extack, "Invalid gateway"); 2885 goto out; 2886 } 2887 cfg->gw.ipv6 = nla_get_in6_addr(gwa); 2888 break; 2889 default: 2890 NL_SET_ERR_MSG(extack, 2891 "Unknown address family for gateway"); 2892 goto out; 2893 } 2894 } else { 2895 /* device only nexthop (no gateway) */ 2896 if (cfg->nh_flags & RTNH_F_ONLINK) { 2897 NL_SET_ERR_MSG(extack, 2898 "ONLINK flag can not be set for nexthop without a gateway"); 2899 goto out; 2900 } 2901 } 2902 2903 if (tb[NHA_ENCAP]) { 2904 cfg->nh_encap = tb[NHA_ENCAP]; 2905 2906 if (!tb[NHA_ENCAP_TYPE]) { 2907 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing"); 2908 goto out; 2909 } 2910 2911 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]); 2912 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack); 2913 if (err < 0) 2914 goto out; 2915 2916 } else if (tb[NHA_ENCAP_TYPE]) { 2917 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing"); 2918 goto out; 2919 } 2920 2921 2922 err = 0; 2923 out: 2924 return err; 2925 } 2926 2927 /* rtnl */ 2928 static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 2929 struct netlink_ext_ack *extack) 2930 { 2931 struct net *net = sock_net(skb->sk); 2932 struct nh_config cfg; 2933 struct nexthop *nh; 2934 int err; 2935 2936 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack); 2937 if (!err) { 2938 nh = nexthop_add(net, &cfg, extack); 2939 if (IS_ERR(nh)) 2940 err = PTR_ERR(nh); 2941 } 2942 2943 return err; 2944 } 2945 2946 static int __nh_valid_get_del_req(const struct nlmsghdr *nlh, 2947 struct nlattr **tb, u32 *id, 2948 struct netlink_ext_ack *extack) 2949 { 2950 struct nhmsg *nhm = nlmsg_data(nlh); 2951 2952 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { 2953 NL_SET_ERR_MSG(extack, "Invalid values in header"); 2954 return -EINVAL; 2955 } 2956 2957 if (!tb[NHA_ID]) { 2958 NL_SET_ERR_MSG(extack, "Nexthop id is missing"); 2959 return -EINVAL; 2960 } 2961 2962 *id = nla_get_u32(tb[NHA_ID]); 2963 if (!(*id)) { 2964 NL_SET_ERR_MSG(extack, "Invalid nexthop id"); 2965 return -EINVAL; 2966 } 2967 2968 return 0; 2969 } 2970 2971 static int nh_valid_get_del_req(const struct nlmsghdr *nlh, u32 *id, 2972 struct netlink_ext_ack *extack) 2973 { 2974 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get)]; 2975 int err; 2976 2977 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 2978 ARRAY_SIZE(rtm_nh_policy_get) - 1, 2979 rtm_nh_policy_get, extack); 2980 if (err < 0) 2981 return err; 2982 2983 return __nh_valid_get_del_req(nlh, tb, id, extack); 2984 } 2985 2986 /* rtnl */ 2987 static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 2988 struct netlink_ext_ack *extack) 2989 { 2990 struct net *net = sock_net(skb->sk); 2991 struct nl_info nlinfo = { 2992 .nlh = nlh, 2993 .nl_net = net, 2994 .portid = NETLINK_CB(skb).portid, 2995 }; 2996 struct nexthop *nh; 2997 int err; 2998 u32 id; 2999 3000 err = nh_valid_get_del_req(nlh, &id, extack); 3001 if (err) 3002 return err; 3003 3004 nh = nexthop_find_by_id(net, id); 3005 if (!nh) 3006 return -ENOENT; 3007 3008 remove_nexthop(net, nh, &nlinfo); 3009 3010 return 0; 3011 } 3012 3013 /* rtnl */ 3014 static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3015 struct netlink_ext_ack *extack) 3016 { 3017 struct net *net = sock_net(in_skb->sk); 3018 struct sk_buff *skb = NULL; 3019 struct nexthop *nh; 3020 int err; 3021 u32 id; 3022 3023 err = nh_valid_get_del_req(nlh, &id, extack); 3024 if (err) 3025 return err; 3026 3027 err = -ENOBUFS; 3028 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3029 if (!skb) 3030 goto out; 3031 3032 err = -ENOENT; 3033 nh = nexthop_find_by_id(net, id); 3034 if (!nh) 3035 goto errout_free; 3036 3037 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid, 3038 nlh->nlmsg_seq, 0); 3039 if (err < 0) { 3040 WARN_ON(err == -EMSGSIZE); 3041 goto errout_free; 3042 } 3043 3044 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3045 out: 3046 return err; 3047 errout_free: 3048 kfree_skb(skb); 3049 goto out; 3050 } 3051 3052 struct nh_dump_filter { 3053 u32 nh_id; 3054 int dev_idx; 3055 int master_idx; 3056 bool group_filter; 3057 bool fdb_filter; 3058 u32 res_bucket_nh_id; 3059 }; 3060 3061 static bool nh_dump_filtered(struct nexthop *nh, 3062 struct nh_dump_filter *filter, u8 family) 3063 { 3064 const struct net_device *dev; 3065 const struct nh_info *nhi; 3066 3067 if (filter->group_filter && !nh->is_group) 3068 return true; 3069 3070 if (!filter->dev_idx && !filter->master_idx && !family) 3071 return false; 3072 3073 if (nh->is_group) 3074 return true; 3075 3076 nhi = rtnl_dereference(nh->nh_info); 3077 if (family && nhi->family != family) 3078 return true; 3079 3080 dev = nhi->fib_nhc.nhc_dev; 3081 if (filter->dev_idx && (!dev || dev->ifindex != filter->dev_idx)) 3082 return true; 3083 3084 if (filter->master_idx) { 3085 struct net_device *master; 3086 3087 if (!dev) 3088 return true; 3089 3090 master = netdev_master_upper_dev_get((struct net_device *)dev); 3091 if (!master || master->ifindex != filter->master_idx) 3092 return true; 3093 } 3094 3095 return false; 3096 } 3097 3098 static int __nh_valid_dump_req(const struct nlmsghdr *nlh, struct nlattr **tb, 3099 struct nh_dump_filter *filter, 3100 struct netlink_ext_ack *extack) 3101 { 3102 struct nhmsg *nhm; 3103 u32 idx; 3104 3105 if (tb[NHA_OIF]) { 3106 idx = nla_get_u32(tb[NHA_OIF]); 3107 if (idx > INT_MAX) { 3108 NL_SET_ERR_MSG(extack, "Invalid device index"); 3109 return -EINVAL; 3110 } 3111 filter->dev_idx = idx; 3112 } 3113 if (tb[NHA_MASTER]) { 3114 idx = nla_get_u32(tb[NHA_MASTER]); 3115 if (idx > INT_MAX) { 3116 NL_SET_ERR_MSG(extack, "Invalid master device index"); 3117 return -EINVAL; 3118 } 3119 filter->master_idx = idx; 3120 } 3121 filter->group_filter = nla_get_flag(tb[NHA_GROUPS]); 3122 filter->fdb_filter = nla_get_flag(tb[NHA_FDB]); 3123 3124 nhm = nlmsg_data(nlh); 3125 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { 3126 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request"); 3127 return -EINVAL; 3128 } 3129 3130 return 0; 3131 } 3132 3133 static int nh_valid_dump_req(const struct nlmsghdr *nlh, 3134 struct nh_dump_filter *filter, 3135 struct netlink_callback *cb) 3136 { 3137 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump)]; 3138 int err; 3139 3140 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 3141 ARRAY_SIZE(rtm_nh_policy_dump) - 1, 3142 rtm_nh_policy_dump, cb->extack); 3143 if (err < 0) 3144 return err; 3145 3146 return __nh_valid_dump_req(nlh, tb, filter, cb->extack); 3147 } 3148 3149 struct rtm_dump_nh_ctx { 3150 u32 idx; 3151 }; 3152 3153 static struct rtm_dump_nh_ctx * 3154 rtm_dump_nh_ctx(struct netlink_callback *cb) 3155 { 3156 struct rtm_dump_nh_ctx *ctx = (void *)cb->ctx; 3157 3158 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); 3159 return ctx; 3160 } 3161 3162 static int rtm_dump_walk_nexthops(struct sk_buff *skb, 3163 struct netlink_callback *cb, 3164 struct rb_root *root, 3165 struct rtm_dump_nh_ctx *ctx, 3166 int (*nh_cb)(struct sk_buff *skb, 3167 struct netlink_callback *cb, 3168 struct nexthop *nh, void *data), 3169 void *data) 3170 { 3171 struct rb_node *node; 3172 int s_idx; 3173 int err; 3174 3175 s_idx = ctx->idx; 3176 for (node = rb_first(root); node; node = rb_next(node)) { 3177 struct nexthop *nh; 3178 3179 nh = rb_entry(node, struct nexthop, rb_node); 3180 if (nh->id < s_idx) 3181 continue; 3182 3183 ctx->idx = nh->id; 3184 err = nh_cb(skb, cb, nh, data); 3185 if (err) 3186 return err; 3187 } 3188 3189 ctx->idx++; 3190 return 0; 3191 } 3192 3193 static int rtm_dump_nexthop_cb(struct sk_buff *skb, struct netlink_callback *cb, 3194 struct nexthop *nh, void *data) 3195 { 3196 struct nhmsg *nhm = nlmsg_data(cb->nlh); 3197 struct nh_dump_filter *filter = data; 3198 3199 if (nh_dump_filtered(nh, filter, nhm->nh_family)) 3200 return 0; 3201 3202 return nh_fill_node(skb, nh, RTM_NEWNEXTHOP, 3203 NETLINK_CB(cb->skb).portid, 3204 cb->nlh->nlmsg_seq, NLM_F_MULTI); 3205 } 3206 3207 /* rtnl */ 3208 static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb) 3209 { 3210 struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb); 3211 struct net *net = sock_net(skb->sk); 3212 struct rb_root *root = &net->nexthop.rb_root; 3213 struct nh_dump_filter filter = {}; 3214 int err; 3215 3216 err = nh_valid_dump_req(cb->nlh, &filter, cb); 3217 if (err < 0) 3218 return err; 3219 3220 err = rtm_dump_walk_nexthops(skb, cb, root, ctx, 3221 &rtm_dump_nexthop_cb, &filter); 3222 if (err < 0) { 3223 if (likely(skb->len)) 3224 goto out; 3225 goto out_err; 3226 } 3227 3228 out: 3229 err = skb->len; 3230 out_err: 3231 cb->seq = net->nexthop.seq; 3232 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 3233 return err; 3234 } 3235 3236 static struct nexthop * 3237 nexthop_find_group_resilient(struct net *net, u32 id, 3238 struct netlink_ext_ack *extack) 3239 { 3240 struct nh_group *nhg; 3241 struct nexthop *nh; 3242 3243 nh = nexthop_find_by_id(net, id); 3244 if (!nh) 3245 return ERR_PTR(-ENOENT); 3246 3247 if (!nh->is_group) { 3248 NL_SET_ERR_MSG(extack, "Not a nexthop group"); 3249 return ERR_PTR(-EINVAL); 3250 } 3251 3252 nhg = rtnl_dereference(nh->nh_grp); 3253 if (!nhg->resilient) { 3254 NL_SET_ERR_MSG(extack, "Nexthop group not of type resilient"); 3255 return ERR_PTR(-EINVAL); 3256 } 3257 3258 return nh; 3259 } 3260 3261 static int nh_valid_dump_nhid(struct nlattr *attr, u32 *nh_id_p, 3262 struct netlink_ext_ack *extack) 3263 { 3264 u32 idx; 3265 3266 if (attr) { 3267 idx = nla_get_u32(attr); 3268 if (!idx) { 3269 NL_SET_ERR_MSG(extack, "Invalid nexthop id"); 3270 return -EINVAL; 3271 } 3272 *nh_id_p = idx; 3273 } else { 3274 *nh_id_p = 0; 3275 } 3276 3277 return 0; 3278 } 3279 3280 static int nh_valid_dump_bucket_req(const struct nlmsghdr *nlh, 3281 struct nh_dump_filter *filter, 3282 struct netlink_callback *cb) 3283 { 3284 struct nlattr *res_tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_dump)]; 3285 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump_bucket)]; 3286 int err; 3287 3288 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 3289 ARRAY_SIZE(rtm_nh_policy_dump_bucket) - 1, 3290 rtm_nh_policy_dump_bucket, NULL); 3291 if (err < 0) 3292 return err; 3293 3294 err = nh_valid_dump_nhid(tb[NHA_ID], &filter->nh_id, cb->extack); 3295 if (err) 3296 return err; 3297 3298 if (tb[NHA_RES_BUCKET]) { 3299 size_t max = ARRAY_SIZE(rtm_nh_res_bucket_policy_dump) - 1; 3300 3301 err = nla_parse_nested(res_tb, max, 3302 tb[NHA_RES_BUCKET], 3303 rtm_nh_res_bucket_policy_dump, 3304 cb->extack); 3305 if (err < 0) 3306 return err; 3307 3308 err = nh_valid_dump_nhid(res_tb[NHA_RES_BUCKET_NH_ID], 3309 &filter->res_bucket_nh_id, 3310 cb->extack); 3311 if (err) 3312 return err; 3313 } 3314 3315 return __nh_valid_dump_req(nlh, tb, filter, cb->extack); 3316 } 3317 3318 struct rtm_dump_res_bucket_ctx { 3319 struct rtm_dump_nh_ctx nh; 3320 u16 bucket_index; 3321 u32 done_nh_idx; /* 1 + the index of the last fully processed NH. */ 3322 }; 3323 3324 static struct rtm_dump_res_bucket_ctx * 3325 rtm_dump_res_bucket_ctx(struct netlink_callback *cb) 3326 { 3327 struct rtm_dump_res_bucket_ctx *ctx = (void *)cb->ctx; 3328 3329 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); 3330 return ctx; 3331 } 3332 3333 struct rtm_dump_nexthop_bucket_data { 3334 struct rtm_dump_res_bucket_ctx *ctx; 3335 struct nh_dump_filter filter; 3336 }; 3337 3338 static int rtm_dump_nexthop_bucket_nh(struct sk_buff *skb, 3339 struct netlink_callback *cb, 3340 struct nexthop *nh, 3341 struct rtm_dump_nexthop_bucket_data *dd) 3342 { 3343 u32 portid = NETLINK_CB(cb->skb).portid; 3344 struct nhmsg *nhm = nlmsg_data(cb->nlh); 3345 struct nh_res_table *res_table; 3346 struct nh_group *nhg; 3347 u16 bucket_index; 3348 int err; 3349 3350 if (dd->ctx->nh.idx < dd->ctx->done_nh_idx) 3351 return 0; 3352 3353 nhg = rtnl_dereference(nh->nh_grp); 3354 res_table = rtnl_dereference(nhg->res_table); 3355 for (bucket_index = dd->ctx->bucket_index; 3356 bucket_index < res_table->num_nh_buckets; 3357 bucket_index++) { 3358 struct nh_res_bucket *bucket; 3359 struct nh_grp_entry *nhge; 3360 3361 bucket = &res_table->nh_buckets[bucket_index]; 3362 nhge = rtnl_dereference(bucket->nh_entry); 3363 if (nh_dump_filtered(nhge->nh, &dd->filter, nhm->nh_family)) 3364 continue; 3365 3366 if (dd->filter.res_bucket_nh_id && 3367 dd->filter.res_bucket_nh_id != nhge->nh->id) 3368 continue; 3369 3370 err = nh_fill_res_bucket(skb, nh, bucket, bucket_index, 3371 RTM_NEWNEXTHOPBUCKET, portid, 3372 cb->nlh->nlmsg_seq, NLM_F_MULTI, 3373 cb->extack); 3374 if (err < 0) { 3375 if (likely(skb->len)) 3376 goto out; 3377 goto out_err; 3378 } 3379 } 3380 3381 dd->ctx->done_nh_idx = dd->ctx->nh.idx + 1; 3382 bucket_index = 0; 3383 3384 out: 3385 err = skb->len; 3386 out_err: 3387 dd->ctx->bucket_index = bucket_index; 3388 return err; 3389 } 3390 3391 static int rtm_dump_nexthop_bucket_cb(struct sk_buff *skb, 3392 struct netlink_callback *cb, 3393 struct nexthop *nh, void *data) 3394 { 3395 struct rtm_dump_nexthop_bucket_data *dd = data; 3396 struct nh_group *nhg; 3397 3398 if (!nh->is_group) 3399 return 0; 3400 3401 nhg = rtnl_dereference(nh->nh_grp); 3402 if (!nhg->resilient) 3403 return 0; 3404 3405 return rtm_dump_nexthop_bucket_nh(skb, cb, nh, dd); 3406 } 3407 3408 /* rtnl */ 3409 static int rtm_dump_nexthop_bucket(struct sk_buff *skb, 3410 struct netlink_callback *cb) 3411 { 3412 struct rtm_dump_res_bucket_ctx *ctx = rtm_dump_res_bucket_ctx(cb); 3413 struct rtm_dump_nexthop_bucket_data dd = { .ctx = ctx }; 3414 struct net *net = sock_net(skb->sk); 3415 struct nexthop *nh; 3416 int err; 3417 3418 err = nh_valid_dump_bucket_req(cb->nlh, &dd.filter, cb); 3419 if (err) 3420 return err; 3421 3422 if (dd.filter.nh_id) { 3423 nh = nexthop_find_group_resilient(net, dd.filter.nh_id, 3424 cb->extack); 3425 if (IS_ERR(nh)) 3426 return PTR_ERR(nh); 3427 err = rtm_dump_nexthop_bucket_nh(skb, cb, nh, &dd); 3428 } else { 3429 struct rb_root *root = &net->nexthop.rb_root; 3430 3431 err = rtm_dump_walk_nexthops(skb, cb, root, &ctx->nh, 3432 &rtm_dump_nexthop_bucket_cb, &dd); 3433 } 3434 3435 if (err < 0) { 3436 if (likely(skb->len)) 3437 goto out; 3438 goto out_err; 3439 } 3440 3441 out: 3442 err = skb->len; 3443 out_err: 3444 cb->seq = net->nexthop.seq; 3445 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 3446 return err; 3447 } 3448 3449 static int nh_valid_get_bucket_req_res_bucket(struct nlattr *res, 3450 u16 *bucket_index, 3451 struct netlink_ext_ack *extack) 3452 { 3453 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_get)]; 3454 int err; 3455 3456 err = nla_parse_nested(tb, ARRAY_SIZE(rtm_nh_res_bucket_policy_get) - 1, 3457 res, rtm_nh_res_bucket_policy_get, extack); 3458 if (err < 0) 3459 return err; 3460 3461 if (!tb[NHA_RES_BUCKET_INDEX]) { 3462 NL_SET_ERR_MSG(extack, "Bucket index is missing"); 3463 return -EINVAL; 3464 } 3465 3466 *bucket_index = nla_get_u16(tb[NHA_RES_BUCKET_INDEX]); 3467 return 0; 3468 } 3469 3470 static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh, 3471 u32 *id, u16 *bucket_index, 3472 struct netlink_ext_ack *extack) 3473 { 3474 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get_bucket)]; 3475 int err; 3476 3477 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 3478 ARRAY_SIZE(rtm_nh_policy_get_bucket) - 1, 3479 rtm_nh_policy_get_bucket, extack); 3480 if (err < 0) 3481 return err; 3482 3483 err = __nh_valid_get_del_req(nlh, tb, id, extack); 3484 if (err) 3485 return err; 3486 3487 if (!tb[NHA_RES_BUCKET]) { 3488 NL_SET_ERR_MSG(extack, "Bucket information is missing"); 3489 return -EINVAL; 3490 } 3491 3492 err = nh_valid_get_bucket_req_res_bucket(tb[NHA_RES_BUCKET], 3493 bucket_index, extack); 3494 if (err) 3495 return err; 3496 3497 return 0; 3498 } 3499 3500 /* rtnl */ 3501 static int rtm_get_nexthop_bucket(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3502 struct netlink_ext_ack *extack) 3503 { 3504 struct net *net = sock_net(in_skb->sk); 3505 struct nh_res_table *res_table; 3506 struct sk_buff *skb = NULL; 3507 struct nh_group *nhg; 3508 struct nexthop *nh; 3509 u16 bucket_index; 3510 int err; 3511 u32 id; 3512 3513 err = nh_valid_get_bucket_req(nlh, &id, &bucket_index, extack); 3514 if (err) 3515 return err; 3516 3517 nh = nexthop_find_group_resilient(net, id, extack); 3518 if (IS_ERR(nh)) 3519 return PTR_ERR(nh); 3520 3521 nhg = rtnl_dereference(nh->nh_grp); 3522 res_table = rtnl_dereference(nhg->res_table); 3523 if (bucket_index >= res_table->num_nh_buckets) { 3524 NL_SET_ERR_MSG(extack, "Bucket index out of bounds"); 3525 return -ENOENT; 3526 } 3527 3528 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3529 if (!skb) 3530 return -ENOBUFS; 3531 3532 err = nh_fill_res_bucket(skb, nh, &res_table->nh_buckets[bucket_index], 3533 bucket_index, RTM_NEWNEXTHOPBUCKET, 3534 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 3535 0, extack); 3536 if (err < 0) { 3537 WARN_ON(err == -EMSGSIZE); 3538 goto errout_free; 3539 } 3540 3541 return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3542 3543 errout_free: 3544 kfree_skb(skb); 3545 return err; 3546 } 3547 3548 static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu) 3549 { 3550 unsigned int hash = nh_dev_hashfn(dev->ifindex); 3551 struct net *net = dev_net(dev); 3552 struct hlist_head *head = &net->nexthop.devhash[hash]; 3553 struct hlist_node *n; 3554 struct nh_info *nhi; 3555 3556 hlist_for_each_entry_safe(nhi, n, head, dev_hash) { 3557 if (nhi->fib_nhc.nhc_dev == dev) { 3558 if (nhi->family == AF_INET) 3559 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu, 3560 orig_mtu); 3561 } 3562 } 3563 } 3564 3565 /* rtnl */ 3566 static int nh_netdev_event(struct notifier_block *this, 3567 unsigned long event, void *ptr) 3568 { 3569 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3570 struct netdev_notifier_info_ext *info_ext; 3571 3572 switch (event) { 3573 case NETDEV_DOWN: 3574 case NETDEV_UNREGISTER: 3575 nexthop_flush_dev(dev, event); 3576 break; 3577 case NETDEV_CHANGE: 3578 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP))) 3579 nexthop_flush_dev(dev, event); 3580 break; 3581 case NETDEV_CHANGEMTU: 3582 info_ext = ptr; 3583 nexthop_sync_mtu(dev, info_ext->ext.mtu); 3584 rt_cache_flush(dev_net(dev)); 3585 break; 3586 } 3587 return NOTIFY_DONE; 3588 } 3589 3590 static struct notifier_block nh_netdev_notifier = { 3591 .notifier_call = nh_netdev_event, 3592 }; 3593 3594 static int nexthops_dump(struct net *net, struct notifier_block *nb, 3595 enum nexthop_event_type event_type, 3596 struct netlink_ext_ack *extack) 3597 { 3598 struct rb_root *root = &net->nexthop.rb_root; 3599 struct rb_node *node; 3600 int err = 0; 3601 3602 for (node = rb_first(root); node; node = rb_next(node)) { 3603 struct nexthop *nh; 3604 3605 nh = rb_entry(node, struct nexthop, rb_node); 3606 err = call_nexthop_notifier(nb, net, event_type, nh, extack); 3607 if (err) 3608 break; 3609 } 3610 3611 return err; 3612 } 3613 3614 int register_nexthop_notifier(struct net *net, struct notifier_block *nb, 3615 struct netlink_ext_ack *extack) 3616 { 3617 int err; 3618 3619 rtnl_lock(); 3620 err = nexthops_dump(net, nb, NEXTHOP_EVENT_REPLACE, extack); 3621 if (err) 3622 goto unlock; 3623 err = blocking_notifier_chain_register(&net->nexthop.notifier_chain, 3624 nb); 3625 unlock: 3626 rtnl_unlock(); 3627 return err; 3628 } 3629 EXPORT_SYMBOL(register_nexthop_notifier); 3630 3631 int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb) 3632 { 3633 int err; 3634 3635 rtnl_lock(); 3636 err = blocking_notifier_chain_unregister(&net->nexthop.notifier_chain, 3637 nb); 3638 if (err) 3639 goto unlock; 3640 nexthops_dump(net, nb, NEXTHOP_EVENT_DEL, NULL); 3641 unlock: 3642 rtnl_unlock(); 3643 return err; 3644 } 3645 EXPORT_SYMBOL(unregister_nexthop_notifier); 3646 3647 void nexthop_set_hw_flags(struct net *net, u32 id, bool offload, bool trap) 3648 { 3649 struct nexthop *nexthop; 3650 3651 rcu_read_lock(); 3652 3653 nexthop = nexthop_find_by_id(net, id); 3654 if (!nexthop) 3655 goto out; 3656 3657 nexthop->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP); 3658 if (offload) 3659 nexthop->nh_flags |= RTNH_F_OFFLOAD; 3660 if (trap) 3661 nexthop->nh_flags |= RTNH_F_TRAP; 3662 3663 out: 3664 rcu_read_unlock(); 3665 } 3666 EXPORT_SYMBOL(nexthop_set_hw_flags); 3667 3668 void nexthop_bucket_set_hw_flags(struct net *net, u32 id, u16 bucket_index, 3669 bool offload, bool trap) 3670 { 3671 struct nh_res_table *res_table; 3672 struct nh_res_bucket *bucket; 3673 struct nexthop *nexthop; 3674 struct nh_group *nhg; 3675 3676 rcu_read_lock(); 3677 3678 nexthop = nexthop_find_by_id(net, id); 3679 if (!nexthop || !nexthop->is_group) 3680 goto out; 3681 3682 nhg = rcu_dereference(nexthop->nh_grp); 3683 if (!nhg->resilient) 3684 goto out; 3685 3686 if (bucket_index >= nhg->res_table->num_nh_buckets) 3687 goto out; 3688 3689 res_table = rcu_dereference(nhg->res_table); 3690 bucket = &res_table->nh_buckets[bucket_index]; 3691 bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP); 3692 if (offload) 3693 bucket->nh_flags |= RTNH_F_OFFLOAD; 3694 if (trap) 3695 bucket->nh_flags |= RTNH_F_TRAP; 3696 3697 out: 3698 rcu_read_unlock(); 3699 } 3700 EXPORT_SYMBOL(nexthop_bucket_set_hw_flags); 3701 3702 void nexthop_res_grp_activity_update(struct net *net, u32 id, u16 num_buckets, 3703 unsigned long *activity) 3704 { 3705 struct nh_res_table *res_table; 3706 struct nexthop *nexthop; 3707 struct nh_group *nhg; 3708 u16 i; 3709 3710 rcu_read_lock(); 3711 3712 nexthop = nexthop_find_by_id(net, id); 3713 if (!nexthop || !nexthop->is_group) 3714 goto out; 3715 3716 nhg = rcu_dereference(nexthop->nh_grp); 3717 if (!nhg->resilient) 3718 goto out; 3719 3720 /* Instead of silently ignoring some buckets, demand that the sizes 3721 * be the same. 3722 */ 3723 res_table = rcu_dereference(nhg->res_table); 3724 if (num_buckets != res_table->num_nh_buckets) 3725 goto out; 3726 3727 for (i = 0; i < num_buckets; i++) { 3728 if (test_bit(i, activity)) 3729 nh_res_bucket_set_busy(&res_table->nh_buckets[i]); 3730 } 3731 3732 out: 3733 rcu_read_unlock(); 3734 } 3735 EXPORT_SYMBOL(nexthop_res_grp_activity_update); 3736 3737 static void __net_exit nexthop_net_exit_batch(struct list_head *net_list) 3738 { 3739 struct net *net; 3740 3741 rtnl_lock(); 3742 list_for_each_entry(net, net_list, exit_list) { 3743 flush_all_nexthops(net); 3744 kfree(net->nexthop.devhash); 3745 } 3746 rtnl_unlock(); 3747 } 3748 3749 static int __net_init nexthop_net_init(struct net *net) 3750 { 3751 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE; 3752 3753 net->nexthop.rb_root = RB_ROOT; 3754 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL); 3755 if (!net->nexthop.devhash) 3756 return -ENOMEM; 3757 BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain); 3758 3759 return 0; 3760 } 3761 3762 static struct pernet_operations nexthop_net_ops = { 3763 .init = nexthop_net_init, 3764 .exit_batch = nexthop_net_exit_batch, 3765 }; 3766 3767 static int __init nexthop_init(void) 3768 { 3769 register_pernet_subsys(&nexthop_net_ops); 3770 3771 register_netdevice_notifier(&nh_netdev_notifier); 3772 3773 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 3774 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0); 3775 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop, 3776 rtm_dump_nexthop, 0); 3777 3778 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 3779 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); 3780 3781 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 3782 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); 3783 3784 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, rtm_get_nexthop_bucket, 3785 rtm_dump_nexthop_bucket, 0); 3786 3787 return 0; 3788 } 3789 subsys_initcall(nexthop_init); 3790