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