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 { 1904 struct fib6_info *f6i; 1905 1906 if (!list_empty(&nh->fi_list)) 1907 rt_cache_flush(net); 1908 1909 list_for_each_entry(f6i, &nh->f6i_list, nh_list) 1910 ipv6_stub->fib6_update_sernum(net, f6i); 1911 } 1912 1913 static int replace_nexthop_grp(struct net *net, struct nexthop *old, 1914 struct nexthop *new, const struct nh_config *cfg, 1915 struct netlink_ext_ack *extack) 1916 { 1917 struct nh_res_table *tmp_table = NULL; 1918 struct nh_res_table *new_res_table; 1919 struct nh_res_table *old_res_table; 1920 struct nh_group *oldg, *newg; 1921 int i, err; 1922 1923 if (!new->is_group) { 1924 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop."); 1925 return -EINVAL; 1926 } 1927 1928 oldg = rtnl_dereference(old->nh_grp); 1929 newg = rtnl_dereference(new->nh_grp); 1930 1931 if (newg->hash_threshold != oldg->hash_threshold) { 1932 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with one of a different type."); 1933 return -EINVAL; 1934 } 1935 1936 if (newg->hash_threshold) { 1937 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, 1938 extack); 1939 if (err) 1940 return err; 1941 } else if (newg->resilient) { 1942 new_res_table = rtnl_dereference(newg->res_table); 1943 old_res_table = rtnl_dereference(oldg->res_table); 1944 1945 /* Accept if num_nh_buckets was not given, but if it was 1946 * given, demand that the value be correct. 1947 */ 1948 if (cfg->nh_grp_res_has_num_buckets && 1949 cfg->nh_grp_res_num_buckets != 1950 old_res_table->num_nh_buckets) { 1951 NL_SET_ERR_MSG(extack, "Can not change number of buckets of a resilient nexthop group."); 1952 return -EINVAL; 1953 } 1954 1955 /* Emit a pre-replace notification so that listeners could veto 1956 * a potentially unsupported configuration. Otherwise, 1957 * individual bucket replacement notifications would need to be 1958 * vetoed, which is something that should only happen if the 1959 * bucket is currently active. 1960 */ 1961 err = call_nexthop_res_table_notifiers(net, new, extack); 1962 if (err) 1963 return err; 1964 1965 if (cfg->nh_grp_res_has_idle_timer) 1966 old_res_table->idle_timer = cfg->nh_grp_res_idle_timer; 1967 if (cfg->nh_grp_res_has_unbalanced_timer) 1968 old_res_table->unbalanced_timer = 1969 cfg->nh_grp_res_unbalanced_timer; 1970 1971 replace_nexthop_grp_res(oldg, newg); 1972 1973 tmp_table = new_res_table; 1974 rcu_assign_pointer(newg->res_table, old_res_table); 1975 rcu_assign_pointer(newg->spare->res_table, old_res_table); 1976 } 1977 1978 /* update parents - used by nexthop code for cleanup */ 1979 for (i = 0; i < newg->num_nh; i++) 1980 newg->nh_entries[i].nh_parent = old; 1981 1982 rcu_assign_pointer(old->nh_grp, newg); 1983 1984 if (newg->resilient) { 1985 rcu_assign_pointer(oldg->res_table, tmp_table); 1986 rcu_assign_pointer(oldg->spare->res_table, tmp_table); 1987 } 1988 1989 for (i = 0; i < oldg->num_nh; i++) 1990 oldg->nh_entries[i].nh_parent = new; 1991 1992 rcu_assign_pointer(new->nh_grp, oldg); 1993 1994 return 0; 1995 } 1996 1997 static void nh_group_v4_update(struct nh_group *nhg) 1998 { 1999 struct nh_grp_entry *nhges; 2000 bool has_v4 = false; 2001 int i; 2002 2003 nhges = nhg->nh_entries; 2004 for (i = 0; i < nhg->num_nh; i++) { 2005 struct nh_info *nhi; 2006 2007 nhi = rtnl_dereference(nhges[i].nh->nh_info); 2008 if (nhi->family == AF_INET) 2009 has_v4 = true; 2010 } 2011 nhg->has_v4 = has_v4; 2012 } 2013 2014 static int replace_nexthop_single_notify_res(struct net *net, 2015 struct nh_res_table *res_table, 2016 struct nexthop *old, 2017 struct nh_info *oldi, 2018 struct nh_info *newi, 2019 struct netlink_ext_ack *extack) 2020 { 2021 u32 nhg_id = res_table->nhg_id; 2022 int err; 2023 u16 i; 2024 2025 for (i = 0; i < res_table->num_nh_buckets; i++) { 2026 struct nh_res_bucket *bucket = &res_table->nh_buckets[i]; 2027 struct nh_grp_entry *nhge; 2028 2029 nhge = rtnl_dereference(bucket->nh_entry); 2030 if (nhge->nh == old) { 2031 err = __call_nexthop_res_bucket_notifiers(net, nhg_id, 2032 i, true, 2033 oldi, newi, 2034 extack); 2035 if (err) 2036 goto err_notify; 2037 } 2038 } 2039 2040 return 0; 2041 2042 err_notify: 2043 while (i-- > 0) { 2044 struct nh_res_bucket *bucket = &res_table->nh_buckets[i]; 2045 struct nh_grp_entry *nhge; 2046 2047 nhge = rtnl_dereference(bucket->nh_entry); 2048 if (nhge->nh == old) 2049 __call_nexthop_res_bucket_notifiers(net, nhg_id, i, 2050 true, newi, oldi, 2051 extack); 2052 } 2053 return err; 2054 } 2055 2056 static int replace_nexthop_single_notify(struct net *net, 2057 struct nexthop *group_nh, 2058 struct nexthop *old, 2059 struct nh_info *oldi, 2060 struct nh_info *newi, 2061 struct netlink_ext_ack *extack) 2062 { 2063 struct nh_group *nhg = rtnl_dereference(group_nh->nh_grp); 2064 struct nh_res_table *res_table; 2065 2066 if (nhg->hash_threshold) { 2067 return call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, 2068 group_nh, extack); 2069 } else if (nhg->resilient) { 2070 res_table = rtnl_dereference(nhg->res_table); 2071 return replace_nexthop_single_notify_res(net, res_table, 2072 old, oldi, newi, 2073 extack); 2074 } 2075 2076 return -EINVAL; 2077 } 2078 2079 static int replace_nexthop_single(struct net *net, struct nexthop *old, 2080 struct nexthop *new, 2081 struct netlink_ext_ack *extack) 2082 { 2083 u8 old_protocol, old_nh_flags; 2084 struct nh_info *oldi, *newi; 2085 struct nh_grp_entry *nhge; 2086 int err; 2087 2088 if (new->is_group) { 2089 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group."); 2090 return -EINVAL; 2091 } 2092 2093 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack); 2094 if (err) 2095 return err; 2096 2097 /* Hardware flags were set on 'old' as 'new' is not in the red-black 2098 * tree. Therefore, inherit the flags from 'old' to 'new'. 2099 */ 2100 new->nh_flags |= old->nh_flags & (RTNH_F_OFFLOAD | RTNH_F_TRAP); 2101 2102 oldi = rtnl_dereference(old->nh_info); 2103 newi = rtnl_dereference(new->nh_info); 2104 2105 newi->nh_parent = old; 2106 oldi->nh_parent = new; 2107 2108 old_protocol = old->protocol; 2109 old_nh_flags = old->nh_flags; 2110 2111 old->protocol = new->protocol; 2112 old->nh_flags = new->nh_flags; 2113 2114 rcu_assign_pointer(old->nh_info, newi); 2115 rcu_assign_pointer(new->nh_info, oldi); 2116 2117 /* Send a replace notification for all the groups using the nexthop. */ 2118 list_for_each_entry(nhge, &old->grp_list, nh_list) { 2119 struct nexthop *nhp = nhge->nh_parent; 2120 2121 err = replace_nexthop_single_notify(net, nhp, old, oldi, newi, 2122 extack); 2123 if (err) 2124 goto err_notify; 2125 } 2126 2127 /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially 2128 * update IPv4 indication in all the groups using the nexthop. 2129 */ 2130 if (oldi->family == AF_INET && newi->family == AF_INET6) { 2131 list_for_each_entry(nhge, &old->grp_list, nh_list) { 2132 struct nexthop *nhp = nhge->nh_parent; 2133 struct nh_group *nhg; 2134 2135 nhg = rtnl_dereference(nhp->nh_grp); 2136 nh_group_v4_update(nhg); 2137 } 2138 } 2139 2140 return 0; 2141 2142 err_notify: 2143 rcu_assign_pointer(new->nh_info, newi); 2144 rcu_assign_pointer(old->nh_info, oldi); 2145 old->nh_flags = old_nh_flags; 2146 old->protocol = old_protocol; 2147 oldi->nh_parent = old; 2148 newi->nh_parent = new; 2149 list_for_each_entry_continue_reverse(nhge, &old->grp_list, nh_list) { 2150 struct nexthop *nhp = nhge->nh_parent; 2151 2152 replace_nexthop_single_notify(net, nhp, old, newi, oldi, NULL); 2153 } 2154 call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, old, extack); 2155 return err; 2156 } 2157 2158 static void __nexthop_replace_notify(struct net *net, struct nexthop *nh, 2159 struct nl_info *info) 2160 { 2161 struct fib6_info *f6i; 2162 2163 if (!list_empty(&nh->fi_list)) { 2164 struct fib_info *fi; 2165 2166 /* expectation is a few fib_info per nexthop and then 2167 * a lot of routes per fib_info. So mark the fib_info 2168 * and then walk the fib tables once 2169 */ 2170 list_for_each_entry(fi, &nh->fi_list, nh_list) 2171 fi->nh_updated = true; 2172 2173 fib_info_notify_update(net, info); 2174 2175 list_for_each_entry(fi, &nh->fi_list, nh_list) 2176 fi->nh_updated = false; 2177 } 2178 2179 list_for_each_entry(f6i, &nh->f6i_list, nh_list) 2180 ipv6_stub->fib6_rt_update(net, f6i, info); 2181 } 2182 2183 /* send RTM_NEWROUTE with REPLACE flag set for all FIB entries 2184 * linked to this nexthop and for all groups that the nexthop 2185 * is a member of 2186 */ 2187 static void nexthop_replace_notify(struct net *net, struct nexthop *nh, 2188 struct nl_info *info) 2189 { 2190 struct nh_grp_entry *nhge; 2191 2192 __nexthop_replace_notify(net, nh, info); 2193 2194 list_for_each_entry(nhge, &nh->grp_list, nh_list) 2195 __nexthop_replace_notify(net, nhge->nh_parent, info); 2196 } 2197 2198 static int replace_nexthop(struct net *net, struct nexthop *old, 2199 struct nexthop *new, const struct nh_config *cfg, 2200 struct netlink_ext_ack *extack) 2201 { 2202 bool new_is_reject = false; 2203 struct nh_grp_entry *nhge; 2204 int err; 2205 2206 /* check that existing FIB entries are ok with the 2207 * new nexthop definition 2208 */ 2209 err = fib_check_nh_list(old, new, extack); 2210 if (err) 2211 return err; 2212 2213 err = fib6_check_nh_list(old, new, extack); 2214 if (err) 2215 return err; 2216 2217 if (!new->is_group) { 2218 struct nh_info *nhi = rtnl_dereference(new->nh_info); 2219 2220 new_is_reject = nhi->reject_nh; 2221 } 2222 2223 list_for_each_entry(nhge, &old->grp_list, nh_list) { 2224 /* if new nexthop is a blackhole, any groups using this 2225 * nexthop cannot have more than 1 path 2226 */ 2227 if (new_is_reject && 2228 nexthop_num_path(nhge->nh_parent) > 1) { 2229 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path"); 2230 return -EINVAL; 2231 } 2232 2233 err = fib_check_nh_list(nhge->nh_parent, new, extack); 2234 if (err) 2235 return err; 2236 2237 err = fib6_check_nh_list(nhge->nh_parent, new, extack); 2238 if (err) 2239 return err; 2240 } 2241 2242 if (old->is_group) 2243 err = replace_nexthop_grp(net, old, new, cfg, extack); 2244 else 2245 err = replace_nexthop_single(net, old, new, extack); 2246 2247 if (!err) { 2248 nh_rt_cache_flush(net, old); 2249 2250 __remove_nexthop(net, new, NULL); 2251 nexthop_put(new); 2252 } 2253 2254 return err; 2255 } 2256 2257 /* called with rtnl_lock held */ 2258 static int insert_nexthop(struct net *net, struct nexthop *new_nh, 2259 struct nh_config *cfg, struct netlink_ext_ack *extack) 2260 { 2261 struct rb_node **pp, *parent = NULL, *next; 2262 struct rb_root *root = &net->nexthop.rb_root; 2263 bool replace = !!(cfg->nlflags & NLM_F_REPLACE); 2264 bool create = !!(cfg->nlflags & NLM_F_CREATE); 2265 u32 new_id = new_nh->id; 2266 int replace_notify = 0; 2267 int rc = -EEXIST; 2268 2269 pp = &root->rb_node; 2270 while (1) { 2271 struct nexthop *nh; 2272 2273 next = *pp; 2274 if (!next) 2275 break; 2276 2277 parent = next; 2278 2279 nh = rb_entry(parent, struct nexthop, rb_node); 2280 if (new_id < nh->id) { 2281 pp = &next->rb_left; 2282 } else if (new_id > nh->id) { 2283 pp = &next->rb_right; 2284 } else if (replace) { 2285 rc = replace_nexthop(net, nh, new_nh, cfg, extack); 2286 if (!rc) { 2287 new_nh = nh; /* send notification with old nh */ 2288 replace_notify = 1; 2289 } 2290 goto out; 2291 } else { 2292 /* id already exists and not a replace */ 2293 goto out; 2294 } 2295 } 2296 2297 if (replace && !create) { 2298 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists"); 2299 rc = -ENOENT; 2300 goto out; 2301 } 2302 2303 if (new_nh->is_group) { 2304 struct nh_group *nhg = rtnl_dereference(new_nh->nh_grp); 2305 struct nh_res_table *res_table; 2306 2307 if (nhg->resilient) { 2308 res_table = rtnl_dereference(nhg->res_table); 2309 2310 /* Not passing the number of buckets is OK when 2311 * replacing, but not when creating a new group. 2312 */ 2313 if (!cfg->nh_grp_res_has_num_buckets) { 2314 NL_SET_ERR_MSG(extack, "Number of buckets not specified for nexthop group insertion"); 2315 rc = -EINVAL; 2316 goto out; 2317 } 2318 2319 nh_res_group_rebalance(nhg, res_table); 2320 2321 /* Do not send bucket notifications, we do full 2322 * notification below. 2323 */ 2324 nh_res_table_upkeep(res_table, false, false); 2325 } 2326 } 2327 2328 rb_link_node_rcu(&new_nh->rb_node, parent, pp); 2329 rb_insert_color(&new_nh->rb_node, root); 2330 2331 /* The initial insertion is a full notification for hash-threshold as 2332 * well as resilient groups. 2333 */ 2334 rc = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new_nh, extack); 2335 if (rc) 2336 rb_erase(&new_nh->rb_node, &net->nexthop.rb_root); 2337 2338 out: 2339 if (!rc) { 2340 nh_base_seq_inc(net); 2341 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo); 2342 if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode) 2343 nexthop_replace_notify(net, new_nh, &cfg->nlinfo); 2344 } 2345 2346 return rc; 2347 } 2348 2349 /* rtnl */ 2350 /* remove all nexthops tied to a device being deleted */ 2351 static void nexthop_flush_dev(struct net_device *dev, unsigned long event) 2352 { 2353 unsigned int hash = nh_dev_hashfn(dev->ifindex); 2354 struct net *net = dev_net(dev); 2355 struct hlist_head *head = &net->nexthop.devhash[hash]; 2356 struct hlist_node *n; 2357 struct nh_info *nhi; 2358 2359 hlist_for_each_entry_safe(nhi, n, head, dev_hash) { 2360 if (nhi->fib_nhc.nhc_dev != dev) 2361 continue; 2362 2363 if (nhi->reject_nh && 2364 (event == NETDEV_DOWN || event == NETDEV_CHANGE)) 2365 continue; 2366 2367 remove_nexthop(net, nhi->nh_parent, NULL); 2368 } 2369 } 2370 2371 /* rtnl; called when net namespace is deleted */ 2372 static void flush_all_nexthops(struct net *net) 2373 { 2374 struct rb_root *root = &net->nexthop.rb_root; 2375 struct rb_node *node; 2376 struct nexthop *nh; 2377 2378 while ((node = rb_first(root))) { 2379 nh = rb_entry(node, struct nexthop, rb_node); 2380 remove_nexthop(net, nh, NULL); 2381 cond_resched(); 2382 } 2383 } 2384 2385 static struct nexthop *nexthop_create_group(struct net *net, 2386 struct nh_config *cfg) 2387 { 2388 struct nlattr *grps_attr = cfg->nh_grp; 2389 struct nexthop_grp *entry = nla_data(grps_attr); 2390 u16 num_nh = nla_len(grps_attr) / sizeof(*entry); 2391 struct nh_group *nhg; 2392 struct nexthop *nh; 2393 int err; 2394 int i; 2395 2396 if (WARN_ON(!num_nh)) 2397 return ERR_PTR(-EINVAL); 2398 2399 nh = nexthop_alloc(); 2400 if (!nh) 2401 return ERR_PTR(-ENOMEM); 2402 2403 nh->is_group = 1; 2404 2405 nhg = nexthop_grp_alloc(num_nh); 2406 if (!nhg) { 2407 kfree(nh); 2408 return ERR_PTR(-ENOMEM); 2409 } 2410 2411 /* spare group used for removals */ 2412 nhg->spare = nexthop_grp_alloc(num_nh); 2413 if (!nhg->spare) { 2414 kfree(nhg); 2415 kfree(nh); 2416 return ERR_PTR(-ENOMEM); 2417 } 2418 nhg->spare->spare = nhg; 2419 2420 for (i = 0; i < nhg->num_nh; ++i) { 2421 struct nexthop *nhe; 2422 struct nh_info *nhi; 2423 2424 nhe = nexthop_find_by_id(net, entry[i].id); 2425 if (!nexthop_get(nhe)) { 2426 err = -ENOENT; 2427 goto out_no_nh; 2428 } 2429 2430 nhi = rtnl_dereference(nhe->nh_info); 2431 if (nhi->family == AF_INET) 2432 nhg->has_v4 = true; 2433 2434 nhg->nh_entries[i].nh = nhe; 2435 nhg->nh_entries[i].weight = entry[i].weight + 1; 2436 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list); 2437 nhg->nh_entries[i].nh_parent = nh; 2438 } 2439 2440 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) { 2441 nhg->hash_threshold = 1; 2442 nhg->is_multipath = true; 2443 } else if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) { 2444 struct nh_res_table *res_table; 2445 2446 res_table = nexthop_res_table_alloc(net, cfg->nh_id, cfg); 2447 if (!res_table) { 2448 err = -ENOMEM; 2449 goto out_no_nh; 2450 } 2451 2452 rcu_assign_pointer(nhg->spare->res_table, res_table); 2453 rcu_assign_pointer(nhg->res_table, res_table); 2454 nhg->resilient = true; 2455 nhg->is_multipath = true; 2456 } 2457 2458 WARN_ON_ONCE(nhg->hash_threshold + nhg->resilient != 1); 2459 2460 if (nhg->hash_threshold) 2461 nh_hthr_group_rebalance(nhg); 2462 2463 if (cfg->nh_fdb) 2464 nhg->fdb_nh = 1; 2465 2466 rcu_assign_pointer(nh->nh_grp, nhg); 2467 2468 return nh; 2469 2470 out_no_nh: 2471 for (i--; i >= 0; --i) { 2472 list_del(&nhg->nh_entries[i].nh_list); 2473 nexthop_put(nhg->nh_entries[i].nh); 2474 } 2475 2476 kfree(nhg->spare); 2477 kfree(nhg); 2478 kfree(nh); 2479 2480 return ERR_PTR(err); 2481 } 2482 2483 static int nh_create_ipv4(struct net *net, struct nexthop *nh, 2484 struct nh_info *nhi, struct nh_config *cfg, 2485 struct netlink_ext_ack *extack) 2486 { 2487 struct fib_nh *fib_nh = &nhi->fib_nh; 2488 struct fib_config fib_cfg = { 2489 .fc_oif = cfg->nh_ifindex, 2490 .fc_gw4 = cfg->gw.ipv4, 2491 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0, 2492 .fc_flags = cfg->nh_flags, 2493 .fc_encap = cfg->nh_encap, 2494 .fc_encap_type = cfg->nh_encap_type, 2495 }; 2496 u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN); 2497 int err; 2498 2499 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack); 2500 if (err) { 2501 fib_nh_release(net, fib_nh); 2502 goto out; 2503 } 2504 2505 if (nhi->fdb_nh) 2506 goto out; 2507 2508 /* sets nh_dev if successful */ 2509 err = fib_check_nh(net, fib_nh, tb_id, 0, extack); 2510 if (!err) { 2511 nh->nh_flags = fib_nh->fib_nh_flags; 2512 fib_info_update_nhc_saddr(net, &fib_nh->nh_common, 2513 fib_nh->fib_nh_scope); 2514 } else { 2515 fib_nh_release(net, fib_nh); 2516 } 2517 out: 2518 return err; 2519 } 2520 2521 static int nh_create_ipv6(struct net *net, struct nexthop *nh, 2522 struct nh_info *nhi, struct nh_config *cfg, 2523 struct netlink_ext_ack *extack) 2524 { 2525 struct fib6_nh *fib6_nh = &nhi->fib6_nh; 2526 struct fib6_config fib6_cfg = { 2527 .fc_table = l3mdev_fib_table(cfg->dev), 2528 .fc_ifindex = cfg->nh_ifindex, 2529 .fc_gateway = cfg->gw.ipv6, 2530 .fc_flags = cfg->nh_flags, 2531 .fc_encap = cfg->nh_encap, 2532 .fc_encap_type = cfg->nh_encap_type, 2533 .fc_is_fdb = cfg->nh_fdb, 2534 }; 2535 int err; 2536 2537 if (!ipv6_addr_any(&cfg->gw.ipv6)) 2538 fib6_cfg.fc_flags |= RTF_GATEWAY; 2539 2540 /* sets nh_dev if successful */ 2541 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL, 2542 extack); 2543 if (err) 2544 ipv6_stub->fib6_nh_release(fib6_nh); 2545 else 2546 nh->nh_flags = fib6_nh->fib_nh_flags; 2547 2548 return err; 2549 } 2550 2551 static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg, 2552 struct netlink_ext_ack *extack) 2553 { 2554 struct nh_info *nhi; 2555 struct nexthop *nh; 2556 int err = 0; 2557 2558 nh = nexthop_alloc(); 2559 if (!nh) 2560 return ERR_PTR(-ENOMEM); 2561 2562 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL); 2563 if (!nhi) { 2564 kfree(nh); 2565 return ERR_PTR(-ENOMEM); 2566 } 2567 2568 nh->nh_flags = cfg->nh_flags; 2569 nh->net = net; 2570 2571 nhi->nh_parent = nh; 2572 nhi->family = cfg->nh_family; 2573 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK; 2574 2575 if (cfg->nh_fdb) 2576 nhi->fdb_nh = 1; 2577 2578 if (cfg->nh_blackhole) { 2579 nhi->reject_nh = 1; 2580 cfg->nh_ifindex = net->loopback_dev->ifindex; 2581 } 2582 2583 switch (cfg->nh_family) { 2584 case AF_INET: 2585 err = nh_create_ipv4(net, nh, nhi, cfg, extack); 2586 break; 2587 case AF_INET6: 2588 err = nh_create_ipv6(net, nh, nhi, cfg, extack); 2589 break; 2590 } 2591 2592 if (err) { 2593 kfree(nhi); 2594 kfree(nh); 2595 return ERR_PTR(err); 2596 } 2597 2598 /* add the entry to the device based hash */ 2599 if (!nhi->fdb_nh) 2600 nexthop_devhash_add(net, nhi); 2601 2602 rcu_assign_pointer(nh->nh_info, nhi); 2603 2604 return nh; 2605 } 2606 2607 /* called with rtnl lock held */ 2608 static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg, 2609 struct netlink_ext_ack *extack) 2610 { 2611 struct nexthop *nh; 2612 int err; 2613 2614 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) { 2615 NL_SET_ERR_MSG(extack, "Replace requires nexthop id"); 2616 return ERR_PTR(-EINVAL); 2617 } 2618 2619 if (!cfg->nh_id) { 2620 cfg->nh_id = nh_find_unused_id(net); 2621 if (!cfg->nh_id) { 2622 NL_SET_ERR_MSG(extack, "No unused id"); 2623 return ERR_PTR(-EINVAL); 2624 } 2625 } 2626 2627 if (cfg->nh_grp) 2628 nh = nexthop_create_group(net, cfg); 2629 else 2630 nh = nexthop_create(net, cfg, extack); 2631 2632 if (IS_ERR(nh)) 2633 return nh; 2634 2635 refcount_set(&nh->refcnt, 1); 2636 nh->id = cfg->nh_id; 2637 nh->protocol = cfg->nh_protocol; 2638 nh->net = net; 2639 2640 err = insert_nexthop(net, nh, cfg, extack); 2641 if (err) { 2642 __remove_nexthop(net, nh, NULL); 2643 nexthop_put(nh); 2644 nh = ERR_PTR(err); 2645 } 2646 2647 return nh; 2648 } 2649 2650 static int rtm_nh_get_timer(struct nlattr *attr, unsigned long fallback, 2651 unsigned long *timer_p, bool *has_p, 2652 struct netlink_ext_ack *extack) 2653 { 2654 unsigned long timer; 2655 u32 value; 2656 2657 if (!attr) { 2658 *timer_p = fallback; 2659 *has_p = false; 2660 return 0; 2661 } 2662 2663 value = nla_get_u32(attr); 2664 timer = clock_t_to_jiffies(value); 2665 if (timer == ~0UL) { 2666 NL_SET_ERR_MSG(extack, "Timer value too large"); 2667 return -EINVAL; 2668 } 2669 2670 *timer_p = timer; 2671 *has_p = true; 2672 return 0; 2673 } 2674 2675 static int rtm_to_nh_config_grp_res(struct nlattr *res, struct nh_config *cfg, 2676 struct netlink_ext_ack *extack) 2677 { 2678 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_policy_new)] = {}; 2679 int err; 2680 2681 if (res) { 2682 err = nla_parse_nested(tb, 2683 ARRAY_SIZE(rtm_nh_res_policy_new) - 1, 2684 res, rtm_nh_res_policy_new, extack); 2685 if (err < 0) 2686 return err; 2687 } 2688 2689 if (tb[NHA_RES_GROUP_BUCKETS]) { 2690 cfg->nh_grp_res_num_buckets = 2691 nla_get_u16(tb[NHA_RES_GROUP_BUCKETS]); 2692 cfg->nh_grp_res_has_num_buckets = true; 2693 if (!cfg->nh_grp_res_num_buckets) { 2694 NL_SET_ERR_MSG(extack, "Number of buckets needs to be non-0"); 2695 return -EINVAL; 2696 } 2697 } 2698 2699 err = rtm_nh_get_timer(tb[NHA_RES_GROUP_IDLE_TIMER], 2700 NH_RES_DEFAULT_IDLE_TIMER, 2701 &cfg->nh_grp_res_idle_timer, 2702 &cfg->nh_grp_res_has_idle_timer, 2703 extack); 2704 if (err) 2705 return err; 2706 2707 return rtm_nh_get_timer(tb[NHA_RES_GROUP_UNBALANCED_TIMER], 2708 NH_RES_DEFAULT_UNBALANCED_TIMER, 2709 &cfg->nh_grp_res_unbalanced_timer, 2710 &cfg->nh_grp_res_has_unbalanced_timer, 2711 extack); 2712 } 2713 2714 static int rtm_to_nh_config(struct net *net, struct sk_buff *skb, 2715 struct nlmsghdr *nlh, struct nh_config *cfg, 2716 struct netlink_ext_ack *extack) 2717 { 2718 struct nhmsg *nhm = nlmsg_data(nlh); 2719 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)]; 2720 int err; 2721 2722 err = nlmsg_parse(nlh, sizeof(*nhm), tb, 2723 ARRAY_SIZE(rtm_nh_policy_new) - 1, 2724 rtm_nh_policy_new, extack); 2725 if (err < 0) 2726 return err; 2727 2728 err = -EINVAL; 2729 if (nhm->resvd || nhm->nh_scope) { 2730 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header"); 2731 goto out; 2732 } 2733 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) { 2734 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header"); 2735 goto out; 2736 } 2737 2738 switch (nhm->nh_family) { 2739 case AF_INET: 2740 case AF_INET6: 2741 break; 2742 case AF_UNSPEC: 2743 if (tb[NHA_GROUP]) 2744 break; 2745 fallthrough; 2746 default: 2747 NL_SET_ERR_MSG(extack, "Invalid address family"); 2748 goto out; 2749 } 2750 2751 memset(cfg, 0, sizeof(*cfg)); 2752 cfg->nlflags = nlh->nlmsg_flags; 2753 cfg->nlinfo.portid = NETLINK_CB(skb).portid; 2754 cfg->nlinfo.nlh = nlh; 2755 cfg->nlinfo.nl_net = net; 2756 2757 cfg->nh_family = nhm->nh_family; 2758 cfg->nh_protocol = nhm->nh_protocol; 2759 cfg->nh_flags = nhm->nh_flags; 2760 2761 if (tb[NHA_ID]) 2762 cfg->nh_id = nla_get_u32(tb[NHA_ID]); 2763 2764 if (tb[NHA_FDB]) { 2765 if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] || 2766 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) { 2767 NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole"); 2768 goto out; 2769 } 2770 if (nhm->nh_flags) { 2771 NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header"); 2772 goto out; 2773 } 2774 cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]); 2775 } 2776 2777 if (tb[NHA_GROUP]) { 2778 if (nhm->nh_family != AF_UNSPEC) { 2779 NL_SET_ERR_MSG(extack, "Invalid family for group"); 2780 goto out; 2781 } 2782 cfg->nh_grp = tb[NHA_GROUP]; 2783 2784 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH; 2785 if (tb[NHA_GROUP_TYPE]) 2786 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]); 2787 2788 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) { 2789 NL_SET_ERR_MSG(extack, "Invalid group type"); 2790 goto out; 2791 } 2792 err = nh_check_attr_group(net, tb, ARRAY_SIZE(tb), 2793 cfg->nh_grp_type, extack); 2794 if (err) 2795 goto out; 2796 2797 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) 2798 err = rtm_to_nh_config_grp_res(tb[NHA_RES_GROUP], 2799 cfg, extack); 2800 2801 /* no other attributes should be set */ 2802 goto out; 2803 } 2804 2805 if (tb[NHA_BLACKHOLE]) { 2806 if (tb[NHA_GATEWAY] || tb[NHA_OIF] || 2807 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) { 2808 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb"); 2809 goto out; 2810 } 2811 2812 cfg->nh_blackhole = 1; 2813 err = 0; 2814 goto out; 2815 } 2816 2817 if (!cfg->nh_fdb && !tb[NHA_OIF]) { 2818 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops"); 2819 goto out; 2820 } 2821 2822 if (!cfg->nh_fdb && tb[NHA_OIF]) { 2823 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]); 2824 if (cfg->nh_ifindex) 2825 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex); 2826 2827 if (!cfg->dev) { 2828 NL_SET_ERR_MSG(extack, "Invalid device index"); 2829 goto out; 2830 } else if (!(cfg->dev->flags & IFF_UP)) { 2831 NL_SET_ERR_MSG(extack, "Nexthop device is not up"); 2832 err = -ENETDOWN; 2833 goto out; 2834 } else if (!netif_carrier_ok(cfg->dev)) { 2835 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down"); 2836 err = -ENETDOWN; 2837 goto out; 2838 } 2839 } 2840 2841 err = -EINVAL; 2842 if (tb[NHA_GATEWAY]) { 2843 struct nlattr *gwa = tb[NHA_GATEWAY]; 2844 2845 switch (cfg->nh_family) { 2846 case AF_INET: 2847 if (nla_len(gwa) != sizeof(u32)) { 2848 NL_SET_ERR_MSG(extack, "Invalid gateway"); 2849 goto out; 2850 } 2851 cfg->gw.ipv4 = nla_get_be32(gwa); 2852 break; 2853 case AF_INET6: 2854 if (nla_len(gwa) != sizeof(struct in6_addr)) { 2855 NL_SET_ERR_MSG(extack, "Invalid gateway"); 2856 goto out; 2857 } 2858 cfg->gw.ipv6 = nla_get_in6_addr(gwa); 2859 break; 2860 default: 2861 NL_SET_ERR_MSG(extack, 2862 "Unknown address family for gateway"); 2863 goto out; 2864 } 2865 } else { 2866 /* device only nexthop (no gateway) */ 2867 if (cfg->nh_flags & RTNH_F_ONLINK) { 2868 NL_SET_ERR_MSG(extack, 2869 "ONLINK flag can not be set for nexthop without a gateway"); 2870 goto out; 2871 } 2872 } 2873 2874 if (tb[NHA_ENCAP]) { 2875 cfg->nh_encap = tb[NHA_ENCAP]; 2876 2877 if (!tb[NHA_ENCAP_TYPE]) { 2878 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing"); 2879 goto out; 2880 } 2881 2882 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]); 2883 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack); 2884 if (err < 0) 2885 goto out; 2886 2887 } else if (tb[NHA_ENCAP_TYPE]) { 2888 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing"); 2889 goto out; 2890 } 2891 2892 2893 err = 0; 2894 out: 2895 return err; 2896 } 2897 2898 /* rtnl */ 2899 static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 2900 struct netlink_ext_ack *extack) 2901 { 2902 struct net *net = sock_net(skb->sk); 2903 struct nh_config cfg; 2904 struct nexthop *nh; 2905 int err; 2906 2907 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack); 2908 if (!err) { 2909 nh = nexthop_add(net, &cfg, extack); 2910 if (IS_ERR(nh)) 2911 err = PTR_ERR(nh); 2912 } 2913 2914 return err; 2915 } 2916 2917 static int __nh_valid_get_del_req(const struct nlmsghdr *nlh, 2918 struct nlattr **tb, u32 *id, 2919 struct netlink_ext_ack *extack) 2920 { 2921 struct nhmsg *nhm = nlmsg_data(nlh); 2922 2923 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { 2924 NL_SET_ERR_MSG(extack, "Invalid values in header"); 2925 return -EINVAL; 2926 } 2927 2928 if (!tb[NHA_ID]) { 2929 NL_SET_ERR_MSG(extack, "Nexthop id is missing"); 2930 return -EINVAL; 2931 } 2932 2933 *id = nla_get_u32(tb[NHA_ID]); 2934 if (!(*id)) { 2935 NL_SET_ERR_MSG(extack, "Invalid nexthop id"); 2936 return -EINVAL; 2937 } 2938 2939 return 0; 2940 } 2941 2942 static int nh_valid_get_del_req(const struct nlmsghdr *nlh, u32 *id, 2943 struct netlink_ext_ack *extack) 2944 { 2945 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get)]; 2946 int err; 2947 2948 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 2949 ARRAY_SIZE(rtm_nh_policy_get) - 1, 2950 rtm_nh_policy_get, extack); 2951 if (err < 0) 2952 return err; 2953 2954 return __nh_valid_get_del_req(nlh, tb, id, extack); 2955 } 2956 2957 /* rtnl */ 2958 static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 2959 struct netlink_ext_ack *extack) 2960 { 2961 struct net *net = sock_net(skb->sk); 2962 struct nl_info nlinfo = { 2963 .nlh = nlh, 2964 .nl_net = net, 2965 .portid = NETLINK_CB(skb).portid, 2966 }; 2967 struct nexthop *nh; 2968 int err; 2969 u32 id; 2970 2971 err = nh_valid_get_del_req(nlh, &id, extack); 2972 if (err) 2973 return err; 2974 2975 nh = nexthop_find_by_id(net, id); 2976 if (!nh) 2977 return -ENOENT; 2978 2979 remove_nexthop(net, nh, &nlinfo); 2980 2981 return 0; 2982 } 2983 2984 /* rtnl */ 2985 static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh, 2986 struct netlink_ext_ack *extack) 2987 { 2988 struct net *net = sock_net(in_skb->sk); 2989 struct sk_buff *skb = NULL; 2990 struct nexthop *nh; 2991 int err; 2992 u32 id; 2993 2994 err = nh_valid_get_del_req(nlh, &id, extack); 2995 if (err) 2996 return err; 2997 2998 err = -ENOBUFS; 2999 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3000 if (!skb) 3001 goto out; 3002 3003 err = -ENOENT; 3004 nh = nexthop_find_by_id(net, id); 3005 if (!nh) 3006 goto errout_free; 3007 3008 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid, 3009 nlh->nlmsg_seq, 0); 3010 if (err < 0) { 3011 WARN_ON(err == -EMSGSIZE); 3012 goto errout_free; 3013 } 3014 3015 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3016 out: 3017 return err; 3018 errout_free: 3019 kfree_skb(skb); 3020 goto out; 3021 } 3022 3023 struct nh_dump_filter { 3024 u32 nh_id; 3025 int dev_idx; 3026 int master_idx; 3027 bool group_filter; 3028 bool fdb_filter; 3029 u32 res_bucket_nh_id; 3030 }; 3031 3032 static bool nh_dump_filtered(struct nexthop *nh, 3033 struct nh_dump_filter *filter, u8 family) 3034 { 3035 const struct net_device *dev; 3036 const struct nh_info *nhi; 3037 3038 if (filter->group_filter && !nh->is_group) 3039 return true; 3040 3041 if (!filter->dev_idx && !filter->master_idx && !family) 3042 return false; 3043 3044 if (nh->is_group) 3045 return true; 3046 3047 nhi = rtnl_dereference(nh->nh_info); 3048 if (family && nhi->family != family) 3049 return true; 3050 3051 dev = nhi->fib_nhc.nhc_dev; 3052 if (filter->dev_idx && (!dev || dev->ifindex != filter->dev_idx)) 3053 return true; 3054 3055 if (filter->master_idx) { 3056 struct net_device *master; 3057 3058 if (!dev) 3059 return true; 3060 3061 master = netdev_master_upper_dev_get((struct net_device *)dev); 3062 if (!master || master->ifindex != filter->master_idx) 3063 return true; 3064 } 3065 3066 return false; 3067 } 3068 3069 static int __nh_valid_dump_req(const struct nlmsghdr *nlh, struct nlattr **tb, 3070 struct nh_dump_filter *filter, 3071 struct netlink_ext_ack *extack) 3072 { 3073 struct nhmsg *nhm; 3074 u32 idx; 3075 3076 if (tb[NHA_OIF]) { 3077 idx = nla_get_u32(tb[NHA_OIF]); 3078 if (idx > INT_MAX) { 3079 NL_SET_ERR_MSG(extack, "Invalid device index"); 3080 return -EINVAL; 3081 } 3082 filter->dev_idx = idx; 3083 } 3084 if (tb[NHA_MASTER]) { 3085 idx = nla_get_u32(tb[NHA_MASTER]); 3086 if (idx > INT_MAX) { 3087 NL_SET_ERR_MSG(extack, "Invalid master device index"); 3088 return -EINVAL; 3089 } 3090 filter->master_idx = idx; 3091 } 3092 filter->group_filter = nla_get_flag(tb[NHA_GROUPS]); 3093 filter->fdb_filter = nla_get_flag(tb[NHA_FDB]); 3094 3095 nhm = nlmsg_data(nlh); 3096 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { 3097 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request"); 3098 return -EINVAL; 3099 } 3100 3101 return 0; 3102 } 3103 3104 static int nh_valid_dump_req(const struct nlmsghdr *nlh, 3105 struct nh_dump_filter *filter, 3106 struct netlink_callback *cb) 3107 { 3108 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump)]; 3109 int err; 3110 3111 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 3112 ARRAY_SIZE(rtm_nh_policy_dump) - 1, 3113 rtm_nh_policy_dump, cb->extack); 3114 if (err < 0) 3115 return err; 3116 3117 return __nh_valid_dump_req(nlh, tb, filter, cb->extack); 3118 } 3119 3120 struct rtm_dump_nh_ctx { 3121 u32 idx; 3122 }; 3123 3124 static struct rtm_dump_nh_ctx * 3125 rtm_dump_nh_ctx(struct netlink_callback *cb) 3126 { 3127 struct rtm_dump_nh_ctx *ctx = (void *)cb->ctx; 3128 3129 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); 3130 return ctx; 3131 } 3132 3133 static int rtm_dump_walk_nexthops(struct sk_buff *skb, 3134 struct netlink_callback *cb, 3135 struct rb_root *root, 3136 struct rtm_dump_nh_ctx *ctx, 3137 int (*nh_cb)(struct sk_buff *skb, 3138 struct netlink_callback *cb, 3139 struct nexthop *nh, void *data), 3140 void *data) 3141 { 3142 struct rb_node *node; 3143 int s_idx; 3144 int err; 3145 3146 s_idx = ctx->idx; 3147 for (node = rb_first(root); node; node = rb_next(node)) { 3148 struct nexthop *nh; 3149 3150 nh = rb_entry(node, struct nexthop, rb_node); 3151 if (nh->id < s_idx) 3152 continue; 3153 3154 ctx->idx = nh->id; 3155 err = nh_cb(skb, cb, nh, data); 3156 if (err) 3157 return err; 3158 } 3159 3160 ctx->idx++; 3161 return 0; 3162 } 3163 3164 static int rtm_dump_nexthop_cb(struct sk_buff *skb, struct netlink_callback *cb, 3165 struct nexthop *nh, void *data) 3166 { 3167 struct nhmsg *nhm = nlmsg_data(cb->nlh); 3168 struct nh_dump_filter *filter = data; 3169 3170 if (nh_dump_filtered(nh, filter, nhm->nh_family)) 3171 return 0; 3172 3173 return nh_fill_node(skb, nh, RTM_NEWNEXTHOP, 3174 NETLINK_CB(cb->skb).portid, 3175 cb->nlh->nlmsg_seq, NLM_F_MULTI); 3176 } 3177 3178 /* rtnl */ 3179 static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb) 3180 { 3181 struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb); 3182 struct net *net = sock_net(skb->sk); 3183 struct rb_root *root = &net->nexthop.rb_root; 3184 struct nh_dump_filter filter = {}; 3185 int err; 3186 3187 err = nh_valid_dump_req(cb->nlh, &filter, cb); 3188 if (err < 0) 3189 return err; 3190 3191 err = rtm_dump_walk_nexthops(skb, cb, root, ctx, 3192 &rtm_dump_nexthop_cb, &filter); 3193 if (err < 0) { 3194 if (likely(skb->len)) 3195 goto out; 3196 goto out_err; 3197 } 3198 3199 out: 3200 err = skb->len; 3201 out_err: 3202 cb->seq = net->nexthop.seq; 3203 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 3204 return err; 3205 } 3206 3207 static struct nexthop * 3208 nexthop_find_group_resilient(struct net *net, u32 id, 3209 struct netlink_ext_ack *extack) 3210 { 3211 struct nh_group *nhg; 3212 struct nexthop *nh; 3213 3214 nh = nexthop_find_by_id(net, id); 3215 if (!nh) 3216 return ERR_PTR(-ENOENT); 3217 3218 if (!nh->is_group) { 3219 NL_SET_ERR_MSG(extack, "Not a nexthop group"); 3220 return ERR_PTR(-EINVAL); 3221 } 3222 3223 nhg = rtnl_dereference(nh->nh_grp); 3224 if (!nhg->resilient) { 3225 NL_SET_ERR_MSG(extack, "Nexthop group not of type resilient"); 3226 return ERR_PTR(-EINVAL); 3227 } 3228 3229 return nh; 3230 } 3231 3232 static int nh_valid_dump_nhid(struct nlattr *attr, u32 *nh_id_p, 3233 struct netlink_ext_ack *extack) 3234 { 3235 u32 idx; 3236 3237 if (attr) { 3238 idx = nla_get_u32(attr); 3239 if (!idx) { 3240 NL_SET_ERR_MSG(extack, "Invalid nexthop id"); 3241 return -EINVAL; 3242 } 3243 *nh_id_p = idx; 3244 } else { 3245 *nh_id_p = 0; 3246 } 3247 3248 return 0; 3249 } 3250 3251 static int nh_valid_dump_bucket_req(const struct nlmsghdr *nlh, 3252 struct nh_dump_filter *filter, 3253 struct netlink_callback *cb) 3254 { 3255 struct nlattr *res_tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_dump)]; 3256 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump_bucket)]; 3257 int err; 3258 3259 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 3260 ARRAY_SIZE(rtm_nh_policy_dump_bucket) - 1, 3261 rtm_nh_policy_dump_bucket, NULL); 3262 if (err < 0) 3263 return err; 3264 3265 err = nh_valid_dump_nhid(tb[NHA_ID], &filter->nh_id, cb->extack); 3266 if (err) 3267 return err; 3268 3269 if (tb[NHA_RES_BUCKET]) { 3270 size_t max = ARRAY_SIZE(rtm_nh_res_bucket_policy_dump) - 1; 3271 3272 err = nla_parse_nested(res_tb, max, 3273 tb[NHA_RES_BUCKET], 3274 rtm_nh_res_bucket_policy_dump, 3275 cb->extack); 3276 if (err < 0) 3277 return err; 3278 3279 err = nh_valid_dump_nhid(res_tb[NHA_RES_BUCKET_NH_ID], 3280 &filter->res_bucket_nh_id, 3281 cb->extack); 3282 if (err) 3283 return err; 3284 } 3285 3286 return __nh_valid_dump_req(nlh, tb, filter, cb->extack); 3287 } 3288 3289 struct rtm_dump_res_bucket_ctx { 3290 struct rtm_dump_nh_ctx nh; 3291 u16 bucket_index; 3292 u32 done_nh_idx; /* 1 + the index of the last fully processed NH. */ 3293 }; 3294 3295 static struct rtm_dump_res_bucket_ctx * 3296 rtm_dump_res_bucket_ctx(struct netlink_callback *cb) 3297 { 3298 struct rtm_dump_res_bucket_ctx *ctx = (void *)cb->ctx; 3299 3300 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); 3301 return ctx; 3302 } 3303 3304 struct rtm_dump_nexthop_bucket_data { 3305 struct rtm_dump_res_bucket_ctx *ctx; 3306 struct nh_dump_filter filter; 3307 }; 3308 3309 static int rtm_dump_nexthop_bucket_nh(struct sk_buff *skb, 3310 struct netlink_callback *cb, 3311 struct nexthop *nh, 3312 struct rtm_dump_nexthop_bucket_data *dd) 3313 { 3314 u32 portid = NETLINK_CB(cb->skb).portid; 3315 struct nhmsg *nhm = nlmsg_data(cb->nlh); 3316 struct nh_res_table *res_table; 3317 struct nh_group *nhg; 3318 u16 bucket_index; 3319 int err; 3320 3321 if (dd->ctx->nh.idx < dd->ctx->done_nh_idx) 3322 return 0; 3323 3324 nhg = rtnl_dereference(nh->nh_grp); 3325 res_table = rtnl_dereference(nhg->res_table); 3326 for (bucket_index = dd->ctx->bucket_index; 3327 bucket_index < res_table->num_nh_buckets; 3328 bucket_index++) { 3329 struct nh_res_bucket *bucket; 3330 struct nh_grp_entry *nhge; 3331 3332 bucket = &res_table->nh_buckets[bucket_index]; 3333 nhge = rtnl_dereference(bucket->nh_entry); 3334 if (nh_dump_filtered(nhge->nh, &dd->filter, nhm->nh_family)) 3335 continue; 3336 3337 if (dd->filter.res_bucket_nh_id && 3338 dd->filter.res_bucket_nh_id != nhge->nh->id) 3339 continue; 3340 3341 err = nh_fill_res_bucket(skb, nh, bucket, bucket_index, 3342 RTM_NEWNEXTHOPBUCKET, portid, 3343 cb->nlh->nlmsg_seq, NLM_F_MULTI, 3344 cb->extack); 3345 if (err < 0) { 3346 if (likely(skb->len)) 3347 goto out; 3348 goto out_err; 3349 } 3350 } 3351 3352 dd->ctx->done_nh_idx = dd->ctx->nh.idx + 1; 3353 bucket_index = 0; 3354 3355 out: 3356 err = skb->len; 3357 out_err: 3358 dd->ctx->bucket_index = bucket_index; 3359 return err; 3360 } 3361 3362 static int rtm_dump_nexthop_bucket_cb(struct sk_buff *skb, 3363 struct netlink_callback *cb, 3364 struct nexthop *nh, void *data) 3365 { 3366 struct rtm_dump_nexthop_bucket_data *dd = data; 3367 struct nh_group *nhg; 3368 3369 if (!nh->is_group) 3370 return 0; 3371 3372 nhg = rtnl_dereference(nh->nh_grp); 3373 if (!nhg->resilient) 3374 return 0; 3375 3376 return rtm_dump_nexthop_bucket_nh(skb, cb, nh, dd); 3377 } 3378 3379 /* rtnl */ 3380 static int rtm_dump_nexthop_bucket(struct sk_buff *skb, 3381 struct netlink_callback *cb) 3382 { 3383 struct rtm_dump_res_bucket_ctx *ctx = rtm_dump_res_bucket_ctx(cb); 3384 struct rtm_dump_nexthop_bucket_data dd = { .ctx = ctx }; 3385 struct net *net = sock_net(skb->sk); 3386 struct nexthop *nh; 3387 int err; 3388 3389 err = nh_valid_dump_bucket_req(cb->nlh, &dd.filter, cb); 3390 if (err) 3391 return err; 3392 3393 if (dd.filter.nh_id) { 3394 nh = nexthop_find_group_resilient(net, dd.filter.nh_id, 3395 cb->extack); 3396 if (IS_ERR(nh)) 3397 return PTR_ERR(nh); 3398 err = rtm_dump_nexthop_bucket_nh(skb, cb, nh, &dd); 3399 } else { 3400 struct rb_root *root = &net->nexthop.rb_root; 3401 3402 err = rtm_dump_walk_nexthops(skb, cb, root, &ctx->nh, 3403 &rtm_dump_nexthop_bucket_cb, &dd); 3404 } 3405 3406 if (err < 0) { 3407 if (likely(skb->len)) 3408 goto out; 3409 goto out_err; 3410 } 3411 3412 out: 3413 err = skb->len; 3414 out_err: 3415 cb->seq = net->nexthop.seq; 3416 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 3417 return err; 3418 } 3419 3420 static int nh_valid_get_bucket_req_res_bucket(struct nlattr *res, 3421 u16 *bucket_index, 3422 struct netlink_ext_ack *extack) 3423 { 3424 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_get)]; 3425 int err; 3426 3427 err = nla_parse_nested(tb, ARRAY_SIZE(rtm_nh_res_bucket_policy_get) - 1, 3428 res, rtm_nh_res_bucket_policy_get, extack); 3429 if (err < 0) 3430 return err; 3431 3432 if (!tb[NHA_RES_BUCKET_INDEX]) { 3433 NL_SET_ERR_MSG(extack, "Bucket index is missing"); 3434 return -EINVAL; 3435 } 3436 3437 *bucket_index = nla_get_u16(tb[NHA_RES_BUCKET_INDEX]); 3438 return 0; 3439 } 3440 3441 static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh, 3442 u32 *id, u16 *bucket_index, 3443 struct netlink_ext_ack *extack) 3444 { 3445 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get_bucket)]; 3446 int err; 3447 3448 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 3449 ARRAY_SIZE(rtm_nh_policy_get_bucket) - 1, 3450 rtm_nh_policy_get_bucket, extack); 3451 if (err < 0) 3452 return err; 3453 3454 err = __nh_valid_get_del_req(nlh, tb, id, extack); 3455 if (err) 3456 return err; 3457 3458 if (!tb[NHA_RES_BUCKET]) { 3459 NL_SET_ERR_MSG(extack, "Bucket information is missing"); 3460 return -EINVAL; 3461 } 3462 3463 err = nh_valid_get_bucket_req_res_bucket(tb[NHA_RES_BUCKET], 3464 bucket_index, extack); 3465 if (err) 3466 return err; 3467 3468 return 0; 3469 } 3470 3471 /* rtnl */ 3472 static int rtm_get_nexthop_bucket(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3473 struct netlink_ext_ack *extack) 3474 { 3475 struct net *net = sock_net(in_skb->sk); 3476 struct nh_res_table *res_table; 3477 struct sk_buff *skb = NULL; 3478 struct nh_group *nhg; 3479 struct nexthop *nh; 3480 u16 bucket_index; 3481 int err; 3482 u32 id; 3483 3484 err = nh_valid_get_bucket_req(nlh, &id, &bucket_index, extack); 3485 if (err) 3486 return err; 3487 3488 nh = nexthop_find_group_resilient(net, id, extack); 3489 if (IS_ERR(nh)) 3490 return PTR_ERR(nh); 3491 3492 nhg = rtnl_dereference(nh->nh_grp); 3493 res_table = rtnl_dereference(nhg->res_table); 3494 if (bucket_index >= res_table->num_nh_buckets) { 3495 NL_SET_ERR_MSG(extack, "Bucket index out of bounds"); 3496 return -ENOENT; 3497 } 3498 3499 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3500 if (!skb) 3501 return -ENOBUFS; 3502 3503 err = nh_fill_res_bucket(skb, nh, &res_table->nh_buckets[bucket_index], 3504 bucket_index, RTM_NEWNEXTHOPBUCKET, 3505 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 3506 0, extack); 3507 if (err < 0) { 3508 WARN_ON(err == -EMSGSIZE); 3509 goto errout_free; 3510 } 3511 3512 return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3513 3514 errout_free: 3515 kfree_skb(skb); 3516 return err; 3517 } 3518 3519 static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu) 3520 { 3521 unsigned int hash = nh_dev_hashfn(dev->ifindex); 3522 struct net *net = dev_net(dev); 3523 struct hlist_head *head = &net->nexthop.devhash[hash]; 3524 struct hlist_node *n; 3525 struct nh_info *nhi; 3526 3527 hlist_for_each_entry_safe(nhi, n, head, dev_hash) { 3528 if (nhi->fib_nhc.nhc_dev == dev) { 3529 if (nhi->family == AF_INET) 3530 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu, 3531 orig_mtu); 3532 } 3533 } 3534 } 3535 3536 /* rtnl */ 3537 static int nh_netdev_event(struct notifier_block *this, 3538 unsigned long event, void *ptr) 3539 { 3540 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3541 struct netdev_notifier_info_ext *info_ext; 3542 3543 switch (event) { 3544 case NETDEV_DOWN: 3545 case NETDEV_UNREGISTER: 3546 nexthop_flush_dev(dev, event); 3547 break; 3548 case NETDEV_CHANGE: 3549 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP))) 3550 nexthop_flush_dev(dev, event); 3551 break; 3552 case NETDEV_CHANGEMTU: 3553 info_ext = ptr; 3554 nexthop_sync_mtu(dev, info_ext->ext.mtu); 3555 rt_cache_flush(dev_net(dev)); 3556 break; 3557 } 3558 return NOTIFY_DONE; 3559 } 3560 3561 static struct notifier_block nh_netdev_notifier = { 3562 .notifier_call = nh_netdev_event, 3563 }; 3564 3565 static int nexthops_dump(struct net *net, struct notifier_block *nb, 3566 struct netlink_ext_ack *extack) 3567 { 3568 struct rb_root *root = &net->nexthop.rb_root; 3569 struct rb_node *node; 3570 int err = 0; 3571 3572 for (node = rb_first(root); node; node = rb_next(node)) { 3573 struct nexthop *nh; 3574 3575 nh = rb_entry(node, struct nexthop, rb_node); 3576 err = call_nexthop_notifier(nb, net, NEXTHOP_EVENT_REPLACE, nh, 3577 extack); 3578 if (err) 3579 break; 3580 } 3581 3582 return err; 3583 } 3584 3585 int register_nexthop_notifier(struct net *net, struct notifier_block *nb, 3586 struct netlink_ext_ack *extack) 3587 { 3588 int err; 3589 3590 rtnl_lock(); 3591 err = nexthops_dump(net, nb, extack); 3592 if (err) 3593 goto unlock; 3594 err = blocking_notifier_chain_register(&net->nexthop.notifier_chain, 3595 nb); 3596 unlock: 3597 rtnl_unlock(); 3598 return err; 3599 } 3600 EXPORT_SYMBOL(register_nexthop_notifier); 3601 3602 int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb) 3603 { 3604 return blocking_notifier_chain_unregister(&net->nexthop.notifier_chain, 3605 nb); 3606 } 3607 EXPORT_SYMBOL(unregister_nexthop_notifier); 3608 3609 void nexthop_set_hw_flags(struct net *net, u32 id, bool offload, bool trap) 3610 { 3611 struct nexthop *nexthop; 3612 3613 rcu_read_lock(); 3614 3615 nexthop = nexthop_find_by_id(net, id); 3616 if (!nexthop) 3617 goto out; 3618 3619 nexthop->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP); 3620 if (offload) 3621 nexthop->nh_flags |= RTNH_F_OFFLOAD; 3622 if (trap) 3623 nexthop->nh_flags |= RTNH_F_TRAP; 3624 3625 out: 3626 rcu_read_unlock(); 3627 } 3628 EXPORT_SYMBOL(nexthop_set_hw_flags); 3629 3630 void nexthop_bucket_set_hw_flags(struct net *net, u32 id, u16 bucket_index, 3631 bool offload, bool trap) 3632 { 3633 struct nh_res_table *res_table; 3634 struct nh_res_bucket *bucket; 3635 struct nexthop *nexthop; 3636 struct nh_group *nhg; 3637 3638 rcu_read_lock(); 3639 3640 nexthop = nexthop_find_by_id(net, id); 3641 if (!nexthop || !nexthop->is_group) 3642 goto out; 3643 3644 nhg = rcu_dereference(nexthop->nh_grp); 3645 if (!nhg->resilient) 3646 goto out; 3647 3648 if (bucket_index >= nhg->res_table->num_nh_buckets) 3649 goto out; 3650 3651 res_table = rcu_dereference(nhg->res_table); 3652 bucket = &res_table->nh_buckets[bucket_index]; 3653 bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP); 3654 if (offload) 3655 bucket->nh_flags |= RTNH_F_OFFLOAD; 3656 if (trap) 3657 bucket->nh_flags |= RTNH_F_TRAP; 3658 3659 out: 3660 rcu_read_unlock(); 3661 } 3662 EXPORT_SYMBOL(nexthop_bucket_set_hw_flags); 3663 3664 void nexthop_res_grp_activity_update(struct net *net, u32 id, u16 num_buckets, 3665 unsigned long *activity) 3666 { 3667 struct nh_res_table *res_table; 3668 struct nexthop *nexthop; 3669 struct nh_group *nhg; 3670 u16 i; 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 /* Instead of silently ignoring some buckets, demand that the sizes 3683 * be the same. 3684 */ 3685 res_table = rcu_dereference(nhg->res_table); 3686 if (num_buckets != res_table->num_nh_buckets) 3687 goto out; 3688 3689 for (i = 0; i < num_buckets; i++) { 3690 if (test_bit(i, activity)) 3691 nh_res_bucket_set_busy(&res_table->nh_buckets[i]); 3692 } 3693 3694 out: 3695 rcu_read_unlock(); 3696 } 3697 EXPORT_SYMBOL(nexthop_res_grp_activity_update); 3698 3699 static void __net_exit nexthop_net_exit(struct net *net) 3700 { 3701 rtnl_lock(); 3702 flush_all_nexthops(net); 3703 rtnl_unlock(); 3704 kfree(net->nexthop.devhash); 3705 } 3706 3707 static int __net_init nexthop_net_init(struct net *net) 3708 { 3709 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE; 3710 3711 net->nexthop.rb_root = RB_ROOT; 3712 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL); 3713 if (!net->nexthop.devhash) 3714 return -ENOMEM; 3715 BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain); 3716 3717 return 0; 3718 } 3719 3720 static struct pernet_operations nexthop_net_ops = { 3721 .init = nexthop_net_init, 3722 .exit = nexthop_net_exit, 3723 }; 3724 3725 static int __init nexthop_init(void) 3726 { 3727 register_pernet_subsys(&nexthop_net_ops); 3728 3729 register_netdevice_notifier(&nh_netdev_notifier); 3730 3731 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 3732 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0); 3733 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop, 3734 rtm_dump_nexthop, 0); 3735 3736 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 3737 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); 3738 3739 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 3740 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); 3741 3742 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, rtm_get_nexthop_bucket, 3743 rtm_dump_nexthop_bucket, 0); 3744 3745 return 0; 3746 } 3747 subsys_initcall(nexthop_init); 3748