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 /* Make sure concurrent readers are not using 'oldg' anymore. */ 1986 synchronize_net(); 1987 rcu_assign_pointer(oldg->res_table, tmp_table); 1988 rcu_assign_pointer(oldg->spare->res_table, tmp_table); 1989 } 1990 1991 for (i = 0; i < oldg->num_nh; i++) 1992 oldg->nh_entries[i].nh_parent = new; 1993 1994 rcu_assign_pointer(new->nh_grp, oldg); 1995 1996 return 0; 1997 } 1998 1999 static void nh_group_v4_update(struct nh_group *nhg) 2000 { 2001 struct nh_grp_entry *nhges; 2002 bool has_v4 = false; 2003 int i; 2004 2005 nhges = nhg->nh_entries; 2006 for (i = 0; i < nhg->num_nh; i++) { 2007 struct nh_info *nhi; 2008 2009 nhi = rtnl_dereference(nhges[i].nh->nh_info); 2010 if (nhi->family == AF_INET) 2011 has_v4 = true; 2012 } 2013 nhg->has_v4 = has_v4; 2014 } 2015 2016 static int replace_nexthop_single_notify_res(struct net *net, 2017 struct nh_res_table *res_table, 2018 struct nexthop *old, 2019 struct nh_info *oldi, 2020 struct nh_info *newi, 2021 struct netlink_ext_ack *extack) 2022 { 2023 u32 nhg_id = res_table->nhg_id; 2024 int err; 2025 u16 i; 2026 2027 for (i = 0; i < res_table->num_nh_buckets; i++) { 2028 struct nh_res_bucket *bucket = &res_table->nh_buckets[i]; 2029 struct nh_grp_entry *nhge; 2030 2031 nhge = rtnl_dereference(bucket->nh_entry); 2032 if (nhge->nh == old) { 2033 err = __call_nexthop_res_bucket_notifiers(net, nhg_id, 2034 i, true, 2035 oldi, newi, 2036 extack); 2037 if (err) 2038 goto err_notify; 2039 } 2040 } 2041 2042 return 0; 2043 2044 err_notify: 2045 while (i-- > 0) { 2046 struct nh_res_bucket *bucket = &res_table->nh_buckets[i]; 2047 struct nh_grp_entry *nhge; 2048 2049 nhge = rtnl_dereference(bucket->nh_entry); 2050 if (nhge->nh == old) 2051 __call_nexthop_res_bucket_notifiers(net, nhg_id, i, 2052 true, newi, oldi, 2053 extack); 2054 } 2055 return err; 2056 } 2057 2058 static int replace_nexthop_single_notify(struct net *net, 2059 struct nexthop *group_nh, 2060 struct nexthop *old, 2061 struct nh_info *oldi, 2062 struct nh_info *newi, 2063 struct netlink_ext_ack *extack) 2064 { 2065 struct nh_group *nhg = rtnl_dereference(group_nh->nh_grp); 2066 struct nh_res_table *res_table; 2067 2068 if (nhg->hash_threshold) { 2069 return call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, 2070 group_nh, extack); 2071 } else if (nhg->resilient) { 2072 res_table = rtnl_dereference(nhg->res_table); 2073 return replace_nexthop_single_notify_res(net, res_table, 2074 old, oldi, newi, 2075 extack); 2076 } 2077 2078 return -EINVAL; 2079 } 2080 2081 static int replace_nexthop_single(struct net *net, struct nexthop *old, 2082 struct nexthop *new, 2083 struct netlink_ext_ack *extack) 2084 { 2085 u8 old_protocol, old_nh_flags; 2086 struct nh_info *oldi, *newi; 2087 struct nh_grp_entry *nhge; 2088 int err; 2089 2090 if (new->is_group) { 2091 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group."); 2092 return -EINVAL; 2093 } 2094 2095 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack); 2096 if (err) 2097 return err; 2098 2099 /* Hardware flags were set on 'old' as 'new' is not in the red-black 2100 * tree. Therefore, inherit the flags from 'old' to 'new'. 2101 */ 2102 new->nh_flags |= old->nh_flags & (RTNH_F_OFFLOAD | RTNH_F_TRAP); 2103 2104 oldi = rtnl_dereference(old->nh_info); 2105 newi = rtnl_dereference(new->nh_info); 2106 2107 newi->nh_parent = old; 2108 oldi->nh_parent = new; 2109 2110 old_protocol = old->protocol; 2111 old_nh_flags = old->nh_flags; 2112 2113 old->protocol = new->protocol; 2114 old->nh_flags = new->nh_flags; 2115 2116 rcu_assign_pointer(old->nh_info, newi); 2117 rcu_assign_pointer(new->nh_info, oldi); 2118 2119 /* Send a replace notification for all the groups using the nexthop. */ 2120 list_for_each_entry(nhge, &old->grp_list, nh_list) { 2121 struct nexthop *nhp = nhge->nh_parent; 2122 2123 err = replace_nexthop_single_notify(net, nhp, old, oldi, newi, 2124 extack); 2125 if (err) 2126 goto err_notify; 2127 } 2128 2129 /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially 2130 * update IPv4 indication in all the groups using the nexthop. 2131 */ 2132 if (oldi->family == AF_INET && newi->family == AF_INET6) { 2133 list_for_each_entry(nhge, &old->grp_list, nh_list) { 2134 struct nexthop *nhp = nhge->nh_parent; 2135 struct nh_group *nhg; 2136 2137 nhg = rtnl_dereference(nhp->nh_grp); 2138 nh_group_v4_update(nhg); 2139 } 2140 } 2141 2142 return 0; 2143 2144 err_notify: 2145 rcu_assign_pointer(new->nh_info, newi); 2146 rcu_assign_pointer(old->nh_info, oldi); 2147 old->nh_flags = old_nh_flags; 2148 old->protocol = old_protocol; 2149 oldi->nh_parent = old; 2150 newi->nh_parent = new; 2151 list_for_each_entry_continue_reverse(nhge, &old->grp_list, nh_list) { 2152 struct nexthop *nhp = nhge->nh_parent; 2153 2154 replace_nexthop_single_notify(net, nhp, old, newi, oldi, NULL); 2155 } 2156 call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, old, extack); 2157 return err; 2158 } 2159 2160 static void __nexthop_replace_notify(struct net *net, struct nexthop *nh, 2161 struct nl_info *info) 2162 { 2163 struct fib6_info *f6i; 2164 2165 if (!list_empty(&nh->fi_list)) { 2166 struct fib_info *fi; 2167 2168 /* expectation is a few fib_info per nexthop and then 2169 * a lot of routes per fib_info. So mark the fib_info 2170 * and then walk the fib tables once 2171 */ 2172 list_for_each_entry(fi, &nh->fi_list, nh_list) 2173 fi->nh_updated = true; 2174 2175 fib_info_notify_update(net, info); 2176 2177 list_for_each_entry(fi, &nh->fi_list, nh_list) 2178 fi->nh_updated = false; 2179 } 2180 2181 list_for_each_entry(f6i, &nh->f6i_list, nh_list) 2182 ipv6_stub->fib6_rt_update(net, f6i, info); 2183 } 2184 2185 /* send RTM_NEWROUTE with REPLACE flag set for all FIB entries 2186 * linked to this nexthop and for all groups that the nexthop 2187 * is a member of 2188 */ 2189 static void nexthop_replace_notify(struct net *net, struct nexthop *nh, 2190 struct nl_info *info) 2191 { 2192 struct nh_grp_entry *nhge; 2193 2194 __nexthop_replace_notify(net, nh, info); 2195 2196 list_for_each_entry(nhge, &nh->grp_list, nh_list) 2197 __nexthop_replace_notify(net, nhge->nh_parent, info); 2198 } 2199 2200 static int replace_nexthop(struct net *net, struct nexthop *old, 2201 struct nexthop *new, const struct nh_config *cfg, 2202 struct netlink_ext_ack *extack) 2203 { 2204 bool new_is_reject = false; 2205 struct nh_grp_entry *nhge; 2206 int err; 2207 2208 /* check that existing FIB entries are ok with the 2209 * new nexthop definition 2210 */ 2211 err = fib_check_nh_list(old, new, extack); 2212 if (err) 2213 return err; 2214 2215 err = fib6_check_nh_list(old, new, extack); 2216 if (err) 2217 return err; 2218 2219 if (!new->is_group) { 2220 struct nh_info *nhi = rtnl_dereference(new->nh_info); 2221 2222 new_is_reject = nhi->reject_nh; 2223 } 2224 2225 list_for_each_entry(nhge, &old->grp_list, nh_list) { 2226 /* if new nexthop is a blackhole, any groups using this 2227 * nexthop cannot have more than 1 path 2228 */ 2229 if (new_is_reject && 2230 nexthop_num_path(nhge->nh_parent) > 1) { 2231 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path"); 2232 return -EINVAL; 2233 } 2234 2235 err = fib_check_nh_list(nhge->nh_parent, new, extack); 2236 if (err) 2237 return err; 2238 2239 err = fib6_check_nh_list(nhge->nh_parent, new, extack); 2240 if (err) 2241 return err; 2242 } 2243 2244 if (old->is_group) 2245 err = replace_nexthop_grp(net, old, new, cfg, extack); 2246 else 2247 err = replace_nexthop_single(net, old, new, extack); 2248 2249 if (!err) { 2250 nh_rt_cache_flush(net, old); 2251 2252 __remove_nexthop(net, new, NULL); 2253 nexthop_put(new); 2254 } 2255 2256 return err; 2257 } 2258 2259 /* called with rtnl_lock held */ 2260 static int insert_nexthop(struct net *net, struct nexthop *new_nh, 2261 struct nh_config *cfg, struct netlink_ext_ack *extack) 2262 { 2263 struct rb_node **pp, *parent = NULL, *next; 2264 struct rb_root *root = &net->nexthop.rb_root; 2265 bool replace = !!(cfg->nlflags & NLM_F_REPLACE); 2266 bool create = !!(cfg->nlflags & NLM_F_CREATE); 2267 u32 new_id = new_nh->id; 2268 int replace_notify = 0; 2269 int rc = -EEXIST; 2270 2271 pp = &root->rb_node; 2272 while (1) { 2273 struct nexthop *nh; 2274 2275 next = *pp; 2276 if (!next) 2277 break; 2278 2279 parent = next; 2280 2281 nh = rb_entry(parent, struct nexthop, rb_node); 2282 if (new_id < nh->id) { 2283 pp = &next->rb_left; 2284 } else if (new_id > nh->id) { 2285 pp = &next->rb_right; 2286 } else if (replace) { 2287 rc = replace_nexthop(net, nh, new_nh, cfg, extack); 2288 if (!rc) { 2289 new_nh = nh; /* send notification with old nh */ 2290 replace_notify = 1; 2291 } 2292 goto out; 2293 } else { 2294 /* id already exists and not a replace */ 2295 goto out; 2296 } 2297 } 2298 2299 if (replace && !create) { 2300 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists"); 2301 rc = -ENOENT; 2302 goto out; 2303 } 2304 2305 if (new_nh->is_group) { 2306 struct nh_group *nhg = rtnl_dereference(new_nh->nh_grp); 2307 struct nh_res_table *res_table; 2308 2309 if (nhg->resilient) { 2310 res_table = rtnl_dereference(nhg->res_table); 2311 2312 /* Not passing the number of buckets is OK when 2313 * replacing, but not when creating a new group. 2314 */ 2315 if (!cfg->nh_grp_res_has_num_buckets) { 2316 NL_SET_ERR_MSG(extack, "Number of buckets not specified for nexthop group insertion"); 2317 rc = -EINVAL; 2318 goto out; 2319 } 2320 2321 nh_res_group_rebalance(nhg, res_table); 2322 2323 /* Do not send bucket notifications, we do full 2324 * notification below. 2325 */ 2326 nh_res_table_upkeep(res_table, false, false); 2327 } 2328 } 2329 2330 rb_link_node_rcu(&new_nh->rb_node, parent, pp); 2331 rb_insert_color(&new_nh->rb_node, root); 2332 2333 /* The initial insertion is a full notification for hash-threshold as 2334 * well as resilient groups. 2335 */ 2336 rc = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new_nh, extack); 2337 if (rc) 2338 rb_erase(&new_nh->rb_node, &net->nexthop.rb_root); 2339 2340 out: 2341 if (!rc) { 2342 nh_base_seq_inc(net); 2343 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo); 2344 if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode) 2345 nexthop_replace_notify(net, new_nh, &cfg->nlinfo); 2346 } 2347 2348 return rc; 2349 } 2350 2351 /* rtnl */ 2352 /* remove all nexthops tied to a device being deleted */ 2353 static void nexthop_flush_dev(struct net_device *dev, unsigned long event) 2354 { 2355 unsigned int hash = nh_dev_hashfn(dev->ifindex); 2356 struct net *net = dev_net(dev); 2357 struct hlist_head *head = &net->nexthop.devhash[hash]; 2358 struct hlist_node *n; 2359 struct nh_info *nhi; 2360 2361 hlist_for_each_entry_safe(nhi, n, head, dev_hash) { 2362 if (nhi->fib_nhc.nhc_dev != dev) 2363 continue; 2364 2365 if (nhi->reject_nh && 2366 (event == NETDEV_DOWN || event == NETDEV_CHANGE)) 2367 continue; 2368 2369 remove_nexthop(net, nhi->nh_parent, NULL); 2370 } 2371 } 2372 2373 /* rtnl; called when net namespace is deleted */ 2374 static void flush_all_nexthops(struct net *net) 2375 { 2376 struct rb_root *root = &net->nexthop.rb_root; 2377 struct rb_node *node; 2378 struct nexthop *nh; 2379 2380 while ((node = rb_first(root))) { 2381 nh = rb_entry(node, struct nexthop, rb_node); 2382 remove_nexthop(net, nh, NULL); 2383 cond_resched(); 2384 } 2385 } 2386 2387 static struct nexthop *nexthop_create_group(struct net *net, 2388 struct nh_config *cfg) 2389 { 2390 struct nlattr *grps_attr = cfg->nh_grp; 2391 struct nexthop_grp *entry = nla_data(grps_attr); 2392 u16 num_nh = nla_len(grps_attr) / sizeof(*entry); 2393 struct nh_group *nhg; 2394 struct nexthop *nh; 2395 int err; 2396 int i; 2397 2398 if (WARN_ON(!num_nh)) 2399 return ERR_PTR(-EINVAL); 2400 2401 nh = nexthop_alloc(); 2402 if (!nh) 2403 return ERR_PTR(-ENOMEM); 2404 2405 nh->is_group = 1; 2406 2407 nhg = nexthop_grp_alloc(num_nh); 2408 if (!nhg) { 2409 kfree(nh); 2410 return ERR_PTR(-ENOMEM); 2411 } 2412 2413 /* spare group used for removals */ 2414 nhg->spare = nexthop_grp_alloc(num_nh); 2415 if (!nhg->spare) { 2416 kfree(nhg); 2417 kfree(nh); 2418 return ERR_PTR(-ENOMEM); 2419 } 2420 nhg->spare->spare = nhg; 2421 2422 for (i = 0; i < nhg->num_nh; ++i) { 2423 struct nexthop *nhe; 2424 struct nh_info *nhi; 2425 2426 nhe = nexthop_find_by_id(net, entry[i].id); 2427 if (!nexthop_get(nhe)) { 2428 err = -ENOENT; 2429 goto out_no_nh; 2430 } 2431 2432 nhi = rtnl_dereference(nhe->nh_info); 2433 if (nhi->family == AF_INET) 2434 nhg->has_v4 = true; 2435 2436 nhg->nh_entries[i].nh = nhe; 2437 nhg->nh_entries[i].weight = entry[i].weight + 1; 2438 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list); 2439 nhg->nh_entries[i].nh_parent = nh; 2440 } 2441 2442 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) { 2443 nhg->hash_threshold = 1; 2444 nhg->is_multipath = true; 2445 } else if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) { 2446 struct nh_res_table *res_table; 2447 2448 res_table = nexthop_res_table_alloc(net, cfg->nh_id, cfg); 2449 if (!res_table) { 2450 err = -ENOMEM; 2451 goto out_no_nh; 2452 } 2453 2454 rcu_assign_pointer(nhg->spare->res_table, res_table); 2455 rcu_assign_pointer(nhg->res_table, res_table); 2456 nhg->resilient = true; 2457 nhg->is_multipath = true; 2458 } 2459 2460 WARN_ON_ONCE(nhg->hash_threshold + nhg->resilient != 1); 2461 2462 if (nhg->hash_threshold) 2463 nh_hthr_group_rebalance(nhg); 2464 2465 if (cfg->nh_fdb) 2466 nhg->fdb_nh = 1; 2467 2468 rcu_assign_pointer(nh->nh_grp, nhg); 2469 2470 return nh; 2471 2472 out_no_nh: 2473 for (i--; i >= 0; --i) { 2474 list_del(&nhg->nh_entries[i].nh_list); 2475 nexthop_put(nhg->nh_entries[i].nh); 2476 } 2477 2478 kfree(nhg->spare); 2479 kfree(nhg); 2480 kfree(nh); 2481 2482 return ERR_PTR(err); 2483 } 2484 2485 static int nh_create_ipv4(struct net *net, struct nexthop *nh, 2486 struct nh_info *nhi, struct nh_config *cfg, 2487 struct netlink_ext_ack *extack) 2488 { 2489 struct fib_nh *fib_nh = &nhi->fib_nh; 2490 struct fib_config fib_cfg = { 2491 .fc_oif = cfg->nh_ifindex, 2492 .fc_gw4 = cfg->gw.ipv4, 2493 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0, 2494 .fc_flags = cfg->nh_flags, 2495 .fc_nlinfo = cfg->nlinfo, 2496 .fc_encap = cfg->nh_encap, 2497 .fc_encap_type = cfg->nh_encap_type, 2498 }; 2499 u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN); 2500 int err; 2501 2502 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack); 2503 if (err) { 2504 fib_nh_release(net, fib_nh); 2505 goto out; 2506 } 2507 2508 if (nhi->fdb_nh) 2509 goto out; 2510 2511 /* sets nh_dev if successful */ 2512 err = fib_check_nh(net, fib_nh, tb_id, 0, extack); 2513 if (!err) { 2514 nh->nh_flags = fib_nh->fib_nh_flags; 2515 fib_info_update_nhc_saddr(net, &fib_nh->nh_common, 2516 fib_nh->fib_nh_scope); 2517 } else { 2518 fib_nh_release(net, fib_nh); 2519 } 2520 out: 2521 return err; 2522 } 2523 2524 static int nh_create_ipv6(struct net *net, struct nexthop *nh, 2525 struct nh_info *nhi, struct nh_config *cfg, 2526 struct netlink_ext_ack *extack) 2527 { 2528 struct fib6_nh *fib6_nh = &nhi->fib6_nh; 2529 struct fib6_config fib6_cfg = { 2530 .fc_table = l3mdev_fib_table(cfg->dev), 2531 .fc_ifindex = cfg->nh_ifindex, 2532 .fc_gateway = cfg->gw.ipv6, 2533 .fc_flags = cfg->nh_flags, 2534 .fc_nlinfo = cfg->nlinfo, 2535 .fc_encap = cfg->nh_encap, 2536 .fc_encap_type = cfg->nh_encap_type, 2537 .fc_is_fdb = cfg->nh_fdb, 2538 }; 2539 int err; 2540 2541 if (!ipv6_addr_any(&cfg->gw.ipv6)) 2542 fib6_cfg.fc_flags |= RTF_GATEWAY; 2543 2544 /* sets nh_dev if successful */ 2545 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL, 2546 extack); 2547 if (err) 2548 ipv6_stub->fib6_nh_release(fib6_nh); 2549 else 2550 nh->nh_flags = fib6_nh->fib_nh_flags; 2551 2552 return err; 2553 } 2554 2555 static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg, 2556 struct netlink_ext_ack *extack) 2557 { 2558 struct nh_info *nhi; 2559 struct nexthop *nh; 2560 int err = 0; 2561 2562 nh = nexthop_alloc(); 2563 if (!nh) 2564 return ERR_PTR(-ENOMEM); 2565 2566 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL); 2567 if (!nhi) { 2568 kfree(nh); 2569 return ERR_PTR(-ENOMEM); 2570 } 2571 2572 nh->nh_flags = cfg->nh_flags; 2573 nh->net = net; 2574 2575 nhi->nh_parent = nh; 2576 nhi->family = cfg->nh_family; 2577 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK; 2578 2579 if (cfg->nh_fdb) 2580 nhi->fdb_nh = 1; 2581 2582 if (cfg->nh_blackhole) { 2583 nhi->reject_nh = 1; 2584 cfg->nh_ifindex = net->loopback_dev->ifindex; 2585 } 2586 2587 switch (cfg->nh_family) { 2588 case AF_INET: 2589 err = nh_create_ipv4(net, nh, nhi, cfg, extack); 2590 break; 2591 case AF_INET6: 2592 err = nh_create_ipv6(net, nh, nhi, cfg, extack); 2593 break; 2594 } 2595 2596 if (err) { 2597 kfree(nhi); 2598 kfree(nh); 2599 return ERR_PTR(err); 2600 } 2601 2602 /* add the entry to the device based hash */ 2603 if (!nhi->fdb_nh) 2604 nexthop_devhash_add(net, nhi); 2605 2606 rcu_assign_pointer(nh->nh_info, nhi); 2607 2608 return nh; 2609 } 2610 2611 /* called with rtnl lock held */ 2612 static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg, 2613 struct netlink_ext_ack *extack) 2614 { 2615 struct nexthop *nh; 2616 int err; 2617 2618 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) { 2619 NL_SET_ERR_MSG(extack, "Replace requires nexthop id"); 2620 return ERR_PTR(-EINVAL); 2621 } 2622 2623 if (!cfg->nh_id) { 2624 cfg->nh_id = nh_find_unused_id(net); 2625 if (!cfg->nh_id) { 2626 NL_SET_ERR_MSG(extack, "No unused id"); 2627 return ERR_PTR(-EINVAL); 2628 } 2629 } 2630 2631 if (cfg->nh_grp) 2632 nh = nexthop_create_group(net, cfg); 2633 else 2634 nh = nexthop_create(net, cfg, extack); 2635 2636 if (IS_ERR(nh)) 2637 return nh; 2638 2639 refcount_set(&nh->refcnt, 1); 2640 nh->id = cfg->nh_id; 2641 nh->protocol = cfg->nh_protocol; 2642 nh->net = net; 2643 2644 err = insert_nexthop(net, nh, cfg, extack); 2645 if (err) { 2646 __remove_nexthop(net, nh, NULL); 2647 nexthop_put(nh); 2648 nh = ERR_PTR(err); 2649 } 2650 2651 return nh; 2652 } 2653 2654 static int rtm_nh_get_timer(struct nlattr *attr, unsigned long fallback, 2655 unsigned long *timer_p, bool *has_p, 2656 struct netlink_ext_ack *extack) 2657 { 2658 unsigned long timer; 2659 u32 value; 2660 2661 if (!attr) { 2662 *timer_p = fallback; 2663 *has_p = false; 2664 return 0; 2665 } 2666 2667 value = nla_get_u32(attr); 2668 timer = clock_t_to_jiffies(value); 2669 if (timer == ~0UL) { 2670 NL_SET_ERR_MSG(extack, "Timer value too large"); 2671 return -EINVAL; 2672 } 2673 2674 *timer_p = timer; 2675 *has_p = true; 2676 return 0; 2677 } 2678 2679 static int rtm_to_nh_config_grp_res(struct nlattr *res, struct nh_config *cfg, 2680 struct netlink_ext_ack *extack) 2681 { 2682 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_policy_new)] = {}; 2683 int err; 2684 2685 if (res) { 2686 err = nla_parse_nested(tb, 2687 ARRAY_SIZE(rtm_nh_res_policy_new) - 1, 2688 res, rtm_nh_res_policy_new, extack); 2689 if (err < 0) 2690 return err; 2691 } 2692 2693 if (tb[NHA_RES_GROUP_BUCKETS]) { 2694 cfg->nh_grp_res_num_buckets = 2695 nla_get_u16(tb[NHA_RES_GROUP_BUCKETS]); 2696 cfg->nh_grp_res_has_num_buckets = true; 2697 if (!cfg->nh_grp_res_num_buckets) { 2698 NL_SET_ERR_MSG(extack, "Number of buckets needs to be non-0"); 2699 return -EINVAL; 2700 } 2701 } 2702 2703 err = rtm_nh_get_timer(tb[NHA_RES_GROUP_IDLE_TIMER], 2704 NH_RES_DEFAULT_IDLE_TIMER, 2705 &cfg->nh_grp_res_idle_timer, 2706 &cfg->nh_grp_res_has_idle_timer, 2707 extack); 2708 if (err) 2709 return err; 2710 2711 return rtm_nh_get_timer(tb[NHA_RES_GROUP_UNBALANCED_TIMER], 2712 NH_RES_DEFAULT_UNBALANCED_TIMER, 2713 &cfg->nh_grp_res_unbalanced_timer, 2714 &cfg->nh_grp_res_has_unbalanced_timer, 2715 extack); 2716 } 2717 2718 static int rtm_to_nh_config(struct net *net, struct sk_buff *skb, 2719 struct nlmsghdr *nlh, struct nh_config *cfg, 2720 struct netlink_ext_ack *extack) 2721 { 2722 struct nhmsg *nhm = nlmsg_data(nlh); 2723 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)]; 2724 int err; 2725 2726 err = nlmsg_parse(nlh, sizeof(*nhm), tb, 2727 ARRAY_SIZE(rtm_nh_policy_new) - 1, 2728 rtm_nh_policy_new, extack); 2729 if (err < 0) 2730 return err; 2731 2732 err = -EINVAL; 2733 if (nhm->resvd || nhm->nh_scope) { 2734 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header"); 2735 goto out; 2736 } 2737 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) { 2738 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header"); 2739 goto out; 2740 } 2741 2742 switch (nhm->nh_family) { 2743 case AF_INET: 2744 case AF_INET6: 2745 break; 2746 case AF_UNSPEC: 2747 if (tb[NHA_GROUP]) 2748 break; 2749 fallthrough; 2750 default: 2751 NL_SET_ERR_MSG(extack, "Invalid address family"); 2752 goto out; 2753 } 2754 2755 memset(cfg, 0, sizeof(*cfg)); 2756 cfg->nlflags = nlh->nlmsg_flags; 2757 cfg->nlinfo.portid = NETLINK_CB(skb).portid; 2758 cfg->nlinfo.nlh = nlh; 2759 cfg->nlinfo.nl_net = net; 2760 2761 cfg->nh_family = nhm->nh_family; 2762 cfg->nh_protocol = nhm->nh_protocol; 2763 cfg->nh_flags = nhm->nh_flags; 2764 2765 if (tb[NHA_ID]) 2766 cfg->nh_id = nla_get_u32(tb[NHA_ID]); 2767 2768 if (tb[NHA_FDB]) { 2769 if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] || 2770 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) { 2771 NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole"); 2772 goto out; 2773 } 2774 if (nhm->nh_flags) { 2775 NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header"); 2776 goto out; 2777 } 2778 cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]); 2779 } 2780 2781 if (tb[NHA_GROUP]) { 2782 if (nhm->nh_family != AF_UNSPEC) { 2783 NL_SET_ERR_MSG(extack, "Invalid family for group"); 2784 goto out; 2785 } 2786 cfg->nh_grp = tb[NHA_GROUP]; 2787 2788 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH; 2789 if (tb[NHA_GROUP_TYPE]) 2790 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]); 2791 2792 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) { 2793 NL_SET_ERR_MSG(extack, "Invalid group type"); 2794 goto out; 2795 } 2796 err = nh_check_attr_group(net, tb, ARRAY_SIZE(tb), 2797 cfg->nh_grp_type, extack); 2798 if (err) 2799 goto out; 2800 2801 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) 2802 err = rtm_to_nh_config_grp_res(tb[NHA_RES_GROUP], 2803 cfg, extack); 2804 2805 /* no other attributes should be set */ 2806 goto out; 2807 } 2808 2809 if (tb[NHA_BLACKHOLE]) { 2810 if (tb[NHA_GATEWAY] || tb[NHA_OIF] || 2811 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) { 2812 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb"); 2813 goto out; 2814 } 2815 2816 cfg->nh_blackhole = 1; 2817 err = 0; 2818 goto out; 2819 } 2820 2821 if (!cfg->nh_fdb && !tb[NHA_OIF]) { 2822 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops"); 2823 goto out; 2824 } 2825 2826 if (!cfg->nh_fdb && tb[NHA_OIF]) { 2827 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]); 2828 if (cfg->nh_ifindex) 2829 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex); 2830 2831 if (!cfg->dev) { 2832 NL_SET_ERR_MSG(extack, "Invalid device index"); 2833 goto out; 2834 } else if (!(cfg->dev->flags & IFF_UP)) { 2835 NL_SET_ERR_MSG(extack, "Nexthop device is not up"); 2836 err = -ENETDOWN; 2837 goto out; 2838 } else if (!netif_carrier_ok(cfg->dev)) { 2839 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down"); 2840 err = -ENETDOWN; 2841 goto out; 2842 } 2843 } 2844 2845 err = -EINVAL; 2846 if (tb[NHA_GATEWAY]) { 2847 struct nlattr *gwa = tb[NHA_GATEWAY]; 2848 2849 switch (cfg->nh_family) { 2850 case AF_INET: 2851 if (nla_len(gwa) != sizeof(u32)) { 2852 NL_SET_ERR_MSG(extack, "Invalid gateway"); 2853 goto out; 2854 } 2855 cfg->gw.ipv4 = nla_get_be32(gwa); 2856 break; 2857 case AF_INET6: 2858 if (nla_len(gwa) != sizeof(struct in6_addr)) { 2859 NL_SET_ERR_MSG(extack, "Invalid gateway"); 2860 goto out; 2861 } 2862 cfg->gw.ipv6 = nla_get_in6_addr(gwa); 2863 break; 2864 default: 2865 NL_SET_ERR_MSG(extack, 2866 "Unknown address family for gateway"); 2867 goto out; 2868 } 2869 } else { 2870 /* device only nexthop (no gateway) */ 2871 if (cfg->nh_flags & RTNH_F_ONLINK) { 2872 NL_SET_ERR_MSG(extack, 2873 "ONLINK flag can not be set for nexthop without a gateway"); 2874 goto out; 2875 } 2876 } 2877 2878 if (tb[NHA_ENCAP]) { 2879 cfg->nh_encap = tb[NHA_ENCAP]; 2880 2881 if (!tb[NHA_ENCAP_TYPE]) { 2882 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing"); 2883 goto out; 2884 } 2885 2886 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]); 2887 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack); 2888 if (err < 0) 2889 goto out; 2890 2891 } else if (tb[NHA_ENCAP_TYPE]) { 2892 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing"); 2893 goto out; 2894 } 2895 2896 2897 err = 0; 2898 out: 2899 return err; 2900 } 2901 2902 /* rtnl */ 2903 static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 2904 struct netlink_ext_ack *extack) 2905 { 2906 struct net *net = sock_net(skb->sk); 2907 struct nh_config cfg; 2908 struct nexthop *nh; 2909 int err; 2910 2911 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack); 2912 if (!err) { 2913 nh = nexthop_add(net, &cfg, extack); 2914 if (IS_ERR(nh)) 2915 err = PTR_ERR(nh); 2916 } 2917 2918 return err; 2919 } 2920 2921 static int __nh_valid_get_del_req(const struct nlmsghdr *nlh, 2922 struct nlattr **tb, u32 *id, 2923 struct netlink_ext_ack *extack) 2924 { 2925 struct nhmsg *nhm = nlmsg_data(nlh); 2926 2927 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { 2928 NL_SET_ERR_MSG(extack, "Invalid values in header"); 2929 return -EINVAL; 2930 } 2931 2932 if (!tb[NHA_ID]) { 2933 NL_SET_ERR_MSG(extack, "Nexthop id is missing"); 2934 return -EINVAL; 2935 } 2936 2937 *id = nla_get_u32(tb[NHA_ID]); 2938 if (!(*id)) { 2939 NL_SET_ERR_MSG(extack, "Invalid nexthop id"); 2940 return -EINVAL; 2941 } 2942 2943 return 0; 2944 } 2945 2946 static int nh_valid_get_del_req(const struct nlmsghdr *nlh, u32 *id, 2947 struct netlink_ext_ack *extack) 2948 { 2949 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get)]; 2950 int err; 2951 2952 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 2953 ARRAY_SIZE(rtm_nh_policy_get) - 1, 2954 rtm_nh_policy_get, extack); 2955 if (err < 0) 2956 return err; 2957 2958 return __nh_valid_get_del_req(nlh, tb, id, extack); 2959 } 2960 2961 /* rtnl */ 2962 static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 2963 struct netlink_ext_ack *extack) 2964 { 2965 struct net *net = sock_net(skb->sk); 2966 struct nl_info nlinfo = { 2967 .nlh = nlh, 2968 .nl_net = net, 2969 .portid = NETLINK_CB(skb).portid, 2970 }; 2971 struct nexthop *nh; 2972 int err; 2973 u32 id; 2974 2975 err = nh_valid_get_del_req(nlh, &id, extack); 2976 if (err) 2977 return err; 2978 2979 nh = nexthop_find_by_id(net, id); 2980 if (!nh) 2981 return -ENOENT; 2982 2983 remove_nexthop(net, nh, &nlinfo); 2984 2985 return 0; 2986 } 2987 2988 /* rtnl */ 2989 static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh, 2990 struct netlink_ext_ack *extack) 2991 { 2992 struct net *net = sock_net(in_skb->sk); 2993 struct sk_buff *skb = NULL; 2994 struct nexthop *nh; 2995 int err; 2996 u32 id; 2997 2998 err = nh_valid_get_del_req(nlh, &id, extack); 2999 if (err) 3000 return err; 3001 3002 err = -ENOBUFS; 3003 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3004 if (!skb) 3005 goto out; 3006 3007 err = -ENOENT; 3008 nh = nexthop_find_by_id(net, id); 3009 if (!nh) 3010 goto errout_free; 3011 3012 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid, 3013 nlh->nlmsg_seq, 0); 3014 if (err < 0) { 3015 WARN_ON(err == -EMSGSIZE); 3016 goto errout_free; 3017 } 3018 3019 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3020 out: 3021 return err; 3022 errout_free: 3023 kfree_skb(skb); 3024 goto out; 3025 } 3026 3027 struct nh_dump_filter { 3028 u32 nh_id; 3029 int dev_idx; 3030 int master_idx; 3031 bool group_filter; 3032 bool fdb_filter; 3033 u32 res_bucket_nh_id; 3034 }; 3035 3036 static bool nh_dump_filtered(struct nexthop *nh, 3037 struct nh_dump_filter *filter, u8 family) 3038 { 3039 const struct net_device *dev; 3040 const struct nh_info *nhi; 3041 3042 if (filter->group_filter && !nh->is_group) 3043 return true; 3044 3045 if (!filter->dev_idx && !filter->master_idx && !family) 3046 return false; 3047 3048 if (nh->is_group) 3049 return true; 3050 3051 nhi = rtnl_dereference(nh->nh_info); 3052 if (family && nhi->family != family) 3053 return true; 3054 3055 dev = nhi->fib_nhc.nhc_dev; 3056 if (filter->dev_idx && (!dev || dev->ifindex != filter->dev_idx)) 3057 return true; 3058 3059 if (filter->master_idx) { 3060 struct net_device *master; 3061 3062 if (!dev) 3063 return true; 3064 3065 master = netdev_master_upper_dev_get((struct net_device *)dev); 3066 if (!master || master->ifindex != filter->master_idx) 3067 return true; 3068 } 3069 3070 return false; 3071 } 3072 3073 static int __nh_valid_dump_req(const struct nlmsghdr *nlh, struct nlattr **tb, 3074 struct nh_dump_filter *filter, 3075 struct netlink_ext_ack *extack) 3076 { 3077 struct nhmsg *nhm; 3078 u32 idx; 3079 3080 if (tb[NHA_OIF]) { 3081 idx = nla_get_u32(tb[NHA_OIF]); 3082 if (idx > INT_MAX) { 3083 NL_SET_ERR_MSG(extack, "Invalid device index"); 3084 return -EINVAL; 3085 } 3086 filter->dev_idx = idx; 3087 } 3088 if (tb[NHA_MASTER]) { 3089 idx = nla_get_u32(tb[NHA_MASTER]); 3090 if (idx > INT_MAX) { 3091 NL_SET_ERR_MSG(extack, "Invalid master device index"); 3092 return -EINVAL; 3093 } 3094 filter->master_idx = idx; 3095 } 3096 filter->group_filter = nla_get_flag(tb[NHA_GROUPS]); 3097 filter->fdb_filter = nla_get_flag(tb[NHA_FDB]); 3098 3099 nhm = nlmsg_data(nlh); 3100 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { 3101 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request"); 3102 return -EINVAL; 3103 } 3104 3105 return 0; 3106 } 3107 3108 static int nh_valid_dump_req(const struct nlmsghdr *nlh, 3109 struct nh_dump_filter *filter, 3110 struct netlink_callback *cb) 3111 { 3112 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump)]; 3113 int err; 3114 3115 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 3116 ARRAY_SIZE(rtm_nh_policy_dump) - 1, 3117 rtm_nh_policy_dump, cb->extack); 3118 if (err < 0) 3119 return err; 3120 3121 return __nh_valid_dump_req(nlh, tb, filter, cb->extack); 3122 } 3123 3124 struct rtm_dump_nh_ctx { 3125 u32 idx; 3126 }; 3127 3128 static struct rtm_dump_nh_ctx * 3129 rtm_dump_nh_ctx(struct netlink_callback *cb) 3130 { 3131 struct rtm_dump_nh_ctx *ctx = (void *)cb->ctx; 3132 3133 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); 3134 return ctx; 3135 } 3136 3137 static int rtm_dump_walk_nexthops(struct sk_buff *skb, 3138 struct netlink_callback *cb, 3139 struct rb_root *root, 3140 struct rtm_dump_nh_ctx *ctx, 3141 int (*nh_cb)(struct sk_buff *skb, 3142 struct netlink_callback *cb, 3143 struct nexthop *nh, void *data), 3144 void *data) 3145 { 3146 struct rb_node *node; 3147 int s_idx; 3148 int err; 3149 3150 s_idx = ctx->idx; 3151 for (node = rb_first(root); node; node = rb_next(node)) { 3152 struct nexthop *nh; 3153 3154 nh = rb_entry(node, struct nexthop, rb_node); 3155 if (nh->id < s_idx) 3156 continue; 3157 3158 ctx->idx = nh->id; 3159 err = nh_cb(skb, cb, nh, data); 3160 if (err) 3161 return err; 3162 } 3163 3164 ctx->idx++; 3165 return 0; 3166 } 3167 3168 static int rtm_dump_nexthop_cb(struct sk_buff *skb, struct netlink_callback *cb, 3169 struct nexthop *nh, void *data) 3170 { 3171 struct nhmsg *nhm = nlmsg_data(cb->nlh); 3172 struct nh_dump_filter *filter = data; 3173 3174 if (nh_dump_filtered(nh, filter, nhm->nh_family)) 3175 return 0; 3176 3177 return nh_fill_node(skb, nh, RTM_NEWNEXTHOP, 3178 NETLINK_CB(cb->skb).portid, 3179 cb->nlh->nlmsg_seq, NLM_F_MULTI); 3180 } 3181 3182 /* rtnl */ 3183 static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb) 3184 { 3185 struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb); 3186 struct net *net = sock_net(skb->sk); 3187 struct rb_root *root = &net->nexthop.rb_root; 3188 struct nh_dump_filter filter = {}; 3189 int err; 3190 3191 err = nh_valid_dump_req(cb->nlh, &filter, cb); 3192 if (err < 0) 3193 return err; 3194 3195 err = rtm_dump_walk_nexthops(skb, cb, root, ctx, 3196 &rtm_dump_nexthop_cb, &filter); 3197 if (err < 0) { 3198 if (likely(skb->len)) 3199 goto out; 3200 goto out_err; 3201 } 3202 3203 out: 3204 err = skb->len; 3205 out_err: 3206 cb->seq = net->nexthop.seq; 3207 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 3208 return err; 3209 } 3210 3211 static struct nexthop * 3212 nexthop_find_group_resilient(struct net *net, u32 id, 3213 struct netlink_ext_ack *extack) 3214 { 3215 struct nh_group *nhg; 3216 struct nexthop *nh; 3217 3218 nh = nexthop_find_by_id(net, id); 3219 if (!nh) 3220 return ERR_PTR(-ENOENT); 3221 3222 if (!nh->is_group) { 3223 NL_SET_ERR_MSG(extack, "Not a nexthop group"); 3224 return ERR_PTR(-EINVAL); 3225 } 3226 3227 nhg = rtnl_dereference(nh->nh_grp); 3228 if (!nhg->resilient) { 3229 NL_SET_ERR_MSG(extack, "Nexthop group not of type resilient"); 3230 return ERR_PTR(-EINVAL); 3231 } 3232 3233 return nh; 3234 } 3235 3236 static int nh_valid_dump_nhid(struct nlattr *attr, u32 *nh_id_p, 3237 struct netlink_ext_ack *extack) 3238 { 3239 u32 idx; 3240 3241 if (attr) { 3242 idx = nla_get_u32(attr); 3243 if (!idx) { 3244 NL_SET_ERR_MSG(extack, "Invalid nexthop id"); 3245 return -EINVAL; 3246 } 3247 *nh_id_p = idx; 3248 } else { 3249 *nh_id_p = 0; 3250 } 3251 3252 return 0; 3253 } 3254 3255 static int nh_valid_dump_bucket_req(const struct nlmsghdr *nlh, 3256 struct nh_dump_filter *filter, 3257 struct netlink_callback *cb) 3258 { 3259 struct nlattr *res_tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_dump)]; 3260 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump_bucket)]; 3261 int err; 3262 3263 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 3264 ARRAY_SIZE(rtm_nh_policy_dump_bucket) - 1, 3265 rtm_nh_policy_dump_bucket, NULL); 3266 if (err < 0) 3267 return err; 3268 3269 err = nh_valid_dump_nhid(tb[NHA_ID], &filter->nh_id, cb->extack); 3270 if (err) 3271 return err; 3272 3273 if (tb[NHA_RES_BUCKET]) { 3274 size_t max = ARRAY_SIZE(rtm_nh_res_bucket_policy_dump) - 1; 3275 3276 err = nla_parse_nested(res_tb, max, 3277 tb[NHA_RES_BUCKET], 3278 rtm_nh_res_bucket_policy_dump, 3279 cb->extack); 3280 if (err < 0) 3281 return err; 3282 3283 err = nh_valid_dump_nhid(res_tb[NHA_RES_BUCKET_NH_ID], 3284 &filter->res_bucket_nh_id, 3285 cb->extack); 3286 if (err) 3287 return err; 3288 } 3289 3290 return __nh_valid_dump_req(nlh, tb, filter, cb->extack); 3291 } 3292 3293 struct rtm_dump_res_bucket_ctx { 3294 struct rtm_dump_nh_ctx nh; 3295 u16 bucket_index; 3296 u32 done_nh_idx; /* 1 + the index of the last fully processed NH. */ 3297 }; 3298 3299 static struct rtm_dump_res_bucket_ctx * 3300 rtm_dump_res_bucket_ctx(struct netlink_callback *cb) 3301 { 3302 struct rtm_dump_res_bucket_ctx *ctx = (void *)cb->ctx; 3303 3304 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); 3305 return ctx; 3306 } 3307 3308 struct rtm_dump_nexthop_bucket_data { 3309 struct rtm_dump_res_bucket_ctx *ctx; 3310 struct nh_dump_filter filter; 3311 }; 3312 3313 static int rtm_dump_nexthop_bucket_nh(struct sk_buff *skb, 3314 struct netlink_callback *cb, 3315 struct nexthop *nh, 3316 struct rtm_dump_nexthop_bucket_data *dd) 3317 { 3318 u32 portid = NETLINK_CB(cb->skb).portid; 3319 struct nhmsg *nhm = nlmsg_data(cb->nlh); 3320 struct nh_res_table *res_table; 3321 struct nh_group *nhg; 3322 u16 bucket_index; 3323 int err; 3324 3325 if (dd->ctx->nh.idx < dd->ctx->done_nh_idx) 3326 return 0; 3327 3328 nhg = rtnl_dereference(nh->nh_grp); 3329 res_table = rtnl_dereference(nhg->res_table); 3330 for (bucket_index = dd->ctx->bucket_index; 3331 bucket_index < res_table->num_nh_buckets; 3332 bucket_index++) { 3333 struct nh_res_bucket *bucket; 3334 struct nh_grp_entry *nhge; 3335 3336 bucket = &res_table->nh_buckets[bucket_index]; 3337 nhge = rtnl_dereference(bucket->nh_entry); 3338 if (nh_dump_filtered(nhge->nh, &dd->filter, nhm->nh_family)) 3339 continue; 3340 3341 if (dd->filter.res_bucket_nh_id && 3342 dd->filter.res_bucket_nh_id != nhge->nh->id) 3343 continue; 3344 3345 err = nh_fill_res_bucket(skb, nh, bucket, bucket_index, 3346 RTM_NEWNEXTHOPBUCKET, portid, 3347 cb->nlh->nlmsg_seq, NLM_F_MULTI, 3348 cb->extack); 3349 if (err < 0) { 3350 if (likely(skb->len)) 3351 goto out; 3352 goto out_err; 3353 } 3354 } 3355 3356 dd->ctx->done_nh_idx = dd->ctx->nh.idx + 1; 3357 bucket_index = 0; 3358 3359 out: 3360 err = skb->len; 3361 out_err: 3362 dd->ctx->bucket_index = bucket_index; 3363 return err; 3364 } 3365 3366 static int rtm_dump_nexthop_bucket_cb(struct sk_buff *skb, 3367 struct netlink_callback *cb, 3368 struct nexthop *nh, void *data) 3369 { 3370 struct rtm_dump_nexthop_bucket_data *dd = data; 3371 struct nh_group *nhg; 3372 3373 if (!nh->is_group) 3374 return 0; 3375 3376 nhg = rtnl_dereference(nh->nh_grp); 3377 if (!nhg->resilient) 3378 return 0; 3379 3380 return rtm_dump_nexthop_bucket_nh(skb, cb, nh, dd); 3381 } 3382 3383 /* rtnl */ 3384 static int rtm_dump_nexthop_bucket(struct sk_buff *skb, 3385 struct netlink_callback *cb) 3386 { 3387 struct rtm_dump_res_bucket_ctx *ctx = rtm_dump_res_bucket_ctx(cb); 3388 struct rtm_dump_nexthop_bucket_data dd = { .ctx = ctx }; 3389 struct net *net = sock_net(skb->sk); 3390 struct nexthop *nh; 3391 int err; 3392 3393 err = nh_valid_dump_bucket_req(cb->nlh, &dd.filter, cb); 3394 if (err) 3395 return err; 3396 3397 if (dd.filter.nh_id) { 3398 nh = nexthop_find_group_resilient(net, dd.filter.nh_id, 3399 cb->extack); 3400 if (IS_ERR(nh)) 3401 return PTR_ERR(nh); 3402 err = rtm_dump_nexthop_bucket_nh(skb, cb, nh, &dd); 3403 } else { 3404 struct rb_root *root = &net->nexthop.rb_root; 3405 3406 err = rtm_dump_walk_nexthops(skb, cb, root, &ctx->nh, 3407 &rtm_dump_nexthop_bucket_cb, &dd); 3408 } 3409 3410 if (err < 0) { 3411 if (likely(skb->len)) 3412 goto out; 3413 goto out_err; 3414 } 3415 3416 out: 3417 err = skb->len; 3418 out_err: 3419 cb->seq = net->nexthop.seq; 3420 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 3421 return err; 3422 } 3423 3424 static int nh_valid_get_bucket_req_res_bucket(struct nlattr *res, 3425 u16 *bucket_index, 3426 struct netlink_ext_ack *extack) 3427 { 3428 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_get)]; 3429 int err; 3430 3431 err = nla_parse_nested(tb, ARRAY_SIZE(rtm_nh_res_bucket_policy_get) - 1, 3432 res, rtm_nh_res_bucket_policy_get, extack); 3433 if (err < 0) 3434 return err; 3435 3436 if (!tb[NHA_RES_BUCKET_INDEX]) { 3437 NL_SET_ERR_MSG(extack, "Bucket index is missing"); 3438 return -EINVAL; 3439 } 3440 3441 *bucket_index = nla_get_u16(tb[NHA_RES_BUCKET_INDEX]); 3442 return 0; 3443 } 3444 3445 static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh, 3446 u32 *id, u16 *bucket_index, 3447 struct netlink_ext_ack *extack) 3448 { 3449 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get_bucket)]; 3450 int err; 3451 3452 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 3453 ARRAY_SIZE(rtm_nh_policy_get_bucket) - 1, 3454 rtm_nh_policy_get_bucket, extack); 3455 if (err < 0) 3456 return err; 3457 3458 err = __nh_valid_get_del_req(nlh, tb, id, extack); 3459 if (err) 3460 return err; 3461 3462 if (!tb[NHA_RES_BUCKET]) { 3463 NL_SET_ERR_MSG(extack, "Bucket information is missing"); 3464 return -EINVAL; 3465 } 3466 3467 err = nh_valid_get_bucket_req_res_bucket(tb[NHA_RES_BUCKET], 3468 bucket_index, extack); 3469 if (err) 3470 return err; 3471 3472 return 0; 3473 } 3474 3475 /* rtnl */ 3476 static int rtm_get_nexthop_bucket(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3477 struct netlink_ext_ack *extack) 3478 { 3479 struct net *net = sock_net(in_skb->sk); 3480 struct nh_res_table *res_table; 3481 struct sk_buff *skb = NULL; 3482 struct nh_group *nhg; 3483 struct nexthop *nh; 3484 u16 bucket_index; 3485 int err; 3486 u32 id; 3487 3488 err = nh_valid_get_bucket_req(nlh, &id, &bucket_index, extack); 3489 if (err) 3490 return err; 3491 3492 nh = nexthop_find_group_resilient(net, id, extack); 3493 if (IS_ERR(nh)) 3494 return PTR_ERR(nh); 3495 3496 nhg = rtnl_dereference(nh->nh_grp); 3497 res_table = rtnl_dereference(nhg->res_table); 3498 if (bucket_index >= res_table->num_nh_buckets) { 3499 NL_SET_ERR_MSG(extack, "Bucket index out of bounds"); 3500 return -ENOENT; 3501 } 3502 3503 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3504 if (!skb) 3505 return -ENOBUFS; 3506 3507 err = nh_fill_res_bucket(skb, nh, &res_table->nh_buckets[bucket_index], 3508 bucket_index, RTM_NEWNEXTHOPBUCKET, 3509 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 3510 0, extack); 3511 if (err < 0) { 3512 WARN_ON(err == -EMSGSIZE); 3513 goto errout_free; 3514 } 3515 3516 return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3517 3518 errout_free: 3519 kfree_skb(skb); 3520 return err; 3521 } 3522 3523 static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu) 3524 { 3525 unsigned int hash = nh_dev_hashfn(dev->ifindex); 3526 struct net *net = dev_net(dev); 3527 struct hlist_head *head = &net->nexthop.devhash[hash]; 3528 struct hlist_node *n; 3529 struct nh_info *nhi; 3530 3531 hlist_for_each_entry_safe(nhi, n, head, dev_hash) { 3532 if (nhi->fib_nhc.nhc_dev == dev) { 3533 if (nhi->family == AF_INET) 3534 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu, 3535 orig_mtu); 3536 } 3537 } 3538 } 3539 3540 /* rtnl */ 3541 static int nh_netdev_event(struct notifier_block *this, 3542 unsigned long event, void *ptr) 3543 { 3544 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3545 struct netdev_notifier_info_ext *info_ext; 3546 3547 switch (event) { 3548 case NETDEV_DOWN: 3549 case NETDEV_UNREGISTER: 3550 nexthop_flush_dev(dev, event); 3551 break; 3552 case NETDEV_CHANGE: 3553 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP))) 3554 nexthop_flush_dev(dev, event); 3555 break; 3556 case NETDEV_CHANGEMTU: 3557 info_ext = ptr; 3558 nexthop_sync_mtu(dev, info_ext->ext.mtu); 3559 rt_cache_flush(dev_net(dev)); 3560 break; 3561 } 3562 return NOTIFY_DONE; 3563 } 3564 3565 static struct notifier_block nh_netdev_notifier = { 3566 .notifier_call = nh_netdev_event, 3567 }; 3568 3569 static int nexthops_dump(struct net *net, struct notifier_block *nb, 3570 enum nexthop_event_type event_type, 3571 struct netlink_ext_ack *extack) 3572 { 3573 struct rb_root *root = &net->nexthop.rb_root; 3574 struct rb_node *node; 3575 int err = 0; 3576 3577 for (node = rb_first(root); node; node = rb_next(node)) { 3578 struct nexthop *nh; 3579 3580 nh = rb_entry(node, struct nexthop, rb_node); 3581 err = call_nexthop_notifier(nb, net, event_type, nh, extack); 3582 if (err) 3583 break; 3584 } 3585 3586 return err; 3587 } 3588 3589 int register_nexthop_notifier(struct net *net, struct notifier_block *nb, 3590 struct netlink_ext_ack *extack) 3591 { 3592 int err; 3593 3594 rtnl_lock(); 3595 err = nexthops_dump(net, nb, NEXTHOP_EVENT_REPLACE, extack); 3596 if (err) 3597 goto unlock; 3598 err = blocking_notifier_chain_register(&net->nexthop.notifier_chain, 3599 nb); 3600 unlock: 3601 rtnl_unlock(); 3602 return err; 3603 } 3604 EXPORT_SYMBOL(register_nexthop_notifier); 3605 3606 int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb) 3607 { 3608 int err; 3609 3610 rtnl_lock(); 3611 err = blocking_notifier_chain_unregister(&net->nexthop.notifier_chain, 3612 nb); 3613 if (err) 3614 goto unlock; 3615 nexthops_dump(net, nb, NEXTHOP_EVENT_DEL, NULL); 3616 unlock: 3617 rtnl_unlock(); 3618 return err; 3619 } 3620 EXPORT_SYMBOL(unregister_nexthop_notifier); 3621 3622 void nexthop_set_hw_flags(struct net *net, u32 id, bool offload, bool trap) 3623 { 3624 struct nexthop *nexthop; 3625 3626 rcu_read_lock(); 3627 3628 nexthop = nexthop_find_by_id(net, id); 3629 if (!nexthop) 3630 goto out; 3631 3632 nexthop->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP); 3633 if (offload) 3634 nexthop->nh_flags |= RTNH_F_OFFLOAD; 3635 if (trap) 3636 nexthop->nh_flags |= RTNH_F_TRAP; 3637 3638 out: 3639 rcu_read_unlock(); 3640 } 3641 EXPORT_SYMBOL(nexthop_set_hw_flags); 3642 3643 void nexthop_bucket_set_hw_flags(struct net *net, u32 id, u16 bucket_index, 3644 bool offload, bool trap) 3645 { 3646 struct nh_res_table *res_table; 3647 struct nh_res_bucket *bucket; 3648 struct nexthop *nexthop; 3649 struct nh_group *nhg; 3650 3651 rcu_read_lock(); 3652 3653 nexthop = nexthop_find_by_id(net, id); 3654 if (!nexthop || !nexthop->is_group) 3655 goto out; 3656 3657 nhg = rcu_dereference(nexthop->nh_grp); 3658 if (!nhg->resilient) 3659 goto out; 3660 3661 if (bucket_index >= nhg->res_table->num_nh_buckets) 3662 goto out; 3663 3664 res_table = rcu_dereference(nhg->res_table); 3665 bucket = &res_table->nh_buckets[bucket_index]; 3666 bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP); 3667 if (offload) 3668 bucket->nh_flags |= RTNH_F_OFFLOAD; 3669 if (trap) 3670 bucket->nh_flags |= RTNH_F_TRAP; 3671 3672 out: 3673 rcu_read_unlock(); 3674 } 3675 EXPORT_SYMBOL(nexthop_bucket_set_hw_flags); 3676 3677 void nexthop_res_grp_activity_update(struct net *net, u32 id, u16 num_buckets, 3678 unsigned long *activity) 3679 { 3680 struct nh_res_table *res_table; 3681 struct nexthop *nexthop; 3682 struct nh_group *nhg; 3683 u16 i; 3684 3685 rcu_read_lock(); 3686 3687 nexthop = nexthop_find_by_id(net, id); 3688 if (!nexthop || !nexthop->is_group) 3689 goto out; 3690 3691 nhg = rcu_dereference(nexthop->nh_grp); 3692 if (!nhg->resilient) 3693 goto out; 3694 3695 /* Instead of silently ignoring some buckets, demand that the sizes 3696 * be the same. 3697 */ 3698 res_table = rcu_dereference(nhg->res_table); 3699 if (num_buckets != res_table->num_nh_buckets) 3700 goto out; 3701 3702 for (i = 0; i < num_buckets; i++) { 3703 if (test_bit(i, activity)) 3704 nh_res_bucket_set_busy(&res_table->nh_buckets[i]); 3705 } 3706 3707 out: 3708 rcu_read_unlock(); 3709 } 3710 EXPORT_SYMBOL(nexthop_res_grp_activity_update); 3711 3712 static void __net_exit nexthop_net_exit(struct net *net) 3713 { 3714 rtnl_lock(); 3715 flush_all_nexthops(net); 3716 rtnl_unlock(); 3717 kfree(net->nexthop.devhash); 3718 } 3719 3720 static int __net_init nexthop_net_init(struct net *net) 3721 { 3722 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE; 3723 3724 net->nexthop.rb_root = RB_ROOT; 3725 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL); 3726 if (!net->nexthop.devhash) 3727 return -ENOMEM; 3728 BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain); 3729 3730 return 0; 3731 } 3732 3733 static struct pernet_operations nexthop_net_ops = { 3734 .init = nexthop_net_init, 3735 .exit = nexthop_net_exit, 3736 }; 3737 3738 static int __init nexthop_init(void) 3739 { 3740 register_pernet_subsys(&nexthop_net_ops); 3741 3742 register_netdevice_notifier(&nh_netdev_notifier); 3743 3744 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 3745 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0); 3746 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop, 3747 rtm_dump_nexthop, 0); 3748 3749 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 3750 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); 3751 3752 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 3753 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); 3754 3755 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, rtm_get_nexthop_bucket, 3756 rtm_dump_nexthop_bucket, 0); 3757 3758 return 0; 3759 } 3760 subsys_initcall(nexthop_init); 3761