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 static void remove_nexthop(struct net *net, struct nexthop *nh, 20 struct nl_info *nlinfo); 21 22 #define NH_DEV_HASHBITS 8 23 #define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS) 24 25 static const struct nla_policy rtm_nh_policy_new[] = { 26 [NHA_ID] = { .type = NLA_U32 }, 27 [NHA_GROUP] = { .type = NLA_BINARY }, 28 [NHA_GROUP_TYPE] = { .type = NLA_U16 }, 29 [NHA_BLACKHOLE] = { .type = NLA_FLAG }, 30 [NHA_OIF] = { .type = NLA_U32 }, 31 [NHA_GATEWAY] = { .type = NLA_BINARY }, 32 [NHA_ENCAP_TYPE] = { .type = NLA_U16 }, 33 [NHA_ENCAP] = { .type = NLA_NESTED }, 34 [NHA_FDB] = { .type = NLA_FLAG }, 35 }; 36 37 static const struct nla_policy rtm_nh_policy_get[] = { 38 [NHA_ID] = { .type = NLA_U32 }, 39 }; 40 41 static const struct nla_policy rtm_nh_policy_dump[] = { 42 [NHA_OIF] = { .type = NLA_U32 }, 43 [NHA_GROUPS] = { .type = NLA_FLAG }, 44 [NHA_MASTER] = { .type = NLA_U32 }, 45 [NHA_FDB] = { .type = NLA_FLAG }, 46 }; 47 48 static bool nexthop_notifiers_is_empty(struct net *net) 49 { 50 return !net->nexthop.notifier_chain.head; 51 } 52 53 static void 54 __nh_notifier_single_info_init(struct nh_notifier_single_info *nh_info, 55 const struct nexthop *nh) 56 { 57 struct nh_info *nhi = rtnl_dereference(nh->nh_info); 58 59 nh_info->dev = nhi->fib_nhc.nhc_dev; 60 nh_info->gw_family = nhi->fib_nhc.nhc_gw_family; 61 if (nh_info->gw_family == AF_INET) 62 nh_info->ipv4 = nhi->fib_nhc.nhc_gw.ipv4; 63 else if (nh_info->gw_family == AF_INET6) 64 nh_info->ipv6 = nhi->fib_nhc.nhc_gw.ipv6; 65 66 nh_info->is_reject = nhi->reject_nh; 67 nh_info->is_fdb = nhi->fdb_nh; 68 nh_info->has_encap = !!nhi->fib_nhc.nhc_lwtstate; 69 } 70 71 static int nh_notifier_single_info_init(struct nh_notifier_info *info, 72 const struct nexthop *nh) 73 { 74 info->type = NH_NOTIFIER_INFO_TYPE_SINGLE; 75 info->nh = kzalloc(sizeof(*info->nh), GFP_KERNEL); 76 if (!info->nh) 77 return -ENOMEM; 78 79 __nh_notifier_single_info_init(info->nh, nh); 80 81 return 0; 82 } 83 84 static void nh_notifier_single_info_fini(struct nh_notifier_info *info) 85 { 86 kfree(info->nh); 87 } 88 89 static int nh_notifier_mp_info_init(struct nh_notifier_info *info, 90 struct nh_group *nhg) 91 { 92 u16 num_nh = nhg->num_nh; 93 int i; 94 95 info->type = NH_NOTIFIER_INFO_TYPE_GRP; 96 info->nh_grp = kzalloc(struct_size(info->nh_grp, nh_entries, num_nh), 97 GFP_KERNEL); 98 if (!info->nh_grp) 99 return -ENOMEM; 100 101 info->nh_grp->num_nh = num_nh; 102 info->nh_grp->is_fdb = nhg->fdb_nh; 103 104 for (i = 0; i < num_nh; i++) { 105 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 106 107 info->nh_grp->nh_entries[i].id = nhge->nh->id; 108 info->nh_grp->nh_entries[i].weight = nhge->weight; 109 __nh_notifier_single_info_init(&info->nh_grp->nh_entries[i].nh, 110 nhge->nh); 111 } 112 113 return 0; 114 } 115 116 static int nh_notifier_grp_info_init(struct nh_notifier_info *info, 117 const struct nexthop *nh) 118 { 119 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 120 121 if (nhg->mpath) 122 return nh_notifier_mp_info_init(info, nhg); 123 return -EINVAL; 124 } 125 126 static void nh_notifier_grp_info_fini(struct nh_notifier_info *info, 127 const struct nexthop *nh) 128 { 129 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 130 131 if (nhg->mpath) 132 kfree(info->nh_grp); 133 } 134 135 static int nh_notifier_info_init(struct nh_notifier_info *info, 136 const struct nexthop *nh) 137 { 138 info->id = nh->id; 139 140 if (nh->is_group) 141 return nh_notifier_grp_info_init(info, nh); 142 else 143 return nh_notifier_single_info_init(info, nh); 144 } 145 146 static void nh_notifier_info_fini(struct nh_notifier_info *info, 147 const struct nexthop *nh) 148 { 149 if (nh->is_group) 150 nh_notifier_grp_info_fini(info, nh); 151 else 152 nh_notifier_single_info_fini(info); 153 } 154 155 static int call_nexthop_notifiers(struct net *net, 156 enum nexthop_event_type event_type, 157 struct nexthop *nh, 158 struct netlink_ext_ack *extack) 159 { 160 struct nh_notifier_info info = { 161 .net = net, 162 .extack = extack, 163 }; 164 int err; 165 166 ASSERT_RTNL(); 167 168 if (nexthop_notifiers_is_empty(net)) 169 return 0; 170 171 err = nh_notifier_info_init(&info, nh); 172 if (err) { 173 NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info"); 174 return err; 175 } 176 177 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain, 178 event_type, &info); 179 nh_notifier_info_fini(&info, nh); 180 181 return notifier_to_errno(err); 182 } 183 184 static int call_nexthop_notifier(struct notifier_block *nb, struct net *net, 185 enum nexthop_event_type event_type, 186 struct nexthop *nh, 187 struct netlink_ext_ack *extack) 188 { 189 struct nh_notifier_info info = { 190 .net = net, 191 .extack = extack, 192 }; 193 int err; 194 195 err = nh_notifier_info_init(&info, nh); 196 if (err) 197 return err; 198 199 err = nb->notifier_call(nb, event_type, &info); 200 nh_notifier_info_fini(&info, nh); 201 202 return notifier_to_errno(err); 203 } 204 205 static unsigned int nh_dev_hashfn(unsigned int val) 206 { 207 unsigned int mask = NH_DEV_HASHSIZE - 1; 208 209 return (val ^ 210 (val >> NH_DEV_HASHBITS) ^ 211 (val >> (NH_DEV_HASHBITS * 2))) & mask; 212 } 213 214 static void nexthop_devhash_add(struct net *net, struct nh_info *nhi) 215 { 216 struct net_device *dev = nhi->fib_nhc.nhc_dev; 217 struct hlist_head *head; 218 unsigned int hash; 219 220 WARN_ON(!dev); 221 222 hash = nh_dev_hashfn(dev->ifindex); 223 head = &net->nexthop.devhash[hash]; 224 hlist_add_head(&nhi->dev_hash, head); 225 } 226 227 static void nexthop_free_group(struct nexthop *nh) 228 { 229 struct nh_group *nhg; 230 int i; 231 232 nhg = rcu_dereference_raw(nh->nh_grp); 233 for (i = 0; i < nhg->num_nh; ++i) { 234 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 235 236 WARN_ON(!list_empty(&nhge->nh_list)); 237 nexthop_put(nhge->nh); 238 } 239 240 WARN_ON(nhg->spare == nhg); 241 242 kfree(nhg->spare); 243 kfree(nhg); 244 } 245 246 static void nexthop_free_single(struct nexthop *nh) 247 { 248 struct nh_info *nhi; 249 250 nhi = rcu_dereference_raw(nh->nh_info); 251 switch (nhi->family) { 252 case AF_INET: 253 fib_nh_release(nh->net, &nhi->fib_nh); 254 break; 255 case AF_INET6: 256 ipv6_stub->fib6_nh_release(&nhi->fib6_nh); 257 break; 258 } 259 kfree(nhi); 260 } 261 262 void nexthop_free_rcu(struct rcu_head *head) 263 { 264 struct nexthop *nh = container_of(head, struct nexthop, rcu); 265 266 if (nh->is_group) 267 nexthop_free_group(nh); 268 else 269 nexthop_free_single(nh); 270 271 kfree(nh); 272 } 273 EXPORT_SYMBOL_GPL(nexthop_free_rcu); 274 275 static struct nexthop *nexthop_alloc(void) 276 { 277 struct nexthop *nh; 278 279 nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL); 280 if (nh) { 281 INIT_LIST_HEAD(&nh->fi_list); 282 INIT_LIST_HEAD(&nh->f6i_list); 283 INIT_LIST_HEAD(&nh->grp_list); 284 INIT_LIST_HEAD(&nh->fdb_list); 285 } 286 return nh; 287 } 288 289 static struct nh_group *nexthop_grp_alloc(u16 num_nh) 290 { 291 struct nh_group *nhg; 292 293 nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL); 294 if (nhg) 295 nhg->num_nh = num_nh; 296 297 return nhg; 298 } 299 300 static void nh_base_seq_inc(struct net *net) 301 { 302 while (++net->nexthop.seq == 0) 303 ; 304 } 305 306 /* no reference taken; rcu lock or rtnl must be held */ 307 struct nexthop *nexthop_find_by_id(struct net *net, u32 id) 308 { 309 struct rb_node **pp, *parent = NULL, *next; 310 311 pp = &net->nexthop.rb_root.rb_node; 312 while (1) { 313 struct nexthop *nh; 314 315 next = rcu_dereference_raw(*pp); 316 if (!next) 317 break; 318 parent = next; 319 320 nh = rb_entry(parent, struct nexthop, rb_node); 321 if (id < nh->id) 322 pp = &next->rb_left; 323 else if (id > nh->id) 324 pp = &next->rb_right; 325 else 326 return nh; 327 } 328 return NULL; 329 } 330 EXPORT_SYMBOL_GPL(nexthop_find_by_id); 331 332 /* used for auto id allocation; called with rtnl held */ 333 static u32 nh_find_unused_id(struct net *net) 334 { 335 u32 id_start = net->nexthop.last_id_allocated; 336 337 while (1) { 338 net->nexthop.last_id_allocated++; 339 if (net->nexthop.last_id_allocated == id_start) 340 break; 341 342 if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated)) 343 return net->nexthop.last_id_allocated; 344 } 345 return 0; 346 } 347 348 static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg) 349 { 350 struct nexthop_grp *p; 351 size_t len = nhg->num_nh * sizeof(*p); 352 struct nlattr *nla; 353 u16 group_type = 0; 354 int i; 355 356 if (nhg->mpath) 357 group_type = NEXTHOP_GRP_TYPE_MPATH; 358 359 if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type)) 360 goto nla_put_failure; 361 362 nla = nla_reserve(skb, NHA_GROUP, len); 363 if (!nla) 364 goto nla_put_failure; 365 366 p = nla_data(nla); 367 for (i = 0; i < nhg->num_nh; ++i) { 368 p->id = nhg->nh_entries[i].nh->id; 369 p->weight = nhg->nh_entries[i].weight - 1; 370 p += 1; 371 } 372 373 return 0; 374 375 nla_put_failure: 376 return -EMSGSIZE; 377 } 378 379 static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh, 380 int event, u32 portid, u32 seq, unsigned int nlflags) 381 { 382 struct fib6_nh *fib6_nh; 383 struct fib_nh *fib_nh; 384 struct nlmsghdr *nlh; 385 struct nh_info *nhi; 386 struct nhmsg *nhm; 387 388 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags); 389 if (!nlh) 390 return -EMSGSIZE; 391 392 nhm = nlmsg_data(nlh); 393 nhm->nh_family = AF_UNSPEC; 394 nhm->nh_flags = nh->nh_flags; 395 nhm->nh_protocol = nh->protocol; 396 nhm->nh_scope = 0; 397 nhm->resvd = 0; 398 399 if (nla_put_u32(skb, NHA_ID, nh->id)) 400 goto nla_put_failure; 401 402 if (nh->is_group) { 403 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 404 405 if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB)) 406 goto nla_put_failure; 407 if (nla_put_nh_group(skb, nhg)) 408 goto nla_put_failure; 409 goto out; 410 } 411 412 nhi = rtnl_dereference(nh->nh_info); 413 nhm->nh_family = nhi->family; 414 if (nhi->reject_nh) { 415 if (nla_put_flag(skb, NHA_BLACKHOLE)) 416 goto nla_put_failure; 417 goto out; 418 } else if (nhi->fdb_nh) { 419 if (nla_put_flag(skb, NHA_FDB)) 420 goto nla_put_failure; 421 } else { 422 const struct net_device *dev; 423 424 dev = nhi->fib_nhc.nhc_dev; 425 if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex)) 426 goto nla_put_failure; 427 } 428 429 nhm->nh_scope = nhi->fib_nhc.nhc_scope; 430 switch (nhi->family) { 431 case AF_INET: 432 fib_nh = &nhi->fib_nh; 433 if (fib_nh->fib_nh_gw_family && 434 nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4)) 435 goto nla_put_failure; 436 break; 437 438 case AF_INET6: 439 fib6_nh = &nhi->fib6_nh; 440 if (fib6_nh->fib_nh_gw_family && 441 nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6)) 442 goto nla_put_failure; 443 break; 444 } 445 446 if (nhi->fib_nhc.nhc_lwtstate && 447 lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate, 448 NHA_ENCAP, NHA_ENCAP_TYPE) < 0) 449 goto nla_put_failure; 450 451 out: 452 nlmsg_end(skb, nlh); 453 return 0; 454 455 nla_put_failure: 456 nlmsg_cancel(skb, nlh); 457 return -EMSGSIZE; 458 } 459 460 static size_t nh_nlmsg_size_grp(struct nexthop *nh) 461 { 462 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 463 size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh; 464 465 return nla_total_size(sz) + 466 nla_total_size(2); /* NHA_GROUP_TYPE */ 467 } 468 469 static size_t nh_nlmsg_size_single(struct nexthop *nh) 470 { 471 struct nh_info *nhi = rtnl_dereference(nh->nh_info); 472 size_t sz; 473 474 /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE 475 * are mutually exclusive 476 */ 477 sz = nla_total_size(4); /* NHA_OIF */ 478 479 switch (nhi->family) { 480 case AF_INET: 481 if (nhi->fib_nh.fib_nh_gw_family) 482 sz += nla_total_size(4); /* NHA_GATEWAY */ 483 break; 484 485 case AF_INET6: 486 /* NHA_GATEWAY */ 487 if (nhi->fib6_nh.fib_nh_gw_family) 488 sz += nla_total_size(sizeof(const struct in6_addr)); 489 break; 490 } 491 492 if (nhi->fib_nhc.nhc_lwtstate) { 493 sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate); 494 sz += nla_total_size(2); /* NHA_ENCAP_TYPE */ 495 } 496 497 return sz; 498 } 499 500 static size_t nh_nlmsg_size(struct nexthop *nh) 501 { 502 size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg)); 503 504 sz += nla_total_size(4); /* NHA_ID */ 505 506 if (nh->is_group) 507 sz += nh_nlmsg_size_grp(nh); 508 else 509 sz += nh_nlmsg_size_single(nh); 510 511 return sz; 512 } 513 514 static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info) 515 { 516 unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0; 517 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 518 struct sk_buff *skb; 519 int err = -ENOBUFS; 520 521 skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any()); 522 if (!skb) 523 goto errout; 524 525 err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags); 526 if (err < 0) { 527 /* -EMSGSIZE implies BUG in nh_nlmsg_size() */ 528 WARN_ON(err == -EMSGSIZE); 529 kfree_skb(skb); 530 goto errout; 531 } 532 533 rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP, 534 info->nlh, gfp_any()); 535 return; 536 errout: 537 if (err < 0) 538 rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err); 539 } 540 541 static bool valid_group_nh(struct nexthop *nh, unsigned int npaths, 542 bool *is_fdb, struct netlink_ext_ack *extack) 543 { 544 if (nh->is_group) { 545 struct nh_group *nhg = rtnl_dereference(nh->nh_grp); 546 547 /* nested multipath (group within a group) is not 548 * supported 549 */ 550 if (nhg->mpath) { 551 NL_SET_ERR_MSG(extack, 552 "Multipath group can not be a nexthop within a group"); 553 return false; 554 } 555 *is_fdb = nhg->fdb_nh; 556 } else { 557 struct nh_info *nhi = rtnl_dereference(nh->nh_info); 558 559 if (nhi->reject_nh && npaths > 1) { 560 NL_SET_ERR_MSG(extack, 561 "Blackhole nexthop can not be used in a group with more than 1 path"); 562 return false; 563 } 564 *is_fdb = nhi->fdb_nh; 565 } 566 567 return true; 568 } 569 570 static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family, 571 struct netlink_ext_ack *extack) 572 { 573 struct nh_info *nhi; 574 575 nhi = rtnl_dereference(nh->nh_info); 576 577 if (!nhi->fdb_nh) { 578 NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops"); 579 return -EINVAL; 580 } 581 582 if (*nh_family == AF_UNSPEC) { 583 *nh_family = nhi->family; 584 } else if (*nh_family != nhi->family) { 585 NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops"); 586 return -EINVAL; 587 } 588 589 return 0; 590 } 591 592 static int nh_check_attr_group(struct net *net, 593 struct nlattr *tb[], size_t tb_size, 594 struct netlink_ext_ack *extack) 595 { 596 unsigned int len = nla_len(tb[NHA_GROUP]); 597 u8 nh_family = AF_UNSPEC; 598 struct nexthop_grp *nhg; 599 unsigned int i, j; 600 u8 nhg_fdb = 0; 601 602 if (!len || len & (sizeof(struct nexthop_grp) - 1)) { 603 NL_SET_ERR_MSG(extack, 604 "Invalid length for nexthop group attribute"); 605 return -EINVAL; 606 } 607 608 /* convert len to number of nexthop ids */ 609 len /= sizeof(*nhg); 610 611 nhg = nla_data(tb[NHA_GROUP]); 612 for (i = 0; i < len; ++i) { 613 if (nhg[i].resvd1 || nhg[i].resvd2) { 614 NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0"); 615 return -EINVAL; 616 } 617 if (nhg[i].weight > 254) { 618 NL_SET_ERR_MSG(extack, "Invalid value for weight"); 619 return -EINVAL; 620 } 621 for (j = i + 1; j < len; ++j) { 622 if (nhg[i].id == nhg[j].id) { 623 NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group"); 624 return -EINVAL; 625 } 626 } 627 } 628 629 if (tb[NHA_FDB]) 630 nhg_fdb = 1; 631 nhg = nla_data(tb[NHA_GROUP]); 632 for (i = 0; i < len; ++i) { 633 struct nexthop *nh; 634 bool is_fdb_nh; 635 636 nh = nexthop_find_by_id(net, nhg[i].id); 637 if (!nh) { 638 NL_SET_ERR_MSG(extack, "Invalid nexthop id"); 639 return -EINVAL; 640 } 641 if (!valid_group_nh(nh, len, &is_fdb_nh, extack)) 642 return -EINVAL; 643 644 if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack)) 645 return -EINVAL; 646 647 if (!nhg_fdb && is_fdb_nh) { 648 NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops"); 649 return -EINVAL; 650 } 651 } 652 for (i = NHA_GROUP_TYPE + 1; i < tb_size; ++i) { 653 if (!tb[i]) 654 continue; 655 if (i == NHA_FDB) 656 continue; 657 NL_SET_ERR_MSG(extack, 658 "No other attributes can be set in nexthop groups"); 659 return -EINVAL; 660 } 661 662 return 0; 663 } 664 665 static bool ipv6_good_nh(const struct fib6_nh *nh) 666 { 667 int state = NUD_REACHABLE; 668 struct neighbour *n; 669 670 rcu_read_lock_bh(); 671 672 n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6); 673 if (n) 674 state = n->nud_state; 675 676 rcu_read_unlock_bh(); 677 678 return !!(state & NUD_VALID); 679 } 680 681 static bool ipv4_good_nh(const struct fib_nh *nh) 682 { 683 int state = NUD_REACHABLE; 684 struct neighbour *n; 685 686 rcu_read_lock_bh(); 687 688 n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev, 689 (__force u32)nh->fib_nh_gw4); 690 if (n) 691 state = n->nud_state; 692 693 rcu_read_unlock_bh(); 694 695 return !!(state & NUD_VALID); 696 } 697 698 static struct nexthop *nexthop_select_path_mp(struct nh_group *nhg, int hash) 699 { 700 struct nexthop *rc = NULL; 701 int i; 702 703 for (i = 0; i < nhg->num_nh; ++i) { 704 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 705 struct nh_info *nhi; 706 707 if (hash > atomic_read(&nhge->mpath.upper_bound)) 708 continue; 709 710 nhi = rcu_dereference(nhge->nh->nh_info); 711 if (nhi->fdb_nh) 712 return nhge->nh; 713 714 /* nexthops always check if it is good and does 715 * not rely on a sysctl for this behavior 716 */ 717 switch (nhi->family) { 718 case AF_INET: 719 if (ipv4_good_nh(&nhi->fib_nh)) 720 return nhge->nh; 721 break; 722 case AF_INET6: 723 if (ipv6_good_nh(&nhi->fib6_nh)) 724 return nhge->nh; 725 break; 726 } 727 728 if (!rc) 729 rc = nhge->nh; 730 } 731 732 return rc; 733 } 734 735 struct nexthop *nexthop_select_path(struct nexthop *nh, int hash) 736 { 737 struct nh_group *nhg; 738 739 if (!nh->is_group) 740 return nh; 741 742 nhg = rcu_dereference(nh->nh_grp); 743 if (nhg->mpath) 744 return nexthop_select_path_mp(nhg, hash); 745 746 /* Unreachable. */ 747 return NULL; 748 } 749 EXPORT_SYMBOL_GPL(nexthop_select_path); 750 751 int nexthop_for_each_fib6_nh(struct nexthop *nh, 752 int (*cb)(struct fib6_nh *nh, void *arg), 753 void *arg) 754 { 755 struct nh_info *nhi; 756 int err; 757 758 if (nh->is_group) { 759 struct nh_group *nhg; 760 int i; 761 762 nhg = rcu_dereference_rtnl(nh->nh_grp); 763 for (i = 0; i < nhg->num_nh; i++) { 764 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 765 766 nhi = rcu_dereference_rtnl(nhge->nh->nh_info); 767 err = cb(&nhi->fib6_nh, arg); 768 if (err) 769 return err; 770 } 771 } else { 772 nhi = rcu_dereference_rtnl(nh->nh_info); 773 err = cb(&nhi->fib6_nh, arg); 774 if (err) 775 return err; 776 } 777 778 return 0; 779 } 780 EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh); 781 782 static int check_src_addr(const struct in6_addr *saddr, 783 struct netlink_ext_ack *extack) 784 { 785 if (!ipv6_addr_any(saddr)) { 786 NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects"); 787 return -EINVAL; 788 } 789 return 0; 790 } 791 792 int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg, 793 struct netlink_ext_ack *extack) 794 { 795 struct nh_info *nhi; 796 bool is_fdb_nh; 797 798 /* fib6_src is unique to a fib6_info and limits the ability to cache 799 * routes in fib6_nh within a nexthop that is potentially shared 800 * across multiple fib entries. If the config wants to use source 801 * routing it can not use nexthop objects. mlxsw also does not allow 802 * fib6_src on routes. 803 */ 804 if (cfg && check_src_addr(&cfg->fc_src, extack) < 0) 805 return -EINVAL; 806 807 if (nh->is_group) { 808 struct nh_group *nhg; 809 810 nhg = rtnl_dereference(nh->nh_grp); 811 if (nhg->has_v4) 812 goto no_v4_nh; 813 is_fdb_nh = nhg->fdb_nh; 814 } else { 815 nhi = rtnl_dereference(nh->nh_info); 816 if (nhi->family == AF_INET) 817 goto no_v4_nh; 818 is_fdb_nh = nhi->fdb_nh; 819 } 820 821 if (is_fdb_nh) { 822 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop"); 823 return -EINVAL; 824 } 825 826 return 0; 827 no_v4_nh: 828 NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop"); 829 return -EINVAL; 830 } 831 EXPORT_SYMBOL_GPL(fib6_check_nexthop); 832 833 /* if existing nexthop has ipv6 routes linked to it, need 834 * to verify this new spec works with ipv6 835 */ 836 static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new, 837 struct netlink_ext_ack *extack) 838 { 839 struct fib6_info *f6i; 840 841 if (list_empty(&old->f6i_list)) 842 return 0; 843 844 list_for_each_entry(f6i, &old->f6i_list, nh_list) { 845 if (check_src_addr(&f6i->fib6_src.addr, extack) < 0) 846 return -EINVAL; 847 } 848 849 return fib6_check_nexthop(new, NULL, extack); 850 } 851 852 static int nexthop_check_scope(struct nh_info *nhi, u8 scope, 853 struct netlink_ext_ack *extack) 854 { 855 if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) { 856 NL_SET_ERR_MSG(extack, 857 "Route with host scope can not have a gateway"); 858 return -EINVAL; 859 } 860 861 if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) { 862 NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop"); 863 return -EINVAL; 864 } 865 866 return 0; 867 } 868 869 /* Invoked by fib add code to verify nexthop by id is ok with 870 * config for prefix; parts of fib_check_nh not done when nexthop 871 * object is used. 872 */ 873 int fib_check_nexthop(struct nexthop *nh, u8 scope, 874 struct netlink_ext_ack *extack) 875 { 876 struct nh_info *nhi; 877 int err = 0; 878 879 if (nh->is_group) { 880 struct nh_group *nhg; 881 882 nhg = rtnl_dereference(nh->nh_grp); 883 if (nhg->fdb_nh) { 884 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop"); 885 err = -EINVAL; 886 goto out; 887 } 888 889 if (scope == RT_SCOPE_HOST) { 890 NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops"); 891 err = -EINVAL; 892 goto out; 893 } 894 895 /* all nexthops in a group have the same scope */ 896 nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info); 897 err = nexthop_check_scope(nhi, scope, extack); 898 } else { 899 nhi = rtnl_dereference(nh->nh_info); 900 if (nhi->fdb_nh) { 901 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop"); 902 err = -EINVAL; 903 goto out; 904 } 905 err = nexthop_check_scope(nhi, scope, extack); 906 } 907 908 out: 909 return err; 910 } 911 912 static int fib_check_nh_list(struct nexthop *old, struct nexthop *new, 913 struct netlink_ext_ack *extack) 914 { 915 struct fib_info *fi; 916 917 list_for_each_entry(fi, &old->fi_list, nh_list) { 918 int err; 919 920 err = fib_check_nexthop(new, fi->fib_scope, extack); 921 if (err) 922 return err; 923 } 924 return 0; 925 } 926 927 static void nh_group_rebalance(struct nh_group *nhg) 928 { 929 int total = 0; 930 int w = 0; 931 int i; 932 933 for (i = 0; i < nhg->num_nh; ++i) 934 total += nhg->nh_entries[i].weight; 935 936 for (i = 0; i < nhg->num_nh; ++i) { 937 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 938 int upper_bound; 939 940 w += nhge->weight; 941 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1; 942 atomic_set(&nhge->mpath.upper_bound, upper_bound); 943 } 944 } 945 946 static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge, 947 struct nl_info *nlinfo) 948 { 949 struct nh_grp_entry *nhges, *new_nhges; 950 struct nexthop *nhp = nhge->nh_parent; 951 struct netlink_ext_ack extack; 952 struct nexthop *nh = nhge->nh; 953 struct nh_group *nhg, *newg; 954 int i, j, err; 955 956 WARN_ON(!nh); 957 958 nhg = rtnl_dereference(nhp->nh_grp); 959 newg = nhg->spare; 960 961 /* last entry, keep it visible and remove the parent */ 962 if (nhg->num_nh == 1) { 963 remove_nexthop(net, nhp, nlinfo); 964 return; 965 } 966 967 newg->has_v4 = false; 968 newg->mpath = nhg->mpath; 969 newg->fdb_nh = nhg->fdb_nh; 970 newg->num_nh = nhg->num_nh; 971 972 /* copy old entries to new except the one getting removed */ 973 nhges = nhg->nh_entries; 974 new_nhges = newg->nh_entries; 975 for (i = 0, j = 0; i < nhg->num_nh; ++i) { 976 struct nh_info *nhi; 977 978 /* current nexthop getting removed */ 979 if (nhg->nh_entries[i].nh == nh) { 980 newg->num_nh--; 981 continue; 982 } 983 984 nhi = rtnl_dereference(nhges[i].nh->nh_info); 985 if (nhi->family == AF_INET) 986 newg->has_v4 = true; 987 988 list_del(&nhges[i].nh_list); 989 new_nhges[j].nh_parent = nhges[i].nh_parent; 990 new_nhges[j].nh = nhges[i].nh; 991 new_nhges[j].weight = nhges[i].weight; 992 list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list); 993 j++; 994 } 995 996 nh_group_rebalance(newg); 997 rcu_assign_pointer(nhp->nh_grp, newg); 998 999 list_del(&nhge->nh_list); 1000 nexthop_put(nhge->nh); 1001 1002 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp, &extack); 1003 if (err) 1004 pr_err("%s\n", extack._msg); 1005 1006 if (nlinfo) 1007 nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo); 1008 } 1009 1010 static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh, 1011 struct nl_info *nlinfo) 1012 { 1013 struct nh_grp_entry *nhge, *tmp; 1014 1015 list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list) 1016 remove_nh_grp_entry(net, nhge, nlinfo); 1017 1018 /* make sure all see the newly published array before releasing rtnl */ 1019 synchronize_net(); 1020 } 1021 1022 static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo) 1023 { 1024 struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp); 1025 int i, num_nh = nhg->num_nh; 1026 1027 for (i = 0; i < num_nh; ++i) { 1028 struct nh_grp_entry *nhge = &nhg->nh_entries[i]; 1029 1030 if (WARN_ON(!nhge->nh)) 1031 continue; 1032 1033 list_del_init(&nhge->nh_list); 1034 } 1035 } 1036 1037 /* not called for nexthop replace */ 1038 static void __remove_nexthop_fib(struct net *net, struct nexthop *nh) 1039 { 1040 struct fib6_info *f6i, *tmp; 1041 bool do_flush = false; 1042 struct fib_info *fi; 1043 1044 list_for_each_entry(fi, &nh->fi_list, nh_list) { 1045 fi->fib_flags |= RTNH_F_DEAD; 1046 do_flush = true; 1047 } 1048 if (do_flush) 1049 fib_flush(net); 1050 1051 /* ip6_del_rt removes the entry from this list hence the _safe */ 1052 list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) { 1053 /* __ip6_del_rt does a release, so do a hold here */ 1054 fib6_info_hold(f6i); 1055 ipv6_stub->ip6_del_rt(net, f6i, 1056 !net->ipv4.sysctl_nexthop_compat_mode); 1057 } 1058 } 1059 1060 static void __remove_nexthop(struct net *net, struct nexthop *nh, 1061 struct nl_info *nlinfo) 1062 { 1063 __remove_nexthop_fib(net, nh); 1064 1065 if (nh->is_group) { 1066 remove_nexthop_group(nh, nlinfo); 1067 } else { 1068 struct nh_info *nhi; 1069 1070 nhi = rtnl_dereference(nh->nh_info); 1071 if (nhi->fib_nhc.nhc_dev) 1072 hlist_del(&nhi->dev_hash); 1073 1074 remove_nexthop_from_groups(net, nh, nlinfo); 1075 } 1076 } 1077 1078 static void remove_nexthop(struct net *net, struct nexthop *nh, 1079 struct nl_info *nlinfo) 1080 { 1081 call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh, NULL); 1082 1083 /* remove from the tree */ 1084 rb_erase(&nh->rb_node, &net->nexthop.rb_root); 1085 1086 if (nlinfo) 1087 nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo); 1088 1089 __remove_nexthop(net, nh, nlinfo); 1090 nh_base_seq_inc(net); 1091 1092 nexthop_put(nh); 1093 } 1094 1095 /* if any FIB entries reference this nexthop, any dst entries 1096 * need to be regenerated 1097 */ 1098 static void nh_rt_cache_flush(struct net *net, struct nexthop *nh) 1099 { 1100 struct fib6_info *f6i; 1101 1102 if (!list_empty(&nh->fi_list)) 1103 rt_cache_flush(net); 1104 1105 list_for_each_entry(f6i, &nh->f6i_list, nh_list) 1106 ipv6_stub->fib6_update_sernum(net, f6i); 1107 } 1108 1109 static int replace_nexthop_grp(struct net *net, struct nexthop *old, 1110 struct nexthop *new, 1111 struct netlink_ext_ack *extack) 1112 { 1113 struct nh_group *oldg, *newg; 1114 int i, err; 1115 1116 if (!new->is_group) { 1117 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop."); 1118 return -EINVAL; 1119 } 1120 1121 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack); 1122 if (err) 1123 return err; 1124 1125 oldg = rtnl_dereference(old->nh_grp); 1126 newg = rtnl_dereference(new->nh_grp); 1127 1128 /* update parents - used by nexthop code for cleanup */ 1129 for (i = 0; i < newg->num_nh; i++) 1130 newg->nh_entries[i].nh_parent = old; 1131 1132 rcu_assign_pointer(old->nh_grp, newg); 1133 1134 for (i = 0; i < oldg->num_nh; i++) 1135 oldg->nh_entries[i].nh_parent = new; 1136 1137 rcu_assign_pointer(new->nh_grp, oldg); 1138 1139 return 0; 1140 } 1141 1142 static void nh_group_v4_update(struct nh_group *nhg) 1143 { 1144 struct nh_grp_entry *nhges; 1145 bool has_v4 = false; 1146 int i; 1147 1148 nhges = nhg->nh_entries; 1149 for (i = 0; i < nhg->num_nh; i++) { 1150 struct nh_info *nhi; 1151 1152 nhi = rtnl_dereference(nhges[i].nh->nh_info); 1153 if (nhi->family == AF_INET) 1154 has_v4 = true; 1155 } 1156 nhg->has_v4 = has_v4; 1157 } 1158 1159 static int replace_nexthop_single(struct net *net, struct nexthop *old, 1160 struct nexthop *new, 1161 struct netlink_ext_ack *extack) 1162 { 1163 u8 old_protocol, old_nh_flags; 1164 struct nh_info *oldi, *newi; 1165 struct nh_grp_entry *nhge; 1166 int err; 1167 1168 if (new->is_group) { 1169 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group."); 1170 return -EINVAL; 1171 } 1172 1173 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack); 1174 if (err) 1175 return err; 1176 1177 /* Hardware flags were set on 'old' as 'new' is not in the red-black 1178 * tree. Therefore, inherit the flags from 'old' to 'new'. 1179 */ 1180 new->nh_flags |= old->nh_flags & (RTNH_F_OFFLOAD | RTNH_F_TRAP); 1181 1182 oldi = rtnl_dereference(old->nh_info); 1183 newi = rtnl_dereference(new->nh_info); 1184 1185 newi->nh_parent = old; 1186 oldi->nh_parent = new; 1187 1188 old_protocol = old->protocol; 1189 old_nh_flags = old->nh_flags; 1190 1191 old->protocol = new->protocol; 1192 old->nh_flags = new->nh_flags; 1193 1194 rcu_assign_pointer(old->nh_info, newi); 1195 rcu_assign_pointer(new->nh_info, oldi); 1196 1197 /* Send a replace notification for all the groups using the nexthop. */ 1198 list_for_each_entry(nhge, &old->grp_list, nh_list) { 1199 struct nexthop *nhp = nhge->nh_parent; 1200 1201 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp, 1202 extack); 1203 if (err) 1204 goto err_notify; 1205 } 1206 1207 /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially 1208 * update IPv4 indication in all the groups using the nexthop. 1209 */ 1210 if (oldi->family == AF_INET && newi->family == AF_INET6) { 1211 list_for_each_entry(nhge, &old->grp_list, nh_list) { 1212 struct nexthop *nhp = nhge->nh_parent; 1213 struct nh_group *nhg; 1214 1215 nhg = rtnl_dereference(nhp->nh_grp); 1216 nh_group_v4_update(nhg); 1217 } 1218 } 1219 1220 return 0; 1221 1222 err_notify: 1223 rcu_assign_pointer(new->nh_info, newi); 1224 rcu_assign_pointer(old->nh_info, oldi); 1225 old->nh_flags = old_nh_flags; 1226 old->protocol = old_protocol; 1227 oldi->nh_parent = old; 1228 newi->nh_parent = new; 1229 list_for_each_entry_continue_reverse(nhge, &old->grp_list, nh_list) { 1230 struct nexthop *nhp = nhge->nh_parent; 1231 1232 call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp, extack); 1233 } 1234 call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, old, extack); 1235 return err; 1236 } 1237 1238 static void __nexthop_replace_notify(struct net *net, struct nexthop *nh, 1239 struct nl_info *info) 1240 { 1241 struct fib6_info *f6i; 1242 1243 if (!list_empty(&nh->fi_list)) { 1244 struct fib_info *fi; 1245 1246 /* expectation is a few fib_info per nexthop and then 1247 * a lot of routes per fib_info. So mark the fib_info 1248 * and then walk the fib tables once 1249 */ 1250 list_for_each_entry(fi, &nh->fi_list, nh_list) 1251 fi->nh_updated = true; 1252 1253 fib_info_notify_update(net, info); 1254 1255 list_for_each_entry(fi, &nh->fi_list, nh_list) 1256 fi->nh_updated = false; 1257 } 1258 1259 list_for_each_entry(f6i, &nh->f6i_list, nh_list) 1260 ipv6_stub->fib6_rt_update(net, f6i, info); 1261 } 1262 1263 /* send RTM_NEWROUTE with REPLACE flag set for all FIB entries 1264 * linked to this nexthop and for all groups that the nexthop 1265 * is a member of 1266 */ 1267 static void nexthop_replace_notify(struct net *net, struct nexthop *nh, 1268 struct nl_info *info) 1269 { 1270 struct nh_grp_entry *nhge; 1271 1272 __nexthop_replace_notify(net, nh, info); 1273 1274 list_for_each_entry(nhge, &nh->grp_list, nh_list) 1275 __nexthop_replace_notify(net, nhge->nh_parent, info); 1276 } 1277 1278 static int replace_nexthop(struct net *net, struct nexthop *old, 1279 struct nexthop *new, struct netlink_ext_ack *extack) 1280 { 1281 bool new_is_reject = false; 1282 struct nh_grp_entry *nhge; 1283 int err; 1284 1285 /* check that existing FIB entries are ok with the 1286 * new nexthop definition 1287 */ 1288 err = fib_check_nh_list(old, new, extack); 1289 if (err) 1290 return err; 1291 1292 err = fib6_check_nh_list(old, new, extack); 1293 if (err) 1294 return err; 1295 1296 if (!new->is_group) { 1297 struct nh_info *nhi = rtnl_dereference(new->nh_info); 1298 1299 new_is_reject = nhi->reject_nh; 1300 } 1301 1302 list_for_each_entry(nhge, &old->grp_list, nh_list) { 1303 /* if new nexthop is a blackhole, any groups using this 1304 * nexthop cannot have more than 1 path 1305 */ 1306 if (new_is_reject && 1307 nexthop_num_path(nhge->nh_parent) > 1) { 1308 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path"); 1309 return -EINVAL; 1310 } 1311 1312 err = fib_check_nh_list(nhge->nh_parent, new, extack); 1313 if (err) 1314 return err; 1315 1316 err = fib6_check_nh_list(nhge->nh_parent, new, extack); 1317 if (err) 1318 return err; 1319 } 1320 1321 if (old->is_group) 1322 err = replace_nexthop_grp(net, old, new, extack); 1323 else 1324 err = replace_nexthop_single(net, old, new, extack); 1325 1326 if (!err) { 1327 nh_rt_cache_flush(net, old); 1328 1329 __remove_nexthop(net, new, NULL); 1330 nexthop_put(new); 1331 } 1332 1333 return err; 1334 } 1335 1336 /* called with rtnl_lock held */ 1337 static int insert_nexthop(struct net *net, struct nexthop *new_nh, 1338 struct nh_config *cfg, struct netlink_ext_ack *extack) 1339 { 1340 struct rb_node **pp, *parent = NULL, *next; 1341 struct rb_root *root = &net->nexthop.rb_root; 1342 bool replace = !!(cfg->nlflags & NLM_F_REPLACE); 1343 bool create = !!(cfg->nlflags & NLM_F_CREATE); 1344 u32 new_id = new_nh->id; 1345 int replace_notify = 0; 1346 int rc = -EEXIST; 1347 1348 pp = &root->rb_node; 1349 while (1) { 1350 struct nexthop *nh; 1351 1352 next = *pp; 1353 if (!next) 1354 break; 1355 1356 parent = next; 1357 1358 nh = rb_entry(parent, struct nexthop, rb_node); 1359 if (new_id < nh->id) { 1360 pp = &next->rb_left; 1361 } else if (new_id > nh->id) { 1362 pp = &next->rb_right; 1363 } else if (replace) { 1364 rc = replace_nexthop(net, nh, new_nh, extack); 1365 if (!rc) { 1366 new_nh = nh; /* send notification with old nh */ 1367 replace_notify = 1; 1368 } 1369 goto out; 1370 } else { 1371 /* id already exists and not a replace */ 1372 goto out; 1373 } 1374 } 1375 1376 if (replace && !create) { 1377 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists"); 1378 rc = -ENOENT; 1379 goto out; 1380 } 1381 1382 rb_link_node_rcu(&new_nh->rb_node, parent, pp); 1383 rb_insert_color(&new_nh->rb_node, root); 1384 1385 rc = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new_nh, extack); 1386 if (rc) 1387 rb_erase(&new_nh->rb_node, &net->nexthop.rb_root); 1388 1389 out: 1390 if (!rc) { 1391 nh_base_seq_inc(net); 1392 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo); 1393 if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode) 1394 nexthop_replace_notify(net, new_nh, &cfg->nlinfo); 1395 } 1396 1397 return rc; 1398 } 1399 1400 /* rtnl */ 1401 /* remove all nexthops tied to a device being deleted */ 1402 static void nexthop_flush_dev(struct net_device *dev, unsigned long event) 1403 { 1404 unsigned int hash = nh_dev_hashfn(dev->ifindex); 1405 struct net *net = dev_net(dev); 1406 struct hlist_head *head = &net->nexthop.devhash[hash]; 1407 struct hlist_node *n; 1408 struct nh_info *nhi; 1409 1410 hlist_for_each_entry_safe(nhi, n, head, dev_hash) { 1411 if (nhi->fib_nhc.nhc_dev != dev) 1412 continue; 1413 1414 if (nhi->reject_nh && 1415 (event == NETDEV_DOWN || event == NETDEV_CHANGE)) 1416 continue; 1417 1418 remove_nexthop(net, nhi->nh_parent, NULL); 1419 } 1420 } 1421 1422 /* rtnl; called when net namespace is deleted */ 1423 static void flush_all_nexthops(struct net *net) 1424 { 1425 struct rb_root *root = &net->nexthop.rb_root; 1426 struct rb_node *node; 1427 struct nexthop *nh; 1428 1429 while ((node = rb_first(root))) { 1430 nh = rb_entry(node, struct nexthop, rb_node); 1431 remove_nexthop(net, nh, NULL); 1432 cond_resched(); 1433 } 1434 } 1435 1436 static struct nexthop *nexthop_create_group(struct net *net, 1437 struct nh_config *cfg) 1438 { 1439 struct nlattr *grps_attr = cfg->nh_grp; 1440 struct nexthop_grp *entry = nla_data(grps_attr); 1441 u16 num_nh = nla_len(grps_attr) / sizeof(*entry); 1442 struct nh_group *nhg; 1443 struct nexthop *nh; 1444 int i; 1445 1446 if (WARN_ON(!num_nh)) 1447 return ERR_PTR(-EINVAL); 1448 1449 nh = nexthop_alloc(); 1450 if (!nh) 1451 return ERR_PTR(-ENOMEM); 1452 1453 nh->is_group = 1; 1454 1455 nhg = nexthop_grp_alloc(num_nh); 1456 if (!nhg) { 1457 kfree(nh); 1458 return ERR_PTR(-ENOMEM); 1459 } 1460 1461 /* spare group used for removals */ 1462 nhg->spare = nexthop_grp_alloc(num_nh); 1463 if (!nhg->spare) { 1464 kfree(nhg); 1465 kfree(nh); 1466 return ERR_PTR(-ENOMEM); 1467 } 1468 nhg->spare->spare = nhg; 1469 1470 for (i = 0; i < nhg->num_nh; ++i) { 1471 struct nexthop *nhe; 1472 struct nh_info *nhi; 1473 1474 nhe = nexthop_find_by_id(net, entry[i].id); 1475 if (!nexthop_get(nhe)) 1476 goto out_no_nh; 1477 1478 nhi = rtnl_dereference(nhe->nh_info); 1479 if (nhi->family == AF_INET) 1480 nhg->has_v4 = true; 1481 1482 nhg->nh_entries[i].nh = nhe; 1483 nhg->nh_entries[i].weight = entry[i].weight + 1; 1484 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list); 1485 nhg->nh_entries[i].nh_parent = nh; 1486 } 1487 1488 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) 1489 nhg->mpath = 1; 1490 1491 WARN_ON_ONCE(nhg->mpath != 1); 1492 1493 if (nhg->mpath) 1494 nh_group_rebalance(nhg); 1495 1496 if (cfg->nh_fdb) 1497 nhg->fdb_nh = 1; 1498 1499 rcu_assign_pointer(nh->nh_grp, nhg); 1500 1501 return nh; 1502 1503 out_no_nh: 1504 for (i--; i >= 0; --i) { 1505 list_del(&nhg->nh_entries[i].nh_list); 1506 nexthop_put(nhg->nh_entries[i].nh); 1507 } 1508 1509 kfree(nhg->spare); 1510 kfree(nhg); 1511 kfree(nh); 1512 1513 return ERR_PTR(-ENOENT); 1514 } 1515 1516 static int nh_create_ipv4(struct net *net, struct nexthop *nh, 1517 struct nh_info *nhi, struct nh_config *cfg, 1518 struct netlink_ext_ack *extack) 1519 { 1520 struct fib_nh *fib_nh = &nhi->fib_nh; 1521 struct fib_config fib_cfg = { 1522 .fc_oif = cfg->nh_ifindex, 1523 .fc_gw4 = cfg->gw.ipv4, 1524 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0, 1525 .fc_flags = cfg->nh_flags, 1526 .fc_encap = cfg->nh_encap, 1527 .fc_encap_type = cfg->nh_encap_type, 1528 }; 1529 u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN); 1530 int err; 1531 1532 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack); 1533 if (err) { 1534 fib_nh_release(net, fib_nh); 1535 goto out; 1536 } 1537 1538 if (nhi->fdb_nh) 1539 goto out; 1540 1541 /* sets nh_dev if successful */ 1542 err = fib_check_nh(net, fib_nh, tb_id, 0, extack); 1543 if (!err) { 1544 nh->nh_flags = fib_nh->fib_nh_flags; 1545 fib_info_update_nhc_saddr(net, &fib_nh->nh_common, 1546 fib_nh->fib_nh_scope); 1547 } else { 1548 fib_nh_release(net, fib_nh); 1549 } 1550 out: 1551 return err; 1552 } 1553 1554 static int nh_create_ipv6(struct net *net, struct nexthop *nh, 1555 struct nh_info *nhi, struct nh_config *cfg, 1556 struct netlink_ext_ack *extack) 1557 { 1558 struct fib6_nh *fib6_nh = &nhi->fib6_nh; 1559 struct fib6_config fib6_cfg = { 1560 .fc_table = l3mdev_fib_table(cfg->dev), 1561 .fc_ifindex = cfg->nh_ifindex, 1562 .fc_gateway = cfg->gw.ipv6, 1563 .fc_flags = cfg->nh_flags, 1564 .fc_encap = cfg->nh_encap, 1565 .fc_encap_type = cfg->nh_encap_type, 1566 .fc_is_fdb = cfg->nh_fdb, 1567 }; 1568 int err; 1569 1570 if (!ipv6_addr_any(&cfg->gw.ipv6)) 1571 fib6_cfg.fc_flags |= RTF_GATEWAY; 1572 1573 /* sets nh_dev if successful */ 1574 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL, 1575 extack); 1576 if (err) 1577 ipv6_stub->fib6_nh_release(fib6_nh); 1578 else 1579 nh->nh_flags = fib6_nh->fib_nh_flags; 1580 1581 return err; 1582 } 1583 1584 static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg, 1585 struct netlink_ext_ack *extack) 1586 { 1587 struct nh_info *nhi; 1588 struct nexthop *nh; 1589 int err = 0; 1590 1591 nh = nexthop_alloc(); 1592 if (!nh) 1593 return ERR_PTR(-ENOMEM); 1594 1595 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL); 1596 if (!nhi) { 1597 kfree(nh); 1598 return ERR_PTR(-ENOMEM); 1599 } 1600 1601 nh->nh_flags = cfg->nh_flags; 1602 nh->net = net; 1603 1604 nhi->nh_parent = nh; 1605 nhi->family = cfg->nh_family; 1606 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK; 1607 1608 if (cfg->nh_fdb) 1609 nhi->fdb_nh = 1; 1610 1611 if (cfg->nh_blackhole) { 1612 nhi->reject_nh = 1; 1613 cfg->nh_ifindex = net->loopback_dev->ifindex; 1614 } 1615 1616 switch (cfg->nh_family) { 1617 case AF_INET: 1618 err = nh_create_ipv4(net, nh, nhi, cfg, extack); 1619 break; 1620 case AF_INET6: 1621 err = nh_create_ipv6(net, nh, nhi, cfg, extack); 1622 break; 1623 } 1624 1625 if (err) { 1626 kfree(nhi); 1627 kfree(nh); 1628 return ERR_PTR(err); 1629 } 1630 1631 /* add the entry to the device based hash */ 1632 if (!nhi->fdb_nh) 1633 nexthop_devhash_add(net, nhi); 1634 1635 rcu_assign_pointer(nh->nh_info, nhi); 1636 1637 return nh; 1638 } 1639 1640 /* called with rtnl lock held */ 1641 static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg, 1642 struct netlink_ext_ack *extack) 1643 { 1644 struct nexthop *nh; 1645 int err; 1646 1647 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) { 1648 NL_SET_ERR_MSG(extack, "Replace requires nexthop id"); 1649 return ERR_PTR(-EINVAL); 1650 } 1651 1652 if (!cfg->nh_id) { 1653 cfg->nh_id = nh_find_unused_id(net); 1654 if (!cfg->nh_id) { 1655 NL_SET_ERR_MSG(extack, "No unused id"); 1656 return ERR_PTR(-EINVAL); 1657 } 1658 } 1659 1660 if (cfg->nh_grp) 1661 nh = nexthop_create_group(net, cfg); 1662 else 1663 nh = nexthop_create(net, cfg, extack); 1664 1665 if (IS_ERR(nh)) 1666 return nh; 1667 1668 refcount_set(&nh->refcnt, 1); 1669 nh->id = cfg->nh_id; 1670 nh->protocol = cfg->nh_protocol; 1671 nh->net = net; 1672 1673 err = insert_nexthop(net, nh, cfg, extack); 1674 if (err) { 1675 __remove_nexthop(net, nh, NULL); 1676 nexthop_put(nh); 1677 nh = ERR_PTR(err); 1678 } 1679 1680 return nh; 1681 } 1682 1683 static int rtm_to_nh_config(struct net *net, struct sk_buff *skb, 1684 struct nlmsghdr *nlh, struct nh_config *cfg, 1685 struct netlink_ext_ack *extack) 1686 { 1687 struct nhmsg *nhm = nlmsg_data(nlh); 1688 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)]; 1689 int err; 1690 1691 err = nlmsg_parse(nlh, sizeof(*nhm), tb, 1692 ARRAY_SIZE(rtm_nh_policy_new) - 1, 1693 rtm_nh_policy_new, extack); 1694 if (err < 0) 1695 return err; 1696 1697 err = -EINVAL; 1698 if (nhm->resvd || nhm->nh_scope) { 1699 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header"); 1700 goto out; 1701 } 1702 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) { 1703 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header"); 1704 goto out; 1705 } 1706 1707 switch (nhm->nh_family) { 1708 case AF_INET: 1709 case AF_INET6: 1710 break; 1711 case AF_UNSPEC: 1712 if (tb[NHA_GROUP]) 1713 break; 1714 fallthrough; 1715 default: 1716 NL_SET_ERR_MSG(extack, "Invalid address family"); 1717 goto out; 1718 } 1719 1720 memset(cfg, 0, sizeof(*cfg)); 1721 cfg->nlflags = nlh->nlmsg_flags; 1722 cfg->nlinfo.portid = NETLINK_CB(skb).portid; 1723 cfg->nlinfo.nlh = nlh; 1724 cfg->nlinfo.nl_net = net; 1725 1726 cfg->nh_family = nhm->nh_family; 1727 cfg->nh_protocol = nhm->nh_protocol; 1728 cfg->nh_flags = nhm->nh_flags; 1729 1730 if (tb[NHA_ID]) 1731 cfg->nh_id = nla_get_u32(tb[NHA_ID]); 1732 1733 if (tb[NHA_FDB]) { 1734 if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] || 1735 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) { 1736 NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole"); 1737 goto out; 1738 } 1739 if (nhm->nh_flags) { 1740 NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header"); 1741 goto out; 1742 } 1743 cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]); 1744 } 1745 1746 if (tb[NHA_GROUP]) { 1747 if (nhm->nh_family != AF_UNSPEC) { 1748 NL_SET_ERR_MSG(extack, "Invalid family for group"); 1749 goto out; 1750 } 1751 cfg->nh_grp = tb[NHA_GROUP]; 1752 1753 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH; 1754 if (tb[NHA_GROUP_TYPE]) 1755 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]); 1756 1757 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) { 1758 NL_SET_ERR_MSG(extack, "Invalid group type"); 1759 goto out; 1760 } 1761 err = nh_check_attr_group(net, tb, ARRAY_SIZE(tb), extack); 1762 1763 /* no other attributes should be set */ 1764 goto out; 1765 } 1766 1767 if (tb[NHA_BLACKHOLE]) { 1768 if (tb[NHA_GATEWAY] || tb[NHA_OIF] || 1769 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) { 1770 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb"); 1771 goto out; 1772 } 1773 1774 cfg->nh_blackhole = 1; 1775 err = 0; 1776 goto out; 1777 } 1778 1779 if (!cfg->nh_fdb && !tb[NHA_OIF]) { 1780 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops"); 1781 goto out; 1782 } 1783 1784 if (!cfg->nh_fdb && tb[NHA_OIF]) { 1785 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]); 1786 if (cfg->nh_ifindex) 1787 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex); 1788 1789 if (!cfg->dev) { 1790 NL_SET_ERR_MSG(extack, "Invalid device index"); 1791 goto out; 1792 } else if (!(cfg->dev->flags & IFF_UP)) { 1793 NL_SET_ERR_MSG(extack, "Nexthop device is not up"); 1794 err = -ENETDOWN; 1795 goto out; 1796 } else if (!netif_carrier_ok(cfg->dev)) { 1797 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down"); 1798 err = -ENETDOWN; 1799 goto out; 1800 } 1801 } 1802 1803 err = -EINVAL; 1804 if (tb[NHA_GATEWAY]) { 1805 struct nlattr *gwa = tb[NHA_GATEWAY]; 1806 1807 switch (cfg->nh_family) { 1808 case AF_INET: 1809 if (nla_len(gwa) != sizeof(u32)) { 1810 NL_SET_ERR_MSG(extack, "Invalid gateway"); 1811 goto out; 1812 } 1813 cfg->gw.ipv4 = nla_get_be32(gwa); 1814 break; 1815 case AF_INET6: 1816 if (nla_len(gwa) != sizeof(struct in6_addr)) { 1817 NL_SET_ERR_MSG(extack, "Invalid gateway"); 1818 goto out; 1819 } 1820 cfg->gw.ipv6 = nla_get_in6_addr(gwa); 1821 break; 1822 default: 1823 NL_SET_ERR_MSG(extack, 1824 "Unknown address family for gateway"); 1825 goto out; 1826 } 1827 } else { 1828 /* device only nexthop (no gateway) */ 1829 if (cfg->nh_flags & RTNH_F_ONLINK) { 1830 NL_SET_ERR_MSG(extack, 1831 "ONLINK flag can not be set for nexthop without a gateway"); 1832 goto out; 1833 } 1834 } 1835 1836 if (tb[NHA_ENCAP]) { 1837 cfg->nh_encap = tb[NHA_ENCAP]; 1838 1839 if (!tb[NHA_ENCAP_TYPE]) { 1840 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing"); 1841 goto out; 1842 } 1843 1844 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]); 1845 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack); 1846 if (err < 0) 1847 goto out; 1848 1849 } else if (tb[NHA_ENCAP_TYPE]) { 1850 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing"); 1851 goto out; 1852 } 1853 1854 1855 err = 0; 1856 out: 1857 return err; 1858 } 1859 1860 /* rtnl */ 1861 static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 1862 struct netlink_ext_ack *extack) 1863 { 1864 struct net *net = sock_net(skb->sk); 1865 struct nh_config cfg; 1866 struct nexthop *nh; 1867 int err; 1868 1869 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack); 1870 if (!err) { 1871 nh = nexthop_add(net, &cfg, extack); 1872 if (IS_ERR(nh)) 1873 err = PTR_ERR(nh); 1874 } 1875 1876 return err; 1877 } 1878 1879 static int __nh_valid_get_del_req(const struct nlmsghdr *nlh, 1880 struct nlattr **tb, u32 *id, 1881 struct netlink_ext_ack *extack) 1882 { 1883 struct nhmsg *nhm = nlmsg_data(nlh); 1884 1885 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { 1886 NL_SET_ERR_MSG(extack, "Invalid values in header"); 1887 return -EINVAL; 1888 } 1889 1890 if (!tb[NHA_ID]) { 1891 NL_SET_ERR_MSG(extack, "Nexthop id is missing"); 1892 return -EINVAL; 1893 } 1894 1895 *id = nla_get_u32(tb[NHA_ID]); 1896 if (!(*id)) { 1897 NL_SET_ERR_MSG(extack, "Invalid nexthop id"); 1898 return -EINVAL; 1899 } 1900 1901 return 0; 1902 } 1903 1904 static int nh_valid_get_del_req(const struct nlmsghdr *nlh, u32 *id, 1905 struct netlink_ext_ack *extack) 1906 { 1907 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get)]; 1908 int err; 1909 1910 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 1911 ARRAY_SIZE(rtm_nh_policy_get) - 1, 1912 rtm_nh_policy_get, extack); 1913 if (err < 0) 1914 return err; 1915 1916 return __nh_valid_get_del_req(nlh, tb, id, extack); 1917 } 1918 1919 /* rtnl */ 1920 static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh, 1921 struct netlink_ext_ack *extack) 1922 { 1923 struct net *net = sock_net(skb->sk); 1924 struct nl_info nlinfo = { 1925 .nlh = nlh, 1926 .nl_net = net, 1927 .portid = NETLINK_CB(skb).portid, 1928 }; 1929 struct nexthop *nh; 1930 int err; 1931 u32 id; 1932 1933 err = nh_valid_get_del_req(nlh, &id, extack); 1934 if (err) 1935 return err; 1936 1937 nh = nexthop_find_by_id(net, id); 1938 if (!nh) 1939 return -ENOENT; 1940 1941 remove_nexthop(net, nh, &nlinfo); 1942 1943 return 0; 1944 } 1945 1946 /* rtnl */ 1947 static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh, 1948 struct netlink_ext_ack *extack) 1949 { 1950 struct net *net = sock_net(in_skb->sk); 1951 struct sk_buff *skb = NULL; 1952 struct nexthop *nh; 1953 int err; 1954 u32 id; 1955 1956 err = nh_valid_get_del_req(nlh, &id, extack); 1957 if (err) 1958 return err; 1959 1960 err = -ENOBUFS; 1961 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1962 if (!skb) 1963 goto out; 1964 1965 err = -ENOENT; 1966 nh = nexthop_find_by_id(net, id); 1967 if (!nh) 1968 goto errout_free; 1969 1970 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid, 1971 nlh->nlmsg_seq, 0); 1972 if (err < 0) { 1973 WARN_ON(err == -EMSGSIZE); 1974 goto errout_free; 1975 } 1976 1977 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 1978 out: 1979 return err; 1980 errout_free: 1981 kfree_skb(skb); 1982 goto out; 1983 } 1984 1985 struct nh_dump_filter { 1986 int dev_idx; 1987 int master_idx; 1988 bool group_filter; 1989 bool fdb_filter; 1990 }; 1991 1992 static bool nh_dump_filtered(struct nexthop *nh, 1993 struct nh_dump_filter *filter, u8 family) 1994 { 1995 const struct net_device *dev; 1996 const struct nh_info *nhi; 1997 1998 if (filter->group_filter && !nh->is_group) 1999 return true; 2000 2001 if (!filter->dev_idx && !filter->master_idx && !family) 2002 return false; 2003 2004 if (nh->is_group) 2005 return true; 2006 2007 nhi = rtnl_dereference(nh->nh_info); 2008 if (family && nhi->family != family) 2009 return true; 2010 2011 dev = nhi->fib_nhc.nhc_dev; 2012 if (filter->dev_idx && (!dev || dev->ifindex != filter->dev_idx)) 2013 return true; 2014 2015 if (filter->master_idx) { 2016 struct net_device *master; 2017 2018 if (!dev) 2019 return true; 2020 2021 master = netdev_master_upper_dev_get((struct net_device *)dev); 2022 if (!master || master->ifindex != filter->master_idx) 2023 return true; 2024 } 2025 2026 return false; 2027 } 2028 2029 static int __nh_valid_dump_req(const struct nlmsghdr *nlh, struct nlattr **tb, 2030 struct nh_dump_filter *filter, 2031 struct netlink_ext_ack *extack) 2032 { 2033 struct nhmsg *nhm; 2034 u32 idx; 2035 2036 if (tb[NHA_OIF]) { 2037 idx = nla_get_u32(tb[NHA_OIF]); 2038 if (idx > INT_MAX) { 2039 NL_SET_ERR_MSG(extack, "Invalid device index"); 2040 return -EINVAL; 2041 } 2042 filter->dev_idx = idx; 2043 } 2044 if (tb[NHA_MASTER]) { 2045 idx = nla_get_u32(tb[NHA_MASTER]); 2046 if (idx > INT_MAX) { 2047 NL_SET_ERR_MSG(extack, "Invalid master device index"); 2048 return -EINVAL; 2049 } 2050 filter->master_idx = idx; 2051 } 2052 filter->group_filter = nla_get_flag(tb[NHA_GROUPS]); 2053 filter->fdb_filter = nla_get_flag(tb[NHA_FDB]); 2054 2055 nhm = nlmsg_data(nlh); 2056 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) { 2057 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request"); 2058 return -EINVAL; 2059 } 2060 2061 return 0; 2062 } 2063 2064 static int nh_valid_dump_req(const struct nlmsghdr *nlh, 2065 struct nh_dump_filter *filter, 2066 struct netlink_callback *cb) 2067 { 2068 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump)]; 2069 int err; 2070 2071 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, 2072 ARRAY_SIZE(rtm_nh_policy_dump) - 1, 2073 rtm_nh_policy_dump, cb->extack); 2074 if (err < 0) 2075 return err; 2076 2077 return __nh_valid_dump_req(nlh, tb, filter, cb->extack); 2078 } 2079 2080 struct rtm_dump_nh_ctx { 2081 u32 idx; 2082 }; 2083 2084 static struct rtm_dump_nh_ctx * 2085 rtm_dump_nh_ctx(struct netlink_callback *cb) 2086 { 2087 struct rtm_dump_nh_ctx *ctx = (void *)cb->ctx; 2088 2089 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); 2090 return ctx; 2091 } 2092 2093 static int rtm_dump_walk_nexthops(struct sk_buff *skb, 2094 struct netlink_callback *cb, 2095 struct rb_root *root, 2096 struct rtm_dump_nh_ctx *ctx, 2097 int (*nh_cb)(struct sk_buff *skb, 2098 struct netlink_callback *cb, 2099 struct nexthop *nh, void *data), 2100 void *data) 2101 { 2102 struct rb_node *node; 2103 int idx = 0, s_idx; 2104 int err; 2105 2106 s_idx = ctx->idx; 2107 for (node = rb_first(root); node; node = rb_next(node)) { 2108 struct nexthop *nh; 2109 2110 if (idx < s_idx) 2111 goto cont; 2112 2113 nh = rb_entry(node, struct nexthop, rb_node); 2114 ctx->idx = idx; 2115 err = nh_cb(skb, cb, nh, data); 2116 if (err) 2117 return err; 2118 cont: 2119 idx++; 2120 } 2121 2122 ctx->idx = idx; 2123 return 0; 2124 } 2125 2126 static int rtm_dump_nexthop_cb(struct sk_buff *skb, struct netlink_callback *cb, 2127 struct nexthop *nh, void *data) 2128 { 2129 struct nhmsg *nhm = nlmsg_data(cb->nlh); 2130 struct nh_dump_filter *filter = data; 2131 2132 if (nh_dump_filtered(nh, filter, nhm->nh_family)) 2133 return 0; 2134 2135 return nh_fill_node(skb, nh, RTM_NEWNEXTHOP, 2136 NETLINK_CB(cb->skb).portid, 2137 cb->nlh->nlmsg_seq, NLM_F_MULTI); 2138 } 2139 2140 /* rtnl */ 2141 static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb) 2142 { 2143 struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb); 2144 struct net *net = sock_net(skb->sk); 2145 struct rb_root *root = &net->nexthop.rb_root; 2146 struct nh_dump_filter filter = {}; 2147 int err; 2148 2149 err = nh_valid_dump_req(cb->nlh, &filter, cb); 2150 if (err < 0) 2151 return err; 2152 2153 err = rtm_dump_walk_nexthops(skb, cb, root, ctx, 2154 &rtm_dump_nexthop_cb, &filter); 2155 if (err < 0) { 2156 if (likely(skb->len)) 2157 goto out; 2158 goto out_err; 2159 } 2160 2161 out: 2162 err = skb->len; 2163 out_err: 2164 cb->seq = net->nexthop.seq; 2165 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 2166 return err; 2167 } 2168 2169 static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu) 2170 { 2171 unsigned int hash = nh_dev_hashfn(dev->ifindex); 2172 struct net *net = dev_net(dev); 2173 struct hlist_head *head = &net->nexthop.devhash[hash]; 2174 struct hlist_node *n; 2175 struct nh_info *nhi; 2176 2177 hlist_for_each_entry_safe(nhi, n, head, dev_hash) { 2178 if (nhi->fib_nhc.nhc_dev == dev) { 2179 if (nhi->family == AF_INET) 2180 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu, 2181 orig_mtu); 2182 } 2183 } 2184 } 2185 2186 /* rtnl */ 2187 static int nh_netdev_event(struct notifier_block *this, 2188 unsigned long event, void *ptr) 2189 { 2190 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 2191 struct netdev_notifier_info_ext *info_ext; 2192 2193 switch (event) { 2194 case NETDEV_DOWN: 2195 case NETDEV_UNREGISTER: 2196 nexthop_flush_dev(dev, event); 2197 break; 2198 case NETDEV_CHANGE: 2199 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP))) 2200 nexthop_flush_dev(dev, event); 2201 break; 2202 case NETDEV_CHANGEMTU: 2203 info_ext = ptr; 2204 nexthop_sync_mtu(dev, info_ext->ext.mtu); 2205 rt_cache_flush(dev_net(dev)); 2206 break; 2207 } 2208 return NOTIFY_DONE; 2209 } 2210 2211 static struct notifier_block nh_netdev_notifier = { 2212 .notifier_call = nh_netdev_event, 2213 }; 2214 2215 static int nexthops_dump(struct net *net, struct notifier_block *nb, 2216 struct netlink_ext_ack *extack) 2217 { 2218 struct rb_root *root = &net->nexthop.rb_root; 2219 struct rb_node *node; 2220 int err = 0; 2221 2222 for (node = rb_first(root); node; node = rb_next(node)) { 2223 struct nexthop *nh; 2224 2225 nh = rb_entry(node, struct nexthop, rb_node); 2226 err = call_nexthop_notifier(nb, net, NEXTHOP_EVENT_REPLACE, nh, 2227 extack); 2228 if (err) 2229 break; 2230 } 2231 2232 return err; 2233 } 2234 2235 int register_nexthop_notifier(struct net *net, struct notifier_block *nb, 2236 struct netlink_ext_ack *extack) 2237 { 2238 int err; 2239 2240 rtnl_lock(); 2241 err = nexthops_dump(net, nb, extack); 2242 if (err) 2243 goto unlock; 2244 err = blocking_notifier_chain_register(&net->nexthop.notifier_chain, 2245 nb); 2246 unlock: 2247 rtnl_unlock(); 2248 return err; 2249 } 2250 EXPORT_SYMBOL(register_nexthop_notifier); 2251 2252 int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb) 2253 { 2254 return blocking_notifier_chain_unregister(&net->nexthop.notifier_chain, 2255 nb); 2256 } 2257 EXPORT_SYMBOL(unregister_nexthop_notifier); 2258 2259 void nexthop_set_hw_flags(struct net *net, u32 id, bool offload, bool trap) 2260 { 2261 struct nexthop *nexthop; 2262 2263 rcu_read_lock(); 2264 2265 nexthop = nexthop_find_by_id(net, id); 2266 if (!nexthop) 2267 goto out; 2268 2269 nexthop->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP); 2270 if (offload) 2271 nexthop->nh_flags |= RTNH_F_OFFLOAD; 2272 if (trap) 2273 nexthop->nh_flags |= RTNH_F_TRAP; 2274 2275 out: 2276 rcu_read_unlock(); 2277 } 2278 EXPORT_SYMBOL(nexthop_set_hw_flags); 2279 2280 static void __net_exit nexthop_net_exit(struct net *net) 2281 { 2282 rtnl_lock(); 2283 flush_all_nexthops(net); 2284 rtnl_unlock(); 2285 kfree(net->nexthop.devhash); 2286 } 2287 2288 static int __net_init nexthop_net_init(struct net *net) 2289 { 2290 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE; 2291 2292 net->nexthop.rb_root = RB_ROOT; 2293 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL); 2294 if (!net->nexthop.devhash) 2295 return -ENOMEM; 2296 BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain); 2297 2298 return 0; 2299 } 2300 2301 static struct pernet_operations nexthop_net_ops = { 2302 .init = nexthop_net_init, 2303 .exit = nexthop_net_exit, 2304 }; 2305 2306 static int __init nexthop_init(void) 2307 { 2308 register_pernet_subsys(&nexthop_net_ops); 2309 2310 register_netdevice_notifier(&nh_netdev_notifier); 2311 2312 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 2313 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0); 2314 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop, 2315 rtm_dump_nexthop, 0); 2316 2317 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 2318 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); 2319 2320 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); 2321 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); 2322 2323 return 0; 2324 } 2325 subsys_initcall(nexthop_init); 2326