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