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