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