1 #include <linux/types.h> 2 #include <linux/skbuff.h> 3 #include <linux/socket.h> 4 #include <linux/sysctl.h> 5 #include <linux/net.h> 6 #include <linux/module.h> 7 #include <linux/if_arp.h> 8 #include <linux/ipv6.h> 9 #include <linux/mpls.h> 10 #include <linux/vmalloc.h> 11 #include <net/ip.h> 12 #include <net/dst.h> 13 #include <net/sock.h> 14 #include <net/arp.h> 15 #include <net/ip_fib.h> 16 #include <net/netevent.h> 17 #include <net/netns/generic.h> 18 #if IS_ENABLED(CONFIG_IPV6) 19 #include <net/ipv6.h> 20 #include <net/addrconf.h> 21 #endif 22 #include <net/nexthop.h> 23 #include "internal.h" 24 25 /* Maximum number of labels to look ahead at when selecting a path of 26 * a multipath route 27 */ 28 #define MAX_MP_SELECT_LABELS 4 29 30 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1) 31 32 static int zero = 0; 33 static int label_limit = (1 << 20) - 1; 34 35 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 36 struct nlmsghdr *nlh, struct net *net, u32 portid, 37 unsigned int nlm_flags); 38 39 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index) 40 { 41 struct mpls_route *rt = NULL; 42 43 if (index < net->mpls.platform_labels) { 44 struct mpls_route __rcu **platform_label = 45 rcu_dereference(net->mpls.platform_label); 46 rt = rcu_dereference(platform_label[index]); 47 } 48 return rt; 49 } 50 51 static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev) 52 { 53 return rcu_dereference_rtnl(dev->mpls_ptr); 54 } 55 56 bool mpls_output_possible(const struct net_device *dev) 57 { 58 return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev); 59 } 60 EXPORT_SYMBOL_GPL(mpls_output_possible); 61 62 static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh) 63 { 64 u8 *nh0_via = PTR_ALIGN((u8 *)&rt->rt_nh[rt->rt_nhn], VIA_ALEN_ALIGN); 65 int nh_index = nh - rt->rt_nh; 66 67 return nh0_via + rt->rt_max_alen * nh_index; 68 } 69 70 static const u8 *mpls_nh_via(const struct mpls_route *rt, 71 const struct mpls_nh *nh) 72 { 73 return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh); 74 } 75 76 static unsigned int mpls_nh_header_size(const struct mpls_nh *nh) 77 { 78 /* The size of the layer 2.5 labels to be added for this route */ 79 return nh->nh_labels * sizeof(struct mpls_shim_hdr); 80 } 81 82 unsigned int mpls_dev_mtu(const struct net_device *dev) 83 { 84 /* The amount of data the layer 2 frame can hold */ 85 return dev->mtu; 86 } 87 EXPORT_SYMBOL_GPL(mpls_dev_mtu); 88 89 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 90 { 91 if (skb->len <= mtu) 92 return false; 93 94 if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu) 95 return false; 96 97 return true; 98 } 99 EXPORT_SYMBOL_GPL(mpls_pkt_too_big); 100 101 static u32 mpls_multipath_hash(struct mpls_route *rt, 102 struct sk_buff *skb, bool bos) 103 { 104 struct mpls_entry_decoded dec; 105 struct mpls_shim_hdr *hdr; 106 bool eli_seen = false; 107 int label_index; 108 u32 hash = 0; 109 110 for (label_index = 0; label_index < MAX_MP_SELECT_LABELS && !bos; 111 label_index++) { 112 if (!pskb_may_pull(skb, sizeof(*hdr) * label_index)) 113 break; 114 115 /* Read and decode the current label */ 116 hdr = mpls_hdr(skb) + label_index; 117 dec = mpls_entry_decode(hdr); 118 119 /* RFC6790 - reserved labels MUST NOT be used as keys 120 * for the load-balancing function 121 */ 122 if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) { 123 hash = jhash_1word(dec.label, hash); 124 125 /* The entropy label follows the entropy label 126 * indicator, so this means that the entropy 127 * label was just added to the hash - no need to 128 * go any deeper either in the label stack or in the 129 * payload 130 */ 131 if (eli_seen) 132 break; 133 } else if (dec.label == MPLS_LABEL_ENTROPY) { 134 eli_seen = true; 135 } 136 137 bos = dec.bos; 138 if (bos && pskb_may_pull(skb, sizeof(*hdr) * label_index + 139 sizeof(struct iphdr))) { 140 const struct iphdr *v4hdr; 141 142 v4hdr = (const struct iphdr *)(mpls_hdr(skb) + 143 label_index); 144 if (v4hdr->version == 4) { 145 hash = jhash_3words(ntohl(v4hdr->saddr), 146 ntohl(v4hdr->daddr), 147 v4hdr->protocol, hash); 148 } else if (v4hdr->version == 6 && 149 pskb_may_pull(skb, sizeof(*hdr) * label_index + 150 sizeof(struct ipv6hdr))) { 151 const struct ipv6hdr *v6hdr; 152 153 v6hdr = (const struct ipv6hdr *)(mpls_hdr(skb) + 154 label_index); 155 156 hash = __ipv6_addr_jhash(&v6hdr->saddr, hash); 157 hash = __ipv6_addr_jhash(&v6hdr->daddr, hash); 158 hash = jhash_1word(v6hdr->nexthdr, hash); 159 } 160 } 161 } 162 163 return hash; 164 } 165 166 static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt, 167 struct sk_buff *skb, bool bos) 168 { 169 int alive = ACCESS_ONCE(rt->rt_nhn_alive); 170 u32 hash = 0; 171 int nh_index = 0; 172 int n = 0; 173 174 /* No need to look further into packet if there's only 175 * one path 176 */ 177 if (rt->rt_nhn == 1) 178 goto out; 179 180 if (alive <= 0) 181 return NULL; 182 183 hash = mpls_multipath_hash(rt, skb, bos); 184 nh_index = hash % alive; 185 if (alive == rt->rt_nhn) 186 goto out; 187 for_nexthops(rt) { 188 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 189 continue; 190 if (n == nh_index) 191 return nh; 192 n++; 193 } endfor_nexthops(rt); 194 195 out: 196 return &rt->rt_nh[nh_index]; 197 } 198 199 static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb, 200 struct mpls_entry_decoded dec) 201 { 202 enum mpls_payload_type payload_type; 203 bool success = false; 204 205 /* The IPv4 code below accesses through the IPv4 header 206 * checksum, which is 12 bytes into the packet. 207 * The IPv6 code below accesses through the IPv6 hop limit 208 * which is 8 bytes into the packet. 209 * 210 * For all supported cases there should always be at least 12 211 * bytes of packet data present. The IPv4 header is 20 bytes 212 * without options and the IPv6 header is always 40 bytes 213 * long. 214 */ 215 if (!pskb_may_pull(skb, 12)) 216 return false; 217 218 payload_type = rt->rt_payload_type; 219 if (payload_type == MPT_UNSPEC) 220 payload_type = ip_hdr(skb)->version; 221 222 switch (payload_type) { 223 case MPT_IPV4: { 224 struct iphdr *hdr4 = ip_hdr(skb); 225 skb->protocol = htons(ETH_P_IP); 226 csum_replace2(&hdr4->check, 227 htons(hdr4->ttl << 8), 228 htons(dec.ttl << 8)); 229 hdr4->ttl = dec.ttl; 230 success = true; 231 break; 232 } 233 case MPT_IPV6: { 234 struct ipv6hdr *hdr6 = ipv6_hdr(skb); 235 skb->protocol = htons(ETH_P_IPV6); 236 hdr6->hop_limit = dec.ttl; 237 success = true; 238 break; 239 } 240 case MPT_UNSPEC: 241 break; 242 } 243 244 return success; 245 } 246 247 static int mpls_forward(struct sk_buff *skb, struct net_device *dev, 248 struct packet_type *pt, struct net_device *orig_dev) 249 { 250 struct net *net = dev_net(dev); 251 struct mpls_shim_hdr *hdr; 252 struct mpls_route *rt; 253 struct mpls_nh *nh; 254 struct mpls_entry_decoded dec; 255 struct net_device *out_dev; 256 struct mpls_dev *mdev; 257 unsigned int hh_len; 258 unsigned int new_header_size; 259 unsigned int mtu; 260 int err; 261 262 /* Careful this entire function runs inside of an rcu critical section */ 263 264 mdev = mpls_dev_get(dev); 265 if (!mdev || !mdev->input_enabled) 266 goto drop; 267 268 if (skb->pkt_type != PACKET_HOST) 269 goto drop; 270 271 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 272 goto drop; 273 274 if (!pskb_may_pull(skb, sizeof(*hdr))) 275 goto drop; 276 277 /* Read and decode the label */ 278 hdr = mpls_hdr(skb); 279 dec = mpls_entry_decode(hdr); 280 281 /* Pop the label */ 282 skb_pull(skb, sizeof(*hdr)); 283 skb_reset_network_header(skb); 284 285 skb_orphan(skb); 286 287 rt = mpls_route_input_rcu(net, dec.label); 288 if (!rt) 289 goto drop; 290 291 nh = mpls_select_multipath(rt, skb, dec.bos); 292 if (!nh) 293 goto drop; 294 295 /* Find the output device */ 296 out_dev = rcu_dereference(nh->nh_dev); 297 if (!mpls_output_possible(out_dev)) 298 goto drop; 299 300 if (skb_warn_if_lro(skb)) 301 goto drop; 302 303 skb_forward_csum(skb); 304 305 /* Verify ttl is valid */ 306 if (dec.ttl <= 1) 307 goto drop; 308 dec.ttl -= 1; 309 310 /* Verify the destination can hold the packet */ 311 new_header_size = mpls_nh_header_size(nh); 312 mtu = mpls_dev_mtu(out_dev); 313 if (mpls_pkt_too_big(skb, mtu - new_header_size)) 314 goto drop; 315 316 hh_len = LL_RESERVED_SPACE(out_dev); 317 if (!out_dev->header_ops) 318 hh_len = 0; 319 320 /* Ensure there is enough space for the headers in the skb */ 321 if (skb_cow(skb, hh_len + new_header_size)) 322 goto drop; 323 324 skb->dev = out_dev; 325 skb->protocol = htons(ETH_P_MPLS_UC); 326 327 if (unlikely(!new_header_size && dec.bos)) { 328 /* Penultimate hop popping */ 329 if (!mpls_egress(rt, skb, dec)) 330 goto drop; 331 } else { 332 bool bos; 333 int i; 334 skb_push(skb, new_header_size); 335 skb_reset_network_header(skb); 336 /* Push the new labels */ 337 hdr = mpls_hdr(skb); 338 bos = dec.bos; 339 for (i = nh->nh_labels - 1; i >= 0; i--) { 340 hdr[i] = mpls_entry_encode(nh->nh_label[i], 341 dec.ttl, 0, bos); 342 bos = false; 343 } 344 } 345 346 /* If via wasn't specified then send out using device address */ 347 if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC) 348 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev, 349 out_dev->dev_addr, skb); 350 else 351 err = neigh_xmit(nh->nh_via_table, out_dev, 352 mpls_nh_via(rt, nh), skb); 353 if (err) 354 net_dbg_ratelimited("%s: packet transmission failed: %d\n", 355 __func__, err); 356 return 0; 357 358 drop: 359 kfree_skb(skb); 360 return NET_RX_DROP; 361 } 362 363 static struct packet_type mpls_packet_type __read_mostly = { 364 .type = cpu_to_be16(ETH_P_MPLS_UC), 365 .func = mpls_forward, 366 }; 367 368 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = { 369 [RTA_DST] = { .type = NLA_U32 }, 370 [RTA_OIF] = { .type = NLA_U32 }, 371 }; 372 373 struct mpls_route_config { 374 u32 rc_protocol; 375 u32 rc_ifindex; 376 u8 rc_via_table; 377 u8 rc_via_alen; 378 u8 rc_via[MAX_VIA_ALEN]; 379 u32 rc_label; 380 u8 rc_output_labels; 381 u32 rc_output_label[MAX_NEW_LABELS]; 382 u32 rc_nlflags; 383 enum mpls_payload_type rc_payload_type; 384 struct nl_info rc_nlinfo; 385 struct rtnexthop *rc_mp; 386 int rc_mp_len; 387 }; 388 389 static struct mpls_route *mpls_rt_alloc(int num_nh, u8 max_alen) 390 { 391 u8 max_alen_aligned = ALIGN(max_alen, VIA_ALEN_ALIGN); 392 struct mpls_route *rt; 393 394 rt = kzalloc(ALIGN(sizeof(*rt) + num_nh * sizeof(*rt->rt_nh), 395 VIA_ALEN_ALIGN) + 396 num_nh * max_alen_aligned, 397 GFP_KERNEL); 398 if (rt) { 399 rt->rt_nhn = num_nh; 400 rt->rt_nhn_alive = num_nh; 401 rt->rt_max_alen = max_alen_aligned; 402 } 403 404 return rt; 405 } 406 407 static void mpls_rt_free(struct mpls_route *rt) 408 { 409 if (rt) 410 kfree_rcu(rt, rt_rcu); 411 } 412 413 static void mpls_notify_route(struct net *net, unsigned index, 414 struct mpls_route *old, struct mpls_route *new, 415 const struct nl_info *info) 416 { 417 struct nlmsghdr *nlh = info ? info->nlh : NULL; 418 unsigned portid = info ? info->portid : 0; 419 int event = new ? RTM_NEWROUTE : RTM_DELROUTE; 420 struct mpls_route *rt = new ? new : old; 421 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0; 422 /* Ignore reserved labels for now */ 423 if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED)) 424 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags); 425 } 426 427 static void mpls_route_update(struct net *net, unsigned index, 428 struct mpls_route *new, 429 const struct nl_info *info) 430 { 431 struct mpls_route __rcu **platform_label; 432 struct mpls_route *rt; 433 434 ASSERT_RTNL(); 435 436 platform_label = rtnl_dereference(net->mpls.platform_label); 437 rt = rtnl_dereference(platform_label[index]); 438 rcu_assign_pointer(platform_label[index], new); 439 440 mpls_notify_route(net, index, rt, new, info); 441 442 /* If we removed a route free it now */ 443 mpls_rt_free(rt); 444 } 445 446 static unsigned find_free_label(struct net *net) 447 { 448 struct mpls_route __rcu **platform_label; 449 size_t platform_labels; 450 unsigned index; 451 452 platform_label = rtnl_dereference(net->mpls.platform_label); 453 platform_labels = net->mpls.platform_labels; 454 for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels; 455 index++) { 456 if (!rtnl_dereference(platform_label[index])) 457 return index; 458 } 459 return LABEL_NOT_SPECIFIED; 460 } 461 462 #if IS_ENABLED(CONFIG_INET) 463 static struct net_device *inet_fib_lookup_dev(struct net *net, 464 const void *addr) 465 { 466 struct net_device *dev; 467 struct rtable *rt; 468 struct in_addr daddr; 469 470 memcpy(&daddr, addr, sizeof(struct in_addr)); 471 rt = ip_route_output(net, daddr.s_addr, 0, 0, 0); 472 if (IS_ERR(rt)) 473 return ERR_CAST(rt); 474 475 dev = rt->dst.dev; 476 dev_hold(dev); 477 478 ip_rt_put(rt); 479 480 return dev; 481 } 482 #else 483 static struct net_device *inet_fib_lookup_dev(struct net *net, 484 const void *addr) 485 { 486 return ERR_PTR(-EAFNOSUPPORT); 487 } 488 #endif 489 490 #if IS_ENABLED(CONFIG_IPV6) 491 static struct net_device *inet6_fib_lookup_dev(struct net *net, 492 const void *addr) 493 { 494 struct net_device *dev; 495 struct dst_entry *dst; 496 struct flowi6 fl6; 497 int err; 498 499 if (!ipv6_stub) 500 return ERR_PTR(-EAFNOSUPPORT); 501 502 memset(&fl6, 0, sizeof(fl6)); 503 memcpy(&fl6.daddr, addr, sizeof(struct in6_addr)); 504 err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6); 505 if (err) 506 return ERR_PTR(err); 507 508 dev = dst->dev; 509 dev_hold(dev); 510 dst_release(dst); 511 512 return dev; 513 } 514 #else 515 static struct net_device *inet6_fib_lookup_dev(struct net *net, 516 const void *addr) 517 { 518 return ERR_PTR(-EAFNOSUPPORT); 519 } 520 #endif 521 522 static struct net_device *find_outdev(struct net *net, 523 struct mpls_route *rt, 524 struct mpls_nh *nh, int oif) 525 { 526 struct net_device *dev = NULL; 527 528 if (!oif) { 529 switch (nh->nh_via_table) { 530 case NEIGH_ARP_TABLE: 531 dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 532 break; 533 case NEIGH_ND_TABLE: 534 dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 535 break; 536 case NEIGH_LINK_TABLE: 537 break; 538 } 539 } else { 540 dev = dev_get_by_index(net, oif); 541 } 542 543 if (!dev) 544 return ERR_PTR(-ENODEV); 545 546 if (IS_ERR(dev)) 547 return dev; 548 549 /* The caller is holding rtnl anyways, so release the dev reference */ 550 dev_put(dev); 551 552 return dev; 553 } 554 555 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt, 556 struct mpls_nh *nh, int oif) 557 { 558 struct net_device *dev = NULL; 559 int err = -ENODEV; 560 561 dev = find_outdev(net, rt, nh, oif); 562 if (IS_ERR(dev)) { 563 err = PTR_ERR(dev); 564 dev = NULL; 565 goto errout; 566 } 567 568 /* Ensure this is a supported device */ 569 err = -EINVAL; 570 if (!mpls_dev_get(dev)) 571 goto errout; 572 573 if ((nh->nh_via_table == NEIGH_LINK_TABLE) && 574 (dev->addr_len != nh->nh_via_alen)) 575 goto errout; 576 577 RCU_INIT_POINTER(nh->nh_dev, dev); 578 579 if (!(dev->flags & IFF_UP)) { 580 nh->nh_flags |= RTNH_F_DEAD; 581 } else { 582 unsigned int flags; 583 584 flags = dev_get_flags(dev); 585 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP))) 586 nh->nh_flags |= RTNH_F_LINKDOWN; 587 } 588 589 return 0; 590 591 errout: 592 return err; 593 } 594 595 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg, 596 struct mpls_route *rt) 597 { 598 struct net *net = cfg->rc_nlinfo.nl_net; 599 struct mpls_nh *nh = rt->rt_nh; 600 int err; 601 int i; 602 603 if (!nh) 604 return -ENOMEM; 605 606 err = -EINVAL; 607 /* Ensure only a supported number of labels are present */ 608 if (cfg->rc_output_labels > MAX_NEW_LABELS) 609 goto errout; 610 611 nh->nh_labels = cfg->rc_output_labels; 612 for (i = 0; i < nh->nh_labels; i++) 613 nh->nh_label[i] = cfg->rc_output_label[i]; 614 615 nh->nh_via_table = cfg->rc_via_table; 616 memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen); 617 nh->nh_via_alen = cfg->rc_via_alen; 618 619 err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex); 620 if (err) 621 goto errout; 622 623 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 624 rt->rt_nhn_alive--; 625 626 return 0; 627 628 errout: 629 return err; 630 } 631 632 static int mpls_nh_build(struct net *net, struct mpls_route *rt, 633 struct mpls_nh *nh, int oif, struct nlattr *via, 634 struct nlattr *newdst) 635 { 636 int err = -ENOMEM; 637 638 if (!nh) 639 goto errout; 640 641 if (newdst) { 642 err = nla_get_labels(newdst, MAX_NEW_LABELS, 643 &nh->nh_labels, nh->nh_label); 644 if (err) 645 goto errout; 646 } 647 648 if (via) { 649 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table, 650 __mpls_nh_via(rt, nh)); 651 if (err) 652 goto errout; 653 } else { 654 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC; 655 } 656 657 err = mpls_nh_assign_dev(net, rt, nh, oif); 658 if (err) 659 goto errout; 660 661 return 0; 662 663 errout: 664 return err; 665 } 666 667 static int mpls_count_nexthops(struct rtnexthop *rtnh, int len, 668 u8 cfg_via_alen, u8 *max_via_alen) 669 { 670 int nhs = 0; 671 int remaining = len; 672 673 if (!rtnh) { 674 *max_via_alen = cfg_via_alen; 675 return 1; 676 } 677 678 *max_via_alen = 0; 679 680 while (rtnh_ok(rtnh, remaining)) { 681 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 682 int attrlen; 683 684 attrlen = rtnh_attrlen(rtnh); 685 nla = nla_find(attrs, attrlen, RTA_VIA); 686 if (nla && nla_len(nla) >= 687 offsetof(struct rtvia, rtvia_addr)) { 688 int via_alen = nla_len(nla) - 689 offsetof(struct rtvia, rtvia_addr); 690 691 if (via_alen <= MAX_VIA_ALEN) 692 *max_via_alen = max_t(u16, *max_via_alen, 693 via_alen); 694 } 695 696 nhs++; 697 rtnh = rtnh_next(rtnh, &remaining); 698 } 699 700 /* leftover implies invalid nexthop configuration, discard it */ 701 return remaining > 0 ? 0 : nhs; 702 } 703 704 static int mpls_nh_build_multi(struct mpls_route_config *cfg, 705 struct mpls_route *rt) 706 { 707 struct rtnexthop *rtnh = cfg->rc_mp; 708 struct nlattr *nla_via, *nla_newdst; 709 int remaining = cfg->rc_mp_len; 710 int nhs = 0; 711 int err = 0; 712 713 change_nexthops(rt) { 714 int attrlen; 715 716 nla_via = NULL; 717 nla_newdst = NULL; 718 719 err = -EINVAL; 720 if (!rtnh_ok(rtnh, remaining)) 721 goto errout; 722 723 /* neither weighted multipath nor any flags 724 * are supported 725 */ 726 if (rtnh->rtnh_hops || rtnh->rtnh_flags) 727 goto errout; 728 729 attrlen = rtnh_attrlen(rtnh); 730 if (attrlen > 0) { 731 struct nlattr *attrs = rtnh_attrs(rtnh); 732 733 nla_via = nla_find(attrs, attrlen, RTA_VIA); 734 nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST); 735 } 736 737 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh, 738 rtnh->rtnh_ifindex, nla_via, nla_newdst); 739 if (err) 740 goto errout; 741 742 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 743 rt->rt_nhn_alive--; 744 745 rtnh = rtnh_next(rtnh, &remaining); 746 nhs++; 747 } endfor_nexthops(rt); 748 749 rt->rt_nhn = nhs; 750 751 return 0; 752 753 errout: 754 return err; 755 } 756 757 static int mpls_route_add(struct mpls_route_config *cfg) 758 { 759 struct mpls_route __rcu **platform_label; 760 struct net *net = cfg->rc_nlinfo.nl_net; 761 struct mpls_route *rt, *old; 762 int err = -EINVAL; 763 u8 max_via_alen; 764 unsigned index; 765 int nhs; 766 767 index = cfg->rc_label; 768 769 /* If a label was not specified during insert pick one */ 770 if ((index == LABEL_NOT_SPECIFIED) && 771 (cfg->rc_nlflags & NLM_F_CREATE)) { 772 index = find_free_label(net); 773 } 774 775 /* Reserved labels may not be set */ 776 if (index < MPLS_LABEL_FIRST_UNRESERVED) 777 goto errout; 778 779 /* The full 20 bit range may not be supported. */ 780 if (index >= net->mpls.platform_labels) 781 goto errout; 782 783 /* Append makes no sense with mpls */ 784 err = -EOPNOTSUPP; 785 if (cfg->rc_nlflags & NLM_F_APPEND) 786 goto errout; 787 788 err = -EEXIST; 789 platform_label = rtnl_dereference(net->mpls.platform_label); 790 old = rtnl_dereference(platform_label[index]); 791 if ((cfg->rc_nlflags & NLM_F_EXCL) && old) 792 goto errout; 793 794 err = -EEXIST; 795 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old) 796 goto errout; 797 798 err = -ENOENT; 799 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old) 800 goto errout; 801 802 err = -EINVAL; 803 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len, 804 cfg->rc_via_alen, &max_via_alen); 805 if (nhs == 0) 806 goto errout; 807 808 err = -ENOMEM; 809 rt = mpls_rt_alloc(nhs, max_via_alen); 810 if (!rt) 811 goto errout; 812 813 rt->rt_protocol = cfg->rc_protocol; 814 rt->rt_payload_type = cfg->rc_payload_type; 815 816 if (cfg->rc_mp) 817 err = mpls_nh_build_multi(cfg, rt); 818 else 819 err = mpls_nh_build_from_cfg(cfg, rt); 820 if (err) 821 goto freert; 822 823 mpls_route_update(net, index, rt, &cfg->rc_nlinfo); 824 825 return 0; 826 827 freert: 828 mpls_rt_free(rt); 829 errout: 830 return err; 831 } 832 833 static int mpls_route_del(struct mpls_route_config *cfg) 834 { 835 struct net *net = cfg->rc_nlinfo.nl_net; 836 unsigned index; 837 int err = -EINVAL; 838 839 index = cfg->rc_label; 840 841 /* Reserved labels may not be removed */ 842 if (index < MPLS_LABEL_FIRST_UNRESERVED) 843 goto errout; 844 845 /* The full 20 bit range may not be supported */ 846 if (index >= net->mpls.platform_labels) 847 goto errout; 848 849 mpls_route_update(net, index, NULL, &cfg->rc_nlinfo); 850 851 err = 0; 852 errout: 853 return err; 854 } 855 856 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \ 857 (&((struct mpls_dev *)0)->field) 858 859 static const struct ctl_table mpls_dev_table[] = { 860 { 861 .procname = "input", 862 .maxlen = sizeof(int), 863 .mode = 0644, 864 .proc_handler = proc_dointvec, 865 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled), 866 }, 867 { } 868 }; 869 870 static int mpls_dev_sysctl_register(struct net_device *dev, 871 struct mpls_dev *mdev) 872 { 873 char path[sizeof("net/mpls/conf/") + IFNAMSIZ]; 874 struct ctl_table *table; 875 int i; 876 877 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL); 878 if (!table) 879 goto out; 880 881 /* Table data contains only offsets relative to the base of 882 * the mdev at this point, so make them absolute. 883 */ 884 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) 885 table[i].data = (char *)mdev + (uintptr_t)table[i].data; 886 887 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name); 888 889 mdev->sysctl = register_net_sysctl(dev_net(dev), path, table); 890 if (!mdev->sysctl) 891 goto free; 892 893 return 0; 894 895 free: 896 kfree(table); 897 out: 898 return -ENOBUFS; 899 } 900 901 static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev) 902 { 903 struct ctl_table *table; 904 905 table = mdev->sysctl->ctl_table_arg; 906 unregister_net_sysctl_table(mdev->sysctl); 907 kfree(table); 908 } 909 910 static struct mpls_dev *mpls_add_dev(struct net_device *dev) 911 { 912 struct mpls_dev *mdev; 913 int err = -ENOMEM; 914 915 ASSERT_RTNL(); 916 917 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); 918 if (!mdev) 919 return ERR_PTR(err); 920 921 err = mpls_dev_sysctl_register(dev, mdev); 922 if (err) 923 goto free; 924 925 rcu_assign_pointer(dev->mpls_ptr, mdev); 926 927 return mdev; 928 929 free: 930 kfree(mdev); 931 return ERR_PTR(err); 932 } 933 934 static void mpls_ifdown(struct net_device *dev, int event) 935 { 936 struct mpls_route __rcu **platform_label; 937 struct net *net = dev_net(dev); 938 unsigned index; 939 940 platform_label = rtnl_dereference(net->mpls.platform_label); 941 for (index = 0; index < net->mpls.platform_labels; index++) { 942 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 943 944 if (!rt) 945 continue; 946 947 change_nexthops(rt) { 948 if (rtnl_dereference(nh->nh_dev) != dev) 949 continue; 950 switch (event) { 951 case NETDEV_DOWN: 952 case NETDEV_UNREGISTER: 953 nh->nh_flags |= RTNH_F_DEAD; 954 /* fall through */ 955 case NETDEV_CHANGE: 956 nh->nh_flags |= RTNH_F_LINKDOWN; 957 ACCESS_ONCE(rt->rt_nhn_alive) = rt->rt_nhn_alive - 1; 958 break; 959 } 960 if (event == NETDEV_UNREGISTER) 961 RCU_INIT_POINTER(nh->nh_dev, NULL); 962 } endfor_nexthops(rt); 963 } 964 965 966 return; 967 } 968 969 static void mpls_ifup(struct net_device *dev, unsigned int nh_flags) 970 { 971 struct mpls_route __rcu **platform_label; 972 struct net *net = dev_net(dev); 973 unsigned index; 974 int alive; 975 976 platform_label = rtnl_dereference(net->mpls.platform_label); 977 for (index = 0; index < net->mpls.platform_labels; index++) { 978 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 979 980 if (!rt) 981 continue; 982 983 alive = 0; 984 change_nexthops(rt) { 985 struct net_device *nh_dev = 986 rtnl_dereference(nh->nh_dev); 987 988 if (!(nh->nh_flags & nh_flags)) { 989 alive++; 990 continue; 991 } 992 if (nh_dev != dev) 993 continue; 994 alive++; 995 nh->nh_flags &= ~nh_flags; 996 } endfor_nexthops(rt); 997 998 ACCESS_ONCE(rt->rt_nhn_alive) = alive; 999 } 1000 1001 return; 1002 } 1003 1004 static int mpls_dev_notify(struct notifier_block *this, unsigned long event, 1005 void *ptr) 1006 { 1007 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1008 struct mpls_dev *mdev; 1009 unsigned int flags; 1010 1011 if (event == NETDEV_REGISTER) { 1012 /* For now just support ethernet devices */ 1013 if ((dev->type == ARPHRD_ETHER) || 1014 (dev->type == ARPHRD_LOOPBACK)) { 1015 mdev = mpls_add_dev(dev); 1016 if (IS_ERR(mdev)) 1017 return notifier_from_errno(PTR_ERR(mdev)); 1018 } 1019 return NOTIFY_OK; 1020 } 1021 1022 mdev = mpls_dev_get(dev); 1023 if (!mdev) 1024 return NOTIFY_OK; 1025 1026 switch (event) { 1027 case NETDEV_DOWN: 1028 mpls_ifdown(dev, event); 1029 break; 1030 case NETDEV_UP: 1031 flags = dev_get_flags(dev); 1032 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1033 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1034 else 1035 mpls_ifup(dev, RTNH_F_DEAD); 1036 break; 1037 case NETDEV_CHANGE: 1038 flags = dev_get_flags(dev); 1039 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1040 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1041 else 1042 mpls_ifdown(dev, event); 1043 break; 1044 case NETDEV_UNREGISTER: 1045 mpls_ifdown(dev, event); 1046 mdev = mpls_dev_get(dev); 1047 if (mdev) { 1048 mpls_dev_sysctl_unregister(mdev); 1049 RCU_INIT_POINTER(dev->mpls_ptr, NULL); 1050 kfree_rcu(mdev, rcu); 1051 } 1052 break; 1053 case NETDEV_CHANGENAME: 1054 mdev = mpls_dev_get(dev); 1055 if (mdev) { 1056 int err; 1057 1058 mpls_dev_sysctl_unregister(mdev); 1059 err = mpls_dev_sysctl_register(dev, mdev); 1060 if (err) 1061 return notifier_from_errno(err); 1062 } 1063 break; 1064 } 1065 return NOTIFY_OK; 1066 } 1067 1068 static struct notifier_block mpls_dev_notifier = { 1069 .notifier_call = mpls_dev_notify, 1070 }; 1071 1072 static int nla_put_via(struct sk_buff *skb, 1073 u8 table, const void *addr, int alen) 1074 { 1075 static const int table_to_family[NEIGH_NR_TABLES + 1] = { 1076 AF_INET, AF_INET6, AF_DECnet, AF_PACKET, 1077 }; 1078 struct nlattr *nla; 1079 struct rtvia *via; 1080 int family = AF_UNSPEC; 1081 1082 nla = nla_reserve(skb, RTA_VIA, alen + 2); 1083 if (!nla) 1084 return -EMSGSIZE; 1085 1086 if (table <= NEIGH_NR_TABLES) 1087 family = table_to_family[table]; 1088 1089 via = nla_data(nla); 1090 via->rtvia_family = family; 1091 memcpy(via->rtvia_addr, addr, alen); 1092 return 0; 1093 } 1094 1095 int nla_put_labels(struct sk_buff *skb, int attrtype, 1096 u8 labels, const u32 label[]) 1097 { 1098 struct nlattr *nla; 1099 struct mpls_shim_hdr *nla_label; 1100 bool bos; 1101 int i; 1102 nla = nla_reserve(skb, attrtype, labels*4); 1103 if (!nla) 1104 return -EMSGSIZE; 1105 1106 nla_label = nla_data(nla); 1107 bos = true; 1108 for (i = labels - 1; i >= 0; i--) { 1109 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos); 1110 bos = false; 1111 } 1112 1113 return 0; 1114 } 1115 EXPORT_SYMBOL_GPL(nla_put_labels); 1116 1117 int nla_get_labels(const struct nlattr *nla, 1118 u32 max_labels, u8 *labels, u32 label[]) 1119 { 1120 unsigned len = nla_len(nla); 1121 unsigned nla_labels; 1122 struct mpls_shim_hdr *nla_label; 1123 bool bos; 1124 int i; 1125 1126 /* len needs to be an even multiple of 4 (the label size) */ 1127 if (len & 3) 1128 return -EINVAL; 1129 1130 /* Limit the number of new labels allowed */ 1131 nla_labels = len/4; 1132 if (nla_labels > max_labels) 1133 return -EINVAL; 1134 1135 nla_label = nla_data(nla); 1136 bos = true; 1137 for (i = nla_labels - 1; i >= 0; i--, bos = false) { 1138 struct mpls_entry_decoded dec; 1139 dec = mpls_entry_decode(nla_label + i); 1140 1141 /* Ensure the bottom of stack flag is properly set 1142 * and ttl and tc are both clear. 1143 */ 1144 if ((dec.bos != bos) || dec.ttl || dec.tc) 1145 return -EINVAL; 1146 1147 switch (dec.label) { 1148 case MPLS_LABEL_IMPLNULL: 1149 /* RFC3032: This is a label that an LSR may 1150 * assign and distribute, but which never 1151 * actually appears in the encapsulation. 1152 */ 1153 return -EINVAL; 1154 } 1155 1156 label[i] = dec.label; 1157 } 1158 *labels = nla_labels; 1159 return 0; 1160 } 1161 EXPORT_SYMBOL_GPL(nla_get_labels); 1162 1163 int nla_get_via(const struct nlattr *nla, u8 *via_alen, 1164 u8 *via_table, u8 via_addr[]) 1165 { 1166 struct rtvia *via = nla_data(nla); 1167 int err = -EINVAL; 1168 int alen; 1169 1170 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) 1171 goto errout; 1172 alen = nla_len(nla) - 1173 offsetof(struct rtvia, rtvia_addr); 1174 if (alen > MAX_VIA_ALEN) 1175 goto errout; 1176 1177 /* Validate the address family */ 1178 switch (via->rtvia_family) { 1179 case AF_PACKET: 1180 *via_table = NEIGH_LINK_TABLE; 1181 break; 1182 case AF_INET: 1183 *via_table = NEIGH_ARP_TABLE; 1184 if (alen != 4) 1185 goto errout; 1186 break; 1187 case AF_INET6: 1188 *via_table = NEIGH_ND_TABLE; 1189 if (alen != 16) 1190 goto errout; 1191 break; 1192 default: 1193 /* Unsupported address family */ 1194 goto errout; 1195 } 1196 1197 memcpy(via_addr, via->rtvia_addr, alen); 1198 *via_alen = alen; 1199 err = 0; 1200 1201 errout: 1202 return err; 1203 } 1204 1205 static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh, 1206 struct mpls_route_config *cfg) 1207 { 1208 struct rtmsg *rtm; 1209 struct nlattr *tb[RTA_MAX+1]; 1210 int index; 1211 int err; 1212 1213 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy); 1214 if (err < 0) 1215 goto errout; 1216 1217 err = -EINVAL; 1218 rtm = nlmsg_data(nlh); 1219 memset(cfg, 0, sizeof(*cfg)); 1220 1221 if (rtm->rtm_family != AF_MPLS) 1222 goto errout; 1223 if (rtm->rtm_dst_len != 20) 1224 goto errout; 1225 if (rtm->rtm_src_len != 0) 1226 goto errout; 1227 if (rtm->rtm_tos != 0) 1228 goto errout; 1229 if (rtm->rtm_table != RT_TABLE_MAIN) 1230 goto errout; 1231 /* Any value is acceptable for rtm_protocol */ 1232 1233 /* As mpls uses destination specific addresses 1234 * (or source specific address in the case of multicast) 1235 * all addresses have universal scope. 1236 */ 1237 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) 1238 goto errout; 1239 if (rtm->rtm_type != RTN_UNICAST) 1240 goto errout; 1241 if (rtm->rtm_flags != 0) 1242 goto errout; 1243 1244 cfg->rc_label = LABEL_NOT_SPECIFIED; 1245 cfg->rc_protocol = rtm->rtm_protocol; 1246 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC; 1247 cfg->rc_nlflags = nlh->nlmsg_flags; 1248 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid; 1249 cfg->rc_nlinfo.nlh = nlh; 1250 cfg->rc_nlinfo.nl_net = sock_net(skb->sk); 1251 1252 for (index = 0; index <= RTA_MAX; index++) { 1253 struct nlattr *nla = tb[index]; 1254 if (!nla) 1255 continue; 1256 1257 switch(index) { 1258 case RTA_OIF: 1259 cfg->rc_ifindex = nla_get_u32(nla); 1260 break; 1261 case RTA_NEWDST: 1262 if (nla_get_labels(nla, MAX_NEW_LABELS, 1263 &cfg->rc_output_labels, 1264 cfg->rc_output_label)) 1265 goto errout; 1266 break; 1267 case RTA_DST: 1268 { 1269 u8 label_count; 1270 if (nla_get_labels(nla, 1, &label_count, 1271 &cfg->rc_label)) 1272 goto errout; 1273 1274 /* Reserved labels may not be set */ 1275 if (cfg->rc_label < MPLS_LABEL_FIRST_UNRESERVED) 1276 goto errout; 1277 1278 break; 1279 } 1280 case RTA_VIA: 1281 { 1282 if (nla_get_via(nla, &cfg->rc_via_alen, 1283 &cfg->rc_via_table, cfg->rc_via)) 1284 goto errout; 1285 break; 1286 } 1287 case RTA_MULTIPATH: 1288 { 1289 cfg->rc_mp = nla_data(nla); 1290 cfg->rc_mp_len = nla_len(nla); 1291 break; 1292 } 1293 default: 1294 /* Unsupported attribute */ 1295 goto errout; 1296 } 1297 } 1298 1299 err = 0; 1300 errout: 1301 return err; 1302 } 1303 1304 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh) 1305 { 1306 struct mpls_route_config cfg; 1307 int err; 1308 1309 err = rtm_to_route_config(skb, nlh, &cfg); 1310 if (err < 0) 1311 return err; 1312 1313 return mpls_route_del(&cfg); 1314 } 1315 1316 1317 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh) 1318 { 1319 struct mpls_route_config cfg; 1320 int err; 1321 1322 err = rtm_to_route_config(skb, nlh, &cfg); 1323 if (err < 0) 1324 return err; 1325 1326 return mpls_route_add(&cfg); 1327 } 1328 1329 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, 1330 u32 label, struct mpls_route *rt, int flags) 1331 { 1332 struct net_device *dev; 1333 struct nlmsghdr *nlh; 1334 struct rtmsg *rtm; 1335 1336 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); 1337 if (nlh == NULL) 1338 return -EMSGSIZE; 1339 1340 rtm = nlmsg_data(nlh); 1341 rtm->rtm_family = AF_MPLS; 1342 rtm->rtm_dst_len = 20; 1343 rtm->rtm_src_len = 0; 1344 rtm->rtm_tos = 0; 1345 rtm->rtm_table = RT_TABLE_MAIN; 1346 rtm->rtm_protocol = rt->rt_protocol; 1347 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 1348 rtm->rtm_type = RTN_UNICAST; 1349 rtm->rtm_flags = 0; 1350 1351 if (nla_put_labels(skb, RTA_DST, 1, &label)) 1352 goto nla_put_failure; 1353 if (rt->rt_nhn == 1) { 1354 const struct mpls_nh *nh = rt->rt_nh; 1355 1356 if (nh->nh_labels && 1357 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels, 1358 nh->nh_label)) 1359 goto nla_put_failure; 1360 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1361 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh), 1362 nh->nh_via_alen)) 1363 goto nla_put_failure; 1364 dev = rtnl_dereference(nh->nh_dev); 1365 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) 1366 goto nla_put_failure; 1367 if (nh->nh_flags & RTNH_F_LINKDOWN) 1368 rtm->rtm_flags |= RTNH_F_LINKDOWN; 1369 if (nh->nh_flags & RTNH_F_DEAD) 1370 rtm->rtm_flags |= RTNH_F_DEAD; 1371 } else { 1372 struct rtnexthop *rtnh; 1373 struct nlattr *mp; 1374 int dead = 0; 1375 int linkdown = 0; 1376 1377 mp = nla_nest_start(skb, RTA_MULTIPATH); 1378 if (!mp) 1379 goto nla_put_failure; 1380 1381 for_nexthops(rt) { 1382 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); 1383 if (!rtnh) 1384 goto nla_put_failure; 1385 1386 dev = rtnl_dereference(nh->nh_dev); 1387 if (dev) 1388 rtnh->rtnh_ifindex = dev->ifindex; 1389 if (nh->nh_flags & RTNH_F_LINKDOWN) { 1390 rtnh->rtnh_flags |= RTNH_F_LINKDOWN; 1391 linkdown++; 1392 } 1393 if (nh->nh_flags & RTNH_F_DEAD) { 1394 rtnh->rtnh_flags |= RTNH_F_DEAD; 1395 dead++; 1396 } 1397 1398 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST, 1399 nh->nh_labels, 1400 nh->nh_label)) 1401 goto nla_put_failure; 1402 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1403 nla_put_via(skb, nh->nh_via_table, 1404 mpls_nh_via(rt, nh), 1405 nh->nh_via_alen)) 1406 goto nla_put_failure; 1407 1408 /* length of rtnetlink header + attributes */ 1409 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; 1410 } endfor_nexthops(rt); 1411 1412 if (linkdown == rt->rt_nhn) 1413 rtm->rtm_flags |= RTNH_F_LINKDOWN; 1414 if (dead == rt->rt_nhn) 1415 rtm->rtm_flags |= RTNH_F_DEAD; 1416 1417 nla_nest_end(skb, mp); 1418 } 1419 1420 nlmsg_end(skb, nlh); 1421 return 0; 1422 1423 nla_put_failure: 1424 nlmsg_cancel(skb, nlh); 1425 return -EMSGSIZE; 1426 } 1427 1428 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) 1429 { 1430 struct net *net = sock_net(skb->sk); 1431 struct mpls_route __rcu **platform_label; 1432 size_t platform_labels; 1433 unsigned int index; 1434 1435 ASSERT_RTNL(); 1436 1437 index = cb->args[0]; 1438 if (index < MPLS_LABEL_FIRST_UNRESERVED) 1439 index = MPLS_LABEL_FIRST_UNRESERVED; 1440 1441 platform_label = rtnl_dereference(net->mpls.platform_label); 1442 platform_labels = net->mpls.platform_labels; 1443 for (; index < platform_labels; index++) { 1444 struct mpls_route *rt; 1445 rt = rtnl_dereference(platform_label[index]); 1446 if (!rt) 1447 continue; 1448 1449 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid, 1450 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 1451 index, rt, NLM_F_MULTI) < 0) 1452 break; 1453 } 1454 cb->args[0] = index; 1455 1456 return skb->len; 1457 } 1458 1459 static inline size_t lfib_nlmsg_size(struct mpls_route *rt) 1460 { 1461 size_t payload = 1462 NLMSG_ALIGN(sizeof(struct rtmsg)) 1463 + nla_total_size(4); /* RTA_DST */ 1464 1465 if (rt->rt_nhn == 1) { 1466 struct mpls_nh *nh = rt->rt_nh; 1467 1468 if (nh->nh_dev) 1469 payload += nla_total_size(4); /* RTA_OIF */ 1470 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */ 1471 payload += nla_total_size(2 + nh->nh_via_alen); 1472 if (nh->nh_labels) /* RTA_NEWDST */ 1473 payload += nla_total_size(nh->nh_labels * 4); 1474 } else { 1475 /* each nexthop is packed in an attribute */ 1476 size_t nhsize = 0; 1477 1478 for_nexthops(rt) { 1479 nhsize += nla_total_size(sizeof(struct rtnexthop)); 1480 /* RTA_VIA */ 1481 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) 1482 nhsize += nla_total_size(2 + nh->nh_via_alen); 1483 if (nh->nh_labels) 1484 nhsize += nla_total_size(nh->nh_labels * 4); 1485 } endfor_nexthops(rt); 1486 /* nested attribute */ 1487 payload += nla_total_size(nhsize); 1488 } 1489 1490 return payload; 1491 } 1492 1493 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 1494 struct nlmsghdr *nlh, struct net *net, u32 portid, 1495 unsigned int nlm_flags) 1496 { 1497 struct sk_buff *skb; 1498 u32 seq = nlh ? nlh->nlmsg_seq : 0; 1499 int err = -ENOBUFS; 1500 1501 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL); 1502 if (skb == NULL) 1503 goto errout; 1504 1505 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags); 1506 if (err < 0) { 1507 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */ 1508 WARN_ON(err == -EMSGSIZE); 1509 kfree_skb(skb); 1510 goto errout; 1511 } 1512 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL); 1513 1514 return; 1515 errout: 1516 if (err < 0) 1517 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err); 1518 } 1519 1520 static int resize_platform_label_table(struct net *net, size_t limit) 1521 { 1522 size_t size = sizeof(struct mpls_route *) * limit; 1523 size_t old_limit; 1524 size_t cp_size; 1525 struct mpls_route __rcu **labels = NULL, **old; 1526 struct mpls_route *rt0 = NULL, *rt2 = NULL; 1527 unsigned index; 1528 1529 if (size) { 1530 labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY); 1531 if (!labels) 1532 labels = vzalloc(size); 1533 1534 if (!labels) 1535 goto nolabels; 1536 } 1537 1538 /* In case the predefined labels need to be populated */ 1539 if (limit > MPLS_LABEL_IPV4NULL) { 1540 struct net_device *lo = net->loopback_dev; 1541 rt0 = mpls_rt_alloc(1, lo->addr_len); 1542 if (!rt0) 1543 goto nort0; 1544 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo); 1545 rt0->rt_protocol = RTPROT_KERNEL; 1546 rt0->rt_payload_type = MPT_IPV4; 1547 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 1548 rt0->rt_nh->nh_via_alen = lo->addr_len; 1549 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr, 1550 lo->addr_len); 1551 } 1552 if (limit > MPLS_LABEL_IPV6NULL) { 1553 struct net_device *lo = net->loopback_dev; 1554 rt2 = mpls_rt_alloc(1, lo->addr_len); 1555 if (!rt2) 1556 goto nort2; 1557 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo); 1558 rt2->rt_protocol = RTPROT_KERNEL; 1559 rt2->rt_payload_type = MPT_IPV6; 1560 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 1561 rt2->rt_nh->nh_via_alen = lo->addr_len; 1562 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr, 1563 lo->addr_len); 1564 } 1565 1566 rtnl_lock(); 1567 /* Remember the original table */ 1568 old = rtnl_dereference(net->mpls.platform_label); 1569 old_limit = net->mpls.platform_labels; 1570 1571 /* Free any labels beyond the new table */ 1572 for (index = limit; index < old_limit; index++) 1573 mpls_route_update(net, index, NULL, NULL); 1574 1575 /* Copy over the old labels */ 1576 cp_size = size; 1577 if (old_limit < limit) 1578 cp_size = old_limit * sizeof(struct mpls_route *); 1579 1580 memcpy(labels, old, cp_size); 1581 1582 /* If needed set the predefined labels */ 1583 if ((old_limit <= MPLS_LABEL_IPV6NULL) && 1584 (limit > MPLS_LABEL_IPV6NULL)) { 1585 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2); 1586 rt2 = NULL; 1587 } 1588 1589 if ((old_limit <= MPLS_LABEL_IPV4NULL) && 1590 (limit > MPLS_LABEL_IPV4NULL)) { 1591 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0); 1592 rt0 = NULL; 1593 } 1594 1595 /* Update the global pointers */ 1596 net->mpls.platform_labels = limit; 1597 rcu_assign_pointer(net->mpls.platform_label, labels); 1598 1599 rtnl_unlock(); 1600 1601 mpls_rt_free(rt2); 1602 mpls_rt_free(rt0); 1603 1604 if (old) { 1605 synchronize_rcu(); 1606 kvfree(old); 1607 } 1608 return 0; 1609 1610 nort2: 1611 mpls_rt_free(rt0); 1612 nort0: 1613 kvfree(labels); 1614 nolabels: 1615 return -ENOMEM; 1616 } 1617 1618 static int mpls_platform_labels(struct ctl_table *table, int write, 1619 void __user *buffer, size_t *lenp, loff_t *ppos) 1620 { 1621 struct net *net = table->data; 1622 int platform_labels = net->mpls.platform_labels; 1623 int ret; 1624 struct ctl_table tmp = { 1625 .procname = table->procname, 1626 .data = &platform_labels, 1627 .maxlen = sizeof(int), 1628 .mode = table->mode, 1629 .extra1 = &zero, 1630 .extra2 = &label_limit, 1631 }; 1632 1633 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 1634 1635 if (write && ret == 0) 1636 ret = resize_platform_label_table(net, platform_labels); 1637 1638 return ret; 1639 } 1640 1641 static const struct ctl_table mpls_table[] = { 1642 { 1643 .procname = "platform_labels", 1644 .data = NULL, 1645 .maxlen = sizeof(int), 1646 .mode = 0644, 1647 .proc_handler = mpls_platform_labels, 1648 }, 1649 { } 1650 }; 1651 1652 static int mpls_net_init(struct net *net) 1653 { 1654 struct ctl_table *table; 1655 1656 net->mpls.platform_labels = 0; 1657 net->mpls.platform_label = NULL; 1658 1659 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL); 1660 if (table == NULL) 1661 return -ENOMEM; 1662 1663 table[0].data = net; 1664 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table); 1665 if (net->mpls.ctl == NULL) { 1666 kfree(table); 1667 return -ENOMEM; 1668 } 1669 1670 return 0; 1671 } 1672 1673 static void mpls_net_exit(struct net *net) 1674 { 1675 struct mpls_route __rcu **platform_label; 1676 size_t platform_labels; 1677 struct ctl_table *table; 1678 unsigned int index; 1679 1680 table = net->mpls.ctl->ctl_table_arg; 1681 unregister_net_sysctl_table(net->mpls.ctl); 1682 kfree(table); 1683 1684 /* An rcu grace period has passed since there was a device in 1685 * the network namespace (and thus the last in flight packet) 1686 * left this network namespace. This is because 1687 * unregister_netdevice_many and netdev_run_todo has completed 1688 * for each network device that was in this network namespace. 1689 * 1690 * As such no additional rcu synchronization is necessary when 1691 * freeing the platform_label table. 1692 */ 1693 rtnl_lock(); 1694 platform_label = rtnl_dereference(net->mpls.platform_label); 1695 platform_labels = net->mpls.platform_labels; 1696 for (index = 0; index < platform_labels; index++) { 1697 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1698 RCU_INIT_POINTER(platform_label[index], NULL); 1699 mpls_rt_free(rt); 1700 } 1701 rtnl_unlock(); 1702 1703 kvfree(platform_label); 1704 } 1705 1706 static struct pernet_operations mpls_net_ops = { 1707 .init = mpls_net_init, 1708 .exit = mpls_net_exit, 1709 }; 1710 1711 static int __init mpls_init(void) 1712 { 1713 int err; 1714 1715 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4); 1716 1717 err = register_pernet_subsys(&mpls_net_ops); 1718 if (err) 1719 goto out; 1720 1721 err = register_netdevice_notifier(&mpls_dev_notifier); 1722 if (err) 1723 goto out_unregister_pernet; 1724 1725 dev_add_pack(&mpls_packet_type); 1726 1727 rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, NULL); 1728 rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, NULL); 1729 rtnl_register(PF_MPLS, RTM_GETROUTE, NULL, mpls_dump_routes, NULL); 1730 err = 0; 1731 out: 1732 return err; 1733 1734 out_unregister_pernet: 1735 unregister_pernet_subsys(&mpls_net_ops); 1736 goto out; 1737 } 1738 module_init(mpls_init); 1739 1740 static void __exit mpls_exit(void) 1741 { 1742 rtnl_unregister_all(PF_MPLS); 1743 dev_remove_pack(&mpls_packet_type); 1744 unregister_netdevice_notifier(&mpls_dev_notifier); 1745 unregister_pernet_subsys(&mpls_net_ops); 1746 } 1747 module_exit(mpls_exit); 1748 1749 MODULE_DESCRIPTION("MultiProtocol Label Switching"); 1750 MODULE_LICENSE("GPL v2"); 1751 MODULE_ALIAS_NETPROTO(PF_MPLS); 1752