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/netconf.h> 11 #include <linux/vmalloc.h> 12 #include <linux/percpu.h> 13 #include <net/ip.h> 14 #include <net/dst.h> 15 #include <net/sock.h> 16 #include <net/arp.h> 17 #include <net/ip_fib.h> 18 #include <net/netevent.h> 19 #include <net/netns/generic.h> 20 #if IS_ENABLED(CONFIG_IPV6) 21 #include <net/ipv6.h> 22 #endif 23 #include <net/addrconf.h> 24 #include <net/nexthop.h> 25 #include "internal.h" 26 27 /* Maximum number of labels to look ahead at when selecting a path of 28 * a multipath route 29 */ 30 #define MAX_MP_SELECT_LABELS 4 31 32 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1) 33 34 static int zero = 0; 35 static int label_limit = (1 << 20) - 1; 36 37 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 38 struct nlmsghdr *nlh, struct net *net, u32 portid, 39 unsigned int nlm_flags); 40 41 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index) 42 { 43 struct mpls_route *rt = NULL; 44 45 if (index < net->mpls.platform_labels) { 46 struct mpls_route __rcu **platform_label = 47 rcu_dereference(net->mpls.platform_label); 48 rt = rcu_dereference(platform_label[index]); 49 } 50 return rt; 51 } 52 53 bool mpls_output_possible(const struct net_device *dev) 54 { 55 return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev); 56 } 57 EXPORT_SYMBOL_GPL(mpls_output_possible); 58 59 static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh) 60 { 61 u8 *nh0_via = PTR_ALIGN((u8 *)&rt->rt_nh[rt->rt_nhn], VIA_ALEN_ALIGN); 62 int nh_index = nh - rt->rt_nh; 63 64 return nh0_via + rt->rt_max_alen * nh_index; 65 } 66 67 static const u8 *mpls_nh_via(const struct mpls_route *rt, 68 const struct mpls_nh *nh) 69 { 70 return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh); 71 } 72 73 static unsigned int mpls_nh_header_size(const struct mpls_nh *nh) 74 { 75 /* The size of the layer 2.5 labels to be added for this route */ 76 return nh->nh_labels * sizeof(struct mpls_shim_hdr); 77 } 78 79 unsigned int mpls_dev_mtu(const struct net_device *dev) 80 { 81 /* The amount of data the layer 2 frame can hold */ 82 return dev->mtu; 83 } 84 EXPORT_SYMBOL_GPL(mpls_dev_mtu); 85 86 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 87 { 88 if (skb->len <= mtu) 89 return false; 90 91 if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu)) 92 return false; 93 94 return true; 95 } 96 EXPORT_SYMBOL_GPL(mpls_pkt_too_big); 97 98 void mpls_stats_inc_outucastpkts(struct net_device *dev, 99 const struct sk_buff *skb) 100 { 101 struct mpls_dev *mdev; 102 103 if (skb->protocol == htons(ETH_P_MPLS_UC)) { 104 mdev = mpls_dev_get(dev); 105 if (mdev) 106 MPLS_INC_STATS_LEN(mdev, skb->len, 107 tx_packets, 108 tx_bytes); 109 } else if (skb->protocol == htons(ETH_P_IP)) { 110 IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); 111 #if IS_ENABLED(CONFIG_IPV6) 112 } else if (skb->protocol == htons(ETH_P_IPV6)) { 113 struct inet6_dev *in6dev = __in6_dev_get(dev); 114 115 if (in6dev) 116 IP6_UPD_PO_STATS(dev_net(dev), in6dev, 117 IPSTATS_MIB_OUT, skb->len); 118 #endif 119 } 120 } 121 EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts); 122 123 static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb) 124 { 125 struct mpls_entry_decoded dec; 126 unsigned int mpls_hdr_len = 0; 127 struct mpls_shim_hdr *hdr; 128 bool eli_seen = false; 129 int label_index; 130 u32 hash = 0; 131 132 for (label_index = 0; label_index < MAX_MP_SELECT_LABELS; 133 label_index++) { 134 mpls_hdr_len += sizeof(*hdr); 135 if (!pskb_may_pull(skb, mpls_hdr_len)) 136 break; 137 138 /* Read and decode the current label */ 139 hdr = mpls_hdr(skb) + label_index; 140 dec = mpls_entry_decode(hdr); 141 142 /* RFC6790 - reserved labels MUST NOT be used as keys 143 * for the load-balancing function 144 */ 145 if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) { 146 hash = jhash_1word(dec.label, hash); 147 148 /* The entropy label follows the entropy label 149 * indicator, so this means that the entropy 150 * label was just added to the hash - no need to 151 * go any deeper either in the label stack or in the 152 * payload 153 */ 154 if (eli_seen) 155 break; 156 } else if (dec.label == MPLS_LABEL_ENTROPY) { 157 eli_seen = true; 158 } 159 160 if (!dec.bos) 161 continue; 162 163 /* found bottom label; does skb have room for a header? */ 164 if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) { 165 const struct iphdr *v4hdr; 166 167 v4hdr = (const struct iphdr *)(hdr + 1); 168 if (v4hdr->version == 4) { 169 hash = jhash_3words(ntohl(v4hdr->saddr), 170 ntohl(v4hdr->daddr), 171 v4hdr->protocol, hash); 172 } else if (v4hdr->version == 6 && 173 pskb_may_pull(skb, mpls_hdr_len + 174 sizeof(struct ipv6hdr))) { 175 const struct ipv6hdr *v6hdr; 176 177 v6hdr = (const struct ipv6hdr *)(hdr + 1); 178 hash = __ipv6_addr_jhash(&v6hdr->saddr, hash); 179 hash = __ipv6_addr_jhash(&v6hdr->daddr, hash); 180 hash = jhash_1word(v6hdr->nexthdr, hash); 181 } 182 } 183 184 break; 185 } 186 187 return hash; 188 } 189 190 static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt, 191 struct sk_buff *skb) 192 { 193 int alive = ACCESS_ONCE(rt->rt_nhn_alive); 194 u32 hash = 0; 195 int nh_index = 0; 196 int n = 0; 197 198 /* No need to look further into packet if there's only 199 * one path 200 */ 201 if (rt->rt_nhn == 1) 202 goto out; 203 204 if (alive <= 0) 205 return NULL; 206 207 hash = mpls_multipath_hash(rt, skb); 208 nh_index = hash % alive; 209 if (alive == rt->rt_nhn) 210 goto out; 211 for_nexthops(rt) { 212 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 213 continue; 214 if (n == nh_index) 215 return nh; 216 n++; 217 } endfor_nexthops(rt); 218 219 out: 220 return &rt->rt_nh[nh_index]; 221 } 222 223 static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb, 224 struct mpls_entry_decoded dec) 225 { 226 enum mpls_payload_type payload_type; 227 bool success = false; 228 229 /* The IPv4 code below accesses through the IPv4 header 230 * checksum, which is 12 bytes into the packet. 231 * The IPv6 code below accesses through the IPv6 hop limit 232 * which is 8 bytes into the packet. 233 * 234 * For all supported cases there should always be at least 12 235 * bytes of packet data present. The IPv4 header is 20 bytes 236 * without options and the IPv6 header is always 40 bytes 237 * long. 238 */ 239 if (!pskb_may_pull(skb, 12)) 240 return false; 241 242 payload_type = rt->rt_payload_type; 243 if (payload_type == MPT_UNSPEC) 244 payload_type = ip_hdr(skb)->version; 245 246 switch (payload_type) { 247 case MPT_IPV4: { 248 struct iphdr *hdr4 = ip_hdr(skb); 249 skb->protocol = htons(ETH_P_IP); 250 csum_replace2(&hdr4->check, 251 htons(hdr4->ttl << 8), 252 htons(dec.ttl << 8)); 253 hdr4->ttl = dec.ttl; 254 success = true; 255 break; 256 } 257 case MPT_IPV6: { 258 struct ipv6hdr *hdr6 = ipv6_hdr(skb); 259 skb->protocol = htons(ETH_P_IPV6); 260 hdr6->hop_limit = dec.ttl; 261 success = true; 262 break; 263 } 264 case MPT_UNSPEC: 265 break; 266 } 267 268 return success; 269 } 270 271 static int mpls_forward(struct sk_buff *skb, struct net_device *dev, 272 struct packet_type *pt, struct net_device *orig_dev) 273 { 274 struct net *net = dev_net(dev); 275 struct mpls_shim_hdr *hdr; 276 struct mpls_route *rt; 277 struct mpls_nh *nh; 278 struct mpls_entry_decoded dec; 279 struct net_device *out_dev; 280 struct mpls_dev *out_mdev; 281 struct mpls_dev *mdev; 282 unsigned int hh_len; 283 unsigned int new_header_size; 284 unsigned int mtu; 285 int err; 286 287 /* Careful this entire function runs inside of an rcu critical section */ 288 289 mdev = mpls_dev_get(dev); 290 if (!mdev) 291 goto drop; 292 293 MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets, 294 rx_bytes); 295 296 if (!mdev->input_enabled) { 297 MPLS_INC_STATS(mdev, rx_dropped); 298 goto drop; 299 } 300 301 if (skb->pkt_type != PACKET_HOST) 302 goto err; 303 304 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 305 goto err; 306 307 if (!pskb_may_pull(skb, sizeof(*hdr))) 308 goto err; 309 310 /* Read and decode the label */ 311 hdr = mpls_hdr(skb); 312 dec = mpls_entry_decode(hdr); 313 314 rt = mpls_route_input_rcu(net, dec.label); 315 if (!rt) { 316 MPLS_INC_STATS(mdev, rx_noroute); 317 goto drop; 318 } 319 320 nh = mpls_select_multipath(rt, skb); 321 if (!nh) 322 goto err; 323 324 /* Pop the label */ 325 skb_pull(skb, sizeof(*hdr)); 326 skb_reset_network_header(skb); 327 328 skb_orphan(skb); 329 330 if (skb_warn_if_lro(skb)) 331 goto err; 332 333 skb_forward_csum(skb); 334 335 /* Verify ttl is valid */ 336 if (dec.ttl <= 1) 337 goto err; 338 dec.ttl -= 1; 339 340 /* Find the output device */ 341 out_dev = rcu_dereference(nh->nh_dev); 342 if (!mpls_output_possible(out_dev)) 343 goto tx_err; 344 345 /* Verify the destination can hold the packet */ 346 new_header_size = mpls_nh_header_size(nh); 347 mtu = mpls_dev_mtu(out_dev); 348 if (mpls_pkt_too_big(skb, mtu - new_header_size)) 349 goto tx_err; 350 351 hh_len = LL_RESERVED_SPACE(out_dev); 352 if (!out_dev->header_ops) 353 hh_len = 0; 354 355 /* Ensure there is enough space for the headers in the skb */ 356 if (skb_cow(skb, hh_len + new_header_size)) 357 goto tx_err; 358 359 skb->dev = out_dev; 360 skb->protocol = htons(ETH_P_MPLS_UC); 361 362 if (unlikely(!new_header_size && dec.bos)) { 363 /* Penultimate hop popping */ 364 if (!mpls_egress(rt, skb, dec)) 365 goto err; 366 } else { 367 bool bos; 368 int i; 369 skb_push(skb, new_header_size); 370 skb_reset_network_header(skb); 371 /* Push the new labels */ 372 hdr = mpls_hdr(skb); 373 bos = dec.bos; 374 for (i = nh->nh_labels - 1; i >= 0; i--) { 375 hdr[i] = mpls_entry_encode(nh->nh_label[i], 376 dec.ttl, 0, bos); 377 bos = false; 378 } 379 } 380 381 mpls_stats_inc_outucastpkts(out_dev, skb); 382 383 /* If via wasn't specified then send out using device address */ 384 if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC) 385 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev, 386 out_dev->dev_addr, skb); 387 else 388 err = neigh_xmit(nh->nh_via_table, out_dev, 389 mpls_nh_via(rt, nh), skb); 390 if (err) 391 net_dbg_ratelimited("%s: packet transmission failed: %d\n", 392 __func__, err); 393 return 0; 394 395 tx_err: 396 out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL; 397 if (out_mdev) 398 MPLS_INC_STATS(out_mdev, tx_errors); 399 goto drop; 400 err: 401 MPLS_INC_STATS(mdev, rx_errors); 402 drop: 403 kfree_skb(skb); 404 return NET_RX_DROP; 405 } 406 407 static struct packet_type mpls_packet_type __read_mostly = { 408 .type = cpu_to_be16(ETH_P_MPLS_UC), 409 .func = mpls_forward, 410 }; 411 412 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = { 413 [RTA_DST] = { .type = NLA_U32 }, 414 [RTA_OIF] = { .type = NLA_U32 }, 415 }; 416 417 struct mpls_route_config { 418 u32 rc_protocol; 419 u32 rc_ifindex; 420 u8 rc_via_table; 421 u8 rc_via_alen; 422 u8 rc_via[MAX_VIA_ALEN]; 423 u32 rc_label; 424 u8 rc_output_labels; 425 u32 rc_output_label[MAX_NEW_LABELS]; 426 u32 rc_nlflags; 427 enum mpls_payload_type rc_payload_type; 428 struct nl_info rc_nlinfo; 429 struct rtnexthop *rc_mp; 430 int rc_mp_len; 431 }; 432 433 static struct mpls_route *mpls_rt_alloc(int num_nh, u8 max_alen) 434 { 435 u8 max_alen_aligned = ALIGN(max_alen, VIA_ALEN_ALIGN); 436 struct mpls_route *rt; 437 438 rt = kzalloc(ALIGN(sizeof(*rt) + num_nh * sizeof(*rt->rt_nh), 439 VIA_ALEN_ALIGN) + 440 num_nh * max_alen_aligned, 441 GFP_KERNEL); 442 if (rt) { 443 rt->rt_nhn = num_nh; 444 rt->rt_nhn_alive = num_nh; 445 rt->rt_max_alen = max_alen_aligned; 446 } 447 448 return rt; 449 } 450 451 static void mpls_rt_free(struct mpls_route *rt) 452 { 453 if (rt) 454 kfree_rcu(rt, rt_rcu); 455 } 456 457 static void mpls_notify_route(struct net *net, unsigned index, 458 struct mpls_route *old, struct mpls_route *new, 459 const struct nl_info *info) 460 { 461 struct nlmsghdr *nlh = info ? info->nlh : NULL; 462 unsigned portid = info ? info->portid : 0; 463 int event = new ? RTM_NEWROUTE : RTM_DELROUTE; 464 struct mpls_route *rt = new ? new : old; 465 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0; 466 /* Ignore reserved labels for now */ 467 if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED)) 468 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags); 469 } 470 471 static void mpls_route_update(struct net *net, unsigned index, 472 struct mpls_route *new, 473 const struct nl_info *info) 474 { 475 struct mpls_route __rcu **platform_label; 476 struct mpls_route *rt; 477 478 ASSERT_RTNL(); 479 480 platform_label = rtnl_dereference(net->mpls.platform_label); 481 rt = rtnl_dereference(platform_label[index]); 482 rcu_assign_pointer(platform_label[index], new); 483 484 mpls_notify_route(net, index, rt, new, info); 485 486 /* If we removed a route free it now */ 487 mpls_rt_free(rt); 488 } 489 490 static unsigned find_free_label(struct net *net) 491 { 492 struct mpls_route __rcu **platform_label; 493 size_t platform_labels; 494 unsigned index; 495 496 platform_label = rtnl_dereference(net->mpls.platform_label); 497 platform_labels = net->mpls.platform_labels; 498 for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels; 499 index++) { 500 if (!rtnl_dereference(platform_label[index])) 501 return index; 502 } 503 return LABEL_NOT_SPECIFIED; 504 } 505 506 #if IS_ENABLED(CONFIG_INET) 507 static struct net_device *inet_fib_lookup_dev(struct net *net, 508 const void *addr) 509 { 510 struct net_device *dev; 511 struct rtable *rt; 512 struct in_addr daddr; 513 514 memcpy(&daddr, addr, sizeof(struct in_addr)); 515 rt = ip_route_output(net, daddr.s_addr, 0, 0, 0); 516 if (IS_ERR(rt)) 517 return ERR_CAST(rt); 518 519 dev = rt->dst.dev; 520 dev_hold(dev); 521 522 ip_rt_put(rt); 523 524 return dev; 525 } 526 #else 527 static struct net_device *inet_fib_lookup_dev(struct net *net, 528 const void *addr) 529 { 530 return ERR_PTR(-EAFNOSUPPORT); 531 } 532 #endif 533 534 #if IS_ENABLED(CONFIG_IPV6) 535 static struct net_device *inet6_fib_lookup_dev(struct net *net, 536 const void *addr) 537 { 538 struct net_device *dev; 539 struct dst_entry *dst; 540 struct flowi6 fl6; 541 int err; 542 543 if (!ipv6_stub) 544 return ERR_PTR(-EAFNOSUPPORT); 545 546 memset(&fl6, 0, sizeof(fl6)); 547 memcpy(&fl6.daddr, addr, sizeof(struct in6_addr)); 548 err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6); 549 if (err) 550 return ERR_PTR(err); 551 552 dev = dst->dev; 553 dev_hold(dev); 554 dst_release(dst); 555 556 return dev; 557 } 558 #else 559 static struct net_device *inet6_fib_lookup_dev(struct net *net, 560 const void *addr) 561 { 562 return ERR_PTR(-EAFNOSUPPORT); 563 } 564 #endif 565 566 static struct net_device *find_outdev(struct net *net, 567 struct mpls_route *rt, 568 struct mpls_nh *nh, int oif) 569 { 570 struct net_device *dev = NULL; 571 572 if (!oif) { 573 switch (nh->nh_via_table) { 574 case NEIGH_ARP_TABLE: 575 dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 576 break; 577 case NEIGH_ND_TABLE: 578 dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 579 break; 580 case NEIGH_LINK_TABLE: 581 break; 582 } 583 } else { 584 dev = dev_get_by_index(net, oif); 585 } 586 587 if (!dev) 588 return ERR_PTR(-ENODEV); 589 590 if (IS_ERR(dev)) 591 return dev; 592 593 /* The caller is holding rtnl anyways, so release the dev reference */ 594 dev_put(dev); 595 596 return dev; 597 } 598 599 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt, 600 struct mpls_nh *nh, int oif) 601 { 602 struct net_device *dev = NULL; 603 int err = -ENODEV; 604 605 dev = find_outdev(net, rt, nh, oif); 606 if (IS_ERR(dev)) { 607 err = PTR_ERR(dev); 608 dev = NULL; 609 goto errout; 610 } 611 612 /* Ensure this is a supported device */ 613 err = -EINVAL; 614 if (!mpls_dev_get(dev)) 615 goto errout; 616 617 if ((nh->nh_via_table == NEIGH_LINK_TABLE) && 618 (dev->addr_len != nh->nh_via_alen)) 619 goto errout; 620 621 RCU_INIT_POINTER(nh->nh_dev, dev); 622 623 if (!(dev->flags & IFF_UP)) { 624 nh->nh_flags |= RTNH_F_DEAD; 625 } else { 626 unsigned int flags; 627 628 flags = dev_get_flags(dev); 629 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP))) 630 nh->nh_flags |= RTNH_F_LINKDOWN; 631 } 632 633 return 0; 634 635 errout: 636 return err; 637 } 638 639 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg, 640 struct mpls_route *rt) 641 { 642 struct net *net = cfg->rc_nlinfo.nl_net; 643 struct mpls_nh *nh = rt->rt_nh; 644 int err; 645 int i; 646 647 if (!nh) 648 return -ENOMEM; 649 650 err = -EINVAL; 651 /* Ensure only a supported number of labels are present */ 652 if (cfg->rc_output_labels > MAX_NEW_LABELS) 653 goto errout; 654 655 nh->nh_labels = cfg->rc_output_labels; 656 for (i = 0; i < nh->nh_labels; i++) 657 nh->nh_label[i] = cfg->rc_output_label[i]; 658 659 nh->nh_via_table = cfg->rc_via_table; 660 memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen); 661 nh->nh_via_alen = cfg->rc_via_alen; 662 663 err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex); 664 if (err) 665 goto errout; 666 667 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 668 rt->rt_nhn_alive--; 669 670 return 0; 671 672 errout: 673 return err; 674 } 675 676 static int mpls_nh_build(struct net *net, struct mpls_route *rt, 677 struct mpls_nh *nh, int oif, struct nlattr *via, 678 struct nlattr *newdst) 679 { 680 int err = -ENOMEM; 681 682 if (!nh) 683 goto errout; 684 685 if (newdst) { 686 err = nla_get_labels(newdst, MAX_NEW_LABELS, 687 &nh->nh_labels, nh->nh_label); 688 if (err) 689 goto errout; 690 } 691 692 if (via) { 693 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table, 694 __mpls_nh_via(rt, nh)); 695 if (err) 696 goto errout; 697 } else { 698 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC; 699 } 700 701 err = mpls_nh_assign_dev(net, rt, nh, oif); 702 if (err) 703 goto errout; 704 705 return 0; 706 707 errout: 708 return err; 709 } 710 711 static int mpls_count_nexthops(struct rtnexthop *rtnh, int len, 712 u8 cfg_via_alen, u8 *max_via_alen) 713 { 714 int nhs = 0; 715 int remaining = len; 716 717 if (!rtnh) { 718 *max_via_alen = cfg_via_alen; 719 return 1; 720 } 721 722 *max_via_alen = 0; 723 724 while (rtnh_ok(rtnh, remaining)) { 725 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 726 int attrlen; 727 728 attrlen = rtnh_attrlen(rtnh); 729 nla = nla_find(attrs, attrlen, RTA_VIA); 730 if (nla && nla_len(nla) >= 731 offsetof(struct rtvia, rtvia_addr)) { 732 int via_alen = nla_len(nla) - 733 offsetof(struct rtvia, rtvia_addr); 734 735 if (via_alen <= MAX_VIA_ALEN) 736 *max_via_alen = max_t(u16, *max_via_alen, 737 via_alen); 738 } 739 740 nhs++; 741 rtnh = rtnh_next(rtnh, &remaining); 742 } 743 744 /* leftover implies invalid nexthop configuration, discard it */ 745 return remaining > 0 ? 0 : nhs; 746 } 747 748 static int mpls_nh_build_multi(struct mpls_route_config *cfg, 749 struct mpls_route *rt) 750 { 751 struct rtnexthop *rtnh = cfg->rc_mp; 752 struct nlattr *nla_via, *nla_newdst; 753 int remaining = cfg->rc_mp_len; 754 int nhs = 0; 755 int err = 0; 756 757 change_nexthops(rt) { 758 int attrlen; 759 760 nla_via = NULL; 761 nla_newdst = NULL; 762 763 err = -EINVAL; 764 if (!rtnh_ok(rtnh, remaining)) 765 goto errout; 766 767 /* neither weighted multipath nor any flags 768 * are supported 769 */ 770 if (rtnh->rtnh_hops || rtnh->rtnh_flags) 771 goto errout; 772 773 attrlen = rtnh_attrlen(rtnh); 774 if (attrlen > 0) { 775 struct nlattr *attrs = rtnh_attrs(rtnh); 776 777 nla_via = nla_find(attrs, attrlen, RTA_VIA); 778 nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST); 779 } 780 781 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh, 782 rtnh->rtnh_ifindex, nla_via, nla_newdst); 783 if (err) 784 goto errout; 785 786 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 787 rt->rt_nhn_alive--; 788 789 rtnh = rtnh_next(rtnh, &remaining); 790 nhs++; 791 } endfor_nexthops(rt); 792 793 rt->rt_nhn = nhs; 794 795 return 0; 796 797 errout: 798 return err; 799 } 800 801 static int mpls_route_add(struct mpls_route_config *cfg) 802 { 803 struct mpls_route __rcu **platform_label; 804 struct net *net = cfg->rc_nlinfo.nl_net; 805 struct mpls_route *rt, *old; 806 int err = -EINVAL; 807 u8 max_via_alen; 808 unsigned index; 809 int nhs; 810 811 index = cfg->rc_label; 812 813 /* If a label was not specified during insert pick one */ 814 if ((index == LABEL_NOT_SPECIFIED) && 815 (cfg->rc_nlflags & NLM_F_CREATE)) { 816 index = find_free_label(net); 817 } 818 819 /* Reserved labels may not be set */ 820 if (index < MPLS_LABEL_FIRST_UNRESERVED) 821 goto errout; 822 823 /* The full 20 bit range may not be supported. */ 824 if (index >= net->mpls.platform_labels) 825 goto errout; 826 827 /* Append makes no sense with mpls */ 828 err = -EOPNOTSUPP; 829 if (cfg->rc_nlflags & NLM_F_APPEND) 830 goto errout; 831 832 err = -EEXIST; 833 platform_label = rtnl_dereference(net->mpls.platform_label); 834 old = rtnl_dereference(platform_label[index]); 835 if ((cfg->rc_nlflags & NLM_F_EXCL) && old) 836 goto errout; 837 838 err = -EEXIST; 839 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old) 840 goto errout; 841 842 err = -ENOENT; 843 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old) 844 goto errout; 845 846 err = -EINVAL; 847 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len, 848 cfg->rc_via_alen, &max_via_alen); 849 if (nhs == 0) 850 goto errout; 851 852 err = -ENOMEM; 853 rt = mpls_rt_alloc(nhs, max_via_alen); 854 if (!rt) 855 goto errout; 856 857 rt->rt_protocol = cfg->rc_protocol; 858 rt->rt_payload_type = cfg->rc_payload_type; 859 860 if (cfg->rc_mp) 861 err = mpls_nh_build_multi(cfg, rt); 862 else 863 err = mpls_nh_build_from_cfg(cfg, rt); 864 if (err) 865 goto freert; 866 867 mpls_route_update(net, index, rt, &cfg->rc_nlinfo); 868 869 return 0; 870 871 freert: 872 mpls_rt_free(rt); 873 errout: 874 return err; 875 } 876 877 static int mpls_route_del(struct mpls_route_config *cfg) 878 { 879 struct net *net = cfg->rc_nlinfo.nl_net; 880 unsigned index; 881 int err = -EINVAL; 882 883 index = cfg->rc_label; 884 885 /* Reserved labels may not be removed */ 886 if (index < MPLS_LABEL_FIRST_UNRESERVED) 887 goto errout; 888 889 /* The full 20 bit range may not be supported */ 890 if (index >= net->mpls.platform_labels) 891 goto errout; 892 893 mpls_route_update(net, index, NULL, &cfg->rc_nlinfo); 894 895 err = 0; 896 errout: 897 return err; 898 } 899 900 static void mpls_get_stats(struct mpls_dev *mdev, 901 struct mpls_link_stats *stats) 902 { 903 struct mpls_pcpu_stats *p; 904 int i; 905 906 memset(stats, 0, sizeof(*stats)); 907 908 for_each_possible_cpu(i) { 909 struct mpls_link_stats local; 910 unsigned int start; 911 912 p = per_cpu_ptr(mdev->stats, i); 913 do { 914 start = u64_stats_fetch_begin(&p->syncp); 915 local = p->stats; 916 } while (u64_stats_fetch_retry(&p->syncp, start)); 917 918 stats->rx_packets += local.rx_packets; 919 stats->rx_bytes += local.rx_bytes; 920 stats->tx_packets += local.tx_packets; 921 stats->tx_bytes += local.tx_bytes; 922 stats->rx_errors += local.rx_errors; 923 stats->tx_errors += local.tx_errors; 924 stats->rx_dropped += local.rx_dropped; 925 stats->tx_dropped += local.tx_dropped; 926 stats->rx_noroute += local.rx_noroute; 927 } 928 } 929 930 static int mpls_fill_stats_af(struct sk_buff *skb, 931 const struct net_device *dev) 932 { 933 struct mpls_link_stats *stats; 934 struct mpls_dev *mdev; 935 struct nlattr *nla; 936 937 mdev = mpls_dev_get(dev); 938 if (!mdev) 939 return -ENODATA; 940 941 nla = nla_reserve_64bit(skb, MPLS_STATS_LINK, 942 sizeof(struct mpls_link_stats), 943 MPLS_STATS_UNSPEC); 944 if (!nla) 945 return -EMSGSIZE; 946 947 stats = nla_data(nla); 948 mpls_get_stats(mdev, stats); 949 950 return 0; 951 } 952 953 static size_t mpls_get_stats_af_size(const struct net_device *dev) 954 { 955 struct mpls_dev *mdev; 956 957 mdev = mpls_dev_get(dev); 958 if (!mdev) 959 return 0; 960 961 return nla_total_size_64bit(sizeof(struct mpls_link_stats)); 962 } 963 964 static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev, 965 u32 portid, u32 seq, int event, 966 unsigned int flags, int type) 967 { 968 struct nlmsghdr *nlh; 969 struct netconfmsg *ncm; 970 bool all = false; 971 972 nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg), 973 flags); 974 if (!nlh) 975 return -EMSGSIZE; 976 977 if (type == NETCONFA_ALL) 978 all = true; 979 980 ncm = nlmsg_data(nlh); 981 ncm->ncm_family = AF_MPLS; 982 983 if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0) 984 goto nla_put_failure; 985 986 if ((all || type == NETCONFA_INPUT) && 987 nla_put_s32(skb, NETCONFA_INPUT, 988 mdev->input_enabled) < 0) 989 goto nla_put_failure; 990 991 nlmsg_end(skb, nlh); 992 return 0; 993 994 nla_put_failure: 995 nlmsg_cancel(skb, nlh); 996 return -EMSGSIZE; 997 } 998 999 static int mpls_netconf_msgsize_devconf(int type) 1000 { 1001 int size = NLMSG_ALIGN(sizeof(struct netconfmsg)) 1002 + nla_total_size(4); /* NETCONFA_IFINDEX */ 1003 bool all = false; 1004 1005 if (type == NETCONFA_ALL) 1006 all = true; 1007 1008 if (all || type == NETCONFA_INPUT) 1009 size += nla_total_size(4); 1010 1011 return size; 1012 } 1013 1014 static void mpls_netconf_notify_devconf(struct net *net, int type, 1015 struct mpls_dev *mdev) 1016 { 1017 struct sk_buff *skb; 1018 int err = -ENOBUFS; 1019 1020 skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL); 1021 if (!skb) 1022 goto errout; 1023 1024 err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, RTM_NEWNETCONF, 1025 0, type); 1026 if (err < 0) { 1027 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */ 1028 WARN_ON(err == -EMSGSIZE); 1029 kfree_skb(skb); 1030 goto errout; 1031 } 1032 1033 rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL); 1034 return; 1035 errout: 1036 if (err < 0) 1037 rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err); 1038 } 1039 1040 static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = { 1041 [NETCONFA_IFINDEX] = { .len = sizeof(int) }, 1042 }; 1043 1044 static int mpls_netconf_get_devconf(struct sk_buff *in_skb, 1045 struct nlmsghdr *nlh) 1046 { 1047 struct net *net = sock_net(in_skb->sk); 1048 struct nlattr *tb[NETCONFA_MAX + 1]; 1049 struct netconfmsg *ncm; 1050 struct net_device *dev; 1051 struct mpls_dev *mdev; 1052 struct sk_buff *skb; 1053 int ifindex; 1054 int err; 1055 1056 err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX, 1057 devconf_mpls_policy); 1058 if (err < 0) 1059 goto errout; 1060 1061 err = -EINVAL; 1062 if (!tb[NETCONFA_IFINDEX]) 1063 goto errout; 1064 1065 ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]); 1066 dev = __dev_get_by_index(net, ifindex); 1067 if (!dev) 1068 goto errout; 1069 1070 mdev = mpls_dev_get(dev); 1071 if (!mdev) 1072 goto errout; 1073 1074 err = -ENOBUFS; 1075 skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL); 1076 if (!skb) 1077 goto errout; 1078 1079 err = mpls_netconf_fill_devconf(skb, mdev, 1080 NETLINK_CB(in_skb).portid, 1081 nlh->nlmsg_seq, RTM_NEWNETCONF, 0, 1082 NETCONFA_ALL); 1083 if (err < 0) { 1084 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */ 1085 WARN_ON(err == -EMSGSIZE); 1086 kfree_skb(skb); 1087 goto errout; 1088 } 1089 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 1090 errout: 1091 return err; 1092 } 1093 1094 static int mpls_netconf_dump_devconf(struct sk_buff *skb, 1095 struct netlink_callback *cb) 1096 { 1097 struct net *net = sock_net(skb->sk); 1098 struct hlist_head *head; 1099 struct net_device *dev; 1100 struct mpls_dev *mdev; 1101 int idx, s_idx; 1102 int h, s_h; 1103 1104 s_h = cb->args[0]; 1105 s_idx = idx = cb->args[1]; 1106 1107 for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { 1108 idx = 0; 1109 head = &net->dev_index_head[h]; 1110 rcu_read_lock(); 1111 cb->seq = net->dev_base_seq; 1112 hlist_for_each_entry_rcu(dev, head, index_hlist) { 1113 if (idx < s_idx) 1114 goto cont; 1115 mdev = mpls_dev_get(dev); 1116 if (!mdev) 1117 goto cont; 1118 if (mpls_netconf_fill_devconf(skb, mdev, 1119 NETLINK_CB(cb->skb).portid, 1120 cb->nlh->nlmsg_seq, 1121 RTM_NEWNETCONF, 1122 NLM_F_MULTI, 1123 NETCONFA_ALL) < 0) { 1124 rcu_read_unlock(); 1125 goto done; 1126 } 1127 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 1128 cont: 1129 idx++; 1130 } 1131 rcu_read_unlock(); 1132 } 1133 done: 1134 cb->args[0] = h; 1135 cb->args[1] = idx; 1136 1137 return skb->len; 1138 } 1139 1140 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \ 1141 (&((struct mpls_dev *)0)->field) 1142 1143 static int mpls_conf_proc(struct ctl_table *ctl, int write, 1144 void __user *buffer, 1145 size_t *lenp, loff_t *ppos) 1146 { 1147 int oval = *(int *)ctl->data; 1148 int ret = proc_dointvec(ctl, write, buffer, lenp, ppos); 1149 1150 if (write) { 1151 struct mpls_dev *mdev = ctl->extra1; 1152 int i = (int *)ctl->data - (int *)mdev; 1153 struct net *net = ctl->extra2; 1154 int val = *(int *)ctl->data; 1155 1156 if (i == offsetof(struct mpls_dev, input_enabled) && 1157 val != oval) { 1158 mpls_netconf_notify_devconf(net, 1159 NETCONFA_INPUT, 1160 mdev); 1161 } 1162 } 1163 1164 return ret; 1165 } 1166 1167 static const struct ctl_table mpls_dev_table[] = { 1168 { 1169 .procname = "input", 1170 .maxlen = sizeof(int), 1171 .mode = 0644, 1172 .proc_handler = mpls_conf_proc, 1173 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled), 1174 }, 1175 { } 1176 }; 1177 1178 static int mpls_dev_sysctl_register(struct net_device *dev, 1179 struct mpls_dev *mdev) 1180 { 1181 char path[sizeof("net/mpls/conf/") + IFNAMSIZ]; 1182 struct net *net = dev_net(dev); 1183 struct ctl_table *table; 1184 int i; 1185 1186 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL); 1187 if (!table) 1188 goto out; 1189 1190 /* Table data contains only offsets relative to the base of 1191 * the mdev at this point, so make them absolute. 1192 */ 1193 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) { 1194 table[i].data = (char *)mdev + (uintptr_t)table[i].data; 1195 table[i].extra1 = mdev; 1196 table[i].extra2 = net; 1197 } 1198 1199 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name); 1200 1201 mdev->sysctl = register_net_sysctl(dev_net(dev), path, table); 1202 if (!mdev->sysctl) 1203 goto free; 1204 1205 return 0; 1206 1207 free: 1208 kfree(table); 1209 out: 1210 return -ENOBUFS; 1211 } 1212 1213 static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev) 1214 { 1215 struct ctl_table *table; 1216 1217 table = mdev->sysctl->ctl_table_arg; 1218 unregister_net_sysctl_table(mdev->sysctl); 1219 kfree(table); 1220 } 1221 1222 static struct mpls_dev *mpls_add_dev(struct net_device *dev) 1223 { 1224 struct mpls_dev *mdev; 1225 int err = -ENOMEM; 1226 int i; 1227 1228 ASSERT_RTNL(); 1229 1230 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); 1231 if (!mdev) 1232 return ERR_PTR(err); 1233 1234 mdev->stats = alloc_percpu(struct mpls_pcpu_stats); 1235 if (!mdev->stats) 1236 goto free; 1237 1238 for_each_possible_cpu(i) { 1239 struct mpls_pcpu_stats *mpls_stats; 1240 1241 mpls_stats = per_cpu_ptr(mdev->stats, i); 1242 u64_stats_init(&mpls_stats->syncp); 1243 } 1244 1245 err = mpls_dev_sysctl_register(dev, mdev); 1246 if (err) 1247 goto free; 1248 1249 mdev->dev = dev; 1250 rcu_assign_pointer(dev->mpls_ptr, mdev); 1251 1252 return mdev; 1253 1254 free: 1255 free_percpu(mdev->stats); 1256 kfree(mdev); 1257 return ERR_PTR(err); 1258 } 1259 1260 static void mpls_dev_destroy_rcu(struct rcu_head *head) 1261 { 1262 struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu); 1263 1264 free_percpu(mdev->stats); 1265 kfree(mdev); 1266 } 1267 1268 static void mpls_ifdown(struct net_device *dev, int event) 1269 { 1270 struct mpls_route __rcu **platform_label; 1271 struct net *net = dev_net(dev); 1272 unsigned int nh_flags = RTNH_F_DEAD | RTNH_F_LINKDOWN; 1273 unsigned int alive; 1274 unsigned index; 1275 1276 platform_label = rtnl_dereference(net->mpls.platform_label); 1277 for (index = 0; index < net->mpls.platform_labels; index++) { 1278 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1279 1280 if (!rt) 1281 continue; 1282 1283 alive = 0; 1284 change_nexthops(rt) { 1285 if (rtnl_dereference(nh->nh_dev) != dev) 1286 goto next; 1287 1288 switch (event) { 1289 case NETDEV_DOWN: 1290 case NETDEV_UNREGISTER: 1291 nh->nh_flags |= RTNH_F_DEAD; 1292 /* fall through */ 1293 case NETDEV_CHANGE: 1294 nh->nh_flags |= RTNH_F_LINKDOWN; 1295 break; 1296 } 1297 if (event == NETDEV_UNREGISTER) 1298 RCU_INIT_POINTER(nh->nh_dev, NULL); 1299 next: 1300 if (!(nh->nh_flags & nh_flags)) 1301 alive++; 1302 } endfor_nexthops(rt); 1303 1304 WRITE_ONCE(rt->rt_nhn_alive, alive); 1305 } 1306 } 1307 1308 static void mpls_ifup(struct net_device *dev, unsigned int nh_flags) 1309 { 1310 struct mpls_route __rcu **platform_label; 1311 struct net *net = dev_net(dev); 1312 unsigned index; 1313 int alive; 1314 1315 platform_label = rtnl_dereference(net->mpls.platform_label); 1316 for (index = 0; index < net->mpls.platform_labels; index++) { 1317 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1318 1319 if (!rt) 1320 continue; 1321 1322 alive = 0; 1323 change_nexthops(rt) { 1324 struct net_device *nh_dev = 1325 rtnl_dereference(nh->nh_dev); 1326 1327 if (!(nh->nh_flags & nh_flags)) { 1328 alive++; 1329 continue; 1330 } 1331 if (nh_dev != dev) 1332 continue; 1333 alive++; 1334 nh->nh_flags &= ~nh_flags; 1335 } endfor_nexthops(rt); 1336 1337 ACCESS_ONCE(rt->rt_nhn_alive) = alive; 1338 } 1339 } 1340 1341 static int mpls_dev_notify(struct notifier_block *this, unsigned long event, 1342 void *ptr) 1343 { 1344 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1345 struct mpls_dev *mdev; 1346 unsigned int flags; 1347 1348 if (event == NETDEV_REGISTER) { 1349 /* For now just support Ethernet, IPGRE, SIT and IPIP devices */ 1350 if (dev->type == ARPHRD_ETHER || 1351 dev->type == ARPHRD_LOOPBACK || 1352 dev->type == ARPHRD_IPGRE || 1353 dev->type == ARPHRD_SIT || 1354 dev->type == ARPHRD_TUNNEL) { 1355 mdev = mpls_add_dev(dev); 1356 if (IS_ERR(mdev)) 1357 return notifier_from_errno(PTR_ERR(mdev)); 1358 } 1359 return NOTIFY_OK; 1360 } 1361 1362 mdev = mpls_dev_get(dev); 1363 if (!mdev) 1364 return NOTIFY_OK; 1365 1366 switch (event) { 1367 case NETDEV_DOWN: 1368 mpls_ifdown(dev, event); 1369 break; 1370 case NETDEV_UP: 1371 flags = dev_get_flags(dev); 1372 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1373 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1374 else 1375 mpls_ifup(dev, RTNH_F_DEAD); 1376 break; 1377 case NETDEV_CHANGE: 1378 flags = dev_get_flags(dev); 1379 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1380 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1381 else 1382 mpls_ifdown(dev, event); 1383 break; 1384 case NETDEV_UNREGISTER: 1385 mpls_ifdown(dev, event); 1386 mdev = mpls_dev_get(dev); 1387 if (mdev) { 1388 mpls_dev_sysctl_unregister(mdev); 1389 RCU_INIT_POINTER(dev->mpls_ptr, NULL); 1390 call_rcu(&mdev->rcu, mpls_dev_destroy_rcu); 1391 } 1392 break; 1393 case NETDEV_CHANGENAME: 1394 mdev = mpls_dev_get(dev); 1395 if (mdev) { 1396 int err; 1397 1398 mpls_dev_sysctl_unregister(mdev); 1399 err = mpls_dev_sysctl_register(dev, mdev); 1400 if (err) 1401 return notifier_from_errno(err); 1402 } 1403 break; 1404 } 1405 return NOTIFY_OK; 1406 } 1407 1408 static struct notifier_block mpls_dev_notifier = { 1409 .notifier_call = mpls_dev_notify, 1410 }; 1411 1412 static int nla_put_via(struct sk_buff *skb, 1413 u8 table, const void *addr, int alen) 1414 { 1415 static const int table_to_family[NEIGH_NR_TABLES + 1] = { 1416 AF_INET, AF_INET6, AF_DECnet, AF_PACKET, 1417 }; 1418 struct nlattr *nla; 1419 struct rtvia *via; 1420 int family = AF_UNSPEC; 1421 1422 nla = nla_reserve(skb, RTA_VIA, alen + 2); 1423 if (!nla) 1424 return -EMSGSIZE; 1425 1426 if (table <= NEIGH_NR_TABLES) 1427 family = table_to_family[table]; 1428 1429 via = nla_data(nla); 1430 via->rtvia_family = family; 1431 memcpy(via->rtvia_addr, addr, alen); 1432 return 0; 1433 } 1434 1435 int nla_put_labels(struct sk_buff *skb, int attrtype, 1436 u8 labels, const u32 label[]) 1437 { 1438 struct nlattr *nla; 1439 struct mpls_shim_hdr *nla_label; 1440 bool bos; 1441 int i; 1442 nla = nla_reserve(skb, attrtype, labels*4); 1443 if (!nla) 1444 return -EMSGSIZE; 1445 1446 nla_label = nla_data(nla); 1447 bos = true; 1448 for (i = labels - 1; i >= 0; i--) { 1449 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos); 1450 bos = false; 1451 } 1452 1453 return 0; 1454 } 1455 EXPORT_SYMBOL_GPL(nla_put_labels); 1456 1457 int nla_get_labels(const struct nlattr *nla, 1458 u32 max_labels, u8 *labels, u32 label[]) 1459 { 1460 unsigned len = nla_len(nla); 1461 unsigned nla_labels; 1462 struct mpls_shim_hdr *nla_label; 1463 bool bos; 1464 int i; 1465 1466 /* len needs to be an even multiple of 4 (the label size) */ 1467 if (len & 3) 1468 return -EINVAL; 1469 1470 /* Limit the number of new labels allowed */ 1471 nla_labels = len/4; 1472 if (nla_labels > max_labels) 1473 return -EINVAL; 1474 1475 nla_label = nla_data(nla); 1476 bos = true; 1477 for (i = nla_labels - 1; i >= 0; i--, bos = false) { 1478 struct mpls_entry_decoded dec; 1479 dec = mpls_entry_decode(nla_label + i); 1480 1481 /* Ensure the bottom of stack flag is properly set 1482 * and ttl and tc are both clear. 1483 */ 1484 if ((dec.bos != bos) || dec.ttl || dec.tc) 1485 return -EINVAL; 1486 1487 switch (dec.label) { 1488 case MPLS_LABEL_IMPLNULL: 1489 /* RFC3032: This is a label that an LSR may 1490 * assign and distribute, but which never 1491 * actually appears in the encapsulation. 1492 */ 1493 return -EINVAL; 1494 } 1495 1496 label[i] = dec.label; 1497 } 1498 *labels = nla_labels; 1499 return 0; 1500 } 1501 EXPORT_SYMBOL_GPL(nla_get_labels); 1502 1503 int nla_get_via(const struct nlattr *nla, u8 *via_alen, 1504 u8 *via_table, u8 via_addr[]) 1505 { 1506 struct rtvia *via = nla_data(nla); 1507 int err = -EINVAL; 1508 int alen; 1509 1510 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) 1511 goto errout; 1512 alen = nla_len(nla) - 1513 offsetof(struct rtvia, rtvia_addr); 1514 if (alen > MAX_VIA_ALEN) 1515 goto errout; 1516 1517 /* Validate the address family */ 1518 switch (via->rtvia_family) { 1519 case AF_PACKET: 1520 *via_table = NEIGH_LINK_TABLE; 1521 break; 1522 case AF_INET: 1523 *via_table = NEIGH_ARP_TABLE; 1524 if (alen != 4) 1525 goto errout; 1526 break; 1527 case AF_INET6: 1528 *via_table = NEIGH_ND_TABLE; 1529 if (alen != 16) 1530 goto errout; 1531 break; 1532 default: 1533 /* Unsupported address family */ 1534 goto errout; 1535 } 1536 1537 memcpy(via_addr, via->rtvia_addr, alen); 1538 *via_alen = alen; 1539 err = 0; 1540 1541 errout: 1542 return err; 1543 } 1544 1545 static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh, 1546 struct mpls_route_config *cfg) 1547 { 1548 struct rtmsg *rtm; 1549 struct nlattr *tb[RTA_MAX+1]; 1550 int index; 1551 int err; 1552 1553 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy); 1554 if (err < 0) 1555 goto errout; 1556 1557 err = -EINVAL; 1558 rtm = nlmsg_data(nlh); 1559 memset(cfg, 0, sizeof(*cfg)); 1560 1561 if (rtm->rtm_family != AF_MPLS) 1562 goto errout; 1563 if (rtm->rtm_dst_len != 20) 1564 goto errout; 1565 if (rtm->rtm_src_len != 0) 1566 goto errout; 1567 if (rtm->rtm_tos != 0) 1568 goto errout; 1569 if (rtm->rtm_table != RT_TABLE_MAIN) 1570 goto errout; 1571 /* Any value is acceptable for rtm_protocol */ 1572 1573 /* As mpls uses destination specific addresses 1574 * (or source specific address in the case of multicast) 1575 * all addresses have universal scope. 1576 */ 1577 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) 1578 goto errout; 1579 if (rtm->rtm_type != RTN_UNICAST) 1580 goto errout; 1581 if (rtm->rtm_flags != 0) 1582 goto errout; 1583 1584 cfg->rc_label = LABEL_NOT_SPECIFIED; 1585 cfg->rc_protocol = rtm->rtm_protocol; 1586 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC; 1587 cfg->rc_nlflags = nlh->nlmsg_flags; 1588 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid; 1589 cfg->rc_nlinfo.nlh = nlh; 1590 cfg->rc_nlinfo.nl_net = sock_net(skb->sk); 1591 1592 for (index = 0; index <= RTA_MAX; index++) { 1593 struct nlattr *nla = tb[index]; 1594 if (!nla) 1595 continue; 1596 1597 switch (index) { 1598 case RTA_OIF: 1599 cfg->rc_ifindex = nla_get_u32(nla); 1600 break; 1601 case RTA_NEWDST: 1602 if (nla_get_labels(nla, MAX_NEW_LABELS, 1603 &cfg->rc_output_labels, 1604 cfg->rc_output_label)) 1605 goto errout; 1606 break; 1607 case RTA_DST: 1608 { 1609 u8 label_count; 1610 if (nla_get_labels(nla, 1, &label_count, 1611 &cfg->rc_label)) 1612 goto errout; 1613 1614 /* Reserved labels may not be set */ 1615 if (cfg->rc_label < MPLS_LABEL_FIRST_UNRESERVED) 1616 goto errout; 1617 1618 break; 1619 } 1620 case RTA_VIA: 1621 { 1622 if (nla_get_via(nla, &cfg->rc_via_alen, 1623 &cfg->rc_via_table, cfg->rc_via)) 1624 goto errout; 1625 break; 1626 } 1627 case RTA_MULTIPATH: 1628 { 1629 cfg->rc_mp = nla_data(nla); 1630 cfg->rc_mp_len = nla_len(nla); 1631 break; 1632 } 1633 default: 1634 /* Unsupported attribute */ 1635 goto errout; 1636 } 1637 } 1638 1639 err = 0; 1640 errout: 1641 return err; 1642 } 1643 1644 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh) 1645 { 1646 struct mpls_route_config cfg; 1647 int err; 1648 1649 err = rtm_to_route_config(skb, nlh, &cfg); 1650 if (err < 0) 1651 return err; 1652 1653 return mpls_route_del(&cfg); 1654 } 1655 1656 1657 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh) 1658 { 1659 struct mpls_route_config cfg; 1660 int err; 1661 1662 err = rtm_to_route_config(skb, nlh, &cfg); 1663 if (err < 0) 1664 return err; 1665 1666 return mpls_route_add(&cfg); 1667 } 1668 1669 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, 1670 u32 label, struct mpls_route *rt, int flags) 1671 { 1672 struct net_device *dev; 1673 struct nlmsghdr *nlh; 1674 struct rtmsg *rtm; 1675 1676 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); 1677 if (nlh == NULL) 1678 return -EMSGSIZE; 1679 1680 rtm = nlmsg_data(nlh); 1681 rtm->rtm_family = AF_MPLS; 1682 rtm->rtm_dst_len = 20; 1683 rtm->rtm_src_len = 0; 1684 rtm->rtm_tos = 0; 1685 rtm->rtm_table = RT_TABLE_MAIN; 1686 rtm->rtm_protocol = rt->rt_protocol; 1687 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 1688 rtm->rtm_type = RTN_UNICAST; 1689 rtm->rtm_flags = 0; 1690 1691 if (nla_put_labels(skb, RTA_DST, 1, &label)) 1692 goto nla_put_failure; 1693 if (rt->rt_nhn == 1) { 1694 const struct mpls_nh *nh = rt->rt_nh; 1695 1696 if (nh->nh_labels && 1697 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels, 1698 nh->nh_label)) 1699 goto nla_put_failure; 1700 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1701 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh), 1702 nh->nh_via_alen)) 1703 goto nla_put_failure; 1704 dev = rtnl_dereference(nh->nh_dev); 1705 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) 1706 goto nla_put_failure; 1707 if (nh->nh_flags & RTNH_F_LINKDOWN) 1708 rtm->rtm_flags |= RTNH_F_LINKDOWN; 1709 if (nh->nh_flags & RTNH_F_DEAD) 1710 rtm->rtm_flags |= RTNH_F_DEAD; 1711 } else { 1712 struct rtnexthop *rtnh; 1713 struct nlattr *mp; 1714 int dead = 0; 1715 int linkdown = 0; 1716 1717 mp = nla_nest_start(skb, RTA_MULTIPATH); 1718 if (!mp) 1719 goto nla_put_failure; 1720 1721 for_nexthops(rt) { 1722 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); 1723 if (!rtnh) 1724 goto nla_put_failure; 1725 1726 dev = rtnl_dereference(nh->nh_dev); 1727 if (dev) 1728 rtnh->rtnh_ifindex = dev->ifindex; 1729 if (nh->nh_flags & RTNH_F_LINKDOWN) { 1730 rtnh->rtnh_flags |= RTNH_F_LINKDOWN; 1731 linkdown++; 1732 } 1733 if (nh->nh_flags & RTNH_F_DEAD) { 1734 rtnh->rtnh_flags |= RTNH_F_DEAD; 1735 dead++; 1736 } 1737 1738 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST, 1739 nh->nh_labels, 1740 nh->nh_label)) 1741 goto nla_put_failure; 1742 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1743 nla_put_via(skb, nh->nh_via_table, 1744 mpls_nh_via(rt, nh), 1745 nh->nh_via_alen)) 1746 goto nla_put_failure; 1747 1748 /* length of rtnetlink header + attributes */ 1749 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; 1750 } endfor_nexthops(rt); 1751 1752 if (linkdown == rt->rt_nhn) 1753 rtm->rtm_flags |= RTNH_F_LINKDOWN; 1754 if (dead == rt->rt_nhn) 1755 rtm->rtm_flags |= RTNH_F_DEAD; 1756 1757 nla_nest_end(skb, mp); 1758 } 1759 1760 nlmsg_end(skb, nlh); 1761 return 0; 1762 1763 nla_put_failure: 1764 nlmsg_cancel(skb, nlh); 1765 return -EMSGSIZE; 1766 } 1767 1768 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) 1769 { 1770 struct net *net = sock_net(skb->sk); 1771 struct mpls_route __rcu **platform_label; 1772 size_t platform_labels; 1773 unsigned int index; 1774 1775 ASSERT_RTNL(); 1776 1777 index = cb->args[0]; 1778 if (index < MPLS_LABEL_FIRST_UNRESERVED) 1779 index = MPLS_LABEL_FIRST_UNRESERVED; 1780 1781 platform_label = rtnl_dereference(net->mpls.platform_label); 1782 platform_labels = net->mpls.platform_labels; 1783 for (; index < platform_labels; index++) { 1784 struct mpls_route *rt; 1785 rt = rtnl_dereference(platform_label[index]); 1786 if (!rt) 1787 continue; 1788 1789 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid, 1790 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 1791 index, rt, NLM_F_MULTI) < 0) 1792 break; 1793 } 1794 cb->args[0] = index; 1795 1796 return skb->len; 1797 } 1798 1799 static inline size_t lfib_nlmsg_size(struct mpls_route *rt) 1800 { 1801 size_t payload = 1802 NLMSG_ALIGN(sizeof(struct rtmsg)) 1803 + nla_total_size(4); /* RTA_DST */ 1804 1805 if (rt->rt_nhn == 1) { 1806 struct mpls_nh *nh = rt->rt_nh; 1807 1808 if (nh->nh_dev) 1809 payload += nla_total_size(4); /* RTA_OIF */ 1810 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */ 1811 payload += nla_total_size(2 + nh->nh_via_alen); 1812 if (nh->nh_labels) /* RTA_NEWDST */ 1813 payload += nla_total_size(nh->nh_labels * 4); 1814 } else { 1815 /* each nexthop is packed in an attribute */ 1816 size_t nhsize = 0; 1817 1818 for_nexthops(rt) { 1819 nhsize += nla_total_size(sizeof(struct rtnexthop)); 1820 /* RTA_VIA */ 1821 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) 1822 nhsize += nla_total_size(2 + nh->nh_via_alen); 1823 if (nh->nh_labels) 1824 nhsize += nla_total_size(nh->nh_labels * 4); 1825 } endfor_nexthops(rt); 1826 /* nested attribute */ 1827 payload += nla_total_size(nhsize); 1828 } 1829 1830 return payload; 1831 } 1832 1833 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 1834 struct nlmsghdr *nlh, struct net *net, u32 portid, 1835 unsigned int nlm_flags) 1836 { 1837 struct sk_buff *skb; 1838 u32 seq = nlh ? nlh->nlmsg_seq : 0; 1839 int err = -ENOBUFS; 1840 1841 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL); 1842 if (skb == NULL) 1843 goto errout; 1844 1845 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags); 1846 if (err < 0) { 1847 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */ 1848 WARN_ON(err == -EMSGSIZE); 1849 kfree_skb(skb); 1850 goto errout; 1851 } 1852 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL); 1853 1854 return; 1855 errout: 1856 if (err < 0) 1857 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err); 1858 } 1859 1860 static int resize_platform_label_table(struct net *net, size_t limit) 1861 { 1862 size_t size = sizeof(struct mpls_route *) * limit; 1863 size_t old_limit; 1864 size_t cp_size; 1865 struct mpls_route __rcu **labels = NULL, **old; 1866 struct mpls_route *rt0 = NULL, *rt2 = NULL; 1867 unsigned index; 1868 1869 if (size) { 1870 labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY); 1871 if (!labels) 1872 labels = vzalloc(size); 1873 1874 if (!labels) 1875 goto nolabels; 1876 } 1877 1878 /* In case the predefined labels need to be populated */ 1879 if (limit > MPLS_LABEL_IPV4NULL) { 1880 struct net_device *lo = net->loopback_dev; 1881 rt0 = mpls_rt_alloc(1, lo->addr_len); 1882 if (!rt0) 1883 goto nort0; 1884 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo); 1885 rt0->rt_protocol = RTPROT_KERNEL; 1886 rt0->rt_payload_type = MPT_IPV4; 1887 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 1888 rt0->rt_nh->nh_via_alen = lo->addr_len; 1889 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr, 1890 lo->addr_len); 1891 } 1892 if (limit > MPLS_LABEL_IPV6NULL) { 1893 struct net_device *lo = net->loopback_dev; 1894 rt2 = mpls_rt_alloc(1, lo->addr_len); 1895 if (!rt2) 1896 goto nort2; 1897 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo); 1898 rt2->rt_protocol = RTPROT_KERNEL; 1899 rt2->rt_payload_type = MPT_IPV6; 1900 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 1901 rt2->rt_nh->nh_via_alen = lo->addr_len; 1902 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr, 1903 lo->addr_len); 1904 } 1905 1906 rtnl_lock(); 1907 /* Remember the original table */ 1908 old = rtnl_dereference(net->mpls.platform_label); 1909 old_limit = net->mpls.platform_labels; 1910 1911 /* Free any labels beyond the new table */ 1912 for (index = limit; index < old_limit; index++) 1913 mpls_route_update(net, index, NULL, NULL); 1914 1915 /* Copy over the old labels */ 1916 cp_size = size; 1917 if (old_limit < limit) 1918 cp_size = old_limit * sizeof(struct mpls_route *); 1919 1920 memcpy(labels, old, cp_size); 1921 1922 /* If needed set the predefined labels */ 1923 if ((old_limit <= MPLS_LABEL_IPV6NULL) && 1924 (limit > MPLS_LABEL_IPV6NULL)) { 1925 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2); 1926 rt2 = NULL; 1927 } 1928 1929 if ((old_limit <= MPLS_LABEL_IPV4NULL) && 1930 (limit > MPLS_LABEL_IPV4NULL)) { 1931 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0); 1932 rt0 = NULL; 1933 } 1934 1935 /* Update the global pointers */ 1936 net->mpls.platform_labels = limit; 1937 rcu_assign_pointer(net->mpls.platform_label, labels); 1938 1939 rtnl_unlock(); 1940 1941 mpls_rt_free(rt2); 1942 mpls_rt_free(rt0); 1943 1944 if (old) { 1945 synchronize_rcu(); 1946 kvfree(old); 1947 } 1948 return 0; 1949 1950 nort2: 1951 mpls_rt_free(rt0); 1952 nort0: 1953 kvfree(labels); 1954 nolabels: 1955 return -ENOMEM; 1956 } 1957 1958 static int mpls_platform_labels(struct ctl_table *table, int write, 1959 void __user *buffer, size_t *lenp, loff_t *ppos) 1960 { 1961 struct net *net = table->data; 1962 int platform_labels = net->mpls.platform_labels; 1963 int ret; 1964 struct ctl_table tmp = { 1965 .procname = table->procname, 1966 .data = &platform_labels, 1967 .maxlen = sizeof(int), 1968 .mode = table->mode, 1969 .extra1 = &zero, 1970 .extra2 = &label_limit, 1971 }; 1972 1973 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 1974 1975 if (write && ret == 0) 1976 ret = resize_platform_label_table(net, platform_labels); 1977 1978 return ret; 1979 } 1980 1981 static const struct ctl_table mpls_table[] = { 1982 { 1983 .procname = "platform_labels", 1984 .data = NULL, 1985 .maxlen = sizeof(int), 1986 .mode = 0644, 1987 .proc_handler = mpls_platform_labels, 1988 }, 1989 { } 1990 }; 1991 1992 static int mpls_net_init(struct net *net) 1993 { 1994 struct ctl_table *table; 1995 1996 net->mpls.platform_labels = 0; 1997 net->mpls.platform_label = NULL; 1998 1999 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL); 2000 if (table == NULL) 2001 return -ENOMEM; 2002 2003 table[0].data = net; 2004 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table); 2005 if (net->mpls.ctl == NULL) { 2006 kfree(table); 2007 return -ENOMEM; 2008 } 2009 2010 return 0; 2011 } 2012 2013 static void mpls_net_exit(struct net *net) 2014 { 2015 struct mpls_route __rcu **platform_label; 2016 size_t platform_labels; 2017 struct ctl_table *table; 2018 unsigned int index; 2019 2020 table = net->mpls.ctl->ctl_table_arg; 2021 unregister_net_sysctl_table(net->mpls.ctl); 2022 kfree(table); 2023 2024 /* An rcu grace period has passed since there was a device in 2025 * the network namespace (and thus the last in flight packet) 2026 * left this network namespace. This is because 2027 * unregister_netdevice_many and netdev_run_todo has completed 2028 * for each network device that was in this network namespace. 2029 * 2030 * As such no additional rcu synchronization is necessary when 2031 * freeing the platform_label table. 2032 */ 2033 rtnl_lock(); 2034 platform_label = rtnl_dereference(net->mpls.platform_label); 2035 platform_labels = net->mpls.platform_labels; 2036 for (index = 0; index < platform_labels; index++) { 2037 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 2038 RCU_INIT_POINTER(platform_label[index], NULL); 2039 mpls_notify_route(net, index, rt, NULL, NULL); 2040 mpls_rt_free(rt); 2041 } 2042 rtnl_unlock(); 2043 2044 kvfree(platform_label); 2045 } 2046 2047 static struct pernet_operations mpls_net_ops = { 2048 .init = mpls_net_init, 2049 .exit = mpls_net_exit, 2050 }; 2051 2052 static struct rtnl_af_ops mpls_af_ops __read_mostly = { 2053 .family = AF_MPLS, 2054 .fill_stats_af = mpls_fill_stats_af, 2055 .get_stats_af_size = mpls_get_stats_af_size, 2056 }; 2057 2058 static int __init mpls_init(void) 2059 { 2060 int err; 2061 2062 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4); 2063 2064 err = register_pernet_subsys(&mpls_net_ops); 2065 if (err) 2066 goto out; 2067 2068 err = register_netdevice_notifier(&mpls_dev_notifier); 2069 if (err) 2070 goto out_unregister_pernet; 2071 2072 dev_add_pack(&mpls_packet_type); 2073 2074 rtnl_af_register(&mpls_af_ops); 2075 2076 rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, NULL); 2077 rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, NULL); 2078 rtnl_register(PF_MPLS, RTM_GETROUTE, NULL, mpls_dump_routes, NULL); 2079 rtnl_register(PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf, 2080 mpls_netconf_dump_devconf, NULL); 2081 err = 0; 2082 out: 2083 return err; 2084 2085 out_unregister_pernet: 2086 unregister_pernet_subsys(&mpls_net_ops); 2087 goto out; 2088 } 2089 module_init(mpls_init); 2090 2091 static void __exit mpls_exit(void) 2092 { 2093 rtnl_unregister_all(PF_MPLS); 2094 rtnl_af_unregister(&mpls_af_ops); 2095 dev_remove_pack(&mpls_packet_type); 2096 unregister_netdevice_notifier(&mpls_dev_notifier); 2097 unregister_pernet_subsys(&mpls_net_ops); 2098 } 2099 module_exit(mpls_exit); 2100 2101 MODULE_DESCRIPTION("MultiProtocol Label Switching"); 2102 MODULE_LICENSE("GPL v2"); 2103 MODULE_ALIAS_NETPROTO(PF_MPLS); 2104