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 /* max memory we will use for mpls_route */ 28 #define MAX_MPLS_ROUTE_MEM 4096 29 30 /* Maximum number of labels to look ahead at when selecting a path of 31 * a multipath route 32 */ 33 #define MAX_MP_SELECT_LABELS 4 34 35 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1) 36 37 static int zero = 0; 38 static int one = 1; 39 static int label_limit = (1 << 20) - 1; 40 static int ttl_max = 255; 41 42 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 43 struct nlmsghdr *nlh, struct net *net, u32 portid, 44 unsigned int nlm_flags); 45 46 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index) 47 { 48 struct mpls_route *rt = NULL; 49 50 if (index < net->mpls.platform_labels) { 51 struct mpls_route __rcu **platform_label = 52 rcu_dereference(net->mpls.platform_label); 53 rt = rcu_dereference(platform_label[index]); 54 } 55 return rt; 56 } 57 58 bool mpls_output_possible(const struct net_device *dev) 59 { 60 return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev); 61 } 62 EXPORT_SYMBOL_GPL(mpls_output_possible); 63 64 static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh) 65 { 66 return (u8 *)nh + rt->rt_via_offset; 67 } 68 69 static const u8 *mpls_nh_via(const struct mpls_route *rt, 70 const struct mpls_nh *nh) 71 { 72 return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh); 73 } 74 75 static unsigned int mpls_nh_header_size(const struct mpls_nh *nh) 76 { 77 /* The size of the layer 2.5 labels to be added for this route */ 78 return nh->nh_labels * sizeof(struct mpls_shim_hdr); 79 } 80 81 unsigned int mpls_dev_mtu(const struct net_device *dev) 82 { 83 /* The amount of data the layer 2 frame can hold */ 84 return dev->mtu; 85 } 86 EXPORT_SYMBOL_GPL(mpls_dev_mtu); 87 88 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 89 { 90 if (skb->len <= mtu) 91 return false; 92 93 if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu)) 94 return false; 95 96 return true; 97 } 98 EXPORT_SYMBOL_GPL(mpls_pkt_too_big); 99 100 void mpls_stats_inc_outucastpkts(struct net_device *dev, 101 const struct sk_buff *skb) 102 { 103 struct mpls_dev *mdev; 104 105 if (skb->protocol == htons(ETH_P_MPLS_UC)) { 106 mdev = mpls_dev_get(dev); 107 if (mdev) 108 MPLS_INC_STATS_LEN(mdev, skb->len, 109 tx_packets, 110 tx_bytes); 111 } else if (skb->protocol == htons(ETH_P_IP)) { 112 IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); 113 #if IS_ENABLED(CONFIG_IPV6) 114 } else if (skb->protocol == htons(ETH_P_IPV6)) { 115 struct inet6_dev *in6dev = __in6_dev_get(dev); 116 117 if (in6dev) 118 IP6_UPD_PO_STATS(dev_net(dev), in6dev, 119 IPSTATS_MIB_OUT, skb->len); 120 #endif 121 } 122 } 123 EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts); 124 125 static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb) 126 { 127 struct mpls_entry_decoded dec; 128 unsigned int mpls_hdr_len = 0; 129 struct mpls_shim_hdr *hdr; 130 bool eli_seen = false; 131 int label_index; 132 u32 hash = 0; 133 134 for (label_index = 0; label_index < MAX_MP_SELECT_LABELS; 135 label_index++) { 136 mpls_hdr_len += sizeof(*hdr); 137 if (!pskb_may_pull(skb, mpls_hdr_len)) 138 break; 139 140 /* Read and decode the current label */ 141 hdr = mpls_hdr(skb) + label_index; 142 dec = mpls_entry_decode(hdr); 143 144 /* RFC6790 - reserved labels MUST NOT be used as keys 145 * for the load-balancing function 146 */ 147 if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) { 148 hash = jhash_1word(dec.label, hash); 149 150 /* The entropy label follows the entropy label 151 * indicator, so this means that the entropy 152 * label was just added to the hash - no need to 153 * go any deeper either in the label stack or in the 154 * payload 155 */ 156 if (eli_seen) 157 break; 158 } else if (dec.label == MPLS_LABEL_ENTROPY) { 159 eli_seen = true; 160 } 161 162 if (!dec.bos) 163 continue; 164 165 /* found bottom label; does skb have room for a header? */ 166 if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) { 167 const struct iphdr *v4hdr; 168 169 v4hdr = (const struct iphdr *)(hdr + 1); 170 if (v4hdr->version == 4) { 171 hash = jhash_3words(ntohl(v4hdr->saddr), 172 ntohl(v4hdr->daddr), 173 v4hdr->protocol, hash); 174 } else if (v4hdr->version == 6 && 175 pskb_may_pull(skb, mpls_hdr_len + 176 sizeof(struct ipv6hdr))) { 177 const struct ipv6hdr *v6hdr; 178 179 v6hdr = (const struct ipv6hdr *)(hdr + 1); 180 hash = __ipv6_addr_jhash(&v6hdr->saddr, hash); 181 hash = __ipv6_addr_jhash(&v6hdr->daddr, hash); 182 hash = jhash_1word(v6hdr->nexthdr, hash); 183 } 184 } 185 186 break; 187 } 188 189 return hash; 190 } 191 192 static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index) 193 { 194 return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size); 195 } 196 197 /* number of alive nexthops (rt->rt_nhn_alive) and the flags for 198 * a next hop (nh->nh_flags) are modified by netdev event handlers. 199 * Since those fields can change at any moment, use READ_ONCE to 200 * access both. 201 */ 202 static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt, 203 struct sk_buff *skb) 204 { 205 u32 hash = 0; 206 int nh_index = 0; 207 int n = 0; 208 u8 alive; 209 210 /* No need to look further into packet if there's only 211 * one path 212 */ 213 if (rt->rt_nhn == 1) 214 return rt->rt_nh; 215 216 alive = READ_ONCE(rt->rt_nhn_alive); 217 if (alive == 0) 218 return NULL; 219 220 hash = mpls_multipath_hash(rt, skb); 221 nh_index = hash % alive; 222 if (alive == rt->rt_nhn) 223 goto out; 224 for_nexthops(rt) { 225 unsigned int nh_flags = READ_ONCE(nh->nh_flags); 226 227 if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 228 continue; 229 if (n == nh_index) 230 return nh; 231 n++; 232 } endfor_nexthops(rt); 233 234 out: 235 return mpls_get_nexthop(rt, nh_index); 236 } 237 238 static bool mpls_egress(struct net *net, struct mpls_route *rt, 239 struct sk_buff *skb, struct mpls_entry_decoded dec) 240 { 241 enum mpls_payload_type payload_type; 242 bool success = false; 243 244 /* The IPv4 code below accesses through the IPv4 header 245 * checksum, which is 12 bytes into the packet. 246 * The IPv6 code below accesses through the IPv6 hop limit 247 * which is 8 bytes into the packet. 248 * 249 * For all supported cases there should always be at least 12 250 * bytes of packet data present. The IPv4 header is 20 bytes 251 * without options and the IPv6 header is always 40 bytes 252 * long. 253 */ 254 if (!pskb_may_pull(skb, 12)) 255 return false; 256 257 payload_type = rt->rt_payload_type; 258 if (payload_type == MPT_UNSPEC) 259 payload_type = ip_hdr(skb)->version; 260 261 switch (payload_type) { 262 case MPT_IPV4: { 263 struct iphdr *hdr4 = ip_hdr(skb); 264 u8 new_ttl; 265 skb->protocol = htons(ETH_P_IP); 266 267 /* If propagating TTL, take the decremented TTL from 268 * the incoming MPLS header, otherwise decrement the 269 * TTL, but only if not 0 to avoid underflow. 270 */ 271 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED || 272 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT && 273 net->mpls.ip_ttl_propagate)) 274 new_ttl = dec.ttl; 275 else 276 new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0; 277 278 csum_replace2(&hdr4->check, 279 htons(hdr4->ttl << 8), 280 htons(new_ttl << 8)); 281 hdr4->ttl = new_ttl; 282 success = true; 283 break; 284 } 285 case MPT_IPV6: { 286 struct ipv6hdr *hdr6 = ipv6_hdr(skb); 287 skb->protocol = htons(ETH_P_IPV6); 288 289 /* If propagating TTL, take the decremented TTL from 290 * the incoming MPLS header, otherwise decrement the 291 * hop limit, but only if not 0 to avoid underflow. 292 */ 293 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED || 294 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT && 295 net->mpls.ip_ttl_propagate)) 296 hdr6->hop_limit = dec.ttl; 297 else if (hdr6->hop_limit) 298 hdr6->hop_limit = hdr6->hop_limit - 1; 299 success = true; 300 break; 301 } 302 case MPT_UNSPEC: 303 /* Should have decided which protocol it is by now */ 304 break; 305 } 306 307 return success; 308 } 309 310 static int mpls_forward(struct sk_buff *skb, struct net_device *dev, 311 struct packet_type *pt, struct net_device *orig_dev) 312 { 313 struct net *net = dev_net(dev); 314 struct mpls_shim_hdr *hdr; 315 struct mpls_route *rt; 316 struct mpls_nh *nh; 317 struct mpls_entry_decoded dec; 318 struct net_device *out_dev; 319 struct mpls_dev *out_mdev; 320 struct mpls_dev *mdev; 321 unsigned int hh_len; 322 unsigned int new_header_size; 323 unsigned int mtu; 324 int err; 325 326 /* Careful this entire function runs inside of an rcu critical section */ 327 328 mdev = mpls_dev_get(dev); 329 if (!mdev) 330 goto drop; 331 332 MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets, 333 rx_bytes); 334 335 if (!mdev->input_enabled) { 336 MPLS_INC_STATS(mdev, rx_dropped); 337 goto drop; 338 } 339 340 if (skb->pkt_type != PACKET_HOST) 341 goto err; 342 343 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 344 goto err; 345 346 if (!pskb_may_pull(skb, sizeof(*hdr))) 347 goto err; 348 349 /* Read and decode the label */ 350 hdr = mpls_hdr(skb); 351 dec = mpls_entry_decode(hdr); 352 353 rt = mpls_route_input_rcu(net, dec.label); 354 if (!rt) { 355 MPLS_INC_STATS(mdev, rx_noroute); 356 goto drop; 357 } 358 359 nh = mpls_select_multipath(rt, skb); 360 if (!nh) 361 goto err; 362 363 /* Pop the label */ 364 skb_pull(skb, sizeof(*hdr)); 365 skb_reset_network_header(skb); 366 367 skb_orphan(skb); 368 369 if (skb_warn_if_lro(skb)) 370 goto err; 371 372 skb_forward_csum(skb); 373 374 /* Verify ttl is valid */ 375 if (dec.ttl <= 1) 376 goto err; 377 dec.ttl -= 1; 378 379 /* Find the output device */ 380 out_dev = rcu_dereference(nh->nh_dev); 381 if (!mpls_output_possible(out_dev)) 382 goto tx_err; 383 384 /* Verify the destination can hold the packet */ 385 new_header_size = mpls_nh_header_size(nh); 386 mtu = mpls_dev_mtu(out_dev); 387 if (mpls_pkt_too_big(skb, mtu - new_header_size)) 388 goto tx_err; 389 390 hh_len = LL_RESERVED_SPACE(out_dev); 391 if (!out_dev->header_ops) 392 hh_len = 0; 393 394 /* Ensure there is enough space for the headers in the skb */ 395 if (skb_cow(skb, hh_len + new_header_size)) 396 goto tx_err; 397 398 skb->dev = out_dev; 399 skb->protocol = htons(ETH_P_MPLS_UC); 400 401 if (unlikely(!new_header_size && dec.bos)) { 402 /* Penultimate hop popping */ 403 if (!mpls_egress(dev_net(out_dev), rt, skb, dec)) 404 goto err; 405 } else { 406 bool bos; 407 int i; 408 skb_push(skb, new_header_size); 409 skb_reset_network_header(skb); 410 /* Push the new labels */ 411 hdr = mpls_hdr(skb); 412 bos = dec.bos; 413 for (i = nh->nh_labels - 1; i >= 0; i--) { 414 hdr[i] = mpls_entry_encode(nh->nh_label[i], 415 dec.ttl, 0, bos); 416 bos = false; 417 } 418 } 419 420 mpls_stats_inc_outucastpkts(out_dev, skb); 421 422 /* If via wasn't specified then send out using device address */ 423 if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC) 424 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev, 425 out_dev->dev_addr, skb); 426 else 427 err = neigh_xmit(nh->nh_via_table, out_dev, 428 mpls_nh_via(rt, nh), skb); 429 if (err) 430 net_dbg_ratelimited("%s: packet transmission failed: %d\n", 431 __func__, err); 432 return 0; 433 434 tx_err: 435 out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL; 436 if (out_mdev) 437 MPLS_INC_STATS(out_mdev, tx_errors); 438 goto drop; 439 err: 440 MPLS_INC_STATS(mdev, rx_errors); 441 drop: 442 kfree_skb(skb); 443 return NET_RX_DROP; 444 } 445 446 static struct packet_type mpls_packet_type __read_mostly = { 447 .type = cpu_to_be16(ETH_P_MPLS_UC), 448 .func = mpls_forward, 449 }; 450 451 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = { 452 [RTA_DST] = { .type = NLA_U32 }, 453 [RTA_OIF] = { .type = NLA_U32 }, 454 [RTA_TTL_PROPAGATE] = { .type = NLA_U8 }, 455 }; 456 457 struct mpls_route_config { 458 u32 rc_protocol; 459 u32 rc_ifindex; 460 u8 rc_via_table; 461 u8 rc_via_alen; 462 u8 rc_via[MAX_VIA_ALEN]; 463 u32 rc_label; 464 u8 rc_ttl_propagate; 465 u8 rc_output_labels; 466 u32 rc_output_label[MAX_NEW_LABELS]; 467 u32 rc_nlflags; 468 enum mpls_payload_type rc_payload_type; 469 struct nl_info rc_nlinfo; 470 struct rtnexthop *rc_mp; 471 int rc_mp_len; 472 }; 473 474 /* all nexthops within a route have the same size based on max 475 * number of labels and max via length for a hop 476 */ 477 static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels) 478 { 479 u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen); 480 struct mpls_route *rt; 481 size_t size; 482 483 size = sizeof(*rt) + num_nh * nh_size; 484 if (size > MAX_MPLS_ROUTE_MEM) 485 return ERR_PTR(-EINVAL); 486 487 rt = kzalloc(size, GFP_KERNEL); 488 if (!rt) 489 return ERR_PTR(-ENOMEM); 490 491 rt->rt_nhn = num_nh; 492 rt->rt_nhn_alive = num_nh; 493 rt->rt_nh_size = nh_size; 494 rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels); 495 496 return rt; 497 } 498 499 static void mpls_rt_free(struct mpls_route *rt) 500 { 501 if (rt) 502 kfree_rcu(rt, rt_rcu); 503 } 504 505 static void mpls_notify_route(struct net *net, unsigned index, 506 struct mpls_route *old, struct mpls_route *new, 507 const struct nl_info *info) 508 { 509 struct nlmsghdr *nlh = info ? info->nlh : NULL; 510 unsigned portid = info ? info->portid : 0; 511 int event = new ? RTM_NEWROUTE : RTM_DELROUTE; 512 struct mpls_route *rt = new ? new : old; 513 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0; 514 /* Ignore reserved labels for now */ 515 if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED)) 516 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags); 517 } 518 519 static void mpls_route_update(struct net *net, unsigned index, 520 struct mpls_route *new, 521 const struct nl_info *info) 522 { 523 struct mpls_route __rcu **platform_label; 524 struct mpls_route *rt; 525 526 ASSERT_RTNL(); 527 528 platform_label = rtnl_dereference(net->mpls.platform_label); 529 rt = rtnl_dereference(platform_label[index]); 530 rcu_assign_pointer(platform_label[index], new); 531 532 mpls_notify_route(net, index, rt, new, info); 533 534 /* If we removed a route free it now */ 535 mpls_rt_free(rt); 536 } 537 538 static unsigned find_free_label(struct net *net) 539 { 540 struct mpls_route __rcu **platform_label; 541 size_t platform_labels; 542 unsigned index; 543 544 platform_label = rtnl_dereference(net->mpls.platform_label); 545 platform_labels = net->mpls.platform_labels; 546 for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels; 547 index++) { 548 if (!rtnl_dereference(platform_label[index])) 549 return index; 550 } 551 return LABEL_NOT_SPECIFIED; 552 } 553 554 #if IS_ENABLED(CONFIG_INET) 555 static struct net_device *inet_fib_lookup_dev(struct net *net, 556 const void *addr) 557 { 558 struct net_device *dev; 559 struct rtable *rt; 560 struct in_addr daddr; 561 562 memcpy(&daddr, addr, sizeof(struct in_addr)); 563 rt = ip_route_output(net, daddr.s_addr, 0, 0, 0); 564 if (IS_ERR(rt)) 565 return ERR_CAST(rt); 566 567 dev = rt->dst.dev; 568 dev_hold(dev); 569 570 ip_rt_put(rt); 571 572 return dev; 573 } 574 #else 575 static struct net_device *inet_fib_lookup_dev(struct net *net, 576 const void *addr) 577 { 578 return ERR_PTR(-EAFNOSUPPORT); 579 } 580 #endif 581 582 #if IS_ENABLED(CONFIG_IPV6) 583 static struct net_device *inet6_fib_lookup_dev(struct net *net, 584 const void *addr) 585 { 586 struct net_device *dev; 587 struct dst_entry *dst; 588 struct flowi6 fl6; 589 int err; 590 591 if (!ipv6_stub) 592 return ERR_PTR(-EAFNOSUPPORT); 593 594 memset(&fl6, 0, sizeof(fl6)); 595 memcpy(&fl6.daddr, addr, sizeof(struct in6_addr)); 596 err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6); 597 if (err) 598 return ERR_PTR(err); 599 600 dev = dst->dev; 601 dev_hold(dev); 602 dst_release(dst); 603 604 return dev; 605 } 606 #else 607 static struct net_device *inet6_fib_lookup_dev(struct net *net, 608 const void *addr) 609 { 610 return ERR_PTR(-EAFNOSUPPORT); 611 } 612 #endif 613 614 static struct net_device *find_outdev(struct net *net, 615 struct mpls_route *rt, 616 struct mpls_nh *nh, int oif) 617 { 618 struct net_device *dev = NULL; 619 620 if (!oif) { 621 switch (nh->nh_via_table) { 622 case NEIGH_ARP_TABLE: 623 dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 624 break; 625 case NEIGH_ND_TABLE: 626 dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 627 break; 628 case NEIGH_LINK_TABLE: 629 break; 630 } 631 } else { 632 dev = dev_get_by_index(net, oif); 633 } 634 635 if (!dev) 636 return ERR_PTR(-ENODEV); 637 638 if (IS_ERR(dev)) 639 return dev; 640 641 /* The caller is holding rtnl anyways, so release the dev reference */ 642 dev_put(dev); 643 644 return dev; 645 } 646 647 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt, 648 struct mpls_nh *nh, int oif) 649 { 650 struct net_device *dev = NULL; 651 int err = -ENODEV; 652 653 dev = find_outdev(net, rt, nh, oif); 654 if (IS_ERR(dev)) { 655 err = PTR_ERR(dev); 656 dev = NULL; 657 goto errout; 658 } 659 660 /* Ensure this is a supported device */ 661 err = -EINVAL; 662 if (!mpls_dev_get(dev)) 663 goto errout; 664 665 if ((nh->nh_via_table == NEIGH_LINK_TABLE) && 666 (dev->addr_len != nh->nh_via_alen)) 667 goto errout; 668 669 RCU_INIT_POINTER(nh->nh_dev, dev); 670 671 if (!(dev->flags & IFF_UP)) { 672 nh->nh_flags |= RTNH_F_DEAD; 673 } else { 674 unsigned int flags; 675 676 flags = dev_get_flags(dev); 677 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP))) 678 nh->nh_flags |= RTNH_F_LINKDOWN; 679 } 680 681 return 0; 682 683 errout: 684 return err; 685 } 686 687 static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table, 688 u8 via_addr[], struct netlink_ext_ack *extack) 689 { 690 struct rtvia *via = nla_data(nla); 691 int err = -EINVAL; 692 int alen; 693 694 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 695 NL_SET_ERR_MSG_ATTR(extack, nla, 696 "Invalid attribute length for RTA_VIA"); 697 goto errout; 698 } 699 alen = nla_len(nla) - 700 offsetof(struct rtvia, rtvia_addr); 701 if (alen > MAX_VIA_ALEN) { 702 NL_SET_ERR_MSG_ATTR(extack, nla, 703 "Invalid address length for RTA_VIA"); 704 goto errout; 705 } 706 707 /* Validate the address family */ 708 switch (via->rtvia_family) { 709 case AF_PACKET: 710 *via_table = NEIGH_LINK_TABLE; 711 break; 712 case AF_INET: 713 *via_table = NEIGH_ARP_TABLE; 714 if (alen != 4) 715 goto errout; 716 break; 717 case AF_INET6: 718 *via_table = NEIGH_ND_TABLE; 719 if (alen != 16) 720 goto errout; 721 break; 722 default: 723 /* Unsupported address family */ 724 goto errout; 725 } 726 727 memcpy(via_addr, via->rtvia_addr, alen); 728 *via_alen = alen; 729 err = 0; 730 731 errout: 732 return err; 733 } 734 735 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg, 736 struct mpls_route *rt) 737 { 738 struct net *net = cfg->rc_nlinfo.nl_net; 739 struct mpls_nh *nh = rt->rt_nh; 740 int err; 741 int i; 742 743 if (!nh) 744 return -ENOMEM; 745 746 nh->nh_labels = cfg->rc_output_labels; 747 for (i = 0; i < nh->nh_labels; i++) 748 nh->nh_label[i] = cfg->rc_output_label[i]; 749 750 nh->nh_via_table = cfg->rc_via_table; 751 memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen); 752 nh->nh_via_alen = cfg->rc_via_alen; 753 754 err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex); 755 if (err) 756 goto errout; 757 758 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 759 rt->rt_nhn_alive--; 760 761 return 0; 762 763 errout: 764 return err; 765 } 766 767 static int mpls_nh_build(struct net *net, struct mpls_route *rt, 768 struct mpls_nh *nh, int oif, struct nlattr *via, 769 struct nlattr *newdst, u8 max_labels, 770 struct netlink_ext_ack *extack) 771 { 772 int err = -ENOMEM; 773 774 if (!nh) 775 goto errout; 776 777 if (newdst) { 778 err = nla_get_labels(newdst, max_labels, &nh->nh_labels, 779 nh->nh_label, extack); 780 if (err) 781 goto errout; 782 } 783 784 if (via) { 785 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table, 786 __mpls_nh_via(rt, nh), extack); 787 if (err) 788 goto errout; 789 } else { 790 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC; 791 } 792 793 err = mpls_nh_assign_dev(net, rt, nh, oif); 794 if (err) 795 goto errout; 796 797 return 0; 798 799 errout: 800 return err; 801 } 802 803 static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len, 804 u8 cfg_via_alen, u8 *max_via_alen, 805 u8 *max_labels) 806 { 807 int remaining = len; 808 u8 nhs = 0; 809 810 *max_via_alen = 0; 811 *max_labels = 0; 812 813 while (rtnh_ok(rtnh, remaining)) { 814 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 815 int attrlen; 816 u8 n_labels = 0; 817 818 attrlen = rtnh_attrlen(rtnh); 819 nla = nla_find(attrs, attrlen, RTA_VIA); 820 if (nla && nla_len(nla) >= 821 offsetof(struct rtvia, rtvia_addr)) { 822 int via_alen = nla_len(nla) - 823 offsetof(struct rtvia, rtvia_addr); 824 825 if (via_alen <= MAX_VIA_ALEN) 826 *max_via_alen = max_t(u16, *max_via_alen, 827 via_alen); 828 } 829 830 nla = nla_find(attrs, attrlen, RTA_NEWDST); 831 if (nla && 832 nla_get_labels(nla, MAX_NEW_LABELS, &n_labels, 833 NULL, NULL) != 0) 834 return 0; 835 836 *max_labels = max_t(u8, *max_labels, n_labels); 837 838 /* number of nexthops is tracked by a u8. 839 * Check for overflow. 840 */ 841 if (nhs == 255) 842 return 0; 843 nhs++; 844 845 rtnh = rtnh_next(rtnh, &remaining); 846 } 847 848 /* leftover implies invalid nexthop configuration, discard it */ 849 return remaining > 0 ? 0 : nhs; 850 } 851 852 static int mpls_nh_build_multi(struct mpls_route_config *cfg, 853 struct mpls_route *rt, u8 max_labels, 854 struct netlink_ext_ack *extack) 855 { 856 struct rtnexthop *rtnh = cfg->rc_mp; 857 struct nlattr *nla_via, *nla_newdst; 858 int remaining = cfg->rc_mp_len; 859 int err = 0; 860 u8 nhs = 0; 861 862 change_nexthops(rt) { 863 int attrlen; 864 865 nla_via = NULL; 866 nla_newdst = NULL; 867 868 err = -EINVAL; 869 if (!rtnh_ok(rtnh, remaining)) 870 goto errout; 871 872 /* neither weighted multipath nor any flags 873 * are supported 874 */ 875 if (rtnh->rtnh_hops || rtnh->rtnh_flags) 876 goto errout; 877 878 attrlen = rtnh_attrlen(rtnh); 879 if (attrlen > 0) { 880 struct nlattr *attrs = rtnh_attrs(rtnh); 881 882 nla_via = nla_find(attrs, attrlen, RTA_VIA); 883 nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST); 884 } 885 886 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh, 887 rtnh->rtnh_ifindex, nla_via, nla_newdst, 888 max_labels, extack); 889 if (err) 890 goto errout; 891 892 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 893 rt->rt_nhn_alive--; 894 895 rtnh = rtnh_next(rtnh, &remaining); 896 nhs++; 897 } endfor_nexthops(rt); 898 899 rt->rt_nhn = nhs; 900 901 return 0; 902 903 errout: 904 return err; 905 } 906 907 static bool mpls_label_ok(struct net *net, unsigned int index, 908 struct netlink_ext_ack *extack) 909 { 910 /* Reserved labels may not be set */ 911 if (index < MPLS_LABEL_FIRST_UNRESERVED) { 912 NL_SET_ERR_MSG(extack, 913 "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher"); 914 return false; 915 } 916 917 /* The full 20 bit range may not be supported. */ 918 if (index >= net->mpls.platform_labels) { 919 NL_SET_ERR_MSG(extack, 920 "Label >= configured maximum in platform_labels"); 921 return false; 922 } 923 924 return true; 925 } 926 927 static int mpls_route_add(struct mpls_route_config *cfg, 928 struct netlink_ext_ack *extack) 929 { 930 struct mpls_route __rcu **platform_label; 931 struct net *net = cfg->rc_nlinfo.nl_net; 932 struct mpls_route *rt, *old; 933 int err = -EINVAL; 934 u8 max_via_alen; 935 unsigned index; 936 u8 max_labels; 937 u8 nhs; 938 939 index = cfg->rc_label; 940 941 /* If a label was not specified during insert pick one */ 942 if ((index == LABEL_NOT_SPECIFIED) && 943 (cfg->rc_nlflags & NLM_F_CREATE)) { 944 index = find_free_label(net); 945 } 946 947 if (!mpls_label_ok(net, index, extack)) 948 goto errout; 949 950 /* Append makes no sense with mpls */ 951 err = -EOPNOTSUPP; 952 if (cfg->rc_nlflags & NLM_F_APPEND) { 953 NL_SET_ERR_MSG(extack, "MPLS does not support route append"); 954 goto errout; 955 } 956 957 err = -EEXIST; 958 platform_label = rtnl_dereference(net->mpls.platform_label); 959 old = rtnl_dereference(platform_label[index]); 960 if ((cfg->rc_nlflags & NLM_F_EXCL) && old) 961 goto errout; 962 963 err = -EEXIST; 964 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old) 965 goto errout; 966 967 err = -ENOENT; 968 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old) 969 goto errout; 970 971 err = -EINVAL; 972 if (cfg->rc_mp) { 973 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len, 974 cfg->rc_via_alen, &max_via_alen, 975 &max_labels); 976 } else { 977 max_via_alen = cfg->rc_via_alen; 978 max_labels = cfg->rc_output_labels; 979 nhs = 1; 980 } 981 982 if (nhs == 0) { 983 NL_SET_ERR_MSG(extack, "Route does not contain a nexthop"); 984 goto errout; 985 } 986 987 err = -ENOMEM; 988 rt = mpls_rt_alloc(nhs, max_via_alen, max_labels); 989 if (IS_ERR(rt)) { 990 err = PTR_ERR(rt); 991 goto errout; 992 } 993 994 rt->rt_protocol = cfg->rc_protocol; 995 rt->rt_payload_type = cfg->rc_payload_type; 996 rt->rt_ttl_propagate = cfg->rc_ttl_propagate; 997 998 if (cfg->rc_mp) 999 err = mpls_nh_build_multi(cfg, rt, max_labels, extack); 1000 else 1001 err = mpls_nh_build_from_cfg(cfg, rt); 1002 if (err) 1003 goto freert; 1004 1005 mpls_route_update(net, index, rt, &cfg->rc_nlinfo); 1006 1007 return 0; 1008 1009 freert: 1010 mpls_rt_free(rt); 1011 errout: 1012 return err; 1013 } 1014 1015 static int mpls_route_del(struct mpls_route_config *cfg, 1016 struct netlink_ext_ack *extack) 1017 { 1018 struct net *net = cfg->rc_nlinfo.nl_net; 1019 unsigned index; 1020 int err = -EINVAL; 1021 1022 index = cfg->rc_label; 1023 1024 if (!mpls_label_ok(net, index, extack)) 1025 goto errout; 1026 1027 mpls_route_update(net, index, NULL, &cfg->rc_nlinfo); 1028 1029 err = 0; 1030 errout: 1031 return err; 1032 } 1033 1034 static void mpls_get_stats(struct mpls_dev *mdev, 1035 struct mpls_link_stats *stats) 1036 { 1037 struct mpls_pcpu_stats *p; 1038 int i; 1039 1040 memset(stats, 0, sizeof(*stats)); 1041 1042 for_each_possible_cpu(i) { 1043 struct mpls_link_stats local; 1044 unsigned int start; 1045 1046 p = per_cpu_ptr(mdev->stats, i); 1047 do { 1048 start = u64_stats_fetch_begin(&p->syncp); 1049 local = p->stats; 1050 } while (u64_stats_fetch_retry(&p->syncp, start)); 1051 1052 stats->rx_packets += local.rx_packets; 1053 stats->rx_bytes += local.rx_bytes; 1054 stats->tx_packets += local.tx_packets; 1055 stats->tx_bytes += local.tx_bytes; 1056 stats->rx_errors += local.rx_errors; 1057 stats->tx_errors += local.tx_errors; 1058 stats->rx_dropped += local.rx_dropped; 1059 stats->tx_dropped += local.tx_dropped; 1060 stats->rx_noroute += local.rx_noroute; 1061 } 1062 } 1063 1064 static int mpls_fill_stats_af(struct sk_buff *skb, 1065 const struct net_device *dev) 1066 { 1067 struct mpls_link_stats *stats; 1068 struct mpls_dev *mdev; 1069 struct nlattr *nla; 1070 1071 mdev = mpls_dev_get(dev); 1072 if (!mdev) 1073 return -ENODATA; 1074 1075 nla = nla_reserve_64bit(skb, MPLS_STATS_LINK, 1076 sizeof(struct mpls_link_stats), 1077 MPLS_STATS_UNSPEC); 1078 if (!nla) 1079 return -EMSGSIZE; 1080 1081 stats = nla_data(nla); 1082 mpls_get_stats(mdev, stats); 1083 1084 return 0; 1085 } 1086 1087 static size_t mpls_get_stats_af_size(const struct net_device *dev) 1088 { 1089 struct mpls_dev *mdev; 1090 1091 mdev = mpls_dev_get(dev); 1092 if (!mdev) 1093 return 0; 1094 1095 return nla_total_size_64bit(sizeof(struct mpls_link_stats)); 1096 } 1097 1098 static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev, 1099 u32 portid, u32 seq, int event, 1100 unsigned int flags, int type) 1101 { 1102 struct nlmsghdr *nlh; 1103 struct netconfmsg *ncm; 1104 bool all = false; 1105 1106 nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg), 1107 flags); 1108 if (!nlh) 1109 return -EMSGSIZE; 1110 1111 if (type == NETCONFA_ALL) 1112 all = true; 1113 1114 ncm = nlmsg_data(nlh); 1115 ncm->ncm_family = AF_MPLS; 1116 1117 if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0) 1118 goto nla_put_failure; 1119 1120 if ((all || type == NETCONFA_INPUT) && 1121 nla_put_s32(skb, NETCONFA_INPUT, 1122 mdev->input_enabled) < 0) 1123 goto nla_put_failure; 1124 1125 nlmsg_end(skb, nlh); 1126 return 0; 1127 1128 nla_put_failure: 1129 nlmsg_cancel(skb, nlh); 1130 return -EMSGSIZE; 1131 } 1132 1133 static int mpls_netconf_msgsize_devconf(int type) 1134 { 1135 int size = NLMSG_ALIGN(sizeof(struct netconfmsg)) 1136 + nla_total_size(4); /* NETCONFA_IFINDEX */ 1137 bool all = false; 1138 1139 if (type == NETCONFA_ALL) 1140 all = true; 1141 1142 if (all || type == NETCONFA_INPUT) 1143 size += nla_total_size(4); 1144 1145 return size; 1146 } 1147 1148 static void mpls_netconf_notify_devconf(struct net *net, int event, 1149 int type, struct mpls_dev *mdev) 1150 { 1151 struct sk_buff *skb; 1152 int err = -ENOBUFS; 1153 1154 skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL); 1155 if (!skb) 1156 goto errout; 1157 1158 err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type); 1159 if (err < 0) { 1160 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */ 1161 WARN_ON(err == -EMSGSIZE); 1162 kfree_skb(skb); 1163 goto errout; 1164 } 1165 1166 rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL); 1167 return; 1168 errout: 1169 if (err < 0) 1170 rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err); 1171 } 1172 1173 static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = { 1174 [NETCONFA_IFINDEX] = { .len = sizeof(int) }, 1175 }; 1176 1177 static int mpls_netconf_get_devconf(struct sk_buff *in_skb, 1178 struct nlmsghdr *nlh, 1179 struct netlink_ext_ack *extack) 1180 { 1181 struct net *net = sock_net(in_skb->sk); 1182 struct nlattr *tb[NETCONFA_MAX + 1]; 1183 struct netconfmsg *ncm; 1184 struct net_device *dev; 1185 struct mpls_dev *mdev; 1186 struct sk_buff *skb; 1187 int ifindex; 1188 int err; 1189 1190 err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX, 1191 devconf_mpls_policy, NULL); 1192 if (err < 0) 1193 goto errout; 1194 1195 err = -EINVAL; 1196 if (!tb[NETCONFA_IFINDEX]) 1197 goto errout; 1198 1199 ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]); 1200 dev = __dev_get_by_index(net, ifindex); 1201 if (!dev) 1202 goto errout; 1203 1204 mdev = mpls_dev_get(dev); 1205 if (!mdev) 1206 goto errout; 1207 1208 err = -ENOBUFS; 1209 skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL); 1210 if (!skb) 1211 goto errout; 1212 1213 err = mpls_netconf_fill_devconf(skb, mdev, 1214 NETLINK_CB(in_skb).portid, 1215 nlh->nlmsg_seq, RTM_NEWNETCONF, 0, 1216 NETCONFA_ALL); 1217 if (err < 0) { 1218 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */ 1219 WARN_ON(err == -EMSGSIZE); 1220 kfree_skb(skb); 1221 goto errout; 1222 } 1223 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 1224 errout: 1225 return err; 1226 } 1227 1228 static int mpls_netconf_dump_devconf(struct sk_buff *skb, 1229 struct netlink_callback *cb) 1230 { 1231 struct net *net = sock_net(skb->sk); 1232 struct hlist_head *head; 1233 struct net_device *dev; 1234 struct mpls_dev *mdev; 1235 int idx, s_idx; 1236 int h, s_h; 1237 1238 s_h = cb->args[0]; 1239 s_idx = idx = cb->args[1]; 1240 1241 for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { 1242 idx = 0; 1243 head = &net->dev_index_head[h]; 1244 rcu_read_lock(); 1245 cb->seq = net->dev_base_seq; 1246 hlist_for_each_entry_rcu(dev, head, index_hlist) { 1247 if (idx < s_idx) 1248 goto cont; 1249 mdev = mpls_dev_get(dev); 1250 if (!mdev) 1251 goto cont; 1252 if (mpls_netconf_fill_devconf(skb, mdev, 1253 NETLINK_CB(cb->skb).portid, 1254 cb->nlh->nlmsg_seq, 1255 RTM_NEWNETCONF, 1256 NLM_F_MULTI, 1257 NETCONFA_ALL) < 0) { 1258 rcu_read_unlock(); 1259 goto done; 1260 } 1261 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 1262 cont: 1263 idx++; 1264 } 1265 rcu_read_unlock(); 1266 } 1267 done: 1268 cb->args[0] = h; 1269 cb->args[1] = idx; 1270 1271 return skb->len; 1272 } 1273 1274 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \ 1275 (&((struct mpls_dev *)0)->field) 1276 1277 static int mpls_conf_proc(struct ctl_table *ctl, int write, 1278 void __user *buffer, 1279 size_t *lenp, loff_t *ppos) 1280 { 1281 int oval = *(int *)ctl->data; 1282 int ret = proc_dointvec(ctl, write, buffer, lenp, ppos); 1283 1284 if (write) { 1285 struct mpls_dev *mdev = ctl->extra1; 1286 int i = (int *)ctl->data - (int *)mdev; 1287 struct net *net = ctl->extra2; 1288 int val = *(int *)ctl->data; 1289 1290 if (i == offsetof(struct mpls_dev, input_enabled) && 1291 val != oval) { 1292 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, 1293 NETCONFA_INPUT, mdev); 1294 } 1295 } 1296 1297 return ret; 1298 } 1299 1300 static const struct ctl_table mpls_dev_table[] = { 1301 { 1302 .procname = "input", 1303 .maxlen = sizeof(int), 1304 .mode = 0644, 1305 .proc_handler = mpls_conf_proc, 1306 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled), 1307 }, 1308 { } 1309 }; 1310 1311 static int mpls_dev_sysctl_register(struct net_device *dev, 1312 struct mpls_dev *mdev) 1313 { 1314 char path[sizeof("net/mpls/conf/") + IFNAMSIZ]; 1315 struct net *net = dev_net(dev); 1316 struct ctl_table *table; 1317 int i; 1318 1319 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL); 1320 if (!table) 1321 goto out; 1322 1323 /* Table data contains only offsets relative to the base of 1324 * the mdev at this point, so make them absolute. 1325 */ 1326 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) { 1327 table[i].data = (char *)mdev + (uintptr_t)table[i].data; 1328 table[i].extra1 = mdev; 1329 table[i].extra2 = net; 1330 } 1331 1332 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name); 1333 1334 mdev->sysctl = register_net_sysctl(net, path, table); 1335 if (!mdev->sysctl) 1336 goto free; 1337 1338 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev); 1339 return 0; 1340 1341 free: 1342 kfree(table); 1343 out: 1344 return -ENOBUFS; 1345 } 1346 1347 static void mpls_dev_sysctl_unregister(struct net_device *dev, 1348 struct mpls_dev *mdev) 1349 { 1350 struct net *net = dev_net(dev); 1351 struct ctl_table *table; 1352 1353 table = mdev->sysctl->ctl_table_arg; 1354 unregister_net_sysctl_table(mdev->sysctl); 1355 kfree(table); 1356 1357 mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev); 1358 } 1359 1360 static struct mpls_dev *mpls_add_dev(struct net_device *dev) 1361 { 1362 struct mpls_dev *mdev; 1363 int err = -ENOMEM; 1364 int i; 1365 1366 ASSERT_RTNL(); 1367 1368 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); 1369 if (!mdev) 1370 return ERR_PTR(err); 1371 1372 mdev->stats = alloc_percpu(struct mpls_pcpu_stats); 1373 if (!mdev->stats) 1374 goto free; 1375 1376 for_each_possible_cpu(i) { 1377 struct mpls_pcpu_stats *mpls_stats; 1378 1379 mpls_stats = per_cpu_ptr(mdev->stats, i); 1380 u64_stats_init(&mpls_stats->syncp); 1381 } 1382 1383 mdev->dev = dev; 1384 1385 err = mpls_dev_sysctl_register(dev, mdev); 1386 if (err) 1387 goto free; 1388 1389 rcu_assign_pointer(dev->mpls_ptr, mdev); 1390 1391 return mdev; 1392 1393 free: 1394 free_percpu(mdev->stats); 1395 kfree(mdev); 1396 return ERR_PTR(err); 1397 } 1398 1399 static void mpls_dev_destroy_rcu(struct rcu_head *head) 1400 { 1401 struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu); 1402 1403 free_percpu(mdev->stats); 1404 kfree(mdev); 1405 } 1406 1407 static void mpls_ifdown(struct net_device *dev, int event) 1408 { 1409 struct mpls_route __rcu **platform_label; 1410 struct net *net = dev_net(dev); 1411 u8 alive, deleted; 1412 unsigned index; 1413 1414 platform_label = rtnl_dereference(net->mpls.platform_label); 1415 for (index = 0; index < net->mpls.platform_labels; index++) { 1416 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1417 1418 if (!rt) 1419 continue; 1420 1421 alive = 0; 1422 deleted = 0; 1423 change_nexthops(rt) { 1424 unsigned int nh_flags = nh->nh_flags; 1425 1426 if (rtnl_dereference(nh->nh_dev) != dev) 1427 goto next; 1428 1429 switch (event) { 1430 case NETDEV_DOWN: 1431 case NETDEV_UNREGISTER: 1432 nh_flags |= RTNH_F_DEAD; 1433 /* fall through */ 1434 case NETDEV_CHANGE: 1435 nh_flags |= RTNH_F_LINKDOWN; 1436 break; 1437 } 1438 if (event == NETDEV_UNREGISTER) 1439 RCU_INIT_POINTER(nh->nh_dev, NULL); 1440 1441 if (nh->nh_flags != nh_flags) 1442 WRITE_ONCE(nh->nh_flags, nh_flags); 1443 next: 1444 if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))) 1445 alive++; 1446 if (!rtnl_dereference(nh->nh_dev)) 1447 deleted++; 1448 } endfor_nexthops(rt); 1449 1450 WRITE_ONCE(rt->rt_nhn_alive, alive); 1451 1452 /* if there are no more nexthops, delete the route */ 1453 if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn) 1454 mpls_route_update(net, index, NULL, NULL); 1455 } 1456 } 1457 1458 static void mpls_ifup(struct net_device *dev, unsigned int flags) 1459 { 1460 struct mpls_route __rcu **platform_label; 1461 struct net *net = dev_net(dev); 1462 unsigned index; 1463 u8 alive; 1464 1465 platform_label = rtnl_dereference(net->mpls.platform_label); 1466 for (index = 0; index < net->mpls.platform_labels; index++) { 1467 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1468 1469 if (!rt) 1470 continue; 1471 1472 alive = 0; 1473 change_nexthops(rt) { 1474 unsigned int nh_flags = nh->nh_flags; 1475 struct net_device *nh_dev = 1476 rtnl_dereference(nh->nh_dev); 1477 1478 if (!(nh_flags & flags)) { 1479 alive++; 1480 continue; 1481 } 1482 if (nh_dev != dev) 1483 continue; 1484 alive++; 1485 nh_flags &= ~flags; 1486 WRITE_ONCE(nh->nh_flags, nh_flags); 1487 } endfor_nexthops(rt); 1488 1489 WRITE_ONCE(rt->rt_nhn_alive, alive); 1490 } 1491 } 1492 1493 static int mpls_dev_notify(struct notifier_block *this, unsigned long event, 1494 void *ptr) 1495 { 1496 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1497 struct mpls_dev *mdev; 1498 unsigned int flags; 1499 1500 if (event == NETDEV_REGISTER) { 1501 /* For now just support Ethernet, IPGRE, SIT and IPIP devices */ 1502 if (dev->type == ARPHRD_ETHER || 1503 dev->type == ARPHRD_LOOPBACK || 1504 dev->type == ARPHRD_IPGRE || 1505 dev->type == ARPHRD_SIT || 1506 dev->type == ARPHRD_TUNNEL) { 1507 mdev = mpls_add_dev(dev); 1508 if (IS_ERR(mdev)) 1509 return notifier_from_errno(PTR_ERR(mdev)); 1510 } 1511 return NOTIFY_OK; 1512 } 1513 1514 mdev = mpls_dev_get(dev); 1515 if (!mdev) 1516 return NOTIFY_OK; 1517 1518 switch (event) { 1519 case NETDEV_DOWN: 1520 mpls_ifdown(dev, event); 1521 break; 1522 case NETDEV_UP: 1523 flags = dev_get_flags(dev); 1524 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1525 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1526 else 1527 mpls_ifup(dev, RTNH_F_DEAD); 1528 break; 1529 case NETDEV_CHANGE: 1530 flags = dev_get_flags(dev); 1531 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1532 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1533 else 1534 mpls_ifdown(dev, event); 1535 break; 1536 case NETDEV_UNREGISTER: 1537 mpls_ifdown(dev, event); 1538 mdev = mpls_dev_get(dev); 1539 if (mdev) { 1540 mpls_dev_sysctl_unregister(dev, mdev); 1541 RCU_INIT_POINTER(dev->mpls_ptr, NULL); 1542 call_rcu(&mdev->rcu, mpls_dev_destroy_rcu); 1543 } 1544 break; 1545 case NETDEV_CHANGENAME: 1546 mdev = mpls_dev_get(dev); 1547 if (mdev) { 1548 int err; 1549 1550 mpls_dev_sysctl_unregister(dev, mdev); 1551 err = mpls_dev_sysctl_register(dev, mdev); 1552 if (err) 1553 return notifier_from_errno(err); 1554 } 1555 break; 1556 } 1557 return NOTIFY_OK; 1558 } 1559 1560 static struct notifier_block mpls_dev_notifier = { 1561 .notifier_call = mpls_dev_notify, 1562 }; 1563 1564 static int nla_put_via(struct sk_buff *skb, 1565 u8 table, const void *addr, int alen) 1566 { 1567 static const int table_to_family[NEIGH_NR_TABLES + 1] = { 1568 AF_INET, AF_INET6, AF_DECnet, AF_PACKET, 1569 }; 1570 struct nlattr *nla; 1571 struct rtvia *via; 1572 int family = AF_UNSPEC; 1573 1574 nla = nla_reserve(skb, RTA_VIA, alen + 2); 1575 if (!nla) 1576 return -EMSGSIZE; 1577 1578 if (table <= NEIGH_NR_TABLES) 1579 family = table_to_family[table]; 1580 1581 via = nla_data(nla); 1582 via->rtvia_family = family; 1583 memcpy(via->rtvia_addr, addr, alen); 1584 return 0; 1585 } 1586 1587 int nla_put_labels(struct sk_buff *skb, int attrtype, 1588 u8 labels, const u32 label[]) 1589 { 1590 struct nlattr *nla; 1591 struct mpls_shim_hdr *nla_label; 1592 bool bos; 1593 int i; 1594 nla = nla_reserve(skb, attrtype, labels*4); 1595 if (!nla) 1596 return -EMSGSIZE; 1597 1598 nla_label = nla_data(nla); 1599 bos = true; 1600 for (i = labels - 1; i >= 0; i--) { 1601 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos); 1602 bos = false; 1603 } 1604 1605 return 0; 1606 } 1607 EXPORT_SYMBOL_GPL(nla_put_labels); 1608 1609 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels, 1610 u32 label[], struct netlink_ext_ack *extack) 1611 { 1612 unsigned len = nla_len(nla); 1613 struct mpls_shim_hdr *nla_label; 1614 u8 nla_labels; 1615 bool bos; 1616 int i; 1617 1618 /* len needs to be an even multiple of 4 (the label size). Number 1619 * of labels is a u8 so check for overflow. 1620 */ 1621 if (len & 3 || len / 4 > 255) { 1622 NL_SET_ERR_MSG_ATTR(extack, nla, 1623 "Invalid length for labels attribute"); 1624 return -EINVAL; 1625 } 1626 1627 /* Limit the number of new labels allowed */ 1628 nla_labels = len/4; 1629 if (nla_labels > max_labels) { 1630 NL_SET_ERR_MSG(extack, "Too many labels"); 1631 return -EINVAL; 1632 } 1633 1634 /* when label == NULL, caller wants number of labels */ 1635 if (!label) 1636 goto out; 1637 1638 nla_label = nla_data(nla); 1639 bos = true; 1640 for (i = nla_labels - 1; i >= 0; i--, bos = false) { 1641 struct mpls_entry_decoded dec; 1642 dec = mpls_entry_decode(nla_label + i); 1643 1644 /* Ensure the bottom of stack flag is properly set 1645 * and ttl and tc are both clear. 1646 */ 1647 if (dec.ttl) { 1648 NL_SET_ERR_MSG_ATTR(extack, nla, 1649 "TTL in label must be 0"); 1650 return -EINVAL; 1651 } 1652 1653 if (dec.tc) { 1654 NL_SET_ERR_MSG_ATTR(extack, nla, 1655 "Traffic class in label must be 0"); 1656 return -EINVAL; 1657 } 1658 1659 if (dec.bos != bos) { 1660 NL_SET_BAD_ATTR(extack, nla); 1661 if (bos) { 1662 NL_SET_ERR_MSG(extack, 1663 "BOS bit must be set in first label"); 1664 } else { 1665 NL_SET_ERR_MSG(extack, 1666 "BOS bit can only be set in first label"); 1667 } 1668 return -EINVAL; 1669 } 1670 1671 switch (dec.label) { 1672 case MPLS_LABEL_IMPLNULL: 1673 /* RFC3032: This is a label that an LSR may 1674 * assign and distribute, but which never 1675 * actually appears in the encapsulation. 1676 */ 1677 NL_SET_ERR_MSG_ATTR(extack, nla, 1678 "Implicit NULL Label (3) can not be used in encapsulation"); 1679 return -EINVAL; 1680 } 1681 1682 label[i] = dec.label; 1683 } 1684 out: 1685 *labels = nla_labels; 1686 return 0; 1687 } 1688 EXPORT_SYMBOL_GPL(nla_get_labels); 1689 1690 static int rtm_to_route_config(struct sk_buff *skb, 1691 struct nlmsghdr *nlh, 1692 struct mpls_route_config *cfg, 1693 struct netlink_ext_ack *extack) 1694 { 1695 struct rtmsg *rtm; 1696 struct nlattr *tb[RTA_MAX+1]; 1697 int index; 1698 int err; 1699 1700 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy, 1701 extack); 1702 if (err < 0) 1703 goto errout; 1704 1705 err = -EINVAL; 1706 rtm = nlmsg_data(nlh); 1707 1708 if (rtm->rtm_family != AF_MPLS) { 1709 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg"); 1710 goto errout; 1711 } 1712 if (rtm->rtm_dst_len != 20) { 1713 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS"); 1714 goto errout; 1715 } 1716 if (rtm->rtm_src_len != 0) { 1717 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS"); 1718 goto errout; 1719 } 1720 if (rtm->rtm_tos != 0) { 1721 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS"); 1722 goto errout; 1723 } 1724 if (rtm->rtm_table != RT_TABLE_MAIN) { 1725 NL_SET_ERR_MSG(extack, 1726 "MPLS only supports the main route table"); 1727 goto errout; 1728 } 1729 /* Any value is acceptable for rtm_protocol */ 1730 1731 /* As mpls uses destination specific addresses 1732 * (or source specific address in the case of multicast) 1733 * all addresses have universal scope. 1734 */ 1735 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) { 1736 NL_SET_ERR_MSG(extack, 1737 "Invalid route scope - MPLS only supports UNIVERSE"); 1738 goto errout; 1739 } 1740 if (rtm->rtm_type != RTN_UNICAST) { 1741 NL_SET_ERR_MSG(extack, 1742 "Invalid route type - MPLS only supports UNICAST"); 1743 goto errout; 1744 } 1745 if (rtm->rtm_flags != 0) { 1746 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS"); 1747 goto errout; 1748 } 1749 1750 cfg->rc_label = LABEL_NOT_SPECIFIED; 1751 cfg->rc_protocol = rtm->rtm_protocol; 1752 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC; 1753 cfg->rc_ttl_propagate = MPLS_TTL_PROP_DEFAULT; 1754 cfg->rc_nlflags = nlh->nlmsg_flags; 1755 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid; 1756 cfg->rc_nlinfo.nlh = nlh; 1757 cfg->rc_nlinfo.nl_net = sock_net(skb->sk); 1758 1759 for (index = 0; index <= RTA_MAX; index++) { 1760 struct nlattr *nla = tb[index]; 1761 if (!nla) 1762 continue; 1763 1764 switch (index) { 1765 case RTA_OIF: 1766 cfg->rc_ifindex = nla_get_u32(nla); 1767 break; 1768 case RTA_NEWDST: 1769 if (nla_get_labels(nla, MAX_NEW_LABELS, 1770 &cfg->rc_output_labels, 1771 cfg->rc_output_label, extack)) 1772 goto errout; 1773 break; 1774 case RTA_DST: 1775 { 1776 u8 label_count; 1777 if (nla_get_labels(nla, 1, &label_count, 1778 &cfg->rc_label, extack)) 1779 goto errout; 1780 1781 if (!mpls_label_ok(cfg->rc_nlinfo.nl_net, 1782 cfg->rc_label, extack)) 1783 goto errout; 1784 break; 1785 } 1786 case RTA_VIA: 1787 { 1788 if (nla_get_via(nla, &cfg->rc_via_alen, 1789 &cfg->rc_via_table, cfg->rc_via, 1790 extack)) 1791 goto errout; 1792 break; 1793 } 1794 case RTA_MULTIPATH: 1795 { 1796 cfg->rc_mp = nla_data(nla); 1797 cfg->rc_mp_len = nla_len(nla); 1798 break; 1799 } 1800 case RTA_TTL_PROPAGATE: 1801 { 1802 u8 ttl_propagate = nla_get_u8(nla); 1803 1804 if (ttl_propagate > 1) { 1805 NL_SET_ERR_MSG_ATTR(extack, nla, 1806 "RTA_TTL_PROPAGATE can only be 0 or 1"); 1807 goto errout; 1808 } 1809 cfg->rc_ttl_propagate = ttl_propagate ? 1810 MPLS_TTL_PROP_ENABLED : 1811 MPLS_TTL_PROP_DISABLED; 1812 break; 1813 } 1814 default: 1815 NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute"); 1816 /* Unsupported attribute */ 1817 goto errout; 1818 } 1819 } 1820 1821 err = 0; 1822 errout: 1823 return err; 1824 } 1825 1826 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 1827 struct netlink_ext_ack *extack) 1828 { 1829 struct mpls_route_config *cfg; 1830 int err; 1831 1832 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL); 1833 if (!cfg) 1834 return -ENOMEM; 1835 1836 err = rtm_to_route_config(skb, nlh, cfg, extack); 1837 if (err < 0) 1838 goto out; 1839 1840 err = mpls_route_del(cfg, extack); 1841 out: 1842 kfree(cfg); 1843 1844 return err; 1845 } 1846 1847 1848 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 1849 struct netlink_ext_ack *extack) 1850 { 1851 struct mpls_route_config *cfg; 1852 int err; 1853 1854 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL); 1855 if (!cfg) 1856 return -ENOMEM; 1857 1858 err = rtm_to_route_config(skb, nlh, cfg, extack); 1859 if (err < 0) 1860 goto out; 1861 1862 err = mpls_route_add(cfg, extack); 1863 out: 1864 kfree(cfg); 1865 1866 return err; 1867 } 1868 1869 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, 1870 u32 label, struct mpls_route *rt, int flags) 1871 { 1872 struct net_device *dev; 1873 struct nlmsghdr *nlh; 1874 struct rtmsg *rtm; 1875 1876 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); 1877 if (nlh == NULL) 1878 return -EMSGSIZE; 1879 1880 rtm = nlmsg_data(nlh); 1881 rtm->rtm_family = AF_MPLS; 1882 rtm->rtm_dst_len = 20; 1883 rtm->rtm_src_len = 0; 1884 rtm->rtm_tos = 0; 1885 rtm->rtm_table = RT_TABLE_MAIN; 1886 rtm->rtm_protocol = rt->rt_protocol; 1887 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 1888 rtm->rtm_type = RTN_UNICAST; 1889 rtm->rtm_flags = 0; 1890 1891 if (nla_put_labels(skb, RTA_DST, 1, &label)) 1892 goto nla_put_failure; 1893 1894 if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) { 1895 bool ttl_propagate = 1896 rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED; 1897 1898 if (nla_put_u8(skb, RTA_TTL_PROPAGATE, 1899 ttl_propagate)) 1900 goto nla_put_failure; 1901 } 1902 if (rt->rt_nhn == 1) { 1903 const struct mpls_nh *nh = rt->rt_nh; 1904 1905 if (nh->nh_labels && 1906 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels, 1907 nh->nh_label)) 1908 goto nla_put_failure; 1909 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1910 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh), 1911 nh->nh_via_alen)) 1912 goto nla_put_failure; 1913 dev = rtnl_dereference(nh->nh_dev); 1914 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) 1915 goto nla_put_failure; 1916 if (nh->nh_flags & RTNH_F_LINKDOWN) 1917 rtm->rtm_flags |= RTNH_F_LINKDOWN; 1918 if (nh->nh_flags & RTNH_F_DEAD) 1919 rtm->rtm_flags |= RTNH_F_DEAD; 1920 } else { 1921 struct rtnexthop *rtnh; 1922 struct nlattr *mp; 1923 u8 linkdown = 0; 1924 u8 dead = 0; 1925 1926 mp = nla_nest_start(skb, RTA_MULTIPATH); 1927 if (!mp) 1928 goto nla_put_failure; 1929 1930 for_nexthops(rt) { 1931 dev = rtnl_dereference(nh->nh_dev); 1932 if (!dev) 1933 continue; 1934 1935 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); 1936 if (!rtnh) 1937 goto nla_put_failure; 1938 1939 rtnh->rtnh_ifindex = dev->ifindex; 1940 if (nh->nh_flags & RTNH_F_LINKDOWN) { 1941 rtnh->rtnh_flags |= RTNH_F_LINKDOWN; 1942 linkdown++; 1943 } 1944 if (nh->nh_flags & RTNH_F_DEAD) { 1945 rtnh->rtnh_flags |= RTNH_F_DEAD; 1946 dead++; 1947 } 1948 1949 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST, 1950 nh->nh_labels, 1951 nh->nh_label)) 1952 goto nla_put_failure; 1953 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1954 nla_put_via(skb, nh->nh_via_table, 1955 mpls_nh_via(rt, nh), 1956 nh->nh_via_alen)) 1957 goto nla_put_failure; 1958 1959 /* length of rtnetlink header + attributes */ 1960 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; 1961 } endfor_nexthops(rt); 1962 1963 if (linkdown == rt->rt_nhn) 1964 rtm->rtm_flags |= RTNH_F_LINKDOWN; 1965 if (dead == rt->rt_nhn) 1966 rtm->rtm_flags |= RTNH_F_DEAD; 1967 1968 nla_nest_end(skb, mp); 1969 } 1970 1971 nlmsg_end(skb, nlh); 1972 return 0; 1973 1974 nla_put_failure: 1975 nlmsg_cancel(skb, nlh); 1976 return -EMSGSIZE; 1977 } 1978 1979 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) 1980 { 1981 struct net *net = sock_net(skb->sk); 1982 struct mpls_route __rcu **platform_label; 1983 size_t platform_labels; 1984 unsigned int index; 1985 1986 ASSERT_RTNL(); 1987 1988 index = cb->args[0]; 1989 if (index < MPLS_LABEL_FIRST_UNRESERVED) 1990 index = MPLS_LABEL_FIRST_UNRESERVED; 1991 1992 platform_label = rtnl_dereference(net->mpls.platform_label); 1993 platform_labels = net->mpls.platform_labels; 1994 for (; index < platform_labels; index++) { 1995 struct mpls_route *rt; 1996 rt = rtnl_dereference(platform_label[index]); 1997 if (!rt) 1998 continue; 1999 2000 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid, 2001 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 2002 index, rt, NLM_F_MULTI) < 0) 2003 break; 2004 } 2005 cb->args[0] = index; 2006 2007 return skb->len; 2008 } 2009 2010 static inline size_t lfib_nlmsg_size(struct mpls_route *rt) 2011 { 2012 size_t payload = 2013 NLMSG_ALIGN(sizeof(struct rtmsg)) 2014 + nla_total_size(4) /* RTA_DST */ 2015 + nla_total_size(1); /* RTA_TTL_PROPAGATE */ 2016 2017 if (rt->rt_nhn == 1) { 2018 struct mpls_nh *nh = rt->rt_nh; 2019 2020 if (nh->nh_dev) 2021 payload += nla_total_size(4); /* RTA_OIF */ 2022 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */ 2023 payload += nla_total_size(2 + nh->nh_via_alen); 2024 if (nh->nh_labels) /* RTA_NEWDST */ 2025 payload += nla_total_size(nh->nh_labels * 4); 2026 } else { 2027 /* each nexthop is packed in an attribute */ 2028 size_t nhsize = 0; 2029 2030 for_nexthops(rt) { 2031 if (!rtnl_dereference(nh->nh_dev)) 2032 continue; 2033 nhsize += nla_total_size(sizeof(struct rtnexthop)); 2034 /* RTA_VIA */ 2035 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) 2036 nhsize += nla_total_size(2 + nh->nh_via_alen); 2037 if (nh->nh_labels) 2038 nhsize += nla_total_size(nh->nh_labels * 4); 2039 } endfor_nexthops(rt); 2040 /* nested attribute */ 2041 payload += nla_total_size(nhsize); 2042 } 2043 2044 return payload; 2045 } 2046 2047 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 2048 struct nlmsghdr *nlh, struct net *net, u32 portid, 2049 unsigned int nlm_flags) 2050 { 2051 struct sk_buff *skb; 2052 u32 seq = nlh ? nlh->nlmsg_seq : 0; 2053 int err = -ENOBUFS; 2054 2055 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL); 2056 if (skb == NULL) 2057 goto errout; 2058 2059 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags); 2060 if (err < 0) { 2061 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */ 2062 WARN_ON(err == -EMSGSIZE); 2063 kfree_skb(skb); 2064 goto errout; 2065 } 2066 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL); 2067 2068 return; 2069 errout: 2070 if (err < 0) 2071 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err); 2072 } 2073 2074 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 2075 struct netlink_ext_ack *extack) 2076 { 2077 struct net *net = sock_net(in_skb->sk); 2078 u32 portid = NETLINK_CB(in_skb).portid; 2079 u32 in_label = LABEL_NOT_SPECIFIED; 2080 struct nlattr *tb[RTA_MAX + 1]; 2081 u32 labels[MAX_NEW_LABELS]; 2082 struct mpls_shim_hdr *hdr; 2083 unsigned int hdr_size = 0; 2084 struct net_device *dev; 2085 struct mpls_route *rt; 2086 struct rtmsg *rtm, *r; 2087 struct nlmsghdr *nlh; 2088 struct sk_buff *skb; 2089 struct mpls_nh *nh; 2090 u8 n_labels; 2091 int err; 2092 2093 err = nlmsg_parse(in_nlh, sizeof(*rtm), tb, RTA_MAX, 2094 rtm_mpls_policy, extack); 2095 if (err < 0) 2096 goto errout; 2097 2098 rtm = nlmsg_data(in_nlh); 2099 2100 if (tb[RTA_DST]) { 2101 u8 label_count; 2102 2103 if (nla_get_labels(tb[RTA_DST], 1, &label_count, 2104 &in_label, extack)) { 2105 err = -EINVAL; 2106 goto errout; 2107 } 2108 2109 if (!mpls_label_ok(net, in_label, extack)) { 2110 err = -EINVAL; 2111 goto errout; 2112 } 2113 } 2114 2115 rt = mpls_route_input_rcu(net, in_label); 2116 if (!rt) { 2117 err = -ENETUNREACH; 2118 goto errout; 2119 } 2120 2121 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 2122 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL); 2123 if (!skb) { 2124 err = -ENOBUFS; 2125 goto errout; 2126 } 2127 2128 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq, 2129 RTM_NEWROUTE, in_label, rt, 0); 2130 if (err < 0) { 2131 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */ 2132 WARN_ON(err == -EMSGSIZE); 2133 goto errout_free; 2134 } 2135 2136 return rtnl_unicast(skb, net, portid); 2137 } 2138 2139 if (tb[RTA_NEWDST]) { 2140 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels, 2141 labels, extack) != 0) { 2142 err = -EINVAL; 2143 goto errout; 2144 } 2145 2146 hdr_size = n_labels * sizeof(struct mpls_shim_hdr); 2147 } 2148 2149 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2150 if (!skb) { 2151 err = -ENOBUFS; 2152 goto errout; 2153 } 2154 2155 skb->protocol = htons(ETH_P_MPLS_UC); 2156 2157 if (hdr_size) { 2158 bool bos; 2159 int i; 2160 2161 if (skb_cow(skb, hdr_size)) { 2162 err = -ENOBUFS; 2163 goto errout_free; 2164 } 2165 2166 skb_reserve(skb, hdr_size); 2167 skb_push(skb, hdr_size); 2168 skb_reset_network_header(skb); 2169 2170 /* Push new labels */ 2171 hdr = mpls_hdr(skb); 2172 bos = true; 2173 for (i = n_labels - 1; i >= 0; i--) { 2174 hdr[i] = mpls_entry_encode(labels[i], 2175 1, 0, bos); 2176 bos = false; 2177 } 2178 } 2179 2180 nh = mpls_select_multipath(rt, skb); 2181 if (!nh) { 2182 err = -ENETUNREACH; 2183 goto errout_free; 2184 } 2185 2186 if (hdr_size) { 2187 skb_pull(skb, hdr_size); 2188 skb_reset_network_header(skb); 2189 } 2190 2191 nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq, 2192 RTM_NEWROUTE, sizeof(*r), 0); 2193 if (!nlh) { 2194 err = -EMSGSIZE; 2195 goto errout_free; 2196 } 2197 2198 r = nlmsg_data(nlh); 2199 r->rtm_family = AF_MPLS; 2200 r->rtm_dst_len = 20; 2201 r->rtm_src_len = 0; 2202 r->rtm_table = RT_TABLE_MAIN; 2203 r->rtm_type = RTN_UNICAST; 2204 r->rtm_scope = RT_SCOPE_UNIVERSE; 2205 r->rtm_protocol = rt->rt_protocol; 2206 r->rtm_flags = 0; 2207 2208 if (nla_put_labels(skb, RTA_DST, 1, &in_label)) 2209 goto nla_put_failure; 2210 2211 if (nh->nh_labels && 2212 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels, 2213 nh->nh_label)) 2214 goto nla_put_failure; 2215 2216 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 2217 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh), 2218 nh->nh_via_alen)) 2219 goto nla_put_failure; 2220 dev = rtnl_dereference(nh->nh_dev); 2221 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) 2222 goto nla_put_failure; 2223 2224 nlmsg_end(skb, nlh); 2225 2226 err = rtnl_unicast(skb, net, portid); 2227 errout: 2228 return err; 2229 2230 nla_put_failure: 2231 nlmsg_cancel(skb, nlh); 2232 err = -EMSGSIZE; 2233 errout_free: 2234 kfree_skb(skb); 2235 return err; 2236 } 2237 2238 static int resize_platform_label_table(struct net *net, size_t limit) 2239 { 2240 size_t size = sizeof(struct mpls_route *) * limit; 2241 size_t old_limit; 2242 size_t cp_size; 2243 struct mpls_route __rcu **labels = NULL, **old; 2244 struct mpls_route *rt0 = NULL, *rt2 = NULL; 2245 unsigned index; 2246 2247 if (size) { 2248 labels = kvzalloc(size, GFP_KERNEL); 2249 if (!labels) 2250 goto nolabels; 2251 } 2252 2253 /* In case the predefined labels need to be populated */ 2254 if (limit > MPLS_LABEL_IPV4NULL) { 2255 struct net_device *lo = net->loopback_dev; 2256 rt0 = mpls_rt_alloc(1, lo->addr_len, 0); 2257 if (IS_ERR(rt0)) 2258 goto nort0; 2259 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo); 2260 rt0->rt_protocol = RTPROT_KERNEL; 2261 rt0->rt_payload_type = MPT_IPV4; 2262 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT; 2263 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 2264 rt0->rt_nh->nh_via_alen = lo->addr_len; 2265 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr, 2266 lo->addr_len); 2267 } 2268 if (limit > MPLS_LABEL_IPV6NULL) { 2269 struct net_device *lo = net->loopback_dev; 2270 rt2 = mpls_rt_alloc(1, lo->addr_len, 0); 2271 if (IS_ERR(rt2)) 2272 goto nort2; 2273 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo); 2274 rt2->rt_protocol = RTPROT_KERNEL; 2275 rt2->rt_payload_type = MPT_IPV6; 2276 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT; 2277 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 2278 rt2->rt_nh->nh_via_alen = lo->addr_len; 2279 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr, 2280 lo->addr_len); 2281 } 2282 2283 rtnl_lock(); 2284 /* Remember the original table */ 2285 old = rtnl_dereference(net->mpls.platform_label); 2286 old_limit = net->mpls.platform_labels; 2287 2288 /* Free any labels beyond the new table */ 2289 for (index = limit; index < old_limit; index++) 2290 mpls_route_update(net, index, NULL, NULL); 2291 2292 /* Copy over the old labels */ 2293 cp_size = size; 2294 if (old_limit < limit) 2295 cp_size = old_limit * sizeof(struct mpls_route *); 2296 2297 memcpy(labels, old, cp_size); 2298 2299 /* If needed set the predefined labels */ 2300 if ((old_limit <= MPLS_LABEL_IPV6NULL) && 2301 (limit > MPLS_LABEL_IPV6NULL)) { 2302 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2); 2303 rt2 = NULL; 2304 } 2305 2306 if ((old_limit <= MPLS_LABEL_IPV4NULL) && 2307 (limit > MPLS_LABEL_IPV4NULL)) { 2308 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0); 2309 rt0 = NULL; 2310 } 2311 2312 /* Update the global pointers */ 2313 net->mpls.platform_labels = limit; 2314 rcu_assign_pointer(net->mpls.platform_label, labels); 2315 2316 rtnl_unlock(); 2317 2318 mpls_rt_free(rt2); 2319 mpls_rt_free(rt0); 2320 2321 if (old) { 2322 synchronize_rcu(); 2323 kvfree(old); 2324 } 2325 return 0; 2326 2327 nort2: 2328 mpls_rt_free(rt0); 2329 nort0: 2330 kvfree(labels); 2331 nolabels: 2332 return -ENOMEM; 2333 } 2334 2335 static int mpls_platform_labels(struct ctl_table *table, int write, 2336 void __user *buffer, size_t *lenp, loff_t *ppos) 2337 { 2338 struct net *net = table->data; 2339 int platform_labels = net->mpls.platform_labels; 2340 int ret; 2341 struct ctl_table tmp = { 2342 .procname = table->procname, 2343 .data = &platform_labels, 2344 .maxlen = sizeof(int), 2345 .mode = table->mode, 2346 .extra1 = &zero, 2347 .extra2 = &label_limit, 2348 }; 2349 2350 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 2351 2352 if (write && ret == 0) 2353 ret = resize_platform_label_table(net, platform_labels); 2354 2355 return ret; 2356 } 2357 2358 #define MPLS_NS_SYSCTL_OFFSET(field) \ 2359 (&((struct net *)0)->field) 2360 2361 static const struct ctl_table mpls_table[] = { 2362 { 2363 .procname = "platform_labels", 2364 .data = NULL, 2365 .maxlen = sizeof(int), 2366 .mode = 0644, 2367 .proc_handler = mpls_platform_labels, 2368 }, 2369 { 2370 .procname = "ip_ttl_propagate", 2371 .data = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate), 2372 .maxlen = sizeof(int), 2373 .mode = 0644, 2374 .proc_handler = proc_dointvec_minmax, 2375 .extra1 = &zero, 2376 .extra2 = &one, 2377 }, 2378 { 2379 .procname = "default_ttl", 2380 .data = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl), 2381 .maxlen = sizeof(int), 2382 .mode = 0644, 2383 .proc_handler = proc_dointvec_minmax, 2384 .extra1 = &one, 2385 .extra2 = &ttl_max, 2386 }, 2387 { } 2388 }; 2389 2390 static int mpls_net_init(struct net *net) 2391 { 2392 struct ctl_table *table; 2393 int i; 2394 2395 net->mpls.platform_labels = 0; 2396 net->mpls.platform_label = NULL; 2397 net->mpls.ip_ttl_propagate = 1; 2398 net->mpls.default_ttl = 255; 2399 2400 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL); 2401 if (table == NULL) 2402 return -ENOMEM; 2403 2404 /* Table data contains only offsets relative to the base of 2405 * the mdev at this point, so make them absolute. 2406 */ 2407 for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++) 2408 table[i].data = (char *)net + (uintptr_t)table[i].data; 2409 2410 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table); 2411 if (net->mpls.ctl == NULL) { 2412 kfree(table); 2413 return -ENOMEM; 2414 } 2415 2416 return 0; 2417 } 2418 2419 static void mpls_net_exit(struct net *net) 2420 { 2421 struct mpls_route __rcu **platform_label; 2422 size_t platform_labels; 2423 struct ctl_table *table; 2424 unsigned int index; 2425 2426 table = net->mpls.ctl->ctl_table_arg; 2427 unregister_net_sysctl_table(net->mpls.ctl); 2428 kfree(table); 2429 2430 /* An rcu grace period has passed since there was a device in 2431 * the network namespace (and thus the last in flight packet) 2432 * left this network namespace. This is because 2433 * unregister_netdevice_many and netdev_run_todo has completed 2434 * for each network device that was in this network namespace. 2435 * 2436 * As such no additional rcu synchronization is necessary when 2437 * freeing the platform_label table. 2438 */ 2439 rtnl_lock(); 2440 platform_label = rtnl_dereference(net->mpls.platform_label); 2441 platform_labels = net->mpls.platform_labels; 2442 for (index = 0; index < platform_labels; index++) { 2443 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 2444 RCU_INIT_POINTER(platform_label[index], NULL); 2445 mpls_notify_route(net, index, rt, NULL, NULL); 2446 mpls_rt_free(rt); 2447 } 2448 rtnl_unlock(); 2449 2450 kvfree(platform_label); 2451 } 2452 2453 static struct pernet_operations mpls_net_ops = { 2454 .init = mpls_net_init, 2455 .exit = mpls_net_exit, 2456 }; 2457 2458 static struct rtnl_af_ops mpls_af_ops __read_mostly = { 2459 .family = AF_MPLS, 2460 .fill_stats_af = mpls_fill_stats_af, 2461 .get_stats_af_size = mpls_get_stats_af_size, 2462 }; 2463 2464 static int __init mpls_init(void) 2465 { 2466 int err; 2467 2468 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4); 2469 2470 err = register_pernet_subsys(&mpls_net_ops); 2471 if (err) 2472 goto out; 2473 2474 err = register_netdevice_notifier(&mpls_dev_notifier); 2475 if (err) 2476 goto out_unregister_pernet; 2477 2478 dev_add_pack(&mpls_packet_type); 2479 2480 rtnl_af_register(&mpls_af_ops); 2481 2482 rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, NULL); 2483 rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, NULL); 2484 rtnl_register(PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes, 2485 NULL); 2486 rtnl_register(PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf, 2487 mpls_netconf_dump_devconf, NULL); 2488 err = 0; 2489 out: 2490 return err; 2491 2492 out_unregister_pernet: 2493 unregister_pernet_subsys(&mpls_net_ops); 2494 goto out; 2495 } 2496 module_init(mpls_init); 2497 2498 static void __exit mpls_exit(void) 2499 { 2500 rtnl_unregister_all(PF_MPLS); 2501 rtnl_af_unregister(&mpls_af_ops); 2502 dev_remove_pack(&mpls_packet_type); 2503 unregister_netdevice_notifier(&mpls_dev_notifier); 2504 unregister_pernet_subsys(&mpls_net_ops); 2505 } 2506 module_exit(mpls_exit); 2507 2508 MODULE_DESCRIPTION("MultiProtocol Label Switching"); 2509 MODULE_LICENSE("GPL v2"); 2510 MODULE_ALIAS_NETPROTO(PF_MPLS); 2511