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/ip_tunnels.h> 20 #include <net/netns/generic.h> 21 #if IS_ENABLED(CONFIG_IPV6) 22 #include <net/ipv6.h> 23 #endif 24 #include <net/addrconf.h> 25 #include <net/nexthop.h> 26 #include "internal.h" 27 28 /* max memory we will use for mpls_route */ 29 #define MAX_MPLS_ROUTE_MEM 4096 30 31 /* Maximum number of labels to look ahead at when selecting a path of 32 * a multipath route 33 */ 34 #define MAX_MP_SELECT_LABELS 4 35 36 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1) 37 38 static int zero = 0; 39 static int one = 1; 40 static int label_limit = (1 << 20) - 1; 41 static int ttl_max = 255; 42 43 #if IS_ENABLED(CONFIG_NET_IP_TUNNEL) 44 static size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e) 45 { 46 return sizeof(struct mpls_shim_hdr); 47 } 48 49 static const struct ip_tunnel_encap_ops mpls_iptun_ops = { 50 .encap_hlen = ipgre_mpls_encap_hlen, 51 }; 52 53 static int ipgre_tunnel_encap_add_mpls_ops(void) 54 { 55 return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS); 56 } 57 58 static void ipgre_tunnel_encap_del_mpls_ops(void) 59 { 60 ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS); 61 } 62 #else 63 static int ipgre_tunnel_encap_add_mpls_ops(void) 64 { 65 return 0; 66 } 67 68 static void ipgre_tunnel_encap_del_mpls_ops(void) 69 { 70 } 71 #endif 72 73 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 74 struct nlmsghdr *nlh, struct net *net, u32 portid, 75 unsigned int nlm_flags); 76 77 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index) 78 { 79 struct mpls_route *rt = NULL; 80 81 if (index < net->mpls.platform_labels) { 82 struct mpls_route __rcu **platform_label = 83 rcu_dereference(net->mpls.platform_label); 84 rt = rcu_dereference(platform_label[index]); 85 } 86 return rt; 87 } 88 89 bool mpls_output_possible(const struct net_device *dev) 90 { 91 return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev); 92 } 93 EXPORT_SYMBOL_GPL(mpls_output_possible); 94 95 static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh) 96 { 97 return (u8 *)nh + rt->rt_via_offset; 98 } 99 100 static const u8 *mpls_nh_via(const struct mpls_route *rt, 101 const struct mpls_nh *nh) 102 { 103 return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh); 104 } 105 106 static unsigned int mpls_nh_header_size(const struct mpls_nh *nh) 107 { 108 /* The size of the layer 2.5 labels to be added for this route */ 109 return nh->nh_labels * sizeof(struct mpls_shim_hdr); 110 } 111 112 unsigned int mpls_dev_mtu(const struct net_device *dev) 113 { 114 /* The amount of data the layer 2 frame can hold */ 115 return dev->mtu; 116 } 117 EXPORT_SYMBOL_GPL(mpls_dev_mtu); 118 119 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 120 { 121 if (skb->len <= mtu) 122 return false; 123 124 if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu)) 125 return false; 126 127 return true; 128 } 129 EXPORT_SYMBOL_GPL(mpls_pkt_too_big); 130 131 void mpls_stats_inc_outucastpkts(struct net_device *dev, 132 const struct sk_buff *skb) 133 { 134 struct mpls_dev *mdev; 135 136 if (skb->protocol == htons(ETH_P_MPLS_UC)) { 137 mdev = mpls_dev_get(dev); 138 if (mdev) 139 MPLS_INC_STATS_LEN(mdev, skb->len, 140 tx_packets, 141 tx_bytes); 142 } else if (skb->protocol == htons(ETH_P_IP)) { 143 IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); 144 #if IS_ENABLED(CONFIG_IPV6) 145 } else if (skb->protocol == htons(ETH_P_IPV6)) { 146 struct inet6_dev *in6dev = __in6_dev_get(dev); 147 148 if (in6dev) 149 IP6_UPD_PO_STATS(dev_net(dev), in6dev, 150 IPSTATS_MIB_OUT, skb->len); 151 #endif 152 } 153 } 154 EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts); 155 156 static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb) 157 { 158 struct mpls_entry_decoded dec; 159 unsigned int mpls_hdr_len = 0; 160 struct mpls_shim_hdr *hdr; 161 bool eli_seen = false; 162 int label_index; 163 u32 hash = 0; 164 165 for (label_index = 0; label_index < MAX_MP_SELECT_LABELS; 166 label_index++) { 167 mpls_hdr_len += sizeof(*hdr); 168 if (!pskb_may_pull(skb, mpls_hdr_len)) 169 break; 170 171 /* Read and decode the current label */ 172 hdr = mpls_hdr(skb) + label_index; 173 dec = mpls_entry_decode(hdr); 174 175 /* RFC6790 - reserved labels MUST NOT be used as keys 176 * for the load-balancing function 177 */ 178 if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) { 179 hash = jhash_1word(dec.label, hash); 180 181 /* The entropy label follows the entropy label 182 * indicator, so this means that the entropy 183 * label was just added to the hash - no need to 184 * go any deeper either in the label stack or in the 185 * payload 186 */ 187 if (eli_seen) 188 break; 189 } else if (dec.label == MPLS_LABEL_ENTROPY) { 190 eli_seen = true; 191 } 192 193 if (!dec.bos) 194 continue; 195 196 /* found bottom label; does skb have room for a header? */ 197 if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) { 198 const struct iphdr *v4hdr; 199 200 v4hdr = (const struct iphdr *)(hdr + 1); 201 if (v4hdr->version == 4) { 202 hash = jhash_3words(ntohl(v4hdr->saddr), 203 ntohl(v4hdr->daddr), 204 v4hdr->protocol, hash); 205 } else if (v4hdr->version == 6 && 206 pskb_may_pull(skb, mpls_hdr_len + 207 sizeof(struct ipv6hdr))) { 208 const struct ipv6hdr *v6hdr; 209 210 v6hdr = (const struct ipv6hdr *)(hdr + 1); 211 hash = __ipv6_addr_jhash(&v6hdr->saddr, hash); 212 hash = __ipv6_addr_jhash(&v6hdr->daddr, hash); 213 hash = jhash_1word(v6hdr->nexthdr, hash); 214 } 215 } 216 217 break; 218 } 219 220 return hash; 221 } 222 223 static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index) 224 { 225 return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size); 226 } 227 228 /* number of alive nexthops (rt->rt_nhn_alive) and the flags for 229 * a next hop (nh->nh_flags) are modified by netdev event handlers. 230 * Since those fields can change at any moment, use READ_ONCE to 231 * access both. 232 */ 233 static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt, 234 struct sk_buff *skb) 235 { 236 u32 hash = 0; 237 int nh_index = 0; 238 int n = 0; 239 u8 alive; 240 241 /* No need to look further into packet if there's only 242 * one path 243 */ 244 if (rt->rt_nhn == 1) 245 return rt->rt_nh; 246 247 alive = READ_ONCE(rt->rt_nhn_alive); 248 if (alive == 0) 249 return NULL; 250 251 hash = mpls_multipath_hash(rt, skb); 252 nh_index = hash % alive; 253 if (alive == rt->rt_nhn) 254 goto out; 255 for_nexthops(rt) { 256 unsigned int nh_flags = READ_ONCE(nh->nh_flags); 257 258 if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 259 continue; 260 if (n == nh_index) 261 return nh; 262 n++; 263 } endfor_nexthops(rt); 264 265 out: 266 return mpls_get_nexthop(rt, nh_index); 267 } 268 269 static bool mpls_egress(struct net *net, struct mpls_route *rt, 270 struct sk_buff *skb, struct mpls_entry_decoded dec) 271 { 272 enum mpls_payload_type payload_type; 273 bool success = false; 274 275 /* The IPv4 code below accesses through the IPv4 header 276 * checksum, which is 12 bytes into the packet. 277 * The IPv6 code below accesses through the IPv6 hop limit 278 * which is 8 bytes into the packet. 279 * 280 * For all supported cases there should always be at least 12 281 * bytes of packet data present. The IPv4 header is 20 bytes 282 * without options and the IPv6 header is always 40 bytes 283 * long. 284 */ 285 if (!pskb_may_pull(skb, 12)) 286 return false; 287 288 payload_type = rt->rt_payload_type; 289 if (payload_type == MPT_UNSPEC) 290 payload_type = ip_hdr(skb)->version; 291 292 switch (payload_type) { 293 case MPT_IPV4: { 294 struct iphdr *hdr4 = ip_hdr(skb); 295 u8 new_ttl; 296 skb->protocol = htons(ETH_P_IP); 297 298 /* If propagating TTL, take the decremented TTL from 299 * the incoming MPLS header, otherwise decrement the 300 * TTL, but only if not 0 to avoid underflow. 301 */ 302 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED || 303 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT && 304 net->mpls.ip_ttl_propagate)) 305 new_ttl = dec.ttl; 306 else 307 new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0; 308 309 csum_replace2(&hdr4->check, 310 htons(hdr4->ttl << 8), 311 htons(new_ttl << 8)); 312 hdr4->ttl = new_ttl; 313 success = true; 314 break; 315 } 316 case MPT_IPV6: { 317 struct ipv6hdr *hdr6 = ipv6_hdr(skb); 318 skb->protocol = htons(ETH_P_IPV6); 319 320 /* If propagating TTL, take the decremented TTL from 321 * the incoming MPLS header, otherwise decrement the 322 * hop limit, but only if not 0 to avoid underflow. 323 */ 324 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED || 325 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT && 326 net->mpls.ip_ttl_propagate)) 327 hdr6->hop_limit = dec.ttl; 328 else if (hdr6->hop_limit) 329 hdr6->hop_limit = hdr6->hop_limit - 1; 330 success = true; 331 break; 332 } 333 case MPT_UNSPEC: 334 /* Should have decided which protocol it is by now */ 335 break; 336 } 337 338 return success; 339 } 340 341 static int mpls_forward(struct sk_buff *skb, struct net_device *dev, 342 struct packet_type *pt, struct net_device *orig_dev) 343 { 344 struct net *net = dev_net(dev); 345 struct mpls_shim_hdr *hdr; 346 struct mpls_route *rt; 347 struct mpls_nh *nh; 348 struct mpls_entry_decoded dec; 349 struct net_device *out_dev; 350 struct mpls_dev *out_mdev; 351 struct mpls_dev *mdev; 352 unsigned int hh_len; 353 unsigned int new_header_size; 354 unsigned int mtu; 355 int err; 356 357 /* Careful this entire function runs inside of an rcu critical section */ 358 359 mdev = mpls_dev_get(dev); 360 if (!mdev) 361 goto drop; 362 363 MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets, 364 rx_bytes); 365 366 if (!mdev->input_enabled) { 367 MPLS_INC_STATS(mdev, rx_dropped); 368 goto drop; 369 } 370 371 if (skb->pkt_type != PACKET_HOST) 372 goto err; 373 374 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 375 goto err; 376 377 if (!pskb_may_pull(skb, sizeof(*hdr))) 378 goto err; 379 380 /* Read and decode the label */ 381 hdr = mpls_hdr(skb); 382 dec = mpls_entry_decode(hdr); 383 384 rt = mpls_route_input_rcu(net, dec.label); 385 if (!rt) { 386 MPLS_INC_STATS(mdev, rx_noroute); 387 goto drop; 388 } 389 390 nh = mpls_select_multipath(rt, skb); 391 if (!nh) 392 goto err; 393 394 /* Pop the label */ 395 skb_pull(skb, sizeof(*hdr)); 396 skb_reset_network_header(skb); 397 398 skb_orphan(skb); 399 400 if (skb_warn_if_lro(skb)) 401 goto err; 402 403 skb_forward_csum(skb); 404 405 /* Verify ttl is valid */ 406 if (dec.ttl <= 1) 407 goto err; 408 dec.ttl -= 1; 409 410 /* Find the output device */ 411 out_dev = rcu_dereference(nh->nh_dev); 412 if (!mpls_output_possible(out_dev)) 413 goto tx_err; 414 415 /* Verify the destination can hold the packet */ 416 new_header_size = mpls_nh_header_size(nh); 417 mtu = mpls_dev_mtu(out_dev); 418 if (mpls_pkt_too_big(skb, mtu - new_header_size)) 419 goto tx_err; 420 421 hh_len = LL_RESERVED_SPACE(out_dev); 422 if (!out_dev->header_ops) 423 hh_len = 0; 424 425 /* Ensure there is enough space for the headers in the skb */ 426 if (skb_cow(skb, hh_len + new_header_size)) 427 goto tx_err; 428 429 skb->dev = out_dev; 430 skb->protocol = htons(ETH_P_MPLS_UC); 431 432 if (unlikely(!new_header_size && dec.bos)) { 433 /* Penultimate hop popping */ 434 if (!mpls_egress(dev_net(out_dev), rt, skb, dec)) 435 goto err; 436 } else { 437 bool bos; 438 int i; 439 skb_push(skb, new_header_size); 440 skb_reset_network_header(skb); 441 /* Push the new labels */ 442 hdr = mpls_hdr(skb); 443 bos = dec.bos; 444 for (i = nh->nh_labels - 1; i >= 0; i--) { 445 hdr[i] = mpls_entry_encode(nh->nh_label[i], 446 dec.ttl, 0, bos); 447 bos = false; 448 } 449 } 450 451 mpls_stats_inc_outucastpkts(out_dev, skb); 452 453 /* If via wasn't specified then send out using device address */ 454 if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC) 455 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev, 456 out_dev->dev_addr, skb); 457 else 458 err = neigh_xmit(nh->nh_via_table, out_dev, 459 mpls_nh_via(rt, nh), skb); 460 if (err) 461 net_dbg_ratelimited("%s: packet transmission failed: %d\n", 462 __func__, err); 463 return 0; 464 465 tx_err: 466 out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL; 467 if (out_mdev) 468 MPLS_INC_STATS(out_mdev, tx_errors); 469 goto drop; 470 err: 471 MPLS_INC_STATS(mdev, rx_errors); 472 drop: 473 kfree_skb(skb); 474 return NET_RX_DROP; 475 } 476 477 static struct packet_type mpls_packet_type __read_mostly = { 478 .type = cpu_to_be16(ETH_P_MPLS_UC), 479 .func = mpls_forward, 480 }; 481 482 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = { 483 [RTA_DST] = { .type = NLA_U32 }, 484 [RTA_OIF] = { .type = NLA_U32 }, 485 [RTA_TTL_PROPAGATE] = { .type = NLA_U8 }, 486 }; 487 488 struct mpls_route_config { 489 u32 rc_protocol; 490 u32 rc_ifindex; 491 u8 rc_via_table; 492 u8 rc_via_alen; 493 u8 rc_via[MAX_VIA_ALEN]; 494 u32 rc_label; 495 u8 rc_ttl_propagate; 496 u8 rc_output_labels; 497 u32 rc_output_label[MAX_NEW_LABELS]; 498 u32 rc_nlflags; 499 enum mpls_payload_type rc_payload_type; 500 struct nl_info rc_nlinfo; 501 struct rtnexthop *rc_mp; 502 int rc_mp_len; 503 }; 504 505 /* all nexthops within a route have the same size based on max 506 * number of labels and max via length for a hop 507 */ 508 static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels) 509 { 510 u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen); 511 struct mpls_route *rt; 512 size_t size; 513 514 size = sizeof(*rt) + num_nh * nh_size; 515 if (size > MAX_MPLS_ROUTE_MEM) 516 return ERR_PTR(-EINVAL); 517 518 rt = kzalloc(size, GFP_KERNEL); 519 if (!rt) 520 return ERR_PTR(-ENOMEM); 521 522 rt->rt_nhn = num_nh; 523 rt->rt_nhn_alive = num_nh; 524 rt->rt_nh_size = nh_size; 525 rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels); 526 527 return rt; 528 } 529 530 static void mpls_rt_free(struct mpls_route *rt) 531 { 532 if (rt) 533 kfree_rcu(rt, rt_rcu); 534 } 535 536 static void mpls_notify_route(struct net *net, unsigned index, 537 struct mpls_route *old, struct mpls_route *new, 538 const struct nl_info *info) 539 { 540 struct nlmsghdr *nlh = info ? info->nlh : NULL; 541 unsigned portid = info ? info->portid : 0; 542 int event = new ? RTM_NEWROUTE : RTM_DELROUTE; 543 struct mpls_route *rt = new ? new : old; 544 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0; 545 /* Ignore reserved labels for now */ 546 if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED)) 547 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags); 548 } 549 550 static void mpls_route_update(struct net *net, unsigned index, 551 struct mpls_route *new, 552 const struct nl_info *info) 553 { 554 struct mpls_route __rcu **platform_label; 555 struct mpls_route *rt; 556 557 ASSERT_RTNL(); 558 559 platform_label = rtnl_dereference(net->mpls.platform_label); 560 rt = rtnl_dereference(platform_label[index]); 561 rcu_assign_pointer(platform_label[index], new); 562 563 mpls_notify_route(net, index, rt, new, info); 564 565 /* If we removed a route free it now */ 566 mpls_rt_free(rt); 567 } 568 569 static unsigned find_free_label(struct net *net) 570 { 571 struct mpls_route __rcu **platform_label; 572 size_t platform_labels; 573 unsigned index; 574 575 platform_label = rtnl_dereference(net->mpls.platform_label); 576 platform_labels = net->mpls.platform_labels; 577 for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels; 578 index++) { 579 if (!rtnl_dereference(platform_label[index])) 580 return index; 581 } 582 return LABEL_NOT_SPECIFIED; 583 } 584 585 #if IS_ENABLED(CONFIG_INET) 586 static struct net_device *inet_fib_lookup_dev(struct net *net, 587 const void *addr) 588 { 589 struct net_device *dev; 590 struct rtable *rt; 591 struct in_addr daddr; 592 593 memcpy(&daddr, addr, sizeof(struct in_addr)); 594 rt = ip_route_output(net, daddr.s_addr, 0, 0, 0); 595 if (IS_ERR(rt)) 596 return ERR_CAST(rt); 597 598 dev = rt->dst.dev; 599 dev_hold(dev); 600 601 ip_rt_put(rt); 602 603 return dev; 604 } 605 #else 606 static struct net_device *inet_fib_lookup_dev(struct net *net, 607 const void *addr) 608 { 609 return ERR_PTR(-EAFNOSUPPORT); 610 } 611 #endif 612 613 #if IS_ENABLED(CONFIG_IPV6) 614 static struct net_device *inet6_fib_lookup_dev(struct net *net, 615 const void *addr) 616 { 617 struct net_device *dev; 618 struct dst_entry *dst; 619 struct flowi6 fl6; 620 int err; 621 622 if (!ipv6_stub) 623 return ERR_PTR(-EAFNOSUPPORT); 624 625 memset(&fl6, 0, sizeof(fl6)); 626 memcpy(&fl6.daddr, addr, sizeof(struct in6_addr)); 627 err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6); 628 if (err) 629 return ERR_PTR(err); 630 631 dev = dst->dev; 632 dev_hold(dev); 633 dst_release(dst); 634 635 return dev; 636 } 637 #else 638 static struct net_device *inet6_fib_lookup_dev(struct net *net, 639 const void *addr) 640 { 641 return ERR_PTR(-EAFNOSUPPORT); 642 } 643 #endif 644 645 static struct net_device *find_outdev(struct net *net, 646 struct mpls_route *rt, 647 struct mpls_nh *nh, int oif) 648 { 649 struct net_device *dev = NULL; 650 651 if (!oif) { 652 switch (nh->nh_via_table) { 653 case NEIGH_ARP_TABLE: 654 dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 655 break; 656 case NEIGH_ND_TABLE: 657 dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 658 break; 659 case NEIGH_LINK_TABLE: 660 break; 661 } 662 } else { 663 dev = dev_get_by_index(net, oif); 664 } 665 666 if (!dev) 667 return ERR_PTR(-ENODEV); 668 669 if (IS_ERR(dev)) 670 return dev; 671 672 /* The caller is holding rtnl anyways, so release the dev reference */ 673 dev_put(dev); 674 675 return dev; 676 } 677 678 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt, 679 struct mpls_nh *nh, int oif) 680 { 681 struct net_device *dev = NULL; 682 int err = -ENODEV; 683 684 dev = find_outdev(net, rt, nh, oif); 685 if (IS_ERR(dev)) { 686 err = PTR_ERR(dev); 687 dev = NULL; 688 goto errout; 689 } 690 691 /* Ensure this is a supported device */ 692 err = -EINVAL; 693 if (!mpls_dev_get(dev)) 694 goto errout; 695 696 if ((nh->nh_via_table == NEIGH_LINK_TABLE) && 697 (dev->addr_len != nh->nh_via_alen)) 698 goto errout; 699 700 RCU_INIT_POINTER(nh->nh_dev, dev); 701 702 if (!(dev->flags & IFF_UP)) { 703 nh->nh_flags |= RTNH_F_DEAD; 704 } else { 705 unsigned int flags; 706 707 flags = dev_get_flags(dev); 708 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP))) 709 nh->nh_flags |= RTNH_F_LINKDOWN; 710 } 711 712 return 0; 713 714 errout: 715 return err; 716 } 717 718 static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table, 719 u8 via_addr[], struct netlink_ext_ack *extack) 720 { 721 struct rtvia *via = nla_data(nla); 722 int err = -EINVAL; 723 int alen; 724 725 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 726 NL_SET_ERR_MSG_ATTR(extack, nla, 727 "Invalid attribute length for RTA_VIA"); 728 goto errout; 729 } 730 alen = nla_len(nla) - 731 offsetof(struct rtvia, rtvia_addr); 732 if (alen > MAX_VIA_ALEN) { 733 NL_SET_ERR_MSG_ATTR(extack, nla, 734 "Invalid address length for RTA_VIA"); 735 goto errout; 736 } 737 738 /* Validate the address family */ 739 switch (via->rtvia_family) { 740 case AF_PACKET: 741 *via_table = NEIGH_LINK_TABLE; 742 break; 743 case AF_INET: 744 *via_table = NEIGH_ARP_TABLE; 745 if (alen != 4) 746 goto errout; 747 break; 748 case AF_INET6: 749 *via_table = NEIGH_ND_TABLE; 750 if (alen != 16) 751 goto errout; 752 break; 753 default: 754 /* Unsupported address family */ 755 goto errout; 756 } 757 758 memcpy(via_addr, via->rtvia_addr, alen); 759 *via_alen = alen; 760 err = 0; 761 762 errout: 763 return err; 764 } 765 766 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg, 767 struct mpls_route *rt) 768 { 769 struct net *net = cfg->rc_nlinfo.nl_net; 770 struct mpls_nh *nh = rt->rt_nh; 771 int err; 772 int i; 773 774 if (!nh) 775 return -ENOMEM; 776 777 nh->nh_labels = cfg->rc_output_labels; 778 for (i = 0; i < nh->nh_labels; i++) 779 nh->nh_label[i] = cfg->rc_output_label[i]; 780 781 nh->nh_via_table = cfg->rc_via_table; 782 memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen); 783 nh->nh_via_alen = cfg->rc_via_alen; 784 785 err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex); 786 if (err) 787 goto errout; 788 789 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 790 rt->rt_nhn_alive--; 791 792 return 0; 793 794 errout: 795 return err; 796 } 797 798 static int mpls_nh_build(struct net *net, struct mpls_route *rt, 799 struct mpls_nh *nh, int oif, struct nlattr *via, 800 struct nlattr *newdst, u8 max_labels, 801 struct netlink_ext_ack *extack) 802 { 803 int err = -ENOMEM; 804 805 if (!nh) 806 goto errout; 807 808 if (newdst) { 809 err = nla_get_labels(newdst, max_labels, &nh->nh_labels, 810 nh->nh_label, extack); 811 if (err) 812 goto errout; 813 } 814 815 if (via) { 816 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table, 817 __mpls_nh_via(rt, nh), extack); 818 if (err) 819 goto errout; 820 } else { 821 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC; 822 } 823 824 err = mpls_nh_assign_dev(net, rt, nh, oif); 825 if (err) 826 goto errout; 827 828 return 0; 829 830 errout: 831 return err; 832 } 833 834 static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len, 835 u8 cfg_via_alen, u8 *max_via_alen, 836 u8 *max_labels) 837 { 838 int remaining = len; 839 u8 nhs = 0; 840 841 *max_via_alen = 0; 842 *max_labels = 0; 843 844 while (rtnh_ok(rtnh, remaining)) { 845 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 846 int attrlen; 847 u8 n_labels = 0; 848 849 attrlen = rtnh_attrlen(rtnh); 850 nla = nla_find(attrs, attrlen, RTA_VIA); 851 if (nla && nla_len(nla) >= 852 offsetof(struct rtvia, rtvia_addr)) { 853 int via_alen = nla_len(nla) - 854 offsetof(struct rtvia, rtvia_addr); 855 856 if (via_alen <= MAX_VIA_ALEN) 857 *max_via_alen = max_t(u16, *max_via_alen, 858 via_alen); 859 } 860 861 nla = nla_find(attrs, attrlen, RTA_NEWDST); 862 if (nla && 863 nla_get_labels(nla, MAX_NEW_LABELS, &n_labels, 864 NULL, NULL) != 0) 865 return 0; 866 867 *max_labels = max_t(u8, *max_labels, n_labels); 868 869 /* number of nexthops is tracked by a u8. 870 * Check for overflow. 871 */ 872 if (nhs == 255) 873 return 0; 874 nhs++; 875 876 rtnh = rtnh_next(rtnh, &remaining); 877 } 878 879 /* leftover implies invalid nexthop configuration, discard it */ 880 return remaining > 0 ? 0 : nhs; 881 } 882 883 static int mpls_nh_build_multi(struct mpls_route_config *cfg, 884 struct mpls_route *rt, u8 max_labels, 885 struct netlink_ext_ack *extack) 886 { 887 struct rtnexthop *rtnh = cfg->rc_mp; 888 struct nlattr *nla_via, *nla_newdst; 889 int remaining = cfg->rc_mp_len; 890 int err = 0; 891 u8 nhs = 0; 892 893 change_nexthops(rt) { 894 int attrlen; 895 896 nla_via = NULL; 897 nla_newdst = NULL; 898 899 err = -EINVAL; 900 if (!rtnh_ok(rtnh, remaining)) 901 goto errout; 902 903 /* neither weighted multipath nor any flags 904 * are supported 905 */ 906 if (rtnh->rtnh_hops || rtnh->rtnh_flags) 907 goto errout; 908 909 attrlen = rtnh_attrlen(rtnh); 910 if (attrlen > 0) { 911 struct nlattr *attrs = rtnh_attrs(rtnh); 912 913 nla_via = nla_find(attrs, attrlen, RTA_VIA); 914 nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST); 915 } 916 917 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh, 918 rtnh->rtnh_ifindex, nla_via, nla_newdst, 919 max_labels, extack); 920 if (err) 921 goto errout; 922 923 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 924 rt->rt_nhn_alive--; 925 926 rtnh = rtnh_next(rtnh, &remaining); 927 nhs++; 928 } endfor_nexthops(rt); 929 930 rt->rt_nhn = nhs; 931 932 return 0; 933 934 errout: 935 return err; 936 } 937 938 static bool mpls_label_ok(struct net *net, unsigned int index, 939 struct netlink_ext_ack *extack) 940 { 941 /* Reserved labels may not be set */ 942 if (index < MPLS_LABEL_FIRST_UNRESERVED) { 943 NL_SET_ERR_MSG(extack, 944 "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher"); 945 return false; 946 } 947 948 /* The full 20 bit range may not be supported. */ 949 if (index >= net->mpls.platform_labels) { 950 NL_SET_ERR_MSG(extack, 951 "Label >= configured maximum in platform_labels"); 952 return false; 953 } 954 955 return true; 956 } 957 958 static int mpls_route_add(struct mpls_route_config *cfg, 959 struct netlink_ext_ack *extack) 960 { 961 struct mpls_route __rcu **platform_label; 962 struct net *net = cfg->rc_nlinfo.nl_net; 963 struct mpls_route *rt, *old; 964 int err = -EINVAL; 965 u8 max_via_alen; 966 unsigned index; 967 u8 max_labels; 968 u8 nhs; 969 970 index = cfg->rc_label; 971 972 /* If a label was not specified during insert pick one */ 973 if ((index == LABEL_NOT_SPECIFIED) && 974 (cfg->rc_nlflags & NLM_F_CREATE)) { 975 index = find_free_label(net); 976 } 977 978 if (!mpls_label_ok(net, index, extack)) 979 goto errout; 980 981 /* Append makes no sense with mpls */ 982 err = -EOPNOTSUPP; 983 if (cfg->rc_nlflags & NLM_F_APPEND) { 984 NL_SET_ERR_MSG(extack, "MPLS does not support route append"); 985 goto errout; 986 } 987 988 err = -EEXIST; 989 platform_label = rtnl_dereference(net->mpls.platform_label); 990 old = rtnl_dereference(platform_label[index]); 991 if ((cfg->rc_nlflags & NLM_F_EXCL) && old) 992 goto errout; 993 994 err = -EEXIST; 995 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old) 996 goto errout; 997 998 err = -ENOENT; 999 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old) 1000 goto errout; 1001 1002 err = -EINVAL; 1003 if (cfg->rc_mp) { 1004 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len, 1005 cfg->rc_via_alen, &max_via_alen, 1006 &max_labels); 1007 } else { 1008 max_via_alen = cfg->rc_via_alen; 1009 max_labels = cfg->rc_output_labels; 1010 nhs = 1; 1011 } 1012 1013 if (nhs == 0) { 1014 NL_SET_ERR_MSG(extack, "Route does not contain a nexthop"); 1015 goto errout; 1016 } 1017 1018 err = -ENOMEM; 1019 rt = mpls_rt_alloc(nhs, max_via_alen, max_labels); 1020 if (IS_ERR(rt)) { 1021 err = PTR_ERR(rt); 1022 goto errout; 1023 } 1024 1025 rt->rt_protocol = cfg->rc_protocol; 1026 rt->rt_payload_type = cfg->rc_payload_type; 1027 rt->rt_ttl_propagate = cfg->rc_ttl_propagate; 1028 1029 if (cfg->rc_mp) 1030 err = mpls_nh_build_multi(cfg, rt, max_labels, extack); 1031 else 1032 err = mpls_nh_build_from_cfg(cfg, rt); 1033 if (err) 1034 goto freert; 1035 1036 mpls_route_update(net, index, rt, &cfg->rc_nlinfo); 1037 1038 return 0; 1039 1040 freert: 1041 mpls_rt_free(rt); 1042 errout: 1043 return err; 1044 } 1045 1046 static int mpls_route_del(struct mpls_route_config *cfg, 1047 struct netlink_ext_ack *extack) 1048 { 1049 struct net *net = cfg->rc_nlinfo.nl_net; 1050 unsigned index; 1051 int err = -EINVAL; 1052 1053 index = cfg->rc_label; 1054 1055 if (!mpls_label_ok(net, index, extack)) 1056 goto errout; 1057 1058 mpls_route_update(net, index, NULL, &cfg->rc_nlinfo); 1059 1060 err = 0; 1061 errout: 1062 return err; 1063 } 1064 1065 static void mpls_get_stats(struct mpls_dev *mdev, 1066 struct mpls_link_stats *stats) 1067 { 1068 struct mpls_pcpu_stats *p; 1069 int i; 1070 1071 memset(stats, 0, sizeof(*stats)); 1072 1073 for_each_possible_cpu(i) { 1074 struct mpls_link_stats local; 1075 unsigned int start; 1076 1077 p = per_cpu_ptr(mdev->stats, i); 1078 do { 1079 start = u64_stats_fetch_begin(&p->syncp); 1080 local = p->stats; 1081 } while (u64_stats_fetch_retry(&p->syncp, start)); 1082 1083 stats->rx_packets += local.rx_packets; 1084 stats->rx_bytes += local.rx_bytes; 1085 stats->tx_packets += local.tx_packets; 1086 stats->tx_bytes += local.tx_bytes; 1087 stats->rx_errors += local.rx_errors; 1088 stats->tx_errors += local.tx_errors; 1089 stats->rx_dropped += local.rx_dropped; 1090 stats->tx_dropped += local.tx_dropped; 1091 stats->rx_noroute += local.rx_noroute; 1092 } 1093 } 1094 1095 static int mpls_fill_stats_af(struct sk_buff *skb, 1096 const struct net_device *dev) 1097 { 1098 struct mpls_link_stats *stats; 1099 struct mpls_dev *mdev; 1100 struct nlattr *nla; 1101 1102 mdev = mpls_dev_get(dev); 1103 if (!mdev) 1104 return -ENODATA; 1105 1106 nla = nla_reserve_64bit(skb, MPLS_STATS_LINK, 1107 sizeof(struct mpls_link_stats), 1108 MPLS_STATS_UNSPEC); 1109 if (!nla) 1110 return -EMSGSIZE; 1111 1112 stats = nla_data(nla); 1113 mpls_get_stats(mdev, stats); 1114 1115 return 0; 1116 } 1117 1118 static size_t mpls_get_stats_af_size(const struct net_device *dev) 1119 { 1120 struct mpls_dev *mdev; 1121 1122 mdev = mpls_dev_get(dev); 1123 if (!mdev) 1124 return 0; 1125 1126 return nla_total_size_64bit(sizeof(struct mpls_link_stats)); 1127 } 1128 1129 static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev, 1130 u32 portid, u32 seq, int event, 1131 unsigned int flags, int type) 1132 { 1133 struct nlmsghdr *nlh; 1134 struct netconfmsg *ncm; 1135 bool all = false; 1136 1137 nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg), 1138 flags); 1139 if (!nlh) 1140 return -EMSGSIZE; 1141 1142 if (type == NETCONFA_ALL) 1143 all = true; 1144 1145 ncm = nlmsg_data(nlh); 1146 ncm->ncm_family = AF_MPLS; 1147 1148 if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0) 1149 goto nla_put_failure; 1150 1151 if ((all || type == NETCONFA_INPUT) && 1152 nla_put_s32(skb, NETCONFA_INPUT, 1153 mdev->input_enabled) < 0) 1154 goto nla_put_failure; 1155 1156 nlmsg_end(skb, nlh); 1157 return 0; 1158 1159 nla_put_failure: 1160 nlmsg_cancel(skb, nlh); 1161 return -EMSGSIZE; 1162 } 1163 1164 static int mpls_netconf_msgsize_devconf(int type) 1165 { 1166 int size = NLMSG_ALIGN(sizeof(struct netconfmsg)) 1167 + nla_total_size(4); /* NETCONFA_IFINDEX */ 1168 bool all = false; 1169 1170 if (type == NETCONFA_ALL) 1171 all = true; 1172 1173 if (all || type == NETCONFA_INPUT) 1174 size += nla_total_size(4); 1175 1176 return size; 1177 } 1178 1179 static void mpls_netconf_notify_devconf(struct net *net, int event, 1180 int type, struct mpls_dev *mdev) 1181 { 1182 struct sk_buff *skb; 1183 int err = -ENOBUFS; 1184 1185 skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL); 1186 if (!skb) 1187 goto errout; 1188 1189 err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type); 1190 if (err < 0) { 1191 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */ 1192 WARN_ON(err == -EMSGSIZE); 1193 kfree_skb(skb); 1194 goto errout; 1195 } 1196 1197 rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL); 1198 return; 1199 errout: 1200 if (err < 0) 1201 rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err); 1202 } 1203 1204 static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = { 1205 [NETCONFA_IFINDEX] = { .len = sizeof(int) }, 1206 }; 1207 1208 static int mpls_netconf_get_devconf(struct sk_buff *in_skb, 1209 struct nlmsghdr *nlh, 1210 struct netlink_ext_ack *extack) 1211 { 1212 struct net *net = sock_net(in_skb->sk); 1213 struct nlattr *tb[NETCONFA_MAX + 1]; 1214 struct netconfmsg *ncm; 1215 struct net_device *dev; 1216 struct mpls_dev *mdev; 1217 struct sk_buff *skb; 1218 int ifindex; 1219 int err; 1220 1221 err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX, 1222 devconf_mpls_policy, NULL); 1223 if (err < 0) 1224 goto errout; 1225 1226 err = -EINVAL; 1227 if (!tb[NETCONFA_IFINDEX]) 1228 goto errout; 1229 1230 ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]); 1231 dev = __dev_get_by_index(net, ifindex); 1232 if (!dev) 1233 goto errout; 1234 1235 mdev = mpls_dev_get(dev); 1236 if (!mdev) 1237 goto errout; 1238 1239 err = -ENOBUFS; 1240 skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL); 1241 if (!skb) 1242 goto errout; 1243 1244 err = mpls_netconf_fill_devconf(skb, mdev, 1245 NETLINK_CB(in_skb).portid, 1246 nlh->nlmsg_seq, RTM_NEWNETCONF, 0, 1247 NETCONFA_ALL); 1248 if (err < 0) { 1249 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */ 1250 WARN_ON(err == -EMSGSIZE); 1251 kfree_skb(skb); 1252 goto errout; 1253 } 1254 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 1255 errout: 1256 return err; 1257 } 1258 1259 static int mpls_netconf_dump_devconf(struct sk_buff *skb, 1260 struct netlink_callback *cb) 1261 { 1262 struct net *net = sock_net(skb->sk); 1263 struct hlist_head *head; 1264 struct net_device *dev; 1265 struct mpls_dev *mdev; 1266 int idx, s_idx; 1267 int h, s_h; 1268 1269 s_h = cb->args[0]; 1270 s_idx = idx = cb->args[1]; 1271 1272 for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { 1273 idx = 0; 1274 head = &net->dev_index_head[h]; 1275 rcu_read_lock(); 1276 cb->seq = net->dev_base_seq; 1277 hlist_for_each_entry_rcu(dev, head, index_hlist) { 1278 if (idx < s_idx) 1279 goto cont; 1280 mdev = mpls_dev_get(dev); 1281 if (!mdev) 1282 goto cont; 1283 if (mpls_netconf_fill_devconf(skb, mdev, 1284 NETLINK_CB(cb->skb).portid, 1285 cb->nlh->nlmsg_seq, 1286 RTM_NEWNETCONF, 1287 NLM_F_MULTI, 1288 NETCONFA_ALL) < 0) { 1289 rcu_read_unlock(); 1290 goto done; 1291 } 1292 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 1293 cont: 1294 idx++; 1295 } 1296 rcu_read_unlock(); 1297 } 1298 done: 1299 cb->args[0] = h; 1300 cb->args[1] = idx; 1301 1302 return skb->len; 1303 } 1304 1305 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \ 1306 (&((struct mpls_dev *)0)->field) 1307 1308 static int mpls_conf_proc(struct ctl_table *ctl, int write, 1309 void __user *buffer, 1310 size_t *lenp, loff_t *ppos) 1311 { 1312 int oval = *(int *)ctl->data; 1313 int ret = proc_dointvec(ctl, write, buffer, lenp, ppos); 1314 1315 if (write) { 1316 struct mpls_dev *mdev = ctl->extra1; 1317 int i = (int *)ctl->data - (int *)mdev; 1318 struct net *net = ctl->extra2; 1319 int val = *(int *)ctl->data; 1320 1321 if (i == offsetof(struct mpls_dev, input_enabled) && 1322 val != oval) { 1323 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, 1324 NETCONFA_INPUT, mdev); 1325 } 1326 } 1327 1328 return ret; 1329 } 1330 1331 static const struct ctl_table mpls_dev_table[] = { 1332 { 1333 .procname = "input", 1334 .maxlen = sizeof(int), 1335 .mode = 0644, 1336 .proc_handler = mpls_conf_proc, 1337 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled), 1338 }, 1339 { } 1340 }; 1341 1342 static int mpls_dev_sysctl_register(struct net_device *dev, 1343 struct mpls_dev *mdev) 1344 { 1345 char path[sizeof("net/mpls/conf/") + IFNAMSIZ]; 1346 struct net *net = dev_net(dev); 1347 struct ctl_table *table; 1348 int i; 1349 1350 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL); 1351 if (!table) 1352 goto out; 1353 1354 /* Table data contains only offsets relative to the base of 1355 * the mdev at this point, so make them absolute. 1356 */ 1357 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) { 1358 table[i].data = (char *)mdev + (uintptr_t)table[i].data; 1359 table[i].extra1 = mdev; 1360 table[i].extra2 = net; 1361 } 1362 1363 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name); 1364 1365 mdev->sysctl = register_net_sysctl(net, path, table); 1366 if (!mdev->sysctl) 1367 goto free; 1368 1369 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev); 1370 return 0; 1371 1372 free: 1373 kfree(table); 1374 out: 1375 return -ENOBUFS; 1376 } 1377 1378 static void mpls_dev_sysctl_unregister(struct net_device *dev, 1379 struct mpls_dev *mdev) 1380 { 1381 struct net *net = dev_net(dev); 1382 struct ctl_table *table; 1383 1384 table = mdev->sysctl->ctl_table_arg; 1385 unregister_net_sysctl_table(mdev->sysctl); 1386 kfree(table); 1387 1388 mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev); 1389 } 1390 1391 static struct mpls_dev *mpls_add_dev(struct net_device *dev) 1392 { 1393 struct mpls_dev *mdev; 1394 int err = -ENOMEM; 1395 int i; 1396 1397 ASSERT_RTNL(); 1398 1399 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); 1400 if (!mdev) 1401 return ERR_PTR(err); 1402 1403 mdev->stats = alloc_percpu(struct mpls_pcpu_stats); 1404 if (!mdev->stats) 1405 goto free; 1406 1407 for_each_possible_cpu(i) { 1408 struct mpls_pcpu_stats *mpls_stats; 1409 1410 mpls_stats = per_cpu_ptr(mdev->stats, i); 1411 u64_stats_init(&mpls_stats->syncp); 1412 } 1413 1414 mdev->dev = dev; 1415 1416 err = mpls_dev_sysctl_register(dev, mdev); 1417 if (err) 1418 goto free; 1419 1420 rcu_assign_pointer(dev->mpls_ptr, mdev); 1421 1422 return mdev; 1423 1424 free: 1425 free_percpu(mdev->stats); 1426 kfree(mdev); 1427 return ERR_PTR(err); 1428 } 1429 1430 static void mpls_dev_destroy_rcu(struct rcu_head *head) 1431 { 1432 struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu); 1433 1434 free_percpu(mdev->stats); 1435 kfree(mdev); 1436 } 1437 1438 static void mpls_ifdown(struct net_device *dev, int event) 1439 { 1440 struct mpls_route __rcu **platform_label; 1441 struct net *net = dev_net(dev); 1442 u8 alive, deleted; 1443 unsigned index; 1444 1445 platform_label = rtnl_dereference(net->mpls.platform_label); 1446 for (index = 0; index < net->mpls.platform_labels; index++) { 1447 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1448 1449 if (!rt) 1450 continue; 1451 1452 alive = 0; 1453 deleted = 0; 1454 change_nexthops(rt) { 1455 unsigned int nh_flags = nh->nh_flags; 1456 1457 if (rtnl_dereference(nh->nh_dev) != dev) 1458 goto next; 1459 1460 switch (event) { 1461 case NETDEV_DOWN: 1462 case NETDEV_UNREGISTER: 1463 nh_flags |= RTNH_F_DEAD; 1464 /* fall through */ 1465 case NETDEV_CHANGE: 1466 nh_flags |= RTNH_F_LINKDOWN; 1467 break; 1468 } 1469 if (event == NETDEV_UNREGISTER) 1470 RCU_INIT_POINTER(nh->nh_dev, NULL); 1471 1472 if (nh->nh_flags != nh_flags) 1473 WRITE_ONCE(nh->nh_flags, nh_flags); 1474 next: 1475 if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))) 1476 alive++; 1477 if (!rtnl_dereference(nh->nh_dev)) 1478 deleted++; 1479 } endfor_nexthops(rt); 1480 1481 WRITE_ONCE(rt->rt_nhn_alive, alive); 1482 1483 /* if there are no more nexthops, delete the route */ 1484 if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn) 1485 mpls_route_update(net, index, NULL, NULL); 1486 } 1487 } 1488 1489 static void mpls_ifup(struct net_device *dev, unsigned int flags) 1490 { 1491 struct mpls_route __rcu **platform_label; 1492 struct net *net = dev_net(dev); 1493 unsigned index; 1494 u8 alive; 1495 1496 platform_label = rtnl_dereference(net->mpls.platform_label); 1497 for (index = 0; index < net->mpls.platform_labels; index++) { 1498 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1499 1500 if (!rt) 1501 continue; 1502 1503 alive = 0; 1504 change_nexthops(rt) { 1505 unsigned int nh_flags = nh->nh_flags; 1506 struct net_device *nh_dev = 1507 rtnl_dereference(nh->nh_dev); 1508 1509 if (!(nh_flags & flags)) { 1510 alive++; 1511 continue; 1512 } 1513 if (nh_dev != dev) 1514 continue; 1515 alive++; 1516 nh_flags &= ~flags; 1517 WRITE_ONCE(nh->nh_flags, nh_flags); 1518 } endfor_nexthops(rt); 1519 1520 WRITE_ONCE(rt->rt_nhn_alive, alive); 1521 } 1522 } 1523 1524 static int mpls_dev_notify(struct notifier_block *this, unsigned long event, 1525 void *ptr) 1526 { 1527 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1528 struct mpls_dev *mdev; 1529 unsigned int flags; 1530 1531 if (event == NETDEV_REGISTER) { 1532 /* For now just support Ethernet, IPGRE, SIT and IPIP devices */ 1533 if (dev->type == ARPHRD_ETHER || 1534 dev->type == ARPHRD_LOOPBACK || 1535 dev->type == ARPHRD_IPGRE || 1536 dev->type == ARPHRD_SIT || 1537 dev->type == ARPHRD_TUNNEL) { 1538 mdev = mpls_add_dev(dev); 1539 if (IS_ERR(mdev)) 1540 return notifier_from_errno(PTR_ERR(mdev)); 1541 } 1542 return NOTIFY_OK; 1543 } 1544 1545 mdev = mpls_dev_get(dev); 1546 if (!mdev) 1547 return NOTIFY_OK; 1548 1549 switch (event) { 1550 case NETDEV_DOWN: 1551 mpls_ifdown(dev, event); 1552 break; 1553 case NETDEV_UP: 1554 flags = dev_get_flags(dev); 1555 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1556 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1557 else 1558 mpls_ifup(dev, RTNH_F_DEAD); 1559 break; 1560 case NETDEV_CHANGE: 1561 flags = dev_get_flags(dev); 1562 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1563 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1564 else 1565 mpls_ifdown(dev, event); 1566 break; 1567 case NETDEV_UNREGISTER: 1568 mpls_ifdown(dev, event); 1569 mdev = mpls_dev_get(dev); 1570 if (mdev) { 1571 mpls_dev_sysctl_unregister(dev, mdev); 1572 RCU_INIT_POINTER(dev->mpls_ptr, NULL); 1573 call_rcu(&mdev->rcu, mpls_dev_destroy_rcu); 1574 } 1575 break; 1576 case NETDEV_CHANGENAME: 1577 mdev = mpls_dev_get(dev); 1578 if (mdev) { 1579 int err; 1580 1581 mpls_dev_sysctl_unregister(dev, mdev); 1582 err = mpls_dev_sysctl_register(dev, mdev); 1583 if (err) 1584 return notifier_from_errno(err); 1585 } 1586 break; 1587 } 1588 return NOTIFY_OK; 1589 } 1590 1591 static struct notifier_block mpls_dev_notifier = { 1592 .notifier_call = mpls_dev_notify, 1593 }; 1594 1595 static int nla_put_via(struct sk_buff *skb, 1596 u8 table, const void *addr, int alen) 1597 { 1598 static const int table_to_family[NEIGH_NR_TABLES + 1] = { 1599 AF_INET, AF_INET6, AF_DECnet, AF_PACKET, 1600 }; 1601 struct nlattr *nla; 1602 struct rtvia *via; 1603 int family = AF_UNSPEC; 1604 1605 nla = nla_reserve(skb, RTA_VIA, alen + 2); 1606 if (!nla) 1607 return -EMSGSIZE; 1608 1609 if (table <= NEIGH_NR_TABLES) 1610 family = table_to_family[table]; 1611 1612 via = nla_data(nla); 1613 via->rtvia_family = family; 1614 memcpy(via->rtvia_addr, addr, alen); 1615 return 0; 1616 } 1617 1618 int nla_put_labels(struct sk_buff *skb, int attrtype, 1619 u8 labels, const u32 label[]) 1620 { 1621 struct nlattr *nla; 1622 struct mpls_shim_hdr *nla_label; 1623 bool bos; 1624 int i; 1625 nla = nla_reserve(skb, attrtype, labels*4); 1626 if (!nla) 1627 return -EMSGSIZE; 1628 1629 nla_label = nla_data(nla); 1630 bos = true; 1631 for (i = labels - 1; i >= 0; i--) { 1632 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos); 1633 bos = false; 1634 } 1635 1636 return 0; 1637 } 1638 EXPORT_SYMBOL_GPL(nla_put_labels); 1639 1640 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels, 1641 u32 label[], struct netlink_ext_ack *extack) 1642 { 1643 unsigned len = nla_len(nla); 1644 struct mpls_shim_hdr *nla_label; 1645 u8 nla_labels; 1646 bool bos; 1647 int i; 1648 1649 /* len needs to be an even multiple of 4 (the label size). Number 1650 * of labels is a u8 so check for overflow. 1651 */ 1652 if (len & 3 || len / 4 > 255) { 1653 NL_SET_ERR_MSG_ATTR(extack, nla, 1654 "Invalid length for labels attribute"); 1655 return -EINVAL; 1656 } 1657 1658 /* Limit the number of new labels allowed */ 1659 nla_labels = len/4; 1660 if (nla_labels > max_labels) { 1661 NL_SET_ERR_MSG(extack, "Too many labels"); 1662 return -EINVAL; 1663 } 1664 1665 /* when label == NULL, caller wants number of labels */ 1666 if (!label) 1667 goto out; 1668 1669 nla_label = nla_data(nla); 1670 bos = true; 1671 for (i = nla_labels - 1; i >= 0; i--, bos = false) { 1672 struct mpls_entry_decoded dec; 1673 dec = mpls_entry_decode(nla_label + i); 1674 1675 /* Ensure the bottom of stack flag is properly set 1676 * and ttl and tc are both clear. 1677 */ 1678 if (dec.ttl) { 1679 NL_SET_ERR_MSG_ATTR(extack, nla, 1680 "TTL in label must be 0"); 1681 return -EINVAL; 1682 } 1683 1684 if (dec.tc) { 1685 NL_SET_ERR_MSG_ATTR(extack, nla, 1686 "Traffic class in label must be 0"); 1687 return -EINVAL; 1688 } 1689 1690 if (dec.bos != bos) { 1691 NL_SET_BAD_ATTR(extack, nla); 1692 if (bos) { 1693 NL_SET_ERR_MSG(extack, 1694 "BOS bit must be set in first label"); 1695 } else { 1696 NL_SET_ERR_MSG(extack, 1697 "BOS bit can only be set in first label"); 1698 } 1699 return -EINVAL; 1700 } 1701 1702 switch (dec.label) { 1703 case MPLS_LABEL_IMPLNULL: 1704 /* RFC3032: This is a label that an LSR may 1705 * assign and distribute, but which never 1706 * actually appears in the encapsulation. 1707 */ 1708 NL_SET_ERR_MSG_ATTR(extack, nla, 1709 "Implicit NULL Label (3) can not be used in encapsulation"); 1710 return -EINVAL; 1711 } 1712 1713 label[i] = dec.label; 1714 } 1715 out: 1716 *labels = nla_labels; 1717 return 0; 1718 } 1719 EXPORT_SYMBOL_GPL(nla_get_labels); 1720 1721 static int rtm_to_route_config(struct sk_buff *skb, 1722 struct nlmsghdr *nlh, 1723 struct mpls_route_config *cfg, 1724 struct netlink_ext_ack *extack) 1725 { 1726 struct rtmsg *rtm; 1727 struct nlattr *tb[RTA_MAX+1]; 1728 int index; 1729 int err; 1730 1731 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy, 1732 extack); 1733 if (err < 0) 1734 goto errout; 1735 1736 err = -EINVAL; 1737 rtm = nlmsg_data(nlh); 1738 1739 if (rtm->rtm_family != AF_MPLS) { 1740 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg"); 1741 goto errout; 1742 } 1743 if (rtm->rtm_dst_len != 20) { 1744 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS"); 1745 goto errout; 1746 } 1747 if (rtm->rtm_src_len != 0) { 1748 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS"); 1749 goto errout; 1750 } 1751 if (rtm->rtm_tos != 0) { 1752 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS"); 1753 goto errout; 1754 } 1755 if (rtm->rtm_table != RT_TABLE_MAIN) { 1756 NL_SET_ERR_MSG(extack, 1757 "MPLS only supports the main route table"); 1758 goto errout; 1759 } 1760 /* Any value is acceptable for rtm_protocol */ 1761 1762 /* As mpls uses destination specific addresses 1763 * (or source specific address in the case of multicast) 1764 * all addresses have universal scope. 1765 */ 1766 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) { 1767 NL_SET_ERR_MSG(extack, 1768 "Invalid route scope - MPLS only supports UNIVERSE"); 1769 goto errout; 1770 } 1771 if (rtm->rtm_type != RTN_UNICAST) { 1772 NL_SET_ERR_MSG(extack, 1773 "Invalid route type - MPLS only supports UNICAST"); 1774 goto errout; 1775 } 1776 if (rtm->rtm_flags != 0) { 1777 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS"); 1778 goto errout; 1779 } 1780 1781 cfg->rc_label = LABEL_NOT_SPECIFIED; 1782 cfg->rc_protocol = rtm->rtm_protocol; 1783 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC; 1784 cfg->rc_ttl_propagate = MPLS_TTL_PROP_DEFAULT; 1785 cfg->rc_nlflags = nlh->nlmsg_flags; 1786 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid; 1787 cfg->rc_nlinfo.nlh = nlh; 1788 cfg->rc_nlinfo.nl_net = sock_net(skb->sk); 1789 1790 for (index = 0; index <= RTA_MAX; index++) { 1791 struct nlattr *nla = tb[index]; 1792 if (!nla) 1793 continue; 1794 1795 switch (index) { 1796 case RTA_OIF: 1797 cfg->rc_ifindex = nla_get_u32(nla); 1798 break; 1799 case RTA_NEWDST: 1800 if (nla_get_labels(nla, MAX_NEW_LABELS, 1801 &cfg->rc_output_labels, 1802 cfg->rc_output_label, extack)) 1803 goto errout; 1804 break; 1805 case RTA_DST: 1806 { 1807 u8 label_count; 1808 if (nla_get_labels(nla, 1, &label_count, 1809 &cfg->rc_label, extack)) 1810 goto errout; 1811 1812 if (!mpls_label_ok(cfg->rc_nlinfo.nl_net, 1813 cfg->rc_label, extack)) 1814 goto errout; 1815 break; 1816 } 1817 case RTA_VIA: 1818 { 1819 if (nla_get_via(nla, &cfg->rc_via_alen, 1820 &cfg->rc_via_table, cfg->rc_via, 1821 extack)) 1822 goto errout; 1823 break; 1824 } 1825 case RTA_MULTIPATH: 1826 { 1827 cfg->rc_mp = nla_data(nla); 1828 cfg->rc_mp_len = nla_len(nla); 1829 break; 1830 } 1831 case RTA_TTL_PROPAGATE: 1832 { 1833 u8 ttl_propagate = nla_get_u8(nla); 1834 1835 if (ttl_propagate > 1) { 1836 NL_SET_ERR_MSG_ATTR(extack, nla, 1837 "RTA_TTL_PROPAGATE can only be 0 or 1"); 1838 goto errout; 1839 } 1840 cfg->rc_ttl_propagate = ttl_propagate ? 1841 MPLS_TTL_PROP_ENABLED : 1842 MPLS_TTL_PROP_DISABLED; 1843 break; 1844 } 1845 default: 1846 NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute"); 1847 /* Unsupported attribute */ 1848 goto errout; 1849 } 1850 } 1851 1852 err = 0; 1853 errout: 1854 return err; 1855 } 1856 1857 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 1858 struct netlink_ext_ack *extack) 1859 { 1860 struct mpls_route_config *cfg; 1861 int err; 1862 1863 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL); 1864 if (!cfg) 1865 return -ENOMEM; 1866 1867 err = rtm_to_route_config(skb, nlh, cfg, extack); 1868 if (err < 0) 1869 goto out; 1870 1871 err = mpls_route_del(cfg, extack); 1872 out: 1873 kfree(cfg); 1874 1875 return err; 1876 } 1877 1878 1879 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 1880 struct netlink_ext_ack *extack) 1881 { 1882 struct mpls_route_config *cfg; 1883 int err; 1884 1885 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL); 1886 if (!cfg) 1887 return -ENOMEM; 1888 1889 err = rtm_to_route_config(skb, nlh, cfg, extack); 1890 if (err < 0) 1891 goto out; 1892 1893 err = mpls_route_add(cfg, extack); 1894 out: 1895 kfree(cfg); 1896 1897 return err; 1898 } 1899 1900 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, 1901 u32 label, struct mpls_route *rt, int flags) 1902 { 1903 struct net_device *dev; 1904 struct nlmsghdr *nlh; 1905 struct rtmsg *rtm; 1906 1907 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); 1908 if (nlh == NULL) 1909 return -EMSGSIZE; 1910 1911 rtm = nlmsg_data(nlh); 1912 rtm->rtm_family = AF_MPLS; 1913 rtm->rtm_dst_len = 20; 1914 rtm->rtm_src_len = 0; 1915 rtm->rtm_tos = 0; 1916 rtm->rtm_table = RT_TABLE_MAIN; 1917 rtm->rtm_protocol = rt->rt_protocol; 1918 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 1919 rtm->rtm_type = RTN_UNICAST; 1920 rtm->rtm_flags = 0; 1921 1922 if (nla_put_labels(skb, RTA_DST, 1, &label)) 1923 goto nla_put_failure; 1924 1925 if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) { 1926 bool ttl_propagate = 1927 rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED; 1928 1929 if (nla_put_u8(skb, RTA_TTL_PROPAGATE, 1930 ttl_propagate)) 1931 goto nla_put_failure; 1932 } 1933 if (rt->rt_nhn == 1) { 1934 const struct mpls_nh *nh = rt->rt_nh; 1935 1936 if (nh->nh_labels && 1937 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels, 1938 nh->nh_label)) 1939 goto nla_put_failure; 1940 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1941 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh), 1942 nh->nh_via_alen)) 1943 goto nla_put_failure; 1944 dev = rtnl_dereference(nh->nh_dev); 1945 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) 1946 goto nla_put_failure; 1947 if (nh->nh_flags & RTNH_F_LINKDOWN) 1948 rtm->rtm_flags |= RTNH_F_LINKDOWN; 1949 if (nh->nh_flags & RTNH_F_DEAD) 1950 rtm->rtm_flags |= RTNH_F_DEAD; 1951 } else { 1952 struct rtnexthop *rtnh; 1953 struct nlattr *mp; 1954 u8 linkdown = 0; 1955 u8 dead = 0; 1956 1957 mp = nla_nest_start(skb, RTA_MULTIPATH); 1958 if (!mp) 1959 goto nla_put_failure; 1960 1961 for_nexthops(rt) { 1962 dev = rtnl_dereference(nh->nh_dev); 1963 if (!dev) 1964 continue; 1965 1966 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); 1967 if (!rtnh) 1968 goto nla_put_failure; 1969 1970 rtnh->rtnh_ifindex = dev->ifindex; 1971 if (nh->nh_flags & RTNH_F_LINKDOWN) { 1972 rtnh->rtnh_flags |= RTNH_F_LINKDOWN; 1973 linkdown++; 1974 } 1975 if (nh->nh_flags & RTNH_F_DEAD) { 1976 rtnh->rtnh_flags |= RTNH_F_DEAD; 1977 dead++; 1978 } 1979 1980 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST, 1981 nh->nh_labels, 1982 nh->nh_label)) 1983 goto nla_put_failure; 1984 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1985 nla_put_via(skb, nh->nh_via_table, 1986 mpls_nh_via(rt, nh), 1987 nh->nh_via_alen)) 1988 goto nla_put_failure; 1989 1990 /* length of rtnetlink header + attributes */ 1991 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; 1992 } endfor_nexthops(rt); 1993 1994 if (linkdown == rt->rt_nhn) 1995 rtm->rtm_flags |= RTNH_F_LINKDOWN; 1996 if (dead == rt->rt_nhn) 1997 rtm->rtm_flags |= RTNH_F_DEAD; 1998 1999 nla_nest_end(skb, mp); 2000 } 2001 2002 nlmsg_end(skb, nlh); 2003 return 0; 2004 2005 nla_put_failure: 2006 nlmsg_cancel(skb, nlh); 2007 return -EMSGSIZE; 2008 } 2009 2010 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) 2011 { 2012 struct net *net = sock_net(skb->sk); 2013 struct mpls_route __rcu **platform_label; 2014 size_t platform_labels; 2015 unsigned int index; 2016 2017 ASSERT_RTNL(); 2018 2019 index = cb->args[0]; 2020 if (index < MPLS_LABEL_FIRST_UNRESERVED) 2021 index = MPLS_LABEL_FIRST_UNRESERVED; 2022 2023 platform_label = rtnl_dereference(net->mpls.platform_label); 2024 platform_labels = net->mpls.platform_labels; 2025 for (; index < platform_labels; index++) { 2026 struct mpls_route *rt; 2027 rt = rtnl_dereference(platform_label[index]); 2028 if (!rt) 2029 continue; 2030 2031 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid, 2032 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 2033 index, rt, NLM_F_MULTI) < 0) 2034 break; 2035 } 2036 cb->args[0] = index; 2037 2038 return skb->len; 2039 } 2040 2041 static inline size_t lfib_nlmsg_size(struct mpls_route *rt) 2042 { 2043 size_t payload = 2044 NLMSG_ALIGN(sizeof(struct rtmsg)) 2045 + nla_total_size(4) /* RTA_DST */ 2046 + nla_total_size(1); /* RTA_TTL_PROPAGATE */ 2047 2048 if (rt->rt_nhn == 1) { 2049 struct mpls_nh *nh = rt->rt_nh; 2050 2051 if (nh->nh_dev) 2052 payload += nla_total_size(4); /* RTA_OIF */ 2053 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */ 2054 payload += nla_total_size(2 + nh->nh_via_alen); 2055 if (nh->nh_labels) /* RTA_NEWDST */ 2056 payload += nla_total_size(nh->nh_labels * 4); 2057 } else { 2058 /* each nexthop is packed in an attribute */ 2059 size_t nhsize = 0; 2060 2061 for_nexthops(rt) { 2062 if (!rtnl_dereference(nh->nh_dev)) 2063 continue; 2064 nhsize += nla_total_size(sizeof(struct rtnexthop)); 2065 /* RTA_VIA */ 2066 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) 2067 nhsize += nla_total_size(2 + nh->nh_via_alen); 2068 if (nh->nh_labels) 2069 nhsize += nla_total_size(nh->nh_labels * 4); 2070 } endfor_nexthops(rt); 2071 /* nested attribute */ 2072 payload += nla_total_size(nhsize); 2073 } 2074 2075 return payload; 2076 } 2077 2078 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 2079 struct nlmsghdr *nlh, struct net *net, u32 portid, 2080 unsigned int nlm_flags) 2081 { 2082 struct sk_buff *skb; 2083 u32 seq = nlh ? nlh->nlmsg_seq : 0; 2084 int err = -ENOBUFS; 2085 2086 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL); 2087 if (skb == NULL) 2088 goto errout; 2089 2090 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags); 2091 if (err < 0) { 2092 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */ 2093 WARN_ON(err == -EMSGSIZE); 2094 kfree_skb(skb); 2095 goto errout; 2096 } 2097 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL); 2098 2099 return; 2100 errout: 2101 if (err < 0) 2102 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err); 2103 } 2104 2105 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 2106 struct netlink_ext_ack *extack) 2107 { 2108 struct net *net = sock_net(in_skb->sk); 2109 u32 portid = NETLINK_CB(in_skb).portid; 2110 u32 in_label = LABEL_NOT_SPECIFIED; 2111 struct nlattr *tb[RTA_MAX + 1]; 2112 u32 labels[MAX_NEW_LABELS]; 2113 struct mpls_shim_hdr *hdr; 2114 unsigned int hdr_size = 0; 2115 struct net_device *dev; 2116 struct mpls_route *rt; 2117 struct rtmsg *rtm, *r; 2118 struct nlmsghdr *nlh; 2119 struct sk_buff *skb; 2120 struct mpls_nh *nh; 2121 u8 n_labels; 2122 int err; 2123 2124 err = nlmsg_parse(in_nlh, sizeof(*rtm), tb, RTA_MAX, 2125 rtm_mpls_policy, extack); 2126 if (err < 0) 2127 goto errout; 2128 2129 rtm = nlmsg_data(in_nlh); 2130 2131 if (tb[RTA_DST]) { 2132 u8 label_count; 2133 2134 if (nla_get_labels(tb[RTA_DST], 1, &label_count, 2135 &in_label, extack)) { 2136 err = -EINVAL; 2137 goto errout; 2138 } 2139 2140 if (!mpls_label_ok(net, in_label, extack)) { 2141 err = -EINVAL; 2142 goto errout; 2143 } 2144 } 2145 2146 rt = mpls_route_input_rcu(net, in_label); 2147 if (!rt) { 2148 err = -ENETUNREACH; 2149 goto errout; 2150 } 2151 2152 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 2153 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL); 2154 if (!skb) { 2155 err = -ENOBUFS; 2156 goto errout; 2157 } 2158 2159 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq, 2160 RTM_NEWROUTE, in_label, rt, 0); 2161 if (err < 0) { 2162 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */ 2163 WARN_ON(err == -EMSGSIZE); 2164 goto errout_free; 2165 } 2166 2167 return rtnl_unicast(skb, net, portid); 2168 } 2169 2170 if (tb[RTA_NEWDST]) { 2171 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels, 2172 labels, extack) != 0) { 2173 err = -EINVAL; 2174 goto errout; 2175 } 2176 2177 hdr_size = n_labels * sizeof(struct mpls_shim_hdr); 2178 } 2179 2180 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2181 if (!skb) { 2182 err = -ENOBUFS; 2183 goto errout; 2184 } 2185 2186 skb->protocol = htons(ETH_P_MPLS_UC); 2187 2188 if (hdr_size) { 2189 bool bos; 2190 int i; 2191 2192 if (skb_cow(skb, hdr_size)) { 2193 err = -ENOBUFS; 2194 goto errout_free; 2195 } 2196 2197 skb_reserve(skb, hdr_size); 2198 skb_push(skb, hdr_size); 2199 skb_reset_network_header(skb); 2200 2201 /* Push new labels */ 2202 hdr = mpls_hdr(skb); 2203 bos = true; 2204 for (i = n_labels - 1; i >= 0; i--) { 2205 hdr[i] = mpls_entry_encode(labels[i], 2206 1, 0, bos); 2207 bos = false; 2208 } 2209 } 2210 2211 nh = mpls_select_multipath(rt, skb); 2212 if (!nh) { 2213 err = -ENETUNREACH; 2214 goto errout_free; 2215 } 2216 2217 if (hdr_size) { 2218 skb_pull(skb, hdr_size); 2219 skb_reset_network_header(skb); 2220 } 2221 2222 nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq, 2223 RTM_NEWROUTE, sizeof(*r), 0); 2224 if (!nlh) { 2225 err = -EMSGSIZE; 2226 goto errout_free; 2227 } 2228 2229 r = nlmsg_data(nlh); 2230 r->rtm_family = AF_MPLS; 2231 r->rtm_dst_len = 20; 2232 r->rtm_src_len = 0; 2233 r->rtm_table = RT_TABLE_MAIN; 2234 r->rtm_type = RTN_UNICAST; 2235 r->rtm_scope = RT_SCOPE_UNIVERSE; 2236 r->rtm_protocol = rt->rt_protocol; 2237 r->rtm_flags = 0; 2238 2239 if (nla_put_labels(skb, RTA_DST, 1, &in_label)) 2240 goto nla_put_failure; 2241 2242 if (nh->nh_labels && 2243 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels, 2244 nh->nh_label)) 2245 goto nla_put_failure; 2246 2247 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 2248 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh), 2249 nh->nh_via_alen)) 2250 goto nla_put_failure; 2251 dev = rtnl_dereference(nh->nh_dev); 2252 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) 2253 goto nla_put_failure; 2254 2255 nlmsg_end(skb, nlh); 2256 2257 err = rtnl_unicast(skb, net, portid); 2258 errout: 2259 return err; 2260 2261 nla_put_failure: 2262 nlmsg_cancel(skb, nlh); 2263 err = -EMSGSIZE; 2264 errout_free: 2265 kfree_skb(skb); 2266 return err; 2267 } 2268 2269 static int resize_platform_label_table(struct net *net, size_t limit) 2270 { 2271 size_t size = sizeof(struct mpls_route *) * limit; 2272 size_t old_limit; 2273 size_t cp_size; 2274 struct mpls_route __rcu **labels = NULL, **old; 2275 struct mpls_route *rt0 = NULL, *rt2 = NULL; 2276 unsigned index; 2277 2278 if (size) { 2279 labels = kvzalloc(size, GFP_KERNEL); 2280 if (!labels) 2281 goto nolabels; 2282 } 2283 2284 /* In case the predefined labels need to be populated */ 2285 if (limit > MPLS_LABEL_IPV4NULL) { 2286 struct net_device *lo = net->loopback_dev; 2287 rt0 = mpls_rt_alloc(1, lo->addr_len, 0); 2288 if (IS_ERR(rt0)) 2289 goto nort0; 2290 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo); 2291 rt0->rt_protocol = RTPROT_KERNEL; 2292 rt0->rt_payload_type = MPT_IPV4; 2293 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT; 2294 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 2295 rt0->rt_nh->nh_via_alen = lo->addr_len; 2296 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr, 2297 lo->addr_len); 2298 } 2299 if (limit > MPLS_LABEL_IPV6NULL) { 2300 struct net_device *lo = net->loopback_dev; 2301 rt2 = mpls_rt_alloc(1, lo->addr_len, 0); 2302 if (IS_ERR(rt2)) 2303 goto nort2; 2304 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo); 2305 rt2->rt_protocol = RTPROT_KERNEL; 2306 rt2->rt_payload_type = MPT_IPV6; 2307 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT; 2308 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 2309 rt2->rt_nh->nh_via_alen = lo->addr_len; 2310 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr, 2311 lo->addr_len); 2312 } 2313 2314 rtnl_lock(); 2315 /* Remember the original table */ 2316 old = rtnl_dereference(net->mpls.platform_label); 2317 old_limit = net->mpls.platform_labels; 2318 2319 /* Free any labels beyond the new table */ 2320 for (index = limit; index < old_limit; index++) 2321 mpls_route_update(net, index, NULL, NULL); 2322 2323 /* Copy over the old labels */ 2324 cp_size = size; 2325 if (old_limit < limit) 2326 cp_size = old_limit * sizeof(struct mpls_route *); 2327 2328 memcpy(labels, old, cp_size); 2329 2330 /* If needed set the predefined labels */ 2331 if ((old_limit <= MPLS_LABEL_IPV6NULL) && 2332 (limit > MPLS_LABEL_IPV6NULL)) { 2333 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2); 2334 rt2 = NULL; 2335 } 2336 2337 if ((old_limit <= MPLS_LABEL_IPV4NULL) && 2338 (limit > MPLS_LABEL_IPV4NULL)) { 2339 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0); 2340 rt0 = NULL; 2341 } 2342 2343 /* Update the global pointers */ 2344 net->mpls.platform_labels = limit; 2345 rcu_assign_pointer(net->mpls.platform_label, labels); 2346 2347 rtnl_unlock(); 2348 2349 mpls_rt_free(rt2); 2350 mpls_rt_free(rt0); 2351 2352 if (old) { 2353 synchronize_rcu(); 2354 kvfree(old); 2355 } 2356 return 0; 2357 2358 nort2: 2359 mpls_rt_free(rt0); 2360 nort0: 2361 kvfree(labels); 2362 nolabels: 2363 return -ENOMEM; 2364 } 2365 2366 static int mpls_platform_labels(struct ctl_table *table, int write, 2367 void __user *buffer, size_t *lenp, loff_t *ppos) 2368 { 2369 struct net *net = table->data; 2370 int platform_labels = net->mpls.platform_labels; 2371 int ret; 2372 struct ctl_table tmp = { 2373 .procname = table->procname, 2374 .data = &platform_labels, 2375 .maxlen = sizeof(int), 2376 .mode = table->mode, 2377 .extra1 = &zero, 2378 .extra2 = &label_limit, 2379 }; 2380 2381 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 2382 2383 if (write && ret == 0) 2384 ret = resize_platform_label_table(net, platform_labels); 2385 2386 return ret; 2387 } 2388 2389 #define MPLS_NS_SYSCTL_OFFSET(field) \ 2390 (&((struct net *)0)->field) 2391 2392 static const struct ctl_table mpls_table[] = { 2393 { 2394 .procname = "platform_labels", 2395 .data = NULL, 2396 .maxlen = sizeof(int), 2397 .mode = 0644, 2398 .proc_handler = mpls_platform_labels, 2399 }, 2400 { 2401 .procname = "ip_ttl_propagate", 2402 .data = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate), 2403 .maxlen = sizeof(int), 2404 .mode = 0644, 2405 .proc_handler = proc_dointvec_minmax, 2406 .extra1 = &zero, 2407 .extra2 = &one, 2408 }, 2409 { 2410 .procname = "default_ttl", 2411 .data = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl), 2412 .maxlen = sizeof(int), 2413 .mode = 0644, 2414 .proc_handler = proc_dointvec_minmax, 2415 .extra1 = &one, 2416 .extra2 = &ttl_max, 2417 }, 2418 { } 2419 }; 2420 2421 static int mpls_net_init(struct net *net) 2422 { 2423 struct ctl_table *table; 2424 int i; 2425 2426 net->mpls.platform_labels = 0; 2427 net->mpls.platform_label = NULL; 2428 net->mpls.ip_ttl_propagate = 1; 2429 net->mpls.default_ttl = 255; 2430 2431 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL); 2432 if (table == NULL) 2433 return -ENOMEM; 2434 2435 /* Table data contains only offsets relative to the base of 2436 * the mdev at this point, so make them absolute. 2437 */ 2438 for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++) 2439 table[i].data = (char *)net + (uintptr_t)table[i].data; 2440 2441 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table); 2442 if (net->mpls.ctl == NULL) { 2443 kfree(table); 2444 return -ENOMEM; 2445 } 2446 2447 return 0; 2448 } 2449 2450 static void mpls_net_exit(struct net *net) 2451 { 2452 struct mpls_route __rcu **platform_label; 2453 size_t platform_labels; 2454 struct ctl_table *table; 2455 unsigned int index; 2456 2457 table = net->mpls.ctl->ctl_table_arg; 2458 unregister_net_sysctl_table(net->mpls.ctl); 2459 kfree(table); 2460 2461 /* An rcu grace period has passed since there was a device in 2462 * the network namespace (and thus the last in flight packet) 2463 * left this network namespace. This is because 2464 * unregister_netdevice_many and netdev_run_todo has completed 2465 * for each network device that was in this network namespace. 2466 * 2467 * As such no additional rcu synchronization is necessary when 2468 * freeing the platform_label table. 2469 */ 2470 rtnl_lock(); 2471 platform_label = rtnl_dereference(net->mpls.platform_label); 2472 platform_labels = net->mpls.platform_labels; 2473 for (index = 0; index < platform_labels; index++) { 2474 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 2475 RCU_INIT_POINTER(platform_label[index], NULL); 2476 mpls_notify_route(net, index, rt, NULL, NULL); 2477 mpls_rt_free(rt); 2478 } 2479 rtnl_unlock(); 2480 2481 kvfree(platform_label); 2482 } 2483 2484 static struct pernet_operations mpls_net_ops = { 2485 .init = mpls_net_init, 2486 .exit = mpls_net_exit, 2487 }; 2488 2489 static struct rtnl_af_ops mpls_af_ops __read_mostly = { 2490 .family = AF_MPLS, 2491 .fill_stats_af = mpls_fill_stats_af, 2492 .get_stats_af_size = mpls_get_stats_af_size, 2493 }; 2494 2495 static int __init mpls_init(void) 2496 { 2497 int err; 2498 2499 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4); 2500 2501 err = register_pernet_subsys(&mpls_net_ops); 2502 if (err) 2503 goto out; 2504 2505 err = register_netdevice_notifier(&mpls_dev_notifier); 2506 if (err) 2507 goto out_unregister_pernet; 2508 2509 dev_add_pack(&mpls_packet_type); 2510 2511 rtnl_af_register(&mpls_af_ops); 2512 2513 rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, 0); 2514 rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, 0); 2515 rtnl_register(PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes, 2516 0); 2517 rtnl_register(PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf, 2518 mpls_netconf_dump_devconf, 0); 2519 err = ipgre_tunnel_encap_add_mpls_ops(); 2520 if (err) 2521 pr_err("Can't add mpls over gre tunnel ops\n"); 2522 2523 err = 0; 2524 out: 2525 return err; 2526 2527 out_unregister_pernet: 2528 unregister_pernet_subsys(&mpls_net_ops); 2529 goto out; 2530 } 2531 module_init(mpls_init); 2532 2533 static void __exit mpls_exit(void) 2534 { 2535 rtnl_unregister_all(PF_MPLS); 2536 rtnl_af_unregister(&mpls_af_ops); 2537 dev_remove_pack(&mpls_packet_type); 2538 unregister_netdevice_notifier(&mpls_dev_notifier); 2539 unregister_pernet_subsys(&mpls_net_ops); 2540 ipgre_tunnel_encap_del_mpls_ops(); 2541 } 2542 module_exit(mpls_exit); 2543 2544 MODULE_DESCRIPTION("MultiProtocol Label Switching"); 2545 MODULE_LICENSE("GPL v2"); 2546 MODULE_ALIAS_NETPROTO(PF_MPLS); 2547