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/nospec.h> 12 #include <linux/vmalloc.h> 13 #include <linux/percpu.h> 14 #include <net/ip.h> 15 #include <net/dst.h> 16 #include <net/sock.h> 17 #include <net/arp.h> 18 #include <net/ip_fib.h> 19 #include <net/netevent.h> 20 #include <net/ip_tunnels.h> 21 #include <net/netns/generic.h> 22 #if IS_ENABLED(CONFIG_IPV6) 23 #include <net/ipv6.h> 24 #endif 25 #include <net/addrconf.h> 26 #include <net/nexthop.h> 27 #include "internal.h" 28 29 /* max memory we will use for mpls_route */ 30 #define MAX_MPLS_ROUTE_MEM 4096 31 32 /* Maximum number of labels to look ahead at when selecting a path of 33 * a multipath route 34 */ 35 #define MAX_MP_SELECT_LABELS 4 36 37 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1) 38 39 static int zero = 0; 40 static int one = 1; 41 static int label_limit = (1 << 20) - 1; 42 static int ttl_max = 255; 43 44 #if IS_ENABLED(CONFIG_NET_IP_TUNNEL) 45 static size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e) 46 { 47 return sizeof(struct mpls_shim_hdr); 48 } 49 50 static const struct ip_tunnel_encap_ops mpls_iptun_ops = { 51 .encap_hlen = ipgre_mpls_encap_hlen, 52 }; 53 54 static int ipgre_tunnel_encap_add_mpls_ops(void) 55 { 56 return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS); 57 } 58 59 static void ipgre_tunnel_encap_del_mpls_ops(void) 60 { 61 ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS); 62 } 63 #else 64 static int ipgre_tunnel_encap_add_mpls_ops(void) 65 { 66 return 0; 67 } 68 69 static void ipgre_tunnel_encap_del_mpls_ops(void) 70 { 71 } 72 #endif 73 74 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 75 struct nlmsghdr *nlh, struct net *net, u32 portid, 76 unsigned int nlm_flags); 77 78 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index) 79 { 80 struct mpls_route *rt = NULL; 81 82 if (index < net->mpls.platform_labels) { 83 struct mpls_route __rcu **platform_label = 84 rcu_dereference(net->mpls.platform_label); 85 rt = rcu_dereference(platform_label[index]); 86 } 87 return rt; 88 } 89 90 bool mpls_output_possible(const struct net_device *dev) 91 { 92 return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev); 93 } 94 EXPORT_SYMBOL_GPL(mpls_output_possible); 95 96 static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh) 97 { 98 return (u8 *)nh + rt->rt_via_offset; 99 } 100 101 static const u8 *mpls_nh_via(const struct mpls_route *rt, 102 const struct mpls_nh *nh) 103 { 104 return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh); 105 } 106 107 static unsigned int mpls_nh_header_size(const struct mpls_nh *nh) 108 { 109 /* The size of the layer 2.5 labels to be added for this route */ 110 return nh->nh_labels * sizeof(struct mpls_shim_hdr); 111 } 112 113 unsigned int mpls_dev_mtu(const struct net_device *dev) 114 { 115 /* The amount of data the layer 2 frame can hold */ 116 return dev->mtu; 117 } 118 EXPORT_SYMBOL_GPL(mpls_dev_mtu); 119 120 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 121 { 122 if (skb->len <= mtu) 123 return false; 124 125 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 126 return false; 127 128 return true; 129 } 130 EXPORT_SYMBOL_GPL(mpls_pkt_too_big); 131 132 void mpls_stats_inc_outucastpkts(struct net_device *dev, 133 const struct sk_buff *skb) 134 { 135 struct mpls_dev *mdev; 136 137 if (skb->protocol == htons(ETH_P_MPLS_UC)) { 138 mdev = mpls_dev_get(dev); 139 if (mdev) 140 MPLS_INC_STATS_LEN(mdev, skb->len, 141 tx_packets, 142 tx_bytes); 143 } else if (skb->protocol == htons(ETH_P_IP)) { 144 IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); 145 #if IS_ENABLED(CONFIG_IPV6) 146 } else if (skb->protocol == htons(ETH_P_IPV6)) { 147 struct inet6_dev *in6dev = __in6_dev_get(dev); 148 149 if (in6dev) 150 IP6_UPD_PO_STATS(dev_net(dev), in6dev, 151 IPSTATS_MIB_OUT, skb->len); 152 #endif 153 } 154 } 155 EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts); 156 157 static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb) 158 { 159 struct mpls_entry_decoded dec; 160 unsigned int mpls_hdr_len = 0; 161 struct mpls_shim_hdr *hdr; 162 bool eli_seen = false; 163 int label_index; 164 u32 hash = 0; 165 166 for (label_index = 0; label_index < MAX_MP_SELECT_LABELS; 167 label_index++) { 168 mpls_hdr_len += sizeof(*hdr); 169 if (!pskb_may_pull(skb, mpls_hdr_len)) 170 break; 171 172 /* Read and decode the current label */ 173 hdr = mpls_hdr(skb) + label_index; 174 dec = mpls_entry_decode(hdr); 175 176 /* RFC6790 - reserved labels MUST NOT be used as keys 177 * for the load-balancing function 178 */ 179 if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) { 180 hash = jhash_1word(dec.label, hash); 181 182 /* The entropy label follows the entropy label 183 * indicator, so this means that the entropy 184 * label was just added to the hash - no need to 185 * go any deeper either in the label stack or in the 186 * payload 187 */ 188 if (eli_seen) 189 break; 190 } else if (dec.label == MPLS_LABEL_ENTROPY) { 191 eli_seen = true; 192 } 193 194 if (!dec.bos) 195 continue; 196 197 /* found bottom label; does skb have room for a header? */ 198 if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) { 199 const struct iphdr *v4hdr; 200 201 v4hdr = (const struct iphdr *)(hdr + 1); 202 if (v4hdr->version == 4) { 203 hash = jhash_3words(ntohl(v4hdr->saddr), 204 ntohl(v4hdr->daddr), 205 v4hdr->protocol, hash); 206 } else if (v4hdr->version == 6 && 207 pskb_may_pull(skb, mpls_hdr_len + 208 sizeof(struct ipv6hdr))) { 209 const struct ipv6hdr *v6hdr; 210 211 v6hdr = (const struct ipv6hdr *)(hdr + 1); 212 hash = __ipv6_addr_jhash(&v6hdr->saddr, hash); 213 hash = __ipv6_addr_jhash(&v6hdr->daddr, hash); 214 hash = jhash_1word(v6hdr->nexthdr, hash); 215 } 216 } 217 218 break; 219 } 220 221 return hash; 222 } 223 224 static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index) 225 { 226 return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size); 227 } 228 229 /* number of alive nexthops (rt->rt_nhn_alive) and the flags for 230 * a next hop (nh->nh_flags) are modified by netdev event handlers. 231 * Since those fields can change at any moment, use READ_ONCE to 232 * access both. 233 */ 234 static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt, 235 struct sk_buff *skb) 236 { 237 u32 hash = 0; 238 int nh_index = 0; 239 int n = 0; 240 u8 alive; 241 242 /* No need to look further into packet if there's only 243 * one path 244 */ 245 if (rt->rt_nhn == 1) 246 return rt->rt_nh; 247 248 alive = READ_ONCE(rt->rt_nhn_alive); 249 if (alive == 0) 250 return NULL; 251 252 hash = mpls_multipath_hash(rt, skb); 253 nh_index = hash % alive; 254 if (alive == rt->rt_nhn) 255 goto out; 256 for_nexthops(rt) { 257 unsigned int nh_flags = READ_ONCE(nh->nh_flags); 258 259 if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 260 continue; 261 if (n == nh_index) 262 return nh; 263 n++; 264 } endfor_nexthops(rt); 265 266 out: 267 return mpls_get_nexthop(rt, nh_index); 268 } 269 270 static bool mpls_egress(struct net *net, struct mpls_route *rt, 271 struct sk_buff *skb, struct mpls_entry_decoded dec) 272 { 273 enum mpls_payload_type payload_type; 274 bool success = false; 275 276 /* The IPv4 code below accesses through the IPv4 header 277 * checksum, which is 12 bytes into the packet. 278 * The IPv6 code below accesses through the IPv6 hop limit 279 * which is 8 bytes into the packet. 280 * 281 * For all supported cases there should always be at least 12 282 * bytes of packet data present. The IPv4 header is 20 bytes 283 * without options and the IPv6 header is always 40 bytes 284 * long. 285 */ 286 if (!pskb_may_pull(skb, 12)) 287 return false; 288 289 payload_type = rt->rt_payload_type; 290 if (payload_type == MPT_UNSPEC) 291 payload_type = ip_hdr(skb)->version; 292 293 switch (payload_type) { 294 case MPT_IPV4: { 295 struct iphdr *hdr4 = ip_hdr(skb); 296 u8 new_ttl; 297 skb->protocol = htons(ETH_P_IP); 298 299 /* If propagating TTL, take the decremented TTL from 300 * the incoming MPLS header, otherwise decrement the 301 * TTL, but only if not 0 to avoid underflow. 302 */ 303 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED || 304 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT && 305 net->mpls.ip_ttl_propagate)) 306 new_ttl = dec.ttl; 307 else 308 new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0; 309 310 csum_replace2(&hdr4->check, 311 htons(hdr4->ttl << 8), 312 htons(new_ttl << 8)); 313 hdr4->ttl = new_ttl; 314 success = true; 315 break; 316 } 317 case MPT_IPV6: { 318 struct ipv6hdr *hdr6 = ipv6_hdr(skb); 319 skb->protocol = htons(ETH_P_IPV6); 320 321 /* If propagating TTL, take the decremented TTL from 322 * the incoming MPLS header, otherwise decrement the 323 * hop limit, but only if not 0 to avoid underflow. 324 */ 325 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED || 326 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT && 327 net->mpls.ip_ttl_propagate)) 328 hdr6->hop_limit = dec.ttl; 329 else if (hdr6->hop_limit) 330 hdr6->hop_limit = hdr6->hop_limit - 1; 331 success = true; 332 break; 333 } 334 case MPT_UNSPEC: 335 /* Should have decided which protocol it is by now */ 336 break; 337 } 338 339 return success; 340 } 341 342 static int mpls_forward(struct sk_buff *skb, struct net_device *dev, 343 struct packet_type *pt, struct net_device *orig_dev) 344 { 345 struct net *net = dev_net(dev); 346 struct mpls_shim_hdr *hdr; 347 struct mpls_route *rt; 348 struct mpls_nh *nh; 349 struct mpls_entry_decoded dec; 350 struct net_device *out_dev; 351 struct mpls_dev *out_mdev; 352 struct mpls_dev *mdev; 353 unsigned int hh_len; 354 unsigned int new_header_size; 355 unsigned int mtu; 356 int err; 357 358 /* Careful this entire function runs inside of an rcu critical section */ 359 360 mdev = mpls_dev_get(dev); 361 if (!mdev) 362 goto drop; 363 364 MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets, 365 rx_bytes); 366 367 if (!mdev->input_enabled) { 368 MPLS_INC_STATS(mdev, rx_dropped); 369 goto drop; 370 } 371 372 if (skb->pkt_type != PACKET_HOST) 373 goto err; 374 375 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 376 goto err; 377 378 if (!pskb_may_pull(skb, sizeof(*hdr))) 379 goto err; 380 381 /* Read and decode the label */ 382 hdr = mpls_hdr(skb); 383 dec = mpls_entry_decode(hdr); 384 385 rt = mpls_route_input_rcu(net, dec.label); 386 if (!rt) { 387 MPLS_INC_STATS(mdev, rx_noroute); 388 goto drop; 389 } 390 391 nh = mpls_select_multipath(rt, skb); 392 if (!nh) 393 goto err; 394 395 /* Pop the label */ 396 skb_pull(skb, sizeof(*hdr)); 397 skb_reset_network_header(skb); 398 399 skb_orphan(skb); 400 401 if (skb_warn_if_lro(skb)) 402 goto err; 403 404 skb_forward_csum(skb); 405 406 /* Verify ttl is valid */ 407 if (dec.ttl <= 1) 408 goto err; 409 dec.ttl -= 1; 410 411 /* Find the output device */ 412 out_dev = rcu_dereference(nh->nh_dev); 413 if (!mpls_output_possible(out_dev)) 414 goto tx_err; 415 416 /* Verify the destination can hold the packet */ 417 new_header_size = mpls_nh_header_size(nh); 418 mtu = mpls_dev_mtu(out_dev); 419 if (mpls_pkt_too_big(skb, mtu - new_header_size)) 420 goto tx_err; 421 422 hh_len = LL_RESERVED_SPACE(out_dev); 423 if (!out_dev->header_ops) 424 hh_len = 0; 425 426 /* Ensure there is enough space for the headers in the skb */ 427 if (skb_cow(skb, hh_len + new_header_size)) 428 goto tx_err; 429 430 skb->dev = out_dev; 431 skb->protocol = htons(ETH_P_MPLS_UC); 432 433 if (unlikely(!new_header_size && dec.bos)) { 434 /* Penultimate hop popping */ 435 if (!mpls_egress(dev_net(out_dev), rt, skb, dec)) 436 goto err; 437 } else { 438 bool bos; 439 int i; 440 skb_push(skb, new_header_size); 441 skb_reset_network_header(skb); 442 /* Push the new labels */ 443 hdr = mpls_hdr(skb); 444 bos = dec.bos; 445 for (i = nh->nh_labels - 1; i >= 0; i--) { 446 hdr[i] = mpls_entry_encode(nh->nh_label[i], 447 dec.ttl, 0, bos); 448 bos = false; 449 } 450 } 451 452 mpls_stats_inc_outucastpkts(out_dev, skb); 453 454 /* If via wasn't specified then send out using device address */ 455 if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC) 456 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev, 457 out_dev->dev_addr, skb); 458 else 459 err = neigh_xmit(nh->nh_via_table, out_dev, 460 mpls_nh_via(rt, nh), skb); 461 if (err) 462 net_dbg_ratelimited("%s: packet transmission failed: %d\n", 463 __func__, err); 464 return 0; 465 466 tx_err: 467 out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL; 468 if (out_mdev) 469 MPLS_INC_STATS(out_mdev, tx_errors); 470 goto drop; 471 err: 472 MPLS_INC_STATS(mdev, rx_errors); 473 drop: 474 kfree_skb(skb); 475 return NET_RX_DROP; 476 } 477 478 static struct packet_type mpls_packet_type __read_mostly = { 479 .type = cpu_to_be16(ETH_P_MPLS_UC), 480 .func = mpls_forward, 481 }; 482 483 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = { 484 [RTA_DST] = { .type = NLA_U32 }, 485 [RTA_OIF] = { .type = NLA_U32 }, 486 [RTA_TTL_PROPAGATE] = { .type = NLA_U8 }, 487 }; 488 489 struct mpls_route_config { 490 u32 rc_protocol; 491 u32 rc_ifindex; 492 u8 rc_via_table; 493 u8 rc_via_alen; 494 u8 rc_via[MAX_VIA_ALEN]; 495 u32 rc_label; 496 u8 rc_ttl_propagate; 497 u8 rc_output_labels; 498 u32 rc_output_label[MAX_NEW_LABELS]; 499 u32 rc_nlflags; 500 enum mpls_payload_type rc_payload_type; 501 struct nl_info rc_nlinfo; 502 struct rtnexthop *rc_mp; 503 int rc_mp_len; 504 }; 505 506 /* all nexthops within a route have the same size based on max 507 * number of labels and max via length for a hop 508 */ 509 static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels) 510 { 511 u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen); 512 struct mpls_route *rt; 513 size_t size; 514 515 size = sizeof(*rt) + num_nh * nh_size; 516 if (size > MAX_MPLS_ROUTE_MEM) 517 return ERR_PTR(-EINVAL); 518 519 rt = kzalloc(size, GFP_KERNEL); 520 if (!rt) 521 return ERR_PTR(-ENOMEM); 522 523 rt->rt_nhn = num_nh; 524 rt->rt_nhn_alive = num_nh; 525 rt->rt_nh_size = nh_size; 526 rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels); 527 528 return rt; 529 } 530 531 static void mpls_rt_free(struct mpls_route *rt) 532 { 533 if (rt) 534 kfree_rcu(rt, rt_rcu); 535 } 536 537 static void mpls_notify_route(struct net *net, unsigned index, 538 struct mpls_route *old, struct mpls_route *new, 539 const struct nl_info *info) 540 { 541 struct nlmsghdr *nlh = info ? info->nlh : NULL; 542 unsigned portid = info ? info->portid : 0; 543 int event = new ? RTM_NEWROUTE : RTM_DELROUTE; 544 struct mpls_route *rt = new ? new : old; 545 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0; 546 /* Ignore reserved labels for now */ 547 if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED)) 548 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags); 549 } 550 551 static void mpls_route_update(struct net *net, unsigned index, 552 struct mpls_route *new, 553 const struct nl_info *info) 554 { 555 struct mpls_route __rcu **platform_label; 556 struct mpls_route *rt; 557 558 ASSERT_RTNL(); 559 560 platform_label = rtnl_dereference(net->mpls.platform_label); 561 rt = rtnl_dereference(platform_label[index]); 562 rcu_assign_pointer(platform_label[index], new); 563 564 mpls_notify_route(net, index, rt, new, info); 565 566 /* If we removed a route free it now */ 567 mpls_rt_free(rt); 568 } 569 570 static unsigned find_free_label(struct net *net) 571 { 572 struct mpls_route __rcu **platform_label; 573 size_t platform_labels; 574 unsigned index; 575 576 platform_label = rtnl_dereference(net->mpls.platform_label); 577 platform_labels = net->mpls.platform_labels; 578 for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels; 579 index++) { 580 if (!rtnl_dereference(platform_label[index])) 581 return index; 582 } 583 return LABEL_NOT_SPECIFIED; 584 } 585 586 #if IS_ENABLED(CONFIG_INET) 587 static struct net_device *inet_fib_lookup_dev(struct net *net, 588 const void *addr) 589 { 590 struct net_device *dev; 591 struct rtable *rt; 592 struct in_addr daddr; 593 594 memcpy(&daddr, addr, sizeof(struct in_addr)); 595 rt = ip_route_output(net, daddr.s_addr, 0, 0, 0); 596 if (IS_ERR(rt)) 597 return ERR_CAST(rt); 598 599 dev = rt->dst.dev; 600 dev_hold(dev); 601 602 ip_rt_put(rt); 603 604 return dev; 605 } 606 #else 607 static struct net_device *inet_fib_lookup_dev(struct net *net, 608 const void *addr) 609 { 610 return ERR_PTR(-EAFNOSUPPORT); 611 } 612 #endif 613 614 #if IS_ENABLED(CONFIG_IPV6) 615 static struct net_device *inet6_fib_lookup_dev(struct net *net, 616 const void *addr) 617 { 618 struct net_device *dev; 619 struct dst_entry *dst; 620 struct flowi6 fl6; 621 int err; 622 623 if (!ipv6_stub) 624 return ERR_PTR(-EAFNOSUPPORT); 625 626 memset(&fl6, 0, sizeof(fl6)); 627 memcpy(&fl6.daddr, addr, sizeof(struct in6_addr)); 628 err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6); 629 if (err) 630 return ERR_PTR(err); 631 632 dev = dst->dev; 633 dev_hold(dev); 634 dst_release(dst); 635 636 return dev; 637 } 638 #else 639 static struct net_device *inet6_fib_lookup_dev(struct net *net, 640 const void *addr) 641 { 642 return ERR_PTR(-EAFNOSUPPORT); 643 } 644 #endif 645 646 static struct net_device *find_outdev(struct net *net, 647 struct mpls_route *rt, 648 struct mpls_nh *nh, int oif) 649 { 650 struct net_device *dev = NULL; 651 652 if (!oif) { 653 switch (nh->nh_via_table) { 654 case NEIGH_ARP_TABLE: 655 dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 656 break; 657 case NEIGH_ND_TABLE: 658 dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh)); 659 break; 660 case NEIGH_LINK_TABLE: 661 break; 662 } 663 } else { 664 dev = dev_get_by_index(net, oif); 665 } 666 667 if (!dev) 668 return ERR_PTR(-ENODEV); 669 670 if (IS_ERR(dev)) 671 return dev; 672 673 /* The caller is holding rtnl anyways, so release the dev reference */ 674 dev_put(dev); 675 676 return dev; 677 } 678 679 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt, 680 struct mpls_nh *nh, int oif) 681 { 682 struct net_device *dev = NULL; 683 int err = -ENODEV; 684 685 dev = find_outdev(net, rt, nh, oif); 686 if (IS_ERR(dev)) { 687 err = PTR_ERR(dev); 688 dev = NULL; 689 goto errout; 690 } 691 692 /* Ensure this is a supported device */ 693 err = -EINVAL; 694 if (!mpls_dev_get(dev)) 695 goto errout; 696 697 if ((nh->nh_via_table == NEIGH_LINK_TABLE) && 698 (dev->addr_len != nh->nh_via_alen)) 699 goto errout; 700 701 RCU_INIT_POINTER(nh->nh_dev, dev); 702 703 if (!(dev->flags & IFF_UP)) { 704 nh->nh_flags |= RTNH_F_DEAD; 705 } else { 706 unsigned int flags; 707 708 flags = dev_get_flags(dev); 709 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP))) 710 nh->nh_flags |= RTNH_F_LINKDOWN; 711 } 712 713 return 0; 714 715 errout: 716 return err; 717 } 718 719 static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table, 720 u8 via_addr[], struct netlink_ext_ack *extack) 721 { 722 struct rtvia *via = nla_data(nla); 723 int err = -EINVAL; 724 int alen; 725 726 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) { 727 NL_SET_ERR_MSG_ATTR(extack, nla, 728 "Invalid attribute length for RTA_VIA"); 729 goto errout; 730 } 731 alen = nla_len(nla) - 732 offsetof(struct rtvia, rtvia_addr); 733 if (alen > MAX_VIA_ALEN) { 734 NL_SET_ERR_MSG_ATTR(extack, nla, 735 "Invalid address length for RTA_VIA"); 736 goto errout; 737 } 738 739 /* Validate the address family */ 740 switch (via->rtvia_family) { 741 case AF_PACKET: 742 *via_table = NEIGH_LINK_TABLE; 743 break; 744 case AF_INET: 745 *via_table = NEIGH_ARP_TABLE; 746 if (alen != 4) 747 goto errout; 748 break; 749 case AF_INET6: 750 *via_table = NEIGH_ND_TABLE; 751 if (alen != 16) 752 goto errout; 753 break; 754 default: 755 /* Unsupported address family */ 756 goto errout; 757 } 758 759 memcpy(via_addr, via->rtvia_addr, alen); 760 *via_alen = alen; 761 err = 0; 762 763 errout: 764 return err; 765 } 766 767 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg, 768 struct mpls_route *rt) 769 { 770 struct net *net = cfg->rc_nlinfo.nl_net; 771 struct mpls_nh *nh = rt->rt_nh; 772 int err; 773 int i; 774 775 if (!nh) 776 return -ENOMEM; 777 778 nh->nh_labels = cfg->rc_output_labels; 779 for (i = 0; i < nh->nh_labels; i++) 780 nh->nh_label[i] = cfg->rc_output_label[i]; 781 782 nh->nh_via_table = cfg->rc_via_table; 783 memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen); 784 nh->nh_via_alen = cfg->rc_via_alen; 785 786 err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex); 787 if (err) 788 goto errout; 789 790 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 791 rt->rt_nhn_alive--; 792 793 return 0; 794 795 errout: 796 return err; 797 } 798 799 static int mpls_nh_build(struct net *net, struct mpls_route *rt, 800 struct mpls_nh *nh, int oif, struct nlattr *via, 801 struct nlattr *newdst, u8 max_labels, 802 struct netlink_ext_ack *extack) 803 { 804 int err = -ENOMEM; 805 806 if (!nh) 807 goto errout; 808 809 if (newdst) { 810 err = nla_get_labels(newdst, max_labels, &nh->nh_labels, 811 nh->nh_label, extack); 812 if (err) 813 goto errout; 814 } 815 816 if (via) { 817 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table, 818 __mpls_nh_via(rt, nh), extack); 819 if (err) 820 goto errout; 821 } else { 822 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC; 823 } 824 825 err = mpls_nh_assign_dev(net, rt, nh, oif); 826 if (err) 827 goto errout; 828 829 return 0; 830 831 errout: 832 return err; 833 } 834 835 static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len, 836 u8 cfg_via_alen, u8 *max_via_alen, 837 u8 *max_labels) 838 { 839 int remaining = len; 840 u8 nhs = 0; 841 842 *max_via_alen = 0; 843 *max_labels = 0; 844 845 while (rtnh_ok(rtnh, remaining)) { 846 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 847 int attrlen; 848 u8 n_labels = 0; 849 850 attrlen = rtnh_attrlen(rtnh); 851 nla = nla_find(attrs, attrlen, RTA_VIA); 852 if (nla && nla_len(nla) >= 853 offsetof(struct rtvia, rtvia_addr)) { 854 int via_alen = nla_len(nla) - 855 offsetof(struct rtvia, rtvia_addr); 856 857 if (via_alen <= MAX_VIA_ALEN) 858 *max_via_alen = max_t(u16, *max_via_alen, 859 via_alen); 860 } 861 862 nla = nla_find(attrs, attrlen, RTA_NEWDST); 863 if (nla && 864 nla_get_labels(nla, MAX_NEW_LABELS, &n_labels, 865 NULL, NULL) != 0) 866 return 0; 867 868 *max_labels = max_t(u8, *max_labels, n_labels); 869 870 /* number of nexthops is tracked by a u8. 871 * Check for overflow. 872 */ 873 if (nhs == 255) 874 return 0; 875 nhs++; 876 877 rtnh = rtnh_next(rtnh, &remaining); 878 } 879 880 /* leftover implies invalid nexthop configuration, discard it */ 881 return remaining > 0 ? 0 : nhs; 882 } 883 884 static int mpls_nh_build_multi(struct mpls_route_config *cfg, 885 struct mpls_route *rt, u8 max_labels, 886 struct netlink_ext_ack *extack) 887 { 888 struct rtnexthop *rtnh = cfg->rc_mp; 889 struct nlattr *nla_via, *nla_newdst; 890 int remaining = cfg->rc_mp_len; 891 int err = 0; 892 u8 nhs = 0; 893 894 change_nexthops(rt) { 895 int attrlen; 896 897 nla_via = NULL; 898 nla_newdst = NULL; 899 900 err = -EINVAL; 901 if (!rtnh_ok(rtnh, remaining)) 902 goto errout; 903 904 /* neither weighted multipath nor any flags 905 * are supported 906 */ 907 if (rtnh->rtnh_hops || rtnh->rtnh_flags) 908 goto errout; 909 910 attrlen = rtnh_attrlen(rtnh); 911 if (attrlen > 0) { 912 struct nlattr *attrs = rtnh_attrs(rtnh); 913 914 nla_via = nla_find(attrs, attrlen, RTA_VIA); 915 nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST); 916 } 917 918 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh, 919 rtnh->rtnh_ifindex, nla_via, nla_newdst, 920 max_labels, extack); 921 if (err) 922 goto errout; 923 924 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) 925 rt->rt_nhn_alive--; 926 927 rtnh = rtnh_next(rtnh, &remaining); 928 nhs++; 929 } endfor_nexthops(rt); 930 931 rt->rt_nhn = nhs; 932 933 return 0; 934 935 errout: 936 return err; 937 } 938 939 static bool mpls_label_ok(struct net *net, unsigned int *index, 940 struct netlink_ext_ack *extack) 941 { 942 bool is_ok = true; 943 944 /* Reserved labels may not be set */ 945 if (*index < MPLS_LABEL_FIRST_UNRESERVED) { 946 NL_SET_ERR_MSG(extack, 947 "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher"); 948 is_ok = false; 949 } 950 951 /* The full 20 bit range may not be supported. */ 952 if (is_ok && *index >= net->mpls.platform_labels) { 953 NL_SET_ERR_MSG(extack, 954 "Label >= configured maximum in platform_labels"); 955 is_ok = false; 956 } 957 958 *index = array_index_nospec(*index, net->mpls.platform_labels); 959 return is_ok; 960 } 961 962 static int mpls_route_add(struct mpls_route_config *cfg, 963 struct netlink_ext_ack *extack) 964 { 965 struct mpls_route __rcu **platform_label; 966 struct net *net = cfg->rc_nlinfo.nl_net; 967 struct mpls_route *rt, *old; 968 int err = -EINVAL; 969 u8 max_via_alen; 970 unsigned index; 971 u8 max_labels; 972 u8 nhs; 973 974 index = cfg->rc_label; 975 976 /* If a label was not specified during insert pick one */ 977 if ((index == LABEL_NOT_SPECIFIED) && 978 (cfg->rc_nlflags & NLM_F_CREATE)) { 979 index = find_free_label(net); 980 } 981 982 if (!mpls_label_ok(net, &index, extack)) 983 goto errout; 984 985 /* Append makes no sense with mpls */ 986 err = -EOPNOTSUPP; 987 if (cfg->rc_nlflags & NLM_F_APPEND) { 988 NL_SET_ERR_MSG(extack, "MPLS does not support route append"); 989 goto errout; 990 } 991 992 err = -EEXIST; 993 platform_label = rtnl_dereference(net->mpls.platform_label); 994 old = rtnl_dereference(platform_label[index]); 995 if ((cfg->rc_nlflags & NLM_F_EXCL) && old) 996 goto errout; 997 998 err = -EEXIST; 999 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old) 1000 goto errout; 1001 1002 err = -ENOENT; 1003 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old) 1004 goto errout; 1005 1006 err = -EINVAL; 1007 if (cfg->rc_mp) { 1008 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len, 1009 cfg->rc_via_alen, &max_via_alen, 1010 &max_labels); 1011 } else { 1012 max_via_alen = cfg->rc_via_alen; 1013 max_labels = cfg->rc_output_labels; 1014 nhs = 1; 1015 } 1016 1017 if (nhs == 0) { 1018 NL_SET_ERR_MSG(extack, "Route does not contain a nexthop"); 1019 goto errout; 1020 } 1021 1022 err = -ENOMEM; 1023 rt = mpls_rt_alloc(nhs, max_via_alen, max_labels); 1024 if (IS_ERR(rt)) { 1025 err = PTR_ERR(rt); 1026 goto errout; 1027 } 1028 1029 rt->rt_protocol = cfg->rc_protocol; 1030 rt->rt_payload_type = cfg->rc_payload_type; 1031 rt->rt_ttl_propagate = cfg->rc_ttl_propagate; 1032 1033 if (cfg->rc_mp) 1034 err = mpls_nh_build_multi(cfg, rt, max_labels, extack); 1035 else 1036 err = mpls_nh_build_from_cfg(cfg, rt); 1037 if (err) 1038 goto freert; 1039 1040 mpls_route_update(net, index, rt, &cfg->rc_nlinfo); 1041 1042 return 0; 1043 1044 freert: 1045 mpls_rt_free(rt); 1046 errout: 1047 return err; 1048 } 1049 1050 static int mpls_route_del(struct mpls_route_config *cfg, 1051 struct netlink_ext_ack *extack) 1052 { 1053 struct net *net = cfg->rc_nlinfo.nl_net; 1054 unsigned index; 1055 int err = -EINVAL; 1056 1057 index = cfg->rc_label; 1058 1059 if (!mpls_label_ok(net, &index, extack)) 1060 goto errout; 1061 1062 mpls_route_update(net, index, NULL, &cfg->rc_nlinfo); 1063 1064 err = 0; 1065 errout: 1066 return err; 1067 } 1068 1069 static void mpls_get_stats(struct mpls_dev *mdev, 1070 struct mpls_link_stats *stats) 1071 { 1072 struct mpls_pcpu_stats *p; 1073 int i; 1074 1075 memset(stats, 0, sizeof(*stats)); 1076 1077 for_each_possible_cpu(i) { 1078 struct mpls_link_stats local; 1079 unsigned int start; 1080 1081 p = per_cpu_ptr(mdev->stats, i); 1082 do { 1083 start = u64_stats_fetch_begin(&p->syncp); 1084 local = p->stats; 1085 } while (u64_stats_fetch_retry(&p->syncp, start)); 1086 1087 stats->rx_packets += local.rx_packets; 1088 stats->rx_bytes += local.rx_bytes; 1089 stats->tx_packets += local.tx_packets; 1090 stats->tx_bytes += local.tx_bytes; 1091 stats->rx_errors += local.rx_errors; 1092 stats->tx_errors += local.tx_errors; 1093 stats->rx_dropped += local.rx_dropped; 1094 stats->tx_dropped += local.tx_dropped; 1095 stats->rx_noroute += local.rx_noroute; 1096 } 1097 } 1098 1099 static int mpls_fill_stats_af(struct sk_buff *skb, 1100 const struct net_device *dev) 1101 { 1102 struct mpls_link_stats *stats; 1103 struct mpls_dev *mdev; 1104 struct nlattr *nla; 1105 1106 mdev = mpls_dev_get(dev); 1107 if (!mdev) 1108 return -ENODATA; 1109 1110 nla = nla_reserve_64bit(skb, MPLS_STATS_LINK, 1111 sizeof(struct mpls_link_stats), 1112 MPLS_STATS_UNSPEC); 1113 if (!nla) 1114 return -EMSGSIZE; 1115 1116 stats = nla_data(nla); 1117 mpls_get_stats(mdev, stats); 1118 1119 return 0; 1120 } 1121 1122 static size_t mpls_get_stats_af_size(const struct net_device *dev) 1123 { 1124 struct mpls_dev *mdev; 1125 1126 mdev = mpls_dev_get(dev); 1127 if (!mdev) 1128 return 0; 1129 1130 return nla_total_size_64bit(sizeof(struct mpls_link_stats)); 1131 } 1132 1133 static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev, 1134 u32 portid, u32 seq, int event, 1135 unsigned int flags, int type) 1136 { 1137 struct nlmsghdr *nlh; 1138 struct netconfmsg *ncm; 1139 bool all = false; 1140 1141 nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg), 1142 flags); 1143 if (!nlh) 1144 return -EMSGSIZE; 1145 1146 if (type == NETCONFA_ALL) 1147 all = true; 1148 1149 ncm = nlmsg_data(nlh); 1150 ncm->ncm_family = AF_MPLS; 1151 1152 if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0) 1153 goto nla_put_failure; 1154 1155 if ((all || type == NETCONFA_INPUT) && 1156 nla_put_s32(skb, NETCONFA_INPUT, 1157 mdev->input_enabled) < 0) 1158 goto nla_put_failure; 1159 1160 nlmsg_end(skb, nlh); 1161 return 0; 1162 1163 nla_put_failure: 1164 nlmsg_cancel(skb, nlh); 1165 return -EMSGSIZE; 1166 } 1167 1168 static int mpls_netconf_msgsize_devconf(int type) 1169 { 1170 int size = NLMSG_ALIGN(sizeof(struct netconfmsg)) 1171 + nla_total_size(4); /* NETCONFA_IFINDEX */ 1172 bool all = false; 1173 1174 if (type == NETCONFA_ALL) 1175 all = true; 1176 1177 if (all || type == NETCONFA_INPUT) 1178 size += nla_total_size(4); 1179 1180 return size; 1181 } 1182 1183 static void mpls_netconf_notify_devconf(struct net *net, int event, 1184 int type, struct mpls_dev *mdev) 1185 { 1186 struct sk_buff *skb; 1187 int err = -ENOBUFS; 1188 1189 skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL); 1190 if (!skb) 1191 goto errout; 1192 1193 err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type); 1194 if (err < 0) { 1195 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */ 1196 WARN_ON(err == -EMSGSIZE); 1197 kfree_skb(skb); 1198 goto errout; 1199 } 1200 1201 rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL); 1202 return; 1203 errout: 1204 if (err < 0) 1205 rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err); 1206 } 1207 1208 static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = { 1209 [NETCONFA_IFINDEX] = { .len = sizeof(int) }, 1210 }; 1211 1212 static int mpls_netconf_get_devconf(struct sk_buff *in_skb, 1213 struct nlmsghdr *nlh, 1214 struct netlink_ext_ack *extack) 1215 { 1216 struct net *net = sock_net(in_skb->sk); 1217 struct nlattr *tb[NETCONFA_MAX + 1]; 1218 struct netconfmsg *ncm; 1219 struct net_device *dev; 1220 struct mpls_dev *mdev; 1221 struct sk_buff *skb; 1222 int ifindex; 1223 int err; 1224 1225 err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX, 1226 devconf_mpls_policy, NULL); 1227 if (err < 0) 1228 goto errout; 1229 1230 err = -EINVAL; 1231 if (!tb[NETCONFA_IFINDEX]) 1232 goto errout; 1233 1234 ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]); 1235 dev = __dev_get_by_index(net, ifindex); 1236 if (!dev) 1237 goto errout; 1238 1239 mdev = mpls_dev_get(dev); 1240 if (!mdev) 1241 goto errout; 1242 1243 err = -ENOBUFS; 1244 skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL); 1245 if (!skb) 1246 goto errout; 1247 1248 err = mpls_netconf_fill_devconf(skb, mdev, 1249 NETLINK_CB(in_skb).portid, 1250 nlh->nlmsg_seq, RTM_NEWNETCONF, 0, 1251 NETCONFA_ALL); 1252 if (err < 0) { 1253 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */ 1254 WARN_ON(err == -EMSGSIZE); 1255 kfree_skb(skb); 1256 goto errout; 1257 } 1258 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 1259 errout: 1260 return err; 1261 } 1262 1263 static int mpls_netconf_dump_devconf(struct sk_buff *skb, 1264 struct netlink_callback *cb) 1265 { 1266 struct net *net = sock_net(skb->sk); 1267 struct hlist_head *head; 1268 struct net_device *dev; 1269 struct mpls_dev *mdev; 1270 int idx, s_idx; 1271 int h, s_h; 1272 1273 s_h = cb->args[0]; 1274 s_idx = idx = cb->args[1]; 1275 1276 for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { 1277 idx = 0; 1278 head = &net->dev_index_head[h]; 1279 rcu_read_lock(); 1280 cb->seq = net->dev_base_seq; 1281 hlist_for_each_entry_rcu(dev, head, index_hlist) { 1282 if (idx < s_idx) 1283 goto cont; 1284 mdev = mpls_dev_get(dev); 1285 if (!mdev) 1286 goto cont; 1287 if (mpls_netconf_fill_devconf(skb, mdev, 1288 NETLINK_CB(cb->skb).portid, 1289 cb->nlh->nlmsg_seq, 1290 RTM_NEWNETCONF, 1291 NLM_F_MULTI, 1292 NETCONFA_ALL) < 0) { 1293 rcu_read_unlock(); 1294 goto done; 1295 } 1296 nl_dump_check_consistent(cb, nlmsg_hdr(skb)); 1297 cont: 1298 idx++; 1299 } 1300 rcu_read_unlock(); 1301 } 1302 done: 1303 cb->args[0] = h; 1304 cb->args[1] = idx; 1305 1306 return skb->len; 1307 } 1308 1309 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \ 1310 (&((struct mpls_dev *)0)->field) 1311 1312 static int mpls_conf_proc(struct ctl_table *ctl, int write, 1313 void __user *buffer, 1314 size_t *lenp, loff_t *ppos) 1315 { 1316 int oval = *(int *)ctl->data; 1317 int ret = proc_dointvec(ctl, write, buffer, lenp, ppos); 1318 1319 if (write) { 1320 struct mpls_dev *mdev = ctl->extra1; 1321 int i = (int *)ctl->data - (int *)mdev; 1322 struct net *net = ctl->extra2; 1323 int val = *(int *)ctl->data; 1324 1325 if (i == offsetof(struct mpls_dev, input_enabled) && 1326 val != oval) { 1327 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, 1328 NETCONFA_INPUT, mdev); 1329 } 1330 } 1331 1332 return ret; 1333 } 1334 1335 static const struct ctl_table mpls_dev_table[] = { 1336 { 1337 .procname = "input", 1338 .maxlen = sizeof(int), 1339 .mode = 0644, 1340 .proc_handler = mpls_conf_proc, 1341 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled), 1342 }, 1343 { } 1344 }; 1345 1346 static int mpls_dev_sysctl_register(struct net_device *dev, 1347 struct mpls_dev *mdev) 1348 { 1349 char path[sizeof("net/mpls/conf/") + IFNAMSIZ]; 1350 struct net *net = dev_net(dev); 1351 struct ctl_table *table; 1352 int i; 1353 1354 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL); 1355 if (!table) 1356 goto out; 1357 1358 /* Table data contains only offsets relative to the base of 1359 * the mdev at this point, so make them absolute. 1360 */ 1361 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) { 1362 table[i].data = (char *)mdev + (uintptr_t)table[i].data; 1363 table[i].extra1 = mdev; 1364 table[i].extra2 = net; 1365 } 1366 1367 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name); 1368 1369 mdev->sysctl = register_net_sysctl(net, path, table); 1370 if (!mdev->sysctl) 1371 goto free; 1372 1373 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev); 1374 return 0; 1375 1376 free: 1377 kfree(table); 1378 out: 1379 return -ENOBUFS; 1380 } 1381 1382 static void mpls_dev_sysctl_unregister(struct net_device *dev, 1383 struct mpls_dev *mdev) 1384 { 1385 struct net *net = dev_net(dev); 1386 struct ctl_table *table; 1387 1388 table = mdev->sysctl->ctl_table_arg; 1389 unregister_net_sysctl_table(mdev->sysctl); 1390 kfree(table); 1391 1392 mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev); 1393 } 1394 1395 static struct mpls_dev *mpls_add_dev(struct net_device *dev) 1396 { 1397 struct mpls_dev *mdev; 1398 int err = -ENOMEM; 1399 int i; 1400 1401 ASSERT_RTNL(); 1402 1403 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); 1404 if (!mdev) 1405 return ERR_PTR(err); 1406 1407 mdev->stats = alloc_percpu(struct mpls_pcpu_stats); 1408 if (!mdev->stats) 1409 goto free; 1410 1411 for_each_possible_cpu(i) { 1412 struct mpls_pcpu_stats *mpls_stats; 1413 1414 mpls_stats = per_cpu_ptr(mdev->stats, i); 1415 u64_stats_init(&mpls_stats->syncp); 1416 } 1417 1418 mdev->dev = dev; 1419 1420 err = mpls_dev_sysctl_register(dev, mdev); 1421 if (err) 1422 goto free; 1423 1424 rcu_assign_pointer(dev->mpls_ptr, mdev); 1425 1426 return mdev; 1427 1428 free: 1429 free_percpu(mdev->stats); 1430 kfree(mdev); 1431 return ERR_PTR(err); 1432 } 1433 1434 static void mpls_dev_destroy_rcu(struct rcu_head *head) 1435 { 1436 struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu); 1437 1438 free_percpu(mdev->stats); 1439 kfree(mdev); 1440 } 1441 1442 static void mpls_ifdown(struct net_device *dev, int event) 1443 { 1444 struct mpls_route __rcu **platform_label; 1445 struct net *net = dev_net(dev); 1446 u8 alive, deleted; 1447 unsigned index; 1448 1449 platform_label = rtnl_dereference(net->mpls.platform_label); 1450 for (index = 0; index < net->mpls.platform_labels; index++) { 1451 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1452 1453 if (!rt) 1454 continue; 1455 1456 alive = 0; 1457 deleted = 0; 1458 change_nexthops(rt) { 1459 unsigned int nh_flags = nh->nh_flags; 1460 1461 if (rtnl_dereference(nh->nh_dev) != dev) 1462 goto next; 1463 1464 switch (event) { 1465 case NETDEV_DOWN: 1466 case NETDEV_UNREGISTER: 1467 nh_flags |= RTNH_F_DEAD; 1468 /* fall through */ 1469 case NETDEV_CHANGE: 1470 nh_flags |= RTNH_F_LINKDOWN; 1471 break; 1472 } 1473 if (event == NETDEV_UNREGISTER) 1474 RCU_INIT_POINTER(nh->nh_dev, NULL); 1475 1476 if (nh->nh_flags != nh_flags) 1477 WRITE_ONCE(nh->nh_flags, nh_flags); 1478 next: 1479 if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))) 1480 alive++; 1481 if (!rtnl_dereference(nh->nh_dev)) 1482 deleted++; 1483 } endfor_nexthops(rt); 1484 1485 WRITE_ONCE(rt->rt_nhn_alive, alive); 1486 1487 /* if there are no more nexthops, delete the route */ 1488 if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn) 1489 mpls_route_update(net, index, NULL, NULL); 1490 } 1491 } 1492 1493 static void mpls_ifup(struct net_device *dev, unsigned int flags) 1494 { 1495 struct mpls_route __rcu **platform_label; 1496 struct net *net = dev_net(dev); 1497 unsigned index; 1498 u8 alive; 1499 1500 platform_label = rtnl_dereference(net->mpls.platform_label); 1501 for (index = 0; index < net->mpls.platform_labels; index++) { 1502 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1503 1504 if (!rt) 1505 continue; 1506 1507 alive = 0; 1508 change_nexthops(rt) { 1509 unsigned int nh_flags = nh->nh_flags; 1510 struct net_device *nh_dev = 1511 rtnl_dereference(nh->nh_dev); 1512 1513 if (!(nh_flags & flags)) { 1514 alive++; 1515 continue; 1516 } 1517 if (nh_dev != dev) 1518 continue; 1519 alive++; 1520 nh_flags &= ~flags; 1521 WRITE_ONCE(nh->nh_flags, nh_flags); 1522 } endfor_nexthops(rt); 1523 1524 WRITE_ONCE(rt->rt_nhn_alive, alive); 1525 } 1526 } 1527 1528 static int mpls_dev_notify(struct notifier_block *this, unsigned long event, 1529 void *ptr) 1530 { 1531 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1532 struct mpls_dev *mdev; 1533 unsigned int flags; 1534 1535 if (event == NETDEV_REGISTER) { 1536 /* For now just support Ethernet, IPGRE, SIT and IPIP devices */ 1537 if (dev->type == ARPHRD_ETHER || 1538 dev->type == ARPHRD_LOOPBACK || 1539 dev->type == ARPHRD_IPGRE || 1540 dev->type == ARPHRD_SIT || 1541 dev->type == ARPHRD_TUNNEL) { 1542 mdev = mpls_add_dev(dev); 1543 if (IS_ERR(mdev)) 1544 return notifier_from_errno(PTR_ERR(mdev)); 1545 } 1546 return NOTIFY_OK; 1547 } 1548 1549 mdev = mpls_dev_get(dev); 1550 if (!mdev) 1551 return NOTIFY_OK; 1552 1553 switch (event) { 1554 case NETDEV_DOWN: 1555 mpls_ifdown(dev, event); 1556 break; 1557 case NETDEV_UP: 1558 flags = dev_get_flags(dev); 1559 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1560 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1561 else 1562 mpls_ifup(dev, RTNH_F_DEAD); 1563 break; 1564 case NETDEV_CHANGE: 1565 flags = dev_get_flags(dev); 1566 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) 1567 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); 1568 else 1569 mpls_ifdown(dev, event); 1570 break; 1571 case NETDEV_UNREGISTER: 1572 mpls_ifdown(dev, event); 1573 mdev = mpls_dev_get(dev); 1574 if (mdev) { 1575 mpls_dev_sysctl_unregister(dev, mdev); 1576 RCU_INIT_POINTER(dev->mpls_ptr, NULL); 1577 call_rcu(&mdev->rcu, mpls_dev_destroy_rcu); 1578 } 1579 break; 1580 case NETDEV_CHANGENAME: 1581 mdev = mpls_dev_get(dev); 1582 if (mdev) { 1583 int err; 1584 1585 mpls_dev_sysctl_unregister(dev, mdev); 1586 err = mpls_dev_sysctl_register(dev, mdev); 1587 if (err) 1588 return notifier_from_errno(err); 1589 } 1590 break; 1591 } 1592 return NOTIFY_OK; 1593 } 1594 1595 static struct notifier_block mpls_dev_notifier = { 1596 .notifier_call = mpls_dev_notify, 1597 }; 1598 1599 static int nla_put_via(struct sk_buff *skb, 1600 u8 table, const void *addr, int alen) 1601 { 1602 static const int table_to_family[NEIGH_NR_TABLES + 1] = { 1603 AF_INET, AF_INET6, AF_DECnet, AF_PACKET, 1604 }; 1605 struct nlattr *nla; 1606 struct rtvia *via; 1607 int family = AF_UNSPEC; 1608 1609 nla = nla_reserve(skb, RTA_VIA, alen + 2); 1610 if (!nla) 1611 return -EMSGSIZE; 1612 1613 if (table <= NEIGH_NR_TABLES) 1614 family = table_to_family[table]; 1615 1616 via = nla_data(nla); 1617 via->rtvia_family = family; 1618 memcpy(via->rtvia_addr, addr, alen); 1619 return 0; 1620 } 1621 1622 int nla_put_labels(struct sk_buff *skb, int attrtype, 1623 u8 labels, const u32 label[]) 1624 { 1625 struct nlattr *nla; 1626 struct mpls_shim_hdr *nla_label; 1627 bool bos; 1628 int i; 1629 nla = nla_reserve(skb, attrtype, labels*4); 1630 if (!nla) 1631 return -EMSGSIZE; 1632 1633 nla_label = nla_data(nla); 1634 bos = true; 1635 for (i = labels - 1; i >= 0; i--) { 1636 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos); 1637 bos = false; 1638 } 1639 1640 return 0; 1641 } 1642 EXPORT_SYMBOL_GPL(nla_put_labels); 1643 1644 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels, 1645 u32 label[], struct netlink_ext_ack *extack) 1646 { 1647 unsigned len = nla_len(nla); 1648 struct mpls_shim_hdr *nla_label; 1649 u8 nla_labels; 1650 bool bos; 1651 int i; 1652 1653 /* len needs to be an even multiple of 4 (the label size). Number 1654 * of labels is a u8 so check for overflow. 1655 */ 1656 if (len & 3 || len / 4 > 255) { 1657 NL_SET_ERR_MSG_ATTR(extack, nla, 1658 "Invalid length for labels attribute"); 1659 return -EINVAL; 1660 } 1661 1662 /* Limit the number of new labels allowed */ 1663 nla_labels = len/4; 1664 if (nla_labels > max_labels) { 1665 NL_SET_ERR_MSG(extack, "Too many labels"); 1666 return -EINVAL; 1667 } 1668 1669 /* when label == NULL, caller wants number of labels */ 1670 if (!label) 1671 goto out; 1672 1673 nla_label = nla_data(nla); 1674 bos = true; 1675 for (i = nla_labels - 1; i >= 0; i--, bos = false) { 1676 struct mpls_entry_decoded dec; 1677 dec = mpls_entry_decode(nla_label + i); 1678 1679 /* Ensure the bottom of stack flag is properly set 1680 * and ttl and tc are both clear. 1681 */ 1682 if (dec.ttl) { 1683 NL_SET_ERR_MSG_ATTR(extack, nla, 1684 "TTL in label must be 0"); 1685 return -EINVAL; 1686 } 1687 1688 if (dec.tc) { 1689 NL_SET_ERR_MSG_ATTR(extack, nla, 1690 "Traffic class in label must be 0"); 1691 return -EINVAL; 1692 } 1693 1694 if (dec.bos != bos) { 1695 NL_SET_BAD_ATTR(extack, nla); 1696 if (bos) { 1697 NL_SET_ERR_MSG(extack, 1698 "BOS bit must be set in first label"); 1699 } else { 1700 NL_SET_ERR_MSG(extack, 1701 "BOS bit can only be set in first label"); 1702 } 1703 return -EINVAL; 1704 } 1705 1706 switch (dec.label) { 1707 case MPLS_LABEL_IMPLNULL: 1708 /* RFC3032: This is a label that an LSR may 1709 * assign and distribute, but which never 1710 * actually appears in the encapsulation. 1711 */ 1712 NL_SET_ERR_MSG_ATTR(extack, nla, 1713 "Implicit NULL Label (3) can not be used in encapsulation"); 1714 return -EINVAL; 1715 } 1716 1717 label[i] = dec.label; 1718 } 1719 out: 1720 *labels = nla_labels; 1721 return 0; 1722 } 1723 EXPORT_SYMBOL_GPL(nla_get_labels); 1724 1725 static int rtm_to_route_config(struct sk_buff *skb, 1726 struct nlmsghdr *nlh, 1727 struct mpls_route_config *cfg, 1728 struct netlink_ext_ack *extack) 1729 { 1730 struct rtmsg *rtm; 1731 struct nlattr *tb[RTA_MAX+1]; 1732 int index; 1733 int err; 1734 1735 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy, 1736 extack); 1737 if (err < 0) 1738 goto errout; 1739 1740 err = -EINVAL; 1741 rtm = nlmsg_data(nlh); 1742 1743 if (rtm->rtm_family != AF_MPLS) { 1744 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg"); 1745 goto errout; 1746 } 1747 if (rtm->rtm_dst_len != 20) { 1748 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS"); 1749 goto errout; 1750 } 1751 if (rtm->rtm_src_len != 0) { 1752 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS"); 1753 goto errout; 1754 } 1755 if (rtm->rtm_tos != 0) { 1756 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS"); 1757 goto errout; 1758 } 1759 if (rtm->rtm_table != RT_TABLE_MAIN) { 1760 NL_SET_ERR_MSG(extack, 1761 "MPLS only supports the main route table"); 1762 goto errout; 1763 } 1764 /* Any value is acceptable for rtm_protocol */ 1765 1766 /* As mpls uses destination specific addresses 1767 * (or source specific address in the case of multicast) 1768 * all addresses have universal scope. 1769 */ 1770 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) { 1771 NL_SET_ERR_MSG(extack, 1772 "Invalid route scope - MPLS only supports UNIVERSE"); 1773 goto errout; 1774 } 1775 if (rtm->rtm_type != RTN_UNICAST) { 1776 NL_SET_ERR_MSG(extack, 1777 "Invalid route type - MPLS only supports UNICAST"); 1778 goto errout; 1779 } 1780 if (rtm->rtm_flags != 0) { 1781 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS"); 1782 goto errout; 1783 } 1784 1785 cfg->rc_label = LABEL_NOT_SPECIFIED; 1786 cfg->rc_protocol = rtm->rtm_protocol; 1787 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC; 1788 cfg->rc_ttl_propagate = MPLS_TTL_PROP_DEFAULT; 1789 cfg->rc_nlflags = nlh->nlmsg_flags; 1790 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid; 1791 cfg->rc_nlinfo.nlh = nlh; 1792 cfg->rc_nlinfo.nl_net = sock_net(skb->sk); 1793 1794 for (index = 0; index <= RTA_MAX; index++) { 1795 struct nlattr *nla = tb[index]; 1796 if (!nla) 1797 continue; 1798 1799 switch (index) { 1800 case RTA_OIF: 1801 cfg->rc_ifindex = nla_get_u32(nla); 1802 break; 1803 case RTA_NEWDST: 1804 if (nla_get_labels(nla, MAX_NEW_LABELS, 1805 &cfg->rc_output_labels, 1806 cfg->rc_output_label, extack)) 1807 goto errout; 1808 break; 1809 case RTA_DST: 1810 { 1811 u8 label_count; 1812 if (nla_get_labels(nla, 1, &label_count, 1813 &cfg->rc_label, extack)) 1814 goto errout; 1815 1816 if (!mpls_label_ok(cfg->rc_nlinfo.nl_net, 1817 &cfg->rc_label, extack)) 1818 goto errout; 1819 break; 1820 } 1821 case RTA_VIA: 1822 { 1823 if (nla_get_via(nla, &cfg->rc_via_alen, 1824 &cfg->rc_via_table, cfg->rc_via, 1825 extack)) 1826 goto errout; 1827 break; 1828 } 1829 case RTA_MULTIPATH: 1830 { 1831 cfg->rc_mp = nla_data(nla); 1832 cfg->rc_mp_len = nla_len(nla); 1833 break; 1834 } 1835 case RTA_TTL_PROPAGATE: 1836 { 1837 u8 ttl_propagate = nla_get_u8(nla); 1838 1839 if (ttl_propagate > 1) { 1840 NL_SET_ERR_MSG_ATTR(extack, nla, 1841 "RTA_TTL_PROPAGATE can only be 0 or 1"); 1842 goto errout; 1843 } 1844 cfg->rc_ttl_propagate = ttl_propagate ? 1845 MPLS_TTL_PROP_ENABLED : 1846 MPLS_TTL_PROP_DISABLED; 1847 break; 1848 } 1849 default: 1850 NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute"); 1851 /* Unsupported attribute */ 1852 goto errout; 1853 } 1854 } 1855 1856 err = 0; 1857 errout: 1858 return err; 1859 } 1860 1861 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 1862 struct netlink_ext_ack *extack) 1863 { 1864 struct mpls_route_config *cfg; 1865 int err; 1866 1867 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL); 1868 if (!cfg) 1869 return -ENOMEM; 1870 1871 err = rtm_to_route_config(skb, nlh, cfg, extack); 1872 if (err < 0) 1873 goto out; 1874 1875 err = mpls_route_del(cfg, extack); 1876 out: 1877 kfree(cfg); 1878 1879 return err; 1880 } 1881 1882 1883 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 1884 struct netlink_ext_ack *extack) 1885 { 1886 struct mpls_route_config *cfg; 1887 int err; 1888 1889 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL); 1890 if (!cfg) 1891 return -ENOMEM; 1892 1893 err = rtm_to_route_config(skb, nlh, cfg, extack); 1894 if (err < 0) 1895 goto out; 1896 1897 err = mpls_route_add(cfg, extack); 1898 out: 1899 kfree(cfg); 1900 1901 return err; 1902 } 1903 1904 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, 1905 u32 label, struct mpls_route *rt, int flags) 1906 { 1907 struct net_device *dev; 1908 struct nlmsghdr *nlh; 1909 struct rtmsg *rtm; 1910 1911 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); 1912 if (nlh == NULL) 1913 return -EMSGSIZE; 1914 1915 rtm = nlmsg_data(nlh); 1916 rtm->rtm_family = AF_MPLS; 1917 rtm->rtm_dst_len = 20; 1918 rtm->rtm_src_len = 0; 1919 rtm->rtm_tos = 0; 1920 rtm->rtm_table = RT_TABLE_MAIN; 1921 rtm->rtm_protocol = rt->rt_protocol; 1922 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 1923 rtm->rtm_type = RTN_UNICAST; 1924 rtm->rtm_flags = 0; 1925 1926 if (nla_put_labels(skb, RTA_DST, 1, &label)) 1927 goto nla_put_failure; 1928 1929 if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) { 1930 bool ttl_propagate = 1931 rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED; 1932 1933 if (nla_put_u8(skb, RTA_TTL_PROPAGATE, 1934 ttl_propagate)) 1935 goto nla_put_failure; 1936 } 1937 if (rt->rt_nhn == 1) { 1938 const struct mpls_nh *nh = rt->rt_nh; 1939 1940 if (nh->nh_labels && 1941 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels, 1942 nh->nh_label)) 1943 goto nla_put_failure; 1944 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1945 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh), 1946 nh->nh_via_alen)) 1947 goto nla_put_failure; 1948 dev = rtnl_dereference(nh->nh_dev); 1949 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) 1950 goto nla_put_failure; 1951 if (nh->nh_flags & RTNH_F_LINKDOWN) 1952 rtm->rtm_flags |= RTNH_F_LINKDOWN; 1953 if (nh->nh_flags & RTNH_F_DEAD) 1954 rtm->rtm_flags |= RTNH_F_DEAD; 1955 } else { 1956 struct rtnexthop *rtnh; 1957 struct nlattr *mp; 1958 u8 linkdown = 0; 1959 u8 dead = 0; 1960 1961 mp = nla_nest_start(skb, RTA_MULTIPATH); 1962 if (!mp) 1963 goto nla_put_failure; 1964 1965 for_nexthops(rt) { 1966 dev = rtnl_dereference(nh->nh_dev); 1967 if (!dev) 1968 continue; 1969 1970 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh)); 1971 if (!rtnh) 1972 goto nla_put_failure; 1973 1974 rtnh->rtnh_ifindex = dev->ifindex; 1975 if (nh->nh_flags & RTNH_F_LINKDOWN) { 1976 rtnh->rtnh_flags |= RTNH_F_LINKDOWN; 1977 linkdown++; 1978 } 1979 if (nh->nh_flags & RTNH_F_DEAD) { 1980 rtnh->rtnh_flags |= RTNH_F_DEAD; 1981 dead++; 1982 } 1983 1984 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST, 1985 nh->nh_labels, 1986 nh->nh_label)) 1987 goto nla_put_failure; 1988 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 1989 nla_put_via(skb, nh->nh_via_table, 1990 mpls_nh_via(rt, nh), 1991 nh->nh_via_alen)) 1992 goto nla_put_failure; 1993 1994 /* length of rtnetlink header + attributes */ 1995 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; 1996 } endfor_nexthops(rt); 1997 1998 if (linkdown == rt->rt_nhn) 1999 rtm->rtm_flags |= RTNH_F_LINKDOWN; 2000 if (dead == rt->rt_nhn) 2001 rtm->rtm_flags |= RTNH_F_DEAD; 2002 2003 nla_nest_end(skb, mp); 2004 } 2005 2006 nlmsg_end(skb, nlh); 2007 return 0; 2008 2009 nla_put_failure: 2010 nlmsg_cancel(skb, nlh); 2011 return -EMSGSIZE; 2012 } 2013 2014 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) 2015 { 2016 struct net *net = sock_net(skb->sk); 2017 struct mpls_route __rcu **platform_label; 2018 size_t platform_labels; 2019 unsigned int index; 2020 2021 ASSERT_RTNL(); 2022 2023 index = cb->args[0]; 2024 if (index < MPLS_LABEL_FIRST_UNRESERVED) 2025 index = MPLS_LABEL_FIRST_UNRESERVED; 2026 2027 platform_label = rtnl_dereference(net->mpls.platform_label); 2028 platform_labels = net->mpls.platform_labels; 2029 for (; index < platform_labels; index++) { 2030 struct mpls_route *rt; 2031 rt = rtnl_dereference(platform_label[index]); 2032 if (!rt) 2033 continue; 2034 2035 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid, 2036 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 2037 index, rt, NLM_F_MULTI) < 0) 2038 break; 2039 } 2040 cb->args[0] = index; 2041 2042 return skb->len; 2043 } 2044 2045 static inline size_t lfib_nlmsg_size(struct mpls_route *rt) 2046 { 2047 size_t payload = 2048 NLMSG_ALIGN(sizeof(struct rtmsg)) 2049 + nla_total_size(4) /* RTA_DST */ 2050 + nla_total_size(1); /* RTA_TTL_PROPAGATE */ 2051 2052 if (rt->rt_nhn == 1) { 2053 struct mpls_nh *nh = rt->rt_nh; 2054 2055 if (nh->nh_dev) 2056 payload += nla_total_size(4); /* RTA_OIF */ 2057 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */ 2058 payload += nla_total_size(2 + nh->nh_via_alen); 2059 if (nh->nh_labels) /* RTA_NEWDST */ 2060 payload += nla_total_size(nh->nh_labels * 4); 2061 } else { 2062 /* each nexthop is packed in an attribute */ 2063 size_t nhsize = 0; 2064 2065 for_nexthops(rt) { 2066 if (!rtnl_dereference(nh->nh_dev)) 2067 continue; 2068 nhsize += nla_total_size(sizeof(struct rtnexthop)); 2069 /* RTA_VIA */ 2070 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) 2071 nhsize += nla_total_size(2 + nh->nh_via_alen); 2072 if (nh->nh_labels) 2073 nhsize += nla_total_size(nh->nh_labels * 4); 2074 } endfor_nexthops(rt); 2075 /* nested attribute */ 2076 payload += nla_total_size(nhsize); 2077 } 2078 2079 return payload; 2080 } 2081 2082 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 2083 struct nlmsghdr *nlh, struct net *net, u32 portid, 2084 unsigned int nlm_flags) 2085 { 2086 struct sk_buff *skb; 2087 u32 seq = nlh ? nlh->nlmsg_seq : 0; 2088 int err = -ENOBUFS; 2089 2090 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL); 2091 if (skb == NULL) 2092 goto errout; 2093 2094 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags); 2095 if (err < 0) { 2096 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */ 2097 WARN_ON(err == -EMSGSIZE); 2098 kfree_skb(skb); 2099 goto errout; 2100 } 2101 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL); 2102 2103 return; 2104 errout: 2105 if (err < 0) 2106 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err); 2107 } 2108 2109 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 2110 struct netlink_ext_ack *extack) 2111 { 2112 struct net *net = sock_net(in_skb->sk); 2113 u32 portid = NETLINK_CB(in_skb).portid; 2114 u32 in_label = LABEL_NOT_SPECIFIED; 2115 struct nlattr *tb[RTA_MAX + 1]; 2116 u32 labels[MAX_NEW_LABELS]; 2117 struct mpls_shim_hdr *hdr; 2118 unsigned int hdr_size = 0; 2119 struct net_device *dev; 2120 struct mpls_route *rt; 2121 struct rtmsg *rtm, *r; 2122 struct nlmsghdr *nlh; 2123 struct sk_buff *skb; 2124 struct mpls_nh *nh; 2125 u8 n_labels; 2126 int err; 2127 2128 err = nlmsg_parse(in_nlh, sizeof(*rtm), tb, RTA_MAX, 2129 rtm_mpls_policy, extack); 2130 if (err < 0) 2131 goto errout; 2132 2133 rtm = nlmsg_data(in_nlh); 2134 2135 if (tb[RTA_DST]) { 2136 u8 label_count; 2137 2138 if (nla_get_labels(tb[RTA_DST], 1, &label_count, 2139 &in_label, extack)) { 2140 err = -EINVAL; 2141 goto errout; 2142 } 2143 2144 if (!mpls_label_ok(net, &in_label, extack)) { 2145 err = -EINVAL; 2146 goto errout; 2147 } 2148 } 2149 2150 rt = mpls_route_input_rcu(net, in_label); 2151 if (!rt) { 2152 err = -ENETUNREACH; 2153 goto errout; 2154 } 2155 2156 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 2157 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL); 2158 if (!skb) { 2159 err = -ENOBUFS; 2160 goto errout; 2161 } 2162 2163 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq, 2164 RTM_NEWROUTE, in_label, rt, 0); 2165 if (err < 0) { 2166 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */ 2167 WARN_ON(err == -EMSGSIZE); 2168 goto errout_free; 2169 } 2170 2171 return rtnl_unicast(skb, net, portid); 2172 } 2173 2174 if (tb[RTA_NEWDST]) { 2175 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels, 2176 labels, extack) != 0) { 2177 err = -EINVAL; 2178 goto errout; 2179 } 2180 2181 hdr_size = n_labels * sizeof(struct mpls_shim_hdr); 2182 } 2183 2184 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2185 if (!skb) { 2186 err = -ENOBUFS; 2187 goto errout; 2188 } 2189 2190 skb->protocol = htons(ETH_P_MPLS_UC); 2191 2192 if (hdr_size) { 2193 bool bos; 2194 int i; 2195 2196 if (skb_cow(skb, hdr_size)) { 2197 err = -ENOBUFS; 2198 goto errout_free; 2199 } 2200 2201 skb_reserve(skb, hdr_size); 2202 skb_push(skb, hdr_size); 2203 skb_reset_network_header(skb); 2204 2205 /* Push new labels */ 2206 hdr = mpls_hdr(skb); 2207 bos = true; 2208 for (i = n_labels - 1; i >= 0; i--) { 2209 hdr[i] = mpls_entry_encode(labels[i], 2210 1, 0, bos); 2211 bos = false; 2212 } 2213 } 2214 2215 nh = mpls_select_multipath(rt, skb); 2216 if (!nh) { 2217 err = -ENETUNREACH; 2218 goto errout_free; 2219 } 2220 2221 if (hdr_size) { 2222 skb_pull(skb, hdr_size); 2223 skb_reset_network_header(skb); 2224 } 2225 2226 nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq, 2227 RTM_NEWROUTE, sizeof(*r), 0); 2228 if (!nlh) { 2229 err = -EMSGSIZE; 2230 goto errout_free; 2231 } 2232 2233 r = nlmsg_data(nlh); 2234 r->rtm_family = AF_MPLS; 2235 r->rtm_dst_len = 20; 2236 r->rtm_src_len = 0; 2237 r->rtm_table = RT_TABLE_MAIN; 2238 r->rtm_type = RTN_UNICAST; 2239 r->rtm_scope = RT_SCOPE_UNIVERSE; 2240 r->rtm_protocol = rt->rt_protocol; 2241 r->rtm_flags = 0; 2242 2243 if (nla_put_labels(skb, RTA_DST, 1, &in_label)) 2244 goto nla_put_failure; 2245 2246 if (nh->nh_labels && 2247 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels, 2248 nh->nh_label)) 2249 goto nla_put_failure; 2250 2251 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC && 2252 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh), 2253 nh->nh_via_alen)) 2254 goto nla_put_failure; 2255 dev = rtnl_dereference(nh->nh_dev); 2256 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) 2257 goto nla_put_failure; 2258 2259 nlmsg_end(skb, nlh); 2260 2261 err = rtnl_unicast(skb, net, portid); 2262 errout: 2263 return err; 2264 2265 nla_put_failure: 2266 nlmsg_cancel(skb, nlh); 2267 err = -EMSGSIZE; 2268 errout_free: 2269 kfree_skb(skb); 2270 return err; 2271 } 2272 2273 static int resize_platform_label_table(struct net *net, size_t limit) 2274 { 2275 size_t size = sizeof(struct mpls_route *) * limit; 2276 size_t old_limit; 2277 size_t cp_size; 2278 struct mpls_route __rcu **labels = NULL, **old; 2279 struct mpls_route *rt0 = NULL, *rt2 = NULL; 2280 unsigned index; 2281 2282 if (size) { 2283 labels = kvzalloc(size, GFP_KERNEL); 2284 if (!labels) 2285 goto nolabels; 2286 } 2287 2288 /* In case the predefined labels need to be populated */ 2289 if (limit > MPLS_LABEL_IPV4NULL) { 2290 struct net_device *lo = net->loopback_dev; 2291 rt0 = mpls_rt_alloc(1, lo->addr_len, 0); 2292 if (IS_ERR(rt0)) 2293 goto nort0; 2294 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo); 2295 rt0->rt_protocol = RTPROT_KERNEL; 2296 rt0->rt_payload_type = MPT_IPV4; 2297 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT; 2298 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 2299 rt0->rt_nh->nh_via_alen = lo->addr_len; 2300 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr, 2301 lo->addr_len); 2302 } 2303 if (limit > MPLS_LABEL_IPV6NULL) { 2304 struct net_device *lo = net->loopback_dev; 2305 rt2 = mpls_rt_alloc(1, lo->addr_len, 0); 2306 if (IS_ERR(rt2)) 2307 goto nort2; 2308 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo); 2309 rt2->rt_protocol = RTPROT_KERNEL; 2310 rt2->rt_payload_type = MPT_IPV6; 2311 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT; 2312 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE; 2313 rt2->rt_nh->nh_via_alen = lo->addr_len; 2314 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr, 2315 lo->addr_len); 2316 } 2317 2318 rtnl_lock(); 2319 /* Remember the original table */ 2320 old = rtnl_dereference(net->mpls.platform_label); 2321 old_limit = net->mpls.platform_labels; 2322 2323 /* Free any labels beyond the new table */ 2324 for (index = limit; index < old_limit; index++) 2325 mpls_route_update(net, index, NULL, NULL); 2326 2327 /* Copy over the old labels */ 2328 cp_size = size; 2329 if (old_limit < limit) 2330 cp_size = old_limit * sizeof(struct mpls_route *); 2331 2332 memcpy(labels, old, cp_size); 2333 2334 /* If needed set the predefined labels */ 2335 if ((old_limit <= MPLS_LABEL_IPV6NULL) && 2336 (limit > MPLS_LABEL_IPV6NULL)) { 2337 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2); 2338 rt2 = NULL; 2339 } 2340 2341 if ((old_limit <= MPLS_LABEL_IPV4NULL) && 2342 (limit > MPLS_LABEL_IPV4NULL)) { 2343 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0); 2344 rt0 = NULL; 2345 } 2346 2347 /* Update the global pointers */ 2348 net->mpls.platform_labels = limit; 2349 rcu_assign_pointer(net->mpls.platform_label, labels); 2350 2351 rtnl_unlock(); 2352 2353 mpls_rt_free(rt2); 2354 mpls_rt_free(rt0); 2355 2356 if (old) { 2357 synchronize_rcu(); 2358 kvfree(old); 2359 } 2360 return 0; 2361 2362 nort2: 2363 mpls_rt_free(rt0); 2364 nort0: 2365 kvfree(labels); 2366 nolabels: 2367 return -ENOMEM; 2368 } 2369 2370 static int mpls_platform_labels(struct ctl_table *table, int write, 2371 void __user *buffer, size_t *lenp, loff_t *ppos) 2372 { 2373 struct net *net = table->data; 2374 int platform_labels = net->mpls.platform_labels; 2375 int ret; 2376 struct ctl_table tmp = { 2377 .procname = table->procname, 2378 .data = &platform_labels, 2379 .maxlen = sizeof(int), 2380 .mode = table->mode, 2381 .extra1 = &zero, 2382 .extra2 = &label_limit, 2383 }; 2384 2385 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 2386 2387 if (write && ret == 0) 2388 ret = resize_platform_label_table(net, platform_labels); 2389 2390 return ret; 2391 } 2392 2393 #define MPLS_NS_SYSCTL_OFFSET(field) \ 2394 (&((struct net *)0)->field) 2395 2396 static const struct ctl_table mpls_table[] = { 2397 { 2398 .procname = "platform_labels", 2399 .data = NULL, 2400 .maxlen = sizeof(int), 2401 .mode = 0644, 2402 .proc_handler = mpls_platform_labels, 2403 }, 2404 { 2405 .procname = "ip_ttl_propagate", 2406 .data = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate), 2407 .maxlen = sizeof(int), 2408 .mode = 0644, 2409 .proc_handler = proc_dointvec_minmax, 2410 .extra1 = &zero, 2411 .extra2 = &one, 2412 }, 2413 { 2414 .procname = "default_ttl", 2415 .data = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl), 2416 .maxlen = sizeof(int), 2417 .mode = 0644, 2418 .proc_handler = proc_dointvec_minmax, 2419 .extra1 = &one, 2420 .extra2 = &ttl_max, 2421 }, 2422 { } 2423 }; 2424 2425 static int mpls_net_init(struct net *net) 2426 { 2427 struct ctl_table *table; 2428 int i; 2429 2430 net->mpls.platform_labels = 0; 2431 net->mpls.platform_label = NULL; 2432 net->mpls.ip_ttl_propagate = 1; 2433 net->mpls.default_ttl = 255; 2434 2435 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL); 2436 if (table == NULL) 2437 return -ENOMEM; 2438 2439 /* Table data contains only offsets relative to the base of 2440 * the mdev at this point, so make them absolute. 2441 */ 2442 for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++) 2443 table[i].data = (char *)net + (uintptr_t)table[i].data; 2444 2445 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table); 2446 if (net->mpls.ctl == NULL) { 2447 kfree(table); 2448 return -ENOMEM; 2449 } 2450 2451 return 0; 2452 } 2453 2454 static void mpls_net_exit(struct net *net) 2455 { 2456 struct mpls_route __rcu **platform_label; 2457 size_t platform_labels; 2458 struct ctl_table *table; 2459 unsigned int index; 2460 2461 table = net->mpls.ctl->ctl_table_arg; 2462 unregister_net_sysctl_table(net->mpls.ctl); 2463 kfree(table); 2464 2465 /* An rcu grace period has passed since there was a device in 2466 * the network namespace (and thus the last in flight packet) 2467 * left this network namespace. This is because 2468 * unregister_netdevice_many and netdev_run_todo has completed 2469 * for each network device that was in this network namespace. 2470 * 2471 * As such no additional rcu synchronization is necessary when 2472 * freeing the platform_label table. 2473 */ 2474 rtnl_lock(); 2475 platform_label = rtnl_dereference(net->mpls.platform_label); 2476 platform_labels = net->mpls.platform_labels; 2477 for (index = 0; index < platform_labels; index++) { 2478 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 2479 RCU_INIT_POINTER(platform_label[index], NULL); 2480 mpls_notify_route(net, index, rt, NULL, NULL); 2481 mpls_rt_free(rt); 2482 } 2483 rtnl_unlock(); 2484 2485 kvfree(platform_label); 2486 } 2487 2488 static struct pernet_operations mpls_net_ops = { 2489 .init = mpls_net_init, 2490 .exit = mpls_net_exit, 2491 }; 2492 2493 static struct rtnl_af_ops mpls_af_ops __read_mostly = { 2494 .family = AF_MPLS, 2495 .fill_stats_af = mpls_fill_stats_af, 2496 .get_stats_af_size = mpls_get_stats_af_size, 2497 }; 2498 2499 static int __init mpls_init(void) 2500 { 2501 int err; 2502 2503 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4); 2504 2505 err = register_pernet_subsys(&mpls_net_ops); 2506 if (err) 2507 goto out; 2508 2509 err = register_netdevice_notifier(&mpls_dev_notifier); 2510 if (err) 2511 goto out_unregister_pernet; 2512 2513 dev_add_pack(&mpls_packet_type); 2514 2515 rtnl_af_register(&mpls_af_ops); 2516 2517 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_NEWROUTE, 2518 mpls_rtm_newroute, NULL, 0); 2519 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_DELROUTE, 2520 mpls_rtm_delroute, NULL, 0); 2521 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETROUTE, 2522 mpls_getroute, mpls_dump_routes, 0); 2523 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETNETCONF, 2524 mpls_netconf_get_devconf, 2525 mpls_netconf_dump_devconf, 0); 2526 err = ipgre_tunnel_encap_add_mpls_ops(); 2527 if (err) 2528 pr_err("Can't add mpls over gre tunnel ops\n"); 2529 2530 err = 0; 2531 out: 2532 return err; 2533 2534 out_unregister_pernet: 2535 unregister_pernet_subsys(&mpls_net_ops); 2536 goto out; 2537 } 2538 module_init(mpls_init); 2539 2540 static void __exit mpls_exit(void) 2541 { 2542 rtnl_unregister_all(PF_MPLS); 2543 rtnl_af_unregister(&mpls_af_ops); 2544 dev_remove_pack(&mpls_packet_type); 2545 unregister_netdevice_notifier(&mpls_dev_notifier); 2546 unregister_pernet_subsys(&mpls_net_ops); 2547 ipgre_tunnel_encap_del_mpls_ops(); 2548 } 2549 module_exit(mpls_exit); 2550 2551 MODULE_DESCRIPTION("MultiProtocol Label Switching"); 2552 MODULE_LICENSE("GPL v2"); 2553 MODULE_ALIAS_NETPROTO(PF_MPLS); 2554