1#include <linux/types.h> 2#include <linux/skbuff.h> 3#include <linux/socket.h> 4#include <linux/sysctl.h> 5#include <linux/net.h> 6#include <linux/module.h> 7#include <linux/if_arp.h> 8#include <linux/ipv6.h> 9#include <linux/mpls.h> 10#include <linux/vmalloc.h> 11#include <net/ip.h> 12#include <net/dst.h> 13#include <net/sock.h> 14#include <net/arp.h> 15#include <net/ip_fib.h> 16#include <net/netevent.h> 17#include <net/netns/generic.h> 18#include "internal.h" 19 20#define LABEL_NOT_SPECIFIED (1<<20) 21#define MAX_NEW_LABELS 2 22 23/* This maximum ha length copied from the definition of struct neighbour */ 24#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))) 25 26struct mpls_route { /* next hop label forwarding entry */ 27 struct net_device __rcu *rt_dev; 28 struct rcu_head rt_rcu; 29 u32 rt_label[MAX_NEW_LABELS]; 30 u8 rt_protocol; /* routing protocol that set this entry */ 31 u8 rt_labels; 32 u8 rt_via_alen; 33 u8 rt_via_table; 34 u8 rt_via[0]; 35}; 36 37static int zero = 0; 38static int label_limit = (1 << 20) - 1; 39 40static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 41 struct nlmsghdr *nlh, struct net *net, u32 portid, 42 unsigned int nlm_flags); 43 44static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index) 45{ 46 struct mpls_route *rt = NULL; 47 48 if (index < net->mpls.platform_labels) { 49 struct mpls_route __rcu **platform_label = 50 rcu_dereference(net->mpls.platform_label); 51 rt = rcu_dereference(platform_label[index]); 52 } 53 return rt; 54} 55 56static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev) 57{ 58 return rcu_dereference_rtnl(dev->mpls_ptr); 59} 60 61static bool mpls_output_possible(const struct net_device *dev) 62{ 63 return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev); 64} 65 66static unsigned int mpls_rt_header_size(const struct mpls_route *rt) 67{ 68 /* The size of the layer 2.5 labels to be added for this route */ 69 return rt->rt_labels * sizeof(struct mpls_shim_hdr); 70} 71 72static unsigned int mpls_dev_mtu(const struct net_device *dev) 73{ 74 /* The amount of data the layer 2 frame can hold */ 75 return dev->mtu; 76} 77 78static bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 79{ 80 if (skb->len <= mtu) 81 return false; 82 83 if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu) 84 return false; 85 86 return true; 87} 88 89static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb, 90 struct mpls_entry_decoded dec) 91{ 92 /* RFC4385 and RFC5586 encode other packets in mpls such that 93 * they don't conflict with the ip version number, making 94 * decoding by examining the ip version correct in everything 95 * except for the strangest cases. 96 * 97 * The strange cases if we choose to support them will require 98 * manual configuration. 99 */ 100 struct iphdr *hdr4; 101 bool success = true; 102 103 /* The IPv4 code below accesses through the IPv4 header 104 * checksum, which is 12 bytes into the packet. 105 * The IPv6 code below accesses through the IPv6 hop limit 106 * which is 8 bytes into the packet. 107 * 108 * For all supported cases there should always be at least 12 109 * bytes of packet data present. The IPv4 header is 20 bytes 110 * without options and the IPv6 header is always 40 bytes 111 * long. 112 */ 113 if (!pskb_may_pull(skb, 12)) 114 return false; 115 116 /* Use ip_hdr to find the ip protocol version */ 117 hdr4 = ip_hdr(skb); 118 if (hdr4->version == 4) { 119 skb->protocol = htons(ETH_P_IP); 120 csum_replace2(&hdr4->check, 121 htons(hdr4->ttl << 8), 122 htons(dec.ttl << 8)); 123 hdr4->ttl = dec.ttl; 124 } 125 else if (hdr4->version == 6) { 126 struct ipv6hdr *hdr6 = ipv6_hdr(skb); 127 skb->protocol = htons(ETH_P_IPV6); 128 hdr6->hop_limit = dec.ttl; 129 } 130 else 131 /* version 0 and version 1 are used by pseudo wires */ 132 success = false; 133 return success; 134} 135 136static int mpls_forward(struct sk_buff *skb, struct net_device *dev, 137 struct packet_type *pt, struct net_device *orig_dev) 138{ 139 struct net *net = dev_net(dev); 140 struct mpls_shim_hdr *hdr; 141 struct mpls_route *rt; 142 struct mpls_entry_decoded dec; 143 struct net_device *out_dev; 144 struct mpls_dev *mdev; 145 unsigned int hh_len; 146 unsigned int new_header_size; 147 unsigned int mtu; 148 int err; 149 150 /* Careful this entire function runs inside of an rcu critical section */ 151 152 mdev = mpls_dev_get(dev); 153 if (!mdev || !mdev->input_enabled) 154 goto drop; 155 156 if (skb->pkt_type != PACKET_HOST) 157 goto drop; 158 159 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 160 goto drop; 161 162 if (!pskb_may_pull(skb, sizeof(*hdr))) 163 goto drop; 164 165 /* Read and decode the label */ 166 hdr = mpls_hdr(skb); 167 dec = mpls_entry_decode(hdr); 168 169 /* Pop the label */ 170 skb_pull(skb, sizeof(*hdr)); 171 skb_reset_network_header(skb); 172 173 skb_orphan(skb); 174 175 rt = mpls_route_input_rcu(net, dec.label); 176 if (!rt) 177 goto drop; 178 179 /* Find the output device */ 180 out_dev = rcu_dereference(rt->rt_dev); 181 if (!mpls_output_possible(out_dev)) 182 goto drop; 183 184 if (skb_warn_if_lro(skb)) 185 goto drop; 186 187 skb_forward_csum(skb); 188 189 /* Verify ttl is valid */ 190 if (dec.ttl <= 1) 191 goto drop; 192 dec.ttl -= 1; 193 194 /* Verify the destination can hold the packet */ 195 new_header_size = mpls_rt_header_size(rt); 196 mtu = mpls_dev_mtu(out_dev); 197 if (mpls_pkt_too_big(skb, mtu - new_header_size)) 198 goto drop; 199 200 hh_len = LL_RESERVED_SPACE(out_dev); 201 if (!out_dev->header_ops) 202 hh_len = 0; 203 204 /* Ensure there is enough space for the headers in the skb */ 205 if (skb_cow(skb, hh_len + new_header_size)) 206 goto drop; 207 208 skb->dev = out_dev; 209 skb->protocol = htons(ETH_P_MPLS_UC); 210 211 if (unlikely(!new_header_size && dec.bos)) { 212 /* Penultimate hop popping */ 213 if (!mpls_egress(rt, skb, dec)) 214 goto drop; 215 } else { 216 bool bos; 217 int i; 218 skb_push(skb, new_header_size); 219 skb_reset_network_header(skb); 220 /* Push the new labels */ 221 hdr = mpls_hdr(skb); 222 bos = dec.bos; 223 for (i = rt->rt_labels - 1; i >= 0; i--) { 224 hdr[i] = mpls_entry_encode(rt->rt_label[i], dec.ttl, 0, bos); 225 bos = false; 226 } 227 } 228 229 err = neigh_xmit(rt->rt_via_table, out_dev, rt->rt_via, skb); 230 if (err) 231 net_dbg_ratelimited("%s: packet transmission failed: %d\n", 232 __func__, err); 233 return 0; 234 235drop: 236 kfree_skb(skb); 237 return NET_RX_DROP; 238} 239 240static struct packet_type mpls_packet_type __read_mostly = { 241 .type = cpu_to_be16(ETH_P_MPLS_UC), 242 .func = mpls_forward, 243}; 244 245static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = { 246 [RTA_DST] = { .type = NLA_U32 }, 247 [RTA_OIF] = { .type = NLA_U32 }, 248}; 249 250struct mpls_route_config { 251 u32 rc_protocol; 252 u32 rc_ifindex; 253 u16 rc_via_table; 254 u16 rc_via_alen; 255 u8 rc_via[MAX_VIA_ALEN]; 256 u32 rc_label; 257 u32 rc_output_labels; 258 u32 rc_output_label[MAX_NEW_LABELS]; 259 u32 rc_nlflags; 260 struct nl_info rc_nlinfo; 261}; 262 263static struct mpls_route *mpls_rt_alloc(size_t alen) 264{ 265 struct mpls_route *rt; 266 267 rt = kzalloc(sizeof(*rt) + alen, GFP_KERNEL); 268 if (rt) 269 rt->rt_via_alen = alen; 270 return rt; 271} 272 273static void mpls_rt_free(struct mpls_route *rt) 274{ 275 if (rt) 276 kfree_rcu(rt, rt_rcu); 277} 278 279static void mpls_notify_route(struct net *net, unsigned index, 280 struct mpls_route *old, struct mpls_route *new, 281 const struct nl_info *info) 282{ 283 struct nlmsghdr *nlh = info ? info->nlh : NULL; 284 unsigned portid = info ? info->portid : 0; 285 int event = new ? RTM_NEWROUTE : RTM_DELROUTE; 286 struct mpls_route *rt = new ? new : old; 287 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0; 288 /* Ignore reserved labels for now */ 289 if (rt && (index >= 16)) 290 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags); 291} 292 293static void mpls_route_update(struct net *net, unsigned index, 294 struct net_device *dev, struct mpls_route *new, 295 const struct nl_info *info) 296{ 297 struct mpls_route __rcu **platform_label; 298 struct mpls_route *rt, *old = NULL; 299 300 ASSERT_RTNL(); 301 302 platform_label = rtnl_dereference(net->mpls.platform_label); 303 rt = rtnl_dereference(platform_label[index]); 304 if (!dev || (rt && (rtnl_dereference(rt->rt_dev) == dev))) { 305 rcu_assign_pointer(platform_label[index], new); 306 old = rt; 307 } 308 309 mpls_notify_route(net, index, old, new, info); 310 311 /* If we removed a route free it now */ 312 mpls_rt_free(old); 313} 314 315static unsigned find_free_label(struct net *net) 316{ 317 struct mpls_route __rcu **platform_label; 318 size_t platform_labels; 319 unsigned index; 320 321 platform_label = rtnl_dereference(net->mpls.platform_label); 322 platform_labels = net->mpls.platform_labels; 323 for (index = 16; index < platform_labels; index++) { 324 if (!rtnl_dereference(platform_label[index])) 325 return index; 326 } 327 return LABEL_NOT_SPECIFIED; 328} 329 330static int mpls_route_add(struct mpls_route_config *cfg) 331{ 332 struct mpls_route __rcu **platform_label; 333 struct net *net = cfg->rc_nlinfo.nl_net; 334 struct net_device *dev = NULL; 335 struct mpls_route *rt, *old; 336 unsigned index; 337 int i; 338 int err = -EINVAL; 339 340 index = cfg->rc_label; 341 342 /* If a label was not specified during insert pick one */ 343 if ((index == LABEL_NOT_SPECIFIED) && 344 (cfg->rc_nlflags & NLM_F_CREATE)) { 345 index = find_free_label(net); 346 } 347 348 /* The first 16 labels are reserved, and may not be set */ 349 if (index < 16) 350 goto errout; 351 352 /* The full 20 bit range may not be supported. */ 353 if (index >= net->mpls.platform_labels) 354 goto errout; 355 356 /* Ensure only a supported number of labels are present */ 357 if (cfg->rc_output_labels > MAX_NEW_LABELS) 358 goto errout; 359 360 err = -ENODEV; 361 dev = dev_get_by_index(net, cfg->rc_ifindex); 362 if (!dev) 363 goto errout; 364 365 /* Ensure this is a supported device */ 366 err = -EINVAL; 367 if (!mpls_dev_get(dev)) 368 goto errout; 369 370 err = -EINVAL; 371 if ((cfg->rc_via_table == NEIGH_LINK_TABLE) && 372 (dev->addr_len != cfg->rc_via_alen)) 373 goto errout; 374 375 /* Append makes no sense with mpls */ 376 err = -EOPNOTSUPP; 377 if (cfg->rc_nlflags & NLM_F_APPEND) 378 goto errout; 379 380 err = -EEXIST; 381 platform_label = rtnl_dereference(net->mpls.platform_label); 382 old = rtnl_dereference(platform_label[index]); 383 if ((cfg->rc_nlflags & NLM_F_EXCL) && old) 384 goto errout; 385 386 err = -EEXIST; 387 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old) 388 goto errout; 389 390 err = -ENOENT; 391 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old) 392 goto errout; 393 394 err = -ENOMEM; 395 rt = mpls_rt_alloc(cfg->rc_via_alen); 396 if (!rt) 397 goto errout; 398 399 rt->rt_labels = cfg->rc_output_labels; 400 for (i = 0; i < rt->rt_labels; i++) 401 rt->rt_label[i] = cfg->rc_output_label[i]; 402 rt->rt_protocol = cfg->rc_protocol; 403 RCU_INIT_POINTER(rt->rt_dev, dev); 404 rt->rt_via_table = cfg->rc_via_table; 405 memcpy(rt->rt_via, cfg->rc_via, cfg->rc_via_alen); 406 407 mpls_route_update(net, index, NULL, rt, &cfg->rc_nlinfo); 408 409 dev_put(dev); 410 return 0; 411 412errout: 413 if (dev) 414 dev_put(dev); 415 return err; 416} 417 418static int mpls_route_del(struct mpls_route_config *cfg) 419{ 420 struct net *net = cfg->rc_nlinfo.nl_net; 421 unsigned index; 422 int err = -EINVAL; 423 424 index = cfg->rc_label; 425 426 /* The first 16 labels are reserved, and may not be removed */ 427 if (index < 16) 428 goto errout; 429 430 /* The full 20 bit range may not be supported */ 431 if (index >= net->mpls.platform_labels) 432 goto errout; 433 434 mpls_route_update(net, index, NULL, NULL, &cfg->rc_nlinfo); 435 436 err = 0; 437errout: 438 return err; 439} 440 441#define MPLS_PERDEV_SYSCTL_OFFSET(field) \ 442 (&((struct mpls_dev *)0)->field) 443 444static const struct ctl_table mpls_dev_table[] = { 445 { 446 .procname = "input", 447 .maxlen = sizeof(int), 448 .mode = 0644, 449 .proc_handler = proc_dointvec, 450 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled), 451 }, 452 { } 453}; 454 455static int mpls_dev_sysctl_register(struct net_device *dev, 456 struct mpls_dev *mdev) 457{ 458 char path[sizeof("net/mpls/conf/") + IFNAMSIZ]; 459 struct ctl_table *table; 460 int i; 461 462 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL); 463 if (!table) 464 goto out; 465 466 /* Table data contains only offsets relative to the base of 467 * the mdev at this point, so make them absolute. 468 */ 469 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) 470 table[i].data = (char *)mdev + (uintptr_t)table[i].data; 471 472 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name); 473 474 mdev->sysctl = register_net_sysctl(dev_net(dev), path, table); 475 if (!mdev->sysctl) 476 goto free; 477 478 return 0; 479 480free: 481 kfree(table); 482out: 483 return -ENOBUFS; 484} 485 486static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev) 487{ 488 struct ctl_table *table; 489 490 table = mdev->sysctl->ctl_table_arg; 491 unregister_net_sysctl_table(mdev->sysctl); 492 kfree(table); 493} 494 495static struct mpls_dev *mpls_add_dev(struct net_device *dev) 496{ 497 struct mpls_dev *mdev; 498 int err = -ENOMEM; 499 500 ASSERT_RTNL(); 501 502 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); 503 if (!mdev) 504 return ERR_PTR(err); 505 506 err = mpls_dev_sysctl_register(dev, mdev); 507 if (err) 508 goto free; 509 510 rcu_assign_pointer(dev->mpls_ptr, mdev); 511 512 return mdev; 513 514free: 515 kfree(mdev); 516 return ERR_PTR(err); 517} 518 519static void mpls_ifdown(struct net_device *dev) 520{ 521 struct mpls_route __rcu **platform_label; 522 struct net *net = dev_net(dev); 523 struct mpls_dev *mdev; 524 unsigned index; 525 526 platform_label = rtnl_dereference(net->mpls.platform_label); 527 for (index = 0; index < net->mpls.platform_labels; index++) { 528 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 529 if (!rt) 530 continue; 531 if (rtnl_dereference(rt->rt_dev) != dev) 532 continue; 533 rt->rt_dev = NULL; 534 } 535 536 mdev = mpls_dev_get(dev); 537 if (!mdev) 538 return; 539 540 mpls_dev_sysctl_unregister(mdev); 541 542 RCU_INIT_POINTER(dev->mpls_ptr, NULL); 543 544 kfree_rcu(mdev, rcu); 545} 546 547static int mpls_dev_notify(struct notifier_block *this, unsigned long event, 548 void *ptr) 549{ 550 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 551 struct mpls_dev *mdev; 552 553 switch(event) { 554 case NETDEV_REGISTER: 555 /* For now just support ethernet devices */ 556 if ((dev->type == ARPHRD_ETHER) || 557 (dev->type == ARPHRD_LOOPBACK)) { 558 mdev = mpls_add_dev(dev); 559 if (IS_ERR(mdev)) 560 return notifier_from_errno(PTR_ERR(mdev)); 561 } 562 break; 563 564 case NETDEV_UNREGISTER: 565 mpls_ifdown(dev); 566 break; 567 case NETDEV_CHANGENAME: 568 mdev = mpls_dev_get(dev); 569 if (mdev) { 570 int err; 571 572 mpls_dev_sysctl_unregister(mdev); 573 err = mpls_dev_sysctl_register(dev, mdev); 574 if (err) 575 return notifier_from_errno(err); 576 } 577 break; 578 } 579 return NOTIFY_OK; 580} 581 582static struct notifier_block mpls_dev_notifier = { 583 .notifier_call = mpls_dev_notify, 584}; 585 586static int nla_put_via(struct sk_buff *skb, 587 u8 table, const void *addr, int alen) 588{ 589 static const int table_to_family[NEIGH_NR_TABLES + 1] = { 590 AF_INET, AF_INET6, AF_DECnet, AF_PACKET, 591 }; 592 struct nlattr *nla; 593 struct rtvia *via; 594 int family = AF_UNSPEC; 595 596 nla = nla_reserve(skb, RTA_VIA, alen + 2); 597 if (!nla) 598 return -EMSGSIZE; 599 600 if (table <= NEIGH_NR_TABLES) 601 family = table_to_family[table]; 602 603 via = nla_data(nla); 604 via->rtvia_family = family; 605 memcpy(via->rtvia_addr, addr, alen); 606 return 0; 607} 608 609int nla_put_labels(struct sk_buff *skb, int attrtype, 610 u8 labels, const u32 label[]) 611{ 612 struct nlattr *nla; 613 struct mpls_shim_hdr *nla_label; 614 bool bos; 615 int i; 616 nla = nla_reserve(skb, attrtype, labels*4); 617 if (!nla) 618 return -EMSGSIZE; 619 620 nla_label = nla_data(nla); 621 bos = true; 622 for (i = labels - 1; i >= 0; i--) { 623 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos); 624 bos = false; 625 } 626 627 return 0; 628} 629 630int nla_get_labels(const struct nlattr *nla, 631 u32 max_labels, u32 *labels, u32 label[]) 632{ 633 unsigned len = nla_len(nla); 634 unsigned nla_labels; 635 struct mpls_shim_hdr *nla_label; 636 bool bos; 637 int i; 638 639 /* len needs to be an even multiple of 4 (the label size) */ 640 if (len & 3) 641 return -EINVAL; 642 643 /* Limit the number of new labels allowed */ 644 nla_labels = len/4; 645 if (nla_labels > max_labels) 646 return -EINVAL; 647 648 nla_label = nla_data(nla); 649 bos = true; 650 for (i = nla_labels - 1; i >= 0; i--, bos = false) { 651 struct mpls_entry_decoded dec; 652 dec = mpls_entry_decode(nla_label + i); 653 654 /* Ensure the bottom of stack flag is properly set 655 * and ttl and tc are both clear. 656 */ 657 if ((dec.bos != bos) || dec.ttl || dec.tc) 658 return -EINVAL; 659 660 switch (dec.label) { 661 case MPLS_LABEL_IMPLNULL: 662 /* RFC3032: This is a label that an LSR may 663 * assign and distribute, but which never 664 * actually appears in the encapsulation. 665 */ 666 return -EINVAL; 667 } 668 669 label[i] = dec.label; 670 } 671 *labels = nla_labels; 672 return 0; 673} 674 675static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh, 676 struct mpls_route_config *cfg) 677{ 678 struct rtmsg *rtm; 679 struct nlattr *tb[RTA_MAX+1]; 680 int index; 681 int err; 682 683 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy); 684 if (err < 0) 685 goto errout; 686 687 err = -EINVAL; 688 rtm = nlmsg_data(nlh); 689 memset(cfg, 0, sizeof(*cfg)); 690 691 if (rtm->rtm_family != AF_MPLS) 692 goto errout; 693 if (rtm->rtm_dst_len != 20) 694 goto errout; 695 if (rtm->rtm_src_len != 0) 696 goto errout; 697 if (rtm->rtm_tos != 0) 698 goto errout; 699 if (rtm->rtm_table != RT_TABLE_MAIN) 700 goto errout; 701 /* Any value is acceptable for rtm_protocol */ 702 703 /* As mpls uses destination specific addresses 704 * (or source specific address in the case of multicast) 705 * all addresses have universal scope. 706 */ 707 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) 708 goto errout; 709 if (rtm->rtm_type != RTN_UNICAST) 710 goto errout; 711 if (rtm->rtm_flags != 0) 712 goto errout; 713 714 cfg->rc_label = LABEL_NOT_SPECIFIED; 715 cfg->rc_protocol = rtm->rtm_protocol; 716 cfg->rc_nlflags = nlh->nlmsg_flags; 717 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid; 718 cfg->rc_nlinfo.nlh = nlh; 719 cfg->rc_nlinfo.nl_net = sock_net(skb->sk); 720 721 for (index = 0; index <= RTA_MAX; index++) { 722 struct nlattr *nla = tb[index]; 723 if (!nla) 724 continue; 725 726 switch(index) { 727 case RTA_OIF: 728 cfg->rc_ifindex = nla_get_u32(nla); 729 break; 730 case RTA_NEWDST: 731 if (nla_get_labels(nla, MAX_NEW_LABELS, 732 &cfg->rc_output_labels, 733 cfg->rc_output_label)) 734 goto errout; 735 break; 736 case RTA_DST: 737 { 738 u32 label_count; 739 if (nla_get_labels(nla, 1, &label_count, 740 &cfg->rc_label)) 741 goto errout; 742 743 /* The first 16 labels are reserved, and may not be set */ 744 if (cfg->rc_label < 16) 745 goto errout; 746 747 break; 748 } 749 case RTA_VIA: 750 { 751 struct rtvia *via = nla_data(nla); 752 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) 753 goto errout; 754 cfg->rc_via_alen = nla_len(nla) - 755 offsetof(struct rtvia, rtvia_addr); 756 if (cfg->rc_via_alen > MAX_VIA_ALEN) 757 goto errout; 758 759 /* Validate the address family */ 760 switch(via->rtvia_family) { 761 case AF_PACKET: 762 cfg->rc_via_table = NEIGH_LINK_TABLE; 763 break; 764 case AF_INET: 765 cfg->rc_via_table = NEIGH_ARP_TABLE; 766 if (cfg->rc_via_alen != 4) 767 goto errout; 768 break; 769 case AF_INET6: 770 cfg->rc_via_table = NEIGH_ND_TABLE; 771 if (cfg->rc_via_alen != 16) 772 goto errout; 773 break; 774 default: 775 /* Unsupported address family */ 776 goto errout; 777 } 778 779 memcpy(cfg->rc_via, via->rtvia_addr, cfg->rc_via_alen); 780 break; 781 } 782 default: 783 /* Unsupported attribute */ 784 goto errout; 785 } 786 } 787 788 err = 0; 789errout: 790 return err; 791} 792 793static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh) 794{ 795 struct mpls_route_config cfg; 796 int err; 797 798 err = rtm_to_route_config(skb, nlh, &cfg); 799 if (err < 0) 800 return err; 801 802 return mpls_route_del(&cfg); 803} 804 805 806static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh) 807{ 808 struct mpls_route_config cfg; 809 int err; 810 811 err = rtm_to_route_config(skb, nlh, &cfg); 812 if (err < 0) 813 return err; 814 815 return mpls_route_add(&cfg); 816} 817 818static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, 819 u32 label, struct mpls_route *rt, int flags) 820{ 821 struct net_device *dev; 822 struct nlmsghdr *nlh; 823 struct rtmsg *rtm; 824 825 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags); 826 if (nlh == NULL) 827 return -EMSGSIZE; 828 829 rtm = nlmsg_data(nlh); 830 rtm->rtm_family = AF_MPLS; 831 rtm->rtm_dst_len = 20; 832 rtm->rtm_src_len = 0; 833 rtm->rtm_tos = 0; 834 rtm->rtm_table = RT_TABLE_MAIN; 835 rtm->rtm_protocol = rt->rt_protocol; 836 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 837 rtm->rtm_type = RTN_UNICAST; 838 rtm->rtm_flags = 0; 839 840 if (rt->rt_labels && 841 nla_put_labels(skb, RTA_NEWDST, rt->rt_labels, rt->rt_label)) 842 goto nla_put_failure; 843 if (nla_put_via(skb, rt->rt_via_table, rt->rt_via, rt->rt_via_alen)) 844 goto nla_put_failure; 845 dev = rtnl_dereference(rt->rt_dev); 846 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) 847 goto nla_put_failure; 848 if (nla_put_labels(skb, RTA_DST, 1, &label)) 849 goto nla_put_failure; 850 851 nlmsg_end(skb, nlh); 852 return 0; 853 854nla_put_failure: 855 nlmsg_cancel(skb, nlh); 856 return -EMSGSIZE; 857} 858 859static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) 860{ 861 struct net *net = sock_net(skb->sk); 862 struct mpls_route __rcu **platform_label; 863 size_t platform_labels; 864 unsigned int index; 865 866 ASSERT_RTNL(); 867 868 index = cb->args[0]; 869 if (index < 16) 870 index = 16; 871 872 platform_label = rtnl_dereference(net->mpls.platform_label); 873 platform_labels = net->mpls.platform_labels; 874 for (; index < platform_labels; index++) { 875 struct mpls_route *rt; 876 rt = rtnl_dereference(platform_label[index]); 877 if (!rt) 878 continue; 879 880 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid, 881 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 882 index, rt, NLM_F_MULTI) < 0) 883 break; 884 } 885 cb->args[0] = index; 886 887 return skb->len; 888} 889 890static inline size_t lfib_nlmsg_size(struct mpls_route *rt) 891{ 892 size_t payload = 893 NLMSG_ALIGN(sizeof(struct rtmsg)) 894 + nla_total_size(2 + rt->rt_via_alen) /* RTA_VIA */ 895 + nla_total_size(4); /* RTA_DST */ 896 if (rt->rt_labels) /* RTA_NEWDST */ 897 payload += nla_total_size(rt->rt_labels * 4); 898 if (rt->rt_dev) /* RTA_OIF */ 899 payload += nla_total_size(4); 900 return payload; 901} 902 903static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, 904 struct nlmsghdr *nlh, struct net *net, u32 portid, 905 unsigned int nlm_flags) 906{ 907 struct sk_buff *skb; 908 u32 seq = nlh ? nlh->nlmsg_seq : 0; 909 int err = -ENOBUFS; 910 911 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL); 912 if (skb == NULL) 913 goto errout; 914 915 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags); 916 if (err < 0) { 917 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */ 918 WARN_ON(err == -EMSGSIZE); 919 kfree_skb(skb); 920 goto errout; 921 } 922 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL); 923 924 return; 925errout: 926 if (err < 0) 927 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err); 928} 929 930static int resize_platform_label_table(struct net *net, size_t limit) 931{ 932 size_t size = sizeof(struct mpls_route *) * limit; 933 size_t old_limit; 934 size_t cp_size; 935 struct mpls_route __rcu **labels = NULL, **old; 936 struct mpls_route *rt0 = NULL, *rt2 = NULL; 937 unsigned index; 938 939 if (size) { 940 labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY); 941 if (!labels) 942 labels = vzalloc(size); 943 944 if (!labels) 945 goto nolabels; 946 } 947 948 /* In case the predefined labels need to be populated */ 949 if (limit > MPLS_LABEL_IPV4NULL) { 950 struct net_device *lo = net->loopback_dev; 951 rt0 = mpls_rt_alloc(lo->addr_len); 952 if (!rt0) 953 goto nort0; 954 RCU_INIT_POINTER(rt0->rt_dev, lo); 955 rt0->rt_protocol = RTPROT_KERNEL; 956 rt0->rt_via_table = NEIGH_LINK_TABLE; 957 memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len); 958 } 959 if (limit > MPLS_LABEL_IPV6NULL) { 960 struct net_device *lo = net->loopback_dev; 961 rt2 = mpls_rt_alloc(lo->addr_len); 962 if (!rt2) 963 goto nort2; 964 RCU_INIT_POINTER(rt2->rt_dev, lo); 965 rt2->rt_protocol = RTPROT_KERNEL; 966 rt2->rt_via_table = NEIGH_LINK_TABLE; 967 memcpy(rt2->rt_via, lo->dev_addr, lo->addr_len); 968 } 969 970 rtnl_lock(); 971 /* Remember the original table */ 972 old = rtnl_dereference(net->mpls.platform_label); 973 old_limit = net->mpls.platform_labels; 974 975 /* Free any labels beyond the new table */ 976 for (index = limit; index < old_limit; index++) 977 mpls_route_update(net, index, NULL, NULL, NULL); 978 979 /* Copy over the old labels */ 980 cp_size = size; 981 if (old_limit < limit) 982 cp_size = old_limit * sizeof(struct mpls_route *); 983 984 memcpy(labels, old, cp_size); 985 986 /* If needed set the predefined labels */ 987 if ((old_limit <= MPLS_LABEL_IPV6NULL) && 988 (limit > MPLS_LABEL_IPV6NULL)) { 989 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2); 990 rt2 = NULL; 991 } 992 993 if ((old_limit <= MPLS_LABEL_IPV4NULL) && 994 (limit > MPLS_LABEL_IPV4NULL)) { 995 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0); 996 rt0 = NULL; 997 } 998 999 /* Update the global pointers */ 1000 net->mpls.platform_labels = limit; 1001 rcu_assign_pointer(net->mpls.platform_label, labels); 1002 1003 rtnl_unlock(); 1004 1005 mpls_rt_free(rt2); 1006 mpls_rt_free(rt0); 1007 1008 if (old) { 1009 synchronize_rcu(); 1010 kvfree(old); 1011 } 1012 return 0; 1013 1014nort2: 1015 mpls_rt_free(rt0); 1016nort0: 1017 kvfree(labels); 1018nolabels: 1019 return -ENOMEM; 1020} 1021 1022static int mpls_platform_labels(struct ctl_table *table, int write, 1023 void __user *buffer, size_t *lenp, loff_t *ppos) 1024{ 1025 struct net *net = table->data; 1026 int platform_labels = net->mpls.platform_labels; 1027 int ret; 1028 struct ctl_table tmp = { 1029 .procname = table->procname, 1030 .data = &platform_labels, 1031 .maxlen = sizeof(int), 1032 .mode = table->mode, 1033 .extra1 = &zero, 1034 .extra2 = &label_limit, 1035 }; 1036 1037 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 1038 1039 if (write && ret == 0) 1040 ret = resize_platform_label_table(net, platform_labels); 1041 1042 return ret; 1043} 1044 1045static const struct ctl_table mpls_table[] = { 1046 { 1047 .procname = "platform_labels", 1048 .data = NULL, 1049 .maxlen = sizeof(int), 1050 .mode = 0644, 1051 .proc_handler = mpls_platform_labels, 1052 }, 1053 { } 1054}; 1055 1056static int mpls_net_init(struct net *net) 1057{ 1058 struct ctl_table *table; 1059 1060 net->mpls.platform_labels = 0; 1061 net->mpls.platform_label = NULL; 1062 1063 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL); 1064 if (table == NULL) 1065 return -ENOMEM; 1066 1067 table[0].data = net; 1068 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table); 1069 if (net->mpls.ctl == NULL) 1070 return -ENOMEM; 1071 1072 return 0; 1073} 1074 1075static void mpls_net_exit(struct net *net) 1076{ 1077 struct mpls_route __rcu **platform_label; 1078 size_t platform_labels; 1079 struct ctl_table *table; 1080 unsigned int index; 1081 1082 table = net->mpls.ctl->ctl_table_arg; 1083 unregister_net_sysctl_table(net->mpls.ctl); 1084 kfree(table); 1085 1086 /* An rcu grace period has passed since there was a device in 1087 * the network namespace (and thus the last in flight packet) 1088 * left this network namespace. This is because 1089 * unregister_netdevice_many and netdev_run_todo has completed 1090 * for each network device that was in this network namespace. 1091 * 1092 * As such no additional rcu synchronization is necessary when 1093 * freeing the platform_label table. 1094 */ 1095 rtnl_lock(); 1096 platform_label = rtnl_dereference(net->mpls.platform_label); 1097 platform_labels = net->mpls.platform_labels; 1098 for (index = 0; index < platform_labels; index++) { 1099 struct mpls_route *rt = rtnl_dereference(platform_label[index]); 1100 RCU_INIT_POINTER(platform_label[index], NULL); 1101 mpls_rt_free(rt); 1102 } 1103 rtnl_unlock(); 1104 1105 kvfree(platform_label); 1106} 1107 1108static struct pernet_operations mpls_net_ops = { 1109 .init = mpls_net_init, 1110 .exit = mpls_net_exit, 1111}; 1112 1113static int __init mpls_init(void) 1114{ 1115 int err; 1116 1117 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4); 1118 1119 err = register_pernet_subsys(&mpls_net_ops); 1120 if (err) 1121 goto out; 1122 1123 err = register_netdevice_notifier(&mpls_dev_notifier); 1124 if (err) 1125 goto out_unregister_pernet; 1126 1127 dev_add_pack(&mpls_packet_type); 1128 1129 rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, NULL); 1130 rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, NULL); 1131 rtnl_register(PF_MPLS, RTM_GETROUTE, NULL, mpls_dump_routes, NULL); 1132 err = 0; 1133out: 1134 return err; 1135 1136out_unregister_pernet: 1137 unregister_pernet_subsys(&mpls_net_ops); 1138 goto out; 1139} 1140module_init(mpls_init); 1141 1142static void __exit mpls_exit(void) 1143{ 1144 rtnl_unregister_all(PF_MPLS); 1145 dev_remove_pack(&mpls_packet_type); 1146 unregister_netdevice_notifier(&mpls_dev_notifier); 1147 unregister_pernet_subsys(&mpls_net_ops); 1148} 1149module_exit(mpls_exit); 1150 1151MODULE_DESCRIPTION("MultiProtocol Label Switching"); 1152MODULE_LICENSE("GPL v2"); 1153MODULE_ALIAS_NETPROTO(PF_MPLS); 1154