kernel/drivers/net/ipvlan/ipvlan_core.c

   1 /* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.com>
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU General Public License as
   5  * published by the Free Software Foundation; either version 2 of
   6  * the License, or (at your option) any later version.
   7  *
   8  */
   9
  10 #include "ipvlan.h"
  11
  12 static u32 ipvlan_jhash_secret __read_mostly;
  13
  14 void ipvlan_init_secret(void)
  15 {
  16         net_get_random_once(&ipvlan_jhash_secret, sizeof(ipvlan_jhash_secret));
  17 }
  18
  19 static void ipvlan_count_rx(const struct ipvl_dev *ipvlan,
  20                             unsigned int len, bool success, bool mcast)
  21 {
  22         if (!ipvlan)
  23                 return;
  24
  25         if (likely(success)) {
  26                 struct ipvl_pcpu_stats *pcptr;
  27
  28                 pcptr = this_cpu_ptr(ipvlan->pcpu_stats);
  29                 u64_stats_update_begin(&pcptr->syncp);
  30                 pcptr->rx_pkts++;
  31                 pcptr->rx_bytes += len;
  32                 if (mcast)
  33                         pcptr->rx_mcast++;
  34                 u64_stats_update_end(&pcptr->syncp);
  35         } else {
  36                 this_cpu_inc(ipvlan->pcpu_stats->rx_errs);
  37         }
  38 }
  39
  40 static u8 ipvlan_get_v6_hash(const void *iaddr)
  41 {
  42         const struct in6_addr *ip6_addr = iaddr;
  43
  44         return __ipv6_addr_jhash(ip6_addr, ipvlan_jhash_secret) &
  45                IPVLAN_HASH_MASK;
  46 }
  47
  48 static u8 ipvlan_get_v4_hash(const void *iaddr)
  49 {
  50         const struct in_addr *ip4_addr = iaddr;
  51
  52         return jhash_1word(ip4_addr->s_addr, ipvlan_jhash_secret) &
  53                IPVLAN_HASH_MASK;
  54 }
  55
  56 struct ipvl_addr *ipvlan_ht_addr_lookup(const struct ipvl_port *port,
  57                                         const void *iaddr, bool is_v6)
  58 {
  59         struct ipvl_addr *addr;
  60         u8 hash;
  61
  62         hash = is_v6 ? ipvlan_get_v6_hash(iaddr) :
  63                ipvlan_get_v4_hash(iaddr);
  64         hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode) {
  65                 if (is_v6 && addr->atype == IPVL_IPV6 &&
  66                     ipv6_addr_equal(&addr->ip6addr, iaddr))
  67                         return addr;
  68                 else if (!is_v6 && addr->atype == IPVL_IPV4 &&
  69                          addr->ip4addr.s_addr ==
  70                                 ((struct in_addr *)iaddr)->s_addr)
  71                         return addr;
  72         }
  73         return NULL;
  74 }
  75
  76 void ipvlan_ht_addr_add(struct ipvl_dev *ipvlan, struct ipvl_addr *addr)
  77 {
  78         struct ipvl_port *port = ipvlan->port;
  79         u8 hash;
  80
  81         hash = (addr->atype == IPVL_IPV6) ?
  82                ipvlan_get_v6_hash(&addr->ip6addr) :
  83                ipvlan_get_v4_hash(&addr->ip4addr);
  84         if (hlist_unhashed(&addr->hlnode))
  85                 hlist_add_head_rcu(&addr->hlnode, &port->hlhead[hash]);
  86 }
  87
  88 void ipvlan_ht_addr_del(struct ipvl_addr *addr, bool sync)
  89 {
  90         hlist_del_init_rcu(&addr->hlnode);
  91         if (sync)
  92                 synchronize_rcu();
  93 }
  94
  95 struct ipvl_addr *ipvlan_find_addr(const struct ipvl_dev *ipvlan,
  96                                    const void *iaddr, bool is_v6)
  97 {
  98         struct ipvl_addr *addr;
  99
 100         list_for_each_entry(addr, &ipvlan->addrs, anode) {
 101                 if ((is_v6 && addr->atype == IPVL_IPV6 &&
 102                     ipv6_addr_equal(&addr->ip6addr, iaddr)) ||
 103                     (!is_v6 && addr->atype == IPVL_IPV4 &&
 104                     addr->ip4addr.s_addr == ((struct in_addr *)iaddr)->s_addr))
 105                         return addr;
 106         }
 107         return NULL;
 108 }
 109
 110 bool ipvlan_addr_busy(struct ipvl_port *port, void *iaddr, bool is_v6)
 111 {
 112         struct ipvl_dev *ipvlan;
 113
 114         ASSERT_RTNL();
 115
 116         list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
 117                 if (ipvlan_find_addr(ipvlan, iaddr, is_v6))
 118                         return true;
 119         }
 120         return false;
 121 }
 122
 123 static void *ipvlan_get_L3_hdr(struct sk_buff *skb, int *type)
 124 {
 125         void *lyr3h = NULL;
 126
 127         switch (skb->protocol) {
 128         case htons(ETH_P_ARP): {
 129                 struct arphdr *arph;
 130
 131                 if (unlikely(!pskb_may_pull(skb, sizeof(*arph))))
 132                         return NULL;
 133
 134                 arph = arp_hdr(skb);
 135                 *type = IPVL_ARP;
 136                 lyr3h = arph;
 137                 break;
 138         }
 139         case htons(ETH_P_IP): {
 140                 u32 pktlen;
 141                 struct iphdr *ip4h;
 142
 143                 if (unlikely(!pskb_may_pull(skb, sizeof(*ip4h))))
 144                         return NULL;
 145
 146                 ip4h = ip_hdr(skb);
 147                 pktlen = ntohs(ip4h->tot_len);
 148                 if (ip4h->ihl < 5 || ip4h->version != 4)
 149                         return NULL;
 150                 if (skb->len < pktlen || pktlen < (ip4h->ihl * 4))
 151                         return NULL;
 152
 153                 *type = IPVL_IPV4;
 154                 lyr3h = ip4h;
 155                 break;
 156         }
 157         case htons(ETH_P_IPV6): {
 158                 struct ipv6hdr *ip6h;
 159
 160                 if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h))))
 161                         return NULL;
 162
 163                 ip6h = ipv6_hdr(skb);
 164                 if (ip6h->version != 6)
 165                         return NULL;
 166
 167                 *type = IPVL_IPV6;
 168                 lyr3h = ip6h;
 169                 /* Only Neighbour Solicitation pkts need different treatment */
 170                 if (ipv6_addr_any(&ip6h->saddr) &&
 171                     ip6h->nexthdr == NEXTHDR_ICMP) {
 172                         *type = IPVL_ICMPV6;
 173                         lyr3h = ip6h + 1;
 174                 }
 175                 break;
 176         }
 177         default:
 178                 return NULL;
 179         }
 180
 181         return lyr3h;
 182 }
 183
 184 unsigned int ipvlan_mac_hash(const unsigned char *addr)
 185 {
 186         u32 hash = jhash_1word(__get_unaligned_cpu32(addr+2),
 187                                ipvlan_jhash_secret);
 188
 189         return hash & IPVLAN_MAC_FILTER_MASK;
 190 }
 191
 192 static void ipvlan_multicast_frame(struct ipvl_port *port, struct sk_buff *skb,
 193                                    const struct ipvl_dev *in_dev, bool local)
 194 {
 195         struct ethhdr *eth = eth_hdr(skb);
 196         struct ipvl_dev *ipvlan;
 197         struct sk_buff *nskb;
 198         unsigned int len;
 199         unsigned int mac_hash;
 200         int ret;
 201
 202         if (skb->protocol == htons(ETH_P_PAUSE))
 203                 return;
 204
 205         rcu_read_lock();
 206         list_for_each_entry_rcu(ipvlan, &port->ipvlans, pnode) {
 207                 if (local && (ipvlan == in_dev))
 208                         continue;
 209
 210                 mac_hash = ipvlan_mac_hash(eth->h_dest);
 211                 if (!test_bit(mac_hash, ipvlan->mac_filters))
 212                         continue;
 213
 214                 ret = NET_RX_DROP;
 215                 len = skb->len + ETH_HLEN;
 216                 nskb = skb_clone(skb, GFP_ATOMIC);
 217                 if (!nskb)
 218                         goto mcast_acct;
 219
 220                 if (ether_addr_equal(eth->h_dest, ipvlan->phy_dev->broadcast))
 221                         nskb->pkt_type = PACKET_BROADCAST;
 222                 else
 223                         nskb->pkt_type = PACKET_MULTICAST;
 224
 225                 nskb->dev = ipvlan->dev;
 226                 if (local)
 227                         ret = dev_forward_skb(ipvlan->dev, nskb);
 228                 else
 229                         ret = netif_rx(nskb);
 230 mcast_acct:
 231                 ipvlan_count_rx(ipvlan, len, ret == NET_RX_SUCCESS, true);
 232         }
 233         rcu_read_unlock();
 234
 235         /* Locally generated? ...Forward a copy to the main-device as
 236          * well. On the RX side we'll ignore it (wont give it to any
 237          * of the virtual devices.
 238          */
 239         if (local) {
 240                 nskb = skb_clone(skb, GFP_ATOMIC);
 241                 if (nskb) {
 242                         if (ether_addr_equal(eth->h_dest, port->dev->broadcast))
 243                                 nskb->pkt_type = PACKET_BROADCAST;
 244                         else
 245                                 nskb->pkt_type = PACKET_MULTICAST;
 246
 247                         dev_forward_skb(port->dev, nskb);
 248                 }
 249         }
 250 }
 251
 252 static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff *skb,
 253                             bool local)
 254 {
 255         struct ipvl_dev *ipvlan = addr->master;
 256         struct net_device *dev = ipvlan->dev;
 257         unsigned int len;
 258         rx_handler_result_t ret = RX_HANDLER_CONSUMED;
 259         bool success = false;
 260
 261         len = skb->len + ETH_HLEN;
 262         if (unlikely(!(dev->flags & IFF_UP))) {
 263                 kfree_skb(skb);
 264                 goto out;
 265         }
 266
 267         skb = skb_share_check(skb, GFP_ATOMIC);
 268         if (!skb)
 269                 goto out;
 270
 271         skb->dev = dev;
 272         skb->pkt_type = PACKET_HOST;
 273
 274         if (local) {
 275                 if (dev_forward_skb(ipvlan->dev, skb) == NET_RX_SUCCESS)
 276                         success = true;
 277         } else {
 278                 ret = RX_HANDLER_ANOTHER;
 279                 success = true;
 280         }
 281
 282 out:
 283         ipvlan_count_rx(ipvlan, len, success, false);
 284         return ret;
 285 }
 286
 287 static struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port,
 288                                             void *lyr3h, int addr_type,
 289                                             bool use_dest)
 290 {
 291         struct ipvl_addr *addr = NULL;
 292
 293         if (addr_type == IPVL_IPV6) {
 294                 struct ipv6hdr *ip6h;
 295                 struct in6_addr *i6addr;
 296
 297                 ip6h = (struct ipv6hdr *)lyr3h;
 298                 i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
 299                 addr = ipvlan_ht_addr_lookup(port, i6addr, true);
 300         } else if (addr_type == IPVL_ICMPV6) {
 301                 struct nd_msg *ndmh;
 302                 struct in6_addr *i6addr;
 303
 304                 /* Make sure that the NeighborSolicitation ICMPv6 packets
 305                  * are handled to avoid DAD issue.
 306                  */
 307                 ndmh = (struct nd_msg *)lyr3h;
 308                 if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
 309                         i6addr = &ndmh->target;
 310                         addr = ipvlan_ht_addr_lookup(port, i6addr, true);
 311                 }
 312         } else if (addr_type == IPVL_IPV4) {
 313                 struct iphdr *ip4h;
 314                 __be32 *i4addr;
 315
 316                 ip4h = (struct iphdr *)lyr3h;
 317                 i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
 318                 addr = ipvlan_ht_addr_lookup(port, i4addr, false);
 319         } else if (addr_type == IPVL_ARP) {
 320                 struct arphdr *arph;
 321                 unsigned char *arp_ptr;
 322                 __be32 dip;
 323
 324                 arph = (struct arphdr *)lyr3h;
 325                 arp_ptr = (unsigned char *)(arph + 1);
 326                 if (use_dest)
 327                         arp_ptr += (2 * port->dev->addr_len) + 4;
 328                 else
 329                         arp_ptr += port->dev->addr_len;
 330
 331                 memcpy(&dip, arp_ptr, 4);
 332                 addr = ipvlan_ht_addr_lookup(port, &dip, false);
 333         }
 334
 335         return addr;
 336 }
 337
 338 static int ipvlan_process_v4_outbound(struct sk_buff *skb)
 339 {
 340         const struct iphdr *ip4h = ip_hdr(skb);
 341         struct net_device *dev = skb->dev;
 342         struct rtable *rt;
 343         int err, ret = NET_XMIT_DROP;
 344         struct flowi4 fl4 = {
 345                 .flowi4_oif = dev_get_iflink(dev),
 346                 .flowi4_tos = RT_TOS(ip4h->tos),
 347                 .flowi4_flags = FLOWI_FLAG_ANYSRC,
 348                 .daddr = ip4h->daddr,
 349                 .saddr = ip4h->saddr,
 350         };
 351
 352         rt = ip_route_output_flow(dev_net(dev), &fl4, NULL);
 353         if (IS_ERR(rt))
 354                 goto err;
 355
 356         if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
 357                 ip_rt_put(rt);
 358                 goto err;
 359         }
 360         skb_dst_drop(skb);
 361         skb_dst_set(skb, &rt->dst);
 362         err = ip_local_out(skb);
 363         if (unlikely(net_xmit_eval(err)))
 364                 dev->stats.tx_errors++;
 365         else
 366                 ret = NET_XMIT_SUCCESS;
 367         goto out;
 368 err:
 369         dev->stats.tx_errors++;
 370         kfree_skb(skb);
 371 out:
 372         return ret;
 373 }
 374
 375 static int ipvlan_process_v6_outbound(struct sk_buff *skb)
 376 {
 377         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 378         struct net_device *dev = skb->dev;
 379         struct dst_entry *dst;
 380         int err, ret = NET_XMIT_DROP;
 381         struct flowi6 fl6 = {
 382                 .flowi6_iif = skb->dev->ifindex,
 383                 .daddr = ip6h->daddr,
 384                 .saddr = ip6h->saddr,
 385                 .flowi6_flags = FLOWI_FLAG_ANYSRC,
 386                 .flowlabel = ip6_flowinfo(ip6h),
 387                 .flowi6_mark = skb->mark,
 388                 .flowi6_proto = ip6h->nexthdr,
 389         };
 390
 391         dst = ip6_route_output(dev_net(dev), NULL, &fl6);
 392         if (dst->error) {
 393                 ret = dst->error;
 394                 dst_release(dst);
 395                 goto err;
 396         }
 397         skb_dst_drop(skb);
 398         skb_dst_set(skb, dst);
 399         err = ip6_local_out(skb);
 400         if (unlikely(net_xmit_eval(err)))
 401                 dev->stats.tx_errors++;
 402         else
 403                 ret = NET_XMIT_SUCCESS;
 404         goto out;
 405 err:
 406         dev->stats.tx_errors++;
 407         kfree_skb(skb);
 408 out:
 409         return ret;
 410 }
 411
 412 static int ipvlan_process_outbound(struct sk_buff *skb,
 413                                    const struct ipvl_dev *ipvlan)
 414 {
 415         struct ethhdr *ethh = eth_hdr(skb);
 416         int ret = NET_XMIT_DROP;
 417
 418         /* In this mode we dont care about multicast and broadcast traffic */
 419         if (is_multicast_ether_addr(ethh->h_dest)) {
 420                 pr_warn_ratelimited("Dropped {multi|broad}cast of type= [%x]\n",
 421                                     ntohs(skb->protocol));
 422                 kfree_skb(skb);
 423                 goto out;
 424         }
 425
 426         /* The ipvlan is a pseudo-L2 device, so the packets that we receive
 427          * will have L2; which need to discarded and processed further
 428          * in the net-ns of the main-device.
 429          */
 430         if (skb_mac_header_was_set(skb)) {
 431                 skb_pull(skb, sizeof(*ethh));
 432                 skb->mac_header = (typeof(skb->mac_header))~0U;
 433                 skb_reset_network_header(skb);
 434         }
 435
 436         if (skb->protocol == htons(ETH_P_IPV6))
 437                 ret = ipvlan_process_v6_outbound(skb);
 438         else if (skb->protocol == htons(ETH_P_IP))
 439                 ret = ipvlan_process_v4_outbound(skb);
 440         else {
 441                 pr_warn_ratelimited("Dropped outbound packet type=%x\n",
 442                                     ntohs(skb->protocol));
 443                 kfree_skb(skb);
 444         }
 445 out:
 446         return ret;
 447 }
 448
 449 static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
 450 {
 451         const struct ipvl_dev *ipvlan = netdev_priv(dev);
 452         void *lyr3h;
 453         struct ipvl_addr *addr;
 454         int addr_type;
 455
 456         lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 457         if (!lyr3h)
 458                 goto out;
 459
 460         addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
 461         if (addr)
 462                 return ipvlan_rcv_frame(addr, skb, true);
 463
 464 out:
 465         skb->dev = ipvlan->phy_dev;
 466         return ipvlan_process_outbound(skb, ipvlan);
 467 }
 468
 469 static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
 470 {
 471         const struct ipvl_dev *ipvlan = netdev_priv(dev);
 472         struct ethhdr *eth = eth_hdr(skb);
 473         struct ipvl_addr *addr;
 474         void *lyr3h;
 475         int addr_type;
 476
 477         if (ether_addr_equal(eth->h_dest, eth->h_source)) {
 478                 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 479                 if (lyr3h) {
 480                         addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
 481                         if (addr)
 482                                 return ipvlan_rcv_frame(addr, skb, true);
 483                 }
 484                 skb = skb_share_check(skb, GFP_ATOMIC);
 485                 if (!skb)
 486                         return NET_XMIT_DROP;
 487
 488                 /* Packet definitely does not belong to any of the
 489                  * virtual devices, but the dest is local. So forward
 490                  * the skb for the main-dev. At the RX side we just return
 491                  * RX_PASS for it to be processed further on the stack.
 492                  */
 493                 return dev_forward_skb(ipvlan->phy_dev, skb);
 494
 495         } else if (is_multicast_ether_addr(eth->h_dest)) {
 496                 u8 ip_summed = skb->ip_summed;
 497
 498                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 499                 ipvlan_multicast_frame(ipvlan->port, skb, ipvlan, true);
 500                 skb->ip_summed = ip_summed;
 501         }
 502
 503         skb->dev = ipvlan->phy_dev;
 504         return dev_queue_xmit(skb);
 505 }
 506
 507 int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
 508 {
 509         struct ipvl_dev *ipvlan = netdev_priv(dev);
 510         struct ipvl_port *port = ipvlan_port_get_rcu(ipvlan->phy_dev);
 511
 512         if (!port)
 513                 goto out;
 514
 515         if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
 516                 goto out;
 517
 518         switch(port->mode) {
 519         case IPVLAN_MODE_L2:
 520                 return ipvlan_xmit_mode_l2(skb, dev);
 521         case IPVLAN_MODE_L3:
 522                 return ipvlan_xmit_mode_l3(skb, dev);
 523         }
 524
 525         /* Should not reach here */
 526         WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
 527                           port->mode);
 528 out:
 529         kfree_skb(skb);
 530         return NET_XMIT_DROP;
 531 }
 532
 533 static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
 534 {
 535         struct ethhdr *eth = eth_hdr(skb);
 536         struct ipvl_addr *addr;
 537         void *lyr3h;
 538         int addr_type;
 539
 540         if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
 541                 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 542                 if (!lyr3h)
 543                         return true;
 544
 545                 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
 546                 if (addr)
 547                         return false;
 548         }
 549
 550         return true;
 551 }
 552
 553 static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
 554                                                  struct ipvl_port *port)
 555 {
 556         void *lyr3h;
 557         int addr_type;
 558         struct ipvl_addr *addr;
 559         struct sk_buff *skb = *pskb;
 560         rx_handler_result_t ret = RX_HANDLER_PASS;
 561
 562         lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 563         if (!lyr3h)
 564                 goto out;
 565
 566         addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
 567         if (addr)
 568                 ret = ipvlan_rcv_frame(addr, skb, false);
 569
 570 out:
 571         return ret;
 572 }
 573
 574 static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
 575                                                  struct ipvl_port *port)
 576 {
 577         struct sk_buff *skb = *pskb;
 578         struct ethhdr *eth = eth_hdr(skb);
 579         rx_handler_result_t ret = RX_HANDLER_PASS;
 580         void *lyr3h;
 581         int addr_type;
 582
 583         if (is_multicast_ether_addr(eth->h_dest)) {
 584                 if (ipvlan_external_frame(skb, port))
 585                         ipvlan_multicast_frame(port, skb, NULL, false);
 586         } else {
 587                 struct ipvl_addr *addr;
 588
 589                 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 590                 if (!lyr3h)
 591                         return ret;
 592
 593                 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
 594                 if (addr)
 595                         ret = ipvlan_rcv_frame(addr, skb, false);
 596         }
 597
 598         return ret;
 599 }
 600
 601 rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
 602 {
 603         struct sk_buff *skb = *pskb;
 604         struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);
 605
 606         if (!port)
 607                 return RX_HANDLER_PASS;
 608
 609         switch (port->mode) {
 610         case IPVLAN_MODE_L2:
 611                 return ipvlan_handle_mode_l2(pskb, port);
 612         case IPVLAN_MODE_L3:
 613                 return ipvlan_handle_mode_l3(pskb, port);
 614         }
 615
 616         /* Should not reach here */
 617         WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
 618                           port->mode);
 619         kfree_skb(skb);
 620         return NET_RX_DROP;
 621 }