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