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;
  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 (IS_ERR(dst))
 381                 goto err;
 382
 383         skb_dst_drop(skb);
 384         skb_dst_set(skb, dst);
 385         err = ip6_local_out(skb);
 386         if (unlikely(net_xmit_eval(err)))
 387                 dev->stats.tx_errors++;
 388         else
 389                 ret = NET_XMIT_SUCCESS;
 390         goto out;
 391 err:
 392         dev->stats.tx_errors++;
 393         kfree_skb(skb);
 394 out:
 395         return ret;
 396 }
 397
 398 static int ipvlan_process_outbound(struct sk_buff *skb,
 399                                    const struct ipvl_dev *ipvlan)
 400 {
 401         struct ethhdr *ethh = eth_hdr(skb);
 402         int ret = NET_XMIT_DROP;
 403
 404         /* In this mode we dont care about multicast and broadcast traffic */
 405         if (is_multicast_ether_addr(ethh->h_dest)) {
 406                 pr_warn_ratelimited("Dropped {multi|broad}cast of type= [%x]\n",
 407                                     ntohs(skb->protocol));
 408                 kfree_skb(skb);
 409                 goto out;
 410         }
 411
 412         /* The ipvlan is a pseudo-L2 device, so the packets that we receive
 413          * will have L2; which need to discarded and processed further
 414          * in the net-ns of the main-device.
 415          */
 416         if (skb_mac_header_was_set(skb)) {
 417                 skb_pull(skb, sizeof(*ethh));
 418                 skb->mac_header = (typeof(skb->mac_header))~0U;
 419                 skb_reset_network_header(skb);
 420         }
 421
 422         if (skb->protocol == htons(ETH_P_IPV6))
 423                 ret = ipvlan_process_v6_outbound(skb);
 424         else if (skb->protocol == htons(ETH_P_IP))
 425                 ret = ipvlan_process_v4_outbound(skb);
 426         else {
 427                 pr_warn_ratelimited("Dropped outbound packet type=%x\n",
 428                                     ntohs(skb->protocol));
 429                 kfree_skb(skb);
 430         }
 431 out:
 432         return ret;
 433 }
 434
 435 static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
 436 {
 437         const struct ipvl_dev *ipvlan = netdev_priv(dev);
 438         void *lyr3h;
 439         struct ipvl_addr *addr;
 440         int addr_type;
 441
 442         lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 443         if (!lyr3h)
 444                 goto out;
 445
 446         addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
 447         if (addr)
 448                 return ipvlan_rcv_frame(addr, skb, true);
 449
 450 out:
 451         skb->dev = ipvlan->phy_dev;
 452         return ipvlan_process_outbound(skb, ipvlan);
 453 }
 454
 455 static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
 456 {
 457         const struct ipvl_dev *ipvlan = netdev_priv(dev);
 458         struct ethhdr *eth = eth_hdr(skb);
 459         struct ipvl_addr *addr;
 460         void *lyr3h;
 461         int addr_type;
 462
 463         if (ether_addr_equal(eth->h_dest, eth->h_source)) {
 464                 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 465                 if (lyr3h) {
 466                         addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
 467                         if (addr)
 468                                 return ipvlan_rcv_frame(addr, skb, true);
 469                 }
 470                 skb = skb_share_check(skb, GFP_ATOMIC);
 471                 if (!skb)
 472                         return NET_XMIT_DROP;
 473
 474                 /* Packet definitely does not belong to any of the
 475                  * virtual devices, but the dest is local. So forward
 476                  * the skb for the main-dev. At the RX side we just return
 477                  * RX_PASS for it to be processed further on the stack.
 478                  */
 479                 return dev_forward_skb(ipvlan->phy_dev, skb);
 480
 481         } else if (is_multicast_ether_addr(eth->h_dest)) {
 482                 u8 ip_summed = skb->ip_summed;
 483
 484                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 485                 ipvlan_multicast_frame(ipvlan->port, skb, ipvlan, true);
 486                 skb->ip_summed = ip_summed;
 487         }
 488
 489         skb->dev = ipvlan->phy_dev;
 490         return dev_queue_xmit(skb);
 491 }
 492
 493 int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
 494 {
 495         struct ipvl_dev *ipvlan = netdev_priv(dev);
 496         struct ipvl_port *port = ipvlan_port_get_rcu(ipvlan->phy_dev);
 497
 498         if (!port)
 499                 goto out;
 500
 501         if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
 502                 goto out;
 503
 504         switch(port->mode) {
 505         case IPVLAN_MODE_L2:
 506                 return ipvlan_xmit_mode_l2(skb, dev);
 507         case IPVLAN_MODE_L3:
 508                 return ipvlan_xmit_mode_l3(skb, dev);
 509         }
 510
 511         /* Should not reach here */
 512         WARN_ONCE(true, "ipvlan_queue_xmit() called for mode = [%hx]\n",
 513                           port->mode);
 514 out:
 515         kfree_skb(skb);
 516         return NET_XMIT_DROP;
 517 }
 518
 519 static bool ipvlan_external_frame(struct sk_buff *skb, struct ipvl_port *port)
 520 {
 521         struct ethhdr *eth = eth_hdr(skb);
 522         struct ipvl_addr *addr;
 523         void *lyr3h;
 524         int addr_type;
 525
 526         if (ether_addr_equal(eth->h_source, skb->dev->dev_addr)) {
 527                 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 528                 if (!lyr3h)
 529                         return true;
 530
 531                 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, false);
 532                 if (addr)
 533                         return false;
 534         }
 535
 536         return true;
 537 }
 538
 539 static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,
 540                                                  struct ipvl_port *port)
 541 {
 542         void *lyr3h;
 543         int addr_type;
 544         struct ipvl_addr *addr;
 545         struct sk_buff *skb = *pskb;
 546         rx_handler_result_t ret = RX_HANDLER_PASS;
 547
 548         lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 549         if (!lyr3h)
 550                 goto out;
 551
 552         addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
 553         if (addr)
 554                 ret = ipvlan_rcv_frame(addr, skb, false);
 555
 556 out:
 557         return ret;
 558 }
 559
 560 static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,
 561                                                  struct ipvl_port *port)
 562 {
 563         struct sk_buff *skb = *pskb;
 564         struct ethhdr *eth = eth_hdr(skb);
 565         rx_handler_result_t ret = RX_HANDLER_PASS;
 566         void *lyr3h;
 567         int addr_type;
 568
 569         if (is_multicast_ether_addr(eth->h_dest)) {
 570                 if (ipvlan_external_frame(skb, port))
 571                         ipvlan_multicast_frame(port, skb, NULL, false);
 572         } else {
 573                 struct ipvl_addr *addr;
 574
 575                 lyr3h = ipvlan_get_L3_hdr(skb, &addr_type);
 576                 if (!lyr3h)
 577                         return ret;
 578
 579                 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
 580                 if (addr)
 581                         ret = ipvlan_rcv_frame(addr, skb, false);
 582         }
 583
 584         return ret;
 585 }
 586
 587 rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
 588 {
 589         struct sk_buff *skb = *pskb;
 590         struct ipvl_port *port = ipvlan_port_get_rcu(skb->dev);
 591
 592         if (!port)
 593                 return RX_HANDLER_PASS;
 594
 595         switch (port->mode) {
 596         case IPVLAN_MODE_L2:
 597                 return ipvlan_handle_mode_l2(pskb, port);
 598         case IPVLAN_MODE_L3:
 599                 return ipvlan_handle_mode_l3(pskb, port);
 600         }
 601
 602         /* Should not reach here */
 603         WARN_ONCE(true, "ipvlan_handle_frame() called for mode = [%hx]\n",
 604                           port->mode);
 605         kfree_skb(skb);
 606         return NET_RX_DROP;
 607 }