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 } 622