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 } 608