datapath/tunnel.c

   1 /*
   2  * Copyright (c) 2010, 2011 Nicira Networks.
   3  * Distributed under the terms of the GNU GPL version 2.
   4  *
   5  * Significant portions of this file may be copied from parts of the Linux
   6  * kernel, by Linus Torvalds and others.
   7  */
   8
   9 #include <linux/if_arp.h>
  10 #include <linux/if_ether.h>
  11 #include <linux/ip.h>
  12 #include <linux/if_vlan.h>
  13 #include <linux/in.h>
  14 #include <linux/in_route.h>
  15 #include <linux/jhash.h>
  16 #include <linux/list.h>
  17 #include <linux/kernel.h>
  18 #include <linux/version.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/rculist.h>
  21
  22 #include <net/dsfield.h>
  23 #include <net/dst.h>
  24 #include <net/icmp.h>
  25 #include <net/inet_ecn.h>
  26 #include <net/ip.h>
  27 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  28 #include <net/ipv6.h>
  29 #endif
  30 #include <net/route.h>
  31 #include <net/xfrm.h>
  32
  33 #include "actions.h"
  34 #include "checksum.h"
  35 #include "datapath.h"
  36 #include "tunnel.h"
  37 #include "vlan.h"
  38 #include "vport.h"
  39 #include "vport-generic.h"
  40 #include "vport-internal_dev.h"
  41
  42 #ifdef NEED_CACHE_TIMEOUT
  43 /*
  44  * On kernels where we can't quickly detect changes in the rest of the system
  45  * we use an expiration time to invalidate the cache.  A shorter expiration
  46  * reduces the length of time that we may potentially blackhole packets while
  47  * a longer time increases performance by reducing the frequency that the
  48  * cache needs to be rebuilt.  A variety of factors may cause the cache to be
  49  * invalidated before the expiration time but this is the maximum.  The time
  50  * is expressed in jiffies.
  51  */
  52 #define MAX_CACHE_EXP HZ
  53 #endif
  54
  55 /*
  56  * Interval to check for and remove caches that are no longer valid.  Caches
  57  * are checked for validity before they are used for packet encapsulation and
  58  * old caches are removed at that time.  However, if no packets are sent through
  59  * the tunnel then the cache will never be destroyed.  Since it holds
  60  * references to a number of system objects, the cache will continue to use
  61  * system resources by not allowing those objects to be destroyed.  The cache
  62  * cleaner is periodically run to free invalid caches.  It does not
  63  * significantly affect system performance.  A lower interval will release
  64  * resources faster but will itself consume resources by requiring more frequent
  65  * checks.  A longer interval may result in messages being printed to the kernel
  66  * message buffer about unreleased resources.  The interval is expressed in
  67  * jiffies.
  68  */
  69 #define CACHE_CLEANER_INTERVAL (5 * HZ)
  70
  71 #define CACHE_DATA_ALIGN 16
  72 #define PORT_TABLE_SIZE  1024
  73
  74 static struct hlist_head *port_table __read_mostly;
  75 static int port_table_count;
  76
  77 static void cache_cleaner(struct work_struct *work);
  78 static DECLARE_DELAYED_WORK(cache_cleaner_wq, cache_cleaner);
  79
  80 /*
  81  * These are just used as an optimization: they don't require any kind of
  82  * synchronization because we could have just as easily read the value before
  83  * the port change happened.
  84  */
  85 static unsigned int key_local_remote_ports __read_mostly;
  86 static unsigned int key_remote_ports __read_mostly;
  87 static unsigned int local_remote_ports __read_mostly;
  88 static unsigned int remote_ports __read_mostly;
  89
  90 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
  91 #define rt_dst(rt) (rt->dst)
  92 #else
  93 #define rt_dst(rt) (rt->u.dst)
  94 #endif
  95
  96 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,1,0)
  97 static struct hh_cache *rt_hh(struct rtable *rt)
  98 {
  99         struct neighbour *neigh = dst_get_neighbour(&rt->dst);
 100         if (!neigh || !(neigh->nud_state & NUD_CONNECTED) ||
 101                         !neigh->hh.hh_len)
 102                 return NULL;
 103         return &neigh->hh;
 104 }
 105 #else
 106 #define rt_hh(rt) (rt_dst(rt).hh)
 107 #endif
 108
 109 static inline struct vport *tnl_vport_to_vport(const struct tnl_vport *tnl_vport)
 110 {
 111         return vport_from_priv(tnl_vport);
 112 }
 113
 114 /* This is analogous to rtnl_dereference for the tunnel cache.  It checks that
 115  * cache_lock is held, so it is only for update side code.
 116  */
 117 static inline struct tnl_cache *cache_dereference(struct tnl_vport *tnl_vport)
 118 {
 119         return rcu_dereference_protected(tnl_vport->cache,
 120                                          lockdep_is_held(&tnl_vport->cache_lock));
 121 }
 122
 123 static inline void schedule_cache_cleaner(void)
 124 {
 125         schedule_delayed_work(&cache_cleaner_wq, CACHE_CLEANER_INTERVAL);
 126 }
 127
 128 static void free_cache(struct tnl_cache *cache)
 129 {
 130         if (!cache)
 131                 return;
 132
 133         flow_put(cache->flow);
 134         ip_rt_put(cache->rt);
 135         kfree(cache);
 136 }
 137
 138 static void free_config_rcu(struct rcu_head *rcu)
 139 {
 140         struct tnl_mutable_config *c = container_of(rcu, struct tnl_mutable_config, rcu);
 141         kfree(c);
 142 }
 143
 144 static void free_cache_rcu(struct rcu_head *rcu)
 145 {
 146         struct tnl_cache *c = container_of(rcu, struct tnl_cache, rcu);
 147         free_cache(c);
 148 }
 149
 150 static void assign_config_rcu(struct vport *vport,
 151                               struct tnl_mutable_config *new_config)
 152 {
 153         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 154         struct tnl_mutable_config *old_config;
 155
 156         old_config = rtnl_dereference(tnl_vport->mutable);
 157         rcu_assign_pointer(tnl_vport->mutable, new_config);
 158         call_rcu(&old_config->rcu, free_config_rcu);
 159 }
 160
 161 static void assign_cache_rcu(struct vport *vport, struct tnl_cache *new_cache)
 162 {
 163         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 164         struct tnl_cache *old_cache;
 165
 166         old_cache = cache_dereference(tnl_vport);
 167         rcu_assign_pointer(tnl_vport->cache, new_cache);
 168
 169         if (old_cache)
 170                 call_rcu(&old_cache->rcu, free_cache_rcu);
 171 }
 172
 173 static unsigned int *find_port_pool(const struct tnl_mutable_config *mutable)
 174 {
 175         if (mutable->flags & TNL_F_IN_KEY_MATCH) {
 176                 if (mutable->key.saddr)
 177                         return &local_remote_ports;
 178                 else
 179                         return &remote_ports;
 180         } else {
 181                 if (mutable->key.saddr)
 182                         return &key_local_remote_ports;
 183                 else
 184                         return &key_remote_ports;
 185         }
 186 }
 187
 188 static u32 port_hash(const struct port_lookup_key *key)
 189 {
 190         return jhash2((u32*)key, (PORT_KEY_LEN / sizeof(u32)), 0);
 191 }
 192
 193 static inline struct hlist_head *find_bucket(u32 hash)
 194 {
 195         return &port_table[(hash & (PORT_TABLE_SIZE - 1))];
 196 }
 197
 198 static void port_table_add_port(struct vport *vport)
 199 {
 200         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 201         const struct tnl_mutable_config *mutable;
 202         u32 hash;
 203
 204         if (port_table_count == 0)
 205                 schedule_cache_cleaner();
 206
 207         mutable = rtnl_dereference(tnl_vport->mutable);
 208         hash = port_hash(&mutable->key);
 209         hlist_add_head_rcu(&tnl_vport->hash_node, find_bucket(hash));
 210         port_table_count++;
 211
 212         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
 213 }
 214
 215 static void port_table_move_port(struct vport *vport,
 216                       struct tnl_mutable_config *new_mutable)
 217 {
 218         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 219         u32 hash;
 220
 221         hash = port_hash(&new_mutable->key);
 222         hlist_del_init_rcu(&tnl_vport->hash_node);
 223         hlist_add_head_rcu(&tnl_vport->hash_node, find_bucket(hash));
 224
 225         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
 226         assign_config_rcu(vport, new_mutable);
 227         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
 228 }
 229
 230 static void port_table_remove_port(struct vport *vport)
 231 {
 232         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 233
 234         hlist_del_init_rcu(&tnl_vport->hash_node);
 235
 236         port_table_count--;
 237         if (port_table_count == 0)
 238                 cancel_delayed_work_sync(&cache_cleaner_wq);
 239
 240         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
 241 }
 242
 243 static struct vport *port_table_lookup(struct port_lookup_key *key,
 244                                        const struct tnl_mutable_config **pmutable)
 245 {
 246         struct hlist_node *n;
 247         struct hlist_head *bucket;
 248         u32 hash = port_hash(key);
 249         struct tnl_vport * tnl_vport;
 250
 251         bucket = find_bucket(hash);
 252
 253         hlist_for_each_entry_rcu(tnl_vport, n, bucket, hash_node) {
 254                 struct tnl_mutable_config *mutable;
 255
 256                 mutable = rcu_dereference_rtnl(tnl_vport->mutable);
 257                 if (!memcmp(&mutable->key, key, PORT_KEY_LEN)) {
 258                         *pmutable = mutable;
 259                         return tnl_vport_to_vport(tnl_vport);
 260                 }
 261         }
 262
 263         return NULL;
 264 }
 265
 266 struct vport *tnl_find_port(__be32 saddr, __be32 daddr, __be64 key,
 267                             int tunnel_type,
 268                             const struct tnl_mutable_config **mutable)
 269 {
 270         struct port_lookup_key lookup;
 271         struct vport *vport;
 272
 273         lookup.saddr = saddr;
 274         lookup.daddr = daddr;
 275
 276         /* First try for exact match on in_key. */
 277         lookup.in_key = key;
 278         lookup.tunnel_type = tunnel_type | TNL_T_KEY_EXACT;
 279         if (key_local_remote_ports) {
 280                 vport = port_table_lookup(&lookup, mutable);
 281                 if (vport)
 282                         return vport;
 283         }
 284         if (key_remote_ports) {
 285                 lookup.saddr = 0;
 286                 vport = port_table_lookup(&lookup, mutable);
 287                 if (vport)
 288                         return vport;
 289
 290                 lookup.saddr = saddr;
 291         }
 292
 293         /* Then try matches that wildcard in_key. */
 294         lookup.in_key = 0;
 295         lookup.tunnel_type = tunnel_type | TNL_T_KEY_MATCH;
 296         if (local_remote_ports) {
 297                 vport = port_table_lookup(&lookup, mutable);
 298                 if (vport)
 299                         return vport;
 300         }
 301         if (remote_ports) {
 302                 lookup.saddr = 0;
 303                 vport = port_table_lookup(&lookup, mutable);
 304                 if (vport)
 305                         return vport;
 306         }
 307
 308         return NULL;
 309 }
 310
 311 static void ecn_decapsulate(struct sk_buff *skb, u8 tos)
 312 {
 313         if (unlikely(INET_ECN_is_ce(tos))) {
 314                 __be16 protocol = skb->protocol;
 315
 316                 skb_set_network_header(skb, ETH_HLEN);
 317
 318                 if (protocol == htons(ETH_P_8021Q)) {
 319                         if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
 320                                 return;
 321
 322                         protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
 323                         skb_set_network_header(skb, VLAN_ETH_HLEN);
 324                 }
 325
 326                 if (protocol == htons(ETH_P_IP)) {
 327                         if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
 328                             + sizeof(struct iphdr))))
 329                                 return;
 330
 331                         IP_ECN_set_ce(ip_hdr(skb));
 332                 }
 333 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 334                 else if (protocol == htons(ETH_P_IPV6)) {
 335                         if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
 336                             + sizeof(struct ipv6hdr))))
 337                                 return;
 338
 339                         IP6_ECN_set_ce(ipv6_hdr(skb));
 340                 }
 341 #endif
 342         }
 343 }
 344
 345 /**
 346  *      tnl_rcv - ingress point for generic tunnel code
 347  *
 348  * @vport: port this packet was received on
 349  * @skb: received packet
 350  * @tos: ToS from encapsulating IP packet, used to copy ECN bits
 351  *
 352  * Must be called with rcu_read_lock.
 353  *
 354  * Packets received by this function are in the following state:
 355  * - skb->data points to the inner Ethernet header.
 356  * - The inner Ethernet header is in the linear data area.
 357  * - skb->csum does not include the inner Ethernet header.
 358  * - The layer pointers are undefined.
 359  */
 360 void tnl_rcv(struct vport *vport, struct sk_buff *skb, u8 tos)
 361 {
 362         struct ethhdr *eh;
 363
 364         skb_reset_mac_header(skb);
 365         eh = eth_hdr(skb);
 366
 367         if (likely(ntohs(eh->h_proto) >= 1536))
 368                 skb->protocol = eh->h_proto;
 369         else
 370                 skb->protocol = htons(ETH_P_802_2);
 371
 372         skb_dst_drop(skb);
 373         nf_reset(skb);
 374         skb_clear_rxhash(skb);
 375         secpath_reset(skb);
 376
 377         ecn_decapsulate(skb, tos);
 378         vlan_set_tci(skb, 0);
 379
 380         if (unlikely(compute_ip_summed(skb, false))) {
 381                 kfree_skb(skb);
 382                 return;
 383         }
 384
 385         vport_receive(vport, skb);
 386 }
 387
 388 static bool check_ipv4_address(__be32 addr)
 389 {
 390         if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr)
 391             || ipv4_is_loopback(addr) || ipv4_is_zeronet(addr))
 392                 return false;
 393
 394         return true;
 395 }
 396
 397 static bool ipv4_should_icmp(struct sk_buff *skb)
 398 {
 399         struct iphdr *old_iph = ip_hdr(skb);
 400
 401         /* Don't respond to L2 broadcast. */
 402         if (is_multicast_ether_addr(eth_hdr(skb)->h_dest))
 403                 return false;
 404
 405         /* Don't respond to L3 broadcast or invalid addresses. */
 406         if (!check_ipv4_address(old_iph->daddr) ||
 407             !check_ipv4_address(old_iph->saddr))
 408                 return false;
 409
 410         /* Only respond to the first fragment. */
 411         if (old_iph->frag_off & htons(IP_OFFSET))
 412                 return false;
 413
 414         /* Don't respond to ICMP error messages. */
 415         if (old_iph->protocol == IPPROTO_ICMP) {
 416                 u8 icmp_type, *icmp_typep;
 417
 418                 icmp_typep = skb_header_pointer(skb, (u8 *)old_iph +
 419                                                 (old_iph->ihl << 2) +
 420                                                 offsetof(struct icmphdr, type) -
 421                                                 skb->data, sizeof(icmp_type),
 422                                                 &icmp_type);
 423
 424                 if (!icmp_typep)
 425                         return false;
 426
 427                 if (*icmp_typep > NR_ICMP_TYPES
 428                         || (*icmp_typep <= ICMP_PARAMETERPROB
 429                                 && *icmp_typep != ICMP_ECHOREPLY
 430                                 && *icmp_typep != ICMP_ECHO))
 431                         return false;
 432         }
 433
 434         return true;
 435 }
 436
 437 static void ipv4_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
 438                             unsigned int mtu, unsigned int payload_length)
 439 {
 440         struct iphdr *iph, *old_iph = ip_hdr(skb);
 441         struct icmphdr *icmph;
 442         u8 *payload;
 443
 444         iph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
 445         icmph = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
 446         payload = skb_put(nskb, payload_length);
 447
 448         /* IP */
 449         iph->version            =       4;
 450         iph->ihl                =       sizeof(struct iphdr) >> 2;
 451         iph->tos                =       (old_iph->tos & IPTOS_TOS_MASK) |
 452                                         IPTOS_PREC_INTERNETCONTROL;
 453         iph->tot_len            =       htons(sizeof(struct iphdr)
 454                                               + sizeof(struct icmphdr)
 455                                               + payload_length);
 456         get_random_bytes(&iph->id, sizeof(iph->id));
 457         iph->frag_off           =       0;
 458         iph->ttl                =       IPDEFTTL;
 459         iph->protocol           =       IPPROTO_ICMP;
 460         iph->daddr              =       old_iph->saddr;
 461         iph->saddr              =       old_iph->daddr;
 462
 463         ip_send_check(iph);
 464
 465         /* ICMP */
 466         icmph->type             =       ICMP_DEST_UNREACH;
 467         icmph->code             =       ICMP_FRAG_NEEDED;
 468         icmph->un.gateway       =       htonl(mtu);
 469         icmph->checksum         =       0;
 470
 471         nskb->csum = csum_partial((u8 *)icmph, sizeof(struct icmphdr), 0);
 472         nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_iph - skb->data,
 473                                             payload, payload_length,
 474                                             nskb->csum);
 475         icmph->checksum = csum_fold(nskb->csum);
 476 }
 477
 478 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 479 static bool ipv6_should_icmp(struct sk_buff *skb)
 480 {
 481         struct ipv6hdr *old_ipv6h = ipv6_hdr(skb);
 482         int addr_type;
 483         int payload_off = (u8 *)(old_ipv6h + 1) - skb->data;
 484         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 485
 486         /* Check source address is valid. */
 487         addr_type = ipv6_addr_type(&old_ipv6h->saddr);
 488         if (addr_type & IPV6_ADDR_MULTICAST || addr_type == IPV6_ADDR_ANY)
 489                 return false;
 490
 491         /* Don't reply to unspecified addresses. */
 492         if (ipv6_addr_type(&old_ipv6h->daddr) == IPV6_ADDR_ANY)
 493                 return false;
 494
 495         /* Don't respond to ICMP error messages. */
 496         payload_off = ipv6_skip_exthdr(skb, payload_off, &nexthdr);
 497         if (payload_off < 0)
 498                 return false;
 499
 500         if (nexthdr == NEXTHDR_ICMP) {
 501                 u8 icmp_type, *icmp_typep;
 502
 503                 icmp_typep = skb_header_pointer(skb, payload_off +
 504                                                 offsetof(struct icmp6hdr,
 505                                                         icmp6_type),
 506                                                 sizeof(icmp_type), &icmp_type);
 507
 508                 if (!icmp_typep || !(*icmp_typep & ICMPV6_INFOMSG_MASK))
 509                         return false;
 510         }
 511
 512         return true;
 513 }
 514
 515 static void ipv6_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
 516                             unsigned int mtu, unsigned int payload_length)
 517 {
 518         struct ipv6hdr *ipv6h, *old_ipv6h = ipv6_hdr(skb);
 519         struct icmp6hdr *icmp6h;
 520         u8 *payload;
 521
 522         ipv6h = (struct ipv6hdr *)skb_put(nskb, sizeof(struct ipv6hdr));
 523         icmp6h = (struct icmp6hdr *)skb_put(nskb, sizeof(struct icmp6hdr));
 524         payload = skb_put(nskb, payload_length);
 525
 526         /* IPv6 */
 527         ipv6h->version          =       6;
 528         ipv6h->priority         =       0;
 529         memset(&ipv6h->flow_lbl, 0, sizeof(ipv6h->flow_lbl));
 530         ipv6h->payload_len      =       htons(sizeof(struct icmp6hdr)
 531                                               + payload_length);
 532         ipv6h->nexthdr          =       NEXTHDR_ICMP;
 533         ipv6h->hop_limit        =       IPV6_DEFAULT_HOPLIMIT;
 534         ipv6_addr_copy(&ipv6h->daddr, &old_ipv6h->saddr);
 535         ipv6_addr_copy(&ipv6h->saddr, &old_ipv6h->daddr);
 536
 537         /* ICMPv6 */
 538         icmp6h->icmp6_type      =       ICMPV6_PKT_TOOBIG;
 539         icmp6h->icmp6_code      =       0;
 540         icmp6h->icmp6_cksum     =       0;
 541         icmp6h->icmp6_mtu       =       htonl(mtu);
 542
 543         nskb->csum = csum_partial((u8 *)icmp6h, sizeof(struct icmp6hdr), 0);
 544         nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_ipv6h - skb->data,
 545                                             payload, payload_length,
 546                                             nskb->csum);
 547         icmp6h->icmp6_cksum = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
 548                                                 sizeof(struct icmp6hdr)
 549                                                 + payload_length,
 550                                                 ipv6h->nexthdr, nskb->csum);
 551 }
 552 #endif /* IPv6 */
 553
 554 bool tnl_frag_needed(struct vport *vport, const struct tnl_mutable_config *mutable,
 555                      struct sk_buff *skb, unsigned int mtu, __be64 flow_key)
 556 {
 557         unsigned int eth_hdr_len = ETH_HLEN;
 558         unsigned int total_length = 0, header_length = 0, payload_length;
 559         struct ethhdr *eh, *old_eh = eth_hdr(skb);
 560         struct sk_buff *nskb;
 561
 562         /* Sanity check */
 563         if (skb->protocol == htons(ETH_P_IP)) {
 564                 if (mtu < IP_MIN_MTU)
 565                         return false;
 566
 567                 if (!ipv4_should_icmp(skb))
 568                         return true;
 569         }
 570 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 571         else if (skb->protocol == htons(ETH_P_IPV6)) {
 572                 if (mtu < IPV6_MIN_MTU)
 573                         return false;
 574
 575                 /*
 576                  * In theory we should do PMTUD on IPv6 multicast messages but
 577                  * we don't have an address to send from so just fragment.
 578                  */
 579                 if (ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST)
 580                         return false;
 581
 582                 if (!ipv6_should_icmp(skb))
 583                         return true;
 584         }
 585 #endif
 586         else
 587                 return false;
 588
 589         /* Allocate */
 590         if (old_eh->h_proto == htons(ETH_P_8021Q))
 591                 eth_hdr_len = VLAN_ETH_HLEN;
 592
 593         payload_length = skb->len - eth_hdr_len;
 594         if (skb->protocol == htons(ETH_P_IP)) {
 595                 header_length = sizeof(struct iphdr) + sizeof(struct icmphdr);
 596                 total_length = min_t(unsigned int, header_length +
 597                                                    payload_length, 576);
 598         }
 599 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 600         else {
 601                 header_length = sizeof(struct ipv6hdr) +
 602                                 sizeof(struct icmp6hdr);
 603                 total_length = min_t(unsigned int, header_length +
 604                                                   payload_length, IPV6_MIN_MTU);
 605         }
 606 #endif
 607
 608         payload_length = total_length - header_length;
 609
 610         nskb = dev_alloc_skb(NET_IP_ALIGN + eth_hdr_len + header_length +
 611                              payload_length);
 612         if (!nskb)
 613                 return false;
 614
 615         skb_reserve(nskb, NET_IP_ALIGN);
 616
 617         /* Ethernet / VLAN */
 618         eh = (struct ethhdr *)skb_put(nskb, eth_hdr_len);
 619         memcpy(eh->h_dest, old_eh->h_source, ETH_ALEN);
 620         memcpy(eh->h_source, mutable->eth_addr, ETH_ALEN);
 621         nskb->protocol = eh->h_proto = old_eh->h_proto;
 622         if (old_eh->h_proto == htons(ETH_P_8021Q)) {
 623                 struct vlan_ethhdr *vh = (struct vlan_ethhdr *)eh;
 624
 625                 vh->h_vlan_TCI = vlan_eth_hdr(skb)->h_vlan_TCI;
 626                 vh->h_vlan_encapsulated_proto = skb->protocol;
 627         } else
 628                 vlan_set_tci(nskb, vlan_get_tci(skb));
 629         skb_reset_mac_header(nskb);
 630
 631         /* Protocol */
 632         if (skb->protocol == htons(ETH_P_IP))
 633                 ipv4_build_icmp(skb, nskb, mtu, payload_length);
 634 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 635         else
 636                 ipv6_build_icmp(skb, nskb, mtu, payload_length);
 637 #endif
 638
 639         /*
 640          * Assume that flow based keys are symmetric with respect to input
 641          * and output and use the key that we were going to put on the
 642          * outgoing packet for the fake received packet.  If the keys are
 643          * not symmetric then PMTUD needs to be disabled since we won't have
 644          * any way of synthesizing packets.
 645          */
 646         if ((mutable->flags & (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION)) ==
 647             (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION))
 648                 OVS_CB(nskb)->tun_id = flow_key;
 649
 650         if (unlikely(compute_ip_summed(nskb, false))) {
 651                 kfree_skb(nskb);
 652                 return false;
 653         }
 654
 655         vport_receive(vport, nskb);
 656
 657         return true;
 658 }
 659
 660 static bool check_mtu(struct sk_buff *skb,
 661                       struct vport *vport,
 662                       const struct tnl_mutable_config *mutable,
 663                       const struct rtable *rt, __be16 *frag_offp)
 664 {
 665         bool df_inherit = mutable->flags & TNL_F_DF_INHERIT;
 666         bool pmtud = mutable->flags & TNL_F_PMTUD;
 667         __be16 frag_off = mutable->flags & TNL_F_DF_DEFAULT ? htons(IP_DF) : 0;
 668         int mtu = 0;
 669         unsigned int packet_length = skb->len - ETH_HLEN;
 670
 671         /* Allow for one level of tagging in the packet length. */
 672         if (!vlan_tx_tag_present(skb) &&
 673             eth_hdr(skb)->h_proto == htons(ETH_P_8021Q))
 674                 packet_length -= VLAN_HLEN;
 675
 676         if (pmtud) {
 677                 int vlan_header = 0;
 678
 679                 /* The tag needs to go in packet regardless of where it
 680                  * currently is, so subtract it from the MTU.
 681                  */
 682                 if (vlan_tx_tag_present(skb) ||
 683                     eth_hdr(skb)->h_proto == htons(ETH_P_8021Q))
 684                         vlan_header = VLAN_HLEN;
 685
 686                 mtu = dst_mtu(&rt_dst(rt))
 687                         - ETH_HLEN
 688                         - mutable->tunnel_hlen
 689                         - vlan_header;
 690         }
 691
 692         if (skb->protocol == htons(ETH_P_IP)) {
 693                 struct iphdr *iph = ip_hdr(skb);
 694
 695                 if (df_inherit)
 696                         frag_off = iph->frag_off & htons(IP_DF);
 697
 698                 if (pmtud && iph->frag_off & htons(IP_DF)) {
 699                         mtu = max(mtu, IP_MIN_MTU);
 700
 701                         if (packet_length > mtu &&
 702                             tnl_frag_needed(vport, mutable, skb, mtu,
 703                                             OVS_CB(skb)->tun_id))
 704                                 return false;
 705                 }
 706         }
 707 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 708         else if (skb->protocol == htons(ETH_P_IPV6)) {
 709                 /* IPv6 requires end hosts to do fragmentation
 710                  * if the packet is above the minimum MTU.
 711                  */
 712                 if (df_inherit && packet_length > IPV6_MIN_MTU)
 713                         frag_off = htons(IP_DF);
 714
 715                 if (pmtud) {
 716                         mtu = max(mtu, IPV6_MIN_MTU);
 717
 718                         if (packet_length > mtu &&
 719                             tnl_frag_needed(vport, mutable, skb, mtu,
 720                                             OVS_CB(skb)->tun_id))
 721                                 return false;
 722                 }
 723         }
 724 #endif
 725
 726         *frag_offp = frag_off;
 727         return true;
 728 }
 729
 730 static void create_tunnel_header(const struct vport *vport,
 731                                  const struct tnl_mutable_config *mutable,
 732                                  const struct rtable *rt, void *header)
 733 {
 734         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 735         struct iphdr *iph = header;
 736
 737         iph->version    = 4;
 738         iph->ihl        = sizeof(struct iphdr) >> 2;
 739         iph->frag_off   = htons(IP_DF);
 740         iph->protocol   = tnl_vport->tnl_ops->ipproto;
 741         iph->tos        = mutable->tos;
 742         iph->daddr      = rt->rt_dst;
 743         iph->saddr      = rt->rt_src;
 744         iph->ttl        = mutable->ttl;
 745         if (!iph->ttl)
 746                 iph->ttl = ip4_dst_hoplimit(&rt_dst(rt));
 747
 748         tnl_vport->tnl_ops->build_header(vport, mutable, iph + 1);
 749 }
 750
 751 static inline void *get_cached_header(const struct tnl_cache *cache)
 752 {
 753         return (void *)cache + ALIGN(sizeof(struct tnl_cache), CACHE_DATA_ALIGN);
 754 }
 755
 756 static inline bool check_cache_valid(const struct tnl_cache *cache,
 757                                      const struct tnl_mutable_config *mutable)
 758 {
 759         struct hh_cache *hh;
 760
 761         if (!cache)
 762                 return false;
 763
 764         hh = rt_hh(cache->rt);
 765         return hh &&
 766 #ifdef NEED_CACHE_TIMEOUT
 767                 time_before(jiffies, cache->expiration) &&
 768 #endif
 769 #ifdef HAVE_RT_GENID
 770                 atomic_read(&init_net.ipv4.rt_genid) == cache->rt->rt_genid &&
 771 #endif
 772 #ifdef HAVE_HH_SEQ
 773                 hh->hh_lock.sequence == cache->hh_seq &&
 774 #endif
 775                 mutable->seq == cache->mutable_seq &&
 776                 (!is_internal_dev(rt_dst(cache->rt).dev) ||
 777                 (cache->flow && !cache->flow->dead));
 778 }
 779
 780 static void __cache_cleaner(struct tnl_vport *tnl_vport)
 781 {
 782         const struct tnl_mutable_config *mutable =
 783                         rcu_dereference(tnl_vport->mutable);
 784         const struct tnl_cache *cache = rcu_dereference(tnl_vport->cache);
 785
 786         if (cache && !check_cache_valid(cache, mutable) &&
 787             spin_trylock_bh(&tnl_vport->cache_lock)) {
 788                 assign_cache_rcu(tnl_vport_to_vport(tnl_vport), NULL);
 789                 spin_unlock_bh(&tnl_vport->cache_lock);
 790         }
 791 }
 792
 793 static void cache_cleaner(struct work_struct *work)
 794 {
 795         int i;
 796
 797         schedule_cache_cleaner();
 798
 799         rcu_read_lock();
 800         for (i = 0; i < PORT_TABLE_SIZE; i++) {
 801                 struct hlist_node *n;
 802                 struct hlist_head *bucket;
 803                 struct tnl_vport  *tnl_vport;
 804
 805                 bucket = &port_table[i];
 806                 hlist_for_each_entry_rcu(tnl_vport, n, bucket, hash_node)
 807                         __cache_cleaner(tnl_vport);
 808         }
 809         rcu_read_unlock();
 810 }
 811
 812 static inline void create_eth_hdr(struct tnl_cache *cache,
 813                                   struct hh_cache *hh)
 814 {
 815         void *cache_data = get_cached_header(cache);
 816         int hh_off;
 817
 818 #ifdef HAVE_HH_SEQ
 819         unsigned hh_seq;
 820
 821         do {
 822                 hh_seq = read_seqbegin(&hh->hh_lock);
 823                 hh_off = HH_DATA_ALIGN(hh->hh_len) - hh->hh_len;
 824                 memcpy(cache_data, (void *)hh->hh_data + hh_off, hh->hh_len);
 825                 cache->hh_len = hh->hh_len;
 826         } while (read_seqretry(&hh->hh_lock, hh_seq));
 827
 828         cache->hh_seq = hh_seq;
 829 #else
 830         read_lock(&hh->hh_lock);
 831         hh_off = HH_DATA_ALIGN(hh->hh_len) - hh->hh_len;
 832         memcpy(cache_data, (void *)hh->hh_data + hh_off, hh->hh_len);
 833         cache->hh_len = hh->hh_len;
 834         read_unlock(&hh->hh_lock);
 835 #endif
 836 }
 837
 838 static struct tnl_cache *build_cache(struct vport *vport,
 839                                      const struct tnl_mutable_config *mutable,
 840                                      struct rtable *rt)
 841 {
 842         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 843         struct tnl_cache *cache;
 844         void *cache_data;
 845         int cache_len;
 846         struct hh_cache *hh;
 847
 848         if (!(mutable->flags & TNL_F_HDR_CACHE))
 849                 return NULL;
 850
 851         /*
 852          * If there is no entry in the ARP cache or if this device does not
 853          * support hard header caching just fall back to the IP stack.
 854          */
 855
 856         hh = rt_hh(rt);
 857         if (!hh)
 858                 return NULL;
 859
 860         /*
 861          * If lock is contended fall back to directly building the header.
 862          * We're not going to help performance by sitting here spinning.
 863          */
 864         if (!spin_trylock(&tnl_vport->cache_lock))
 865                 return NULL;
 866
 867         cache = cache_dereference(tnl_vport);
 868         if (check_cache_valid(cache, mutable))
 869                 goto unlock;
 870         else
 871                 cache = NULL;
 872
 873         cache_len = LL_RESERVED_SPACE(rt_dst(rt).dev) + mutable->tunnel_hlen;
 874
 875         cache = kzalloc(ALIGN(sizeof(struct tnl_cache), CACHE_DATA_ALIGN) +
 876                         cache_len, GFP_ATOMIC);
 877         if (!cache)
 878                 goto unlock;
 879
 880         create_eth_hdr(cache, hh);
 881         cache_data = get_cached_header(cache) + cache->hh_len;
 882         cache->len = cache->hh_len + mutable->tunnel_hlen;
 883
 884         create_tunnel_header(vport, mutable, rt, cache_data);
 885
 886         cache->mutable_seq = mutable->seq;
 887         cache->rt = rt;
 888 #ifdef NEED_CACHE_TIMEOUT
 889         cache->expiration = jiffies + tnl_vport->cache_exp_interval;
 890 #endif
 891
 892         if (is_internal_dev(rt_dst(rt).dev)) {
 893                 struct sw_flow_key flow_key;
 894                 struct vport *dst_vport;
 895                 struct sk_buff *skb;
 896                 int err;
 897                 int flow_key_len;
 898                 struct sw_flow *flow;
 899
 900                 dst_vport = internal_dev_get_vport(rt_dst(rt).dev);
 901                 if (!dst_vport)
 902                         goto done;
 903
 904                 skb = alloc_skb(cache->len, GFP_ATOMIC);
 905                 if (!skb)
 906                         goto done;
 907
 908                 __skb_put(skb, cache->len);
 909                 memcpy(skb->data, get_cached_header(cache), cache->len);
 910
 911                 err = flow_extract(skb, dst_vport->port_no, &flow_key,
 912                                    &flow_key_len);
 913
 914                 consume_skb(skb);
 915                 if (err)
 916                         goto done;
 917
 918                 flow = flow_tbl_lookup(rcu_dereference(dst_vport->dp->table),
 919                                          &flow_key, flow_key_len);
 920                 if (flow) {
 921                         cache->flow = flow;
 922                         flow_hold(flow);
 923                 }
 924         }
 925
 926 done:
 927         assign_cache_rcu(vport, cache);
 928
 929 unlock:
 930         spin_unlock(&tnl_vport->cache_lock);
 931
 932         return cache;
 933 }
 934
 935 static struct rtable *find_route(struct vport *vport,
 936                                  const struct tnl_mutable_config *mutable,
 937                                  u8 tos, struct tnl_cache **cache)
 938 {
 939         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 940         struct tnl_cache *cur_cache = rcu_dereference(tnl_vport->cache);
 941
 942         *cache = NULL;
 943         tos = RT_TOS(tos);
 944
 945         if (likely(tos == mutable->tos && check_cache_valid(cur_cache, mutable))) {
 946                 *cache = cur_cache;
 947                 return cur_cache->rt;
 948         } else {
 949                 struct rtable *rt;
 950 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)
 951                 struct flowi fl = { .nl_u = { .ip4_u =
 952                                               { .daddr = mutable->key.daddr,
 953                                                 .saddr = mutable->key.saddr,
 954                                                 .tos = tos } },
 955                                     .proto = tnl_vport->tnl_ops->ipproto };
 956
 957                 if (unlikely(ip_route_output_key(&init_net, &rt, &fl)))
 958                         return NULL;
 959 #else
 960                 struct flowi4 fl = { .daddr = mutable->key.daddr,
 961                                      .saddr = mutable->key.saddr,
 962                                      .flowi4_tos = tos,
 963                                      .flowi4_proto = tnl_vport->tnl_ops->ipproto };
 964
 965                 rt = ip_route_output_key(&init_net, &fl);
 966                 if (IS_ERR(rt))
 967                         return NULL;
 968 #endif
 969
 970                 if (likely(tos == mutable->tos))
 971                         *cache = build_cache(vport, mutable, rt);
 972
 973                 return rt;
 974         }
 975 }
 976
 977 static inline bool need_linearize(const struct sk_buff *skb)
 978 {
 979         int i;
 980
 981         if (unlikely(skb_shinfo(skb)->frag_list))
 982                 return true;
 983
 984         /*
 985          * Generally speaking we should linearize if there are paged frags.
 986          * However, if all of the refcounts are 1 we know nobody else can
 987          * change them from underneath us and we can skip the linearization.
 988          */
 989         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
 990                 if (unlikely(page_count(skb_shinfo(skb)->frags[i].page) > 1))
 991                         return true;
 992
 993         return false;
 994 }
 995
 996 static struct sk_buff *handle_offloads(struct sk_buff *skb,
 997                                        const struct tnl_mutable_config *mutable,
 998                                        const struct rtable *rt)
 999 {
1000         int min_headroom;
1001         int err;
1002
1003         min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len
1004                         + mutable->tunnel_hlen
1005                         + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
1006
1007         if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
1008                 int head_delta = SKB_DATA_ALIGN(min_headroom -
1009                                                 skb_headroom(skb) +
1010                                                 16);
1011                 err = pskb_expand_head(skb, max_t(int, head_delta, 0),
1012                                         0, GFP_ATOMIC);
1013                 if (unlikely(err))
1014                         goto error_free;
1015         }
1016
1017         forward_ip_summed(skb, true);
1018
1019         if (skb_is_gso(skb)) {
1020                 struct sk_buff *nskb;
1021
1022                 nskb = skb_gso_segment(skb, 0);
1023                 if (IS_ERR(nskb)) {
1024                         kfree_skb(skb);
1025                         err = PTR_ERR(nskb);
1026                         goto error;
1027                 }
1028
1029                 consume_skb(skb);
1030                 skb = nskb;
1031         } else if (get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
1032                 /* Pages aren't locked and could change at any time.
1033                  * If this happens after we compute the checksum, the
1034                  * checksum will be wrong.  We linearize now to avoid
1035                  * this problem.
1036                  */
1037                 if (unlikely(need_linearize(skb))) {
1038                         err = __skb_linearize(skb);
1039                         if (unlikely(err))
1040                                 goto error_free;
1041                 }
1042
1043                 err = skb_checksum_help(skb);
1044                 if (unlikely(err))
1045                         goto error_free;
1046         }
1047
1048         set_ip_summed(skb, OVS_CSUM_NONE);
1049
1050         return skb;
1051
1052 error_free:
1053         kfree_skb(skb);
1054 error:
1055         return ERR_PTR(err);
1056 }
1057
1058 static int send_frags(struct sk_buff *skb,
1059                       const struct tnl_mutable_config *mutable)
1060 {
1061         int sent_len;
1062
1063         sent_len = 0;
1064         while (skb) {
1065                 struct sk_buff *next = skb->next;
1066                 int frag_len = skb->len - mutable->tunnel_hlen;
1067                 int err;
1068
1069                 skb->next = NULL;
1070                 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
1071
1072                 err = ip_local_out(skb);
1073                 skb = next;
1074                 if (unlikely(net_xmit_eval(err)))
1075                         goto free_frags;
1076                 sent_len += frag_len;
1077         }
1078
1079         return sent_len;
1080
1081 free_frags:
1082         /*
1083          * There's no point in continuing to send fragments once one has been
1084          * dropped so just free the rest.  This may help improve the congestion
1085          * that caused the first packet to be dropped.
1086          */
1087         tnl_free_linked_skbs(skb);
1088         return sent_len;
1089 }
1090
1091 int tnl_send(struct vport *vport, struct sk_buff *skb)
1092 {
1093         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1094         const struct tnl_mutable_config *mutable = rcu_dereference(tnl_vport->mutable);
1095
1096         enum vport_err_type err = VPORT_E_TX_ERROR;
1097         struct rtable *rt;
1098         struct dst_entry *unattached_dst = NULL;
1099         struct tnl_cache *cache;
1100         int sent_len = 0;
1101         __be16 frag_off = 0;
1102         u8 ttl;
1103         u8 inner_tos;
1104         u8 tos;
1105
1106         /* Validate the protocol headers before we try to use them. */
1107         if (skb->protocol == htons(ETH_P_8021Q) &&
1108             !vlan_tx_tag_present(skb)) {
1109                 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
1110                         goto error_free;
1111
1112                 skb->protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
1113                 skb_set_network_header(skb, VLAN_ETH_HLEN);
1114         }
1115
1116         if (skb->protocol == htons(ETH_P_IP)) {
1117                 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
1118                     + sizeof(struct iphdr))))
1119                         skb->protocol = 0;
1120         }
1121 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1122         else if (skb->protocol == htons(ETH_P_IPV6)) {
1123                 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
1124                     + sizeof(struct ipv6hdr))))
1125                         skb->protocol = 0;
1126         }
1127 #endif
1128
1129         /* ToS */
1130         if (skb->protocol == htons(ETH_P_IP))
1131                 inner_tos = ip_hdr(skb)->tos;
1132 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1133         else if (skb->protocol == htons(ETH_P_IPV6))
1134                 inner_tos = ipv6_get_dsfield(ipv6_hdr(skb));
1135 #endif
1136         else
1137                 inner_tos = 0;
1138
1139         if (mutable->flags & TNL_F_TOS_INHERIT)
1140                 tos = inner_tos;
1141         else
1142                 tos = mutable->tos;
1143
1144         tos = INET_ECN_encapsulate(tos, inner_tos);
1145
1146         /* Route lookup */
1147         rt = find_route(vport, mutable, tos, &cache);
1148         if (unlikely(!rt))
1149                 goto error_free;
1150         if (unlikely(!cache))
1151                 unattached_dst = &rt_dst(rt);
1152
1153         /* Reset SKB */
1154         nf_reset(skb);
1155         secpath_reset(skb);
1156         skb_dst_drop(skb);
1157         skb_clear_rxhash(skb);
1158
1159         /* Offloading */
1160         skb = handle_offloads(skb, mutable, rt);
1161         if (IS_ERR(skb))
1162                 goto error;
1163
1164         /* MTU */
1165         if (unlikely(!check_mtu(skb, vport, mutable, rt, &frag_off))) {
1166                 err = VPORT_E_TX_DROPPED;
1167                 goto error_free;
1168         }
1169
1170         /*
1171          * If we are over the MTU, allow the IP stack to handle fragmentation.
1172          * Fragmentation is a slow path anyways.
1173          */
1174         if (unlikely(skb->len + mutable->tunnel_hlen > dst_mtu(&rt_dst(rt)) &&
1175                      cache)) {
1176                 unattached_dst = &rt_dst(rt);
1177                 dst_hold(unattached_dst);
1178                 cache = NULL;
1179         }
1180
1181         /* TTL */
1182         ttl = mutable->ttl;
1183         if (!ttl)
1184                 ttl = ip4_dst_hoplimit(&rt_dst(rt));
1185
1186         if (mutable->flags & TNL_F_TTL_INHERIT) {
1187                 if (skb->protocol == htons(ETH_P_IP))
1188                         ttl = ip_hdr(skb)->ttl;
1189 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1190                 else if (skb->protocol == htons(ETH_P_IPV6))
1191                         ttl = ipv6_hdr(skb)->hop_limit;
1192 #endif
1193         }
1194
1195         while (skb) {
1196                 struct iphdr *iph;
1197                 struct sk_buff *next_skb = skb->next;
1198                 skb->next = NULL;
1199
1200                 if (unlikely(vlan_deaccel_tag(skb)))
1201                         goto next;
1202
1203                 if (likely(cache)) {
1204                         skb_push(skb, cache->len);
1205                         memcpy(skb->data, get_cached_header(cache), cache->len);
1206                         skb_reset_mac_header(skb);
1207                         skb_set_network_header(skb, cache->hh_len);
1208
1209                 } else {
1210                         skb_push(skb, mutable->tunnel_hlen);
1211                         create_tunnel_header(vport, mutable, rt, skb->data);
1212                         skb_reset_network_header(skb);
1213
1214                         if (next_skb)
1215                                 skb_dst_set(skb, dst_clone(unattached_dst));
1216                         else {
1217                                 skb_dst_set(skb, unattached_dst);
1218                                 unattached_dst = NULL;
1219                         }
1220                 }
1221                 skb_set_transport_header(skb, skb_network_offset(skb) + sizeof(struct iphdr));
1222
1223                 iph = ip_hdr(skb);
1224                 iph->tos = tos;
1225                 iph->ttl = ttl;
1226                 iph->frag_off = frag_off;
1227                 ip_select_ident(iph, &rt_dst(rt), NULL);
1228
1229                 skb = tnl_vport->tnl_ops->update_header(vport, mutable, &rt_dst(rt), skb);
1230                 if (unlikely(!skb))
1231                         goto next;
1232
1233                 if (likely(cache)) {
1234                         int orig_len = skb->len - cache->len;
1235                         struct vport *cache_vport = internal_dev_get_vport(rt_dst(rt).dev);
1236
1237                         skb->protocol = htons(ETH_P_IP);
1238                         iph = ip_hdr(skb);
1239                         iph->tot_len = htons(skb->len - skb_network_offset(skb));
1240                         ip_send_check(iph);
1241
1242                         if (cache_vport) {
1243                                 if (unlikely(compute_ip_summed(skb, true))) {
1244                                         kfree_skb(skb);
1245                                         goto next;
1246                                 }
1247
1248                                 OVS_CB(skb)->flow = cache->flow;
1249                                 vport_receive(cache_vport, skb);
1250                                 sent_len += orig_len;
1251                         } else {
1252                                 int xmit_err;
1253
1254                                 skb->dev = rt_dst(rt).dev;
1255                                 xmit_err = dev_queue_xmit(skb);
1256
1257                                 if (likely(net_xmit_eval(xmit_err) == 0))
1258                                         sent_len += orig_len;
1259                         }
1260                 } else
1261                         sent_len += send_frags(skb, mutable);
1262
1263 next:
1264                 skb = next_skb;
1265         }
1266
1267         if (unlikely(sent_len == 0))
1268                 vport_record_error(vport, VPORT_E_TX_DROPPED);
1269
1270         goto out;
1271
1272 error_free:
1273         tnl_free_linked_skbs(skb);
1274 error:
1275         vport_record_error(vport, err);
1276 out:
1277         dst_release(unattached_dst);
1278         return sent_len;
1279 }
1280
1281 static const struct nla_policy tnl_policy[OVS_TUNNEL_ATTR_MAX + 1] = {
1282         [OVS_TUNNEL_ATTR_FLAGS]    = { .type = NLA_U32 },
1283         [OVS_TUNNEL_ATTR_DST_IPV4] = { .type = NLA_U32 },
1284         [OVS_TUNNEL_ATTR_SRC_IPV4] = { .type = NLA_U32 },
1285         [OVS_TUNNEL_ATTR_OUT_KEY]  = { .type = NLA_U64 },
1286         [OVS_TUNNEL_ATTR_IN_KEY]   = { .type = NLA_U64 },
1287         [OVS_TUNNEL_ATTR_TOS]      = { .type = NLA_U8 },
1288         [OVS_TUNNEL_ATTR_TTL]      = { .type = NLA_U8 },
1289 };
1290
1291 /* Sets OVS_TUNNEL_ATTR_* fields in 'mutable', which must initially be zeroed. */
1292 static int tnl_set_config(struct nlattr *options, const struct tnl_ops *tnl_ops,
1293                           const struct vport *cur_vport,
1294                           struct tnl_mutable_config *mutable)
1295 {
1296         const struct vport *old_vport;
1297         const struct tnl_mutable_config *old_mutable;
1298         struct nlattr *a[OVS_TUNNEL_ATTR_MAX + 1];
1299         int err;
1300
1301         if (!options)
1302                 return -EINVAL;
1303
1304         err = nla_parse_nested(a, OVS_TUNNEL_ATTR_MAX, options, tnl_policy);
1305         if (err)
1306                 return err;
1307
1308         if (!a[OVS_TUNNEL_ATTR_FLAGS] || !a[OVS_TUNNEL_ATTR_DST_IPV4])
1309                 return -EINVAL;
1310
1311         mutable->flags = nla_get_u32(a[OVS_TUNNEL_ATTR_FLAGS]) & TNL_F_PUBLIC;
1312
1313         if (a[OVS_TUNNEL_ATTR_SRC_IPV4])
1314                 mutable->key.saddr = nla_get_be32(a[OVS_TUNNEL_ATTR_SRC_IPV4]);
1315         mutable->key.daddr = nla_get_be32(a[OVS_TUNNEL_ATTR_DST_IPV4]);
1316
1317         if (a[OVS_TUNNEL_ATTR_TOS]) {
1318                 mutable->tos = nla_get_u8(a[OVS_TUNNEL_ATTR_TOS]);
1319                 if (mutable->tos != RT_TOS(mutable->tos))
1320                         return -EINVAL;
1321         }
1322
1323         if (a[OVS_TUNNEL_ATTR_TTL])
1324                 mutable->ttl = nla_get_u8(a[OVS_TUNNEL_ATTR_TTL]);
1325
1326         mutable->key.tunnel_type = tnl_ops->tunnel_type;
1327         if (!a[OVS_TUNNEL_ATTR_IN_KEY]) {
1328                 mutable->key.tunnel_type |= TNL_T_KEY_MATCH;
1329                 mutable->flags |= TNL_F_IN_KEY_MATCH;
1330         } else {
1331                 mutable->key.tunnel_type |= TNL_T_KEY_EXACT;
1332                 mutable->key.in_key = nla_get_be64(a[OVS_TUNNEL_ATTR_IN_KEY]);
1333         }
1334
1335         if (!a[OVS_TUNNEL_ATTR_OUT_KEY])
1336                 mutable->flags |= TNL_F_OUT_KEY_ACTION;
1337         else
1338                 mutable->out_key = nla_get_be64(a[OVS_TUNNEL_ATTR_OUT_KEY]);
1339
1340         mutable->tunnel_hlen = tnl_ops->hdr_len(mutable);
1341         if (mutable->tunnel_hlen < 0)
1342                 return mutable->tunnel_hlen;
1343
1344         mutable->tunnel_hlen += sizeof(struct iphdr);
1345
1346         old_vport = port_table_lookup(&mutable->key, &old_mutable);
1347         if (old_vport && old_vport != cur_vport)
1348                 return -EEXIST;
1349
1350         return 0;
1351 }
1352
1353 struct vport *tnl_create(const struct vport_parms *parms,
1354                          const struct vport_ops *vport_ops,
1355                          const struct tnl_ops *tnl_ops)
1356 {
1357         struct vport *vport;
1358         struct tnl_vport *tnl_vport;
1359         struct tnl_mutable_config *mutable;
1360         int initial_frag_id;
1361         int err;
1362
1363         vport = vport_alloc(sizeof(struct tnl_vport), vport_ops, parms);
1364         if (IS_ERR(vport)) {
1365                 err = PTR_ERR(vport);
1366                 goto error;
1367         }
1368
1369         tnl_vport = tnl_vport_priv(vport);
1370
1371         strcpy(tnl_vport->name, parms->name);
1372         tnl_vport->tnl_ops = tnl_ops;
1373
1374         mutable = kzalloc(sizeof(struct tnl_mutable_config), GFP_KERNEL);
1375         if (!mutable) {
1376                 err = -ENOMEM;
1377                 goto error_free_vport;
1378         }
1379
1380         vport_gen_rand_ether_addr(mutable->eth_addr);
1381
1382         get_random_bytes(&initial_frag_id, sizeof(int));
1383         atomic_set(&tnl_vport->frag_id, initial_frag_id);
1384
1385         err = tnl_set_config(parms->options, tnl_ops, NULL, mutable);
1386         if (err)
1387                 goto error_free_mutable;
1388
1389         spin_lock_init(&tnl_vport->cache_lock);
1390
1391 #ifdef NEED_CACHE_TIMEOUT
1392         tnl_vport->cache_exp_interval = MAX_CACHE_EXP -
1393                                        (net_random() % (MAX_CACHE_EXP / 2));
1394 #endif
1395
1396         rcu_assign_pointer(tnl_vport->mutable, mutable);
1397
1398         port_table_add_port(vport);
1399         return vport;
1400
1401 error_free_mutable:
1402         kfree(mutable);
1403 error_free_vport:
1404         vport_free(vport);
1405 error:
1406         return ERR_PTR(err);
1407 }
1408
1409 int tnl_set_options(struct vport *vport, struct nlattr *options)
1410 {
1411         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1412         const struct tnl_mutable_config *old_mutable;
1413         struct tnl_mutable_config *mutable;
1414         int err;
1415
1416         mutable = kzalloc(sizeof(struct tnl_mutable_config), GFP_KERNEL);
1417         if (!mutable) {
1418                 err = -ENOMEM;
1419                 goto error;
1420         }
1421
1422         /* Copy fields whose values should be retained. */
1423         old_mutable = rtnl_dereference(tnl_vport->mutable);
1424         mutable->seq = old_mutable->seq + 1;
1425         memcpy(mutable->eth_addr, old_mutable->eth_addr, ETH_ALEN);
1426
1427         /* Parse the others configured by userspace. */
1428         err = tnl_set_config(options, tnl_vport->tnl_ops, vport, mutable);
1429         if (err)
1430                 goto error_free;
1431
1432         if (port_hash(&mutable->key) != port_hash(&old_mutable->key))
1433                 port_table_move_port(vport, mutable);
1434         else
1435                 assign_config_rcu(vport, mutable);
1436
1437         return 0;
1438
1439 error_free:
1440         kfree(mutable);
1441 error:
1442         return err;
1443 }
1444
1445 int tnl_get_options(const struct vport *vport, struct sk_buff *skb)
1446 {
1447         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1448         const struct tnl_mutable_config *mutable = rcu_dereference_rtnl(tnl_vport->mutable);
1449
1450         NLA_PUT_U32(skb, OVS_TUNNEL_ATTR_FLAGS, mutable->flags & TNL_F_PUBLIC);
1451         NLA_PUT_BE32(skb, OVS_TUNNEL_ATTR_DST_IPV4, mutable->key.daddr);
1452
1453         if (!(mutable->flags & TNL_F_IN_KEY_MATCH))
1454                 NLA_PUT_BE64(skb, OVS_TUNNEL_ATTR_IN_KEY, mutable->key.in_key);
1455         if (!(mutable->flags & TNL_F_OUT_KEY_ACTION))
1456                 NLA_PUT_BE64(skb, OVS_TUNNEL_ATTR_OUT_KEY, mutable->out_key);
1457         if (mutable->key.saddr)
1458                 NLA_PUT_BE32(skb, OVS_TUNNEL_ATTR_SRC_IPV4, mutable->key.saddr);
1459         if (mutable->tos)
1460                 NLA_PUT_U8(skb, OVS_TUNNEL_ATTR_TOS, mutable->tos);
1461         if (mutable->ttl)
1462                 NLA_PUT_U8(skb, OVS_TUNNEL_ATTR_TTL, mutable->ttl);
1463
1464         return 0;
1465
1466 nla_put_failure:
1467         return -EMSGSIZE;
1468 }
1469
1470 static void free_port_rcu(struct rcu_head *rcu)
1471 {
1472         struct tnl_vport *tnl_vport = container_of(rcu,
1473                                                    struct tnl_vport, rcu);
1474
1475         free_cache((struct tnl_cache __force *)tnl_vport->cache);
1476         kfree((struct tnl_mutable __force *)tnl_vport->mutable);
1477         vport_free(tnl_vport_to_vport(tnl_vport));
1478 }
1479
1480 void tnl_destroy(struct vport *vport)
1481 {
1482         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1483         const struct tnl_mutable_config *mutable;
1484
1485         mutable = rtnl_dereference(tnl_vport->mutable);
1486         port_table_remove_port(vport);
1487         call_rcu(&tnl_vport->rcu, free_port_rcu);
1488 }
1489
1490 int tnl_set_addr(struct vport *vport, const unsigned char *addr)
1491 {
1492         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1493         struct tnl_mutable_config *mutable;
1494
1495         mutable = kmemdup(rtnl_dereference(tnl_vport->mutable),
1496                           sizeof(struct tnl_mutable_config), GFP_KERNEL);
1497         if (!mutable)
1498                 return -ENOMEM;
1499
1500         memcpy(mutable->eth_addr, addr, ETH_ALEN);
1501         assign_config_rcu(vport, mutable);
1502
1503         return 0;
1504 }
1505
1506 const char *tnl_get_name(const struct vport *vport)
1507 {
1508         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1509         return tnl_vport->name;
1510 }
1511
1512 const unsigned char *tnl_get_addr(const struct vport *vport)
1513 {
1514         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1515         return rcu_dereference_rtnl(tnl_vport->mutable)->eth_addr;
1516 }
1517
1518 void tnl_free_linked_skbs(struct sk_buff *skb)
1519 {
1520         while (skb) {
1521                 struct sk_buff *next = skb->next;
1522                 kfree_skb(skb);
1523                 skb = next;
1524         }
1525 }
1526
1527 int tnl_init(void)
1528 {
1529         int i;
1530
1531         port_table = kmalloc(PORT_TABLE_SIZE * sizeof(struct hlist_head *),
1532                         GFP_KERNEL);
1533         if (!port_table)
1534                 return -ENOMEM;
1535
1536         for (i = 0; i < PORT_TABLE_SIZE; i++)
1537                 INIT_HLIST_HEAD(&port_table[i]);
1538
1539         return 0;
1540 }
1541
1542 void tnl_exit(void)
1543 {
1544         int i;
1545
1546         for (i = 0; i < PORT_TABLE_SIZE; i++) {
1547                 struct tnl_vport * tnl_vport;
1548                 struct hlist_head *hash_head;
1549                 struct hlist_node *n;
1550
1551                 hash_head = &port_table[i];
1552                 hlist_for_each_entry(tnl_vport, n, hash_head, hash_node) {
1553                         BUG();
1554                         goto out;
1555                 }
1556         }
1557 out:
1558         kfree(port_table);
1559 }