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  56  * Interval to check for and remove caches that are no longer valid.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 static inline struct vport *tnl_vport_to_vport(const struct tnl_vport *tnl_vport)
  97 {
  98         return vport_from_priv(tnl_vport);
  99 }
 100
 101 /* This is analogous to rtnl_dereference for the tunnel cache.  It checks that
 102  * cache_lock is held, so it is only for update side code.
 103  */
 104 static inline struct tnl_cache *cache_dereference(struct tnl_vport *tnl_vport)
 105 {
 106         return rcu_dereference_protected(tnl_vport->cache,
 107                                          lockdep_is_held(&tnl_vport->cache_lock));
 108 }
 109
 110 static inline void schedule_cache_cleaner(void)
 111 {
 112         schedule_delayed_work(&cache_cleaner_wq, CACHE_CLEANER_INTERVAL);
 113 }
 114
 115 static void free_cache(struct tnl_cache *cache)
 116 {
 117         if (!cache)
 118                 return;
 119
 120         flow_put(cache->flow);
 121         ip_rt_put(cache->rt);
 122         kfree(cache);
 123 }
 124
 125 static void free_config_rcu(struct rcu_head *rcu)
 126 {
 127         struct tnl_mutable_config *c = container_of(rcu, struct tnl_mutable_config, rcu);
 128         kfree(c);
 129 }
 130
 131 static void free_cache_rcu(struct rcu_head *rcu)
 132 {
 133         struct tnl_cache *c = container_of(rcu, struct tnl_cache, rcu);
 134         free_cache(c);
 135 }
 136
 137 static void assign_config_rcu(struct vport *vport,
 138                               struct tnl_mutable_config *new_config)
 139 {
 140         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 141         struct tnl_mutable_config *old_config;
 142
 143         old_config = rtnl_dereference(tnl_vport->mutable);
 144         rcu_assign_pointer(tnl_vport->mutable, new_config);
 145         call_rcu(&old_config->rcu, free_config_rcu);
 146 }
 147
 148 static void assign_cache_rcu(struct vport *vport, struct tnl_cache *new_cache)
 149 {
 150         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 151         struct tnl_cache *old_cache;
 152
 153         old_cache = cache_dereference(tnl_vport);
 154         rcu_assign_pointer(tnl_vport->cache, new_cache);
 155
 156         if (old_cache)
 157                 call_rcu(&old_cache->rcu, free_cache_rcu);
 158 }
 159
 160 static unsigned int *find_port_pool(const struct tnl_mutable_config *mutable)
 161 {
 162         if (mutable->flags & TNL_F_IN_KEY_MATCH) {
 163                 if (mutable->saddr)
 164                         return &local_remote_ports;
 165                 else
 166                         return &remote_ports;
 167         } else {
 168                 if (mutable->saddr)
 169                         return &key_local_remote_ports;
 170                 else
 171                         return &key_remote_ports;
 172         }
 173 }
 174
 175 struct port_lookup_key {
 176         const struct tnl_mutable_config *mutable;
 177         __be64 key;
 178         u32 tunnel_type;
 179         __be32 saddr;
 180         __be32 daddr;
 181 };
 182
 183 /*
 184  * Modifies 'target' to store the rcu_dereferenced pointer that was used to do
 185  * the comparision.
 186  */
 187 static int port_cmp(const struct tnl_vport *tnl_vport,
 188                     struct port_lookup_key *lookup)
 189 {
 190         lookup->mutable = rcu_dereference_rtnl(tnl_vport->mutable);
 191
 192         return (lookup->mutable->tunnel_type == lookup->tunnel_type &&
 193                 lookup->mutable->daddr == lookup->daddr &&
 194                 lookup->mutable->in_key == lookup->key &&
 195                 lookup->mutable->saddr == lookup->saddr);
 196 }
 197
 198 static u32 port_hash(struct port_lookup_key *k)
 199 {
 200         u32 x = jhash_3words((__force u32)k->saddr, (__force u32)k->daddr,
 201                              k->tunnel_type, 0);
 202         return jhash_2words((__force u64)k->key >> 32, (__force u32)k->key, x);
 203 }
 204
 205 static u32 mutable_hash(const struct tnl_mutable_config *mutable)
 206 {
 207         struct port_lookup_key lookup;
 208
 209         lookup.saddr = mutable->saddr;
 210         lookup.daddr = mutable->daddr;
 211         lookup.key = mutable->in_key;
 212         lookup.tunnel_type = mutable->tunnel_type;
 213
 214         return port_hash(&lookup);
 215 }
 216
 217
 218 static inline struct hlist_head *find_bucket(u32 hash)
 219 {
 220         return &port_table[(hash & (PORT_TABLE_SIZE - 1))];
 221 }
 222
 223 static void port_table_add_port(struct vport *vport)
 224 {
 225         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 226         u32 hash = mutable_hash(rtnl_dereference(tnl_vport->mutable));
 227
 228         if (port_table_count == 0)
 229                 schedule_cache_cleaner();
 230
 231         hlist_add_head_rcu(&tnl_vport->hash_node, find_bucket(hash));
 232         port_table_count++;
 233
 234         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
 235 }
 236
 237 static void port_table_move_port(struct vport *vport,
 238                       struct tnl_mutable_config *new_mutable)
 239 {
 240         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 241         u32 hash;
 242
 243         hash = mutable_hash(new_mutable);
 244         hlist_del_init_rcu(&tnl_vport->hash_node);
 245         hlist_add_head_rcu(&tnl_vport->hash_node, find_bucket(hash));
 246
 247         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
 248         assign_config_rcu(vport, new_mutable);
 249         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
 250 }
 251
 252 static void port_table_remove_port(struct vport *vport)
 253 {
 254         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 255
 256         hlist_del_init_rcu(&tnl_vport->hash_node);
 257
 258         port_table_count--;
 259         if (port_table_count == 0)
 260                 cancel_delayed_work_sync(&cache_cleaner_wq);
 261
 262         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
 263 }
 264
 265 static struct tnl_vport *port_table_lookup(struct port_lookup_key *lookup)
 266 {
 267         struct hlist_node *n;
 268         struct hlist_head *bucket;
 269         u32 hash = port_hash(lookup);
 270         struct tnl_vport * tnl_vport;
 271
 272         bucket = find_bucket(hash);
 273
 274         hlist_for_each_entry_rcu(tnl_vport, n, bucket, hash_node) {
 275                 if (!port_cmp(tnl_vport, lookup))
 276                         return tnl_vport;
 277         }
 278
 279         return NULL;
 280 }
 281
 282 struct vport *tnl_find_port(__be32 saddr, __be32 daddr, __be64 key,
 283                             int tunnel_type,
 284                             const struct tnl_mutable_config **mutable)
 285 {
 286         struct port_lookup_key lookup;
 287         struct tnl_vport * tnl_vport;
 288
 289         lookup.saddr = saddr;
 290         lookup.daddr = daddr;
 291
 292         if (tunnel_type & TNL_T_KEY_EXACT) {
 293                 lookup.key = key;
 294                 lookup.tunnel_type = tunnel_type & ~TNL_T_KEY_MATCH;
 295
 296                 if (key_local_remote_ports) {
 297                         tnl_vport = port_table_lookup(&lookup);
 298                         if (tnl_vport)
 299                                 goto found;
 300                 }
 301
 302                 if (key_remote_ports) {
 303                         lookup.saddr = 0;
 304                         tnl_vport = port_table_lookup(&lookup);
 305                         if (tnl_vport)
 306                                 goto found;
 307
 308                         lookup.saddr = saddr;
 309                 }
 310         }
 311
 312         if (tunnel_type & TNL_T_KEY_MATCH) {
 313                 lookup.key = 0;
 314                 lookup.tunnel_type = tunnel_type & ~TNL_T_KEY_EXACT;
 315
 316                 if (local_remote_ports) {
 317                         tnl_vport = port_table_lookup(&lookup);
 318                         if (tnl_vport)
 319                                 goto found;
 320                 }
 321
 322                 if (remote_ports) {
 323                         lookup.saddr = 0;
 324                         tnl_vport = port_table_lookup(&lookup);
 325                         if (tnl_vport)
 326                                 goto found;
 327                 }
 328         }
 329
 330         return NULL;
 331
 332 found:
 333         *mutable = lookup.mutable;
 334         return tnl_vport_to_vport(tnl_vport);
 335 }
 336
 337 static void ecn_decapsulate(struct sk_buff *skb, u8 tos)
 338 {
 339         if (unlikely(INET_ECN_is_ce(tos))) {
 340                 __be16 protocol = skb->protocol;
 341
 342                 skb_set_network_header(skb, ETH_HLEN);
 343
 344                 if (protocol == htons(ETH_P_8021Q)) {
 345                         if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
 346                                 return;
 347
 348                         protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
 349                         skb_set_network_header(skb, VLAN_ETH_HLEN);
 350                 }
 351
 352                 if (protocol == htons(ETH_P_IP)) {
 353                         if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
 354                             + sizeof(struct iphdr))))
 355                                 return;
 356
 357                         IP_ECN_set_ce(ip_hdr(skb));
 358                 }
 359 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 360                 else if (protocol == htons(ETH_P_IPV6)) {
 361                         if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
 362                             + sizeof(struct ipv6hdr))))
 363                                 return;
 364
 365                         IP6_ECN_set_ce(ipv6_hdr(skb));
 366                 }
 367 #endif
 368         }
 369 }
 370
 371 /**
 372  *      tnl_rcv - ingress point for generic tunnel code
 373  *
 374  * @vport: port this packet was received on
 375  * @skb: received packet
 376  * @tos: ToS from encapsulating IP packet, used to copy ECN bits
 377  *
 378  * Must be called with rcu_read_lock.
 379  *
 380  * Packets received by this function are in the following state:
 381  * - skb->data points to the inner Ethernet header.
 382  * - The inner Ethernet header is in the linear data area.
 383  * - skb->csum does not include the inner Ethernet header.
 384  * - The layer pointers are undefined.
 385  */
 386 void tnl_rcv(struct vport *vport, struct sk_buff *skb, u8 tos)
 387 {
 388         struct ethhdr *eh;
 389
 390         skb_reset_mac_header(skb);
 391         eh = eth_hdr(skb);
 392
 393         if (likely(ntohs(eh->h_proto) >= 1536))
 394                 skb->protocol = eh->h_proto;
 395         else
 396                 skb->protocol = htons(ETH_P_802_2);
 397
 398         skb_dst_drop(skb);
 399         nf_reset(skb);
 400         skb_clear_rxhash(skb);
 401         secpath_reset(skb);
 402
 403         ecn_decapsulate(skb, tos);
 404         vlan_set_tci(skb, 0);
 405
 406         if (unlikely(compute_ip_summed(skb, false))) {
 407                 kfree_skb(skb);
 408                 return;
 409         }
 410
 411         vport_receive(vport, skb);
 412 }
 413
 414 static bool check_ipv4_address(__be32 addr)
 415 {
 416         if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr)
 417             || ipv4_is_loopback(addr) || ipv4_is_zeronet(addr))
 418                 return false;
 419
 420         return true;
 421 }
 422
 423 static bool ipv4_should_icmp(struct sk_buff *skb)
 424 {
 425         struct iphdr *old_iph = ip_hdr(skb);
 426
 427         /* Don't respond to L2 broadcast. */
 428         if (is_multicast_ether_addr(eth_hdr(skb)->h_dest))
 429                 return false;
 430
 431         /* Don't respond to L3 broadcast or invalid addresses. */
 432         if (!check_ipv4_address(old_iph->daddr) ||
 433             !check_ipv4_address(old_iph->saddr))
 434                 return false;
 435
 436         /* Only respond to the first fragment. */
 437         if (old_iph->frag_off & htons(IP_OFFSET))
 438                 return false;
 439
 440         /* Don't respond to ICMP error messages. */
 441         if (old_iph->protocol == IPPROTO_ICMP) {
 442                 u8 icmp_type, *icmp_typep;
 443
 444                 icmp_typep = skb_header_pointer(skb, (u8 *)old_iph +
 445                                                 (old_iph->ihl << 2) +
 446                                                 offsetof(struct icmphdr, type) -
 447                                                 skb->data, sizeof(icmp_type),
 448                                                 &icmp_type);
 449
 450                 if (!icmp_typep)
 451                         return false;
 452
 453                 if (*icmp_typep > NR_ICMP_TYPES
 454                         || (*icmp_typep <= ICMP_PARAMETERPROB
 455                                 && *icmp_typep != ICMP_ECHOREPLY
 456                                 && *icmp_typep != ICMP_ECHO))
 457                         return false;
 458         }
 459
 460         return true;
 461 }
 462
 463 static void ipv4_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
 464                             unsigned int mtu, unsigned int payload_length)
 465 {
 466         struct iphdr *iph, *old_iph = ip_hdr(skb);
 467         struct icmphdr *icmph;
 468         u8 *payload;
 469
 470         iph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
 471         icmph = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
 472         payload = skb_put(nskb, payload_length);
 473
 474         /* IP */
 475         iph->version            =       4;
 476         iph->ihl                =       sizeof(struct iphdr) >> 2;
 477         iph->tos                =       (old_iph->tos & IPTOS_TOS_MASK) |
 478                                         IPTOS_PREC_INTERNETCONTROL;
 479         iph->tot_len            =       htons(sizeof(struct iphdr)
 480                                               + sizeof(struct icmphdr)
 481                                               + payload_length);
 482         get_random_bytes(&iph->id, sizeof(iph->id));
 483         iph->frag_off           =       0;
 484         iph->ttl                =       IPDEFTTL;
 485         iph->protocol           =       IPPROTO_ICMP;
 486         iph->daddr              =       old_iph->saddr;
 487         iph->saddr              =       old_iph->daddr;
 488
 489         ip_send_check(iph);
 490
 491         /* ICMP */
 492         icmph->type             =       ICMP_DEST_UNREACH;
 493         icmph->code             =       ICMP_FRAG_NEEDED;
 494         icmph->un.gateway       =       htonl(mtu);
 495         icmph->checksum         =       0;
 496
 497         nskb->csum = csum_partial((u8 *)icmph, sizeof(struct icmphdr), 0);
 498         nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_iph - skb->data,
 499                                             payload, payload_length,
 500                                             nskb->csum);
 501         icmph->checksum = csum_fold(nskb->csum);
 502 }
 503
 504 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 505 static bool ipv6_should_icmp(struct sk_buff *skb)
 506 {
 507         struct ipv6hdr *old_ipv6h = ipv6_hdr(skb);
 508         int addr_type;
 509         int payload_off = (u8 *)(old_ipv6h + 1) - skb->data;
 510         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 511
 512         /* Check source address is valid. */
 513         addr_type = ipv6_addr_type(&old_ipv6h->saddr);
 514         if (addr_type & IPV6_ADDR_MULTICAST || addr_type == IPV6_ADDR_ANY)
 515                 return false;
 516
 517         /* Don't reply to unspecified addresses. */
 518         if (ipv6_addr_type(&old_ipv6h->daddr) == IPV6_ADDR_ANY)
 519                 return false;
 520
 521         /* Don't respond to ICMP error messages. */
 522         payload_off = ipv6_skip_exthdr(skb, payload_off, &nexthdr);
 523         if (payload_off < 0)
 524                 return false;
 525
 526         if (nexthdr == NEXTHDR_ICMP) {
 527                 u8 icmp_type, *icmp_typep;
 528
 529                 icmp_typep = skb_header_pointer(skb, payload_off +
 530                                                 offsetof(struct icmp6hdr,
 531                                                         icmp6_type),
 532                                                 sizeof(icmp_type), &icmp_type);
 533
 534                 if (!icmp_typep || !(*icmp_typep & ICMPV6_INFOMSG_MASK))
 535                         return false;
 536         }
 537
 538         return true;
 539 }
 540
 541 static void ipv6_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
 542                             unsigned int mtu, unsigned int payload_length)
 543 {
 544         struct ipv6hdr *ipv6h, *old_ipv6h = ipv6_hdr(skb);
 545         struct icmp6hdr *icmp6h;
 546         u8 *payload;
 547
 548         ipv6h = (struct ipv6hdr *)skb_put(nskb, sizeof(struct ipv6hdr));
 549         icmp6h = (struct icmp6hdr *)skb_put(nskb, sizeof(struct icmp6hdr));
 550         payload = skb_put(nskb, payload_length);
 551
 552         /* IPv6 */
 553         ipv6h->version          =       6;
 554         ipv6h->priority         =       0;
 555         memset(&ipv6h->flow_lbl, 0, sizeof(ipv6h->flow_lbl));
 556         ipv6h->payload_len      =       htons(sizeof(struct icmp6hdr)
 557                                               + payload_length);
 558         ipv6h->nexthdr          =       NEXTHDR_ICMP;
 559         ipv6h->hop_limit        =       IPV6_DEFAULT_HOPLIMIT;
 560         ipv6_addr_copy(&ipv6h->daddr, &old_ipv6h->saddr);
 561         ipv6_addr_copy(&ipv6h->saddr, &old_ipv6h->daddr);
 562
 563         /* ICMPv6 */
 564         icmp6h->icmp6_type      =       ICMPV6_PKT_TOOBIG;
 565         icmp6h->icmp6_code      =       0;
 566         icmp6h->icmp6_cksum     =       0;
 567         icmp6h->icmp6_mtu       =       htonl(mtu);
 568
 569         nskb->csum = csum_partial((u8 *)icmp6h, sizeof(struct icmp6hdr), 0);
 570         nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_ipv6h - skb->data,
 571                                             payload, payload_length,
 572                                             nskb->csum);
 573         icmp6h->icmp6_cksum = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
 574                                                 sizeof(struct icmp6hdr)
 575                                                 + payload_length,
 576                                                 ipv6h->nexthdr, nskb->csum);
 577 }
 578 #endif /* IPv6 */
 579
 580 bool tnl_frag_needed(struct vport *vport, const struct tnl_mutable_config *mutable,
 581                      struct sk_buff *skb, unsigned int mtu, __be64 flow_key)
 582 {
 583         unsigned int eth_hdr_len = ETH_HLEN;
 584         unsigned int total_length = 0, header_length = 0, payload_length;
 585         struct ethhdr *eh, *old_eh = eth_hdr(skb);
 586         struct sk_buff *nskb;
 587
 588         /* Sanity check */
 589         if (skb->protocol == htons(ETH_P_IP)) {
 590                 if (mtu < IP_MIN_MTU)
 591                         return false;
 592
 593                 if (!ipv4_should_icmp(skb))
 594                         return true;
 595         }
 596 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 597         else if (skb->protocol == htons(ETH_P_IPV6)) {
 598                 if (mtu < IPV6_MIN_MTU)
 599                         return false;
 600
 601                 /*
 602                  * In theory we should do PMTUD on IPv6 multicast messages but
 603                  * we don't have an address to send from so just fragment.
 604                  */
 605                 if (ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST)
 606                         return false;
 607
 608                 if (!ipv6_should_icmp(skb))
 609                         return true;
 610         }
 611 #endif
 612         else
 613                 return false;
 614
 615         /* Allocate */
 616         if (old_eh->h_proto == htons(ETH_P_8021Q))
 617                 eth_hdr_len = VLAN_ETH_HLEN;
 618
 619         payload_length = skb->len - eth_hdr_len;
 620         if (skb->protocol == htons(ETH_P_IP)) {
 621                 header_length = sizeof(struct iphdr) + sizeof(struct icmphdr);
 622                 total_length = min_t(unsigned int, header_length +
 623                                                    payload_length, 576);
 624         }
 625 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 626         else {
 627                 header_length = sizeof(struct ipv6hdr) +
 628                                 sizeof(struct icmp6hdr);
 629                 total_length = min_t(unsigned int, header_length +
 630                                                   payload_length, IPV6_MIN_MTU);
 631         }
 632 #endif
 633
 634         payload_length = total_length - header_length;
 635
 636         nskb = dev_alloc_skb(NET_IP_ALIGN + eth_hdr_len + header_length +
 637                              payload_length);
 638         if (!nskb)
 639                 return false;
 640
 641         skb_reserve(nskb, NET_IP_ALIGN);
 642
 643         /* Ethernet / VLAN */
 644         eh = (struct ethhdr *)skb_put(nskb, eth_hdr_len);
 645         memcpy(eh->h_dest, old_eh->h_source, ETH_ALEN);
 646         memcpy(eh->h_source, mutable->eth_addr, ETH_ALEN);
 647         nskb->protocol = eh->h_proto = old_eh->h_proto;
 648         if (old_eh->h_proto == htons(ETH_P_8021Q)) {
 649                 struct vlan_ethhdr *vh = (struct vlan_ethhdr *)eh;
 650
 651                 vh->h_vlan_TCI = vlan_eth_hdr(skb)->h_vlan_TCI;
 652                 vh->h_vlan_encapsulated_proto = skb->protocol;
 653         } else
 654                 vlan_set_tci(nskb, vlan_get_tci(skb));
 655         skb_reset_mac_header(nskb);
 656
 657         /* Protocol */
 658         if (skb->protocol == htons(ETH_P_IP))
 659                 ipv4_build_icmp(skb, nskb, mtu, payload_length);
 660 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 661         else
 662                 ipv6_build_icmp(skb, nskb, mtu, payload_length);
 663 #endif
 664
 665         /*
 666          * Assume that flow based keys are symmetric with respect to input
 667          * and output and use the key that we were going to put on the
 668          * outgoing packet for the fake received packet.  If the keys are
 669          * not symmetric then PMTUD needs to be disabled since we won't have
 670          * any way of synthesizing packets.
 671          */
 672         if ((mutable->flags & (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION)) ==
 673             (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION))
 674                 OVS_CB(nskb)->tun_id = flow_key;
 675
 676         if (unlikely(compute_ip_summed(nskb, false))) {
 677                 kfree_skb(nskb);
 678                 return false;
 679         }
 680
 681         vport_receive(vport, nskb);
 682
 683         return true;
 684 }
 685
 686 static bool check_mtu(struct sk_buff *skb,
 687                       struct vport *vport,
 688                       const struct tnl_mutable_config *mutable,
 689                       const struct rtable *rt, __be16 *frag_offp)
 690 {
 691         bool df_inherit = mutable->flags & TNL_F_DF_INHERIT;
 692         bool pmtud = mutable->flags & TNL_F_PMTUD;
 693         __be16 frag_off = mutable->flags & TNL_F_DF_DEFAULT ? htons(IP_DF) : 0;
 694         int mtu = 0;
 695         unsigned int packet_length = skb->len - ETH_HLEN;
 696
 697         /* Allow for one level of tagging in the packet length. */
 698         if (!vlan_tx_tag_present(skb) &&
 699             eth_hdr(skb)->h_proto == htons(ETH_P_8021Q))
 700                 packet_length -= VLAN_HLEN;
 701
 702         if (pmtud) {
 703                 int vlan_header = 0;
 704
 705                 /* The tag needs to go in packet regardless of where it
 706                  * currently is, so subtract it from the MTU.
 707                  */
 708                 if (vlan_tx_tag_present(skb) ||
 709                     eth_hdr(skb)->h_proto == htons(ETH_P_8021Q))
 710                         vlan_header = VLAN_HLEN;
 711
 712                 mtu = dst_mtu(&rt_dst(rt))
 713                         - ETH_HLEN
 714                         - mutable->tunnel_hlen
 715                         - vlan_header;
 716         }
 717
 718         if (skb->protocol == htons(ETH_P_IP)) {
 719                 struct iphdr *iph = ip_hdr(skb);
 720
 721                 if (df_inherit)
 722                         frag_off = iph->frag_off & htons(IP_DF);
 723
 724                 if (pmtud && iph->frag_off & htons(IP_DF)) {
 725                         mtu = max(mtu, IP_MIN_MTU);
 726
 727                         if (packet_length > mtu &&
 728                             tnl_frag_needed(vport, mutable, skb, mtu,
 729                                             OVS_CB(skb)->tun_id))
 730                                 return false;
 731                 }
 732         }
 733 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 734         else if (skb->protocol == htons(ETH_P_IPV6)) {
 735                 /* IPv6 requires end hosts to do fragmentation
 736                  * if the packet is above the minimum MTU.
 737                  */
 738                 if (df_inherit && packet_length > IPV6_MIN_MTU)
 739                         frag_off = htons(IP_DF);
 740
 741                 if (pmtud) {
 742                         mtu = max(mtu, IPV6_MIN_MTU);
 743
 744                         if (packet_length > mtu &&
 745                             tnl_frag_needed(vport, mutable, skb, mtu,
 746                                             OVS_CB(skb)->tun_id))
 747                                 return false;
 748                 }
 749         }
 750 #endif
 751
 752         *frag_offp = frag_off;
 753         return true;
 754 }
 755
 756 static void create_tunnel_header(const struct vport *vport,
 757                                  const struct tnl_mutable_config *mutable,
 758                                  const struct rtable *rt, void *header)
 759 {
 760         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 761         struct iphdr *iph = header;
 762
 763         iph->version    = 4;
 764         iph->ihl        = sizeof(struct iphdr) >> 2;
 765         iph->frag_off   = htons(IP_DF);
 766         iph->protocol   = tnl_vport->tnl_ops->ipproto;
 767         iph->tos        = mutable->tos;
 768         iph->daddr      = rt->rt_dst;
 769         iph->saddr      = rt->rt_src;
 770         iph->ttl        = mutable->ttl;
 771         if (!iph->ttl)
 772                 iph->ttl = ip4_dst_hoplimit(&rt_dst(rt));
 773
 774         tnl_vport->tnl_ops->build_header(vport, mutable, iph + 1);
 775 }
 776
 777 static inline void *get_cached_header(const struct tnl_cache *cache)
 778 {
 779         return (void *)cache + ALIGN(sizeof(struct tnl_cache), CACHE_DATA_ALIGN);
 780 }
 781
 782 static inline bool check_cache_valid(const struct tnl_cache *cache,
 783                                      const struct tnl_mutable_config *mutable)
 784 {
 785         return cache &&
 786 #ifdef NEED_CACHE_TIMEOUT
 787                 time_before(jiffies, cache->expiration) &&
 788 #endif
 789 #ifdef HAVE_RT_GENID
 790                 atomic_read(&init_net.ipv4.rt_genid) == cache->rt->rt_genid &&
 791 #endif
 792 #ifdef HAVE_HH_SEQ
 793                 rt_dst(cache->rt).hh->hh_lock.sequence == cache->hh_seq &&
 794 #endif
 795                 mutable->seq == cache->mutable_seq &&
 796                 (!is_internal_dev(rt_dst(cache->rt).dev) ||
 797                 (cache->flow && !cache->flow->dead));
 798 }
 799
 800 static void __cache_cleaner(struct tnl_vport *tnl_vport)
 801 {
 802         const struct tnl_mutable_config *mutable =
 803                         rcu_dereference(tnl_vport->mutable);
 804         const struct tnl_cache *cache = rcu_dereference(tnl_vport->cache);
 805
 806         if (cache && !check_cache_valid(cache, mutable) &&
 807             spin_trylock_bh(&tnl_vport->cache_lock)) {
 808                 assign_cache_rcu(tnl_vport_to_vport(tnl_vport), NULL);
 809                 spin_unlock_bh(&tnl_vport->cache_lock);
 810         }
 811 }
 812
 813 static void cache_cleaner(struct work_struct *work)
 814 {
 815         int i;
 816
 817         schedule_cache_cleaner();
 818
 819         rcu_read_lock();
 820         for (i = 0; i < PORT_TABLE_SIZE; i++) {
 821                 struct hlist_node *n;
 822                 struct hlist_head *bucket;
 823                 struct tnl_vport  *tnl_vport;
 824
 825                 bucket = &port_table[i];
 826                 hlist_for_each_entry_rcu(tnl_vport, n, bucket, hash_node)
 827                         __cache_cleaner(tnl_vport);
 828         }
 829         rcu_read_unlock();
 830 }
 831
 832 static inline void create_eth_hdr(struct tnl_cache *cache,
 833                                   const struct rtable *rt)
 834 {
 835         void *cache_data = get_cached_header(cache);
 836         int hh_len = rt_dst(rt).hh->hh_len;
 837         int hh_off = HH_DATA_ALIGN(rt_dst(rt).hh->hh_len) - hh_len;
 838
 839 #ifdef HAVE_HH_SEQ
 840         unsigned hh_seq;
 841
 842         do {
 843                 hh_seq = read_seqbegin(&rt_dst(rt).hh->hh_lock);
 844                 memcpy(cache_data, (void *)rt_dst(rt).hh->hh_data + hh_off, hh_len);
 845         } while (read_seqretry(&rt_dst(rt).hh->hh_lock, hh_seq));
 846
 847         cache->hh_seq = hh_seq;
 848 #else
 849         read_lock_bh(&rt_dst(rt).hh->hh_lock);
 850         memcpy(cache_data, (void *)rt_dst(rt).hh->hh_data + hh_off, hh_len);
 851         read_unlock_bh(&rt_dst(rt).hh->hh_lock);
 852 #endif
 853 }
 854
 855 static struct tnl_cache *build_cache(struct vport *vport,
 856                                      const struct tnl_mutable_config *mutable,
 857                                      struct rtable *rt)
 858 {
 859         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 860         struct tnl_cache *cache;
 861         void *cache_data;
 862         int cache_len;
 863
 864         if (!(mutable->flags & TNL_F_HDR_CACHE))
 865                 return NULL;
 866
 867         /*
 868          * If there is no entry in the ARP cache or if this device does not
 869          * support hard header caching just fall back to the IP stack.
 870          */
 871         if (!rt_dst(rt).hh)
 872                 return NULL;
 873
 874         /*
 875          * If lock is contended fall back to directly building the header.
 876          * We're not going to help performance by sitting here spinning.
 877          */
 878         if (!spin_trylock_bh(&tnl_vport->cache_lock))
 879                 return NULL;
 880
 881         cache = cache_dereference(tnl_vport);
 882         if (check_cache_valid(cache, mutable))
 883                 goto unlock;
 884         else
 885                 cache = NULL;
 886
 887         cache_len = rt_dst(rt).hh->hh_len + mutable->tunnel_hlen;
 888
 889         cache = kzalloc(ALIGN(sizeof(struct tnl_cache), CACHE_DATA_ALIGN) +
 890                         cache_len, GFP_ATOMIC);
 891         if (!cache)
 892                 goto unlock;
 893
 894         cache->len = cache_len;
 895
 896         create_eth_hdr(cache, rt);
 897         cache_data = get_cached_header(cache) + rt_dst(rt).hh->hh_len;
 898
 899         create_tunnel_header(vport, mutable, rt, cache_data);
 900
 901         cache->mutable_seq = mutable->seq;
 902         cache->rt = rt;
 903 #ifdef NEED_CACHE_TIMEOUT
 904         cache->expiration = jiffies + tnl_vport->cache_exp_interval;
 905 #endif
 906
 907         if (is_internal_dev(rt_dst(rt).dev)) {
 908                 struct sw_flow_key flow_key;
 909                 struct vport *dst_vport;
 910                 struct sk_buff *skb;
 911                 bool is_frag;
 912                 int err;
 913                 int flow_key_len;
 914                 struct sw_flow *flow;
 915
 916                 dst_vport = internal_dev_get_vport(rt_dst(rt).dev);
 917                 if (!dst_vport)
 918                         goto done;
 919
 920                 skb = alloc_skb(cache->len, GFP_ATOMIC);
 921                 if (!skb)
 922                         goto done;
 923
 924                 __skb_put(skb, cache->len);
 925                 memcpy(skb->data, get_cached_header(cache), cache->len);
 926
 927                 err = flow_extract(skb, dst_vport->port_no, &flow_key,
 928                                    &flow_key_len, &is_frag);
 929
 930                 consume_skb(skb);
 931                 if (err || is_frag)
 932                         goto done;
 933
 934                 flow = flow_tbl_lookup(rcu_dereference(dst_vport->dp->table),
 935                                          &flow_key, flow_key_len);
 936                 if (flow) {
 937                         cache->flow = flow;
 938                         flow_hold(flow);
 939                 }
 940         }
 941
 942 done:
 943         assign_cache_rcu(vport, cache);
 944
 945 unlock:
 946         spin_unlock_bh(&tnl_vport->cache_lock);
 947
 948         return cache;
 949 }
 950
 951 static struct rtable *find_route(struct vport *vport,
 952                                  const struct tnl_mutable_config *mutable,
 953                                  u8 tos, struct tnl_cache **cache)
 954 {
 955         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 956         struct tnl_cache *cur_cache = rcu_dereference(tnl_vport->cache);
 957
 958         *cache = NULL;
 959         tos = RT_TOS(tos);
 960
 961         if (likely(tos == mutable->tos && check_cache_valid(cur_cache, mutable))) {
 962                 *cache = cur_cache;
 963                 return cur_cache->rt;
 964         } else {
 965                 struct rtable *rt;
 966 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)
 967                 struct flowi fl = { .nl_u = { .ip4_u =
 968                                               { .daddr = mutable->daddr,
 969                                                 .saddr = mutable->saddr,
 970                                                 .tos = tos } },
 971                                     .proto = tnl_vport->tnl_ops->ipproto };
 972
 973                 if (unlikely(ip_route_output_key(&init_net, &rt, &fl)))
 974                         return NULL;
 975 #else
 976                 struct flowi4 fl = { .daddr = mutable->daddr,
 977                                      .saddr = mutable->saddr,
 978                                      .flowi4_tos = tos,
 979                                      .flowi4_proto = tnl_vport->tnl_ops->ipproto };
 980
 981                 rt = ip_route_output_key(&init_net, &fl);
 982                 if (IS_ERR(rt))
 983                         return NULL;
 984 #endif
 985
 986                 if (likely(tos == mutable->tos))
 987                         *cache = build_cache(vport, mutable, rt);
 988
 989                 return rt;
 990         }
 991 }
 992
 993 static inline bool need_linearize(const struct sk_buff *skb)
 994 {
 995         int i;
 996
 997         if (unlikely(skb_shinfo(skb)->frag_list))
 998                 return true;
 999
1000         /*
1001          * Generally speaking we should linearize if there are paged frags.
1002          * However, if all of the refcounts are 1 we know nobody else can
1003          * change them from underneath us and we can skip the linearization.
1004          */
1005         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1006                 if (unlikely(page_count(skb_shinfo(skb)->frags[i].page) > 1))
1007                         return true;
1008
1009         return false;
1010 }
1011
1012 static struct sk_buff *handle_offloads(struct sk_buff *skb,
1013                                        const struct tnl_mutable_config *mutable,
1014                                        const struct rtable *rt)
1015 {
1016         int min_headroom;
1017         int err;
1018
1019         min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len
1020                         + mutable->tunnel_hlen
1021                         + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
1022
1023         if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
1024                 int head_delta = SKB_DATA_ALIGN(min_headroom -
1025                                                 skb_headroom(skb) +
1026                                                 16);
1027                 err = pskb_expand_head(skb, max_t(int, head_delta, 0),
1028                                         0, GFP_ATOMIC);
1029                 if (unlikely(err))
1030                         goto error_free;
1031         }
1032
1033         forward_ip_summed(skb, true);
1034
1035         if (skb_is_gso(skb)) {
1036                 struct sk_buff *nskb;
1037
1038                 nskb = skb_gso_segment(skb, 0);
1039                 if (IS_ERR(nskb)) {
1040                         kfree_skb(skb);
1041                         err = PTR_ERR(nskb);
1042                         goto error;
1043                 }
1044
1045                 consume_skb(skb);
1046                 skb = nskb;
1047         } else if (get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
1048                 /* Pages aren't locked and could change at any time.
1049                  * If this happens after we compute the checksum, the
1050                  * checksum will be wrong.  We linearize now to avoid
1051                  * this problem.
1052                  */
1053                 if (unlikely(need_linearize(skb))) {
1054                         err = __skb_linearize(skb);
1055                         if (unlikely(err))
1056                                 goto error_free;
1057                 }
1058
1059                 err = skb_checksum_help(skb);
1060                 if (unlikely(err))
1061                         goto error_free;
1062         }
1063
1064         set_ip_summed(skb, OVS_CSUM_NONE);
1065
1066         return skb;
1067
1068 error_free:
1069         kfree_skb(skb);
1070 error:
1071         return ERR_PTR(err);
1072 }
1073
1074 static int send_frags(struct sk_buff *skb,
1075                       const struct tnl_mutable_config *mutable)
1076 {
1077         int sent_len;
1078
1079         sent_len = 0;
1080         while (skb) {
1081                 struct sk_buff *next = skb->next;
1082                 int frag_len = skb->len - mutable->tunnel_hlen;
1083                 int err;
1084
1085                 skb->next = NULL;
1086                 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
1087
1088                 err = ip_local_out(skb);
1089                 skb = next;
1090                 if (unlikely(net_xmit_eval(err)))
1091                         goto free_frags;
1092                 sent_len += frag_len;
1093         }
1094
1095         return sent_len;
1096
1097 free_frags:
1098         /*
1099          * There's no point in continuing to send fragments once one has been
1100          * dropped so just free the rest.  This may help improve the congestion
1101          * that caused the first packet to be dropped.
1102          */
1103         tnl_free_linked_skbs(skb);
1104         return sent_len;
1105 }
1106
1107 int tnl_send(struct vport *vport, struct sk_buff *skb)
1108 {
1109         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1110         const struct tnl_mutable_config *mutable = rcu_dereference(tnl_vport->mutable);
1111
1112         enum vport_err_type err = VPORT_E_TX_ERROR;
1113         struct rtable *rt;
1114         struct dst_entry *unattached_dst = NULL;
1115         struct tnl_cache *cache;
1116         int sent_len = 0;
1117         __be16 frag_off = 0;
1118         u8 ttl;
1119         u8 inner_tos;
1120         u8 tos;
1121
1122         /* Validate the protocol headers before we try to use them. */
1123         if (skb->protocol == htons(ETH_P_8021Q) &&
1124             !vlan_tx_tag_present(skb)) {
1125                 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
1126                         goto error_free;
1127
1128                 skb->protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
1129                 skb_set_network_header(skb, VLAN_ETH_HLEN);
1130         }
1131
1132         if (skb->protocol == htons(ETH_P_IP)) {
1133                 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
1134                     + sizeof(struct iphdr))))
1135                         skb->protocol = 0;
1136         }
1137 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1138         else if (skb->protocol == htons(ETH_P_IPV6)) {
1139                 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
1140                     + sizeof(struct ipv6hdr))))
1141                         skb->protocol = 0;
1142         }
1143 #endif
1144
1145         /* ToS */
1146         if (skb->protocol == htons(ETH_P_IP))
1147                 inner_tos = ip_hdr(skb)->tos;
1148 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1149         else if (skb->protocol == htons(ETH_P_IPV6))
1150                 inner_tos = ipv6_get_dsfield(ipv6_hdr(skb));
1151 #endif
1152         else
1153                 inner_tos = 0;
1154
1155         if (mutable->flags & TNL_F_TOS_INHERIT)
1156                 tos = inner_tos;
1157         else
1158                 tos = mutable->tos;
1159
1160         tos = INET_ECN_encapsulate(tos, inner_tos);
1161
1162         /* Route lookup */
1163         rt = find_route(vport, mutable, tos, &cache);
1164         if (unlikely(!rt))
1165                 goto error_free;
1166         if (unlikely(!cache))
1167                 unattached_dst = &rt_dst(rt);
1168
1169         /* Reset SKB */
1170         nf_reset(skb);
1171         secpath_reset(skb);
1172         skb_dst_drop(skb);
1173         skb_clear_rxhash(skb);
1174
1175         /* Offloading */
1176         skb = handle_offloads(skb, mutable, rt);
1177         if (IS_ERR(skb))
1178                 goto error;
1179
1180         /* MTU */
1181         if (unlikely(!check_mtu(skb, vport, mutable, rt, &frag_off))) {
1182                 err = VPORT_E_TX_DROPPED;
1183                 goto error_free;
1184         }
1185
1186         /*
1187          * If we are over the MTU, allow the IP stack to handle fragmentation.
1188          * Fragmentation is a slow path anyways.
1189          */
1190         if (unlikely(skb->len + mutable->tunnel_hlen > dst_mtu(&rt_dst(rt)) &&
1191                      cache)) {
1192                 unattached_dst = &rt_dst(rt);
1193                 dst_hold(unattached_dst);
1194                 cache = NULL;
1195         }
1196
1197         /* TTL */
1198         ttl = mutable->ttl;
1199         if (!ttl)
1200                 ttl = ip4_dst_hoplimit(&rt_dst(rt));
1201
1202         if (mutable->flags & TNL_F_TTL_INHERIT) {
1203                 if (skb->protocol == htons(ETH_P_IP))
1204                         ttl = ip_hdr(skb)->ttl;
1205 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1206                 else if (skb->protocol == htons(ETH_P_IPV6))
1207                         ttl = ipv6_hdr(skb)->hop_limit;
1208 #endif
1209         }
1210
1211         while (skb) {
1212                 struct iphdr *iph;
1213                 struct sk_buff *next_skb = skb->next;
1214                 skb->next = NULL;
1215
1216                 if (unlikely(vlan_deaccel_tag(skb)))
1217                         goto next;
1218
1219                 if (likely(cache)) {
1220                         skb_push(skb, cache->len);
1221                         memcpy(skb->data, get_cached_header(cache), cache->len);
1222                         skb_reset_mac_header(skb);
1223                         skb_set_network_header(skb, rt_dst(rt).hh->hh_len);
1224
1225                 } else {
1226                         skb_push(skb, mutable->tunnel_hlen);
1227                         create_tunnel_header(vport, mutable, rt, skb->data);
1228                         skb_reset_network_header(skb);
1229
1230                         if (next_skb)
1231                                 skb_dst_set(skb, dst_clone(unattached_dst));
1232                         else {
1233                                 skb_dst_set(skb, unattached_dst);
1234                                 unattached_dst = NULL;
1235                         }
1236                 }
1237                 skb_set_transport_header(skb, skb_network_offset(skb) + sizeof(struct iphdr));
1238
1239                 iph = ip_hdr(skb);
1240                 iph->tos = tos;
1241                 iph->ttl = ttl;
1242                 iph->frag_off = frag_off;
1243                 ip_select_ident(iph, &rt_dst(rt), NULL);
1244
1245                 skb = tnl_vport->tnl_ops->update_header(vport, mutable, &rt_dst(rt), skb);
1246                 if (unlikely(!skb))
1247                         goto next;
1248
1249                 if (likely(cache)) {
1250                         int orig_len = skb->len - cache->len;
1251                         struct vport *cache_vport = internal_dev_get_vport(rt_dst(rt).dev);
1252
1253                         skb->protocol = htons(ETH_P_IP);
1254                         iph = ip_hdr(skb);
1255                         iph->tot_len = htons(skb->len - skb_network_offset(skb));
1256                         ip_send_check(iph);
1257
1258                         if (cache_vport) {
1259                                 if (unlikely(compute_ip_summed(skb, true))) {
1260                                         kfree_skb(skb);
1261                                         goto next;
1262                                 }
1263
1264                                 OVS_CB(skb)->flow = cache->flow;
1265                                 vport_receive(cache_vport, skb);
1266                                 sent_len += orig_len;
1267                         } else {
1268                                 int xmit_err;
1269
1270                                 skb->dev = rt_dst(rt).dev;
1271                                 xmit_err = dev_queue_xmit(skb);
1272
1273                                 if (likely(net_xmit_eval(xmit_err) == 0))
1274                                         sent_len += orig_len;
1275                         }
1276                 } else
1277                         sent_len += send_frags(skb, mutable);
1278
1279 next:
1280                 skb = next_skb;
1281         }
1282
1283         if (unlikely(sent_len == 0))
1284                 vport_record_error(vport, VPORT_E_TX_DROPPED);
1285
1286         goto out;
1287
1288 error_free:
1289         tnl_free_linked_skbs(skb);
1290 error:
1291         vport_record_error(vport, err);
1292 out:
1293         dst_release(unattached_dst);
1294         return sent_len;
1295 }
1296
1297 static const struct nla_policy tnl_policy[OVS_TUNNEL_ATTR_MAX + 1] = {
1298         [OVS_TUNNEL_ATTR_FLAGS]    = { .type = NLA_U32 },
1299         [OVS_TUNNEL_ATTR_DST_IPV4] = { .type = NLA_U32 },
1300         [OVS_TUNNEL_ATTR_SRC_IPV4] = { .type = NLA_U32 },
1301         [OVS_TUNNEL_ATTR_OUT_KEY]  = { .type = NLA_U64 },
1302         [OVS_TUNNEL_ATTR_IN_KEY]   = { .type = NLA_U64 },
1303         [OVS_TUNNEL_ATTR_TOS]      = { .type = NLA_U8 },
1304         [OVS_TUNNEL_ATTR_TTL]      = { .type = NLA_U8 },
1305 };
1306
1307 /* Sets OVS_TUNNEL_ATTR_* fields in 'mutable', which must initially be zeroed. */
1308 static int tnl_set_config(struct nlattr *options, const struct tnl_ops *tnl_ops,
1309                           const struct vport *cur_vport,
1310                           struct tnl_mutable_config *mutable)
1311 {
1312         const struct vport *old_vport;
1313         const struct tnl_mutable_config *old_mutable;
1314         struct nlattr *a[OVS_TUNNEL_ATTR_MAX + 1];
1315         int err;
1316
1317         if (!options)
1318                 return -EINVAL;
1319
1320         err = nla_parse_nested(a, OVS_TUNNEL_ATTR_MAX, options, tnl_policy);
1321         if (err)
1322                 return err;
1323
1324         if (!a[OVS_TUNNEL_ATTR_FLAGS] || !a[OVS_TUNNEL_ATTR_DST_IPV4])
1325                 return -EINVAL;
1326
1327         mutable->flags = nla_get_u32(a[OVS_TUNNEL_ATTR_FLAGS]) & TNL_F_PUBLIC;
1328
1329         if (a[OVS_TUNNEL_ATTR_SRC_IPV4])
1330                 mutable->saddr = nla_get_be32(a[OVS_TUNNEL_ATTR_SRC_IPV4]);
1331         mutable->daddr = nla_get_be32(a[OVS_TUNNEL_ATTR_DST_IPV4]);
1332
1333         if (a[OVS_TUNNEL_ATTR_TOS]) {
1334                 mutable->tos = nla_get_u8(a[OVS_TUNNEL_ATTR_TOS]);
1335                 if (mutable->tos != RT_TOS(mutable->tos))
1336                         return -EINVAL;
1337         }
1338
1339         if (a[OVS_TUNNEL_ATTR_TTL])
1340                 mutable->ttl = nla_get_u8(a[OVS_TUNNEL_ATTR_TTL]);
1341
1342         mutable->tunnel_type = tnl_ops->tunnel_type;
1343         if (!a[OVS_TUNNEL_ATTR_IN_KEY]) {
1344                 mutable->tunnel_type |= TNL_T_KEY_MATCH;
1345                 mutable->flags |= TNL_F_IN_KEY_MATCH;
1346         } else {
1347                 mutable->tunnel_type |= TNL_T_KEY_EXACT;
1348                 mutable->in_key = nla_get_be64(a[OVS_TUNNEL_ATTR_IN_KEY]);
1349         }
1350
1351         if (!a[OVS_TUNNEL_ATTR_OUT_KEY])
1352                 mutable->flags |= TNL_F_OUT_KEY_ACTION;
1353         else
1354                 mutable->out_key = nla_get_be64(a[OVS_TUNNEL_ATTR_OUT_KEY]);
1355
1356         mutable->tunnel_hlen = tnl_ops->hdr_len(mutable);
1357         if (mutable->tunnel_hlen < 0)
1358                 return mutable->tunnel_hlen;
1359
1360         mutable->tunnel_hlen += sizeof(struct iphdr);
1361
1362         old_vport = tnl_find_port(mutable->saddr, mutable->daddr,
1363                                   mutable->in_key, mutable->tunnel_type,
1364                                   &old_mutable);
1365
1366         if (old_vport && old_vport != cur_vport)
1367                 return -EEXIST;
1368
1369         return 0;
1370 }
1371
1372 struct vport *tnl_create(const struct vport_parms *parms,
1373                          const struct vport_ops *vport_ops,
1374                          const struct tnl_ops *tnl_ops)
1375 {
1376         struct vport *vport;
1377         struct tnl_vport *tnl_vport;
1378         struct tnl_mutable_config *mutable;
1379         int initial_frag_id;
1380         int err;
1381
1382         vport = vport_alloc(sizeof(struct tnl_vport), vport_ops, parms);
1383         if (IS_ERR(vport)) {
1384                 err = PTR_ERR(vport);
1385                 goto error;
1386         }
1387
1388         tnl_vport = tnl_vport_priv(vport);
1389
1390         strcpy(tnl_vport->name, parms->name);
1391         tnl_vport->tnl_ops = tnl_ops;
1392
1393         mutable = kzalloc(sizeof(struct tnl_mutable_config), GFP_KERNEL);
1394         if (!mutable) {
1395                 err = -ENOMEM;
1396                 goto error_free_vport;
1397         }
1398
1399         vport_gen_rand_ether_addr(mutable->eth_addr);
1400
1401         get_random_bytes(&initial_frag_id, sizeof(int));
1402         atomic_set(&tnl_vport->frag_id, initial_frag_id);
1403
1404         err = tnl_set_config(parms->options, tnl_ops, NULL, mutable);
1405         if (err)
1406                 goto error_free_mutable;
1407
1408         spin_lock_init(&tnl_vport->cache_lock);
1409
1410 #ifdef NEED_CACHE_TIMEOUT
1411         tnl_vport->cache_exp_interval = MAX_CACHE_EXP -
1412                                        (net_random() % (MAX_CACHE_EXP / 2));
1413 #endif
1414
1415         rcu_assign_pointer(tnl_vport->mutable, mutable);
1416
1417         port_table_add_port(vport);
1418         return vport;
1419
1420 error_free_mutable:
1421         kfree(mutable);
1422 error_free_vport:
1423         vport_free(vport);
1424 error:
1425         return ERR_PTR(err);
1426 }
1427
1428 int tnl_set_options(struct vport *vport, struct nlattr *options)
1429 {
1430         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1431         const struct tnl_mutable_config *old_mutable;
1432         struct tnl_mutable_config *mutable;
1433         int err;
1434
1435         mutable = kzalloc(sizeof(struct tnl_mutable_config), GFP_KERNEL);
1436         if (!mutable) {
1437                 err = -ENOMEM;
1438                 goto error;
1439         }
1440
1441         /* Copy fields whose values should be retained. */
1442         old_mutable = rtnl_dereference(tnl_vport->mutable);
1443         mutable->seq = old_mutable->seq + 1;
1444         memcpy(mutable->eth_addr, old_mutable->eth_addr, ETH_ALEN);
1445
1446         /* Parse the others configured by userspace. */
1447         err = tnl_set_config(options, tnl_vport->tnl_ops, vport, mutable);
1448         if (err)
1449                 goto error_free;
1450
1451         if (mutable_hash(mutable) != mutable_hash(old_mutable))
1452                 port_table_move_port(vport, mutable);
1453
1454         return 0;
1455
1456 error_free:
1457         kfree(mutable);
1458 error:
1459         return err;
1460 }
1461
1462 int tnl_get_options(const struct vport *vport, struct sk_buff *skb)
1463 {
1464         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1465         const struct tnl_mutable_config *mutable = rcu_dereference_rtnl(tnl_vport->mutable);
1466
1467         NLA_PUT_U32(skb, OVS_TUNNEL_ATTR_FLAGS, mutable->flags & TNL_F_PUBLIC);
1468         NLA_PUT_BE32(skb, OVS_TUNNEL_ATTR_DST_IPV4, mutable->daddr);
1469
1470         if (!(mutable->flags & TNL_F_IN_KEY_MATCH))
1471                 NLA_PUT_BE64(skb, OVS_TUNNEL_ATTR_IN_KEY, mutable->in_key);
1472         if (!(mutable->flags & TNL_F_OUT_KEY_ACTION))
1473                 NLA_PUT_BE64(skb, OVS_TUNNEL_ATTR_OUT_KEY, mutable->out_key);
1474         if (mutable->saddr)
1475                 NLA_PUT_BE32(skb, OVS_TUNNEL_ATTR_SRC_IPV4, mutable->saddr);
1476         if (mutable->tos)
1477                 NLA_PUT_U8(skb, OVS_TUNNEL_ATTR_TOS, mutable->tos);
1478         if (mutable->ttl)
1479                 NLA_PUT_U8(skb, OVS_TUNNEL_ATTR_TTL, mutable->ttl);
1480
1481         return 0;
1482
1483 nla_put_failure:
1484         return -EMSGSIZE;
1485 }
1486
1487 static void free_port_rcu(struct rcu_head *rcu)
1488 {
1489         struct tnl_vport *tnl_vport = container_of(rcu,
1490                                                    struct tnl_vport, rcu);
1491
1492         free_cache((struct tnl_cache __force *)tnl_vport->cache);
1493         kfree((struct tnl_mutable __force *)tnl_vport->mutable);
1494         vport_free(tnl_vport_to_vport(tnl_vport));
1495 }
1496
1497 void tnl_destroy(struct vport *vport)
1498 {
1499         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1500         const struct tnl_mutable_config *mutable;
1501
1502         mutable = rtnl_dereference(tnl_vport->mutable);
1503         port_table_remove_port(vport);
1504         call_rcu(&tnl_vport->rcu, free_port_rcu);
1505 }
1506
1507 int tnl_set_addr(struct vport *vport, const unsigned char *addr)
1508 {
1509         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1510         struct tnl_mutable_config *mutable;
1511
1512         mutable = kmemdup(rtnl_dereference(tnl_vport->mutable),
1513                           sizeof(struct tnl_mutable_config), GFP_KERNEL);
1514         if (!mutable)
1515                 return -ENOMEM;
1516
1517         memcpy(mutable->eth_addr, addr, ETH_ALEN);
1518         assign_config_rcu(vport, mutable);
1519
1520         return 0;
1521 }
1522
1523 const char *tnl_get_name(const struct vport *vport)
1524 {
1525         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1526         return tnl_vport->name;
1527 }
1528
1529 const unsigned char *tnl_get_addr(const struct vport *vport)
1530 {
1531         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
1532         return rcu_dereference_rtnl(tnl_vport->mutable)->eth_addr;
1533 }
1534
1535 void tnl_free_linked_skbs(struct sk_buff *skb)
1536 {
1537         while (skb) {
1538                 struct sk_buff *next = skb->next;
1539                 kfree_skb(skb);
1540                 skb = next;
1541         }
1542 }
1543
1544 int tnl_init(void)
1545 {
1546         int i;
1547
1548         port_table = kmalloc(PORT_TABLE_SIZE * sizeof(struct hlist_head *),
1549                         GFP_KERNEL);
1550         if (!port_table)
1551                 return -ENOMEM;
1552
1553         for (i = 0; i < PORT_TABLE_SIZE; i++)
1554                 INIT_HLIST_HEAD(&port_table[i]);
1555
1556         return 0;
1557 }
1558
1559 void tnl_exit(void)
1560 {
1561         int i;
1562
1563         for (i = 0; i < PORT_TABLE_SIZE; i++) {
1564                 struct tnl_vport * tnl_vport;
1565                 struct hlist_head *hash_head;
1566                 struct hlist_node *n;
1567
1568                 hash_head = &port_table[i];
1569                 hlist_for_each_entry(tnl_vport, n, hash_head, hash_node) {
1570                         BUG();
1571                         goto out;
1572                 }
1573         }
1574 out:
1575         kfree(port_table);
1576 }