datapath/tunnel.c

   1 /*
   2  * Copyright (c) 2007-2012 Nicira, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 2 of the GNU General Public
   6  * License as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  16  * 02110-1301, USA
  17  */
  18
  19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/if_arp.h>
  22 #include <linux/if_ether.h>
  23 #include <linux/ip.h>
  24 #include <linux/if_vlan.h>
  25 #include <linux/igmp.h>
  26 #include <linux/in.h>
  27 #include <linux/in_route.h>
  28 #include <linux/inetdevice.h>
  29 #include <linux/jhash.h>
  30 #include <linux/list.h>
  31 #include <linux/kernel.h>
  32 #include <linux/version.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/rculist.h>
  35
  36 #include <net/dsfield.h>
  37 #include <net/dst.h>
  38 #include <net/icmp.h>
  39 #include <net/inet_ecn.h>
  40 #include <net/ip.h>
  41 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  42 #include <net/ipv6.h>
  43 #endif
  44 #include <net/route.h>
  45 #include <net/xfrm.h>
  46
  47 #include "checksum.h"
  48 #include "compat.h"
  49 #include "datapath.h"
  50 #include "tunnel.h"
  51 #include "vlan.h"
  52 #include "vport.h"
  53 #include "vport-internal_dev.h"
  54
  55 #define PORT_TABLE_SIZE  1024
  56
  57 static struct hlist_head *port_table __read_mostly;
  58
  59 /*
  60  * These are just used as an optimization: they don't require any kind of
  61  * synchronization because we could have just as easily read the value before
  62  * the port change happened.
  63  */
  64 static unsigned int key_local_remote_ports __read_mostly;
  65 static unsigned int key_remote_ports __read_mostly;
  66 static unsigned int key_multicast_ports __read_mostly;
  67 static unsigned int local_remote_ports __read_mostly;
  68 static unsigned int remote_ports __read_mostly;
  69 static unsigned int null_ports __read_mostly;
  70 static unsigned int multicast_ports __read_mostly;
  71
  72 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
  73 #define rt_dst(rt) (rt->dst)
  74 #else
  75 #define rt_dst(rt) (rt->u.dst)
  76 #endif
  77
  78 static struct vport *tnl_vport_to_vport(const struct tnl_vport *tnl_vport)
  79 {
  80         return vport_from_priv(tnl_vport);
  81 }
  82
  83 static void free_config_rcu(struct rcu_head *rcu)
  84 {
  85         struct tnl_mutable_config *c = container_of(rcu, struct tnl_mutable_config, rcu);
  86         kfree(c);
  87 }
  88
  89 /* Frees the portion of 'mutable' that requires RTNL and thus can't happen
  90  * within an RCU callback.  Fortunately this part doesn't require waiting for
  91  * an RCU grace period.
  92  */
  93 static void free_mutable_rtnl(struct tnl_mutable_config *mutable)
  94 {
  95         ASSERT_RTNL();
  96         if (ipv4_is_multicast(mutable->key.daddr) && mutable->mlink) {
  97                 struct in_device *in_dev;
  98                 in_dev = inetdev_by_index(port_key_get_net(&mutable->key), mutable->mlink);
  99                 if (in_dev)
 100                         ip_mc_dec_group(in_dev, mutable->key.daddr);
 101         }
 102 }
 103
 104 static void assign_config_rcu(struct vport *vport,
 105                               struct tnl_mutable_config *new_config)
 106 {
 107         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 108         struct tnl_mutable_config *old_config;
 109
 110         old_config = rtnl_dereference(tnl_vport->mutable);
 111         rcu_assign_pointer(tnl_vport->mutable, new_config);
 112
 113         free_mutable_rtnl(old_config);
 114         call_rcu(&old_config->rcu, free_config_rcu);
 115 }
 116
 117 static unsigned int *find_port_pool(const struct tnl_mutable_config *mutable)
 118 {
 119         bool is_multicast = ipv4_is_multicast(mutable->key.daddr);
 120
 121         if (mutable->flags & TNL_F_IN_KEY_MATCH) {
 122                 if (mutable->key.saddr)
 123                         return &local_remote_ports;
 124                 else if (is_multicast)
 125                         return &multicast_ports;
 126                 else
 127                         return &remote_ports;
 128         } else {
 129                 if (mutable->key.saddr)
 130                         return &key_local_remote_ports;
 131                 else if (is_multicast)
 132                         return &key_multicast_ports;
 133                 else if (mutable->key.daddr)
 134                         return &key_remote_ports;
 135                 else
 136                         return &null_ports;
 137         }
 138 }
 139
 140 static u32 port_hash(const struct port_lookup_key *key)
 141 {
 142         return jhash2((u32 *)key, (PORT_KEY_LEN / sizeof(u32)), 0);
 143 }
 144
 145 static struct hlist_head *find_bucket(u32 hash)
 146 {
 147         return &port_table[(hash & (PORT_TABLE_SIZE - 1))];
 148 }
 149
 150 static void port_table_add_port(struct vport *vport)
 151 {
 152         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 153         const struct tnl_mutable_config *mutable;
 154         u32 hash;
 155
 156         mutable = rtnl_dereference(tnl_vport->mutable);
 157         hash = port_hash(&mutable->key);
 158         hlist_add_head_rcu(&tnl_vport->hash_node, find_bucket(hash));
 159
 160         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
 161 }
 162
 163 static void port_table_move_port(struct vport *vport,
 164                       struct tnl_mutable_config *new_mutable)
 165 {
 166         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 167         u32 hash;
 168
 169         hash = port_hash(&new_mutable->key);
 170         hlist_del_init_rcu(&tnl_vport->hash_node);
 171         hlist_add_head_rcu(&tnl_vport->hash_node, find_bucket(hash));
 172
 173         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
 174         assign_config_rcu(vport, new_mutable);
 175         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
 176 }
 177
 178 static void port_table_remove_port(struct vport *vport)
 179 {
 180         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 181
 182         hlist_del_init_rcu(&tnl_vport->hash_node);
 183
 184         (*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
 185 }
 186
 187 static struct vport *port_table_lookup(struct port_lookup_key *key,
 188                                        const struct tnl_mutable_config **pmutable)
 189 {
 190         struct hlist_node *n;
 191         struct hlist_head *bucket;
 192         u32 hash = port_hash(key);
 193         struct tnl_vport *tnl_vport;
 194
 195         bucket = find_bucket(hash);
 196
 197         hlist_for_each_entry_rcu(tnl_vport, n, bucket, hash_node) {
 198                 struct tnl_mutable_config *mutable;
 199
 200                 mutable = rcu_dereference_rtnl(tnl_vport->mutable);
 201                 if (!memcmp(&mutable->key, key, PORT_KEY_LEN)) {
 202                         *pmutable = mutable;
 203                         return tnl_vport_to_vport(tnl_vport);
 204                 }
 205         }
 206
 207         return NULL;
 208 }
 209
 210 struct vport *ovs_tnl_find_port(struct net *net, __be32 saddr, __be32 daddr,
 211                                 __be64 key, int tunnel_type,
 212                                 const struct tnl_mutable_config **mutable)
 213 {
 214         struct port_lookup_key lookup;
 215         struct vport *vport;
 216         bool is_multicast = ipv4_is_multicast(saddr);
 217
 218         port_key_set_net(&lookup, net);
 219         lookup.saddr = saddr;
 220         lookup.daddr = daddr;
 221
 222         /* First try for exact match on in_key. */
 223         lookup.in_key = key;
 224         lookup.tunnel_type = tunnel_type | TNL_T_KEY_EXACT;
 225         if (!is_multicast && key_local_remote_ports) {
 226                 vport = port_table_lookup(&lookup, mutable);
 227                 if (vport)
 228                         return vport;
 229         }
 230         if (key_remote_ports) {
 231                 lookup.saddr = 0;
 232                 vport = port_table_lookup(&lookup, mutable);
 233                 if (vport)
 234                         return vport;
 235
 236                 lookup.saddr = saddr;
 237         }
 238
 239         /* Then try matches that wildcard in_key. */
 240         lookup.in_key = 0;
 241         lookup.tunnel_type = tunnel_type | TNL_T_KEY_MATCH;
 242         if (!is_multicast && local_remote_ports) {
 243                 vport = port_table_lookup(&lookup, mutable);
 244                 if (vport)
 245                         return vport;
 246         }
 247         if (remote_ports) {
 248                 lookup.saddr = 0;
 249                 vport = port_table_lookup(&lookup, mutable);
 250                 if (vport)
 251                         return vport;
 252         }
 253
 254         if (is_multicast) {
 255                 lookup.saddr = 0;
 256                 lookup.daddr = saddr;
 257                 if (key_multicast_ports) {
 258                         lookup.tunnel_type = tunnel_type | TNL_T_KEY_EXACT;
 259                         lookup.in_key = key;
 260                         vport = port_table_lookup(&lookup, mutable);
 261                         if (vport)
 262                                 return vport;
 263                 }
 264                 if (multicast_ports) {
 265                         lookup.tunnel_type = tunnel_type | TNL_T_KEY_MATCH;
 266                         lookup.in_key = 0;
 267                         vport = port_table_lookup(&lookup, mutable);
 268                         if (vport)
 269                                 return vport;
 270                 }
 271         }
 272
 273         if (null_ports) {
 274                 lookup.daddr = 0;
 275                 lookup.saddr = 0;
 276                 lookup.in_key = 0;
 277                 lookup.tunnel_type = tunnel_type;
 278                 vport = port_table_lookup(&lookup, mutable);
 279                 if (vport)
 280                         return vport;
 281         }
 282         return NULL;
 283 }
 284
 285 static void ecn_decapsulate(struct sk_buff *skb)
 286 {
 287         if (unlikely(INET_ECN_is_ce(OVS_CB(skb)->tun_key->ipv4_tos))) {
 288                 __be16 protocol = skb->protocol;
 289
 290                 skb_set_network_header(skb, ETH_HLEN);
 291
 292                 if (protocol == htons(ETH_P_8021Q)) {
 293                         if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
 294                                 return;
 295
 296                         protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
 297                         skb_set_network_header(skb, VLAN_ETH_HLEN);
 298                 }
 299
 300                 if (protocol == htons(ETH_P_IP)) {
 301                         if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
 302                             + sizeof(struct iphdr))))
 303                                 return;
 304
 305                         IP_ECN_set_ce(ip_hdr(skb));
 306                 }
 307 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 308                 else if (protocol == htons(ETH_P_IPV6)) {
 309                         if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
 310                             + sizeof(struct ipv6hdr))))
 311                                 return;
 312
 313                         IP6_ECN_set_ce(ipv6_hdr(skb));
 314                 }
 315 #endif
 316         }
 317 }
 318
 319 /**
 320  *      ovs_tnl_rcv - ingress point for generic tunnel code
 321  *
 322  * @vport: port this packet was received on
 323  * @skb: received packet
 324  * @tos: ToS from encapsulating IP packet, used to copy ECN bits
 325  *
 326  * Must be called with rcu_read_lock.
 327  *
 328  * Packets received by this function are in the following state:
 329  * - skb->data points to the inner Ethernet header.
 330  * - The inner Ethernet header is in the linear data area.
 331  * - skb->csum does not include the inner Ethernet header.
 332  * - The layer pointers are undefined.
 333  */
 334 void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb)
 335 {
 336         struct ethhdr *eh;
 337
 338         skb_reset_mac_header(skb);
 339         eh = eth_hdr(skb);
 340
 341         if (likely(ntohs(eh->h_proto) >= 1536))
 342                 skb->protocol = eh->h_proto;
 343         else
 344                 skb->protocol = htons(ETH_P_802_2);
 345
 346         skb_dst_drop(skb);
 347         nf_reset(skb);
 348         skb_clear_rxhash(skb);
 349         secpath_reset(skb);
 350
 351         ecn_decapsulate(skb);
 352         vlan_set_tci(skb, 0);
 353
 354         if (unlikely(compute_ip_summed(skb, false))) {
 355                 kfree_skb(skb);
 356                 return;
 357         }
 358
 359         ovs_vport_receive(vport, skb);
 360 }
 361
 362 static struct rtable *find_route(struct net *net,
 363                 __be32 *saddr, __be32 daddr, u8 ipproto,
 364                 u8 tos, u32 skb_mark)
 365 {
 366         struct rtable *rt;
 367         /* Tunnel configuration keeps DSCP part of TOS bits, But Linux
 368          * router expect RT_TOS bits only. */
 369
 370 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)
 371         struct flowi fl = { .nl_u = { .ip4_u = {
 372                                         .daddr = daddr,
 373                                         .saddr = *saddr,
 374 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
 375                                         .fwmark = skb_mark,
 376 #endif
 377                                         .tos   = RT_TOS(tos) } },
 378 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
 379                                         .mark = skb_mark,
 380 #endif
 381                                         .proto = ipproto };
 382
 383         if (unlikely(ip_route_output_key(net, &rt, &fl)))
 384                 return ERR_PTR(-EADDRNOTAVAIL);
 385         *saddr = fl.nl_u.ip4_u.saddr;
 386         return rt;
 387 #else
 388         struct flowi4 fl = { .daddr = daddr,
 389                              .saddr = *saddr,
 390                              .flowi4_tos = RT_TOS(tos),
 391                              .flowi4_mark = skb_mark,
 392                              .flowi4_proto = ipproto };
 393
 394         rt = ip_route_output_key(net, &fl);
 395         *saddr = fl.saddr;
 396         return rt;
 397 #endif
 398 }
 399
 400 static bool need_linearize(const struct sk_buff *skb)
 401 {
 402         int i;
 403
 404         if (unlikely(skb_shinfo(skb)->frag_list))
 405                 return true;
 406
 407         /*
 408          * Generally speaking we should linearize if there are paged frags.
 409          * However, if all of the refcounts are 1 we know nobody else can
 410          * change them from underneath us and we can skip the linearization.
 411          */
 412         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
 413                 if (unlikely(page_count(skb_frag_page(&skb_shinfo(skb)->frags[i])) > 1))
 414                         return true;
 415
 416         return false;
 417 }
 418
 419 static struct sk_buff *handle_offloads(struct sk_buff *skb,
 420                                        const struct tnl_mutable_config *mutable,
 421                                        const struct rtable *rt,
 422                                        int tunnel_hlen)
 423 {
 424         int min_headroom;
 425         int err;
 426
 427         min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len
 428                         + tunnel_hlen
 429                         + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
 430
 431         if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
 432                 int head_delta = SKB_DATA_ALIGN(min_headroom -
 433                                                 skb_headroom(skb) +
 434                                                 16);
 435                 err = pskb_expand_head(skb, max_t(int, head_delta, 0),
 436                                         0, GFP_ATOMIC);
 437                 if (unlikely(err))
 438                         goto error_free;
 439         }
 440
 441         forward_ip_summed(skb, true);
 442
 443         if (skb_is_gso(skb)) {
 444                 struct sk_buff *nskb;
 445
 446                 nskb = __skb_gso_segment(skb, 0, false);
 447                 if (IS_ERR(nskb)) {
 448                         kfree_skb(skb);
 449                         err = PTR_ERR(nskb);
 450                         goto error;
 451                 }
 452
 453                 consume_skb(skb);
 454                 skb = nskb;
 455         } else if (get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
 456                 /* Pages aren't locked and could change at any time.
 457                  * If this happens after we compute the checksum, the
 458                  * checksum will be wrong.  We linearize now to avoid
 459                  * this problem.
 460                  */
 461                 if (unlikely(need_linearize(skb))) {
 462                         err = __skb_linearize(skb);
 463                         if (unlikely(err))
 464                                 goto error_free;
 465                 }
 466
 467                 err = skb_checksum_help(skb);
 468                 if (unlikely(err))
 469                         goto error_free;
 470         }
 471
 472         set_ip_summed(skb, OVS_CSUM_NONE);
 473
 474         return skb;
 475
 476 error_free:
 477         kfree_skb(skb);
 478 error:
 479         return ERR_PTR(err);
 480 }
 481
 482 static int send_frags(struct sk_buff *skb,
 483                       int tunnel_hlen)
 484 {
 485         int sent_len;
 486
 487         sent_len = 0;
 488         while (skb) {
 489                 struct sk_buff *next = skb->next;
 490                 int frag_len = skb->len - tunnel_hlen;
 491                 int err;
 492
 493                 skb->next = NULL;
 494                 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 495
 496                 err = ip_local_out(skb);
 497                 skb = next;
 498                 if (unlikely(net_xmit_eval(err)))
 499                         goto free_frags;
 500                 sent_len += frag_len;
 501         }
 502
 503         return sent_len;
 504
 505 free_frags:
 506         /*
 507          * There's no point in continuing to send fragments once one has been
 508          * dropped so just free the rest.  This may help improve the congestion
 509          * that caused the first packet to be dropped.
 510          */
 511         ovs_tnl_free_linked_skbs(skb);
 512         return sent_len;
 513 }
 514
 515 int ovs_tnl_send(struct vport *vport, struct sk_buff *skb)
 516 {
 517         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 518         const struct tnl_mutable_config *mutable = rcu_dereference(tnl_vport->mutable);
 519         enum vport_err_type err = VPORT_E_TX_ERROR;
 520         struct rtable *rt;
 521         struct ovs_key_ipv4_tunnel tun_key;
 522         int sent_len = 0;
 523         int tunnel_hlen;
 524         __be16 frag_off;
 525         __be32 daddr;
 526         __be32 saddr;
 527         u32 skb_mark;
 528         u8 ttl;
 529         u8 tos;
 530
 531         /* Validate the protocol headers before we try to use them. */
 532         if (skb->protocol == htons(ETH_P_8021Q) &&
 533             !vlan_tx_tag_present(skb)) {
 534                 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
 535                         goto error_free;
 536
 537                 skb->protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
 538                 skb_set_network_header(skb, VLAN_ETH_HLEN);
 539         }
 540
 541         if (skb->protocol == htons(ETH_P_IP)) {
 542                 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
 543                     + sizeof(struct iphdr))))
 544                         skb->protocol = 0;
 545         }
 546 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 547         else if (skb->protocol == htons(ETH_P_IPV6)) {
 548                 if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
 549                     + sizeof(struct ipv6hdr))))
 550                         skb->protocol = 0;
 551         }
 552 #endif
 553
 554         /* If OVS_CB(skb)->tun_key is NULL, point it at the local tun_key here,
 555          * and zero it out.
 556          */
 557         if (!OVS_CB(skb)->tun_key) {
 558                 memset(&tun_key, 0, sizeof(tun_key));
 559                 OVS_CB(skb)->tun_key = &tun_key;
 560         }
 561
 562         tunnel_hlen = tnl_vport->tnl_ops->hdr_len(mutable, OVS_CB(skb)->tun_key);
 563         if (unlikely(tunnel_hlen < 0)) {
 564                 err = VPORT_E_TX_DROPPED;
 565                 goto error_free;
 566         }
 567         tunnel_hlen += sizeof(struct iphdr);
 568
 569         if (OVS_CB(skb)->tun_key->ipv4_dst) {
 570                 daddr = OVS_CB(skb)->tun_key->ipv4_dst;
 571                 saddr = OVS_CB(skb)->tun_key->ipv4_src;
 572                 tos = OVS_CB(skb)->tun_key->ipv4_tos;
 573                 ttl = OVS_CB(skb)->tun_key->ipv4_ttl;
 574                 frag_off = OVS_CB(skb)->tun_key->tun_flags &
 575                                 OVS_TNL_F_DONT_FRAGMENT ?  htons(IP_DF) : 0;
 576         } else {
 577                 u8 inner_tos;
 578                 daddr = mutable->key.daddr;
 579                 saddr = mutable->key.saddr;
 580
 581                 if (unlikely(!daddr)) {
 582                         /* Trying to sent packet from Null-port without
 583                          * tunnel info? Drop this packet. */
 584                         err = VPORT_E_TX_DROPPED;
 585                         goto error_free;
 586                 }
 587
 588                 /* ToS */
 589                 if (skb->protocol == htons(ETH_P_IP))
 590                         inner_tos = ip_hdr(skb)->tos;
 591 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 592                 else if (skb->protocol == htons(ETH_P_IPV6))
 593                         inner_tos = ipv6_get_dsfield(ipv6_hdr(skb));
 594 #endif
 595                 else
 596                         inner_tos = 0;
 597
 598                 if (mutable->flags & TNL_F_TOS_INHERIT)
 599                         tos = inner_tos;
 600                 else
 601                         tos = mutable->tos;
 602
 603                 tos = INET_ECN_encapsulate(tos, inner_tos);
 604
 605                 /* TTL */
 606                 ttl = mutable->ttl;
 607                 if (mutable->flags & TNL_F_TTL_INHERIT) {
 608                         if (skb->protocol == htons(ETH_P_IP))
 609                                 ttl = ip_hdr(skb)->ttl;
 610 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 611                         else if (skb->protocol == htons(ETH_P_IPV6))
 612                                 ttl = ipv6_hdr(skb)->hop_limit;
 613 #endif
 614                 }
 615
 616                 frag_off = mutable->flags & TNL_F_DF_DEFAULT ? htons(IP_DF) : 0;
 617         }
 618
 619         /* Route lookup */
 620         skb_mark = skb_get_mark(skb);
 621         rt = find_route(port_key_get_net(&mutable->key), &saddr, daddr,
 622                           tnl_vport->tnl_ops->ipproto, tos, skb_mark);
 623         if (IS_ERR(rt))
 624                 goto error_free;
 625
 626         /* Reset SKB */
 627         nf_reset(skb);
 628         secpath_reset(skb);
 629         skb_dst_drop(skb);
 630         skb_clear_rxhash(skb);
 631
 632         /* Offloading */
 633         skb = handle_offloads(skb, mutable, rt, tunnel_hlen);
 634         if (IS_ERR(skb)) {
 635                 skb = NULL;
 636                 goto err_free_rt;
 637         }
 638
 639         /* TTL Fixup. */
 640         if (!OVS_CB(skb)->tun_key->ipv4_dst) {
 641                 if (!(mutable->flags & TNL_F_TTL_INHERIT)) {
 642                         if (!ttl)
 643                                 ttl = ip4_dst_hoplimit(&rt_dst(rt));
 644                 }
 645         }
 646
 647         while (skb) {
 648                 struct iphdr *iph;
 649                 struct sk_buff *next_skb = skb->next;
 650                 skb->next = NULL;
 651
 652                 if (unlikely(vlan_deaccel_tag(skb)))
 653                         goto next;
 654
 655                 skb_push(skb, tunnel_hlen);
 656                 skb_reset_network_header(skb);
 657                 skb_set_transport_header(skb, sizeof(struct iphdr));
 658
 659                 if (next_skb)
 660                         skb_dst_set(skb, dst_clone(&rt_dst(rt)));
 661                 else
 662                         skb_dst_set(skb, &rt_dst(rt));
 663
 664                 /* Push IP header. */
 665                 iph = ip_hdr(skb);
 666                 iph->version    = 4;
 667                 iph->ihl        = sizeof(struct iphdr) >> 2;
 668                 iph->protocol   = tnl_vport->tnl_ops->ipproto;
 669                 iph->daddr      = daddr;
 670                 iph->saddr      = saddr;
 671                 iph->tos        = tos;
 672                 iph->ttl        = ttl;
 673                 iph->frag_off   = frag_off;
 674                 ip_select_ident(iph, &rt_dst(rt), NULL);
 675
 676                 /* Push Tunnel header. */
 677                 skb = tnl_vport->tnl_ops->build_header(vport, mutable,
 678                                                         &rt_dst(rt), skb, tunnel_hlen);
 679                 if (unlikely(!skb))
 680                         goto next;
 681
 682                 sent_len += send_frags(skb, tunnel_hlen);
 683
 684 next:
 685                 skb = next_skb;
 686         }
 687
 688         if (unlikely(sent_len == 0))
 689                 ovs_vport_record_error(vport, VPORT_E_TX_DROPPED);
 690
 691         return sent_len;
 692
 693 err_free_rt:
 694         ip_rt_put(rt);
 695 error_free:
 696         ovs_tnl_free_linked_skbs(skb);
 697         ovs_vport_record_error(vport, err);
 698         return sent_len;
 699 }
 700
 701 static const struct nla_policy tnl_policy[OVS_TUNNEL_ATTR_MAX + 1] = {
 702         [OVS_TUNNEL_ATTR_FLAGS]    = { .type = NLA_U32 },
 703         [OVS_TUNNEL_ATTR_DST_IPV4] = { .type = NLA_U32 },
 704         [OVS_TUNNEL_ATTR_SRC_IPV4] = { .type = NLA_U32 },
 705         [OVS_TUNNEL_ATTR_OUT_KEY]  = { .type = NLA_U64 },
 706         [OVS_TUNNEL_ATTR_IN_KEY]   = { .type = NLA_U64 },
 707         [OVS_TUNNEL_ATTR_TOS]      = { .type = NLA_U8 },
 708         [OVS_TUNNEL_ATTR_TTL]      = { .type = NLA_U8 },
 709         [OVS_TUNNEL_ATTR_DST_PORT] = { .type = NLA_U16 },
 710 };
 711
 712 /* Sets OVS_TUNNEL_ATTR_* fields in 'mutable', which must initially be
 713  * zeroed. */
 714 static int tnl_set_config(struct net *net, struct nlattr *options,
 715                           const struct tnl_ops *tnl_ops,
 716                           const struct vport *cur_vport,
 717                           struct tnl_mutable_config *mutable)
 718 {
 719         const struct vport *old_vport;
 720         const struct tnl_mutable_config *old_mutable;
 721         struct nlattr *a[OVS_TUNNEL_ATTR_MAX + 1];
 722         int err;
 723
 724         port_key_set_net(&mutable->key, net);
 725         mutable->key.tunnel_type = tnl_ops->tunnel_type;
 726         if (!options)
 727                 goto out;
 728
 729         err = nla_parse_nested(a, OVS_TUNNEL_ATTR_MAX, options, tnl_policy);
 730         if (err)
 731                 return err;
 732
 733         /* Process attributes possibly useful for null_ports first */
 734         if (a[OVS_TUNNEL_ATTR_DST_PORT])
 735                 mutable->dst_port =
 736                         htons(nla_get_u16(a[OVS_TUNNEL_ATTR_DST_PORT]));
 737
 738         if (a[OVS_TUNNEL_ATTR_DST_IPV4])
 739                 mutable->key.daddr = nla_get_be32(a[OVS_TUNNEL_ATTR_DST_IPV4]);
 740
 741         /* Skip the rest if configuring a null_port */
 742         if (!mutable->key.daddr)
 743                 goto out;
 744
 745         if (a[OVS_TUNNEL_ATTR_FLAGS])
 746                 mutable->flags = nla_get_u32(a[OVS_TUNNEL_ATTR_FLAGS])
 747                         & TNL_F_PUBLIC;
 748
 749         if (a[OVS_TUNNEL_ATTR_SRC_IPV4]) {
 750                 if (ipv4_is_multicast(mutable->key.daddr))
 751                         return -EINVAL;
 752                 mutable->key.saddr = nla_get_be32(a[OVS_TUNNEL_ATTR_SRC_IPV4]);
 753         }
 754
 755         if (a[OVS_TUNNEL_ATTR_TOS]) {
 756                 mutable->tos = nla_get_u8(a[OVS_TUNNEL_ATTR_TOS]);
 757                 /* Reject ToS config with ECN bits set. */
 758                 if (mutable->tos & INET_ECN_MASK)
 759                         return -EINVAL;
 760         }
 761
 762         if (a[OVS_TUNNEL_ATTR_TTL])
 763                 mutable->ttl = nla_get_u8(a[OVS_TUNNEL_ATTR_TTL]);
 764
 765         if (!a[OVS_TUNNEL_ATTR_IN_KEY]) {
 766                 mutable->key.tunnel_type |= TNL_T_KEY_MATCH;
 767                 mutable->flags |= TNL_F_IN_KEY_MATCH;
 768         } else {
 769                 mutable->key.tunnel_type |= TNL_T_KEY_EXACT;
 770                 mutable->key.in_key = nla_get_be64(a[OVS_TUNNEL_ATTR_IN_KEY]);
 771         }
 772
 773         if (!a[OVS_TUNNEL_ATTR_OUT_KEY])
 774                 mutable->flags |= TNL_F_OUT_KEY_ACTION;
 775         else
 776                 mutable->out_key = nla_get_be64(a[OVS_TUNNEL_ATTR_OUT_KEY]);
 777
 778         mutable->mlink = 0;
 779         if (ipv4_is_multicast(mutable->key.daddr)) {
 780                 struct net_device *dev;
 781                 struct rtable *rt;
 782                 __be32 saddr = mutable->key.saddr;
 783
 784                 rt = find_route(port_key_get_net(&mutable->key),
 785                              &saddr, mutable->key.daddr,
 786                              tnl_ops->ipproto, mutable->tos, 0);
 787                 if (IS_ERR(rt))
 788                         return -EADDRNOTAVAIL;
 789                 dev = rt_dst(rt).dev;
 790                 ip_rt_put(rt);
 791                 if (__in_dev_get_rtnl(dev) == NULL)
 792                         return -EADDRNOTAVAIL;
 793                 mutable->mlink = dev->ifindex;
 794                 ip_mc_inc_group(__in_dev_get_rtnl(dev), mutable->key.daddr);
 795         }
 796
 797 out:
 798         old_vport = port_table_lookup(&mutable->key, &old_mutable);
 799         if (old_vport && old_vport != cur_vport)
 800                 return -EEXIST;
 801
 802         return 0;
 803 }
 804
 805 struct vport *ovs_tnl_create(const struct vport_parms *parms,
 806                              const struct vport_ops *vport_ops,
 807                              const struct tnl_ops *tnl_ops)
 808 {
 809         struct vport *vport;
 810         struct tnl_vport *tnl_vport;
 811         struct tnl_mutable_config *mutable;
 812         int err;
 813
 814         vport = ovs_vport_alloc(sizeof(struct tnl_vport), vport_ops, parms);
 815         if (IS_ERR(vport)) {
 816                 err = PTR_ERR(vport);
 817                 goto error;
 818         }
 819
 820         tnl_vport = tnl_vport_priv(vport);
 821
 822         strcpy(tnl_vport->name, parms->name);
 823         tnl_vport->tnl_ops = tnl_ops;
 824
 825         mutable = kzalloc(sizeof(struct tnl_mutable_config), GFP_KERNEL);
 826         if (!mutable) {
 827                 err = -ENOMEM;
 828                 goto error_free_vport;
 829         }
 830
 831         err = tnl_set_config(ovs_dp_get_net(parms->dp), parms->options, tnl_ops,
 832                              NULL, mutable);
 833         if (err)
 834                 goto error_free_mutable;
 835
 836         rcu_assign_pointer(tnl_vport->mutable, mutable);
 837
 838         port_table_add_port(vport);
 839         return vport;
 840
 841 error_free_mutable:
 842         free_mutable_rtnl(mutable);
 843         kfree(mutable);
 844 error_free_vport:
 845         ovs_vport_free(vport);
 846 error:
 847         return ERR_PTR(err);
 848 }
 849
 850 int ovs_tnl_set_options(struct vport *vport, struct nlattr *options)
 851 {
 852         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 853         const struct tnl_mutable_config *old_mutable;
 854         struct tnl_mutable_config *mutable;
 855         int err;
 856
 857         old_mutable = rtnl_dereference(tnl_vport->mutable);
 858         if (!old_mutable->key.daddr)
 859                 return -EINVAL;
 860
 861         mutable = kzalloc(sizeof(struct tnl_mutable_config), GFP_KERNEL);
 862         if (!mutable) {
 863                 err = -ENOMEM;
 864                 goto error;
 865         }
 866
 867         /* Parse the others configured by userspace. */
 868         err = tnl_set_config(ovs_dp_get_net(vport->dp), options, tnl_vport->tnl_ops,
 869                              vport, mutable);
 870         if (err)
 871                 goto error_free;
 872
 873         if (port_hash(&mutable->key) != port_hash(&old_mutable->key))
 874                 port_table_move_port(vport, mutable);
 875         else
 876                 assign_config_rcu(vport, mutable);
 877
 878         return 0;
 879
 880 error_free:
 881         free_mutable_rtnl(mutable);
 882         kfree(mutable);
 883 error:
 884         return err;
 885 }
 886
 887 int ovs_tnl_get_options(const struct vport *vport, struct sk_buff *skb)
 888 {
 889         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 890         const struct tnl_mutable_config *mutable = rcu_dereference_rtnl(tnl_vport->mutable);
 891
 892         if (mutable->dst_port && nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT,
 893                                              ntohs(mutable->dst_port)))
 894                 goto nla_put_failure;
 895
 896         /* Skip the rest for null_ports */
 897         if (!mutable->key.daddr)
 898                 return 0;
 899
 900         if (nla_put_be32(skb, OVS_TUNNEL_ATTR_DST_IPV4, mutable->key.daddr))
 901                 goto nla_put_failure;
 902         if (nla_put_u32(skb, OVS_TUNNEL_ATTR_FLAGS,
 903                         mutable->flags & TNL_F_PUBLIC))
 904                 goto nla_put_failure;
 905         if (!(mutable->flags & TNL_F_IN_KEY_MATCH) &&
 906             nla_put_be64(skb, OVS_TUNNEL_ATTR_IN_KEY, mutable->key.in_key))
 907                 goto nla_put_failure;
 908         if (!(mutable->flags & TNL_F_OUT_KEY_ACTION) &&
 909             nla_put_be64(skb, OVS_TUNNEL_ATTR_OUT_KEY, mutable->out_key))
 910                 goto nla_put_failure;
 911         if (mutable->key.saddr &&
 912             nla_put_be32(skb, OVS_TUNNEL_ATTR_SRC_IPV4, mutable->key.saddr))
 913                 goto nla_put_failure;
 914         if (mutable->tos && nla_put_u8(skb, OVS_TUNNEL_ATTR_TOS, mutable->tos))
 915                 goto nla_put_failure;
 916         if (mutable->ttl && nla_put_u8(skb, OVS_TUNNEL_ATTR_TTL, mutable->ttl))
 917                 goto nla_put_failure;
 918
 919         return 0;
 920
 921 nla_put_failure:
 922         return -EMSGSIZE;
 923 }
 924
 925 static void free_port_rcu(struct rcu_head *rcu)
 926 {
 927         struct tnl_vport *tnl_vport = container_of(rcu,
 928                                                    struct tnl_vport, rcu);
 929
 930         kfree((struct tnl_mutable __force *)tnl_vport->mutable);
 931         ovs_vport_free(tnl_vport_to_vport(tnl_vport));
 932 }
 933
 934 void ovs_tnl_destroy(struct vport *vport)
 935 {
 936         struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 937         struct tnl_mutable_config *mutable;
 938
 939         mutable = rtnl_dereference(tnl_vport->mutable);
 940         port_table_remove_port(vport);
 941         free_mutable_rtnl(mutable);
 942         call_rcu(&tnl_vport->rcu, free_port_rcu);
 943 }
 944
 945 const char *ovs_tnl_get_name(const struct vport *vport)
 946 {
 947         const struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
 948         return tnl_vport->name;
 949 }
 950
 951 void ovs_tnl_free_linked_skbs(struct sk_buff *skb)
 952 {
 953         while (skb) {
 954                 struct sk_buff *next = skb->next;
 955                 kfree_skb(skb);
 956                 skb = next;
 957         }
 958 }
 959
 960 int ovs_tnl_init(void)
 961 {
 962         int i;
 963
 964         port_table = kmalloc(PORT_TABLE_SIZE * sizeof(struct hlist_head *),
 965                              GFP_KERNEL);
 966         if (!port_table)
 967                 return -ENOMEM;
 968
 969         for (i = 0; i < PORT_TABLE_SIZE; i++)
 970                 INIT_HLIST_HEAD(&port_table[i]);
 971
 972         return 0;
 973 }
 974
 975 void ovs_tnl_exit(void)
 976 {
 977         kfree(port_table);
 978 }