net/openvswitch/vport.c

   1 /*
   2  * Copyright (c) 2007-2014 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 #include <linux/etherdevice.h>
  20 #include <linux/if.h>
  21 #include <linux/if_vlan.h>
  22 #include <linux/jhash.h>
  23 #include <linux/kernel.h>
  24 #include <linux/list.h>
  25 #include <linux/mutex.h>
  26 #include <linux/percpu.h>
  27 #include <linux/rcupdate.h>
  28 #include <linux/rtnetlink.h>
  29 #include <linux/compat.h>
  30 #include <net/net_namespace.h>
  31 #include <linux/module.h>
  32
  33 #include "datapath.h"
  34 #include "vport.h"
  35 #include "vport-internal_dev.h"
  36
  37 static void ovs_vport_record_error(struct vport *,
  38                                    enum vport_err_type err_type);
  39
  40 static LIST_HEAD(vport_ops_list);
  41
  42 /* Protected by RCU read lock for reading, ovs_mutex for writing. */
  43 static struct hlist_head *dev_table;
  44 #define VPORT_HASH_BUCKETS 1024
  45
  46 /**
  47  *      ovs_vport_init - initialize vport subsystem
  48  *
  49  * Called at module load time to initialize the vport subsystem.
  50  */
  51 int ovs_vport_init(void)
  52 {
  53         dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
  54                             GFP_KERNEL);
  55         if (!dev_table)
  56                 return -ENOMEM;
  57
  58         return 0;
  59 }
  60
  61 /**
  62  *      ovs_vport_exit - shutdown vport subsystem
  63  *
  64  * Called at module exit time to shutdown the vport subsystem.
  65  */
  66 void ovs_vport_exit(void)
  67 {
  68         kfree(dev_table);
  69 }
  70
  71 static struct hlist_head *hash_bucket(const struct net *net, const char *name)
  72 {
  73         unsigned int hash = jhash(name, strlen(name), (unsigned long) net);
  74         return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
  75 }
  76
  77 int ovs_vport_ops_register(struct vport_ops *ops)
  78 {
  79         int err = -EEXIST;
  80         struct vport_ops *o;
  81
  82         ovs_lock();
  83         list_for_each_entry(o, &vport_ops_list, list)
  84                 if (ops->type == o->type)
  85                         goto errout;
  86
  87         list_add_tail(&ops->list, &vport_ops_list);
  88         err = 0;
  89 errout:
  90         ovs_unlock();
  91         return err;
  92 }
  93 EXPORT_SYMBOL_GPL(ovs_vport_ops_register);
  94
  95 void ovs_vport_ops_unregister(struct vport_ops *ops)
  96 {
  97         ovs_lock();
  98         list_del(&ops->list);
  99         ovs_unlock();
 100 }
 101 EXPORT_SYMBOL_GPL(ovs_vport_ops_unregister);
 102
 103 /**
 104  *      ovs_vport_locate - find a port that has already been created
 105  *
 106  * @name: name of port to find
 107  *
 108  * Must be called with ovs or RCU read lock.
 109  */
 110 struct vport *ovs_vport_locate(const struct net *net, const char *name)
 111 {
 112         struct hlist_head *bucket = hash_bucket(net, name);
 113         struct vport *vport;
 114
 115         hlist_for_each_entry_rcu(vport, bucket, hash_node)
 116                 if (!strcmp(name, vport->ops->get_name(vport)) &&
 117                     net_eq(ovs_dp_get_net(vport->dp), net))
 118                         return vport;
 119
 120         return NULL;
 121 }
 122
 123 /**
 124  *      ovs_vport_alloc - allocate and initialize new vport
 125  *
 126  * @priv_size: Size of private data area to allocate.
 127  * @ops: vport device ops
 128  *
 129  * Allocate and initialize a new vport defined by @ops.  The vport will contain
 130  * a private data area of size @priv_size that can be accessed using
 131  * vport_priv().  vports that are no longer needed should be released with
 132  * vport_free().
 133  */
 134 struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
 135                           const struct vport_parms *parms)
 136 {
 137         struct vport *vport;
 138         size_t alloc_size;
 139
 140         alloc_size = sizeof(struct vport);
 141         if (priv_size) {
 142                 alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
 143                 alloc_size += priv_size;
 144         }
 145
 146         vport = kzalloc(alloc_size, GFP_KERNEL);
 147         if (!vport)
 148                 return ERR_PTR(-ENOMEM);
 149
 150         vport->dp = parms->dp;
 151         vport->port_no = parms->port_no;
 152         vport->ops = ops;
 153         INIT_HLIST_NODE(&vport->dp_hash_node);
 154
 155         if (ovs_vport_set_upcall_portids(vport, parms->upcall_portids)) {
 156                 kfree(vport);
 157                 return ERR_PTR(-EINVAL);
 158         }
 159
 160         vport->percpu_stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 161         if (!vport->percpu_stats) {
 162                 kfree(vport);
 163                 return ERR_PTR(-ENOMEM);
 164         }
 165
 166         return vport;
 167 }
 168 EXPORT_SYMBOL_GPL(ovs_vport_alloc);
 169
 170 /**
 171  *      ovs_vport_free - uninitialize and free vport
 172  *
 173  * @vport: vport to free
 174  *
 175  * Frees a vport allocated with vport_alloc() when it is no longer needed.
 176  *
 177  * The caller must ensure that an RCU grace period has passed since the last
 178  * time @vport was in a datapath.
 179  */
 180 void ovs_vport_free(struct vport *vport)
 181 {
 182         /* vport is freed from RCU callback or error path, Therefore
 183          * it is safe to use raw dereference.
 184          */
 185         kfree(rcu_dereference_raw(vport->upcall_portids));
 186         free_percpu(vport->percpu_stats);
 187         kfree(vport);
 188 }
 189 EXPORT_SYMBOL_GPL(ovs_vport_free);
 190
 191 static struct vport_ops *ovs_vport_lookup(const struct vport_parms *parms)
 192 {
 193         struct vport_ops *ops;
 194
 195         list_for_each_entry(ops, &vport_ops_list, list)
 196                 if (ops->type == parms->type)
 197                         return ops;
 198
 199         return NULL;
 200 }
 201
 202 /**
 203  *      ovs_vport_add - add vport device (for kernel callers)
 204  *
 205  * @parms: Information about new vport.
 206  *
 207  * Creates a new vport with the specified configuration (which is dependent on
 208  * device type).  ovs_mutex must be held.
 209  */
 210 struct vport *ovs_vport_add(const struct vport_parms *parms)
 211 {
 212         struct vport_ops *ops;
 213         struct vport *vport;
 214
 215         ops = ovs_vport_lookup(parms);
 216         if (ops) {
 217                 struct hlist_head *bucket;
 218
 219                 if (!try_module_get(ops->owner))
 220                         return ERR_PTR(-EAFNOSUPPORT);
 221
 222                 vport = ops->create(parms);
 223                 if (IS_ERR(vport)) {
 224                         module_put(ops->owner);
 225                         return vport;
 226                 }
 227
 228                 bucket = hash_bucket(ovs_dp_get_net(vport->dp),
 229                                      vport->ops->get_name(vport));
 230                 hlist_add_head_rcu(&vport->hash_node, bucket);
 231                 return vport;
 232         }
 233
 234         /* Unlock to attempt module load and return -EAGAIN if load
 235          * was successful as we need to restart the port addition
 236          * workflow.
 237          */
 238         ovs_unlock();
 239         request_module("vport-type-%d", parms->type);
 240         ovs_lock();
 241
 242         if (!ovs_vport_lookup(parms))
 243                 return ERR_PTR(-EAFNOSUPPORT);
 244         else
 245                 return ERR_PTR(-EAGAIN);
 246 }
 247
 248 /**
 249  *      ovs_vport_set_options - modify existing vport device (for kernel callers)
 250  *
 251  * @vport: vport to modify.
 252  * @options: New configuration.
 253  *
 254  * Modifies an existing device with the specified configuration (which is
 255  * dependent on device type).  ovs_mutex must be held.
 256  */
 257 int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
 258 {
 259         if (!vport->ops->set_options)
 260                 return -EOPNOTSUPP;
 261         return vport->ops->set_options(vport, options);
 262 }
 263
 264 /**
 265  *      ovs_vport_del - delete existing vport device
 266  *
 267  * @vport: vport to delete.
 268  *
 269  * Detaches @vport from its datapath and destroys it.  It is possible to fail
 270  * for reasons such as lack of memory.  ovs_mutex must be held.
 271  */
 272 void ovs_vport_del(struct vport *vport)
 273 {
 274         ASSERT_OVSL();
 275
 276         hlist_del_rcu(&vport->hash_node);
 277         module_put(vport->ops->owner);
 278         vport->ops->destroy(vport);
 279 }
 280
 281 /**
 282  *      ovs_vport_get_stats - retrieve device stats
 283  *
 284  * @vport: vport from which to retrieve the stats
 285  * @stats: location to store stats
 286  *
 287  * Retrieves transmit, receive, and error stats for the given device.
 288  *
 289  * Must be called with ovs_mutex or rcu_read_lock.
 290  */
 291 void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
 292 {
 293         int i;
 294
 295         memset(stats, 0, sizeof(*stats));
 296
 297         /* We potentially have 2 sources of stats that need to be combined:
 298          * those we have collected (split into err_stats and percpu_stats) from
 299          * set_stats() and device error stats from netdev->get_stats() (for
 300          * errors that happen  downstream and therefore aren't reported through
 301          * our vport_record_error() function).
 302          * Stats from first source are reported by ovs (OVS_VPORT_ATTR_STATS).
 303          * netdev-stats can be directly read over netlink-ioctl.
 304          */
 305
 306         stats->rx_errors  = atomic_long_read(&vport->err_stats.rx_errors);
 307         stats->tx_errors  = atomic_long_read(&vport->err_stats.tx_errors);
 308         stats->tx_dropped = atomic_long_read(&vport->err_stats.tx_dropped);
 309         stats->rx_dropped = atomic_long_read(&vport->err_stats.rx_dropped);
 310
 311         for_each_possible_cpu(i) {
 312                 const struct pcpu_sw_netstats *percpu_stats;
 313                 struct pcpu_sw_netstats local_stats;
 314                 unsigned int start;
 315
 316                 percpu_stats = per_cpu_ptr(vport->percpu_stats, i);
 317
 318                 do {
 319                         start = u64_stats_fetch_begin_irq(&percpu_stats->syncp);
 320                         local_stats = *percpu_stats;
 321                 } while (u64_stats_fetch_retry_irq(&percpu_stats->syncp, start));
 322
 323                 stats->rx_bytes         += local_stats.rx_bytes;
 324                 stats->rx_packets       += local_stats.rx_packets;
 325                 stats->tx_bytes         += local_stats.tx_bytes;
 326                 stats->tx_packets       += local_stats.tx_packets;
 327         }
 328 }
 329
 330 /**
 331  *      ovs_vport_get_options - retrieve device options
 332  *
 333  * @vport: vport from which to retrieve the options.
 334  * @skb: sk_buff where options should be appended.
 335  *
 336  * Retrieves the configuration of the given device, appending an
 337  * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
 338  * vport-specific attributes to @skb.
 339  *
 340  * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
 341  * negative error code if a real error occurred.  If an error occurs, @skb is
 342  * left unmodified.
 343  *
 344  * Must be called with ovs_mutex or rcu_read_lock.
 345  */
 346 int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
 347 {
 348         struct nlattr *nla;
 349         int err;
 350
 351         if (!vport->ops->get_options)
 352                 return 0;
 353
 354         nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
 355         if (!nla)
 356                 return -EMSGSIZE;
 357
 358         err = vport->ops->get_options(vport, skb);
 359         if (err) {
 360                 nla_nest_cancel(skb, nla);
 361                 return err;
 362         }
 363
 364         nla_nest_end(skb, nla);
 365         return 0;
 366 }
 367
 368 /**
 369  *      ovs_vport_set_upcall_portids - set upcall portids of @vport.
 370  *
 371  * @vport: vport to modify.
 372  * @ids: new configuration, an array of port ids.
 373  *
 374  * Sets the vport's upcall_portids to @ids.
 375  *
 376  * Returns 0 if successful, -EINVAL if @ids is zero length or cannot be parsed
 377  * as an array of U32.
 378  *
 379  * Must be called with ovs_mutex.
 380  */
 381 int ovs_vport_set_upcall_portids(struct vport *vport, const struct nlattr *ids)
 382 {
 383         struct vport_portids *old, *vport_portids;
 384
 385         if (!nla_len(ids) || nla_len(ids) % sizeof(u32))
 386                 return -EINVAL;
 387
 388         old = ovsl_dereference(vport->upcall_portids);
 389
 390         vport_portids = kmalloc(sizeof(*vport_portids) + nla_len(ids),
 391                                 GFP_KERNEL);
 392         if (!vport_portids)
 393                 return -ENOMEM;
 394
 395         vport_portids->n_ids = nla_len(ids) / sizeof(u32);
 396         vport_portids->rn_ids = reciprocal_value(vport_portids->n_ids);
 397         nla_memcpy(vport_portids->ids, ids, nla_len(ids));
 398
 399         rcu_assign_pointer(vport->upcall_portids, vport_portids);
 400
 401         if (old)
 402                 kfree_rcu(old, rcu);
 403         return 0;
 404 }
 405
 406 /**
 407  *      ovs_vport_get_upcall_portids - get the upcall_portids of @vport.
 408  *
 409  * @vport: vport from which to retrieve the portids.
 410  * @skb: sk_buff where portids should be appended.
 411  *
 412  * Retrieves the configuration of the given vport, appending the
 413  * %OVS_VPORT_ATTR_UPCALL_PID attribute which is the array of upcall
 414  * portids to @skb.
 415  *
 416  * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room.
 417  * If an error occurs, @skb is left unmodified.  Must be called with
 418  * ovs_mutex or rcu_read_lock.
 419  */
 420 int ovs_vport_get_upcall_portids(const struct vport *vport,
 421                                  struct sk_buff *skb)
 422 {
 423         struct vport_portids *ids;
 424
 425         ids = rcu_dereference_ovsl(vport->upcall_portids);
 426
 427         if (vport->dp->user_features & OVS_DP_F_VPORT_PIDS)
 428                 return nla_put(skb, OVS_VPORT_ATTR_UPCALL_PID,
 429                                ids->n_ids * sizeof(u32), (void *)ids->ids);
 430         else
 431                 return nla_put_u32(skb, OVS_VPORT_ATTR_UPCALL_PID, ids->ids[0]);
 432 }
 433
 434 /**
 435  *      ovs_vport_find_upcall_portid - find the upcall portid to send upcall.
 436  *
 437  * @vport: vport from which the missed packet is received.
 438  * @skb: skb that the missed packet was received.
 439  *
 440  * Uses the skb_get_hash() to select the upcall portid to send the
 441  * upcall.
 442  *
 443  * Returns the portid of the target socket.  Must be called with rcu_read_lock.
 444  */
 445 u32 ovs_vport_find_upcall_portid(const struct vport *vport, struct sk_buff *skb)
 446 {
 447         struct vport_portids *ids;
 448         u32 ids_index;
 449         u32 hash;
 450
 451         ids = rcu_dereference(vport->upcall_portids);
 452
 453         if (ids->n_ids == 1 && ids->ids[0] == 0)
 454                 return 0;
 455
 456         hash = skb_get_hash(skb);
 457         ids_index = hash - ids->n_ids * reciprocal_divide(hash, ids->rn_ids);
 458         return ids->ids[ids_index];
 459 }
 460
 461 /**
 462  *      ovs_vport_receive - pass up received packet to the datapath for processing
 463  *
 464  * @vport: vport that received the packet
 465  * @skb: skb that was received
 466  * @tun_key: tunnel (if any) that carried packet
 467  *
 468  * Must be called with rcu_read_lock.  The packet cannot be shared and
 469  * skb->data should point to the Ethernet header.
 470  */
 471 void ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
 472                        const struct ovs_tunnel_info *tun_info)
 473 {
 474         struct pcpu_sw_netstats *stats;
 475         struct sw_flow_key key;
 476         int error;
 477
 478         stats = this_cpu_ptr(vport->percpu_stats);
 479         u64_stats_update_begin(&stats->syncp);
 480         stats->rx_packets++;
 481         stats->rx_bytes += skb->len +
 482                            (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
 483         u64_stats_update_end(&stats->syncp);
 484
 485         OVS_CB(skb)->input_vport = vport;
 486         OVS_CB(skb)->egress_tun_info = NULL;
 487         /* Extract flow from 'skb' into 'key'. */
 488         error = ovs_flow_key_extract(tun_info, skb, &key);
 489         if (unlikely(error)) {
 490                 kfree_skb(skb);
 491                 return;
 492         }
 493         ovs_dp_process_packet(skb, &key);
 494 }
 495 EXPORT_SYMBOL_GPL(ovs_vport_receive);
 496
 497 /**
 498  *      ovs_vport_send - send a packet on a device
 499  *
 500  * @vport: vport on which to send the packet
 501  * @skb: skb to send
 502  *
 503  * Sends the given packet and returns the length of data sent.  Either ovs
 504  * lock or rcu_read_lock must be held.
 505  */
 506 int ovs_vport_send(struct vport *vport, struct sk_buff *skb)
 507 {
 508         int sent = vport->ops->send(vport, skb);
 509
 510         if (likely(sent > 0)) {
 511                 struct pcpu_sw_netstats *stats;
 512
 513                 stats = this_cpu_ptr(vport->percpu_stats);
 514
 515                 u64_stats_update_begin(&stats->syncp);
 516                 stats->tx_packets++;
 517                 stats->tx_bytes += sent;
 518                 u64_stats_update_end(&stats->syncp);
 519         } else if (sent < 0) {
 520                 ovs_vport_record_error(vport, VPORT_E_TX_ERROR);
 521         } else {
 522                 ovs_vport_record_error(vport, VPORT_E_TX_DROPPED);
 523         }
 524         return sent;
 525 }
 526
 527 /**
 528  *      ovs_vport_record_error - indicate device error to generic stats layer
 529  *
 530  * @vport: vport that encountered the error
 531  * @err_type: one of enum vport_err_type types to indicate the error type
 532  *
 533  * If using the vport generic stats layer indicate that an error of the given
 534  * type has occurred.
 535  */
 536 static void ovs_vport_record_error(struct vport *vport,
 537                                    enum vport_err_type err_type)
 538 {
 539         switch (err_type) {
 540         case VPORT_E_RX_DROPPED:
 541                 atomic_long_inc(&vport->err_stats.rx_dropped);
 542                 break;
 543
 544         case VPORT_E_RX_ERROR:
 545                 atomic_long_inc(&vport->err_stats.rx_errors);
 546                 break;
 547
 548         case VPORT_E_TX_DROPPED:
 549                 atomic_long_inc(&vport->err_stats.tx_dropped);
 550                 break;
 551
 552         case VPORT_E_TX_ERROR:
 553                 atomic_long_inc(&vport->err_stats.tx_errors);
 554                 break;
 555         }
 556
 557 }
 558
 559 static void free_vport_rcu(struct rcu_head *rcu)
 560 {
 561         struct vport *vport = container_of(rcu, struct vport, rcu);
 562
 563         ovs_vport_free(vport);
 564 }
 565
 566 void ovs_vport_deferred_free(struct vport *vport)
 567 {
 568         if (!vport)
 569                 return;
 570
 571         call_rcu(&vport->rcu, free_vport_rcu);
 572 }
 573 EXPORT_SYMBOL_GPL(ovs_vport_deferred_free);
 574
 575 int ovs_tunnel_get_egress_info(struct ovs_tunnel_info *egress_tun_info,
 576                                struct net *net,
 577                                const struct ovs_tunnel_info *tun_info,
 578                                u8 ipproto,
 579                                u32 skb_mark,
 580                                __be16 tp_src,
 581                                __be16 tp_dst)
 582 {
 583         const struct ovs_key_ipv4_tunnel *tun_key;
 584         struct rtable *rt;
 585         struct flowi4 fl;
 586
 587         if (unlikely(!tun_info))
 588                 return -EINVAL;
 589
 590         tun_key = &tun_info->tunnel;
 591
 592         /* Route lookup to get srouce IP address.
 593          * The process may need to be changed if the corresponding process
 594          * in vports ops changed.
 595          */
 596         rt = ovs_tunnel_route_lookup(net, tun_key, skb_mark, &fl, ipproto);
 597         if (IS_ERR(rt))
 598                 return PTR_ERR(rt);
 599
 600         ip_rt_put(rt);
 601
 602         /* Generate egress_tun_info based on tun_info,
 603          * saddr, tp_src and tp_dst
 604          */
 605         __ovs_flow_tun_info_init(egress_tun_info,
 606                                  fl.saddr, tun_key->ipv4_dst,
 607                                  tun_key->ipv4_tos,
 608                                  tun_key->ipv4_ttl,
 609                                  tp_src, tp_dst,
 610                                  tun_key->tun_id,
 611                                  tun_key->tun_flags,
 612                                  tun_info->options,
 613                                  tun_info->options_len);
 614
 615         return 0;
 616 }
 617 EXPORT_SYMBOL_GPL(ovs_tunnel_get_egress_info);
 618
 619 int ovs_vport_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
 620                                   struct ovs_tunnel_info *info)
 621 {
 622         /* get_egress_tun_info() is only implemented on tunnel ports. */
 623         if (unlikely(!vport->ops->get_egress_tun_info))
 624                 return -EINVAL;
 625
 626         return vport->ops->get_egress_tun_info(vport, skb, info);
 627 }