linux/net/openvswitch/vport.c
<<
>>
Prefs
   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
  37static LIST_HEAD(vport_ops_list);
  38
  39/* Protected by RCU read lock for reading, ovs_mutex for writing. */
  40static struct hlist_head *dev_table;
  41#define VPORT_HASH_BUCKETS 1024
  42
  43/**
  44 *      ovs_vport_init - initialize vport subsystem
  45 *
  46 * Called at module load time to initialize the vport subsystem.
  47 */
  48int ovs_vport_init(void)
  49{
  50        dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
  51                            GFP_KERNEL);
  52        if (!dev_table)
  53                return -ENOMEM;
  54
  55        return 0;
  56}
  57
  58/**
  59 *      ovs_vport_exit - shutdown vport subsystem
  60 *
  61 * Called at module exit time to shutdown the vport subsystem.
  62 */
  63void ovs_vport_exit(void)
  64{
  65        kfree(dev_table);
  66}
  67
  68static struct hlist_head *hash_bucket(const struct net *net, const char *name)
  69{
  70        unsigned int hash = jhash(name, strlen(name), (unsigned long) net);
  71        return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
  72}
  73
  74int __ovs_vport_ops_register(struct vport_ops *ops)
  75{
  76        int err = -EEXIST;
  77        struct vport_ops *o;
  78
  79        ovs_lock();
  80        list_for_each_entry(o, &vport_ops_list, list)
  81                if (ops->type == o->type)
  82                        goto errout;
  83
  84        list_add_tail(&ops->list, &vport_ops_list);
  85        err = 0;
  86errout:
  87        ovs_unlock();
  88        return err;
  89}
  90EXPORT_SYMBOL_GPL(__ovs_vport_ops_register);
  91
  92void ovs_vport_ops_unregister(struct vport_ops *ops)
  93{
  94        ovs_lock();
  95        list_del(&ops->list);
  96        ovs_unlock();
  97}
  98EXPORT_SYMBOL_GPL(ovs_vport_ops_unregister);
  99
 100/**
 101 *      ovs_vport_locate - find a port that has already been created
 102 *
 103 * @name: name of port to find
 104 *
 105 * Must be called with ovs or RCU read lock.
 106 */
 107struct vport *ovs_vport_locate(const struct net *net, const char *name)
 108{
 109        struct hlist_head *bucket = hash_bucket(net, name);
 110        struct vport *vport;
 111
 112        hlist_for_each_entry_rcu(vport, bucket, hash_node)
 113                if (!strcmp(name, ovs_vport_name(vport)) &&
 114                    net_eq(ovs_dp_get_net(vport->dp), net))
 115                        return vport;
 116
 117        return NULL;
 118}
 119
 120/**
 121 *      ovs_vport_alloc - allocate and initialize new vport
 122 *
 123 * @priv_size: Size of private data area to allocate.
 124 * @ops: vport device ops
 125 *
 126 * Allocate and initialize a new vport defined by @ops.  The vport will contain
 127 * a private data area of size @priv_size that can be accessed using
 128 * vport_priv().  vports that are no longer needed should be released with
 129 * vport_free().
 130 */
 131struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
 132                          const struct vport_parms *parms)
 133{
 134        struct vport *vport;
 135        size_t alloc_size;
 136
 137        alloc_size = sizeof(struct vport);
 138        if (priv_size) {
 139                alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
 140                alloc_size += priv_size;
 141        }
 142
 143        vport = kzalloc(alloc_size, GFP_KERNEL);
 144        if (!vport)
 145                return ERR_PTR(-ENOMEM);
 146
 147        vport->dp = parms->dp;
 148        vport->port_no = parms->port_no;
 149        vport->ops = ops;
 150        INIT_HLIST_NODE(&vport->dp_hash_node);
 151
 152        if (ovs_vport_set_upcall_portids(vport, parms->upcall_portids)) {
 153                kfree(vport);
 154                return ERR_PTR(-EINVAL);
 155        }
 156
 157        return vport;
 158}
 159EXPORT_SYMBOL_GPL(ovs_vport_alloc);
 160
 161/**
 162 *      ovs_vport_free - uninitialize and free vport
 163 *
 164 * @vport: vport to free
 165 *
 166 * Frees a vport allocated with vport_alloc() when it is no longer needed.
 167 *
 168 * The caller must ensure that an RCU grace period has passed since the last
 169 * time @vport was in a datapath.
 170 */
 171void ovs_vport_free(struct vport *vport)
 172{
 173        /* vport is freed from RCU callback or error path, Therefore
 174         * it is safe to use raw dereference.
 175         */
 176        kfree(rcu_dereference_raw(vport->upcall_portids));
 177        kfree(vport);
 178}
 179EXPORT_SYMBOL_GPL(ovs_vport_free);
 180
 181static struct vport_ops *ovs_vport_lookup(const struct vport_parms *parms)
 182{
 183        struct vport_ops *ops;
 184
 185        list_for_each_entry(ops, &vport_ops_list, list)
 186                if (ops->type == parms->type)
 187                        return ops;
 188
 189        return NULL;
 190}
 191
 192/**
 193 *      ovs_vport_add - add vport device (for kernel callers)
 194 *
 195 * @parms: Information about new vport.
 196 *
 197 * Creates a new vport with the specified configuration (which is dependent on
 198 * device type).  ovs_mutex must be held.
 199 */
 200struct vport *ovs_vport_add(const struct vport_parms *parms)
 201{
 202        struct vport_ops *ops;
 203        struct vport *vport;
 204
 205        ops = ovs_vport_lookup(parms);
 206        if (ops) {
 207                struct hlist_head *bucket;
 208
 209                if (!try_module_get(ops->owner))
 210                        return ERR_PTR(-EAFNOSUPPORT);
 211
 212                vport = ops->create(parms);
 213                if (IS_ERR(vport)) {
 214                        module_put(ops->owner);
 215                        return vport;
 216                }
 217
 218                bucket = hash_bucket(ovs_dp_get_net(vport->dp),
 219                                     ovs_vport_name(vport));
 220                hlist_add_head_rcu(&vport->hash_node, bucket);
 221                return vport;
 222        }
 223
 224        /* Unlock to attempt module load and return -EAGAIN if load
 225         * was successful as we need to restart the port addition
 226         * workflow.
 227         */
 228        ovs_unlock();
 229        request_module("vport-type-%d", parms->type);
 230        ovs_lock();
 231
 232        if (!ovs_vport_lookup(parms))
 233                return ERR_PTR(-EAFNOSUPPORT);
 234        else
 235                return ERR_PTR(-EAGAIN);
 236}
 237
 238/**
 239 *      ovs_vport_set_options - modify existing vport device (for kernel callers)
 240 *
 241 * @vport: vport to modify.
 242 * @options: New configuration.
 243 *
 244 * Modifies an existing device with the specified configuration (which is
 245 * dependent on device type).  ovs_mutex must be held.
 246 */
 247int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
 248{
 249        if (!vport->ops->set_options)
 250                return -EOPNOTSUPP;
 251        return vport->ops->set_options(vport, options);
 252}
 253
 254/**
 255 *      ovs_vport_del - delete existing vport device
 256 *
 257 * @vport: vport to delete.
 258 *
 259 * Detaches @vport from its datapath and destroys it.  ovs_mutex must
 260 * be held.
 261 */
 262void ovs_vport_del(struct vport *vport)
 263{
 264        ASSERT_OVSL();
 265
 266        hlist_del_rcu(&vport->hash_node);
 267        module_put(vport->ops->owner);
 268        vport->ops->destroy(vport);
 269}
 270
 271/**
 272 *      ovs_vport_get_stats - retrieve device stats
 273 *
 274 * @vport: vport from which to retrieve the stats
 275 * @stats: location to store stats
 276 *
 277 * Retrieves transmit, receive, and error stats for the given device.
 278 *
 279 * Must be called with ovs_mutex or rcu_read_lock.
 280 */
 281void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
 282{
 283        const struct rtnl_link_stats64 *dev_stats;
 284        struct rtnl_link_stats64 temp;
 285
 286        dev_stats = dev_get_stats(vport->dev, &temp);
 287        stats->rx_errors  = dev_stats->rx_errors;
 288        stats->tx_errors  = dev_stats->tx_errors;
 289        stats->tx_dropped = dev_stats->tx_dropped;
 290        stats->rx_dropped = dev_stats->rx_dropped;
 291
 292        stats->rx_bytes   = dev_stats->rx_bytes;
 293        stats->rx_packets = dev_stats->rx_packets;
 294        stats->tx_bytes   = dev_stats->tx_bytes;
 295        stats->tx_packets = dev_stats->tx_packets;
 296}
 297
 298/**
 299 *      ovs_vport_get_options - retrieve device options
 300 *
 301 * @vport: vport from which to retrieve the options.
 302 * @skb: sk_buff where options should be appended.
 303 *
 304 * Retrieves the configuration of the given device, appending an
 305 * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
 306 * vport-specific attributes to @skb.
 307 *
 308 * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
 309 * negative error code if a real error occurred.  If an error occurs, @skb is
 310 * left unmodified.
 311 *
 312 * Must be called with ovs_mutex or rcu_read_lock.
 313 */
 314int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
 315{
 316        struct nlattr *nla;
 317        int err;
 318
 319        if (!vport->ops->get_options)
 320                return 0;
 321
 322        nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
 323        if (!nla)
 324                return -EMSGSIZE;
 325
 326        err = vport->ops->get_options(vport, skb);
 327        if (err) {
 328                nla_nest_cancel(skb, nla);
 329                return err;
 330        }
 331
 332        nla_nest_end(skb, nla);
 333        return 0;
 334}
 335
 336/**
 337 *      ovs_vport_set_upcall_portids - set upcall portids of @vport.
 338 *
 339 * @vport: vport to modify.
 340 * @ids: new configuration, an array of port ids.
 341 *
 342 * Sets the vport's upcall_portids to @ids.
 343 *
 344 * Returns 0 if successful, -EINVAL if @ids is zero length or cannot be parsed
 345 * as an array of U32.
 346 *
 347 * Must be called with ovs_mutex.
 348 */
 349int ovs_vport_set_upcall_portids(struct vport *vport, const struct nlattr *ids)
 350{
 351        struct vport_portids *old, *vport_portids;
 352
 353        if (!nla_len(ids) || nla_len(ids) % sizeof(u32))
 354                return -EINVAL;
 355
 356        old = ovsl_dereference(vport->upcall_portids);
 357
 358        vport_portids = kmalloc(sizeof(*vport_portids) + nla_len(ids),
 359                                GFP_KERNEL);
 360        if (!vport_portids)
 361                return -ENOMEM;
 362
 363        vport_portids->n_ids = nla_len(ids) / sizeof(u32);
 364        vport_portids->rn_ids = reciprocal_value(vport_portids->n_ids);
 365        nla_memcpy(vport_portids->ids, ids, nla_len(ids));
 366
 367        rcu_assign_pointer(vport->upcall_portids, vport_portids);
 368
 369        if (old)
 370                kfree_rcu(old, rcu);
 371        return 0;
 372}
 373
 374/**
 375 *      ovs_vport_get_upcall_portids - get the upcall_portids of @vport.
 376 *
 377 * @vport: vport from which to retrieve the portids.
 378 * @skb: sk_buff where portids should be appended.
 379 *
 380 * Retrieves the configuration of the given vport, appending the
 381 * %OVS_VPORT_ATTR_UPCALL_PID attribute which is the array of upcall
 382 * portids to @skb.
 383 *
 384 * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room.
 385 * If an error occurs, @skb is left unmodified.  Must be called with
 386 * ovs_mutex or rcu_read_lock.
 387 */
 388int ovs_vport_get_upcall_portids(const struct vport *vport,
 389                                 struct sk_buff *skb)
 390{
 391        struct vport_portids *ids;
 392
 393        ids = rcu_dereference_ovsl(vport->upcall_portids);
 394
 395        if (vport->dp->user_features & OVS_DP_F_VPORT_PIDS)
 396                return nla_put(skb, OVS_VPORT_ATTR_UPCALL_PID,
 397                               ids->n_ids * sizeof(u32), (void *)ids->ids);
 398        else
 399                return nla_put_u32(skb, OVS_VPORT_ATTR_UPCALL_PID, ids->ids[0]);
 400}
 401
 402/**
 403 *      ovs_vport_find_upcall_portid - find the upcall portid to send upcall.
 404 *
 405 * @vport: vport from which the missed packet is received.
 406 * @skb: skb that the missed packet was received.
 407 *
 408 * Uses the skb_get_hash() to select the upcall portid to send the
 409 * upcall.
 410 *
 411 * Returns the portid of the target socket.  Must be called with rcu_read_lock.
 412 */
 413u32 ovs_vport_find_upcall_portid(const struct vport *vport, struct sk_buff *skb)
 414{
 415        struct vport_portids *ids;
 416        u32 ids_index;
 417        u32 hash;
 418
 419        ids = rcu_dereference(vport->upcall_portids);
 420
 421        if (ids->n_ids == 1 && ids->ids[0] == 0)
 422                return 0;
 423
 424        hash = skb_get_hash(skb);
 425        ids_index = hash - ids->n_ids * reciprocal_divide(hash, ids->rn_ids);
 426        return ids->ids[ids_index];
 427}
 428
 429/**
 430 *      ovs_vport_receive - pass up received packet to the datapath for processing
 431 *
 432 * @vport: vport that received the packet
 433 * @skb: skb that was received
 434 * @tun_key: tunnel (if any) that carried packet
 435 *
 436 * Must be called with rcu_read_lock.  The packet cannot be shared and
 437 * skb->data should point to the Ethernet header.
 438 */
 439int ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
 440                      const struct ip_tunnel_info *tun_info)
 441{
 442        struct sw_flow_key key;
 443        int error;
 444
 445        OVS_CB(skb)->input_vport = vport;
 446        OVS_CB(skb)->mru = 0;
 447        OVS_CB(skb)->cutlen = 0;
 448        if (unlikely(dev_net(skb->dev) != ovs_dp_get_net(vport->dp))) {
 449                u32 mark;
 450
 451                mark = skb->mark;
 452                skb_scrub_packet(skb, true);
 453                skb->mark = mark;
 454                tun_info = NULL;
 455        }
 456
 457        /* Extract flow from 'skb' into 'key'. */
 458        error = ovs_flow_key_extract(tun_info, skb, &key);
 459        if (unlikely(error)) {
 460                kfree_skb(skb);
 461                return error;
 462        }
 463        ovs_dp_process_packet(skb, &key);
 464        return 0;
 465}
 466
 467static unsigned int packet_length(const struct sk_buff *skb,
 468                                  struct net_device *dev)
 469{
 470        unsigned int length = skb->len - dev->hard_header_len;
 471
 472        if (!skb_vlan_tag_present(skb) &&
 473            eth_type_vlan(skb->protocol))
 474                length -= VLAN_HLEN;
 475
 476        /* Don't subtract for multiple VLAN tags. Most (all?) drivers allow
 477         * (ETH_LEN + VLAN_HLEN) in addition to the mtu value, but almost none
 478         * account for 802.1ad. e.g. is_skb_forwardable().
 479         */
 480
 481        return length;
 482}
 483
 484void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)
 485{
 486        int mtu = vport->dev->mtu;
 487
 488        switch (vport->dev->type) {
 489        case ARPHRD_NONE:
 490                if (mac_proto == MAC_PROTO_ETHERNET) {
 491                        skb_reset_network_header(skb);
 492                        skb_reset_mac_len(skb);
 493                        skb->protocol = htons(ETH_P_TEB);
 494                } else if (mac_proto != MAC_PROTO_NONE) {
 495                        WARN_ON_ONCE(1);
 496                        goto drop;
 497                }
 498                break;
 499        case ARPHRD_ETHER:
 500                if (mac_proto != MAC_PROTO_ETHERNET)
 501                        goto drop;
 502                break;
 503        default:
 504                goto drop;
 505        }
 506
 507        if (unlikely(packet_length(skb, vport->dev) > mtu &&
 508                     !skb_is_gso(skb))) {
 509                net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
 510                                     vport->dev->name,
 511                                     packet_length(skb, vport->dev), mtu);
 512                vport->dev->stats.tx_errors++;
 513                goto drop;
 514        }
 515
 516        skb->dev = vport->dev;
 517        vport->ops->send(skb);
 518        return;
 519
 520drop:
 521        kfree_skb(skb);
 522}
 523