linux/net/openvswitch/vport.c
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   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#include <linux/dcache.h>
  20#include <linux/etherdevice.h>
  21#include <linux/if.h>
  22#include <linux/if_vlan.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
  31#include "vport.h"
  32#include "vport-internal_dev.h"
  33
  34/* List of statically compiled vport implementations.  Don't forget to also
  35 * add yours to the list at the bottom of vport.h. */
  36static const struct vport_ops *vport_ops_list[] = {
  37        &ovs_netdev_vport_ops,
  38        &ovs_internal_vport_ops,
  39};
  40
  41/* Protected by RCU read lock for reading, RTNL lock for writing. */
  42static struct hlist_head *dev_table;
  43#define VPORT_HASH_BUCKETS 1024
  44
  45/**
  46 *      ovs_vport_init - initialize vport subsystem
  47 *
  48 * Called at module load time to initialize the vport subsystem.
  49 */
  50int ovs_vport_init(void)
  51{
  52        dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
  53                            GFP_KERNEL);
  54        if (!dev_table)
  55                return -ENOMEM;
  56
  57        return 0;
  58}
  59
  60/**
  61 *      ovs_vport_exit - shutdown vport subsystem
  62 *
  63 * Called at module exit time to shutdown the vport subsystem.
  64 */
  65void ovs_vport_exit(void)
  66{
  67        kfree(dev_table);
  68}
  69
  70static struct hlist_head *hash_bucket(const char *name)
  71{
  72        unsigned int hash = full_name_hash(name, strlen(name));
  73        return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
  74}
  75
  76/**
  77 *      ovs_vport_locate - find a port that has already been created
  78 *
  79 * @name: name of port to find
  80 *
  81 * Must be called with RTNL or RCU read lock.
  82 */
  83struct vport *ovs_vport_locate(const char *name)
  84{
  85        struct hlist_head *bucket = hash_bucket(name);
  86        struct vport *vport;
  87        struct hlist_node *node;
  88
  89        hlist_for_each_entry_rcu(vport, node, bucket, hash_node)
  90                if (!strcmp(name, vport->ops->get_name(vport)))
  91                        return vport;
  92
  93        return NULL;
  94}
  95
  96/**
  97 *      ovs_vport_alloc - allocate and initialize new vport
  98 *
  99 * @priv_size: Size of private data area to allocate.
 100 * @ops: vport device ops
 101 *
 102 * Allocate and initialize a new vport defined by @ops.  The vport will contain
 103 * a private data area of size @priv_size that can be accessed using
 104 * vport_priv().  vports that are no longer needed should be released with
 105 * vport_free().
 106 */
 107struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
 108                          const struct vport_parms *parms)
 109{
 110        struct vport *vport;
 111        size_t alloc_size;
 112
 113        alloc_size = sizeof(struct vport);
 114        if (priv_size) {
 115                alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
 116                alloc_size += priv_size;
 117        }
 118
 119        vport = kzalloc(alloc_size, GFP_KERNEL);
 120        if (!vport)
 121                return ERR_PTR(-ENOMEM);
 122
 123        vport->dp = parms->dp;
 124        vport->port_no = parms->port_no;
 125        vport->upcall_pid = parms->upcall_pid;
 126        vport->ops = ops;
 127
 128        vport->percpu_stats = alloc_percpu(struct vport_percpu_stats);
 129        if (!vport->percpu_stats) {
 130                kfree(vport);
 131                return ERR_PTR(-ENOMEM);
 132        }
 133
 134        spin_lock_init(&vport->stats_lock);
 135
 136        return vport;
 137}
 138
 139/**
 140 *      ovs_vport_free - uninitialize and free vport
 141 *
 142 * @vport: vport to free
 143 *
 144 * Frees a vport allocated with vport_alloc() when it is no longer needed.
 145 *
 146 * The caller must ensure that an RCU grace period has passed since the last
 147 * time @vport was in a datapath.
 148 */
 149void ovs_vport_free(struct vport *vport)
 150{
 151        free_percpu(vport->percpu_stats);
 152        kfree(vport);
 153}
 154
 155/**
 156 *      ovs_vport_add - add vport device (for kernel callers)
 157 *
 158 * @parms: Information about new vport.
 159 *
 160 * Creates a new vport with the specified configuration (which is dependent on
 161 * device type).  RTNL lock must be held.
 162 */
 163struct vport *ovs_vport_add(const struct vport_parms *parms)
 164{
 165        struct vport *vport;
 166        int err = 0;
 167        int i;
 168
 169        ASSERT_RTNL();
 170
 171        for (i = 0; i < ARRAY_SIZE(vport_ops_list); i++) {
 172                if (vport_ops_list[i]->type == parms->type) {
 173                        vport = vport_ops_list[i]->create(parms);
 174                        if (IS_ERR(vport)) {
 175                                err = PTR_ERR(vport);
 176                                goto out;
 177                        }
 178
 179                        hlist_add_head_rcu(&vport->hash_node,
 180                                           hash_bucket(vport->ops->get_name(vport)));
 181                        return vport;
 182                }
 183        }
 184
 185        err = -EAFNOSUPPORT;
 186
 187out:
 188        return ERR_PTR(err);
 189}
 190
 191/**
 192 *      ovs_vport_set_options - modify existing vport device (for kernel callers)
 193 *
 194 * @vport: vport to modify.
 195 * @port: New configuration.
 196 *
 197 * Modifies an existing device with the specified configuration (which is
 198 * dependent on device type).  RTNL lock must be held.
 199 */
 200int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
 201{
 202        ASSERT_RTNL();
 203
 204        if (!vport->ops->set_options)
 205                return -EOPNOTSUPP;
 206        return vport->ops->set_options(vport, options);
 207}
 208
 209/**
 210 *      ovs_vport_del - delete existing vport device
 211 *
 212 * @vport: vport to delete.
 213 *
 214 * Detaches @vport from its datapath and destroys it.  It is possible to fail
 215 * for reasons such as lack of memory.  RTNL lock must be held.
 216 */
 217void ovs_vport_del(struct vport *vport)
 218{
 219        ASSERT_RTNL();
 220
 221        hlist_del_rcu(&vport->hash_node);
 222
 223        vport->ops->destroy(vport);
 224}
 225
 226/**
 227 *      ovs_vport_get_stats - retrieve device stats
 228 *
 229 * @vport: vport from which to retrieve the stats
 230 * @stats: location to store stats
 231 *
 232 * Retrieves transmit, receive, and error stats for the given device.
 233 *
 234 * Must be called with RTNL lock or rcu_read_lock.
 235 */
 236void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
 237{
 238        int i;
 239
 240        memset(stats, 0, sizeof(*stats));
 241
 242        /* We potentially have 2 sources of stats that need to be combined:
 243         * those we have collected (split into err_stats and percpu_stats) from
 244         * set_stats() and device error stats from netdev->get_stats() (for
 245         * errors that happen  downstream and therefore aren't reported through
 246         * our vport_record_error() function).
 247         * Stats from first source are reported by ovs (OVS_VPORT_ATTR_STATS).
 248         * netdev-stats can be directly read over netlink-ioctl.
 249         */
 250
 251        spin_lock_bh(&vport->stats_lock);
 252
 253        stats->rx_errors        = vport->err_stats.rx_errors;
 254        stats->tx_errors        = vport->err_stats.tx_errors;
 255        stats->tx_dropped       = vport->err_stats.tx_dropped;
 256        stats->rx_dropped       = vport->err_stats.rx_dropped;
 257
 258        spin_unlock_bh(&vport->stats_lock);
 259
 260        for_each_possible_cpu(i) {
 261                const struct vport_percpu_stats *percpu_stats;
 262                struct vport_percpu_stats local_stats;
 263                unsigned int start;
 264
 265                percpu_stats = per_cpu_ptr(vport->percpu_stats, i);
 266
 267                do {
 268                        start = u64_stats_fetch_begin_bh(&percpu_stats->sync);
 269                        local_stats = *percpu_stats;
 270                } while (u64_stats_fetch_retry_bh(&percpu_stats->sync, start));
 271
 272                stats->rx_bytes         += local_stats.rx_bytes;
 273                stats->rx_packets       += local_stats.rx_packets;
 274                stats->tx_bytes         += local_stats.tx_bytes;
 275                stats->tx_packets       += local_stats.tx_packets;
 276        }
 277}
 278
 279/**
 280 *      ovs_vport_get_options - retrieve device options
 281 *
 282 * @vport: vport from which to retrieve the options.
 283 * @skb: sk_buff where options should be appended.
 284 *
 285 * Retrieves the configuration of the given device, appending an
 286 * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
 287 * vport-specific attributes to @skb.
 288 *
 289 * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
 290 * negative error code if a real error occurred.  If an error occurs, @skb is
 291 * left unmodified.
 292 *
 293 * Must be called with RTNL lock or rcu_read_lock.
 294 */
 295int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
 296{
 297        struct nlattr *nla;
 298
 299        nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
 300        if (!nla)
 301                return -EMSGSIZE;
 302
 303        if (vport->ops->get_options) {
 304                int err = vport->ops->get_options(vport, skb);
 305                if (err) {
 306                        nla_nest_cancel(skb, nla);
 307                        return err;
 308                }
 309        }
 310
 311        nla_nest_end(skb, nla);
 312        return 0;
 313}
 314
 315/**
 316 *      ovs_vport_receive - pass up received packet to the datapath for processing
 317 *
 318 * @vport: vport that received the packet
 319 * @skb: skb that was received
 320 *
 321 * Must be called with rcu_read_lock.  The packet cannot be shared and
 322 * skb->data should point to the Ethernet header.  The caller must have already
 323 * called compute_ip_summed() to initialize the checksumming fields.
 324 */
 325void ovs_vport_receive(struct vport *vport, struct sk_buff *skb)
 326{
 327        struct vport_percpu_stats *stats;
 328
 329        stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
 330
 331        u64_stats_update_begin(&stats->sync);
 332        stats->rx_packets++;
 333        stats->rx_bytes += skb->len;
 334        u64_stats_update_end(&stats->sync);
 335
 336        ovs_dp_process_received_packet(vport, skb);
 337}
 338
 339/**
 340 *      ovs_vport_send - send a packet on a device
 341 *
 342 * @vport: vport on which to send the packet
 343 * @skb: skb to send
 344 *
 345 * Sends the given packet and returns the length of data sent.  Either RTNL
 346 * lock or rcu_read_lock must be held.
 347 */
 348int ovs_vport_send(struct vport *vport, struct sk_buff *skb)
 349{
 350        int sent = vport->ops->send(vport, skb);
 351
 352        if (likely(sent)) {
 353                struct vport_percpu_stats *stats;
 354
 355                stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
 356
 357                u64_stats_update_begin(&stats->sync);
 358                stats->tx_packets++;
 359                stats->tx_bytes += sent;
 360                u64_stats_update_end(&stats->sync);
 361        }
 362        return sent;
 363}
 364
 365/**
 366 *      ovs_vport_record_error - indicate device error to generic stats layer
 367 *
 368 * @vport: vport that encountered the error
 369 * @err_type: one of enum vport_err_type types to indicate the error type
 370 *
 371 * If using the vport generic stats layer indicate that an error of the given
 372 * type has occured.
 373 */
 374void ovs_vport_record_error(struct vport *vport, enum vport_err_type err_type)
 375{
 376        spin_lock(&vport->stats_lock);
 377
 378        switch (err_type) {
 379        case VPORT_E_RX_DROPPED:
 380                vport->err_stats.rx_dropped++;
 381                break;
 382
 383        case VPORT_E_RX_ERROR:
 384                vport->err_stats.rx_errors++;
 385                break;
 386
 387        case VPORT_E_TX_DROPPED:
 388                vport->err_stats.tx_dropped++;
 389                break;
 390
 391        case VPORT_E_TX_ERROR:
 392                vport->err_stats.tx_errors++;
 393                break;
 394        };
 395
 396        spin_unlock(&vport->stats_lock);
 397}
 398
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