net/openvswitch/vport.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 #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
  32 #include "datapath.h"
  33 #include "vport.h"
  34 #include "vport-internal_dev.h"
  35
  36 static void ovs_vport_record_error(struct vport *,
  37                                    enum vport_err_type err_type);
  38
  39 /* List of statically compiled vport implementations.  Don't forget to also
  40  * add yours to the list at the bottom of vport.h. */
  41 static const struct vport_ops *vport_ops_list[] = {
  42         &ovs_netdev_vport_ops,
  43         &ovs_internal_vport_ops,
  44
  45 #ifdef CONFIG_OPENVSWITCH_GRE
  46         &ovs_gre_vport_ops,
  47 #endif
  48 #ifdef CONFIG_OPENVSWITCH_VXLAN
  49         &ovs_vxlan_vport_ops,
  50 #endif
  51 };
  52
  53 /* Protected by RCU read lock for reading, ovs_mutex for writing. */
  54 static struct hlist_head *dev_table;
  55 #define VPORT_HASH_BUCKETS 1024
  56
  57 /**
  58  *      ovs_vport_init - initialize vport subsystem
  59  *
  60  * Called at module load time to initialize the vport subsystem.
  61  */
  62 int ovs_vport_init(void)
  63 {
  64         dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
  65                             GFP_KERNEL);
  66         if (!dev_table)
  67                 return -ENOMEM;
  68
  69         return 0;
  70 }
  71
  72 /**
  73  *      ovs_vport_exit - shutdown vport subsystem
  74  *
  75  * Called at module exit time to shutdown the vport subsystem.
  76  */
  77 void ovs_vport_exit(void)
  78 {
  79         kfree(dev_table);
  80 }
  81
  82 static struct hlist_head *hash_bucket(struct net *net, const char *name)
  83 {
  84         unsigned int hash = jhash(name, strlen(name), (unsigned long) net);
  85         return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
  86 }
  87
  88 /**
  89  *      ovs_vport_locate - find a port that has already been created
  90  *
  91  * @name: name of port to find
  92  *
  93  * Must be called with ovs or RCU read lock.
  94  */
  95 struct vport *ovs_vport_locate(struct net *net, const char *name)
  96 {
  97         struct hlist_head *bucket = hash_bucket(net, name);
  98         struct vport *vport;
  99
 100         hlist_for_each_entry_rcu(vport, bucket, hash_node)
 101                 if (!strcmp(name, vport->ops->get_name(vport)) &&
 102                     net_eq(ovs_dp_get_net(vport->dp), net))
 103                         return vport;
 104
 105         return NULL;
 106 }
 107
 108 /**
 109  *      ovs_vport_alloc - allocate and initialize new vport
 110  *
 111  * @priv_size: Size of private data area to allocate.
 112  * @ops: vport device ops
 113  *
 114  * Allocate and initialize a new vport defined by @ops.  The vport will contain
 115  * a private data area of size @priv_size that can be accessed using
 116  * vport_priv().  vports that are no longer needed should be released with
 117  * vport_free().
 118  */
 119 struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
 120                           const struct vport_parms *parms)
 121 {
 122         struct vport *vport;
 123         size_t alloc_size;
 124
 125         alloc_size = sizeof(struct vport);
 126         if (priv_size) {
 127                 alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
 128                 alloc_size += priv_size;
 129         }
 130
 131         vport = kzalloc(alloc_size, GFP_KERNEL);
 132         if (!vport)
 133                 return ERR_PTR(-ENOMEM);
 134
 135         vport->dp = parms->dp;
 136         vport->port_no = parms->port_no;
 137         vport->upcall_portid = parms->upcall_portid;
 138         vport->ops = ops;
 139         INIT_HLIST_NODE(&vport->dp_hash_node);
 140
 141         vport->percpu_stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 142         if (!vport->percpu_stats) {
 143                 kfree(vport);
 144                 return ERR_PTR(-ENOMEM);
 145         }
 146
 147         spin_lock_init(&vport->stats_lock);
 148
 149         return vport;
 150 }
 151
 152 /**
 153  *      ovs_vport_free - uninitialize and free vport
 154  *
 155  * @vport: vport to free
 156  *
 157  * Frees a vport allocated with vport_alloc() when it is no longer needed.
 158  *
 159  * The caller must ensure that an RCU grace period has passed since the last
 160  * time @vport was in a datapath.
 161  */
 162 void ovs_vport_free(struct vport *vport)
 163 {
 164         free_percpu(vport->percpu_stats);
 165         kfree(vport);
 166 }
 167
 168 /**
 169  *      ovs_vport_add - add vport device (for kernel callers)
 170  *
 171  * @parms: Information about new vport.
 172  *
 173  * Creates a new vport with the specified configuration (which is dependent on
 174  * device type).  ovs_mutex must be held.
 175  */
 176 struct vport *ovs_vport_add(const struct vport_parms *parms)
 177 {
 178         struct vport *vport;
 179         int err = 0;
 180         int i;
 181
 182         for (i = 0; i < ARRAY_SIZE(vport_ops_list); i++) {
 183                 if (vport_ops_list[i]->type == parms->type) {
 184                         struct hlist_head *bucket;
 185
 186                         vport = vport_ops_list[i]->create(parms);
 187                         if (IS_ERR(vport)) {
 188                                 err = PTR_ERR(vport);
 189                                 goto out;
 190                         }
 191
 192                         bucket = hash_bucket(ovs_dp_get_net(vport->dp),
 193                                              vport->ops->get_name(vport));
 194                         hlist_add_head_rcu(&vport->hash_node, bucket);
 195                         return vport;
 196                 }
 197         }
 198
 199         err = -EAFNOSUPPORT;
 200
 201 out:
 202         return ERR_PTR(err);
 203 }
 204
 205 /**
 206  *      ovs_vport_set_options - modify existing vport device (for kernel callers)
 207  *
 208  * @vport: vport to modify.
 209  * @options: New configuration.
 210  *
 211  * Modifies an existing device with the specified configuration (which is
 212  * dependent on device type).  ovs_mutex must be held.
 213  */
 214 int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
 215 {
 216         if (!vport->ops->set_options)
 217                 return -EOPNOTSUPP;
 218         return vport->ops->set_options(vport, options);
 219 }
 220
 221 /**
 222  *      ovs_vport_del - delete existing vport device
 223  *
 224  * @vport: vport to delete.
 225  *
 226  * Detaches @vport from its datapath and destroys it.  It is possible to fail
 227  * for reasons such as lack of memory.  ovs_mutex must be held.
 228  */
 229 void ovs_vport_del(struct vport *vport)
 230 {
 231         ASSERT_OVSL();
 232
 233         hlist_del_rcu(&vport->hash_node);
 234
 235         vport->ops->destroy(vport);
 236 }
 237
 238 /**
 239  *      ovs_vport_get_stats - retrieve device stats
 240  *
 241  * @vport: vport from which to retrieve the stats
 242  * @stats: location to store stats
 243  *
 244  * Retrieves transmit, receive, and error stats for the given device.
 245  *
 246  * Must be called with ovs_mutex or rcu_read_lock.
 247  */
 248 void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
 249 {
 250         int i;
 251
 252         memset(stats, 0, sizeof(*stats));
 253
 254         /* We potentially have 2 sources of stats that need to be combined:
 255          * those we have collected (split into err_stats and percpu_stats) from
 256          * set_stats() and device error stats from netdev->get_stats() (for
 257          * errors that happen  downstream and therefore aren't reported through
 258          * our vport_record_error() function).
 259          * Stats from first source are reported by ovs (OVS_VPORT_ATTR_STATS).
 260          * netdev-stats can be directly read over netlink-ioctl.
 261          */
 262
 263         spin_lock_bh(&vport->stats_lock);
 264
 265         stats->rx_errors        = vport->err_stats.rx_errors;
 266         stats->tx_errors        = vport->err_stats.tx_errors;
 267         stats->tx_dropped       = vport->err_stats.tx_dropped;
 268         stats->rx_dropped       = vport->err_stats.rx_dropped;
 269
 270         spin_unlock_bh(&vport->stats_lock);
 271
 272         for_each_possible_cpu(i) {
 273                 const struct pcpu_sw_netstats *percpu_stats;
 274                 struct pcpu_sw_netstats local_stats;
 275                 unsigned int start;
 276
 277                 percpu_stats = per_cpu_ptr(vport->percpu_stats, i);
 278
 279                 do {
 280                         start = u64_stats_fetch_begin_irq(&percpu_stats->syncp);
 281                         local_stats = *percpu_stats;
 282                 } while (u64_stats_fetch_retry_irq(&percpu_stats->syncp, start));
 283
 284                 stats->rx_bytes         += local_stats.rx_bytes;
 285                 stats->rx_packets       += local_stats.rx_packets;
 286                 stats->tx_bytes         += local_stats.tx_bytes;
 287                 stats->tx_packets       += local_stats.tx_packets;
 288         }
 289 }
 290
 291 /**
 292  *      ovs_vport_get_options - retrieve device options
 293  *
 294  * @vport: vport from which to retrieve the options.
 295  * @skb: sk_buff where options should be appended.
 296  *
 297  * Retrieves the configuration of the given device, appending an
 298  * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
 299  * vport-specific attributes to @skb.
 300  *
 301  * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
 302  * negative error code if a real error occurred.  If an error occurs, @skb is
 303  * left unmodified.
 304  *
 305  * Must be called with ovs_mutex or rcu_read_lock.
 306  */
 307 int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
 308 {
 309         struct nlattr *nla;
 310         int err;
 311
 312         if (!vport->ops->get_options)
 313                 return 0;
 314
 315         nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
 316         if (!nla)
 317                 return -EMSGSIZE;
 318
 319         err = vport->ops->get_options(vport, skb);
 320         if (err) {
 321                 nla_nest_cancel(skb, nla);
 322                 return err;
 323         }
 324
 325         nla_nest_end(skb, nla);
 326         return 0;
 327 }
 328
 329 /**
 330  *      ovs_vport_receive - pass up received packet to the datapath for processing
 331  *
 332  * @vport: vport that received the packet
 333  * @skb: skb that was received
 334  * @tun_key: tunnel (if any) that carried packet
 335  *
 336  * Must be called with rcu_read_lock.  The packet cannot be shared and
 337  * skb->data should point to the Ethernet header.
 338  */
 339 void ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
 340                        struct ovs_key_ipv4_tunnel *tun_key)
 341 {
 342         struct pcpu_sw_netstats *stats;
 343
 344         stats = this_cpu_ptr(vport->percpu_stats);
 345         u64_stats_update_begin(&stats->syncp);
 346         stats->rx_packets++;
 347         stats->rx_bytes += skb->len;
 348         u64_stats_update_end(&stats->syncp);
 349
 350         OVS_CB(skb)->tun_key = tun_key;
 351         ovs_dp_process_received_packet(vport, skb);
 352 }
 353
 354 /**
 355  *      ovs_vport_send - send a packet on a device
 356  *
 357  * @vport: vport on which to send the packet
 358  * @skb: skb to send
 359  *
 360  * Sends the given packet and returns the length of data sent.  Either ovs
 361  * lock or rcu_read_lock must be held.
 362  */
 363 int ovs_vport_send(struct vport *vport, struct sk_buff *skb)
 364 {
 365         int sent = vport->ops->send(vport, skb);
 366
 367         if (likely(sent > 0)) {
 368                 struct pcpu_sw_netstats *stats;
 369
 370                 stats = this_cpu_ptr(vport->percpu_stats);
 371
 372                 u64_stats_update_begin(&stats->syncp);
 373                 stats->tx_packets++;
 374                 stats->tx_bytes += sent;
 375                 u64_stats_update_end(&stats->syncp);
 376         } else if (sent < 0) {
 377                 ovs_vport_record_error(vport, VPORT_E_TX_ERROR);
 378                 kfree_skb(skb);
 379         } else
 380                 ovs_vport_record_error(vport, VPORT_E_TX_DROPPED);
 381
 382         return sent;
 383 }
 384
 385 /**
 386  *      ovs_vport_record_error - indicate device error to generic stats layer
 387  *
 388  * @vport: vport that encountered the error
 389  * @err_type: one of enum vport_err_type types to indicate the error type
 390  *
 391  * If using the vport generic stats layer indicate that an error of the given
 392  * type has occurred.
 393  */
 394 static void ovs_vport_record_error(struct vport *vport,
 395                                    enum vport_err_type err_type)
 396 {
 397         spin_lock(&vport->stats_lock);
 398
 399         switch (err_type) {
 400         case VPORT_E_RX_DROPPED:
 401                 vport->err_stats.rx_dropped++;
 402                 break;
 403
 404         case VPORT_E_RX_ERROR:
 405                 vport->err_stats.rx_errors++;
 406                 break;
 407
 408         case VPORT_E_TX_DROPPED:
 409                 vport->err_stats.tx_dropped++;
 410                 break;
 411
 412         case VPORT_E_TX_ERROR:
 413                 vport->err_stats.tx_errors++;
 414                 break;
 415         }
 416
 417         spin_unlock(&vport->stats_lock);
 418 }
 419
 420 static void free_vport_rcu(struct rcu_head *rcu)
 421 {
 422         struct vport *vport = container_of(rcu, struct vport, rcu);
 423
 424         ovs_vport_free(vport);
 425 }
 426
 427 void ovs_vport_deferred_free(struct vport *vport)
 428 {
 429         if (!vport)
 430                 return;
 431
 432         call_rcu(&vport->rcu, free_vport_rcu);
 433 }