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 /* List of statically compiled vport implementations.  Don't forget to also
  37  * add yours to the list at the bottom of vport.h. */
  38 static const struct vport_ops *vport_ops_list[] = {
  39         &ovs_netdev_vport_ops,
  40         &ovs_internal_vport_ops,
  41 };
  42
  43 /* Protected by RCU read lock for reading, RTNL lock for writing. */
  44 static struct hlist_head *dev_table;
  45 #define VPORT_HASH_BUCKETS 1024
  46
  47 /**
  48  *      ovs_vport_init - initialize vport subsystem
  49  *
  50  * Called at module load time to initialize the vport subsystem.
  51  */
  52 int ovs_vport_init(void)
  53 {
  54         dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
  55                             GFP_KERNEL);
  56         if (!dev_table)
  57                 return -ENOMEM;
  58
  59         return 0;
  60 }
  61
  62 /**
  63  *      ovs_vport_exit - shutdown vport subsystem
  64  *
  65  * Called at module exit time to shutdown the vport subsystem.
  66  */
  67 void ovs_vport_exit(void)
  68 {
  69         kfree(dev_table);
  70 }
  71
  72 static struct hlist_head *hash_bucket(struct net *net, const char *name)
  73 {
  74         unsigned int hash = jhash(name, strlen(name), (unsigned long) net);
  75         return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
  76 }
  77
  78 /**
  79  *      ovs_vport_locate - find a port that has already been created
  80  *
  81  * @name: name of port to find
  82  *
  83  * Must be called with RTNL or RCU read lock.
  84  */
  85 struct vport *ovs_vport_locate(struct net *net, const char *name)
  86 {
  87         struct hlist_head *bucket = hash_bucket(net, name);
  88         struct vport *vport;
  89         struct hlist_node *node;
  90
  91         hlist_for_each_entry_rcu(vport, node, bucket, hash_node)
  92                 if (!strcmp(name, vport->ops->get_name(vport)) &&
  93                     net_eq(ovs_dp_get_net(vport->dp), net))
  94                         return vport;
  95
  96         return NULL;
  97 }
  98
  99 /**
 100  *      ovs_vport_alloc - allocate and initialize new vport
 101  *
 102  * @priv_size: Size of private data area to allocate.
 103  * @ops: vport device ops
 104  *
 105  * Allocate and initialize a new vport defined by @ops.  The vport will contain
 106  * a private data area of size @priv_size that can be accessed using
 107  * vport_priv().  vports that are no longer needed should be released with
 108  * vport_free().
 109  */
 110 struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
 111                           const struct vport_parms *parms)
 112 {
 113         struct vport *vport;
 114         size_t alloc_size;
 115
 116         alloc_size = sizeof(struct vport);
 117         if (priv_size) {
 118                 alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
 119                 alloc_size += priv_size;
 120         }
 121
 122         vport = kzalloc(alloc_size, GFP_KERNEL);
 123         if (!vport)
 124                 return ERR_PTR(-ENOMEM);
 125
 126         vport->dp = parms->dp;
 127         vport->port_no = parms->port_no;
 128         vport->upcall_portid = parms->upcall_portid;
 129         vport->ops = ops;
 130         INIT_HLIST_NODE(&vport->dp_hash_node);
 131
 132         vport->percpu_stats = alloc_percpu(struct vport_percpu_stats);
 133         if (!vport->percpu_stats) {
 134                 kfree(vport);
 135                 return ERR_PTR(-ENOMEM);
 136         }
 137
 138         spin_lock_init(&vport->stats_lock);
 139
 140         return vport;
 141 }
 142
 143 /**
 144  *      ovs_vport_free - uninitialize and free vport
 145  *
 146  * @vport: vport to free
 147  *
 148  * Frees a vport allocated with vport_alloc() when it is no longer needed.
 149  *
 150  * The caller must ensure that an RCU grace period has passed since the last
 151  * time @vport was in a datapath.
 152  */
 153 void ovs_vport_free(struct vport *vport)
 154 {
 155         free_percpu(vport->percpu_stats);
 156         kfree(vport);
 157 }
 158
 159 /**
 160  *      ovs_vport_add - add vport device (for kernel callers)
 161  *
 162  * @parms: Information about new vport.
 163  *
 164  * Creates a new vport with the specified configuration (which is dependent on
 165  * device type).  RTNL lock must be held.
 166  */
 167 struct vport *ovs_vport_add(const struct vport_parms *parms)
 168 {
 169         struct vport *vport;
 170         int err = 0;
 171         int i;
 172
 173         ASSERT_RTNL();
 174
 175         for (i = 0; i < ARRAY_SIZE(vport_ops_list); i++) {
 176                 if (vport_ops_list[i]->type == parms->type) {
 177                         struct hlist_head *bucket;
 178
 179                         vport = vport_ops_list[i]->create(parms);
 180                         if (IS_ERR(vport)) {
 181                                 err = PTR_ERR(vport);
 182                                 goto out;
 183                         }
 184
 185                         bucket = hash_bucket(ovs_dp_get_net(vport->dp),
 186                                              vport->ops->get_name(vport));
 187                         hlist_add_head_rcu(&vport->hash_node, bucket);
 188                         return vport;
 189                 }
 190         }
 191
 192         err = -EAFNOSUPPORT;
 193
 194 out:
 195         return ERR_PTR(err);
 196 }
 197
 198 /**
 199  *      ovs_vport_set_options - modify existing vport device (for kernel callers)
 200  *
 201  * @vport: vport to modify.
 202  * @port: New configuration.
 203  *
 204  * Modifies an existing device with the specified configuration (which is
 205  * dependent on device type).  RTNL lock must be held.
 206  */
 207 int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
 208 {
 209         ASSERT_RTNL();
 210
 211         if (!vport->ops->set_options)
 212                 return -EOPNOTSUPP;
 213         return vport->ops->set_options(vport, options);
 214 }
 215
 216 /**
 217  *      ovs_vport_del - delete existing vport device
 218  *
 219  * @vport: vport to delete.
 220  *
 221  * Detaches @vport from its datapath and destroys it.  It is possible to fail
 222  * for reasons such as lack of memory.  RTNL lock must be held.
 223  */
 224 void ovs_vport_del(struct vport *vport)
 225 {
 226         ASSERT_RTNL();
 227
 228         hlist_del_rcu(&vport->hash_node);
 229
 230         vport->ops->destroy(vport);
 231 }
 232
 233 /**
 234  *      ovs_vport_get_stats - retrieve device stats
 235  *
 236  * @vport: vport from which to retrieve the stats
 237  * @stats: location to store stats
 238  *
 239  * Retrieves transmit, receive, and error stats for the given device.
 240  *
 241  * Must be called with RTNL lock or rcu_read_lock.
 242  */
 243 void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
 244 {
 245         int i;
 246
 247         memset(stats, 0, sizeof(*stats));
 248
 249         /* We potentially have 2 sources of stats that need to be combined:
 250          * those we have collected (split into err_stats and percpu_stats) from
 251          * set_stats() and device error stats from netdev->get_stats() (for
 252          * errors that happen  downstream and therefore aren't reported through
 253          * our vport_record_error() function).
 254          * Stats from first source are reported by ovs (OVS_VPORT_ATTR_STATS).
 255          * netdev-stats can be directly read over netlink-ioctl.
 256          */
 257
 258         spin_lock_bh(&vport->stats_lock);
 259
 260         stats->rx_errors        = vport->err_stats.rx_errors;
 261         stats->tx_errors        = vport->err_stats.tx_errors;
 262         stats->tx_dropped       = vport->err_stats.tx_dropped;
 263         stats->rx_dropped       = vport->err_stats.rx_dropped;
 264
 265         spin_unlock_bh(&vport->stats_lock);
 266
 267         for_each_possible_cpu(i) {
 268                 const struct vport_percpu_stats *percpu_stats;
 269                 struct vport_percpu_stats local_stats;
 270                 unsigned int start;
 271
 272                 percpu_stats = per_cpu_ptr(vport->percpu_stats, i);
 273
 274                 do {
 275                         start = u64_stats_fetch_begin_bh(&percpu_stats->sync);
 276                         local_stats = *percpu_stats;
 277                 } while (u64_stats_fetch_retry_bh(&percpu_stats->sync, start));
 278
 279                 stats->rx_bytes         += local_stats.rx_bytes;
 280                 stats->rx_packets       += local_stats.rx_packets;
 281                 stats->tx_bytes         += local_stats.tx_bytes;
 282                 stats->tx_packets       += local_stats.tx_packets;
 283         }
 284 }
 285
 286 /**
 287  *      ovs_vport_get_options - retrieve device options
 288  *
 289  * @vport: vport from which to retrieve the options.
 290  * @skb: sk_buff where options should be appended.
 291  *
 292  * Retrieves the configuration of the given device, appending an
 293  * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
 294  * vport-specific attributes to @skb.
 295  *
 296  * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
 297  * negative error code if a real error occurred.  If an error occurs, @skb is
 298  * left unmodified.
 299  *
 300  * Must be called with RTNL lock or rcu_read_lock.
 301  */
 302 int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
 303 {
 304         struct nlattr *nla;
 305
 306         nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
 307         if (!nla)
 308                 return -EMSGSIZE;
 309
 310         if (vport->ops->get_options) {
 311                 int err = vport->ops->get_options(vport, skb);
 312                 if (err) {
 313                         nla_nest_cancel(skb, nla);
 314                         return err;
 315                 }
 316         }
 317
 318         nla_nest_end(skb, nla);
 319         return 0;
 320 }
 321
 322 /**
 323  *      ovs_vport_receive - pass up received packet to the datapath for processing
 324  *
 325  * @vport: vport that received the packet
 326  * @skb: skb that was received
 327  *
 328  * Must be called with rcu_read_lock.  The packet cannot be shared and
 329  * skb->data should point to the Ethernet header.  The caller must have already
 330  * called compute_ip_summed() to initialize the checksumming fields.
 331  */
 332 void ovs_vport_receive(struct vport *vport, struct sk_buff *skb)
 333 {
 334         struct vport_percpu_stats *stats;
 335
 336         stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
 337
 338         u64_stats_update_begin(&stats->sync);
 339         stats->rx_packets++;
 340         stats->rx_bytes += skb->len;
 341         u64_stats_update_end(&stats->sync);
 342
 343         ovs_dp_process_received_packet(vport, skb);
 344 }
 345
 346 /**
 347  *      ovs_vport_send - send a packet on a device
 348  *
 349  * @vport: vport on which to send the packet
 350  * @skb: skb to send
 351  *
 352  * Sends the given packet and returns the length of data sent.  Either RTNL
 353  * lock or rcu_read_lock must be held.
 354  */
 355 int ovs_vport_send(struct vport *vport, struct sk_buff *skb)
 356 {
 357         int sent = vport->ops->send(vport, skb);
 358
 359         if (likely(sent)) {
 360                 struct vport_percpu_stats *stats;
 361
 362                 stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
 363
 364                 u64_stats_update_begin(&stats->sync);
 365                 stats->tx_packets++;
 366                 stats->tx_bytes += sent;
 367                 u64_stats_update_end(&stats->sync);
 368         }
 369         return sent;
 370 }
 371
 372 /**
 373  *      ovs_vport_record_error - indicate device error to generic stats layer
 374  *
 375  * @vport: vport that encountered the error
 376  * @err_type: one of enum vport_err_type types to indicate the error type
 377  *
 378  * If using the vport generic stats layer indicate that an error of the given
 379  * type has occured.
 380  */
 381 void ovs_vport_record_error(struct vport *vport, enum vport_err_type err_type)
 382 {
 383         spin_lock(&vport->stats_lock);
 384
 385         switch (err_type) {
 386         case VPORT_E_RX_DROPPED:
 387                 vport->err_stats.rx_dropped++;
 388                 break;
 389
 390         case VPORT_E_RX_ERROR:
 391                 vport->err_stats.rx_errors++;
 392                 break;
 393
 394         case VPORT_E_TX_DROPPED:
 395                 vport->err_stats.tx_dropped++;
 396                 break;
 397
 398         case VPORT_E_TX_ERROR:
 399                 vport->err_stats.tx_errors++;
 400                 break;
 401         };
 402
 403         spin_unlock(&vport->stats_lock);
 404 }