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         int i;
 125
 126         alloc_size = sizeof(struct vport);
 127         if (priv_size) {
 128                 alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
 129                 alloc_size += priv_size;
 130         }
 131
 132         vport = kzalloc(alloc_size, GFP_KERNEL);
 133         if (!vport)
 134                 return ERR_PTR(-ENOMEM);
 135
 136         vport->dp = parms->dp;
 137         vport->port_no = parms->port_no;
 138         vport->upcall_portid = parms->upcall_portid;
 139         vport->ops = ops;
 140         INIT_HLIST_NODE(&vport->dp_hash_node);
 141
 142         vport->percpu_stats = alloc_percpu(struct pcpu_sw_netstats);
 143         if (!vport->percpu_stats) {
 144                 kfree(vport);
 145                 return ERR_PTR(-ENOMEM);
 146         }
 147
 148         for_each_possible_cpu(i) {
 149                 struct pcpu_sw_netstats *vport_stats;
 150                 vport_stats = per_cpu_ptr(vport->percpu_stats, i);
 151                 u64_stats_init(&vport_stats->syncp);
 152         }
 153
 154
 155         spin_lock_init(&vport->stats_lock);
 156
 157         return vport;
 158 }
 159
 160 /**
 161  *      ovs_vport_free - uninitialize and free vport
 162  *
 163  * @vport: vport to free
 164  *
 165  * Frees a vport allocated with vport_alloc() when it is no longer needed.
 166  *
 167  * The caller must ensure that an RCU grace period has passed since the last
 168  * time @vport was in a datapath.
 169  */
 170 void ovs_vport_free(struct vport *vport)
 171 {
 172         free_percpu(vport->percpu_stats);
 173         kfree(vport);
 174 }
 175
 176 /**
 177  *      ovs_vport_add - add vport device (for kernel callers)
 178  *
 179  * @parms: Information about new vport.
 180  *
 181  * Creates a new vport with the specified configuration (which is dependent on
 182  * device type).  ovs_mutex must be held.
 183  */
 184 struct vport *ovs_vport_add(const struct vport_parms *parms)
 185 {
 186         struct vport *vport;
 187         int err = 0;
 188         int i;
 189
 190         for (i = 0; i < ARRAY_SIZE(vport_ops_list); i++) {
 191                 if (vport_ops_list[i]->type == parms->type) {
 192                         struct hlist_head *bucket;
 193
 194                         vport = vport_ops_list[i]->create(parms);
 195                         if (IS_ERR(vport)) {
 196                                 err = PTR_ERR(vport);
 197                                 goto out;
 198                         }
 199
 200                         bucket = hash_bucket(ovs_dp_get_net(vport->dp),
 201                                              vport->ops->get_name(vport));
 202                         hlist_add_head_rcu(&vport->hash_node, bucket);
 203                         return vport;
 204                 }
 205         }
 206
 207         err = -EAFNOSUPPORT;
 208
 209 out:
 210         return ERR_PTR(err);
 211 }
 212
 213 /**
 214  *      ovs_vport_set_options - modify existing vport device (for kernel callers)
 215  *
 216  * @vport: vport to modify.
 217  * @options: New configuration.
 218  *
 219  * Modifies an existing device with the specified configuration (which is
 220  * dependent on device type).  ovs_mutex must be held.
 221  */
 222 int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
 223 {
 224         if (!vport->ops->set_options)
 225                 return -EOPNOTSUPP;
 226         return vport->ops->set_options(vport, options);
 227 }
 228
 229 /**
 230  *      ovs_vport_del - delete existing vport device
 231  *
 232  * @vport: vport to delete.
 233  *
 234  * Detaches @vport from its datapath and destroys it.  It is possible to fail
 235  * for reasons such as lack of memory.  ovs_mutex must be held.
 236  */
 237 void ovs_vport_del(struct vport *vport)
 238 {
 239         ASSERT_OVSL();
 240
 241         hlist_del_rcu(&vport->hash_node);
 242
 243         vport->ops->destroy(vport);
 244 }
 245
 246 /**
 247  *      ovs_vport_get_stats - retrieve device stats
 248  *
 249  * @vport: vport from which to retrieve the stats
 250  * @stats: location to store stats
 251  *
 252  * Retrieves transmit, receive, and error stats for the given device.
 253  *
 254  * Must be called with ovs_mutex or rcu_read_lock.
 255  */
 256 void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
 257 {
 258         int i;
 259
 260         memset(stats, 0, sizeof(*stats));
 261
 262         /* We potentially have 2 sources of stats that need to be combined:
 263          * those we have collected (split into err_stats and percpu_stats) from
 264          * set_stats() and device error stats from netdev->get_stats() (for
 265          * errors that happen  downstream and therefore aren't reported through
 266          * our vport_record_error() function).
 267          * Stats from first source are reported by ovs (OVS_VPORT_ATTR_STATS).
 268          * netdev-stats can be directly read over netlink-ioctl.
 269          */
 270
 271         spin_lock_bh(&vport->stats_lock);
 272
 273         stats->rx_errors        = vport->err_stats.rx_errors;
 274         stats->tx_errors        = vport->err_stats.tx_errors;
 275         stats->tx_dropped       = vport->err_stats.tx_dropped;
 276         stats->rx_dropped       = vport->err_stats.rx_dropped;
 277
 278         spin_unlock_bh(&vport->stats_lock);
 279
 280         for_each_possible_cpu(i) {
 281                 const struct pcpu_sw_netstats *percpu_stats;
 282                 struct pcpu_sw_netstats local_stats;
 283                 unsigned int start;
 284
 285                 percpu_stats = per_cpu_ptr(vport->percpu_stats, i);
 286
 287                 do {
 288                         start = u64_stats_fetch_begin_bh(&percpu_stats->syncp);
 289                         local_stats = *percpu_stats;
 290                 } while (u64_stats_fetch_retry_bh(&percpu_stats->syncp, start));
 291
 292                 stats->rx_bytes         += local_stats.rx_bytes;
 293                 stats->rx_packets       += local_stats.rx_packets;
 294                 stats->tx_bytes         += local_stats.tx_bytes;
 295                 stats->tx_packets       += local_stats.tx_packets;
 296         }
 297 }
 298
 299 /**
 300  *      ovs_vport_get_options - retrieve device options
 301  *
 302  * @vport: vport from which to retrieve the options.
 303  * @skb: sk_buff where options should be appended.
 304  *
 305  * Retrieves the configuration of the given device, appending an
 306  * %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
 307  * vport-specific attributes to @skb.
 308  *
 309  * Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
 310  * negative error code if a real error occurred.  If an error occurs, @skb is
 311  * left unmodified.
 312  *
 313  * Must be called with ovs_mutex or rcu_read_lock.
 314  */
 315 int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
 316 {
 317         struct nlattr *nla;
 318         int err;
 319
 320         if (!vport->ops->get_options)
 321                 return 0;
 322
 323         nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
 324         if (!nla)
 325                 return -EMSGSIZE;
 326
 327         err = vport->ops->get_options(vport, skb);
 328         if (err) {
 329                 nla_nest_cancel(skb, nla);
 330                 return err;
 331         }
 332
 333         nla_nest_end(skb, nla);
 334         return 0;
 335 }
 336
 337 /**
 338  *      ovs_vport_receive - pass up received packet to the datapath for processing
 339  *
 340  * @vport: vport that received the packet
 341  * @skb: skb that was received
 342  * @tun_key: tunnel (if any) that carried packet
 343  *
 344  * Must be called with rcu_read_lock.  The packet cannot be shared and
 345  * skb->data should point to the Ethernet header.
 346  */
 347 void ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
 348                        struct ovs_key_ipv4_tunnel *tun_key)
 349 {
 350         struct pcpu_sw_netstats *stats;
 351
 352         stats = this_cpu_ptr(vport->percpu_stats);
 353         u64_stats_update_begin(&stats->syncp);
 354         stats->rx_packets++;
 355         stats->rx_bytes += skb->len;
 356         u64_stats_update_end(&stats->syncp);
 357
 358         OVS_CB(skb)->tun_key = tun_key;
 359         ovs_dp_process_received_packet(vport, skb);
 360 }
 361
 362 /**
 363  *      ovs_vport_send - send a packet on a device
 364  *
 365  * @vport: vport on which to send the packet
 366  * @skb: skb to send
 367  *
 368  * Sends the given packet and returns the length of data sent.  Either ovs
 369  * lock or rcu_read_lock must be held.
 370  */
 371 int ovs_vport_send(struct vport *vport, struct sk_buff *skb)
 372 {
 373         int sent = vport->ops->send(vport, skb);
 374
 375         if (likely(sent > 0)) {
 376                 struct pcpu_sw_netstats *stats;
 377
 378                 stats = this_cpu_ptr(vport->percpu_stats);
 379
 380                 u64_stats_update_begin(&stats->syncp);
 381                 stats->tx_packets++;
 382                 stats->tx_bytes += sent;
 383                 u64_stats_update_end(&stats->syncp);
 384         } else if (sent < 0) {
 385                 ovs_vport_record_error(vport, VPORT_E_TX_ERROR);
 386                 kfree_skb(skb);
 387         } else
 388                 ovs_vport_record_error(vport, VPORT_E_TX_DROPPED);
 389
 390         return sent;
 391 }
 392
 393 /**
 394  *      ovs_vport_record_error - indicate device error to generic stats layer
 395  *
 396  * @vport: vport that encountered the error
 397  * @err_type: one of enum vport_err_type types to indicate the error type
 398  *
 399  * If using the vport generic stats layer indicate that an error of the given
 400  * type has occurred.
 401  */
 402 static void ovs_vport_record_error(struct vport *vport,
 403                                    enum vport_err_type err_type)
 404 {
 405         spin_lock(&vport->stats_lock);
 406
 407         switch (err_type) {
 408         case VPORT_E_RX_DROPPED:
 409                 vport->err_stats.rx_dropped++;
 410                 break;
 411
 412         case VPORT_E_RX_ERROR:
 413                 vport->err_stats.rx_errors++;
 414                 break;
 415
 416         case VPORT_E_TX_DROPPED:
 417                 vport->err_stats.tx_dropped++;
 418                 break;
 419
 420         case VPORT_E_TX_ERROR:
 421                 vport->err_stats.tx_errors++;
 422                 break;
 423         }
 424
 425         spin_unlock(&vport->stats_lock);
 426 }
 427
 428 static void free_vport_rcu(struct rcu_head *rcu)
 429 {
 430         struct vport *vport = container_of(rcu, struct vport, rcu);
 431
 432         ovs_vport_free(vport);
 433 }
 434
 435 void ovs_vport_deferred_free(struct vport *vport)
 436 {
 437         if (!vport)
 438                 return;
 439
 440         call_rcu(&vport->rcu, free_vport_rcu);
 441 }