lib/netdev-provider.h

   1 /*
   2  * Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef NETDEV_PROVIDER_H
  18 #define NETDEV_PROVIDER_H 1
  19
  20 /* Generic interface to network devices. */
  21
  22 #include "netdev.h"
  23 #include "list.h"
  24 #include "shash.h"
  25 #include "smap.h"
  26
  27 #ifdef  __cplusplus
  28 extern "C" {
  29 #endif
  30
  31 /* A network device (e.g. an Ethernet device).
  32  *
  33  * This structure should be treated as opaque by network device
  34  * implementations. */
  35 struct netdev_dev {
  36     char *name;                         /* Name of network device. */
  37     const struct netdev_class *netdev_class; /* Functions to control
  38                                                 this device. */
  39     int ref_cnt;                        /* Times this devices was opened. */
  40     struct shash_node *node;            /* Pointer to element in global map. */
  41 };
  42
  43 void netdev_dev_init(struct netdev_dev *, const char *name,
  44                      const struct netdev_class *);
  45 void netdev_dev_uninit(struct netdev_dev *, bool destroy);
  46 const char *netdev_dev_get_type(const struct netdev_dev *);
  47 const struct netdev_class *netdev_dev_get_class(const struct netdev_dev *);
  48 const char *netdev_dev_get_name(const struct netdev_dev *);
  49 struct netdev_dev *netdev_dev_from_name(const char *name);
  50 void netdev_dev_get_devices(const struct netdev_class *,
  51                             struct shash *device_list);
  52
  53 static inline void netdev_dev_assert_class(const struct netdev_dev *netdev_dev,
  54                                            const struct netdev_class *class_)
  55 {
  56     ovs_assert(netdev_dev->netdev_class == class_);
  57 }
  58
  59 /* A instance of an open network device.
  60  *
  61  * This structure should be treated as opaque by network device
  62  * implementations. */
  63 struct netdev {
  64     struct netdev_dev *netdev_dev;   /* Parent netdev_dev. */
  65     struct list node;                /* Element in global list. */
  66
  67     enum netdev_flags save_flags;    /* Initial device flags. */
  68     enum netdev_flags changed_flags; /* Flags that we changed. */
  69 };
  70
  71 void netdev_init(struct netdev *, struct netdev_dev *);
  72 void netdev_uninit(struct netdev *, bool close);
  73 struct netdev_dev *netdev_get_dev(const struct netdev *);
  74
  75 static inline void netdev_assert_class(const struct netdev *netdev,
  76                                        const struct netdev_class *netdev_class)
  77 {
  78     netdev_dev_assert_class(netdev_get_dev(netdev), netdev_class);
  79 }
  80
  81 /* Network device class structure, to be defined by each implementation of a
  82  * network device.
  83  *
  84  * These functions return 0 if successful or a positive errno value on failure,
  85  * except where otherwise noted. */
  86 struct netdev_class {
  87     /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc.
  88      *
  89      * One of the providers should supply a "system" type, since this is
  90      * the type assumed if no type is specified when opening a netdev.
  91      * The "system" type corresponds to an existing network device on
  92      * the system. */
  93     const char *type;
  94
  95     /* Called when the netdev provider is registered, typically at program
  96      * startup.  Returning an error from this function will prevent any network
  97      * device in this class from being opened.
  98      *
  99      * This function may be set to null if a network device class needs no
 100      * initialization at registration time. */
 101     int (*init)(void);
 102
 103     /* Performs periodic work needed by netdevs of this class.  May be null if
 104      * no periodic work is necessary. */
 105     void (*run)(void);
 106
 107     /* Arranges for poll_block() to wake up if the "run" member function needs
 108      * to be called.  Implementations are additionally required to wake
 109      * whenever something changes in any of its netdevs which would cause their
 110      * ->change_seq() function to change its result.  May be null if nothing is
 111      * needed here. */
 112     void (*wait)(void);
 113
 114     /* Attempts to create a network device named 'name' in 'netdev_class'.  On
 115      * success sets 'netdev_devp' to the newly created device. */
 116     int (*create)(const struct netdev_class *netdev_class, const char *name,
 117                   struct netdev_dev **netdev_devp);
 118
 119     /* Destroys 'netdev_dev'.
 120      *
 121      * Netdev devices maintain a reference count that is incremented on
 122      * netdev_open() and decremented on netdev_close().  If 'netdev_dev'
 123      * has a non-zero reference count, then this function will not be
 124      * called. */
 125     void (*destroy)(struct netdev_dev *netdev_dev);
 126
 127     /* Fetches the device 'netdev_dev''s configuration, storing it in 'args'.
 128      * The caller owns 'args' and pre-initializes it to an empty smap.
 129      *
 130      * If this netdev class does not have any configuration options, this may
 131      * be a null pointer. */
 132     int (*get_config)(struct netdev_dev *netdev_dev, struct smap *args);
 133
 134     /* Changes the device 'netdev_dev''s configuration to 'args'.
 135      *
 136      * If this netdev class does not support configuration, this may be a null
 137      * pointer. */
 138     int (*set_config)(struct netdev_dev *netdev_dev, const struct smap *args);
 139
 140     /* Returns the tunnel configuration of 'netdev_dev'.  If 'netdev_dev' is
 141      * not a tunnel, returns null.
 142      *
 143      * If this function would always return null, it may be null instead. */
 144     const struct netdev_tunnel_config *
 145         (*get_tunnel_config)(const struct netdev_dev *netdev_dev);
 146
 147     /* Attempts to open a network device.  On success, sets 'netdevp'
 148      * to the new network device. */
 149     int (*open)(struct netdev_dev *netdev_dev, struct netdev **netdevp);
 150
 151     /* Closes 'netdev'. */
 152     void (*close)(struct netdev *netdev);
 153 \f
 154 /* ## ----------------- ## */
 155 /* ## Receiving Packets ## */
 156 /* ## ----------------- ## */
 157
 158 /* The network provider interface is mostly used for inspecting and configuring
 159  * device "metadata", not for sending and receiving packets directly.  It may
 160  * be impractical to implement these functions on some operating systems and
 161  * hardware.  These functions may all be NULL in such cases.
 162  *
 163  * (However, the "dpif-netdev" implementation, which is the easiest way to
 164  * integrate Open vSwitch with a new operating system or hardware, does require
 165  * the ability to receive packets.) */
 166
 167     /* Attempts to set up 'netdev' for receiving packets with ->recv().
 168      * Returns 0 if successful, otherwise a positive errno value.  Return
 169      * EOPNOTSUPP to indicate that the network device does not implement packet
 170      * reception through this interface.  This function may be set to null if
 171      * it would always return EOPNOTSUPP anyhow.  (This will prevent the
 172      * network device from being usefully used by the netdev-based "userspace
 173      * datapath".)*/
 174     int (*listen)(struct netdev *netdev);
 175
 176     /* Attempts to receive a packet from 'netdev' into the 'size' bytes in
 177      * 'buffer'.  If successful, returns the number of bytes in the received
 178      * packet, otherwise a negative errno value.  Returns -EAGAIN immediately
 179      * if no packet is ready to be received.
 180      *
 181      * Returns -EMSGSIZE, and discards the packet, if the received packet is
 182      * longer than 'size' bytes.
 183      *
 184      * This function can only be expected to return a packet if ->listen() has
 185      * been called successfully.
 186      *
 187      * May be null if not needed, such as for a network device that does not
 188      * implement packet reception through the 'recv' member function. */
 189     int (*recv)(struct netdev *netdev, void *buffer, size_t size);
 190
 191     /* Registers with the poll loop to wake up from the next call to
 192      * poll_block() when a packet is ready to be received with netdev_recv() on
 193      * 'netdev'.
 194      *
 195      * May be null if not needed, such as for a network device that does not
 196      * implement packet reception through the 'recv' member function. */
 197     void (*recv_wait)(struct netdev *netdev);
 198
 199     /* Discards all packets waiting to be received from 'netdev'.
 200      *
 201      * May be null if not needed, such as for a network device that does not
 202      * implement packet reception through the 'recv' member function. */
 203     int (*drain)(struct netdev *netdev);
 204 \f
 205     /* Sends the 'size'-byte packet in 'buffer' on 'netdev'.  Returns 0 if
 206      * successful, otherwise a positive errno value.  Returns EAGAIN without
 207      * blocking if the packet cannot be queued immediately.  Returns EMSGSIZE
 208      * if a partial packet was transmitted or if the packet is too big or too
 209      * small to transmit on the device.
 210      *
 211      * The caller retains ownership of 'buffer' in all cases.
 212      *
 213      * The network device is expected to maintain a packet transmission queue,
 214      * so that the caller does not ordinarily have to do additional queuing of
 215      * packets.
 216      *
 217      * May return EOPNOTSUPP if a network device does not implement packet
 218      * transmission through this interface.  This function may be set to null
 219      * if it would always return EOPNOTSUPP anyhow.  (This will prevent the
 220      * network device from being usefully used by the netdev-based "userspace
 221      * datapath".  It will also prevent the OVS implementation of bonding from
 222      * working properly over 'netdev'.) */
 223     int (*send)(struct netdev *netdev, const void *buffer, size_t size);
 224
 225     /* Registers with the poll loop to wake up from the next call to
 226      * poll_block() when the packet transmission queue for 'netdev' has
 227      * sufficient room to transmit a packet with netdev_send().
 228      *
 229      * The network device is expected to maintain a packet transmission queue,
 230      * so that the caller does not ordinarily have to do additional queuing of
 231      * packets.  Thus, this function is unlikely to ever be useful.
 232      *
 233      * May be null if not needed, such as for a network device that does not
 234      * implement packet transmission through the 'send' member function. */
 235     void (*send_wait)(struct netdev *netdev);
 236
 237     /* Sets 'netdev''s Ethernet address to 'mac' */
 238     int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]);
 239
 240     /* Retrieves 'netdev''s Ethernet address into 'mac'.
 241      *
 242      * This address will be advertised as 'netdev''s MAC address through the
 243      * OpenFlow protocol, among other uses. */
 244     int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]);
 245
 246     /* Retrieves 'netdev''s MTU into '*mtup'.
 247      *
 248      * The MTU is the maximum size of transmitted (and received) packets, in
 249      * bytes, not including the hardware header; thus, this is typically 1500
 250      * bytes for Ethernet devices.
 251      *
 252      * If 'netdev' does not have an MTU (e.g. as some tunnels do not), then
 253      * this function should return EOPNOTSUPP.  This function may be set to
 254      * null if it would always return EOPNOTSUPP. */
 255     int (*get_mtu)(const struct netdev *netdev, int *mtup);
 256
 257     /* Sets 'netdev''s MTU to 'mtu'.
 258      *
 259      * If 'netdev' does not have an MTU (e.g. as some tunnels do not), then
 260      * this function should return EOPNOTSUPP.  This function may be set to
 261      * null if it would always return EOPNOTSUPP. */
 262     int (*set_mtu)(const struct netdev *netdev, int mtu);
 263
 264     /* Returns the ifindex of 'netdev', if successful, as a positive number.
 265      * On failure, returns a negative errno value.
 266      *
 267      * The desired semantics of the ifindex value are a combination of those
 268      * specified by POSIX for if_nametoindex() and by SNMP for ifIndex.  An
 269      * ifindex value should be unique within a host and remain stable at least
 270      * until reboot.  SNMP says an ifindex "ranges between 1 and the value of
 271      * ifNumber" but many systems do not follow this rule anyhow.
 272      *
 273      * This function may be set to null if it would always return -EOPNOTSUPP.
 274      */
 275     int (*get_ifindex)(const struct netdev *netdev);
 276
 277     /* Sets 'carrier' to true if carrier is active (link light is on) on
 278      * 'netdev'.
 279      *
 280      * May be null if device does not provide carrier status (will be always
 281      * up as long as device is up).
 282      */
 283     int (*get_carrier)(const struct netdev *netdev, bool *carrier);
 284
 285     /* Returns the number of times 'netdev''s carrier has changed since being
 286      * initialized.
 287      *
 288      * If null, callers will assume the number of carrier resets is zero. */
 289     long long int (*get_carrier_resets)(const struct netdev *netdev);
 290
 291     /* Forces ->get_carrier() to poll 'netdev''s MII registers for link status
 292      * instead of checking 'netdev''s carrier.  'netdev''s MII registers will
 293      * be polled once ever 'interval' milliseconds.  If 'netdev' does not
 294      * support MII, another method may be used as a fallback.  If 'interval' is
 295      * less than or equal to zero, reverts ->get_carrier() to its normal
 296      * behavior.
 297      *
 298      * Most network devices won't support this feature and will set this
 299      * function pointer to NULL, which is equivalent to returning EOPNOTSUPP.
 300      */
 301     int (*set_miimon_interval)(struct netdev *netdev, long long int interval);
 302
 303     /* Retrieves current device stats for 'netdev' into 'stats'.
 304      *
 305      * A network device that supports some statistics but not others, it should
 306      * set the values of the unsupported statistics to all-1-bits
 307      * (UINT64_MAX). */
 308     int (*get_stats)(const struct netdev *netdev, struct netdev_stats *);
 309
 310     /* Sets the device stats for 'netdev' to 'stats'.
 311      *
 312      * Most network devices won't support this feature and will set this
 313      * function pointer to NULL, which is equivalent to returning EOPNOTSUPP.
 314      *
 315      * Some network devices might only allow setting their stats to 0. */
 316     int (*set_stats)(struct netdev *netdev, const struct netdev_stats *);
 317
 318     /* Stores the features supported by 'netdev' into each of '*current',
 319      * '*advertised', '*supported', and '*peer'.  Each value is a bitmap of
 320      * NETDEV_F_* bits.
 321      *
 322      * This function may be set to null if it would always return EOPNOTSUPP.
 323      */
 324     int (*get_features)(const struct netdev *netdev,
 325                         enum netdev_features *current,
 326                         enum netdev_features *advertised,
 327                         enum netdev_features *supported,
 328                         enum netdev_features *peer);
 329
 330     /* Set the features advertised by 'netdev' to 'advertise', which is a
 331      * set of NETDEV_F_* bits.
 332      *
 333      * This function may be set to null for a network device that does not
 334      * support configuring advertisements. */
 335     int (*set_advertisements)(struct netdev *netdev,
 336                               enum netdev_features advertise);
 337
 338     /* Attempts to set input rate limiting (policing) policy, such that up to
 339      * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative
 340      * burst size of 'kbits' kb.
 341      *
 342      * This function may be set to null if policing is not supported. */
 343     int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate,
 344                         unsigned int kbits_burst);
 345
 346     /* Adds to 'types' all of the forms of QoS supported by 'netdev', or leaves
 347      * it empty if 'netdev' does not support QoS.  Any names added to 'types'
 348      * should be documented as valid for the "type" column in the "QoS" table
 349      * in vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 350      *
 351      * Every network device must support disabling QoS with a type of "", but
 352      * this function must not add "" to 'types'.
 353      *
 354      * The caller is responsible for initializing 'types' (e.g. with
 355      * sset_init()) before calling this function.  The caller retains ownership
 356      * of 'types'.
 357      *
 358      * May be NULL if 'netdev' does not support QoS at all. */
 359     int (*get_qos_types)(const struct netdev *netdev, struct sset *types);
 360
 361     /* Queries 'netdev' for its capabilities regarding the specified 'type' of
 362      * QoS.  On success, initializes 'caps' with the QoS capabilities.
 363      *
 364      * Should return EOPNOTSUPP if 'netdev' does not support 'type'.  May be
 365      * NULL if 'netdev' does not support QoS at all. */
 366     int (*get_qos_capabilities)(const struct netdev *netdev,
 367                                 const char *type,
 368                                 struct netdev_qos_capabilities *caps);
 369
 370     /* Queries 'netdev' about its currently configured form of QoS.  If
 371      * successful, stores the name of the current form of QoS into '*typep'
 372      * and any details of configuration as string key-value pairs in
 373      * 'details'.
 374      *
 375      * A '*typep' of "" indicates that QoS is currently disabled on 'netdev'.
 376      *
 377      * The caller initializes 'details' before calling this function.  The
 378      * caller takes ownership of the string key-values pairs added to
 379      * 'details'.
 380      *
 381      * The netdev retains ownership of '*typep'.
 382      *
 383      * '*typep' will be one of the types returned by netdev_get_qos_types() for
 384      * 'netdev'.  The contents of 'details' should be documented as valid for
 385      * '*typep' in the "other_config" column in the "QoS" table in
 386      * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 387      *
 388      * May be NULL if 'netdev' does not support QoS at all. */
 389     int (*get_qos)(const struct netdev *netdev,
 390                    const char **typep, struct smap *details);
 391
 392     /* Attempts to reconfigure QoS on 'netdev', changing the form of QoS to
 393      * 'type' with details of configuration from 'details'.
 394      *
 395      * On error, the previous QoS configuration is retained.
 396      *
 397      * When this function changes the type of QoS (not just 'details'), this
 398      * also resets all queue configuration for 'netdev' to their defaults
 399      * (which depend on the specific type of QoS).  Otherwise, the queue
 400      * configuration for 'netdev' is unchanged.
 401      *
 402      * 'type' should be "" (to disable QoS) or one of the types returned by
 403      * netdev_get_qos_types() for 'netdev'.  The contents of 'details' should
 404      * be documented as valid for the given 'type' in the "other_config" column
 405      * in the "QoS" table in vswitchd/vswitch.xml (which is built as
 406      * ovs-vswitchd.conf.db(8)).
 407      *
 408      * May be NULL if 'netdev' does not support QoS at all. */
 409     int (*set_qos)(struct netdev *netdev,
 410                    const char *type, const struct smap *details);
 411
 412     /* Queries 'netdev' for information about the queue numbered 'queue_id'.
 413      * If successful, adds that information as string key-value pairs to
 414      * 'details'.  Returns 0 if successful, otherwise a positive errno value.
 415      *
 416      * Should return EINVAL if 'queue_id' is greater than or equal to the
 417      * number of supported queues (as reported in the 'n_queues' member of
 418      * struct netdev_qos_capabilities by 'get_qos_capabilities').
 419      *
 420      * The caller initializes 'details' before calling this function.  The
 421      * caller takes ownership of the string key-values pairs added to
 422      * 'details'.
 423      *
 424      * The returned contents of 'details' should be documented as valid for the
 425      * given 'type' in the "other_config" column in the "Queue" table in
 426      * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 427      */
 428     int (*get_queue)(const struct netdev *netdev,
 429                      unsigned int queue_id, struct smap *details);
 430
 431     /* Configures the queue numbered 'queue_id' on 'netdev' with the key-value
 432      * string pairs in 'details'.  The contents of 'details' should be
 433      * documented as valid for the given 'type' in the "other_config" column in
 434      * the "Queue" table in vswitchd/vswitch.xml (which is built as
 435      * ovs-vswitchd.conf.db(8)).  Returns 0 if successful, otherwise a positive
 436      * errno value.  On failure, the given queue's configuration should be
 437      * unmodified.
 438      *
 439      * Should return EINVAL if 'queue_id' is greater than or equal to the
 440      * number of supported queues (as reported in the 'n_queues' member of
 441      * struct netdev_qos_capabilities by 'get_qos_capabilities'), or if
 442      * 'details' is invalid for the type of queue.
 443      *
 444      * This function does not modify 'details', and the caller retains
 445      * ownership of it.
 446      *
 447      * May be NULL if 'netdev' does not support QoS at all. */
 448     int (*set_queue)(struct netdev *netdev,
 449                      unsigned int queue_id, const struct smap *details);
 450
 451     /* Attempts to delete the queue numbered 'queue_id' from 'netdev'.
 452      *
 453      * Should return EINVAL if 'queue_id' is greater than or equal to the
 454      * number of supported queues (as reported in the 'n_queues' member of
 455      * struct netdev_qos_capabilities by 'get_qos_capabilities').  Should
 456      * return EOPNOTSUPP if 'queue_id' is valid but may not be deleted (e.g. if
 457      * 'netdev' has a fixed set of queues with the current QoS mode).
 458      *
 459      * May be NULL if 'netdev' does not support QoS at all, or if all of its
 460      * QoS modes have fixed sets of queues. */
 461     int (*delete_queue)(struct netdev *netdev, unsigned int queue_id);
 462
 463     /* Obtains statistics about 'queue_id' on 'netdev'.  Fills 'stats' with the
 464      * queue's statistics.  May set individual members of 'stats' to all-1-bits
 465      * if the statistic is unavailable.
 466      *
 467      * May be NULL if 'netdev' does not support QoS at all. */
 468     int (*get_queue_stats)(const struct netdev *netdev, unsigned int queue_id,
 469                            struct netdev_queue_stats *stats);
 470
 471     /* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's
 472      * ID, its configuration, and the 'aux' specified by the caller.  The order
 473      * of iteration is unspecified, but (when successful) each queue is visited
 474      * exactly once.
 475      *
 476      * 'cb' will not modify or free the 'details' argument passed in.  It may
 477      * delete or modify the queue passed in as its 'queue_id' argument.  It may
 478      * modify but will not delete any other queue within 'netdev'.  If 'cb'
 479      * adds new queues, then ->dump_queues is allowed to visit some queues
 480      * twice or not at all.
 481      */
 482     int (*dump_queues)(const struct netdev *netdev,
 483                        void (*cb)(unsigned int queue_id,
 484                                   const struct smap *details,
 485                                   void *aux),
 486                        void *aux);
 487
 488     /* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's
 489      * ID, its statistics, and the 'aux' specified by the caller.  The order of
 490      * iteration is unspecified, but (when successful) each queue must be
 491      * visited exactly once.
 492      *
 493      * 'cb' will not modify or free the statistics passed in. */
 494     int (*dump_queue_stats)(const struct netdev *netdev,
 495                             void (*cb)(unsigned int queue_id,
 496                                        struct netdev_queue_stats *,
 497                                        void *aux),
 498                             void *aux);
 499
 500     /* If 'netdev' has an assigned IPv4 address, sets '*address' to that
 501      * address and '*netmask' to the associated netmask.
 502      *
 503      * The following error values have well-defined meanings:
 504      *
 505      *   - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address.
 506      *
 507      *   - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'.
 508      *
 509      * This function may be set to null if it would always return EOPNOTSUPP
 510      * anyhow. */
 511     int (*get_in4)(const struct netdev *netdev, struct in_addr *address,
 512                    struct in_addr *netmask);
 513
 514     /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask.  If
 515      * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared.
 516      *
 517      * This function may be set to null if it would always return EOPNOTSUPP
 518      * anyhow. */
 519     int (*set_in4)(struct netdev *netdev, struct in_addr addr,
 520                    struct in_addr mask);
 521
 522     /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address.
 523      *
 524      * The following error values have well-defined meanings:
 525      *
 526      *   - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address.
 527      *
 528      *   - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'.
 529      *
 530      * This function may be set to null if it would always return EOPNOTSUPP
 531      * anyhow. */
 532     int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6);
 533
 534     /* Adds 'router' as a default IP gateway for the TCP/IP stack that
 535      * corresponds to 'netdev'.
 536      *
 537      * This function may be set to null if it would always return EOPNOTSUPP
 538      * anyhow. */
 539     int (*add_router)(struct netdev *netdev, struct in_addr router);
 540
 541     /* Looks up the next hop for 'host'.  If succesful, stores the next hop
 542      * gateway's address (0 if 'host' is on a directly connected network) in
 543      * '*next_hop' and a copy of the name of the device to reach 'host' in
 544      * '*netdev_name', and returns 0.  The caller is responsible for freeing
 545      * '*netdev_name' (by calling free()).
 546      *
 547      * This function may be set to null if it would always return EOPNOTSUPP
 548      * anyhow. */
 549     int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop,
 550                         char **netdev_name);
 551
 552     /* Retrieves driver information of the device.
 553      *
 554      * Populates 'smap' with key-value pairs representing the status of the
 555      * device.  'smap' is a set of key-value string pairs representing netdev
 556      * type specific information.  For more information see
 557      * ovs-vswitchd.conf.db(5).
 558      *
 559      * The caller is responsible for destroying 'smap' and its data.
 560      *
 561      * This function may be set to null if it would always return EOPNOTSUPP
 562      * anyhow. */
 563     int (*get_status)(const struct netdev *netdev, struct smap *smap);
 564
 565     /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the
 566      * corresponding MAC address in 'mac'.  A return value of ENXIO, in
 567      * particular, indicates that there is no ARP table entry for 'ip' on
 568      * 'netdev'.
 569      *
 570      * This function may be set to null if it would always return EOPNOTSUPP
 571      * anyhow. */
 572     int (*arp_lookup)(const struct netdev *netdev, ovs_be32 ip,
 573                       uint8_t mac[6]);
 574
 575     /* Retrieves the current set of flags on 'netdev' into '*old_flags'.
 576      * Then, turns off the flags that are set to 1 in 'off' and turns on the
 577      * flags that are set to 1 in 'on'.  (No bit will be set to 1 in both 'off'
 578      * and 'on'; that is, off & on == 0.)
 579      *
 580      * This function may be invoked from a signal handler.  Therefore, it
 581      * should not do anything that is not signal-safe (such as logging). */
 582     int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
 583                         enum netdev_flags on, enum netdev_flags *old_flags);
 584
 585     /* Returns a sequence number which indicates changes in one of 'netdev''s
 586      * properties.  The returned sequence number must be nonzero so that
 587      * callers have a value which they may use as a reset when tracking
 588      * 'netdev'.
 589      *
 590      * Minimally, the returned sequence number is required to change whenever
 591      * 'netdev''s flags, features, ethernet address, or carrier changes.  The
 592      * returned sequence number is allowed to change even when 'netdev' doesn't
 593      * change, although implementations should try to avoid this. */
 594     unsigned int (*change_seq)(const struct netdev *netdev);
 595 };
 596
 597 int netdev_register_provider(const struct netdev_class *);
 598 int netdev_unregister_provider(const char *type);
 599 const struct netdev_class *netdev_lookup_provider(const char *type);
 600
 601 extern const struct netdev_class netdev_linux_class;
 602 extern const struct netdev_class netdev_internal_class;
 603 extern const struct netdev_class netdev_tap_class;
 604 #ifdef __FreeBSD__
 605 extern const struct netdev_class netdev_bsd_class;
 606 #endif
 607
 608 #ifdef  __cplusplus
 609 }
 610 #endif
 611
 612 #endif /* netdev.h */