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  * Network device implementations may read these members but should not modify
  34  * them. */
  35 struct netdev {
  36     /* The following do not change during the lifetime of a struct netdev. */
  37     char *name;                         /* Name of network device. */
  38     const struct netdev_class *netdev_class; /* Functions to control
  39                                                 this device. */
  40
  41     /* The following are protected by 'netdev_mutex' (internal to netdev.c). */
  42     int n_rxq;
  43     int ref_cnt;                        /* Times this devices was opened. */
  44     struct shash_node *node;            /* Pointer to element in global map. */
  45     struct list saved_flags_list; /* Contains "struct netdev_saved_flags". */
  46 };
  47
  48 const char *netdev_get_type(const struct netdev *);
  49 const struct netdev_class *netdev_get_class(const struct netdev *);
  50 const char *netdev_get_name(const struct netdev *);
  51 struct netdev *netdev_from_name(const char *name);
  52 void netdev_get_devices(const struct netdev_class *,
  53                         struct shash *device_list);
  54
  55 /* A data structure for capturing packets received by a network device.
  56  *
  57  * Network device implementations may read these members but should not modify
  58  * them.
  59  *
  60  * None of these members change during the lifetime of a struct netdev_rxq. */
  61 struct netdev_rxq {
  62     struct netdev *netdev;      /* Owns a reference to the netdev. */
  63     int queue_id;
  64 };
  65
  66 struct netdev *netdev_rxq_get_netdev(const struct netdev_rxq *);
  67
  68 /* Network device class structure, to be defined by each implementation of a
  69  * network device.
  70  *
  71  * These functions return 0 if successful or a positive errno value on failure,
  72  * except where otherwise noted.
  73  *
  74  *
  75  * Data Structures
  76  * ===============
  77  *
  78  * These functions work primarily with two different kinds of data structures:
  79  *
  80  *   - "struct netdev", which represents a network device.
  81  *
  82  *   - "struct netdev_rxq", which represents a handle for capturing packets
  83  *     received on a network device
  84  *
  85  * Each of these data structures contains all of the implementation-independent
  86  * generic state for the respective concept, called the "base" state.  None of
  87  * them contains any extra space for implementations to use.  Instead, each
  88  * implementation is expected to declare its own data structure that contains
  89  * an instance of the generic data structure plus additional
  90  * implementation-specific members, called the "derived" state.  The
  91  * implementation can use casts or (preferably) the CONTAINER_OF macro to
  92  * obtain access to derived state given only a pointer to the embedded generic
  93  * data structure.
  94  *
  95  *
  96  * Life Cycle
  97  * ==========
  98  *
  99  * Four stylized functions accompany each of these data structures:
 100  *
 101  *            "alloc"          "construct"        "destruct"       "dealloc"
 102  *            ------------   ----------------  ---------------  --------------
 103  * netdev      ->alloc        ->construct        ->destruct        ->dealloc
 104  * netdev_rxq  ->rxq_alloc    ->rxq_construct    ->rxq_destruct    ->rxq_dealloc
 105  *
 106  * Any instance of a given data structure goes through the following life
 107  * cycle:
 108  *
 109  *   1. The client calls the "alloc" function to obtain raw memory.  If "alloc"
 110  *      fails, skip all the other steps.
 111  *
 112  *   2. The client initializes all of the data structure's base state.  If this
 113  *      fails, skip to step 7.
 114  *
 115  *   3. The client calls the "construct" function.  The implementation
 116  *      initializes derived state.  It may refer to the already-initialized
 117  *      base state.  If "construct" fails, skip to step 6.
 118  *
 119  *   4. The data structure is now initialized and in use.
 120  *
 121  *   5. When the data structure is no longer needed, the client calls the
 122  *      "destruct" function.  The implementation uninitializes derived state.
 123  *      The base state has not been uninitialized yet, so the implementation
 124  *      may still refer to it.
 125  *
 126  *   6. The client uninitializes all of the data structure's base state.
 127  *
 128  *   7. The client calls the "dealloc" to free the raw memory.  The
 129  *      implementation must not refer to base or derived state in the data
 130  *      structure, because it has already been uninitialized.
 131  *
 132  * If netdev support multi-queue IO then netdev->construct should set initialize
 133  * netdev->n_rxq to number of queues.
 134  *
 135  * Each "alloc" function allocates and returns a new instance of the respective
 136  * data structure.  The "alloc" function is not given any information about the
 137  * use of the new data structure, so it cannot perform much initialization.
 138  * Its purpose is just to ensure that the new data structure has enough room
 139  * for base and derived state.  It may return a null pointer if memory is not
 140  * available, in which case none of the other functions is called.
 141  *
 142  * Each "construct" function initializes derived state in its respective data
 143  * structure.  When "construct" is called, all of the base state has already
 144  * been initialized, so the "construct" function may refer to it.  The
 145  * "construct" function is allowed to fail, in which case the client calls the
 146  * "dealloc" function (but not the "destruct" function).
 147  *
 148  * Each "destruct" function uninitializes and frees derived state in its
 149  * respective data structure.  When "destruct" is called, the base state has
 150  * not yet been uninitialized, so the "destruct" function may refer to it.  The
 151  * "destruct" function is not allowed to fail.
 152  *
 153  * Each "dealloc" function frees raw memory that was allocated by the the
 154  * "alloc" function.  The memory's base and derived members might not have ever
 155  * been initialized (but if "construct" returned successfully, then it has been
 156  * "destruct"ed already).  The "dealloc" function is not allowed to fail.
 157  *
 158  *
 159  * Device Change Notification
 160  * ==========================
 161  *
 162  * Minimally, implementations are required to report changes to netdev flags,
 163  * features, ethernet address or carrier through connectivity_seq. Changes to
 164  * other properties are allowed to cause notification through this interface,
 165  * although implementations should try to avoid this. connectivity_seq_get()
 166  * can be used to acquire a reference to the struct seq. The interface is
 167  * described in detail in seq.h. */
 168 struct netdev_class {
 169     /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc.
 170      *
 171      * One of the providers should supply a "system" type, since this is
 172      * the type assumed if no type is specified when opening a netdev.
 173      * The "system" type corresponds to an existing network device on
 174      * the system. */
 175     const char *type;
 176
 177 /* ## ------------------- ## */
 178 /* ## Top-Level Functions ## */
 179 /* ## ------------------- ## */
 180
 181     /* Called when the netdev provider is registered, typically at program
 182      * startup.  Returning an error from this function will prevent any network
 183      * device in this class from being opened.
 184      *
 185      * This function may be set to null if a network device class needs no
 186      * initialization at registration time. */
 187     int (*init)(void);
 188
 189     /* Performs periodic work needed by netdevs of this class.  May be null if
 190      * no periodic work is necessary. */
 191     void (*run)(void);
 192
 193     /* Arranges for poll_block() to wake up if the "run" member function needs
 194      * to be called.  Implementations are additionally required to wake
 195      * whenever something changes in any of its netdevs which would cause their
 196      * ->change_seq() function to change its result.  May be null if nothing is
 197      * needed here. */
 198     void (*wait)(void);
 199
 200 /* ## ---------------- ## */
 201 /* ## netdev Functions ## */
 202 /* ## ---------------- ## */
 203
 204     /* Life-cycle functions for a netdev.  See the large comment above on
 205      * struct netdev_class. */
 206     struct netdev *(*alloc)(void);
 207     int (*construct)(struct netdev *);
 208     void (*destruct)(struct netdev *);
 209     void (*dealloc)(struct netdev *);
 210
 211     /* Fetches the device 'netdev''s configuration, storing it in 'args'.
 212      * The caller owns 'args' and pre-initializes it to an empty smap.
 213      *
 214      * If this netdev class does not have any configuration options, this may
 215      * be a null pointer. */
 216     int (*get_config)(const struct netdev *netdev, struct smap *args);
 217
 218     /* Changes the device 'netdev''s configuration to 'args'.
 219      *
 220      * If this netdev class does not support configuration, this may be a null
 221      * pointer. */
 222     int (*set_config)(struct netdev *netdev, const struct smap *args);
 223
 224     /* Returns the tunnel configuration of 'netdev'.  If 'netdev' is
 225      * not a tunnel, returns null.
 226      *
 227      * If this function would always return null, it may be null instead. */
 228     const struct netdev_tunnel_config *
 229         (*get_tunnel_config)(const struct netdev *netdev);
 230
 231     /* Sends the buffer on 'netdev'.
 232      * Returns 0 if successful, otherwise a positive errno value.  Returns
 233      * EAGAIN without blocking if the packet cannot be queued immediately.
 234      * Returns EMSGSIZE if a partial packet was transmitted or if the packet
 235      * is too big or too small to transmit on the device.
 236      *
 237      * To retain ownership of 'buffer' caller can set may_steal to false.
 238      *
 239      * The network device is expected to maintain a packet transmission queue,
 240      * so that the caller does not ordinarily have to do additional queuing of
 241      * packets.
 242      *
 243      * May return EOPNOTSUPP if a network device does not implement packet
 244      * transmission through this interface.  This function may be set to null
 245      * if it would always return EOPNOTSUPP anyhow.  (This will prevent the
 246      * network device from being usefully used by the netdev-based "userspace
 247      * datapath".  It will also prevent the OVS implementation of bonding from
 248      * working properly over 'netdev'.) */
 249     int (*send)(struct netdev *netdev, struct ofpbuf *buffer, bool may_steal);
 250
 251     /* Registers with the poll loop to wake up from the next call to
 252      * poll_block() when the packet transmission queue for 'netdev' has
 253      * sufficient room to transmit a packet with netdev_send().
 254      *
 255      * The network device is expected to maintain a packet transmission queue,
 256      * so that the caller does not ordinarily have to do additional queuing of
 257      * packets.  Thus, this function is unlikely to ever be useful.
 258      *
 259      * May be null if not needed, such as for a network device that does not
 260      * implement packet transmission through the 'send' member function. */
 261     void (*send_wait)(struct netdev *netdev);
 262
 263     /* Sets 'netdev''s Ethernet address to 'mac' */
 264     int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]);
 265
 266     /* Retrieves 'netdev''s Ethernet address into 'mac'.
 267      *
 268      * This address will be advertised as 'netdev''s MAC address through the
 269      * OpenFlow protocol, among other uses. */
 270     int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]);
 271
 272     /* Retrieves 'netdev''s MTU into '*mtup'.
 273      *
 274      * The MTU is the maximum size of transmitted (and received) packets, in
 275      * bytes, not including the hardware header; thus, this is typically 1500
 276      * bytes for Ethernet devices.
 277      *
 278      * If 'netdev' does not have an MTU (e.g. as some tunnels do not), then
 279      * this function should return EOPNOTSUPP.  This function may be set to
 280      * null if it would always return EOPNOTSUPP. */
 281     int (*get_mtu)(const struct netdev *netdev, int *mtup);
 282
 283     /* Sets 'netdev''s MTU to 'mtu'.
 284      *
 285      * If 'netdev' does not have an MTU (e.g. as some tunnels do not), then
 286      * this function should return EOPNOTSUPP.  This function may be set to
 287      * null if it would always return EOPNOTSUPP. */
 288     int (*set_mtu)(const struct netdev *netdev, int mtu);
 289
 290     /* Returns the ifindex of 'netdev', if successful, as a positive number.
 291      * On failure, returns a negative errno value.
 292      *
 293      * The desired semantics of the ifindex value are a combination of those
 294      * specified by POSIX for if_nametoindex() and by SNMP for ifIndex.  An
 295      * ifindex value should be unique within a host and remain stable at least
 296      * until reboot.  SNMP says an ifindex "ranges between 1 and the value of
 297      * ifNumber" but many systems do not follow this rule anyhow.
 298      *
 299      * This function may be set to null if it would always return -EOPNOTSUPP.
 300      */
 301     int (*get_ifindex)(const struct netdev *netdev);
 302
 303     /* Sets 'carrier' to true if carrier is active (link light is on) on
 304      * 'netdev'.
 305      *
 306      * May be null if device does not provide carrier status (will be always
 307      * up as long as device is up).
 308      */
 309     int (*get_carrier)(const struct netdev *netdev, bool *carrier);
 310
 311     /* Returns the number of times 'netdev''s carrier has changed since being
 312      * initialized.
 313      *
 314      * If null, callers will assume the number of carrier resets is zero. */
 315     long long int (*get_carrier_resets)(const struct netdev *netdev);
 316
 317     /* Forces ->get_carrier() to poll 'netdev''s MII registers for link status
 318      * instead of checking 'netdev''s carrier.  'netdev''s MII registers will
 319      * be polled once ever 'interval' milliseconds.  If 'netdev' does not
 320      * support MII, another method may be used as a fallback.  If 'interval' is
 321      * less than or equal to zero, reverts ->get_carrier() to its normal
 322      * behavior.
 323      *
 324      * Most network devices won't support this feature and will set this
 325      * function pointer to NULL, which is equivalent to returning EOPNOTSUPP.
 326      */
 327     int (*set_miimon_interval)(struct netdev *netdev, long long int interval);
 328
 329     /* Retrieves current device stats for 'netdev' into 'stats'.
 330      *
 331      * A network device that supports some statistics but not others, it should
 332      * set the values of the unsupported statistics to all-1-bits
 333      * (UINT64_MAX). */
 334     int (*get_stats)(const struct netdev *netdev, struct netdev_stats *);
 335
 336     /* Sets the device stats for 'netdev' to 'stats'.
 337      *
 338      * Most network devices won't support this feature and will set this
 339      * function pointer to NULL, which is equivalent to returning EOPNOTSUPP.
 340      *
 341      * Some network devices might only allow setting their stats to 0. */
 342     int (*set_stats)(struct netdev *netdev, const struct netdev_stats *);
 343
 344     /* Stores the features supported by 'netdev' into each of '*current',
 345      * '*advertised', '*supported', and '*peer'.  Each value is a bitmap of
 346      * NETDEV_F_* bits.
 347      *
 348      * This function may be set to null if it would always return EOPNOTSUPP.
 349      */
 350     int (*get_features)(const struct netdev *netdev,
 351                         enum netdev_features *current,
 352                         enum netdev_features *advertised,
 353                         enum netdev_features *supported,
 354                         enum netdev_features *peer);
 355
 356     /* Set the features advertised by 'netdev' to 'advertise', which is a
 357      * set of NETDEV_F_* bits.
 358      *
 359      * This function may be set to null for a network device that does not
 360      * support configuring advertisements. */
 361     int (*set_advertisements)(struct netdev *netdev,
 362                               enum netdev_features advertise);
 363
 364     /* Attempts to set input rate limiting (policing) policy, such that up to
 365      * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative
 366      * burst size of 'kbits' kb.
 367      *
 368      * This function may be set to null if policing is not supported. */
 369     int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate,
 370                         unsigned int kbits_burst);
 371
 372     /* Adds to 'types' all of the forms of QoS supported by 'netdev', or leaves
 373      * it empty if 'netdev' does not support QoS.  Any names added to 'types'
 374      * should be documented as valid for the "type" column in the "QoS" table
 375      * in vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 376      *
 377      * Every network device must support disabling QoS with a type of "", but
 378      * this function must not add "" to 'types'.
 379      *
 380      * The caller is responsible for initializing 'types' (e.g. with
 381      * sset_init()) before calling this function.  The caller retains ownership
 382      * of 'types'.
 383      *
 384      * May be NULL if 'netdev' does not support QoS at all. */
 385     int (*get_qos_types)(const struct netdev *netdev, struct sset *types);
 386
 387     /* Queries 'netdev' for its capabilities regarding the specified 'type' of
 388      * QoS.  On success, initializes 'caps' with the QoS capabilities.
 389      *
 390      * Should return EOPNOTSUPP if 'netdev' does not support 'type'.  May be
 391      * NULL if 'netdev' does not support QoS at all. */
 392     int (*get_qos_capabilities)(const struct netdev *netdev,
 393                                 const char *type,
 394                                 struct netdev_qos_capabilities *caps);
 395
 396     /* Queries 'netdev' about its currently configured form of QoS.  If
 397      * successful, stores the name of the current form of QoS into '*typep'
 398      * and any details of configuration as string key-value pairs in
 399      * 'details'.
 400      *
 401      * A '*typep' of "" indicates that QoS is currently disabled on 'netdev'.
 402      *
 403      * The caller initializes 'details' before calling this function.  The
 404      * caller takes ownership of the string key-values pairs added to
 405      * 'details'.
 406      *
 407      * The netdev retains ownership of '*typep'.
 408      *
 409      * '*typep' will be one of the types returned by netdev_get_qos_types() for
 410      * 'netdev'.  The contents of 'details' should be documented as valid for
 411      * '*typep' in the "other_config" column in the "QoS" table in
 412      * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 413      *
 414      * May be NULL if 'netdev' does not support QoS at all. */
 415     int (*get_qos)(const struct netdev *netdev,
 416                    const char **typep, struct smap *details);
 417
 418     /* Attempts to reconfigure QoS on 'netdev', changing the form of QoS to
 419      * 'type' with details of configuration from 'details'.
 420      *
 421      * On error, the previous QoS configuration is retained.
 422      *
 423      * When this function changes the type of QoS (not just 'details'), this
 424      * also resets all queue configuration for 'netdev' to their defaults
 425      * (which depend on the specific type of QoS).  Otherwise, the queue
 426      * configuration for 'netdev' is unchanged.
 427      *
 428      * 'type' should be "" (to disable QoS) or one of the types returned by
 429      * netdev_get_qos_types() for 'netdev'.  The contents of 'details' should
 430      * be documented as valid for the given 'type' in the "other_config" column
 431      * in the "QoS" table in vswitchd/vswitch.xml (which is built as
 432      * ovs-vswitchd.conf.db(8)).
 433      *
 434      * May be NULL if 'netdev' does not support QoS at all. */
 435     int (*set_qos)(struct netdev *netdev,
 436                    const char *type, const struct smap *details);
 437
 438     /* Queries 'netdev' for information about the queue numbered 'queue_id'.
 439      * If successful, adds that information as string key-value pairs to
 440      * 'details'.  Returns 0 if successful, otherwise a positive errno value.
 441      *
 442      * Should return EINVAL if 'queue_id' is greater than or equal to the
 443      * number of supported queues (as reported in the 'n_queues' member of
 444      * struct netdev_qos_capabilities by 'get_qos_capabilities').
 445      *
 446      * The caller initializes 'details' before calling this function.  The
 447      * caller takes ownership of the string key-values pairs added to
 448      * 'details'.
 449      *
 450      * The returned contents of 'details' should be documented as valid for the
 451      * given 'type' in the "other_config" column in the "Queue" table in
 452      * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 453      */
 454     int (*get_queue)(const struct netdev *netdev,
 455                      unsigned int queue_id, struct smap *details);
 456
 457     /* Configures the queue numbered 'queue_id' on 'netdev' with the key-value
 458      * string pairs in 'details'.  The contents of 'details' should be
 459      * documented as valid for the given 'type' in the "other_config" column in
 460      * the "Queue" table in vswitchd/vswitch.xml (which is built as
 461      * ovs-vswitchd.conf.db(8)).  Returns 0 if successful, otherwise a positive
 462      * errno value.  On failure, the given queue's configuration should be
 463      * unmodified.
 464      *
 465      * Should return EINVAL if 'queue_id' is greater than or equal to the
 466      * number of supported queues (as reported in the 'n_queues' member of
 467      * struct netdev_qos_capabilities by 'get_qos_capabilities'), or if
 468      * 'details' is invalid for the type of queue.
 469      *
 470      * This function does not modify 'details', and the caller retains
 471      * ownership of it.
 472      *
 473      * May be NULL if 'netdev' does not support QoS at all. */
 474     int (*set_queue)(struct netdev *netdev,
 475                      unsigned int queue_id, const struct smap *details);
 476
 477     /* Attempts to delete the queue numbered 'queue_id' from 'netdev'.
 478      *
 479      * Should return EINVAL if 'queue_id' is greater than or equal to the
 480      * number of supported queues (as reported in the 'n_queues' member of
 481      * struct netdev_qos_capabilities by 'get_qos_capabilities').  Should
 482      * return EOPNOTSUPP if 'queue_id' is valid but may not be deleted (e.g. if
 483      * 'netdev' has a fixed set of queues with the current QoS mode).
 484      *
 485      * May be NULL if 'netdev' does not support QoS at all, or if all of its
 486      * QoS modes have fixed sets of queues. */
 487     int (*delete_queue)(struct netdev *netdev, unsigned int queue_id);
 488
 489     /* Obtains statistics about 'queue_id' on 'netdev'.  Fills 'stats' with the
 490      * queue's statistics.  May set individual members of 'stats' to all-1-bits
 491      * if the statistic is unavailable.
 492      *
 493      * May be NULL if 'netdev' does not support QoS at all. */
 494     int (*get_queue_stats)(const struct netdev *netdev, unsigned int queue_id,
 495                            struct netdev_queue_stats *stats);
 496
 497     /* Attempts to begin dumping the queues in 'netdev'.  On success, returns 0
 498      * and initializes '*statep' with any data needed for iteration.  On
 499      * failure, returns a positive errno value.
 500      *
 501      * May be NULL if 'netdev' does not support QoS at all. */
 502     int (*queue_dump_start)(const struct netdev *netdev, void **statep);
 503
 504     /* Attempts to retrieve another queue from 'netdev' for 'state', which was
 505      * initialized by a successful call to the 'queue_dump_start' function for
 506      * 'netdev'.  On success, stores a queue ID into '*queue_id' and fills
 507      * 'details' with the configuration of the queue with that ID.  Returns EOF
 508      * if the last queue has been dumped, or a positive errno value on error.
 509      * This function will not be called again once it returns nonzero once for
 510      * a given iteration (but the 'queue_dump_done' function will be called
 511      * afterward).
 512      *
 513      * The caller initializes and clears 'details' before calling this
 514      * function.  The caller takes ownership of the string key-values pairs
 515      * added to 'details'.
 516      *
 517      * The returned contents of 'details' should be documented as valid for the
 518      * given 'type' in the "other_config" column in the "Queue" table in
 519      * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 520      *
 521      * May be NULL if 'netdev' does not support QoS at all. */
 522     int (*queue_dump_next)(const struct netdev *netdev, void *state,
 523                            unsigned int *queue_id, struct smap *details);
 524
 525     /* Releases resources from 'netdev' for 'state', which was initialized by a
 526      * successful call to the 'queue_dump_start' function for 'netdev'.
 527      *
 528      * May be NULL if 'netdev' does not support QoS at all. */
 529     int (*queue_dump_done)(const struct netdev *netdev, void *state);
 530
 531     /* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's
 532      * ID, its statistics, and the 'aux' specified by the caller.  The order of
 533      * iteration is unspecified, but (when successful) each queue must be
 534      * visited exactly once.
 535      *
 536      * 'cb' will not modify or free the statistics passed in. */
 537     int (*dump_queue_stats)(const struct netdev *netdev,
 538                             void (*cb)(unsigned int queue_id,
 539                                        struct netdev_queue_stats *,
 540                                        void *aux),
 541                             void *aux);
 542
 543     /* If 'netdev' has an assigned IPv4 address, sets '*address' to that
 544      * address and '*netmask' to the associated netmask.
 545      *
 546      * The following error values have well-defined meanings:
 547      *
 548      *   - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address.
 549      *
 550      *   - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'.
 551      *
 552      * This function may be set to null if it would always return EOPNOTSUPP
 553      * anyhow. */
 554     int (*get_in4)(const struct netdev *netdev, struct in_addr *address,
 555                    struct in_addr *netmask);
 556
 557     /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask.  If
 558      * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared.
 559      *
 560      * This function may be set to null if it would always return EOPNOTSUPP
 561      * anyhow. */
 562     int (*set_in4)(struct netdev *netdev, struct in_addr addr,
 563                    struct in_addr mask);
 564
 565     /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address.
 566      *
 567      * The following error values have well-defined meanings:
 568      *
 569      *   - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address.
 570      *
 571      *   - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'.
 572      *
 573      * This function may be set to null if it would always return EOPNOTSUPP
 574      * anyhow. */
 575     int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6);
 576
 577     /* Adds 'router' as a default IP gateway for the TCP/IP stack that
 578      * corresponds to 'netdev'.
 579      *
 580      * This function may be set to null if it would always return EOPNOTSUPP
 581      * anyhow. */
 582     int (*add_router)(struct netdev *netdev, struct in_addr router);
 583
 584     /* Looks up the next hop for 'host'.  If successful, stores the next hop
 585      * gateway's address (0 if 'host' is on a directly connected network) in
 586      * '*next_hop' and a copy of the name of the device to reach 'host' in
 587      * '*netdev_name', and returns 0.  The caller is responsible for freeing
 588      * '*netdev_name' (by calling free()).
 589      *
 590      * This function may be set to null if it would always return EOPNOTSUPP
 591      * anyhow. */
 592     int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop,
 593                         char **netdev_name);
 594
 595     /* Retrieves driver information of the device.
 596      *
 597      * Populates 'smap' with key-value pairs representing the status of the
 598      * device.  'smap' is a set of key-value string pairs representing netdev
 599      * type specific information.  For more information see
 600      * ovs-vswitchd.conf.db(5).
 601      *
 602      * The caller is responsible for destroying 'smap' and its data.
 603      *
 604      * This function may be set to null if it would always return EOPNOTSUPP
 605      * anyhow. */
 606     int (*get_status)(const struct netdev *netdev, struct smap *smap);
 607
 608     /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the
 609      * corresponding MAC address in 'mac'.  A return value of ENXIO, in
 610      * particular, indicates that there is no ARP table entry for 'ip' on
 611      * 'netdev'.
 612      *
 613      * This function may be set to null if it would always return EOPNOTSUPP
 614      * anyhow. */
 615     int (*arp_lookup)(const struct netdev *netdev, ovs_be32 ip,
 616                       uint8_t mac[6]);
 617
 618     /* Retrieves the current set of flags on 'netdev' into '*old_flags'.  Then,
 619      * turns off the flags that are set to 1 in 'off' and turns on the flags
 620      * that are set to 1 in 'on'.  (No bit will be set to 1 in both 'off' and
 621      * 'on'; that is, off & on == 0.)
 622      *
 623      * This function may be invoked from a signal handler.  Therefore, it
 624      * should not do anything that is not signal-safe (such as logging). */
 625     int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
 626                         enum netdev_flags on, enum netdev_flags *old_flags);
 627
 628 /* ## -------------------- ## */
 629 /* ## netdev_rxq Functions ## */
 630 /* ## -------------------- ## */
 631
 632 /* If a particular netdev class does not support receiving packets, all these
 633  * function pointers must be NULL. */
 634
 635     /* Life-cycle functions for a netdev_rxq.  See the large comment above on
 636      * struct netdev_class. */
 637     struct netdev_rxq *(*rxq_alloc)(void);
 638     int (*rxq_construct)(struct netdev_rxq *);
 639     void (*rxq_destruct)(struct netdev_rxq *);
 640     void (*rxq_dealloc)(struct netdev_rxq *);
 641
 642     /* Attempts to receive batch of packets from 'rx' and place array of pointers
 643      * into '*pkt'. netdev is responsible for allocating buffers.
 644      * '*cnt' points to packet count for given batch. Once packets are returned
 645      * to caller, netdev should give up ownership of ofpbuf data.
 646      *
 647      * Implementations should allocate buffer with DP_NETDEV_HEADROOM headroom
 648      * and add a VLAN header which is obtained out-of-band to the packet.
 649      *
 650      * Caller is expected to pass array of size MAX_RX_BATCH.
 651      * This function may be set to null if it would always return EOPNOTSUPP
 652      * anyhow. */
 653     int (*rxq_recv)(struct netdev_rxq *rx, struct ofpbuf **pkt, int *cnt);
 654
 655     /* Registers with the poll loop to wake up from the next call to
 656      * poll_block() when a packet is ready to be received with netdev_rxq_recv()
 657      * on 'rx'. */
 658     void (*rxq_wait)(struct netdev_rxq *rx);
 659
 660     /* Discards all packets waiting to be received from 'rx'. */
 661     int (*rxq_drain)(struct netdev_rxq *rx);
 662 };
 663
 664 int netdev_register_provider(const struct netdev_class *);
 665 int netdev_unregister_provider(const char *type);
 666
 667 extern const struct netdev_class netdev_linux_class;
 668 extern const struct netdev_class netdev_internal_class;
 669 extern const struct netdev_class netdev_tap_class;
 670 #if defined(__FreeBSD__) || defined(__NetBSD__)
 671 extern const struct netdev_class netdev_bsd_class;
 672 #endif
 673
 674 #ifdef  __cplusplus
 675 }
 676 #endif
 677
 678 #endif /* netdev.h */