lib/netdev-provider.h

   1 /*
   2  * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014 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 "connectivity.h"
  23 #include "netdev.h"
  24 #include "list.h"
  25 #include "ovs-numa.h"
  26 #include "seq.h"
  27 #include "shash.h"
  28 #include "smap.h"
  29
  30 #ifdef  __cplusplus
  31 extern "C" {
  32 #endif
  33
  34 #define NETDEV_NUMA_UNSPEC OVS_NUMA_UNSPEC
  35
  36 /* A network device (e.g. an Ethernet device).
  37  *
  38  * Network device implementations may read these members but should not modify
  39  * them. */
  40 struct netdev {
  41     /* The following do not change during the lifetime of a struct netdev. */
  42     char *name;                         /* Name of network device. */
  43     const struct netdev_class *netdev_class; /* Functions to control
  44                                                 this device. */
  45
  46     /* A sequence number which indicates changes in one of 'netdev''s
  47      * properties.   It must be nonzero so that users have a value which
  48      * they may use as a reset when tracking 'netdev'.
  49      *
  50      * Minimally, the sequence number is required to change whenever
  51      * 'netdev''s flags, features, ethernet address, or carrier changes. */
  52     uint64_t change_seq;
  53
  54     /* The following are protected by 'netdev_mutex' (internal to netdev.c). */
  55     int n_rxq;
  56     int ref_cnt;                        /* Times this devices was opened. */
  57     struct shash_node *node;            /* Pointer to element in global map. */
  58     struct list saved_flags_list; /* Contains "struct netdev_saved_flags". */
  59 };
  60
  61 static void
  62 netdev_change_seq_changed(const struct netdev *netdev_)
  63 {
  64     struct netdev *netdev = CONST_CAST(struct netdev *, netdev_);
  65     seq_change(connectivity_seq_get());
  66     netdev->change_seq++;
  67     if (!netdev->change_seq) {
  68         netdev->change_seq++;
  69     }
  70 }
  71
  72 const char *netdev_get_type(const struct netdev *);
  73 const struct netdev_class *netdev_get_class(const struct netdev *);
  74 const char *netdev_get_name(const struct netdev *);
  75 struct netdev *netdev_from_name(const char *name);
  76 void netdev_get_devices(const struct netdev_class *,
  77                         struct shash *device_list);
  78 struct netdev **netdev_get_vports(size_t *size);
  79
  80 /* A data structure for capturing packets received by a network device.
  81  *
  82  * Network device implementations may read these members but should not modify
  83  * them.
  84  *
  85  * None of these members change during the lifetime of a struct netdev_rxq. */
  86 struct netdev_rxq {
  87     struct netdev *netdev;      /* Owns a reference to the netdev. */
  88     int queue_id;
  89 };
  90
  91 struct netdev *netdev_rxq_get_netdev(const struct netdev_rxq *);
  92
  93 /* Network device class structure, to be defined by each implementation of a
  94  * network device.
  95  *
  96  * These functions return 0 if successful or a positive errno value on failure,
  97  * except where otherwise noted.
  98  *
  99  *
 100  * Data Structures
 101  * ===============
 102  *
 103  * These functions work primarily with two different kinds of data structures:
 104  *
 105  *   - "struct netdev", which represents a network device.
 106  *
 107  *   - "struct netdev_rxq", which represents a handle for capturing packets
 108  *     received on a network device
 109  *
 110  * Each of these data structures contains all of the implementation-independent
 111  * generic state for the respective concept, called the "base" state.  None of
 112  * them contains any extra space for implementations to use.  Instead, each
 113  * implementation is expected to declare its own data structure that contains
 114  * an instance of the generic data structure plus additional
 115  * implementation-specific members, called the "derived" state.  The
 116  * implementation can use casts or (preferably) the CONTAINER_OF macro to
 117  * obtain access to derived state given only a pointer to the embedded generic
 118  * data structure.
 119  *
 120  *
 121  * Life Cycle
 122  * ==========
 123  *
 124  * Four stylized functions accompany each of these data structures:
 125  *
 126  *            "alloc"          "construct"        "destruct"       "dealloc"
 127  *            ------------   ----------------  ---------------  --------------
 128  * netdev      ->alloc        ->construct        ->destruct        ->dealloc
 129  * netdev_rxq  ->rxq_alloc    ->rxq_construct    ->rxq_destruct    ->rxq_dealloc
 130  *
 131  * Any instance of a given data structure goes through the following life
 132  * cycle:
 133  *
 134  *   1. The client calls the "alloc" function to obtain raw memory.  If "alloc"
 135  *      fails, skip all the other steps.
 136  *
 137  *   2. The client initializes all of the data structure's base state.  If this
 138  *      fails, skip to step 7.
 139  *
 140  *   3. The client calls the "construct" function.  The implementation
 141  *      initializes derived state.  It may refer to the already-initialized
 142  *      base state.  If "construct" fails, skip to step 6.
 143  *
 144  *   4. The data structure is now initialized and in use.
 145  *
 146  *   5. When the data structure is no longer needed, the client calls the
 147  *      "destruct" function.  The implementation uninitializes derived state.
 148  *      The base state has not been uninitialized yet, so the implementation
 149  *      may still refer to it.
 150  *
 151  *   6. The client uninitializes all of the data structure's base state.
 152  *
 153  *   7. The client calls the "dealloc" to free the raw memory.  The
 154  *      implementation must not refer to base or derived state in the data
 155  *      structure, because it has already been uninitialized.
 156  *
 157  * If netdev support multi-queue IO then netdev->construct should set initialize
 158  * netdev->n_rxq to number of queues.
 159  *
 160  * Each "alloc" function allocates and returns a new instance of the respective
 161  * data structure.  The "alloc" function is not given any information about the
 162  * use of the new data structure, so it cannot perform much initialization.
 163  * Its purpose is just to ensure that the new data structure has enough room
 164  * for base and derived state.  It may return a null pointer if memory is not
 165  * available, in which case none of the other functions is called.
 166  *
 167  * Each "construct" function initializes derived state in its respective data
 168  * structure.  When "construct" is called, all of the base state has already
 169  * been initialized, so the "construct" function may refer to it.  The
 170  * "construct" function is allowed to fail, in which case the client calls the
 171  * "dealloc" function (but not the "destruct" function).
 172  *
 173  * Each "destruct" function uninitializes and frees derived state in its
 174  * respective data structure.  When "destruct" is called, the base state has
 175  * not yet been uninitialized, so the "destruct" function may refer to it.  The
 176  * "destruct" function is not allowed to fail.
 177  *
 178  * Each "dealloc" function frees raw memory that was allocated by the the
 179  * "alloc" function.  The memory's base and derived members might not have ever
 180  * been initialized (but if "construct" returned successfully, then it has been
 181  * "destruct"ed already).  The "dealloc" function is not allowed to fail.
 182  *
 183  *
 184  * Device Change Notification
 185  * ==========================
 186  *
 187  * Minimally, implementations are required to report changes to netdev flags,
 188  * features, ethernet address or carrier through connectivity_seq. Changes to
 189  * other properties are allowed to cause notification through this interface,
 190  * although implementations should try to avoid this. connectivity_seq_get()
 191  * can be used to acquire a reference to the struct seq. The interface is
 192  * described in detail in seq.h. */
 193 struct netdev_class {
 194     /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc.
 195      *
 196      * One of the providers should supply a "system" type, since this is
 197      * the type assumed if no type is specified when opening a netdev.
 198      * The "system" type corresponds to an existing network device on
 199      * the system. */
 200     const char *type;
 201
 202 /* ## ------------------- ## */
 203 /* ## Top-Level Functions ## */
 204 /* ## ------------------- ## */
 205
 206     /* Called when the netdev provider is registered, typically at program
 207      * startup.  Returning an error from this function will prevent any network
 208      * device in this class from being opened.
 209      *
 210      * This function may be set to null if a network device class needs no
 211      * initialization at registration time. */
 212     int (*init)(void);
 213
 214     /* Performs periodic work needed by netdevs of this class.  May be null if
 215      * no periodic work is necessary. */
 216     void (*run)(void);
 217
 218     /* Arranges for poll_block() to wake up if the "run" member function needs
 219      * to be called.  Implementations are additionally required to wake
 220      * whenever something changes in any of its netdevs which would cause their
 221      * ->change_seq() function to change its result.  May be null if nothing is
 222      * needed here. */
 223     void (*wait)(void);
 224
 225 /* ## ---------------- ## */
 226 /* ## netdev Functions ## */
 227 /* ## ---------------- ## */
 228
 229     /* Life-cycle functions for a netdev.  See the large comment above on
 230      * struct netdev_class. */
 231     struct netdev *(*alloc)(void);
 232     int (*construct)(struct netdev *);
 233     void (*destruct)(struct netdev *);
 234     void (*dealloc)(struct netdev *);
 235
 236     /* Fetches the device 'netdev''s configuration, storing it in 'args'.
 237      * The caller owns 'args' and pre-initializes it to an empty smap.
 238      *
 239      * If this netdev class does not have any configuration options, this may
 240      * be a null pointer. */
 241     int (*get_config)(const struct netdev *netdev, struct smap *args);
 242
 243     /* Changes the device 'netdev''s configuration to 'args'.
 244      *
 245      * If this netdev class does not support configuration, this may be a null
 246      * pointer. */
 247     int (*set_config)(struct netdev *netdev, const struct smap *args);
 248
 249     /* Returns the tunnel configuration of 'netdev'.  If 'netdev' is
 250      * not a tunnel, returns null.
 251      *
 252      * If this function would always return null, it may be null instead. */
 253     const struct netdev_tunnel_config *
 254         (*get_tunnel_config)(const struct netdev *netdev);
 255
 256     /* Returns the id of the numa node the 'netdev' is on.  If there is no
 257      * such info, returns NETDEV_NUMA_UNSPEC. */
 258     int (*get_numa_id)(const struct netdev *netdev);
 259
 260     /* Sends buffers on 'netdev'.
 261      * Returns 0 if successful (for every buffer), otherwise a positive errno value.
 262      * Returns EAGAIN without blocking if one or more packets cannot be
 263      * queued immediately. Returns EMSGSIZE if a partial packet was transmitted
 264      * or if a packet is too big or too small to transmit on the device.
 265      *
 266      * If the function returns a non-zero value, some of the packets might have
 267      * been sent anyway.
 268      *
 269      * To retain ownership of 'buffers' caller can set may_steal to false.
 270      *
 271      * The network device is expected to maintain a packet transmission queue,
 272      * so that the caller does not ordinarily have to do additional queuing of
 273      * packets.
 274      *
 275      * May return EOPNOTSUPP if a network device does not implement packet
 276      * transmission through this interface.  This function may be set to null
 277      * if it would always return EOPNOTSUPP anyhow.  (This will prevent the
 278      * network device from being usefully used by the netdev-based "userspace
 279      * datapath".  It will also prevent the OVS implementation of bonding from
 280      * working properly over 'netdev'.) */
 281     int (*send)(struct netdev *netdev, struct dpif_packet **buffers, int cnt,
 282                 bool may_steal);
 283
 284     /* Registers with the poll loop to wake up from the next call to
 285      * poll_block() when the packet transmission queue for 'netdev' has
 286      * sufficient room to transmit a packet with netdev_send().
 287      *
 288      * The network device is expected to maintain a packet transmission queue,
 289      * so that the caller does not ordinarily have to do additional queuing of
 290      * packets.  Thus, this function is unlikely to ever be useful.
 291      *
 292      * May be null if not needed, such as for a network device that does not
 293      * implement packet transmission through the 'send' member function. */
 294     void (*send_wait)(struct netdev *netdev);
 295
 296     /* Sets 'netdev''s Ethernet address to 'mac' */
 297     int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]);
 298
 299     /* Retrieves 'netdev''s Ethernet address into 'mac'.
 300      *
 301      * This address will be advertised as 'netdev''s MAC address through the
 302      * OpenFlow protocol, among other uses. */
 303     int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]);
 304
 305     /* Retrieves 'netdev''s MTU into '*mtup'.
 306      *
 307      * The MTU is the maximum size of transmitted (and received) packets, in
 308      * bytes, not including the hardware header; thus, this is typically 1500
 309      * bytes for Ethernet devices.
 310      *
 311      * If 'netdev' does not have an MTU (e.g. as some tunnels do not), then
 312      * this function should return EOPNOTSUPP.  This function may be set to
 313      * null if it would always return EOPNOTSUPP. */
 314     int (*get_mtu)(const struct netdev *netdev, int *mtup);
 315
 316     /* Sets 'netdev''s MTU to 'mtu'.
 317      *
 318      * If 'netdev' does not have an MTU (e.g. as some tunnels do not), then
 319      * this function should return EOPNOTSUPP.  This function may be set to
 320      * null if it would always return EOPNOTSUPP. */
 321     int (*set_mtu)(const struct netdev *netdev, int mtu);
 322
 323     /* Returns the ifindex of 'netdev', if successful, as a positive number.
 324      * On failure, returns a negative errno value.
 325      *
 326      * The desired semantics of the ifindex value are a combination of those
 327      * specified by POSIX for if_nametoindex() and by SNMP for ifIndex.  An
 328      * ifindex value should be unique within a host and remain stable at least
 329      * until reboot.  SNMP says an ifindex "ranges between 1 and the value of
 330      * ifNumber" but many systems do not follow this rule anyhow.
 331      *
 332      * This function may be set to null if it would always return -EOPNOTSUPP.
 333      */
 334     int (*get_ifindex)(const struct netdev *netdev);
 335
 336     /* Sets 'carrier' to true if carrier is active (link light is on) on
 337      * 'netdev'.
 338      *
 339      * May be null if device does not provide carrier status (will be always
 340      * up as long as device is up).
 341      */
 342     int (*get_carrier)(const struct netdev *netdev, bool *carrier);
 343
 344     /* Returns the number of times 'netdev''s carrier has changed since being
 345      * initialized.
 346      *
 347      * If null, callers will assume the number of carrier resets is zero. */
 348     long long int (*get_carrier_resets)(const struct netdev *netdev);
 349
 350     /* Forces ->get_carrier() to poll 'netdev''s MII registers for link status
 351      * instead of checking 'netdev''s carrier.  'netdev''s MII registers will
 352      * be polled once ever 'interval' milliseconds.  If 'netdev' does not
 353      * support MII, another method may be used as a fallback.  If 'interval' is
 354      * less than or equal to zero, reverts ->get_carrier() to its normal
 355      * behavior.
 356      *
 357      * Most network devices won't support this feature and will set this
 358      * function pointer to NULL, which is equivalent to returning EOPNOTSUPP.
 359      */
 360     int (*set_miimon_interval)(struct netdev *netdev, long long int interval);
 361
 362     /* Retrieves current device stats for 'netdev' into 'stats'.
 363      *
 364      * A network device that supports some statistics but not others, it should
 365      * set the values of the unsupported statistics to all-1-bits
 366      * (UINT64_MAX). */
 367     int (*get_stats)(const struct netdev *netdev, struct netdev_stats *);
 368
 369     /* Sets the device stats for 'netdev' to 'stats'.
 370      *
 371      * Most network devices won't support this feature and will set this
 372      * function pointer to NULL, which is equivalent to returning EOPNOTSUPP.
 373      *
 374      * Some network devices might only allow setting their stats to 0. */
 375     int (*set_stats)(struct netdev *netdev, const struct netdev_stats *);
 376
 377     /* Stores the features supported by 'netdev' into each of '*current',
 378      * '*advertised', '*supported', and '*peer'.  Each value is a bitmap of
 379      * NETDEV_F_* bits.
 380      *
 381      * This function may be set to null if it would always return EOPNOTSUPP.
 382      */
 383     int (*get_features)(const struct netdev *netdev,
 384                         enum netdev_features *current,
 385                         enum netdev_features *advertised,
 386                         enum netdev_features *supported,
 387                         enum netdev_features *peer);
 388
 389     /* Set the features advertised by 'netdev' to 'advertise', which is a
 390      * set of NETDEV_F_* bits.
 391      *
 392      * This function may be set to null for a network device that does not
 393      * support configuring advertisements. */
 394     int (*set_advertisements)(struct netdev *netdev,
 395                               enum netdev_features advertise);
 396
 397     /* Attempts to set input rate limiting (policing) policy, such that up to
 398      * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative
 399      * burst size of 'kbits' kb.
 400      *
 401      * This function may be set to null if policing is not supported. */
 402     int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate,
 403                         unsigned int kbits_burst);
 404
 405     /* Adds to 'types' all of the forms of QoS supported by 'netdev', or leaves
 406      * it empty if 'netdev' does not support QoS.  Any names added to 'types'
 407      * should be documented as valid for the "type" column in the "QoS" table
 408      * in vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 409      *
 410      * Every network device must support disabling QoS with a type of "", but
 411      * this function must not add "" to 'types'.
 412      *
 413      * The caller is responsible for initializing 'types' (e.g. with
 414      * sset_init()) before calling this function.  The caller retains ownership
 415      * of 'types'.
 416      *
 417      * May be NULL if 'netdev' does not support QoS at all. */
 418     int (*get_qos_types)(const struct netdev *netdev, struct sset *types);
 419
 420     /* Queries 'netdev' for its capabilities regarding the specified 'type' of
 421      * QoS.  On success, initializes 'caps' with the QoS capabilities.
 422      *
 423      * Should return EOPNOTSUPP if 'netdev' does not support 'type'.  May be
 424      * NULL if 'netdev' does not support QoS at all. */
 425     int (*get_qos_capabilities)(const struct netdev *netdev,
 426                                 const char *type,
 427                                 struct netdev_qos_capabilities *caps);
 428
 429     /* Queries 'netdev' about its currently configured form of QoS.  If
 430      * successful, stores the name of the current form of QoS into '*typep'
 431      * and any details of configuration as string key-value pairs in
 432      * 'details'.
 433      *
 434      * A '*typep' of "" indicates that QoS is currently disabled on 'netdev'.
 435      *
 436      * The caller initializes 'details' before calling this function.  The
 437      * caller takes ownership of the string key-values pairs added to
 438      * 'details'.
 439      *
 440      * The netdev retains ownership of '*typep'.
 441      *
 442      * '*typep' will be one of the types returned by netdev_get_qos_types() for
 443      * 'netdev'.  The contents of 'details' should be documented as valid for
 444      * '*typep' in the "other_config" column in the "QoS" table in
 445      * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 446      *
 447      * May be NULL if 'netdev' does not support QoS at all. */
 448     int (*get_qos)(const struct netdev *netdev,
 449                    const char **typep, struct smap *details);
 450
 451     /* Attempts to reconfigure QoS on 'netdev', changing the form of QoS to
 452      * 'type' with details of configuration from 'details'.
 453      *
 454      * On error, the previous QoS configuration is retained.
 455      *
 456      * When this function changes the type of QoS (not just 'details'), this
 457      * also resets all queue configuration for 'netdev' to their defaults
 458      * (which depend on the specific type of QoS).  Otherwise, the queue
 459      * configuration for 'netdev' is unchanged.
 460      *
 461      * 'type' should be "" (to disable QoS) or one of the types returned by
 462      * netdev_get_qos_types() for 'netdev'.  The contents of 'details' should
 463      * be documented as valid for the given 'type' in the "other_config" column
 464      * in the "QoS" table in vswitchd/vswitch.xml (which is built as
 465      * ovs-vswitchd.conf.db(8)).
 466      *
 467      * May be NULL if 'netdev' does not support QoS at all. */
 468     int (*set_qos)(struct netdev *netdev,
 469                    const char *type, const struct smap *details);
 470
 471     /* Queries 'netdev' for information about the queue numbered 'queue_id'.
 472      * If successful, adds that information as string key-value pairs to
 473      * 'details'.  Returns 0 if successful, otherwise a positive errno value.
 474      *
 475      * Should return EINVAL if 'queue_id' is greater than or equal to the
 476      * number of supported queues (as reported in the 'n_queues' member of
 477      * struct netdev_qos_capabilities by 'get_qos_capabilities').
 478      *
 479      * The caller initializes 'details' before calling this function.  The
 480      * caller takes ownership of the string key-values pairs added to
 481      * 'details'.
 482      *
 483      * The returned contents of 'details' should be documented as valid for the
 484      * given 'type' in the "other_config" column in the "Queue" table in
 485      * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 486      */
 487     int (*get_queue)(const struct netdev *netdev,
 488                      unsigned int queue_id, struct smap *details);
 489
 490     /* Configures the queue numbered 'queue_id' on 'netdev' with the key-value
 491      * string pairs in 'details'.  The contents of 'details' should be
 492      * documented as valid for the given 'type' in the "other_config" column in
 493      * the "Queue" table in vswitchd/vswitch.xml (which is built as
 494      * ovs-vswitchd.conf.db(8)).  Returns 0 if successful, otherwise a positive
 495      * errno value.  On failure, the given queue's configuration should be
 496      * unmodified.
 497      *
 498      * Should return EINVAL if 'queue_id' is greater than or equal to the
 499      * number of supported queues (as reported in the 'n_queues' member of
 500      * struct netdev_qos_capabilities by 'get_qos_capabilities'), or if
 501      * 'details' is invalid for the type of queue.
 502      *
 503      * This function does not modify 'details', and the caller retains
 504      * ownership of it.
 505      *
 506      * May be NULL if 'netdev' does not support QoS at all. */
 507     int (*set_queue)(struct netdev *netdev,
 508                      unsigned int queue_id, const struct smap *details);
 509
 510     /* Attempts to delete the queue numbered 'queue_id' from 'netdev'.
 511      *
 512      * Should return EINVAL if 'queue_id' is greater than or equal to the
 513      * number of supported queues (as reported in the 'n_queues' member of
 514      * struct netdev_qos_capabilities by 'get_qos_capabilities').  Should
 515      * return EOPNOTSUPP if 'queue_id' is valid but may not be deleted (e.g. if
 516      * 'netdev' has a fixed set of queues with the current QoS mode).
 517      *
 518      * May be NULL if 'netdev' does not support QoS at all, or if all of its
 519      * QoS modes have fixed sets of queues. */
 520     int (*delete_queue)(struct netdev *netdev, unsigned int queue_id);
 521
 522     /* Obtains statistics about 'queue_id' on 'netdev'.  Fills 'stats' with the
 523      * queue's statistics.  May set individual members of 'stats' to all-1-bits
 524      * if the statistic is unavailable.
 525      *
 526      * May be NULL if 'netdev' does not support QoS at all. */
 527     int (*get_queue_stats)(const struct netdev *netdev, unsigned int queue_id,
 528                            struct netdev_queue_stats *stats);
 529
 530     /* Attempts to begin dumping the queues in 'netdev'.  On success, returns 0
 531      * and initializes '*statep' with any data needed for iteration.  On
 532      * failure, returns a positive errno value.
 533      *
 534      * May be NULL if 'netdev' does not support QoS at all. */
 535     int (*queue_dump_start)(const struct netdev *netdev, void **statep);
 536
 537     /* Attempts to retrieve another queue from 'netdev' for 'state', which was
 538      * initialized by a successful call to the 'queue_dump_start' function for
 539      * 'netdev'.  On success, stores a queue ID into '*queue_id' and fills
 540      * 'details' with the configuration of the queue with that ID.  Returns EOF
 541      * if the last queue has been dumped, or a positive errno value on error.
 542      * This function will not be called again once it returns nonzero once for
 543      * a given iteration (but the 'queue_dump_done' function will be called
 544      * afterward).
 545      *
 546      * The caller initializes and clears 'details' before calling this
 547      * function.  The caller takes ownership of the string key-values pairs
 548      * added to 'details'.
 549      *
 550      * The returned contents of 'details' should be documented as valid for the
 551      * given 'type' in the "other_config" column in the "Queue" table in
 552      * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
 553      *
 554      * May be NULL if 'netdev' does not support QoS at all. */
 555     int (*queue_dump_next)(const struct netdev *netdev, void *state,
 556                            unsigned int *queue_id, struct smap *details);
 557
 558     /* Releases resources from 'netdev' for 'state', which was initialized by a
 559      * successful call to the 'queue_dump_start' function for 'netdev'.
 560      *
 561      * May be NULL if 'netdev' does not support QoS at all. */
 562     int (*queue_dump_done)(const struct netdev *netdev, void *state);
 563
 564     /* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's
 565      * ID, its statistics, and the 'aux' specified by the caller.  The order of
 566      * iteration is unspecified, but (when successful) each queue must be
 567      * visited exactly once.
 568      *
 569      * 'cb' will not modify or free the statistics passed in. */
 570     int (*dump_queue_stats)(const struct netdev *netdev,
 571                             void (*cb)(unsigned int queue_id,
 572                                        struct netdev_queue_stats *,
 573                                        void *aux),
 574                             void *aux);
 575
 576     /* If 'netdev' has an assigned IPv4 address, sets '*address' to that
 577      * address and '*netmask' to the associated netmask.
 578      *
 579      * The following error values have well-defined meanings:
 580      *
 581      *   - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address.
 582      *
 583      *   - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'.
 584      *
 585      * This function may be set to null if it would always return EOPNOTSUPP
 586      * anyhow. */
 587     int (*get_in4)(const struct netdev *netdev, struct in_addr *address,
 588                    struct in_addr *netmask);
 589
 590     /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask.  If
 591      * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared.
 592      *
 593      * This function may be set to null if it would always return EOPNOTSUPP
 594      * anyhow. */
 595     int (*set_in4)(struct netdev *netdev, struct in_addr addr,
 596                    struct in_addr mask);
 597
 598     /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address.
 599      *
 600      * The following error values have well-defined meanings:
 601      *
 602      *   - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address.
 603      *
 604      *   - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'.
 605      *
 606      * This function may be set to null if it would always return EOPNOTSUPP
 607      * anyhow. */
 608     int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6);
 609
 610     /* Adds 'router' as a default IP gateway for the TCP/IP stack that
 611      * corresponds to 'netdev'.
 612      *
 613      * This function may be set to null if it would always return EOPNOTSUPP
 614      * anyhow. */
 615     int (*add_router)(struct netdev *netdev, struct in_addr router);
 616
 617     /* Looks up the next hop for 'host' in the host's routing table.  If
 618      * successful, stores the next hop gateway's address (0 if 'host' is on a
 619      * directly connected network) in '*next_hop' and a copy of the name of the
 620      * device to reach 'host' in '*netdev_name', and returns 0.  The caller is
 621      * responsible for freeing '*netdev_name' (by calling free()).
 622      *
 623      * This function may be set to null if it would always return EOPNOTSUPP
 624      * anyhow. */
 625     int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop,
 626                         char **netdev_name);
 627
 628     /* Retrieves driver information of the device.
 629      *
 630      * Populates 'smap' with key-value pairs representing the status of the
 631      * device.  'smap' is a set of key-value string pairs representing netdev
 632      * type specific information.  For more information see
 633      * ovs-vswitchd.conf.db(5).
 634      *
 635      * The caller is responsible for destroying 'smap' and its data.
 636      *
 637      * This function may be set to null if it would always return EOPNOTSUPP
 638      * anyhow. */
 639     int (*get_status)(const struct netdev *netdev, struct smap *smap);
 640
 641     /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the
 642      * corresponding MAC address in 'mac'.  A return value of ENXIO, in
 643      * particular, indicates that there is no ARP table entry for 'ip' on
 644      * 'netdev'.
 645      *
 646      * This function may be set to null if it would always return EOPNOTSUPP
 647      * anyhow. */
 648     int (*arp_lookup)(const struct netdev *netdev, ovs_be32 ip,
 649                       uint8_t mac[6]);
 650
 651     /* Retrieves the current set of flags on 'netdev' into '*old_flags'.  Then,
 652      * turns off the flags that are set to 1 in 'off' and turns on the flags
 653      * that are set to 1 in 'on'.  (No bit will be set to 1 in both 'off' and
 654      * 'on'; that is, off & on == 0.)
 655      *
 656      * This function may be invoked from a signal handler.  Therefore, it
 657      * should not do anything that is not signal-safe (such as logging). */
 658     int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
 659                         enum netdev_flags on, enum netdev_flags *old_flags);
 660
 661 /* ## -------------------- ## */
 662 /* ## netdev_rxq Functions ## */
 663 /* ## -------------------- ## */
 664
 665 /* If a particular netdev class does not support receiving packets, all these
 666  * function pointers must be NULL. */
 667
 668     /* Life-cycle functions for a netdev_rxq.  See the large comment above on
 669      * struct netdev_class. */
 670     struct netdev_rxq *(*rxq_alloc)(void);
 671     int (*rxq_construct)(struct netdev_rxq *);
 672     void (*rxq_destruct)(struct netdev_rxq *);
 673     void (*rxq_dealloc)(struct netdev_rxq *);
 674
 675     /* Attempts to receive batch of packets from 'rx' and place array of
 676      * pointers into '*pkts'. netdev is responsible for allocating buffers.
 677      * '*cnt' points to packet count for given batch. Once packets are returned
 678      * to caller, netdev should give up ownership of ofpbuf data.
 679      *
 680      * Implementations should allocate buffer with DP_NETDEV_HEADROOM headroom
 681      * and add a VLAN header which is obtained out-of-band to the packet.
 682      *
 683      * Caller is expected to pass array of size MAX_RX_BATCH.
 684      * This function may be set to null if it would always return EOPNOTSUPP
 685      * anyhow. */
 686     int (*rxq_recv)(struct netdev_rxq *rx, struct dpif_packet **pkts,
 687                     int *cnt);
 688
 689     /* Registers with the poll loop to wake up from the next call to
 690      * poll_block() when a packet is ready to be received with netdev_rxq_recv()
 691      * on 'rx'. */
 692     void (*rxq_wait)(struct netdev_rxq *rx);
 693
 694     /* Discards all packets waiting to be received from 'rx'. */
 695     int (*rxq_drain)(struct netdev_rxq *rx);
 696 };
 697
 698 int netdev_register_provider(const struct netdev_class *);
 699 int netdev_unregister_provider(const char *type);
 700
 701 extern const struct netdev_class netdev_linux_class;
 702 extern const struct netdev_class netdev_internal_class;
 703 extern const struct netdev_class netdev_tap_class;
 704 #if defined(__FreeBSD__) || defined(__NetBSD__)
 705 extern const struct netdev_class netdev_bsd_class;
 706 #endif
 707
 708 #ifdef  __cplusplus
 709 }
 710 #endif
 711
 712 #endif /* netdev.h */