2 * Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
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:
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #ifndef NETDEV_PROVIDER_H
18 #define NETDEV_PROVIDER_H 1
20 /* Generic interface to network devices. */
22 #include "connectivity.h"
33 /* A network device (e.g. an Ethernet device).
35 * Network device implementations may read these members but should not modify
38 /* The following do not change during the lifetime of a struct netdev. */
39 char *name; /* Name of network device. */
40 const struct netdev_class *netdev_class; /* Functions to control
43 /* A sequence number which indicates changes in one of 'netdev''s
44 * properties. It must be nonzero so that users have a value which
45 * they may use as a reset when tracking 'netdev'.
47 * Minimally, the sequence number is required to change whenever
48 * 'netdev''s flags, features, ethernet address, or carrier changes. */
51 /* The following are protected by 'netdev_mutex' (internal to netdev.c). */
53 int ref_cnt; /* Times this devices was opened. */
54 struct shash_node *node; /* Pointer to element in global map. */
55 struct list saved_flags_list; /* Contains "struct netdev_saved_flags". */
59 netdev_change_seq_changed(struct netdev *netdev)
61 seq_change(connectivity_seq_get());
63 if (!netdev->change_seq) {
68 const char *netdev_get_type(const struct netdev *);
69 const struct netdev_class *netdev_get_class(const struct netdev *);
70 const char *netdev_get_name(const struct netdev *);
71 struct netdev *netdev_from_name(const char *name);
72 void netdev_get_devices(const struct netdev_class *,
73 struct shash *device_list);
75 /* A data structure for capturing packets received by a network device.
77 * Network device implementations may read these members but should not modify
80 * None of these members change during the lifetime of a struct netdev_rxq. */
82 struct netdev *netdev; /* Owns a reference to the netdev. */
86 struct netdev *netdev_rxq_get_netdev(const struct netdev_rxq *);
88 /* Network device class structure, to be defined by each implementation of a
91 * These functions return 0 if successful or a positive errno value on failure,
92 * except where otherwise noted.
98 * These functions work primarily with two different kinds of data structures:
100 * - "struct netdev", which represents a network device.
102 * - "struct netdev_rxq", which represents a handle for capturing packets
103 * received on a network device
105 * Each of these data structures contains all of the implementation-independent
106 * generic state for the respective concept, called the "base" state. None of
107 * them contains any extra space for implementations to use. Instead, each
108 * implementation is expected to declare its own data structure that contains
109 * an instance of the generic data structure plus additional
110 * implementation-specific members, called the "derived" state. The
111 * implementation can use casts or (preferably) the CONTAINER_OF macro to
112 * obtain access to derived state given only a pointer to the embedded generic
119 * Four stylized functions accompany each of these data structures:
121 * "alloc" "construct" "destruct" "dealloc"
122 * ------------ ---------------- --------------- --------------
123 * netdev ->alloc ->construct ->destruct ->dealloc
124 * netdev_rxq ->rxq_alloc ->rxq_construct ->rxq_destruct ->rxq_dealloc
126 * Any instance of a given data structure goes through the following life
129 * 1. The client calls the "alloc" function to obtain raw memory. If "alloc"
130 * fails, skip all the other steps.
132 * 2. The client initializes all of the data structure's base state. If this
133 * fails, skip to step 7.
135 * 3. The client calls the "construct" function. The implementation
136 * initializes derived state. It may refer to the already-initialized
137 * base state. If "construct" fails, skip to step 6.
139 * 4. The data structure is now initialized and in use.
141 * 5. When the data structure is no longer needed, the client calls the
142 * "destruct" function. The implementation uninitializes derived state.
143 * The base state has not been uninitialized yet, so the implementation
144 * may still refer to it.
146 * 6. The client uninitializes all of the data structure's base state.
148 * 7. The client calls the "dealloc" to free the raw memory. The
149 * implementation must not refer to base or derived state in the data
150 * structure, because it has already been uninitialized.
152 * If netdev support multi-queue IO then netdev->construct should set initialize
153 * netdev->n_rxq to number of queues.
155 * Each "alloc" function allocates and returns a new instance of the respective
156 * data structure. The "alloc" function is not given any information about the
157 * use of the new data structure, so it cannot perform much initialization.
158 * Its purpose is just to ensure that the new data structure has enough room
159 * for base and derived state. It may return a null pointer if memory is not
160 * available, in which case none of the other functions is called.
162 * Each "construct" function initializes derived state in its respective data
163 * structure. When "construct" is called, all of the base state has already
164 * been initialized, so the "construct" function may refer to it. The
165 * "construct" function is allowed to fail, in which case the client calls the
166 * "dealloc" function (but not the "destruct" function).
168 * Each "destruct" function uninitializes and frees derived state in its
169 * respective data structure. When "destruct" is called, the base state has
170 * not yet been uninitialized, so the "destruct" function may refer to it. The
171 * "destruct" function is not allowed to fail.
173 * Each "dealloc" function frees raw memory that was allocated by the the
174 * "alloc" function. The memory's base and derived members might not have ever
175 * been initialized (but if "construct" returned successfully, then it has been
176 * "destruct"ed already). The "dealloc" function is not allowed to fail.
179 * Device Change Notification
180 * ==========================
182 * Minimally, implementations are required to report changes to netdev flags,
183 * features, ethernet address or carrier through connectivity_seq. Changes to
184 * other properties are allowed to cause notification through this interface,
185 * although implementations should try to avoid this. connectivity_seq_get()
186 * can be used to acquire a reference to the struct seq. The interface is
187 * described in detail in seq.h. */
188 struct netdev_class {
189 /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc.
191 * One of the providers should supply a "system" type, since this is
192 * the type assumed if no type is specified when opening a netdev.
193 * The "system" type corresponds to an existing network device on
197 /* ## ------------------- ## */
198 /* ## Top-Level Functions ## */
199 /* ## ------------------- ## */
201 /* Called when the netdev provider is registered, typically at program
202 * startup. Returning an error from this function will prevent any network
203 * device in this class from being opened.
205 * This function may be set to null if a network device class needs no
206 * initialization at registration time. */
209 /* Performs periodic work needed by netdevs of this class. May be null if
210 * no periodic work is necessary. */
213 /* Arranges for poll_block() to wake up if the "run" member function needs
214 * to be called. Implementations are additionally required to wake
215 * whenever something changes in any of its netdevs which would cause their
216 * ->change_seq() function to change its result. May be null if nothing is
220 /* ## ---------------- ## */
221 /* ## netdev Functions ## */
222 /* ## ---------------- ## */
224 /* Life-cycle functions for a netdev. See the large comment above on
225 * struct netdev_class. */
226 struct netdev *(*alloc)(void);
227 int (*construct)(struct netdev *);
228 void (*destruct)(struct netdev *);
229 void (*dealloc)(struct netdev *);
231 /* Fetches the device 'netdev''s configuration, storing it in 'args'.
232 * The caller owns 'args' and pre-initializes it to an empty smap.
234 * If this netdev class does not have any configuration options, this may
235 * be a null pointer. */
236 int (*get_config)(const struct netdev *netdev, struct smap *args);
238 /* Changes the device 'netdev''s configuration to 'args'.
240 * If this netdev class does not support configuration, this may be a null
242 int (*set_config)(struct netdev *netdev, const struct smap *args);
244 /* Returns the tunnel configuration of 'netdev'. If 'netdev' is
245 * not a tunnel, returns null.
247 * If this function would always return null, it may be null instead. */
248 const struct netdev_tunnel_config *
249 (*get_tunnel_config)(const struct netdev *netdev);
251 /* Sends the buffer on 'netdev'.
252 * Returns 0 if successful, otherwise a positive errno value. Returns
253 * EAGAIN without blocking if the packet cannot be queued immediately.
254 * Returns EMSGSIZE if a partial packet was transmitted or if the packet
255 * is too big or too small to transmit on the device.
257 * To retain ownership of 'buffer' caller can set may_steal to false.
259 * The network device is expected to maintain a packet transmission queue,
260 * so that the caller does not ordinarily have to do additional queuing of
263 * May return EOPNOTSUPP if a network device does not implement packet
264 * transmission through this interface. This function may be set to null
265 * if it would always return EOPNOTSUPP anyhow. (This will prevent the
266 * network device from being usefully used by the netdev-based "userspace
267 * datapath". It will also prevent the OVS implementation of bonding from
268 * working properly over 'netdev'.) */
269 int (*send)(struct netdev *netdev, struct ofpbuf *buffer, bool may_steal);
271 /* Registers with the poll loop to wake up from the next call to
272 * poll_block() when the packet transmission queue for 'netdev' has
273 * sufficient room to transmit a packet with netdev_send().
275 * The network device is expected to maintain a packet transmission queue,
276 * so that the caller does not ordinarily have to do additional queuing of
277 * packets. Thus, this function is unlikely to ever be useful.
279 * May be null if not needed, such as for a network device that does not
280 * implement packet transmission through the 'send' member function. */
281 void (*send_wait)(struct netdev *netdev);
283 /* Sets 'netdev''s Ethernet address to 'mac' */
284 int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]);
286 /* Retrieves 'netdev''s Ethernet address into 'mac'.
288 * This address will be advertised as 'netdev''s MAC address through the
289 * OpenFlow protocol, among other uses. */
290 int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]);
292 /* Retrieves 'netdev''s MTU into '*mtup'.
294 * The MTU is the maximum size of transmitted (and received) packets, in
295 * bytes, not including the hardware header; thus, this is typically 1500
296 * bytes for Ethernet devices.
298 * If 'netdev' does not have an MTU (e.g. as some tunnels do not), then
299 * this function should return EOPNOTSUPP. This function may be set to
300 * null if it would always return EOPNOTSUPP. */
301 int (*get_mtu)(const struct netdev *netdev, int *mtup);
303 /* Sets 'netdev''s MTU to 'mtu'.
305 * If 'netdev' does not have an MTU (e.g. as some tunnels do not), then
306 * this function should return EOPNOTSUPP. This function may be set to
307 * null if it would always return EOPNOTSUPP. */
308 int (*set_mtu)(const struct netdev *netdev, int mtu);
310 /* Returns the ifindex of 'netdev', if successful, as a positive number.
311 * On failure, returns a negative errno value.
313 * The desired semantics of the ifindex value are a combination of those
314 * specified by POSIX for if_nametoindex() and by SNMP for ifIndex. An
315 * ifindex value should be unique within a host and remain stable at least
316 * until reboot. SNMP says an ifindex "ranges between 1 and the value of
317 * ifNumber" but many systems do not follow this rule anyhow.
319 * This function may be set to null if it would always return -EOPNOTSUPP.
321 int (*get_ifindex)(const struct netdev *netdev);
323 /* Sets 'carrier' to true if carrier is active (link light is on) on
326 * May be null if device does not provide carrier status (will be always
327 * up as long as device is up).
329 int (*get_carrier)(const struct netdev *netdev, bool *carrier);
331 /* Returns the number of times 'netdev''s carrier has changed since being
334 * If null, callers will assume the number of carrier resets is zero. */
335 long long int (*get_carrier_resets)(const struct netdev *netdev);
337 /* Forces ->get_carrier() to poll 'netdev''s MII registers for link status
338 * instead of checking 'netdev''s carrier. 'netdev''s MII registers will
339 * be polled once ever 'interval' milliseconds. If 'netdev' does not
340 * support MII, another method may be used as a fallback. If 'interval' is
341 * less than or equal to zero, reverts ->get_carrier() to its normal
344 * Most network devices won't support this feature and will set this
345 * function pointer to NULL, which is equivalent to returning EOPNOTSUPP.
347 int (*set_miimon_interval)(struct netdev *netdev, long long int interval);
349 /* Retrieves current device stats for 'netdev' into 'stats'.
351 * A network device that supports some statistics but not others, it should
352 * set the values of the unsupported statistics to all-1-bits
354 int (*get_stats)(const struct netdev *netdev, struct netdev_stats *);
356 /* Sets the device stats for 'netdev' to 'stats'.
358 * Most network devices won't support this feature and will set this
359 * function pointer to NULL, which is equivalent to returning EOPNOTSUPP.
361 * Some network devices might only allow setting their stats to 0. */
362 int (*set_stats)(struct netdev *netdev, const struct netdev_stats *);
364 /* Stores the features supported by 'netdev' into each of '*current',
365 * '*advertised', '*supported', and '*peer'. Each value is a bitmap of
368 * This function may be set to null if it would always return EOPNOTSUPP.
370 int (*get_features)(const struct netdev *netdev,
371 enum netdev_features *current,
372 enum netdev_features *advertised,
373 enum netdev_features *supported,
374 enum netdev_features *peer);
376 /* Set the features advertised by 'netdev' to 'advertise', which is a
377 * set of NETDEV_F_* bits.
379 * This function may be set to null for a network device that does not
380 * support configuring advertisements. */
381 int (*set_advertisements)(struct netdev *netdev,
382 enum netdev_features advertise);
384 /* Attempts to set input rate limiting (policing) policy, such that up to
385 * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative
386 * burst size of 'kbits' kb.
388 * This function may be set to null if policing is not supported. */
389 int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate,
390 unsigned int kbits_burst);
392 /* Adds to 'types' all of the forms of QoS supported by 'netdev', or leaves
393 * it empty if 'netdev' does not support QoS. Any names added to 'types'
394 * should be documented as valid for the "type" column in the "QoS" table
395 * in vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
397 * Every network device must support disabling QoS with a type of "", but
398 * this function must not add "" to 'types'.
400 * The caller is responsible for initializing 'types' (e.g. with
401 * sset_init()) before calling this function. The caller retains ownership
404 * May be NULL if 'netdev' does not support QoS at all. */
405 int (*get_qos_types)(const struct netdev *netdev, struct sset *types);
407 /* Queries 'netdev' for its capabilities regarding the specified 'type' of
408 * QoS. On success, initializes 'caps' with the QoS capabilities.
410 * Should return EOPNOTSUPP if 'netdev' does not support 'type'. May be
411 * NULL if 'netdev' does not support QoS at all. */
412 int (*get_qos_capabilities)(const struct netdev *netdev,
414 struct netdev_qos_capabilities *caps);
416 /* Queries 'netdev' about its currently configured form of QoS. If
417 * successful, stores the name of the current form of QoS into '*typep'
418 * and any details of configuration as string key-value pairs in
421 * A '*typep' of "" indicates that QoS is currently disabled on 'netdev'.
423 * The caller initializes 'details' before calling this function. The
424 * caller takes ownership of the string key-values pairs added to
427 * The netdev retains ownership of '*typep'.
429 * '*typep' will be one of the types returned by netdev_get_qos_types() for
430 * 'netdev'. The contents of 'details' should be documented as valid for
431 * '*typep' in the "other_config" column in the "QoS" table in
432 * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
434 * May be NULL if 'netdev' does not support QoS at all. */
435 int (*get_qos)(const struct netdev *netdev,
436 const char **typep, struct smap *details);
438 /* Attempts to reconfigure QoS on 'netdev', changing the form of QoS to
439 * 'type' with details of configuration from 'details'.
441 * On error, the previous QoS configuration is retained.
443 * When this function changes the type of QoS (not just 'details'), this
444 * also resets all queue configuration for 'netdev' to their defaults
445 * (which depend on the specific type of QoS). Otherwise, the queue
446 * configuration for 'netdev' is unchanged.
448 * 'type' should be "" (to disable QoS) or one of the types returned by
449 * netdev_get_qos_types() for 'netdev'. The contents of 'details' should
450 * be documented as valid for the given 'type' in the "other_config" column
451 * in the "QoS" table in vswitchd/vswitch.xml (which is built as
452 * ovs-vswitchd.conf.db(8)).
454 * May be NULL if 'netdev' does not support QoS at all. */
455 int (*set_qos)(struct netdev *netdev,
456 const char *type, const struct smap *details);
458 /* Queries 'netdev' for information about the queue numbered 'queue_id'.
459 * If successful, adds that information as string key-value pairs to
460 * 'details'. Returns 0 if successful, otherwise a positive errno value.
462 * Should return EINVAL if 'queue_id' is greater than or equal to the
463 * number of supported queues (as reported in the 'n_queues' member of
464 * struct netdev_qos_capabilities by 'get_qos_capabilities').
466 * The caller initializes 'details' before calling this function. The
467 * caller takes ownership of the string key-values pairs added to
470 * The returned contents of 'details' should be documented as valid for the
471 * given 'type' in the "other_config" column in the "Queue" table in
472 * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
474 int (*get_queue)(const struct netdev *netdev,
475 unsigned int queue_id, struct smap *details);
477 /* Configures the queue numbered 'queue_id' on 'netdev' with the key-value
478 * string pairs in 'details'. The contents of 'details' should be
479 * documented as valid for the given 'type' in the "other_config" column in
480 * the "Queue" table in vswitchd/vswitch.xml (which is built as
481 * ovs-vswitchd.conf.db(8)). Returns 0 if successful, otherwise a positive
482 * errno value. On failure, the given queue's configuration should be
485 * Should return EINVAL if 'queue_id' is greater than or equal to the
486 * number of supported queues (as reported in the 'n_queues' member of
487 * struct netdev_qos_capabilities by 'get_qos_capabilities'), or if
488 * 'details' is invalid for the type of queue.
490 * This function does not modify 'details', and the caller retains
493 * May be NULL if 'netdev' does not support QoS at all. */
494 int (*set_queue)(struct netdev *netdev,
495 unsigned int queue_id, const struct smap *details);
497 /* Attempts to delete the queue numbered 'queue_id' from 'netdev'.
499 * Should return EINVAL if 'queue_id' is greater than or equal to the
500 * number of supported queues (as reported in the 'n_queues' member of
501 * struct netdev_qos_capabilities by 'get_qos_capabilities'). Should
502 * return EOPNOTSUPP if 'queue_id' is valid but may not be deleted (e.g. if
503 * 'netdev' has a fixed set of queues with the current QoS mode).
505 * May be NULL if 'netdev' does not support QoS at all, or if all of its
506 * QoS modes have fixed sets of queues. */
507 int (*delete_queue)(struct netdev *netdev, unsigned int queue_id);
509 /* Obtains statistics about 'queue_id' on 'netdev'. Fills 'stats' with the
510 * queue's statistics. May set individual members of 'stats' to all-1-bits
511 * if the statistic is unavailable.
513 * May be NULL if 'netdev' does not support QoS at all. */
514 int (*get_queue_stats)(const struct netdev *netdev, unsigned int queue_id,
515 struct netdev_queue_stats *stats);
517 /* Attempts to begin dumping the queues in 'netdev'. On success, returns 0
518 * and initializes '*statep' with any data needed for iteration. On
519 * failure, returns a positive errno value.
521 * May be NULL if 'netdev' does not support QoS at all. */
522 int (*queue_dump_start)(const struct netdev *netdev, void **statep);
524 /* Attempts to retrieve another queue from 'netdev' for 'state', which was
525 * initialized by a successful call to the 'queue_dump_start' function for
526 * 'netdev'. On success, stores a queue ID into '*queue_id' and fills
527 * 'details' with the configuration of the queue with that ID. Returns EOF
528 * if the last queue has been dumped, or a positive errno value on error.
529 * This function will not be called again once it returns nonzero once for
530 * a given iteration (but the 'queue_dump_done' function will be called
533 * The caller initializes and clears 'details' before calling this
534 * function. The caller takes ownership of the string key-values pairs
535 * added to 'details'.
537 * The returned contents of 'details' should be documented as valid for the
538 * given 'type' in the "other_config" column in the "Queue" table in
539 * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
541 * May be NULL if 'netdev' does not support QoS at all. */
542 int (*queue_dump_next)(const struct netdev *netdev, void *state,
543 unsigned int *queue_id, struct smap *details);
545 /* Releases resources from 'netdev' for 'state', which was initialized by a
546 * successful call to the 'queue_dump_start' function for 'netdev'.
548 * May be NULL if 'netdev' does not support QoS at all. */
549 int (*queue_dump_done)(const struct netdev *netdev, void *state);
551 /* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's
552 * ID, its statistics, and the 'aux' specified by the caller. The order of
553 * iteration is unspecified, but (when successful) each queue must be
554 * visited exactly once.
556 * 'cb' will not modify or free the statistics passed in. */
557 int (*dump_queue_stats)(const struct netdev *netdev,
558 void (*cb)(unsigned int queue_id,
559 struct netdev_queue_stats *,
563 /* If 'netdev' has an assigned IPv4 address, sets '*address' to that
564 * address and '*netmask' to the associated netmask.
566 * The following error values have well-defined meanings:
568 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address.
570 * - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'.
572 * This function may be set to null if it would always return EOPNOTSUPP
574 int (*get_in4)(const struct netdev *netdev, struct in_addr *address,
575 struct in_addr *netmask);
577 /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask. If
578 * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared.
580 * This function may be set to null if it would always return EOPNOTSUPP
582 int (*set_in4)(struct netdev *netdev, struct in_addr addr,
583 struct in_addr mask);
585 /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address.
587 * The following error values have well-defined meanings:
589 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address.
591 * - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'.
593 * This function may be set to null if it would always return EOPNOTSUPP
595 int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6);
597 /* Adds 'router' as a default IP gateway for the TCP/IP stack that
598 * corresponds to 'netdev'.
600 * This function may be set to null if it would always return EOPNOTSUPP
602 int (*add_router)(struct netdev *netdev, struct in_addr router);
604 /* Looks up the next hop for 'host'. If successful, stores the next hop
605 * gateway's address (0 if 'host' is on a directly connected network) in
606 * '*next_hop' and a copy of the name of the device to reach 'host' in
607 * '*netdev_name', and returns 0. The caller is responsible for freeing
608 * '*netdev_name' (by calling free()).
610 * This function may be set to null if it would always return EOPNOTSUPP
612 int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop,
615 /* Retrieves driver information of the device.
617 * Populates 'smap' with key-value pairs representing the status of the
618 * device. 'smap' is a set of key-value string pairs representing netdev
619 * type specific information. For more information see
620 * ovs-vswitchd.conf.db(5).
622 * The caller is responsible for destroying 'smap' and its data.
624 * This function may be set to null if it would always return EOPNOTSUPP
626 int (*get_status)(const struct netdev *netdev, struct smap *smap);
628 /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the
629 * corresponding MAC address in 'mac'. A return value of ENXIO, in
630 * particular, indicates that there is no ARP table entry for 'ip' on
633 * This function may be set to null if it would always return EOPNOTSUPP
635 int (*arp_lookup)(const struct netdev *netdev, ovs_be32 ip,
638 /* Retrieves the current set of flags on 'netdev' into '*old_flags'. Then,
639 * turns off the flags that are set to 1 in 'off' and turns on the flags
640 * that are set to 1 in 'on'. (No bit will be set to 1 in both 'off' and
641 * 'on'; that is, off & on == 0.)
643 * This function may be invoked from a signal handler. Therefore, it
644 * should not do anything that is not signal-safe (such as logging). */
645 int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
646 enum netdev_flags on, enum netdev_flags *old_flags);
648 /* ## -------------------- ## */
649 /* ## netdev_rxq Functions ## */
650 /* ## -------------------- ## */
652 /* If a particular netdev class does not support receiving packets, all these
653 * function pointers must be NULL. */
655 /* Life-cycle functions for a netdev_rxq. See the large comment above on
656 * struct netdev_class. */
657 struct netdev_rxq *(*rxq_alloc)(void);
658 int (*rxq_construct)(struct netdev_rxq *);
659 void (*rxq_destruct)(struct netdev_rxq *);
660 void (*rxq_dealloc)(struct netdev_rxq *);
662 /* Attempts to receive batch of packets from 'rx' and place array of pointers
663 * into '*pkt'. netdev is responsible for allocating buffers.
664 * '*cnt' points to packet count for given batch. Once packets are returned
665 * to caller, netdev should give up ownership of ofpbuf data.
667 * Implementations should allocate buffer with DP_NETDEV_HEADROOM headroom
668 * and add a VLAN header which is obtained out-of-band to the packet.
670 * Caller is expected to pass array of size MAX_RX_BATCH.
671 * This function may be set to null if it would always return EOPNOTSUPP
673 int (*rxq_recv)(struct netdev_rxq *rx, struct ofpbuf **pkt, int *cnt);
675 /* Registers with the poll loop to wake up from the next call to
676 * poll_block() when a packet is ready to be received with netdev_rxq_recv()
678 void (*rxq_wait)(struct netdev_rxq *rx);
680 /* Discards all packets waiting to be received from 'rx'. */
681 int (*rxq_drain)(struct netdev_rxq *rx);
684 int netdev_register_provider(const struct netdev_class *);
685 int netdev_unregister_provider(const char *type);
687 extern const struct netdev_class netdev_linux_class;
688 extern const struct netdev_class netdev_internal_class;
689 extern const struct netdev_class netdev_tap_class;
690 #if defined(__FreeBSD__) || defined(__NetBSD__)
691 extern const struct netdev_class netdev_bsd_class;
698 #endif /* netdev.h */