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