2 * Copyright (c) 2009, 2010 Nicira Networks.
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. */
37 /* A network device (e.g. an Ethernet device).
39 * This structure should be treated as opaque by network device
42 char *name; /* Name of network device. */
43 const struct netdev_class *netdev_class; /* Functions to control
45 int ref_cnt; /* Times this devices was opened. */
46 struct shash_node *node; /* Pointer to element in global map. */
47 struct arg *args; /* Argument list from last config. */
48 int n_args; /* Number of arguments in 'args'. */
51 void netdev_dev_init(struct netdev_dev *, const char *name,
52 const struct netdev_class *);
53 void netdev_dev_uninit(struct netdev_dev *, bool destroy);
54 const char *netdev_dev_get_type(const struct netdev_dev *);
55 const struct netdev_class *netdev_dev_get_class(const struct netdev_dev *);
56 const char *netdev_dev_get_name(const struct netdev_dev *);
57 struct netdev_dev *netdev_dev_from_name(const char *name);
58 void netdev_dev_get_devices(const struct netdev_class *,
59 struct shash *device_list);
61 static inline void netdev_dev_assert_class(const struct netdev_dev *netdev_dev,
62 const struct netdev_class *class_)
64 assert(netdev_dev->netdev_class == class_);
67 /* A instance of an open network device.
69 * This structure should be treated as opaque by network device
72 struct netdev_dev *netdev_dev; /* Parent netdev_dev. */
73 struct list node; /* Element in global list. */
75 enum netdev_flags save_flags; /* Initial device flags. */
76 enum netdev_flags changed_flags; /* Flags that we changed. */
78 int ref_cnt; /* Times this 'netdev' was opened. */
81 void netdev_init(struct netdev *, struct netdev_dev *);
82 void netdev_uninit(struct netdev *, bool close);
83 struct netdev_dev *netdev_get_dev(const struct netdev *);
85 static inline void netdev_assert_class(const struct netdev *netdev,
86 const struct netdev_class *netdev_class)
88 netdev_dev_assert_class(netdev_get_dev(netdev), netdev_class);
91 /* A network device notifier.
93 * Network device implementations should use netdev_notifier_init() to
94 * initialize this structure, but they may freely read its members after
96 struct netdev_notifier {
97 struct netdev *netdev;
98 void (*cb)(struct netdev_notifier *);
101 void netdev_notifier_init(struct netdev_notifier *, struct netdev *,
102 void (*cb)(struct netdev_notifier *), void *aux);
104 /* Network device class structure, to be defined by each implementation of a
107 * These functions return 0 if successful or a positive errno value on failure,
108 * except where otherwise noted. */
109 struct netdev_class {
110 /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc.
112 * One of the providers should supply a "system" type, since this is
113 * the type assumed if no type is specified when opening a netdev.
114 * The "system" type corresponds to an existing network device on
118 /* Called when the netdev provider is registered, typically at program
119 * startup. Returning an error from this function will prevent any network
120 * device in this class from being opened.
122 * This function may be set to null if a network device class needs no
123 * initialization at registration time. */
126 /* Performs periodic work needed by netdevs of this class. May be null if
127 * no periodic work is necessary. */
130 /* Arranges for poll_block() to wake up if the "run" member function needs
131 * to be called. May be null if nothing is needed here. */
134 /* Attempts to create a network device of 'type' with 'name'.
135 * 'type' corresponds to the 'type' field used in the netdev_class
136 * structure. On success sets 'netdev_devp' to the newly created device. */
137 int (*create)(const char *name, const char *type, const struct shash *args,
138 struct netdev_dev **netdev_devp);
140 /* Destroys 'netdev_dev'.
142 * Netdev devices maintain a reference count that is incremented on
143 * netdev_open() and decremented on netdev_close(). If 'netdev_dev'
144 * has a non-zero reference count, then this function will not be
146 void (*destroy)(struct netdev_dev *netdev_dev);
148 /* Reconfigures the device 'netdev_dev' with 'args'.
150 * If this netdev class does not support reconfiguring a netdev
151 * device, this may be a null pointer.
153 int (*reconfigure)(struct netdev_dev *netdev_dev, const struct shash *args);
155 /* Attempts to open a network device. On success, sets 'netdevp'
156 * to the new network device.
158 * 'ethertype' may be a 16-bit Ethernet protocol value in host byte order
159 * to capture frames of that type received on the device. It may also be
160 * one of the 'enum netdev_pseudo_ethertype' values to receive frames in
161 * one of those categories. */
162 int (*open)(struct netdev_dev *netdev_dev, int ethertype,
163 struct netdev **netdevp);
165 /* Closes 'netdev'. */
166 void (*close)(struct netdev *netdev);
168 /* Enumerates the names of all network devices of this class.
170 * The caller has already initialized 'all_names' and might already have
171 * added some names to it. This function should not disturb any existing
172 * names in 'all_names'.
174 * If this netdev class does not support enumeration, this may be a null
176 int (*enumerate)(struct svec *all_names);
178 /* Attempts to receive a packet from 'netdev' into the 'size' bytes in
179 * 'buffer'. If successful, returns the number of bytes in the received
180 * packet, otherwise a negative errno value. Returns -EAGAIN immediately
181 * if no packet is ready to be received.
183 * May return -EOPNOTSUPP if a network device does not implement packet
184 * reception through this interface. This function may be set to null if
185 * it would always return -EOPNOTSUPP anyhow. (This will disable the OVS
186 * integrated DHCP client and OpenFlow controller discovery, and prevent
187 * the network device from being usefully used by the netdev-based
188 * "userspace datapath".) */
189 int (*recv)(struct netdev *netdev, void *buffer, size_t size);
191 /* Registers with the poll loop to wake up from the next call to
192 * poll_block() when a packet is ready to be received with netdev_recv() on
195 * May be null if not needed, such as for a network device that does not
196 * implement packet reception through the 'recv' member function. */
197 void (*recv_wait)(struct netdev *netdev);
199 /* Discards all packets waiting to be received from 'netdev'.
201 * May be null if not needed, such as for a network device that does not
202 * implement packet reception through the 'recv' member function. */
203 int (*drain)(struct netdev *netdev);
205 /* Sends the 'size'-byte packet in 'buffer' on 'netdev'. Returns 0 if
206 * successful, otherwise a positive errno value. Returns EAGAIN without
207 * blocking if the packet cannot be queued immediately. Returns EMSGSIZE
208 * if a partial packet was transmitted or if the packet is too big or too
209 * small to transmit on the device.
211 * The caller retains ownership of 'buffer' in all cases.
213 * The network device is expected to maintain a packet transmission queue,
214 * so that the caller does not ordinarily have to do additional queuing of
217 * May return EOPNOTSUPP if a network device does not implement packet
218 * transmission through this interface. This function may be set to null
219 * if it would always return EOPNOTSUPP anyhow. (This will disable the OVS
220 * integrated DHCP client and OpenFlow controller discovery, and prevent
221 * the network device from being usefully used by the netdev-based
222 * "userspace datapath".) */
223 int (*send)(struct netdev *netdev, const void *buffer, size_t size);
225 /* Registers with the poll loop to wake up from the next call to
226 * poll_block() when the packet transmission queue for 'netdev' has
227 * sufficient room to transmit a packet with netdev_send().
229 * The network device is expected to maintain a packet transmission queue,
230 * so that the caller does not ordinarily have to do additional queuing of
231 * packets. Thus, this function is unlikely to ever be useful.
233 * May be null if not needed, such as for a network device that does not
234 * implement packet transmission through the 'send' member function. */
235 void (*send_wait)(struct netdev *netdev);
237 /* Sets 'netdev''s Ethernet address to 'mac' */
238 int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]);
240 /* Retrieves 'netdev''s Ethernet address into 'mac'. */
241 int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]);
243 /* Retrieves 'netdev''s MTU into '*mtup'.
245 * The MTU is the maximum size of transmitted (and received) packets, in
246 * bytes, not including the hardware header; thus, this is typically 1500
247 * bytes for Ethernet devices.*/
248 int (*get_mtu)(const struct netdev *netdev, int *mtup);
250 /* Returns the ifindex of 'netdev', if successful, as a positive number.
251 * On failure, returns a negative errno value.
253 * The desired semantics of the ifindex value are a combination of those
254 * specified by POSIX for if_nametoindex() and by SNMP for ifIndex. An
255 * ifindex value should be unique within a host and remain stable at least
256 * until reboot. SNMP says an ifindex "ranges between 1 and the value of
257 * ifNumber" but many systems do not follow this rule anyhow.
259 * This function may be set to null if it would always return -EOPNOTSUPP.
261 int (*get_ifindex)(const struct netdev *netdev);
263 /* Sets 'carrier' to true if carrier is active (link light is on) on
265 int (*get_carrier)(const struct netdev *netdev, bool *carrier);
267 /* Retrieves current device stats for 'netdev' into 'stats'.
269 * A network device that supports some statistics but not others, it should
270 * set the values of the unsupported statistics to all-1-bits
272 int (*get_stats)(const struct netdev *netdev, struct netdev_stats *);
274 /* Sets the device stats for 'netdev' to 'stats'.
276 * Most network devices won't support this feature and will set this
277 * function pointer to NULL, which is equivalent to returning EOPNOTSUPP.
279 * Some network devices might only allow setting their stats to 0. */
280 int (*set_stats)(struct netdev *netdev, const struct netdev_stats *);
282 /* Stores the features supported by 'netdev' into each of '*current',
283 * '*advertised', '*supported', and '*peer'. Each value is a bitmap of
284 * "enum ofp_port_features" bits, in host byte order.
286 * This function may be set to null if it would always return EOPNOTSUPP.
288 int (*get_features)(struct netdev *netdev,
289 uint32_t *current, uint32_t *advertised,
290 uint32_t *supported, uint32_t *peer);
292 /* Set the features advertised by 'netdev' to 'advertise', which is a
293 * bitmap of "enum ofp_port_features" bits, in host byte order.
295 * This function may be set to null for a network device that does not
296 * support configuring advertisements. */
297 int (*set_advertisements)(struct netdev *netdev, uint32_t advertise);
299 /* If 'netdev' is a VLAN network device (e.g. one created with vconfig(8)),
300 * sets '*vlan_vid' to the VLAN VID associated with that device and returns
303 * Returns ENOENT if 'netdev' is a network device that is not a
306 * This function should be set to null if it doesn't make any sense for
307 * your network device (it probably doesn't). */
308 int (*get_vlan_vid)(const struct netdev *netdev, int *vlan_vid);
310 /* Attempts to set input rate limiting (policing) policy, such that up to
311 * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative
312 * burst size of 'kbits' kb.
314 * This function may be set to null if policing is not supported. */
315 int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate,
316 unsigned int kbits_burst);
318 /* If 'netdev' has an assigned IPv4 address, sets '*address' to that
319 * address and '*netmask' to the associated netmask.
321 * The following error values have well-defined meanings:
323 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address.
325 * - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'.
327 * This function may be set to null if it would always return EOPNOTSUPP
329 int (*get_in4)(const struct netdev *netdev, struct in_addr *address,
330 struct in_addr *netmask);
332 /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask. If
333 * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared.
335 * This function may be set to null if it would always return EOPNOTSUPP
337 int (*set_in4)(struct netdev *netdev, struct in_addr addr,
338 struct in_addr mask);
340 /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address.
342 * The following error values have well-defined meanings:
344 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address.
346 * - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'.
348 * This function may be set to null if it would always return EOPNOTSUPP
350 int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6);
352 /* Adds 'router' as a default IP gateway for the TCP/IP stack that
353 * corresponds to 'netdev'.
355 * This function may be set to null if it would always return EOPNOTSUPP
357 int (*add_router)(struct netdev *netdev, struct in_addr router);
359 /* Looks up the next hop for 'host'. If succesful, stores the next hop
360 * gateway's address (0 if 'host' is on a directly connected network) in
361 * '*next_hop' and a copy of the name of the device to reach 'host' in
362 * '*netdev_name', and returns 0. The caller is responsible for freeing
363 * '*netdev_name' (by calling free()).
365 * This function may be set to null if it would always return EOPNOTSUPP
367 int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop,
370 /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the
371 * corresponding MAC address in 'mac'. A return value of ENXIO, in
372 * particular, indicates that there is no ARP table entry for 'ip' on
375 * This function may be set to null if it would always return EOPNOTSUPP
377 int (*arp_lookup)(const struct netdev *netdev, uint32_t ip, uint8_t mac[6]);
379 /* Retrieves the current set of flags on 'netdev' into '*old_flags'.
380 * Then, turns off the flags that are set to 1 in 'off' and turns on the
381 * flags that are set to 1 in 'on'. (No bit will be set to 1 in both 'off'
382 * and 'on'; that is, off & on == 0.)
384 * This function may be invoked from a signal handler. Therefore, it
385 * should not do anything that is not signal-safe (such as logging). */
386 int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
387 enum netdev_flags on, enum netdev_flags *old_flags);
389 /* Arranges for 'cb' to be called whenever one of the attributes of
390 * 'netdev' changes and sets '*notifierp' to a newly created
391 * netdev_notifier that represents this arrangement. The created notifier
392 * will have its 'netdev', 'cb', and 'aux' members set to the values of the
393 * corresponding parameters. */
394 int (*poll_add)(struct netdev *netdev,
395 void (*cb)(struct netdev_notifier *notifier), void *aux,
396 struct netdev_notifier **notifierp);
398 /* Cancels poll notification for 'notifier'. */
399 void (*poll_remove)(struct netdev_notifier *notifier);
402 extern const struct netdev_class netdev_linux_class;
403 extern const struct netdev_class netdev_tap_class;
404 extern const struct netdev_class netdev_patch_class;
405 extern const struct netdev_class netdev_gre_class;
411 #endif /* netdev.h */