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. */
28 /* A network device (e.g. an Ethernet device).
30 * This structure should be treated as opaque by network device
33 char *name; /* Name of network device. */
34 const struct netdev_class *class; /* Functions to control this device. */
35 int ref_cnt; /* Times this devices was opened. */
36 struct shash_node *node; /* Pointer to element in global map. */
37 uint32_t args_hash; /* Hash of arguments for the device. */
40 void netdev_dev_init(struct netdev_dev *, const char *name,
41 const struct netdev_class *);
42 void netdev_dev_uninit(struct netdev_dev *, bool destroy);
43 const char *netdev_dev_get_type(const struct netdev_dev *);
44 const char *netdev_dev_get_name(const struct netdev_dev *);
46 static inline void netdev_dev_assert_class(const struct netdev_dev *netdev_dev,
47 const struct netdev_class *class)
49 assert(netdev_dev->class == class);
52 /* A instance of an open network device.
54 * This structure should be treated as opaque by network device
57 struct netdev_dev *netdev_dev; /* Parent netdev_dev. */
58 struct list node; /* Element in global list. */
60 enum netdev_flags save_flags; /* Initial device flags. */
61 enum netdev_flags changed_flags; /* Flags that we changed. */
64 void netdev_init(struct netdev *, struct netdev_dev *);
65 void netdev_uninit(struct netdev *, bool close);
66 struct netdev_dev *netdev_get_dev(const struct netdev *);
68 static inline void netdev_assert_class(const struct netdev *netdev,
69 const struct netdev_class *class)
71 netdev_dev_assert_class(netdev_get_dev(netdev), class);
74 /* A network device notifier.
76 * Network device implementations should use netdev_notifier_init() to
77 * initialize this structure, but they may freely read its members after
79 struct netdev_notifier {
80 struct netdev *netdev;
81 void (*cb)(struct netdev_notifier *);
84 void netdev_notifier_init(struct netdev_notifier *, struct netdev *,
85 void (*cb)(struct netdev_notifier *), void *aux);
87 /* Network device class structure, to be defined by each implementation of a
90 * These functions return 0 if successful or a positive errno value on failure,
91 * except where otherwise noted. */
93 /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc.
95 * One of the providers should supply a "system" type, since this is
96 * the type assumed if no type is specified when opening a netdev.
97 * The "system" type corresponds to an existing network device on
101 /* Called only once, at program startup. Returning an error from this
102 * function will prevent any network device in this class from being
105 * This function may be set to null if a network device class needs no
106 * initialization at program startup. */
109 /* Performs periodic work needed by netdevs of this class. May be null if
110 * no periodic work is necessary. */
113 /* Arranges for poll_block() to wake up if the "run" member function needs
114 * to be called. May be null if nothing is needed here. */
117 /* Attempts to create a network device of 'type' with 'name'.
118 * 'type' corresponds to the 'type' field used in the netdev_class
119 * structure. On success sets 'netdev_devp' to the newly created device. */
120 int (*create)(const char *name, const char *type, const struct shash *args,
121 struct netdev_dev **netdev_devp);
123 /* Destroys 'netdev_dev'.
125 * Netdev devices maintain a reference count that is incremented on
126 * netdev_open() and decremented on netdev_close(). If 'netdev_dev'
127 * has a non-zero reference count, then this function will not be
129 void (*destroy)(struct netdev_dev *netdev_dev);
131 /* Reconfigures the device 'netdev_dev' with 'args'.
133 * If this netdev class does not support reconfiguring a netdev
134 * device, this may be a null pointer.
136 int (*reconfigure)(struct netdev_dev *netdev_dev, const struct shash *args);
138 /* Attempts to open a network device. On success, sets 'netdevp'
139 * to the new network device.
141 * 'ethertype' may be a 16-bit Ethernet protocol value in host byte order
142 * to capture frames of that type received on the device. It may also be
143 * one of the 'enum netdev_pseudo_ethertype' values to receive frames in
144 * one of those categories. */
145 int (*open)(struct netdev_dev *netdev_dev, int ethertype,
146 struct netdev **netdevp);
148 /* Closes 'netdev'. */
149 void (*close)(struct netdev *netdev);
151 /* Enumerates the names of all network devices of this class.
153 * The caller has already initialized 'all_names' and might already have
154 * added some names to it. This function should not disturb any existing
155 * names in 'all_names'.
157 * If this netdev class does not support enumeration, this may be a null
159 int (*enumerate)(struct svec *all_names);
161 /* Attempts to receive a packet from 'netdev' into the 'size' bytes in
162 * 'buffer'. If successful, returns the number of bytes in the received
163 * packet, otherwise a negative errno value. Returns -EAGAIN immediately
164 * if no packet is ready to be received. */
165 int (*recv)(struct netdev *netdev, void *buffer, size_t size);
167 /* Registers with the poll loop to wake up from the next call to
168 * poll_block() when a packet is ready to be received with netdev_recv() on
170 void (*recv_wait)(struct netdev *netdev);
172 /* Discards all packets waiting to be received from 'netdev'. */
173 int (*drain)(struct netdev *netdev);
175 /* Sends the 'size'-byte packet in 'buffer' on 'netdev'. Returns 0 if
176 * successful, otherwise a positive errno value. Returns EAGAIN without
177 * blocking if the packet cannot be queued immediately. Returns EMSGSIZE
178 * if a partial packet was transmitted or if the packet is too big or too
179 * small to transmit on the device.
181 * The caller retains ownership of 'buffer' in all cases.
183 * The network device is expected to maintain a packet transmission queue,
184 * so that the caller does not ordinarily have to do additional queuing of
186 int (*send)(struct netdev *netdev, const void *buffer, size_t size);
188 /* Registers with the poll loop to wake up from the next call to
189 * poll_block() when the packet transmission queue for 'netdev' has
190 * sufficient room to transmit a packet with netdev_send().
192 * The network device is expected to maintain a packet transmission queue,
193 * so that the caller does not ordinarily have to do additional queuing of
194 * packets. Thus, this function is unlikely to ever be useful. */
195 void (*send_wait)(struct netdev *netdev);
197 /* Sets 'netdev''s Ethernet address to 'mac' */
198 int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]);
200 /* Retrieves 'netdev''s Ethernet address into 'mac'. */
201 int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]);
203 /* Retrieves 'netdev''s MTU into '*mtup'.
205 * The MTU is the maximum size of transmitted (and received) packets, in
206 * bytes, not including the hardware header; thus, this is typically 1500
207 * bytes for Ethernet devices.*/
208 int (*get_mtu)(const struct netdev *netdev, int *mtup);
210 /* Returns the ifindex of 'netdev', if successful, as a positive number.
211 * On failure, returns a negative errno value.
213 * The desired semantics of the ifindex value are a combination of those
214 * specified by POSIX for if_nametoindex() and by SNMP for ifIndex. An
215 * ifindex value should be unique within a host and remain stable at least
216 * until reboot. SNMP says an ifindex "ranges between 1 and the value of
217 * ifNumber" but many systems do not follow this rule anyhow. */
218 int (*get_ifindex)(const struct netdev *netdev);
220 /* Sets 'carrier' to true if carrier is active (link light is on) on
222 int (*get_carrier)(const struct netdev *netdev, bool *carrier);
224 /* Retrieves current device stats for 'netdev' into 'stats'.
226 * A network device that supports some statistics but not others, it should
227 * set the values of the unsupported statistics to all-1-bits
229 int (*get_stats)(const struct netdev *netdev, struct netdev_stats *);
231 /* Stores the features supported by 'netdev' into each of '*current',
232 * '*advertised', '*supported', and '*peer'. Each value is a bitmap of
233 * "enum ofp_port_features" bits, in host byte order. */
234 int (*get_features)(struct netdev *netdev,
235 uint32_t *current, uint32_t *advertised,
236 uint32_t *supported, uint32_t *peer);
238 /* Set the features advertised by 'netdev' to 'advertise', which is a
239 * bitmap of "enum ofp_port_features" bits, in host byte order.
241 * This function may be set to null for a network device that does not
242 * support configuring advertisements. */
243 int (*set_advertisements)(struct netdev *netdev, uint32_t advertise);
245 /* If 'netdev' is a VLAN network device (e.g. one created with vconfig(8)),
246 * sets '*vlan_vid' to the VLAN VID associated with that device and returns
249 * Returns ENOENT if 'netdev' is a network device that is not a
252 * This function should be set to null if it doesn't make any sense for
253 * your network device (it probably doesn't). */
254 int (*get_vlan_vid)(const struct netdev *netdev, int *vlan_vid);
256 /* Attempts to set input rate limiting (policing) policy, such that up to
257 * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative
258 * burst size of 'kbits' kb.
260 * This function may be set to null if policing is not supported. */
261 int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate,
262 unsigned int kbits_burst);
264 /* If 'netdev' has an assigned IPv4 address, sets '*address' to that
265 * address and '*netmask' to the associated netmask.
267 * The following error values have well-defined meanings:
269 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address.
271 * - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'.
273 * This function may be set to null if it would always return EOPNOTSUPP
275 int (*get_in4)(const struct netdev *netdev, struct in_addr *address,
276 struct in_addr *netmask);
278 /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask. If
279 * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared.
281 * This function may be set to null if it would always return EOPNOTSUPP
283 int (*set_in4)(struct netdev *netdev, struct in_addr addr,
284 struct in_addr mask);
286 /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address.
288 * The following error values have well-defined meanings:
290 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address.
292 * - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'.
294 * This function may be set to null if it would always return EOPNOTSUPP
296 int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6);
298 /* Adds 'router' as a default IP gateway for the TCP/IP stack that
299 * corresponds to 'netdev'.
301 * This function may be set to null if it would always return EOPNOTSUPP
303 int (*add_router)(struct netdev *netdev, struct in_addr router);
305 /* Looks up the next hop for 'host'. If succesful, stores the next hop
306 * gateway's address (0 if 'host' is on a directly connected network) in
307 * '*next_hop' and a copy of the name of the device to reach 'host' in
308 * '*netdev_name', and returns 0. The caller is responsible for freeing
309 * '*netdev_name' (by calling free()).
311 * This function may be set to null if it would always return EOPNOTSUPP
313 int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop,
316 /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the
317 * corresponding MAC address in 'mac'. A return value of ENXIO, in
318 * particular, indicates that there is no ARP table entry for 'ip' on
321 * This function may be set to null if it would always return EOPNOTSUPP
323 int (*arp_lookup)(const struct netdev *netdev, uint32_t ip, uint8_t mac[6]);
325 /* Retrieves the current set of flags on 'netdev' into '*old_flags'.
326 * Then, turns off the flags that are set to 1 in 'off' and turns on the
327 * flags that are set to 1 in 'on'. (No bit will be set to 1 in both 'off'
328 * and 'on'; that is, off & on == 0.)
330 * This function may be invoked from a signal handler. Therefore, it
331 * should not do anything that is not signal-safe (such as logging). */
332 int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
333 enum netdev_flags on, enum netdev_flags *old_flags);
335 /* Arranges for 'cb' to be called whenever one of the attributes of
336 * 'netdev' changes and sets '*notifierp' to a newly created
337 * netdev_notifier that represents this arrangement. The created notifier
338 * will have its 'netdev', 'cb', and 'aux' members set to the values of the
339 * corresponding parameters. */
340 int (*poll_add)(struct netdev *netdev,
341 void (*cb)(struct netdev_notifier *notifier), void *aux,
342 struct netdev_notifier **notifierp);
344 /* Cancels poll notification for 'notifier'. */
345 void (*poll_remove)(struct netdev_notifier *notifier);
348 extern const struct netdev_class netdev_linux_class;
349 extern const struct netdev_class netdev_tap_class;
350 extern const struct netdev_class netdev_gre_class;
352 #endif /* netdev.h */