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 *);
45 struct netdev_dev *netdev_dev_from_name(const char *name);
46 void netdev_dev_get_devices(const struct netdev_class *,
47 struct shash *device_list);
49 static inline void netdev_dev_assert_class(const struct netdev_dev *netdev_dev,
50 const struct netdev_class *class)
52 assert(netdev_dev->class == class);
55 /* A instance of an open network device.
57 * This structure should be treated as opaque by network device
60 struct netdev_dev *netdev_dev; /* Parent netdev_dev. */
61 struct list node; /* Element in global list. */
63 enum netdev_flags save_flags; /* Initial device flags. */
64 enum netdev_flags changed_flags; /* Flags that we changed. */
67 void netdev_init(struct netdev *, struct netdev_dev *);
68 void netdev_uninit(struct netdev *, bool close);
69 struct netdev_dev *netdev_get_dev(const struct netdev *);
71 static inline void netdev_assert_class(const struct netdev *netdev,
72 const struct netdev_class *class)
74 netdev_dev_assert_class(netdev_get_dev(netdev), class);
77 /* A network device notifier.
79 * Network device implementations should use netdev_notifier_init() to
80 * initialize this structure, but they may freely read its members after
82 struct netdev_notifier {
83 struct netdev *netdev;
84 void (*cb)(struct netdev_notifier *);
87 void netdev_notifier_init(struct netdev_notifier *, struct netdev *,
88 void (*cb)(struct netdev_notifier *), void *aux);
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. */
96 /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc.
98 * One of the providers should supply a "system" type, since this is
99 * the type assumed if no type is specified when opening a netdev.
100 * The "system" type corresponds to an existing network device on
104 /* Called only once, at program startup. Returning an error from this
105 * function will prevent any network device in this class from being
108 * This function may be set to null if a network device class needs no
109 * initialization at program startup. */
112 /* Performs periodic work needed by netdevs of this class. May be null if
113 * no periodic work is necessary. */
116 /* Arranges for poll_block() to wake up if the "run" member function needs
117 * to be called. May be null if nothing is needed here. */
120 /* Attempts to create a network device of 'type' with 'name'.
121 * 'type' corresponds to the 'type' field used in the netdev_class
122 * structure. On success sets 'netdev_devp' to the newly created device. */
123 int (*create)(const char *name, const char *type, const struct shash *args,
124 struct netdev_dev **netdev_devp);
126 /* Destroys 'netdev_dev'.
128 * Netdev devices maintain a reference count that is incremented on
129 * netdev_open() and decremented on netdev_close(). If 'netdev_dev'
130 * has a non-zero reference count, then this function will not be
132 void (*destroy)(struct netdev_dev *netdev_dev);
134 /* Reconfigures the device 'netdev_dev' with 'args'.
136 * If this netdev class does not support reconfiguring a netdev
137 * device, this may be a null pointer.
139 int (*reconfigure)(struct netdev_dev *netdev_dev, const struct shash *args);
141 /* Attempts to open a network device. On success, sets 'netdevp'
142 * to the new network device.
144 * 'ethertype' may be a 16-bit Ethernet protocol value in host byte order
145 * to capture frames of that type received on the device. It may also be
146 * one of the 'enum netdev_pseudo_ethertype' values to receive frames in
147 * one of those categories. */
148 int (*open)(struct netdev_dev *netdev_dev, int ethertype,
149 struct netdev **netdevp);
151 /* Closes 'netdev'. */
152 void (*close)(struct netdev *netdev);
154 /* Enumerates the names of all network devices of this class.
156 * The caller has already initialized 'all_names' and might already have
157 * added some names to it. This function should not disturb any existing
158 * names in 'all_names'.
160 * If this netdev class does not support enumeration, this may be a null
162 int (*enumerate)(struct svec *all_names);
164 /* Attempts to receive a packet from 'netdev' into the 'size' bytes in
165 * 'buffer'. If successful, returns the number of bytes in the received
166 * packet, otherwise a negative errno value. Returns -EAGAIN immediately
167 * if no packet is ready to be received. */
168 int (*recv)(struct netdev *netdev, void *buffer, size_t size);
170 /* Registers with the poll loop to wake up from the next call to
171 * poll_block() when a packet is ready to be received with netdev_recv() on
173 void (*recv_wait)(struct netdev *netdev);
175 /* Discards all packets waiting to be received from 'netdev'. */
176 int (*drain)(struct netdev *netdev);
178 /* Sends the 'size'-byte packet in 'buffer' on 'netdev'. Returns 0 if
179 * successful, otherwise a positive errno value. Returns EAGAIN without
180 * blocking if the packet cannot be queued immediately. Returns EMSGSIZE
181 * if a partial packet was transmitted or if the packet is too big or too
182 * small to transmit on the device.
184 * The caller retains ownership of 'buffer' in all cases.
186 * The network device is expected to maintain a packet transmission queue,
187 * so that the caller does not ordinarily have to do additional queuing of
189 int (*send)(struct netdev *netdev, const void *buffer, size_t size);
191 /* Registers with the poll loop to wake up from the next call to
192 * poll_block() when the packet transmission queue for 'netdev' has
193 * sufficient room to transmit a packet with netdev_send().
195 * The network device is expected to maintain a packet transmission queue,
196 * so that the caller does not ordinarily have to do additional queuing of
197 * packets. Thus, this function is unlikely to ever be useful. */
198 void (*send_wait)(struct netdev *netdev);
200 /* Sets 'netdev''s Ethernet address to 'mac' */
201 int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]);
203 /* Retrieves 'netdev''s Ethernet address into 'mac'. */
204 int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]);
206 /* Retrieves 'netdev''s MTU into '*mtup'.
208 * The MTU is the maximum size of transmitted (and received) packets, in
209 * bytes, not including the hardware header; thus, this is typically 1500
210 * bytes for Ethernet devices.*/
211 int (*get_mtu)(const struct netdev *netdev, int *mtup);
213 /* Returns the ifindex of 'netdev', if successful, as a positive number.
214 * On failure, returns a negative errno value.
216 * The desired semantics of the ifindex value are a combination of those
217 * specified by POSIX for if_nametoindex() and by SNMP for ifIndex. An
218 * ifindex value should be unique within a host and remain stable at least
219 * until reboot. SNMP says an ifindex "ranges between 1 and the value of
220 * ifNumber" but many systems do not follow this rule anyhow. */
221 int (*get_ifindex)(const struct netdev *netdev);
223 /* Sets 'carrier' to true if carrier is active (link light is on) on
225 int (*get_carrier)(const struct netdev *netdev, bool *carrier);
227 /* Retrieves current device stats for 'netdev' into 'stats'.
229 * A network device that supports some statistics but not others, it should
230 * set the values of the unsupported statistics to all-1-bits
232 int (*get_stats)(const struct netdev *netdev, struct netdev_stats *);
234 /* Stores the features supported by 'netdev' into each of '*current',
235 * '*advertised', '*supported', and '*peer'. Each value is a bitmap of
236 * "enum ofp_port_features" bits, in host byte order. */
237 int (*get_features)(struct netdev *netdev,
238 uint32_t *current, uint32_t *advertised,
239 uint32_t *supported, uint32_t *peer);
241 /* Set the features advertised by 'netdev' to 'advertise', which is a
242 * bitmap of "enum ofp_port_features" bits, in host byte order.
244 * This function may be set to null for a network device that does not
245 * support configuring advertisements. */
246 int (*set_advertisements)(struct netdev *netdev, uint32_t advertise);
248 /* If 'netdev' is a VLAN network device (e.g. one created with vconfig(8)),
249 * sets '*vlan_vid' to the VLAN VID associated with that device and returns
252 * Returns ENOENT if 'netdev' is a network device that is not a
255 * This function should be set to null if it doesn't make any sense for
256 * your network device (it probably doesn't). */
257 int (*get_vlan_vid)(const struct netdev *netdev, int *vlan_vid);
259 /* Attempts to set input rate limiting (policing) policy, such that up to
260 * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative
261 * burst size of 'kbits' kb.
263 * This function may be set to null if policing is not supported. */
264 int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate,
265 unsigned int kbits_burst);
267 /* If 'netdev' has an assigned IPv4 address, sets '*address' to that
268 * address and '*netmask' to the associated netmask.
270 * The following error values have well-defined meanings:
272 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address.
274 * - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'.
276 * This function may be set to null if it would always return EOPNOTSUPP
278 int (*get_in4)(const struct netdev *netdev, struct in_addr *address,
279 struct in_addr *netmask);
281 /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask. If
282 * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared.
284 * This function may be set to null if it would always return EOPNOTSUPP
286 int (*set_in4)(struct netdev *netdev, struct in_addr addr,
287 struct in_addr mask);
289 /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address.
291 * The following error values have well-defined meanings:
293 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address.
295 * - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'.
297 * This function may be set to null if it would always return EOPNOTSUPP
299 int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6);
301 /* Adds 'router' as a default IP gateway for the TCP/IP stack that
302 * corresponds to 'netdev'.
304 * This function may be set to null if it would always return EOPNOTSUPP
306 int (*add_router)(struct netdev *netdev, struct in_addr router);
308 /* Looks up the next hop for 'host'. If succesful, stores the next hop
309 * gateway's address (0 if 'host' is on a directly connected network) in
310 * '*next_hop' and a copy of the name of the device to reach 'host' in
311 * '*netdev_name', and returns 0. The caller is responsible for freeing
312 * '*netdev_name' (by calling free()).
314 * This function may be set to null if it would always return EOPNOTSUPP
316 int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop,
319 /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the
320 * corresponding MAC address in 'mac'. A return value of ENXIO, in
321 * particular, indicates that there is no ARP table entry for 'ip' on
324 * This function may be set to null if it would always return EOPNOTSUPP
326 int (*arp_lookup)(const struct netdev *netdev, uint32_t ip, uint8_t mac[6]);
328 /* Retrieves the current set of flags on 'netdev' into '*old_flags'.
329 * Then, turns off the flags that are set to 1 in 'off' and turns on the
330 * flags that are set to 1 in 'on'. (No bit will be set to 1 in both 'off'
331 * and 'on'; that is, off & on == 0.)
333 * This function may be invoked from a signal handler. Therefore, it
334 * should not do anything that is not signal-safe (such as logging). */
335 int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
336 enum netdev_flags on, enum netdev_flags *old_flags);
338 /* Arranges for 'cb' to be called whenever one of the attributes of
339 * 'netdev' changes and sets '*notifierp' to a newly created
340 * netdev_notifier that represents this arrangement. The created notifier
341 * will have its 'netdev', 'cb', and 'aux' members set to the values of the
342 * corresponding parameters. */
343 int (*poll_add)(struct netdev *netdev,
344 void (*cb)(struct netdev_notifier *notifier), void *aux,
345 struct netdev_notifier **notifierp);
347 /* Cancels poll notification for 'notifier'. */
348 void (*poll_remove)(struct netdev_notifier *notifier);
351 extern const struct netdev_class netdev_linux_class;
352 extern const struct netdev_class netdev_tap_class;
353 extern const struct netdev_class netdev_gre_class;
355 #endif /* netdev.h */