2 * Copyright (c) 2009 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. */
27 /* A network device object that was created through the netdev_create()
30 * This structure should be treated as opaque by network device
33 const struct netdev_class *class;
36 bool created; /* Was netdev_create() called? */
39 void netdev_obj_init(struct netdev_obj *, const char *name,
40 const struct netdev_class *, bool created);
41 static inline void netdev_obj_assert_class(const struct netdev_obj *netdev_obj,
42 const struct netdev_class *class)
44 assert(netdev_obj->class == class);
46 const char *netdev_obj_get_type(const struct netdev_obj *netdev_obj);
47 const char *netdev_obj_get_name(const struct netdev_obj *netdev_obj);
49 /* A network device (e.g. an Ethernet device).
51 * This structure should be treated as opaque by network device
54 const struct netdev_class *class;
55 char *name; /* e.g. "eth0" */
57 enum netdev_flags save_flags; /* Initial device flags. */
58 enum netdev_flags changed_flags; /* Flags that we changed. */
59 struct list node; /* Element in global list. */
62 void netdev_init(struct netdev *, const char *name,
63 const struct netdev_class *);
64 static inline void netdev_assert_class(const struct netdev *netdev,
65 const struct netdev_class *class)
67 assert(netdev->class == class);
69 const char *netdev_get_type(const struct netdev *netdev);
71 /* A network device notifier.
73 * Network device implementations should use netdev_notifier_init() to
74 * initialize this structure, but they may freely read its members after
76 struct netdev_notifier {
77 struct netdev *netdev;
78 void (*cb)(struct netdev_notifier *);
81 void netdev_notifier_init(struct netdev_notifier *, struct netdev *,
82 void (*cb)(struct netdev_notifier *), void *aux);
84 /* Network device class structure, to be defined by each implementation of a
87 * These functions return 0 if successful or a positive errno value on failure,
88 * except where otherwise noted. */
90 /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc.
92 * One of the providers should supply a "system" type, since this is
93 * the type assumed when a device name was not bound through the
94 * netdev_create() call. The "system" type corresponds to an
95 * existing network device on the system. */
98 /* Called only once, at program startup. Returning an error from this
99 * function will prevent any network device in this class from being
102 * This function may be set to null if a network device class needs no
103 * initialization at program startup. */
106 /* Performs periodic work needed by netdevs of this class. May be null if
107 * no periodic work is necessary. */
110 /* Arranges for poll_block() to wake up if the "run" member function needs
111 * to be called. May be null if nothing is needed here. */
114 /* Attempts to create a network device object of 'type' with 'name'.
115 * 'type' corresponds to the 'type' field used in the netdev_class
118 * The 'created' flag indicates that the user called netdev_create()
119 * and thus will eventually call netdev_destroy(). If the flag is
120 * false, then the object was dynamically created based on a call to
121 * netdev_open() without first calling netdev_create() and will be
122 * automatically destroyed when no more netdevs have 'name' open. A
123 * provider implementation should pass this flag to netdev_obj_init(). */
124 int (*create)(const char *name, const char *type,
125 const struct shash *args, bool created);
127 /* Destroys 'netdev_obj'.
129 * Netdev objects maintain a reference count that is incremented on
130 * netdev_open() and decremented on netdev_close(). If 'netdev_obj'
131 * has a non-zero reference count, then this function will not be
133 void (*destroy)(struct netdev_obj *netdev_obj);
135 /* Reconfigures the device object 'netdev_obj' with 'args'.
137 * If this netdev class does not support reconfiguring a netdev
138 * object, this may be a null pointer.
140 int (*reconfigure)(struct netdev_obj *netdev_obj,
141 const struct shash *args);
143 /* Attempts to open a network device. On success, sets '*netdevp' to the
144 * new network device. 'name' is the network device name provided by
145 * the user. This name is useful for error messages but must not be
148 * 'ethertype' may be a 16-bit Ethernet protocol value in host byte order
149 * to capture frames of that type received on the device. It may also be
150 * one of the 'enum netdev_pseudo_ethertype' values to receive frames in
151 * one of those categories. */
152 int (*open)(const char *name, int ethertype, struct netdev **netdevp);
154 /* Closes 'netdev'. */
155 void (*close)(struct netdev *netdev);
157 /* Enumerates the names of all network devices of this class.
159 * The caller has already initialized 'all_names' and might already have
160 * added some names to it. This function should not disturb any existing
161 * names in 'all_names'.
163 * If this netdev class does not support enumeration, this may be a null
165 int (*enumerate)(struct svec *all_names);
167 /* Attempts to receive a packet from 'netdev' into the 'size' bytes in
168 * 'buffer'. If successful, returns the number of bytes in the received
169 * packet, otherwise a negative errno value. Returns -EAGAIN immediately
170 * if no packet is ready to be received. */
171 int (*recv)(struct netdev *netdev, void *buffer, size_t size);
173 /* Registers with the poll loop to wake up from the next call to
174 * poll_block() when a packet is ready to be received with netdev_recv() on
176 void (*recv_wait)(struct netdev *netdev);
178 /* Discards all packets waiting to be received from 'netdev'. */
179 int (*drain)(struct netdev *netdev);
181 /* Sends the 'size'-byte packet in 'buffer' on 'netdev'. Returns 0 if
182 * successful, otherwise a positive errno value. Returns EAGAIN without
183 * blocking if the packet cannot be queued immediately. Returns EMSGSIZE
184 * if a partial packet was transmitted or if the packet is too big or too
185 * small to transmit on the device.
187 * The caller retains ownership of 'buffer' in all cases.
189 * The network device is expected to maintain a packet transmission queue,
190 * so that the caller does not ordinarily have to do additional queuing of
192 int (*send)(struct netdev *netdev, const void *buffer, size_t size);
194 /* Registers with the poll loop to wake up from the next call to
195 * poll_block() when the packet transmission queue for 'netdev' has
196 * sufficient room to transmit a packet with netdev_send().
198 * The network device is expected to maintain a packet transmission queue,
199 * so that the caller does not ordinarily have to do additional queuing of
200 * packets. Thus, this function is unlikely to ever be useful. */
201 void (*send_wait)(struct netdev *netdev);
203 /* Sets 'netdev''s Ethernet address to 'mac' */
204 int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]);
206 /* Retrieves 'netdev''s Ethernet address into 'mac'. */
207 int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]);
209 /* Retrieves 'netdev''s MTU into '*mtup'.
211 * The MTU is the maximum size of transmitted (and received) packets, in
212 * bytes, not including the hardware header; thus, this is typically 1500
213 * bytes for Ethernet devices.*/
214 int (*get_mtu)(const struct netdev *, int *mtup);
216 /* Returns the ifindex of 'netdev', if successful, as a positive number.
217 * On failure, returns a negative errno value.
219 * The desired semantics of the ifindex value are a combination of those
220 * specified by POSIX for if_nametoindex() and by SNMP for ifIndex. An
221 * ifindex value should be unique within a host and remain stable at least
222 * until reboot. SNMP says an ifindex "ranges between 1 and the value of
223 * ifNumber" but many systems do not follow this rule anyhow. */
224 int (*get_ifindex)(const struct netdev *);
226 /* Sets 'carrier' to true if carrier is active (link light is on) on
228 int (*get_carrier)(const struct netdev *netdev, bool *carrier);
230 /* Retrieves current device stats for 'netdev' into 'stats'.
232 * A network device that supports some statistics but not others, it should
233 * set the values of the unsupported statistics to all-1-bits
235 int (*get_stats)(const struct netdev *netdev, struct netdev_stats *stats);
237 /* Stores the features supported by 'netdev' into each of '*current',
238 * '*advertised', '*supported', and '*peer'. Each value is a bitmap of
239 * "enum ofp_port_features" bits, in host byte order. */
240 int (*get_features)(struct netdev *netdev,
241 uint32_t *current, uint32_t *advertised,
242 uint32_t *supported, uint32_t *peer);
244 /* Set the features advertised by 'netdev' to 'advertise', which is a
245 * bitmap of "enum ofp_port_features" bits, in host byte order.
247 * This function may be set to null for a network device that does not
248 * support configuring advertisements. */
249 int (*set_advertisements)(struct netdev *, uint32_t advertise);
251 /* If 'netdev' is a VLAN network device (e.g. one created with vconfig(8)),
252 * sets '*vlan_vid' to the VLAN VID associated with that device and returns
255 * Returns ENOENT if 'netdev_name' is the name of a network device that is
258 * This function should be set to null if it doesn't make any sense for
259 * your network device (it probably doesn't). */
260 int (*get_vlan_vid)(const struct netdev *netdev, int *vlan_vid);
262 /* Attempts to set input rate limiting (policing) policy, such that up to
263 * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative
264 * burst size of 'kbits' kb.
266 * This function may be set to null if policing is not supported. */
267 int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate,
268 unsigned int kbits_burst);
270 /* If 'netdev' has an assigned IPv4 address, sets '*address' to that
271 * address and '*netmask' to the associated netmask.
273 * The following error values have well-defined meanings:
275 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address.
277 * - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'.
279 * This function may be set to null if it would always return EOPNOTSUPP
281 int (*get_in4)(const struct netdev *netdev, struct in_addr *address,
282 struct in_addr *netmask);
284 /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask. If
285 * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared.
287 * This function may be set to null if it would always return EOPNOTSUPP
289 int (*set_in4)(struct netdev *, struct in_addr addr, struct in_addr mask);
291 /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address.
293 * The following error values have well-defined meanings:
295 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address.
297 * - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'.
299 * This function may be set to null if it would always return EOPNOTSUPP
301 int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6);
303 /* Adds 'router' as a default IP gateway for the TCP/IP stack that
304 * corresponds to 'netdev'.
306 * This function may be set to null if it would always return EOPNOTSUPP
308 int (*add_router)(struct netdev *netdev, struct in_addr router);
310 /* Looks up the next hop for 'host'. If succesful, stores the next hop
311 * gateway's address (0 if 'host' is on a directly connected network) in
312 * '*next_hop' and a copy of the name of the device to reach 'host' in
313 * '*netdev_name', and returns 0. The caller is responsible for freeing
314 * '*netdev_name' (by calling free()).
316 * This function may be set to null if it would always return EOPNOTSUPP
318 int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop,
321 /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the
322 * corresponding MAC address in 'mac'. A return value of ENXIO, in
323 * particular, indicates that there is no ARP table entry for 'ip' on
326 * This function may be set to null if it would always return EOPNOTSUPP
328 int (*arp_lookup)(const struct netdev *, uint32_t ip, uint8_t mac[6]);
330 /* Retrieves the current set of flags on 'netdev' into '*old_flags'. Then,
331 * turns off the flags that are set to 1 in 'off' and turns on the flags
332 * that are set to 1 in 'on'. (No bit will be set to 1 in both 'off' and
333 * 'on'; that is, off & on == 0.)
335 * This function may be invoked from a signal handler. Therefore, it
336 * should not do anything that is not signal-safe (such as logging). */
337 int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
338 enum netdev_flags on, enum netdev_flags *old_flags);
340 /* Arranges for 'cb' to be called whenever one of the attributes of
341 * 'netdev' changes and sets '*notifierp' to a newly created
342 * netdev_notifier that represents this arrangement. The created notifier
343 * will have its 'netdev', 'cb', and 'aux' members set to the values of the
344 * corresponding parameters. */
345 int (*poll_add)(struct netdev *netdev,
346 void (*cb)(struct netdev_notifier *), void *aux,
347 struct netdev_notifier **notifierp);
349 /* Cancels poll notification for 'notifier'. */
350 void (*poll_remove)(struct netdev_notifier *notifier);
353 extern const struct netdev_class netdev_linux_class;
354 extern const struct netdev_class netdev_tap_class;
355 extern const struct netdev_class netdev_gre_class;
357 #endif /* netdev.h */