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. */
31 /* A network device object that was created through the netdev_create()
34 * This structure should be treated as opaque by network device
37 const struct netdev_class *netdev_class;
39 bool created; /* Was netdev_create() called? */
42 void netdev_obj_init(struct netdev_obj *, const char *name,
43 const struct netdev_class *, bool created);
44 static inline void netdev_obj_assert_class(const struct netdev_obj *netdev_obj,
45 const struct netdev_class *class_)
47 assert(netdev_obj->netdev_class == class_);
50 /* A network device (e.g. an Ethernet device).
52 * This structure should be treated as opaque by network device
55 const struct netdev_class *netdev_class;
56 char *name; /* e.g. "eth0" */
58 enum netdev_flags save_flags; /* Initial device flags. */
59 enum netdev_flags changed_flags; /* Flags that we changed. */
60 struct list node; /* Element in global list. */
63 void netdev_init(struct netdev *, const char *name,
64 const struct netdev_class *);
65 static inline void netdev_assert_class(const struct netdev *netdev,
66 const struct netdev_class *netdev_class)
68 assert(netdev->netdev_class == netdev_class);
70 const char *netdev_get_type(const struct netdev *netdev);
72 /* A network device notifier.
74 * Network device implementations should use netdev_notifier_init() to
75 * initialize this structure, but they may freely read its members after
77 struct netdev_notifier {
78 struct netdev *netdev;
79 void (*cb)(struct netdev_notifier *);
82 void netdev_notifier_init(struct netdev_notifier *, struct netdev *,
83 void (*cb)(struct netdev_notifier *), void *aux);
85 /* Network device class structure, to be defined by each implementation of a
88 * These functions return 0 if successful or a positive errno value on failure,
89 * except where otherwise noted. */
91 /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc.
93 * One of the providers should supply a "system" type, since this is
94 * the type assumed when a device name was not bound through the
95 * netdev_create() call. The "system" type corresponds to an
96 * existing network device on the system. */
99 /* Called only once, at program startup. Returning an error from this
100 * function will prevent any network device in this class from being
103 * This function may be set to null if a network device class needs no
104 * initialization at program startup. */
107 /* Performs periodic work needed by netdevs of this class. May be null if
108 * no periodic work is necessary. */
111 /* Arranges for poll_block() to wake up if the "run" member function needs
112 * to be called. May be null if nothing is needed here. */
115 /* Attempts to create a network device object of 'type' with 'name'.
116 * 'type' corresponds to the 'type' field used in the netdev_class
119 * The 'created' flag indicates that the user called netdev_create()
120 * and thus will eventually call netdev_destroy(). If the flag is
121 * false, then the object was dynamically created based on a call to
122 * netdev_open() without first calling netdev_create() and will be
123 * automatically destroyed when no more netdevs have 'name' open. A
124 * provider implementation should pass this flag to netdev_obj_init(). */
125 int (*create)(const char *name, const char *type,
126 const struct shash *args, bool created);
128 /* Destroys 'netdev_obj'.
130 * Netdev objects maintain a reference count that is incremented on
131 * netdev_open() and decremented on netdev_close(). If 'netdev_obj'
132 * has a non-zero reference count, then this function will not be
134 void (*destroy)(struct netdev_obj *netdev_obj);
136 /* Reconfigures the device object 'netdev_obj' with 'args'.
138 * If this netdev class does not support reconfiguring a netdev
139 * object, this may be a null pointer.
141 int (*reconfigure)(struct netdev_obj *netdev_obj,
142 const struct shash *args);
144 /* Attempts to open a network device. On success, sets '*netdevp' to the
145 * new network device. 'name' is the network device name provided by
146 * the user. This name is useful for error messages but must not be
149 * 'ethertype' may be a 16-bit Ethernet protocol value in host byte order
150 * to capture frames of that type received on the device. It may also be
151 * one of the 'enum netdev_pseudo_ethertype' values to receive frames in
152 * one of those categories. */
153 int (*open)(const char *name, int ethertype, struct netdev **netdevp);
155 /* Closes 'netdev'. */
156 void (*close)(struct netdev *netdev);
158 /* Enumerates the names of all network devices of this class.
160 * The caller has already initialized 'all_names' and might already have
161 * added some names to it. This function should not disturb any existing
162 * names in 'all_names'.
164 * If this netdev class does not support enumeration, this may be a null
166 int (*enumerate)(struct svec *all_names);
168 /* Attempts to receive a packet from 'netdev' into the 'size' bytes in
169 * 'buffer'. If successful, returns the number of bytes in the received
170 * packet, otherwise a negative errno value. Returns -EAGAIN immediately
171 * if no packet is ready to be received. */
172 int (*recv)(struct netdev *netdev, void *buffer, size_t size);
174 /* Registers with the poll loop to wake up from the next call to
175 * poll_block() when a packet is ready to be received with netdev_recv() on
177 void (*recv_wait)(struct netdev *netdev);
179 /* Discards all packets waiting to be received from 'netdev'. */
180 int (*drain)(struct netdev *netdev);
182 /* Sends the 'size'-byte packet in 'buffer' on 'netdev'. Returns 0 if
183 * successful, otherwise a positive errno value. Returns EAGAIN without
184 * blocking if the packet cannot be queued immediately. Returns EMSGSIZE
185 * if a partial packet was transmitted or if the packet is too big or too
186 * small to transmit on the device.
188 * The caller retains ownership of 'buffer' in all cases.
190 * The network device is expected to maintain a packet transmission queue,
191 * so that the caller does not ordinarily have to do additional queuing of
193 int (*send)(struct netdev *netdev, const void *buffer, size_t size);
195 /* Registers with the poll loop to wake up from the next call to
196 * poll_block() when the packet transmission queue for 'netdev' has
197 * sufficient room to transmit a packet with netdev_send().
199 * The network device is expected to maintain a packet transmission queue,
200 * so that the caller does not ordinarily have to do additional queuing of
201 * packets. Thus, this function is unlikely to ever be useful. */
202 void (*send_wait)(struct netdev *netdev);
204 /* Sets 'netdev''s Ethernet address to 'mac' */
205 int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]);
207 /* Retrieves 'netdev''s Ethernet address into 'mac'. */
208 int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]);
210 /* Retrieves 'netdev''s MTU into '*mtup'.
212 * The MTU is the maximum size of transmitted (and received) packets, in
213 * bytes, not including the hardware header; thus, this is typically 1500
214 * bytes for Ethernet devices.*/
215 int (*get_mtu)(const struct netdev *, int *mtup);
217 /* Returns the ifindex of 'netdev', if successful, as a positive number.
218 * On failure, returns a negative errno value.
220 * The desired semantics of the ifindex value are a combination of those
221 * specified by POSIX for if_nametoindex() and by SNMP for ifIndex. An
222 * ifindex value should be unique within a host and remain stable at least
223 * until reboot. SNMP says an ifindex "ranges between 1 and the value of
224 * ifNumber" but many systems do not follow this rule anyhow. */
225 int (*get_ifindex)(const struct netdev *);
227 /* Sets 'carrier' to true if carrier is active (link light is on) on
229 int (*get_carrier)(const struct netdev *netdev, bool *carrier);
231 /* Retrieves current device stats for 'netdev' into 'stats'.
233 * A network device that supports some statistics but not others, it should
234 * set the values of the unsupported statistics to all-1-bits
236 int (*get_stats)(const struct netdev *netdev, struct netdev_stats *stats);
238 /* Stores the features supported by 'netdev' into each of '*current',
239 * '*advertised', '*supported', and '*peer'. Each value is a bitmap of
240 * "enum ofp_port_features" bits, in host byte order. */
241 int (*get_features)(struct netdev *netdev,
242 uint32_t *current, uint32_t *advertised,
243 uint32_t *supported, uint32_t *peer);
245 /* Set the features advertised by 'netdev' to 'advertise', which is a
246 * bitmap of "enum ofp_port_features" bits, in host byte order.
248 * This function may be set to null for a network device that does not
249 * support configuring advertisements. */
250 int (*set_advertisements)(struct netdev *, uint32_t advertise);
252 /* If 'netdev' is a VLAN network device (e.g. one created with vconfig(8)),
253 * sets '*vlan_vid' to the VLAN VID associated with that device and returns
256 * Returns ENOENT if 'netdev_name' is the name of a network device that is
259 * This function should be set to null if it doesn't make any sense for
260 * your network device (it probably doesn't). */
261 int (*get_vlan_vid)(const struct netdev *netdev, int *vlan_vid);
263 /* Attempts to set input rate limiting (policing) policy, such that up to
264 * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative
265 * burst size of 'kbits' kb.
267 * This function may be set to null if policing is not supported. */
268 int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate,
269 unsigned int kbits_burst);
271 /* If 'netdev' has an assigned IPv4 address, sets '*address' to that
272 * address and '*netmask' to the associated netmask.
274 * The following error values have well-defined meanings:
276 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address.
278 * - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'.
280 * This function may be set to null if it would always return EOPNOTSUPP
282 int (*get_in4)(const struct netdev *netdev, struct in_addr *address,
283 struct in_addr *netmask);
285 /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask. If
286 * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared.
288 * This function may be set to null if it would always return EOPNOTSUPP
290 int (*set_in4)(struct netdev *, struct in_addr addr, struct in_addr mask);
292 /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address.
294 * The following error values have well-defined meanings:
296 * - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address.
298 * - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'.
300 * This function may be set to null if it would always return EOPNOTSUPP
302 int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6);
304 /* Adds 'router' as a default IP gateway for the TCP/IP stack that
305 * corresponds to 'netdev'.
307 * This function may be set to null if it would always return EOPNOTSUPP
309 int (*add_router)(struct netdev *netdev, struct in_addr router);
311 /* Looks up the next hop for 'host'. If succesful, stores the next hop
312 * gateway's address (0 if 'host' is on a directly connected network) in
313 * '*next_hop' and a copy of the name of the device to reach 'host' in
314 * '*netdev_name', and returns 0. The caller is responsible for freeing
315 * '*netdev_name' (by calling free()).
317 * This function may be set to null if it would always return EOPNOTSUPP
319 int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop,
322 /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the
323 * corresponding MAC address in 'mac'. A return value of ENXIO, in
324 * particular, indicates that there is no ARP table entry for 'ip' on
327 * This function may be set to null if it would always return EOPNOTSUPP
329 int (*arp_lookup)(const struct netdev *, uint32_t ip, uint8_t mac[6]);
331 /* Retrieves the current set of flags on 'netdev' into '*old_flags'. Then,
332 * turns off the flags that are set to 1 in 'off' and turns on the flags
333 * that are set to 1 in 'on'. (No bit will be set to 1 in both 'off' and
334 * 'on'; that is, off & on == 0.)
336 * This function may be invoked from a signal handler. Therefore, it
337 * should not do anything that is not signal-safe (such as logging). */
338 int (*update_flags)(struct netdev *netdev, enum netdev_flags off,
339 enum netdev_flags on, enum netdev_flags *old_flags);
341 /* Arranges for 'cb' to be called whenever one of the attributes of
342 * 'netdev' changes and sets '*notifierp' to a newly created
343 * netdev_notifier that represents this arrangement. The created notifier
344 * will have its 'netdev', 'cb', and 'aux' members set to the values of the
345 * corresponding parameters. */
346 int (*poll_add)(struct netdev *netdev,
347 void (*cb)(struct netdev_notifier *), void *aux,
348 struct netdev_notifier **notifierp);
350 /* Cancels poll notification for 'notifier'. */
351 void (*poll_remove)(struct netdev_notifier *notifier);
354 extern const struct netdev_class netdev_linux_class;
355 extern const struct netdev_class netdev_tap_class;
361 #endif /* netdev.h */