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 DPIF_PROVIDER_H
18 #define DPIF_PROVIDER_H 1
20 /* Provider interface to dpifs, which provide an interface to an Open vSwitch
21 * datapath. A datapath is a collection of physical or virtual ports that are
22 * exposed over OpenFlow as a single switch. Datapaths and the collections of
23 * ports that they contain may be fixed or dynamic. */
26 #include "openflow/openflow.h"
34 /* Open vSwitch datapath interface.
36 * This structure should be treated as opaque by dpif implementations. */
38 const struct dpif_class *dpif_class;
41 uint8_t netflow_engine_type;
42 uint8_t netflow_engine_id;
45 void dpif_init(struct dpif *, const struct dpif_class *, const char *name,
46 uint8_t netflow_engine_type, uint8_t netflow_engine_id);
47 void dpif_uninit(struct dpif *dpif, bool close);
49 static inline void dpif_assert_class(const struct dpif *dpif,
50 const struct dpif_class *dpif_class)
52 assert(dpif->dpif_class == dpif_class);
55 /* Datapath interface class structure, to be defined by each implementation of
56 * a datapath interface.
58 * These functions return 0 if successful or a positive errno value on failure,
59 * except where otherwise noted.
61 * These functions are expected to execute synchronously, that is, to block as
62 * necessary to obtain a result. Thus, they may not return EAGAIN or
63 * EWOULDBLOCK or EINPROGRESS. We may relax this requirement in the future if
64 * and when we encounter performance problems. */
66 /* Type of dpif in this class, e.g. "system", "netdev", etc.
68 * One of the providers should supply a "system" type, since this is
69 * the type assumed if no type is specified when opening a dpif. */
72 /* Performs periodic work needed by dpifs of this class, if any is
76 /* Arranges for poll_block() to wake up if the "run" member function needs
80 /* Enumerates the names of all known created datapaths, if possible, into
81 * 'all_dps'. The caller has already initialized 'all_dps' and other dpif
82 * classes might already have added names to it.
84 * This is used by the vswitch at startup, so that it can delete any
85 * datapaths that are not configured.
87 * Some kinds of datapaths might not be practically enumerable, in which
88 * case this function may be a null pointer. */
89 int (*enumerate)(struct svec *all_dps);
91 /* Attempts to open an existing dpif called 'name', if 'create' is false,
92 * or to open an existing dpif or create a new one, if 'create' is true.
94 * 'dpif_class' is the class of dpif to open.
96 * If successful, stores a pointer to the new dpif in '*dpifp', which must
97 * have class 'dpif_class'. On failure there are no requirements on what
98 * is stored in '*dpifp'. */
99 int (*open)(const struct dpif_class *dpif_class,
100 const char *name, bool create, struct dpif **dpifp);
102 /* Closes 'dpif' and frees associated memory. */
103 void (*close)(struct dpif *dpif);
105 /* Enumerates all names that may be used to open 'dpif' into 'all_names'.
106 * The Linux datapath, for example, supports opening a datapath both by
107 * number, e.g. "dp0", and by the name of the datapath's local port. For
108 * some datapaths, this might be an infinite set (e.g. in a file name,
109 * slashes may be duplicated any number of times), in which case only the
110 * names most likely to be used should be enumerated.
112 * The caller has already initialized 'all_names' and might already have
113 * added some names to it. This function should not disturb any existing
114 * names in 'all_names'.
116 * If a datapath class does not support multiple names for a datapath, this
117 * function may be a null pointer.
119 * This is used by the vswitch at startup, */
120 int (*get_all_names)(const struct dpif *dpif, struct svec *all_names);
122 /* Attempts to destroy the dpif underlying 'dpif'.
124 * If successful, 'dpif' will not be used again except as an argument for
125 * the 'close' member function. */
126 int (*destroy)(struct dpif *dpif);
128 /* Retrieves statistics for 'dpif' into 'stats'. */
129 int (*get_stats)(const struct dpif *dpif, struct odp_stats *stats);
131 /* Retrieves 'dpif''s current treatment of IP fragments into '*drop_frags':
132 * true indicates that fragments are dropped, false indicates that
133 * fragments are treated in the same way as other IP packets (except that
134 * the L4 header cannot be read). */
135 int (*get_drop_frags)(const struct dpif *dpif, bool *drop_frags);
137 /* Changes 'dpif''s treatment of IP fragments to 'drop_frags', whose
138 * meaning is the same as for the get_drop_frags member function. */
139 int (*set_drop_frags)(struct dpif *dpif, bool drop_frags);
141 /* Creates a new port in 'dpif' connected to network device 'devname'.
142 * 'flags' is a set of ODP_PORT_* flags. If successful, sets '*port_no'
143 * to the new port's port number. */
144 int (*port_add)(struct dpif *dpif, const char *devname, uint16_t flags,
147 /* Removes port numbered 'port_no' from 'dpif'. */
148 int (*port_del)(struct dpif *dpif, uint16_t port_no);
150 /* Queries 'dpif' for a port with the given 'port_no' or 'devname'. Stores
151 * information about the port into '*port' if successful. */
152 int (*port_query_by_number)(const struct dpif *dpif, uint16_t port_no,
153 struct odp_port *port);
154 int (*port_query_by_name)(const struct dpif *dpif, const char *devname,
155 struct odp_port *port);
157 /* Stores in 'ports' information about up to 'n' ports attached to 'dpif',
158 * in no particular order. Returns the number of ports attached to 'dpif'
159 * (not the number stored), if successful, otherwise a negative errno
161 int (*port_list)(const struct dpif *dpif, struct odp_port *ports, int n);
163 /* Polls for changes in the set of ports in 'dpif'. If the set of ports in
164 * 'dpif' has changed, then this function should do one of the
167 * - Preferably: store the name of the device that was added to or deleted
168 * from 'dpif' in '*devnamep' and return 0. The caller is responsible
169 * for freeing '*devnamep' (with free()) when it no longer needs it.
171 * - Alternatively: return ENOBUFS, without indicating the device that was
174 * Occasional 'false positives', in which the function returns 0 while
175 * indicating a device that was not actually added or deleted or returns
176 * ENOBUFS without any change, are acceptable.
178 * If the set of ports in 'dpif' has not changed, returns EAGAIN. May also
179 * return other positive errno values to indicate that something has gone
181 int (*port_poll)(const struct dpif *dpif, char **devnamep);
183 /* Arranges for the poll loop to wake up when 'port_poll' will return a
184 * value other than EAGAIN. */
185 void (*port_poll_wait)(const struct dpif *dpif);
187 /* For each flow 'flow' in the 'n' flows in 'flows':
189 * - If a flow matching 'flow->key' exists in 'dpif':
191 * Stores 0 into 'flow->stats.error' and stores statistics for the flow
192 * into 'flow->stats'.
194 * If 'flow->n_actions' is zero, then 'flow->actions' is ignored. If
195 * 'flow->n_actions' is nonzero, then 'flow->actions' should point to
196 * an array of the specified number of actions. At most that many of
197 * the flow's actions will be copied into that array.
198 * 'flow->n_actions' will be updated to the number of actions actually
199 * present in the flow, which may be greater than the number stored if
200 * the flow has more actions than space available in the array.
202 * - Flow-specific errors are indicated by a positive errno value in
203 * 'flow->stats.error'. In particular, ENOENT indicates that no flow
204 * matching 'flow->key' exists in 'dpif'. When an error value is stored,
205 * the contents of 'flow->key' are preserved but other members of 'flow'
206 * should be treated as indeterminate.
208 * Returns 0 if all 'n' flows in 'flows' were updated (whether they were
209 * individually successful or not is indicated by 'flow->stats.error',
210 * however). Returns a positive errno value if an error that prevented
211 * this update occurred, in which the caller must not depend on any
212 * elements in 'flows' being updated or not updated.
214 int (*flow_get)(const struct dpif *dpif, struct odp_flow flows[], int n);
216 /* Adds or modifies a flow in 'dpif' as specified in 'put':
218 * - If the flow specified in 'put->flow' does not exist in 'dpif', then
219 * behavior depends on whether ODPPF_CREATE is specified in 'put->flags':
220 * if it is, the flow will be added, otherwise the operation will fail
223 * - Otherwise, the flow specified in 'put->flow' does exist in 'dpif'.
224 * Behavior in this case depends on whether ODPPF_MODIFY is specified in
225 * 'put->flags': if it is, the flow's actions will be updated, otherwise
226 * the operation will fail with EEXIST. If the flow's actions are
227 * updated, then its statistics will be zeroed if ODPPF_ZERO_STATS is set
228 * in 'put->flags', left as-is otherwise.
230 int (*flow_put)(struct dpif *dpif, struct odp_flow_put *put);
232 /* Deletes a flow matching 'flow->key' from 'dpif' or returns ENOENT if
233 * 'dpif' does not contain such a flow.
235 * If successful, updates 'flow->stats', 'flow->n_actions', and
236 * 'flow->actions' as described in more detail under the flow_get member
238 int (*flow_del)(struct dpif *dpif, struct odp_flow *flow);
240 /* Deletes all flows from 'dpif' and clears all of its queues of received
242 int (*flow_flush)(struct dpif *dpif);
244 /* Stores up to 'n' flows in 'dpif' into 'flows', updating their statistics
245 * and actions as described under the flow_get member function. If
246 * successful, returns the number of flows actually present in 'dpif',
247 * which might be greater than the number stored (if 'dpif' has more than
248 * 'n' flows). On failure, returns a negative errno value. */
249 int (*flow_list)(const struct dpif *dpif, struct odp_flow flows[], int n);
251 /* Performs the 'n_actions' actions in 'actions' on the Ethernet frame
252 * specified in 'packet'. */
253 int (*execute)(struct dpif *dpif,
254 const union odp_action actions[], int n_actions,
255 const struct ofpbuf *packet);
257 /* Retrieves 'dpif''s "listen mask" into '*listen_mask'. Each ODPL_* bit
258 * set in '*listen_mask' indicates the 'dpif' will receive messages of the
259 * corresponding type when it calls the recv member function. */
260 int (*recv_get_mask)(const struct dpif *dpif, int *listen_mask);
262 /* Sets 'dpif''s "listen mask" to 'listen_mask'. Each ODPL_* bit set in
263 * 'listen_mask' indicates the 'dpif' will receive messages of the
264 * corresponding type when it calls the recv member function. */
265 int (*recv_set_mask)(struct dpif *dpif, int listen_mask);
267 /* Retrieves 'dpif''s sFlow sampling probability into '*probability'.
268 * Return value is 0 or a positive errno value. EOPNOTSUPP indicates that
269 * the datapath does not support sFlow, as does a null pointer.
271 * '*probability' is expressed as the number of packets out of UINT_MAX to
272 * sample, e.g. probability/UINT_MAX is the probability of sampling a given
274 int (*get_sflow_probability)(const struct dpif *dpif,
275 uint32_t *probability);
277 /* Sets 'dpif''s sFlow sampling probability to 'probability'. Return value
278 * is 0 or a positive errno value. EOPNOTSUPP indicates that the datapath
279 * does not support sFlow, as does a null pointer.
281 * 'probability' is expressed as the number of packets out of UINT_MAX to
282 * sample, e.g. probability/UINT_MAX is the probability of sampling a given
284 int (*set_sflow_probability)(struct dpif *dpif, uint32_t probability);
286 /* Translates OpenFlow queue ID 'queue_id' (in host byte order) into a
287 * priority value for use in the ODPAT_SET_PRIORITY action in
289 int (*queue_to_priority)(const struct dpif *dpif, uint32_t queue_id,
292 /* Attempts to receive a message from 'dpif'. If successful, stores the
293 * message into '*packetp'. The message, if one is received, must begin
294 * with 'struct odp_msg' as a header, and must have at least
295 * DPIF_RECV_MSG_PADDING bytes of headroom (allocated using
296 * e.g. ofpbuf_reserve()). Only messages of the types selected with the
297 * set_listen_mask member function should be received.
299 * This function must not block. If no message is ready to be received
300 * when it is called, it should return EAGAIN without blocking. */
301 int (*recv)(struct dpif *dpif, struct ofpbuf **packetp);
303 /* Arranges for the poll loop to wake up when 'dpif' has a message queued
304 * to be received with the recv member function. */
305 void (*recv_wait)(struct dpif *dpif);
308 extern const struct dpif_class dpif_linux_class;
309 extern const struct dpif_class dpif_netdev_class;
315 #endif /* dpif-provider.h */