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
26 /* Open vSwitch datapath interface.
28 * This structure should be treated as opaque by dpif implementations. */
30 const struct dpif_class *class;
33 uint8_t netflow_engine_type;
34 uint8_t netflow_engine_id;
37 void dpif_init(struct dpif *, const struct dpif_class *, const char *name,
38 uint8_t netflow_engine_type, uint8_t netflow_engine_id);
39 void dpif_uninit(struct dpif *dpif, bool close);
41 static inline void dpif_assert_class(const struct dpif *dpif,
42 const struct dpif_class *class)
44 assert(dpif->class == class);
47 /* Datapath interface class structure, to be defined by each implementation of
48 * a datapath interface.
50 * These functions return 0 if successful or a positive errno value on failure,
51 * except where otherwise noted.
53 * These functions are expected to execute synchronously, that is, to block as
54 * necessary to obtain a result. Thus, they may not return EAGAIN or
55 * EWOULDBLOCK or EINPROGRESS. We may relax this requirement in the future if
56 * and when we encounter performance problems. */
58 /* Type of dpif in this class, e.g. "system", "netdev", etc.
60 * One of the providers should supply a "system" type, since this is
61 * the type assumed if no type is specified when opening a dpif. */
64 /* Performs periodic work needed by dpifs of this class, if any is
68 /* Arranges for poll_block() to wake up if the "run" member function needs
72 /* Enumerates the names of all known created datapaths, if possible, into
73 * 'all_dps'. The caller has already initialized 'all_dps' and other dpif
74 * classes might already have added names to it.
76 * This is used by the vswitch at startup, so that it can delete any
77 * datapaths that are not configured.
79 * Some kinds of datapaths might not be practically enumerable, in which
80 * case this function may be a null pointer. */
81 int (*enumerate)(struct svec *all_dps);
83 /* Attempts to open an existing dpif called 'name', if 'create' is false,
84 * or to open an existing dpif or create a new one, if 'create' is true.
85 * 'type' corresponds to the 'type' field used in the dpif_class
88 * If successful, stores a pointer to the new dpif in '*dpifp'. On failure
89 * there are no requirements on what is stored in '*dpifp'. */
90 int (*open)(const char *name, const char *type, bool create,
93 /* Closes 'dpif' and frees associated memory. */
94 void (*close)(struct dpif *dpif);
96 /* Enumerates all names that may be used to open 'dpif' into 'all_names'.
97 * The Linux datapath, for example, supports opening a datapath both by
98 * number, e.g. "dp0", and by the name of the datapath's local port. For
99 * some datapaths, this might be an infinite set (e.g. in a file name,
100 * slashes may be duplicated any number of times), in which case only the
101 * names most likely to be used should be enumerated.
103 * The caller has already initialized 'all_names' and might already have
104 * added some names to it. This function should not disturb any existing
105 * names in 'all_names'.
107 * If a datapath class does not support multiple names for a datapath, this
108 * function may be a null pointer.
110 * This is used by the vswitch at startup, */
111 int (*get_all_names)(const struct dpif *dpif, struct svec *all_names);
113 /* Attempts to destroy the dpif underlying 'dpif'.
115 * If successful, 'dpif' will not be used again except as an argument for
116 * the 'close' member function. */
117 int (*delete)(struct dpif *dpif);
119 /* Retrieves statistics for 'dpif' into 'stats'. */
120 int (*get_stats)(const struct dpif *dpif, struct odp_stats *stats);
122 /* Retrieves 'dpif''s current treatment of IP fragments into '*drop_frags':
123 * true indicates that fragments are dropped, false indicates that
124 * fragments are treated in the same way as other IP packets (except that
125 * the L4 header cannot be read). */
126 int (*get_drop_frags)(const struct dpif *dpif, bool *drop_frags);
128 /* Changes 'dpif''s treatment of IP fragments to 'drop_frags', whose
129 * meaning is the same as for the get_drop_frags member function. */
130 int (*set_drop_frags)(struct dpif *dpif, bool drop_frags);
132 /* Creates a new port in 'dpif' connected to network device 'devname'.
133 * 'flags' is a set of ODP_PORT_* flags. If successful, sets '*port_no'
134 * to the new port's port number. */
135 int (*port_add)(struct dpif *dpif, const char *devname, uint16_t flags,
138 /* Removes port numbered 'port_no' from 'dpif'. */
139 int (*port_del)(struct dpif *dpif, uint16_t port_no);
141 /* Queries 'dpif' for a port with the given 'port_no' or 'devname'. Stores
142 * information about the port into '*port' if successful. */
143 int (*port_query_by_number)(const struct dpif *dpif, uint16_t port_no,
144 struct odp_port *port);
145 int (*port_query_by_name)(const struct dpif *dpif, const char *devname,
146 struct odp_port *port);
148 /* Stores in 'ports' information about up to 'n' ports attached to 'dpif',
149 * in no particular order. Returns the number of ports attached to 'dpif'
150 * (not the number stored), if successful, otherwise a negative errno
152 int (*port_list)(const struct dpif *dpif, struct odp_port *ports, int n);
154 /* Polls for changes in the set of ports in 'dpif'. If the set of ports in
155 * 'dpif' has changed, then this function should do one of the
158 * - Preferably: store the name of the device that was added to or deleted
159 * from 'dpif' in '*devnamep' and return 0. The caller is responsible
160 * for freeing '*devnamep' (with free()) when it no longer needs it.
162 * - Alternatively: return ENOBUFS, without indicating the device that was
165 * Occasional 'false positives', in which the function returns 0 while
166 * indicating a device that was not actually added or deleted or returns
167 * ENOBUFS without any change, are acceptable.
169 * If the set of ports in 'dpif' has not changed, returns EAGAIN. May also
170 * return other positive errno values to indicate that something has gone
172 int (*port_poll)(const struct dpif *dpif, char **devnamep);
174 /* Arranges for the poll loop to wake up when 'port_poll' will return a
175 * value other than EAGAIN. */
176 void (*port_poll_wait)(const struct dpif *dpif);
178 /* Stores in 'ports' the port numbers of up to 'n' ports that belong to
179 * 'group' in 'dpif'. Returns the number of ports in 'group' (not the
180 * number stored), if successful, otherwise a negative errno value. */
181 int (*port_group_get)(const struct dpif *dpif, int group,
182 uint16_t ports[], int n);
184 /* Changes port group 'group' in 'dpif' to consist of the 'n' ports whose
185 * numbers are given in 'ports'.
187 * Use the get_stats member function to obtain the number of supported port
189 int (*port_group_set)(struct dpif *dpif, int group,
190 const uint16_t ports[], int n);
192 /* For each flow 'flow' in the 'n' flows in 'flows':
194 * - If a flow matching 'flow->key' exists in 'dpif':
196 * Stores 0 into 'flow->stats.error' and stores statistics for the flow
197 * into 'flow->stats'.
199 * If 'flow->n_actions' is zero, then 'flow->actions' is ignored. If
200 * 'flow->n_actions' is nonzero, then 'flow->actions' should point to
201 * an array of the specified number of actions. At most that many of
202 * the flow's actions will be copied into that array.
203 * 'flow->n_actions' will be updated to the number of actions actually
204 * present in the flow, which may be greater than the number stored if
205 * the flow has more actions than space available in the array.
207 * - Flow-specific errors are indicated by a positive errno value in
208 * 'flow->stats.error'. In particular, ENOENT indicates that no flow
209 * matching 'flow->key' exists in 'dpif'. When an error value is stored,
210 * the contents of 'flow->key' are preserved but other members of 'flow'
211 * should be treated as indeterminate.
213 * Returns 0 if all 'n' flows in 'flows' were updated (whether they were
214 * individually successful or not is indicated by 'flow->stats.error',
215 * however). Returns a positive errno value if an error that prevented
216 * this update occurred, in which the caller must not depend on any
217 * elements in 'flows' being updated or not updated.
219 int (*flow_get)(const struct dpif *dpif, struct odp_flow flows[], int n);
221 /* Adds or modifies a flow in 'dpif' as specified in 'put':
223 * - If the flow specified in 'put->flow' does not exist in 'dpif', then
224 * behavior depends on whether ODPPF_CREATE is specified in 'put->flags':
225 * if it is, the flow will be added, otherwise the operation will fail
228 * - Otherwise, the flow specified in 'put->flow' does exist in 'dpif'.
229 * Behavior in this case depends on whether ODPPF_MODIFY is specified in
230 * 'put->flags': if it is, the flow's actions will be updated, otherwise
231 * the operation will fail with EEXIST. If the flow's actions are
232 * updated, then its statistics will be zeroed if ODPPF_ZERO_STATS is set
233 * in 'put->flags', left as-is otherwise.
235 int (*flow_put)(struct dpif *dpif, struct odp_flow_put *put);
237 /* Deletes a flow matching 'flow->key' from 'dpif' or returns ENOENT if
238 * 'dpif' does not contain such a flow.
240 * If successful, updates 'flow->stats', 'flow->n_actions', and
241 * 'flow->actions' as described in more detail under the flow_get member
243 int (*flow_del)(struct dpif *dpif, struct odp_flow *flow);
245 /* Deletes all flows from 'dpif' and clears all of its queues of received
247 int (*flow_flush)(struct dpif *dpif);
249 /* Stores up to 'n' flows in 'dpif' into 'flows', updating their statistics
250 * and actions as described under the flow_get member function. If
251 * successful, returns the number of flows actually present in 'dpif',
252 * which might be greater than the number stored (if 'dpif' has more than
253 * 'n' flows). On failure, returns a negative errno value. */
254 int (*flow_list)(const struct dpif *dpif, struct odp_flow flows[], int n);
256 /* Performs the 'n_actions' actions in 'actions' on the Ethernet frame
257 * specified in 'packet'.
259 * Pretends that the frame was originally received on the port numbered
260 * 'in_port'. This affects only ODPAT_OUTPUT_GROUP actions, which will not
261 * send a packet out their input port. Specify the number of an unused
262 * port (e.g. UINT16_MAX is currently always unused) to avoid this
264 int (*execute)(struct dpif *dpif, uint16_t in_port,
265 const union odp_action actions[], int n_actions,
266 const struct ofpbuf *packet);
268 /* Retrieves 'dpif''s "listen mask" into '*listen_mask'. Each ODPL_* bit
269 * set in '*listen_mask' indicates the 'dpif' will receive messages of the
270 * corresponding type when it calls the recv member function. */
271 int (*recv_get_mask)(const struct dpif *dpif, int *listen_mask);
273 /* Sets 'dpif''s "listen mask" to 'listen_mask'. Each ODPL_* bit set in
274 * 'listen_mask' indicates the 'dpif' will receive messages of the
275 * corresponding type when it calls the recv member function. */
276 int (*recv_set_mask)(struct dpif *dpif, int listen_mask);
278 /* Attempts to receive a message from 'dpif'. If successful, stores the
279 * message into '*packetp'. The message, if one is received, must begin
280 * with 'struct odp_msg' as a header. Only messages of the types selected
281 * with the set_listen_mask member function should be received.
283 * This function must not block. If no message is ready to be received
284 * when it is called, it should return EAGAIN without blocking. */
285 int (*recv)(struct dpif *dpif, struct ofpbuf **packetp);
287 /* Arranges for the poll loop to wake up when 'dpif' has a message queued
288 * to be received with the recv member function. */
289 void (*recv_wait)(struct dpif *dpif);
292 extern const struct dpif_class dpif_linux_class;
293 extern const struct dpif_class dpif_netdev_class;
295 #endif /* dpif-provider.h */