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openvswitch/lib/dpif-provider.h
2011-03-31 16:42:01 -07:00

361 lines
16 KiB
C

/*
* Copyright (c) 2009, 2010, 2011 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef DPIF_PROVIDER_H
#define DPIF_PROVIDER_H 1
/* Provider interface to dpifs, which provide an interface to an Open vSwitch
* datapath. A datapath is a collection of physical or virtual ports that are
* exposed over OpenFlow as a single switch. Datapaths and the collections of
* ports that they contain may be fixed or dynamic. */
#include <assert.h>
#include "openflow/openflow.h"
#include "dpif.h"
#include "util.h"
#ifdef __cplusplus
extern "C" {
#endif
/* Open vSwitch datapath interface.
*
* This structure should be treated as opaque by dpif implementations. */
struct dpif {
const struct dpif_class *dpif_class;
char *base_name;
char *full_name;
uint8_t netflow_engine_type;
uint8_t netflow_engine_id;
};
void dpif_init(struct dpif *, const struct dpif_class *, const char *name,
uint8_t netflow_engine_type, uint8_t netflow_engine_id);
void dpif_uninit(struct dpif *dpif, bool close);
static inline void dpif_assert_class(const struct dpif *dpif,
const struct dpif_class *dpif_class)
{
assert(dpif->dpif_class == dpif_class);
}
/* Datapath interface class structure, to be defined by each implementation of
* a datapath interface.
*
* These functions return 0 if successful or a positive errno value on failure,
* except where otherwise noted.
*
* These functions are expected to execute synchronously, that is, to block as
* necessary to obtain a result. Thus, they may not return EAGAIN or
* EWOULDBLOCK or EINPROGRESS. We may relax this requirement in the future if
* and when we encounter performance problems. */
struct dpif_class {
/* Type of dpif in this class, e.g. "system", "netdev", etc.
*
* One of the providers should supply a "system" type, since this is
* the type assumed if no type is specified when opening a dpif. */
const char *type;
/* Performs periodic work needed by dpifs of this class, if any is
* necessary. */
void (*run)(void);
/* Arranges for poll_block() to wake up if the "run" member function needs
* to be called. */
void (*wait)(void);
/* Enumerates the names of all known created datapaths, if possible, into
* 'all_dps'. The caller has already initialized 'all_dps' and other dpif
* classes might already have added names to it.
*
* This is used by the vswitch at startup, so that it can delete any
* datapaths that are not configured.
*
* Some kinds of datapaths might not be practically enumerable, in which
* case this function may be a null pointer. */
int (*enumerate)(struct sset *all_dps);
/* Attempts to open an existing dpif called 'name', if 'create' is false,
* or to open an existing dpif or create a new one, if 'create' is true.
*
* 'dpif_class' is the class of dpif to open.
*
* If successful, stores a pointer to the new dpif in '*dpifp', which must
* have class 'dpif_class'. On failure there are no requirements on what
* is stored in '*dpifp'. */
int (*open)(const struct dpif_class *dpif_class,
const char *name, bool create, struct dpif **dpifp);
/* Closes 'dpif' and frees associated memory. */
void (*close)(struct dpif *dpif);
/* Attempts to destroy the dpif underlying 'dpif'.
*
* If successful, 'dpif' will not be used again except as an argument for
* the 'close' member function. */
int (*destroy)(struct dpif *dpif);
/* Retrieves statistics for 'dpif' into 'stats'. */
int (*get_stats)(const struct dpif *dpif, struct odp_stats *stats);
/* Retrieves 'dpif''s current treatment of IP fragments into '*drop_frags':
* true indicates that fragments are dropped, false indicates that
* fragments are treated in the same way as other IP packets (except that
* the L4 header cannot be read). */
int (*get_drop_frags)(const struct dpif *dpif, bool *drop_frags);
/* Changes 'dpif''s treatment of IP fragments to 'drop_frags', whose
* meaning is the same as for the get_drop_frags member function. */
int (*set_drop_frags)(struct dpif *dpif, bool drop_frags);
/* Adds 'netdev' as a new port in 'dpif'. If successful, sets '*port_no'
* to the new port's port number. */
int (*port_add)(struct dpif *dpif, struct netdev *netdev,
uint16_t *port_no);
/* Removes port numbered 'port_no' from 'dpif'. */
int (*port_del)(struct dpif *dpif, uint16_t port_no);
/* Queries 'dpif' for a port with the given 'port_no' or 'devname'. Stores
* information about the port into '*port' if successful.
*
* The caller takes ownership of data in 'port' and must free it with
* dpif_port_destroy() when it is no longer needed. */
int (*port_query_by_number)(const struct dpif *dpif, uint16_t port_no,
struct dpif_port *port);
int (*port_query_by_name)(const struct dpif *dpif, const char *devname,
struct dpif_port *port);
/* Returns one greater than the largest port number accepted in flow
* actions. */
int (*get_max_ports)(const struct dpif *dpif);
/* Attempts to begin dumping the ports in a dpif. On success, returns 0
* and initializes '*statep' with any data needed for iteration. On
* failure, returns a positive errno value. */
int (*port_dump_start)(const struct dpif *dpif, void **statep);
/* Attempts to retrieve another port from 'dpif' for 'state', which was
* initialized by a successful call to the 'port_dump_start' function for
* 'dpif'. On success, stores a new dpif_port into 'port' and returns 0.
* Returns EOF if the end of the port table has been reached, or a positive
* errno value on error. This function will not be called again once it
* returns nonzero once for a given iteration (but the 'port_dump_done'
* function will be called afterward).
*
* The dpif provider retains ownership of the data stored in 'port'. It
* must remain valid until at least the next call to 'port_dump_next' or
* 'port_dump_done' for 'state'. */
int (*port_dump_next)(const struct dpif *dpif, void *state,
struct dpif_port *port);
/* Releases resources from 'dpif' for 'state', which was initialized by a
* successful call to the 'port_dump_start' function for 'dpif'. */
int (*port_dump_done)(const struct dpif *dpif, void *state);
/* Polls for changes in the set of ports in 'dpif'. If the set of ports in
* 'dpif' has changed, then this function should do one of the
* following:
*
* - Preferably: store the name of the device that was added to or deleted
* from 'dpif' in '*devnamep' and return 0. The caller is responsible
* for freeing '*devnamep' (with free()) when it no longer needs it.
*
* - Alternatively: return ENOBUFS, without indicating the device that was
* added or deleted.
*
* Occasional 'false positives', in which the function returns 0 while
* indicating a device that was not actually added or deleted or returns
* ENOBUFS without any change, are acceptable.
*
* If the set of ports in 'dpif' has not changed, returns EAGAIN. May also
* return other positive errno values to indicate that something has gone
* wrong. */
int (*port_poll)(const struct dpif *dpif, char **devnamep);
/* Arranges for the poll loop to wake up when 'port_poll' will return a
* value other than EAGAIN. */
void (*port_poll_wait)(const struct dpif *dpif);
/* Queries 'dpif' for a flow entry. The flow is specified by the Netlink
* attributes with types ODP_KEY_ATTR_* in the 'key_len' bytes starting at
* 'key'.
*
* Returns 0 if successful. If no flow matches, returns ENOENT. On other
* failure, returns a positive errno value.
*
* If 'actionsp' is nonnull, then on success '*actionsp' must be set to an
* ofpbuf owned by the caller that contains the Netlink attributes for the
* flow's actions. The caller must free the ofpbuf (with ofpbuf_delete())
* when it is no longer needed.
*
* If 'stats' is nonnull, then on success it must be updated with the
* flow's statistics. */
int (*flow_get)(const struct dpif *dpif,
const struct nlattr *key, size_t key_len,
struct ofpbuf **actionsp, struct dpif_flow_stats *stats);
/* Adds or modifies a flow in 'dpif'. The flow is specified by the Netlink
* attributes with types ODP_KEY_ATTR_* in the 'key_len' bytes starting at
* 'key'. The associated actions are specified by the Netlink attributes
* with types ODP_ACTION_ATTR_* in the 'actions_len' bytes starting at
* 'actions'.
*
* - If the flow's key does not exist in 'dpif', then the flow will be
* added if 'flags' includes DPIF_FP_CREATE. Otherwise the operation
* will fail with ENOENT.
*
* If the operation succeeds, then 'stats', if nonnull, must be zeroed.
*
* - If the flow's key does exist in 'dpif', then the flow's actions will
* be updated if 'flags' includes DPIF_FP_MODIFY. Otherwise the
* operation will fail with EEXIST. If the flow's actions are updated,
* then its statistics will be zeroed if 'flags' includes
* DPIF_FP_ZERO_STATS, and left as-is otherwise.
*
* If the operation succeeds, then 'stats', if nonnull, must be set to
* the flow's statistics before the update.
*/
int (*flow_put)(struct dpif *dpif, enum dpif_flow_put_flags flags,
const struct nlattr *key, size_t key_len,
const struct nlattr *actions, size_t actions_len,
struct dpif_flow_stats *stats);
/* Deletes a flow from 'dpif' and returns 0, or returns ENOENT if 'dpif'
* does not contain such a flow. The flow is specified by the Netlink
* attributes with types ODP_KEY_ATTR_* in the 'key_len' bytes starting at
* 'key'.
*
* If the operation succeeds, then 'stats', if nonnull, must be set to the
* flow's statistics before its deletion. */
int (*flow_del)(struct dpif *dpif,
const struct nlattr *key, size_t key_len,
struct dpif_flow_stats *stats);
/* Deletes all flows from 'dpif' and clears all of its queues of received
* packets. */
int (*flow_flush)(struct dpif *dpif);
/* Attempts to begin dumping the flows in a dpif. On success, returns 0
* and initializes '*statep' with any data needed for iteration. On
* failure, returns a positive errno value. */
int (*flow_dump_start)(const struct dpif *dpif, void **statep);
/* Attempts to retrieve another flow from 'dpif' for 'state', which was
* initialized by a successful call to the 'flow_dump_start' function for
* 'dpif'. On success, updates the output parameters as described below
* and returns 0. Returns EOF if the end of the flow table has been
* reached, or a positive errno value on error. This function will not be
* called again once it returns nonzero within a given iteration (but the
* 'flow_dump_done' function will be called afterward).
*
* On success, if 'key' and 'key_len' are nonnull then '*key' and
* '*key_len' must be set to Netlink attributes with types ODP_KEY_ATTR_*
* representing the dumped flow's key. If 'actions' and 'actions_len' are
* nonnull then they should be set to Netlink attributes with types
* ODP_ACTION_ATTR_* representing the dumped flow's actions. If 'stats'
* is nonnull then it should be set to the dumped flow's statistics.
*
* All of the returned data is owned by 'dpif', not by the caller, and the
* caller must not modify or free it. 'dpif' must guarantee that it
* remains accessible and unchanging until at least the next call to
* 'flow_dump_next' or 'flow_dump_done' for 'state'. */
int (*flow_dump_next)(const struct dpif *dpif, void *state,
const struct nlattr **key, size_t *key_len,
const struct nlattr **actions, size_t *actions_len,
const struct dpif_flow_stats **stats);
/* Releases resources from 'dpif' for 'state', which was initialized by a
* successful call to the 'flow_dump_start' function for 'dpif'. */
int (*flow_dump_done)(const struct dpif *dpif, void *state);
/* Performs the 'actions_len' bytes of actions in 'actions' on the Ethernet
* frame specified in 'packet'. */
int (*execute)(struct dpif *dpif, const struct nlattr *actions,
size_t actions_len, const struct ofpbuf *packet);
/* Retrieves 'dpif''s "listen mask" into '*listen_mask'. A 1-bit of value
* 2**X set in '*listen_mask' indicates that 'dpif' will receive messages
* of the type (from "enum dpif_upcall_type") with value X when its 'recv'
* function is called. */
int (*recv_get_mask)(const struct dpif *dpif, int *listen_mask);
/* Sets 'dpif''s "listen mask" to 'listen_mask'. A 1-bit of value 2**X set
* in '*listen_mask' requests that 'dpif' will receive messages of the type
* (from "enum dpif_upcall_type") with value X when its 'recv' function is
* called. */
int (*recv_set_mask)(struct dpif *dpif, int listen_mask);
/* Retrieves 'dpif''s sFlow sampling probability into '*probability'.
* Return value is 0 or a positive errno value. EOPNOTSUPP indicates that
* the datapath does not support sFlow, as does a null pointer.
*
* '*probability' is expressed as the number of packets out of UINT_MAX to
* sample, e.g. probability/UINT_MAX is the probability of sampling a given
* packet. */
int (*get_sflow_probability)(const struct dpif *dpif,
uint32_t *probability);
/* Sets 'dpif''s sFlow sampling probability to 'probability'. Return value
* is 0 or a positive errno value. EOPNOTSUPP indicates that the datapath
* does not support sFlow, as does a null pointer.
*
* 'probability' is expressed as the number of packets out of UINT_MAX to
* sample, e.g. probability/UINT_MAX is the probability of sampling a given
* packet. */
int (*set_sflow_probability)(struct dpif *dpif, uint32_t probability);
/* Translates OpenFlow queue ID 'queue_id' (in host byte order) into a
* priority value for use in the ODP_ACTION_ATTR_SET_PRIORITY action in
* '*priority'. */
int (*queue_to_priority)(const struct dpif *dpif, uint32_t queue_id,
uint32_t *priority);
/* Polls for an upcall from 'dpif'. If successful, stores the upcall into
* '*upcall'. Only upcalls of the types selected with the set_listen_mask
* member function should be received.
*
* The caller takes ownership of the data that 'upcall' points to.
* 'upcall->key' and 'upcall->actions' (if nonnull) point into data owned
* by 'upcall->packet', so their memory cannot be freed separately. (This
* is hardly a great way to do things but it works out OK for the dpif
* providers that exist so far.)
*
* For greatest efficiency, 'upcall->packet' should have at least
* offsetof(struct ofp_packet_in, data) bytes of headroom.
*
* This function must not block. If no upcall is pending when it is
* called, it should return EAGAIN without blocking. */
int (*recv)(struct dpif *dpif, struct dpif_upcall *upcall);
/* Arranges for the poll loop to wake up when 'dpif' has a message queued
* to be received with the recv member function. */
void (*recv_wait)(struct dpif *dpif);
/* Throws away any queued upcalls that 'dpif' currently has ready to
* return. */
void (*recv_purge)(struct dpif *dpif);
};
extern const struct dpif_class dpif_linux_class;
extern const struct dpif_class dpif_netdev_class;
#ifdef __cplusplus
}
#endif
#endif /* dpif-provider.h */