/* * Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc. * * 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 "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) { ovs_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; /* 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); /* Returns the type to pass to netdev_open() when a dpif of class * 'dpif_class' has a port of type 'type', for a few special cases * when a netdev type differs from a port type. For example, when * using the userspace datapath, a port of type "internal" needs to * be opened as "tap". * * Returns either 'type' itself or a string literal, which must not * be freed. */ const char *(*port_open_type)(const struct dpif_class *dpif_class, const char *type); /* 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); /* Performs periodic work needed by 'dpif', if any is necessary. */ void (*run)(struct dpif *dpif); /* Arranges for poll_block() to wake up if the "run" member function needs * to be called for 'dpif'. */ void (*wait)(struct dpif *dpif); /* Retrieves statistics for 'dpif' into 'stats'. */ int (*get_stats)(const struct dpif *dpif, struct dpif_dp_stats *stats); /* Adds 'netdev' as a new port in 'dpif'. If '*port_no' is not * UINT32_MAX, attempts to use that as the port's port number. * * If port is successfully added, sets '*port_no' to the new port's * port number. Returns EBUSY if caller attempted to choose a port * number, and it was in use. */ int (*port_add)(struct dpif *dpif, struct netdev *netdev, odp_port_t *port_no); /* Removes port numbered 'port_no' from 'dpif'. */ int (*port_del)(struct dpif *dpif, odp_port_t port_no); /* Queries 'dpif' for a port with the given 'port_no' or 'devname'. * If 'port' is not null, stores information about the port into * '*port' if successful. * * If 'port' is not null, 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, odp_port_t port_no, struct dpif_port *port); int (*port_query_by_name)(const struct dpif *dpif, const char *devname, struct dpif_port *port); /* Returns the Netlink PID value to supply in OVS_ACTION_ATTR_USERSPACE * actions as the OVS_USERSPACE_ATTR_PID attribute's value, for use in * flows whose packets arrived on port 'port_no'. In the case where the * provider allocates multiple Netlink PIDs to a single port, it may use * 'hash' to spread load among them. The caller need not use a particular * hash function; a 5-tuple hash is suitable. * * (The datapath implementation might use some different hash function for * distributing packets received via flow misses among PIDs. This means * that packets received via flow misses might be reordered relative to * packets received via userspace actions. This is not ordinarily a * problem.) * * A 'port_no' of UINT32_MAX should be treated as a special case. The * implementation should return a reserved PID, not allocated to any port, * that the client may use for special purposes. * * The return value only needs to be meaningful when DPIF_UC_ACTION has * been enabled in the 'dpif''s listen mask, and it is allowed to change * when DPIF_UC_ACTION is disabled and then re-enabled. * * A dpif provider that doesn't have meaningful Netlink PIDs can use NULL * for this function. This is equivalent to always returning 0. */ uint32_t (*port_get_pid)(const struct dpif *dpif, odp_port_t port_no, uint32_t hash); /* 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 OVS_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 OVS_KEY_ATTR_* in the 'put->key_len' bytes * starting at 'put->key'. The associated actions are specified by the * Netlink attributes with types OVS_ACTION_ATTR_* in the * 'put->actions_len' bytes starting at 'put->actions'. * * - If the flow's key does not exist in 'dpif', then the flow will be * added if 'put->flags' includes DPIF_FP_CREATE. Otherwise the * operation will fail with ENOENT. * * If the operation succeeds, then 'put->stats', if nonnull, must be * zeroed. * * - If the flow's key does exist in 'dpif', then the flow's actions will * be updated if 'put->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 'put->flags' includes * DPIF_FP_ZERO_STATS, and left as-is otherwise. * * If the operation succeeds, then 'put->stats', if nonnull, must be set * to the flow's statistics before the update. */ int (*flow_put)(struct dpif *dpif, const struct dpif_flow_put *put); /* 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 OVS_KEY_ATTR_* in the 'del->key_len' bytes * starting at 'del->key'. * * If the operation succeeds, then 'del->stats', if nonnull, must be set to * the flow's statistics before its deletion. */ int (*flow_del)(struct dpif *dpif, const struct dpif_flow_del *del); /* Deletes all flows from 'dpif' and clears all of its queues of received * packets. */ int (*flow_flush)(struct dpif *dpif); /* Allocates thread-local state for use with the function 'flow_dump_next'. * On return, initializes '*statep' with any private data needed for * iteration. */ void (*flow_dump_state_init)(void **statep); /* Attempts to begin dumping the flows in a dpif. On success, returns 0 * and initializes '*iterp' with any shared data needed for iteration. * On failure, returns a positive errno value. */ int (*flow_dump_start)(const struct dpif *dpif, void **iterp); /* Attempts to retrieve another flow from 'dpif' for 'iter', using * 'state' for storage. 'iter' must have been initialized by a successful * call to the 'flow_dump_start' function for 'dpif'. 'state' must have * been initialised with a call to the 'flow_dump_state_init' 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. Multiple threads may use the same 'dpif' * and 'iter' with this function, but all other parameters must be * different for each thread. If this function returns non-zero, * subsequent calls with the same arguments will also return non-zero. * * On success: * * - If 'key' and 'key_len' are nonnull, then '*key' and '*key_len' * must be set to Netlink attributes with types OVS_KEY_ATTR_* * representing the dumped flow's key. * * - If 'mask' and 'mask_len' are nonnull then '*mask' and '*mask_len' * must be set to Netlink attributes with types of OVS_KEY_ATTR_* * representing the dumped flow's mask. * * - If 'actions' and 'actions_len' are nonnull then they should be set * to Netlink attributes with types OVS_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 'iter' and 'state'. */ int (*flow_dump_next)(const struct dpif *dpif, void *iter, void *state, const struct nlattr **key, size_t *key_len, const struct nlattr **mask, size_t *mask_len, const struct nlattr **actions, size_t *actions_len, const struct dpif_flow_stats **stats); /* Determines whether the next call to 'flow_dump_next' with 'state' will * modify or free the keys that it previously returned. 'state' must have * been initialized by a call to 'flow_dump_state_init' for 'dpif'. * * 'dpif' guarantees that data returned by flow_dump_next() will remain * accessible and unchanging until the next call. This function provides a * way for callers to determine whether that guarantee extends beyond the * next call. * * Returns true if the next call to flow_dump_next() is expected to be * destructive to previously returned keys for 'state', false otherwise. */ bool (*flow_dump_next_may_destroy_keys)(void *state); /* Releases resources from 'dpif' for 'iter', which was initialized by a * successful call to the 'flow_dump_start' function for 'dpif'. Callers * must ensure that this function is called once within a given iteration, * as the final flow dump operation. */ int (*flow_dump_done)(const struct dpif *dpif, void *iter); /* Releases 'state' which was initialized by a call to the * 'flow_dump_state_init' function for this 'dpif'. */ void (*flow_dump_state_uninit)(void *statep); /* Performs the 'execute->actions_len' bytes of actions in * 'execute->actions' on the Ethernet frame in 'execute->packet' * and on the packet metadata in 'execute->md'. * May modify both packet and metadata. */ int (*execute)(struct dpif *dpif, struct dpif_execute *execute); /* Executes each of the 'n_ops' operations in 'ops' on 'dpif', in the order * in which they are specified, placing each operation's results in the * "output" members documented in comments. * * This function is optional. It is only worthwhile to implement it if * 'dpif' can perform operations in batch faster than individually. */ void (*operate)(struct dpif *dpif, struct dpif_op **ops, size_t n_ops); /* Enables or disables receiving packets with dpif_recv() for 'dpif'. * Turning packet receive off and then back on is allowed to change Netlink * PID assignments (see ->port_get_pid()). The client is responsible for * updating flows as necessary if it does this. */ int (*recv_set)(struct dpif *dpif, bool enable); /* Refreshes the poll loops and Netlink sockets associated to each port, * when the number of upcall handlers (upcall receiving thread) is changed * to 'n_handlers' and receiving packets for 'dpif' is enabled by * recv_set(). * * Since multiple upcall handlers can read upcalls simultaneously from * 'dpif', each port can have multiple Netlink sockets, one per upcall * handler. So, handlers_set() is responsible for the following tasks: * * When receiving upcall is enabled, extends or creates the * configuration to support: * * - 'n_handlers' Netlink sockets for each port. * * - 'n_handlers' poll loops, one for each upcall handler. * * - registering the Netlink sockets for the same upcall handler to * the corresponding poll loop. * */ int (*handlers_set)(struct dpif *dpif, uint32_t n_handlers); /* Translates OpenFlow queue ID 'queue_id' (in host byte order) into a * priority value used for setting packet priority. */ int (*queue_to_priority)(const struct dpif *dpif, uint32_t queue_id, uint32_t *priority); /* Polls for an upcall from 'dpif' for an upcall handler. Since there * can be multiple poll loops (see ->handlers_set()), 'handler_id' is * needed as index to identify the corresponding poll loop. If * successful, stores the upcall into '*upcall', using 'buf' for * storage. Should only be called if 'recv_set' has been used to enable * receiving packets from 'dpif'. * * The implementation should point 'upcall->key' and 'upcall->userdata' * (if any) into data in the caller-provided 'buf'. The implementation may * also use 'buf' for storing the data of 'upcall->packet'. If necessary * to make room, the implementation may reallocate the data in 'buf'. * * The caller owns the data of 'upcall->packet' and may modify it. If * packet's headroom is exhausted as it is manipulated, 'upcall->packet' * will be reallocated. This requires the data of 'upcall->packet' to be * released with ofpbuf_uninit() before 'upcall' is destroyed. However, * when an error is returned, the 'upcall->packet' may be uninitialized * and should not be released. * * 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, uint32_t handler_id, struct dpif_upcall *upcall, struct ofpbuf *buf); /* Arranges for the poll loop for an upcall handler to wake up when 'dpif' * has a message queued to be received with the recv member functions. * Since there can be multiple poll loops (see ->handlers_set()), * 'handler_id' is needed as index to identify the corresponding poll loop. * */ void (*recv_wait)(struct dpif *dpif, uint32_t handler_id); /* 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; extern const struct dpif_class dpif_planetlab_class; #ifdef __cplusplus } #endif #endif /* dpif-provider.h */