X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fnetdev-provider.h;h=c2123dc6717f603d851874d3b2a48c448c51a8eb;hb=41ca1e0afb4b261a217c9fdaf672ef606e8434f9;hp=19230a16403c0efd09f497223453636f04fc62e9;hpb=89608a13e3bee2bf92456033c1573014a7d939c3;p=sliver-openvswitch.git diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h index 19230a164..c2123dc67 100644 --- a/lib/netdev-provider.h +++ b/lib/netdev-provider.h @@ -19,8 +19,10 @@ /* Generic interface to network devices. */ +#include "connectivity.h" #include "netdev.h" #include "list.h" +#include "seq.h" #include "shash.h" #include "smap.h" @@ -30,31 +32,160 @@ extern "C" { /* A network device (e.g. an Ethernet device). * - * Network device implementations should treat this structure as opaque. */ + * Network device implementations may read these members but should not modify + * them. */ struct netdev { + /* The following do not change during the lifetime of a struct netdev. */ char *name; /* Name of network device. */ const struct netdev_class *netdev_class; /* Functions to control this device. */ + + /* A sequence number which indicates changes in one of 'netdev''s + * properties. It must be nonzero so that users have a value which + * they may use as a reset when tracking 'netdev'. + * + * Minimally, the sequence number is required to change whenever + * 'netdev''s flags, features, ethernet address, or carrier changes. */ + uint64_t change_seq; + + /* The following are protected by 'netdev_mutex' (internal to netdev.c). */ + int n_rxq; int ref_cnt; /* Times this devices was opened. */ struct shash_node *node; /* Pointer to element in global map. */ struct list saved_flags_list; /* Contains "struct netdev_saved_flags". */ }; -void netdev_init(struct netdev *, const char *name, - const struct netdev_class *); -void netdev_uninit(struct netdev *, bool destroy); +static void +netdev_change_seq_changed(struct netdev *netdev) +{ + seq_change(connectivity_seq_get()); + netdev->change_seq++; + if (!netdev->change_seq) { + netdev->change_seq++; + } +} + const char *netdev_get_type(const struct netdev *); const struct netdev_class *netdev_get_class(const struct netdev *); const char *netdev_get_name(const struct netdev *); struct netdev *netdev_from_name(const char *name); void netdev_get_devices(const struct netdev_class *, struct shash *device_list); +struct netdev **netdev_get_vports(size_t *size); + +/* A data structure for capturing packets received by a network device. + * + * Network device implementations may read these members but should not modify + * them. + * + * None of these members change during the lifetime of a struct netdev_rxq. */ +struct netdev_rxq { + struct netdev *netdev; /* Owns a reference to the netdev. */ + int queue_id; +}; + +struct netdev *netdev_rxq_get_netdev(const struct netdev_rxq *); /* Network device class structure, to be defined by each implementation of a * network device. * * These functions return 0 if successful or a positive errno value on failure, - * except where otherwise noted. */ + * except where otherwise noted. + * + * + * Data Structures + * =============== + * + * These functions work primarily with two different kinds of data structures: + * + * - "struct netdev", which represents a network device. + * + * - "struct netdev_rxq", which represents a handle for capturing packets + * received on a network device + * + * Each of these data structures contains all of the implementation-independent + * generic state for the respective concept, called the "base" state. None of + * them contains any extra space for implementations to use. Instead, each + * implementation is expected to declare its own data structure that contains + * an instance of the generic data structure plus additional + * implementation-specific members, called the "derived" state. The + * implementation can use casts or (preferably) the CONTAINER_OF macro to + * obtain access to derived state given only a pointer to the embedded generic + * data structure. + * + * + * Life Cycle + * ========== + * + * Four stylized functions accompany each of these data structures: + * + * "alloc" "construct" "destruct" "dealloc" + * ------------ ---------------- --------------- -------------- + * netdev ->alloc ->construct ->destruct ->dealloc + * netdev_rxq ->rxq_alloc ->rxq_construct ->rxq_destruct ->rxq_dealloc + * + * Any instance of a given data structure goes through the following life + * cycle: + * + * 1. The client calls the "alloc" function to obtain raw memory. If "alloc" + * fails, skip all the other steps. + * + * 2. The client initializes all of the data structure's base state. If this + * fails, skip to step 7. + * + * 3. The client calls the "construct" function. The implementation + * initializes derived state. It may refer to the already-initialized + * base state. If "construct" fails, skip to step 6. + * + * 4. The data structure is now initialized and in use. + * + * 5. When the data structure is no longer needed, the client calls the + * "destruct" function. The implementation uninitializes derived state. + * The base state has not been uninitialized yet, so the implementation + * may still refer to it. + * + * 6. The client uninitializes all of the data structure's base state. + * + * 7. The client calls the "dealloc" to free the raw memory. The + * implementation must not refer to base or derived state in the data + * structure, because it has already been uninitialized. + * + * If netdev support multi-queue IO then netdev->construct should set initialize + * netdev->n_rxq to number of queues. + * + * Each "alloc" function allocates and returns a new instance of the respective + * data structure. The "alloc" function is not given any information about the + * use of the new data structure, so it cannot perform much initialization. + * Its purpose is just to ensure that the new data structure has enough room + * for base and derived state. It may return a null pointer if memory is not + * available, in which case none of the other functions is called. + * + * Each "construct" function initializes derived state in its respective data + * structure. When "construct" is called, all of the base state has already + * been initialized, so the "construct" function may refer to it. The + * "construct" function is allowed to fail, in which case the client calls the + * "dealloc" function (but not the "destruct" function). + * + * Each "destruct" function uninitializes and frees derived state in its + * respective data structure. When "destruct" is called, the base state has + * not yet been uninitialized, so the "destruct" function may refer to it. The + * "destruct" function is not allowed to fail. + * + * Each "dealloc" function frees raw memory that was allocated by the the + * "alloc" function. The memory's base and derived members might not have ever + * been initialized (but if "construct" returned successfully, then it has been + * "destruct"ed already). The "dealloc" function is not allowed to fail. + * + * + * Device Change Notification + * ========================== + * + * Minimally, implementations are required to report changes to netdev flags, + * features, ethernet address or carrier through connectivity_seq. Changes to + * other properties are allowed to cause notification through this interface, + * although implementations should try to avoid this. connectivity_seq_get() + * can be used to acquire a reference to the struct seq. The interface is + * described in detail in seq.h. */ struct netdev_class { /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc. * @@ -64,6 +195,10 @@ struct netdev_class { * the system. */ const char *type; +/* ## ------------------- ## */ +/* ## Top-Level Functions ## */ +/* ## ------------------- ## */ + /* Called when the netdev provider is registered, typically at program * startup. Returning an error from this function will prevent any network * device in this class from being opened. @@ -83,18 +218,16 @@ struct netdev_class { * needed here. */ void (*wait)(void); - /* Attempts to create a network device named 'name' in 'netdev_class'. On - * success sets 'netdevp' to the newly created device. */ - int (*create)(const struct netdev_class *netdev_class, const char *name, - struct netdev **netdevp); +/* ## ---------------- ## */ +/* ## netdev Functions ## */ +/* ## ---------------- ## */ - /* Destroys 'netdev'. - * - * Netdev devices maintain a reference count that is incremented on - * netdev_open() and decremented on netdev_close(). If 'netdev' - * has a non-zero reference count, then this function will not be - * called. */ - void (*destroy)(struct netdev *netdev); + /* Life-cycle functions for a netdev. See the large comment above on + * struct netdev_class. */ + struct netdev *(*alloc)(void); + int (*construct)(struct netdev *); + void (*destruct)(struct netdev *); + void (*dealloc)(struct netdev *); /* Fetches the device 'netdev''s configuration, storing it in 'args'. * The caller owns 'args' and pre-initializes it to an empty smap. @@ -116,25 +249,13 @@ struct netdev_class { const struct netdev_tunnel_config * (*get_tunnel_config)(const struct netdev *netdev); - /* Attempts to open a netdev_rx for receiving packets from 'netdev'. + /* Sends the buffer on 'netdev'. * Returns 0 if successful, otherwise a positive errno value. Returns - * EOPNOTSUPP to indicate that the network device does not implement packet - * reception through this interface. This function may be set to null if - * it would always return EOPNOTSUPP anyhow. (This will prevent the - * network device from being usefully used by the netdev-based "userspace - * datapath".) - * - * On success, the implementation must set '*rxp' to a 'netdev_rx' for - * 'netdev' that it has already initialized (with netdev_rx_init()). */ - int (*rx_open)(struct netdev *netdev, struct netdev_rx **rxp); - - /* Sends the 'size'-byte packet in 'buffer' on 'netdev'. Returns 0 if - * successful, otherwise a positive errno value. Returns EAGAIN without - * blocking if the packet cannot be queued immediately. Returns EMSGSIZE - * if a partial packet was transmitted or if the packet is too big or too - * small to transmit on the device. + * EAGAIN without blocking if the packet cannot be queued immediately. + * Returns EMSGSIZE if a partial packet was transmitted or if the packet + * is too big or too small to transmit on the device. * - * The caller retains ownership of 'buffer' in all cases. + * To retain ownership of 'buffer' caller can set may_steal to false. * * The network device is expected to maintain a packet transmission queue, * so that the caller does not ordinarily have to do additional queuing of @@ -146,7 +267,7 @@ struct netdev_class { * network device from being usefully used by the netdev-based "userspace * datapath". It will also prevent the OVS implementation of bonding from * working properly over 'netdev'.) */ - int (*send)(struct netdev *netdev, const void *buffer, size_t size); + int (*send)(struct netdev *netdev, struct ofpbuf *buffer, bool may_steal); /* Registers with the poll loop to wake up from the next call to * poll_block() when the packet transmission queue for 'netdev' has @@ -394,22 +515,39 @@ struct netdev_class { int (*get_queue_stats)(const struct netdev *netdev, unsigned int queue_id, struct netdev_queue_stats *stats); - /* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's - * ID, its configuration, and the 'aux' specified by the caller. The order - * of iteration is unspecified, but (when successful) each queue is visited - * exactly once. - * - * 'cb' will not modify or free the 'details' argument passed in. It may - * delete or modify the queue passed in as its 'queue_id' argument. It may - * modify but will not delete any other queue within 'netdev'. If 'cb' - * adds new queues, then ->dump_queues is allowed to visit some queues - * twice or not at all. - */ - int (*dump_queues)(const struct netdev *netdev, - void (*cb)(unsigned int queue_id, - const struct smap *details, - void *aux), - void *aux); + /* Attempts to begin dumping the queues in 'netdev'. On success, returns 0 + * and initializes '*statep' with any data needed for iteration. On + * failure, returns a positive errno value. + * + * May be NULL if 'netdev' does not support QoS at all. */ + int (*queue_dump_start)(const struct netdev *netdev, void **statep); + + /* Attempts to retrieve another queue from 'netdev' for 'state', which was + * initialized by a successful call to the 'queue_dump_start' function for + * 'netdev'. On success, stores a queue ID into '*queue_id' and fills + * 'details' with the configuration of the queue with that ID. Returns EOF + * if the last queue has been dumped, 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 'queue_dump_done' function will be called + * afterward). + * + * The caller initializes and clears 'details' before calling this + * function. The caller takes ownership of the string key-values pairs + * added to 'details'. + * + * The returned contents of 'details' should be documented as valid for the + * given 'type' in the "other_config" column in the "Queue" table in + * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)). + * + * May be NULL if 'netdev' does not support QoS at all. */ + int (*queue_dump_next)(const struct netdev *netdev, void *state, + unsigned int *queue_id, struct smap *details); + + /* Releases resources from 'netdev' for 'state', which was initialized by a + * successful call to the 'queue_dump_start' function for 'netdev'. + * + * May be NULL if 'netdev' does not support QoS at all. */ + int (*queue_dump_done)(const struct netdev *netdev, void *state); /* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's * ID, its statistics, and the 'aux' specified by the caller. The order of @@ -508,63 +646,44 @@ struct netdev_class { int (*update_flags)(struct netdev *netdev, enum netdev_flags off, enum netdev_flags on, enum netdev_flags *old_flags); - /* Returns a sequence number which indicates changes in one of 'netdev''s - * properties. The returned sequence number must be nonzero so that - * callers have a value which they may use as a reset when tracking - * 'netdev'. - * - * Minimally, the returned sequence number is required to change whenever - * 'netdev''s flags, features, ethernet address, or carrier changes. The - * returned sequence number is allowed to change even when 'netdev' doesn't - * change, although implementations should try to avoid this. */ - unsigned int (*change_seq)(const struct netdev *netdev); -}; - -/* A data structure for capturing packets received by a network device. - * - * This structure should be treated as opaque by network device - * implementations. */ -struct netdev_rx { - const struct netdev_rx_class *rx_class; - struct netdev *netdev; -}; +/* ## -------------------- ## */ +/* ## netdev_rxq Functions ## */ +/* ## -------------------- ## */ -void netdev_rx_init(struct netdev_rx *, struct netdev *, - const struct netdev_rx_class *); -void netdev_rx_uninit(struct netdev_rx *); -struct netdev *netdev_rx_get_netdev(const struct netdev_rx *); +/* If a particular netdev class does not support receiving packets, all these + * function pointers must be NULL. */ -struct netdev_rx_class { - /* Destroys 'rx'. */ - void (*destroy)(struct netdev_rx *rx); + /* Life-cycle functions for a netdev_rxq. See the large comment above on + * struct netdev_class. */ + struct netdev_rxq *(*rxq_alloc)(void); + int (*rxq_construct)(struct netdev_rxq *); + void (*rxq_destruct)(struct netdev_rxq *); + void (*rxq_dealloc)(struct netdev_rxq *); - /* Attempts to receive a packet from 'rx' into the 'size' bytes in - * 'buffer'. If successful, returns the number of bytes in the received - * packet, otherwise a negative errno value. Returns -EAGAIN immediately - * if no packet is ready to be received. + /* Attempts to receive batch of packets from 'rx' and place array of pointers + * into '*pkt'. netdev is responsible for allocating buffers. + * '*cnt' points to packet count for given batch. Once packets are returned + * to caller, netdev should give up ownership of ofpbuf data. * - * Must return -EMSGSIZE, and discard the packet, if the received packet - * is longer than 'size' bytes. */ - int (*recv)(struct netdev_rx *rx, void *buffer, size_t size); + * Implementations should allocate buffer with DP_NETDEV_HEADROOM headroom + * and add a VLAN header which is obtained out-of-band to the packet. + * + * Caller is expected to pass array of size MAX_RX_BATCH. + * This function may be set to null if it would always return EOPNOTSUPP + * anyhow. */ + int (*rxq_recv)(struct netdev_rxq *rx, struct ofpbuf **pkt, int *cnt); /* Registers with the poll loop to wake up from the next call to - * poll_block() when a packet is ready to be received with netdev_rx_recv() + * poll_block() when a packet is ready to be received with netdev_rxq_recv() * on 'rx'. */ - void (*wait)(struct netdev_rx *rx); + void (*rxq_wait)(struct netdev_rxq *rx); /* Discards all packets waiting to be received from 'rx'. */ - int (*drain)(struct netdev_rx *rx); + int (*rxq_drain)(struct netdev_rxq *rx); }; -static inline void netdev_rx_assert_class(const struct netdev_rx *rx, - const struct netdev_rx_class *class_) -{ - ovs_assert(rx->rx_class == class_); -} - int netdev_register_provider(const struct netdev_class *); int netdev_unregister_provider(const char *type); -const struct netdev_class *netdev_lookup_provider(const char *type); extern const struct netdev_class netdev_linux_class; extern const struct netdev_class netdev_internal_class;