/* OpenFlow connections. */
struct connmgr *connmgr;
+
+ /* Flow table operation tracking. */
+ int state; /* Internal state. */
+ struct list pending; /* List of "struct ofopgroup"s. */
+ struct hmap deletions; /* All OFOPERATION_DELETE "ofoperation"s. */
};
struct ofproto *ofproto_lookup(const char *name);
* should not modify them. */
struct rule {
struct ofproto *ofproto; /* The ofproto that contains this rule. */
+ struct list ofproto_node; /* Owned by ofproto base code. */
struct cls_rule cr; /* In owning ofproto's classifier. */
+ struct ofoperation *pending; /* Operation now in progress, if nonnull. */
+
ovs_be64 flow_cookie; /* Controller-issued identifier. */
long long int created; /* Creation time. */
void ofproto_rule_expire(struct rule *, uint8_t reason);
void ofproto_rule_destroy(struct rule *);
+void ofoperation_complete(struct ofoperation *, int status);
+struct rule *ofoperation_get_victim(struct ofoperation *);
+
/* ofproto class structure, to be defined by each ofproto implementation.
*
*
/* ## --------------------------- ## */
/* Life-cycle functions for an "ofproto" (see "Life Cycle" above).
+ *
+ *
+ * Construction
+ * ============
*
* ->construct() should not modify most base members of the ofproto. In
* particular, the client will initialize the ofproto's 'ports' member
* allowed to fail with an error.
*
* ->construct() returns 0 if successful, otherwise a positive errno
- * value. */
+ * value.
+ *
+ *
+ * Destruction
+ * ===========
+ *
+ * ->destruct() must do at least the following:
+ *
+ * - If 'ofproto' has any pending asynchronous operations, ->destruct()
+ * must complete all of them by calling ofoperation_complete().
+ *
+ * - If 'ofproto' has any rules left in any of its flow tables, ->
+ */
struct ofproto *(*alloc)(void);
int (*construct)(struct ofproto *ofproto);
void (*destruct)(struct ofproto *ofproto);
/* ## OpenFlow Rule Functions ## */
/* ## ----------------------- ## */
+
+
/* Chooses an appropriate table for 'cls_rule' within 'ofproto'. On
* success, stores the table ID into '*table_idp' and returns 0. On
* failure, returns an OpenFlow error code (as returned by ofp_mkerr()).
/* Life-cycle functions for a "struct rule" (see "Life Cycle" above).
*
- * ->rule_construct() should first check whether the rule is acceptable:
*
- * - Validate that the matching rule in 'rule->cr' is supported by the
- * datapath. If not, then return an OpenFlow error code (as returned
- * by ofp_mkerr()).
+ * Asynchronous Operation Support
+ * ==============================
+ *
+ * The life-cycle operations on rules can operate asynchronously, meaning
+ * that ->rule_construct() and ->rule_destruct() only need to initiate
+ * their respective operations and do not need to wait for them to complete
+ * before they return. ->rule_modify_actions() also operates
+ * asynchronously.
+ *
+ * An ofproto implementation reports the success or failure of an
+ * asynchronous operation on a rule using the rule's 'pending' member,
+ * which points to a opaque "struct ofoperation" that represents the
+ * ongoing opreation. When the operation completes, the ofproto
+ * implementation calls ofoperation_complete(), passing the ofoperation and
+ * an error indication.
+ *
+ * Only the following contexts may call ofoperation_complete():
+ *
+ * - The function called to initiate the operation,
+ * e.g. ->rule_construct() or ->rule_destruct(). This is the best
+ * choice if the operation completes quickly.
+ *
+ * - The implementation's ->run() function.
+ *
+ * - The implementation's ->destruct() function.
+ *
+ * The ofproto base code updates the flow table optimistically, assuming
+ * that the operation will probably succeed:
+ *
+ * - ofproto adds or replaces the rule in the flow table before calling
+ * ->rule_construct().
+ *
+ * - ofproto updates the rule's actions before calling
+ * ->rule_modify_actions().
+ *
+ * - ofproto removes the rule before calling ->rule_destruct().
*
- * For example, if the datapath does not support registers, then it
- * should return an error if 'rule->cr' does not wildcard all
+ * With one exception, when an asynchronous operation completes with an
+ * error, ofoperation_complete() backs out the already applied changes:
+ *
+ * - If adding or replacing a rule in the flow table fails, ofproto
+ * removes the new rule or restores the original rule.
+ *
+ * - If modifying a rule's actions fails, ofproto restores the original
+ * actions.
+ *
+ * - Removing a rule is not allowed to fail. It must always succeed.
+ *
+ * The ofproto base code serializes operations: if any operation is in
+ * progress on a given rule, ofproto postpones initiating any new operation
+ * on that rule until the pending operation completes. Therefore, every
+ * operation must eventually complete through a call to
+ * ofoperation_complete() to avoid delaying new operations indefinitely
+ * (including any OpenFlow request that affects the rule in question, even
+ * just to query its statistics).
+ *
+ *
+ * Construction
+ * ============
+ *
+ * When ->rule_construct() is called, the caller has already inserted
+ * 'rule' into 'rule->ofproto''s flow table numbered 'rule->table_id'.
+ * There are two cases:
+ *
+ * - 'rule' is a new rule in its flow table. In this case,
+ * ofoperation_get_victim(rule) returns NULL.
+ *
+ * - 'rule' is replacing an existing rule in its flow table that had the
+ * same matching criteria and priority. In this case,
+ * ofoperation_get_victim(rule) returns the rule being replaced.
+ *
+ * ->rule_construct() should set the following in motion:
+ *
+ * - Validate that the matching rule in 'rule->cr' is supported by the
+ * datapath. For example, if the rule's table does not support
+ * registers, then it is an error if 'rule->cr' does not wildcard all
* registers.
*
* - Validate that 'rule->actions' and 'rule->n_actions' are well-formed
- * OpenFlow actions that can be correctly implemented by the datapath.
- * If not, then return an OpenFlow error code (as returned by
- * ofp_mkerr()).
- *
- * The validate_actions() function (in ofp-util.c) can be useful as a
- * model for action validation, but it accepts all of the OpenFlow
- * actions that OVS understands. If your ofproto implementation only
+ * OpenFlow actions that the datapath can correctly implement. The
+ * validate_actions() function (in ofp-util.c) can be useful as a model
+ * for action validation, but it accepts all of the OpenFlow actions
+ * that OVS understands. If your ofproto implementation only
* implements a subset of those, then you should implement your own
* action validation.
*
- * If the rule is acceptable, then ->rule_construct() should modify the
- * flow table:
+ * - If the rule is valid, update the datapath flow table, adding the new
+ * rule or replacing the existing one.
*
- * - If there was already a rule with exactly the same matching criteria
- * and priority in the classifier, then it should destroy it (with
- * ofproto_rule_destroy()).
+ * (On failure, the ofproto code will roll back the insertion from the flow
+ * table, either removing 'rule' or replacing it by the flow that was
+ * originally in its place.)
*
- * To the greatest extent possible, the old rule should be destroyed
- * only if inserting the new rule succeeds; that is, ->rule_construct()
- * should be transactional.
+ * ->rule_construct() must act in one of the following ways:
*
- * The function classifier_find_rule_exactly() can locate such a rule.
+ * - If it succeeds, it must call ofoperation_complete() and return 0.
*
- * - Insert the new rule into the ofproto's 'cls' classifier, and into
- * the datapath flow table.
+ * - If it fails, it must act in one of the following ways:
*
- * The function classifier_insert() inserts a rule into the classifier.
+ * * Call ofoperation_complete() and return 0.
*
- * Other than inserting 'rule->cr' into the classifier, ->rule_construct()
- * should not modify any base members of struct rule.
+ * * Return an OpenFlow error code (as returned by ofp_mkerr()). (Do
+ * not call ofoperation_complete() in this case.)
*
- * ->rule_destruct() should remove 'rule' from the ofproto's 'cls'
- * classifier (e.g. with classifier_remove()) and from the datapath flow
- * table. */
+ * In the former case, ->rule_destruct() will be called; in the latter
+ * case, it will not. ->rule_dealloc() will be called in either case.
+ *
+ * - If the operation is only partially complete, then it must return 0.
+ * Later, when the operation is complete, the ->run() or ->destruct()
+ * function must call ofoperation_complete() to report success or
+ * failure.
+ *
+ * ->rule_construct() should not modify any base members of struct rule.
+ *
+ *
+ * Destruction
+ * ===========
+ *
+ * When ->rule_destruct() is called, the caller has already removed 'rule'
+ * from 'rule->ofproto''s flow table. ->rule_destruct() should set in
+ * motion removing 'rule' from the datapath flow table. If removal
+ * completes synchronously, it should call ofoperation_complete().
+ * Otherwise, the ->run() or ->destruct() function must later call
+ * ofoperation_complete() after the operation completes.
+ *
+ * Rule destruction must not fail. */
struct rule *(*rule_alloc)(void);
int (*rule_construct)(struct rule *rule);
void (*rule_destruct)(struct rule *rule);
/* Obtains statistics for 'rule', storing the number of packets that have
* matched it in '*packet_count' and the number of bytes in those packets
- * in '*byte_count'. */
+ * in '*byte_count'. UINT64_MAX indicates that the packet count or byte
+ * count is unknown. */
void (*rule_get_stats)(struct rule *rule, uint64_t *packet_count,
uint64_t *byte_count);
int (*rule_execute)(struct rule *rule, struct flow *flow,
struct ofpbuf *packet);
- /* Validates that the 'n' elements in 'actions' are well-formed OpenFlow
- * actions that can be correctly implemented by the datapath. If not, then
- * return an OpenFlow error code (as returned by ofp_mkerr()). If so,
- * then update the datapath to implement the new actions and return 0.
+ /* When ->rule_modify_actions() is called, the caller has already replaced
+ * the OpenFlow actions in 'rule' by a new set. (The original actions are
+ * in rule->pending->actions.)
+ *
+ * ->rule_modify_actions() should set the following in motion:
+ *
+ * - Validate that the actions now in 'rule' are well-formed OpenFlow
+ * actions that the datapath can correctly implement.
+ *
+ * - Update the datapath flow table with the new actions.
+ *
+ * If the operation synchronously completes, ->rule_modify_actions() may
+ * call ofoperation_complete() before it returns. Otherwise, ->run()
+ * should call ofoperation_complete() later, after the operation does
+ * complete.
+ *
+ * If the operation fails, then the base ofproto code will restore the
+ * original 'actions' and 'n_actions' of 'rule'.
*
- * When this function runs, 'rule' still has its original actions. If this
- * function returns 0, then the caller will update 'rule' with the new
- * actions and free the old ones. */
- int (*rule_modify_actions)(struct rule *rule,
- const union ofp_action *actions, size_t n);
+ * ->rule_modify_actions() should not modify any base members of struct
+ * rule. */
+ void (*rule_modify_actions)(struct rule *rule);
/* These functions implement the OpenFlow IP fragment handling policy. By
* default ('drop_frags' == false), an OpenFlow switch should treat IP
void ofproto_add_flow(struct ofproto *, const struct cls_rule *,
const union ofp_action *, size_t n_actions);
-void ofproto_delete_flow(struct ofproto *, const struct cls_rule *);
+bool ofproto_delete_flow(struct ofproto *, const struct cls_rule *);
void ofproto_flush_flows(struct ofproto *);
#endif /* ofproto/private.h */
projects / openvswitch / blobdiff