X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=include%2Fopenflow%2Fnicira-ext.h;h=1104dbf8396e60da6e00ea940723b5647e7737a6;hb=2b07c8b182b76e4e3a162796d3ae273ef51d4131;hp=82deeb0f72ae22fbaaac5ac540c6b931ad96f511;hpb=e2a3d183f60b93265c095ede1379194916444822;p=openvswitch diff --git a/include/openflow/nicira-ext.h b/include/openflow/nicira-ext.h index 82deeb0f..1104dbf8 100644 --- a/include/openflow/nicira-ext.h +++ b/include/openflow/nicira-ext.h @@ -117,6 +117,11 @@ enum nicira_type { NXT_SET_ASYNC_CONFIG = 19, /* struct nx_async_config. */ NXT_SET_CONTROLLER_ID = 20, /* struct nx_controller_id. */ + + /* Flow table monitoring (see also NXST_FLOW_MONITOR). */ + NXT_FLOW_MONITOR_CANCEL = 21, /* struct nx_flow_monitor_cancel. */ + NXT_FLOW_MONITOR_PAUSED = 22, /* struct nicira_header. */ + NXT_FLOW_MONITOR_RESUMED = 23, /* struct nicira_header. */ }; /* Header for Nicira vendor stats request and reply messages. */ @@ -131,7 +136,10 @@ OFP_ASSERT(sizeof(struct nicira_stats_msg) == 24); enum nicira_stats_type { /* Flexible flow specification (aka NXM = Nicira Extended Match). */ NXST_FLOW, /* Analogous to OFPST_FLOW. */ - NXST_AGGREGATE /* Analogous to OFPST_AGGREGATE. */ + NXST_AGGREGATE, /* Analogous to OFPST_AGGREGATE. */ + + /* Flow table monitoring. */ + NXST_FLOW_MONITOR, }; /* Fields to use when hashing flows. */ @@ -1976,5 +1984,240 @@ struct nx_action_controller { uint8_t zero; /* Must be zero. */ }; OFP_ASSERT(sizeof(struct nx_action_controller) == 16); + +/* Flow Table Monitoring + * ===================== + * + * NXST_FLOW_MONITOR allows a controller to keep track of changes to OpenFlow + * flow table(s) or subsets of them, with the following workflow: + * + * 1. The controller sends an NXST_FLOW_MONITOR request to begin monitoring + * flows. The 'id' in the request must be unique among all monitors that + * the controller has started and not yet canceled on this OpenFlow + * connection. + * + * 2. The switch responds with an NXST_FLOW_MONITOR reply. If the request's + * 'flags' included NXFMF_INITIAL, the reply includes all the flows that + * matched the request at the time of the request (with event NXFME_ADDED). + * If 'flags' did not include NXFMF_INITIAL, the reply is empty. + * + * The reply uses the xid of the request (as do all replies to OpenFlow + * requests). + * + * 3. Whenever a change to a flow table entry matches some outstanding monitor + * request's criteria and flags, the switch sends a notification to the + * controller as an additional NXST_FLOW_MONITOR reply with xid 0. + * + * When multiple outstanding monitors match a single change, only a single + * notification is sent. This merged notification includes the information + * requested in any of the individual monitors. That is, if any of the + * matching monitors requests actions (NXFMF_ACTIONS), the notification + * includes actions, and if any of the monitors request full changes for the + * controller's own changes (NXFMF_OWN), the controller's own changes will + * be included in full. + * + * 4. The controller may cancel a monitor with NXT_FLOW_MONITOR_CANCEL. No + * further notifications will be sent on the basis of the canceled monitor + * afterward. + * + * + * Buffer Management + * ================= + * + * OpenFlow messages for flow monitor notifications can overflow the buffer + * space available to the switch, either temporarily (e.g. due to network + * conditions slowing OpenFlow traffic) or more permanently (e.g. the sustained + * rate of flow table change exceeds the network bandwidth between switch and + * controller). + * + * When Open vSwitch's notification buffer space reaches a limiting threshold, + * OVS reacts as follows: + * + * 1. OVS sends an NXT_FLOW_MONITOR_PAUSED message to the controller, following + * all the already queued notifications. After it receives this message, + * the controller knows that its view of the flow table, as represented by + * flow monitor notifications, is incomplete. + * + * 2. As long as the notification buffer is not empty: + * + * - NXMFE_ADD and NXFME_MODIFIED notifications will not be sent. + * + * - NXFME_DELETED notifications will still be sent, but only for flows + * that existed before OVS sent NXT_FLOW_MONITOR_PAUSED. + * + * - NXFME_ABBREV notifications will not be sent. They are treated as + * the expanded version (and therefore only the NXFME_DELETED + * components, if any, are sent). + * + * 3. When the notification buffer empties, OVS sends NXFME_ADD notifications + * for flows added since the buffer reached its limit and NXFME_MODIFIED + * notifications for flows that existed before the limit was reached and + * changed after the limit was reached. + * + * 4. OVS sends an NXT_FLOW_MONITOR_RESUMED message to the controller. After + * it receives this message, the controller knows that its view of the flow + * table, as represented by flow monitor notifications, is again complete. + * + * This allows the maximum buffer space requirement for notifications to be + * bounded by the limit plus the maximum number of supported flows. + * + * + * "Flow Removed" messages + * ======================= + * + * The flow monitor mechanism is independent of OFPT_FLOW_REMOVED and + * NXT_FLOW_REMOVED. Flow monitor updates for deletion are sent if + * NXFMF_DELETE is set on a monitor, regardless of whether the + * OFPFF_SEND_FLOW_REM flag was set when the flow was added. */ + +/* NXST_FLOW_MONITOR request. + * + * The NXST_FLOW_MONITOR request's body consists of an array of zero or more + * instances of this structure. The request arranges to monitor the flows + * that match the specified criteria, which are interpreted in the same way as + * for NXST_FLOW. + * + * 'id' identifies a particular monitor for the purpose of allowing it to be + * canceled later with NXT_FLOW_MONITOR_CANCEL. 'id' must be unique among + * existing monitors that have not already been canceled. + * + * The reply includes the initial flow matches for monitors that have the + * NXFMF_INITIAL flag set. No single flow will be included in the reply more + * than once, even if more than one requested monitor matches that flow. The + * reply will be empty if none of the monitors has NXFMF_INITIAL set or if none + * of the monitors initially matches any flows. + * + * For NXFMF_ADD, an event will be reported if 'out_port' matches against the + * actions of the flow being added or, for a flow that is replacing an existing + * flow, if 'out_port' matches against the actions of the flow being replaced. + * For NXFMF_DELETE, 'out_port' matches against the actions of a flow being + * deleted. For NXFMF_MODIFY, an event will be reported if 'out_port' matches + * either the old or the new actions. */ +struct nx_flow_monitor_request { + ovs_be32 id; /* Controller-assigned ID for this monitor. */ + ovs_be16 flags; /* NXFMF_*. */ + ovs_be16 out_port; /* Required output port, if not OFPP_NONE. */ + ovs_be16 match_len; /* Length of nx_match. */ + uint8_t table_id; /* One table's ID or 0xff for all tables. */ + uint8_t zeros[5]; /* Align to 64 bits (must be zero). */ + /* Followed by: + * - Exactly match_len (possibly 0) bytes containing the nx_match, then + * - Exactly (match_len + 7)/8*8 - match_len (between 0 and 7) bytes of + * all-zero bytes. */ +}; +OFP_ASSERT(sizeof(struct nx_flow_monitor_request) == 16); + +/* 'flags' bits in struct nx_flow_monitor_request. */ +enum nx_flow_monitor_flags { + /* When to send updates. */ + NXFMF_INITIAL = 1 << 0, /* Initially matching flows. */ + NXFMF_ADD = 1 << 1, /* New matching flows as they are added. */ + NXFMF_DELETE = 1 << 2, /* Old matching flows as they are removed. */ + NXFMF_MODIFY = 1 << 3, /* Matching flows as they are changed. */ + + /* What to include in updates. */ + NXFMF_ACTIONS = 1 << 4, /* If set, actions are included. */ + NXFMF_OWN = 1 << 5, /* If set, include own changes in full. */ +}; + +/* NXST_FLOW_MONITOR reply header. + * + * The body of an NXST_FLOW_MONITOR reply is an array of variable-length + * structures, each of which begins with this header. The 'length' member may + * be used to traverse the array, and the 'event' member may be used to + * determine the particular structure. + * + * Every instance is a multiple of 8 bytes long. */ +struct nx_flow_update_header { + ovs_be16 length; /* Length of this entry. */ + ovs_be16 event; /* One of NXFME_*. */ + /* ...other data depending on 'event'... */ +}; +OFP_ASSERT(sizeof(struct nx_flow_update_header) == 4); + +/* 'event' values in struct nx_flow_update_header. */ +enum nx_flow_update_event { + /* struct nx_flow_update_full. */ + NXFME_ADDED = 0, /* Flow was added. */ + NXFME_DELETED = 1, /* Flow was deleted. */ + NXFME_MODIFIED = 2, /* Flow (generally its actions) was changed. */ + + /* struct nx_flow_update_abbrev. */ + NXFME_ABBREV = 3, /* Abbreviated reply. */ +}; + +/* NXST_FLOW_MONITOR reply for NXFME_ADDED, NXFME_DELETED, and + * NXFME_MODIFIED. */ +struct nx_flow_update_full { + ovs_be16 length; /* Length is 24. */ + ovs_be16 event; /* One of NXFME_*. */ + ovs_be16 reason; /* OFPRR_* for NXFME_DELETED, else zero. */ + ovs_be16 priority; /* Priority of the entry. */ + ovs_be16 idle_timeout; /* Number of seconds idle before expiration. */ + ovs_be16 hard_timeout; /* Number of seconds before expiration. */ + ovs_be16 match_len; /* Length of nx_match. */ + uint8_t table_id; /* ID of flow's table. */ + uint8_t pad; /* Reserved, currently zeroed. */ + ovs_be64 cookie; /* Opaque controller-issued identifier. */ + /* Followed by: + * - Exactly match_len (possibly 0) bytes containing the nx_match, then + * - Exactly (match_len + 7)/8*8 - match_len (between 0 and 7) bytes of + * all-zero bytes, then + * - Actions to fill out the remainder 'length' bytes (always a multiple + * of 8). If NXFMF_ACTIONS was not specified, or 'event' is + * NXFME_DELETED, no actions are included. + */ +}; +OFP_ASSERT(sizeof(struct nx_flow_update_full) == 24); + +/* NXST_FLOW_MONITOR reply for NXFME_ABBREV. + * + * When the controller does not specify NXFMF_OWN in a monitor request, any + * flow tables changes due to the controller's own requests (on the same + * OpenFlow channel) will be abbreviated, when possible, to this form, which + * simply specifies the 'xid' of the OpenFlow request (e.g. an OFPT_FLOW_MOD or + * NXT_FLOW_MOD) that caused the change. + * + * Some changes cannot be abbreviated and will be sent in full: + * + * - Changes that only partially succeed. This can happen if, for example, + * a flow_mod with type OFPFC_MODIFY affects multiple flows, but only some + * of those modifications succeed (e.g. due to hardware limitations). + * + * This cannot occur with the current implementation of the Open vSwitch + * software datapath. It could happen with other datapath implementations. + * + * - Changes that race with conflicting changes made by other controllers or + * other flow_mods (not separated by barriers) by the same controller. + * + * This cannot occur with the current Open vSwitch implementation + * (regardless of datapath) because Open vSwitch internally serializes + * potentially conflicting changes. + * + * A flow_mod that does not change the flow table will not trigger any + * notification, even an abbreviated one. For example, a "modify" or "delete" + * flow_mod that does not match any flows will not trigger a notification. + * Whether an "add" or "modify" that specifies all the same parameters that a + * flow already has triggers a notification is unspecified and subject to + * change in future versions of Open vSwitch. + * + * OVS will always send the notifications for a given flow table change before + * the reply to a OFPT_BARRIER_REQUEST request that precedes the flow table + * change. Thus, if the controller does not receive an abbreviated + * notification for a flow_mod before the next OFPT_BARRIER_REPLY, it will + * never receive one. */ +struct nx_flow_update_abbrev { + ovs_be16 length; /* Length is 8. */ + ovs_be16 event; /* NXFME_ABBREV. */ + ovs_be32 xid; /* Controller-specified xid from flow_mod. */ +}; +OFP_ASSERT(sizeof(struct nx_flow_update_abbrev) == 8); + +/* Used by a controller to cancel an outstanding monitor. */ +struct nx_flow_monitor_cancel { + struct nicira_header nxh; /* Type NXT_FLOW_MONITOR_CANCEL. */ + ovs_be32 id; /* 'id' from nx_flow_monitor_request. */ +}; +OFP_ASSERT(sizeof(struct nx_flow_monitor_cancel) == 20); #endif /* openflow/nicira-ext.h */