1 Commits

Author	SHA1	Message	Date
Anton Nayshtut	717333f4e4	FST: Add the Fast Session Transfer (FST) module ... Fast Session Transfer (FST) is the transfer of a session from a channel to another channel in a different frequency band. The term "session" refers to non-physical layer state information kept by a pair of stations (STAs) that communicate directly (i.e., excludes forwarding). The FST is implemented in accordance with IEEE Std 802.11ad-2012. Definitions * FST interface - an interface for which FST functionality is enabled * FST group - a bunch of FST interfaces representing single multi-band STA * FST peer - a multi-band capable STA connected * FST module - multi-band operation functionality implemented in accordance with IEEE Std 802.11ad-2012 (see 10.32 Multi-band operation) as a part of hostapd/wpa_supplicant * FST manager - an external application that implements custom FST related logic, using the FST module's interfaces accessible via CLI or D-Bus This commit introduces only the FST module. Integration of the FST module into the hostapd/wpa_supplicant and corresponding CLI/D-Bus interfaces and FST related tests are covered in separate commits. FST manager application is out of scope of these commits. As FST aggregates a few interfaces into FST group, the FST module uses global CLI for both commands and notifications. It also exposes alternative non-interface based D-Bus subtree for this purposes. Configuration and Initialization * FST functionality can enabled by compilation flag (CONFIG_FST) * hostapd/wpa_supplicant controlling multiple interfaces are used for FST * once enabled by compilation, the FST can be enabled for specific interfaces in the configuration files * FST interfaces are aggregated in FST groups (fst_group_id config file entry), where each FST group: - represents one multi-band device - should have two or more FST interfaces in it * priority (fst_priority config file entry) must be configured for each FST interface. FST interface with higher priority is the interface FST will always try to switch to. Thus, for example, for the maximal throughput, it should be the fastest FST interface in the FST setup. * default Link Loss Timeout (LLT) value can be configured for each FST interface (fst_llt config file entry). It represents LLT to be used by FST when this interface is active. * FST interfaces advertise the Multi-band capability by including the Multi-band element in the corresponding frames FST CLI commands: * fst list_groups - list FST groups configured. * fst list_ifaces - list FST interfaces which belong to specific group * fst iface_peers - list Multi-Band STAs connected to specific interface * fst list_sessions - list existing FST sessions * fst session_get - get FST session info * fst session_add - create FST session object * fst session_set - set FST session parameters (old_iface, new_iface, peer_addr, llt) * fst session_initiate - initiate FST setup * fst session_respond - respond to FST setup establishemnt attempt by counterpart * fst session_transfer - initiate FST switch * fst session_teardown - tear down FST Setup but leave the session object for reuse * fst session_remove - remove FST session object FST CLI notifications: * FST-EVENT-PEER - peer state changed (CONNECT/DISCONNECT) * FST-EVENT-SESSION - FST session level notification with following sub-events: - EVENT_FST_SESSION_STATE - FST session state changed - EVENT_FST_ESTABLISHED - previously initiated FST session became established - EVENT_FST_SETUP - new FST session object created due to FST session negotiation attempt by counterpart All the FST CLI commands and notifications are also implemented on D-Bus for wpa_supplicant. IEEE 802.11 standard compliance FST module implements FST setup statemachine in compliance with IEEE 802.11ad (P802.11-REVmc/D3.3), as it described in 10.32 Multi-band operation (see also Figure 10-34 - States of the FST setup protocol). Thus, for example, the FST module initiates FST switch automatically when FST setup becomes established with LLT=0 in accordance with 10.32.2.2 Transitioning between states. At the moment, FST module only supports non-transparent STA-based FST (see 10.32.1 General). Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>	2015-07-16 18:26:15 +03:00