There are multiple mechanisms for inter-process communication. For example, Linux version of wpa_supplicant is using UNIX domain sockets for the control interface and Windows version UDP sockets. The use of the functions defined in wpa_ctrl.h can be used to hide the details of the used IPC from external programs.
wpa_supplicant uses the control interface for two types of communication: commands and unsolicited event messages. Commands are a pair of messages, a request from the external program and a response from wpa_supplicant. These can be executed using wpa_ctrl_request(). Unsolicited event messages are sent by wpa_supplicant to the control interface connection without specific request from the external program for receiving each message. However, the external program needs to attach to the control interface with wpa_ctrl_attach() to receive these unsolicited messages.
If the control interface connection is used both for commands and unsolicited event messages, there is potential for receiving an unsolicited message between the command request and response. wpa_ctrl_request() caller will need to supply a callback, msg_cb, for processing these messages. Often it is easier to open two control interface connections by calling wpa_ctrl_open() twice and then use one of the connections for commands and the other one for unsolicited messages. This way command request/response pairs will not be broken by unsolicited messages. wpa_cli is an example of how to use only one connection for both purposes and wpa_gui demonstrates how to use two separate connections.
Once the control interface connection is not needed anymore, it should be closed by calling wpa_ctrl_close(). If the connection was used for unsolicited event messages, it should be first detached by calling wpa_ctrl_detach().
PONG if the connection is open and wpa_supplicant is processing commands.variable=value format. For example:
dot11RSNAOptionImplemented=TRUE dot11RSNAPreauthenticationImplemented=TRUE dot11RSNAEnabled=FALSE dot11RSNAPreauthenticationEnabled=FALSE dot11RSNAConfigVersion=1 dot11RSNAConfigPairwiseKeysSupported=5 dot11RSNAConfigGroupCipherSize=128 dot11RSNAConfigPMKLifetime=43200 dot11RSNAConfigPMKReauthThreshold=70 dot11RSNAConfigNumberOfPTKSAReplayCounters=1 dot11RSNAConfigSATimeout=60 dot11RSNAAuthenticationSuiteSelected=00-50-f2-2 dot11RSNAPairwiseCipherSelected=00-50-f2-4 dot11RSNAGroupCipherSelected=00-50-f2-4 dot11RSNAPMKIDUsed= dot11RSNAAuthenticationSuiteRequested=00-50-f2-2 dot11RSNAPairwiseCipherRequested=00-50-f2-4 dot11RSNAGroupCipherRequested=00-50-f2-4 dot11RSNAConfigNumberOfGTKSAReplayCounters=0 dot11RSNA4WayHandshakeFailures=0 dot1xSuppPaeState=5 dot1xSuppHeldPeriod=60 dot1xSuppAuthPeriod=30 dot1xSuppStartPeriod=30 dot1xSuppMaxStart=3 dot1xSuppSuppControlledPortStatus=Authorized dot1xSuppBackendPaeState=2 dot1xSuppEapolFramesRx=0 dot1xSuppEapolFramesTx=440 dot1xSuppEapolStartFramesTx=2 dot1xSuppEapolLogoffFramesTx=0 dot1xSuppEapolRespFramesTx=0 dot1xSuppEapolReqIdFramesRx=0 dot1xSuppEapolReqFramesRx=0 dot1xSuppInvalidEapolFramesRx=0 dot1xSuppEapLengthErrorFramesRx=0 dot1xSuppLastEapolFrameVersion=0 dot1xSuppLastEapolFrameSource=00:00:00:00:00:00
variable=value format. For example:
bssid=02:00:01:02:03:04 ssid=test network pairwise_cipher=CCMP group_cipher=CCMP key_mgmt=WPA-PSK wpa_state=COMPLETED ip_address=192.168.1.21 Supplicant PAE state=AUTHENTICATED suppPortStatus=Authorized EAP state=SUCCESS
variable=value pairs).
bssid=02:00:01:02:03:04 ssid=test network id=0 pairwise_cipher=CCMP group_cipher=CCMP key_mgmt=WPA-PSK wpa_state=COMPLETED ip_address=192.168.1.21 Supplicant PAE state=AUTHENTICATED suppPortStatus=Authorized heldPeriod=60 authPeriod=30 startPeriod=30 maxStart=3 portControl=Auto Supplicant Backend state=IDLE EAP state=SUCCESS reqMethod=0 methodState=NONE decision=COND_SUCC ClientTimeout=60
Index / AA / PMKID / expiration (in seconds) / opportunistic 1 / 02:00:01:02:03:04 / 000102030405060708090a0b0c0d0e0f / 41362 / 0 2 / 02:00:01:33:55:77 / 928389281928383b34afb34ba4212345 / 362 / 1
Example command:
SET EAPOL::heldPeriod 45
LIST_NETWORKS command output.
network id / ssid / bssid / flags 0 example network any [CURRENT]
(note: fields are separated with tabs)
REASSOCIATE command before connecting.
bssid / frequency / signal level / flags / ssid 00:09:5b:95:e0:4e 2412 208 [WPA-PSK-CCMP] jkm private 02:55:24:33:77:a3 2462 187 [WPA-PSK-TKIP] testing 00:09:5b:95:e0:4f 2412 209 jkm guest
(note: fields are separated with tabs)
LIST_NETWORKS command output.LIST_NETWORKS command output.LIST_NETWORKS command output.ENABLE_NETWORK command. ADD_NETWORK returns the network id of the new network or FAIL on failure.LIST_NETWORKS command output.LIST_NETWORKS command output.This command uses the same variables and data formats as the configuration file. See example wpa_supplicant.conf for more details.
LIST_NETWORKS command output.CTRL-REQ- (WPA_CTRL_REQ macro) in an unsolicited event message. An external program, e.g., a GUI, can provide such information by using CTRL-RSP- (WPA_CTRL_RSP macro) prefix in a command with matching field name.The following fields can be requested in this way from the user:
CTRL-REQ-<field name>-<network id>-<human readable text> CTRL-RSP-<field name>-<network id>-<value>
For example, request from wpa_supplicant:
CTRL-REQ-PASSWORD-1-Password needed for SSID test-network
And a matching reply from the GUI:
CTRL-RSP-PASSWORD-1-secret
Example request/reply pairs:
GET_CAPABILITY eap AKA FAST GTC LEAP MD5 MSCHAPV2 OTP PAX PEAP PSK SIM TLS TTLS
GET_CAPABILITY pairwise CCMP TKIP NONE
GET_CAPABILITY pairwise strict
GET_CAPABILITY group CCMP TKIP WEP104 WEP40
GET_CAPABILITY key_mgmt WPA-PSK WPA-EAP IEEE8021X NONE
GET_CAPABILITY proto RSN WPA
GET_CAPABILITY auth_alg OPEN SHARED LEAP
wlan0 eth0
1.4.2