Wpa_supplicant Wireless Network Configuration

 

Currently, you can use wireless-tools or wpa_supplicant to configure the wireless network. Remember that the configuration of the wireless network is global, not for specific interfaces.

 

Wpa_supplicant is a good choice, but its disadvantage is that it does not support all drivers. Go to the wpa_supplicant website to obtain the list of supported drivers. In addition, wpa_supplicant can only connect to wireless networks with Essid configured. Wireless-tools supports almost all wireless NICs and drivers, but it cannot connect to those APs that only support WPA.

The compiled wpa_supplicant source code shows two main executable tools: wpa_supplicant and wpa_cli. Wpa_supplicant is the core program, and its relationship with wpa_cli is the relationship between the service and the client: wpa_supplicant is run in the background, and wpa_cli is used to search, set, and connect to the network.

How can I use wpa_supplicant to enable a Wi-Fi connection?

Step by step:

1. Run the wpa_supplicant program;

 

Run:/system/bin/wpa_supplicant-D-dwext-iwlan0-C/data/MISC/WiFi/wpa_supplicant.conf

Where:

-D: Add debugging information

-Dwext: wext, driver name

-Iwlan0: wlan0, Network Interface Name

/System/bin/wpa_supplicant: wpa_supplicant executable program path

/Data/MISC/WiFi/wpa_supplicant.conf: Path of the configuration file wpa_supplicant

2. Run the command line tool wpa_cli;

Run: wpa_cli-iwlan0-P/data/system/wpa_supplicant

Note: wpa_supplicant in-P/data/system/wpa_supplicant is not an executable program, but a control socket.

The interactive mode is displayed. The interactive mode commands are as follows:

 

 

Full command	Short command	Description
Status	Stat	Displays the current connection status
Disconnect	Disc	Prevents wpa_supplicant from connecting to any Access Point
Quit	Q	Exits wpa_cli
Terminate	Term	Kills wpa_supplicant
Reconfigure	Recon	Reloads wpa_supplicant with the configuration file supplied (-C parameter)
Scan	Scan	Scans for available access points (only scans it, doesn' t display anything)
Scan_result	Scan_r	Displays the results of the last scan
List_networks	List_n	Displays a list of configured networks and their status (active or not, enabled or disabled)
Select_network	Select_n	Select a network among those defined to initiate a connection (ie select_network 0)
Enable_network	Enable_n	Makes a configured network available for selection (ie enable_network 0)
Disable_network	Disable_n	Makes a configured network unavailable for selection (ie disable_network 0)
Remove_network	Remove_n	Removes a network and its configuration from the List (ie remove_network 0)
Add_network	Add_n	Adds a new network to the list. Its ID will be created automatically
Set_network	Set_n	Shows a very short list of available options to configure a network when supplied with no parameters. See next section for a list of extremely useful parameters to be used with set_network and get_network.
Get_network	Get_n	Displays the required parameter for the specified network. see next section for a list of parameters
Save_config	Save_c	Saves the configuration

 

Set the basic network format: set_network <network ID> <key> <parameter> [<parameter>]

Basic Format for displaying network information: get_network <network ID> <key>

The following table lists the corresponding parameters:

 

 

Key	Description	Parameters
SSID	Access Point name	String
Id_str	String identifying the network	String
Priority	Connection priority over other APs	Number (0 being the default low priority)
Bssid	MAC address of the Access Point	MAC address
Scan_ssid	Enable/disbale SSID Scan	0, 1, 2
Key_mgmt	Type of key management	WPA-PSK, wpa_eap, none
Pairwise	Pairwise ciphers for WPA	CCMP, TKIP
Group = TKIP	Group ciphers for WPA	CCMP, TKIP, wep104, wep40
PSK	Pre-shared key (clear or encrypted)	String
Wep_key0	WEP Key (up to 4: wep_key [0123])	String
EAP	Extensible Authentication Protocol	MD5, mschapv2, OTP, GTC, TLS, PEAP, ttls
Identity	EAP identity string	String
Password	EAP Password	String
Ca_cert	Pathname to CA certificate file	/Full/path/to/certificate
Client_cert	Pathname to client certificate	/Full/path/to/certificate (PEM/der)
Private_key	Pathname to a client Private Key File	/Full/path/to/private_key (PEM/der/pfx)

 

 

Eg.1 connect to unencrypted AP

> Add_network (it will display a network ID for you, assume it returns 0)

> Set_network 0 SSID "666"

> Set_network 0 key_mgmt none

> Enable_network 0

> Quit

Eg.2 connect to the WEP encrypted AP

> Add_network (assume return 1)

> Set_network 1 SSID "666"

> Set_network 1 key_mgmt none

> Set_network 1 wep_key0 "your AP password"

> Enable_network 1

Eg.3, connect WPA-PSK/WPA2-PSK encrypted AP

> Add_network (assume return 2)

> Set_network 2 SSID "666"

> Set_network 2 PSK "your pre-shared key"

> Enable_network 2

At this point, the WiFi module can connect to the AP.

3. Use the command line tool wpa_cli to connect to the Wi-Fi network. Of course, you can also use the wpa_supplicant configuration file to connect.

Review the Command executed when running wpa_supplicant:

/System/bin/wpa_supplicant-D-dwext-iwlan0-C/data/MISC/WiFi/wpa_supplicant.conf

We added-C/data/MISC/WiFi/wpa_supplicant.conf during execution. We can write the settings of the AP we want to connect to in a certain format into the wpa_supplicant.conf configuration file.

Eg.

Ctrl_interface = dir =/data/system/wpa_supplicant group = system update_config = 1

Network = {

SSID = "my access point"

PROTO = WPA

Key_mgmt = WPA-PSK

PSK = "you pass words"

}

Wpa_supplicant Wireless Network Configuration