wpa_supplicant無線網絡配置

目前可以使用wireless-tools 或wpa_supplicant工具來配置無線網絡。請記住重要的一點是，對無線網絡的配置是全局性的，而非針對具體的接口。

   wpa_supplicant是一個較好的選擇，但缺點是它不支援所有的驅動。請浏覽wpa_supplicant網站獲得它所支援的驅動清單。另外，wpa_supplicant目前隻能連接配接到那些你已經配置好ESSID的無線網絡。wireless-tools支援幾乎所有的無線網卡和驅動，但它不能連接配接到那些隻支援WPA的AP。

    經過編譯後的wpa_supplicant源程式可以看到兩個主要的可執行工具：wpa_supplicant和wpa_cli。wpa_supplicant是核心程式，它和wpa_cli的關系就是服務和用戶端的關系：背景運作wpa_supplicant，使用wpa_cli來搜尋、設定、和連接配接網絡。

       如何用wpa_supplicant使能一個wifi連接配接？

Step by step：

1、運作wpa_supplicant程式；

執行：/system/bin/wpa_supplicant -d -Dwext -iwlan0 -c/data/misc/wifi/wpa_supplicant.conf

其中：

-d ：增加調試資訊

-Dwext ：wext，驅動名稱

-iwlan0 ：wlan0，網絡接口名稱

/system/bin/wpa_supplicant ：wpa_supplicant可執行程式path

/data/misc/wifi/wpa_supplicant.conf ：wpa_supplicant的配置檔案path

2、運作指令行工具wpa_cli ；

執行 ：wpa_cli -iwlan0 -p/data/system/wpa_supplicant

注，-p/data/system/wpa_supplicant中的wpa_supplicant并不是可執行程式，而是個控制套接字。

此時會進入互動模式。其中互動模式的指令如下表：

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

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

設定網絡的基本格式：set_network <network id> <key> <parameter> [<parameter>]

顯示網絡資訊的基本格式：get_network <network id> <key>

相應的參數如下表：

Key

Parameters

ssid

Access point name

string

id_str

String identifying the network

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)

wep_key0

WEP key (up to 4: wep_key[0123])

eap

Extensible Authentication Protocol

MD5, MSCHAPV2, OTP, GTC, TLS, PEAP, TTLS

identity

EAP identity string

password

EAP password

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、連接配接無加密的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、連接配接WEP加密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、連接配接WPA-PSK/WPA2-PSK加密的AP

>add_network   (assume return 2)

>set_network 2 ssid "666"

>set_network 2 psk "your pre-shared key"

>enable_network 2

到此，wifi子產品就能連接配接上AP了。

3、以上是通過指令行工具wpa_cli來實作wifi網絡的連接配接。當然，也可以通過wpa_supplicant的配置檔案來實作連接配接。

再回顧下運作wpa_supplicant時執行的指令：

/system/bin/wpa_supplicant -d -Dwext -iwlan0 -c/data/misc/wifi/wpa_supplicant.conf

我們在執行時加上了-c/data/misc/wifi/wpa_supplicant.conf，我們可以将我們要連接配接的AP的設定以一定的格式寫入wpa_supplicant.conf配置檔案中即可。

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"

}