WiFi wpa_ Detailed description of supplicant hostpad interface

wpa_supplicant/hostapd yes Linux Next use as sta/ap Interface for network card operation , The project is basically completed , Organize here .

One 、wpa_supplicant part

wpa_supplicant It's a connection 、 To configure WIFI Tools for . It mainly includes two programs ：wpa_supplicant And wpa_cli. The relationship between the two is server And client The relationship between . Usually , We can go through wpa_cli To carry out WIFI Configuration and connection of , If there is a special need , You can write an application to call directly wpa_supplicant Direct development of interfaces .
This article mainly talks about how to pass wpa_cli Conduct WIFI Configuration and connection of .

2. Usage method
2.1 start-up wpa_supplicant application
wpa_supplicant -D nl80211 -i wlan0 -c /etc/wpa_supplicant.conf -B
Be careful ：/etc/wpa_supplicant.conf In the document , Add the following code .

ctrl_interface=/var/run/wpa_supplicant
update_config=1

2.2 start-up wpa_cli application

 wpa_cli -i wlan0 scan              Search the neighborhood wifi The Internet 
 wpa_cli -i wlan0 scan_result       Print search wifi Network results 
 wpa_cli -i wlan0 add_network       Add a network connection 

2.21 Such as If you want to connect, the encryption method is ：[WPA-PSK-CCMP+TKIP][WPA2-PSK-CCMP+TKIP][ESS] (wpa encryption ) wifi The name is ：wifi_name wifi The password is ：wifi_psk

 wpa_cli -i wlan0 set_network 0 ssid '"wifi_name"'
 wpa_cli -i wlan0 set_network 0 psk '"wifi_psk"'
 wpa_cli -i wlan0 enable_network 0

2.22 If you want to connect, the encryption method is ：[WEP][ESS] (wep encryption )
wifi The name is ：wifi_name
wifi The password is ：wifi_psk

 wpa_cli -i wlan0 set_network 0 ssid '"wpa_name"'
 wpa_cli -i wlan0 set_network 0 key_mgmt NONE
 wpa_cli -i wlan0 set_network 0 wep_key0 '"wap_psk"'
 wpa_cli -i wlan0 enable_network 0

2.23 If you want to connect, the encryption method is ：[ESS] ( No encryption )
wifi The name is ：wifi_name

 wpa_cli -i wlan0 set_network 0 ssid '"wifi_name"'
 wpa_cli -i wlan0 set_network 0 key_mgmt NONE
 wpa_cli -i wlan0 enable_network 0

2.3 Distribute ip,netmask,gateway,dns
udhcpc -i wlan0 -s /etc/udhcpc.script -q

completion of enforcement , You can connect to the network .

2.4 Save connection
wpa_cli -i wlan0 save_config
2.5 disconnect
wpa_cli -i wlan0 disable_network 0
2.6 Connect to an existing connection

$ wpa_cli -i wlan0 list_network              List all saved connections 
$ wpa_cli -i wlan0 select_network 0          Connect the 1 A saved connection 
$ wpa_cli -i wlan0 enable_network 0          Enabling section 1 A saved connection 

2.7 To break off wifi

$ ifconfig wlan0 down
$ killall udhcpc
$ killall wpa_supplicant

Two 、 hostapd part
hostapd yes Host Access Point Daemon , Provide information on Linux The strength of wireless access points WPA2 Encryption and authentication .
To configure hostapd It's simple , It supports WPA2-Personal and Enterprise, Provide for the right to WPA2-Personal Unique modification of , It can make managing it more complex or simpler .

udhcpd -f /etc/wificfg/udhcpd.conf &
hostapd -t /etc/wificfg/hostapd.conf	&

/*************************************************************************************************************************/

3、 ... and 、 Actual operation script ：
The above is a memo written according to your usual work , Query usage ; Remember the following sta/ap The operation of , And several configuration files under embedded ：
1. wpa-supplicant Common operation ：

wpa_supplicant -D nl80211 -i wlan0 -c/home/ky/wpa_supplicant.conf -B
wpa_cli -i wlan0 scan
wpa_cli -i wlan0 scan_result 
wpa_cli -i wlan0 add_network
wpa_cli -i wlan0 set_network 0 ssid '"ky"'
wpa_cli -i wlan0 set_network 0 psk '"12345678"'
wpa_cli -i wlan0 enable_network 0
udhcpc -i wlan0

wpa_cli -i wlan0 disable_network 0
wpa_cli -i wlan0 disable_network 1
wpa_cli -i wlan3 remove_network 0

wpa_cli -i wlan0 save_config
wpa_cli -i wlan0 list_network             
wpa_cli -i wlan0 select_network 2
wpa_cli -i wlan0 enable_network 2
udhcpc -i wlan0

wpa_supplicant.conf Profile contents ：

ctrl_interface=/var/run/wpa_supplicant
update_config=1

network={
    
        ssid="hky"
        psk="12345678"
}

2.hostapd Shoushun ：
ap The model is relatively simple

udhcpd -f /etc/wificfg/udhcpd.conf &
hostapd -t /etc/wificfg/hostapd.conf	&

udhcpd.conf Profile contents ： It is similar to the router configuration interface
It is worth noting that Lease documents (lease_file ) This configuration file , Usually based on /var/tmp/ In the catalog ,WiFi AP The mode cannot be assigned IP Maybe this file was not created , use touch Just build one

start           192.168.219.2
end             192.168.219.254
interface		wlan1
lease_file      /etc/wificfg/udhcpd.lease
opt     dns     168.95.1.1 192.168.10.2 192.168.10.10
option  subnet  192.168.0.0	netmask 255.255.255.0
opt     router  192.168.10.2
opt     wins    192.168.10.10
option  dns     129.219.13.81
option  domain  local
option  lease   864000

hostapd.conf Profile contents : Formulated the AP Of ssid password encryption a/b/g/n Etc , Of course, the working mode can also be WiFi Module commands to change

#
# This will give you a minimal, insecure wireless network.
# 
# DO NOT BE SATISFIED WITH THAT!!!
#
# A complete, well commented example configuration file is
# available here:
#
#	/usr/share/doc/hostapd/hostapd.conf
#
# For more information, look here:
#
# http://wireless.kernel.org/en/users/Documentation/hostapd
# ctrl_interface=/var/run/hostapd
ctrl_interface_group=root

# Some usable default settings...
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0

# Uncomment these for base WPA & WPA2 support with a pre-shared key
wpa=2
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

# DO NOT FORGET TO SET A WPA PASSPHRASE!!
wpa_passphrase=12345678

# Most modern wireless drivers in the kernel need driver=nl80211
driver=nl80211

# Customize these for your local configuration...
interface=wlan1
hw_mode=g
channel=11
ssid=ssidtest

over 了