WIFI STA and AP Bridging Introduction

1. Configuration Modification¶

Kernel config:

make menuconfig
1:
Networking support -> Wireless:
<*> cfg80211 - wireless configuration API
2:
Device Drivers->Generic Driver options
[*] Support for uevent helper
3:
Networking support → Networking options
<M> 802.1d Ethernet Bridging

SSD21x: Modify project/kbuild/customize/4.9.84/p3/dispcam/kernel_mod_list_late

SSD20x: Modify project/kbuild/4.9.84/i2m/configs/nvr/011A/glibc/8.2.1/xxx/modules/kernel_mod_list

Add llc.ko, stp.ko and bridge.ko in turn.

2. Board Modification¶

0: modify /appconfigs/wpa_supplicant.conf, and add the information of external AP,
/ # vi appconfigs/wpa_supplicant.conf
ctrl_interface=/tmp/wifi/run/wpa_supplicant
update_config=1

network={
    ssid="aryl iPhone"
    psk="123456789a"
}

1. Load the driver

   cd /config/wifi
   
   mkdir -p /tmp/wifi/run/wpa_supplicant
   
   insmod llc.ko
   insmod stp.ko
   insmod bridge.ko
   

2. Add a configuration to hostapd.conf

   interface=p2p0 //ssw101/2b uses p2p0 as ap interface.
   bridge=br0  //fixed
   hw_mode=g  //fixed
   channel=1
   

   Note: The front and back of the channel used for bridging are the same, wlan0 is connected to the ap channel, and the corresponding channel must be filled in here.

3. Add environment variables.

   Add the so file used by wifi to the system. Generally it is export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/lib:pwd under /config/wifi

4. Initialize wifi

   ssd20x series reference script ./ssw01blnit.sh

   ssd21x series reference script ./sigma_wifi_init.sh

   Note: sh: write error: Invalid argument can be ignored.

5. Establish network adaptor bridging

   ifconfig wlan0 up
   ifconfig p2p0 up
   ifconfig wlan0 0.0.0.0
   ifconfig p2p0 0.0.0.0
   brctl addbr br0
   brctl addif br0 wlan0
   brctl addif br0 p2p0
   ifconfig br0 up
   

6. Connect wifi to sta

   ./wpa_supplicant -Dnl80211 -i wlan0 -c /appconfigs/wpa_supplicant.conf -b br0 &
   udhcpc -S /etc/init.d/udhcpc.script -i br0
   

7. Open AP mode

   ./hostapd -B /config/wifi/hostapd.conf
   ./dnsmasq -i p2p0 --no-daemon -C /config/wifi/dnsmasq.conf &
   

AP:

SSID: ssw101bap

pwd: 12345678

If sta connect to WAN successfully, it can also link network normally when pc connected to ssw101bap.

Note: When sta is connected to wifi, it prompts wlan0 is not sta mode, it may be that the wifi driver and the kernel do not match. Please find the corresponding wifi module manufacturer to provide a new ko.