wifi获取不到IP地址

如果supplicant已经启动，在连接具体AP时一直处于获取IP地址的状态，则很可能是dhcpcd服务没有启动，dhcpcd没有启动可以修改init.rc。将dhcpcd_eth0服务，wpa_supplicant服务放在zygote服务之下执行。如下：
service zygote /system/bin/app_process -Xzygote /system/bin --zygote --start-system-server
        socket zygote stream 666
        onrestart write /sys/android_power/request_state wake
        onrestart write /sys/power/state on
        onrestart restart media
        onrestart restart netd

service wifi_up /system/bin/ifconfig eth0 up
        disabled
        oneshot

service wifi_down /system/bin/ifconfig eth0 down
        disabled
        oneshot

# modify and add for wifi dhcp serivce
service dhcpcd_eth0 /system/bin/logwrapper /system/bin/dhcpcd -f /system/etc/dhcpcd/dhcpcd.conf -d -B eth0
        user root
        group wifi inet
     disabled
     oneshot
   
# add service for wifi
service wpa_supplicant /system/bin/logwrapper /system/bin/wpa_supplicant \
                        -Dwext -ieth0 -c/system/etc/wifi/wpa_supplicant.conf
        user root
        group wifi inet
        socket wpa_eth0 dgram 660 wifi wifi
        oneshot
如果dhcpcd启动不了，也可以检查WifiStateTracker.java中的mInterfaceName是否正确，如果驱动定义的接口为eth0，则mInterfaceName也应该为eth0。
如果不是eth0，则因该检查init.rc中是否有setprop wifi.interface eth0的配置。