DHCP not working for Rooted Android

I have read on the web that DHCP no longer works on Android device that has been rooted.

The suggested solution is to remove files under /data/misc/dhcp.
This solution did not work for me.

So, the correct way to do is to analyze what was wrong.

You will need adb shell access to your phone.
Start DHCP and see what the error says :

1|shell@ms013g:/ $ dhcpcd wlan0                                               
dhcpcd[20547]: open `/data/misc/dhcp/dhcpcd-wlan0.pid': Permission denied
dhcpcd[20547]: version 5.5.6 starting
dhcpcd[20547]: ipv6rs: Operation not permitted
dhcpcd[20547]: wlan0: if_init: Permission denied
dhcpcd[20547]: wlan0: interface not found or invalid
 
The error complains about permission access to PID file. This file records the PID of DHCP client. If the client is not running, then this file needs to be deleted.

The next log shows what was wrong with DHCP :


root@ms013g:/ # dhcpcd wlan0
dhcpcd[20789]: version 5.5.6 starting
dhcpcd[20790]: /system/etc/dhcpcd/dhcpcd-run-hooks: Permission denied
dhcpcd[20791]: /system/etc/dhcpcd/dhcpcd-run-hooks: Permission denied
dhcpcd[20789]: wlan0: waiting for carrier

^Cdhcpcd[20789]: received SIGINT, stopping
dhcpcd[20789]: wlan0: removing interface









1|root@ms013g:/ # cd /system/etc/dhcpcd/                                      
root@ms013g:/system/etc/dhcpcd # ls -al
drwxr-xr-x system   system            2014-01-10 16:33 dhcpcd-hooks
-r-xr-x--- system   system       1009 2014-01-10 16:33 dhcpcd-run-hooks
 
We need to change this run hooks permission to 555. My next problem is that /system is mounted read only. Need to change it first to Read Write :

mount -o remount,rw /dev/block/platform/msm_sdcc.1/by-name/system /system
 
root@ms013g:/system/etc/dhcpcd # mount | grep system                          
/dev/block/platform/msm_sdcc.1/by-name/system /system ext4 rw,seclabel,relatime,errors=panic,data=ordered 0 0
 
root@ms013g:/system/etc/dhcpcd # chmod 555 dhcpcd-run-hooks                   
root@ms013g:/system/etc/dhcpcd # ls -al
drwxr-xr-x system   system            2014-01-10 16:33 dhcpcd-hooks
-r-xr-xr-x system   system       1009 2014-01-10 16:33 dhcpcd-run-hooks
 
root@ms013g:/system/etc/dhcpcd # dhcpcd wlan0
dhcpcd[20855]: version 5.5.6 starting
dhcpcd[20855]: wlan0: waiting for carrier
dhcpcd[20855]: wlan0: carrier acquired
dhcpcd[20855]: wlan0: sending IPv6 Router Solicitation
dhcpcd[20855]: wlan0: sendmsg: Network is unreachable
dhcpcd[20855]: wlan0: rebinding lease of 192.168.200.58
dhcpcd[20855]: wlan0: acknowledged 192.168.200.58 from 192.168.200.17
dhcpcd[20855]: wlan0: checking for 192.168.200.58
dhcpcd[20855]: wlan0: sending IPv6 Router Solicitation
dhcpcd[20855]: wlan0: sendmsg: Network is unreachable
dhcpcd[20855]: wlan0: leased 192.168.200.58 for 43200 seconds
dhcpcd[20855]: forked to background, child pid 20985