Udhcpc environment values

fans1314 · September 24, 2021, 10:58am

recently, i see the doc: https://udhcp.busybox.net/README.udhcpc
i can`t understand how these udhcpc environment values are from? where they are be created? ex:

router - A list of routers
dns - A list of DNS server

Thanks!

vgaetera · September 24, 2021, 11:19am

fans1314 · September 26, 2021, 12:54am

i still cannot understand where these environment values are from?

vgaetera · September 26, 2021, 1:32am

github.com

openwrt/openwrt/blob/master/package/network/config/netifd/files/lib/netifd/proto/dhcp.sh#L66-L68

    
      
          	proto_run_command "$config" udhcpc \
          		-p /var/run/udhcpc-$iface.pid \
          		-s /lib/netifd/dhcp.script \

github.com

openwrt/openwrt/blob/master/package/network/config/netifd/files/lib/netifd/dhcp.script#L113-L114

    
      
          # user rules
          [ -f /etc/udhcpc.user ] && . /etc/udhcpc.user "$@"

fans1314 · September 26, 2021, 2:01am

sorry for that, i still cannot understand it?
and i want to add customized dns address to udhcpc`s events, how i do it?

Thanks!

vgaetera · September 26, 2021, 2:03am

https://openwrt.org/docs/guide-user/base-system/dhcp_configuration#upstream_dns_provider

mrhaav · September 26, 2021, 2:12pm

Can you explain a little bit more what you want to do?
Have you seen this thread?

I use udhcpc.user to update my DNS via LoopiaAPI.
Every time the router renew the IP address from my ISP, udhcpc.user is triggered.