Multiple udhcpc processes

For Developers
1

In the OpenWRT system, whenever an interface is up and configured in DHCP mode to allocate an IP address, a udhcpc process is triggered to be responsible for the IP address lease application and management of that interface. for axample

udhcpc -p /var/run/udhcpc-eth1.pid -s /lib/netifd/dhcp.script -f -t 0 -i eth1 -x hostname:OpenWrt -C -R -O 12

This results in the need for multiple udhcpc processes in the case of multiple interfaces.

Is there a way to modify it so that only one DHCP process is responsible for IP address allocation for all interfaces?

2

I don't believe so. What's the particular issue with how it operates at the moment?

3

udhcp (busybox) is different from dhcpcd , it is available as a package, but not integrated with netifd scripts.

4

i mean, for example,in ubuntu, systemd-networkd (which is similar to netifd) contains its own in-built DHCP client implementation so no external DHCP clients would be started unless they're configured elsewhere.

maybe it works more efficiently

5

If you want it you can instrument udhcpcd in netifd scripts, otherwise it works as you documented - new daemon for 2nd interface in the rather unbelievable case of 2 dhcp client interfaces.

6

OpenWRT isn't ubuntu. And, in any event, something being done differently by a different OS doesn't indicate any problem or issue with OpenWRT.

Is there an actual issue you have or have seen from the use of multiple instances of udhcpc?

7

well, in the case of multiple interfaces, the system needs to start multiple instances of the same executable program. I am worried about the waste of system resources and overload. For example, when I create 4000 vlan interfaces, 4000 udhcpc processes may be required to run at the same time

8

Have you created or started 4000 vlan interfaces? Have you had any issues with system resources or overloads because of udhcpc?

9

But you are welcome to integrate dhcpcd with netifd scripts.