dnsmasq: dhcp-script option not working

[potchin]

Model | Raspberry Pi 4 Model B Rev 1.4
Architecture | ARMv8 Processor rev 3
Target Platform | bcm27xx/bcm2711
Firmware Version | OpenWrt 22.03.0-rc1 r19302-df622768da / LuCI openwrt-22.03 branch git-22.083.69105-af8e91c
Kernel Version | 5.10.111
dnsmasq - 2.86-13

Adding the dhcp-script option to /etc/dnsmasq.conf always results in an error rather than the script being called. For example, setting..

dhcp-script = /bin/echo

will result in...

Sun May  8 19:47:23 2022 daemon.err dnsmasq[1]: failed to execute /bin/echo: No such file or directory

Just for sanity...

root@gateway:/etc# ls -l /bin/echo
lrwxrwxrwx    1 root     root             7 Apr 20 11:37 /bin/echo -> busybox
root@gateway:/etc# which echo
/bin/echo
root@gateway:/etc# echo test
test

Link to the openwrt documentation which mentions this feature.

This is a regression from 21.02, I have been using this option previously

[dave14305]

It’s a ujail issue perhaps. dnsmasq can’t access the file if it’s outside of its permitted ujail mounts.

Why not use the uci dhcp config option dhcpscript?

[potchin]

I found that there's a directory already available (/etc/hotplug.d/dhcp) which I can just drop scripts in so I have changed my setup to use that now, thanks for the suggestion.

Its probably worth updating the documentation nonetheless, especially as its a regression from 21.02

[jow-]

Mention of dhcp-script removed from the linked wiki page