It was changed to use "LOG_NOTICE" since 2019-04-16. What's your OpenWrt version?
There is a script /usr/sbin/odhcpd-update that can cause SIGHUP to be sent to dnsmasq. Dnsmasq will kill cache and reload. odhcpd-update . This was controlled by uci option dhcp.odhcpd.leasetrigger
I rebooted the router last night to make sure it wasn't something transient. This morning the log file is completely full, just those messages repeated, over and over.
Thanks! Interesting that the bug report has been open for a year and hasn't even been commented on.
I would think (assuming the config reload is a required, benign and not exploitable through DoS) the fix would be to have these messages suppressed by the UCI 'quietdhcp' flag. I would certainly not call this behaviour 'quiet' it makes trying to trace actual problems in the log very difficult.
Yes, as I noted in my posted: I'm using a pretty large adblock list, so the system load during the reload is not insignificant and /could/ be used as a DoS attack
I am seeing the same "odhcpd" messages in my system, but they do not trigger a "dnsmasq" reload.
I do not have a "config odhcpd 'odhcpd'" section at "/etc/config/dhcp" (do I need one?), and browsing the contents of "/usr/sbin/odhcpd-update", I see a suspicious "procd_send_signal dnsmasq" command there.
I must admit to not knowing the internals of DHCP on linux all that well, particularly for IPv6. I'm running davidc502's build for WRT32X and with IPv6 enabled it seems to be the standard config to dnsmasq and odhcpd both running and I have the " config odhcpd 'odhcpd' " entry in my " /etc/config/dhcp "
If it's possible to do v4 and v6 DHCP from the same daemon, it would make sense to do so, I imagine!
So my understanding is that dnsmasq was the 'original' combined DNS and DHCP server for OpenWRT because it had a smaller footprint than odhcp. However odhcp was introduced to allow DHCPv6 support.
Was there any logic to the decision of keeping dnsmasq doing DHCP(v4) instead of moving it all to odhcp?
There is a guide here on how to make dnsmasq do DNS/RA only and setup odhcp to service DHCPv4 and DHCPv6
edit - well actually they are two separate guides, one on disabling dnsmasq's DHCP function and one on removing dnsmasq and installing odhcp for DHCPv4 and v6. With a bit of mix and match it should be possible to have dnsmasq do DNS only and odhcp do all DHCP.
I can't try this right now, but generally it should go...
uci set dhcp.lan.ignore="1"
uci commit dhcp
service dnsmasq restart
service odhcpd restart
Then
opkg update
opkg remove odhcpd-ipv6only
opkg install odhcpd
uci set dhcp.lan.dhcpv4="server"
uci set dhcp.odhcpd.maindhcp="1"
uci commit dhcp
service odhcpd restart
Mainly because dnsmasq does not allow for dynamic IPv6 prefix management. You either need to let it handle everything autonomously, breaking many system integrations or you have to frequently pregenerate updated configs for it and restart the process, leading to a loss of state.