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Opened 21 months ago

Last modified 21 months ago

#22300 new defect

Network + DHCP not working - dnsmasq fails to start

Reported by: zzz2002 Owned by: developers
Priority: normal Milestone: Designated Driver (Trunk)
Component: base system Version: Trunk
Keywords: Cc:

Description

Updated to 2016-04-26 sysupgrade snapshot for WNDR3700v2.
Could not get any connection through the router or from the router to the WAN/DMZ.
Syslog shows errors DNSMASQ fails to start with "dnsmasq" unknown user or group.
I added "dnsmasq" to both passwd and group (used same parms as network for entry in passwd). dnsmasq will now start, but connections problems persist. It looks as though there is no rout through the router, as I can get from the router to the WAN ... with this change.
Unfortunately could not do any further testing as needed to get router up.
Reverted to earlier binary.
Was unable to capture logs or config.

Attachments (0)

Change History (5)

comment:1 follow-up: Changed 21 months ago by anonymous

I see there was a change entitled "dnsmasq: run as dedicated UID/GID".
I took a quick look at the commit and in it they are using the user & group id of dnsmasq.
I cannot find the user dnsmasq being setup in either passwd or group files.
I assume that it is supposed to be setup by somebody, somewhere.

comment:2 in reply to: ↑ 1 Changed 21 months ago by hnyman

Replying to anonymous:

I see there was a change entitled "dnsmasq: run as dedicated UID/GID".
I took a quick look at the commit and in it they are using the user & group id of dnsmasq.
I cannot find the user dnsmasq being setup in either passwd or group files.
I assume that it is supposed to be setup by somebody, somewhere.

Yes, it is. Defined in the Makefile and the the installation routine creates the user and group.
https://dev.openwrt.org/browser/trunk/package/network/services/dnsmasq/Makefile?rev=49252#L37

This bug is duplicate of #22271, #22277 and #22278.
Info also at https://forum.openwrt.org/viewtopic.php?id=64476

49252 breaks things in a major way in a sysupgrade with settings preserved, as dnsmasq does not start after the sysupgrade and that breaks DNS and DHCP.

If a router is flashed with a new firmware with revision >= 49252 and the old settings are saved during the sysupgrade, the new firmware will expect to find the user "dnsmasq" in /etc/password and /etc/shadow as well as the group "dnsmasq" in /etc/group but as those values are not found in the saved old settings, dnsmasq does not start and all connectivity breaks down. (The required values were created to the new settings files in the firmware itself, but you overwrote the new files by the old saved settings.)

I fixed my own router by manually copying /rom/etc/passwd, /rom/etc/shadow and /rom/etc/group to /etc (and rebooting)

other possible fixes:
1) use "firstboot" command to reset the router, or select Reset in Luci.
2) manually edit those three files and add the lines shown in comment 1 of bug #22271

comment:3 Changed 21 months ago by anonymous

da.., looks as though I will have to do a clean install. that gives me a problem as I cannot get the VLANs to setup correctly. Its something I am doing wrong but I cannot work out what it is.
OH well, baack on head!!

comment:4 Changed 21 months ago by anonymous

Its time I did a clean install!!!!

comment:5 Changed 21 months ago by zzz2002

Can we mark this as closed

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