[LEDE-DEV] Trouble with dnsmasq

[e9hack]

Hi,

I've some trouble with dnsmasq since the last kernel update but it isn't an issue of the kernel. After reboot (or
sysupgrade), dnsmasq isn't able to do a name resolution of hosts provided by the host file:

Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: read /tmp/hosts/dhcp.cfg02411c - 0 addresses

The file contains 5 entries. I did add some logger calls and check the syslog:

Tue Nov 21 22:18:16 2017 user.notice [DNSMASQ:790]: start boot()
Tue Nov 21 22:18:16 2017 user.notice [DNSMASQ:790]: start start_service()
Tue Nov 21 22:18:16 2017 user.notice [DNSMASQ:790]: end start_service()
Tue Nov 21 22:18:17 2017 user.notice [DNSMASQ:790]: end boot()
Tue Nov 21 22:18:37 2017 user.notice [DNSMASQ:1061]: start reload_service()
Tue Nov 21 22:18:37 2017 user.notice [DNSMASQ:1061]: start start_service()
Tue Nov 21 22:18:39 2017 user.notice [DNSMASQ:1061]: echo "# auto-generated config file from /etc/config/dhcp" >
/tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:18:44 2017 user.notice [DNSMASQ:1061]: echo "192.168.a.b HOST1" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:18:44 2017 user.notice [DNSMASQ:1061]: echo "192.168.a.b HOST2" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:18:44 2017 user.notice [DNSMASQ:1061]: echo "192.168.a.b HOST3" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:18:44 2017 user.notice [DNSMASQ:1061]: echo "192.168.a.b HOST4" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:21:32 2017 user.notice [DNSMASQ:1061]: echo "192.168.a.b HOST5" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:21:38 2017 user.notice [DNSMASQ:1061]: end start_service()
Tue Nov 21 22:21:40 2017 user.notice [DNSMASQ:1061]: end reload_service()
Tue Nov 21 22:21:41 2017 user.notice [DNSMASQ:1430]: start reload_service()
Tue Nov 21 22:21:41 2017 user.notice [DNSMASQ:1430]: start start_service()
Tue Nov 21 22:21:41 2017 user.notice [DNSMASQ:1430]: echo "# auto-generated config file from /etc/config/dhcp" >
/tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: started, version 2.79test1-2-g6fd5d79 cachesize 150
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: compile time options: IPv6 GNU-getopt no-DBus no-i18n no-IDN DHCP
DHCPv6 no-Lua TFTP no-conntrack no-ipset auth DNSSEC no-ID loop-detect inotify
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq-dhcp[1410]: DHCP, IP range 192.168.a.b -- 192.168.a.b, lease time 2d
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain test
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain onion
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain localhost
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain local
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain invalid
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain example.net
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain example.org
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain example.com
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using 3 more local addresses
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: reading /tmp/resolv.conf.auto
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain test
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain onion
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain localhost
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain local
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain invalid
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain example.net
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain example.org
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using local addresses only for domain example.com
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using nameserver 192.168.a.b#53
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using nameserver fec0:a:b:c:d:e#53
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using nameserver fec0:a:b:c:d:f#53
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: using 3 more local addresses
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: read /etc/hosts - 1 addresses
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq[1410]: read /tmp/hosts/dhcp.cfg02411c - 0 addresses
Tue Nov 21 22:21:42 2017 daemon.info dnsmasq-dhcp[1410]: read /etc/ethers - 0 addresses
Tue Nov 21 22:21:42 2017 user.notice [DNSMASQ:1430]: echo "192.168.a.b HOST1" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:21:42 2017 user.notice [DNSMASQ:1430]: echo "192.168.a.b HOST2" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:21:42 2017 user.notice [DNSMASQ:1430]: echo "192.168.a.b HOST3" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:21:42 2017 user.notice [DNSMASQ:1430]: echo "192.168.a.b HOST4" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:21:42 2017 user.notice [DNSMASQ:1430]: echo "192.168.a.b HOST5" >> /tmp/hosts/dhcp.cfg02411c
Tue Nov 21 22:21:43 2017 user.notice [DNSMASQ:1430]: end start_service()
Tue Nov 21 22:21:43 2017 user.notice [DNSMASQ:1430]: end reload_service()

It look likes that reload_service()/start_service() is called twice. The first call generates the host file properly and
starts dnsmasq. Before dnsmasq is able to read the host file, the second call of reload_service()/start_service()
overwrites the host file. Now the host file contains the first line only, which is a comment.

Independently of this, the reload_service()/start_service() functions are called every 2..10min which
overwrites/generates the host file again.

Any idea?

Regards,
Hartmut