dnsmasq: write atomic host file

Different invocations of the dnsmasq init script (e.g. at startup by procd)
will rewrite the dhcp host file which might result into dnsmasq reading an
empty dhcp host file as it is being rewritten by the dnsmasq init script.
Let the dnsmasq init script first write to a temp dhcp host file so it does
not overwrite the contents of the existing dhcp host file.

Reported-by: Hartmut Birr <e9hack@gmail.com>
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
This commit is contained in:
Hans Dedecker 2017-12-07 10:11:50 +01:00
parent 94fcd92913
commit a39ddff428
2 changed files with 6 additions and 4 deletions

View File

@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
PKG_NAME:=dnsmasq
PKG_VERSION:=2.78
PKG_RELEASE:=5
PKG_RELEASE:=6
PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
PKG_SOURCE_URL:=http://thekelleys.org.uk/dnsmasq/

View File

@ -294,7 +294,7 @@ dhcp_host_add() {
config_get_bool dns "$cfg" dns 0
[ "$dns" = "1" -a -n "$ip" -a -n "$name" ] && {
echo "$ip $name${DOMAIN:+.$DOMAIN}" >> $HOSTFILE
echo "$ip $name${DOMAIN:+.$DOMAIN}" >> $HOSTFILE_TMP
}
config_get mac "$cfg" mac
@ -635,7 +635,7 @@ dhcp_domain_add() {
record="${record:+$record }$name"
done
echo "$ip $record" >> $HOSTFILE
echo "$ip $record" >> $HOSTFILE_TMP
}
dhcp_srv_add() {
@ -741,6 +741,7 @@ dnsmasq_start()
CONFIGFILE="${BASECONFIGFILE}.${cfg}"
CONFIGFILE_TMP="${CONFIGFILE}.$$"
HOSTFILE="${BASEHOSTFILE}.${cfg}"
HOSTFILE_TMP="${HOSTFILE}.$$"
BASEDHCPSTAMPFILE_CFG="${BASEDHCPSTAMPFILE}.${cfg}"
# before we can call xappend
@ -751,7 +752,7 @@ dnsmasq_start()
chown dnsmasq:dnsmasq /var/run/dnsmasq
echo "# auto-generated config file from /etc/config/dhcp" > $CONFIGFILE_TMP
echo "# auto-generated config file from /etc/config/dhcp" > $HOSTFILE
echo "# auto-generated config file from /etc/config/dhcp" > $HOSTFILE_TMP
local dnsmasqconffile="/etc/dnsmasq.${cfg}.conf"
if [ ! -r "$dnsmasqconffile" ]; then
@ -998,6 +999,7 @@ dnsmasq_start()
echo >> $CONFIGFILE_TMP
mv -f $CONFIGFILE_TMP $CONFIGFILE
mv -f $HOSTFILE_TMP $HOSTFILE
[ "$resolvfile" = "/tmp/resolv.conf.auto" ] && {
rm -f /tmp/resolv.conf