dnsmasq: pass environment variables to hotplug

dnsmasq passes a limited amount of information via DHCP script arguments. Much
more information is available through environment variables starting with
DNSMASQ_, such as DNSMASQ_INTERFACE. However, when the dhcp-script builds its
JSON environment and passes it to hotplug, all of this information is discarded
since it is not copied to the JSON environment.

Personally, I have a custom-made set of DDNS scripts and rely on environment
variables such as DNSMASQ_INTERFACE in order to determine which DNS zones
to update. So, not being able to access these variables was detrimental to me.
I patched in a quick copy of all DNSMASQ_ variables to the JSON environment
so that they can be used in hotplug scripts. In order to do so I also copied
/usr/bin/env into dnsmasq's chroot jail.

Signed-off-by: Chuck R <github@chuck.cloud>

Link: https://github.com/openwrt/openwrt/pull/16354
Signed-off-by: John Crispin <john@phrozen.org>
This commit is contained in:
Chuck R 2024-09-08 14:28:06 -05:00 committed by John Crispin
parent 794291bbdf
commit 36f309af05
2 changed files with 10 additions and 1 deletions

View File

@ -8,6 +8,15 @@ json_init
json_add_array env
hotplugobj=""
oldIFS=$IFS
IFS=$'\n'
for var in $(env); do
if [ "${var}" != "${var#DNSMASQ_}" ]; then
json_add_string "" "${var%%=*}=${var#*=}"
fi
done
IFS=$oldIFS
case "$1" in
add | del | old | arp-add | arp-del)
json_add_string "" "MACADDR=$2"

View File

@ -20,7 +20,7 @@ BASEDHCPSTAMPFILE="/var/run/dnsmasq"
DHCPBOGUSHOSTNAMEFILE="/usr/share/dnsmasq/dhcpbogushostname.conf"
RFC6761FILE="/usr/share/dnsmasq/rfc6761.conf"
DHCPSCRIPT="/usr/lib/dnsmasq/dhcp-script.sh"
DHCPSCRIPT_DEPENDS="/usr/share/libubox/jshn.sh /usr/bin/jshn /bin/ubus"
DHCPSCRIPT_DEPENDS="/usr/share/libubox/jshn.sh /usr/bin/jshn /bin/ubus /usr/bin/env"
DNSMASQ_DHCP_VER=4