ddns-scripts: update bind-nsupdate to json

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

net/ddns-scripts/files/usr/lib/ddns/update_nsupdate.sh

@@ -0,0 +1,48 @@
+#
+#.Distributed under the terms of the GNU General Public License (GPL) version 2.0
+#
+# The script directly updates a PowerDNS (or maybe bind server) via nsupdate from bind-client package.
+#.based on github request #957 by Jan Riechers <de at r-jan dot de>
+#.2015 Christian Schoenebeck <christian dot schoenebeck at gmail dot com>
+#
+# This script is parsed by dynamic_dns_functions.sh inside send_update() function
+#
+# using following options from /etc/config/ddns
+# option username   - keyname 
+# option password   - shared secret (base64 encoded)
+# option domain     - full qualified domain to update
+# option dns_server - DNS server to update
+#
+# variable __IP already defined with the ip-address to use for update
+#
+local __TTL=600		#.preset DNS TTL (in seconds)
+local __RRTYPE __PW __TCP
+local __PROG=$(command -v nsupdate)			# BIND nsupdate ?
+[ -z "$__PROG" ] && __PROG=$(command -v knsupdate)	# Knot nsupdate ?
+
+[ -z "$__PROG" ]     && write_log 14 "'nsupdate' or 'knsupdate' not installed !"
+[ -z "$username" ]   && write_log 14 "Service section not configured correctly! Missing 'username'"
+[ -z "$password" ]   && write_log 14 "Service section not configured correctly! Missing 'password'"
+[ -z "$dns_server" ] && write_log 14 "Service section not configured correctly! Missing 'dns_server'"
+
+[ $use_ipv6 -ne 0 ] && __RRTYPE="AAAA" || __RRTYPE="A"
+[ $force_dnstcp -ne 0 ] && __TCP="-v" || __TCP=""
+
+# create command file
+cat >$DATFILE <<-EOF
+server $dns_server
+key $username $password
+update del $domain $__RRTYPE
+update add $domain $__TTL $__RRTYPE $__IP
+show
+send
+answer
+quit
+EOF
+
+$__PROG -d $__TCP $DATFILE >$ERRFILE 2>&1
+
+# nsupdate always return success
+write_log 7 "(k)nsupdate reports:${N}$(cat $ERRFILE)"
+
+return 0