Improve DNS diagnostics

This set of changes should make debugging kresd easier. The part with verbose logging is a bit hacky but we need to get things moving quickly to enable diagnosing problems with Google services.

diagnostics/modules/dns.module

@@ -4,7 +4,30 @@ help="
 gather dns related informations
 "
 
+run_prefix () {
+	echo "Attempting to resolve ${1}"
+}
+
+run_dig () {
+	run_prefix "${1}"
+	dig @127.0.0.1 +dnssec "${1}"
+}
+
+run_nslookup () {
+	run_prefix "${1}"
+	nslookup "${1}" 127.0.0.1
+}
+
 run () {
+	# dig has richer output format
+	which dig &> /dev/null
+	if [ "$?" -eq 0 ]
+	then
+		QTOOL="dig"
+	else
+		QTOOL="nslookup"
+	fi
+
 	# resolver config
 	uci -q show resolver
 	echo
@@ -23,15 +46,15 @@ run () {
 	RESOLVER="$(uci get resolver.common.prefered_resolver)"
 	ps w | grep ${RESOLVER}
 
-	# try to resolve some server
-	nslookup api.turris.cz 127.0.0.1  # should pass
-	nslookup www.rhybar.cz 127.0.0.1  # should fail
-	nslookup *.wilda.rhybar.0skar.cz 127.0.0.1  # should fail
-	nslookup *.wilda.nsec.0skar.cz 127.0.0.1  # should pass
-	nslookup *.wild.nsec.0skar.cz 127.0.0.1  # should pass
-	nslookup *.wilda.0skar.cz 127.0.0.1  # should pass
-	nslookup *.wild.0skar.cz 127.0.0.1  # should pass
-	nslookup www.wilda.nsec.0skar.cz 127.0.0.1  # should pass
-	nslookup www.wilda.0skar.cz 127.0.0.1  # should pass
-	nslookup *.wilda.rhybar.ecdsa.0skar.cz 127.0.0.1  # should fail
+	echo "== resolution attempts =="
+	run_${QTOOL} api.turris.cz  # should pass
+	run_${QTOOL} www.rhybar.cz  # should fail
+	run_${QTOOL} *.wilda.rhybar.0skar.cz  # should fail
+	run_${QTOOL} *.wilda.nsec.0skar.cz  # should pass
+	run_${QTOOL} *.wild.nsec.0skar.cz  # should pass
+	run_${QTOOL} *.wilda.0skar.cz  # should pass
+	run_${QTOOL} *.wild.0skar.cz  # should pass
+	run_${QTOOL} www.wilda.nsec.0skar.cz  # should pass
+	run_${QTOOL} www.wilda.0skar.cz  # should pass
+	run_${QTOOL} *.wilda.rhybar.ecdsa.0skar.cz  # should fail
 }