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

@@ -18,6 +18,11 @@ run_nslookup () {
 	nslookup "${1}" 127.0.0.1
 }
 
+run_kresd_command () {
+	KRESD_TTY="$(uci get resolver.kresd.rundir)/tty/$(pidof kresd)"
+	echo "${1}" | socat - "unix-connect:${KRESD_TTY}"
+}
+
 run () {
 	# dig has richer output format
 	which dig &> /dev/null
@@ -46,6 +51,12 @@ run () {
 	RESOLVER="$(uci get resolver.common.prefered_resolver)"
 	ps w | grep ${RESOLVER}
 
+	if [ "${RESOLVER}" == "kresd" ]
+	then
+		echo "== enable verbose logging (reboot to disable it) =="
+		run_kresd_command "verbose(true)"
+	fi
+
 	echo "== resolution attempts =="
 	run_${QTOOL} api.turris.cz  # should pass
 	run_${QTOOL} www.rhybar.cz  # should fail