unbound: improve startup and dhcp script robustness

- prevent rapid overlap in DHCP script updates
- check and allow localhost forwards with specific applications
- add option for rate limiting inbound queries
- change UCI list to table format with Unbound conf references

Signed-off-by: Eric Luehrsen <ericluehrsen@gmail.com>

net/unbound/files/iptools.sh

@@ -82,7 +82,7 @@ domain_ptr_ip4() {
 ##############################################################################
 
 host_ptr_ip4() {
-  # Get omplete host ...in-addr.arpa.
+  # Get complete host ...in-addr.arpa.
   echo "$1" | awk -F. \
   '{ x = ( $4"."$3"."$2"."$1".in-addr.arpa" ) ;
   sub(/\/[0-9]+/,"",x) ;
@@ -136,6 +136,7 @@ valid_subnet_any() {
     echo "not"
   fi
 }
+
 ##############################################################################
 
 private_subnet() {
@@ -152,6 +153,17 @@ private_subnet() {
 
 ##############################################################################
 
+local_subnet() {
+  # local subnet 2nd place is limited to one digit to improve the filter
+  case "$1" in
+    127"."[0-9]"."[0-9]*) echo "ok" ;;
+    ::1) echo "ok" ;;
+    *) echo "not" ;;
+  esac
+}
+
+##############################################################################
+
 domain_ptr_any() {
   local subnet=$1
   local arpa validip4 validip6