`action.d/bsd-ipfw.conf`: fixed selection of rule-no by large list or initial `lowest_rule_num`, exit code can't be larger than 255 (gh-2836)

ChangeLog

@@ -52,6 +52,7 @@ ver. 0.10.6-dev (20??/??/??) - development edition
    with `jq`, gh-2140, gh-2656)
 * `action.d/nftables.conf` (type=multiport only): fixed port range selector, replacing `:` with `-` (gh-2763)
 * `action.d/firewallcmd-*.conf` (multiport only): fixed port range selector, replacing `:` with `-` (gh-2821)
+* `action.d/bsd-ipfw.conf`: fixed selection of rule-no by large list or initial `lowest_rule_num` (gh-2836)
 * `filter.d/common.conf`: avoid substitute of default values in related `lt_*` section, `__prefix_line`
   should be interpolated in definition section (inside the filter-config, gh-2650)
 * `filter.d/courier-smtp.conf`: prefregex extended to consider port in log-message (gh-2697)

config/action.d/bsd-ipfw.conf

@@ -14,7 +14,10 @@
 # Notes.:  command executed on demand at the first ban (or at the start of Fail2Ban if actionstart_on_demand is set to false).
 # Values:  CMD
 #
-actionstart = ipfw show | fgrep -c -m 1 -s 'table(<table>)' > /dev/null 2>&1 || ( ipfw show | awk 'BEGIN { b = <lowest_rule_num> } { if ($1 < b) {} else if ($1 == b) { b = $1 + 1 } else { e = b } } END { if (e) exit e <br> else exit b }'; num=$?; ipfw -q add $num <blocktype> <block> from table\(<table>\) to me <port>; echo $num > "<startstatefile>" )
+actionstart = ipfw show | fgrep -c -m 1 -s 'table(<table>)' > /dev/null 2>&1 || (
+    num=$(ipfw show | awk 'BEGIN { b = <lowest_rule_num> } { if ($1 < b) {} else if ($1 == b) { b = $1 + 1 } else { e = b } } END { if (e) print e <br> else print b }');
+    ipfw -q add "$num" <blocktype> <block> from table\(<table>\) to me <port>; echo "$num" > "<startstatefile>"
+  )
 
 
 # Option:  actionstop