Merge pull request #2769 from pi-hole/new/arp-flush

Add new "pihole arpflush" command

advanced/Scripts/piholeARPTable.sh

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+# shellcheck disable=SC1090
+
+# Pi-hole: A black hole for Internet advertisements
+# (c) 2019 Pi-hole, LLC (https://pi-hole.net)
+# Network-wide ad blocking via your own hardware.
+#
+# ARP table interaction
+#
+# This file is copyright under the latest version of the EUPL.
+# Please see LICENSE file for your rights under this license.
+
+coltable="/opt/pihole/COL_TABLE"
+if [[ -f ${coltable} ]]; then
+    source ${coltable}
+fi
+
+# Determine database location
+# Obtain DBFILE=... setting from pihole-FTL.db
+# Constructed to return nothing when
+# a) the setting is not present in the config file, or
+# b) the setting is commented out (e.g. "#DBFILE=...")
+FTLconf="/etc/pihole/pihole-FTL.conf"
+if [ -e "$FTLconf" ]; then
+    DBFILE="$(sed -n -e 's/^\s*DBFILE\s*=\s*//p' ${FTLconf})"
+fi
+# Test for empty string. Use standard path in this case.
+if [ -z "$DBFILE" ]; then
+    DBFILE="/etc/pihole/pihole-FTL.db"
+fi
+
+
+flushARP(){
+    local output
+    if [[ "${args[1]}" != "quiet" ]]; then
+        echo -ne "  ${INFO} Flushing network table ..."
+    fi
+
+    # Flush ARP cache to avoid re-adding of dead entries
+    if ! output=$(ip neigh flush all 2>&1); then
+        echo -e "${OVER}  ${CROSS} Failed to clear ARP cache"
+        echo "  Output: ${output}"
+        return 1
+    fi
+
+    # Truncate network_addresses table in pihole-FTL.db
+    # This needs to be done before we can truncate the network table due to
+    # foreign key contraints
+    if ! output=$(sqlite3 "${DBFILE}" "DELETE FROM network_addresses" 2>&1); then
+        echo -e "${OVER}  ${CROSS} Failed to truncate network_addresses table"
+        echo "  Database location: ${DBFILE}"
+        echo "  Output: ${output}"
+        return 1
+    fi
+
+    # Truncate network table in pihole-FTL.db
+    if ! output=$(sqlite3 "${DBFILE}" "DELETE FROM network" 2>&1); then
+        echo -e "${OVER}  ${CROSS} Failed to truncate network table"
+        echo "  Database location: ${DBFILE}"
+        echo "  Output: ${output}"
+        return 1
+    fi
+
+    if [[ "${args[1]}" != "quiet" ]]; then
+        echo -e "${OVER}  ${TICK} Flushed network table"
+    fi
+}
+
+args=("$@")
+
+case "${args[0]}" in
+    "arpflush"            ) flushARP;;
+esac