commit 37825d9db59c7266dc73466b33958be085788221
Author: Sándor <sandros@noreply.localhost>
Date:   Fri Feb 23 19:56:21 2024 +0100

    Add check_dnsbl.sh

diff --git a/check_dnsbl.sh b/check_dnsbl.sh
new file mode 100644
index 0000000..e4477ac
--- /dev/null
+++ b/check_dnsbl.sh
@@ -0,0 +1,50 @@
+#!/bin/bash
+
+# Test if any IP4 and IP6 addresses of a hostname blocked on a DNSBL
+# 2024-02-23
+# by Sandros
+
+# Parameter check
+if [[ $# -ne 2 ]]; then
+    echo "Usage: ./${0##*/} <hostname> <blacklist service>"
+    exit 1
+fi
+
+# Get IPs
+IPS=$(dig +short $1 A | sort -u)
+IP6S=$(dig +short $1 AAAA | sort -u)
+
+IPSP=""
+
+# Prepare IP4 addresses
+if [ ! -z "$IPS" ]; then
+        for IP in $IPS; do
+                # Check IP format
+                if [[ ! ${IP##*[[:space:]]} =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
+                        # skip if invalid
+                        continue
+                fi
+
+                # Reverse IP octet order
+                IPSP="$IPSP $(sed -r 's/([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9]+)/\4.\3.\2.\1/' <<< ${IP##*[[:space:]]})."
+        done
+fi
+
+# Prepare IP6 addresses
+if [ ! -z "$IP6S" ]; then
+        for IP6 in $IP6S; do
+                IPSP="$IPSP $(sipcalc $IP6 | fgrep Expanded | cut -d '-' -f 2 | sed 's/://g' | rev | sed 's/[0-9a-f]/&./g')"
+        done
+fi
+
+# Loop through IPs
+listed=0
+for IP in $IPSP; do
+        # Performs the actual lookup against blacklists
+        if host -W 2 -t a $IP$2 >/dev/null 2>&1; then
+                ((listed++))
+        fi
+done
+
+echo $listed
+exit 0
\ No newline at end of file