From 8975e81c7e5ee56a41ee64780381fee63cb5eea8 Mon Sep 17 00:00:00 2001
From: NCLtech <philgibbons@ncltech.org>
Date: Sat, 7 Sep 2024 23:47:28 +0100
Subject: [PATCH] Added additional function to check and report when the VPN
 connectivity is restored

---
 run_check.sh | 91 +++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 75 insertions(+), 16 deletions(-)

diff --git a/run_check.sh b/run_check.sh
index 831af2f..a053ea3 100755
--- a/run_check.sh
+++ b/run_check.sh
@@ -1,14 +1,17 @@
 #!/bin/bash
 
 # Mullvad_VPN_Check
-# A script that checks for a Mullvad VPN connection and if there isn't one, will send and alert
-
+# A script that checks for a Mullvad VPN connection, logs the status,
+# and sends alerts if the VPN status changes.
 
 # Set Discord webhook
 WEBHOOK_URL="DISCORD_WEBHOOK_URL"
 
-# Function to run alert
-run_alert() {
+# Temp file to store the VPN connection status
+STATUS_FILE="/tmp/vpn_status.log"
+
+# Function to send VPN down alert
+vpn_down_alert() {
 curl -H "Content-Type: application/json" -X POST --data @- "$WEBHOOK_URL" <<EOF
 {
   "content": null,
@@ -38,29 +41,85 @@ curl -H "Content-Type: application/json" -X POST --data @- "$WEBHOOK_URL" <<EOF
 EOF
 }
 
-# Function to check if "mullvad_exit_ip" is false
-check_mullvad_exit_ip() {
+# Function to send VPN restored alert
+vpn_up_alert() {
+curl -H "Content-Type: application/json" -X POST --data @- "$WEBHOOK_URL" <<EOF
+{
+  "content": null,
+  "embeds": [
+    {
+      "title": "VPN Connectivity - RESTORED",
+      "description": "\"$(hostname)\" is now going through a Mullvad VPN connection",
+      "color": 3066993,
+      "fields": [
+        {
+          "name": "Date and Time of Test:",
+          "value": "$(date +'%Y-%m-%d %H:%M:%S')"
+        },
+        {
+          "name": "Current ISP",
+          "value": "$ORG"
+        },
+        {
+          "name": "Current IP",
+          "value": "$IP"
+        }
+      ]
+    }
+  ],
+  "attachments": []
+}
+EOF
+}
+
+# Function to check the VPN status and act accordingly
+check_vpn_status() {
     mullvad_exit_ip="$1"
+
+    # Check the current status (true for VPN, false for no VPN)
     if [ "$mullvad_exit_ip" = "false" ]; then
-        run_alert
-        echo "Alert sent!"
+        echo "VPN not connected, sending alert..."
+        
+        # Send alert if VPN was connected last time
+        if [ "$previous_status" = "true" ]; then
+            vpn_down_alert
+            echo "VPN down alert sent!"
+        fi
+
+        # Log the current status
+        echo "false" > "$STATUS_FILE"
     else
-        echo "VPN connection through Mullvad detected."
-        exit 1 # Exit with error code to indicate condition not met
+        echo "VPN connected."
+
+        # Send a "VPN restored" alert if VPN was not connected last time
+        if [ "$previous_status" = "false" ]; then
+            vpn_up_alert
+            echo "VPN restored alert sent!"
+        fi
+
+        # Log the current status
+        echo "true" > "$STATUS_FILE"
     fi
 }
 
-# Fetch JSON data
+# Fetch JSON data from Mullvad API
 json=$(curl -s https://ipv4.am.i.mullvad.net/json)
 
-# Get Reported IP
+# Get Reported IP and ISP
 IP=$(echo "$json" | grep -oE '"ip":\s*"[^"]+"' | grep -oE '[0-9.]+')
-# Get Reported ISP
 ORG=$(echo "$json" | grep -oP '(?<="organization":")[^"]+')
 
-# Parse JSON and extract "mullvad_exit_ip"
+# Parse JSON and extract "mullvad_exit_ip" (true if VPN, false if not)
 mullvad_exit_ip=$(jq -r '.mullvad_exit_ip' <<< "$json")
 
-# Check if "mullvad_exit_ip" is false
-check_mullvad_exit_ip "$mullvad_exit_ip"
+# Check if the status log file exists, if not create it with a default value (false)
+if [ ! -f "$STATUS_FILE" ]; then
+    echo "false" > "$STATUS_FILE"
+fi
+
+# Read the previous VPN status from the log file
+previous_status=$(cat "$STATUS_FILE")
+
+# Check the current VPN status and take action
+check_vpn_status "$mullvad_exit_ip"