feat: detect VPN status

3 files changed, 66 insertions, 0 deletions

diff --git a/Common/net.py b/Common/net.py
new file mode 100644
index 0000000..126bb5c
--- /dev/null
+++ b/Common/net.py
@@ -0,0 +1,54 @@
+"""
+Networking Stuff.
+"""
+
+import requests
+import socket
+
+
+def is_vpn_connected():
+    """
+    Determine whether our VPN is connected. Checks whether our IP address
+    comes from a pool of public addresses associated with our VPN provider.
+
+    @return: is_vpn_connected - Connection Status [Bool]
+    """
+
+    # List of public IPs associated with VPN nodes.
+    vpn_list = load_vpn_list()
+
+    # Resolve using socket to avoid getting an IPv6 address
+    r = requests.get("http://%s" % socket.gethostbyname('icanhazip.com'))
+    ip = r.text.split()[0]
+
+    if ip in vpn_list:
+        return True
+    else:
+        return False
+
+
+def load_vpn_list(fname='vpn_list'):
+    """
+    Load list of external IP addresses associated with a VPN provider.
+
+    Format is one IP per line, i.e.
+    1.1.1.1
+    1.1.1.2
+    ...
+
+    See also vpn_list_example.
+
+    @param: fname      - File name for list of external IPs [String]
+    @returns: vpn_list - List of external IPs               [List of String]
+    """
+
+    # Loading gives lines = [ '1.1.1.1\n', '1.1.1.2\n' ].
+    # After stripping, gives vpn_list = [ '1.1.1.1', '1.1.1.1' ].
+    with open(fname, 'r') as f:
+        lines = f.readlines()
+        vpn_list = []
+        for line in lines:
+            vpn_list.append(line.strip())
+
+    # Return
+    return vpn_list
diff --git a/ticker.py b/ticker.py
index a75e4ef..f830a70 100644
--- a/ticker.py
+++ b/ticker.py
@@ -4,6 +4,7 @@ Read, Parse, Post Stats to InfluxDB.
 
 import Common.sensors as sensors
 import Common.influx as influx
+import Common.net as net
 
 
 # #############################################################################
@@ -12,6 +13,11 @@ import Common.influx as influx
 readings, epochs = sensors.get_netatmo_readings()
 
 # #############################################################################
+# Check VPN Status
+# #############################################################################
+is_vpn_connected = net.is_vpn_connected()
+
+# #############################################################################
 # Build Data Post
 # NB: For InfluxDB >=0.9.3, integer data points require a trailing i.
 #     For example, ncpus_allocated,parititon=cpu value=5i
@@ -28,6 +34,10 @@ for module_name, module_values in zip(readings.keys(), readings.values()):
               epochs[module_name] )
         lines.append(line)
 
+# VPN Status
+line = "is_vpn_connected value=%s" % is_vpn_connected
+lines.append(line)
+
 # Join
 data = "\n".join(lines)
 
diff --git a/vpn_list_example b/vpn_list_example
new file mode 100644
index 0000000..1499e9e
--- /dev/null
+++ b/vpn_list_example
@@ -0,0 +1,2 @@
+1.1.1.1
+1.1.1.2