From bd217f066655aca116f99f7c1fa949bf3293494b Mon Sep 17 00:00:00 2001
From: Franziska Kunsmann <hi@kunsmann.eu>
Date: Thu, 10 Dec 2020 16:14:17 +0100
Subject: [PATCH] bundles/pppd: automatically restart pppoe (once per hour) if
 no public ip address can be found

---
 .../pppd/files/restart-pppoe-if-no-public-ip  | 46 +++++++++++++++++++
 bundles/pppd/items.py                         |  3 ++
 bundles/pppd/metadata.py                      |  4 ++
 nodes/home/router.py                          |  2 +-
 4 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 bundles/pppd/files/restart-pppoe-if-no-public-ip

diff --git a/bundles/pppd/files/restart-pppoe-if-no-public-ip b/bundles/pppd/files/restart-pppoe-if-no-public-ip
new file mode 100644
index 0000000..04e1fcd
--- /dev/null
+++ b/bundles/pppd/files/restart-pppoe-if-no-public-ip
@@ -0,0 +1,46 @@
+#!/usr/bin/env python3
+
+from datetime import datetime
+from ipaddress import ip_address
+from subprocess import run
+from sys import exit
+
+import netifaces
+
+now = int(datetime.timestamp(datetime.utcnow()))
+
+try:
+    with open('/var/tmp/pppd-last-restart.status', 'r') as f:
+        last_restart = int(f.read().strip())
+except:
+    last_restart = 0
+
+if now-3600 < last_restart:
+    print('Last restart is less than an hour ago, exiting ...')
+    exit(0)
+
+ifaces = set()
+for i in netifaces.interfaces():
+    if i.startswith('ppp'):
+        ifaces.add(i)
+
+system_has_public_ip = False
+for iface in ifaces:
+    for type in [netifaces.AF_INET, netifaces.AF_INET6]:
+        for ip in netifaces.ifaddresses(iface)[type]:
+            try:
+                addr = ip_address(ip['addr'])
+
+                if not addr.is_private and not addr.is_loopback:
+                    system_has_public_ip = True
+            except:
+                # Apparently not an ip
+                pass
+
+if not system_has_public_ip:
+    run(['systemctl', 'restart', 'pppoe'])
+
+    with open('/var/tmp/pppd-last-restart.status', 'w') as f:
+        f.write(now)
+
+    print('pppoe.service has been restarted')
diff --git a/bundles/pppd/items.py b/bundles/pppd/items.py
index c281c74..3f4395a 100644
--- a/bundles/pppd/items.py
+++ b/bundles/pppd/items.py
@@ -81,6 +81,9 @@ files = {
             'svc_systemd:pppoe:restart',
         },
     },
+    '/usr/local/bin/restart-pppoe-if-no-public-ip': {
+        'mode': '0755',
+    },
 }
 
 if 'dyndns' in node.metadata['pppd']:
diff --git a/bundles/pppd/metadata.py b/bundles/pppd/metadata.py
index 909dfe3..ca29ca4 100644
--- a/bundles/pppd/metadata.py
+++ b/bundles/pppd/metadata.py
@@ -4,7 +4,11 @@ defaults = {
             'ppp': {},
             'pppoe': {},
             'python3-requests': {},
+            'python3-netifaces': {},
             'ndisc6': {},
         },
     },
+    'cron': {
+        'restart-pppoe-if-no-public-ip': '*/5 * * * *    root    /usr/local/bin/restart-pppoe-if-no-public-ip',
+    },
 }
diff --git a/nodes/home/router.py b/nodes/home/router.py
index e2706f1..997d42d 100644
--- a/nodes/home/router.py
+++ b/nodes/home/router.py
@@ -41,7 +41,7 @@ nodes['home.router'] = {
             # connected longer than 24 hours. We install this cronjob
             # to make sure we don't get disconnected randomly during the
             # day.
-            'restart_pppd': '23 2 * * *    root    systemctl restart pppoe',
+            'restart_pppd': '23 2 * * *    root    systemctl restart pppoe && date -u +%s > /var/tmp/pppd-last-restart.status',
         },
         'dhcpd': {
             'subnets': {