From 2daa8aa6892d990d12c50bf16095dac0e1f179c7 Mon Sep 17 00:00:00 2001
From: Christian Poessinger <christian@poessinger.com>
Date: Fri, 10 Dec 2021 22:10:10 +0100
Subject: wwan: T3795: only run ModemManager when interface is in use

(cherry picked from commit a8ebb4817955b3f33f773a4d05c753dfc77958cd)
---
 src/conf_mode/interfaces-wwan.py | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

(limited to 'src')

diff --git a/src/conf_mode/interfaces-wwan.py b/src/conf_mode/interfaces-wwan.py
index f013e5411..7fdd0d447 100755
--- a/src/conf_mode/interfaces-wwan.py
+++ b/src/conf_mode/interfaces-wwan.py
@@ -17,6 +17,7 @@
 import os
 
 from sys import exit
+from time import sleep
 
 from vyos.config import Config
 from vyos.configdict import get_interface_dict
@@ -28,10 +29,14 @@ from vyos.util import cmd
 from vyos.util import call
 from vyos.util import dict_search
 from vyos.util import DEVNULL
+from vyos.util import is_systemd_service_active
+from vyos.template import render
 from vyos import ConfigError
 from vyos import airbag
 airbag.enable()
 
+service_name = 'ModemManager.service'
+
 def get_config(config=None):
     """
     Retrive CLI config as dictionary. Dictionary can never be empty, as at least the
@@ -44,6 +49,20 @@ def get_config(config=None):
     base = ['interfaces', 'wwan']
     wwan = get_interface_dict(conf, base)
 
+    # We need to know the amount of other WWAN interfaces as ModemManager needs
+    # to be started or stopped.
+    conf.set_level(base)
+    wwan['other_interfaces'] = conf.get_config_dict([], key_mangling=('-', '_'),
+                                                    get_first_key=True,
+                                                    no_tag_node_value_mangle=True)
+
+    # This if-clause is just to be sure - it will always evaluate to true
+    ifname = wwan['ifname']
+    if ifname in wwan['other_interfaces']:
+        del wwan['other_interfaces'][ifname]
+    if len(wwan['other_interfaces']) == 0:
+        del wwan['other_interfaces']
+
     return wwan
 
 def verify(wwan):
@@ -64,6 +83,18 @@ def generate(wwan):
     return None
 
 def apply(wwan):
+    if not is_systemd_service_active(service_name):
+        cmd(f'systemctl start {service_name}')
+
+        counter = 100
+        # Wait until a modem is detected and then we can continue
+        while counter > 0:
+            counter -= 1
+            tmp = cmd('mmcli -L')
+            if tmp != 'No modems were found':
+                break
+            sleep(0.250)
+
     # we only need the modem number. wwan0 -> 0, wwan1 -> 1
     modem = wwan['ifname'].lstrip('wwan')
     base_cmd = f'mmcli --modem {modem}'
@@ -73,6 +104,11 @@ def apply(wwan):
     w = WWANIf(wwan['ifname'])
     if 'deleted' in wwan or 'disable' in wwan:
         w.remove()
+
+        # There are no other WWAN interfaces - stop the daemon
+        if 'other_interfaces' not in wwan:
+            cmd(f'systemctl stop {service_name}')
+
         return None
 
     ip_type = 'ipv4'
@@ -93,6 +129,9 @@ def apply(wwan):
     call(command, stdout=DEVNULL)
     w.update(wwan)
 
+    if 'other_interfaces' not in wwan and 'deleted' in wwan:
+        cmd(f'systemctl start {service_name}')
+
     return None
 
 if __name__ == '__main__':
-- 
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