ping.py: add stricter pass/fail check

the ping test should only pass if not a single ping is lost

Change-Id: If089f77df1ffe991f26f1546558d51aac242df83

sysmocom/suites/4g/ping.py

@@ -20,6 +20,13 @@ wait(ue.is_registered)
 print('UE is attached')
 
 proc = ue.run_netns_wait('ping', ('ping', '-c', '10', epc.tun_addr()))
+
+# Check zero lost pings
+num_sent = int([x for x in proc.get_stdout().split('\n') if x.find('packets transmitted') != -1][0].split(' ')[0])
+num_received = int([x for x in proc.get_stdout().split('\n') if x.find('packets transmitted, ') != -1][0].split('packets transmitted, ')[1].split(' received')[0])
+if num_received != num_sent:
+  raise Exception("{}\n\nError: Detected {} lost pings".format(proc.get_stdout(), num_sent - num_received))
+
 output = proc.get_stdout()
 print(output)
-test.set_report_stdout(output)
+test.set_report_stdout(output)