vyos.util: provide single implementation for get_json_iface_options()

There had been four implementations of "ip -d -j link show interface" scattered
accross the codebase. Those implementations have now been combined into a new
helper:

vyos.util.get_json_iface_options()

6 files changed, 28 insertions, 69 deletions

diff --git a/python/vyos/util.py b/python/vyos/util.py
index ab5029c92..17a7dda91 100644
--- a/python/vyos/util.py
+++ b/python/vyos/util.py
@@ -645,3 +645,13 @@ def dict_search(path, dict):
     for p in parts[:-1]:
         c = c.get(p, {})
     return c.get(parts[-1], None)
+
+def get_json_iface_options(interface):
+    """ Returns the used encapsulation protocol for given interface.
+        If interface does not exist, None is returned.
+    """
+    if not os.path.exists(f'/sys/class/net/{interface}'):
+        return None
+    from json import loads
+    tmp = loads(cmd(f'ip -d -j link show {interface}'))[0]
+    return tmp
diff --git a/smoketest/scripts/cli/base_interfaces_test.py b/smoketest/scripts/cli/base_interfaces_test.py
index 1426e80c2..0c6f43427 100644
--- a/smoketest/scripts/cli/base_interfaces_test.py
+++ b/smoketest/scripts/cli/base_interfaces_test.py
@@ -14,7 +14,6 @@
 
 import os
 import unittest
-import json
 
 from binascii import hexlify
 
@@ -30,6 +29,7 @@ from vyos.util import read_file
 from vyos.util import cmd
 from vyos.util import dict_search
 from vyos.util import process_named_running
+from vyos.util import get_json_iface_options
 from vyos.validate import is_intf_addr_assigned
 from vyos.validate import is_ipv6_link_local
 
@@ -317,7 +317,7 @@ class BasicInterfaceTest:
 
             for interface in self._interfaces:
                 for vif_s in self._qinq_range:
-                    tmp = json.loads(cmd(f'ip -d -j link show dev {interface}.{vif_s}'))[0]
+                    tmp = get_json_iface_options(f'{interface}.{vif_s}')
                     self.assertEqual(dict_search('linkinfo.info_data.protocol', tmp), '802.1ad')
 
                     for vif_c in self._vlan_range:
diff --git a/smoketest/scripts/cli/test_interfaces_erspan.py b/smoketest/scripts/cli/test_interfaces_erspan.py
index d0814f2fb..cbb41d0c9 100755
--- a/smoketest/scripts/cli/test_interfaces_erspan.py
+++ b/smoketest/scripts/cli/test_interfaces_erspan.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2020 VyOS maintainers and contributors
+# Copyright (C) 2020-2021 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -15,20 +15,15 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import unittest
-import json
 
 from vyos.configsession import ConfigSession
 from vyos.configsession import ConfigSessionError
-from vyos.util import cmd
+from vyos.util import get_json_iface_options
 
 from base_interfaces_test import BasicInterfaceTest
 
 mtu = 1500
 
-def erspan_conf(interface):
-    tmp = cmd(f'ip -d -j link show {interface}')
-    return json.loads(tmp)[0]
-
 class ERSPanTunnelInterfaceTest(BasicInterfaceTest.BaseTest):
     def setUp(self):
         super().setUp()
@@ -57,7 +52,7 @@ class ERSPanTunnelInterfaceTest(BasicInterfaceTest.BaseTest):
 
         self.session.commit()
 
-        conf = erspan_conf(interface)
+        conf = get_json_iface_options(interface)
         self.assertEqual(interface, conf['ifname'])
         self.assertEqual(encapsulation, conf['linkinfo']['info_kind'])
         self.assertEqual(mtu, conf['mtu'])
@@ -78,7 +73,7 @@ class ERSPanTunnelInterfaceTest(BasicInterfaceTest.BaseTest):
 
         self.session.commit()
 
-        conf = erspan_conf(interface)
+        conf = get_json_iface_options(interface)
         self.assertEqual(interface, conf['ifname'])
         self.assertEqual(encapsulation, conf['linkinfo']['info_kind'])
         self.assertEqual(mtu, conf['mtu'])
diff --git a/smoketest/scripts/cli/test_interfaces_macsec.py b/smoketest/scripts/cli/test_interfaces_macsec.py
index d6bef993a..2f1898b6f 100755
--- a/smoketest/scripts/cli/test_interfaces_macsec.py
+++ b/smoketest/scripts/cli/test_interfaces_macsec.py
@@ -25,6 +25,7 @@ from vyos.configsession import ConfigSessionError
 from vyos.ifconfig import Section
 from vyos.util import cmd
 from vyos.util import read_file
+from vyos.util import get_json_iface_options
 from vyos.util import process_named_running
 
 def get_config_value(interface, key):
@@ -33,13 +34,7 @@ def get_config_value(interface, key):
     return tmp[0]
 
 def get_cipher(interface):
-    """ Returns the used encapsulation protocol for given interface.
-        If interface does not exist, None is returned.
-    """
-    if not os.path.exists(f'/sys/class/net/{interface}'):
-        return None
-    from json import loads
-    tmp = loads(cmd(f'ip -d -j link show {interface}'))[0]
+    tmp = get_json_iface_options(interface)
     return tmp['linkinfo']['info_data']['cipher_suite'].lower()
 
 class MACsecInterfaceTest(BasicInterfaceTest.BaseTest):
diff --git a/smoketest/scripts/cli/test_interfaces_tunnel.py b/smoketest/scripts/cli/test_interfaces_tunnel.py
index cc8fbd527..b5ee3e412 100755
--- a/smoketest/scripts/cli/test_interfaces_tunnel.py
+++ b/smoketest/scripts/cli/test_interfaces_tunnel.py
@@ -15,11 +15,10 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import unittest
-import json
 
 from vyos.configsession import ConfigSession
 from vyos.configsession import ConfigSessionError
-from vyos.util import cmd
+from vyos.util import get_json_iface_options
 from vyos.template import inc_ip
 
 from base_interfaces_test import BasicInterfaceTest
@@ -29,38 +28,6 @@ remote_ip6 = '2001:db8::ffff'
 source_if = 'dum2222'
 mtu = 1476
 
-def tunnel_conf(interface):
-    tmp = cmd(f'ip -d -j link show {interface}')
-    # {'address': '2.2.2.2',
-    #  'broadcast': '192.0.2.10',
-    #  'flags': ['POINTOPOINT', 'NOARP', 'UP', 'LOWER_UP'],
-    #  'group': 'default',
-    #  'gso_max_segs': 65535,
-    #  'gso_max_size': 65536,
-    #  'ifindex': 10,
-    #  'ifname': 'tun10',
-    #  'inet6_addr_gen_mode': 'none',
-    #  'link': None,
-    #  'link_pointtopoint': True,
-    #  'link_type': 'gre',
-    #  'linkinfo': {'info_data': {'local': '2.2.2.2',
-    #                             'pmtudisc': True,
-    #                             'remote': '192.0.2.10',
-    #                             'tos': '0x1',
-    #                             'ttl': 255},
-    #               'info_kind': 'gre'},
-    #  'linkmode': 'DEFAULT',
-    #  'max_mtu': 65511,
-    #  'min_mtu': 68,
-    #  'mtu': 1476,
-    #  'num_rx_queues': 1,
-    #  'num_tx_queues': 1,
-    #  'operstate': 'UNKNOWN',
-    #  'promiscuity': 0,
-    #  'qdisc': 'noqueue',
-    #  'txqlen': 1000}
-    return json.loads(tmp)[0]
-
 class TunnelInterfaceTest(BasicInterfaceTest.BaseTest):
     @classmethod
     def setUpClass(cls):
@@ -117,7 +84,7 @@ class TunnelInterfaceTest(BasicInterfaceTest.BaseTest):
             # Check if commit is ok
             self.session.commit()
 
-            conf = tunnel_conf(interface)
+            conf = get_json_iface_options(interface)
             if encapsulation not in ['sit', 'gretap']:
                 self.assertEqual(source_if, conf['link'])
 
@@ -160,7 +127,7 @@ class TunnelInterfaceTest(BasicInterfaceTest.BaseTest):
             # Check if commit is ok
             self.session.commit()
 
-            conf = tunnel_conf(interface)
+            conf = get_json_iface_options(interface)
             self.assertEqual(interface, conf['ifname'])
             self.assertEqual(mtu, conf['mtu'])
             self.assertEqual(source_if, conf['link'])
@@ -218,7 +185,7 @@ class TunnelInterfaceTest(BasicInterfaceTest.BaseTest):
         # Check if commit is ok
         self.session.commit()
 
-        conf = tunnel_conf(interface)
+        conf = get_json_iface_options(interface)
         self.assertEqual(mtu,           conf['mtu'])
         self.assertEqual(interface,     conf['ifname'])
         self.assertEqual(encapsulation, conf['linkinfo']['info_kind'])
@@ -240,7 +207,7 @@ class TunnelInterfaceTest(BasicInterfaceTest.BaseTest):
         # Check if commit is ok
         self.session.commit()
 
-        conf = tunnel_conf(interface)
+        conf = get_json_iface_options(interface)
         self.assertEqual(mtu,           conf['mtu'])
         self.assertEqual(interface,     conf['ifname'])
         self.assertEqual(encapsulation, conf['linkinfo']['info_kind'])
@@ -254,7 +221,7 @@ class TunnelInterfaceTest(BasicInterfaceTest.BaseTest):
         # Check if commit is ok
         self.session.commit()
 
-        conf = tunnel_conf(interface)
+        conf = get_json_iface_options(interface)
         self.assertEqual(new_remote,    conf['linkinfo']['info_data']['remote'])
 
 if __name__ == '__main__':
diff --git a/src/conf_mode/interfaces-tunnel.py b/src/conf_mode/interfaces-tunnel.py
index 2d2f29f94..0ffff06a1 100755
--- a/src/conf_mode/interfaces-tunnel.py
+++ b/src/conf_mode/interfaces-tunnel.py
@@ -34,22 +34,12 @@ from vyos.ifconfig import Interface
 from vyos.ifconfig import TunnelIf
 from vyos.template import is_ipv4
 from vyos.template import is_ipv6
-from vyos.util import cmd
+from vyos.util import get_json_iface_options
 from vyos.util import dict_search
 from vyos import ConfigError
 from vyos import airbag
 airbag.enable()
 
-def get_tunnel_encapsulation(interface):
-    """ Returns the used encapsulation protocol for given interface.
-        If interface does not exist, None is returned.
-    """
-    if not os.path.exists(f'/sys/class/net/{interface}'):
-        return None
-    from json import loads
-    tmp = loads(cmd(f'ip -d -j link show {interface}'))[0]
-    return tmp['linkinfo']['info_kind']
-
 def get_config(config=None):
     """
     Retrive CLI config as dictionary. Dictionary can never be empty, as at least
@@ -111,7 +101,9 @@ def apply(tunnel):
     # If a gretap tunnel is already existing we can not "simply" change local or
     # remote addresses. This returns "Operation not supported" by the Kernel.
     # There is no other solution to destroy and recreate the tunnel.
-    encap = get_tunnel_encapsulation(interface)
+    encap = ''
+    tmp = get_json_iface_options(interface)
+    if tmp: encap = dict_search('linkinfo.info_kind', tmp)
 
     if 'deleted' in tunnel or 'encapsulation_changed' in tunnel or encap == 'gretap':
         if interface in interfaces():