1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
#!/usr/bin/env python3
#
# Copyright (C) 2020 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
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import os
import jinja2
from sys import exit
from copy import deepcopy
from subprocess import check_call, CalledProcessError
from vyos.config import Config
from vyos.configdict import list_diff
from vyos import ConfigError
config_file = r'/etc/iproute2/rt_tables.d/vyos-vrf.conf'
# Please be careful if you edit the template.
config_tmpl = """
### Autogenerated by vrf.py ###
#
# Routing table ID to name mapping reference
# id vrf name comment
{% for vrf in vrf_add -%}
{{ "%-10s" | format(vrf.table) }} {{ "%-16s" | format(vrf.name) }} # {{ vrf.description }}
{% endfor -%}
"""
default_config_data = {
'bind_to_all': 0,
'deleted': False,
'vrf_add': [],
'vrf_existing': [],
'vrf_remove': []
}
def _cmd(command):
"""
Run any arbitrary command on the system
"""
try:
check_call(command.split())
except CalledProcessError as e:
pass
raise ConfigError(f'Error operationg on VRF: {e}')
def interfaces_with_vrf(match):
matched = []
config = Config()
section = config.get_config_dict('interfaces')
for type in section:
interfaces = section[type]
for name in interfaces:
interface = interfaces[name]
if 'vrf' in interface:
v = interface.get('vrf', '')
if v == match:
matched.append(name)
return matched
def get_config():
conf = Config()
vrf_config = deepcopy(default_config_data)
cfg_base = ['vrf']
if not conf.exists(cfg_base):
# get all currently effetive VRFs and mark them for deletion
vrf_config['vrf_remove'] = conf.list_effective_nodes(cfg_base + ['name'])
else:
# Should services be allowed to bind to all VRFs?
if conf.exists(['bind-to-all']):
vrf_config['bind_to_all'] = 1
# Determine vrf interfaces (currently effective) - to determine which
# vrf interface is no longer present and needs to be removed
eff_vrf = conf.list_effective_nodes(cfg_base + ['name'])
act_vrf = conf.list_nodes(cfg_base + ['name'])
vrf_config['vrf_remove'] = list_diff(eff_vrf, act_vrf)
# read in individual VRF definition and build up
# configuration
for name in conf.list_nodes(cfg_base + ['name']):
vrf_inst = {
'description' : '\0',
'members': [],
'name' : name,
'table' : '',
'table_mod': False
}
conf.set_level(cfg_base + ['name', name])
if conf.exists(['table']):
# VRF table can't be changed on demand, thus we need to read in the
# current and the effective routing table number
act_table = conf.return_value(['table'])
eff_table = conf.return_effective_value(['table'])
vrf_inst['table'] = act_table
if eff_table and eff_table != act_table:
vrf_inst['table_mod'] = True
if conf.exists(['description']):
vrf_inst['description'] = conf.return_value(['description'])
# find member interfaces of this particulat VRF
vrf_inst['members'] = interfaces_with_vrf(name)
# append individual VRF configuration to global configuration list
vrf_config['vrf_add'].append(vrf_inst)
# check VRFs which need to be removed as they are not allowed to have
# interfaces attached
tmp = []
for name in vrf_config['vrf_remove']:
vrf_inst = {
'members': [],
'name' : name,
}
# find member interfaces of this particulat VRF
vrf_inst['members'] = interfaces_with_vrf(name)
# append individual VRF configuration to temporary configuration list
tmp.append(vrf_inst)
# replace values in vrf_remove with list of dictionaries
# as we need it in verify() - we can't delete a VRF with members attached
vrf_config['vrf_remove'] = tmp
return vrf_config
def verify(vrf_config):
# ensure VRF is not assigned to any interface
for vrf in vrf_config['vrf_remove']:
if len(vrf['members']) > 0:
raise ConfigError('VRF "{}" can not be deleted as it has active members'.format(vrf['name']))
# routing table id can't be changed - OS restriction
for vrf in vrf_config['vrf_add']:
if vrf['table_mod']:
raise ConfigError('VRF routing table id modification is not possible')
# add test to see if routing table already exists or not?
return None
def generate(vrf_config):
tmpl = jinja2.Template(config_tmpl)
config_text = tmpl.render(vrf_config)
with open(config_file, 'w') as f:
f.write(config_text)
return None
def apply(vrf_config):
# https://github.com/torvalds/linux/blob/master/Documentation/networking/vrf.txt
# set the default VRF global behaviour
bind_all = vrf_config['bind_to_all']
_cmd(f'sysctl -wq net.ipv4.tcp_l3mdev_accept={bind_all}')
_cmd(f'sysctl -wq net.ipv4.udp_l3mdev_accept={bind_all}')
for vrf_name in vrf_config['vrf_remove']:
if os.path.isdir(f'/sys/class/net/{vrf_name}'):
_cmd(f'ip link delete dev {vrf_name}')
for vrf in vrf_config['vrf_add']:
name = vrf['name']
table = vrf['table']
if not os.path.isdir(f'/sys/class/net/{name}'):
_cmd(f'ip link add {name} type vrf table {table}')
_cmd(f'ip link set dev {name} up')
_cmd(f'ip -4 rule add oif {name} lookup {table}')
_cmd(f'ip -4 rule add iif {name} lookup {table}')
_cmd(f'ip -6 rule add oif {name} lookup {table}')
_cmd(f'ip -6 rule add iif {name} lookup {table}')
# set VRF description for e.g. SNMP monitoring
with open(f'/sys/class/net/{name}/ifalias', 'w') as f:
f.write(vrf['description'])
return None
if __name__ == '__main__':
try:
c = get_config()
verify(c)
generate(c)
apply(c)
except ConfigError as e:
print(e)
exit(1)
|
