summaryrefslogtreecommitdiff
path: root/src/conf_mode/policy.py
blob: d461511f831e250dd766566c763ee87eddbc4d1a (plain)
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
#!/usr/bin/env python3
#
# Copyright (C) 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
# 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/>.

from sys import exit

from vyos.config import Config
from vyos.configdict import dict_merge
from vyos.template import render_to_string
from vyos.util import dict_search
from vyos import ConfigError
from vyos import frr
from vyos import airbag
airbag.enable()

def get_config(config=None):
    if config:
        conf = config
    else:
        conf = Config()

    base = ['policy']
    policy = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True,
                                  no_tag_node_value_mangle=True)

    return policy

def verify(policy):
    if not policy:
        return None

    for policy_type in ['access_list', 'access_list6', 'as_path_list',
                        'community_list', 'extcommunity_list', 'large_community_list',
                        'prefix_list', 'prefix_list6', 'route_map']:
        # Bail out early and continue with next policy type
        if policy_type not in policy:
            continue

        # instance can be an ACL name/number, prefix-list name or route-map name
        for instance, instance_config in policy[policy_type].items():
            # If no rule was found within the instance ... sad, but we can leave
            # early as nothing needs to be verified
            if 'rule' not in instance_config:
                continue

            # human readable instance name (hypen instead of underscore)
            policy_hr = policy_type.replace('_', '-')
            for rule, rule_config in instance_config['rule'].items():
                mandatory_error = f'must be specified for "{policy_hr} {instance} rule {rule}"!'
                if 'action' not in rule_config:
                    raise ConfigError(f'Action {mandatory_error}')

                if policy_type == 'access_list':
                    if 'source' not in rule_config:
                        raise ConfigError(f'Source {mandatory_error}')

                    if int(instance) in range(100, 200) or int(instance) in range(2000, 2700):
                        if 'destination' not in rule_config:
                            raise ConfigError(f'Destination {mandatory_error}')

                if policy_type == 'access_list6':
                    if 'source' not in rule_config:
                        raise ConfigError(f'Source {mandatory_error}')

                if policy_type in ['as_path_list', 'community_list', 'extcommunity_list',
                                   'large_community_list']:
                    if 'regex' not in rule_config:
                        raise ConfigError(f'Regex {mandatory_error}')


    return None

def generate(policy):
    if not policy:
        policy['new_frr_config'] = ''
        return None

    policy['new_frr_config'] = render_to_string('frr/policy.frr.tmpl', policy)
    return None

def apply(policy):
    bgp_daemon = 'bgpd'
    zebra_daemon = 'zebra'

    # Save original configuration prior to starting any commit actions
    frr_cfg = frr.FRRConfig()

    # The route-map used for the FIB (zebra) is part of the zebra daemon
    frr_cfg.load_configuration(bgp_daemon)
    frr_cfg.modify_section(r'^bgp as-path access-list .*')
    frr_cfg.modify_section(r'^bgp community-list .*')
    frr_cfg.modify_section(r'^bgp extcommunity-list .*')
    frr_cfg.modify_section(r'^bgp large-community-list .*')
    frr_cfg.add_before('^line vty', policy['new_frr_config'])
    frr_cfg.commit_configuration(bgp_daemon)

    # The route-map used for the FIB (zebra) is part of the zebra daemon
    frr_cfg.load_configuration(zebra_daemon)
    frr_cfg.modify_section(r'^access-list .*')
    frr_cfg.modify_section(r'^ipv6 access-list .*')
    frr_cfg.modify_section(r'^ip prefix-list .*')
    frr_cfg.modify_section(r'^ipv6 prefix-list .*')
    frr_cfg.modify_section(r'^route-map .*')
    frr_cfg.add_before('^line vty', policy['new_frr_config'])
    frr_cfg.commit_configuration(zebra_daemon)

    # If FRR config is blank, rerun the blank commit x times due to frr-reload
    # behavior/bug not properly clearing out on one commit.
    if policy['new_frr_config'] == '':
        for a in range(5):
            frr_cfg.commit_configuration(zebra_daemon)

    # Save configuration to /run/frr/config/frr.conf
    frr.save_configuration()

    return None

if __name__ == '__main__':
    try:
        c = get_config()
        verify(c)
        generate(c)
        apply(c)
    except ConfigError as e:
        print(e)
        exit(1)