summaryrefslogtreecommitdiff
path: root/src/conf_mode/protocols_bgp.py
blob: a3f32fd2de3e678b72af30f892372e01d835f640 (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
#!/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/>.

from sys import exit

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

config_file = r'/tmp/bgp.frr'

def get_config():
    conf = Config()
    base = ['protocols', 'nbgp']
    bgp = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True)

    # XXX: any reason we can not move this into the FRR template?
    # we shall not call vtysh directly, especially not in get_config()
    if not conf.exists(base):
        bgp = {}
        call('vtysh -c \"conf t\" -c \"no ip protocol bgp\" ')

    if not conf.exists(base + ['route-map']):
        call('vtysh -c \"conf t\" -c \"no ip protocol bgp\" ')

    return bgp

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

    # Check if declared more than one ASN
    if len(bgp) > 1:
        raise ConfigError('Only one BGP AS can be defined!')

    for asn, asn_config in bgp.items():
        # Common verification for both peer-group and neighbor statements
        for neigh in ['neighbor', 'peer_group']:
            # bail out early if there is no neighbor or peer-group statement
            # this also saves one indention level
            if neigh not in asn_config:
                continue

            #for neighbor, config in asn_config[neigh].items():
                '''
                # These checks need to be modified. Because peer-group can be declared without 'remote-as'.
                # When 'remote-as' configured for specific neighbor in peer-group. For example
                #

                set protocols nbgp 65001 neighbor 100.64.0.2 peer-group 'FOO'
                set protocols nbgp 65001 neighbor 100.64.0.2 remote-as '65002'
                set protocols nbgp 65001 peer-group FOO

                '''
                #if 'remote_as' not in config and 'peer_group' not in config:
                #    raise ConfigError(f'BGP remote-as must be specified for "{neighbor}"!')

                #if 'remote_as' in config and 'peer_group' in config:
                #    raise ConfigError(f'BGP peer-group member "{neighbor}" cannot override remote-as of peer-group!')

    return None

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

    # only one BGP AS is supported, so we can directly send the first key
    # of the config dict
    asn = list(bgp.keys())[0]
    bgp[asn]['asn'] = asn

    # render(config) not needed, its only for debug
    render(config_file, 'frr/bgp.frr.tmpl', bgp[asn])
    bgp['new_frr_config'] = render_to_string('frr/bgp.frr.tmpl', bgp[asn])

    return None

def apply(bgp):
    # Save original configuration prior to starting any commit actions
    frr_cfg = frr.FRRConfig()
    frr_cfg.load_configuration(daemon='bgpd')
    frr_cfg.modify_section(f'router bgp \S+', '')
    frr_cfg.add_before(r'(ip prefix-list .*|route-map .*|line vty)', bgp['new_frr_config'])
    frr_cfg.commit_configuration(daemon='bgpd')

    # 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 bgp['new_frr_config'] == '':
        for a in range(5):
            frr_cfg.commit_configuration(daemon='bgpd')

    # Debugging
    '''
    print('')
    print('--------- DEBUGGING ----------')
    print(f'Existing config:\n{frr_cfg["original_config"]}\n\n')
    print(f'Replacement config:\n{bgp["new_frr_config"]}\n\n')
    print(f'Modified config:\n{frr_cfg["modified_config"]}\n\n')
    '''

    return None

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