summaryrefslogtreecommitdiff
path: root/src/op_mode/show_dhcp.py
blob: 4e3e082636305287efaadfebd2da7a9bd6e6e744 (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
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
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
#!/usr/bin/env python3
#
# Copyright (C) 2018-2019 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 json
import argparse
import ipaddress
import tabulate
import sys
import collections
import os
from datetime import datetime

from isc_dhcp_leases import Lease, IscDhcpLeases

from vyos.config import Config
from vyos.util import run


lease_file = "/config/dhcpd.leases"
pool_key = "shared-networkname"

lease_display_fields = collections.OrderedDict()
lease_display_fields['ip'] = 'IP address'
lease_display_fields['hardware_address'] = 'Hardware address'
lease_display_fields['state'] = 'State'
lease_display_fields['start'] = 'Lease start'
lease_display_fields['end'] = 'Lease expiration'
lease_display_fields['remaining'] = 'Remaining'
lease_display_fields['pool'] = 'Pool'
lease_display_fields['hostname'] = 'Hostname'

lease_valid_states = ['all', 'active', 'free', 'expired', 'released', 'abandoned', 'reset', 'backup']

def in_pool(lease, pool):
    if pool_key in lease.sets:
        if lease.sets[pool_key] == pool:
            return True

    return False

def utc_to_local(utc_dt):
    return datetime.fromtimestamp((utc_dt - datetime(1970,1,1)).total_seconds())

def get_lease_data(lease):
    data = {}

    # isc-dhcp lease times are in UTC so we need to convert them to local time to display
    try:
        data["start"] = utc_to_local(lease.start).strftime("%Y/%m/%d %H:%M:%S")
    except:
        data["start"] = ""

    try:
        data["end"] = utc_to_local(lease.end).strftime("%Y/%m/%d %H:%M:%S")
    except:
        data["end"] = ""

    try:
        data["remaining"] = lease.end - datetime.utcnow()
        # negative timedelta prints wrong so bypass it
        if (data["remaining"].days >= 0):
            # substraction gives us a timedelta object which can't be formatted with strftime
            # so we use str(), split gets rid of the microseconds
            data["remaining"] = str(data["remaining"]).split('.')[0]
        else:
            data["remaining"] = ""
    except:
        data["remaining"] = ""

    # currently not used but might come in handy
    # todo: parse into datetime string
    for prop in ['tstp', 'tsfp', 'atsfp', 'cltt']:
        if prop in lease.data:
            data[prop] = lease.data[prop]
        else:
            data[prop] = ''

    data["hardware_address"] = lease.ethernet
    data["hostname"] = lease.hostname

    data["state"] = lease.binding_state
    data["ip"] = lease.ip

    try:
        data["pool"] = lease.sets[pool_key]
    except:
        data["pool"] = ""

    return data

def get_leases(leases, state, pool=None, sort='ip'):
    # get leases from file
    leases = IscDhcpLeases(lease_file).get()

    # filter leases by state
    if 'all' not in state:
        leases = list(filter(lambda x: x.binding_state in state, leases))

    # filter leases by pool name
    if pool is not None:
        if config.exists_effective("service dhcp-server shared-network-name {0}".format(pool)):
            leases = list(filter(lambda x: in_pool(x, pool), leases))
        else:
            print("Pool {0} does not exist.".format(pool))
            sys.exit(0)

    # should maybe filter all state=active by lease.valid here?

    # sort by start time to dedupe (newest lease overrides older)
    leases = sorted(leases, key = lambda lease: lease.start)

    # dedupe by converting to dict
    leases_dict = {}
    for lease in leases:
        # dedupe by IP
        leases_dict[lease.ip] = lease

    # convert the lease data
    leases = list(map(get_lease_data, leases_dict.values()))

    # apply output/display sort
    if sort == 'ip':
        leases = sorted(leases, key = lambda lease: int(ipaddress.ip_address(lease['ip'])))
    else:
        leases = sorted(leases, key = lambda lease: lease[sort])

    return leases

def show_leases(leases):
    lease_list = []
    for l in leases:
        lease_list_params = []
        for k in lease_display_fields.keys():
            lease_list_params.append(l[k])
        lease_list.append(lease_list_params)

    output = tabulate.tabulate(lease_list, lease_display_fields.values())

    print(output)

def get_pool_size(config, pool):
    size = 0
    subnets = config.list_effective_nodes("service dhcp-server shared-network-name {0} subnet".format(pool))
    for s in subnets:
        ranges = config.list_effective_nodes("service dhcp-server shared-network-name {0} subnet {1} range".format(pool, s))
        for r in ranges:
            start = config.return_effective_value("service dhcp-server shared-network-name {0} subnet {1} range {2} start".format(pool, s, r))
            stop = config.return_effective_value("service dhcp-server shared-network-name {0} subnet {1} range {2} stop".format(pool, s, r))

            size += int(ipaddress.ip_address(stop)) - int(ipaddress.ip_address(start))

    return size

def show_pool_stats(stats):
    headers = ["Pool", "Size", "Leases", "Available", "Usage"]
    output = tabulate.tabulate(stats, headers)

    print(output)

if __name__ == '__main__':
    parser = argparse.ArgumentParser()

    group = parser.add_mutually_exclusive_group()
    group.add_argument("-l", "--leases", action="store_true", help="Show DHCP leases")
    group.add_argument("-s", "--statistics", action="store_true", help="Show DHCP statistics")
    group.add_argument("--allowed", type=str, choices=["pool", "sort", "state"], help="Show allowed values for argument")

    parser.add_argument("-p", "--pool", type=str, help="Show lease for specific pool")
    parser.add_argument("-S", "--sort", type=str, choices=lease_display_fields.keys(), default='ip', help="Sort by")
    parser.add_argument("-t", "--state", type=str, nargs="+", choices=lease_valid_states, default="active", help="Lease state to show (can specify multiple with spaces)")
    parser.add_argument("-j", "--json", action="store_true", default=False, help="Produce JSON output")

    args = parser.parse_args()

    # Do nothing if service is not configured
    config = Config()
    if not config.exists_effective('service dhcp-server'):
        print("DHCP service is not configured.")
        sys.exit(0)

    # if dhcp server is down, inactive leases may still be shown as active, so warn the user.
    if run('systemctl -q is-active isc-dhcpv4-server.service') != 0:
        print("WARNING: DHCP server is configured but not started. Data may be stale.")

    if args.leases:
        leases = get_leases(lease_file, args.state, args.pool, args.sort)

        if args.json:
            print(json.dumps(leases, indent=4))
        else:
            show_leases(leases)

    elif args.statistics:
        pools = []

        # Get relevant pools
        if args.pool:
            pools = [args.pool]
        else:
            pools = config.list_effective_nodes("service dhcp-server shared-network-name")

        # Get pool usage stats
        stats = []
        for p in pools:
            size = get_pool_size(config, p)
            leases = len(get_leases(lease_file, state='active', pool=p))

            if size != 0:
                use_percentage = round(leases / size * 100)
            else:
                use_percentage = 0

            if args.json:
                pool_stats = {"pool": p, "size": size, "leases": leases,
                              "available": (size - leases), "percentage": use_percentage}
            else:
                # For tabulate
                pool_stats = [p, size, leases, size - leases, "{0}%".format(use_percentage)]
            stats.append(pool_stats)

        # Print stats
        if args.json:
            print(json.dumps(stats, indent=4))
        else:
            show_pool_stats(stats)

    elif args.allowed == 'pool':
        print(' '.join(config.list_effective_nodes("service dhcp-server shared-network-name")))
    elif args.allowed == 'sort':
        print(' '.join(lease_display_fields.keys()))
    elif args.allowed == 'state':
        print(' '.join(lease_valid_states))
    else:
        parser.print_help()