1 files changed, 219 insertions, 0 deletions
diff --git a/src/op_mode/show_dhcpv6.py b/src/op_mode/show_dhcpv6.py
new file mode 100755
index 000000000..ac211fb0a
--- /dev/null
+++ b/src/op_mode/show_dhcpv6.py
@@ -0,0 +1,219 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018-2020 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/>.
+#
+# TODO: merge with show_dhcp.py
+
+from json import dumps
+from argparse import ArgumentParser
+from ipaddress import ip_address
+from tabulate import tabulate
+from sys import exit
+from collections import OrderedDict
+from datetime import datetime
+
+from isc_dhcp_leases import Lease, IscDhcpLeases
+
+from vyos.config import Config
+from vyos.util import call
+
+lease_file = "/config/dhcpdv6.leases"
+pool_key = "shared-networkname"
+
+lease_display_fields = OrderedDict()
+lease_display_fields['ip'] = 'IPv6 address'
+lease_display_fields['state'] = 'State'
+lease_display_fields['last_comm'] = 'Last communication'
+lease_display_fields['expires'] = 'Lease expiration'
+lease_display_fields['remaining'] = 'Remaining'
+lease_display_fields['type'] = 'Type'
+lease_display_fields['pool'] = 'Pool'
+lease_display_fields['iaid_duid'] = 'IAID_DUID'
+
+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 format_hex_string(in_str):
+    out_str = ""
+
+    # if input is divisible by 2, add : every 2 chars
+    if len(in_str) > 0 and len(in_str) % 2 == 0:
+        out_str = ':'.join(a+b for a,b in zip(in_str[::2], in_str[1::2]))
+    else:
+        out_str = in_str
+
+    return out_str
+
+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["expires"] = utc_to_local(lease.end).strftime("%Y/%m/%d %H:%M:%S")
+    except:
+        data["expires"] = ""
+
+    try:
+        data["last_comm"] = utc_to_local(lease.last_communication).strftime("%Y/%m/%d %H:%M:%S")
+    except:
+        data["last_comm"] = ""
+
+    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"] = ""
+
+    # isc-dhcp records lease declarations as ia_{na|ta|pd} IAID_DUID {...}
+    # where IAID_DUID is the combined IAID and DUID
+    data["iaid_duid"] = format_hex_string(lease.host_identifier_string)
+
+    lease_types_long = {"na": "non-temporary", "ta": "temporary", "pd": "prefix delegation"}
+    data["type"] = lease_types_long[lease.type]
+
+    data["state"] = lease.binding_state
+    data["ip"] = lease.ip
+
+    try:
+        data["pool"] = lease.sets[pool_key]
+    except:
+        data["pool"] = ""
+
+    return data
+
+def get_leases(config, leases, state, pool=None, sort='ip'):
+    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))
+            exit(0)
+
+    # should maybe filter all state=active by lease.valid here?
+
+    # sort by last_comm time to dedupe (newest lease overrides older)
+    leases = sorted(leases, key = lambda lease: lease.last_communication)
+
+    # 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 k: int(ip_address(k['ip'])))
+    else:
+        leases = sorted(leases, key = lambda k: k[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(lease_list, lease_display_fields.values())
+
+    print(output)
+
+if __name__ == '__main__':
+    parser = ArgumentParser()
+
+    group = parser.add_mutually_exclusive_group()
+    group.add_argument("-l", "--leases", action="store_true", help="Show DHCPv6 leases")
+    group.add_argument("-s", "--statistics", action="store_true", help="Show DHCPv6 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, default='ip', help="Sort by")
+    parser.add_argument("-t", "--state", type=str, nargs="+", 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()
+
+    conf = Config()
+
+    if args.allowed == 'pool':
+        if conf.exists_effective('service dhcpv6-server'):
+            print(' '.join(conf.list_effective_nodes("service dhcpv6-server shared-network-name")))
+        exit(0)
+    elif args.allowed == 'sort':
+        print(' '.join(lease_display_fields.keys()))
+        exit(0)
+    elif args.allowed == 'state':
+        print(' '.join(lease_valid_states))
+        exit(0)
+    elif args.allowed:
+        parser.print_help()
+        exit(1)
+
+    if args.sort not in lease_display_fields.keys():
+        print(f'Invalid sort key, choose from: {list(lease_display_fields.keys())}')
+        exit(0)
+
+    if not set(args.state) < set(lease_valid_states):
+            print(f'Invalid lease state, choose from: {lease_valid_states}')
+            exit(0)
+
+    # Do nothing if service is not configured
+    if not conf.exists_effective('service dhcpv6-server'):
+        print("DHCPv6 service is not configured")
+        exit(0)
+
+    # if dhcp server is down, inactive leases may still be shown as active, so warn the user.
+    if call('systemctl -q is-active isc-dhcp-server6.service') != 0:
+        print("WARNING: DHCPv6 server is configured but not started. Data may be stale.")
+
+    if args.leases:
+        leases = get_leases(conf, lease_file, args.state, args.pool, args.sort)
+
+        if args.json:
+            print(dumps(leases, indent=4))
+        else:
+            show_leases(leases)
+    elif args.statistics:
+        print("DHCPv6 statistics option is not available")
+    else:
+        parser.print_help()
+        exit(1)