Script para coletar os leases do dhcp e exibir de forma organizada.
Não é de minha autoria.

#!/usr/bin/python
import datetime, bisect

def parse_timestamp(raw_str):
tokens = raw_str.split()

if len(tokens) == 1:
if tokens[0].lower() == ‘never’:
return ‘never’;

else:
raise Exception(‘Parse error in timestamp’)

elif len(tokens) == 3:
return datetime.datetime.strptime(‘ ‘.join(tokens[1:]),
‘%Y/%m/%d %H:%M:%S’)

else:
raise Exception(‘Parse error in timestamp’)

def timestamp_is_ge(t1, t2):
if t1 == ‘never’:
return True

elif t2 == ‘never’:
return False

else:
return t1 >= t2

def timestamp_is_lt(t1, t2):
if t1 == ‘never’:
return False

elif t2 == ‘never’:
return t1 != ‘never’

else:
return t1 < t2 def timestamp_is_between(t, tstart, tend): return timestamp_is_ge(t, tstart) and timestamp_is_lt(t, tend) def parse_hardware(raw_str): tokens = raw_str.split() if len(tokens) == 2: return tokens[1] else: raise Exception('Parse error in hardware') def strip_endquotes(raw_str): return raw_str.strip('"') def identity(raw_str): return raw_str def parse_binding_state(raw_str): tokens = raw_str.split() if len(tokens) == 2: return tokens[1] else: raise Exception('Parse error in binding state') def parse_next_binding_state(raw_str): tokens = raw_str.split() if len(tokens) == 3: return tokens[2] else: raise Exception('Parse error in next binding state') def parse_rewind_binding_state(raw_str): tokens = raw_str.split() if len(tokens) == 3: return tokens[2] else: raise Exception('Parse error in next binding state') def parse_leases_file(leases_file): valid_keys = { 'starts': parse_timestamp, 'ends': parse_timestamp, 'tstp': parse_timestamp, 'tsfp': parse_timestamp, 'atsfp': parse_timestamp, 'cltt': parse_timestamp, 'hardware': parse_hardware, 'binding': parse_binding_state, 'next': parse_next_binding_state, 'rewind': parse_rewind_binding_state, 'uid': strip_endquotes, 'client-hostname': strip_endquotes, 'option': identity, 'set': identity, 'on': identity, 'abandoned': None, 'bootp': None, 'reserved': None, } leases_db = {} lease_rec = {} in_lease = False for line in leases_file: if line.lstrip().startswith('#'): continue tokens = line.split() if len(tokens) == 0: continue key = tokens[0].lower() if key == 'lease': if not in_lease: ip_address = tokens[1] lease_rec = {'ip_address' : ip_address} in_lease = True else: raise Exception('Parse error in leases file') elif key == '}': if in_lease: for k in valid_keys: if callable(valid_keys[k]): lease_rec[k] = lease_rec.get(k, '') else: lease_rec[k] = False ip_address = lease_rec['ip_address'] if ip_address in leases_db: leases_db[ip_address].insert(0, lease_rec) else: leases_db[ip_address] = [lease_rec] lease_rec = {} in_lease = False else: raise Exception('Parse error in leases file') elif key in valid_keys: if in_lease: value = line[(line.index(key) + len(key)):] value = value.strip().rstrip(';').rstrip() if callable(valid_keys[key]): lease_rec[key] = valid_keys[key](value) else: lease_rec[key] = True else: raise Exception('Parse error in leases file') else: if in_lease: raise Exception('Parse error in leases file') if in_lease: raise Exception('Parse error in leases file') return leases_db def round_timedelta(tdelta): return datetime.timedelta(tdelta.days, tdelta.seconds + (0 if tdelta.microseconds < 500000 else 1)) def timestamp_now(): n = datetime.datetime.utcnow() return datetime.datetime(n.year, n.month, n.day, n.hour, n.minute, n.second + (0 if n.microsecond < 500000 else 1)) def lease_is_active(lease_rec, as_of_ts): return timestamp_is_between(as_of_ts, lease_rec['starts'], lease_rec['ends']) def ipv4_to_int(ipv4_addr): parts = ipv4_addr.split('.') return (int(parts[0]) << 24) + (int(parts[1]) << 16) + \ (int(parts[2]) << 8) + int(parts[3]) def select_active_leases(leases_db, as_of_ts): retarray = [] sortedarray = [] for ip_address in leases_db: lease_rec = leases_db[ip_address][0] if lease_is_active(lease_rec, as_of_ts): ip_as_int = ipv4_to_int(ip_address) insertpos = bisect.bisect(sortedarray, ip_as_int) sortedarray.insert(insertpos, ip_as_int) retarray.insert(insertpos, lease_rec) return retarray ############################################################################## myfile = open('/var/lib/dhcp/dhcpd.leases', 'r') leases = parse_leases_file(myfile) myfile.close() now = timestamp_now() report_dataset = select_active_leases(leases, now) print('+------------------------------------------------------------------------------') print('| DHCPD ACTIVE LEASES REPORT') print('+-----------------+-------------------+----------------------+-----------------') print('| IP Address | MAC Address | Expires (days,H:M:S) | Client Hostname ') print('+-----------------+-------------------+----------------------+-----------------') for lease in report_dataset: print('| ' + format(lease['ip_address'], '<15') + ' | ' + \ format(lease['hardware'], '<17') + ' | ' + \ format(str((lease['ends'] - now) if lease['ends'] != 'never' else 'never'), '>20′) + ‘ | ‘ + \
lease[‘client-hostname’])

print(‘+—————–+——————-+———————-+—————–‘)
print(‘| Total Active Leases: ‘ + str(len(report_dataset)))
print(‘| Report generated (UTC): ‘ + str(now))
print(‘+——————————————————————————‘)