"""A minimalistic syslogd.
2000-06-09/bb: created
2000-06-12/bb: added constants from syslog.h,
config options for time format, stop string
"""
import sys, string, time, socket, re
from SocketServer import *
# constants from syslog.h
LOG_EMERG = 0
LOG_ALERT = 1
LOG_CRIT = 2
LOG_ERR = 3
LOG_WARNING = 4
LOG_NOTICE = 5
LOG_INFO = 6
LOG_DEBUG = 7
LOG_PRIMASK = 0x07
def LOG_PRI(p): return p & LOG_PRIMASK
def LOG_MAKEPRI(fac, pri): return fac << 3 | pri
LOG_KERN = 0 << 3
LOG_USER = 1 << 3
LOG_MAIL = 2 << 3
LOG_DAEMON = 3 << 3
LOG_AUTH = 4 << 3
LOG_SYSLOG = 5 << 3
LOG_LPR = 6 << 3
LOG_NEWS = 7 << 3
LOG_UUCP = 8 << 3
LOG_CRON = 9 << 3
LOG_AUTHPRIV = 10 << 3
LOG_FTP = 11 << 3
LOG_LOCAL0 = 16 << 3
LOG_LOCAL1 = 17 << 3
LOG_LOCAL2 = 18 << 3
LOG_LOCAL3 = 19 << 3
LOG_LOCAL4 = 20 << 3
LOG_LOCAL5 = 21 << 3
LOG_LOCAL6 = 22 << 3
LOG_LOCAL7 = 23 << 3
LOG_NFACILITIES = 24
LOG_FACMASK = 0x03F8
def LOG_FAC(p): return (p & LOG_FACMASK) >> 3
def LOG_MASK(pri): return 1 << pri
def LOG_UPTO(pri): return (1 << pri + 1) - 1
# end syslog.h
def LOG_UNPACK(p): return (p & LOG_FACMASK, LOG_PRI(p))
fac_values = {} # mapping of facility constants to their values
fac_names = {} # mapping of values to names
pri_values = {}
pri_names = {}
for i, j in globals().items():
if i[:4] == 'LOG_' and type(j) == type(0):
if j > LOG_PRIMASK or i == 'LOG_KERN':
n, v = fac_names, fac_values
else:
n, v = pri_names, pri_values
i = i[4:].lower()
v[i] = j
n[j] = i
del i, j, n, v
conf_pat = re.compile(r'''
^\s* # leading space
([\w*]+) # facility
\.([=!]?) # separator plus optional modifier
([\w*]+) # priority
\s+
([|@]?) # target type fifo/remote host
(\S+) # target
''', re.VERBOSE)
class InterruptibleServer:
"Mix-in class for {TCP,UDP}Server that allows to stop the service"
def serve(self):
"Run the service until it is stopped with the stop() method."
self.running = 1
while self.running:
try:
self.handle_request()
except KeyboardInterrupt:
self.stop()
def stop(self): # called by handle_request()
"Stop the service."
self.running = 0
SYSLOG_PORT = socket.getservbyname('syslog', 'udp')
class Syslogd(ThreadingUDPServer, InterruptibleServer):
def __init__(self, addr='', port=SYSLOG_PORT, pri=LOG_DEBUG, timefmt=None, magic=None):
UDPServer.__init__(self, (addr, port), None)
self.hostmap = {} # client address/name mapping
self.priority = pri
self.timefmt = timefmt or '%b %d %H:%M:%S'
self.stop_magic = magic or '_stop'
print 'syslogd started'
def finish_request(self, (msg, sock), client_address):
# get the time when the message arrives
tm = time.time()
# Messages are in the form "[[float]]<int>message text...\n"
# The [[float]] and <int> parts and the newline are optional.
# The float denotes the original event time in case the
# event comes through a gateway from a client that is not
# syslog-compatible (Windows NT comes to mind :-).
# extract original event time, if present
if msg[:2] == '[[':
pos = msg.find(']]')
try:
tm = float(msg[2:pos])
except:
pass
msg = msg[pos+2:] # use rest of message
# extract log facility and priority, if present
if msg[:1] == '<':
pos = msg.find('>')
fac, pri = LOG_UNPACK(int(msg[1:pos]))
msg = msg[pos+1:]
elif msg and msg[0] < ' ':
fac, pri = LOG_KERN, ord(msg[0])
msg = msg[1:]
else:
fac, pri = None, None
# check if we can discard this message
if pri is not None and pri > self.priority:
return
# build the client address/name mapping
client = client_address[0]
try:
host = self.hostmap[client]
except KeyError:
try:
host = socket.gethostbyaddr(client)[0]
host = host.split('.')[0] # keep only the host name
except socket.error:
host = client
self.hostmap[client] = host
# print the message
tm = time.strftime(self.timefmt, time.localtime(tm))
if 0: # fac is not None and pri is not None:
fp = ' <%s,%s>' % (fac_names[fac], pri_names[pri])
else:
fp = ''
sys.stdout.write(tm + ' ' + host + fp + ': ' + msg.strip() + '\n')
# stop the server if the magic stop string appears in the message
if msg.find(self.stop_magic) >= 0:
print 'stopped.'
self.stop()
if __name__ == '__main__':
Syslogd(timefmt='%H:%M:%S').serve()
