contrib/check_nmap.py

   1 #!/usr/bin/python
   2 # Change the above line if python is somewhere else
   3
   4 #
   5 # check_nmap
   6 #
   7 # Program: nmap plugin for Nagios
   8 # License: GPL
   9 # Copyright (c)  2000 Jacob Lundqvist (jaclu@galdrion.com)
  10 #
  11 _version_ = '1.21'
  12 #
  13 #
  14 # Description:
  15 #
  16 # Does a nmap scan, compares open ports to those given on command-line
  17 # Reports warning for closed that should be open and error for
  18 # open that should be closed.
  19 # If optional ports are given, no warning is given if they are closed
  20 # and they are included in the list of valid ports.
  21 #
  22 #   Requirements:
  23 #     python
  24 #     nmap
  25 #
  26 # History
  27 # -------
  28 # 1.21   2004-07-23 rippeld@hillsboroughcounty.org Updated parsing of nmap output to correctly identify closed ports
  29 # 1.20   2000-07-15 jaclu Updated params to correctly comply to plugin-standard
  30 #                         moved support classes to utils.py
  31 # 1.16   2000-07-14 jaclu made options and return codes more compatible with
  32 #                         the plugin developer-guidelines
  33 # 1.15   2000-07-14 jaclu added random string to temp-file name
  34 # 1.14   2000-07-14 jaclu added check for error from subproc
  35 # 1.10   2000-07-14 jaclu converted main part to class
  36 # 1.08   2000-07-13 jaclu better param parsing
  37 # 1.07   2000-07-13 jaclu changed nmap param to -P0
  38 # 1.06   2000-07-13 jaclu make sure tmp file is deleted on errors
  39 # 1.05   2000-07-12 jaclu in debug mode, show exit code
  40 # 1.03   2000-07-12 jaclu error handling on nmap output
  41 # 1.01   2000-07-12 jaclu added license
  42 # 1.00   2000-07-12 jaclu implemented timeout handling
  43 # 0.20   2000-07-10 jaclu Initial release
  44
  45
  46 import sys, os, string, whrandom
  47
  48 import tempfile
  49 from getopt import getopt
  50
  51 #
  52 # import generic Nagios-plugin stuff
  53 #
  54 import utils
  55
  56 # Where temp files should be placed
  57 tempfile.tempdir='/usr/local/nagios/var'
  58
  59 # Base name for tempfile
  60 tempfile.template='check_nmap_tmp.'
  61
  62 # location and possibly params for nmap
  63 nmap_cmd='/usr/bin/nmap -P0'
  64
  65
  66
  67
  68
  69
  70 #
  71 #  the class that does all the real work in this plugin...
  72 #
  73 #
  74 class CheckNmap:
  75
  76     # Retcodes, so we are compatible with nagios
  77     #ERROR=    -1
  78     UNKNOWN=  -1
  79     OK=        0
  80     WARNING=   1
  81     CRITICAL=  2
  82
  83
  84     def __init__(self,cmd_line=[]):
  85         """Constructor.
  86            arguments:
  87              cmd_line: normaly sys.argv[1:] if called as standalone program
  88         """
  89         self.tmp_file=''
  90         self.host=''       # host to check
  91         self.timeout=10
  92         self.debug=0       # 1= show debug info
  93         self.ports=[]      # list of mandatory ports
  94         self.opt_ports=[]  # list of optional ports
  95         self.ranges=''     # port ranges for nmap
  96         self.exit_code=0   # numerical exit-code
  97         self.exit_msg=''   # message to caller
  98
  99         self.ParseCmdLine(cmd_line)
 100
 101     def Run(self):
 102         """Actually run the process.
 103            This method should be called exactly once.
 104         """
 105
 106         #
 107         # Only call check_host if cmd line was accepted earlier
 108         #
 109         if self.exit_code==0:
 110             self.CheckHost()
 111
 112         self.CleanUp()
 113         return self.exit_code,self.exit_msg
 114
 115     def Version(self):
 116         return 'check_nmap %s' % _version_
 117
 118     #-----------------------------------------
 119     #
 120     # class internal stuff below...
 121     #
 122     #-----------------------------------------
 123
 124     #
 125     # Param checks
 126     #
 127     def param2int_list(self,s):
 128         lst=string.split(string.replace(s,',',' '))
 129         try:
 130             for i in range(len(lst)):
 131                 lst[i]=int(lst[i])
 132         except:
 133             lst=[]
 134         return lst
 135
 136     def ParseCmdLine(self,cmd_line):
 137         try:
 138             opt_list=getopt(cmd_line,'vH:ho:p:r:t:V',['debug','host=','help',
 139                 'optional=','port=','range=','timeout','version'])
 140             for opt in opt_list[0]:
 141                 if opt[0]=='-v' or opt[0]=='--debug':
 142                     self.debug=1
 143                 elif opt[0]=='-H' or opt[0]=='--host':
 144                     self.host=opt[1]
 145                 elif opt[0]=='-h' or opt[0]=='--help':
 146                     doc_help()
 147                     self.exit_code=1 # request termination
 148                     break
 149                 elif opt[0]=='-o' or opt[0]=='--optional':
 150                     self.opt_ports=self.param2int_list(opt[1])
 151                 elif opt[0]=='-p' or opt[0]=='--port':
 152                     self.ports=self.param2int_list(opt[1])
 153                 elif opt[0]=='-r' or opt[0]=='--range':
 154                     r=string.replace(opt[1],':','-')
 155                     self.ranges=r
 156                 elif opt[0]=='-t' or opt[0]=='--timeout':
 157                     self.timeout=opt[1]
 158                 elif opt[0]=='-V' or opt[0]=='--version':
 159                     print self.Version()
 160                     self.exit_code=1 # request termination
 161                     break
 162                 else:
 163                     self.host=''
 164                     break
 165
 166         except:
 167             # unknown param
 168             self.host=''
 169
 170         if self.debug:
 171             print 'Params:'
 172             print '-------'
 173             print 'host             = %s' % self.host
 174             print 'timeout          = %s' % self.timeout
 175             print 'ports            = %s' % self.ports
 176             print 'optional ports   = %s' % self.opt_ports
 177             print 'ranges           = %s' % self.ranges
 178             print
 179
 180         #
 181         # a option that wishes us to terminate now has been given...
 182         #
 183         # This way, you can test params in debug mode and see what this
 184         # program recognised by suplying a version param at the end of
 185         # the cmd-line
 186         #
 187         if self.exit_code<>0:
 188             sys.exit(self.UNKNOWN)
 189
 190         if self.host=='':
 191             doc_syntax()
 192             self.exit_code=self.UNKNOWN
 193             self.exit_msg='UNKNOWN: bad params, try running without any params for syntax'
 194
 195
 196     def CheckHost(self):
 197         'Check one host using nmap.'
 198         #
 199         # Create a tmp file for storing nmap output
 200         #
 201         # The tempfile module from python 1.5.2 is stupid
 202         # two processes runing at aprox the same time gets
 203         # the same tempfile...
 204         # For this reason I use a random suffix for the tmp-file
 205         # Still not 100% safe, but reduces the risk significally
 206         # I also inserted checks at various places, so that
 207         # _if_ two processes in deed get the same tmp-file
 208         # the only result is a normal error message to nagios
 209         #
 210         r=whrandom.whrandom()
 211         self.tmp_file=tempfile.mktemp('.%s')%r.randint(0,100000)
 212         if self.debug:
 213             print 'Tmpfile is: %s'%self.tmp_file
 214         #
 215         # If a range is given, only run nmap on this range
 216         #
 217         if self.ranges<>'':
 218             global nmap_cmd # needed, to avoid error on next line
 219                             # since we assigns to nmap_cmd :)
 220             nmap_cmd='%s -p %s' %(nmap_cmd,self.ranges)
 221         #
 222         # Prepare a task
 223         #
 224         t=utils.Task('%s %s' %(nmap_cmd,self.host))
 225         #
 226         # Configure a time-out handler
 227         #
 228         th=utils.TimeoutHandler(t.Kill, time_to_live=self.timeout,
 229                                 debug=self.debug)
 230         #
 231         #  Fork of nmap cmd
 232         #
 233         t.Run(detach=0, stdout=self.tmp_file,stderr='/dev/null')
 234         #
 235         # Wait for completition, error or timeout
 236         #
 237         nmap_exit_code=t.Wait(idlefunc=th.Check, interval=1)
 238         #
 239         # Check for timeout
 240         #
 241         if th.WasTimeOut():
 242             self.exit_code=self.CRITICAL
 243             self.exit_msg='CRITICAL - Plugin timed out after %s seconds' % self.timeout
 244             return
 245         #
 246         # Check for exit status of subprocess
 247         # Must do this after check for timeout, since the subprocess
 248         # also returns error if aborted.
 249         #
 250         if nmap_exit_code <> 0:
 251             self.exit_code=self.UNKNOWN
 252             self.exit_msg='nmap program failed with code %s' % nmap_exit_code
 253             return
 254         #
 255         # Read output
 256         #
 257         try:
 258             f = open(self.tmp_file, 'r')
 259             output=f.readlines()
 260             f.close()
 261         except:
 262             self.exit_code=self.UNKNOWN
 263             self.exit_msg='Unable to get output from nmap'
 264             return
 265
 266         #
 267         # Store open ports in list
 268         #  scans for lines where first word contains '/'
 269         #  and stores part before '/'
 270         #
 271         self.active_ports=[]
 272         try:
 273             for l in output:
 274                 if len(l)<2:
 275                     continue
 276                 s=string.split(l)[0]
 277                 if string.find(s,'/')<1:
 278                     continue
 279                 p=string.split(s,'/')[0]
 280                 if string.find(l,'open')>1:
 281                     self.active_ports.append(int(p))
 282         except:
 283             # failure due to strange output...
 284             pass
 285
 286         if self.debug:
 287             print 'Ports found by nmap:   ',self.active_ports
 288         #
 289         # Filter out optional ports, we don't check status for them...
 290         #
 291         try:
 292             for p in self.opt_ports:
 293                 self.active_ports.remove(p)
 294
 295             if self.debug and len(self.opt_ports)>0:
 296                 print 'optional ports removed:',self.active_ports
 297         except:
 298             # under extreame loads the remove(p) above failed for me
 299             # a few times, this exception hanlder handles
 300             # this bug-alike situation...
 301             pass
 302
 303         opened=self.CheckOpen()
 304         closed=self.CheckClosed()
 305
 306         if opened <>'':
 307             self.exit_code=self.CRITICAL
 308             self.exit_msg='PORTS CRITICAL - Open:%s Closed:%s'%(opened,closed)
 309         elif closed <>'':
 310             self.exit_code=self.WARNING
 311             self.exit_msg='PORTS WARNING - Closed:%s'%closed
 312         else:
 313             self.exit_code=self.OK
 314             self.exit_msg='PORTS ok - Only defined ports open'
 315
 316
 317     #
 318     # Compares requested ports on with actually open ports
 319     # returns all open that should be closed
 320     #
 321     def CheckOpen(self):
 322         opened=''
 323         for p in self.active_ports:
 324             if p not in self.ports:
 325                 opened='%s %s' %(opened,p)
 326         return opened
 327
 328     #
 329     # Compares requested ports with actually open ports
 330     # returns all ports that are should be open
 331     #
 332     def CheckClosed(self):
 333         closed=''
 334         for p in self.ports:
 335             if p not in self.active_ports:
 336                 closed='%s %s' % (closed,p)
 337         return closed
 338
 339
 340     def CleanUp(self):
 341         #
 342         # If temp file exists, get rid of it
 343         #
 344         if self.tmp_file<>'' and os.path.isfile(self.tmp_file):
 345             try:
 346                 os.remove(self.tmp_file)
 347             except:
 348                 # temp-file colition, some other process already
 349                 # removed the same file...
 350                 pass
 351
 352         #
 353         # Show numerical exits as string in debug mode
 354         #
 355         if self.debug:
 356             print 'Exitcode:',self.exit_code,
 357             if self.exit_code==self.UNKNOWN:
 358                 print 'UNKNOWN'
 359             elif self.exit_code==self.OK:
 360                 print 'OK'
 361             elif self.exit_code==self.WARNING:
 362                 print 'WARNING'
 363             elif self.exit_code==self.CRITICAL:
 364                 print 'CRITICAL'
 365             else:
 366                 print 'undefined'
 367         #
 368         # Check if invalid exit code
 369         #
 370         if self.exit_code<-1 or self.exit_code>2:
 371             self.exit_msg=self.exit_msg+' - undefined exit code (%s)' % self.exit_code
 372             self.exit_code=self.UNKNOWN
 373
 374
 375
 376
 377
 378 #
 379 # Help texts
 380 #
 381 def doc_head():
 382     print """
 383 check_nmap plugin for Nagios
 384 Copyright (c) 2000 Jacob Lundqvist (jaclu@galdrion.com)
 385 License: GPL
 386 Version: %s""" % _version_
 387
 388
 389 def doc_syntax():
 390     print """
 391 Usage: check_ports [-v|--debug] [-H|--host host] [-V|--version] [-h|--help]
 392                    [-o|--optional port1,port2,port3 ...] [-r|--range range]
 393                    [-p|--port port1,port2,port3 ...] [-t|--timeout timeout]"""
 394
 395
 396 def doc_help():
 397     'Help is displayed if run without params.'
 398     doc_head()
 399     doc_syntax()
 400     print """
 401 Options:
 402  -h         = help (this screen ;-)
 403  -v         = debug mode, show some extra output
 404  -H host    = host to check (name or IP#)
 405  -o ports   = optional ports that can be open (one or more),
 406               no warning is given if optional port is closed
 407  -p ports   = ports that should be open (one or more)
 408  -r range   = port range to feed to nmap.  Example: :1024,2049,3000:7000
 409  -t timeout = timeout in seconds, default 10
 410  -V         = Version info
 411
 412 This plugin attempts to verify open ports on the specified host.
 413
 414 If all specified ports are open, OK is returned.
 415 If any of them are closed, WARNING is returned (except for optional ports)
 416 If other ports are open, CRITICAL is returned
 417
 418 If possible, supply an IP address for the host address,
 419 as this will bypass the DNS lookup.
 420 """
 421
 422
 423 #
 424 # Main
 425 #
 426 if __name__ == '__main__':
 427
 428     if len (sys.argv) < 2:
 429         #
 430         # No params given, show syntax and exit
 431         #
 432         doc_syntax()
 433         sys.exit(-1)
 434
 435     nmap=CheckNmap(sys.argv[1:])
 436     exit_code,exit_msg=nmap.Run()
 437
 438     #
 439     # Give Nagios a msg and a code
 440     #
 441     print exit_msg
 442     sys.exit(exit_code)