make-secnet-sites

   1 #! /usr/bin/env python
   2 # Copyright (C) 2001-2002 Stephen Early <steve@greenend.org.uk>
   3 #
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 2 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program; if not, write to the Free Software
  16 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17
  18 """VPN sites file manipulation.
  19
  20 This program enables VPN site descriptions to be submitted for
  21 inclusion in a central database, and allows the resulting database to
  22 be turned into a secnet configuration file.
  23
  24 A database file can be turned into a secnet configuration file simply:
  25 make-secnet-sites.py [infile [outfile]]
  26
  27 It would be wise to run secnet with the "--just-check-config" option
  28 before installing the output on a live system.
  29
  30 The program expects to be invoked via userv to manage the database; it
  31 relies on the USERV_USER and USERV_GROUP environment variables. The
  32 command line arguments for this invocation are:
  33
  34 make-secnet-sites.py -u header-filename groupfiles-directory output-file \
  35   group
  36
  37 All but the last argument are expected to be set by userv; the 'group'
  38 argument is provided by the user. A suitable userv configuration file
  39 fragment is:
  40
  41 reset
  42 no-disconnect-hup
  43 no-suppress-args
  44 cd ~/secnet/sites-test/
  45 execute ~/secnet/make-secnet-sites.py -u vpnheader groupfiles sites
  46
  47 This program is part of secnet. It relies on the "ipaddr" library from
  48 Cendio Systems AB.
  49
  50 """
  51
  52 import string
  53 import time
  54 import sys
  55 import os
  56 import getopt
  57 import re
  58
  59 # The ipaddr library is installed as part of secnet
  60 sys.path.append("/usr/local/share/secnet")
  61 sys.path.append("/usr/share/secnet")
  62 import ipaddr
  63
  64 VERSION="0.1.18"
  65
  66 # Classes describing possible datatypes in the configuration file
  67
  68 class single_ipaddr:
  69         "An IP address"
  70         def __init__(self,w):
  71                 self.addr=ipaddr.ipaddr(w[1])
  72         def __str__(self):
  73                 return '"%s"'%self.addr.ip_str()
  74
  75 class networks:
  76         "A set of IP addresses specified as a list of networks"
  77         def __init__(self,w):
  78                 self.set=ipaddr.ip_set()
  79                 for i in w[1:]:
  80                         x=string.split(i,"/")
  81                         self.set.append(ipaddr.network(x[0],x[1],
  82                                 ipaddr.DEMAND_NETWORK))
  83         def __str__(self):
  84                 return string.join(map(lambda x:'"%s/%s"'%(x.ip_str(),
  85                         x.mask.netmask_bits_str),
  86                         self.set.as_list_of_networks()),",")
  87
  88 class dhgroup:
  89         "A Diffie-Hellman group"
  90         def __init__(self,w):
  91                 self.mod=w[1]
  92                 self.gen=w[2]
  93         def __str__(self):
  94                 return 'diffie-hellman("%s","%s")'%(self.mod,self.gen)
  95
  96 class hash:
  97         "A choice of hash function"
  98         def __init__(self,w):
  99                 self.ht=w[1]
 100                 if (self.ht!='md5' and self.ht!='sha1'):
 101                         complain("unknown hash type %s"%(self.ht))
 102         def __str__(self):
 103                 return '%s'%(self.ht)
 104
 105 class email:
 106         "An email address"
 107         def __init__(self,w):
 108                 self.addr=w[1]
 109         def __str__(self):
 110                 return '<%s>'%(self.addr)
 111
 112 class boolean:
 113         "A boolean"
 114         def __init__(self,w):
 115                 if re.match('[TtYy1]',w[1]):
 116                         self.b=True
 117                 elif re.match('[FfNn0]',w[1]):
 118                         self.b=False
 119                 else:
 120                         complain("invalid boolean value");
 121         def __str__(self):
 122                 return ['False','True'][self.b]
 123
 124 class num:
 125         "A decimal number"
 126         def __init__(self,w):
 127                 self.n=string.atol(w[1])
 128         def __str__(self):
 129                 return '%d'%(self.n)
 130
 131 class address:
 132         "A DNS name and UDP port number"
 133         def __init__(self,w):
 134                 self.adr=w[1]
 135                 self.port=string.atoi(w[2])
 136                 if (self.port<1 or self.port>65535):
 137                         complain("invalid port number")
 138         def __str__(self):
 139                 return '"%s"; port %d'%(self.adr,self.port)
 140
 141 class rsakey:
 142         "An RSA public key"
 143         def __init__(self,w):
 144                 self.l=string.atoi(w[1])
 145                 self.e=w[2]
 146                 self.n=w[3]
 147         def __str__(self):
 148                 return 'rsa-public("%s","%s")'%(self.e,self.n)
 149
 150 # Possible properties of configuration nodes
 151 keywords={
 152  'contact':(email,"Contact address"),
 153  'dh':(dhgroup,"Diffie-Hellman group"),
 154  'hash':(hash,"Hash function"),
 155  'key-lifetime':(num,"Maximum key lifetime (ms)"),
 156  'setup-timeout':(num,"Key setup timeout (ms)"),
 157  'setup-retries':(num,"Maximum key setup packet retries"),
 158  'wait-time':(num,"Time to wait after unsuccessful key setup (ms)"),
 159  'renegotiate-time':(num,"Time after key setup to begin renegotiation (ms)"),
 160  'restrict-nets':(networks,"Allowable networks"),
 161  'networks':(networks,"Claimed networks"),
 162  'pubkey':(rsakey,"RSA public site key"),
 163  'peer':(single_ipaddr,"Tunnel peer IP address"),
 164  'address':(address,"External contact address and port"),
 165  'mobile':(boolean,"Site is mobile"),
 166 }
 167
 168 def sp(name,value):
 169         "Simply output a property - the default case"
 170         return "%s %s;\n"%(name,value)
 171
 172 # All levels support these properties
 173 global_properties={
 174         'contact':(lambda name,value:"# Contact email address: %s\n"%(value)),
 175         'dh':sp,
 176         'hash':sp,
 177         'key-lifetime':sp,
 178         'setup-timeout':sp,
 179         'setup-retries':sp,
 180         'wait-time':sp,
 181         'renegotiate-time':sp,
 182         'restrict-nets':(lambda name,value:"# restrict-nets %s\n"%value),
 183 }
 184
 185 class level:
 186         "A level in the configuration hierarchy"
 187         depth=0
 188         leaf=0
 189         allow_properties={}
 190         require_properties={}
 191         def __init__(self,w):
 192                 self.name=w[1]
 193                 self.properties={}
 194                 self.children={}
 195         def indent(self,w,t):
 196                 w.write("                 "[:t])
 197         def prop_out(self,n):
 198                 return self.allow_properties[n](n,str(self.properties[n]))
 199         def output_props(self,w,ind):
 200                 for i in self.properties.keys():
 201                         if self.allow_properties[i]:
 202                                 self.indent(w,ind)
 203                                 w.write("%s"%self.prop_out(i))
 204         def output_data(self,w,ind,np):
 205                 self.indent(w,ind)
 206                 w.write("%s {\n"%(self.name))
 207                 self.output_props(w,ind+2)
 208                 if self.depth==1: w.write("\n");
 209                 for c in self.children.values():
 210                         c.output_data(w,ind+2,np+self.name+"/")
 211                 self.indent(w,ind)
 212                 w.write("};\n")
 213
 214 class vpnlevel(level):
 215         "VPN level in the configuration hierarchy"
 216         depth=1
 217         leaf=0
 218         type="vpn"
 219         allow_properties=global_properties.copy()
 220         require_properties={
 221          'contact':"VPN admin contact address"
 222         }
 223         def __init__(self,w):
 224                 level.__init__(self,w)
 225         def output_vpnflat(self,w,ind,h):
 226                 "Output flattened list of site names for this VPN"
 227                 self.indent(w,ind)
 228                 w.write("%s {\n"%(self.name))
 229                 for i in self.children.keys():
 230                         self.children[i].output_vpnflat(w,ind+2,
 231                                 h+"/"+self.name+"/"+i)
 232                 w.write("\n")
 233                 self.indent(w,ind+2)
 234                 w.write("all-sites %s;\n"%
 235                         string.join(self.children.keys(),','))
 236                 self.indent(w,ind)
 237                 w.write("};\n")
 238
 239 class locationlevel(level):
 240         "Location level in the configuration hierarchy"
 241         depth=2
 242         leaf=0
 243         type="location"
 244         allow_properties=global_properties.copy()
 245         require_properties={
 246          'contact':"Location admin contact address",
 247         }
 248         def __init__(self,w):
 249                 level.__init__(self,w)
 250                 self.group=w[2]
 251         def output_vpnflat(self,w,ind,h):
 252                 self.indent(w,ind)
 253                 # The "h=h,self=self" abomination below exists because
 254                 # Python didn't support nested_scopes until version 2.1
 255                 w.write("%s %s;\n"%(self.name,string.join(
 256                         map(lambda x,h=h,self=self:
 257                                 h+"/"+x,self.children.keys()),',')))
 258
 259 class sitelevel(level):
 260         "Site level (i.e. a leafnode) in the configuration hierarchy"
 261         depth=3
 262         leaf=1
 263         type="site"
 264         allow_properties=global_properties.copy()
 265         allow_properties.update({
 266          'address':sp,
 267          'networks':None,
 268          'peer':None,
 269          'pubkey':(lambda n,v:"key %s;\n"%v),
 270          'mobile':sp,
 271         })
 272         require_properties={
 273          'dh':"Diffie-Hellman group",
 274          'contact':"Site admin contact address",
 275          'address':"Site external access address",
 276          'networks':"Networks claimed by the site",
 277          'hash':"hash function",
 278          'peer':"Gateway address of the site",
 279          'pubkey':"RSA public key of the site",
 280         }
 281         def __init__(self,w):
 282                 level.__init__(self,w)
 283         def output_data(self,w,ind,np):
 284                 self.indent(w,ind)
 285                 w.write("%s {\n"%(self.name))
 286                 self.indent(w,ind+2)
 287                 w.write("name \"%s\";\n"%(np+self.name))
 288                 self.output_props(w,ind+2)
 289                 self.indent(w,ind+2)
 290                 w.write("link netlink {\n");
 291                 self.indent(w,ind+4)
 292                 w.write("routes %s;\n"%str(self.properties["networks"]))
 293                 self.indent(w,ind+4)
 294                 w.write("ptp-address %s;\n"%str(self.properties["peer"]))
 295                 self.indent(w,ind+2)
 296                 w.write("};\n")
 297                 self.indent(w,ind)
 298                 w.write("};\n")
 299
 300 # Levels in the configuration file
 301 # (depth,properties)
 302 levels={'vpn':vpnlevel, 'location':locationlevel, 'site':sitelevel}
 303
 304 # Reserved vpn/location/site names
 305 reserved={'all-sites':None}
 306 reserved.update(keywords)
 307 reserved.update(levels)
 308
 309 def complain(msg):
 310         "Complain about a particular input line"
 311         global complaints
 312         print ("%s line %d: "%(file,line))+msg
 313         complaints=complaints+1
 314 def moan(msg):
 315         "Complain about something in general"
 316         global complaints
 317         print msg;
 318         complaints=complaints+1
 319
 320 root=level(['root','root'])   # All vpns are children of this node
 321 obstack=[root]
 322 allow_defs=0   # Level above which new definitions are permitted
 323
 324 def set_property(obj,w):
 325         "Set a property on a configuration node"
 326         if obj.properties.has_key(w[0]):
 327                 complain("%s %s already has property %s defined"%
 328                         (obj.type,obj.name,w[0]))
 329         else:
 330                 obj.properties[w[0]]=keywords[w[0]][0](w)
 331
 332 def pline(i,allow_include=False):
 333         "Process a configuration file line"
 334         global allow_defs, obstack, root
 335         w=string.split(i)
 336         if len(w)==0: return
 337         keyword=w[0]
 338         current=obstack[len(obstack)-1]
 339         if keyword=='end-definitions':
 340                 allow_defs=sitelevel.depth
 341                 obstack=[root]
 342                 return
 343         if keyword=='include':
 344                 if not allow_include:
 345                         complain("include not permitted here")
 346                         return
 347                 if len(w) != 2:
 348                         complain("include requires one argument")
 349                         return
 350                 newfile=os.path.join(os.path.dirname(file),w[1])
 351                 pfilepath(newfile,allow_include=allow_include)
 352                 return
 353         if levels.has_key(keyword):
 354                 # We may go up any number of levels, but only down by one
 355                 newdepth=levels[keyword].depth
 356                 currentdepth=len(obstack) # actually +1...
 357                 if newdepth<=currentdepth:
 358                         obstack=obstack[:newdepth]
 359                 if newdepth>currentdepth:
 360                         complain("May not go from level %d to level %d"%
 361                                 (currentdepth-1,newdepth))
 362                 # See if it's a new one (and whether that's permitted)
 363                 # or an existing one
 364                 current=obstack[len(obstack)-1]
 365                 if current.children.has_key(w[1]):
 366                         # Not new
 367                         current=current.children[w[1]]
 368                         if service and group and current.depth==2:
 369                                 if group!=current.group:
 370                                         complain("Incorrect group!")
 371                 else:
 372                         # New
 373                         # Ignore depth check for now
 374                         nl=levels[keyword](w)
 375                         if nl.depth<allow_defs:
 376                                 complain("New definitions not allowed at "
 377                                         "level %d"%nl.depth)
 378                         current.children[w[1]]=nl
 379                         current=nl
 380                 obstack.append(current)
 381                 return
 382         if current.allow_properties.has_key(keyword):
 383                 set_property(current,w)
 384                 return
 385         else:
 386                 complain("Property %s not allowed at %s level"%
 387                         (keyword,current.type))
 388                 return
 389
 390         complain("unknown keyword '%s'"%(keyword))
 391
 392 def pfilepath(pathname,allow_include=False):
 393         f=open(pathname)
 394         pfile(pathname,f.readlines(),allow_include=allow_include)
 395         f.close()
 396
 397 def pfile(name,lines,allow_include=False):
 398         "Process a file"
 399         global file,line
 400         file=name
 401         line=0
 402         for i in lines:
 403                 line=line+1
 404                 if (i[0]=='#'): continue
 405                 if (i[len(i)-1]=='\n'): i=i[:len(i)-1] # strip trailing LF
 406                 pline(i,allow_include=allow_include)
 407
 408 def outputsites(w):
 409         "Output include file for secnet configuration"
 410         w.write("# secnet sites file autogenerated by make-secnet-sites "
 411                 +"version %s\n"%VERSION)
 412         w.write("# %s\n"%time.asctime(time.localtime(time.time())))
 413         w.write("# Command line: %s\n\n"%string.join(sys.argv))
 414
 415         # Raw VPN data section of file
 416         w.write("vpn-data {\n")
 417         for i in root.children.values():
 418                 i.output_data(w,2,"")
 419         w.write("};\n")
 420
 421         # Per-VPN flattened lists
 422         w.write("vpn {\n")
 423         for i in root.children.values():
 424                 i.output_vpnflat(w,2,"vpn-data")
 425         w.write("};\n")
 426
 427         # Flattened list of sites
 428         w.write("all-sites %s;\n"%string.join(map(lambda x:"vpn/%s/all-sites"%
 429                 x,root.children.keys()),","))
 430
 431 # Are we being invoked from userv?
 432 service=0
 433 # If we are, which group does the caller want to modify?
 434 group=None
 435
 436 line=0
 437 file=None
 438 complaints=0
 439
 440 if len(sys.argv)<2:
 441         pfile("stdin",sys.stdin.readlines())
 442         of=sys.stdout
 443 else:
 444         if sys.argv[1]=='-u':
 445                 if len(sys.argv)!=6:
 446                         print "Wrong number of arguments"
 447                         sys.exit(1)
 448                 service=1
 449                 header=sys.argv[2]
 450                 groupfiledir=sys.argv[3]
 451                 sitesfile=sys.argv[4]
 452                 group=sys.argv[5]
 453                 if not os.environ.has_key("USERV_USER"):
 454                         print "Environment variable USERV_USER not found"
 455                         sys.exit(1)
 456                 user=os.environ["USERV_USER"]
 457                 # Check that group is in USERV_GROUP
 458                 if not os.environ.has_key("USERV_GROUP"):
 459                         print "Environment variable USERV_GROUP not found"
 460                         sys.exit(1)
 461                 ugs=os.environ["USERV_GROUP"]
 462                 ok=0
 463                 for i in string.split(ugs):
 464                         if group==i: ok=1
 465                 if not ok:
 466                         print "caller not in group %s"%group
 467                         sys.exit(1)
 468                 pfilepath(header,allow_include=True)
 469                 userinput=sys.stdin.readlines()
 470                 pfile("user input",userinput)
 471         else:
 472                 if len(sys.argv)>3:
 473                         print "Too many arguments"
 474                         sys.exit(1)
 475                 pfilepath(sys.argv[1],allow_include=True)
 476                 of=sys.stdout
 477                 if len(sys.argv)>2:
 478                         of=open(sys.argv[2],'w')
 479
 480 # Sanity check section
 481 # Delete nodes where leaf=0 that have no children
 482
 483 def live(n):
 484         "Number of leafnodes below node n"
 485         if n.leaf: return 1
 486         for i in n.children.keys():
 487                 if live(n.children[i]): return 1
 488         return 0
 489 def delempty(n):
 490         "Delete nodes that have no leafnode children"
 491         for i in n.children.keys():
 492                 delempty(n.children[i])
 493                 if not live(n.children[i]):
 494                         del n.children[i]
 495 delempty(root)
 496
 497 # Check that all constraints are met (as far as I can tell
 498 # restrict-nets/networks/peer are the only special cases)
 499
 500 def checkconstraints(n,p,ra):
 501         new_p=p.copy()
 502         new_p.update(n.properties)
 503         for i in n.require_properties.keys():
 504                 if not new_p.has_key(i):
 505                         moan("%s %s is missing property %s"%
 506                                 (n.type,n.name,i))
 507         for i in new_p.keys():
 508                 if not n.allow_properties.has_key(i):
 509                         moan("%s %s has forbidden property %s"%
 510                                 (n.type,n.name,i))
 511         # Check address range restrictions
 512         if n.properties.has_key("restrict-nets"):
 513                 new_ra=ra.intersection(n.properties["restrict-nets"].set)
 514         else:
 515                 new_ra=ra
 516         if n.properties.has_key("networks"):
 517                 # I'd like to do this:
 518                 # n.properties["networks"].set.is_subset(new_ra)
 519                 # but there isn't an is_subset() method
 520                 # Instead we see if we intersect with the complement of new_ra
 521                 rac=new_ra.complement()
 522                 i=rac.intersection(n.properties["networks"].set)
 523                 if not i.is_empty():
 524                         moan("%s %s networks out of bounds"%(n.type,n.name))
 525                 if n.properties.has_key("peer"):
 526                         if not n.properties["networks"].set.contains(
 527                                 n.properties["peer"].addr):
 528                                 moan("%s %s peer not in networks"%(n.type,n.name))
 529         for i in n.children.keys():
 530                 checkconstraints(n.children[i],new_p,new_ra)
 531
 532 checkconstraints(root,{},ipaddr.complete_set)
 533
 534 if complaints>0:
 535         if complaints==1: print "There was 1 problem."
 536         else: print "There were %d problems."%(complaints)
 537         sys.exit(1)
 538
 539 if service:
 540         # Put the user's input into their group file, and rebuild the main
 541         # sites file
 542         f=open(groupfiledir+"/T"+group,'w')
 543         f.write("# Section submitted by user %s, %s\n"%
 544                 (user,time.asctime(time.localtime(time.time()))))
 545         f.write("# Checked by make-secnet-sites version %s\n\n"%VERSION)
 546         for i in userinput: f.write(i)
 547         f.write("\n")
 548         f.close()
 549         os.rename(groupfiledir+"/T"+group,groupfiledir+"/R"+group)
 550         f=open(sitesfile+"-tmp",'w')
 551         f.write("# sites file autogenerated by make-secnet-sites\n")
 552         f.write("# generated %s, invoked by %s\n"%
 553                 (time.asctime(time.localtime(time.time())),user))
 554         f.write("# use make-secnet-sites to turn this file into a\n")
 555         f.write("# valid /etc/secnet/sites.conf file\n\n")
 556         for i in headerinput: f.write(i)
 557         files=os.listdir(groupfiledir)
 558         for i in files:
 559                 if i[0]=='R':
 560                         j=open(groupfiledir+"/"+i)
 561                         f.write(j.read())
 562                         j.close()
 563         f.write("# end of sites file\n")
 564         f.close()
 565         os.rename(sitesfile+"-tmp",sitesfile)
 566 else:
 567         outputsites(of)