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          'address':None,
 271          'mobile':sp,
 272         })
 273         require_properties={
 274          'dh':"Diffie-Hellman group",
 275          'contact':"Site admin contact 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 prefix=''
 324
 325 def set_property(obj,w):
 326         "Set a property on a configuration node"
 327         if obj.properties.has_key(w[0]):
 328                 complain("%s %s already has property %s defined"%
 329                         (obj.type,obj.name,w[0]))
 330         else:
 331                 obj.properties[w[0]]=keywords[w[0]][0](w)
 332
 333 def pline(i,allow_include=False):
 334         "Process a configuration file line"
 335         global allow_defs, obstack, root
 336         w=string.split(i)
 337         if len(w)==0: return
 338         keyword=w[0]
 339         current=obstack[len(obstack)-1]
 340         if keyword=='end-definitions':
 341                 allow_defs=sitelevel.depth
 342                 obstack=[root]
 343                 return
 344         if keyword=='include':
 345                 if not allow_include:
 346                         complain("include not permitted here")
 347                         return
 348                 if len(w) != 2:
 349                         complain("include requires one argument")
 350                         return
 351                 newfile=os.path.join(os.path.dirname(file),w[1])
 352                 pfilepath(newfile,allow_include=allow_include)
 353                 return
 354         if levels.has_key(keyword):
 355                 # We may go up any number of levels, but only down by one
 356                 newdepth=levels[keyword].depth
 357                 currentdepth=len(obstack) # actually +1...
 358                 if newdepth<=currentdepth:
 359                         obstack=obstack[:newdepth]
 360                 if newdepth>currentdepth:
 361                         complain("May not go from level %d to level %d"%
 362                                 (currentdepth-1,newdepth))
 363                 # See if it's a new one (and whether that's permitted)
 364                 # or an existing one
 365                 current=obstack[len(obstack)-1]
 366                 if current.children.has_key(w[1]):
 367                         # Not new
 368                         current=current.children[w[1]]
 369                         if service and group and current.depth==2:
 370                                 if group!=current.group:
 371                                         complain("Incorrect group!")
 372                 else:
 373                         # New
 374                         # Ignore depth check for now
 375                         nl=levels[keyword](w)
 376                         if nl.depth<allow_defs:
 377                                 complain("New definitions not allowed at "
 378                                         "level %d"%nl.depth)
 379                         current.children[w[1]]=nl
 380                         current=nl
 381                 obstack.append(current)
 382                 return
 383         if current.allow_properties.has_key(keyword):
 384                 set_property(current,w)
 385                 return
 386         else:
 387                 complain("Property %s not allowed at %s level"%
 388                         (keyword,current.type))
 389                 return
 390
 391         complain("unknown keyword '%s'"%(keyword))
 392
 393 def pfilepath(pathname,allow_include=False):
 394         f=open(pathname)
 395         lines=f.readlines()
 396         pfile(pathname,lines,allow_include=allow_include)
 397         f.close()
 398         return lines
 399
 400 def pfile(name,lines,allow_include=False):
 401         "Process a file"
 402         global file,line
 403         file=name
 404         line=0
 405         for i in lines:
 406                 line=line+1
 407                 if (i[0]=='#'): continue
 408                 if (i[len(i)-1]=='\n'): i=i[:len(i)-1] # strip trailing LF
 409                 pline(i,allow_include=allow_include)
 410
 411 def outputsites(w):
 412         "Output include file for secnet configuration"
 413         w.write("# secnet sites file autogenerated by make-secnet-sites "
 414                 +"version %s\n"%VERSION)
 415         w.write("# %s\n"%time.asctime(time.localtime(time.time())))
 416         w.write("# Command line: %s\n\n"%string.join(sys.argv))
 417
 418         # Raw VPN data section of file
 419         w.write(prefix+"vpn-data {\n")
 420         for i in root.children.values():
 421                 i.output_data(w,2,"")
 422         w.write("};\n")
 423
 424         # Per-VPN flattened lists
 425         w.write(prefix+"vpn {\n")
 426         for i in root.children.values():
 427                 i.output_vpnflat(w,2,prefix+"vpn-data")
 428         w.write("};\n")
 429
 430         # Flattened list of sites
 431         w.write(prefix+"all-sites %s;\n"%string.join(
 432                 map(lambda x:"%svpn/%s/all-sites"%(prefix,x),
 433                         root.children.keys()),","))
 434
 435 # Are we being invoked from userv?
 436 service=0
 437 # If we are, which group does the caller want to modify?
 438 group=None
 439
 440 line=0
 441 file=None
 442 complaints=0
 443
 444 if len(sys.argv)<2:
 445         pfile("stdin",sys.stdin.readlines())
 446         of=sys.stdout
 447 else:
 448         if sys.argv[1]=='-u':
 449                 if len(sys.argv)!=6:
 450                         print "Wrong number of arguments"
 451                         sys.exit(1)
 452                 service=1
 453                 header=sys.argv[2]
 454                 groupfiledir=sys.argv[3]
 455                 sitesfile=sys.argv[4]
 456                 group=sys.argv[5]
 457                 if not os.environ.has_key("USERV_USER"):
 458                         print "Environment variable USERV_USER not found"
 459                         sys.exit(1)
 460                 user=os.environ["USERV_USER"]
 461                 # Check that group is in USERV_GROUP
 462                 if not os.environ.has_key("USERV_GROUP"):
 463                         print "Environment variable USERV_GROUP not found"
 464                         sys.exit(1)
 465                 ugs=os.environ["USERV_GROUP"]
 466                 ok=0
 467                 for i in string.split(ugs):
 468                         if group==i: ok=1
 469                 if not ok:
 470                         print "caller not in group %s"%group
 471                         sys.exit(1)
 472                 headerinput=pfilepath(header,allow_include=True)
 473                 userinput=sys.stdin.readlines()
 474                 pfile("user input",userinput)
 475         else:
 476                 if sys.argv[1]=='-P':
 477                         prefix=sys.argv[2]
 478                         sys.argv[1:3]=[]
 479                 if len(sys.argv)>3:
 480                         print "Too many arguments"
 481                         sys.exit(1)
 482                 pfilepath(sys.argv[1],allow_include=True)
 483                 of=sys.stdout
 484                 if len(sys.argv)>2:
 485                         of=open(sys.argv[2],'w')
 486
 487 # Sanity check section
 488 # Delete nodes where leaf=0 that have no children
 489
 490 def live(n):
 491         "Number of leafnodes below node n"
 492         if n.leaf: return 1
 493         for i in n.children.keys():
 494                 if live(n.children[i]): return 1
 495         return 0
 496 def delempty(n):
 497         "Delete nodes that have no leafnode children"
 498         for i in n.children.keys():
 499                 delempty(n.children[i])
 500                 if not live(n.children[i]):
 501                         del n.children[i]
 502 delempty(root)
 503
 504 # Check that all constraints are met (as far as I can tell
 505 # restrict-nets/networks/peer are the only special cases)
 506
 507 def checkconstraints(n,p,ra):
 508         new_p=p.copy()
 509         new_p.update(n.properties)
 510         for i in n.require_properties.keys():
 511                 if not new_p.has_key(i):
 512                         moan("%s %s is missing property %s"%
 513                                 (n.type,n.name,i))
 514         for i in new_p.keys():
 515                 if not n.allow_properties.has_key(i):
 516                         moan("%s %s has forbidden property %s"%
 517                                 (n.type,n.name,i))
 518         # Check address range restrictions
 519         if n.properties.has_key("restrict-nets"):
 520                 new_ra=ra.intersection(n.properties["restrict-nets"].set)
 521         else:
 522                 new_ra=ra
 523         if n.properties.has_key("networks"):
 524                 # I'd like to do this:
 525                 # n.properties["networks"].set.is_subset(new_ra)
 526                 # but there isn't an is_subset() method
 527                 # Instead we see if we intersect with the complement of new_ra
 528                 rac=new_ra.complement()
 529                 i=rac.intersection(n.properties["networks"].set)
 530                 if not i.is_empty():
 531                         moan("%s %s networks out of bounds"%(n.type,n.name))
 532                 if n.properties.has_key("peer"):
 533                         if not n.properties["networks"].set.contains(
 534                                 n.properties["peer"].addr):
 535                                 moan("%s %s peer not in networks"%(n.type,n.name))
 536         for i in n.children.keys():
 537                 checkconstraints(n.children[i],new_p,new_ra)
 538
 539 checkconstraints(root,{},ipaddr.complete_set)
 540
 541 if complaints>0:
 542         if complaints==1: print "There was 1 problem."
 543         else: print "There were %d problems."%(complaints)
 544         sys.exit(1)
 545
 546 if service:
 547         # Put the user's input into their group file, and rebuild the main
 548         # sites file
 549         f=open(groupfiledir+"/T"+group,'w')
 550         f.write("# Section submitted by user %s, %s\n"%
 551                 (user,time.asctime(time.localtime(time.time()))))
 552         f.write("# Checked by make-secnet-sites version %s\n\n"%VERSION)
 553         for i in userinput: f.write(i)
 554         f.write("\n")
 555         f.close()
 556         os.rename(groupfiledir+"/T"+group,groupfiledir+"/R"+group)
 557         f=open(sitesfile+"-tmp",'w')
 558         f.write("# sites file autogenerated by make-secnet-sites\n")
 559         f.write("# generated %s, invoked by %s\n"%
 560                 (time.asctime(time.localtime(time.time())),user))
 561         f.write("# use make-secnet-sites to turn this file into a\n")
 562         f.write("# valid /etc/secnet/sites.conf file\n\n")
 563         for i in headerinput: f.write(i)
 564         files=os.listdir(groupfiledir)
 565         for i in files:
 566                 if i[0]=='R':
 567                         j=open(groupfiledir+"/"+i)
 568                         f.write(j.read())
 569                         j.close()
 570         f.write("# end of sites file\n")
 571         f.close()
 572         os.rename(sitesfile+"-tmp",sitesfile)
 573 else:
 574         outputsites(of)