sfatables/sfatables

   1 #!/usr/bin/python
   2
   3 # This file parses an sfatables command and generates XML files that parameterize
   4 # matches and targets. Each such XML file defines a rule. Rules are dropped in directories
   5 # that represent 'chains.' SFA loads rules from various chains and invokes them at certain
   6 # 'hook points.' For example, it invokes rules in the 'OUTGOING' chain before returning
   7 # the output of 'get_resources.'
   8
   9 import sys
  10 import os
  11 import pdb
  12 import libxml2
  13
  14 from optparse import OptionParser
  15 from sfatables import commands, matches, targets
  16 from sfatables.xmlextension import Xmlextension
  17
  18 def load_commands(module, list):
  19     command_dict={}
  20
  21     for command_name in list:
  22         command_module = __import__(".".join([module,command_name]),fromlist=[module])
  23         command = getattr(command_module, command_name)
  24         command_dict[command_name]=command()
  25
  26     return command_dict
  27
  28 def load_xml_extensions(module, list):
  29     ext_dict={}
  30
  31     for ext_name in list:
  32         module = Xmlextension(ext_name)
  33         ext_dict[ext_name]=module
  34
  35     return ext_dict
  36
  37
  38 def create_parser(command_dict):
  39     parser = OptionParser(usage="sfatables [command] [chain] [match] [target]",
  40                              description='See "man sfatables" for more detail.')
  41
  42     for k in command_dict.keys():
  43         command = command_dict[k]
  44         for (short_option,long_option) in command.options:
  45             parser.add_option(short_option,long_option,dest=command.type,action=command.action,const=k,help=command.help,metavar="CHAIN")
  46
  47     return parser
  48
  49 def create_parser_xml_ext(ext_dict):
  50     parser = OptionParser(usage="sfatables [command] [chain] [match] [target]",
  51                              description='See "man sfatables" for more detail.')
  52
  53     for k in ext_dict.keys():
  54         command = ext_dict[k]
  55         for arg in command.arguments:
  56             parser.add_option('',"--"+arg['name'],dest=arg['name'],help=arg['help'],metavar=arg['target'])
  57
  58     return parser
  59
  60
  61 def partition(sep, lst):
  62     ret = []
  63     curpart = []
  64     for item in lst:
  65         if (item==sep):
  66             ret.append(curpart)
  67             curpart=[]
  68         else:
  69             curpart.append(item)
  70     ret.append(curpart)
  71
  72     return ret
  73
  74
  75 def main():
  76     # sfatables <command> -- <match> -- <target>
  77     pargs = partition('--', sys.argv[1:])
  78
  79     command_dict = load_commands("sfatables.commands",commands.all)
  80     command_parser = create_parser(command_dict)
  81     (options, args) = command_parser.parse_args(pargs[0])
  82     setattr(options, 'args', args)
  83
  84     command = command_dict[options.command]
  85
  86     if (command.matches):
  87         if (len(pargs)<2):
  88             raise Exception("Must specify match for this command")
  89         match_dict = load_xml_extensions("sfatables.matches",matches.all)
  90         match_parser = create_parser_xml_ext(match_dict)
  91         matches_str = ",".join(match_dict.keys())
  92         match_parser.add_option('-m','--match',dest='match_name',help='Match name (one of %s)'%matches_str, metavar = 'MATCH')
  93         (match_options, args) = match_parser.parse_args(pargs[1])
  94         try:
  95             match_name = match_options.match_name
  96         except Exception:
  97             print "Must specify match name with -m"
  98
  99         if (match_dict.has_key(match_name)):
 100             setattr(match_options, 'arguments', match_dict[match_name].arguments)
 101         else:
 102             raise Exception('Match %s not found'%match_name)
 103
 104     else:
 105         match_options=None
 106
 107     if (command.targets):
 108         if (len(pargs)<3):
 109             raise Exception("Must specify a target for this command")
 110         target_dict = load_xml_extensions("sfatables.targets",targets.all)
 111         target_parser = create_parser_xml_ext(target_dict)
 112         targets_str = ",".join(target_dict.keys())
 113         target_parser.add_option('-j','--jump',dest='target_name',help='Target name (one of %s)'%targets, metavar = 'TARGET')
 114         (target_options, args) = target_parser.parse_args(pargs[2])
 115         try:
 116             target_name = target_options.target_name
 117         except Exception:
 118             print "Must specify target name with -m"
 119
 120 #        if (target_dict.has_key(target_name)):
 121 #            setattr(target_options, 'arguments', target_dict[target_name].arguments)
 122 #        else:
 123 #            raise Exception('Target %s not found'%target_name)
 124
 125     else:
 126         target_options = None
 127
 128     command(options, match_options, target_options)
 129
 130 if __name__=='__main__':
 131     main()