#! /usr/bin/python -Es
# Copyright (C) 2012 Red Hat 
# see file 'COPYING' for use and warranty information
#
# setrans is a tool for analyzing process transistions in SELinux policy
#
#    This program is free software; you can redistribute it and/or
#    modify it under the terms of the GNU General Public License as
#    published by the Free Software Foundation; either version 2 of
#    the License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA     
#                                        02111-1307  USA
#
#  
import setools, sys
search=setools.sesearch
seinfo=setools.seinfo
def usage(parser, msg):
    parser.print_help()

    sys.stderr.write("\n%s\n" % msg)
    sys.stderr.flush()
    sys.exit(1)


def expand_attribute(attribute):
    try:
        return seinfo(setools.ATTRIBUTE, attribute)[0]["types"]
    except RuntimeError:
        return [ attribute ]

def get_types(src, tclass, perm):
    allows=search([setools.ALLOW],{setools.SCONTEXT:src,setools.CLASS:tclass, setools.PERMS:perm})

    tlist = []
    for l in map(lambda y: y[setools.TCONTEXT], filter(lambda x: set(perm).issubset(x[setools.PERMS]), allows)):
        tlist = tlist + expand_attribute(l)
    return tlist

if __name__ == '__main__':
    try:
        import argparse
        parser = argparse.ArgumentParser(description='SELinux Communication Analysys Tool')
        parser.add_argument("-c", "--class", required=False, dest="tclass",  default="file", help="Class to use for communications, Default 'file'")
        
        parser.add_argument("-s", "--sourceaccess", required=False, dest="sourceaccess",  default="open,write", help="Comma separate list of permissions for the source type to use, Default 'open,write'")
        parser.add_argument("-t", "--targetaccess", required=False, dest="targetaccess",  default="open,read", help="Comman separated list of permissions for the target type to use, Default 'open,read'")
        parser.add_argument("source", help="Source type")
        parser.add_argument("target", help="Source type")
        args = parser.parse_args()

        writable = get_types(args.source, args.tclass, args.sourceaccess.split(","))
        readable = get_types(args.target, args.tclass, args.targetaccess.split(","))
        out = list(set(writable) & set(readable))
        for t in out:
            print t

    except IndexError:
        usage(parser,"")
    except TypeError, e:
        usage(parser,e)