#! /usr/bin/python -Es
# Copyright (C) 2011 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
failedlist = []
def get_trans(src, dest, slist, tlist = []):
    foundstr = ""
    trans=search([setools.ALLOW],{setools.SCONTEXT:src})
    targets = map(lambda y: y[setools.TCONTEXT], filter(lambda x: "transition" in x[setools.PERMS], trans))

    failedlist.append(src)
    if src in tlist:
        return False

    for f in failedlist:
        if f in targets:
            targets.remove(f)

    if len(targets) == 0:
        return False

    tlist.append(src)
    
    if dest in targets:
        slist.append(tlist + [ dest ])
        return True

    for t in targets:
        get_trans(t,dest, slist, tlist)
        if t in tlist:
            tlist.remove(t)

    return True

def verify_domain(domain):
    try:
        d = seinfo(setools.TYPE, domain)[0]
        if "domain" not in d["attributes"]:
            raise RuntimeError
    except RuntimeError:
        raise TypeError("Types must be process/domain types")

def setrans(source, dest):
    slist=[]
    verify_domain(source)
    verify_domain(dest)
    get_trans(source,dest, slist)
    return slist

def usage(msg=None):
    if msg:
        print msg
    print "%s SOURCE_PROCESS_TYPE DEST_PROCESS_TYPE" % sys.argv[0] 

try:
    for l in setrans(sys.argv[1], sys.argv[2]):
        print " --> ".join(l)
except IndexError:
    usage()
except TypeError, e:
    usage(e)