#!/usr/bin/python3 -Es

#

# Authors: Karl MacMillan <kmacmillan@mentalrootkit.com>

#

# Copyright (C) 2006 Red Hat

# see file 'COPYING' for use and warranty information

#

# 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; version 2 only

#

# 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

#

# Parse interfaces and output extracted information about them

# suitable for policy generation. By default writes the output

# to the default location (obtained from sepolgen.defaults), but

# will output to another file provided as an argument:

#   sepolgen-ifgen [headers] [output-filename]

import sys

import os

import tempfile

import subprocess

import selinux

import sepolgen.refparser as refparser

import sepolgen.defaults as defaults

import sepolgen.interfaces as interfaces

VERSION = "%prog .1"

ATTR_HELPER = "/usr/bin/sepolgen-ifgen-attr-helper"

def parse_options():

    from optparse import OptionParser

    parser = OptionParser(version=VERSION)

    parser.add_option("-o", "--output", dest="output", default=defaults.interface_info(),

                      help="filename to store output")

    parser.add_option("-i", "--interfaces", dest="headers", default=defaults.headers(),

                      help="location of the interface header files")

    parser.add_option("-a", "--attribute_info", dest="attribute_info")

    parser.add_option("-p", "--policy", dest="policy_path")

    parser.add_option("-v", "--verbose", action="store_true", default=False,

                      help="print debuging output")

    parser.add_option("-d", "--debug", action="store_true", default=False,

                      help="extra debugging output")

    parser.add_option("--attr-helper", default=ATTR_HELPER,

                      help="path to sepolgen-ifgen-attr-helper")

    parser.add_option("--no_attrs", action="store_true", default=False,

                      help="do not retrieve attribute access from kernel policy")

    options, args = parser.parse_args()

    return options

def get_policy():

    p = selinux.selinux_current_policy_path()

    if p and os.path.exists(p):

        return p

    i = selinux.security_policyvers()

    p = selinux.selinux_binary_policy_path() + "." + str(i)

    while i > 0 and not os.path.exists(p):

        i = i - 1

        p = selinux.selinux_binary_policy_path() + "." + str(i)

    if i > 0:

        return p

    return None

def get_attrs(policy_path, attr_helper):

    try:

        if not policy_path:

            policy_path = get_policy()

        if not policy_path:

            sys.stderr.write("No installed policy to check\n")

            return None

        outfile = tempfile.NamedTemporaryFile()

    except IOError as e:

        sys.stderr.write("could not open attribute output file\n")

        return None

    except OSError:

        # SELinux Disabled Machine

        return None

    fd = open("/dev/null", "w")

    ret = subprocess.Popen([attr_helper, policy_path, outfile.name], stdout=fd).wait()

    fd.close()

    if ret != 0:

        sys.stderr.write("could not run attribute helper\n")

        return None

    attrs = interfaces.AttributeSet()

    try:

        attrs.from_file(outfile)

    except:

        print("error parsing attribute info")

        return None

    return attrs

def main():

    options = parse_options()

    # Open the output first to generate errors before parsing

    try:

        f = open(options.output, "w")

    except IOError as e:

        sys.stderr.write("could not open output file [%s]\n" % options.output)

        return 1

    if options.verbose:

        log = sys.stdout

    else:

        log = None

    # Get the attibutes from the binary

    attrs = None

    if not options.no_attrs:

        attrs = get_attrs(options.policy_path, options.attr_helper)

        if attrs is None:

            return 1

    # Parse the headers

    try:

        headers = refparser.parse_headers(options.headers, output=log, debug=options.debug)

    except ValueError as e:

        sys.stderr.write("error parsing headers: %s\n" % e)

        return 1

    if_set = interfaces.InterfaceSet(output=log)

    if_set.add_headers(headers, attributes=attrs)

    if_set.to_file(f)

    f.close()

    if refparser.success:

        return 0

    else:

        return 1

if __name__ == "__main__":

    sys.exit(main())