File: //usr/share/selinux/devel/include/support/segenxml.py
#!/usr/bin/env python3
# Author(s): Donald Miner <dminer@tresys.com>
# Dave Sugar <dsugar@tresys.com>
# Brian Williams <bwilliams@tresys.com>
# Caleb Case <ccase@tresys.com>
#
# Copyright (C) 2005 - 2006 Tresys Technology, LLC
# 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.
"""
This script generates XML documentation information for layers specified
by the user.
"""
import sys
import os
import re
import getopt
# GLOBALS
# Default values of command line arguments:
output_dir = ""
# Pre compiled regular expressions:
# Matches either an interface or a template declaration. Will give the tuple:
# ("interface" or "template", name)
# Some examples:
# "interface(`kernel_read_system_state',`"
# -> ("interface", "kernel_read_system_state")
# "template(`base_user_template',`"
# -> ("template", "base_user_template")
INTERFACE = re.compile(r"^\s*(interface|template)\(`(\w*)'")
# Matches either a gen_bool or a gen_tunable statement. Will give the tuple:
# ("tunable" or "bool", name, "true" or "false")
# Some examples:
# "gen_bool(secure_mode, false)"
# -> ("bool", "secure_mode", "false")
# "gen_tunable(allow_kerberos, false)"
# -> ("tunable", "allow_kerberos", "false")
BOOLEAN = re.compile(r"^\s*gen_(tunable|bool)\(\s*\`?\s*(\w*)\s*\'?\s*,\s*(true|false)\s*\)")
TEMPLATE_BOOLEAN = re.compile(r"^\s*gen_(tunable|bool)\(\s*\`?\s*([\w\$]*)\s*\'?\s*,\s*(true|false)\s*\)")
# Matches a XML comment in the policy, which is defined as any line starting
# with two # and at least one character of white space. Will give the single
# valued tuple:
# ("comment")
# Some Examples:
# "## <summary>"
# -> ("<summary>")
# "## The domain allowed access. "
# -> ("The domain allowed access.")
XML_COMMENT = re.compile(r"^\s*##\s+(.*?)\s*$")
# Matches a template call in the policy, which is defined as any line having
# a function call like structure, being a string, followed by a set of
# arguments between an opening and closing bracket. Regexp cannot deal with
# unknown number of arguments, so we will split arguments in the code later on.
# Some examples:
# "userdom_user_access_template(gpg, gpg_t)"
# "zarafa_domain_template(gateway)"
TEMPLATE_CALL = re.compile(r"^\s*(\w*_template)\(\s*(\w*)\s*(?:,\s*(?:[^,)]*)\s*)*\)")
# FUNCTIONS
def getModuleXML(file_name):
'''
Returns the XML data for a module in a list, one line per list item.
'''
# Gather information.
module_dir = os.path.dirname(file_name)
module_name = os.path.basename(file_name)
module_te = "%s/%s.te" % (module_dir, module_name)
module_if = "%s/%s.if" % (module_dir, module_name)
# Try to open the file, if it can't, just ignore it.
try:
module_file = open(module_if, "r")
module_code = module_file.readlines()
module_file.close()
except OSError:
warning("cannot open file %s for read, skipping" % file_name)
return []
module_buf = []
# Infer the module name, which is the base of the file name.
module_buf.append("<module name=\"%s\" filename=\"%s\">\n"
% (os.path.splitext(os.path.split(file_name)[-1])[0], module_if))
temp_buf = []
interface = None
# finding_header is a flag to denote whether we are still looking
# for the XML documentation at the head of the file.
finding_header = True
# Get rid of whitespace at top of file
while(module_code and module_code[0].isspace()):
module_code = module_code[1:]
# Go line by line and figure out what to do with it.
line_num = 0
for line in module_code:
line_num += 1
if finding_header:
# If there is a XML comment, add it to the temp buffer.
comment = XML_COMMENT.match(line)
if comment:
temp_buf.append(comment.group(1) + "\n")
continue
# Once a line that is not an XML comment is reached,
# either put the XML out to module buffer as the
# module's documentation, or attribute it to an
# interface/template.
elif temp_buf:
finding_header = False
interface = INTERFACE.match(line)
if not interface:
module_buf += temp_buf
temp_buf = []
continue
# Skip over empty lines
if line.isspace():
continue
# Grab a comment and add it to the temporary buffer, if it
# is there.
comment = XML_COMMENT.match(line)
if comment:
temp_buf.append(comment.group(1) + "\n")
continue
# Grab the interface information. This is only not true when
# the interface is at the top of the file and there is no
# documentation for the module.
if not interface:
interface = INTERFACE.match(line)
if interface:
# Add the opening tag for the interface/template
groups = interface.groups()
module_buf.append("<%s name=\"%s\" lineno=\"%s\">\n" % (groups[0], groups[1], line_num))
# Add all the comments attributed to this interface to
# the module buffer.
if temp_buf:
module_buf += temp_buf
temp_buf = []
# Add default summaries and parameters so that the
# DTD is happy.
else:
warning ("unable to find XML for %s %s()" % (groups[0], groups[1]))
module_buf.append("<summary>\n")
module_buf.append("Summary is missing!\n")
module_buf.append("</summary>\n")
module_buf.append("<param name=\"?\">\n")
module_buf.append("<summary>\n")
module_buf.append("Parameter descriptions are missing!\n")
module_buf.append("</summary>\n")
module_buf.append("</param>\n")
# Close the interface/template tag.
module_buf.append("</%s>\n" % interface.group(1))
interface = None
continue
# If the line is a boolean/tunable definition, ignore it for now (these
# lines are processed later on) and dismiss the XML comment received
# thus far as it is otherwise attributed to an interface.
tunable = TEMPLATE_BOOLEAN.match(line)
if tunable:
temp_buf = []
continue
# If the file just had a header, add the comments to the module buffer.
if finding_header:
module_buf += temp_buf
# Otherwise there are some lingering XML comments at the bottom, warn
# the user.
elif temp_buf:
warning("orphan XML comments at bottom of file %s" % file_name)
# Process the TE file if it exists.
module_buf = module_buf + getTunableXML(module_te, "both")
module_buf.append("</module>\n")
return module_buf
def getTunableXML(file_name, kind):
'''
Return all the XML for the tunables/bools in the file specified.
'''
# Try to open the file, if it can't, just ignore it.
try:
tunable_file = open(file_name, "r")
tunable_code = tunable_file.readlines()
tunable_file.close()
except OSError:
warning("cannot open file %s for read, skipping" % file_name)
return []
tunable_buf = []
temp_buf = []
tunable_processed_code = []
# We first go through the code and substitute template calls with the
# complete template content. This needs to happen iteratively, because
# a template can call another template. In order to ensure no cyclic
# template calls keep us busy, we max out at 9999 substitutions
has_changed = True
subst_threshold = 9999
while (has_changed and (subst_threshold > 0)):
has_changed = False
for line in tunable_code:
# Get the template call match
template_call = TEMPLATE_CALL.match(line)
# If we reach a template call, read in the template data
# from the template directory, but substitute all $1 with
# the second match, $2 with the third match, etc.
if template_call:
# Read template file based on template_call.group(1)
try:
template_file = open(templatedir + "/" + template_call.group(1) + ".iftemplate", "r")
template_code = template_file.readlines()
template_file.close()
except OSError:
warning("cannot open file %s for read, bailing out" % (templatedir + "/" + template_call.group(1) + ".iftemplate"))
return []
# Substitute content (i.e. $1 for argument 1, $2 for argument 2, etc.)
template_split = re.findall(r"[\w\" {}]+", line.strip())
for index, item in enumerate(template_code):
for group in range(1, len(template_split)):
template_code[index] = template_code[index].replace("$" + str(group), template_split[group].strip())
# Now 'inject' the code in the tunable_code variable
tunable_processed_code.extend(template_code)
has_changed = True
subst_threshold -= 1
else:
tunable_processed_code.append(line)
# It is a bad practice to try and update lists while in a loop, so we
# created an intermediate one and are now assigning it back
tunable_code = tunable_processed_code
tunable_processed_code = []
# If subst_threshold is 0 or less we want to know
if (subst_threshold <= 0):
warning("Detected a possible loop in policy code and template usage")
# Find tunables and booleans line by line and use the comments above
# them.
for line in tunable_code:
# If it is an XML comment, add it to the buffer and go on.
comment = XML_COMMENT.match(line)
if comment:
temp_buf.append(comment.group(1) + "\n")
continue
# Get the boolean/tunable data.
boolean = BOOLEAN.match(line)
# If we reach a boolean/tunable declaration, attribute all XML
# in the temp buffer to it and add XML to the tunable buffer.
if boolean:
# If there is a gen_bool in a tunable file or a
# gen_tunable in a boolean file, error and exit.
# Skip if both kinds are valid.
if kind != "both":
if boolean.group(1) != kind:
error("%s in a %s file." % (boolean.group(1), kind))
tunable_buf.append("<%s name=\"%s\" dftval=\"%s\">\n" % boolean.groups())
tunable_buf += temp_buf
temp_buf = []
tunable_buf.append("</%s>\n" % boolean.group(1))
# If there are XML comments at the end of the file, they aren't
# attributed to anything. These are ignored.
if len(temp_buf):
warning("orphan XML comments at bottom of file %s" % file_name)
# If the caller requested a the global_tunables and global_booleans to be
# output to a file output them now
if len(output_dir) > 0:
xmlfile = os.path.split(file_name)[1] + ".xml"
try:
xml_outfile = open(output_dir + "/" + xmlfile, "w")
for tunable_line in tunable_buf:
xml_outfile.write (tunable_line)
xml_outfile.close()
except OSError:
warning ("cannot write to file %s, skipping creation" % xmlfile)
return tunable_buf
def usage():
"""
Displays a message describing the proper usage of this script.
"""
sys.stdout.write("usage: %s [-w] [-T <templatedir>] [-mtb] <file>\n\n" % sys.argv[0])
sys.stdout.write("-w --warn\t\t\tshow warnings\n"+\
"-m --module <file>\t\tname of module to process\n"+\
"-t --tunable <file>\t\tname of global tunable file to process\n"+\
"-b --boolean <file>\t\tname of global boolean file to process\n"+\
"-T --templates <dir>\t\tname of template directory to use\n\n")
sys.stdout.write("examples:\n")
sys.stdout.write("> %s -w -T tmp/templates -m policy/modules/apache\n" % sys.argv[0])
sys.stdout.write("> %s -t policy/global_tunables\n" % sys.argv[0])
def warning(description):
'''
Warns the user of a non-critical error.
'''
if warn:
sys.stderr.write("%s: " % sys.argv[0] )
sys.stderr.write("warning: " + description + "\n")
def error(description):
'''
Describes an error and exists the program.
'''
sys.stderr.write("%s: " % sys.argv[0] )
sys.stderr.write("error: " + description + "\n")
sys.stderr.flush()
sys.exit(1)
# MAIN PROGRAM
# Defaults
warn = False
module = False
tunable = False
boolean = False
templatedir = ''
# Check that there are command line arguments.
if len(sys.argv) <= 1:
usage()
sys.exit(1)
# Parse command line args
try:
opts, args = getopt.getopt(sys.argv[1:], 'whm:t:b:T:', ['warn', 'help', 'module=', 'tunable=', 'boolean=', 'templates='])
except getopt.GetoptError:
usage()
sys.exit(2)
for o, a in opts:
if o in ('-w', '--warn'):
warn = True
elif o in ('-h', '--help'):
usage()
sys.exit(0)
elif o in ('-m', '--module'):
module = a
elif o in ('-t', '--tunable'):
tunable = a
elif o in ('-b', '--boolean'):
boolean = a
elif o in ('-T', '--templates'):
templatedir = a
else:
usage()
sys.exit(2)
if module:
sys.stdout.writelines(getModuleXML(module))
elif tunable:
sys.stdout.writelines(getTunableXML(tunable, "tunable"))
elif boolean:
sys.stdout.writelines(getTunableXML(boolean, "bool"))
else:
usage()
sys.exit(2)