#!/usr/bin/python

#  Author: Donald Miner <dminer@tresys.com>

#

# Copyright (C) 2003 - 2005 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 glob

import re

# GLOBALS

# Default values of command line arguments:

directory = "./"

warn = False

meta = "metadata"

layers = []

tunable_files = []

bool_files = []

# 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("^\s*(interface|template)\(`([A-Za-z0-9_]*)'")

# 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("^\s*gen_(tunable|bool)\(\s*([A-Za-z0-9_]*)\s*,\s*(true|false)\s*\)")

# 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("^##\s+(.*?)\s*$")

# FUNCTIONS

def getModuleXML(file_name):

	'''

	Returns the XML data for a module in a list, one line per list item.

	'''

	# Try to open the file, if it cant, just ignore it.

	try:

		module_file = open(file_name, "r")

		module_code = module_file.readlines()

		module_file.close()

	except:

		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\">\n" 

		% os.path.splitext(os.path.split(file_name)[-1])[0])

	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.

	for line in module_code:

		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 temprorary 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

			module_buf.append("<%s name=\"%s\">\n" % interface.groups())

			# 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:

				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("Parameter descriptions are missing!\n")

				module_buf.append("</param>\n")

			# Close the interface/template tag.

			module_buf.append("</%s>\n" % interface.group(1))

			interface = None

			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)

	module_buf.append("</module>\n")

	return module_buf

def getLayerXML(directory):

	'''

	Returns the XML documentation for a layer.

	'''

	layer_buf = []

	# Infer the layer name from the directory name.

	layer_buf.append("<layer name=\"%s\">\n" % os.path.basename(directory))

	# Try to open the metadata file for this directory and if it exists,

	# append the contents to the buffer.

	try:

		layer_meta = open(directory+"/"+meta, "r")

		layer_buf += layer_meta.readlines()

		layer_meta.close()

	except:

		warning("cannot open file %s for read, assuming no data"\

			% meta)

	# For each module file in the layer, add its XML.

	for module in glob.glob("%s/*.if" % directory):

		layer_buf += getModuleXML(module)

	layer_buf.append("</layer>\n")

	return layer_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 cant, just ignore it.

	try:

		tunable_file = open(file_name, "r")

		tunable_code = tunable_file.readlines()

		tunable_file.close()

	except:

		warning("cannot open file %s for read, skipping" % file_name)

		return []

	tunable_buf = []

	temp_buf = []

	# 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))

			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.

			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 arn't

	# attributed to anything. These are ignored.

	if len(temp_buf):

		warning("orphan XML comments at bottom of file %s" % file_name)

	return tunable_buf

def getPolicyXML(directory):

	'''

	Return the compelete reference policy XML documentation through a list,

	one line per item.

	'''

	# Keep track of original path so that it will change back at the end.

	old_dir = os.path.abspath(os.path.curdir)

	# Attempt to change directory into the policy directory. If it doesn't

	# exist just return an empty documentation.

	try:

		os.chdir(directory)

	except:

		warning("cannot change directory to %s, ignoring"\

			% directory)

		return []

	policy_buf = []

	policy_buf.append("<policy>\n")

	# Add to the XML each layer specified by the user.

	for layer in layers:

		policy_buf += getLayerXML(layer)

	# Add to the XML each tunable file specified by the user.

	for tunable_file in tunable_files:

		policy_buf += getTunableXML(tunable_file, "tunable")

	# Add to the XML each bool file specified by the user.

	for bool_file in bool_files:

		policy_buf += getTunableXML(bool_file, "bool")

	policy_buf.append("</policy>\n")

	# Return to old directory.

	try:

		os.chdir(old_dir)

	except:

		error("cannot change directory to %s" % old_dir)

	return policy_buf

def usage():

	"""

	Displays a message describing the proper usage of this script.

	"""

	sys.stdout.write("usage: %s [-w] [-d directory] [-m file] "\

		% sys.argv[0])

	sys.stdout.write("layerdirectory [layerdirectory...]\n\n")

	sys.stdout.write("Options:\n")

	sys.stdout.write("-w --warn		--	"+\

				"show warnings\n")

	sys.stdout.write("-m --meta <file>	--	"+\

				"the filename of the metadata in each layer\n")

	sys.stdout.write("-d --directory <dir>	--	"+\

				"directory where the layers are\n")

	sys.stdout.write("-t --tunable <file>	--	"+\

				"A file containing tunable declarations\n")

	sys.stdout.write("-b --bool <file>      --      "+\

				"A file containing bool declarations\n")

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

# Check that there are command line arguments.

if len(sys.argv) <= 1:

	usage()

	sys.exit(1)

# Parse the command line arguments

for i in range(1, len(sys.argv)):

	if sys.argv[i-1] in ("-d", "--directory", "-m", "--meta",\

					"-t", "--tunable", "-b", "--bool"):

		continue

	elif sys.argv[i] in ("-w", "--warn"):

		warn = True

	elif sys.argv[i] in ("-d", "--directory"):

		if i < len(sys.argv)-1:

			directory = sys.argv[i+1]

		else:

			usage()

	elif sys.argv[i] in ("-m", "--meta"):

		if i < len(sys.argv)-1:

			meta = sys.argv[i+1]

		else:

			usage()

	elif sys.argv[i] in ("-t", "--tunable"):

		if i < len(sys.argv)-1:

			tunable_files.append(sys.argv[i+1])

		else:

			usage()

	elif sys.argv[i] in ("-b", "--bool"):

		if i < len(sys.argv)-1:

			bool_files.append(sys.argv[i+1])

		else:

			usage()

	else:

		layers.append(sys.argv[i])

# Generate the XML and output it to a file

lines = getPolicyXML(directory)

for s in lines:

	sys.stdout.write(s)