596 lines
21 KiB
Python
Executable file
596 lines
21 KiB
Python
Executable file
#!/usr/bin/env python3
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# Wireshark - Network traffic analyzer
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# By Gerald Combs <gerald@wireshark.org>
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# Copyright 1998 Gerald Combs
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#
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# SPDX-License-Identifier: GPL-2.0-or-later
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import os
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import re
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import subprocess
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import argparse
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import signal
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# This utility scans for tfs items, and works out if standard ones
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# could have been used intead (from epan/tfs.c)
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# Can also check for value_string where common tfs could be used instead.
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# TODO:
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# - check how many of the definitions in epan/tfs.c are used in other dissectors
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# - although even if unused, might be in external dissectors?
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# - consider merging Item class with check_typed_item_calls.py ?
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# Try to exit soon after Ctrl-C is pressed.
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should_exit = False
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def signal_handler(sig, frame):
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global should_exit
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should_exit = True
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print('You pressed Ctrl+C - exiting')
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signal.signal(signal.SIGINT, signal_handler)
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# Test for whether the given file was automatically generated.
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def isGeneratedFile(filename):
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# Check file exists - e.g. may have been deleted in a recent commit.
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if not os.path.exists(filename):
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return False
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# Open file
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f_read = open(os.path.join(filename), 'r')
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lines_tested = 0
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for line in f_read:
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# The comment to say that its generated is near the top, so give up once
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# get a few lines down.
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if lines_tested > 10:
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f_read.close()
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return False
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if (line.find('Generated automatically') != -1 or
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line.find('Generated Automatically') != -1 or
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line.find('Autogenerated from') != -1 or
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line.find('is autogenerated') != -1 or
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line.find('automatically generated by Pidl') != -1 or
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line.find('Created by: The Qt Meta Object Compiler') != -1 or
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line.find('This file was generated') != -1 or
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line.find('This filter was automatically generated') != -1 or
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line.find('This file is auto generated, do not edit!') != -1 or
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line.find('This file is auto generated') != -1):
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f_read.close()
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return True
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lines_tested = lines_tested + 1
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# OK, looks like a hand-written file!
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f_read.close()
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return False
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# Keep track of custom entries that might appear in multiple dissectors,
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# so we can consider adding them to tfs.c
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custom_tfs_entries = {}
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def AddCustomEntry(val1, val2, file):
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global custom_tfs_entries
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if (val1, val2) in custom_tfs_entries:
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custom_tfs_entries[(val1, val2)].append(file)
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else:
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custom_tfs_entries[(val1, val2)] = [file]
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class TFS:
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def __init__(self, file, name, val1, val2):
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self.file = file
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self.name = name
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self.val1 = val1
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self.val2 = val2
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global warnings_found
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# Should not be empty
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if not len(val1) or not len(val2):
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print('Warning:', file, name, 'has an empty field', self)
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warnings_found += 1
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#else:
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# Strange if one begins with capital but other doesn't?
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#if val1[0].isalpha() and val2[0].isalpha():
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# if val1[0].isupper() != val2[0].isupper():
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# print(file, name, 'one starts lowercase and the other upper', self)
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# Leading or trailing space should not be needed.
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if val1.startswith(' ') or val1.endswith(' '):
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print('Note: ' + self.file + ' ' + self.name + ' - false val begins or ends with space \"' + self.val1 + '\"')
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if val2.startswith(' ') or val2.endswith(' '):
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print('Note: ' + self.file + ' ' + self.name + ' - true val begins or ends with space \"' + self.val2 + '\"')
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# Should really not be identical...
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if val1.lower() == val2.lower():
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print('Warning:', file, name, 'true and false strings are the same', self)
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warnings_found += 1
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# Shouldn't both be negation (with exception..)
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if (file != os.path.join('epan', 'dissectors', 'packet-smb.c') and (val1.lower().find('not ') != -1) and (val2.lower().find('not ') != -1)):
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print('Warning:', file, name, self, 'both strings contain not')
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warnings_found += 1
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# Not expecting full-stops inside strings..
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if val1.find('.') != -1 or val2.find('.') != -1:
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print('Warning:', file, name, 'Period found in string', self)
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warnings_found += 1
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def __str__(self):
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return '{' + '"' + self.val1 + '", "' + self.val2 + '"}'
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class ValueString:
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def __init__(self, file, name, vals):
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self.file = file
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self.name = name
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self.raw_vals = vals
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self.parsed_vals = {}
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self.looks_like_tfs = True
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no_lines = self.raw_vals.count('{')
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if no_lines != 3:
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self.looks_like_tfs = False
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return
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# Now parse out each entry in the value_string
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matches = re.finditer(r'\{([\"a-zA-Z\s\d\,]*)\}', self.raw_vals)
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for m in matches:
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entry = m[1]
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# Check each entry looks like part of a TFS entry.
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match = re.match(r'\s*([01])\,\s*\"([a-zA-Z\d\s]*\s*)\"', entry)
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if match:
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if match[1] == '1':
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self.parsed_vals[True] = match[2]
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else:
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self.parsed_vals[False] = match[2]
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# Now have both entries
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if len(self.parsed_vals) == 2:
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break
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else:
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self.looks_like_tfs = False
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break
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def __str__(self):
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return '{' + '"' + self.raw_vals + '"}'
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field_widths = {
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'FT_BOOLEAN' : 64, # TODO: Width depends upon 'display' field
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'FT_CHAR' : 8,
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'FT_UINT8' : 8,
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'FT_INT8' : 8,
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'FT_UINT16' : 16,
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'FT_INT16' : 16,
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'FT_UINT24' : 24,
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'FT_INT24' : 24,
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'FT_UINT32' : 32,
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'FT_INT32' : 32,
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'FT_UINT40' : 40,
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'FT_INT40' : 40,
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'FT_UINT48' : 48,
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'FT_INT48' : 48,
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'FT_UINT56' : 56,
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'FT_INT56' : 56,
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'FT_UINT64' : 64,
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'FT_INT64' : 64
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}
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# Simplified version of class that is in check_typed_item_calls.py
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class Item:
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previousItem = None
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def __init__(self, filename, hf, filter, label, item_type, type_modifier, strings, macros, mask=None,
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check_mask=False):
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self.filename = filename
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self.hf = hf
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self.filter = filter
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self.label = label
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self.strings = strings
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self.mask = mask
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# N.B. Not sestting mask by looking up macros.
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self.item_type = item_type
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self.type_modifier = type_modifier
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self.set_mask_value(macros)
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self.bits_set = 0
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for n in range(0, self.get_field_width_in_bits()):
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if self.check_bit(self.mask_value, n):
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self.bits_set += 1
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def check_bit(self, value, n):
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return (value & (0x1 << n)) != 0
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def __str__(self):
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return 'Item ({0} "{1}" {2} type={3}:{4} strings={5} mask={6})'.format(self.filename, self.label, self.filter,
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self.item_type, self.type_modifier, self.strings, self.mask)
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def set_mask_value(self, macros):
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try:
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self.mask_read = True
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# Substitute mask if found as a macro..
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if self.mask in macros:
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self.mask = macros[self.mask]
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elif any(not c in '0123456789abcdefABCDEFxX' for c in self.mask):
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self.mask_read = False
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self.mask_value = 0
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return
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# Read according to the appropriate base.
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if self.mask.startswith('0x'):
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self.mask_value = int(self.mask, 16)
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elif self.mask.startswith('0'):
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self.mask_value = int(self.mask, 8)
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else:
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self.mask_value = int(self.mask, 10)
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except:
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self.mask_read = False
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self.mask_value = 0
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# Return true if bit position n is set in value.
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def check_bit(self, value, n):
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return (value & (0x1 << n)) != 0
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def get_field_width_in_bits(self):
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if self.item_type == 'FT_BOOLEAN':
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if self.type_modifier == 'NULL':
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return 8 # i.e. 1 byte
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elif self.type_modifier == 'BASE_NONE':
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return 8
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elif self.type_modifier == 'SEP_DOT': # from proto.h, only meant for FT_BYTES
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return 64
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else:
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try:
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# For FT_BOOLEAN, modifier is just numerical number of bits. Round up to next nibble.
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return int((int(self.type_modifier) + 3)/4)*4
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except:
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#print('oops', self)
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return 0
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else:
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if self.item_type in field_widths:
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# Lookup fixed width for this type
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return field_widths[self.item_type]
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else:
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#print('returning 0 for', self)
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return 0
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def removeComments(code_string):
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code_string = re.sub(re.compile(r"/\*.*?\*/",re.DOTALL ) ,"" ,code_string) # C-style comment
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code_string = re.sub(re.compile(r"//.*?\n" ) ,"" ,code_string) # C++-style comment
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code_string = re.sub(re.compile(r"#if 0.*?#endif",re.DOTALL ) ,"" , code_string) # Ignored region
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return code_string
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# Look for true_false_string items in a dissector file.
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def findTFS(filename):
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tfs_found = {}
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with open(filename, 'r', encoding="utf8") as f:
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contents = f.read()
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# Example: const true_false_string tfs_yes_no = { "Yes", "No" };
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# Remove comments so as not to trip up RE.
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contents = removeComments(contents)
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matches = re.finditer(r'\sconst\s*true_false_string\s*([a-zA-Z0-9_]*)\s*=\s*{\s*\"([a-zA-Z_0-9/:! ]*)\"\s*,\s*\"([a-zA-Z_0-9/:! ]*)\"', contents)
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for m in matches:
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name = m.group(1)
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val1 = m.group(2)
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val2 = m.group(3)
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# Store this entry.
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tfs_found[name] = TFS(filename, name, val1, val2)
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return tfs_found
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# Look for value_string entries in a dissector file.
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def findValueStrings(filename):
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vals_found = {}
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#static const value_string radio_type_vals[] =
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#{
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# { 0, "FDD"},
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# { 1, "TDD"},
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# { 0, NULL }
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#};
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with open(filename, 'r', encoding="utf8") as f:
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contents = f.read()
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# Remove comments so as not to trip up RE.
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contents = removeComments(contents)
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matches = re.finditer(r'.*const value_string\s*([a-zA-Z0-9_]*)\s*\[\s*\]\s*\=\s*\{([\{\}\d\,a-zA-Z0-9\s\"]*)\};', contents)
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for m in matches:
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name = m.group(1)
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vals = m.group(2)
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vals_found[name] = ValueString(filename, name, vals)
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return vals_found
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# Look for hf items (i.e. full item to be registered) in a dissector file.
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def find_items(filename, macros, check_mask=False, mask_exact_width=False, check_label=False, check_consecutive=False):
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is_generated = isGeneratedFile(filename)
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items = {}
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with open(filename, 'r', encoding="utf8") as f:
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contents = f.read()
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# Remove comments so as not to trip up RE.
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contents = removeComments(contents)
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# N.B. re extends all the way to HFILL to avoid greedy matching
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matches = re.finditer( r'.*\{\s*\&(hf_[a-z_A-Z0-9]*)\s*,\s*{\s*\"(.*?)\"\s*,\s*\"(.*?)\"\s*,\s*(.*?)\s*,\s*([0-9A-Z_\|\s]*?)\s*,\s*(.*?)\s*,\s*(.*?)\s*,\s*([a-zA-Z0-9\W\s_\u00f6\u00e4]*?)\s*,\s*HFILL', contents)
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for m in matches:
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# Store this item.
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hf = m.group(1)
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items[hf] = Item(filename, hf, filter=m.group(3), label=m.group(2), item_type=m.group(4),
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type_modifier=m.group(5),
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strings=m.group(6),
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macros=macros,
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mask=m.group(7))
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return items
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def find_macros(filename):
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macros = {}
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with open(filename, 'r', encoding="utf8") as f:
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contents = f.read()
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# Remove comments so as not to trip up RE.
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contents = removeComments(contents)
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matches = re.finditer( r'#define\s*([A-Z0-9_]*)\s*([0-9xa-fA-F]*)\n', contents)
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for m in matches:
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# Store this mapping.
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macros[m.group(1)] = m.group(2)
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return macros
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def is_dissector_file(filename):
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p = re.compile(r'.*packet-.*\.c')
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return p.match(filename)
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def findDissectorFilesInFolder(folder):
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# Look at files in sorted order, to give some idea of how far through is.
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files = []
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for f in sorted(os.listdir(folder)):
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if should_exit:
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return
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if is_dissector_file(f):
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filename = os.path.join(folder, f)
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files.append(filename)
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return files
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warnings_found = 0
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errors_found = 0
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tfs_found = 0
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# Check the given dissector file.
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def checkFile(filename, common_tfs, look_for_common=False, check_value_strings=False):
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global warnings_found
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global errors_found
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# Check file exists - e.g. may have been deleted in a recent commit.
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if not os.path.exists(filename):
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print(filename, 'does not exist!')
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return
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# Find items.
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file_tfs = findTFS(filename)
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# See if any of these items already existed in tfs.c
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for f in file_tfs:
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for c in common_tfs:
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found = False
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#
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# Do not do this check for plugins; plugins cannot import
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# data values from libwireshark (functions, yes; data
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# values, no).
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#
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# Test whether there's a common prefix for the file name
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# and "plugin/epan/"; if so, this is a plugin, and there
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# is no common path and os.path.commonprefix returns an
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# empty string, otherwise it returns the common path, so
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# we check whether the common path is an empty string.
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#
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if os.path.commonprefix([filename, 'plugin/epan/']) == '':
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exact_case = False
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if file_tfs[f].val1 == common_tfs[c].val1 and file_tfs[f].val2 == common_tfs[c].val2:
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found = True
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exact_case = True
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elif file_tfs[f].val1.upper() == common_tfs[c].val1.upper() and file_tfs[f].val2.upper() == common_tfs[c].val2.upper():
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found = True
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if found:
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print("Error:" if exact_case else "Warn: ", filename, f, "- could have used", c, 'from tfs.c instead: ', common_tfs[c],
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'' if exact_case else ' (capitalisation differs)')
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if exact_case:
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errors_found += 1
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else:
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warnings_found += 1
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break
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if not found:
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if look_for_common:
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AddCustomEntry(file_tfs[f].val1, file_tfs[f].val2, filename)
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if check_value_strings:
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# Get macros
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macros = find_macros(filename)
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# Get value_string entries.
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vs = findValueStrings(filename)
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# Also get hf items
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items = find_items(filename, macros, check_mask=True)
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for v in vs:
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if vs[v].looks_like_tfs:
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found = False
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exact_case = False
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#print('Candidate', v, vs[v])
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for c in common_tfs:
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found = False
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#
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# Do not do this check for plugins; plugins cannot import
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# data values from libwireshark (functions, yes; data
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# values, no).
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#
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# Test whether there's a common prefix for the file name
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# and "plugin/epan/"; if so, this is a plugin, and there
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# is no common path and os.path.commonprefix returns an
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# empty string, otherwise it returns the common path, so
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# we check whether the common path is an empty string.
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#
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if os.path.commonprefix([filename, 'plugin/epan/']) == '':
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exact_case = False
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if common_tfs[c].val1 == vs[v].parsed_vals[True] and common_tfs[c].val2 == vs[v].parsed_vals[False]:
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found = True
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exact_case = True
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elif common_tfs[c].val1.upper() == vs[v].parsed_vals[True].upper() and common_tfs[c].val2.upper() == vs[v].parsed_vals[False].upper():
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found = True
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# Do values match?
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if found:
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# OK, now look for items that:
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# - have VALS(v) AND
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# - have a mask width of 1 bit (no good if field can have values > 1...)
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for i in items:
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if re.match(r'VALS\(\s*'+v+r'\s*\)', items[i].strings):
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if items[i].bits_set == 1:
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print("Warn:" if exact_case else "Note:", filename, 'value_string', "'"+v+"'",
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"- could have used", c, 'from tfs.c instead: ', common_tfs[c], 'for', i,
|
|
'' if exact_case else ' (capitalisation differs)')
|
|
if exact_case:
|
|
warnings_found += 1
|
|
|
|
|
|
|
|
#################################################################
|
|
# Main logic.
|
|
|
|
# command-line args. Controls which dissector files should be checked.
|
|
# If no args given, will just scan epan/dissectors folder.
|
|
parser = argparse.ArgumentParser(description='Check calls in dissectors')
|
|
parser.add_argument('--file', action='append',
|
|
help='specify individual dissector file to test')
|
|
parser.add_argument('--commits', action='store',
|
|
help='last N commits to check')
|
|
parser.add_argument('--open', action='store_true',
|
|
help='check open files')
|
|
parser.add_argument('--check-value-strings', action='store_true',
|
|
help='check whether value_strings could have been tfs?')
|
|
|
|
parser.add_argument('--common', action='store_true',
|
|
help='check for potential new entries for tfs.c')
|
|
|
|
|
|
args = parser.parse_args()
|
|
|
|
|
|
# Get files from wherever command-line args indicate.
|
|
files = []
|
|
if args.file:
|
|
# Add specified file(s)
|
|
for f in args.file:
|
|
if not f.startswith('epan'):
|
|
f = os.path.join('epan', 'dissectors', f)
|
|
if not os.path.isfile(f):
|
|
print('Chosen file', f, 'does not exist.')
|
|
exit(1)
|
|
else:
|
|
files.append(f)
|
|
elif args.commits:
|
|
# Get files affected by specified number of commits.
|
|
command = ['git', 'diff', '--name-only', 'HEAD~' + args.commits]
|
|
files = [f.decode('utf-8')
|
|
for f in subprocess.check_output(command).splitlines()]
|
|
# Will examine dissector files only
|
|
files = list(filter(lambda f : is_dissector_file(f), files))
|
|
elif args.open:
|
|
# Unstaged changes.
|
|
command = ['git', 'diff', '--name-only']
|
|
files = [f.decode('utf-8')
|
|
for f in subprocess.check_output(command).splitlines()]
|
|
# Only interested in dissector files.
|
|
files = list(filter(lambda f : is_dissector_file(f), files))
|
|
# Staged changes.
|
|
command = ['git', 'diff', '--staged', '--name-only']
|
|
files_staged = [f.decode('utf-8')
|
|
for f in subprocess.check_output(command).splitlines()]
|
|
# Only interested in dissector files.
|
|
files_staged = list(filter(lambda f : is_dissector_file(f), files_staged))
|
|
for f in files_staged:
|
|
if not f in files:
|
|
files.append(f)
|
|
else:
|
|
# Find all dissector files from folder.
|
|
files = findDissectorFilesInFolder(os.path.join('epan', 'dissectors'))
|
|
|
|
|
|
# If scanning a subset of files, list them here.
|
|
print('Examining:')
|
|
if args.file or args.commits or args.open:
|
|
if files:
|
|
print(' '.join(files), '\n')
|
|
else:
|
|
print('No files to check.\n')
|
|
else:
|
|
print('All dissector modules\n')
|
|
|
|
|
|
# Get standard/ shared ones.
|
|
tfs_entries = findTFS(os.path.join('epan', 'tfs.c'))
|
|
|
|
# Now check the files to see if they could have used shared ones instead.
|
|
for f in files:
|
|
if should_exit:
|
|
exit(1)
|
|
if not isGeneratedFile(f):
|
|
checkFile(f, tfs_entries, look_for_common=args.common, check_value_strings=args.check_value_strings)
|
|
|
|
# Report on commonly-defined values.
|
|
if args.common:
|
|
# Looking for items that could potentially be moved to tfs.c
|
|
for c in custom_tfs_entries:
|
|
# Only want to see items that have 3 or more occurrences.
|
|
# Even then, probably only want to consider ones that sound generic.
|
|
if len(custom_tfs_entries[c]) > 2:
|
|
print(c, 'appears', len(custom_tfs_entries[c]), 'times, in: ', custom_tfs_entries[c])
|
|
|
|
|
|
# Show summary.
|
|
print(warnings_found, 'warnings found')
|
|
if errors_found:
|
|
print(errors_found, 'errors found')
|
|
exit(1)
|