contrib/cryptsetup/tests/fileDiffer.py

   1 #!/usr/bin/python
   2
   3 #
   4 # Usage: fileDiffer <afile> <bfile> <list of disk changes>
   5 #
   6
   7 # LUKS
   8 # quick regression test suite
   9 # Tests LUKS images for changes at certain disk offsets
  10 #
  11 # Does fast python code has to look ugly or is it just me?
  12
  13 import sys
  14
  15 class changes:
  16         pass
  17
  18 def parseArgs(args):
  19         aFileName = args[1]
  20         bFileName = args[2]
  21         changelist = []
  22         args[0:3] = []
  23         for i in args:
  24                 mychanges = changes();
  25                 if i.startswith('A'):
  26                         mychanges.mode = 'ALLOWED'
  27                 if i.startswith('R'):
  28                         mychanges.mode = 'REQUIRED'
  29                         mychanges.strictness = 'RANDOM'
  30                 if i.startswith('S'):
  31                         mychanges.mode = 'REQUIRED'
  32                         mychanges.strictness = 'SEMANTIC'
  33
  34                 dashIndex = i.find('-')
  35                 if dashIndex == -1:
  36                         mychanges.starts = int(i[1:])
  37                         mychanges.ends = mychanges.starts
  38                 else:
  39                         mychanges.starts = int(i[1:dashIndex])
  40                         mychanges.ends = int(i[dashIndex+1:])
  41                 mychanges.miss = 0
  42                 changelist.append(mychanges)
  43         mychanges = changes();
  44         mychanges.starts = 0
  45 #       mychanges.ends will be fixed later
  46         mychanges.mode = 'FORBIDDEN'
  47         changelist.append(mychanges)
  48         return [aFileName, bFileName, changelist]
  49
  50 def mode(i):
  51         for c in changelist:
  52                 if i >= c.starts and i<=c.ends:
  53                         return c
  54 def cleanchanges(i):
  55         newchangelist=[]
  56         for c in changelist:
  57                 if i <= c.starts or i <= c.ends:
  58                         newchangelist.append(c)
  59         return newchangelist
  60
  61 [aFileName, bFileName, changelist] = parseArgs(sys.argv)
  62
  63 aFile = open(aFileName,'r')
  64 bFile = open(bFileName,'r')
  65
  66 aString = aFile.read()
  67 bString = bFile.read()
  68
  69 if len(aString) != len(bString):
  70         sys.exit("Mismatch different file sizes")
  71
  72 fileLen = len(aString)
  73 fileLen10th = fileLen/10
  74
  75 # Create a catch all entry
  76 changelist[-1].ends = fileLen
  77
  78 print "Changes list: (FORBIDDEN default)"
  79 print "start\tend\tmode\t\tstrictness"
  80 for i in changelist:
  81         if i.mode == 'REQUIRED':
  82                 print "%d\t%d\t%s\t%s" % (i.starts, i.ends, i.mode, i.strictness)
  83         else:
  84                 print "%d\t%d\t%s" % (i.starts, i.ends, i.mode)
  85
  86
  87 filepos = 0
  88 fileLen10thC = 0
  89 print "[..........]"
  90 sys.stdout.write("[")
  91 sys.stdout.flush()
  92
  93 modeNotTrivial = 1
  94 while filepos < fileLen:
  95
  96         if modeNotTrivial == 1:
  97                 c = mode(filepos)
  98 #       print (filepos, c.mode)
  99         if c.mode == 'REQUIRED':
 100                 if aString[filepos] == bString[filepos]:
 101                         c.miss = c.miss + 1
 102         else:
 103                 if aString[filepos] != bString[filepos] and c.mode != 'ALLOWED':
 104                         sys.exit("Mismatch at %d: change forbidden" % filepos)
 105
 106         # Do some maintaince, print progress bar, and clean changelist
 107         #
 108         # Maintaining two counters appears to be faster than modulo operation
 109         if fileLen10thC == fileLen10th:
 110                 fileLen10thC = 0
 111                 sys.stdout.write(".")
 112                 sys.stdout.flush()
 113                 changelist = cleanchanges(filepos)
 114                 if len(changelist) == 1:
 115                         modeNotTrivial = 0
 116         filepos = filepos + 1
 117         fileLen10thC = fileLen10thC + 1
 118
 119 for c in changelist:
 120         if c.mode == 'REQUIRED':
 121                 if c.strictness == 'SEMANTIC' and c.miss == (c.ends-c.starts+1):
 122                         sys.exit("Mismatch: not even a single change in region %d-%d." % (c.starts, c.ends))
 123                 # This is not correct. We should do a statistical test
 124                 # of the sampled data against the hypothetical distribution
 125                 # of collision. Chi-Square Test.
 126                 if c.strictness == 'RANDOM' and c.miss == (c.ends-c.starts+1):
 127                         sys.exit("Mismatch: not even a single change in region %d-%d." % (c.starts, c.ends))
 128
 129 print ".] - everything ok"