emm.py: a script to analyze EMM / CAPMT filtering from log

diff --git a/support/emm.py b/support/emm.py
new file mode 100755 (executable)
index 0000000..f159a62
--- /dev/null
+++ b/support/emm.py
@@ -0,0 +1,110 @@
+#!/usr/bin/env python
+#
+
+import sys
+
+FILTERS = []
+
+class Filter:
+
+  def __init__(self, params):
+    self.demux = params.demux
+    self.adapter = params.adapter
+    self.filter = params.filter
+    self.pid = params.pid
+
+class Params:
+
+  pass
+
+def extract(line, what):
+  pos = line.find(what)
+  if pos < 0: return None
+  return line[pos + len(what):]
+
+def extract_params(line, kdelim='='):
+  line = line.strip().lstrip()
+  if line[0] == '(' and line[-1] == ')':
+    line = line[1:-1]
+  a = line.split(',')
+  r = Params()
+  for b in a:
+    b = b.lstrip().strip()
+    pos = b.find(kdelim)
+    if pos >= 0: setattr(r, b[:pos], b[pos+1:])
+  return r
+
+def from_hex(line, tdelim=' '):
+  line = line.strip().lstrip()
+  if tdelim:
+    pos = line.find(tdelim)
+    if pos >= 0:
+      line = line[:pos]
+  line = line.replace(':', '').replace('{', '').replace('}', '').replace(' ', '')
+  return line.decode('hex')
+0
+def emm(line, oline):
+  pos = line.find('(')
+  if pos < 0: return
+  params = extract_params(line[pos:], kdelim=' ')
+  data = from_hex(line)
+  while len(data) < 18: data += '\x00'
+  for f in FILTERS:
+    if f.pid != params.pid: continue
+    if ord(data[0]) & ord(f.mask[0]) != ord(f.value[0]): continue
+    ok = 1
+    for i in range(1, min(16, len(data)-2)):
+      if ord(data[i+2]) & ord(f.mask[i]) != ord(f.value[i]):
+        ok = 0
+        break
+    if ok:
+      d = data[0] + data[3:]
+      print 'match! filter=%s, pid=%s' % (f.filter, f.pid)
+      print '  emm  : %s' % (d.encode('hex'))
+      print '  data : %s' % (f.value.encode('hex'))
+      print '  mask : %s' % (f.mask.encode('hex'))
+      print '  (%s)' % (oline.lstrip().strip())
+
+def filter(line):
+  params = extract_params(line)
+  for f in FILTERS:
+    if f.filter == params.filter:
+      FILTERS.remove(f)
+      break
+  FILTERS.append(Filter(params))
+
+def filter_data(idx, line):
+  data = from_hex(line[:47], tdelim='')
+  if idx == 1:
+    FILTERS[-1].value = data
+  elif idx == 2:
+    FILTERS[-1].mask = data
+  elif idx == 3:
+    FILTERS[-1].mode = data
+
+fp = open(sys.argv[1])
+fcnt = 0
+while 1:
+  line = fp.readline()
+  if not line: break
+  if fcnt:
+    e = extract(line, '[  TRACE]:capmt: ')
+    if e:
+      filter_data(fcnt, e)
+      fcnt += 1
+      if fcnt > 3: fcnt = 0
+      continue
+  e = extract(line, '[  TRACE]:descrambler: EMM message ')
+  if e:
+    emm(e, line)
+    continue
+  e = extract(line, '[  TRACE]:capmt: tvheadend: setting filter: ')
+  if e:
+    filter(e)
+    fcnt = 1
+fp.close()
+
+for f in FILTERS:
+  print 'FILTER DUMP: filter=%s, pid=%s' % (f.filter, f.pid)
+  print '  data : %s' % (f.value.encode('hex'))
+  print '  mask : %s' % (f.mask.encode('hex'))