def readHeaders(filename):
"""Read all of the headers from a file"""
fh = open(filename)
data = fh.read()
fh.close()
#data = filename
parser = getHeaderBNF()
intRE = re.compile(r'^\d+$')
opRE = re.compile(r'^[+\-*]|<<|>>$')
refCounts = {}
headerList = []
headers = {}
for item in parser.parseString(data, True):
#print item
#print item.hdr
if item.hdr not in headers:
hdr = Header(item.hdr)
headerList.append(hdr)
headers[item.hdr] = hdr
if item.fields != '':
for fieldData in item.fields:
(name, width) = fieldData[0:2]
if width == '*':
width = None
else:
width = int(width)
hdr.addField(name, width)
if len(fieldData) == 3:
hdr.addExtractField(name)
if item.pseudofields != '':
for (name, width) in item.pseudofields:
if width == '*':
width = None
else:
width = int(width)
hdr.addPseudofield(name, width)
if item.next_header != '':
if item.next_header.field != '':
hdr.setNextHeader(str(item.next_header.field))
else:
from_fields = item.next_header.mapping.from_header.asList()
rangeCount = 0
widths = hdr.getFieldWidths(from_fields)
hdrMap = {}
for (keys, value) in item.next_header.mapping.maplist:
for key in keys:
if key.find('0x') == 0:
key = int(key, 16)
elif key.find('b') == 0:
pass
else:
key = int(key)
(mask, data) = crackKey(hdr, key, from_fields)
hdrMap[key] = ((mask, data), value)
# Approximate counting of the number of entries covered
wildcards = 0
for i in xrange(len(widths)):
fieldWidth = widths[i]
fieldMask = mask[i]
wildcards += sum([(~fieldMask >> shift) & 1 for shift in xrange(fieldWidth)])
rangeCount += 2 ** wildcards
# Attempt to sort the header map by key
keys = hdrMap.keys()
keys.sort()
hdrList = []
for key in keys:
hdrList.append(hdrMap[key])
# Add a wildcard entry if we haven't covered all inputs
if rangeCount < 2 ** sum(widths) and wantWildcard:
hdrList.append((([0] * len(from_fields), [0] * len(from_fields)), None))
hdr.setNextHeader((from_fields, hdrList))
if item.next_header_def != '':
if item.next_header == '' or item.next_header.field != '':
raise Exception("next_header_def value specified but next_header is not specified/is not a map")
from_fields = item.next_header.mapping.from_header.asList()
(mask, data) = crackKey(hdr, item.next_header_def[0], from_fields)
hdr.setDefNxtHdrVal((mask, data))
if item.maxvar != '':
item.maxvar = str(item.maxvar)
if item.maxvar not in refCounts:
refCounts[item.maxvar] = RefCount(item.maxvar)
hdr.setRefCount(refCounts[item.maxvar])
if item.maxval != '':
if not hdr.getRefCount():
if item.hdr not in refCounts:
refCounts[item.hdr] = RefCount(item.hdr)
hdr.setRefCount(refCounts[item.hdr])
hdr.getRefCount().setMax(int(item.maxval[0]))
if item.hdr_len != '':
newExp = []
if type(item.hdr_len[0]) == str:
newExp.append(item.hdr_len[0])
else:
#print item.hdr_len[0]
#print type(item.hdr_len[0])
#print len(item.hdr_len[0])
#print len(item.hdr_len.asList())
for exp in item.hdr_len[0]:
if intRE.match(exp):
exp = int(exp)
newExp.append(exp)
elif opRE.match(exp):
newExp.append(exp)
else:
newExp.append(exp)
hdr.setCalcLength(newExp)
#hdr.setMax(int(item.maxval[0]))
if item.max_len != '':
hdr.setMaxLength(int(item.max_len[0]))
#print hdr
else:
print "Error: header '%s' seen multiple times" % item.hdr
sys.exit(-1)
#print hdr
# Merge fixed/deterministic transitions if requested
if shouldMergeFixedTransitions:
headerList = mergeTransitions(headerList, headers)
# Work out which headers are reachable
if shouldTrimNonReachable:
headerList = trimNonReachable(headerList, headers)
return (headerList, headers)
def readHeaders(filename):
"""Read all of the headers from a file"""
fh = open(filename)
data = fh.read()
fh.close()
#data = filename
parser = getHeaderBNF()
intRE = re.compile(r'^\d+$')
opRE = re.compile(r'^[+\-*]|<<|>>$')
refCounts = {}
headerList = []
headers = {}
for item in parser.parseString(data, True):
#print item
#print item.hdr
if item.hdr not in headers:
hdr = Header(item.hdr)
headerList.append(hdr)
headers[item.hdr] = hdr
if item.fields != '':
for fieldData in item.fields:
(name, width) = fieldData[0:2]
if width == '*':
width = None
else:
width = int(width)
hdr.addField(name, width)
if len(fieldData) == 3:
hdr.addExtractField(name)
if item.pseudofields != '':
for (name, width) in item.pseudofields:
if width == '*':
width = None
else:
width = int(width)
hdr.addPseudofield(name, width)
if item.next_header != '':
if item.next_header.field != '':
hdr.setNextHeader(str(item.next_header.field))
else:
from_fields = item.next_header.mapping.from_header.asList()
rangeCount = 0
widths = hdr.getFieldWidths(from_fields)
hdrMap = {}
for (keys, value) in item.next_header.mapping.maplist:
for key in keys:
if key.find('0x') == 0:
key = int(key, 16)
elif key.find('b') == 0:
pass
else:
key = int(key)
(mask, data) = crackKey(hdr, key, from_fields)
hdrMap[key] = ((mask, data), value)
# Approximate counting of the number of entries covered
wildcards = 0
for i in xrange(len(widths)):
fieldWidth = widths[i]
fieldMask = mask[i]
wildcards += sum([
(~fieldMask >> shift) & 1
for shift in xrange(fieldWidth)
])
rangeCount += 2**wildcards
# Attempt to sort the header map by key
keys = hdrMap.keys()
keys.sort()
hdrList = []
for key in keys:
hdrList.append(hdrMap[key])
# Add a wildcard entry if we haven't covered all inputs
if rangeCount < 2**sum(widths) and wantWildcard:
hdrList.append((([0] * len(from_fields),
[0] * len(from_fields)), None))
hdr.setNextHeader((from_fields, hdrList))
if item.next_header_def != '':
if item.next_header == '' or item.next_header.field != '':
raise Exception(
"next_header_def value specified but next_header is not specified/is not a map"
)
from_fields = item.next_header.mapping.from_header.asList()
(mask, data) = crackKey(hdr, item.next_header_def[0],
from_fields)
hdr.setDefNxtHdrVal((mask, data))
if item.maxvar != '':
item.maxvar = str(item.maxvar)
if item.maxvar not in refCounts:
refCounts[item.maxvar] = RefCount(item.maxvar)
hdr.setRefCount(refCounts[item.maxvar])
if item.maxval != '':
if not hdr.getRefCount():
if item.hdr not in refCounts:
refCounts[item.hdr] = RefCount(item.hdr)
hdr.setRefCount(refCounts[item.hdr])
hdr.getRefCount().setMax(int(item.maxval[0]))
if item.hdr_len != '':
newExp = []
if type(item.hdr_len[0]) == str:
newExp.append(item.hdr_len[0])
else:
#print item.hdr_len[0]
#print type(item.hdr_len[0])
#print len(item.hdr_len[0])
#print len(item.hdr_len.asList())
for exp in item.hdr_len[0]:
if intRE.match(exp):
exp = int(exp)
newExp.append(exp)
elif opRE.match(exp):
newExp.append(exp)
else:
newExp.append(exp)
hdr.setCalcLength(newExp)
#hdr.setMax(int(item.maxval[0]))
if item.max_len != '':
hdr.setMaxLength(int(item.max_len[0]))
#print hdr
else:
print "Error: header '%s' seen multiple times" % item.hdr
sys.exit(-1)
#print hdr
# Merge fixed/deterministic transitions if requested
if shouldMergeFixedTransitions:
headerList = mergeTransitions(headerList, headers)
# Work out which headers are reachable
if shouldTrimNonReachable:
headerList = trimNonReachable(headerList, headers)
return (headerList, headers)
