def buildMessage(msgtype,
token,
code,
messageId,
options=[],
payload=[],
securityContext=None,
partialIV=None):
assert msgtype in d.TYPE_ALL
assert code in d.METHOD_ALL + d.COAP_RC_ALL
message = []
TKL = 0
if token:
# determine token length
for tokenLen in range(1, 8 + 1):
if token < (1 << (8 * tokenLen)):
TKL = tokenLen
break
if not TKL:
raise ValueError('token {0} too long'.format(token))
# header
message += [d.COAP_VERSION << 6 | msgtype << 4 | TKL]
message += [code]
message += u.int2buf(messageId, 2)
message += u.int2buf(token, TKL)
# options
options = sortOptions(options)
if securityContext:
# invoke oscoap to protect the message
(outerOptions,
newPayload) = oscoap.protectMessage(context=securityContext,
version=d.COAP_VERSION,
code=code,
options=options,
payload=payload,
partialIV=partialIV)
else:
(outerOptions, newPayload) = (options, payload)
# add encoded options
message += encodeOptions(outerOptions)
# add payload
message += encodePayload(newPayload)
return message
def _writePcapMessage(self,timestamp,srcIp,destIp,srcPort,destPort,payload):
bytesToWrite = []
# IPv6 message
bytesToWrite += [0x06<<4] # version + traffic_class[high]
bytesToWrite += [0x00]*3 # traffic_class[low] + flow_label
bytesToWrite += u.int2buf(8+len(payload),2) # payload length (incl. UDP header)
bytesToWrite += [17] # next header (17==UDP)
bytesToWrite += [64] # hop limit
bytesToWrite += srcIp # source address
bytesToWrite += destIp # destination addres
# UDP header
bytesToWrite += u.int2buf(srcPort,2) # source port
bytesToWrite += u.int2buf(destPort,2) # destination port
bytesToWrite += u.int2buf(len(payload),2) # length
bytesToWrite += u.int2buf(
u.calcUdpCheckSum(
srcIp,
destIp,
srcPort,
destPort,
payload,
),
2
) # checksum
# payload
bytesToWrite += payload # payload
# format PCAP message header
ts_sec = int(timestamp)
ts_usec = int((timestamp-ts_sec)*1000000)
pcapMsgHeader = struct.pack(
'IIII',
ts_sec, # ts_sec
ts_usec, # ts_usec
len(bytesToWrite), # incl_len
len(bytesToWrite), # orig_len
)
# write to file
stringToWrite = ''.join(
[pcapMsgHeader]+[''.join([chr(b) for b in bytesToWrite])]
)
self.pcapFile.write(stringToWrite)
self.pcapFile.flush()
log.debug('written {0} bytes'.format(len(stringToWrite)))
def _receiveFromCoAP(self, timestamp, sender, data):
'''
Receive CoAP response and forward it to the mesh network.
Appends UDP and IPv6 headers to the CoAP message and forwards it on the Eventbus towards the mesh.
'''
self.coapClient.close()
# UDP
udplen = len(data) + 8
udp = u.int2buf(self.coapClient.udpPort,2) # src port
udp += u.int2buf(sender[1],2) # dest port
udp += [udplen >> 8, udplen & 0xff] # length
udp += [0x00, 0x00] # checksum
udp += data
# destination address of the packet is CoAP client's IPv6 address (address of the mote)
dstIpv6Address = u.ipv6AddrString2Bytes(self.coapClient.ipAddress)
assert len(dstIpv6Address)==16
# source address of the packet is DAG root's IPV6 address
# use the same prefix (link-local or global) as in the destination address
srcIpv6Address = dstIpv6Address[:8]
srcIpv6Address += self.dagRootEui64
assert len(srcIpv6Address)==16
# CRC See https://tools.ietf.org/html/rfc2460.
udp[6:8] = openvisualizer.openvisualizer_utils.calculatePseudoHeaderCRC(
src=srcIpv6Address,
dst=dstIpv6Address,
length=[0x00, 0x00] + udp[4:6],
nh=[0x00, 0x00, 0x00, 17], # UDP as next header
payload=data,
)
# IPv6
ip = [6 << 4] # v6 + traffic class (upper nybble)
ip += [0x00, 0x00, 0x00] # traffic class (lower nibble) + flow label
ip += udp[4:6] # payload length
ip += [17] # next header (protocol); UDP=17
ip += [64] # hop limit (pick a safe value)
ip += srcIpv6Address # source
ip += dstIpv6Address # destination
ip += udp
# announce network prefix
self.dispatch(
signal = 'v6ToMesh',
data = ip
)
def _writePcapMessage(self, timestamp, srcIp, destIp, srcPort, destPort,
payload):
bytesToWrite = []
# IPv6 message
bytesToWrite += [0x06 << 4] # version + traffic_class[high]
bytesToWrite += [0x00] * 3 # traffic_class[low] + flow_label
bytesToWrite += u.int2buf(8 + len(payload),
2) # payload length (incl. UDP header)
bytesToWrite += [17] # next header (17==UDP)
bytesToWrite += [64] # hop limit
bytesToWrite += srcIp # source address
bytesToWrite += destIp # destination addres
# UDP header
bytesToWrite += u.int2buf(srcPort, 2) # source port
bytesToWrite += u.int2buf(destPort, 2) # destination port
bytesToWrite += u.int2buf(len(payload), 2) # length
bytesToWrite += u.int2buf(
u.calcUdpCheckSum(
srcIp,
destIp,
srcPort,
destPort,
payload,
), 2) # checksum
# payload
bytesToWrite += payload # payload
# format PCAP message header
ts_sec = int(timestamp)
ts_usec = int((timestamp - ts_sec) * 1000000)
pcapMsgHeader = struct.pack(
'IIII',
ts_sec, # ts_sec
ts_usec, # ts_usec
len(bytesToWrite), # incl_len
len(bytesToWrite), # orig_len
)
# write to file
stringToWrite = ''.join([pcapMsgHeader] +
[''.join([chr(b) for b in bytesToWrite])])
self.pcapFile.write(stringToWrite)
self.pcapFile.flush()
log.debug('written {0} bytes'.format(len(stringToWrite)))
def _receiveFromCoAP(self, timestamp, sender, data):
'''
Receive CoAP response and forward it to the mesh network.
Appends UDP and IPv6 headers to the CoAP message and forwards it on the Eventbus towards the mesh.
'''
self.coapClient.close()
# UDP
udplen = len(data) + 8
udp = u.int2buf(sender[1], 2) # src port
udp += u.int2buf(self.coapClient.udpPort, 2) # dest port
udp += [udplen >> 8, udplen & 0xff] # length
udp += [0x00, 0x00] # checksum
udp += data
# destination address of the packet is CoAP client's IPv6 address (address of the mote)
dstIpv6Address = u.ipv6AddrString2Bytes(self.coapClient.ipAddress)
assert len(dstIpv6Address) == 16
# source address of the packet is DAG root's IPV6 address
# use the same prefix (link-local or global) as in the destination address
srcIpv6Address = dstIpv6Address[:8]
srcIpv6Address += self.dagRootEui64
assert len(srcIpv6Address) == 16
# CRC See https://tools.ietf.org/html/rfc2460.
udp[6:
8] = openvisualizer.openvisualizer_utils.calculatePseudoHeaderCRC(
src=srcIpv6Address,
dst=dstIpv6Address,
length=[0x00, 0x00] + udp[4:6],
nh=[0x00, 0x00, 0x00, 17], # UDP as next header
payload=udp,
)
# IPv6
ip = [6 << 4] # v6 + traffic class (upper nybble)
ip += [0x00, 0x00, 0x00] # traffic class (lower nibble) + flow label
ip += udp[4:6] # payload length
ip += [17] # next header (protocol); UDP=17
ip += [64] # hop limit (pick a safe value)
ip += srcIpv6Address # source
ip += dstIpv6Address # destination
ip += udp
# announce network prefix
self.dispatch(signal='v6ToMesh', data=ip)
def getRequestSecurityParams(objectSecurityOption):
if objectSecurityOption:
context = objectSecurityOption.context
newSequenceNumber = objectSecurityOption.context.getSequenceNumber()
# convert sequence number to string that is the length of the IV
newSequenceNumber = u.buf2str(
u.int2buf(newSequenceNumber, context.aeadAlgorithm.ivLength))
return (context, newSequenceNumber)
else:
return (None, None)
def test_int2buf(logFixture, validint2buf):
(val, len, output) = validint2buf
log.debug('val: {0}'.format(val))
log.debug('len: {0}'.format(len))
log.debug('output: {0}'.format(output))
result = coapUtils.int2buf(val, len)
log.debug('result: {0}'.format(result))
assert tuple(result) == output
def test_int2buf(logFixture, validint2buf):
(val,len,output) = validint2buf
log.debug('val: {0}'.format(val))
log.debug('len: {0}'.format(len))
log.debug('output: {0}'.format(output))
result = coapUtils.int2buf(val,len)
log.debug('result: {0}'.format(result))
assert tuple(result)==output
def toBytes(self, lastOptionNum):
payload = self.getPayloadBytes()
delta = self.optionNumber - lastOptionNum
# optionDelta and optionDeltaExt fields
if delta <= 12:
optionDelta = delta
optionDeltaExt = u.int2buf(delta, 0)
elif delta <= (0xff + 13):
optionDelta = 13
optionDeltaExt = u.int2buf(delta - 13, 1)
elif delta <= (0xffff + 269):
optionDelta = 14
optionDeltaExt = u.int2buf(delta - 269, 2)
else:
raise ValueError('delta is too large: {0}'.format(delta))
# optionLength and optionLengthExt fields
if len(payload) <= 12:
optionLength = len(payload)
optionLengthExt = u.int2buf(len(payload), 0)
elif len(payload) <= (0xff + 13):
optionLength = 13
optionLengthExt = u.int2buf(len(payload) - 13, 1)
elif len(payload) <= (0xffff + 269):
optionLength = 14
optionLengthExt = u.int2buf(len(payload) - 269, 2)
else:
raise ValueError('payload is too long, {0} bytes'.format(
len(payload)))
returnVal = []
returnVal += [optionDelta << 4 | optionLength]
returnVal += optionDeltaExt
returnVal += optionLengthExt
returnVal += payload
return returnVal
