def _dispatchMeshDebugPacket(self, zep):
'''
Wraps ZEP-based debug packet, for outgoing mesh 6LoWPAN message,
with UDP and IPv6 headers. Then forwards as an event to the
Internet interface.
'''
# UDP
udplen = len(zep)+8
udp = [0x00,0x00] # src port (unused)
udp += [0x45,0x5a] # dest port (17754)
udp += [udplen >> 8, udplen & 0xff] # length
udp += [0x00,0x00] # checksum
udp += zep
# Common address for source and destination
addr = []
addr += openTun.IPV6PREFIX
addr += openTun.IPV6HOST
# CRC See https://tools.ietf.org/html/rfc2460.
# not sure if the payload contains the udp header in this case.
udp[6:8] = u.calculatePseudoHeaderCRC(
src = addr,
dst = addr,
length = [0x00,0x00]+udp[4:6],
nh = [0x00,0x00,0x00,17],
payload = zep,
)
# 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)
ip += [8] # hop limit (pick a safe value)
ip += addr # source
ip += addr # destination
ip += udp
dispatcher.send(
sender = self.name,
signal = 'v6ToInternet',
data = ip,
)
def _dispatchMeshDebugPacket(self, zep):
'''
Wraps ZEP-based debug packet, for outgoing mesh 6LoWPAN message,
with UDP and IPv6 headers. Then forwards as an event to the
Internet interface.
'''
# UDP
udplen = len(zep) + 8
udp = [0x00, 0x00] # src port (unused)
udp += [0x45, 0x5a] # dest port (17754)
udp += [udplen >> 8, udplen & 0xff] # length
udp += [0x00, 0x00] # checksum
udp += zep
# Common address for source and destination
addr = []
addr += openTun.IPV6PREFIX
addr += openTun.IPV6HOST
# CRC See https://tools.ietf.org/html/rfc2460.
# not sure if the payload contains the udp header in this case.
udp[6:8] = u.calculatePseudoHeaderCRC(
src=addr,
dst=addr,
length=[0x00, 0x00] + udp[4:6],
nh=[0x00, 0x00, 0x00, 17],
payload=zep,
)
# 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)
ip += [8] # hop limit (pick a safe value)
ip += addr # source
ip += addr # destination
ip += udp
dispatcher.send(
sender=self.name,
signal='v6ToInternet',
data=ip,
)
def _meshToV6_notif(self, sender, signal, data):
'''
Converts a 6LowPAN packet into a IPv6 packet.
This function dispatches the IPv6 packet with signal 'according to the destination address, protocol_type and port'.
'''
try:
ipv6dic = {}
#build lowpan dictionary from the data
ipv6dic = self.lowpan_to_ipv6(data)
success = True
dispatchSignal = None
#read next header
if ipv6dic['next_header'] == self.IANA_IPv6HOPHEADER:
#hop by hop header present, check flags and parse
if (ipv6dic['hop_flags'] & self.O_FLAG) == self.O_FLAG:
#error -- this packet has gone downstream somewhere.
log.error(
"detected possible downstream link on upstream route from {0}"
.format(",".join(str(c) for c in ipv6dic['src_addr'])))
if (ipv6dic['hop_flags'] & self.R_FLAG) == self.R_FLAG:
#error -- loop in the route
log.error(
"detected possible loop on upstream route from {0}".
format(",".join(str(c) for c in ipv6dic['src_addr'])))
#skip the header and process the rest of the message.
ipv6dic['next_header'] = ipv6dic['hop_next_header']
#===================================================================
if ipv6dic['next_header'] == self.IPV6_HEADER:
#ipv6 header (inner)
ipv6dic_inner = {}
# prasing the iphc inner header and get the next_header
ipv6dic_inner = self.lowpan_to_ipv6(
[ipv6dic['pre_hop'], ipv6dic['payload']])
ipv6dic['next_header'] = ipv6dic_inner['next_header']
ipv6dic['payload'] = ipv6dic_inner['payload']
ipv6dic['payload_length'] = ipv6dic_inner['payload_length']
ipv6dic['src_addr'] = ipv6dic_inner['src_addr']
if not ipv6dic.has_key('hop_limit'):
ipv6dic['hop_limit'] = ipv6dic_inner['hop_limit']
ipv6dic['dst_addr'] = ipv6dic_inner['dst_addr']
ipv6dic['flow_label'] = ipv6dic_inner['flow_label']
if ipv6dic['next_header'] == self.IANA_ICMPv6:
#icmp header
if len(ipv6dic['payload']) < 5:
log.critical(
"wrong payload lenght on ICMPv6 packet {0}".format(
",".join(str(c) for c in data)))
print "wrong payload lenght on ICMPv6 packet {0}".format(
",".join(str(c) for c in data))
return
ipv6dic['icmpv6_type'] = ipv6dic['payload'][0]
ipv6dic['icmpv6_code'] = ipv6dic['payload'][1]
ipv6dic['icmpv6_checksum'] = ipv6dic['payload'][2:4]
ipv6dic['app_payload'] = ipv6dic['payload'][4:]
#this function does the job
dispatchSignal = (tuple(ipv6dic['dst_addr']),
self.PROTO_ICMPv6, ipv6dic['icmpv6_type'])
elif ipv6dic['next_header'] == self.IANA_UDP:
#udp header -- can be compressed.. assume first it is not compressed.
if len(ipv6dic['payload']) < 5:
log.critical(
"wrong payload lenght on UDP packet {0}".format(
",".join(str(c) for c in data)))
print "wrong payload lenght on UDP packet {0}".format(
",".join(str(c) for c in data))
return
if ipv6dic['payload'][0] & self.NHC_UDP_MASK == self.NHC_UDP_ID:
lowpan_nhc = ipv6dic['payload'][0]
udp_header_length = 0
newUdp = []
newUdp_header_length = 0
if lowpan_nhc & self.NHC_UDP_PORTS_MASK == self.NHC_UDP_PORTS_INLINE:
src_port = u.buf2int(ipv6dic['payload'][1:3])
dest_port = u.buf2int(ipv6dic['payload'][3:5])
udp_header_length = 5
elif lowpan_nhc & self.NHC_UDP_PORTS_MASK == self.NHC_UDP_PORTS_16S_8D:
src_port = u.buf2int(ipv6dic['payload'][1:3])
dest_port = 0xf000 + ipv6dic['payload'][3]
udp_header_length = 4
elif lowpan_nhc & self.NHC_UDP_PORTS_MASK == self.NHC_UDP_PORTS_8S_16D:
src_port = 0xf000 + ipv6dic['payload'][1]
dest_port = u.buf2int(ipv6dic['payload'][2:4])
udp_header_length = 4
elif lowpan_nhc & self.NHC_UDP_PORTS_MASK == self.NHC_UDP_PORTS_4S_4D:
src_port = 0xf0b0 + (
(ipv6dic['payload'][1] >> 4) & 0x0f)
dest_port = 0xf0b0 + (
(ipv6dic['payload'][1] >> 0) & 0x0f)
udp_header_length = 2
newUdp = [src_port >> 8, src_port & 0x00ff]
newUdp += [dest_port >> 8, dest_port & 0x00ff]
idxLen = len(newUdp) # remember index of payload length
newUdp += [0x00, 0x00] # length (placeholder)
newUdp_header_length += 2
udp_header_length += 2 # skip two bytes checksum following
idxCS = len(newUdp) # remember index of checksum
newUdp += [0x00, 0x00] # Checksum (placeholder)
newUdp_header_length += 2
#append payload to compute crc again
newUdp += ipv6dic['payload'][
udp_header_length:] # data octets
udp_len = [
0, len(ipv6dic['payload'][udp_header_length:]) + 8
]
newUdp[idxLen] = udp_len[0]
newUdp[idxLen + 1] = udp_len[1]
checksum = u.calculatePseudoHeaderCRC(
ipv6dic['src_addr'], ipv6dic['dst_addr'], udp_len,
[0, ipv6dic['next_header']], newUdp)
#fill crc with the right value.
newUdp[idxCS] = checksum[0]
newUdp[idxCS + 1] = checksum[1]
#keep fields for later processing if needed
ipv6dic['udp_src_port'] = u.buf2int(newUdp[0:2])
ipv6dic['udp_dest_port'] = u.buf2int(newUdp[2:4])
ipv6dic['udp_length'] = newUdp[4:6]
ipv6dic['udp_checksum'] = newUdp[6:8]
ipv6dic['app_payload'] = newUdp[8:]
#substitute udp header by the uncompressed header.
ipv6dic['payload'] = newUdp
ipv6dic['payload_length'] = len(newUdp)
else:
#No UDP header compressed
ipv6dic['udp_src_port'] = u.buf2int(ipv6dic['payload'][:2])
ipv6dic['udp_dest_port'] = u.buf2int(
ipv6dic['payload'][2:4])
ipv6dic['udp_length'] = ipv6dic['payload'][4:6]
ipv6dic['udp_checksum'] = ipv6dic['payload'][6:8]
ipv6dic['app_payload'] = ipv6dic['payload'][8:]
dispatchSignal = (tuple(ipv6dic['dst_addr']), self.PROTO_UDP,
ipv6dic['udp_dest_port'])
#keep payload and app_payload in case we want to assemble the message later.
#as source address is being retrieved from the IPHC header, the signal includes it in case
#receiver such as RPL DAO processing needs to know the source.
success = self._dispatchProtocol(
dispatchSignal, (ipv6dic['src_addr'], ipv6dic['app_payload']))
if success:
return
# assemble the packet and dispatch it again as nobody answer
ipv6pkt = self.reassemble_ipv6_packet(ipv6dic)
self.dispatch('v6ToInternet', ipv6pkt)
except (ValueError, NotImplementedError) as err:
log.error(err)
pass
def _meshToV6_notif(self,sender,signal,data):
'''
Converts a 6LowPAN packet into a IPv6 packet.
This function dispatches the IPv6 packet with signal 'according to the destination address, protocol_type and port'.
'''
try:
ipv6dic={}
#build lowpan dictionary from the data
ipv6dic = self.lowpan_to_ipv6(data)
success = True
dispatchSignal = None
hopbyhop_header_present = False
#read next header
if ipv6dic['next_header']==self.IANA_IPv6HOPHEADER:
# mark hop by hop header present, check hop_flags after obtaining src_addr in IPV6 header.
hopbyhop_header_present = True
#skip the header and process the rest of the message.
ipv6dic['next_header'] = ipv6dic['hop_next_header']
#===================================================================
if ipv6dic['next_header']==self.IPV6_HEADER:
#ipv6 header (inner)
ipv6dic_inner = {}
# parsing the iphc inner header and get the next_header
ipv6dic_inner = self.lowpan_to_ipv6([ipv6dic['pre_hop'],ipv6dic['payload']])
ipv6dic['next_header'] = ipv6dic_inner['next_header']
ipv6dic['payload'] = ipv6dic_inner['payload']
ipv6dic['payload_length'] = ipv6dic_inner['payload_length']
ipv6dic['src_addr'] = ipv6dic_inner['src_addr']
if not ipv6dic.has_key('hop_limit'):
ipv6dic['hop_limit'] = ipv6dic_inner['hop_limit']
ipv6dic['dst_addr'] = ipv6dic_inner['dst_addr']
ipv6dic['flow_label'] = ipv6dic_inner['flow_label']
if hopbyhop_header_present:
#hop by hop header present, check hop_flags
if (ipv6dic['hop_flags'] & self.O_FLAG) == self.O_FLAG:
#error -- this packet has gone downstream somewhere.
log.error("detected possible downstream link on upstream route from {0}".format(",".join(str(c) for c in ipv6dic['src_addr'])))
if (ipv6dic['hop_flags'] & self.R_FLAG) == self.R_FLAG:
#error -- loop in the route
log.error("detected possible loop on upstream route from {0}".format(",".join(str(c) for c in ipv6dic['src_addr'])))
if ipv6dic['next_header']==self.IANA_ICMPv6:
#icmp header
if len(ipv6dic['payload'])<5:
log.critical("wrong payload lenght on ICMPv6 packet {0}".format(",".join(str(c) for c in data)))
print "wrong payload lenght on ICMPv6 packet {0}".format(",".join(str(c) for c in data))
return
ipv6dic['icmpv6_type']=ipv6dic['payload'][0]
ipv6dic['icmpv6_code']=ipv6dic['payload'][1]
ipv6dic['icmpv6_checksum']=ipv6dic['payload'][2:4]
ipv6dic['app_payload']=ipv6dic['payload'][4:]
#this function does the job
dispatchSignal=(tuple(ipv6dic['dst_addr']),self.PROTO_ICMPv6,ipv6dic['icmpv6_type'])
elif ipv6dic['next_header']==self.IANA_UDP:
#udp header -- can be compressed.. assume first it is not compressed.
if len(ipv6dic['payload'])<5:
log.critical("wrong payload lenght on UDP packet {0}".format(",".join(str(c) for c in data)))
print "wrong payload lenght on UDP packet {0}".format(",".join(str(c) for c in data))
return
if ipv6dic['payload'][0] & self.NHC_UDP_MASK==self.NHC_UDP_ID:
lowpan_nhc = ipv6dic['payload'][0]
udp_header_length = 0
newUdp = []
newUdp_header_length = 0
if lowpan_nhc & self.NHC_UDP_PORTS_MASK == self.NHC_UDP_PORTS_INLINE:
src_port = u.buf2int(ipv6dic['payload'][1:3])
dest_port = u.buf2int(ipv6dic['payload'][3:5])
udp_header_length = 5
elif lowpan_nhc & self.NHC_UDP_PORTS_MASK == self.NHC_UDP_PORTS_16S_8D:
src_port = u.buf2int(ipv6dic['payload'][1:3])
dest_port = 0xf000 + ipv6dic['payload'][3]
udp_header_length = 4
elif lowpan_nhc & self.NHC_UDP_PORTS_MASK == self.NHC_UDP_PORTS_8S_16D:
src_port = 0xf000 + ipv6dic['payload'][1]
dest_port = u.buf2int(ipv6dic['payload'][2:4])
udp_header_length = 4
elif lowpan_nhc & self.NHC_UDP_PORTS_MASK == self.NHC_UDP_PORTS_4S_4D:
src_port = 0xf0b0 +((ipv6dic['payload'][1] >> 4) & 0x0f)
dest_port = 0xf0b0 +((ipv6dic['payload'][1] >> 0) & 0x0f)
udp_header_length = 2
newUdp = [src_port >>8 , src_port & 0x00ff]
newUdp += [dest_port >>8 , dest_port & 0x00ff]
idxLen = len(newUdp) # remember index of payload length
newUdp += [0x00,0x00] # length (placeholder)
newUdp_header_length += 2
udp_header_length += 2 # skip two bytes checksum following
idxCS = len(newUdp) # remember index of checksum
newUdp += [0x00,0x00] # Checksum (placeholder)
newUdp_header_length += 2
#append payload to compute crc again
newUdp += ipv6dic['payload'][udp_header_length:] # data octets
udp_len = [0, len(ipv6dic['payload'][udp_header_length:])+8]
newUdp[idxLen] = udp_len[0]
newUdp[idxLen+1] = udp_len[1]
checksum = u.calculatePseudoHeaderCRC(ipv6dic['src_addr'],ipv6dic['dst_addr'],udp_len,[0,ipv6dic['next_header']],newUdp)
#fill crc with the right value.
newUdp[idxCS] = checksum[0]
newUdp[idxCS+1] = checksum[1]
#keep fields for later processing if needed
ipv6dic['udp_src_port'] = u.buf2int(newUdp[0:2])
ipv6dic['udp_dest_port'] = u.buf2int(newUdp[2:4])
ipv6dic['udp_length'] = newUdp[4:6]
ipv6dic['udp_checksum'] = newUdp[6:8]
ipv6dic['app_payload'] = newUdp[8:]
#substitute udp header by the uncompressed header.
ipv6dic['payload'] = newUdp
ipv6dic['payload_length'] = len(newUdp)
else:
#No UDP header compressed
ipv6dic['udp_src_port']=u.buf2int(ipv6dic['payload'][:2])
ipv6dic['udp_dest_port']=u.buf2int(ipv6dic['payload'][2:4])
ipv6dic['udp_length']=ipv6dic['payload'][4:6]
ipv6dic['udp_checksum']=ipv6dic['payload'][6:8]
ipv6dic['app_payload']=ipv6dic['payload'][8:]
dispatchSignal=(tuple(ipv6dic['dst_addr']),self.PROTO_UDP,ipv6dic['udp_dest_port'])
#keep payload and app_payload in case we want to assemble the message later.
#as source address is being retrieved from the IPHC header, the signal includes it in case
#receiver such as RPL DAO processing needs to know the source.
success = self._dispatchProtocol(dispatchSignal,(ipv6dic['src_addr'],ipv6dic['app_payload']))
if success:
return
# assemble the packet and dispatch it again as nobody answer
ipv6pkt=self.reassemble_ipv6_packet(ipv6dic)
self.dispatch('v6ToInternet',ipv6pkt)
except (ValueError,IndexError,NotImplementedError) as err:
log.error(err)
pass
def _sendDIO(self):
"""
Send a DIO.
"""
# don't send DIO if I didn't discover the DAGroot's EUI64
if not self.dagRootEui64:
return
# the list of bytes to be sent to the DAGroot.
# - [8B] destination MAC address
# - [variable] IPHC+ header
dio = []
# next hop: broadcast address
nextHop = [0xFF] * 8
# IPHC header
dio += [0x78] # dispatch byte
dio += [0x33] # dam sam
idxNH = len(dio)
dio += [0x3A] # next header (0x3A=ICMPv6)
dio += [0x00] # HLIM
# ICMPv6 header
idxICMPv6 = len(dio) # remember where ICMPv6 starts
dio += [155] # ICMPv6 type (155=RPL)
dio += [0x01] # ICMPv6 CODE (for RPL 0x01=DIO)
idxICMPv6CS = len(dio) # remember where ICMPv6 checksum starts
dio += [0x00, 0x00] # placeholder for checksum (filled out later)
# DIO header
dio += [0x00] # instance ID
dio += [0x00] # version number
dio += [0x00, 0x00] # rank
dio += [self.DIO_OPT_GROUNDED | self.MOP_DIO_A | self.MOP_DIO_B | self.MOP_DIO_C] # options: G | 0 | MOP | Prf
dio += [0x00] # DTSN
dio += [0x00] # flags
dio += [0x00] # reserved
# DODAGID
with self.stateLock:
idxSrc = len(dio) # this is a little hack as the source is the dodag
dio += self.networkPrefix
dio += self.dagRootEui64
# wireshark calculates the IPv6 source and destination from the
# 6LoWPAN header. It is lot aware of the network prefix and uses
# link-local addresses. We do the same in this implementation to avoid
# checksum errors in Wireshark.
wiresharkSrc = [0xFE, 0x80] + [0x00] * 6 + [dio[idxSrc + 8] | 0x02] + dio[idxSrc + 9 : idxSrc + 16]
wiresharkDst = [0xFE, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFE, 0x00, 0xFF, 0xFF]
# calculate ICMPv6 checksum over ICMPv6header+ (RFC4443)
checksum = u.calculatePseudoHeaderCRC(
src=wiresharkSrc,
dst=wiresharkDst,
length=[0x00, 0x00, 0x00, len(dio[idxICMPv6:])],
nh=[0x00] + dio[idxNH : idxNH + 1],
payload=dio[idxICMPv6:],
)
dio[idxICMPv6CS] = checksum[0]
dio[idxICMPv6CS + 1] = checksum[1]
# log
if log.isEnabledFor(logging.DEBUG):
log.debug("sending DIO {0}".format(u.formatBuf(dio)))
# dispatch
self.dispatch(signal="bytesToMesh", data=(nextHop, dio))
def _sendDIO(self):
'''
Send a DIO.
'''
# don't send DIO if I didn't discover the DAGroot's EUI64
if not self.dagRootEui64:
return
# the list of bytes to be sent to the DAGroot.
# - [8B] destination MAC address
# - [variable] IPHC+ header
dio = []
# next hop: broadcast address
nextHop = [0xff] * 8
# IPHC header
dio += [0x78] # dispatch byte
dio += [0x33] # dam sam
idxNH = len(dio)
dio += [0x3A] # next header (0x3A=ICMPv6)
dio += [0x00] # HLIM
# ICMPv6 header
idxICMPv6 = len(dio) # remember where ICMPv6 starts
dio += [155] # ICMPv6 type (155=RPL)
dio += [0x01] # ICMPv6 CODE (for RPL 0x01=DIO)
idxICMPv6CS = len(dio) # remember where ICMPv6 checksum starts
dio += [0x00, 0x00] # placeholder for checksum (filled out later)
# DIO header
dio += [0x00] # instance ID
dio += [0x00] # version number
dio += [0x00, 0x00] # rank
dio += [
self.DIO_OPT_GROUNDED | self.MOP_DIO_A | self.MOP_DIO_B
| self.MOP_DIO_C
] # options: G | 0 | MOP | Prf
dio += [0x00] # DTSN
dio += [0x00] # flags
dio += [0x00] # reserved
# DODAGID
with self.stateLock:
idxSrc = len(
dio) # this is a little hack as the source is the dodag
dio += self.networkPrefix
dio += self.dagRootEui64
# wireshark calculates the IPv6 source and destination from the
# 6LoWPAN header. It is lot aware of the network prefix and uses
# link-local addresses. We do the same in this implementation to avoid
# checksum errors in Wireshark.
wiresharkSrc = [0xfe, 0x80] + [0x00] * 6 + [
dio[idxSrc + 8] | 0x02
] + dio[idxSrc + 9:idxSrc + 16]
wiresharkDst = [
0xfe,
0x80,
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0x00,
0xff,
0xfe,
0x00,
0xff,
0xff,
]
# calculate ICMPv6 checksum over ICMPv6header+ (RFC4443)
checksum = u.calculatePseudoHeaderCRC(
src=wiresharkSrc,
dst=wiresharkDst,
length=[0x00, 0x00, 0x00, len(dio[idxICMPv6:])],
nh=[0x00] + dio[idxNH:idxNH + 1],
payload=dio[idxICMPv6:],
)
dio[idxICMPv6CS] = checksum[0]
dio[idxICMPv6CS + 1] = checksum[1]
# log
if log.isEnabledFor(logging.DEBUG):
log.debug('sending DIO {0}'.format(u.formatBuf(dio)))
# dispatch
self.dispatch(signal='bytesToMesh', data=(nextHop, dio))
