# MQTT-SN layer unit tests
# Copyright (C) 2019 Martine Lenders <m.lenders@fu-berlin.de>
#
# This program is published under GPLv2 license
#
# Type the following command to start the test
# $ test/run_tests -P "load_contrib('mqttsn')" -t test/contrib/mqttsn.uts

+ Syntax check
= Import the MQTT-SN layer
from scapy.contrib.mqttsn import *

+ MQTT-SN protocol test

= MQTTSN + MQTTSNAdvertise, packet instantiation and len field adjust
p = MQTTSN() / MQTTSNAdvertise(gw_id=142, duration=54403)
assert p.len is None
assert p.type == ADVERTISE
assert p.gw_id == 142
assert p.duration == 54403
b = bytes(p)
p = MQTTSN(b)
assert p.len == 5
assert p.type == ADVERTISE
assert p.gw_id == 142
assert p.duration == 54403

= MQTTSNAdvertise, packet dissection
b = b"\x05\x00\x98\x2b\x9a"
p = MQTTSN(b)
assert p.len == 5
assert p.type == ADVERTISE
assert p.gw_id == 0x98
assert p.duration == 0x2b9a

= MQTTSNSearchGW, packet instantiation
p = MQTTSN() / MQTTSNSearchGW(radius=175)
assert p.len is None
assert p.type == SEARCHGW
assert p.radius == 175

= MQTTSNSearchGW, packet dissection
b = b"\x03\x01\xcc"
p = MQTTSN(b)
assert p.len == 3
assert p.type == SEARCHGW
assert p.radius == 0xcc

= MQTTSNGwInfo, packet instantiation
p = MQTTSN() / MQTTSNGwInfo(gw_id=135, gw_addr="test\0test")
assert p.len is None
assert p.type == GWINFO
assert p.gw_id == 135
assert p.gw_addr == b"test\x00test"

= MQTTSN + MQTTSNGwInfo, packet instantiation and len field adjust
p = MQTTSN(len=7) / MQTTSNGwInfo(gw_id=7, gw_addr="test") / "xyz"
assert p.len == 7
assert p.type == GWINFO
assert p.gw_id == 7
assert p.gw_addr == b"test"
assert p.load == b"xyz"
b = bytes(p)
p = MQTTSN(b)
assert p.len == 7
assert p.type == GWINFO
assert p.gw_id == 7
assert p.gw_addr == b"test"
assert p.load == b"xyz"

= MQTTSNGwInfo, packet dissection
b = b"\x07\x02\x14testing"
p = MQTTSN(b)
assert p.len == 7
assert p.type == GWINFO
assert p.gw_id == 0x14
assert p.gw_addr == b"test"
assert p.load == b"ing"

= MQTTSNGwInfo, packet dissection - invalid length
b = b"\x01\x00\x01\x02\x14test"
p = MQTTSN(b)
print(type(p), repr(p))
assert p.len == 1
assert p.type == GWINFO
assert p.gw_id == 0x14
assert p.gw_addr == b""

= MQTTSNConnect, packet instantiation
p = MQTTSN() / MQTTSNConnect(duration=40666, client_id="test")
assert p.len is None
assert p.type == CONNECT
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.prot_id == 1
assert p.duration == 40666
assert p.client_id == b"test"

= MQTTSNConnect, packet dissection
b = b"\x0a\x04\x04\x1a\x77\x5btesting"
p = MQTTSN(b)
assert p.len == 10
assert p.type == CONNECT
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 1
assert p.tid_type == TID_NORMAL
assert p.prot_id == 0x1a
assert p.duration == 0x775b
assert p.client_id == b"test"
assert p.load == b"ing"

= MQTTSNConnack, packet instantiation
p = MQTTSN() / MQTTSNConnack()
assert p.len is None
assert p.type == CONNACK
assert p.return_code == ACCEPTED

= MQTTSNConnack, packet dissection
b = b"\x03\x05\x02"
p = MQTTSN(b)
assert p.len == 3
assert p.type == CONNACK
assert p.return_code == REJ_TID

= MQTTSNWillTopicReq, packet instantiation
p = MQTTSN() / MQTTSNWillTopicReq()
assert p.len is None
assert p.type == WILLTOPICREQ

= MQTTSNWillTopicReq, packet dissection
b = b"\x02\x06"
p = MQTTSN(b)
assert p.len == 2
assert p.type == WILLTOPICREQ

= MQTTSNWillTopic, packet instantiation
p = MQTTSN() / MQTTSNWillTopic(will_topic="/test")
assert p.len is None
assert p.type == WILLTOPIC
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.will_topic == b"/test"

= MQTTSNWillTopic, packet dissection
b = b"\x08\x07\x00/testing"
p = MQTTSN(b)
assert p.len == 8
assert p.type == WILLTOPIC
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.will_topic == b"/test"

= MQTTSNWillMsgReq, packet instantiation
p = MQTTSN() / MQTTSNWillMsgReq()
assert p.len is None
assert p.type == WILLMSGREQ

= MQTTSNWillMsgReq, packet dissection
b = b"\x02\x08"
p = MQTTSN(b)
assert p.len == 2
assert p.type == WILLMSGREQ

= MQTTSNWillMsg, packet instantiation
p = MQTTSN() / MQTTSNWillMsg(will_msg="test")
assert p.len is None
assert p.type == WILLMSG
assert p.will_msg == b"test"

= MQTTSNWillMsg, packet dissection
b = b"\x06\x09testing"
p = MQTTSN(b)
assert p.len == 6
assert p.type == WILLMSG
assert p.will_msg == b"test"
assert p.load == b"ing"

= MQTTSNRegister, packet instantiation
p = MQTTSN() / MQTTSNRegister(mid=30533, topic_name="/test")
assert p.len is None
assert p.type == REGISTER
assert p.tid == 0
assert p.mid == 30533
assert p.topic_name == b"/test"

= MQTTSNRegister, packet dissection
b = b"\x0b\x0a\0\0\x48\x8a/testing"
p = MQTTSN(b)
assert p.len == 11
assert p.type == REGISTER
assert p.tid == 0
assert p.mid == 0x488a
assert p.topic_name == b"/test"
assert p.load == b"ing"

= MQTTSNRegack, packet instantiation
p = MQTTSN() / MQTTSNRegack(tid=61547, mid=8593, return_code=REJ_NOTSUP)
assert p.len is None
assert p.type == REGACK
assert p.tid == 61547
assert p.mid == 8593
assert p.return_code == REJ_NOTSUP

= MQTTSNRegack, packet dissection
b = b"\x08\x0b\xc5\xe8\x31\x87\x01"
p = MQTTSN(b)
assert p.len == 8
assert p.type == REGACK
assert p.tid == 0xc5e8
assert p.mid == 0x3187
assert p.return_code == REJ_CONJ

= MQTTSNPublish, packet instantiation
p = MQTTSN() / MQTTSNPublish(qos=QOS_1, tid=52032, mid=35252,
                             data="Hello world!")
assert p.len is None
assert p.type == PUBLISH
assert p.dup == 0
assert p.qos == QOS_1
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.tid == 52032
assert p.mid == 35252
assert p.data == b"Hello world!"

= MQTTSNPublish, packet instantiation - long data
p = MQTTSN() / MQTTSNPublish(qos=QOS_NEG1, tid=62839, mid=36181,
                             data=726 * "X")
assert p.len is None
assert p.type == PUBLISH
assert p.dup == 0
assert p.qos == QOS_NEG1
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.tid == 62839
assert p.mid == 36181
assert p.data == 726 * b"X"
# Check if length field was constructed correctly
b = bytes(p)
assert b[:3] == b'\x01\x02\xdf'
p = MQTTSN(b)
assert p.len == 735
assert p.data == 726 * b"X"

= MQTTSNPublish, packet dissection
b = b"\x0b\x0c\x40\x19\x7f\x6a\x26testing"
p = MQTTSN(b)
assert p.len == 11
assert p.type == PUBLISH
assert p.dup == 0
assert p.qos == QOS_2
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.tid == 0x197f
assert p.mid == 0x6a26
assert p.data == b"test"
assert p.load == b"ing"

= MQTTSNPublish, packet dissection - long data
b = b"\x01\x04\x64\x0c" + b"\x00\xb1\x39\xd7\x4a" + (1115 * b"X")
p = MQTTSN(b)
assert p.len == 0x0464 == (4 + 5 + 1115)
assert p.type == PUBLISH
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.tid == 0xb139
assert p.mid == 0xd74a
assert p.data == 1115 * b"X"

= MQTTSNPuback, packet instantiation
p = MQTTSN() / MQTTSNPuback(tid=27610, mid=30284, return_code=ACCEPTED)
assert p.len is None
assert p.type == PUBACK
assert p.tid == 27610
assert p.mid == 30284
assert p.return_code == ACCEPTED

= MQTTSNPuback, packet dissection
b = b"\x08\x0d\x03\xda\x73\x9a\x02"
p = MQTTSN(b)
assert p.len == 8
assert p.type == PUBACK
assert p.tid == 0x03da
assert p.mid == 0x739a
assert p.return_code == REJ_TID

= MQTTSNPubcomp, packet instantiation
p = MQTTSN() / MQTTSNPubcomp(mid=36193)
assert p.len is None
assert p.type == PUBCOMP
assert p.mid == 36193

= MQTTSNPubcomp, packet dissection
b = b"\x04\x0e\x26\xa2"
p = MQTTSN(b)
assert p.len == 4
assert p.type == PUBCOMP
assert p.mid == 0x26a2

= MQTTSNPubrec, packet instantiation
p = MQTTSN() / MQTTSNPubrec(mid=44837)
assert p.len is None
assert p.type == PUBREC
assert p.mid == 44837

= MQTTSNPubrec, packet dissection
b = b"\x04\x0f\x36\xc4"
p = MQTTSN(b)
assert p.len == 4
assert p.type == PUBREC
assert p.mid == 0x36c4

= MQTTSNPubrel, packet instantiation
p = MQTTSN() / MQTTSNPubrel(mid=42834)
assert p.len is None
assert p.type == PUBREL
assert p.mid == 42834

= MQTTSNPubrel, packet dissection
b = b"\x04\x10\x94\x0f"
p = MQTTSN(b)
assert p.len == 4
assert p.type == PUBREL
assert p.mid == 0x940f

= MQTTSNSubscribe, packet instantiation - topic name
p = MQTTSN() / MQTTSNSubscribe(mid=63780, topic_name="/test")
assert p.len is None
assert p.type == SUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.topic_name == b"/test"
assert p.short_topic is None
assert p.tid is None

= MQTTSNSubscribe, packet instantiation - predefined topic ID
p = MQTTSN() / MQTTSNSubscribe(mid=63780, tid_type=TID_PREDEF,
                               tid=1187)
assert p.len is None
assert p.type == SUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_PREDEF
assert p.topic_name is None
assert p.short_topic is None
assert p.tid == 1187

= MQTTSNSubscribe, packet instantiation - short topic
p = MQTTSN() / MQTTSNSubscribe(mid=63780, tid_type=TID_SHORT, short_topic="fx")
assert p.len is None
assert p.type == SUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_SHORT
assert p.topic_name is None
assert p.short_topic == b"fx"
assert p.tid is None

= MQTTSNSubscribe, packet dissection - topic name
b = b"\x07\x12\x00\x66\x8a/t"
p = MQTTSN(b)
assert p.len == 7
assert p.type == SUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.mid == 0x668a
assert p.topic_name == b"/t"
assert p.short_topic is None
assert p.tid is None

= MQTTSNSubscribe, packet dissection - short topic
b = b"\x07\x12\x01\x66\x8a/t"
p = MQTTSN(b)
assert p.len == 7
assert p.type == SUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_PREDEF
assert p.mid == 0x668a
assert p.topic_name is None
assert p.short_topic is None
assert p.tid == (ord("/") << 8 | ord("t")) == 12148

= MQTTSNSubscribe, packet dissection - predefined topic ID
b = b"\x07\x12\x02\x66\x8a/t"
p = MQTTSN(b)
assert p.len == 7
assert p.type == SUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_SHORT
assert p.mid == 0x668a
assert p.topic_name is None
assert p.short_topic == b"/t"
assert p.tid is None

= MQTTSNSuback, packet instantiation
p = MQTTSN() / MQTTSNSuback(qos=QOS_0, tid=5496, mid=63108,
                             return_code=REJ_TID)
assert p.len is None
assert p.type == SUBACK
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.tid == 5496
assert p.mid == 63108
assert p.return_code == REJ_TID

= MQTTSNSuback, packet dissection
b = b"\x08\x13\xa4\x93\x0b\x02\xc6\x00"
p = MQTTSN(b)
assert p.len == 8
assert p.type == SUBACK
assert p.dup == 1
assert p.qos == QOS_1
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 1
assert p.tid_type == TID_NORMAL
assert p.tid == 0x930b
assert p.mid == 0x02c6
assert p.return_code == ACCEPTED

= MQTTSNUnsubscribe, packet instantiation - topic name
p = MQTTSN() / MQTTSNUnsubscribe(mid=63780, topic_name="/test")
assert p.len is None
assert p.type == UNSUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.topic_name == b"/test"
assert p.short_topic is None
assert p.tid is None

= MQTTSNUnsubscribe, packet instantiation - predefined topic ID
p = MQTTSN() / MQTTSNUnsubscribe(mid=63780, tid_type=TID_PREDEF,
                                 tid=1187)
assert p.len is None
assert p.type == UNSUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_PREDEF
assert p.topic_name is None
assert p.short_topic is None
assert p.tid == 1187

= MQTTSNUnsubscribe, packet instantiation - short topic
p = MQTTSN() / MQTTSNUnsubscribe(mid=63780, tid_type=TID_SHORT,
                                 short_topic="fx")
assert p.len is None
assert p.type == UNSUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_SHORT
assert p.topic_name is None
assert p.short_topic == b"fx"
assert p.tid is None

= MQTTSNUnsubscribe, packet dissection - topic name
b = b"\x07\x14\x00\x66\x8a/t"
p = MQTTSN(b)
assert p.len == 7
assert p.type == UNSUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.mid == 0x668a
assert p.topic_name == b"/t"
assert p.short_topic is None
assert p.tid is None

= MQTTSNUnsubscribe, packet dissection - short topic
b = b"\x07\x14\x01\x66\x8a/t"
p = MQTTSN(b)
assert p.len == 7
assert p.type == UNSUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_PREDEF
assert p.mid == 0x668a
assert p.topic_name is None
assert p.short_topic is None
assert p.tid == (ord("/") << 8 | ord("t")) == 12148

= MQTTSNUnsubscribe, packet dissection - predefined topic ID
b = b"\x07\x14\x02\x66\x8a/t"
p = MQTTSN(b)
assert p.len == 7
assert p.type == UNSUBSCRIBE
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_SHORT
assert p.mid == 0x668a
assert p.topic_name is None
assert p.short_topic == b"/t"
assert p.tid is None

= MQTTSNUnsuback, packet instantiation
p = MQTTSN() / MQTTSNUnsuback(mid=44541)
assert p.len is None
assert p.type == UNSUBACK
assert p.mid == 44541

= MQTTSNUnsuback, packet dissection
b = b"\x08\x15\xcb\x3d"
p = MQTTSN(b)
assert p.len == 8
assert p.type == UNSUBACK
assert p.mid == 0xcb3d

= MQTTSNPingReq, packet instantiation - no client ID
p = MQTTSN() / MQTTSNPingReq()
assert p.len is None
assert p.type == PINGREQ
assert p.client_id == b""

= MQTTSNPingReq, packet instantiation - with client ID
p = MQTTSN() / MQTTSNPingReq(client_id="test")
assert p.len is None
assert p.type == PINGREQ
assert p.client_id == b"test"

= MQTTSNPingReq, packet dissection
b = b"\x07\x16hello"
p = MQTTSN(b)
assert p.len == 7
assert p.type == PINGREQ
assert p.client_id == b"hello"

= MQTTSNPingResp, packet instantiation
p = MQTTSN() / MQTTSNPingResp()
assert p.len is None
assert p.type == PINGRESP

= MQTTSNPingResp, packet dissection
b = b"\x02\x17"
p = MQTTSN(b)
assert p.len == 2
assert p.type == PINGRESP

= MQTTSNDisconnect, packet instantiation and len field adjust - w/o duration
p = MQTTSN() / MQTTSNDisconnect()
assert p.len is None
assert p.type == DISCONNECT
assert p.duration is None
b = bytes(p)
p = MQTTSN(b)
assert p.len == 2
assert p.type == DISCONNECT

= MQTTSNDisconnect, packet instantiation and len field adjust - w duration
p = MQTTSN() / MQTTSNDisconnect(duration=19567)
assert p.len is None
assert p.type == DISCONNECT
assert p.duration == 19567
b = bytes(p)
p = MQTTSN(b)
assert p.len == 4
assert p.type == DISCONNECT
assert p.duration == 19567

= MQTTSNDisconnect, packet dissection - w/o duration
b = b"\x02\x18"
p = MQTTSN(b)
assert p.len == 2
assert p.type == DISCONNECT

= MQTTSNDisconnect, packet dissection - w duration
b = b"\x04\x18\x03\x12"
p = MQTTSN(b)
assert p.len == 4
assert p.type == DISCONNECT
assert p.duration == 0x0312

= MQTTSNWillTopicUpd, packet instantiation
p = MQTTSN() / MQTTSNWillTopicUpd(will_topic="/test")
assert p.len is None
assert p.type == WILLTOPICUPD
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.will_topic == b"/test"

= MQTTSNWillTopicUpd, packet dissection
b = b"\x08\x1a\x00/testing"
p = MQTTSN(b)
assert p.len == 8
assert p.type == WILLTOPICUPD
assert p.dup == 0
assert p.qos == QOS_0
assert p.retain == 0
assert p.will == 0
assert p.cleansess == 0
assert p.tid_type == TID_NORMAL
assert p.will_topic == b"/test"

= MQTTSNWillTopicResp, packet instantiation
p = MQTTSN() / MQTTSNWillTopicResp()
assert p.len is None
assert p.type == WILLTOPICRESP
assert p.return_code == ACCEPTED

= MQTTSNWillTopicResp, packet dissection
b = b"\x03\x1b\x02"
p = MQTTSN(b)
assert p.len == 3
assert p.type == WILLTOPICRESP
assert p.return_code == REJ_TID

= MQTTSNWillMsgUpd, packet instantiation
p = MQTTSN() / MQTTSNWillMsgUpd(will_msg="test")
assert p.len is None
assert p.type == WILLMSGUPD
assert p.will_msg == b"test"

= MQTTSNWillMsgUpd, packet dissection
b = b"\x06\x1ctesting"
p = MQTTSN(b)
assert p.len == 6
assert p.type == WILLMSGUPD
assert p.will_msg == b"test"
assert p.load == b"ing"

= MQTTSNWillMsgResp, packet instantiation
p = MQTTSN() / MQTTSNWillMsgResp()
assert p.len is None
assert p.type == WILLMSGRESP
assert p.return_code == ACCEPTED

= MQTTSNWillMsgResp, packet dissection
b = b"\x03\x1d\x02"
p = MQTTSN(b)
assert p.len == 3
assert p.type == WILLMSGRESP
assert p.return_code == REJ_TID

= MQTTSNEncaps, packet instantiation
p = MQTTSN() / MQTTSNEncaps(radius=1, w_node_id="test") / MQTTSN() / \
    MQTTSNConnack()
assert p.len is None
assert p.type == ENCAPS_MSG
assert p.radius == 1
assert p.w_node_id == b"test"
assert p.payload.payload.len is None
assert p.payload.payload.type == CONNACK
assert p.payload.payload.return_code == ACCEPTED
b = bytes(p)
p = MQTTSN(b)
assert p.len == 7
assert p.type == ENCAPS_MSG
assert p.radius == 1
assert p.w_node_id == b"test"
assert p.return_code == ACCEPTED
assert p.payload.payload.len == 3
assert p.payload.payload.type == CONNACK
assert p.payload.payload.return_code == ACCEPTED

= MQTTSNEncaps, packet dissection
b = b"\x07\xfe\x02test\x03\x05\x00"
p = MQTTSN(b)
assert p.len == 7
assert p.type == ENCAPS_MSG
assert p.radius == 2
assert p.w_node_id == b"test"
assert p.payload.payload.len == 3
assert p.payload.payload.type == CONNACK
assert p.payload.payload.return_code == ACCEPTED

= MQTTSNEncaps, packet dissection -- long payload
b = b"\x07\xfe\x02test" + b"\x01\x04\x64\x0c" + b"\x00\xb1\x39\xd7\x4a" + \
        (1115 * b"X")
p = MQTTSN(b)
assert p.len == 7
assert p.type == ENCAPS_MSG
assert p.radius == 2
assert p.w_node_id == b"test"
assert p.payload.payload.len == 4 + 5 + 1115 == 0x0464
assert p.payload.payload.type == PUBLISH
assert p.payload.payload.dup == 0
assert p.payload.payload.qos == QOS_0
assert p.payload.payload.retain == 0
assert p.payload.payload.will == 0
assert p.payload.payload.cleansess == 0
assert p.payload.payload.tid_type == TID_NORMAL
assert p.payload.payload.tid == 0xb139
assert p.payload.payload.mid == 0xd74a
assert p.payload.payload.data == 1115 * b"X"

= MQTTSN without payload
p = MQTTSN()
assert bytes(p) == b"\x02\x00"

= MQTTSN without payload -- invalid lengths
p = MQTTSN(len=1)
try:
    bytes(p)        # expect Scapy_Exception
    assert false
except Scapy_Exception:
    pass

p = MQTTSN(len=0x10000)
try:
    bytes(p)        # expect Scapy_Exception
    assert false
except Scapy_Exception:
    pass

b = '\x01'
try:
    p = MQTTSN(b)   # expect Scapy_Exception
    assert false
except Scapy_Exception:
    pass

b = '\x01\x02'
try:
    p = MQTTSN(b)   # expect Scapy_Exception
    assert false
except Scapy_Exception:
    pass


= MQTT-SN RandVariableFieldLen
assert type(MQTTSN().fieldtype["len"].randval()) == RandVariableFieldLen
assert type(MQTTSN().fieldtype["len"].randval() + 0) == int

= Disect full IPv6 packages
~ dport == 1883 (0x75b)
b = b"\x60\x00\x00\x00\x00\x2c\x11\x40\x20\x01\x0d\xb8\x00\x00\x00\x00" \
    b"\x17\x11\x6b\x10\x65\xf7\x5f\x0a\x20\x01\x0d\xb8\x00\x00\x00\x00" \
    b"\x17\x11\x6b\x10\x65\xfd\xbe\x06\xc0\x00\x07\x5b\x00\x2c\x40\x7e" \
    b"\x0b\x0a\0\0\x48\x8a/testing"
p = IPv6(b)
assert MQTTSNRegister in p

~ sport == 1883 (0x75b)
b = b"\x60\x00\x00\x00\x00\x0f\x11\x40\x20\x01\x0d\xb8\x00\x00\x00\x00" \
    b"\x17\x11\x6b\x10\x65\xfd\xbe\x06\x20\x01\x0d\xb8\x00\x00\x00\x00" \
    b"\x17\x11\x6b\x10\x65\xf7\x5f\x0a\x07\x5b\xc0\x00\x00\x0f\x62\x7c" \
    b"\x07\x0d\x00\x01\x86\x2f\x00"
p = IPv6(b)
assert MQTTSNPuback in p

= UDP packet instantiation
b = bytes(UDP() / MQTTSN() / MQTTSNConnack())
p = UDP(b)
assert MQTTSNConnack in p
assert p.sport == 1883
assert p.dport == 1883