Accessing RTPS submessages

[gianpiero]

Hello,

I am trying to access RTPS messages using pyshark. An RTPS message can have multuple SUBMESSAGES. See wireshark output:

When I use pyshark like this:

import pyshark
capture = pyshark.LiveCapture(interface='en0', display_filter='rtps && rtps.sm.id == 0x15')
capture.sniff(timeout=50)
 print(capture[0])

I get the correct answer with two submessageId: (two entries with values 0x09 and 0x15) like in wireshark (see full output at the end)

BUT how do i access the two submessageId individually?

I can see one of them

capture[0].rtps.sm_id

(0x09)

I would expect to get a list.. something like

capture[0].rtps.sm[i].id

with i = 0, 1,...

Is it possible to access the submessages separately?

---

output of print(capture[0]):

Packet (Length: 794)
Layer ETH
:	Destination: 01:00:5e:7f:00:01
	Address: 01:00:5e:7f:00:01
	.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
	.... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
	Source: 90:9c:4a:c4:91:3f
	.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
	.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
	Type: IPv4 (0x0800)
	Address: 90:9c:4a:c4:91:3f
Layer IP
:	0100 .... = Version: 4
	.... 0101 = Header Length: 20 bytes (5)
	Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
	0000 00.. = Differentiated Services Codepoint: Default (0)
	.... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
	Total Length: 780
	Identification: 0x128a (4746)
	000. .... = Flags: 0x0
	0... .... = Reserved bit: Not set
	.0.. .... = Don't fragment: Not set
	..0. .... = More fragments: Not set
	...0 0000 0000 0000 = Fragment Offset: 0
	Time to Live: 1
	Protocol: UDP (17)
	Header Checksum: 0xf21e [validation disabled]
	Header checksum status: Unverified
	Source Address: 192.168.1.144
	Destination Address: 239.255.0.1
Layer UDP
:	Source Port: 55343
	Destination Port: 7400
	Length: 760
	Checksum: 0x9b5d [unverified]
	Checksum Status: Unverified
	Stream index: 11
	Timestamps
	Time since first frame: 0.000000000 seconds
	Time since previous frame: 0.000000000 seconds
	UDP payload (752 bytes)
Layer RTPS
:	Magic: RTPS
	Protocol version: 2.3
	major: 2
	minor: 3
	vendorId: 01.01 (Real-Time Innovations, Inc. - Connext DDS)
	guidPrefix: 0101340aec4939a98b48049c
	hostId: 0x0101340a
	appId: 0xec4939a9
	instanceId: 0x8b48049c
	Default port mapping: MULTICAST_METATRAFFIC, domainId=0
	domain_id: 0
	traffic_nature: MULTICAST_METATRAFFIC (2)
	submessageId: INFO_TS (0x09)
	Flags: 0x01, Endianness bit
	0... .... = Reserved: Not set
	.... ..0. = Timestamp flag: Not set
	.... ...1 = Endianness bit: Set
	octetsToNextHeader: 8
	Timestamp: Sep 25, 2023 22:15:09.163557999 UTC
	.... 0... = Serialized Key: Not set
	.... .1.. = Data present: Set
	.... ..0. = Inline QoS: Not set
	0000 0000 0000 0000 = Extra flags: 0x0000
	Octets to inline QoS: 16
	readerEntityId: ENTITYID_UNKNOWN (0x00000000)
	readerEntityKey: 0x000000
	readerEntityKind: Application-defined unknown kind (0x00)
	writerEntityId: ENTITYID_BUILTIN_PARTICIPANT_WRITER (0x000100c2)
	writerEntityKey: 0x000100
	writerEntityKind: Built-in writer (with key) (0xc2)
	writerSeqNumber: 1
	encapsulation kind: PL_CDR_LE (0x0003)
	encapsulation options: 0x0000
	parameterId: PID_PARTICIPANT_GUID (0x0050)
	parameterLength: 16
	Participant GUID: 0101340a ec4939a9 8b48049c 000001c1
	hostId: 0x0101340a
	appId: 0xec4939a9
	instanceId: 0x8b48049c
	entityId: ENTITYID_PARTICIPANT (0x000001c1)
	entityKey: 0x000001
	entityKind: Built-in participant (0xc1)
	Flags: 0x00000c3f, Participant Message DataReader, Participant Message DataWriter, Subscription Detector, Subscription Announcer, Publication Detector, Publication Announcer, Participant Detector, Participant Announcer
	.... 0... .... .... .... .... .... .... = Participant Secure Reader: Not set
	.... .0.. .... .... .... .... .... .... = Participant Secure Writer: Not set
	.... ..0. .... .... .... .... .... .... = Secure Participant Volatile Message Reader: Not set
	.... ...0 .... .... .... .... .... .... = Secure Participant Volatile Message Writer: Not set
	.... .... 0... .... .... .... .... .... = Participant Stateless Message Reader: Not set
	.... .... .0.. .... .... .... .... .... = Participant Stateless Message Writer: Not set
	.... .... ..0. .... .... .... .... .... = Secure Participant Message Reader: Not set
	.... .... ...0 .... .... .... .... .... = Secure Participant Message Writer: Not set
	.... .... .... 0... .... .... .... .... = Secure Subscription Reader: Not set
	.... .... .... .0.. .... .... .... .... = Secure Subscription Writer: Not set
	.... .... .... ..0. .... .... .... .... = Secure Publication Reader: Not set
	.... .... .... ...0 .... .... .... .... = Secure Publication Writer: Not set
	.... .... .... .... .... 1... .... .... = Participant Message DataReader: Set
	.... .... .... .... .... .1.. .... .... = Participant Message DataWriter: Set
	.... .... .... .... .... ..0. .... .... = Participant State Detector: Not set
	.... .... .... .... .... ...0 .... .... = Participant State Announcer: Not set
	.... .... .... .... .... .... 0... .... = Participant Proxy Detector: Not set
	.... .... .... .... .... .... .0.. .... = Participant Proxy Announcer: Not set
	.... .... .... .... .... .... ..1. .... = Subscription Detector: Set
	.... .... .... .... .... .... ...1 .... = Subscription Announcer: Set
	.... .... .... .... .... .... .... 1... = Publication Detector: Set
	.... .... .... .... .... .... .... .1.. = Publication Announcer: Set
	.... .... .... .... .... .... .... ..1. = Participant Detector: Set
	.... .... .... .... .... .... .... ...1 = Participant Announcer: Set
	parameterData: 01000000
	Built-in Endpoint QoS: 0x00000001
	Major: 6
	Minor: 1
	Release: 0
	Revision: 0
	Property Name: dds.sys_info.hostname
	Value: napoli
	Kind: LOCATOR_KIND_UDPV4 (0x00000001)
	Port: 7415
	Address: 192.168.1.144
	seconds: 100
	fraction: 0
	classID: 1
	messageSizeMax: 65507
	Flags: 0x00000003, Service Request Reader, Service Request Writer
	.... .... .... .... .... .... .0.. .... = Cloud Discovery Service Announcer: Not set
	.... .... .... .... .... .... ..0. .... = Secure Service Request Reader: Not set
	.... .... .... .... .... .... ...0 .... = Secure Service Request Writer: Not set
	.... .... .... .... .... .... .... 0... = Locator Ping Reader: Not set
	.... .... .... .... .... .... .... .0.. = Locator Ping Writer: Not set
	.... .... .... .... .... .... .... ..1. = Service Request Reader: Set
	.... .... .... .... .... .... .... ...1 = Service Request Writer: Set
	Protocol version: 2.3
	major: 2
	minor: 3
	vendorId: 01.01 (Real-Time Innovations, Inc. - Connext DDS)
	serializedData
	serializedData:
	PID_PARTICIPANT_GUID
	PID_BUILTIN_ENDPOINT_SET
	PID_BUILTIN_ENDPOINT_QOS
	PID_PROTOCOL_VERSION
	PID_VENDOR_ID
	PID_PRODUCT_VERSION
	Product version: 6.1.0.0
	PID_PROPERTY_LIST (7 properties)
	Property List
	PID_DEFAULT_UNICAST_LOCATOR (LOCATOR_KIND_UDPV4, 192.168.1.144:7415)
	locator
	PID_METATRAFFIC_UNICAST_LOCATOR (LOCATOR_KIND_UDPV4, 192.168.1.144:7414)
	locator
	PID_METATRAFFIC_MULTICAST_LOCATOR (LOCATOR_KIND_UDPV4, 239.255.0.1:7400)
	locator
	PID_PARTICIPANT_LEASE_DURATION
	lease_duration: 100.000000 sec (100s + 0x00000000)
	PID_DOMAIN_ID
	PID_RTI_DOMAIN_ID
	PID_TRANSPORT_INFO_LIST
	transportInfo 1: UDPv4
	PID_REACHABILITY_LEASE_DURATION
	lease_duration: INFINITE
	PID_VENDOR_BUILTIN_ENDPOINT_SET
	PID_SENTINEL
	domain_id: 0
	domain_id: 0
	submessageId: DATA (0x15)
	Flags: 0x05, Data present, Endianness bit
	.0.. .... = Reserved: Not set
	..0. .... = Reserved: Not set
	...0 .... = Reserved: Not set
	.... 0... = Reserved: Not set
	.... .0.. = Reserved: Not set
	0... .... = Reserved: Not set
	.0.. .... = Reserved: Not set
	..0. .... = Reserved: Not set
	...0 .... = Reserved: Not set
	.... .... .... .... 0000 .... .... .... = Reserved: Not set
	.... ...1 = Endianness bit: Set
	octetsToNextHeader: 716
	parameterId: PID_BUILTIN_ENDPOINT_SET (0x0058)
	parameterId: PID_BUILTIN_ENDPOINT_QOS (0x0077)
	parameterId: PID_PROTOCOL_VERSION (0x0015)
	parameterId: PID_VENDOR_ID (0x0016)
	parameterId: PID_PRODUCT_VERSION (0x8000)
	parameterId: PID_PROPERTY_LIST (0x0059)
	parameterId: PID_DEFAULT_UNICAST_LOCATOR (0x0031)
	parameterId: PID_METATRAFFIC_UNICAST_LOCATOR (0x0032)
	parameterId: PID_METATRAFFIC_MULTICAST_LOCATOR (0x0033)
	parameterId: PID_PARTICIPANT_LEASE_DURATION (0x0002)
	parameterId: PID_DOMAIN_ID (0x000f)
	parameterId: PID_RTI_DOMAIN_ID (0x800f)
	parameterId: PID_TRANSPORT_INFO_LIST (0x8010)
	parameterId: PID_REACHABILITY_LEASE_DURATION (0x8016)
	parameterId: PID_VENDOR_BUILTIN_ENDPOINT_SET (0x8017)
	parameterId: PID_SENTINEL (0x0001)
	parameterLength: 4
	parameterLength: 4
	parameterLength: 4
	parameterLength: 4
	parameterLength: 4
	parameterLength: 476
	parameterLength: 24
	parameterLength: 24
	parameterLength: 24
	parameterLength: 8
	parameterLength: 4
	parameterLength: 4
	parameterLength: 12
	parameterLength: 8
	parameterLength: 4
	parameterData: 06010000
	parameterData: 00000000
	parameterData: 00000000
	parameterData: 0100000001000000e3ff0000
	parameterData: ffffff7fffffffff
	parameterData: 03000000
	Property Name: dds.sys_info.process_id
	Property Name: dds.sys_info.executable_filepath
	Property Name: dds.sys_info.target
	Property Name: dds.sys_info.creation_timestamp
	Property Name: dds.sys_info.execution_timestamp
	Property Name: dds.sys_info.username
	Value: 39382
	Value: /Applications/rti_connext_dds-6.1.0/resource/app/bin/x64Darwin17clang9.0/RTI Shapes Demo.app/Contents/MacOS/rtishapesdemo
	Value: x64Darwin17clang9.0
	Value: 2021-09-27 14:19:17Z
	Value: 2023-09-25 14:10:01Z
	Value: gianpiero
	Kind: LOCATOR_KIND_UDPV4 (0x00000001)
	Kind: LOCATOR_KIND_UDPV4 (0x00000001)
	Port: 7414
	Port: 7400
	Address: 192.168.1.144
	Address: 239.255.0.1
	seconds: 2147483647
	fraction: 4294967295