this app will provide api to decode a range of offset within a packet, using either big endian or little endian to sequence number, then check are those sequence in order or not.
Example: ICMP https://osqa-ask.wireshark.org/questions/3172/icmp-sequence-number-be-vs-le/
Wireshark ICMP has both big endian and little endian format, but the actual ICMP seq in packet are BE at 41-42 byte (14 Eth + 20 IP + Type (1B) + Code (1B) + CheckSum (2B) + ID (2B))
Test1: 10K sequential ICMP echo request
HTTP POST Request:
{
"Encoding": "BigEndian",
"StartOffsetZeroIndex": 40,
"Length": 2,
"PacketURL": "https://storage.googleapis.com/projectgolive-648ad.appspot.com/10K_icmp_request.pcapng",
"ReadLocalDownloadedFile": false
}
HTTP Response:
{
"PacketURL": "https://storage.googleapis.com/projectgolive-648ad.appspot.com/10K_icmp_request.pcapng",
"PacketLength": 10000,
"NumberOfGaps": 0,
"NumberOfOutOfOrder": 0,
"GapIndex": null,
"GapMap": {},
"OutOfOrderSeq": null
}
======================================================================================================= Test2: Intentionally skip certain sequence to simulate the packet lost scenario.
tshark -r 10K_Normal_icmp_request.pcapng -Y "!(icmp.seq == 937) && !(icmp.seq == 1115) && !(icmp.seq == 2000) && !(icmp.seq == 6654) && !(icmp.seq == 2245) && !(icmp.seq == 5000)" -w random_missing_packet.pcap
HTTP POST Request:
{
"Encoding": "BigEndian",
"StartOffsetZeroIndex": 40,
"Length": 2,
"PacketURL": "https://storage.googleapis.com/projectgolive-648ad.appspot.com/random_missing_packet.pcap",
"ReadLocalDownloadedFile": false
}
HTTP Response:
{
"PacketURL": "https://storage.googleapis.com/projectgolive-648ad.appspot.com/random_missing_packet.pcap",
"PacketLength": 9994,
"NumberOfGaps": 6,
"NumberOfOutOfOrder": 0,
"GapIndex": [
937,
1115,
2000,
2245,
5000,
6654
],
"GapMap": {
"1115": "seq gap 2",
"2000": "seq gap 2",
"2245": "seq gap 2",
"5000": "seq gap 2",
"6654": "seq gap 2",
"937": "seq gap 2"
},
"OutOfOrderSeq": null
}
======================================================================================================= Test3: Out of order test, to simulate a bunch of packets arrives late due to possible network congestion. First to simulate the out of order packets
editcap -r 10K_Normal_icmp_request.pcapng tmp1-1000.pcap 1-1000
editcap -r 10K_Normal_icmp_request.pcapng tmp1001-1100.pcap 1001-1100
editcap -r 10K_Normal_icmp_request.pcapng tmp1101-1200.pcap 1101-1200
editcap -r 10K_Normal_icmp_request.pcapng tmp1201-10000.pcap 1201-10000
mergecap -w outOfOrder.pcap -a tmp1-1000.pcap tmp1101-1200.pcap tmp1001-1100.pcap tmp1201-10000.pcap
HTTP POST Request:
{
"Encoding": "BigEndian",
"StartOffsetZeroIndex": 40,
"Length": 2,
"PacketURL": "https://storage.googleapis.com/projectgolive-648ad.appspot.com/outOfOrder.pcap",
"ReadLocalDownloadedFile": false
}
HTTP Response:
{
"PacketURL": "https://storage.googleapis.com/projectgolive-648ad.appspot.com/outOfOrder.pcap",
"PacketLength": 10000,
"NumberOfGaps": 3,
"NumberOfOutOfOrder": 3,
"GapIndex": [
1000,
1200,
1100
],
"GapMap": {
"1000": "seq gap 101",
"1100": "seq gap 101",
"1200": "seq gap -199"
},
"OutOfOrderSeq": [
1000,
1200,
1100
]
}
======================================================================================================= Test4: iperf3 udp test Based on eyeball checking, the sequence number of iperf3 udp packet should be a 4 bytes from 41-44 bytes (inclusive)
HTTP POST Request:
{
"Encoding": "BigEndian",
"StartOffsetZeroIndex": 40,
"Length": 4,
"PacketURL": "https://storage.googleapis.com/projectgolive-648ad.appspot.com/iperf3_udp2.pcapng",
"ReadLocalDownloadedFile": false
}
HTTP Response:
{
"PacketURL": "https://storage.googleapis.com/projectgolive-648ad.appspot.com/iperf3_udp2.pcapng",
"PacketLength": 267851,
"NumberOfGaps": 0,
"NumberOfOutOfOrder": 0,
"GapIndex": null,
"GapMap": {},
"OutOfOrderSeq": null
}
The allocated memory looks quite normal even when checking a 400 MB size file.
[GIN] 2022/07/16 - 03:36:08 | 200 | 516.096834ms | 127.0.0.1 | POST "/config"
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
Alloc = 8 MiB TotalAlloc = 999 MiB Sys = 30 MiB NumGC = 127
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