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feat(core): SYN+ACK and FIN go once, as in Java, measured with Java FILIUS

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TcpRun loses exactly one frame (loseFirst: the card's output buffer drops
it; the sender's packet log still shows it, as with setDrop) in three new
stories: lostSynAck, lostFin, lostLastFin.

Measured: Java never repeats a SYN+ACK or a FIN. The server gives a
handshake up after one timeout (3 RTT) and closes with a FIN from SYN_RCVD
(its boundary check sometimes lets it wait twice; it means once). After its
FIN a socket waits at most five times, each wait ended by a segment or the
timeout; then it is gone. The core does the same (TCP_CLOSING_WAITS, with
TIME_WAIT in the loop) and shows CLOSED where Java leaves the state
standing (a named Java bug).

One departure: a repeated SYN in SYN_RCVD gets the SYN+ACK once more and
the wait starts anew; Java closes there, but its client never repeats the
SYN. lostSynAck is compared up to the second SYN (JAVA_UNTIL); the rest is
an engine test.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
julian.kiedaisch
2026-09-30 18:08:18 +00:00
co-authored by Claude Opus 5.5
parent a88fa1512c
commit 7e0348636c
11 changed files with 1056 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files
packages/core/test/scenarios/tcp-java-lostSynAck.java.json
+172
View File
@@ -0,0 +1,172 @@
{
"frames": {
"00000000-0000-0000-0000-000000000101": [
{
"time": 855,
"source": "02:00:00:00:01:12",
"destination": "FF:FF:FF:FF:FF:FF",
"arp": 1,
"senderIp": "192.168.0.20",
"targetIp": "192.168.0.10"
},
{
"time": 856,
"source": "02:00:00:00:01:11",
"destination": "02:00:00:00:01:12",
"arp": 2,
"senderIp": "192.168.0.10",
"targetIp": "192.168.0.20"
},
{
"time": 1083,
"source": "02:00:00:00:01:12",
"destination": "02:00:00:00:01:11",
"sourceIp": "192.168.0.20",
"destinationIp": "192.168.0.10",
"protocol": 6,
"sourcePort": 52633,
"destinationPort": 80,
"payload": null,
"tcpFlags": "S",
"sequence": 2000000,
"acknowledgement": 0
},
{
"time": 1085,
"source": "02:00:00:00:01:11",
"destination": "02:00:00:00:01:12",
"sourceIp": "192.168.0.10",
"destinationIp": "192.168.0.20",
"protocol": 6,
"sourcePort": 80,
"destinationPort": 52633,
"payload": null,
"tcpFlags": "SA",
"sequence": 1000000,
"acknowledgement": 2000001
},
{
"time": 17585,
"source": "02:00:00:00:01:11",
"destination": "02:00:00:00:01:12",
"sourceIp": "192.168.0.10",
"destinationIp": "192.168.0.20",
"protocol": 6,
"sourcePort": 80,
"destinationPort": 52633,
"payload": null,
"tcpFlags": "F",
"sequence": 1000001,
"acknowledgement": 0
}
],
"00000000-0000-0000-0000-000000000102": [
{
"time": 733,
"source": "02:00:00:00:01:12",
"destination": "FF:FF:FF:FF:FF:FF",
"arp": 1,
"senderIp": "192.168.0.20",
"targetIp": "192.168.0.10"
},
{
"time": 968,
"source": "02:00:00:00:01:11",
"destination": "02:00:00:00:01:12",
"arp": 2,
"senderIp": "192.168.0.10",
"targetIp": "192.168.0.20"
},
{
"time": 970,
"source": "02:00:00:00:01:12",
"destination": "02:00:00:00:01:11",
"sourceIp": "192.168.0.20",
"destinationIp": "192.168.0.10",
"protocol": 6,
"sourcePort": 52633,
"destinationPort": 80,
"payload": null,
"tcpFlags": "S",
"sequence": 2000000,
"acknowledgement": 0
},
{
"time": 17697,
"source": "02:00:00:00:01:11",
"destination": "02:00:00:00:01:12",
"sourceIp": "192.168.0.10",
"destinationIp": "192.168.0.20",
"protocol": 6,
"sourcePort": 80,
"destinationPort": 52633,
"payload": null,
"tcpFlags": "F",
"sequence": 1000001,
"acknowledgement": 0
}
],
"00000000-0000-0000-0000-000000000103": [
{
"time": 855,
"source": "02:00:00:00:01:12",
"destination": "FF:FF:FF:FF:FF:FF",
"arp": 1,
"senderIp": "192.168.0.20",
"targetIp": "192.168.0.10"
}
]
},
"events": [
[
218,
"server oeffnen called"
],
[
719,
"client verbinden called"
],
[
1085,
"lost SYN+ACK"
],
[
9025,
"client verbinden failed TimeOutException"
],
[
17632,
"server oeffnen returned"
]
],
"states": {
"server": [
[
221,
"LISTEN"
],
[
1085,
"SYN_RCVD"
],
[
17585,
"FIN_WAIT_1"
]
],
"client": [
[
719,
"CLOSED"
],
[
731,
"SYN_SENT"
],
[
8980,
"CLOSED"
]
]
}
}