updateInboundClientIps wrote the [LIMIT_IP] lines that drive the jail
while the scan's transaction was still open, and marked the addresses in
bannedSeen at the same time. A commit failure after that point rolls the
database back but takes nothing back from the log: fail2ban proceeds to
ban addresses the panel never recorded, and the in-memory bannedSeen
entry makes the next scan skip them, so the rollback is never repaired.
Selection stays inside the transaction. processObserved now collects one
pendingBan per enforced client and publishes after the commit succeeds,
disconnecting only the clients whose lines actually reached the log. The
Xray disconnects already ran after the commit for the same reason.
Recording moved with the write rather than with the decision:
selectAdvancedSinceLastBan no longer mutates anything, and
recordBannedSeen runs once a line is on disk. It also runs for clients
with nothing to ban, because that is the pass that forgets addresses a
client no longer exceeds its limit with - pruning used to be a side
effect of the filter, and skipping it left a stale entry that suppressed
the next legitimate ban.
The log file is opened once per scan instead of once per client, the
write error is checked instead of discarded, and Close is reported.
updateInboundClientIps no longer reports shouldCleanLog, because the
only thing that set it was the ban branch that moved out; processObserved
sets it when a publication actually happens. disAllowedIps went with the
write it served.
Tests: a transaction failed at COMMIT through a deferred foreign key
leaves no line and no bannedSeen entry; a publication that cannot open
the log leaves the address retryable; a client returning under its limit
has its entry forgotten, so going over again is banned a second time; a
committed over-limit scan publishes and reports; and writeBanLines
surfaces a write error rather than swallowing it.
When a client's connection drops without a clean TCP close, xray-core
keeps its online-map entry until the session context ends (idle policy),
minutes after the kernel socket is gone. The 10s IP-limit scan kept
seeing that stale IP as the oldest live one and re-emitted the same
[LIMIT_IP] Disconnecting OLD IP line plus a RemoveUser/AddUser cycle
every scan - operators measured 100+ repeats over ~1000s for a single
network switch, forcing absurd fail2ban maxretry values to avoid
banning legitimate mobile users.
The core refreshes an entry's lastSeen only when a new connection from
that IP is dispatched, never on traffic, so a frozen lastSeen across
scans is a dead connection, not a reconnect. Track the lastSeen of each
banned (email, ip) pair and skip the log line and disconnect until it
advances; a real reconnect moves lastSeen and is enforced exactly as
before, and an age cutoff that could misclassify long-lived active
tunnels is deliberately avoided.
Closes#5893
n0ctal