Feature #6063


exception-policy: stream async policy

Added by Victor Julien 5 months ago. Updated 5 days ago.

Target version:


For streams that are using async routing, allow applying a separate exception policy.

Async detection would match the logic the async-oneside option uses today:

Client -> Server: SYN followed by ACK matching the 3whs. SEQ of this packet would be ISN+1. If no SYN/ACK has been seen we’d be in async mode.
Server -> Client: SYN/ACK as first packet.

In both cases we'd apply a new exception policy.

Suggested defaults:
- IDS: ignore
- IPS, async-oneside disabled: drop-packet (not drop flow as otherwise an injected packet might trigger a flow drop?)
- IPS, async-oneside enabled: ignore

Subtasks 1 (1 open0 closed)

Feature #6083: exception-policy: stream async policy (6.0.x backport)AssignedJuliana Fajardini ReichowActions
Actions #1

Updated by Victor Julien 4 months ago

  • Label Needs backport to 6.0 added
Actions #2

Updated by OISF Ticketbot 4 months ago

  • Subtask #6083 added
Actions #3

Updated by OISF Ticketbot 4 months ago

  • Label deleted (Needs backport to 6.0)
Actions #4

Updated by Victor Julien 4 months ago

  • Target version changed from 7.0.0-rc2 to 7.0.1
Actions #5

Updated by Jamie Lavigne 3 months ago

I am curious about this one, could you provide some additional context on how this feature works?

I assume this is related to asymmetrically routed connections (not asynchronous) but I'm interested in how suricata would distinguish those and whether this would support matching connections where the client-to-server side of the connection is seen by suricata but the server-to-client side is not (i.e. what load balancers call "DSR", direct server return).

Today the existing midstream-policy matches on connections that are asymmetrically routed in the opposite way (where suricata doesn't see the SYN) but not this one, so I'm curious if this feature is related to adding support for both directions or if it's something different.

Actions #6

Updated by Juliana Fajardini Reichow 27 days ago

  • Target version changed from 7.0.1 to 7.0.2
Actions #7

Updated by Victor Julien 5 days ago

  • Description updated (diff)

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