Bug ID 476886: When ICAP cuts off request payload, OneConnect does not drop the connection

Last Modified: Sep 13, 2023

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
11.5.1 HF1, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.1 HF10, 11.5.1 HF11, 11.5.2 HF1, 11.5.3 HF1, 11.5.3 HF2, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.6.0, 11.6.1, 11.6.2, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.1.0 HF1, 12.1.0 HF2, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.0.0, 11.6.0 HF4, 11.5.2, 11.4.1 HF9

Opened: Aug 26, 2014

Severity: 3-Major

Related Article: K15727

Symptoms

After sending an ICAP preview, the BIG-IP system waits for a response from the ICAP server. If the BIG-IP system receives the complete ICAP response before it has completed sending the ICAP request (for example, when the response contains an encapsulated 302 redirect), it stops sending the request payload and closes the TCP connection. However when a OneConnect profile (CONNPOOL filter) is on the IVS, the TCP connection to the ICAP server is not terminated.

Impact

The ICAP server cannot detect the end of the ICAP request so might get confused.

Conditions

This occurs when the following conditions are met: -- Using ICAP and OneConnect profiles on an IVS. -- The BIG-IP ICAP client has resumed sending the request body on receiving a 200-OK response after the preview. -- ICAP server response completes before it has received the entire request body (for example, encapsulated redirect).

Workaround

Do not use OneConnect. As an alternative, if the ICAP server completes its response, it could ignore any further input from the client until it detects another RESPMOD or REQMOD indicating the beginning of a new transaction. ICAP servers are not required to do this, but it would allow connection reuse in the case where the server completes its response before the request is complete.

Fix Information

In this release, if the BIG-IP system receives the complete ICAP response from the ICAP server before it has completed sending the ICAP request, and a OneConnect profile is on the IVS, the TCP connection to the ICAP server is terminated and that connection is not reused.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips