Now available from Snort.org, Snort 2.9.0 and DAQ 0.2. I'll be writing some articles at some point to expand upon some of the functionality of Snort 2.9, but for now, know that there are some very nice new keywords in 2.9 and also an improved Stream model, as well as lots of improvements all over the place in the engine.
...and now some cut and paste from the release notes! Download it now!
[*] New Additions
* Feature rich IPS mode including improvements to Stream for
inline deployments. Additionally a common active response API is
used for all packet responses, including those from Stream,
Respond, or React. A new response module, respond3, supports the
syntax of both resp & resp2, including strafing for passive
deployments. When Snort is deployed inline, a new preprocessor
has been added to handle packet normalization to allow Snort
to interpret a packet the same way as the receiving host.
* Use of a Data Acquisition API (DAQ) that supports many different
packet access methods including libpcap, netfilterq, IPFW, and
afpacket. For libpcap, version 1.0 or higher is now required.
The DAQ library can be updated independently from Snort and is
a separate module that Snort links to.
* A new rule option 'byte_extract' that allows extracted values to
be used in subsequent rule options for isdataat, byte_test,
byte_jump, and content distance/within/depth/offset.
* Two new rule options to support base64 decoding of certain pieces
of data and inspection of the base64 data via subsequent rule
* Added a new pattern matcher that supports Intel's Quick Assist
Technology for improved performance on supported hardware
platforms. Visit http://www.intel.com to find out more about
Intel Quick Assist.
* Updates to HTTP Inspect to extract and log IP addresses from
X-Forward-For and True-Client-IP header fields when Snort generates
events on HTTP traffic.
* Updates to SMTP preprocessor to support MIME attachment decoding
across multiple packets.
* Updates to the Snort packet decoders for IPv6 for improvements to