Snort 3 is the next generation Snort IPS (Intrusion Prevention System). This file will show you what Snort++ has to offer and guide you through the steps from download to demo. If you are unfamiliar with Snort you should take a look at the Snort documentation first. We will cover the following topics:
This version of Snort++ includes new features as well as all Snort 2.X features and bug fixes for the base version of Snort except as indicated below:
Project = Snort++
Binary = snort
Version = 3.0.0 (Build 250) from 2.9.11
Here are some key features of Snort++:
- Support multiple packet processing threads
- Use a shared configuration and attribute table
- Use a simple, scriptable configuration
- Make key components pluggable
- Autodetect services for portless configuration
- Support sticky buffers in rules
- Autogenerate reference documentation
- Provide better cross platform support
- Facilitate component testing
Additional features on the roadmap include:
- Use a shared network map
- Support pipelining of packet processing
- Support hardware offload and data plane integration
- Support proxy mode
- Windows support
If you already build Snort, you may have everything you need. If not, grab the latest:
- cmake to build from source
- daq from https://github.com/snort3/libdaq for packet IO
- dnet from https://github.com/dugsong/libdnet.git for network utility functions
- g++ >= 5 or other C++14 compiler
- hwloc from https://www.open-mpi.org/projects/hwloc/ for CPU affinity management
- LuaJIT from http://luajit.org for configuration and scripting
- OpenSSL from https://www.openssl.org/source/ for SHA and MD5 file signatures, the protected_content rule option, and SSL service detection
- pcap from http://www.tcpdump.org for tcpdump style logging
- pcre from http://www.pcre.org for regular expression pattern matching
- pkgconfig from https://www.freedesktop.org/wiki/Software/pkg-config/ to locate build dependencies
- zlib from http://www.zlib.net for decompression
Additional packages provide optional features. Check the manual for more.
There is a source tarball available in the Downloads section on snort.org:
snort-3.0.0-a3.tar.gz
You can also get the code with:
git clone git://github.com/snort3/snort3.git
There are separate extras packages for cmake that provide additional features and demonstrate how to build plugins. The source for extras is in snort3_extra.git repo.
Follow these steps:
- Set up source directory:
-
If you are using a github clone:
cd snort3/ -
Otherwise, do this:
tar zxf snort-tarball cd snort-3.0.0*
-
Setup install path:
export my_path=/path/to/snorty -
Compile and install:
-
To build with cmake and make, run configure_cmake.sh. It will automatically create and populate a new subdirectory named 'build'.
./configure_cmake.sh --prefix=$my_path cd build make -j $(nproc) install
Note:
- If you can do src/snort -V you built successfully.
- If you are familiar with cmake, you can run cmake/ccmake instead of configure_cmake.sh.
- cmake --help will list any available generators, such as Xcode. Feel free to use one, however help with those will be provided separately.
Here are some examples.
-
Snort++ provides lots of help from the command line, including:
$my_path/bin/snort --help $my_path/bin/snort --help-module suppress $my_path/bin/snort --help-config | grep thread
-
Examine and dump a pcap. In the following, replace a.pcap with your favorite:
$my_path/bin/snort -r a.pcap $my_path/bin/snort -L dump -d -e -q -r a.pcap
-
Verify a config, with or w/o rules:
$my_path/bin/snort -c $my_path/etc/snort/snort.lua $my_path/bin/snort -c $my_path/etc/snort/snort.lua -R $my_path/etc/snort/sample.rules
-
Run IDS mode. In the following, replace pcaps/ with a path to a directory with one or more *.pcap files:
$my_path/bin/snort -c $my_path/etc/snort/snort.lua -R $my_path/etc/snort/sample.rules \ -r a.pcap -A alert_test -n 100000
-
Let's suppress 1:2123. We could edit the conf or just do this:
$my_path/bin/snort -c $my_path/etc/snort/snort.lua -R $my_path/etc/snort/sample.rules \ -r a.pcap -A alert_test -n 100000 --lua "suppress = { { gid = 1, sid = 2123 } }"
-
Go whole hog on a directory with multiple packet threads:
$my_path/bin/snort -c $my_path/etc/snort/snort.lua -R $my_path/etc/snort/sample.rules \ --pcap-filter \*.pcap --pcap-dir pcaps/ -A alert_fast --max-packet-threads 8
Additional examples are given in doc/usage.txt.
Take a look at the manual, parts of which are generated by the code so it stays up to date:
$my_path/share/doc/snort/snort_manual.pdf
$my_path/share/doc/snort/snort_manual.html
$my_path/share/doc/snort/snort_manual/index.htmlIt does not yet have much on the how and why, but it does have all the currently available configuration, etc. Some key changes to rules:
- you must use comma separated content sub options like this: content:"foo", nocase;
- buffer selectors must appear before the content and remain in effect until changed
- pcre buffer selectors were deleted
- check the manual for more on Snort++ vs Snort
- check the manual reference section to understand how parameters are defined, etc.
It also covers new features not demonstrated here:
- snort2lua, a tool to convert Snort 2.X conf and rules to the new form
- a new HTTP inspector
- a binder, for mapping configuration to traffic
- a wizard for port-independent configuration
- improved rule parsing - arbitrary whitespace, C style comments, #begin/#end comments
- local and remote command line shell
o")~
We hope you are as excited about Snort++ as we are. Although a lot of work remains, we wanted to give you a chance to try it out and let us know what you think on the snort-users list. In the meantime, we'll keep our snout to the grindstone.