Category Archives: oisf

Suricata 3.0 is out!

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suri-400x400Today, almost 2 years after the release of Suricata 2.0, we released 3.0! This new version of Suricata improves performance, scalability, accuracy and general robustness. Next to this, it brings a lot of new features.

New features are too numerous to mention here, but I’d like to highlight a few:

  • netmap support: finally a high speed capture method for our FreeBSD friends, IDS and IPS
  • multi-tenancy: single instance, multiple detection configs
  • JSON stats: making it much easier to graph the stats in ELK, etc
  • Much improved Lua support: many more fields/protocols available, output scripts

Check the full list here in the announcement: http://suricata-ids.org/2016/01/27/suricata-3-0-available/

New release model

As explained here, this is the first release of the new release model where we’ll be trying for 3 ‘major’ releases a year. We originally hoped for a month of release candidate cycles, but due to some issues found and the holidays + travel on my end it turned into 2 months.

My goal is to optimize our testing and planning to reduce this further, as this release cycle process is effectively an implicit ‘freeze’. Take a look at the number of open pull requests to see what I mean. For the next cycle I’ll also make the freeze explicit, and announce it.

Looking forward

While doing a release is great, my mind is already busy with the next steps. We have a bunch of things coming that are exciting to me.

Performance: my detection engine rewrite work has been tested by many already, and reports are quite positive. I’ve heard reports up to 25% increase, which is a great bonus considering the work was started to clean up this messy code.

ICS/SCADA: Jason Ish is finalizing a DNP3 parser that is very full featured, with detection, logging and lua support. Other protocols are also being developed.

Documentation: we’re in the process of moving our user docs from the wiki to sphinx. This means we’ll have versioned docs, nice pdf exports, etc. It’s already 180 pages!

Plus lots of other things. Keep an eye out on our mailing lists, bug tracker or IRC channel.

New Suricata release model

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suri-400x400As the team is back from a very successful week in Barcelona, I’d like to take a moment on what we discussed and decided on with regards to development.

One thing no one was happy with is how the release schedules are working. Releases were meant to reasonably frequent, but the time between major releases was growing longer and longer. The 2.0 branch for example, is closing in on 2 years as the stable branch. The result is that many people are missing out on many of the improvements we’ve been doing. Currently many people using Suricata actually use a beta version, of even our git master, in production!

What we’re going to try is time based releases. Pretty much releases will be more like snapshots of the development branch. We think this can work as our dev branch is more and more stable due to our extensive QA setup.

Of course, we’ll have to make sure we’re not going to merge super intrusive changes just before a release. We’ll likely get into some pattern of merge windows and (feature) freezes, but how this will exactly play out is something we’ll figure out as we go.

We’re going to try to shoot for 3 of such releases per year.

In our redmine ticket tracker, I’ve also created a new pseudo-version ‘Soon’. Things we think should be addressed for the next release, will be added there. But we’ll retarget the tickets when they are actually implemented.

Since it’s already almost 2 years since we’ve done 2.0, we think the next release warrants a larger jump in the versioning. So we’re going to call it 3.0. The first release candidate will likely be released this week hopefully followed by a stable in December.

Suricata has been added to Debian Backports

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Thanks to the hard work of Arturo Borrero Gonzalez, Suricata has just been added to the openlogo-100Debian ‘backports’ repository. This allows users of Debian stable to run up to date versions of Suricata.

The ‘Backports’ repository makes the Suricata and libhtp packages from Debian Testing available to ‘stable’ users. As ‘testing’ is currently in a freeze, it may take a bit of time before 2.0.5 and libhtp 0.5.16 appear.

Anyway, here is how to use it.

Install

First add backports repo to your sources:

# echo "deb http://http.debian.net/debian wheezy-backports main" > /etc/apt/sources.list.d/backports.list
# apt-get update

As explained here http://backports.debian.org/Instructions/, this will not affect your normal packages.

To prove this, check:

# apt-get install suricata -s
Conf libhtp1 (0.2.6-2 Debian:7.7/stable [amd64])
Conf suricata (1.2.1-2 Debian:7.7/stable [amd64])

Not what we want, as that is still the old version.

To install Suricata from backports, we need to specify the repo:

# apt-get install -t wheezy-backports suricata -s
Conf libhtp1 (0.5.15-1~bpo70+1 Debian Backports:/wheezy-backports [amd64])
Conf suricata (2.0.4-1~bpo70+1 Debian Backports:/wheezy-backports [amd64])

Let’s do it!

# apt-get install -t wheezy-backports suricata
...
Setting up suricata (2.0.4-1~bpo70+1) ...
[FAIL] suricata disabled, please adjust the configuration to your needs ... failed!
[FAIL] and then set RUN to 'yes' in /etc/default/suricata to enable it. ... failed!

Suricata 2.0.4 is now installed, but it’s not yet running.
To see what features have been compiled in, run:

# suricata --build-info
This is Suricata version 2.0.4 RELEASE

Suricata Configuration:
  AF_PACKET support:                       yes
  PF_RING support:                         no
  NFQueue support:                         yes
  NFLOG support:                           no
  IPFW support:                            no
  DAG enabled:                             no
  Napatech enabled:                        no
  Unix socket enabled:                     yes
  Detection enabled:                       yes

  libnss support:                          yes
  libnspr support:                         yes
  libjansson support:                      yes
  Prelude support:                         yes
  PCRE jit:                                yes
  LUA support:                             yes
  libluajit:                               yes
  libgeoip:                                no
  Non-bundled htp:                         yes
  Old barnyard2 support:                   no
  CUDA enabled:                            no

  Suricatasc install:                      yes

It has Luajit enabled, libjansson for the JSON output, NFQ and AF_PACKET IPS modes, NSS for MD5 checksums and unix sockets. Quite a good feature set.

Run

To get it running, we need a few more steps:

Edit /etc/default/suricata:

1. Change RUN=no to RUN=yes
2. Change LISTENMODE to “af-packet”:

Now lets start it.

# service suricata start
Starting suricata in IDS (af-packet) mode... done.

And confirm that it’s running.

# ps aux|grep suricata
root     20295  1.8  4.1 200212 42544 ?        Ssl  00:50   0:00 /usr/bin/suricata -c /etc/suricata/suricata-debian.yaml --pidfile /var/run/suricata.pid --af-packet -D

Check if we’re seeing traffic:

# tail /var/log/suricata/stats.log -f|grep capture
capture.kernel_packets    | RxAFPeth01                | 406
capture.kernel_drops      | RxAFPeth01                | 0
capture.kernel_packets    | RxAFPeth11                | 0
capture.kernel_drops      | RxAFPeth11                | 0
capture.kernel_packets    | RxAFPeth01                | 411
capture.kernel_drops      | RxAFPeth01                | 0
capture.kernel_packets    | RxAFPeth11                | 0
capture.kernel_drops      | RxAFPeth11                | 0
capture.kernel_packets    | RxAFPeth01                | 417
capture.kernel_drops      | RxAFPeth01                | 0
capture.kernel_packets    | RxAFPeth11                | 0
capture.kernel_drops      | RxAFPeth11                | 0
capture.kernel_packets    | RxAFPeth01                | 587
capture.kernel_drops      | RxAFPeth01                | 0
capture.kernel_packets    | RxAFPeth11                | 0
capture.kernel_drops      | RxAFPeth11                | 0
capture.kernel_packets    | RxAFPeth01                | 593
capture.kernel_drops      | RxAFPeth01                | 0
capture.kernel_packets    | RxAFPeth11                | 0
capture.kernel_drops      | RxAFPeth11                | 0

Logging

As the init script starts Suricata in daemon mode, we need to enable logging to file:

Edit /etc/suricata/suricata-debian.yaml and go to the “logging:” section, there change the “file” portion to look like:

  - file:
      enabled: yes
      filename: /var/log/suricata/suricata.log

Note: in the YAML indentation matters, so make sure it’s exactly right.

Rules

Oinkmaster is automatically installed, so lets use that:

First create the rules directory:

mkdir /etc/suricata/rules/

Open /etc/oinkmaster.conf in your editor and add:

url = https://rules.emergingthreats.net/open/suricata-2.0/emerging.rules.tar.gz

Then run:

# oinkmaster -C /etc/oinkmaster.conf -o /etc/suricata/rules
Loading /etc/oinkmaster.conf
Downloading file from https://rules.emergingthreats.net/open/suricata-2.0/emerging.rules.tar.gz... done.
...

Edit /etc/suricata/suricata-debian.yaml and change “default-rule-path” to:

default-rule-path: /etc/suricata/rules

Finally, restart to load the new rules:

# service suricata restart

Validate

Now that Suricata is running with rules, lets see if it works:

# wget http://www.testmyids.com
--2015-01-08 01:21:30--  http://www.testmyids.com/
Resolving www.testmyids.com (www.testmyids.com)... 82.165.177.154

This should trigger a specific rule:

# tail /var/log/suricata/fast.log 
01/08/2015-01:21:30.870346  [**] [1:2100498:7] GPL ATTACK_RESPONSE id check returned root [**] [Classification: Potentially Bad Traffic] [Priority: 2] {TCP} 82.165.177.154:80 -> 192.168.122.181:59190

Success! 🙂

Thanks

Thanks to Arturo Borrero Gonzalez for taking on this work for us. Also many thanks for Pierre Chifflier for maintaining the Suricata and libhtp packages in Debian.

Profiling Suricata with JEMALLOC

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JEMALLOC is a memory allocation library: http://www.canonware.com/jemalloc/

It offers many interesting things for a tool like Suricata. Ken Steele of EZchip (formerly Tilera) made me aware of it. In Ken’s testing it helps performance.

Install

wget http://www.canonware.com/download/jemalloc/jemalloc-3.6.0.tar.bz2
tar xvfj jemalloc-3.6.0.tar.bz2
cd jemalloc-3.6.0
./configure --prefix=/opt/jemalloc/
make
sudo make install

Then use it by preloading it:

LD_PRELOAD=/opt/jemalloc/lib/libjemalloc.so ./src/suricata -c suricata.yaml -l tmp/ -r ~/sync/pcap/sandnet.pcap -S emerging-all.rules -v

I haven’t benchmarked this, but if you’re running a high performance setup it may certainly be worth a shot.

Profiling

The library comes with many interesting profiling and debugging features.

make clean
./configure --prefix=/opt/jemalloc-prof/ --enable-prof
make
sudo make install

Start Suricata like this:

LD_PRELOAD=/opt/jemalloc-prof/lib/libjemalloc.so ./src/suricata -c suricata.yaml -l tmp/ -r ~/sync/pcap/sandnet.pcap -S emerging-all.rules -v

Now we don’t see any change as we need to tell jemalloc what we want.

Exit stats

Dumps a lot of stats to the screen.

MALLOC_CONF=stats_print:true LD_PRELOAD=/opt/jemalloc-prof/lib/libjemalloc.so ./src/suricata -c suricata.yaml -l tmp/ -r ~/sync/pcap/sandnet.pcap -S emerging-all.rules -v

Memory leak checks

MALLOC_CONF=prof_leak:true,lg_prof_sample:0 LD_PRELOAD=/opt/jemalloc-prof/lib/libjemalloc.so ./src/suricata -c suricata.yaml -l tmp/ -r ~/sync/pcap/sandnet.pcap -S emerging-all.rules -v
[... suricata output ...]
<jemalloc>: Leak summary: 2011400 bytes, 4523 objects, 645 contexts
<jemalloc>: Run pprof on "jeprof.22760.0.f.heap" for leak detail

Then use the pprof tool that comes with jemalloc to inspect the dumped stats.

$ /opt/jemalloc-prof/bin/pprof --show_bytes ./src/suricata jeprof.22760.0.f.heap
Using local file ./src/suricata.
Using local file jeprof.22760.0.f.heap.
Welcome to pprof!  For help, type 'help'.
(pprof) top
Total: 2011400 B
1050112  52.2%  52.2%  1050112  52.2% PacketGetFromAlloc
600064  29.8%  82.0%   600064  29.8% SCProfilePacketStart
103936   5.2%  87.2%   103936   5.2% SCACCreateDeltaTable
65536   3.3%  90.5%    66192   3.3% pcap_fopen_offline
35520   1.8%  92.2%    35520   1.8% ConfNodeNew
26688   1.3%  93.6%    26688   1.3% __GI___strdup
20480   1.0%  94.6%    20480   1.0% MemBufferCreateNew
20480   1.0%  95.6%    20480   1.0% _TmSlotSetFuncAppend
14304   0.7%  96.3%    14304   0.7% pcre_compile2
14064   0.7%  97.0%    25736   1.3% SCPerfRegisterQualifiedCounter

So it seems we don’t properly clean up our packet pools yet.

Create a PDF of this info:

$ /opt/jemalloc-prof/bin/pprof --show_bytes --pdf ./src/suricata jeprof.22760.0.f.heap > jemalloc.pdf

Dumping stats during runtime

Dump stats after every 16MiB of allocations (lg_prof_interval:24, means every 2^24 bytes, so 16MiB)

I’ve done this in a separate directory since it dumps many files.

$ mkdir jemalloc-profile
$ cd jemalloc-profile/
$ MALLOC_CONF="prof:true,prof_prefix:victor.out,lg_prof_interval:24" LD_PRELOAD=/opt/jemalloc-prof/lib/libjemalloc.so ../src/suricata -c ../suricata.yaml -l ../tmp/ -r ~/sync/pcap/sandnet.pcap -S ../emerging-all.rules -v

Then you should see new *.heap files appear, many during startup. But after some time it should slow down.

You can then visualize the diff between two dumps:

$ /opt/jemalloc-prof/bin/pprof --show_bytes --pdf ../src/suricata --base victor.out.24159.150.i150.heap victor.out.24159.200.i200.heap > jemalloc.pdf

This creates a PDF of the 200th dump taking the 150th dump as a baseline. As we dump every ~16MiB, this covers about 50 * 16 = 800MiB worth of allocations.

Further reading

http://www.canonware.com/jemalloc/
https://github.com/jemalloc/jemalloc/wiki
https://github.com/jemalloc/jemalloc/wiki/Use-Case%3A-Heap-Profiling

Many thanks to Ken Steele for pointing me to the lib and providing me with some good examples.

Suricata Training Tour

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After a lot of preparations, it’s finally going to happen: official Suricata trainings!

In the next couple of months I’ll be doing at least 3 sessions: a home match (Amsterdam), a workshop in Luxembourg and a session at DeepSec. Next to this, we’re planning various US based sessions on the East coast and West coast.

I’m really looking forward to doing these sessions. Other than the official content, there will be plenty of room for questions and discussions.

Hope to see you soon! 🙂

Suricata 2.0 and beyond

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Today I finally released Suricata 2.0. The 2.0 branch opened in December 2012. In the little over a year that it’s development lasted, we have closed 183 tickets. We made 1174 commits, with the following stats:

582 files changed, 94782 insertions(+), 63243 deletions(-)

So, a significant update! In total, 17 different people made commits. I’m really happy with how much code and features were contributed. When starting Suricata this was what I really hoped for, and it seems to be working!

Eve

The feature I’m most excited about is ‘Eve’. It’s the nickname of a new logging output module ‘Extendible Event Format’. It’s an all JSON event stream that is very easy to parse using 3rd party tools. The heavy lifting has been done by Tom Decanio. Combined with Logstash, Elasticsearch and Kibana, this allows for really easy graphical dashboard creation. This is a nice addition to the existing tools which are generally more alert centered.

kibana300 kibana300map kibana-suri

Splunk support is easy as well, as Eric Leblond has shown:

regit-Screenshot-from-2014-03-05-231712

Looking forward

While doing releases is important and somewhat nice too, the developer in me is always glad when they are over. Leading up to a release there is a slow down of development, when most time is spent on fixing release critical bugs and doing some polishing. This slow down is a necessary evil, but I’m glad when we can start merging bigger changes again.

In the short term, I shooting for a fairly quick 2.0.1 release. There are some known issues that will be addressed in that.

More interestingly from a development perspective is the opening of the 2.1 branch. I’ll likely open that in a few weeks. There are a number of features in progress for 2.1. I’m working on speeding up pcap recording, which is currently quite inefficient. More interestingly, Lua output scripting. A preview of this work is available here  with some example scripts here.

Others are working on nice things as well: improving protocol support for detection and logging, nflog and netmap support, taxii/stix integration, extending our TLS support and more.

I’m hoping the 2.1 cycle will be shorter than the last, but we’ll see how it goes 🙂

Suricata Development Update

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SuricataWith the holidays approaching and the 1.4.7 and 2.0beta2 releases out, I thought it was a good moment for some reflection on how development is going.

I feel things are going very well. It’s great to work with a group that approaches this project from different angles. OISF has budget have people work on overall features, quality and support. Next to that, our consortium supporters help develop the project: Tilera’s Ken Steele is working on the Tile hardware support, doing lots optimizations. Many of which benefit performance and overall quality for the whole project. Tom Decanio of Npulse is doing great work on the output side, unifying the outputs to be machine readable. Jason Ish of Emulex/Endace is helping out the configuration API, defrag, etc. Others, both from the larger community and our consortium, are helping as well.

QA

At our last meetup in Luxembourg, we’ve spend quite a bit of time discussing how we can improve the quality of Suricata. Since then, we’ve been working hard to add better and more regression and quality testing.

We’ve been using a Buildbot setup for some time now, where on a number of platforms we do basic build testing. First, this was done only against the git master(s). Eric has then created a new method using a script call prscript. It’s purpose is to push a git branch to our buildbot _before_ it’s even considered for inclusion.

Recently, with cooperation of Emerging Threats, we’ve been extending this setup to include a large set of rule+pcap matches that are checked against each commit. This too is part of the pre-include QA process.

There are many more plans to extend this setup further. I’ve set up a private buildbot instance to serve as a staging area. Things we’ll be adding soon:
– valgrind testing
– DrMemory testing
– clang/scan-build
– cppcheck

Ideally, each of those tools would report 0 issues, but thats hard in practice. Sometimes there are false positives. Most tools support some form of suppression, so one of the tasks is to create those.

We’ve spend some time updating our documents regarding contributing to our code base. Please take a moment to a general contribution page, aimed at devs new to the project.

Next to this, this document describes quality requirements for our code, commits and pull requests.

Suricata 2.0

Our roadmap shows a late January 2.0 final release. It might slip a little bit, as we have a few larger changes to make:
– a logging API rewrite is in progress
– “united” output, an all JSON log method written by Tom Decanio of Npulse [5]
– app-layer API cleanup and update that Anoop is working on [6]

Wrapping up, I think 2013 was a very good year for Suricata. 2014 will hopefully be even better. We will be announcing some new support soon, are improving our training curicullum and will just be working hard to make Suricata better.

But first, the holidays. Cheers!

Suricata profiling per keyword

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Last week I’ve added some more profiling options to Suricata. It’s part of the current git master. It’s enabled only when --enable-profiling and then through the suricata.yaml:

profiling:
  # per keyword profiling
  keywords:
    enabled: yes
    filename: keyword_perf.log
    append: yes

This will output a table similar to below:

--------------------------------------------------------------------------
Date: 11/7/2013 -- 15:13:11
--------------------------------------------------------------------------
Stats for: total
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
threshold        355324491   190574   409      72276       1864.00     3625.00     1860.00    
content          1274592063  534328   196738   312321      2385.00     2424.00     2362.00    
pcre             56626031    11149    824      254562      5079.00     12234.00    4507.00    
byte_test        153287955   128254   32109    67989       1195.00     1658.00     1040.00    
byte_jump        3676404     2041     2041     15939       1801.00     1801.00     0.00       
flow             38276182    22842    22842    63987       1675.00     1675.00     0.00       
isdataat         580764      558      556      2427        1040.00     1040.00     1017.00    
dsize            2212029     2062     2061     3711        1072.00     1072.00     789.00     
flowbits         1677209     874      870      9873        1919.00     1923.00     884.00     
itype            1653        2        1        1386        826.00      267.00      1386.00    
icode            27383781    93827    2        25545       291.00      1021.00     291.00     
flags            192751968   245519   189709   255639      785.00      753.00      892.00     
urilen           6149297     6142     1099     28299       1001.00     1395.00     915.00     
byte_extract     143091      78       78       7743        1834.00     1834.00     0.00       
--------------------------------------------------------------------------
Stats for: packet
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
flow             38276182    22842    22842    63987       1675.00     1675.00     0.00       
dsize            2212029     2062     2061     3711        1072.00     1072.00     789.00     
flowbits         351171      294      290      5526        1194.00     1198.00     884.00     
itype            1653        2        1        1386        826.00      267.00      1386.00    
icode            27383781    93827    2        25545       291.00      1021.00     291.00     
flags            192751968   245519   189709   255639      785.00      753.00      892.00     
--------------------------------------------------------------------------
Stats for: packet/stream payload
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
content          1203990910  512902   183628   312321      2347.00     2365.00     2337.00    
pcre             28087301    6598     54       254562      4256.00     12279.00    4190.00    
byte_test        153287955   128254   32109    67989       1195.00     1658.00     1040.00    
byte_jump        3676404     2041     2041     15939       1801.00     1801.00     0.00       
isdataat         578172      556      554      2427        1039.00     1039.00     1017.00    
byte_extract     143091      78       78       7743        1834.00     1834.00     0.00       
--------------------------------------------------------------------------
Stats for: http uri
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
content          44775802    13102    8351     60993       3417.00     3257.00     3698.00    
pcre             18284421    3646     97       61338       5014.00     8916.00     4908.00    
isdataat         2592        2        2        1725        1296.00     1296.00     0.00       
urilen           6149297     6142     1099     28299       1001.00     1395.00     915.00     
--------------------------------------------------------------------------
Stats for: http raw uri
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
pcre             9534        2        0        4953        4767.00     0.00        4767.00    
--------------------------------------------------------------------------
Stats for: http client body
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
content          1556904     441      181      58476       3530.00     2874.00     3986.00    
pcre             63924       6        6        17358       10654.00    10654.00    0.00       
--------------------------------------------------------------------------
Stats for: http headers
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
content          23688244    7631     4348     31098       3104.00     3311.00     2829.00    
pcre             9998970     859      667      71904       11640.00    12727.00    7862.00    
--------------------------------------------------------------------------
Stats for: http stat code
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
content          80052       39       20       3699        2052.00     2199.00     1898.00    
--------------------------------------------------------------------------
Stats for: http method
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
content          476334      203      201      27240       2346.00     2351.00     1846.00    
--------------------------------------------------------------------------
Stats for: http cookie
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
content          23817       10       9        2763        2381.00     2384.00     2358.00    
pcre             181881      38       0        13095       4786.00     0.00        4786.00    
--------------------------------------------------------------------------
Stats for: post-match
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
flowbits         1326038     580      580      9873        2286.00     2286.00     0.00       
--------------------------------------------------------------------------
Stats for: threshold
--------------------------------------------------------------------------
Keyword          Ticks       Checks   Matches  Max Ticks   Avg         Avg Match   Avg No Match
---------------- ----------- -------- -------- ----------- ----------- ----------- ----------- 
threshold        355324491   190574   409      72276       1864.00     3625.00     1860.00

The first part has the totals for all keywords. After this the stats are broken down per buffer type.

Part of this work was sponsored by Emerging Threats.

More on Suricata lua flowints

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This morning I added flowint lua functions for incrementing and decrementing flowints. From the commit:

Add flowint lua functions for incrementing and decrementing flowints.

First use creates the var and inits to 0. So a call:

    a = ScFlowintIncr(0)

Results in a == 1.

If the var reached UINT_MAX (2^32), it’s not further incremented. If the
var reaches 0 it’s not decremented further.

Calling ScFlowintDecr on a uninitialized var will init it to 0.

Example script:

    function init (args)
        local needs = {}
        needs["http.request_headers"] = tostring(true)
        needs["flowint"] = {"cnt_incr"}
        return needs
    end

    function match(args)
        a = ScFlowintIncr(0);
        if a == 23 then
            return 1
        end

        return 0
    end
    return 0

This script matches the 23rd time it’s invoked on a flow.

Compared to yesterday’s flowint script and the earlier flowvar based counting script, this performs better:

   Num      Rule         Gid      Rev      Ticks        %      Checks   Matches  Max Ticks   Avg Ticks   Avg Match   Avg No Match
  -------- ------------ -------- -------- ------------ ------ -------- -------- ----------- ----------- ----------- -------------- 
  1        1            1        0        2434188332   59.71  82249    795      711777      29595.35    7683.20     29809.22   
  2        2            1        0        1015328580   24.91  82249    795      154398      12344.57    3768.66     12428.27   
  3        3            1        0        626858067    15.38  82249    795      160731      7621.47     3439.91     7662.28

The rules:

alert http any any -> any any (msg:"LUAJIT HTTP flowvar match"; luajit:lua_flowvar_cnt.lua; flow:to_server; sid:1;)
alert http any any -> any any (msg:"LUAJIT HTTP flowint match"; luajit:lua_flowint_cnt.lua; flow:to_server; sid:2;)
alert http any any -> any any (msg:"LUAJIT HTTP flowint incr match"; luajit:lua_flowint_incr_cnt.lua; flow:to_server; sid:3;)

Please comment, discuss, review etc on the oisf-devel list.