70c16f50e7
Until now the flow manager would walk the entire flow hash table on an
interval. It would thus touch all flows, leading to a lot of memory
and cache pressure. In scenario's where the number of tracked flows run
into the hundreds on thousands, and the memory used can run into many
hundreds of megabytes or even gigabytes, this would lead to serious
performance degradation.
This patch introduces a new approach. A timestamp per flow bucket
(hash row) is maintained by the flow manager. It holds the timestamp
of the earliest possible timeout of a flow in the list. The hash walk
skips rows with timestamps beyond the current time.
As the timestamp depends on the flows in the hash row's list, and on
the 'state' of each flow in the list, any addition of a flow or
changing of a flow's state invalidates the timestamp. The flow manager
then has to walk the list again to set a new timestamp.
A utility function FlowUpdateState is introduced to change Flow states,
taking care of the bucket timestamp invalidation while at it.
Empty flow buckets use a special value so that we don't have to take
the flow bucket lock to find out the bucket is empty.
This patch also adds more performance counters:
flow_mgr.flows_checked | Total | 929
flow_mgr.flows_notimeout | Total | 391
flow_mgr.flows_timeout | Total | 538
flow_mgr.flows_removed | Total | 277
flow_mgr.flows_timeout_inuse | Total | 261
flow_mgr.rows_checked | Total | 1000000
flow_mgr.rows_skipped | Total | 998835
flow_mgr.rows_empty | Total | 290
flow_mgr.rows_maxlen | Total | 2
flow_mgr.flows_checked: number of flows checked for timeout in the
last pass
flow_mgr.flows_notimeout: number of flows out of flow_mgr.flows_checked
that didn't time out
flow_mgr.flows_timeout: number of out of flow_mgr.flows_checked that
did reach the time out
flow_mgr.flows_removed: number of flows out of flow_mgr.flows_timeout
that were really removed
flow_mgr.flows_timeout_inuse: number of flows out of flow_mgr.flows_timeout
that were still in use or needed work
flow_mgr.rows_checked: hash table rows checked
flow_mgr.rows_skipped: hash table rows skipped because non of the flows
would time out anyway
The counters below are only relating to rows that were not skipped.
flow_mgr.rows_empty: empty hash rows
flow_mgr.rows_maxlen: max number of flows per hash row. Best to keep low,
so increase hash-size if needed.
flow_mgr.rows_busy: row skipped because it was locked by another thread
|
10 years ago | |
|---|---|---|
| benches | 17 years ago | |
| contrib | 11 years ago | |
| doc | 11 years ago | |
| lua | 12 years ago | |
| m4 | 17 years ago | |
| qa | 10 years ago | |
| rules | 10 years ago | |
| scripts | 10 years ago | |
| src | 10 years ago | |
| .gitignore | 10 years ago | |
| .travis.yml | 10 years ago | |
| COPYING | 11 years ago | |
| ChangeLog | 10 years ago | |
| LICENSE | 11 years ago | |
| Makefile.am | 10 years ago | |
| Makefile.cvs | 17 years ago | |
| README.md | 10 years ago | |
| acsite.m4 | 17 years ago | |
| autogen.sh | 14 years ago | |
| classification.config | 16 years ago | |
| config.rpath | 13 years ago | |
| configure.ac | 10 years ago | |
| doxygen.cfg | 10 years ago | |
| reference.config | 12 years ago | |
| suricata.yaml.in | 10 years ago | |
| threshold.config | 14 years ago | |
README.md
======== Suricata
Introduction
Suricata is a network IDS, IPS and NSM engine.
Installation
https://redmine.openinfosecfoundation.org/projects/suricata/wiki/Suricata_Installation
User Guide
https://redmine.openinfosecfoundation.org/projects/suricata/wiki/Suricata_User_Guide
Contributing
We're happily taking patches and other contributions. Please see https://redmine.openinfosecfoundation.org/projects/suricata/wiki/Contributing for how to get started.
Suricata is a complex piece of software dealing with mostly untrusted input. Mishandling this input will have serious consequences: in IPS mode a crash may knock a network offline; in passive mode a compromise of the IDS may lead to loss of critical and confidential data; missed detection may lead to undetected compromise of the network. In other words, we think the stakes are pretty high, especially since in many common cases the IDS/IPS will be directly reachable by an attacker.
For this reason, we have developed a QA process that is quite extensive. A consequence is that contributing to Suricata can be a somewhat lengthy process.
On a high level, the steps are:
-
Travis-CI based build & unit testing. This runs automatically when a pull request is made.
-
Review by devs from the team and community
-
QA runs
Overview of Suricata's QA steps
Trusted devs and core team members are able to submit builds to our (semi) public Buildbot instance. It will run a series of build tests and a regression suite to confirm no existing features break.
The final QA run takes a few hours minimally, and is started by Victor. It currently runs:
- extensive build tests on different OS', compilers, optimization levels, configure features
- static code analysis using cppcheck, scan-build
- runtime code analysis using valgrind, DrMemory, AddressSanitizer, LeakSanitizer
- regression tests for past bugs
- output validation of logging
- unix socket testing
- pcap based fuzz testing using ASAN and LSAN
Next to these tests, based on the type of code change further tests can be run manually:
- traffic replay testing (multi-gigabit)
- large pcap collection processing (multi-terabytes)
- AFL based fuzz testing (might take multiple days or even weeks)
- pcap based performance testing
- live performance testing
- various other manual tests based on evaluation of the proposed changes
It's important to realize that almost all of the tests above are used as acceptance tests. If something fails, it's up to you to address this in your code.
One step of the QA is currently run post-merge. We submit builds to the Coverity Scan program. Due to limitations of this (free) service, we can submit once a day max. Of course it can happen that after the merge the community will find issues. For both cases we request you to help address the issues as they may come up.
FAQ
Q: Will you accept my PR?
A: That depends on a number of things, including the code quality. With new features it also depends on whether the team and/or the community think the feature is useful, how much it affects other code and features, the risk of performance regressions, etc.
Q: When will my PR be merged?
A: It depends, if it's a major feature or considered a high risk change, it will probably go into the next major version.
Q: Why was my PR closed?
A: As documented in the Suricata Github workflow here https://redmine.openinfosecfoundation.org/projects/suricata/wiki/Github_work_flow, we expect a new pull request for every change.
Normally, the team (or community) will give feedback on a pull request after which it is expected to be replaced by an improved PR. So look at the comments. If you disagree with the comments we can still discuss them in the closed PR.
If the PR was closed without comments it's likely due to QA failure. If the Travis-CI check failed, the PR should be fixed right away. No need for a discussion about it, unless you believe the QA failure is incorrect.
Q: the compiler/code analyser/tool is wrong, what now?
A: to assist in the automation of the QA, we're not accepting warnings or errors to stay. In some cases this could mean that we add a suppression if the tool supports that (e.g. valgrind, DrMemory). Some warnings can be disabled. In some exceptional cases the only 'solution' is to refactor the code to work around a static code checker limitation false positive. While frusterating, we prefer this over leaving warnings in the output. Warnings tend to get ignored and then increase risk of hiding other warnings.
Q: I think your QA test is wrong
A: If you really think it is, we can discuss how to improve it. But don't come to this conclusion to quickly, moreoften it's the code that turns out to be wrong.
Q: do you require signing of a contributor license agreement?
A: Yes, we do this to keep the ownership of Suricata in one hand: the Open Information Security Foundation. See http://suricata-ids.org/about/open-source/ and http://suricata-ids.org/about/contribution-agreement/