With the circular reference gone, we can now make use
of a convenience library for the Suricata program
as well as any other programs that depend on the same
source such as the fuzzer.
While its not a libtool convenience library, it serves
the same purpose and is a common idiom in Make and CMake
projects whereas the COMMON_SOURCES approach was more
of a hack we had to resort to until the circular
reference was resolved.
Expose the "SuricataContext" required by Rust as a function. During
normal startup we register this context with the Rust code, but
plugins written in Rust will need to get the same registration
done, but to do this in a plugin, the plugin code must
call and set the context within its address space.
A filetype plugin is a plugin that implements an eve filetype. Most
of the current filetypes could likely be implemented as such a plugin.
Such a plugin must implement Open, Close and Write, where Write
is provided the formatted JSON to be logged.
This commit also includes the plumbing for plugin loading. Example
plugin to come.
Plugins are loaded by the "plugin" section in the configuration
file:
plugins:
- /path/to/directory/plugins
- /path/to/plugin_file.so
This can also be done on the command line with:
--set plugins.0=/path/plugin_file.so
Goals:
- reduce locking
- take advantage of 'hot' caches
- better locality
Locking reduction
New flow spare pool. The global pool is implmented as a list of blocks,
where each block has a 100 spare flows. Worker threads fetch a block at
a time, storing the block in the local thread storage.
Flow Recycler now returns flows to the pool is blocks as well.
Flow Recycler fetches all flows to be processed in one step instead of
one at a time.
Cache 'hot'ness
Worker threads now check the timeout of flows they evaluate during lookup.
The worker will have to read the flow into cache anyway, so the added
overhead of checking the timeout value is minimal. When a flow is considered
timed out, one of 2 things happens:
- if the flow is 'owned' by the thread it is handled locally. Handling means
checking if the flow needs 'timeout' work.
- otherwise, the flow is added to a special 'evicted' list in the flow
bucket where it will be picked up by the flow manager.
Flow Manager timing
By default the flow manager now tries to do passes of the flow hash in
smaller steps, where the goal is to do full pass in 8 x the lowest timeout
value it has to enforce. So if the lowest timeout value is 30s, a full pass
will take 4 minutes. The goal here is to reduce locking overhead and not
get in the way of the workers.
In emergency mode each pass is full, and lower timeouts are used.
Timing of the flow manager is also no longer relying on pthread condition
variables, as these generally cause waking up much quicker than the desired
timout. Instead a simple (u)sleep loop is used.
Both changes reduce the number of hash passes a lot.
Emergency behavior
In emergency mode there a number of changes to the workers. In this scenario
the flow memcap is fully used up and it is unavoidable that some flows won't
be tracked.
1. flow spare pool fetches are reduced to once a second. This avoids locking
overhead, while the chance of success was very low.
2. getting an active flow directly from the hash skips flows that had very
recent activity to avoid the scenario where all flows get only into the
NEW state before getting reused. Rather allow some to have a chance of
completing.
3. TCP packets that are not SYN packets will not get a used flow, unless
stream.midstream is enabled. The goal here is again to avoid evicting
active flows unnecessarily.
Better Localily
Flow Manager injects flows into the worker threads now, instead of one or
two packets. Advantage of this is that the worker threads can get packets
from their local packet pools, avoiding constant overhead of packets returning
to 'foreign' pools.
Counters
A lot of flow counters have been added and some have been renamed.
Overall the worker threads increment 'flow.wrk.*' counters, while the flow
manager increments 'flow.mgr.*'.
Additionally, none of the counters are snapshots anymore, they all increment
over time. The flow.memuse and flow.spare counters are exceptions.
Misc
FlowQueue has been split into a FlowQueuePrivate (unlocked) and FlowQueue.
Flow no longer has 'prev' pointers and used a unified 'next' pointer for
both hash and queue use.
This commit adds MAC address output to the EVE-JSON format. We follow the
remarks made in Redmine ticket #962: for packets, log MAC src/dst as a
scalar field in EVE; for flows, log MAC src/dst as lists in EVE. Field names
are different between flow and packet context to avoid type confusion
(src_mac vs. src_macs). Configuration approach and JSON representation is
taken from previous GitHub PR #2700.
Fixes https://redmine.openinfosecfoundation.org/issues/2689
Adds a new source file to handle this keyword.
And modifies documentation, Makefile, and registration accordingly.
url_decode decodes url-encoded data, ie replacing '+' with space
and '%HH' with its value.
Match on Hassh using ssh.hassh, ssh.hassh.server, ssh.hassh.string, ssh.hassh.server.string keywords, e.g:
alert ssh any any -> any any (msg:"match SSH hash"; ssh.hassh; content:"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"; sid:1000010;)
alert ssh any any -> any any (msg:"match SSH hash-server"; ssh.hassh.server; content:"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"; sid:1000020;)
alert ssh any any -> any any (msg:"match SSH hash-string"; ssh.hassh.string; content:"none,zlib@openssh.com,zlib"; sid:1000030;)
alert ssh any any -> any any (msg:"match SSH hash-server-string"; ssh.hassh.server.string; content:"umac-64-etm@openssh.com,umac-128-etm@openssh.com,"; sid:1000040;)
File store v1 has been deprecated and was scheduled for removal
by June 2020.
Log an error if a file-store configuration is loaded without
version set to 2.
This commit adds support for the Remote Framebuffer Protocol (RFB) as
used, for example, by various VNC implementations. It targets the
official versions 3.3, 3.7 and 3.8 of the protocol and provides logging
for the RFB handshake communication for now. Logged events include
endpoint versions, details of the security (i.e. authentication)
exchange as well as metadata about the image transfer parameters.
Detection is enabled using keywords for:
- rfb.name: Session name as sticky buffer
- rfb.sectype: Security type, e.g. VNC-style challenge-response
- rfb.secresult: Result of the security exchange, e.g. OK, FAIL, ...
The latter could be used, for example, to detect brute-force attempts
on open VNC servers, while the name could be used to map unwanted VNC
sessions to the desktop owners or machines.
We also ship example EVE-JSON output and keyword docs as part of the
Sphinx source for Suricata's RTD documentation.
Jason Ish
Emmanuel Thompson
Carl Smith
Jeff Lucovsky
Ali Jad Khalil
Philippe Antoine
Victor Julien
Sascha Steinbiss
Shivani Bhardwaj
Vadym Malakhatko
Pierre Chifflier
Frank Honza
Danny Browning
Giuseppe Longo