eBPF has a data type which is a per CPU array. By adding one element
to the array it is in fact added to all per CPU arrays in the kernel.
This allows to have a lockless structure in the kernel even when doing
counter update.
In userspace, we need to update the flow bypass code to fetch all
elements of the per CPU arrays.
This patch implements bypass capability for af-packet.
The filter only bypass TCP and UDP in IPv4 and IPv6. It don't
don't bypass IPv6 with extended headers.
This patch also introduces a bypassed flow manager that takes
care of timeouting the bypassed flows. It uses a 60 sec
timeout on flow. As they are supposed to be active we can
try that. If they are not active then we don't care to get them
back in Suricata.
This patch introduces the ebpf cluster mode. This mode is using
an extended BPF function that is loaded into the kernel and
provide the load balancing.
An example of cluster function is provided in the ebpf
subdirectory and provide ippair load balancing function.
This is a function which uses the same method as
the one used in autofp ippair to provide a symetrical
load balancing based on IP addresses.
A simple filter example allowing to drop IPv6 is added to the
source.
This patch also prepares the infrastructure to be able to load
and use map inside eBPF files. This will be used later for flow
bypass.
This adds a new module that permits to decompress
swf file compressed with zlib or lzma algorithms.
The API that performs decompression will take a compressed
buffer and build a new decompressed buffer following the
FWS format which represents an uncompressed file.
The maximum buffer that can be created is up to 50mb.
During the inspection phase actually is not possible to catch
an error if it occurs.
This patch permits to store events in the detection engine
such that we can match on events and catch them.
Implement a basic autoreconnect support. It tries to reconnect once
when connection has been lost. If it fails, it discards the command
and try again to connect at next command.
This patch updates the unix socket protocol. Messages send from
the server and the client have now a '\n' at the end. This allows
both sides to detect easily the end of a command.
As a side effect, this fixes the problem of long answer in
suricatasc. There is now a limit at the arbitrary value of 65536.
Backward compatility is preserved as a client with the older
version of the protocol can still connect to a Suricata with
version 2 of the protocol.
Under eve/alert, introduce a new metadata configuration
section. If no provided, or simply yes defaults will be used.
Otherwise this a map with fields that can be toggled on and
off. The defaults are:
outputs:
- eve-log:
types:
- alert:
metadata:
app-layer: true
flow: true
rule:
raw: false
metadata: true
To enable something that is disabled by default, or to disable
something that is enabled by default, only that key need to
be changed, everything else will keep its default value.
For SIEM analysis it is often useful to refer to the actual rules to
find out why a specific alert has been triggered when the signature
message does not convey enough information.
Turn on the new rule flag to include the rule text in eve alert output.
The feature is turned off by default.
With a rule like this:
alert dns $HOME_NET any -> 8.8.8.8 any (msg:"Google DNS server contacted"; sid:42;)
The eve alert output might look something like this (pretty-printed for
readability):
{
"timestamp": "2017-08-14T12:35:05.830812+0200",
"flow_id": 1919856770919772,
"in_iface": "eth0",
"event_type": "alert",
"src_ip": "10.20.30.40",
"src_port": 50968,
"dest_ip": "8.8.8.8",
"dest_port": 53,
"proto": "UDP",
"alert": {
"action": "allowed",
"gid": 1,
"signature_id": 42,
"rev": 0,
"signature": "Google DNS server contacted",
"category": "",
"severity": 3,
"rule": "alert dns $HOME_NET any -> 8.8.8.8 any (msg:\"Google DNS server contacted\"; sid:43;)"
},
"app_proto": "dns",
"flow": {
"pkts_toserver": 1,
"pkts_toclient": 0,
"bytes_toserver": 81,
"bytes_toclient": 0,
"start": "2017-08-14T12:35:05.830812+0200"
}
}
Feature #2020
Metadata of the signature can now conditionaly put in the alert
events. This will allow user to get more context about the events
generated by the alert.
detect-metadata: conditional parsing
Only parses metadata if an output module will use the information.
Patch also adds a unittest to check metadata is not parsed if not
asked to.
output-json-alert: optional output keys as array
Update rule metadata configuration to have an option to output
value as array. Also adds an option to log only a series of keys
as array. This is useful in the case of some ruleset where from
instance the `tag` key is used multiple time.
(Jason Ish) rule metadata: always log as lists
After review of rule metadata, we can't make assumptions
on what should be a list or not. So log everything as a list.
This patch updates the Signature structure so it contains the
metadata under a key value form.
Later patch will make that dictionary available in the events.
Both the suricata.yaml and eve configuration sections
included the eve-log section from suricata.yaml. First,
sync these up with the actual suricata.yaml then break
it out into its own file, so only one file needs to
be kept in sync with the actual configuration file.
By default log metadata.
Remove toggles for individual protocol types and just use a
single toggle to control including the app-layer with the
alert.
The metadata (currently app-layer and flow) can be disabled
by setting metadata to a falsey value, but its removed
from the default configuration (but wil be in docs)
Give traffic/id and traffic/label flowbits special handling
in the eve output. Instead of just logging them as flowbits,
give them their own top level object.
{
"traffic": {
"id": ["id0", "id1"],
"label": ["label0", "label1"]
}
}
Eric Leblond
Giuseppe Longo
Maurizio Abba
Jason Ish
Martin Natano
Victor Julien