- Fix parsing of empty question sections (when QDCOUNT == 0). In this
case, the DNS parser would extract two 2-byte fields for use in either
"dns_query_reply" or "dns_rejected" events (dependent on value of
RCODE) as qclass and qtype parameters. This is not correct, because
such fields don't actually exist in the DNS message format when
QDCOUNT is 0. As a result, these events are no longer raised when
there's an empty question section. Scripts that depends on checking
for an empty question section can do that in the "dns_message" event.
- Add a new "dns_unknown_reply" event, for when Bro does not know how
to fully parse a particular resource record type. This helps fix a
problem in the default DNS scripts where the logic to complete
request-reply pair matching doesn't work because it's waiting on more
RR events to complete the reply. i.e. it expects ANCOUNT number of
dns_*_reply events and will wait until it gets that many before
completing a request-reply pair and logging it to dns.log. This could
cause bogus replies to match a previous request if they happen to
share a DNS transaction ID.
The event now really returns the extension. If openssl supports printing
it, it is converted into the openssl ascii output.
The output does not always look pretty because it can contain newlines.
New event syntax:
event x509_extension(c: connection, is_orig: bool, cert:X509, extension: X509_extension_info)
Example output for extension:
[name=X509v3 Extended Key Usage,
short_name=extendedKeyUsage,
oid=2.5.29.37,
critical=F,
value=TLS Web Server Authentication, TLS Web Client Authentication]
[name=X509v3 Certificate Policies,
short_name=certificatePolicies,
oid=2.5.29.32,
critical=F,
value=Policy: 1.3.6.1.4.1.6449.1.2.1.3.4^J CPS: https://secure.comodo.com/CPS^J]
If a file is nothing but gaps (e.g. due to missing/dropped packets), Bro
can sometimes detect a file is supposed to have been present and never
saw any of its content, but failed to raise file_over_new_connection
events for it. This was mostly apparent because the tx_hosts/rx_hosts
fields in files.log would not be populated in such cases (but are now
with this change).
If TCP endpoint A and B are synchronized at some point, but A
closes/aborts/crashes and B goes on without knowledge of it and then A
tries to re-synchronize, Bro could end up seeing something like
(sequence numbers made up):
A: SYN 100
B: ACK 500
A: RST 500
The final sequence number of A, in this case, is not useful in the
context of determining the number of data bytes sent by A, so Bro now
reports that as 0 (where before it could often be misleadingly large).
The previous behavior was to accomodate SYN/FIN/RST-filtered traces by
not reporting missing data (via the content_gap event) for such
connections. The new behavior always reports gaps for connections that
are established and terminate normally, but sequence numbers indicate
that all data packets of the connection were missed. The behavior can
be reverted by redef'ing "detect_filtered_trace".
In the case multiple FIN packets are seen from a TCP endpoint (e.g.
when one is retransmitted), only the first counted towards a byte in the
sequence space. This could cause a subsequent FIN packet to induce an
incorrect wrap around in the sequence numbers (e.g. the retransmitted
FIN packet now is one sequence number behind the the first) and
misleadingly large connection sizes. The change is to always treat a
FIN packet as counting one byte in to the sequence space.
When an anonymoys function was defined inside an initialization
context, that context transfered over to the function body and could
lead to spurious error messages.
This is mainly an experiment to see if this makes sense. I'm not very
fond of the arguments being wrapped into a discriminating union, but I
like it better than other alternatives at least.
The new code is untested.
The Plugin.cc file is now just a standard class, with the interface
changed a bit to make it more easy to write. However, there're still
some conventions that one must follow to make everything work (like
using the right namespace structure).
This commit also includes the option to compile built-in plugins
dynamically instead of statically by adding
SET(BRO_PLUGIN_BUILD_DYNAMIC TRUE) to their CMake config. This hasn't
been tested much yet, and I'm still undecided if it's somethign we
would want to do by default--but we could now if wanted. :)
Also some minor other cleanup of plugin APIs and built infrastructure.
All tested on MacOS only currently.
* origin/topic/jsiwek/libmagic-integration:
Don't use LOG_* options to ExternalProject_Add if not supported.
Integrate libmagic 5.16 via CMake ExternalProject.
BIT-1116 #merged
This includes enhanced GRE headers. GRE tunnels are treated just like
IP-in-IP tunnels by parsing past the GRE header in between the delivery
and payload IP packets.
* origin/fastpath:
Improve GeoIP City database support.
Broxygen init fixes, addresses BIT-1110.
Fix for packet writing to make it use the global snaplength.
Fix for traffic with TCP segmentation offloading with IP header len field being set to zero.
When trying to open a city database, it now considers both the "REV0"
and "REV1" versions of the city database instead of just the former.
The extra fields of the "REV1" version (metro/area code) aren't yet put
in geo_location records, this change just allows this version of the
city database to be opened w/ same functionality as the other version.
This should be convenient because libGeoIP expects either version to
live at the same file system path, it's hard to tell which version
you've got, and current free GeoLite databases seem to be "REV1".
- Don't check mtime of bro binary if BRO_DISABLE_BROXYGEN env var set.
- Fix failure to locate bro binary if invoking from a relative
path and '.' isn't in PATH.
- The reassembly behavior can be modified per-file by enabling or
disabling the reassembler and/or modifying the size of the reassembly
buffer.
- Changed the file extraction analyzer to use the stream to avoid
issues with the chunk based approach not immediately triggering
the file_new event due to mime-type detection delay. Early chunks
frequently ended up lost before.
- Generally things are working now and I'd consider this in testing.
Includes:
- Cleanup of the plugin API, in particular generally changing
const char* to std::string
- Renaming environment variable BRO_PLUGINS to BRO_PLUGIN_PATH,
defaulting to <prefix>/lib/bro/plugins
- Reworking how dynamic plugins are searched and activated. See
doc/devel/plugins.rst for details.
- New @load-plugin directive to explicitly activate a plugin
- Support for Darwin. (Linux untested right now)
- The init-plugin updates come with support for "make test", "make
sdist", and "make bdist" (see how-to).
- Test updates.
Notes: The new hook mechanism, which allows plugins to hook into Bro's
core a well-defined points, is still essentially untested.
- Move more functionality into base class.
- Remove cctors and assignment operators (weren't actually needed anymore)
- Switch from const char* to std::string.
A bunch of infrastructure work to move IOSource, IOSourceRegistry (now
iosource::Manager) and PktSrc/PktDumper code into iosource/, and over
to a plugin structure.
Other IOSources aren't touched yet, they are still in src/*.
It compiles and does something with a small trace, but that's all I've
tested so far. There are quite certainly a number of problems left, as
well as various TODOs and cleanup; and nothing's cast in stone yet.
Will continue to work on this.
- Internals: move type alias table to private static BroType member.
- Sphinx extension: now uses absolute path to bro binary.
- reST ouput formatting: remove "param" from function desriptions
and change package overview docs so script link+summaries render
consistently.
- First:
Due to architectural constraints, it is very hard for the
input framework to handle optional records. For an optional record,
either the whole record has to be missing, or all non-optional elements
of the record have to be defined. This information is not available
to input readers after the records have been unrolled into the threading
types.
Behavior so far was to treat optional records like they are non-optional,
without warning. The patch changes this behavior to emit an error on stream-
creation (during type-checking) and refusing to open the file. I think this
is a better idea - the behavior so far was undocumented and unintuitive.
- Second:
For table and event streams, reader backend creation was done very early,
before actually checking if all arguments are valid. Initialization is moved
after the checks now - this makes a number of delete statements unnecessary.
Also - I suspect threads of failed input reader instances were not deleted
until shutdown
- Third:
Add a couple more consistency checks, e.g. checking if the destination value
of a table has the same type as we need. We did not check everything in all
instances, instead we just assigned the things without caring (which works,
but is not really desirable).
This change also exposed a few bugs in other testcases where table definitions
were wrong (did not respect $want_record)
- Fourth:
Improve error messages and write testcases for all error messages (I think).
