The generation of weird events, by default, are now rate-limited
according to these tunable options:
- Weird::sampling_whitelist
- Weird::sampling_threshold
- Weird::sampling_rate
- Weird::sampling_duration
The new get_reporter_stats() BIF also allows one to query the
total number of weirds generated (pre-sampling) which the new
policy/misc/weird-stats.bro script uses periodically to populate
a weird_stats.log.
There's also new reporter BIFs to allow generating weirds from the
script-layer such that they go through the same, internal
rate-limiting/sampling mechanisms:
- Reporter::conn_weird
- Reporter::flow_weird
- Reporter::net_weird
Some of the code was adapted from previous work by Johanna Amann.
expose SMB_Data.Trans_Parameters and SMB_Data.Trans_Data fields of
SMB_COM_TRANSACTION (0x25) message type. See MS-CIFS section
2.2.4.33.1.
These fields are exposed to the script level as Bro strings. Note that
this commit also expose a new event smb1_transaction_response.
SMB error handling improved. The analyzer isn't destroyed when a problem
is encoutered anymore. The flowbuffer in the parser is now flushed and
the analyzer is set to resync against an SMB command. This was needed
because there is some state about open files that is kept within the
parser itself which was being destroyed and that was causing analysis
after content gaps or parse errors to be faulty. The new mechanism
doesn't detroy the parser so parsing after gaps is improved.
DCE_RPC handling in SMB is improved in the edge case where a drive
mapping isn't seen. There is a new const named SMB::pipe_filenames
which is used as a heuristic for identifying "files" opened on named
pipe shares. If the share mapping type isn't known and a filename
in this set is found, the share type will change to "PIPE" by
generating an event named "smb_pipe_connect_heuristic". Reads and
writes to that file will be sent to the DCE_RPC analyzer instead of
to the files framework.
The concept of "unknown" share types has been removed due to the new
heuristic detection of share types.
Some general clean up of how the SMB cmd log is written and when.
