Add rate-limiting sampling mechanism for weird events

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.
This commit is contained in:
Jon Siwek 2018-07-26 19:57:36 -05:00
parent e60b0bfb25
commit 35827eeb31
25 changed files with 1037 additions and 10 deletions

View file

@ -23,12 +23,14 @@ enum TimerType {
TIMER_CONN_STATUS_UPDATE,
TIMER_DNS_EXPIRE,
TIMER_FILE_ANALYSIS_INACTIVITY,
TIMER_FLOW_WEIRD_EXPIRE,
TIMER_FRAG,
TIMER_INCREMENTAL_SEND,
TIMER_INCREMENTAL_WRITE,
TIMER_INTERCONN,
TIMER_IP_TUNNEL_INACTIVITY,
TIMER_NB_EXPIRE,
TIMER_NET_WEIRD_EXPIRE,
TIMER_NETWORK,
TIMER_NTP_EXPIRE,
TIMER_PROFILE,