Mirror/zeek
1
0
Fork 0
mirror of https://github.com/zeek/zeek.git synced 2025-10-02 06:38:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Fix type clash fatal error with log filters that use $ext_func and $include/$exclude

Browse source 
The logging manager's Manager::TraverseRecord(), called when adding a
log filter to a stream, skipped any fields intoduced by a filter's
$ext_func when such fields weren't mentioned in a $include restriction
or mentioned in an $exclude restriction. This was inconsistent with
Manager::RecordToFilterVals, used when actually writing log entries,
which does include those values.

The result was that the record indices descent in Manager::RecordToFilterVals
expects to find only record values, when in fact only the record
provided by ext_func is present. This leads to type mismatches and
hard Zeek exits like this one:

1300475173.475401 fatal error in zeek/share/zeek//base/init-bare.zeek, line 4810: Val::CONVERTER (string/record) (zeek)

The fix makes ext_func's field additions decisive, meaning the
filter's include/exclude lists don't apply to it. If a user really
wants to override this, they can reset the filter's ext_func back to
our no-op default.

The included btest produces the above error when the fix is not present.
This commit is contained in:
Christian Kreibich 2020-11-10 16:34:04 -08:00
parent ee31673154
commit f97a33e14d
4 changed files with 123 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

31
testing/btest/scripts/base/frameworks/logging/field-extension-include-exclude.zeek Normal file
View file

@ -0,0 +1,31 @@
# This tests the intersection of log filters with a custom extension
# function that also use $include/$exclude: the extension function
# overrides those restrictions.
#
# @TEST-EXEC: zeek -b -r $TRACES/wikipedia.trace %INPUT
# @TEST-EXEC: btest-diff conn-inc.log
# @TEST-EXEC: btest-diff conn-exc.log
@load base/protocols/conn
type Extension: record {
write_ts: time &log;
stream: string &log;
system_name: string &log;
};
function add_extension(path: string): Extension
{
return Extension($write_ts = network_time(),
$stream = path,
$system_name = peer_description);
}
redef Log::default_ext_func = add_extension;
event zeek_init()
{
Log::remove_default_filter(Conn::LOG);
Log::add_filter(Conn::LOG, [$name="default-inc", $path="conn-inc", $include=set("ts", "uid", "id.orig_h", "id.resp_h")]);
Log::add_filter(Conn::LOG, [$name="default-exc", $path="conn-exc", $exclude=set("_write_ts")]);
}