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

init-bare: Default Tunnel::max_depth to 4

Browse source 
In AWS GLB environments, the max_depth of 2 is easily reached due to packets
being encapsulated with GENEVE and VXLAN [1]. Any additional encapsulation
layer causes Zeek raise a weird and ignore the inner traffic. Bump the default
maximum depth to 4, while not common it's not unusual either to observe
this in the wild.

[1] https://docs.aws.amazon.com/vpc/latest/mirroring/traffic-mirroring-packet-formats.html

Closes #3439
This commit is contained in:
Arne Welzel 2023-11-30 16:32:50 +01:00
parent 4c960fd7d5
commit fddbdf6232
6 changed files with 37 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

2
scripts/base/init-bare.zeek
View file

@ -5220,7 +5220,7 @@ module Tunnel;
export {
## The maximum depth of a tunnel to decapsulate until giving up.
## Setting this to zero will disable all types of tunnel decapsulation.
const max_depth: count = 2 &redef;
const max_depth: count = 4 &redef;
## With this set, the Teredo analyzer waits until it sees both sides
## of a connection using a valid Teredo encapsulation before issuing

6
testing/btest/Baseline/core.tunnels.max-depth/conn.log.cut Normal file
View file

@ -0,0 +1,6 @@
### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
uid id.orig_h id.resp_p id.resp_h id.resp_p proto history service tunnel_parents
CtPZjS20MLrsMUOJi2 4.4.4.4 53 4.4.4.9 53 udp D dns C4J4Th3PJpwUYZZ6gc
CHhAvVGS1DHFjwGM9 1.1.1.1 4789 1.1.1.9 4789 udp D vxlan -
ClEkJM2Vm5giqnMf4h 2.2.2.2 4789 2.2.2.9 4789 udp D vxlan CHhAvVGS1DHFjwGM9
C4J4Th3PJpwUYZZ6gc 3.3.3.3 4789 3.3.3.9 4789 udp D vxlan ClEkJM2Vm5giqnMf4h

3
testing/btest/Baseline/core.tunnels.max-depth/dns.log.cut Normal file
View file

@ -0,0 +1,3 @@
### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
uid id.orig_h id.resp_p id.resp_h id.resp_p query
CtPZjS20MLrsMUOJi2 4.4.4.4 53 4.4.4.9 53 www.bbc.com

16
testing/btest/Baseline/core.tunnels.max-depth/tunnel.log Normal file
View file

@ -0,0 +1,16 @@
### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
#separator \x09
#set_separator ,
#empty_field (empty)
#unset_field -
#path tunnel
#open XXXX-XX-XX-XX-XX-XX
#fields ts uid id.orig_h id.orig_p id.resp_h id.resp_p tunnel_type action
#types time string addr port addr port enum enum
XXXXXXXXXX.XXXXXX CHhAvVGS1DHFjwGM9 1.1.1.1 4789 1.1.1.9 4789 Tunnel::VXLAN Tunnel::DISCOVER
XXXXXXXXXX.XXXXXX ClEkJM2Vm5giqnMf4h 2.2.2.2 4789 2.2.2.9 4789 Tunnel::VXLAN Tunnel::DISCOVER
XXXXXXXXXX.XXXXXX C4J4Th3PJpwUYZZ6gc 3.3.3.3 4789 3.3.3.9 4789 Tunnel::VXLAN Tunnel::DISCOVER
XXXXXXXXXX.XXXXXX CHhAvVGS1DHFjwGM9 1.1.1.1 4789 1.1.1.9 4789 Tunnel::VXLAN Tunnel::CLOSE
XXXXXXXXXX.XXXXXX ClEkJM2Vm5giqnMf4h 2.2.2.2 4789 2.2.2.9 4789 Tunnel::VXLAN Tunnel::CLOSE
XXXXXXXXXX.XXXXXX C4J4Th3PJpwUYZZ6gc 3.3.3.3 4789 3.3.3.9 4789 Tunnel::VXLAN Tunnel::CLOSE
#close XXXX-XX-XX-XX-XX-XX

BIN
testing/btest/Traces/tunnels/vxlan-triple-v2.pcap Normal file
View file

Binary file not shown.

11
testing/btest/core/tunnels/max-depth.zeek Normal file
View file

@ -0,0 +1,11 @@
# @TEST-DOC: A DNS request encapsulated in 3 layers of VXLAN. Funky but not all that unusual.
# @TEST-EXEC: zeek -b -r $TRACES/tunnels/vxlan-triple-v2.pcap %INPUT
# @TEST-EXEC: zeek-cut -m uid id.orig_h id.resp_p id.resp_h id.resp_p proto history service tunnel_parents < conn.log > conn.log.cut
# @TEST-EXEC: zeek-cut -m uid id.orig_h id.resp_p id.resp_h id.resp_p query < dns.log > dns.log.cut
# @TEST-EXEC: btest-diff conn.log.cut
# @TEST-EXEC: btest-diff tunnel.log
# @TEST-EXEC: btest-diff dns.log.cut
#
@load base/frameworks/tunnels
@load base/protocols/conn
@load base/protocols/dns