From bdad4e046872e054ec7783b2f04b73a8a690a045 Mon Sep 17 00:00:00 2001 From: Viacheslav Hletenko Date: Wed, 20 Sep 2023 11:46:42 +0000 Subject: T5217: Add firewall synproxy Add ability to SYNPROXY connections It is useful to protect against TCP SYN flood attacks and port-scanners set firewall global-options syn-cookies 'enable' set firewall ipv4 input filter rule 10 action 'synproxy' set firewall ipv4 input filter rule 10 destination port '22' set firewall ipv4 input filter rule 10 inbound-interface interface-name 'eth1' set firewall ipv4 input filter rule 10 protocol 'tcp' set firewall ipv4 input filter rule 10 synproxy tcp mss '1460' set firewall ipv4 input filter rule 10 synproxy tcp window-scale '7' --- smoketest/scripts/cli/test_firewall.py | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) (limited to 'smoketest') diff --git a/smoketest/scripts/cli/test_firewall.py b/smoketest/scripts/cli/test_firewall.py index 676be5305..7fd13d92a 100755 --- a/smoketest/scripts/cli/test_firewall.py +++ b/smoketest/scripts/cli/test_firewall.py @@ -1,6 +1,6 @@ #!/usr/bin/env python3 # -# Copyright (C) 2021-2022 VyOS maintainers and contributors +# Copyright (C) 2021-2023 VyOS maintainers and contributors # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License version 2 or later as @@ -338,6 +338,31 @@ class TestFirewall(VyOSUnitTestSHIM.TestCase): self.verify_nftables(nftables_search, 'ip vyos_filter') + def test_ipv4_synproxy(self): + tcp_mss = '1460' + tcp_wscale = '7' + dport = '22' + + self.cli_set(['firewall', 'ipv4', 'input', 'filter', 'rule', '10', 'action', 'drop']) + self.cli_set(['firewall', 'ipv4', 'input', 'filter', 'rule', '10', 'protocol', 'tcp']) + self.cli_set(['firewall', 'ipv4', 'input', 'filter', 'rule', '10', 'destination', 'port', dport]) + self.cli_set(['firewall', 'ipv4', 'input', 'filter', 'rule', '10', 'synproxy', 'tcp', 'mss', tcp_mss]) + self.cli_set(['firewall', 'ipv4', 'input', 'filter', 'rule', '10', 'synproxy', 'tcp', 'window-scale', tcp_wscale]) + + with self.assertRaises(ConfigSessionError): + self.cli_commit() + + self.cli_set(['firewall', 'ipv4', 'input', 'filter', 'rule', '10', 'action', 'synproxy']) + + self.cli_commit() + + nftables_search = [ + [f'tcp dport {dport} ct state invalid,untracked', f'synproxy mss {tcp_mss} wscale {tcp_wscale} timestamp sack-perm'] + ] + + self.verify_nftables(nftables_search, 'ip vyos_filter') + + def test_ipv4_mask(self): name = 'smoketest-mask' interface = 'eth0' -- cgit v1.2.3