From 84a83ecc4c78bf2e0954658ea539e42b4c015fa2 Mon Sep 17 00:00:00 2001
From: sarthurdev <965089+sarthurdev@users.noreply.github.com>
Date: Mon, 3 Jan 2022 22:17:08 +0100
Subject: firewall: T4130: Fix firewall state-policy errors
Also fixes:
* Issue with multiple state-policy rules being created on firewall updates
* Prevents interface rules being inserted before state-policy
---
src/conf_mode/firewall-interface.py | 27 +++++++++++++++++++++++++--
src/conf_mode/firewall.py | 28 +++++++++++++++++++++++++---
2 files changed, 50 insertions(+), 5 deletions(-)
(limited to 'src')
diff --git a/src/conf_mode/firewall-interface.py b/src/conf_mode/firewall-interface.py
index 3a17dc5a4..516fa6c48 100755
--- a/src/conf_mode/firewall-interface.py
+++ b/src/conf_mode/firewall-interface.py
@@ -107,6 +107,15 @@ def cleanup_rule(table, chain, ifname, new_name=None):
run(f'nft delete rule {table} {chain} handle {handle_search[1]}')
return retval
+def state_policy_handle(table, chain):
+ results = cmd(f'nft -a list chain {table} {chain}').split("\n")
+ for line in results:
+ if 'jump VYOS_STATE_POLICY' in line:
+ handle_search = re.search('handle (\d+)', line)
+ if handle_search:
+ return handle_search[1]
+ return None
+
def apply(if_firewall):
ifname = if_firewall['ifname']
@@ -118,18 +127,32 @@ def apply(if_firewall):
name = dict_search_args(if_firewall, direction, 'name')
if name:
rule_exists = cleanup_rule('ip filter', chain, ifname, name)
+ rule_action = 'insert'
+ rule_prefix = ''
if not rule_exists:
- run(f'nft insert rule ip filter {chain} {if_prefix}ifname {ifname} counter jump {name}')
+ handle = state_policy_handle('ip filter', chain)
+ if handle:
+ rule_action = 'add'
+ rule_prefix = f'position {handle}'
+
+ run(f'nft {rule_action} rule ip filter {chain} {rule_prefix} {if_prefix}ifname {ifname} counter jump {name}')
else:
cleanup_rule('ip filter', chain, ifname)
ipv6_name = dict_search_args(if_firewall, direction, 'ipv6_name')
if ipv6_name:
rule_exists = cleanup_rule('ip6 filter', ipv6_chain, ifname, ipv6_name)
+ rule_action = 'insert'
+ rule_prefix = ''
if not rule_exists:
- run(f'nft insert rule ip6 filter {ipv6_chain} {if_prefix}ifname {ifname} counter jump {ipv6_name}')
+ handle = state_policy_handle('ip filter', chain)
+ if handle:
+ rule_action = 'add'
+ rule_prefix = f'position {handle}'
+
+ run(f'nft {rule_action} rule ip6 filter {ipv6_chain} {rule_prefix} {if_prefix}ifname {ifname} counter jump {ipv6_name}')
else:
cleanup_rule('ip6 filter', ipv6_chain, ifname)
diff --git a/src/conf_mode/firewall.py b/src/conf_mode/firewall.py
index 5ac48c9ba..8e037c679 100755
--- a/src/conf_mode/firewall.py
+++ b/src/conf_mode/firewall.py
@@ -205,13 +205,20 @@ def verify(firewall):
def cleanup_commands(firewall):
commands = []
for table in ['ip filter', 'ip6 filter']:
+ state_chain = 'VYOS_STATE_POLICY' if table == 'ip filter' else 'VYOS_STATE_POLICY6'
json_str = cmd(f'nft -j list table {table}')
obj = loads(json_str)
if 'nftables' not in obj:
continue
for item in obj['nftables']:
if 'chain' in item:
- if item['chain']['name'] not in preserve_chains:
+ if item['chain']['name'] in ['VYOS_STATE_POLICY', 'VYOS_STATE_POLICY6']:
+ chain = item['chain']['name']
+ if 'state_policy' not in firewall:
+ commands.append(f'delete chain {table} {chain}')
+ else:
+ commands.append(f'flush chain {table} {chain}')
+ elif item['chain']['name'] not in preserve_chains:
chain = item['chain']['name']
if table == 'ip filter' and dict_search_args(firewall, 'name', chain):
commands.append(f'flush chain {table} {chain}')
@@ -219,6 +226,14 @@ def cleanup_commands(firewall):
commands.append(f'flush chain {table} {chain}')
else:
commands.append(f'delete chain {table} {chain}')
+ elif 'rule' in item:
+ rule = item['rule']
+ if rule['chain'] in ['VYOS_FW_IN', 'VYOS_FW_OUTPUT', 'VYOS_FW_LOCAL', 'VYOS_FW6_IN', 'VYOS_FW6_OUTPUT', 'VYOS_FW6_LOCAL']:
+ if 'expr' in rule and any([True for expr in rule['expr'] if dict_search_args(expr, 'jump', 'target') == state_chain]):
+ if 'state_policy' not in firewall:
+ chain = rule['chain']
+ handle = rule['handle']
+ commands.append(f'delete rule {table} {chain} handle {handle}')
return commands
def generate(firewall):
@@ -286,6 +301,11 @@ def post_apply_trap(firewall):
cmd(base_cmd + ' '.join(objects))
+def state_policy_rule_exists():
+ # Determine if state policy rules already exist in nft
+ search_str = cmd(f'nft list chain ip filter VYOS_FW_IN')
+ return 'VYOS_STATE_POLICY' in search_str
+
def apply(firewall):
if 'first_install' in firewall:
run('nfct helper add rpc inet tcp')
@@ -296,9 +316,11 @@ def apply(firewall):
if install_result == 1:
raise ConfigError('Failed to apply firewall')
- if 'state_policy' in firewall:
- for chain in ['INPUT', 'OUTPUT', 'FORWARD']:
+ if 'state_policy' in firewall and not state_policy_rule_exists():
+ for chain in ['VYOS_FW_IN', 'VYOS_FW_OUTPUT', 'VYOS_FW_LOCAL']:
cmd(f'nft insert rule ip filter {chain} jump VYOS_STATE_POLICY')
+
+ for chain in ['VYOS_FW6_IN', 'VYOS_FW6_OUTPUT', 'VYOS_FW6_LOCAL']:
cmd(f'nft insert rule ip6 filter {chain} jump VYOS_STATE_POLICY6')
apply_sysfs(firewall)
--
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