Sunil Mohan Adapa a62b7c7522
firewall: Use privileged decorator, drop showing running status
- If a daemon is not-running, we already show an error message to the user. Use
that mechanism instead of the custom one.

Tests:

- Functional tests work.
- Initial setup for firewall on first boot works.
  - Default zone of the firewalld is set to external in /etc/firewalld.conf
- Status of various apps is shown properly in the app page
- If firewalld is not running, the app page is still displayed properly and
  message that firewalld is not running is shown.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>
2022-10-08 18:52:00 -04:00

73 lines
2.4 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
"""Configuration helper for FreedomBox firewall interface."""
import subprocess
import augeas
from plinth import action_utils
from plinth.actions import privileged
def _flush_iptables_rules():
"""Flush firewalld iptables rules before restarting it.
This is workaround for
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914694
This workaround can be removed if the bug is fixed or if firewalld starts
defaulting to nftables again.
The bug leads to firewalld failing to flush rules when there are custom
chains in the rules. This only happens on firewalld iptables backend when
nftables is running with iptables compatibility.
Flushing the tables before a restart will make the restart succeed and
after the restart nftables backend is used avoiding the problem.
"""
rule_template = '*{table}\n-F\n-X\n-Z\nCOMMIT\n'
iptables_rules = ''
ip6tables_rules = ''
for table in ['security', 'raw', 'mangle', 'nat', 'filter']:
iptables_rules += rule_template.format(table=table)
ip6tables_rules += rule_template.format(table=table)
subprocess.run(['iptables-restore'], input=iptables_rules.encode(),
check=True)
subprocess.run(['ip6tables-restore'], input=iptables_rules.encode(),
check=True)
def set_firewall_backend(backend):
"""Set FirewallBackend attribute to the specified string."""
conf_file = '/etc/firewalld/firewalld.conf'
aug = augeas.Augeas(flags=augeas.Augeas.NO_LOAD +
augeas.Augeas.NO_MODL_AUTOLOAD)
# lens for shell-script config file
aug.set('/augeas/load/Shellvars/lens', 'Shellvars.lns')
aug.set('/augeas/load/Shellvars/incl[last() + 1]', conf_file)
aug.load()
old_backend = aug.get('/files/{}/FirewallBackend'.format(conf_file))
aug.set('/files/{}/FirewallBackend'.format(conf_file),
'{}'.format(backend))
aug.save()
if old_backend == 'iptables':
_flush_iptables_rules()
if backend != old_backend:
action_utils.service_restart('firewalld')
@privileged
def setup():
"""Perform basic firewalld setup."""
action_utils.service_enable('firewalld')
subprocess.run(['firewall-cmd', '--set-default-zone=external'],
stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
check=True)
set_firewall_backend('nftables')