salt/salt/modules/nftables.py
2014-07-28 19:52:01 -05:00

860 lines
24 KiB
Python

# -*- coding: utf-8 -*-
'''
Support for nftables
'''
# Import python libs
import logging
import re
# Import salt libs
import salt.utils
from salt.state import STATE_INTERNAL_KEYWORDS as _STATE_INTERNAL_KEYWORDS
from salt.exceptions import (
CommandExecutionError
)
# Set up logging
log = logging.getLogger(__name__)
_NFTABLES_FAMILIES = {
'ipv4': 'ip',
'ip4': 'ip',
'ip': 'ip',
'ipv6': 'ip6',
'ip6': 'ip6',
'arp': 'arp',
'bridge': 'bridge'
}
def __virtual__():
'''
Only load the module if nftables is installed
'''
if salt.utils.which('nft'):
return 'nftables'
return False
def _nftables_cmd():
'''
Return correct command
'''
return 'nft'
def _conf(family='ip'):
'''
Use the same file for rules for now.
'''
if __grains__['os_family'] == 'RedHat':
return '/etc/nftables'
elif __grains__['os_family'] == 'Arch':
return '/etc/nftables'
elif __grains__['os_family'] == 'Debian':
return '/etc/nftables'
elif __grains__['os'] == 'Gentoo':
return '/etc/nftables'
else:
return False
def version():
'''
Return version from nftables --version
CLI Example:
.. code-block:: bash
salt '*' nftables.version
'''
cmd = '{0} --version' . format(_nftables_cmd())
out = __salt__['cmd.run'](cmd).split()
return out[1]
def build_rule(table=None, chain=None, command=None, position='', full=None, family='ipv4',
**kwargs):
'''
Build a well-formatted nftables rule based on kwargs.
A `table` and `chain` are not required, unless `full` is True.
If `full` is `True`, then `table`, `chain` and `command` are required.
`command` may be specified as either insert, append, or delete.
This will return the nftables command, exactly as it would
be used from the command line.
If a position is required (as with `insert` or `delete`), it may be specified as
`position`. This will only be useful if `full` is True.
If `connstate` is passed in, it will automatically be changed to `state`.
CLI Examples:
.. code-block:: bash
salt '*' nftables.build_rule match=state \\
connstate=RELATED,ESTABLISHED jump=ACCEPT
salt '*' nftables.build_rule filter input command=insert position=3 \\
full=True match=state state=related,established jump=accept
IPv6:
salt '*' nftables.build_rule match=state \\
connstate=related,established jump=accept \\
family=ipv6
salt '*' nftables.build_rule filter input command=insert position=3 \\
full=True match=state state=related,established jump=accept \\
family=ipv6
'''
if 'target' in kwargs:
kwargs['jump'] = kwargs['target']
del kwargs['target']
for ignore in list(_STATE_INTERNAL_KEYWORDS) + ['chain', 'save', 'table']:
if ignore in kwargs:
del kwargs[ignore]
rule = ''
proto = ''
nft_family = _NFTABLES_FAMILIES[family]
if 'if' in kwargs:
rule += 'meta iifname {0} '.format(kwargs['if'])
del kwargs['if']
if 'of' in kwargs:
rule += 'meta oifname {0} '.format(kwargs['of'])
del kwargs['of']
if 'proto' in kwargs:
proto = kwargs['proto']
if 'state' in kwargs:
del kwargs['state']
if 'connstate' in kwargs:
rule += 'ct state {{ {0}}} '.format(kwargs['connstate'])
del kwargs['connstate']
if 'dport' in kwargs:
kwargs['dport'] = str(kwargs['dport'])
if ':' in kwargs['dport']:
kwargs['dport'] = kwargs['dport'].replace(':', '-')
rule += 'dport {{ {0}}} '.format(kwargs['dport'])
del kwargs['dport']
if 'sport' in kwargs:
kwargs['sport'] = str(kwargs['sport'])
if ':' in kwargs['sport']:
kwargs['sport'] = kwargs['sport'].replace(':', '-')
rule += 'sport {{ {0}}} '.format(kwargs['sport'])
del kwargs['sport']
if 'dports' in kwargs:
# nftables reverse sorts the ports from
# high to low, create rule like this
# so that the check will work
_dports = kwargs['dports'].split(',')
_dports = [int(x) for x in _dports]
_dports.sort(reverse=True)
kwargs['dports'] = ', '.join(str(x) for x in _dports)
rule += 'dport {{ {0}}} '.format(kwargs['dports'])
del kwargs['dports']
if 'sports' in kwargs:
# nftables reverse sorts the ports from
# high to low, create rule like this
# so that the check will work
_sports = kwargs['sports'].split(',')
_sports = [int(x) for x in _sports]
_sports.sort(reverse=True)
kwargs['sports'] = ', '.join(str(x) for x in _sports)
rule += 'sport {{ {0} }} '.format(kwargs['sports'])
del kwargs['sports']
# Jumps should appear last, except for any arguments that are passed to
# jumps, which of course need to follow.
after_jump = []
if 'jump' in kwargs:
after_jump.append('{0} '.format(kwargs['jump']))
del kwargs['jump']
if 'j' in kwargs:
after_jump.append('{0} '.format(kwargs['j']))
del kwargs['j']
if 'to-port' in kwargs:
after_jump.append('--to-port {0} '.format(kwargs['to-port']))
del kwargs['to-port']
if 'to-ports' in kwargs:
after_jump.append('--to-ports {0} '.format(kwargs['to-ports']))
del kwargs['to-ports']
if 'to-destination' in kwargs:
after_jump.append('--to-destination {0} '.
format(kwargs['to-destination']))
del kwargs['to-destination']
if 'reject-with' in kwargs:
after_jump.append('--reject-with {0} '.format(kwargs['reject-with']))
del kwargs['reject-with']
for item in after_jump:
rule += item
# Strip trailing spaces off rule
rule = rule.strip()
# Insert the protocol prior to dport or sport
rule = rule.replace('dport', '{0} dport'.format(proto))
rule = rule.replace('sport', '{0} sport'.format(proto))
if full in ['True', 'true']:
if not table:
return 'Error: Table needs to be specified'
if not chain:
return 'Error: Chain needs to be specified'
if not command:
return 'Error: Command needs to be specified'
if command in ['Insert', 'insert', 'INSERT']:
if position:
return '{0} insert rule {1} {2} {3} position {4} {5}'.\
format(_nftables_cmd(), nft_family, table,
chain, position, rule)
else:
return '{0} insert rule {1} {2} {3} {4}'.\
format(_nftables_cmd(), nft_family, table,
chain, rule)
return '{0} {1} rule {2} {3} {4} {5}'.format(_nftables_cmd(),
command, nft_family, table, chain, rule)
return rule
def get_saved_rules(conf_file=None, family='ipv4'):
'''
Return a data structure of the rules in the conf file
CLI Example:
.. code-block:: bash
salt '*' nftables.get_saved_rules
'''
if _conf() and not conf_file:
conf_file = _conf()
lines = salt.utils.fopen(conf_file).readlines()
rules = []
for line in lines:
tmpline = line.strip()
if not tmpline:
continue
if tmpline.startswith('#'):
continue
rules.append(line)
return rules
def get_rules(family='ipv4'):
'''
Return a data structure of the current, in-memory rules
CLI Example:
.. code-block:: bash
salt '*' nftables.get_rules
salt '*' nftables.get_rules family=ipv6
'''
nft_family = _NFTABLES_FAMILIES[family]
rules = []
cmd = '{0} --numeric --numeric --numeric list tables {1}'.\
format(_nftables_cmd(), nft_family)
out = __salt__['cmd.run'](cmd)
if not out:
return rules
tables = re.split('\n+', out)
for table in tables:
table_name = table.split(' ')[1]
cmd = '{0} --numeric --numeric --numeric list table {1} {2}'.format(_nftables_cmd(),
nft_family, table_name)
out = __salt__['cmd.run'](cmd)
rules.append(out)
return rules
def save(filename=None, family='ipv4'):
'''
Save the current in-memory rules to disk
CLI Example:
.. code-block:: bash
salt '*' nftables.save /etc/nftables
'''
if _conf() and not filename:
filename = _conf()
nft_families = ['ip', 'ip6', 'arp', 'bridge']
rules = "#! nft -f\n"
for family in nft_families:
out = get_rules(family)
if out:
rules += '\n'
rules = rules + '\n'.join(out)
rules = rules + '\n'
try:
with salt.utils.fopen(filename, 'w+') as _fh:
# Write out any changes
_fh.writelines(rules)
except (IOError, OSError) as exc:
raise CommandExecutionError(
'Problem writing to configuration file: {0}'.format(exc)
)
return rules
def get_rule_handle(table='filter', chain=None, rule=None, family='ipv4'):
'''
Get the handle for a particular rule
This function accepts a rule in a standard nftables command format,
starting with the chain. Trying to force users to adapt to a new
method of creating rules would be irritating at best, and we
already have a parser that can handle it.
CLI Example:
.. code-block:: bash
salt '*' nftables.get_rule_handle filter input \\
rule='input tcp dport 22 log accept'
IPv6:
salt '*' nftables.get_rule_handle filter input \\
rule='input tcp dport 22 log accept' \\
family=ipv6
'''
if not chain:
return 'Error: Chain needs to be specified'
if not rule:
return 'Error: Rule needs to be specified'
if not check_table(table, family=family):
return 'Error: table {0} in family {1} does not exist'.\
format(table, family)
if not check_chain(table, chain, family=family):
return 'Error: chain {0} in table {1} in family {1} does not exist'.\
format(chain, table, family)
if not check(table, chain, rule, family=family):
return 'Error: rule {0} chain {1} in table {2} in family {3} does not exist'.\
format(rule, chain, table, family)
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} --numeric --numeric --numeric --handle list chain {1} {2} {3}'.\
format(_nftables_cmd(), nft_family, table, chain)
out = __salt__['cmd.run'](cmd)
rules = re.split('\n+', out)
pat = re.compile(r'{0} # handle (?P<handle>\d+)'.format(rule))
for rule in rules:
match = pat.search(rule)
if match:
handle = match.group('handle')
return handle
def check(table='filter', chain=None, rule=None, family='ipv4'):
'''
Check for the existence of a rule in the table and chain
This function accepts a rule in a standard nftables command format,
starting with the chain. Trying to force users to adapt to a new
method of creating rules would be irritating at best, and we
already have a parser that can handle it.
CLI Example:
.. code-block:: bash
salt '*' nftables.check filter input \\
rule='input tcp dport 22 log accept'
IPv6:
salt '*' nftables.check filter input \\
rule='input tcp dport 22 log accept' \\
family=ipv6
'''
if not chain:
return 'Error: Chain needs to be specified'
if not rule:
return 'Error: Rule needs to be specified'
if not check_table(table, family=family):
return 'Error: table {0} in family {1} does not exist'.\
format(table, family)
if not check_chain(table, chain, family=family):
return 'Error: chain {0} in table {1} in family {1} does not exist'.\
format(chain, table, family)
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} --handle --numeric --numeric --numeric list chain {1} {2} {3}'.\
format(_nftables_cmd(), nft_family, table, chain)
search_rule = '{0} #'.format(rule)
out = __salt__['cmd.run'](cmd).find(search_rule)
if out != -1:
out = ''
else:
return False
if not out:
return True
return out
def check_chain(table='filter', chain=None, family='ipv4'):
'''
.. versionadded:: 2014.7.0
Check for the existence of a chain in the table
CLI Example:
.. code-block:: bash
salt '*' nftables.check_chain filter input
IPv6:
salt '*' nftables.check_chain filter input family=ipv6
'''
if not chain:
return 'Error: Chain needs to be specified'
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} list table {1} {2}' . format(_nftables_cmd(), nft_family, table)
out = __salt__['cmd.run'](cmd).find('chain {0} {{'.format(chain))
if out != -1:
out = ''
else:
return False
if not out:
return True
return out
def check_table(table=None, family='ipv4'):
'''
Check for the existence of a table
CLI Example::
salt '*' nftables.check_table nat
'''
if not table:
return 'Error: table needs to be specified'
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} list tables {1}' . format(_nftables_cmd(), nft_family)
out = __salt__['cmd.run'](cmd).find('table {0}'.format(table))
if out != -1:
out = ''
else:
return False
if not out:
return True
return out
def new_table(table, family='ipv4'):
'''
.. versionadded:: 2014.7.0
Create new custom table.
CLI Example:
.. code-block:: bash
salt '*' nftables.new_table filter
IPv6:
salt '*' nftables.new_table filter family=ipv6
'''
if not table:
return 'Error: table needs to be specified'
if check_table(table, family=family):
return 'Error: table {0} in family {1} already exists'.\
format(table, family)
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} add table {1} {2}'.format(_nftables_cmd(), nft_family, table)
out = __salt__['cmd.run'](cmd)
if not out:
out = True
return out
def delete_table(table, family='ipv4'):
'''
.. versionadded:: 2014.7.0
Create new custom table.
CLI Example:
.. code-block:: bash
salt '*' nftables.delete_table filter
IPv6:
salt '*' nftables.delete_table filter family=ipv6
'''
if not table:
return 'Error: table needs to be specified'
if not check_table(table, family=family):
return 'Error: table {0} in family {1} does not exist' . format(table, family)
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} delete table {1} {2}'.format(_nftables_cmd(), nft_family, table)
out = __salt__['cmd.run'](cmd)
if not out:
out = True
return out
def new_chain(table='filter', chain=None, table_type=None, hook=None, priority=None, family='ipv4'):
'''
.. versionadded:: 2014.7.0
Create new chain to the specified table.
CLI Example:
.. code-block:: bash
salt '*' nftables.new_chain filter input
salt '*' nftables.new_chain filter input \\
table_type=filter hook=input priority=0
salt '*' nftables.new_chain filter foo
IPv6:
salt '*' nftables.new_chain filter input family=ipv6
salt '*' nftables.new_chain filter input \\
table_type=filter hook=input priority=0 family=ipv6
salt '*' nftables.new_chain filter foo family=ipv6
'''
if not chain:
return 'Error: Chain needs to be specified'
if not check_table(table, family=family):
return 'Error: table {0} in family {1} does not exist'.\
format(table, family)
if check_chain(table, chain, family=family):
return 'Error: chain {0} in table {1} in family {1} already exists'.\
format(chain, table, family)
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} add chain {1} {2} {3}'.\
format(_nftables_cmd(), nft_family, table, chain)
if table_type or hook or priority:
if table_type and hook and str(priority):
cmd = r'{0} \{{ type {1} hook {2} priority {3}\; \}}'.\
format(cmd, table_type, hook, priority)
else:
# Specifiy one, rqeuire all
return 'Error: table_type hook and priority required'
out = __salt__['cmd.run'](cmd)
if not out:
out = True
return out
def delete_chain(table='filter', chain=None, family='ipv4'):
'''
.. versionadded:: 2014.7.0
Delete the chain from the specified table.
CLI Example:
.. code-block:: bash
salt '*' nftables.delete_chain filter input
salt '*' nftables.delete_chain filter foo
IPv6:
salt '*' nftables.delete_chain filter input family=ipv6
salt '*' nftables.delete_chain filter foo family=ipv6
'''
if not chain:
return 'Error: Chain needs to be specified'
if not check_table(table, family=family):
return 'Error: table {0} in family {1} does not exist'.\
format(table, family)
if not check_chain(table, chain, family=family):
return 'Error: chain {0} in table {1} in family {1} does not exist'.\
format(chain, table, family)
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} delete chain {1} {2} {3}'.\
format(_nftables_cmd(), nft_family, table, chain)
out = __salt__['cmd.run'](cmd)
if not out:
out = True
return out
def append(table='filter', chain=None, rule=None, family='ipv4'):
'''
Append a rule to the specified table & chain.
This function accepts a rule in a standard nftables command format,
starting with the chain. Trying to force users to adapt to a new
method of creating rules would be irritating at best, and we
already have a parser that can handle it.
CLI Example:
.. code-block:: bash
salt '*' nftables.append filter input \\
rule='input tcp dport 22 log accept'
IPv6:
salt '*' nftables.append filter input \\
rule='input tcp dport 22 log accept' \\
family=ipv6
'''
if not chain:
return 'Error: Chain needs to be specified'
if not rule:
return 'Error: Rule needs to be specified'
if not check_table(table, family=family):
return 'Error: table {0} in family {1} does not exist'.\
format(table, family)
if not check_chain(table, chain, family=family):
return 'Error: chain {0} in table {1} in family {1} does not exist'.\
format(chain, table, family)
if check(table, chain, rule, family=family):
return 'Error: rule {0} chain {1} in table {2} in family {3} already exists'.\
format(rule, chain, table, family)
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} add rule {1} {2} {3} {4}'.\
format(_nftables_cmd(), nft_family, table, chain, rule)
out = __salt__['cmd.run'](cmd)
if len(out) == 0:
return True
else:
return False
def insert(table='filter', chain=None, position=None, rule=None, family='ipv4'):
'''
Insert a rule into the specified table & chain, at the specified position.
If position is not specified, rule will be inserted in first position.
This function accepts a rule in a standard nftables command format,
starting with the chain. Trying to force users to adapt to a new
method of creating rules would be irritating at best, and we
already have a parser that can handle it.
CLI Examples:
.. code-block:: bash
salt '*' nftables.insert filter input \\
rule='input tcp dport 22 log accept'
salt '*' nftables.insert filter input position=3 \\
rule='input tcp dport 22 log accept'
IPv6:
salt '*' nftables.insert filter input \\
rule='input tcp dport 22 log accept' \\
family=ipv6
salt '*' nftables.insert filter input position=3 \\
rule='input tcp dport 22 log accept' \\
family=ipv6
'''
if not chain:
return 'Error: Chain needs to be specified'
if not rule:
return 'Error: Rule needs to be specified'
if not check_table(table, family=family):
return 'Error: table {0} in family {1} does not exist'.\
format(table, family)
if not check_chain(table, chain, family=family):
return 'Error: chain {0} in table {1} in family {1} does not exist'.\
format(chain, table, family)
if check(table, chain, rule, family=family):
return 'Error: rule {0} chain {1} in table {2} in family {3} already exists'.\
format(rule, chain, table, family)
nft_family = _NFTABLES_FAMILIES[family]
if position:
cmd = '{0} insert rule {1} {2} {3} position {4} {5}'.\
format(_nftables_cmd(), nft_family, table, chain, position, rule)
else:
cmd = '{0} insert rule {1} {2} {3} {4}'.\
format(_nftables_cmd(), nft_family, table, chain, rule)
out = __salt__['cmd.run'](cmd)
if len(out) == 0:
return True
else:
return False
def delete(table, chain=None, position=None, rule=None, family='ipv4'):
'''
Delete a rule from the specified table & chain, specifying either the rule
in its entirety, or the rule's position in the chain.
This function accepts a rule in a standard nftables command format,
starting with the chain. Trying to force users to adapt to a new
method of creating rules would be irritating at best, and we
already have a parser that can handle it.
CLI Examples:
.. code-block:: bash
salt '*' nftables.delete filter input position=3
salt '*' nftables.delete filter input \\
rule='input tcp dport 22 log accept'
IPv6:
salt '*' nftables.delete filter input position=3 family=ipv6
salt '*' nftables.delete filter input \\
rule='input tcp dport 22 log accept' \\
family=ipv6
'''
if position and rule:
return 'Error: Only specify a position or a rule, not both'
if not check_table(table, family=family):
return 'Error: table {0} in family {1} does not exist'.\
format(table, family)
if not check_chain(table, chain, family=family):
return 'Error: chain {0} in table {1} in family {1} does not exist'.\
format(chain, table, family)
if not check(table, chain, rule, family=family):
return 'Error: rule {0} chain {1} in table {2} in family {3} does not exist'.\
format(rule, chain, table, family)
# nftables rules can only be deleted using the handle
# if we don't have it, find it.
if not position:
position = get_rule_handle(table, chain, rule, family)
nft_family = _NFTABLES_FAMILIES[family]
cmd = '{0} delete rule {1} {2} {3} handle {4}'.\
format(_nftables_cmd(), nft_family, table, chain, position)
out = __salt__['cmd.run'](cmd)
if len(out) == 0:
return True
else:
return False
def flush(table='filter', chain='', family='ipv4'):
'''
Flush the chain in the specified table, flush all chains in the specified
table if chain is not specified.
CLI Example:
.. code-block:: bash
salt '*' nftables.flush filter
salt '*' nftables.flush filter input
IPv6:
salt '*' nftables.flush filter input family=ipv6
'''
if not check_table(table, family=family):
return 'Error: table {0} in family {1} does not exist'.\
format(table, family)
nft_family = _NFTABLES_FAMILIES[family]
if chain:
if not check_chain(table, chain, family=family):
return 'Error: chain {0} in table {1} in family {1} does not exist'.\
format(chain, table, nft_family)
cmd = '{0} flush chain {1} {2} {3}'.\
format(_nftables_cmd(), nft_family, table, chain)
else:
cmd = '{0} flush table {1} {2}'.\
format(_nftables_cmd(), nft_family, table)
out = __salt__['cmd.run'](cmd)
if len(out) == 0:
return True
else:
return False