#!/usr/bin/python # -*- coding: utf-8 -*- # Copyright: (c) 2015, Linus Unnebäck # Copyright: (c) 2017, Sébastien DA ROCHA # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt) from __future__ import absolute_import, division, print_function __metaclass__ = type ANSIBLE_METADATA = {'metadata_version': '1.1', 'status': ['preview'], 'supported_by': 'core'} DOCUMENTATION = r''' --- module: iptables short_description: Modify iptables rules version_added: "2.0" author: - Linus Unnebäck (@LinusU) - Sébastien DA ROCHA (@sebastiendarocha) description: - C(iptables) is used to set up, maintain, and inspect the tables of IP packet filter rules in the Linux kernel. - This module does not handle the saving and/or loading of rules, but rather only manipulates the current rules that are present in memory. This is the same as the behaviour of the C(iptables) and C(ip6tables) command which this module uses internally. notes: - This module just deals with individual rules.If you need advanced chaining of rules the recommended way is to template the iptables restore file. options: table: description: - This option specifies the packet matching table which the command should operate on. - If the kernel is configured with automatic module loading, an attempt will be made to load the appropriate module for that table if it is not already there. type: str choices: [ filter, nat, mangle, raw, security ] default: filter state: description: - Whether the rule should be absent or present. type: str choices: [ absent, present ] default: present action: description: - Whether the rule should be appended at the bottom or inserted at the top. - If the rule already exists the chain will not be modified. type: str choices: [ append, insert ] default: append version_added: "2.2" rule_num: description: - Insert the rule as the given rule number. - This works only with C(action=insert). type: str version_added: "2.5" ip_version: description: - Which version of the IP protocol this rule should apply to. type: str choices: [ ipv4, ipv6 ] default: ipv4 chain: description: - Specify the iptables chain to modify. - This could be a user-defined chain or one of the standard iptables chains, like C(INPUT), C(FORWARD), C(OUTPUT), C(PREROUTING), C(POSTROUTING), C(SECMARK) or C(CONNSECMARK). type: str protocol: description: - The protocol of the rule or of the packet to check. - The specified protocol can be one of C(tcp), C(udp), C(udplite), C(icmp), C(esp), C(ah), C(sctp) or the special keyword C(all), or it can be a numeric value, representing one of these protocols or a different one. - A protocol name from I(/etc/protocols) is also allowed. - A C(!) argument before the protocol inverts the test. - The number zero is equivalent to all. - C(all) will match with all protocols and is taken as default when this option is omitted. type: str source: description: - Source specification. - Address can be either a network name, a hostname, a network IP address (with /mask), or a plain IP address. - Hostnames will be resolved once only, before the rule is submitted to the kernel. Please note that specifying any name to be resolved with a remote query such as DNS is a really bad idea. - The mask can be either a network mask or a plain number, specifying the number of 1's at the left side of the network mask. Thus, a mask of 24 is equivalent to 255.255.255.0. A C(!) argument before the address specification inverts the sense of the address. type: str destination: description: - Destination specification. - Address can be either a network name, a hostname, a network IP address (with /mask), or a plain IP address. - Hostnames will be resolved once only, before the rule is submitted to the kernel. Please note that specifying any name to be resolved with a remote query such as DNS is a really bad idea. - The mask can be either a network mask or a plain number, specifying the number of 1's at the left side of the network mask. Thus, a mask of 24 is equivalent to 255.255.255.0. A C(!) argument before the address specification inverts the sense of the address. type: str tcp_flags: description: - TCP flags specification. - C(tcp_flags) expects a dict with the two keys C(flags) and C(flags_set). type: dict default: {} version_added: "2.4" suboptions: flags: description: - List of flags you want to examine. type: list flags_set: description: - Flags to be set. type: list match: description: - Specifies a match to use, that is, an extension module that tests for a specific property. - The set of matches make up the condition under which a target is invoked. - Matches are evaluated first to last if specified as an array and work in short-circuit fashion, i.e. if one extension yields false, evaluation will stop. type: list default: [] jump: description: - This specifies the target of the rule; i.e., what to do if the packet matches it. - The target can be a user-defined chain (other than the one this rule is in), one of the special builtin targets which decide the fate of the packet immediately, or an extension (see EXTENSIONS below). - If this option is omitted in a rule (and the goto parameter is not used), then matching the rule will have no effect on the packet's fate, but the counters on the rule will be incremented. type: str gateway: description: - This specifies the IP address of host to send the cloned packets. - This option is only valid when C(jump) is set to C(TEE). type: str version_added: "2.8" log_prefix: description: - Specifies a log text for the rule. Only make sense with a LOG jump. type: str version_added: "2.5" log_level: description: - Logging level according to the syslogd-defined priorities. - The value can be strings or numbers from 1-8. - This parameter is only applicable if C(jump) is set to C(LOG). type: str version_added: "2.8" choices: [ '0', '1', '2', '3', '4', '5', '6', '7', 'emerg', 'alert', 'crit', 'error', 'warning', 'notice', 'info', 'debug' ] goto: description: - This specifies that the processing should continue in a user specified chain. - Unlike the jump argument return will not continue processing in this chain but instead in the chain that called us via jump. type: str in_interface: description: - Name of an interface via which a packet was received (only for packets entering the C(INPUT), C(FORWARD) and C(PREROUTING) chains). - When the C(!) argument is used before the interface name, the sense is inverted. - If the interface name ends in a C(+), then any interface which begins with this name will match. - If this option is omitted, any interface name will match. type: str out_interface: description: - Name of an interface via which a packet is going to be sent (for packets entering the C(FORWARD), C(OUTPUT) and C(POSTROUTING) chains). - When the C(!) argument is used before the interface name, the sense is inverted. - If the interface name ends in a C(+), then any interface which begins with this name will match. - If this option is omitted, any interface name will match. type: str fragment: description: - This means that the rule only refers to second and further fragments of fragmented packets. - Since there is no way to tell the source or destination ports of such a packet (or ICMP type), such a packet will not match any rules which specify them. - When the "!" argument precedes fragment argument, the rule will only match head fragments, or unfragmented packets. type: str set_counters: description: - This enables the administrator to initialize the packet and byte counters of a rule (during C(INSERT), C(APPEND), C(REPLACE) operations). type: str source_port: description: - Source port or port range specification. - This can either be a service name or a port number. - An inclusive range can also be specified, using the format C(first:last). - If the first port is omitted, C(0) is assumed; if the last is omitted, C(65535) is assumed. - If the first port is greater than the second one they will be swapped. type: str destination_port: description: - "Destination port or port range specification. This can either be a service name or a port number. An inclusive range can also be specified, using the format first:last. If the first port is omitted, '0' is assumed; if the last is omitted, '65535' is assumed. If the first port is greater than the second one they will be swapped. This is only valid if the rule also specifies one of the following protocols: tcp, udp, dccp or sctp." type: str to_ports: description: - This specifies a destination port or range of ports to use, without this, the destination port is never altered. - This is only valid if the rule also specifies one of the protocol C(tcp), C(udp), C(dccp) or C(sctp). type: str to_destination: description: - This specifies a destination address to use with C(DNAT). - Without this, the destination address is never altered. type: str version_added: "2.1" to_source: description: - This specifies a source address to use with C(SNAT). - Without this, the source address is never altered. type: str version_added: "2.2" syn: description: - This allows matching packets that have the SYN bit set and the ACK and RST bits unset. - When negated, this matches all packets with the RST or the ACK bits set. type: str choices: [ ignore, match, negate ] default: ignore version_added: "2.5" set_dscp_mark: description: - This allows specifying a DSCP mark to be added to packets. It takes either an integer or hex value. - Mutually exclusive with C(set_dscp_mark_class). type: str version_added: "2.1" set_dscp_mark_class: description: - This allows specifying a predefined DiffServ class which will be translated to the corresponding DSCP mark. - Mutually exclusive with C(set_dscp_mark). type: str version_added: "2.1" comment: description: - This specifies a comment that will be added to the rule. type: str ctstate: description: - C(ctstate) is a list of the connection states to match in the conntrack module. - Possible states are C(INVALID), C(NEW), C(ESTABLISHED), C(RELATED), C(UNTRACKED), C(SNAT), C(DNAT) type: list default: [] src_range: description: - Specifies the source IP range to match in the iprange module. type: str version_added: "2.8" dst_range: description: - Specifies the destination IP range to match in the iprange module. type: str version_added: "2.8" limit: description: - Specifies the maximum average number of matches to allow per second. - The number can specify units explicitly, using `/second', `/minute', `/hour' or `/day', or parts of them (so `5/second' is the same as `5/s'). type: str limit_burst: description: - Specifies the maximum burst before the above limit kicks in. type: str version_added: "2.1" uid_owner: description: - Specifies the UID or username to use in match by owner rule. - From Ansible 2.6 when the C(!) argument is prepended then the it inverts the rule to apply instead to all users except that one specified. type: str version_added: "2.1" gid_owner: description: - Specifies the GID or group to use in match by owner rule. type: str version_added: "2.9" reject_with: description: - 'Specifies the error packet type to return while rejecting. It implies "jump: REJECT"' type: str version_added: "2.1" icmp_type: description: - This allows specification of the ICMP type, which can be a numeric ICMP type, type/code pair, or one of the ICMP type names shown by the command 'iptables -p icmp -h' type: str version_added: "2.2" flush: description: - Flushes the specified table and chain of all rules. - If no chain is specified then the entire table is purged. - Ignores all other parameters. type: bool version_added: "2.2" policy: description: - Set the policy for the chain to the given target. - Only built-in chains can have policies. - This parameter requires the C(chain) parameter. - Ignores all other parameters. type: str choices: [ ACCEPT, DROP, QUEUE, RETURN ] version_added: "2.2" wait: description: - Wait N seconds for the xtables lock to prevent multiple instances of the program from running concurrently. type: str version_added: "2.10" ''' EXAMPLES = r''' - name: Block specific IP iptables: chain: INPUT source: 8.8.8.8 jump: DROP become: yes - name: Forward port 80 to 8600 iptables: table: nat chain: PREROUTING in_interface: eth0 protocol: tcp match: tcp destination_port: 80 jump: REDIRECT to_ports: 8600 comment: Redirect web traffic to port 8600 become: yes - name: Allow related and established connections iptables: chain: INPUT ctstate: ESTABLISHED,RELATED jump: ACCEPT become: yes - name: Allow new incoming SYN packets on TCP port 22 (SSH). iptables: chain: INPUT protocol: tcp destination_port: 22 ctstate: NEW syn: match jump: ACCEPT comment: Accept new SSH connections. - name: Match on IP ranges iptables: chain: FORWARD src_range: 192.168.1.100-192.168.1.199 dst_range: 10.0.0.1-10.0.0.50 jump: ACCEPT - name: Tag all outbound tcp packets with DSCP mark 8 iptables: chain: OUTPUT jump: DSCP table: mangle set_dscp_mark: 8 protocol: tcp - name: Tag all outbound tcp packets with DSCP DiffServ class CS1 iptables: chain: OUTPUT jump: DSCP table: mangle set_dscp_mark_class: CS1 protocol: tcp - name: Insert a rule on line 5 iptables: chain: INPUT protocol: tcp destination_port: 8080 jump: ACCEPT action: insert rule_num: 5 - name: Set the policy for the INPUT chain to DROP iptables: chain: INPUT policy: DROP - name: Reject tcp with tcp-reset iptables: chain: INPUT protocol: tcp reject_with: tcp-reset ip_version: ipv4 - name: Set tcp flags iptables: chain: OUTPUT jump: DROP protocol: tcp tcp_flags: flags: ALL flags_set: - ACK - RST - SYN - FIN - name: iptables flush filter iptables: chain: "{{ item }}" flush: yes with_items: [ 'INPUT', 'FORWARD', 'OUTPUT' ] - name: iptables flush nat iptables: table: nat chain: '{{ item }}' flush: yes with_items: [ 'INPUT', 'OUTPUT', 'PREROUTING', 'POSTROUTING' ] - name: Log packets arriving into an user-defined chain iptables: chain: LOGGING action: append state: present limit: 2/second limit_burst: 20 log_prefix: "IPTABLES:INFO: " log_level: info ''' import re from distutils.version import LooseVersion from ansible.module_utils.basic import AnsibleModule IPTABLES_WAIT_SUPPORT_ADDED = '1.4.20' IPTABLES_WAIT_WITH_SECONDS_SUPPORT_ADDED = '1.6.0' BINS = dict( ipv4='iptables', ipv6='ip6tables', ) ICMP_TYPE_OPTIONS = dict( ipv4='--icmp-type', ipv6='--icmpv6-type', ) def append_param(rule, param, flag, is_list): if is_list: for item in param: append_param(rule, item, flag, False) else: if param is not None: if param[0] == '!': rule.extend(['!', flag, param[1:]]) else: rule.extend([flag, param]) def append_tcp_flags(rule, param, flag): if param: if 'flags' in param and 'flags_set' in param: rule.extend([flag, ','.join(param['flags']), ','.join(param['flags_set'])]) def append_match_flag(rule, param, flag, negatable): if param == 'match': rule.extend([flag]) elif negatable and param == 'negate': rule.extend(['!', flag]) def append_csv(rule, param, flag): if param: rule.extend([flag, ','.join(param)]) def append_match(rule, param, match): if param: rule.extend(['-m', match]) def append_jump(rule, param, jump): if param: rule.extend(['-j', jump]) def append_wait(rule, param, flag): if param: rule.extend([flag, param]) def construct_rule(params): rule = [] append_wait(rule, params['wait'], '-w') append_param(rule, params['protocol'], '-p', False) append_param(rule, params['source'], '-s', False) append_param(rule, params['destination'], '-d', False) append_param(rule, params['match'], '-m', True) append_tcp_flags(rule, params['tcp_flags'], '--tcp-flags') append_param(rule, params['jump'], '-j', False) if params.get('jump') and params['jump'].lower() == 'tee': append_param(rule, params['gateway'], '--gateway', False) append_param(rule, params['log_prefix'], '--log-prefix', False) append_param(rule, params['log_level'], '--log-level', False) append_param(rule, params['to_destination'], '--to-destination', False) append_param(rule, params['to_source'], '--to-source', False) append_param(rule, params['goto'], '-g', False) append_param(rule, params['in_interface'], '-i', False) append_param(rule, params['out_interface'], '-o', False) append_param(rule, params['fragment'], '-f', False) append_param(rule, params['set_counters'], '-c', False) append_param(rule, params['source_port'], '--source-port', False) append_param(rule, params['destination_port'], '--destination-port', False) append_param(rule, params['to_ports'], '--to-ports', False) append_param(rule, params['set_dscp_mark'], '--set-dscp', False) append_param( rule, params['set_dscp_mark_class'], '--set-dscp-class', False) append_match_flag(rule, params['syn'], '--syn', True) append_match(rule, params['comment'], 'comment') append_param(rule, params['comment'], '--comment', False) if 'conntrack' in params['match']: append_csv(rule, params['ctstate'], '--ctstate') elif 'state' in params['match']: append_csv(rule, params['ctstate'], '--state') elif params['ctstate']: append_match(rule, params['ctstate'], 'conntrack') append_csv(rule, params['ctstate'], '--ctstate') if 'iprange' in params['match']: append_param(rule, params['src_range'], '--src-range', False) append_param(rule, params['dst_range'], '--dst-range', False) elif params['src_range'] or params['dst_range']: append_match(rule, params['src_range'] or params['dst_range'], 'iprange') append_param(rule, params['src_range'], '--src-range', False) append_param(rule, params['dst_range'], '--dst-range', False) append_match(rule, params['limit'] or params['limit_burst'], 'limit') append_param(rule, params['limit'], '--limit', False) append_param(rule, params['limit_burst'], '--limit-burst', False) append_match(rule, params['uid_owner'], 'owner') append_match_flag(rule, params['uid_owner'], '--uid-owner', True) append_param(rule, params['uid_owner'], '--uid-owner', False) append_match(rule, params['gid_owner'], 'owner') append_match_flag(rule, params['gid_owner'], '--gid-owner', True) append_param(rule, params['gid_owner'], '--gid-owner', False) if params['jump'] is None: append_jump(rule, params['reject_with'], 'REJECT') append_param(rule, params['reject_with'], '--reject-with', False) append_param( rule, params['icmp_type'], ICMP_TYPE_OPTIONS[params['ip_version']], False) return rule def push_arguments(iptables_path, action, params, make_rule=True): cmd = [iptables_path] cmd.extend(['-t', params['table']]) cmd.extend([action, params['chain']]) if action == '-I' and params['rule_num']: cmd.extend([params['rule_num']]) if make_rule: cmd.extend(construct_rule(params)) return cmd def check_present(iptables_path, module, params): cmd = push_arguments(iptables_path, '-C', params) rc, _, __ = module.run_command(cmd, check_rc=False) return (rc == 0) def append_rule(iptables_path, module, params): cmd = push_arguments(iptables_path, '-A', params) module.run_command(cmd, check_rc=True) def insert_rule(iptables_path, module, params): cmd = push_arguments(iptables_path, '-I', params) module.run_command(cmd, check_rc=True) def remove_rule(iptables_path, module, params): cmd = push_arguments(iptables_path, '-D', params) module.run_command(cmd, check_rc=True) def flush_table(iptables_path, module, params): cmd = push_arguments(iptables_path, '-F', params, make_rule=False) module.run_command(cmd, check_rc=True) def set_chain_policy(iptables_path, module, params): cmd = push_arguments(iptables_path, '-P', params, make_rule=False) cmd.append(params['policy']) module.run_command(cmd, check_rc=True) def get_chain_policy(iptables_path, module, params): cmd = push_arguments(iptables_path, '-L', params) rc, out, _ = module.run_command(cmd, check_rc=True) chain_header = out.split("\n")[0] result = re.search(r'\(policy ([A-Z]+)\)', chain_header) if result: return result.group(1) return None def get_iptables_version(iptables_path, module): cmd = [iptables_path, '--version'] rc, out, _ = module.run_command(cmd, check_rc=True) return out.split('v')[1].rstrip('\n') def main(): module = AnsibleModule( supports_check_mode=True, argument_spec=dict( table=dict(type='str', default='filter', choices=['filter', 'nat', 'mangle', 'raw', 'security']), state=dict(type='str', default='present', choices=['absent', 'present']), action=dict(type='str', default='append', choices=['append', 'insert']), ip_version=dict(type='str', default='ipv4', choices=['ipv4', 'ipv6']), chain=dict(type='str'), rule_num=dict(type='str'), protocol=dict(type='str'), wait=dict(type='str'), source=dict(type='str'), to_source=dict(type='str'), destination=dict(type='str'), to_destination=dict(type='str'), match=dict(type='list', default=[]), tcp_flags=dict(type='dict', options=dict( flags=dict(type='list'), flags_set=dict(type='list')) ), jump=dict(type='str'), gateway=dict(type='str'), log_prefix=dict(type='str'), log_level=dict(type='str', choices=['0', '1', '2', '3', '4', '5', '6', '7', 'emerg', 'alert', 'crit', 'error', 'warning', 'notice', 'info', 'debug'], default=None, ), goto=dict(type='str'), in_interface=dict(type='str'), out_interface=dict(type='str'), fragment=dict(type='str'), set_counters=dict(type='str'), source_port=dict(type='str'), destination_port=dict(type='str'), to_ports=dict(type='str'), set_dscp_mark=dict(type='str'), set_dscp_mark_class=dict(type='str'), comment=dict(type='str'), ctstate=dict(type='list', default=[]), src_range=dict(type='str'), dst_range=dict(type='str'), limit=dict(type='str'), limit_burst=dict(type='str'), uid_owner=dict(type='str'), gid_owner=dict(type='str'), reject_with=dict(type='str'), icmp_type=dict(type='str'), syn=dict(type='str', default='ignore', choices=['ignore', 'match', 'negate']), flush=dict(type='bool', default=False), policy=dict(type='str', choices=['ACCEPT', 'DROP', 'QUEUE', 'RETURN']), ), mutually_exclusive=( ['set_dscp_mark', 'set_dscp_mark_class'], ['flush', 'policy'], ), required_if=[ ['jump', 'TEE', ['gateway']], ['jump', 'tee', ['gateway']], ] ) args = dict( changed=False, failed=False, ip_version=module.params['ip_version'], table=module.params['table'], chain=module.params['chain'], flush=module.params['flush'], rule=' '.join(construct_rule(module.params)), state=module.params['state'], ) ip_version = module.params['ip_version'] iptables_path = module.get_bin_path(BINS[ip_version], True) # Check if chain option is required if args['flush'] is False and args['chain'] is None: module.fail_json(msg="Either chain or flush parameter must be specified.") if module.params.get('log_prefix', None) or module.params.get('log_level', None): if module.params['jump'] is None: module.params['jump'] = 'LOG' elif module.params['jump'] != 'LOG': module.fail_json(msg="Logging options can only be used with the LOG jump target.") # Check if wait option is supported iptables_version = LooseVersion(get_iptables_version(iptables_path, module)) if iptables_version >= LooseVersion(IPTABLES_WAIT_SUPPORT_ADDED): if iptables_version < LooseVersion(IPTABLES_WAIT_WITH_SECONDS_SUPPORT_ADDED): module.params['wait'] = '' else: module.params['wait'] = None # Flush the table if args['flush'] is True: args['changed'] = True if not module.check_mode: flush_table(iptables_path, module, module.params) # Set the policy elif module.params['policy']: current_policy = get_chain_policy(iptables_path, module, module.params) if not current_policy: module.fail_json(msg='Can\'t detect current policy') changed = current_policy != module.params['policy'] args['changed'] = changed if changed and not module.check_mode: set_chain_policy(iptables_path, module, module.params) else: insert = (module.params['action'] == 'insert') rule_is_present = check_present(iptables_path, module, module.params) should_be_present = (args['state'] == 'present') # Check if target is up to date args['changed'] = (rule_is_present != should_be_present) if args['changed'] is False: # Target is already up to date module.exit_json(**args) # Check only; don't modify if not module.check_mode: if should_be_present: if insert: insert_rule(iptables_path, module, module.params) else: append_rule(iptables_path, module, module.params) else: remove_rule(iptables_path, module, module.params) module.exit_json(**args) if __name__ == '__main__': main()