#!/usr/bin/python
# -*- coding: utf-8 -*-

# Copyright (c) 2014, Dan Keder <dan.keder@gmail.com>
# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
# SPDX-License-Identifier: GPL-3.0-or-later

from __future__ import absolute_import, division, print_function
__metaclass__ = type

DOCUMENTATION = r'''
---
module: seport
short_description: Manages SELinux network port type definitions
description:
    - Manages SELinux network port type definitions.
extends_documentation_fragment:
    - community.general.attributes
attributes:
  check_mode:
    support: full
  diff_mode:
    support: none
options:
  ports:
    description:
      - Ports or port ranges.
      - Can be a list (since 2.6) or comma separated string.
    type: list
    elements: str
    required: true
  proto:
    description:
      - Protocol for the specified port.
    type: str
    required: true
    choices: [ tcp, udp ]
  setype:
    description:
      - SELinux type for the specified port.
    type: str
    required: true
  state:
    description:
      - Desired boolean value.
    type: str
    choices: [ absent, present ]
    default: present
  reload:
    description:
      - Reload SELinux policy after commit.
    type: bool
    default: true
  ignore_selinux_state:
    description:
    - Run independent of selinux runtime state
    type: bool
    default: false
  local:
    description:
    - Work with local modifications only.
    type: bool
    default: false
    version_added: 5.6.0
notes:
   - The changes are persistent across reboots.
   - Not tested on any debian based system.
requirements:
- libselinux-python
- policycoreutils-python
author:
- Dan Keder (@dankeder)
'''

EXAMPLES = r'''
- name: Allow Apache to listen on tcp port 8888
  community.general.seport:
    ports: 8888
    proto: tcp
    setype: http_port_t
    state: present

- name: Allow sshd to listen on tcp port 8991
  community.general.seport:
    ports: 8991
    proto: tcp
    setype: ssh_port_t
    state: present

- name: Allow memcached to listen on tcp ports 10000-10100 and 10112
  community.general.seport:
    ports: 10000-10100,10112
    proto: tcp
    setype: memcache_port_t
    state: present

- name: Allow memcached to listen on tcp ports 10000-10100 and 10112
  community.general.seport:
    ports:
      - 10000-10100
      - 10112
    proto: tcp
    setype: memcache_port_t
    state: present

- name: Remove tcp port 22 local modification if exists
  community.general.seport:
    ports: 22
    protocol: tcp
    setype: ssh_port_t
    state: absent
    local: true
'''

import traceback

SELINUX_IMP_ERR = None
try:
    import selinux
    HAVE_SELINUX = True
except ImportError:
    SELINUX_IMP_ERR = traceback.format_exc()
    HAVE_SELINUX = False

SEOBJECT_IMP_ERR = None
try:
    import seobject
    HAVE_SEOBJECT = True
except ImportError:
    SEOBJECT_IMP_ERR = traceback.format_exc()
    HAVE_SEOBJECT = False

from ansible.module_utils.basic import AnsibleModule, missing_required_lib
from ansible.module_utils.common.text.converters import to_native


def get_runtime_status(ignore_selinux_state=False):
    return ignore_selinux_state or selinux.is_selinux_enabled()


def semanage_port_get_ports(seport, setype, proto, local):
    """ Get the list of ports that have the specified type definition.

    :param community.general.seport: Instance of seobject.portRecords

    :type setype: str
    :param setype: SELinux type.

    :type proto: str
    :param proto: Protocol ('tcp' or 'udp')

    :rtype: list
    :return: List of ports that have the specified SELinux type.
    """
    records = seport.get_all_by_type(locallist=local)
    if (setype, proto) in records:
        return records[(setype, proto)]
    else:
        return []


def semanage_port_get_type(seport, port, proto):
    """ Get the SELinux type of the specified port.

    :param community.general.seport: Instance of seobject.portRecords

    :type port: str
    :param port: Port or port range (example: "8080", "8080-9090")

    :type proto: str
    :param proto: Protocol ('tcp' or 'udp')

    :rtype: tuple
    :return: Tuple containing the SELinux type and MLS/MCS level, or None if not found.
    """
    if isinstance(port, str):
        ports = port.split('-', 1)
        if len(ports) == 1:
            ports.extend(ports)
    else:
        ports = (port, port)

    key = (int(ports[0]), int(ports[1]), proto)

    records = seport.get_all()
    return records.get(key)


def semanage_port_add(module, ports, proto, setype, do_reload, serange='s0', sestore='', local=False):
    """ Add SELinux port type definition to the policy.

    :type module: AnsibleModule
    :param module: Ansible module

    :type ports: list
    :param ports: List of ports and port ranges to add (e.g. ["8080", "8080-9090"])

    :type proto: str
    :param proto: Protocol ('tcp' or 'udp')

    :type setype: str
    :param setype: SELinux type

    :type do_reload: bool
    :param do_reload: Whether to reload SELinux policy after commit

    :type serange: str
    :param serange: SELinux MLS/MCS range (defaults to 's0')

    :type sestore: str
    :param sestore: SELinux store

    :rtype: bool
    :return: True if the policy was changed, otherwise False
    """
    change = False
    try:
        seport = seobject.portRecords(sestore)
        seport.set_reload(do_reload)
        ports_by_type = semanage_port_get_ports(seport, setype, proto, local)
        for port in ports:
            if port in ports_by_type:
                continue

            change = True
            if module.check_mode:
                continue
            port_type = semanage_port_get_type(seport, port, proto)
            if port_type is None:
                seport.add(port, proto, serange, setype)
            else:
                seport.modify(port, proto, serange, setype)

    except (ValueError, IOError, KeyError, OSError, RuntimeError) as e:
        module.fail_json(msg="%s: %s\n" % (e.__class__.__name__, to_native(e)), exception=traceback.format_exc())

    return change


def semanage_port_del(module, ports, proto, setype, do_reload, sestore='', local=False):
    """ Delete SELinux port type definition from the policy.

    :type module: AnsibleModule
    :param module: Ansible module

    :type ports: list
    :param ports: List of ports and port ranges to delete (e.g. ["8080", "8080-9090"])

    :type proto: str
    :param proto: Protocol ('tcp' or 'udp')

    :type setype: str
    :param setype: SELinux type.

    :type do_reload: bool
    :param do_reload: Whether to reload SELinux policy after commit

    :type sestore: str
    :param sestore: SELinux store

    :rtype: bool
    :return: True if the policy was changed, otherwise False
    """
    change = False
    try:
        seport = seobject.portRecords(sestore)
        seport.set_reload(do_reload)
        ports_by_type = semanage_port_get_ports(seport, setype, proto, local)
        for port in ports:
            if port in ports_by_type:
                change = True
                if not module.check_mode:
                    seport.delete(port, proto)

    except (ValueError, IOError, KeyError, OSError, RuntimeError) as e:
        module.fail_json(msg="%s: %s\n" % (e.__class__.__name__, to_native(e)), exception=traceback.format_exc())

    return change


def main():
    module = AnsibleModule(
        argument_spec=dict(
            ignore_selinux_state=dict(type='bool', default=False),
            ports=dict(type='list', elements='str', required=True),
            proto=dict(type='str', required=True, choices=['tcp', 'udp']),
            setype=dict(type='str', required=True),
            state=dict(type='str', default='present', choices=['absent', 'present']),
            reload=dict(type='bool', default=True),
            local=dict(type='bool', default=False)
        ),
        supports_check_mode=True,
    )

    if not HAVE_SELINUX:
        module.fail_json(msg=missing_required_lib("libselinux-python"), exception=SELINUX_IMP_ERR)

    if not HAVE_SEOBJECT:
        module.fail_json(msg=missing_required_lib("policycoreutils-python"), exception=SEOBJECT_IMP_ERR)

    ignore_selinux_state = module.params['ignore_selinux_state']

    if not get_runtime_status(ignore_selinux_state):
        module.fail_json(msg="SELinux is disabled on this host.")

    ports = module.params['ports']
    proto = module.params['proto']
    setype = module.params['setype']
    state = module.params['state']
    do_reload = module.params['reload']
    local = module.params['local']

    result = {
        'ports': ports,
        'proto': proto,
        'setype': setype,
        'state': state,
    }

    if state == 'present':
        result['changed'] = semanage_port_add(module, ports, proto, setype, do_reload, local=local)
    elif state == 'absent':
        result['changed'] = semanage_port_del(module, ports, proto, setype, do_reload, local=local)
    else:
        module.fail_json(msg='Invalid value of argument "state": {0}'.format(state))

    module.exit_json(**result)


if __name__ == '__main__':
    main()
