# SPDX-License-Identifier: GPL-2.0-or-later
#
# Copyright (C) 2007,2008,2011,2012 Red Hat, Inc.
#
# Authors:
# Thomas Woerner <twoerner@redhat.com>

import socket
import os
import os.path
import shlex
import string
import tempfile
from firewall.core.logger import log
from firewall.config import FIREWALLD_TEMPDIR, FIREWALLD_PIDFILE

NOPRINT_TRANS_TABLE = {
    # Limit to C0 and C1 code points. Building entries for all unicode code
    # points requires too much memory.
    # C0 = [0, 31]
    # C1 = [127, 159]
    #
    i: None
    for i in range(0, 160)
    if not (i > 31 and i < 127)
}


def getPortID(port):
    """Check and Get port id from port string or port id using socket.getservbyname

    @param port port string or port id
    @return Port id if valid, -1 if port can not be found and -2 if port is too big
    """

    if isinstance(port, int):
        _id = port
    else:
        if port:
            port = port.strip()
        try:
            _id = int(port)
        except ValueError:
            try:
                _id = socket.getservbyname(port)
            except socket.error:
                return -1
    if _id > 65535:
        return -2
    return _id


def getPortRange(ports):
    """Get port range for port range string or single port id

    @param ports an integer or port string or port range string
    @return Array containing start and end port id for a valid range or -1 if port can not be found and -2 if port is too big for integer input or -1 for invalid ranges or None if the range is ambiguous.
    """

    # (port, port)  or [port, port] case
    if isinstance(ports, tuple) or isinstance(ports, list):
        return ports

    # "<port-id>" case
    if isinstance(ports, int) or ports.isdigit():
        id1 = getPortID(ports)
        if id1 >= 0:
            return (id1,)
        return id1

    splits = ports.split("-")

    # "<port-id>-<port-id>" case
    if len(splits) == 2 and splits[0].isdigit() and splits[1].isdigit():
        id1 = getPortID(splits[0])
        id2 = getPortID(splits[1])
        if id1 >= 0 and id2 >= 0:
            if id1 < id2:
                return (id1, id2)
            elif id1 > id2:
                return (id2, id1)
            else:  # ids are the same
                return (id1,)

    # everything else "<port-str>[-<port-str>]"
    matched = []
    for i in range(len(splits), 0, -1):
        id1 = getPortID("-".join(splits[:i]))
        port2 = "-".join(splits[i:])
        if len(port2) > 0:
            id2 = getPortID(port2)
            if id1 >= 0 and id2 >= 0:
                if id1 < id2:
                    matched.append((id1, id2))
                elif id1 > id2:
                    matched.append((id2, id1))
                else:
                    matched.append((id1,))
        else:
            if id1 >= 0:
                matched.append((id1,))
                if i == len(splits):
                    # full match, stop here
                    break
    if len(matched) < 1:
        return -1
    elif len(matched) > 1:
        return None
    return matched[0]


def portStr(port, delimiter=":"):
    """Create port and port range string

    @param port port or port range int or [int, int]
    @param delimiter of the output string for port ranges, default ':'
    @return Port or port range string, empty string if port isn't specified, None if port or port range is not valid
    """
    if port == "":
        return ""

    _range = getPortRange(port)
    if isinstance(_range, int) and _range < 0:
        return None
    elif len(_range) == 1:
        return "%s" % _range
    else:
        return "%s%s%s" % (_range[0], delimiter, _range[1])


def portInPortRange(port, range):
    _port = getPortRange(port)
    _range = getPortRange(range)

    if len(_port) == 1:
        if len(_range) == 1:
            return getPortID(_port[0]) == getPortID(_range[0])
        if (
            len(_range) == 2
            and getPortID(_port[0]) >= getPortID(_range[0])
            and getPortID(_port[0]) <= getPortID(_range[1])
        ):
            return True
    elif len(_port) == 2:
        if (
            len(_range) == 2
            and getPortID(_port[0]) >= getPortID(_range[0])
            and getPortID(_port[0]) <= getPortID(_range[1])
            and getPortID(_port[1]) >= getPortID(_range[0])
            and getPortID(_port[1]) <= getPortID(_range[1])
        ):
            return True

    return False


def coalescePortRange(new_range, ranges):
    """Coalesce a port range with existing list of port ranges

    @param new_range tuple/list/string
    @param ranges list of tuple/list/string
    @return tuple of (list of ranges added after coalescing, list of removed original ranges)
    """

    coalesced_range = getPortRange(new_range)
    # normalize singleton ranges, e.g. (x,) --> (x,x)
    if len(coalesced_range) == 1:
        coalesced_range = (coalesced_range[0], coalesced_range[0])
    _ranges = map(getPortRange, ranges)
    _ranges = sorted(
        map(lambda x: (x[0], x[0]) if len(x) == 1 else x, _ranges), key=lambda x: x[0]
    )

    removed_ranges = []
    for range in _ranges:
        if coalesced_range[0] <= range[0] and coalesced_range[1] >= range[1]:
            # new range covers this
            removed_ranges.append(range)
        elif (
            coalesced_range[0] <= range[0]
            and coalesced_range[1] < range[1]
            and coalesced_range[1] >= range[0]
        ):
            # expand beginning of range
            removed_ranges.append(range)
            coalesced_range = (coalesced_range[0], range[1])
        elif (
            coalesced_range[0] > range[0]
            and coalesced_range[1] >= range[1]
            and coalesced_range[0] <= range[1]
        ):
            # expand end of range
            removed_ranges.append(range)
            coalesced_range = (range[0], coalesced_range[1])

    # normalize singleton ranges, e.g. (x,x) --> (x,)
    removed_ranges = list(map(lambda x: (x[0],) if x[0] == x[1] else x, removed_ranges))
    if coalesced_range[0] == coalesced_range[1]:
        coalesced_range = (coalesced_range[0],)

    return ([coalesced_range], removed_ranges)


def breakPortRange(remove_range, ranges):
    """break a port range from existing list of port ranges

    @param remove_range tuple/list/string
    @param ranges list of tuple/list/string
    @return tuple of (list of ranges added after breaking up, list of removed original ranges)
    """

    remove_range = getPortRange(remove_range)
    # normalize singleton ranges, e.g. (x,) --> (x,x)
    if len(remove_range) == 1:
        remove_range = (remove_range[0], remove_range[0])
    _ranges = map(getPortRange, ranges)
    _ranges = sorted(
        map(lambda x: (x[0], x[0]) if len(x) == 1 else x, _ranges), key=lambda x: x[0]
    )

    removed_ranges = []
    added_ranges = []
    for range in _ranges:
        if remove_range[0] <= range[0] and remove_range[1] >= range[1]:
            # remove entire range
            removed_ranges.append(range)
        elif (
            remove_range[0] <= range[0]
            and remove_range[1] < range[1]
            and remove_range[1] >= range[0]
        ):
            # remove from beginning of range
            removed_ranges.append(range)
            added_ranges.append((remove_range[1] + 1, range[1]))
        elif (
            remove_range[0] > range[0]
            and remove_range[1] >= range[1]
            and remove_range[0] <= range[1]
        ):
            # remove from end of range
            removed_ranges.append(range)
            added_ranges.append((range[0], remove_range[0] - 1))
        elif remove_range[0] > range[0] and remove_range[1] < range[1]:
            # remove inside range
            removed_ranges.append(range)
            added_ranges.append((range[0], remove_range[0] - 1))
            added_ranges.append((remove_range[1] + 1, range[1]))

    # normalize singleton ranges, e.g. (x,x) --> (x,)
    removed_ranges = list(map(lambda x: (x[0],) if x[0] == x[1] else x, removed_ranges))
    added_ranges = list(map(lambda x: (x[0],) if x[0] == x[1] else x, added_ranges))

    return (added_ranges, removed_ranges)


def getServiceName(port, proto):
    """Check and Get service name from port and proto string combination using socket.getservbyport

    @param port string or id
    @param protocol string
    @return Service name if port and protocol are valid, else None
    """

    try:
        name = socket.getservbyport(int(port), proto)
    except socket.error:
        return None
    return name


def checkIP(ip):
    """Check IPv4 address.

    @param ip address string
    @return True if address is valid, else False
    """

    try:
        socket.inet_pton(socket.AF_INET, ip)
    except socket.error:
        return False
    return True


def normalizeIP6(ip):
    """Normalize the IPv6 address

    This is mostly about converting URL-like IPv6 address to normal ones.
    e.g. [1234::4321] --> 1234:4321
    """
    return ip.strip("[]")


def checkIP6(ip):
    """Check IPv6 address.

    @param ip address string
    @return True if address is valid, else False
    """

    try:
        socket.inet_pton(socket.AF_INET6, normalizeIP6(ip))
    except socket.error:
        return False
    return True


def checkIPnMask(ip):
    index = ip.find("/")
    if index != -1:
        addr = ip[:index]
        mask = ip[index + 1 :]
        if not addr or not mask:
            return False
    else:
        addr = ip
        mask = None
    if not checkIP(addr):
        return False
    if mask:
        if "." in mask:
            return checkIP(mask)
        else:
            try:
                i = int(mask)
            except ValueError:
                return False
            if i < 0 or i > 32:
                return False
    return True


def stripNonPrintableCharacters(rule_str):
    return rule_str.translate(NOPRINT_TRANS_TABLE)


def checkIP6nMask(ip):
    index = ip.find("/")
    if index != -1:
        addr = ip[:index]
        mask = ip[index + 1 :]
        if not addr or not mask:
            return False
    else:
        addr = ip
        mask = None
    if not checkIP6(addr):
        return False
    if mask:
        try:
            i = int(mask)
        except ValueError:
            return False
        if i < 0 or i > 128:
            return False

    return True


def checkProtocol(protocol):
    try:
        i = int(protocol)
    except ValueError:
        # string
        try:
            socket.getprotobyname(protocol)
        except socket.error:
            return False
    else:
        if i < 0 or i > 255:
            return False

    return True


def checkTcpMssClamp(tcp_mss_clamp_value):
    if tcp_mss_clamp_value:
        if tcp_mss_clamp_value.isdigit():
            if int(tcp_mss_clamp_value) < 536:
                return False
        elif tcp_mss_clamp_value == "None":
            return True
        elif tcp_mss_clamp_value != "pmtu":
            return False
    return True


def checkInterface(iface):
    """Check interface string

    @param interface string
    @return True if interface is valid (maximum 16 chars and does not contain ' ', '/', '!', ':', '*'), else False
    """

    if not iface or len(iface) > 16:
        return False
    for ch in [" ", "/", "!", "*"]:
        # !:* are limits for iptables <= 1.4.5
        if ch in iface:
            return False
    # disabled old iptables check
    # if iface == "+":
    #    # limit for iptables <= 1.4.5
    #    return False
    return True


def checkUINT16(val):
    try:
        x = int(val, 0)
    except ValueError:
        return False
    else:
        if x >= 0 and x <= 65535:
            return True
    return False


def checkUINT32(val):
    try:
        x = int(val, 0)
    except ValueError:
        return False
    else:
        if x >= 0 and x <= 4294967295:
            return True
    return False


def firewalld_is_active():
    """Check if firewalld is active

    @return True if there is a firewalld pid file and the pid is used by firewalld
    """

    if not os.path.exists(FIREWALLD_PIDFILE):
        return False

    try:
        with open(FIREWALLD_PIDFILE, "r") as fd:
            pid = fd.readline()
    except Exception:
        return False

    if not os.path.exists("/proc/%s" % pid):
        return False

    try:
        with open("/proc/%s/cmdline" % pid, "r") as fd:
            cmdline = fd.readline()
    except Exception:
        return False

    if "firewalld" in cmdline:
        return True

    return False


def tempFile():
    try:
        if not os.path.exists(FIREWALLD_TEMPDIR):
            os.mkdir(FIREWALLD_TEMPDIR, 0o750)

        return tempfile.NamedTemporaryFile(
            mode="wt", prefix="temp.", dir=FIREWALLD_TEMPDIR, delete=False
        )
    except Exception as msg:
        log.error("Failed to create temporary file: %s" % msg)
        raise


def readfile(filename):
    try:
        with open(filename, "r") as f:
            return f.readlines()
    except Exception as e:
        log.error('Failed to read file "%s": %s' % (filename, e))
    return None


def writefile(filename, line):
    try:
        with open(filename, "w") as f:
            f.write(line)
    except Exception as e:
        log.error('Failed to write to file "%s": %s' % (filename, e))
        return False
    return True


def enable_ip_forwarding(ipv):
    if ipv == "ipv4":
        return writefile("/proc/sys/net/ipv4/ip_forward", "1\n")
    elif ipv == "ipv6":
        return writefile("/proc/sys/net/ipv6/conf/all/forwarding", "1\n")
    return False


def get_nf_conntrack_short_name(module):
    return module.replace("_", "-").replace("nf-conntrack-", "")


def check_port(port):
    _range = getPortRange(port)
    if (
        _range == -2
        or _range == -1
        or _range is None
        or (len(_range) == 2 and _range[0] >= _range[1])
    ):
        if _range == -2:
            log.debug2("'%s': port > 65535" % port)
        elif _range == -1:
            log.debug2("'%s': port is invalid" % port)
        elif _range is None:
            log.debug2("'%s': port is ambiguous" % port)
        elif len(_range) == 2 and _range[0] >= _range[1]:
            log.debug2("'%s': range start >= end" % port)
        return False
    return True


def check_address(ipv, source):
    if ipv == "ipv4":
        return checkIPnMask(source)
    elif ipv == "ipv6":
        return checkIP6nMask(source)
    else:
        return False


def check_single_address(ipv, source):
    if ipv == "ipv4":
        return checkIP(source)
    elif ipv == "ipv6":
        return checkIP6(source)
    else:
        return False


def check_mac(mac):
    if len(mac) == 12 + 5:
        # 0 1 : 3 4 : 6 7 : 9 10 : 12 13 : 15 16
        for i in (2, 5, 8, 11, 14):
            if mac[i] != ":":
                return False
        for i in (0, 1, 3, 4, 6, 7, 9, 10, 12, 13, 15, 16):
            if mac[i] not in string.hexdigits:
                return False
        return True
    return False


def uniqify(_list):
    # removes duplicates from list, whilst preserving order
    output = []
    for x in _list:
        if x not in output:
            output.append(x)
    return output


def ppid_of_pid(pid):
    """Get parent for pid"""
    try:
        f = os.popen("ps -o ppid -h -p %d 2>/dev/null" % pid)
        pid = int(f.readlines()[0].strip())
        f.close()
    except Exception:
        return None
    return pid


def max_policy_name_len():
    """
    iptables limits length of chain to (currently) 28 chars.
    The longest chain we create is POST_<policy>_allow,
    which leaves 28 - 11 = 17 chars for <policy>.
    """
    from firewall.core.ipXtables import POLICY_CHAIN_PREFIX
    from firewall.core.base import SHORTCUTS

    longest_shortcut = max(map(len, SHORTCUTS.values()))
    return 28 - (longest_shortcut + len(POLICY_CHAIN_PREFIX) + len("_allow"))


def max_zone_name_len():
    """
    Netfilter limits length of chain to (currently) 28 chars.
    The longest chain we create is POST_<zone>_allow,
    which leaves 28 - 11 = 17 chars for <zone>.
    """
    from firewall.core.base import SHORTCUTS

    longest_shortcut = max(map(len, SHORTCUTS.values()))
    return 28 - (longest_shortcut + len("__allow"))


def checkUser(user):
    if len(user) < 1 or len(user) > os.sysconf("SC_LOGIN_NAME_MAX"):
        return False
    for c in user:
        if (
            c not in string.ascii_letters
            and c not in string.digits
            and c not in [".", "-", "_", "$"]
        ):
            return False
    return True


def checkUid(uid):
    if isinstance(uid, str):
        try:
            uid = int(uid)
        except ValueError:
            return False
    if uid >= 0 and uid <= 2**31 - 1:
        return True
    return False


def checkCommand(command):
    if len(command) < 1 or len(command) > 1024:
        return False
    for ch in ["|", "\n", "\0"]:
        if ch in command:
            return False
    if command[0] != "/":
        return False
    return True


def checkContext(context):
    splits = context.split(":")
    if len(splits) not in [4, 5]:
        return False
    # user ends with _u if not root
    if splits[0] != "root" and splits[0][-2:] != "_u":
        return False
    # role ends with _r
    if splits[1][-2:] != "_r":
        return False
    # type ends with _t
    if splits[2][-2:] != "_t":
        return False
    # level might also contain :
    if len(splits[3]) < 1:
        return False
    return True


def joinArgs(args):
    return " ".join(shlex.quote(a) for a in args)


def splitArgs(_string):
    return shlex.split(_string)


def wrong_args_for_callable(fcn, *a, **kw):
    import inspect

    # Check whether fcn(*a, **kw) will fail due to invalid
    # arguments.

    sig = inspect.signature(fcn)

    try:
        sig.bind(*a, **kw)
    except TypeError:
        return False
    return True
