"""
A few checks to make sure the environment is sane
"""

import errno
import itertools
import logging
import os
import re
import socket
import stat
import sys

import salt.defaults.exitcodes
import salt.utils.files
import salt.utils.path
import salt.utils.platform
import salt.utils.user
from salt._logging import LOG_LEVELS
from salt.exceptions import CommandExecutionError, SaltClientError, SaltSystemExit

# Original Author: Jeff Schroeder <jeffschroeder@computer.org>


try:
    import win32file
    import salt.utils.win_reg
except ImportError:
    import resource

log = logging.getLogger(__name__)

ROOT_DIR = "c:\\salt" if salt.utils.platform.is_windows() else "/"
DEFAULT_SCHEMES = ["tcp://", "udp://", "file://"]


def zmq_version():
    """
    ZeroMQ python bindings >= 2.1.9 are required
    """
    try:
        import zmq
    except Exception:  # pylint: disable=broad-except
        # Return True for local mode
        return True
    ver = zmq.__version__
    # The last matched group can be None if the version
    # is something like 3.1 and that will work properly
    match = re.match(r"^(\d+)\.(\d+)(?:\.(\d+))?", ver)

    # Fallthrough and hope for the best
    if not match:
        log.warning("Using untested zmq python bindings version: '%s'", ver)
        return True

    major, minor, point = match.groups()

    if major.isdigit():
        major = int(major)
    if minor.isdigit():
        minor = int(minor)

    # point very well could be None
    if point and point.isdigit():
        point = int(point)

    if major == 2 and minor == 1:
        # zmq 2.1dev could be built against a newer libzmq
        if "dev" in ver and not point:
            log.warning("Using dev zmq module, please report unexpected results")
            return True
        elif point and point >= 9:
            return True
    elif major > 2 or (major == 2 and minor > 1):
        return True

    # If all else fails, gracefully croak and warn the user
    log.critical("ZeroMQ python bindings >= 2.1.9 are required")
    if "salt-master" in sys.argv[0]:
        log.critical(
            "The Salt Master is unstable using a ZeroMQ version "
            "lower than 2.1.11 and requires this fix: http://lists.zeromq."
            "org/pipermail/zeromq-dev/2011-June/012094.html"
        )
    return False


def lookup_family(hostname):
    """
    Lookup a hostname and determine its address family. The first address returned
    will be AF_INET6 if the system is IPv6-enabled, and AF_INET otherwise.
    """
    # If lookups fail, fall back to AF_INET sockets (and v4 addresses).
    fallback = socket.AF_INET
    try:
        hostnames = socket.getaddrinfo(
            hostname or None, None, socket.AF_UNSPEC, socket.SOCK_STREAM
        )
        if not hostnames:
            return fallback
        h = hostnames[0]
        return h[0]
    except socket.gaierror:
        return fallback


def verify_socket(interface, pub_port, ret_port):
    """
    Attempt to bind to the sockets to verify that they are available
    """

    addr_family = lookup_family(interface)
    for port in pub_port, ret_port:
        sock = socket.socket(addr_family, socket.SOCK_STREAM)
        try:
            sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
            sock.bind((interface, int(port)))
        except Exception as exc:  # pylint: disable=broad-except
            msg = "Unable to bind socket {}:{}".format(interface, port)
            if exc.args:
                msg = "{}, error: {}".format(msg, str(exc))
            else:
                msg = "{}, this might not be a problem.".format(msg)
            msg += "; Is there another salt-master running?"
            log.warning(msg)
            return False
        finally:
            sock.close()

    return True


def verify_logs_filter(files):
    """
    Filter files to verify.
    """
    to_verify = []
    for filename in files:
        verify_file = True
        for scheme in DEFAULT_SCHEMES:
            if filename.startswith(scheme):
                verify_file = False
                break
        if verify_file:
            to_verify.append(filename)
    return to_verify


def verify_log_files(files, user):
    """
    Verify the log files exist and are owned by the named user.  Filenames that
    begin with tcp:// and udp:// will be filtered out. Filenames that begin
    with file:// are handled correctly
    """
    return verify_files(verify_logs_filter(files), user)


def _get_pwnam(user):
    """
    Get the user from passwords database
    """
    if salt.utils.platform.is_windows():
        return True
    import pwd  # after confirming not running Windows

    try:
        return pwd.getpwnam(user)
    except KeyError:
        print(
            "Failed to prepare the Salt environment for user {}. "
            "The user is not available.".format(user),
            file=sys.stderr,
            flush=True,
        )
        sys.exit(salt.defaults.exitcodes.EX_NOUSER)


def verify_files(files, user):
    """
    Verify that the named files exist and are owned by the named user
    """
    if salt.utils.platform.is_windows():
        return True

    # after confirming not running Windows
    pwnam = _get_pwnam(user)
    uid = pwnam[2]

    for fn_ in files:
        dirname = os.path.dirname(fn_)
        try:
            if dirname:
                try:
                    os.makedirs(dirname)
                except OSError as err:
                    if err.errno != errno.EEXIST:
                        raise
            if not os.path.isfile(fn_):
                with salt.utils.files.fopen(fn_, "w"):
                    pass

        except OSError as err:
            if os.path.isfile(dirname):
                msg = "Failed to create path {}, is {} a file?".format(fn_, dirname)
                raise SaltSystemExit(msg=msg)
            if err.errno != errno.EACCES:
                raise
            msg = 'No permissions to access "{}", are you running as the correct user?'.format(
                fn_
            )
            raise SaltSystemExit(msg=msg)

        except OSError as err:  # pylint: disable=duplicate-except
            msg = 'Failed to create path "{}" - {}'.format(fn_, err)
            raise SaltSystemExit(msg=msg)

        stats = os.stat(fn_)
        if uid != stats.st_uid:
            try:
                os.chown(fn_, uid, -1)
            except OSError:
                pass
    return True


def verify_env(
    dirs, user, permissive=False, pki_dir="", skip_extra=False, root_dir=ROOT_DIR
):
    """
    Verify that the named directories are in place and that the environment
    can shake the salt
    """
    if salt.utils.platform.is_windows():
        return win_verify_env(
            root_dir, dirs, permissive=permissive, skip_extra=skip_extra
        )

    # after confirming not running Windows
    pwnam = _get_pwnam(user)
    uid = pwnam[2]
    gid = pwnam[3]
    groups = salt.utils.user.get_gid_list(user, include_default=False)

    for dir_ in dirs:
        if not dir_:
            continue
        if not os.path.isdir(dir_):
            try:
                with salt.utils.files.set_umask(0o022):
                    os.makedirs(dir_)
                # If starting the process as root, chown the new dirs
                if os.getuid() == 0:
                    os.chown(dir_, uid, gid)
            except OSError as err:
                msg = 'Failed to create directory path "{0}" - {1}\n'
                sys.stderr.write(msg.format(dir_, err))
                sys.exit(err.errno)

        mode = os.stat(dir_)
        # If starting the process as root, chown the new dirs
        if os.getuid() == 0:
            fmode = os.stat(dir_)
            if fmode.st_uid != uid or fmode.st_gid != gid:
                if permissive and fmode.st_gid in groups:
                    # Allow the directory to be owned by any group root
                    # belongs to if we say it's ok to be permissive
                    pass
                else:
                    # chown the file for the new user
                    os.chown(dir_, uid, gid)
            for subdir in [a for a in os.listdir(dir_) if "jobs" not in a]:
                fsubdir = os.path.join(dir_, subdir)
                if "{}jobs".format(os.path.sep) in fsubdir:
                    continue
                for root, dirs, files in salt.utils.path.os_walk(fsubdir):
                    for name in itertools.chain(files, dirs):
                        if name.startswith("."):
                            continue
                        path = os.path.join(root, name)
                        try:
                            fmode = os.stat(path)
                            if fmode.st_uid != uid or fmode.st_gid != gid:
                                if permissive and fmode.st_gid in groups:
                                    pass
                                else:
                                    # chown the file for the new user
                                    os.chown(path, uid, gid)
                        except OSError:
                            continue

        # Allow the pki dir to be 700 or 750, but nothing else.
        # This prevents other users from writing out keys, while
        # allowing the use-case of 3rd-party software (like django)
        # to read in what it needs to integrate.
        #
        # If the permissions aren't correct, default to the more secure 700.
        # If acls are enabled, the pki_dir needs to remain readable, this
        # is still secure because the private keys are still only readable
        # by the user running the master
        if dir_ == pki_dir:
            smode = stat.S_IMODE(mode.st_mode)
            if smode != 448 and smode != 488:
                if os.access(dir_, os.W_OK):
                    os.chmod(dir_, 448)
                else:
                    log.critical(
                        'Unable to securely set the permissions of "%s".', dir_
                    )

    if skip_extra is False:
        # Run the extra verification checks
        zmq_version()


def check_user(user):
    """
    Check user and assign process uid/gid.
    """
    if salt.utils.platform.is_windows():
        return True
    if user == salt.utils.user.get_user():
        return True

    # after confirming not running Windows
    pwuser = _get_pwnam(user)

    try:
        if hasattr(os, "initgroups"):
            os.initgroups(user, pwuser.pw_gid)  # pylint: disable=minimum-python-version
        else:
            os.setgroups(salt.utils.user.get_gid_list(user, include_default=False))
        os.setgid(pwuser.pw_gid)
        os.setuid(pwuser.pw_uid)

        # We could just reset the whole environment but let's just override
        # the variables we can get from pwuser
        if "HOME" in os.environ:
            os.environ["HOME"] = pwuser.pw_dir

        if "SHELL" in os.environ:
            os.environ["SHELL"] = pwuser.pw_shell

        for envvar in ("USER", "LOGNAME"):
            if envvar in os.environ:
                os.environ[envvar] = pwuser.pw_name

    except OSError:
        log.critical('Salt configured to run as user "%s" but unable to switch.', user)
        return False
    return True


def list_path_traversal(path):
    """
    Returns a full list of directories leading up to, and including, a path.

    So list_path_traversal('/path/to/salt') would return:
        ['/', '/path', '/path/to', '/path/to/salt']
    in that order.

    This routine has been tested on Windows systems as well.
    list_path_traversal('c:\\path\\to\\salt') on Windows would return:
        ['c:\\', 'c:\\path', 'c:\\path\\to', 'c:\\path\\to\\salt']
    """
    out = [path]
    (head, tail) = os.path.split(path)
    if tail == "":
        # paths with trailing separators will return an empty string
        out = [head]
        (head, tail) = os.path.split(head)
    while head != out[0]:
        # loop until head is the same two consecutive times
        out.insert(0, head)
        (head, tail) = os.path.split(head)
    return out


def check_path_traversal(path, user="root", skip_perm_errors=False):
    """
    Walk from the root up to a directory and verify that the current
    user has access to read each directory. This is used for  making
    sure a user can read all parent directories of the minion's  key
    before trying to go and generate a new key and raising an IOError
    """
    for tpath in list_path_traversal(path):
        if not os.access(tpath, os.R_OK):
            msg = "Could not access {}.".format(tpath)
            if not os.path.exists(tpath):
                msg += " Path does not exist."
            else:
                current_user = salt.utils.user.get_user()
                # Make the error message more intelligent based on how
                # the user invokes salt-call or whatever other script.
                if user != current_user:
                    msg += " Try running as user {}.".format(user)
                else:
                    msg += " Please give {} read permissions.".format(user)

            # We don't need to bail on config file permission errors
            # if the CLI
            # process is run with the -a flag
            if skip_perm_errors:
                return
            # Propagate this exception up so there isn't a sys.exit()
            # in the middle of code that could be imported elsewhere.
            raise SaltClientError(msg)


def check_max_open_files(opts):
    """
    Check the number of max allowed open files and adjust if needed
    """
    mof_c = opts.get("max_open_files", 100000)
    if sys.platform.startswith("win"):
        # Check the Windows API for more detail on this
        # http://msdn.microsoft.com/en-us/library/xt874334(v=vs.71).aspx
        # and the python binding http://timgolden.me.uk/pywin32-docs/win32file.html
        mof_s = mof_h = win32file._getmaxstdio()
    else:
        mof_s, mof_h = resource.getrlimit(resource.RLIMIT_NOFILE)

    accepted_keys_dir = os.path.join(opts.get("pki_dir"), "minions")
    accepted_count = len(os.listdir(accepted_keys_dir))

    log.debug("This salt-master instance has accepted %s minion keys.", accepted_count)

    level = logging.INFO

    if (accepted_count * 4) <= mof_s:
        # We check for the soft value of max open files here because that's the
        # value the user chose to raise to.
        #
        # The number of accepted keys multiplied by four(4) is lower than the
        # soft value, everything should be OK
        return

    msg = (
        "The number of accepted minion keys({}) should be lower than 1/4 "
        "of the max open files soft setting({}). ".format(accepted_count, mof_s)
    )

    if accepted_count >= mof_s:
        # This should never occur, it might have already crashed
        msg += "salt-master will crash pretty soon! "
        level = logging.CRITICAL
    elif (accepted_count * 2) >= mof_s:
        # This is way too low, CRITICAL
        level = logging.CRITICAL
    elif (accepted_count * 3) >= mof_s:
        level = logging.WARNING
        # The accepted count is more than 3 time, WARN
    elif (accepted_count * 4) >= mof_s:
        level = logging.INFO

    if mof_c < mof_h:
        msg += (
            "According to the system's hard limit, there's still a "
            "margin of {} to raise the salt's max_open_files "
            "setting. ".format(mof_h - mof_c)
        )

    msg += "Please consider raising this value."
    log.log(level=level, msg=msg)


def _realpath_darwin(path):
    base = ""
    for part in path.split(os.path.sep)[1:]:
        if base != "":
            if os.path.islink(os.path.sep.join([base, part])):
                base = os.readlink(os.path.sep.join([base, part]))
            else:
                base = os.path.abspath(os.path.sep.join([base, part]))
        else:
            base = os.path.abspath(os.path.sep.join([base, part]))
    return base


def _realpath_windows(path):
    base = ""
    for part in path.split(os.path.sep):
        if base != "":
            try:
                # Need to use salt.utils.path.readlink as it handles junctions
                part = salt.utils.path.readlink(os.path.sep.join([base, part]))
                base = os.path.abspath(part)
            except OSError:
                base = os.path.abspath(os.path.sep.join([base, part]))
        else:
            base = part
    # Python 3.8 added support for directory junctions which prefixes the
    # return with `\\?\`. We need to strip that off.
    # https://docs.python.org/3/library/os.html#os.readlink
    if base.startswith("\\\\?\\"):
        base = base[4:]
    return base


def _realpath(path):
    """
    Cross platform realpath method. On Windows when python 3, this method
    uses the os.readlink method to resolve any filesystem links.
    All other platforms and version use ``os.path.realpath``.
    """
    if salt.utils.platform.is_darwin():
        return _realpath_darwin(path)
    elif salt.utils.platform.is_windows():
        return _realpath_windows(path)
    return os.path.realpath(path)


def clean_path(root, path, subdir=False):
    """
    Accepts the root the path needs to be under and verifies that the path is
    under said root. Pass in subdir=True if the path can result in a
    subdirectory of the root instead of having to reside directly in the root
    """
    real_root = _realpath(root)
    if not os.path.isabs(real_root):
        return ""
    if not os.path.isabs(path):
        path = os.path.join(root, path)
    path = os.path.normpath(path)
    real_path = _realpath(path)
    if subdir:
        if real_path.startswith(real_root):
            return real_path
    else:
        if os.path.dirname(real_path) == os.path.normpath(real_root):
            return real_path
    return ""


def valid_id(opts, id_):
    """
    Returns if the passed id is valid
    """
    try:
        if any(x in id_ for x in ("/", "\\", "\0")):
            return False
        return bool(clean_path(opts["pki_dir"], id_))
    except (AttributeError, KeyError, TypeError, UnicodeDecodeError):
        return False


def safe_py_code(code):
    """
    Check a string to see if it has any potentially unsafe routines which
    could be executed via python, this routine is used to improve the
    safety of modules suct as virtualenv
    """
    bads = ("import", ";", "subprocess", "eval", "open", "file", "exec", "input")
    for bad in bads:
        if code.count(bad):
            return False
    return True


def verify_log(opts):
    """
    If an insecre logging configuration is found, show a warning
    """
    level = LOG_LEVELS.get(str(opts.get("log_level")).lower(), logging.NOTSET)

    if level < logging.INFO:
        log.warning(
            "Insecure logging configuration detected! Sensitive data may be logged."
        )


def win_verify_env(path, dirs, permissive=False, pki_dir="", skip_extra=False):
    """
    Verify that the named directories are in place and that the environment
    can shake the salt
    """
    import salt.utils.win_functions
    import salt.utils.win_dacl
    import salt.utils.path

    # Make sure the file_roots is not set to something unsafe since permissions
    # on that directory are reset

    # `salt.utils.path.safe_path` will consider anything inside `C:\Windows` to
    # be unsafe. In some instances the test suite uses
    # `C:\Windows\Temp\salt-tests-tmpdir\rootdir` as the file_roots. So, we need
    # to consider anything in `C:\Windows\Temp` to be safe
    system_root = os.environ.get("SystemRoot", r"C:\Windows")
    allow_path = "\\".join([system_root, "TEMP"])
    if not salt.utils.path.safe_path(path=path, allow_path=allow_path):
        raise CommandExecutionError(
            "`file_roots` set to a possibly unsafe location: {}".format(path)
        )

    # Create the root path directory if missing
    if not os.path.isdir(path):
        os.makedirs(path)

    current_user = salt.utils.win_functions.get_current_user()
    # Set permissions to the registry key
    if salt.utils.win_functions.is_admin(current_user):
        reg_path = "HKLM\\SOFTWARE\\Salt Project\\salt"
        if not salt.utils.win_reg.key_exists(
            hive="HKLM", key="SOFTWARE\\Salt Project\\salt"
        ):
            salt.utils.win_reg.set_value(
                hive="HKLM", key="SOFTWARE\\Salt Project\\salt"
            )
        try:
            # Make the Administrators group owner
            # Use the SID to be locale agnostic
            salt.utils.win_dacl.set_owner(
                obj_name=reg_path, principal="S-1-5-32-544", obj_type="registry"
            )
        except CommandExecutionError:
            log.critical("Unable to securely set the owner of '%s'.", reg_path)

        try:
            # Get a clean dacl by not passing an obj_name
            dacl = salt.utils.win_dacl.dacl(obj_type="registry")

            # Add aces to the dacl, use the GUID (locale non-specific)
            # Administrators Group
            dacl.add_ace(
                principal="S-1-5-32-544",
                access_mode="grant",
                permissions="full_control",
                applies_to="this_key_subkeys",
            )
            # System
            dacl.add_ace(
                principal="S-1-5-18",
                access_mode="grant",
                permissions="full_control",
                applies_to="this_key_subkeys",
            )
            # Owner
            dacl.add_ace(
                principal="S-1-3-4",
                access_mode="grant",
                permissions="full_control",
                applies_to="this_key_subkeys",
            )

            # Save the dacl to the object
            dacl.save(obj_name=reg_path, protected=True)

        except CommandExecutionError:
            log.critical("Unable to securely set the permissions of '%s'.", reg_path)

    # Set permissions to the root path directory
    if salt.utils.win_functions.is_admin(current_user):
        try:
            # Make the Administrators group owner
            # Use the SID to be locale agnostic
            salt.utils.win_dacl.set_owner(obj_name=path, principal="S-1-5-32-544")

        except CommandExecutionError:
            log.critical('Unable to securely set the owner of "%s".', path)

        if not permissive:
            try:
                # Get a clean dacl by not passing an obj_name
                dacl = salt.utils.win_dacl.dacl()

                # Add aces to the dacl, use the GUID (locale non-specific)
                # Administrators Group
                dacl.add_ace(
                    principal="S-1-5-32-544",
                    access_mode="grant",
                    permissions="full_control",
                    applies_to="this_folder_subfolders_files",
                )
                # System
                dacl.add_ace(
                    principal="S-1-5-18",
                    access_mode="grant",
                    permissions="full_control",
                    applies_to="this_folder_subfolders_files",
                )
                # Owner
                dacl.add_ace(
                    principal="S-1-3-4",
                    access_mode="grant",
                    permissions="full_control",
                    applies_to="this_folder_subfolders_files",
                )

                # Save the dacl to the object
                dacl.save(obj_name=path, protected=True)

            except CommandExecutionError:
                log.critical("Unable to securely set the permissions of '%s'", path)

    # Create the directories
    for dir_ in dirs:
        if not dir_:
            continue
        if not os.path.isdir(dir_):
            try:
                os.makedirs(dir_)
            except OSError as err:
                msg = 'Failed to create directory path "{0}" - {1}\n'
                sys.stderr.write(msg.format(dir_, err))
                sys.exit(err.errno)

        # The PKI dir gets its own permissions
        if dir_ == pki_dir:
            try:
                # Make Administrators group the owner
                salt.utils.win_dacl.set_owner(obj_name=path, principal="S-1-5-32-544")

                # Give Admins, System and Owner permissions
                # Get a clean dacl by not passing an obj_name
                dacl = salt.utils.win_dacl.dacl()

                # Add aces to the dacl, use the GUID (locale non-specific)
                # Administrators Group
                dacl.add_ace(
                    principal="S-1-5-32-544",
                    access_mode="grant",
                    permissions="full_control",
                    applies_to="this_folder_subfolders_files",
                )
                # System
                dacl.add_ace(
                    principal="S-1-5-18",
                    access_mode="grant",
                    permissions="full_control",
                    applies_to="this_folder_subfolders_files",
                )
                # Owner
                dacl.add_ace(
                    principal="S-1-3-4",
                    access_mode="grant",
                    permissions="full_control",
                    applies_to="this_folder_subfolders_files",
                )

                # Save the dacl to the object
                dacl.save(obj_name=dir_, protected=True)

            except CommandExecutionError:
                log.critical("Unable to securely set the permissions of '%s'.", dir_)

    if skip_extra is False:
        # Run the extra verification checks
        zmq_version()
