# Functions to read and access the zeekctl configuration.

import configparser
import hashlib
import os
import re
import socket
import subprocess
import sys

from ZeekControl import events, options
from ZeekControl import node as node_mod
from ZeekControl.exceptions import ConfigurationError, RuntimeEnvironmentError

from .state import SqliteState
from .version import VERSION

# Class storing the zeekctl configuration.
#
# This class provides access to four types of configuration/state:
#
# - the global zeekctl configuration from zeekctl.cfg
# - the node configuration from node.cfg
# - dynamic state variables which are kept across restarts in spool/state.db

Config = None  # Globally accessible instance of Configuration.


class NodeStore:
    def __init__(self):
        self.nodestore = {}
        self.nodenameslower = []

    def add_node(self, node):
        # Add a node to the nodestore, but first check for duplicate node
        # names. This check is not case-sensitive, because names are stored
        # lowercase in the state db, and some filesystems are not
        # case-sensitive (working dir name is node name).
        # Duplicate node names can occur either because the user defined two
        # nodes that differ only by case (e.g. "Worker-1" and "worker-1"), or
        # if a user defines a node name that conflicts with an auto-generated
        # one (e.g. "worker-1" with lb_procs=2 and "worker-1-2").
        namelower = node.name.lower()
        if namelower in self.nodenameslower:
            matchname = ""
            for nn in self.nodestore:
                if nn.lower() == namelower:
                    matchname = nn
                    break
            raise ConfigurationError(
                f'node name "{node.name}" is a duplicate of "{matchname}"'
            )

        self.nodestore[node.name] = node
        self.nodenameslower.append(namelower)


class Configuration:
    def __init__(
        self, basedir, libdir, libdirinternal, cfgfile, zeekscriptdir, ui, state=None
    ):
        self.ui = ui
        self.basedir = basedir
        self.libdir = libdir
        self.libdirinternal = libdirinternal
        self.cfgfile = cfgfile
        self.zeekscriptdir = zeekscriptdir
        global Config
        Config = self

        self.config = {}
        self.state = {}
        self.nodestore = {}

        self.localaddrs = self._get_local_addrs()

        # Read zeekctl.cfg.
        self.config = self._read_config(cfgfile)

        self._initialize_options()
        self._check_options()

        if state:
            self.state_store = state
        else:
            self.state_store = SqliteState(self.statefile)

        self.read_state()
        self._update_cfg_state()

    def reload_cfg(self):
        self.config = self._read_config(self.cfgfile)
        self._initialize_options()
        self._check_options()
        self._update_cfg_state()

    def _initialize_options(self):
        from ZeekControl import execute

        # Set defaults for options we get passed in.
        self.init_option("zeekbase", self.basedir)
        self.init_option("zeekscriptdir", self.zeekscriptdir)
        self.init_option("version", VERSION)
        self.init_option("libdir", self.libdir)
        self.init_option("libdirinternal", self.libdirinternal)

        # Initialize options that are not already set.
        errors = False
        for opt in options.options:
            if opt.dontinit:
                continue

            if opt.legacy_name:
                old_key = opt.legacy_name.lower()
                if old_key in self.config:
                    self.ui.error(
                        f"option '{opt.legacy_name}' is no longer supported, please use '{opt.name}' instead"
                    )
                    errors = True
                    continue

            self.init_option(opt.name, opt.default)

        if errors:
            sys.exit(1)

        # Set defaults for options we derive dynamically.
        self.init_option("mailto", "{}".format(os.getenv("USER")))
        self.init_option("mailfrom", f"Zeek <zeek@{socket.gethostname()}>")
        self.init_option("mailalarmsto", self.config["mailto"])

        # Determine operating system.
        success, output = execute.run_localcmd("uname")
        if not success or not output:
            raise RuntimeEnvironmentError(f"failed to run uname: {output}")
        self.init_option("os", output.strip())

        # Determine the CPU pinning command.
        pin_cmd = ""
        if self.config["os"] == "Linux":
            pin_cmd = "taskset -c"
        elif self.config["os"] == "FreeBSD":
            pin_cmd = "cpuset -l"

        self.init_option("pin_command", pin_cmd)

        # Find the time command (should be a GNU time for best results).
        time_cmd = ""
        success, output = execute.run_localcmd("which time")
        if success and output:
            # On redhat-based systems, path to cmd is prefixed with '\t' on 2nd
            # line when alias is defined.
            time_cmd = output.splitlines()[-1].strip()

        self.init_option("time", time_cmd)

        # Calculate the log expire interval (in minutes).
        minutes = self._get_interval_minutes("logexpireinterval")
        self.init_option("logexpireminutes", minutes)

    # Do a basic sanity check on zeekctl options.
    def _check_options(self):
        # Option names must be valid bash variable names because we will
        # write them to zeekctl-config.sh (note that zeekctl will convert "."
        # to "_" when it writes to zeekctl-config.sh).
        allowedchars = re.compile("^[a-z0-9_.]+$")
        nostartdigit = re.compile("^[^0-9]")

        for key, value in self.config.items():
            if re.match(allowedchars, key) is None:
                raise ConfigurationError(
                    f'zeekctl option name "{key}" contains invalid characters (allowed characters: a-z, 0-9, ., and _)'
                )
            if re.match(nostartdigit, key) is None:
                raise ConfigurationError(
                    f'zeekctl option name "{key}" cannot start with a number'
                )

            # No zeekctl option ever requires the entire value to be wrapped in
            # quotes, and since doing so can cause problems, we don't allow it.
            if isinstance(value, str):
                if (
                    value.startswith('"')
                    and value.endswith('"')
                    or value.startswith("'")
                    and value.endswith("'")
                ):
                    raise ConfigurationError(
                        f'value of zeekctl option "{key}" cannot be wrapped in quotes'
                    )

        dirs = (
            "zeekbase",
            "logdir",
            "spooldir",
            "cfgdir",
            "zeekscriptdir",
            "bindir",
            "libdirinternal",
            "plugindir",
            "scriptsdir",
        )
        files = ("makearchivename",)

        for d in dirs:
            v = self.config[d]
            if not os.path.isdir(v):
                raise ConfigurationError(
                    f'zeekctl option "{d}" directory not found: {v}'
                )

        for f in files:
            v = self.config[f]
            if not os.path.isfile(v):
                raise ConfigurationError(f'zeekctl option "{f}" file not found: {v}')

        # Verify that logs don't expire more quickly than the rotation interval
        logexpireseconds = 60 * self.config["logexpireminutes"]
        if 0 < logexpireseconds < self.config["logrotationinterval"]:
            raise ConfigurationError(
                "Log expire interval cannot be shorter than the log rotation interval"
            )

        if self.config["usewebsocket"]:
            if events.websockets_errmsg is not None:
                self.ui.warn(
                    f"zeekctl option UseWebSocket is set, but websockets non-functional: {events.websockets_errmsg}"
                )

        if not self.config["usewebsocket"]:
            # If UseWebSocket isn't configured, then commands for non-Broker
            # backends will not work. Warn the user here. We could imply UseWebSocket = 1,
            # but that results in the manager listening on a new port, so better
            # to not have the user explicitly toggle it on.
            clusterbackend = self.config["clusterbackend"]
            if clusterbackend.lower() != "broker":
                self.ui.warn(
                    f"zeekctl netstats and print commands with cluster backend '{clusterbackend}' require UseWebSocket = 1"
                )

    # Convert a time interval string (from the value of the given option name)
    # to an integer number of minutes.
    def _get_interval_minutes(self, optname):
        # Conversion table for time units to minutes.
        units = {"day": 24 * 60, "hr": 60, "min": 1}

        ss = self.config[optname]
        try:
            # If no time unit, assume it's days (for backward compatibility).
            v = int(ss) * units["day"]
            return v
        except ValueError:
            pass

        # Time interval is a non-negative integer followed by an optional
        # space, followed by a time unit.
        mm = re.match("([0-9]+) ?(day|hr|min)s?$", ss)
        if mm is None:
            raise ConfigurationError(
                f'value of zeekctl option "{optname}" is invalid (value must be integer followed by a time unit "day", "hr", or "min"): {ss}'
            )

        v = int(mm.group(1))
        v *= units[mm.group(2)]

        return v

    def initPostPlugins(self):
        # Read node.cfg
        self.nodestore = self._read_nodes()

        # If "env_vars" was specified in zeekctl.cfg, then apply to all nodes.
        varlist = self.config.get("env_vars")
        if varlist:
            try:
                global_env_vars = self._get_env_var_dict(varlist)
            except ConfigurationError as err:
                raise ConfigurationError(f"zeekctl config: {err}")

            for node in self.nodes():
                for key, val in global_env_vars.items():
                    # Values from node.cfg take precedence over zeekctl.cfg
                    node.env_vars.setdefault(key, val)

        # Check state store for any running nodes that are no longer in the
        # current node config.
        self._warn_dangling_zeek()

        # Set the standalone config option.
        standalone = len(self.nodestore) == 1

        self.init_option("standalone", standalone)

    # Provides access to the configuration options via the dereference operator.
    # Lookup the attribute in zeekctl options first, then in the dynamic state
    # variables.
    def __getattr__(self, attr):
        if attr in self.config:
            return self.config[attr]
        if attr in self.state:
            return self.state[attr]
        raise AttributeError(f"unknown config attribute {attr}")

    # Returns a sorted list of all zeekctl.cfg entries.
    # Includes dynamic variables if dynamic is true.
    def options(self, dynamic=True):
        optlist = list(self.config.items())
        if dynamic:
            optlist += list(self.state.items())

        optlist.sort()
        return optlist

    # Returns a list of Nodes (the list will be empty if no matching nodes
    # are found).  The returned list is sorted by node type, and by node name
    # for each type.
    # - By default (i.e. tag is None), all Nodes are returned.
    # - If tag is a node group name (e.g. "workers"), all nodes belonging to
    #   that group are returned.
    # - If tag is the name of a node, then that node is returned.
    def nodes(self, tag=None):
        nodetype = node_mod.group_type(tag)
        if nodetype == "_ALL_":
            tag = None

        nodes = []
        for n in self.nodestore.values():
            if nodetype == n.type or tag == n.name or tag is None:
                nodes += [n]

        nodes.sort(key=node_mod.sortnode)

        return nodes

    # Returns the manager Node (cluster config) or standalone Node (standalone
    # config).  Returns None if neither are available.
    def manager(self):
        if self.config["standalone"]:
            n = self.nodes()
        else:
            n = self.nodes(node_mod.manager_group())

        if not n:
            return None

        return n[0]

    def loggers(self):
        return self.nodes(node_mod.logger_group())

    def proxies(self):
        return self.nodes(node_mod.proxy_group())

    def workers(self):
        return self.nodes(node_mod.worker_group())

    # Returns a list of nodes which is a subset of the result a similar call to
    # nodes() would yield but within which each host appears only once.
    # If "exclude_local" is True, then the returned list will not include
    # nodes that are on the local host.
    def hosts(self, tag=None, exclude_local=False):
        hosts = {}
        nodelist = []
        for node in self.nodes(tag):
            if node.host in hosts:
                continue

            if exclude_local and node.addr in self.localaddrs:
                continue

            hosts[node.host] = 1
            nodelist.append(node)

        return nodelist

    # Replace all occurences of "${option}", with option being either
    # zeekctl.cfg option or a dynamic variable, with the corresponding value.
    # Defaults to replacement with the empty string for unknown options.
    def subst(self, text):
        while True:
            match = re.search(r"(\$\{([A-Za-z][A-Za-z0-9]*)(:([^}]+))?\})", text)
            if not match:
                return text

            key = match.group(2).lower()
            try:
                value = str(self.__getattr__(key))
            except AttributeError:
                value = match.group(4)
                if value is None:
                    value = ""

            text = text[0 : match.start(1)] + value + text[match.end(1) :]

    # Convert string into list of integers (ValueError is raised if any
    # item in the list is not a non-negative integer).
    def _get_pin_cpu_list(self, text, numprocs):
        if not text:
            return []

        cpulist = [int(x) for x in text.split(",")]
        # Minimum allowed CPU number is zero.
        if min(cpulist) < 0:
            raise ValueError

        # Make sure list is at least as long as number of worker processes.
        cpulen = len(cpulist)
        if numprocs > cpulen:
            cpulist = [cpulist[i % cpulen] for i in range(numprocs)]

        return cpulist

    # Convert a string consisting of a comma-separated list of environment
    # variables (e.g. "VAR1=123, VAR2=456") to a dictionary.
    # If the string is empty, then return an empty dictionary.
    def _get_env_var_dict(self, text):
        env_vars = {}

        if text:
            for keyval in text.split(","):
                try:
                    key, val = keyval.split("=", 1)
                except ValueError:
                    raise ConfigurationError(
                        f"missing '=' in env_vars option value: {keyval}"
                    )

                key = key.strip()
                if not key:
                    raise ConfigurationError(
                        f"env_vars option value must contain at least one environment variable name: {keyval}"
                    )

                env_vars[key] = val.strip()

        return env_vars

    # Parse node.cfg.
    def _read_nodes(self):
        config = configparser.ConfigParser()
        fname = self.nodecfg
        try:
            if not config.read(fname):
                raise ConfigurationError(f"cannot read node config file: {fname}")
        except configparser.MissingSectionHeaderError as err:
            raise ConfigurationError(err)

        nodestore = NodeStore()

        counts = {}
        for sec in config.sections():
            node = node_mod.Node(self, sec)

            # Note that the keys are converted to lowercase by configparser.
            for key, val in config.items(sec):
                key = key.replace(".", "_")

                if key not in node_mod.Node._keys:
                    self.ui.warn(
                        f"ignoring unrecognized node config option '{key}' given for node '{sec}'"
                    )
                    continue

                node.__dict__[key] = val

            # Perform a sanity check on the node, and update nodestore.
            self._check_node(node, nodestore, counts)

        # Perform a sanity check on the nodestore (make sure we have a valid
        # cluster config, etc.).
        self._check_nodestore(nodestore.nodestore)

        return nodestore.nodestore

    def _check_node(self, node, nodestore, counts):
        if not node.type:
            raise ConfigurationError(f"no type given for node {node.name}")

        if node.type not in node_mod.node_types():
            raise ConfigurationError(
                f"unknown node type '{node.type}' given for node '{node.name}'"
            )

        if not node.host:
            raise ConfigurationError(f"no host given for node '{node.name}'")

        try:
            addrinfo = socket.getaddrinfo(node.host, None, 0, 0, socket.SOL_TCP)
        except socket.gaierror as e:
            raise ConfigurationError(
                f"hostname lookup failed for '{node.host}' in node config [{e.args[1]}]"
            )

        addrs = [addr[4][0] for addr in addrinfo]

        # By default, just use the first IP addr in the list.
        addr_str = addrs[0]

        # Choose the first IPv4 addr (if any) in the list.
        for ip in addrs:
            if ":" not in ip:
                addr_str = ip
                break

        # zone_id is handled manually, so strip it if it's there
        node.addr = addr_str.split("%")[0]

        # Convert env_vars from a string to a dictionary.
        try:
            node.env_vars = self._get_env_var_dict(node.env_vars)
        except ConfigurationError as err:
            raise ConfigurationError(f"node '{node.name}' config: {err}")

        # Each node gets a number unique across its type.
        try:
            counts[node.type] += 1
        except KeyError:
            counts[node.type] = 1

        node.count = counts[node.type]

        numprocs = 0

        if node.lb_procs:
            if not node_mod.is_worker(node):
                raise ConfigurationError(
                    f"node '{node.name}' config: load balancing node config options are only for worker nodes"
                )
            try:
                numprocs = int(node.lb_procs)
            except ValueError:
                raise ConfigurationError(
                    f"number of load-balanced processes must be an integer for node '{node.name}'"
                )
            if numprocs < 1:
                raise ConfigurationError(
                    f"number of load-balanced processes must be greater than zero for node '{node.name}'"
                )
        elif node.lb_method:
            raise ConfigurationError(
                f"number of load-balanced processes not specified for node '{node.name}'"
            )

        try:
            pin_cpus = self._get_pin_cpu_list(node.pin_cpus, numprocs)
        except ValueError:
            raise ConfigurationError(
                f"pin cpus list must contain only non-negative integers for node '{node.name}'"
            )

        if pin_cpus:
            node.pin_cpus = pin_cpus[0]

        if node.lb_procs:
            if not node.lb_method:
                raise ConfigurationError(
                    f"no load balancing method given for node '{node.name}'"
                )

            if node.lb_method not in (
                "af_packet",
                "pf_ring",
                "myricom",
                "custom",
                "interfaces",
            ):
                raise ConfigurationError(
                    f"unknown load balancing method '{node.lb_method}' given for node '{node.name}'"
                )

            if node.lb_method == "interfaces":
                if not node.lb_interfaces:
                    raise ConfigurationError(
                        f"list of load-balanced interfaces not specified for node '{node.name}'"
                    )

                # get list of interfaces to use, and assign one to each node
                netifs = node.lb_interfaces.split(",")

                if len(netifs) != numprocs:
                    raise ConfigurationError(
                        f"number of load-balanced interfaces is not same as number of load-balanced processes for node '{node.name}'"
                    )

                node.interface = netifs.pop().strip()

            origname = node.name
            # node names will have a numerical suffix
            node.name = f"{node.name}-1"

            for num in range(2, numprocs + 1):
                newnode = node.copy()

                # Update the node attrs that need to be changed
                newname = f"{origname}-{num:d}"
                newnode.name = newname
                counts[node.type] += 1
                newnode.count = counts[node.type]
                if pin_cpus:
                    newnode.pin_cpus = pin_cpus[num - 1]

                if newnode.lb_method == "interfaces":
                    newnode.interface = netifs.pop().strip()

                nodestore.add_node(newnode)

        nodestore.add_node(node)

    def _check_nodestore(self, nodestore):
        if not nodestore:
            raise ConfigurationError("no nodes found in node config")

        standalone = False
        manager = False
        proxy = False

        manageronlocalhost = False
        # Note: this is a subset of localaddrs
        localhostaddrs = "127.0.0.1", "::1"

        for n in nodestore.values():
            if node_mod.is_manager(n):
                if manager:
                    raise ConfigurationError(
                        "only one manager can be defined in node config"
                    )
                manager = True
                if n.addr in localhostaddrs:
                    manageronlocalhost = True

                if n.addr not in self.localaddrs:
                    raise ConfigurationError(
                        "must run zeekctl on same machine as the manager node. The manager node has IP address {} and this machine has IP addresses: {}".format(
                            n.addr, ", ".join(self.localaddrs)
                        )
                    )

            elif node_mod.is_proxy(n):
                proxy = True

            elif node_mod.is_standalone(n):
                standalone = True
                if n.addr not in self.localaddrs:
                    raise ConfigurationError(
                        "must run zeekctl on same machine as the standalone node. The standalone node has IP address {} and this machine has IP addresses: {}".format(
                            n.addr, ", ".join(self.localaddrs)
                        )
                    )

        if standalone:
            if len(nodestore) > 1:
                raise ConfigurationError(
                    "more than one node defined in standalone node config"
                )
        else:
            if not manager:
                raise ConfigurationError("no manager defined in node config")
            elif not proxy:
                raise ConfigurationError("no proxy defined in node config")

        # If manager is on localhost, then all other nodes must be on localhost
        if manageronlocalhost:
            for n in nodestore.values():
                if not node_mod.is_manager(n) and n.addr not in localhostaddrs:
                    raise ConfigurationError(
                        "all nodes must use localhost/127.0.0.1/::1 when manager uses it"
                    )

    def _to_bool(self, val):
        if val.lower() in ("1", "true"):
            return True
        if val.lower() in ("0", "false"):
            return False
        raise ValueError(f"invalid boolean: '{val}'")

    # Parses zeekctl.cfg and returns a dictionary of all entries.
    def _read_config(self, fname):
        type_converters = {"bool": self._to_bool, "int": int, "string": str}
        config = {}

        opt_names = set()
        for opt in options.options:
            # Convert key to lowercase because keys are stored in lowercase.
            key = opt.name.lower()
            opt_names.add(key)
            if opt.legacy_name:
                opt_names.add(opt.legacy_name.lower())

        with open(fname) as f:
            for line in f:
                line = line.strip()
                if not line or line.startswith("#"):
                    continue

                args = line.split("=", 1)
                if len(args) != 2:
                    raise ConfigurationError(f"zeekctl config syntax error: {line}")

                key, val = args
                # Option names are not case-sensitive.
                key = key.strip().lower()

                # Warn about unrecognized options, but we can't check plugin
                # options here because no plugins have been loaded yet.
                if "." not in key and key not in opt_names:
                    self.ui.warn(f"ignoring unrecognized zeekctl option: {key}")
                    continue

                # if the key already exists, just overwrite with new value
                config[key] = val.strip()

        # Convert option values to correct data type
        for opt in options.options:
            # Convert key to lowercase because keys are stored in lowercase.
            key = opt.name.lower()
            if key in config:
                try:
                    config[key] = type_converters[opt.type](config[key])
                except ValueError:
                    raise ConfigurationError(
                        f"zeekctl option '{key}' has invalid value '{config[key]}' for type {opt.type}"
                    )

        return config

    # Initialize a global option if not already set.
    def init_option(self, key, val):
        # Store option names in lowercase, because they are not case-sensitive.
        key = key.lower()

        if key not in self.config:
            if isinstance(val, str):
                self.config[key] = self.subst(val)
            else:
                self.config[key] = val

    # Set a global option (regardless of whether or not it is already set).
    def set_option(self, key, val):
        # Store option names in lowercase, because they are not case-sensitive.
        key = key.lower()

        self.config[key] = val

    # Returns value of an option, or None if the option is not defined.
    def get_option(self, key):
        # Convert key to lowercase because keys are stored in lowercase.
        return self.config.get(key.lower())

    # Set a dynamic state variable.
    def set_state(self, key, val):
        key = key.lower()
        if self.state.get(key) == val:
            return

        self.state[key] = val
        self.state_store.set(key, val)

    # Returns value of state variable, or the specified default value if the
    # state variable is not defined.
    def get_state(self, key, default=None):
        return self.state.get(key.lower(), default)

    # Read dynamic state variables.
    def read_state(self):
        self.state = dict(self.state_store.items())

    # Use the ifconfig command to find local IP addrs.
    def _get_local_addrs_ifconfig(self):
        try:
            # On Linux, ifconfig is often not in the user's standard PATH.
            # Also need to set LANG here to ensure that the output of ifconfig
            # is consistent regardless of which locale the system is using.
            proc = subprocess.Popen(
                ["PATH=$PATH:/sbin:/usr/sbin LANG=C ifconfig", "-a"],
                stdout=subprocess.PIPE,
                stderr=subprocess.PIPE,
                shell=True,
            )
            out, err = proc.communicate()
        except OSError:
            return False

        success = proc.returncode == 0
        if not success:
            return False

        localaddrs = []
        out = out.decode()

        # The output of ifconfig varies by OS and by IPv4 vs IPv6.
        # Linux example:
        #   inet addr:127.0.0.1
        #   inet6 addr: ::1/128
        # BSD (and OS X) example:
        #   inet 127.0.0.1
        #   inet6 ::1
        #   inet6 fe80::1%lo0
        for line in out.splitlines():
            fields = line.split()
            if len(fields) < 3:
                continue

            if fields[0] != "inet" and fields[0] != "inet6":
                continue

            addrstr = fields[1]

            if addrstr[-1] == ":" and addrstr.count(":") == 1:
                addrstr = fields[2]

            if addrstr.count(":") == 1:
                # Remove "addr:" prefix (if any).
                addrstr = addrstr.split(":")[1]

            # Remove everything after "/" or "%" (if any)
            addrstr = addrstr.split("/")[0]
            addrstr = addrstr.split("%")[0]

            if _is_valid_addr(addrstr):
                localaddrs.append(addrstr)

        if not localaddrs:
            self.ui.warn(
                'failed to extract IP addresses from the "ifconfig -a" command output'
            )

        return localaddrs

    # Use the ip command to find local IP addrs.
    def _get_local_addrs_ip(self):
        try:
            # On Linux, "ip" is sometimes not in the user's standard PATH.
            proc = subprocess.Popen(
                ["PATH=$PATH:/sbin:/usr/sbin ip address"],
                stdout=subprocess.PIPE,
                stderr=subprocess.PIPE,
                shell=True,
            )
            out, err = proc.communicate()
        except OSError:
            return False

        success = proc.returncode == 0
        if not success:
            return False

        localaddrs = []
        out = out.decode()

        # Here is an example portion of "ip" command output:
        #    inet 127.0.0.1/8
        #    inet6 ::1/128
        for line in out.splitlines():
            fields = line.split()
            if len(fields) < 2:
                continue

            if fields[0] != "inet" and fields[0] != "inet6":
                continue

            addrstr = fields[1]
            addrstr = addrstr.split("/")[0]
            addrstr = addrstr.split("%")[0]

            if _is_valid_addr(addrstr):
                localaddrs.append(addrstr)

        if not localaddrs:
            self.ui.warn(
                'failed to extract IP addresses from the "ip address" command output'
            )

        return localaddrs

    # Return a list of the IP addresses associated with local interfaces.
    # For IPv6 addresses, zone_id and prefix length are removed if present.
    def _get_local_addrs(self):
        # ifconfig is more portable so try it first
        localaddrs = self._get_local_addrs_ifconfig()

        if not localaddrs:
            # On some Linux systems ifconfig has been superseded by ip.
            localaddrs = self._get_local_addrs_ip()

        # Fallback to localhost if we did not find any IP addrs.
        if not localaddrs:
            self.ui.warn(
                'failed to find local IP addresses with "ifconfig -a" or "ip address" commands'
            )

            localaddrs = ["127.0.0.1", "::1"]
            try:
                addrinfo = socket.getaddrinfo(
                    socket.gethostname(), None, 0, 0, socket.SOL_TCP
                )
            except Exception:
                addrinfo = []

            for ai in addrinfo:
                localaddrs.append(ai[4][0])

        return localaddrs

    # Record the Zeek version.
    def record_zeek_version(self):
        version = self._get_zeek_version()
        self.set_state("zeekversion", version)

    # Record the state of the zeekctl config files.
    def _update_cfg_state(self):
        self.set_state("configchksum", self._get_zeekctlcfg_hash(filehash=True))
        self.set_state("confignodechksum", self._get_nodecfg_hash(filehash=True))

    # Returns True if the zeekctl config files have changed since last reload.
    def is_cfg_changed(self):
        try:
            if "configchksum" in self.state:
                if self.state["configchksum"] != self._get_zeekctlcfg_hash(
                    filehash=True
                ):
                    return True

            if "confignodechksum" in self.state:
                if self.state["confignodechksum"] != self._get_nodecfg_hash(
                    filehash=True
                ):
                    return True
        except OSError:
            # If we can't read the config files, then do nothing.
            pass

        return False

    # Check if the user has already run the "install" or "deploy" commands.
    def is_zeekctl_installed(self):
        return os.path.isfile(
            os.path.join(self.config["policydirsiteinstallauto"], "zeekctl-config.zeek")
        )

    # Warn user to run zeekctl deploy if any changes are detected to zeekctl
    # config options, node config, Zeek version, or if certain state variables
    # are missing.
    def warn_zeekctl_install(self):
        missingstate = False

        # Check if node config has changed since last install.
        if "hash-nodecfg" in self.state:
            nodehash = self._get_nodecfg_hash()

            if nodehash != self.state["hash-nodecfg"]:
                self.ui.warn(
                    'zeekctl node config has changed (run the zeekctl "deploy" command)'
                )

                return
        else:
            missingstate = True

        # If this is a fresh install (i.e., zeekctl install not yet run), then
        # inform the user what to do.
        if not self.is_zeekctl_installed():
            self.ui.info('Hint: Run the zeekctl "deploy" command to get started.')
            return

        # Check if Zeek version is different from the previously-installed
        # version.
        if "zeekversion" in self.state:
            oldversion = self.state["zeekversion"]

            version = self._get_zeek_version()

            if version != oldversion:
                self.ui.warn(
                    'new zeek version detected (run the zeekctl "deploy" command)'
                )
                return
        else:
            missingstate = True

        # Check if any config values have changed since last install.
        if "hash-zeekctlcfg" in self.state:
            cfghash = self._get_zeekctlcfg_hash()
            if cfghash != self.state["hash-zeekctlcfg"]:
                self.ui.warn(
                    'zeekctl config has changed (run the zeekctl "deploy" command)'
                )
                return
        else:
            missingstate = True

        # If any of the state variables don't exist, then we need to install
        # (this would most likely indicate an upgrade install was performed
        # over an old version that didn't have the state.db file).
        if missingstate:
            self.ui.warn(
                'state database needs updating (run the zeekctl "deploy" command)'
            )
            return

    # Warn if there might be any dangling Zeek nodes (i.e., nodes that are
    # still running but are either no longer part of the current node
    # configuration or have moved to a new host).
    def _warn_dangling_zeek(self):
        nodes = {}
        for n in self.nodes():
            # Convert node name to lowercase because below we are using
            # node names from the state db (which is lowercase).
            nodes[n.name.lower()] = n.host

        for key in self.state.keys():
            # Look for a PID associated with a Zeek node
            if not key.endswith("-pid"):
                continue

            pid = self.get_state(key)
            if not pid:
                continue

            # Get node name and host name for this node
            nname = key[:-4]
            hostkey = key.replace("-pid", "-host")
            hname = self.get_state(hostkey)
            if not hname:
                continue

            # If node is not a known node or if host has changed, then
            # we must warn about dangling Zeek node.
            if nname not in nodes or hname != nodes[nname]:
                self.ui.warn(
                    f'Zeek node "{nname}" possibly still running on host "{hname}" (PID {pid})'
                )
                # Set the "expected running" flag to False so cron doesn't try
                # to start this node.
                expectkey = key.replace("-pid", "-expect-running")
                self.set_state(expectkey, False)
                # Clear the PID so we don't keep getting warnings.
                self.set_state(key, None)

    # Return a hash value (as a string) of the current zeekctl configuration.
    def _get_zeekctlcfg_hash(self, filehash=False):
        if filehash:
            with open(self.cfgfile) as ff:
                data = ff.read()
        else:
            data = str(sorted(self.config.items()))

        data = data.encode()

        hh = hashlib.sha1()
        hh.update(data)
        return hh.hexdigest()

    # Return a hash value (as a string) of the current zeekctl node config.
    def _get_nodecfg_hash(self, filehash=False):
        if filehash:
            with open(self.nodecfg) as ff:
                data = ff.read()
        else:
            nn = []
            for n in self.nodes():
                nn.append(
                    tuple(
                        [
                            (key, val)
                            for key, val in n.items()
                            if not key.startswith("_")
                        ]
                    )
                )
            data = str(nn)

        data = data.encode()

        hh = hashlib.sha1()
        hh.update(data)
        return hh.hexdigest()

    # Update the stored hash value of the current zeekctl config.
    def update_cfg_hash(self):
        cfghash = self._get_zeekctlcfg_hash()
        nodehash = self._get_nodecfg_hash()

        self.set_state("hash-zeekctlcfg", cfghash)
        self.set_state("hash-nodecfg", nodehash)

    # Runs Zeek to get its version number.
    def _get_zeek_version(self):
        from ZeekControl import execute

        zeek = self.config["zeek"]
        if not os.path.lexists(zeek):
            raise ConfigurationError(f"cannot find Zeek binary: {zeek}")

        version = ""
        success, output = execute.run_localcmd(f"{zeek} -v")
        if success and output:
            version = output.splitlines()[-1]
        else:
            msg = " with no output"
            if output:
                msg = f" with output:\n{output}"
            raise RuntimeEnvironmentError(f'running "zeek -v" failed{msg}')

        match = re.search(".* version ([^ ]*).*$", version)
        if not match:
            raise RuntimeEnvironmentError(
                f'cannot determine Zeek version ("zeek -v" output: {version.strip()})'
            )

        version = match.group(1)
        # If zeek is built with the "--enable-debug" configure option, then it
        # appends "-debug" to the version string.
        if version.endswith("-debug"):
            version = version[:-6]

        return version


# Check if a string is a valid representation of an IP address or not.
def _is_valid_addr(ipstr):
    try:
        if ":" in ipstr:
            socket.inet_pton(socket.AF_INET6, ipstr)
        else:
            socket.inet_pton(socket.AF_INET, ipstr)
    except OSError:
        return False

    return True
