# Copyright 2020-2021 VyOS maintainers and contributors <maintainers@vyos.io> # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This library is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library. If not, see <http://www.gnu.org/licenses/>. import os import re import sys # # NOTE: Do not import full classes here, move your import to the function # where it is used so it is as local as possible to the execution # from subprocess import Popen from subprocess import PIPE from subprocess import STDOUT from subprocess import DEVNULL def popen(command, flag='', shell=None, input=None, timeout=None, env=None, stdout=PIPE, stderr=PIPE, decode='utf-8'): """ popen is a wrapper helper aound subprocess.Popen with it default setting it will return a tuple (out, err) out: the output of the program run err: the error code returned by the program it can be affected by the following flags: shell: do not try to auto-detect if a shell is required for example if a pipe (|) or redirection (>, >>) is used input: data to sent to the child process via STDIN the data should be bytes but string will be converted timeout: time after which the command will be considered to have failed env: mapping that defines the environment variables for the new process stdout: define how the output of the program should be handled - PIPE (default), sends stdout to the output - DEVNULL, discard the output stderr: define how the output of the program should be handled - None (default), send/merge the data to/with stderr - PIPE, popen will append it to output - STDOUT, send the data to be merged with stdout - DEVNULL, discard the output decode: specify the expected text encoding (utf-8, ascii, ...) the default is explicitely utf-8 which is python's own default usage: get both stdout and stderr: popen('command', stdout=PIPE, stderr=STDOUT) discard stdout and get stderr: popen('command', stdout=DEVNUL, stderr=PIPE) """ # airbag must be left as an import in the function as otherwise we have a # a circual import dependency from vyos import debug from vyos import airbag # log if the flag is set, otherwise log if command is set if not debug.enabled(flag): flag = 'command' cmd_msg = f"cmd '{command}'" debug.message(cmd_msg, flag) use_shell = shell stdin = None if shell is None: use_shell = False if ' ' in command: use_shell = True if env: use_shell = True if input: stdin = PIPE input = input.encode() if type(input) is str else input p = Popen(command, stdin=stdin, stdout=stdout, stderr=stderr, env=env, shell=use_shell) pipe = p.communicate(input, timeout) pipe_out = b'' if stdout == PIPE: pipe_out = pipe[0] pipe_err = b'' if stderr == PIPE: pipe_err = pipe[1] str_out = pipe_out.decode(decode).replace('\r\n', '\n').strip() str_err = pipe_err.decode(decode).replace('\r\n', '\n').strip() out_msg = f"returned (out):\n{str_out}" if str_out: debug.message(out_msg, flag) if str_err: err_msg = f"returned (err):\n{str_err}" # this message will also be send to syslog via airbag debug.message(err_msg, flag, destination=sys.stderr) # should something go wrong, report this too via airbag airbag.noteworthy(cmd_msg) airbag.noteworthy(out_msg) airbag.noteworthy(err_msg) return str_out, p.returncode def run(command, flag='', shell=None, input=None, timeout=None, env=None, stdout=DEVNULL, stderr=PIPE, decode='utf-8'): """ A wrapper around popen, which discard the stdout and will return the error code of a command """ _, code = popen( command, flag, stdout=stdout, stderr=stderr, input=input, timeout=timeout, env=env, shell=shell, decode=decode, ) return code def cmd(command, flag='', shell=None, input=None, timeout=None, env=None, stdout=PIPE, stderr=PIPE, decode='utf-8', raising=None, message='', expect=[0]): """ A wrapper around popen, which returns the stdout and will raise the error code of a command raising: specify which call should be used when raising the class should only require a string as parameter (default is OSError) with the error code expect: a list of error codes to consider as normal """ decoded, code = popen( command, flag, stdout=stdout, stderr=stderr, input=input, timeout=timeout, env=env, shell=shell, decode=decode, ) if code not in expect: feedback = message + '\n' if message else '' feedback += f'failed to run command: {command}\n' feedback += f'returned: {decoded}\n' feedback += f'exit code: {code}' if raising is None: # error code can be recovered with .errno raise OSError(code, feedback) else: raise raising(feedback) return decoded def call(command, flag='', shell=None, input=None, timeout=None, env=None, stdout=PIPE, stderr=PIPE, decode='utf-8'): """ A wrapper around popen, which print the stdout and will return the error code of a command """ out, code = popen( command, flag, stdout=stdout, stderr=stderr, input=input, timeout=timeout, env=env, shell=shell, decode=decode, ) if out: print(out) return code def read_file(fname, defaultonfailure=None): """ read the content of a file, stripping any end characters (space, newlines) should defaultonfailure be not None, it is returned on failure to read """ try: """ Read a file to string """ with open(fname, 'r') as f: data = f.read().strip() return data except Exception as e: if defaultonfailure is not None: return defaultonfailure raise e def write_file(fname, data, defaultonfailure=None, user=None, group=None): """ Write content of data to given fname, should defaultonfailure be not None, it is returned on failure to read. If directory of file is not present, it is auto-created. """ dirname = os.path.dirname(fname) if not os.path.isdir(dirname): os.makedirs(dirname, mode=0o755, exist_ok=False) chown(dirname, user, group) try: """ Write a file to string """ bytes = 0 with open(fname, 'w') as f: bytes = f.write(data) chown(fname, user, group) return bytes except Exception as e: if defaultonfailure is not None: return defaultonfailure raise e def read_json(fname, defaultonfailure=None): """ read and json decode the content of a file should defaultonfailure be not None, it is returned on failure to read """ import json try: with open(fname, 'r') as f: data = json.load(f) return data except Exception as e: if defaultonfailure is not None: return defaultonfailure raise e def chown(path, user, group): """ change file/directory owner """ from pwd import getpwnam from grp import getgrnam if user is None or group is None: return False # path may also be an open file descriptor if not isinstance(path, int) and not os.path.exists(path): return False uid = getpwnam(user).pw_uid gid = getgrnam(group).gr_gid os.chown(path, uid, gid) return True def chmod(path, bitmask): # path may also be an open file descriptor if not isinstance(path, int) and not os.path.exists(path): return if bitmask is None: return os.chmod(path, bitmask) def chmod_600(path): """ make file only read/writable by owner """ from stat import S_IRUSR, S_IWUSR bitmask = S_IRUSR | S_IWUSR chmod(path, bitmask) def chmod_750(path): """ make file/directory only executable to user and group """ from stat import S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IXGRP bitmask = S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP chmod(path, bitmask) def chmod_755(path): """ make file executable by all """ from stat import S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IXGRP, S_IROTH, S_IXOTH bitmask = S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP | \ S_IROTH | S_IXOTH chmod(path, bitmask) def makedir(path, user=None, group=None): if os.path.exists(path): return os.makedirs(path, mode=0o755) chown(path, user, group) def colon_separated_to_dict(data_string, uniquekeys=False): """ Converts a string containing newline-separated entries of colon-separated key-value pairs into a dict. Such files are common in Linux /proc filesystem Args: data_string (str): data string uniquekeys (bool): whether to insist that keys are unique or not Returns: dict Raises: ValueError: if uniquekeys=True and the data string has duplicate keys. Note: If uniquekeys=True, then dict entries are always strings, otherwise they are always lists of strings. """ import re key_value_re = re.compile('([^:]+)\s*\:\s*(.*)') data_raw = re.split('\n', data_string) data = {} for l in data_raw: l = l.strip() if l: match = re.match(key_value_re, l) if match: key = match.groups()[0].strip() value = match.groups()[1].strip() if key in data.keys(): if uniquekeys: raise ValueError("Data string has duplicate keys: {0}".format(key)) else: data[key].append(value) else: if uniquekeys: data[key] = value else: data[key] = [value] else: pass return data def _mangle_dict_keys(data, regex, replacement, abs_path=[], no_tag_node_value_mangle=False, mod=0): """ Mangles dict keys according to a regex and replacement character. Some libraries like Jinja2 do not like certain characters in dict keys. This function can be used for replacing all offending characters with something acceptable. Args: data (dict): Original dict to mangle Returns: dict """ from vyos.xml import is_tag new_dict = {} for key in data.keys(): save_mod = mod save_path = abs_path[:] abs_path.append(key) if not is_tag(abs_path): new_key = re.sub(regex, replacement, key) else: if mod%2: new_key = key else: new_key = re.sub(regex, replacement, key) if no_tag_node_value_mangle: mod += 1 value = data[key] if isinstance(value, dict): new_dict[new_key] = _mangle_dict_keys(value, regex, replacement, abs_path=abs_path, mod=mod, no_tag_node_value_mangle=no_tag_node_value_mangle) else: new_dict[new_key] = value mod = save_mod abs_path = save_path[:] return new_dict def mangle_dict_keys(data, regex, replacement, abs_path=[], no_tag_node_value_mangle=False): return _mangle_dict_keys(data, regex, replacement, abs_path=abs_path, no_tag_node_value_mangle=no_tag_node_value_mangle, mod=0) def _get_sub_dict(d, lpath): k = lpath[0] if k not in d.keys(): return {} c = {k: d[k]} lpath = lpath[1:] if not lpath: return c elif not isinstance(c[k], dict): return {} return _get_sub_dict(c[k], lpath) def get_sub_dict(source, lpath, get_first_key=False): """ Returns the sub-dict of a nested dict, defined by path of keys. Args: source (dict): Source dict to extract from lpath (list[str]): sequence of keys Returns: source, if lpath is empty, else {key : source[..]..[key]} for key the last element of lpath, if exists {} otherwise """ if not isinstance(source, dict): raise TypeError("source must be of type dict") if not isinstance(lpath, list): raise TypeError("path must be of type list") if not lpath: return source ret = _get_sub_dict(source, lpath) if get_first_key and lpath and ret: tmp = next(iter(ret.values())) if not isinstance(tmp, dict): raise TypeError("Data under node is not of type dict") ret = tmp return ret def process_running(pid_file): """ Checks if a process with PID in pid_file is running """ from psutil import pid_exists if not os.path.isfile(pid_file): return False with open(pid_file, 'r') as f: pid = f.read().strip() return pid_exists(int(pid)) def process_named_running(name): """ Checks if process with given name is running and returns its PID. If Process is not running, return None """ from psutil import process_iter for p in process_iter(): if name in p.name(): return p.pid return None def seconds_to_human(s, separator=""): """ Converts number of seconds passed to a human-readable interval such as 1w4d18h35m59s """ s = int(s) week = 60 * 60 * 24 * 7 day = 60 * 60 * 24 hour = 60 * 60 remainder = 0 result = "" weeks = s // week if weeks > 0: result = "{0}w".format(weeks) s = s % week days = s // day if days > 0: result = "{0}{1}{2}d".format(result, separator, days) s = s % day hours = s // hour if hours > 0: result = "{0}{1}{2}h".format(result, separator, hours) s = s % hour minutes = s // 60 if minutes > 0: result = "{0}{1}{2}m".format(result, separator, minutes) s = s % 60 seconds = s if seconds > 0: result = "{0}{1}{2}s".format(result, separator, seconds) return result def get_cfg_group_id(): from grp import getgrnam from vyos.defaults import cfg_group group_data = getgrnam(cfg_group) return group_data.gr_gid def file_is_persistent(path): import re location = r'^(/config|/opt/vyatta/etc/config)' absolute = os.path.abspath(os.path.dirname(path)) return re.match(location,absolute) def wait_for_inotify(file_path, pre_hook=None, event_type=None, timeout=None, sleep_interval=0.1): """ Waits for an inotify event to occur """ if not os.path.dirname(file_path): raise ValueError( "File path {} does not have a directory part (required for inotify watching)".format(file_path)) if not os.path.basename(file_path): raise ValueError( "File path {} does not have a file part, do not know what to watch for".format(file_path)) from inotify.adapters import Inotify from time import time from time import sleep time_start = time() i = Inotify() i.add_watch(os.path.dirname(file_path)) if pre_hook: pre_hook() for event in i.event_gen(yield_nones=True): if (timeout is not None) and ((time() - time_start) > timeout): # If the function didn't return until this point, # the file failed to have been written to and closed within the timeout raise OSError("Waiting for file {} to be written has failed".format(file_path)) # Most such events don't take much time, so it's better to check right away # and sleep later. if event is not None: (_, type_names, path, filename) = event if filename == os.path.basename(file_path): if event_type in type_names: return sleep(sleep_interval) def wait_for_file_write_complete(file_path, pre_hook=None, timeout=None, sleep_interval=0.1): """ Waits for a process to close a file after opening it in write mode. """ wait_for_inotify(file_path, event_type='IN_CLOSE_WRITE', pre_hook=pre_hook, timeout=timeout, sleep_interval=sleep_interval) def commit_in_progress(): """ Not to be used in normal op mode scripts! """ # The CStore backend locks the config by opening a file # The file is not removed after commit, so just checking # if it exists is insufficient, we need to know if it's open by anyone # There are two ways to check if any other process keeps a file open. # The first one is to try opening it and see if the OS objects. # That's faster but prone to race conditions and can be intrusive. # The other one is to actually check if any process keeps it open. # It's non-intrusive but needs root permissions, else you can't check # processes of other users. # # Since this will be used in scripts that modify the config outside of the CLI # framework, those knowingly have root permissions. # For everything else, we add a safeguard. from psutil import process_iter from psutil import NoSuchProcess from getpass import getuser from vyos.defaults import commit_lock if getuser() != 'root': raise OSError('This functions needs to be run as root to return correct results!') for proc in process_iter(): try: files = proc.open_files() if files: for f in files: if f.path == commit_lock: return True except NoSuchProcess as err: # Process died before we could examine it pass # Default case return False def wait_for_commit_lock(): """ Not to be used in normal op mode scripts! """ from time import sleep # Very synchronous approach to multiprocessing while commit_in_progress(): sleep(1) def ask_yes_no(question, default=False) -> bool: """Ask a yes/no question via input() and return their answer.""" from sys import stdout default_msg = "[Y/n]" if default else "[y/N]" while True: try: stdout.write("%s %s " % (question, default_msg)) c = input().lower() if c == '': return default elif c in ("y", "ye", "yes"): return True elif c in ("n", "no"): return False else: stdout.write("Please respond with yes/y or no/n\n") except EOFError: stdout.write("\nPlease respond with yes/y or no/n\n") def is_admin() -> bool: """Look if current user is in sudo group""" from getpass import getuser from grp import getgrnam current_user = getuser() (_, _, _, admin_group_members) = getgrnam('sudo') return current_user in admin_group_members def mac2eui64(mac, prefix=None): """ Convert a MAC address to a EUI64 address or, with prefix provided, a full IPv6 address. Thankfully copied from https://gist.github.com/wido/f5e32576bb57b5cc6f934e177a37a0d3 """ import re from ipaddress import ip_network # http://tools.ietf.org/html/rfc4291#section-2.5.1 eui64 = re.sub(r'[.:-]', '', mac).lower() eui64 = eui64[0:6] + 'fffe' + eui64[6:] eui64 = hex(int(eui64[0:2], 16) ^ 2)[2:].zfill(2) + eui64[2:] if prefix is None: return ':'.join(re.findall(r'.{4}', eui64)) else: try: net = ip_network(prefix, strict=False) euil = int('0x{0}'.format(eui64), 16) return str(net[euil]) except: # pylint: disable=bare-except return def get_half_cpus(): """ return 1/2 of the numbers of available CPUs """ cpu = os.cpu_count() if cpu > 1: cpu /= 2 return int(cpu) def check_kmod(k_mod): """ Common utility function to load required kernel modules on demand """ from vyos import ConfigError if isinstance(k_mod, str): k_mod = k_mod.split() for module in k_mod: if not os.path.exists(f'/sys/module/{module}'): if call(f'modprobe {module}') != 0: raise ConfigError(f'Loading Kernel module {module} failed') def find_device_file(device): """ Recurively search /dev for the given device file and return its full path. If no device file was found 'None' is returned """ from fnmatch import fnmatch for root, dirs, files in os.walk('/dev'): for basename in files: if fnmatch(basename, device): return os.path.join(root, basename) return None def dict_search(path, dict_object): """ Traverse Python dictionary (dict_object) delimited by dot (.). Return value of key if found, None otherwise. This is faster implementation then jmespath.search('foo.bar', dict_object)""" if not isinstance(dict_object, dict) or not path: return None parts = path.split('.') inside = parts[:-1] if not inside: if path not in dict_object: return None return dict_object[path] c = dict_object for p in parts[:-1]: c = c.get(p, {}) return c.get(parts[-1], None) def get_interface_config(interface): """ Returns the used encapsulation protocol for given interface. If interface does not exist, None is returned. """ if not os.path.exists(f'/sys/class/net/{interface}'): return None from json import loads tmp = loads(cmd(f'ip -d -j link show {interface}'))[0] return tmp def is_systemd_service_active(service): """ Test is a specified systemd service is activated. Returns True if service is active, false otherwise. Copied from: https://unix.stackexchange.com/a/435317 """ tmp = cmd(f'systemctl show --value -p ActiveState {service}') return bool((tmp == 'active')) def is_systemd_service_running(service): """ Test is a specified systemd service is actually running. Returns True if service is running, false otherwise. Copied from: https://unix.stackexchange.com/a/435317 """ tmp = cmd(f'systemctl show --value -p SubState {service}') return bool((tmp == 'running'))