# configtree -- a standalone VyOS config file manipulation library (Python bindings) # Copyright (C) 2018-2022 VyOS maintainers and contributors # # 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA import os import re import json from ctypes import cdll, c_char_p, c_void_p, c_int, c_bool LIBPATH = '/usr/lib/libvyosconfig.so.0' def escape_backslash(string: str) -> str: """Escape single backslashes in string that are not in escape sequence""" p = re.compile(r'(?<!\\)[\\](?!b|f|n|r|t|\\[^bfnrt])') result = p.sub(r'\\\\', string) return result def extract_version(s): """ Extract the version string from the config string """ t = re.split('(^//)', s, maxsplit=1, flags=re.MULTILINE) return (s, ''.join(t[1:])) def check_path(path): # Necessary type checking if not isinstance(path, list): raise TypeError("Expected a list, got a {}".format(type(path))) else: pass class ConfigTreeError(Exception): pass class ConfigTree(object): def __init__(self, config_string=None, address=None, libpath=LIBPATH): if config_string is None and address is None: raise TypeError("ConfigTree() requires one of 'config_string' or 'address'") self.__config = None self.__lib = cdll.LoadLibrary(libpath) # Import functions self.__from_string = self.__lib.from_string self.__from_string.argtypes = [c_char_p] self.__from_string.restype = c_void_p self.__get_error = self.__lib.get_error self.__get_error.argtypes = [] self.__get_error.restype = c_char_p self.__to_string = self.__lib.to_string self.__to_string.argtypes = [c_void_p, c_bool] self.__to_string.restype = c_char_p self.__to_commands = self.__lib.to_commands self.__to_commands.argtypes = [c_void_p, c_char_p] self.__to_commands.restype = c_char_p self.__to_json = self.__lib.to_json self.__to_json.argtypes = [c_void_p] self.__to_json.restype = c_char_p self.__to_json_ast = self.__lib.to_json_ast self.__to_json_ast.argtypes = [c_void_p] self.__to_json_ast.restype = c_char_p self.__set_add_value = self.__lib.set_add_value self.__set_add_value.argtypes = [c_void_p, c_char_p, c_char_p] self.__set_add_value.restype = c_int self.__delete_value = self.__lib.delete_value self.__delete_value.argtypes = [c_void_p, c_char_p, c_char_p] self.__delete_value.restype = c_int self.__delete = self.__lib.delete_node self.__delete.argtypes = [c_void_p, c_char_p] self.__delete.restype = c_int self.__rename = self.__lib.rename_node self.__rename.argtypes = [c_void_p, c_char_p, c_char_p] self.__rename.restype = c_int self.__copy = self.__lib.copy_node self.__copy.argtypes = [c_void_p, c_char_p, c_char_p] self.__copy.restype = c_int self.__set_replace_value = self.__lib.set_replace_value self.__set_replace_value.argtypes = [c_void_p, c_char_p, c_char_p] self.__set_replace_value.restype = c_int self.__set_valueless = self.__lib.set_valueless self.__set_valueless.argtypes = [c_void_p, c_char_p] self.__set_valueless.restype = c_int self.__exists = self.__lib.exists self.__exists.argtypes = [c_void_p, c_char_p] self.__exists.restype = c_int self.__list_nodes = self.__lib.list_nodes self.__list_nodes.argtypes = [c_void_p, c_char_p] self.__list_nodes.restype = c_char_p self.__return_value = self.__lib.return_value self.__return_value.argtypes = [c_void_p, c_char_p] self.__return_value.restype = c_char_p self.__return_values = self.__lib.return_values self.__return_values.argtypes = [c_void_p, c_char_p] self.__return_values.restype = c_char_p self.__is_tag = self.__lib.is_tag self.__is_tag.argtypes = [c_void_p, c_char_p] self.__is_tag.restype = c_int self.__set_tag = self.__lib.set_tag self.__set_tag.argtypes = [c_void_p, c_char_p] self.__set_tag.restype = c_int self.__get_subtree = self.__lib.get_subtree self.__get_subtree.argtypes = [c_void_p, c_char_p] self.__get_subtree.restype = c_void_p self.__destroy = self.__lib.destroy self.__destroy.argtypes = [c_void_p] if address is None: config_section, version_section = extract_version(config_string) config_section = escape_backslash(config_section) config = self.__from_string(config_section.encode()) if config is None: msg = self.__get_error().decode() raise ValueError("Failed to parse config: {0}".format(msg)) else: self.__config = config self.__version = version_section else: self.__config = address self.__version = '' self.__migration = os.environ.get('VYOS_MIGRATION') def __del__(self): if self.__config is not None: self.__destroy(self.__config) def __str__(self): return self.to_string() def _get_config(self): return self.__config def to_string(self, ordered_values=False): config_string = self.__to_string(self.__config, ordered_values).decode() config_string = "{0}\n{1}".format(config_string, self.__version) return config_string def to_commands(self, op="set"): return self.__to_commands(self.__config, op.encode()).decode() def to_json(self): return self.__to_json(self.__config).decode() def to_json_ast(self): return self.__to_json_ast(self.__config).decode() def set(self, path, value=None, replace=True): """Set new entry in VyOS configuration. path: configuration path e.g. 'system dns forwarding listen-address' value: value to be added to node, e.g. '172.18.254.201' replace: True: current occurance will be replaced False: new value will be appended to current occurances - use this for adding values to a multi node """ check_path(path) path_str = " ".join(map(str, path)).encode() if value is None: self.__set_valueless(self.__config, path_str) else: if replace: self.__set_replace_value(self.__config, path_str, str(value).encode()) else: self.__set_add_value(self.__config, path_str, str(value).encode()) if self.__migration: print(f"- op: set path: {path} value: {value} replace: {replace}") def delete(self, path): check_path(path) path_str = " ".join(map(str, path)).encode() res = self.__delete(self.__config, path_str) if (res != 0): raise ConfigTreeError(f"Path doesn't exist: {path}") if self.__migration: print(f"- op: delete path: {path}") def delete_value(self, path, value): check_path(path) path_str = " ".join(map(str, path)).encode() res = self.__delete_value(self.__config, path_str, value.encode()) if (res != 0): if res == 1: raise ConfigTreeError(f"Path doesn't exist: {path}") elif res == 2: raise ConfigTreeError(f"Value doesn't exist: '{value}'") else: raise ConfigTreeError() if self.__migration: print(f"- op: delete_value path: {path} value: {value}") def rename(self, path, new_name): check_path(path) path_str = " ".join(map(str, path)).encode() newname_str = new_name.encode() # Check if a node with intended new name already exists new_path = path[:-1] + [new_name] if self.exists(new_path): raise ConfigTreeError() res = self.__rename(self.__config, path_str, newname_str) if (res != 0): raise ConfigTreeError("Path [{}] doesn't exist".format(path)) if self.__migration: print(f"- op: rename old_path: {path} new_path: {new_path}") def copy(self, old_path, new_path): check_path(old_path) check_path(new_path) oldpath_str = " ".join(map(str, old_path)).encode() newpath_str = " ".join(map(str, new_path)).encode() # Check if a node with intended new name already exists if self.exists(new_path): raise ConfigTreeError() res = self.__copy(self.__config, oldpath_str, newpath_str) if (res != 0): msg = self.__get_error().decode() raise ConfigTreeError(msg) if self.__migration: print(f"- op: copy old_path: {old_path} new_path: {new_path}") def exists(self, path): check_path(path) path_str = " ".join(map(str, path)).encode() res = self.__exists(self.__config, path_str) if (res == 0): return False else: return True def list_nodes(self, path): check_path(path) path_str = " ".join(map(str, path)).encode() res_json = self.__list_nodes(self.__config, path_str).decode() res = json.loads(res_json) if res is None: raise ConfigTreeError("Path [{}] doesn't exist".format(path_str)) else: return res def return_value(self, path): check_path(path) path_str = " ".join(map(str, path)).encode() res_json = self.__return_value(self.__config, path_str).decode() res = json.loads(res_json) if res is None: raise ConfigTreeError("Path [{}] doesn't exist".format(path_str)) else: return res def return_values(self, path): check_path(path) path_str = " ".join(map(str, path)).encode() res_json = self.__return_values(self.__config, path_str).decode() res = json.loads(res_json) if res is None: raise ConfigTreeError("Path [{}] doesn't exist".format(path_str)) else: return res def is_tag(self, path): check_path(path) path_str = " ".join(map(str, path)).encode() res = self.__is_tag(self.__config, path_str) if (res >= 1): return True else: return False def set_tag(self, path): check_path(path) path_str = " ".join(map(str, path)).encode() res = self.__set_tag(self.__config, path_str) if (res == 0): return True else: raise ConfigTreeError("Path [{}] doesn't exist".format(path_str)) def get_subtree(self, path, with_node=False): check_path(path) path_str = " ".join(map(str, path)).encode() res = self.__get_subtree(self.__config, path_str, with_node) subt = ConfigTree(address=res) return subt def show_diff(left, right, path=[], commands=False, libpath=LIBPATH): if left is None: left = ConfigTree(config_string='\n') if right is None: right = ConfigTree(config_string='\n') if not (isinstance(left, ConfigTree) and isinstance(right, ConfigTree)): raise TypeError("Arguments must be instances of ConfigTree") if path: if (not left.exists(path)) and (not right.exists(path)): raise ConfigTreeError(f"Path {path} doesn't exist") check_path(path) path_str = " ".join(map(str, path)).encode() __lib = cdll.LoadLibrary(libpath) __show_diff = __lib.show_diff __show_diff.argtypes = [c_bool, c_char_p, c_void_p, c_void_p] __show_diff.restype = c_char_p __get_error = __lib.get_error __get_error.argtypes = [] __get_error.restype = c_char_p res = __show_diff(commands, path_str, left._get_config(), right._get_config()) res = res.decode() if res == "#1@": msg = __get_error().decode() raise ConfigTreeError(msg) return res def union(left, right, libpath=LIBPATH): if left is None: left = ConfigTree(config_string='\n') if right is None: right = ConfigTree(config_string='\n') if not (isinstance(left, ConfigTree) and isinstance(right, ConfigTree)): raise TypeError("Arguments must be instances of ConfigTree") __lib = cdll.LoadLibrary(libpath) __tree_union = __lib.tree_union __tree_union.argtypes = [c_void_p, c_void_p] __tree_union.restype = c_void_p __get_error = __lib.get_error __get_error.argtypes = [] __get_error.restype = c_char_p res = __tree_union( left._get_config(), right._get_config()) tree = ConfigTree(address=res) return tree def reference_tree_to_json(from_dir, to_file, libpath=LIBPATH): __lib = cdll.LoadLibrary(libpath) __reference_tree_to_json = __lib.reference_tree_to_json __reference_tree_to_json.argtypes = [c_char_p, c_char_p] __get_error = __lib.get_error __get_error.argtypes = [] __get_error.restype = c_char_p res = __reference_tree_to_json(from_dir.encode(), to_file.encode()) if res == 1: msg = __get_error().decode() raise ConfigTreeError(msg) class DiffTree: def __init__(self, left, right, path=[], libpath=LIBPATH): if left is None: left = ConfigTree(config_string='\n') if right is None: right = ConfigTree(config_string='\n') if not (isinstance(left, ConfigTree) and isinstance(right, ConfigTree)): raise TypeError("Arguments must be instances of ConfigTree") if path: if not left.exists(path): raise ConfigTreeError(f"Path {path} doesn't exist in lhs tree") if not right.exists(path): raise ConfigTreeError(f"Path {path} doesn't exist in rhs tree") self.left = left self.right = right self.__lib = cdll.LoadLibrary(libpath) self.__diff_tree = self.__lib.diff_tree self.__diff_tree.argtypes = [c_char_p, c_void_p, c_void_p] self.__diff_tree.restype = c_void_p self.__trim_tree = self.__lib.trim_tree self.__trim_tree.argtypes = [c_void_p, c_void_p] self.__trim_tree.restype = c_void_p check_path(path) path_str = " ".join(map(str, path)).encode() res = self.__diff_tree(path_str, left._get_config(), right._get_config()) # full diff config_tree and python dict representation self.full = ConfigTree(address=res) self.dict = json.loads(self.full.to_json()) # config_tree sub-trees self.add = self.full.get_subtree(['add']) self.sub = self.full.get_subtree(['sub']) self.inter = self.full.get_subtree(['inter']) # trim sub(-tract) tree to get delete tree for commands ref = self.right.get_subtree(path, with_node=True) if path else self.right res = self.__trim_tree(self.sub._get_config(), ref._get_config()) self.delete = ConfigTree(address=res) def to_commands(self): add = self.add.to_commands() delete = self.delete.to_commands(op="delete") return delete + "\n" + add