#!/usr/bin/python -u # -*- coding: utf-8 -*- import os import sys import subprocess import syslog import copy import jinja2 import ipaddr as ipaddress from swsssdk import ConfigDBConnector # FILE PAM_AUTH_CONF = "/etc/pam.d/common-auth-sonic" PAM_AUTH_CONF_TEMPLATE = "/usr/share/sonic/templates/common-auth-sonic.j2" NSS_TACPLUS_CONF = "/etc/tacplus_nss.conf" NSS_TACPLUS_CONF_TEMPLATE = "/usr/share/sonic/templates/tacplus_nss.conf.j2" NSS_CONF = "/etc/nsswitch.conf" # TACACS+ TACPLUS_SERVER_PASSKEY_DEFAULT = "" TACPLUS_SERVER_TIMEOUT_DEFAULT = "5" TACPLUS_SERVER_AUTH_TYPE_DEFAULT = "pap" def is_true(val): if val == 'True' or val == 'true': return True else: return False def sub(l, start, end): return l[start:end] def obfuscate(data): if data: return data[0] + '*****' else: return data def update_feature_state(feature_name, state): if state == "enabled": start_cmds = [] start_cmds.append("sudo systemctl unmask {}.service".format(feature_name)) start_cmds.append("sudo systemctl enable {}.service".format(feature_name)) start_cmds.append("sudo systemctl start {}.service".format(feature_name)) for cmd in start_cmds: syslog.syslog(syslog.LOG_INFO, "Running cmd: '{}'".format(cmd)) try: subprocess.check_call(cmd, shell=True) except subprocess.CalledProcessError as err: syslog.syslog(syslog.LOG_ERR, "'{}' failed. RC: {}, output: {}" .format(err.cmd, err.returncode, err.output)) continue syslog.syslog(syslog.LOG_INFO, "Feature '{}' is enabled and started".format(feature_name)) elif state == "disabled": stop_cmds = [] stop_cmds.append("sudo systemctl stop {}.service".format(feature_name)) stop_cmds.append("sudo systemctl disable {}.service".format(feature_name)) stop_cmds.append("sudo systemctl mask {}.service".format(feature_name)) for cmd in stop_cmds: syslog.syslog(syslog.LOG_INFO, "Running cmd: '{}'".format(cmd)) try: subprocess.check_call(cmd, shell=True) except subprocess.CalledProcessError as err: syslog.syslog(syslog.LOG_ERR, "'{}' failed. RC: {}, output: {}" .format(err.cmd, err.returncode, err.output)) continue syslog.syslog(syslog.LOG_INFO, "Feature '{}' is stopped and disabled".format(feature_name)) else: syslog.syslog(syslog.LOG_ERR, "Unexpected state value '{}' for feature '{}'".format(state, feature_name)) class Iptables(object): def __init__(self): ''' Default MSS to 1460 - (MTU 1500 - 40 (TCP/IP Overhead)) For IPv6, it would be 1440 - (MTU 1500 - 60 octects) ''' self.tcpmss = 1460 self.tcp6mss = 1440 def is_ip_prefix_in_key(self, key): ''' Function to check if IP address is present in the key. If it is present, then the key would be a tuple or else, it shall be be string ''' return (isinstance(key, tuple)) def load(self, lpbk_table): for row in lpbk_table: self.iptables_handler(row, lpbk_table[row]) def command(self, chain, ip, ver, op): cmd = 'iptables' if ver == '4' else 'ip6tables' cmd += ' -t mangle --{} {} -p tcp --tcp-flags SYN SYN'.format(op, chain) cmd += ' -d' if chain == 'PREROUTING' else ' -s' mss = self.tcpmss if ver == '4' else self.tcp6mss cmd += ' {} -j TCPMSS --set-mss {}'.format(ip, mss) return cmd def iptables_handler(self, key, data, add=True): if not self.is_ip_prefix_in_key(key): return iface, ip = key ip_str = ip.split("/")[0] ip_addr = ipaddress.IPAddress(ip_str) if isinstance(ip_addr, ipaddress.IPv6Address): ver = '6' else: ver = '4' self.mangle_handler(ip_str, ver, add) def mangle_handler(self, ip, ver, add): if not add: op = 'delete' else: op = 'check' iptables_cmds = [] chains = ['PREROUTING', 'POSTROUTING'] for chain in chains: cmd = self.command(chain, ip, ver, op) if not add: iptables_cmds.append(cmd) else: ''' For add case, first check if rule exists. Iptables just appends to the chain as a new rule even if it is the same as an existing one. Check this and do nothing if rule exists ''' ret = subprocess.call(cmd, shell=True) if ret == 0: syslog.syslog(syslog.LOG_INFO, "{} rule exists in {}".format(ip, chain)) else: # Modify command from Check to Append iptables_cmds.append(cmd.replace("check", "append")) for cmd in iptables_cmds: syslog.syslog(syslog.LOG_INFO, "Running cmd - {}".format(cmd)) try: subprocess.check_call(cmd, shell=True) except subprocess.CalledProcessError as err: syslog.syslog(syslog.LOG_ERR, "'{}' failed. RC: {}, output: {}" .format(err.cmd, err.returncode, err.output)) class AaaCfg(object): def __init__(self): self.auth_default = { 'login': 'local', } self.tacplus_global_default = { 'auth_type': TACPLUS_SERVER_AUTH_TYPE_DEFAULT, 'timeout': TACPLUS_SERVER_TIMEOUT_DEFAULT, 'passkey': TACPLUS_SERVER_PASSKEY_DEFAULT } self.auth = {} self.tacplus_global = {} self.tacplus_servers = {} self.debug = False # Load conf from ConfigDb def load(self, aaa_conf, tac_global_conf, tacplus_conf): for row in aaa_conf: self.aaa_update(row, aaa_conf[row], modify_conf=False) for row in tac_global_conf: self.tacacs_global_update(row, tac_global_conf[row], modify_conf=False) for row in tacplus_conf: self.tacacs_server_update(row, tacplus_conf[row], modify_conf=False) self.modify_conf_file() def aaa_update(self, key, data, modify_conf=True): if key == 'authentication': self.auth = data if 'failthrough' in data: self.auth['failthrough'] = is_true(data['failthrough']) if 'debug' in data: self.debug = is_true(data['debug']) if modify_conf: self.modify_conf_file() def tacacs_global_update(self, key, data, modify_conf=True): if key == 'global': self.tacplus_global = data if modify_conf: self.modify_conf_file() def tacacs_server_update(self, key, data, modify_conf=True): if data == {}: if key in self.tacplus_servers: del self.tacplus_servers[key] else: self.tacplus_servers[key] = data if modify_conf: self.modify_conf_file() def modify_single_file(self, filename, operations=None): if operations: cmd = "sed -e {0} {1} > {1}.new; mv -f {1} {1}.old; mv -f {1}.new {1}".format(' -e '.join(operations), filename) os.system(cmd) def modify_conf_file(self): auth = self.auth_default.copy() auth.update(self.auth) tacplus_global = self.tacplus_global_default.copy() tacplus_global.update(self.tacplus_global) if 'src_ip' in tacplus_global: src_ip = tacplus_global['src_ip'] else: src_ip = None servers_conf = [] if self.tacplus_servers: for addr in self.tacplus_servers: server = tacplus_global.copy() server['ip'] = addr server.update(self.tacplus_servers[addr]) servers_conf.append(server) servers_conf = sorted(servers_conf, key=lambda t: int(t['priority']), reverse=True) template_file = os.path.abspath(PAM_AUTH_CONF_TEMPLATE) env = jinja2.Environment(loader=jinja2.FileSystemLoader('/'), trim_blocks=True) env.filters['sub'] = sub template = env.get_template(template_file) pam_conf = template.render(auth=auth, src_ip=src_ip, servers=servers_conf) with open(PAM_AUTH_CONF, 'w') as f: f.write(pam_conf) # Modify common-auth include file in /etc/pam.d/login and sshd if os.path.isfile(PAM_AUTH_CONF): self.modify_single_file('/etc/pam.d/sshd', [ "'/^@include/s/common-auth$/common-auth-sonic/'" ]) self.modify_single_file('/etc/pam.d/login', [ "'/^@include/s/common-auth$/common-auth-sonic/'" ]) else: self.modify_single_file('/etc/pam.d/sshd', [ "'/^@include/s/common-auth-sonic$/common-auth/'" ]) self.modify_single_file('/etc/pam.d/login', [ "'/^@include/s/common-auth-sonic$/common-auth/'" ]) # Add tacplus in nsswitch.conf if TACACS+ enable if 'tacacs+' in auth['login']: if os.path.isfile(NSS_CONF): self.modify_single_file(NSS_CONF, [ "'/tacplus/b'", "'/^passwd/s/compat/tacplus &/'", "'/^passwd/s/files/tacplus &/'" ]) else: if os.path.isfile(NSS_CONF): self.modify_single_file(NSS_CONF, [ "'/^passwd/s/tacplus //g'" ]) # Set tacacs+ server in nss-tacplus conf template_file = os.path.abspath(NSS_TACPLUS_CONF_TEMPLATE) template = env.get_template(template_file) nss_tacplus_conf = template.render(debug=self.debug, src_ip=src_ip, servers=servers_conf) with open(NSS_TACPLUS_CONF, 'w') as f: f.write(nss_tacplus_conf) class HostConfigDaemon: def __init__(self): self.config_db = ConfigDBConnector() self.config_db.connect(wait_for_init=True, retry_on=True) syslog.syslog(syslog.LOG_INFO, 'ConfigDB connect success') aaa = self.config_db.get_table('AAA') tacacs_global = self.config_db.get_table('TACPLUS') tacacs_server = self.config_db.get_table('TACPLUS_SERVER') self.aaacfg = AaaCfg() self.aaacfg.load(aaa, tacacs_global, tacacs_server) lpbk_table = self.config_db.get_table('LOOPBACK_INTERFACE') self.iptables = Iptables() self.iptables.load(lpbk_table) def update_all_feature_states(self): feature_table = self.config_db.get_table('FEATURE') for feature_name in feature_table.keys(): if not feature_name: syslog.syslog(syslog.LOG_WARNING, "Feature is None") continue state = feature_table[feature_name]['state'] if not state: syslog.syslog(syslog.LOG_WARNING, "Eanble state of feature '{}' is None".format(feature_name)) continue update_feature_state(feature_name, state) def aaa_handler(self, key, data): self.aaacfg.aaa_update(key, data) def tacacs_server_handler(self, key, data): self.aaacfg.tacacs_server_update(key, data) log_data = copy.deepcopy(data) if 'passkey' in log_data: log_data['passkey'] = obfuscate(log_data['passkey']) syslog.syslog(syslog.LOG_INFO, 'value of {} changed to {}'.format(key, log_data)) def tacacs_global_handler(self, key, data): self.aaacfg.tacacs_global_update(key, data) log_data = copy.deepcopy(data) if 'passkey' in log_data: log_data['passkey'] = obfuscate(log_data['passkey']) syslog.syslog(syslog.LOG_INFO, 'value of {} changed to {}'.format(key, log_data)) def lpbk_handler(self, key, data): key = ConfigDBConnector.deserialize_key(key) # Check if delete operation by fetch existing keys keys = self.config_db.get_keys('LOOPBACK_INTERFACE') if key in keys: add = True else: add = False self.iptables.iptables_handler(key, data, add) def feature_state_handler(self, key, data): feature_name = key feature_table = self.config_db.get_table('FEATURE') if feature_name not in feature_table.keys(): syslog.syslog(syslog.LOG_WARNING, "Feature '{}' not in FEATURE table".format(feature_name)) return state = feature_table[feature_name]['state'] if not state: syslog.syslog(syslog.LOG_WARNING, "Enable state of feature '{}' is None".format(feature_name)) return update_feature_state(feature_name, state) def start(self): # Update all feature states once upon starting self.update_all_feature_states() self.config_db.subscribe('AAA', lambda table, key, data: self.aaa_handler(key, data)) self.config_db.subscribe('TACPLUS_SERVER', lambda table, key, data: self.tacacs_server_handler(key, data)) self.config_db.subscribe('TACPLUS', lambda table, key, data: self.tacacs_global_handler(key, data)) self.config_db.subscribe('LOOPBACK_INTERFACE', lambda table, key, data: self.lpbk_handler(key, data)) self.config_db.subscribe('FEATURE', lambda table, key, data: self.feature_state_handler(key, data)) self.config_db.listen() def main(): daemon = HostConfigDaemon() daemon.start() if __name__ == "__main__": main()