T833: accel-ppp: pptp implementation

1 files changed, 351 insertions, 0 deletions

diff --git a/src/conf_mode/accel_pptp.py b/src/conf_mode/accel_pptp.py
new file mode 100755
index 000000000..5ac02a1cc
--- /dev/null
+++ b/src/conf_mode/accel_pptp.py
@@ -0,0 +1,351 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+#
+
+import sys
+import os
+import re
+import subprocess
+import jinja2
+import socket
+import time
+import syslog as sl
+
+from vyos.config import Config
+from vyos import ConfigError
+
+pidfile = r'/var/run/accel_pptp.pid'
+pptp_cnf_dir = r'/etc/accel-ppp/pptp'
+chap_secrets = pptp_cnf_dir + '/chap-secrets'
+pptp_conf = pptp_cnf_dir + '/pptp.config'
+# accel-pppd -d -c /etc/accel-ppp/pppoe/pppoe.config -p /var/run/accel_pppoe.pid
+
+### config path creation
+if not os.path.exists(pptp_cnf_dir):
+  os.makedirs(pptp_cnf_dir)
+  sl.syslog(sl.LOG_NOTICE, pptp_cnf_dir  + " created")
+
+pptp_config = '''
+### generated by accel_pptp.py ###
+[modules]
+log_syslog
+pptp
+ippool
+chap-secrets
+{% if authentication['auth_proto'] %}
+{{ authentication['auth_proto'] }}
+{% else %}
+auth_mschap_v2
+{% endif %}
+radius
+
+[core]
+thread-count={{thread_cnt}}
+
+[log]
+syslog=accel-pptp,daemon
+copy=1
+level=5
+
+{% if dns %}
+[dns]
+{% if dns[0] %}
+dns1={{dns[0]}}
+{% endif %}
+{% if dns[1] %}
+dns2={{dns[1]}}
+{% endif %}
+{% endif %}
+
+{% if wins %}
+[wins]
+{% if wins[0] %}
+wins1={{wins[0]}}
+{% endif %}
+{% if wins[1] %}
+wins2={{wins[1]}}
+{% endif %}
+{% endif %}
+
+[pptp]
+bind={{outside_addr}}
+verbose=5
+ppp-max-mtu={{mtu}}
+
+[client-ip-range]
+0.0.0.0/0
+
+[ip-pool]
+tunnel={{client_ip_pool}}
+gw-ip-address={{gw_ip}}
+
+{% if authentication['mode'] == 'local' %}
+[chap-secrets]
+chap-secrets=/etc/accel-ppp/pptp/chap-secrets
+{% endif %}
+
+[ppp]
+verbose=5
+check-ip=1
+single-session=replace
+
+{% if authentication['mode'] == 'radius' %}
+[radius]
+{% for rsrv in authentication['radiussrv']: %}
+server={{rsrv}},{{authentication['radiussrv'][rsrv]['secret']}},\
+req-limit={{authentication['radiussrv'][rsrv]['req-limit']}},\
+fail-time={{authentication['radiussrv'][rsrv]['fail-time']}}
+{% endfor %}
+timeout=30
+acct-timeout=30
+max-try=3
+{%endif %}
+
+[cli]
+tcp=127.0.0.1:2003
+'''
+
+### pptp chap secrets
+chap_secrets_conf = '''
+# username  server  password  acceptable local IP addresses
+{% for user in authentication['local-users'] %}
+{% if authentication['local-users'][user]['state'] == 'enabled' %}
+{{user}}\t*\t{{authentication['local-users'][user]['passwd']}}\t{{authentication['local-users'][user]['ip']}}
+{% endif %}
+{% endfor %}
+'''
+###
+# inline helper functions
+###
+# depending on hw and threads, daemon needs a little to start
+# if it takes longer than 100 * 0.5 secs, exception is being raised
+# not sure if that's the best way to check it, but it worked so far quite well 
+###
+def chk_con():
+  cnt = 0
+  s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+  while True:
+    try:
+      s.connect(("127.0.0.1", 2003))
+      break
+    except ConnectionRefusedError:
+      time.sleep(0.5)
+      cnt +=1
+      if cnt == 100:
+        raise("failed to start pptp server")
+        break
+
+### chap_secrets file if auth mode local
+def write_chap_secrets(c):
+  tmpl = jinja2.Template(chap_secrets_conf, trim_blocks=True)
+  chap_secrets_txt = tmpl.render(c)
+  old_umask = os.umask(0o077)
+  open(chap_secrets,'w').write(chap_secrets_txt)
+  os.umask(old_umask)
+  sl.syslog(sl.LOG_NOTICE, chap_secrets + ' written')
+
+def accel_cmd(cmd=''):
+  if not cmd:
+    return None
+  try:
+    ret = subprocess.check_output(['/usr/bin/accel-cmd','-p','2003',cmd]).decode().strip()
+    return ret
+  except:
+    return 1
+
+### 
+# inline helper functions end
+###
+
+def get_config():
+  c = Config()
+  if not c.exists('vpn pptp remote-access '):
+    return None
+
+  c.set_level('vpn pptp remote-access')
+  config_data = {
+    'authentication'  : {
+        'mode'          : 'local',
+        'local-users'   : {
+        },
+    'radiussrv'         : {},
+    'auth_proto'        : 'auth_mschap_v2' 
+    },
+    'outside_addr'    : '',
+    'dns'             : [],
+    'wins'            : [],
+    'client_ip_pool'  : '',
+    'mtu'   : '1436',
+  }
+
+  ### general options ###
+
+  if c.exists('dns-servers server-1'):
+    config_data['dns'].append( c.return_value('dns-servers server-1'))
+  if c.exists('dns-servers server-2'):
+    config_data['dns'].append( c.return_value('dns-servers server-2'))
+  if c.exists('wins-servers server-1'):
+    config_data['wins'].append( c.return_value('wins-servers server-1'))
+  if c.exists('wins-servers server-2'):
+    config_data['wins'].append( c.return_value('wins-servers server-2'))
+  if c.exists('outside-address'):
+    config_data['outside_addr'] = c.return_value('outside-address')
+
+  ### auth local 
+  if c.exists('authentication mode local'):
+    if c.exists('authentication local-users username'):
+      for usr in c.list_nodes('authentication local-users username'):
+        config_data['authentication']['local-users'].update(
+          {
+            usr : {
+              'passwd' : '',
+              'state'  : 'enabled',
+              'ip'     : ''
+            }
+          }
+        )
+
+        if c.exists('authentication local-users username ' + usr + ' password'):
+          config_data['authentication']['local-users'][usr]['passwd'] = c.return_value('authentication local-users username ' + usr + ' password')
+        if c.exists('authentication local-users username ' + usr + ' disable'):
+          config_data['authentication']['local-users'][usr]['state'] = 'disable'
+        if c.exists('authentication local-users username ' + usr + ' static-ip'):
+          config_data['authentication']['local-users'][usr]['ip'] = c.return_value('authentication local-users username ' + usr + ' static-ip')
+
+  ### authentication mode radius servers and settings
+
+  if c.exists('authentication mode radius'):
+    config_data['authentication']['mode'] = 'radius'
+    rsrvs = c.list_nodes('authentication radius server')
+    for rsrv in rsrvs:
+      if c.return_value('authentication radius server ' + rsrv + ' fail-time') == None:
+        ftime = '0'
+      else:
+        ftime = str(c.return_value('authentication radius server ' + rsrv + ' fail-time'))
+      if c.return_value('authentication radius-server ' + rsrv + ' req-limit') == None:
+        reql = '0'
+      else:
+        reql = str(c.return_value('authentication radius server ' + rsrv + ' req-limit'))
+
+      config_data['authentication']['radiussrv'].update(
+        {
+          rsrv  : {
+            'secret'  : c.return_value('authentication radius server ' + rsrv + ' key'),
+            'fail-time' : ftime,
+            'req-limit' : reql
+            }
+        }
+      )
+
+  if c.exists('client-ip-pool'):
+    if c.exists('client-ip-pool start'):
+      config_data['client_ip_pool'] = c.return_value('client-ip-pool start')
+    if c.exists('client-ip-pool stop'):
+      config_data['client_ip_pool'] += '-' + re.search('[0-9]+$', c.return_value('client-ip-pool stop')).group(0)
+  if c.exists('mtu'):
+    config_data['mtu'] = c.return_value('mtu')
+
+
+  ### gateway address 
+  if c.exists('gateway-address'):
+    config_data['gw_ip'] = c.return_value('gateway-address') 
+  else:
+    config_data['gw_ip'] = re.sub('[0-9]+$','1',config_data['client_ip_pool'])    
+  
+  if c.exists('authentication require'):
+    if c.return_value('authentication require') == 'pap':
+      config_data['authentication']['auth_proto'] = 'auth_pap'
+    if c.return_value('authentication require') == 'chap':
+      config_data['authentication']['auth_proto'] = 'auth_chap_md5'
+    if c.return_value('authentication require') == 'mschap':
+      config_data['authentication']['auth_proto'] = 'auth_mschap_v1'
+    if c.return_value('authentication require') == 'mschap-v2':
+      config_data['authentication']['auth_proto'] = 'auth_mschap_v2'
+  
+  return config_data
+
+def verify(c):
+  if c == None:
+    return None
+
+  if c['authentication']['mode'] == 'local':
+    if not c['authentication']['local-users']:
+      raise ConfigError('pppoe-server authentication local-users required')
+    for usr in c['authentication']['local-users']:
+      if not c['authentication']['local-users'][usr]['passwd']:
+        raise ConfigError('user ' + usr + ' requires a password')
+
+  if c['authentication']['mode'] == 'radius':
+    if len(c['authentication']['radiussrv']) == 0:
+      raise ConfigError('radius server required')
+    for rsrv in c['authentication']['radiussrv']:
+      if c['authentication']['radiussrv'][rsrv]['secret'] == None:
+        raise ConfigError('radius server ' + rsrv + ' needs a secret configured')
+
+def generate(c):
+  if c == None:
+    return None
+  
+  ### accel-cmd reload doesn't work so any change results in a restart of the daemon
+  try:
+    if os.cpu_count() == 1:
+      c['thread_cnt'] = 1
+    else:
+      c['thread_cnt'] = int(os.cpu_count()/2)
+  except KeyError:
+    if os.cpu_count() == 1:
+      c['thread_cnt'] = 1
+    else:
+      c['thread_cnt'] = int(os.cpu_count()/2)
+
+  tmpl = jinja2.Template(pptp_config, trim_blocks=True)
+  config_text = tmpl.render(c)
+  open(pptp_conf,'w').write(config_text)
+
+  if c['authentication']['local-users']:
+    write_chap_secrets(c)
+
+  return c
+
+def apply(c):
+  if c == None:
+    if os.path.exists(pidfile):
+      accel_cmd('shutdown hard')
+      if os.path.exists(pidfile):
+        os.remove(pidfile)
+    return None
+
+  if not os.path.exists(pidfile):
+    ret = subprocess.call(['/usr/sbin/accel-pppd','-c',pptp_conf,'-p',pidfile,'-d'])
+    chk_con()
+    if ret !=0 and os.path.exists(pidfile):
+      os.remove(pidfile)
+      raise ConfigError('accel-pppd failed to start')
+  else:
+    ### if gw ip changes, only restart doesn't work
+    accel_cmd('restart')
+    sl.syslog(sl.LOG_NOTICE, "reloading config via daemon restart")
+
+if __name__ == '__main__':
+  try:
+    c = get_config()
+    verify(c)
+    generate(c)
+    apply(c)
+  except ConfigError as e:
+    print(e)
+    sys.exit(1)