Introduce support for AmarisoftEPC

* A new abstract generic base class EPC is created
* srsEPC and AmarisoftEPC inherit from that class
* options are loaded from defaults.conf in cascade. First generic "epc",
  afterwards the specific enb type.
* A new scenario is added to select the EPC type to use. srsEPC is the
  default unless stated by an scenario.
* AmarisoftEPC delegates setup of the tun IP address to an "ifup"
  script. As a result, since we run without root permissions (ony with
  CAP_NET_ADMIN), the ifup script itself is unablet o set the IP
  address. To solve this, we introduce a new osmo-gsm-tester helper
  script which must be installed in the slave node which can be called
  through sudo to increase privileges to do so.

With this commit, I can already get srsUE<->amarisoftENB<->amarisoftEPC
to pass ping and iperf3 4g tests.

Change-Id: Ia50ea6a74b63b2d688c8d683aea11416ad40a6d3

example/defaults.conf

@@ -93,12 +93,17 @@ osmo_bts_oc2g:
   trx_list:
   - nominal_power: 25
 
-srsepc:
+epc:
+  type: srsepc
   mcc: 901
   mnc: 70
+srsepc:
   rlc_drb_mode: UM
   enable_pcap: false
 
+amarisoftepc:
+  license_server_addr: 10.12.1.139
+
 enb:
   mcc: 901
   mnc: 70

example/scenarios/cfg-epc-type@.conf

@@ -0,0 +1,3 @@
+config:
+  epc:
+    type: ${param1}

src/osmo_gsm_tester/amarisoft_epc.py

@@ -0,0 +1,203 @@
+# osmo_gsm_tester: specifics for running an SRS EPC process
+#
+# Copyright (C) 2020 by sysmocom - s.f.m.c. GmbH
+#
+# Author: Pau Espin Pedrol <pespin@sysmocom.de>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# 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 os
+import pprint
+
+from . import log, util, config, template, process, remote
+from . import epc
+
+#def rlc_drb_mode2qci(rlc_drb_mode):
+#    if rlc_drb_mode.upper() == "UM":
+#        return 7;
+#    elif rlc_drb_mode.upper() == "AM":
+#        return 9;
+#    raise log.Error('Unexpected rlc_drb_mode', rlc_drb_mode=rlc_drb_mode)
+
+class AmarisoftEPC(epc.EPC):
+
+    REMOTE_DIR = '/osmo-gsm-tester-amarisoftepc'
+    BINFILE = 'ltemme'
+    CFGFILE = 'amarisoft_ltemme.cfg'
+    LOGFILE = 'ltemme.log'
+    IFUPFILE = 'mme-ifup'
+
+    def __init__(self, suite_run, run_node):
+        super().__init__(suite_run, run_node, 'amarisoftepc')
+        self.run_dir = None
+        self.config_file = None
+        self.log_file = None
+        self.ifup_file = None
+        self.process = None
+        self.rem_host = None
+        self.remote_inst = None
+        self.remote_config_file = None
+        self.remote_log_file = None
+        self.remote_ifup_file =None
+        self._bin_prefix = None
+        self.inst = None
+        self.subscriber_list = []
+
+    def bin_prefix(self):
+        if self._bin_prefix is None:
+            self._bin_prefix = os.getenv('AMARISOFT_PATH_EPC', AmarisoftEPC.REMOTE_DIR)
+        return self._bin_prefix
+
+    def cleanup(self):
+        if self.process is None:
+            return
+        if self._run_node.is_local():
+            return
+        # copy back files (may not exist, for instance if there was an early error of process):
+        try:
+            self.rem_host.scpfrom('scp-back-log', self.remote_log_file, self.log_file)
+        except Exception as e:
+            self.log(repr(e))
+
+    def start(self):
+        self.log('Starting amarisoftepc')
+        self.run_dir = util.Dir(self.suite_run.get_test_run_dir().new_dir(self.name()))
+        self.configure()
+        if self._run_node.is_local():
+            self.start_locally()
+        else:
+            self.start_remotely()
+
+    def start_remotely(self):
+        remote_binary = self.remote_inst.child('', AmarisoftEPC.BINFILE)
+        # setting capabilities will later disable use of LD_LIBRARY_PATH from ELF loader -> modify RPATH instead.
+        self.log('Setting RPATH for amarisoftepc')
+        self.rem_host.change_elf_rpath(remote_binary, str(self.remote_inst))
+        # amarisoftepc requires CAP_NET_ADMIN to create tunnel devices: ioctl(TUNSETIFF):
+        self.log('Applying CAP_NET_ADMIN capability to amarisoftepc')
+        self.rem_host.setcap_net_admin(remote_binary)
+
+        args = (remote_binary, self.remote_config_file)
+
+        self.process = self.rem_host.RemoteProcess(AmarisoftEPC.BINFILE, args)
+        #self.process = self.rem_host.RemoteProcessFixIgnoreSIGHUP(AmarisoftEPC.BINFILE, remote_run_dir, args)
+        self.suite_run.remember_to_stop(self.process)
+        self.process.launch()
+
+    def start_locally(self):
+        binary = self.inst.child('', BINFILE)
+
+        env = {}
+        # setting capabilities will later disable use of LD_LIBRARY_PATH from ELF loader -> modify RPATH instead.
+        self.log('Setting RPATH for amarisoftepc')
+        util.change_elf_rpath(binary, util.prepend_library_path(str(self.inst)), self.run_dir.new_dir('patchelf'))
+        # amarisoftepc requires CAP_NET_ADMIN to create tunnel devices: ioctl(TUNSETIFF):
+        self.log('Applying CAP_NET_ADMIN capability to amarisoftepc')
+        util.setcap_net_admin(binary, self.run_dir.new_dir('setcap_net_admin'))
+
+        self.dbg(run_dir=self.run_dir, binary=binary, env=env)
+        args = (binary, os.path.abspath(self.config_file))
+
+        self.process = process.Process(self.name(), self.run_dir, args, env=env)
+        self.suite_run.remember_to_stop(self.process)
+        self.process.launch()
+
+    def configure(self):
+        self.inst = util.Dir(os.path.abspath(self.bin_prefix()))
+        if not self.inst.isfile('', AmarisoftEPC.BINFILE):
+            raise log.Error('No %s binary in' % AmarisoftEPC.BINFILE, self.inst)
+
+        self.config_file = self.run_dir.child(AmarisoftEPC.CFGFILE)
+        self.log_file = self.run_dir.child(AmarisoftEPC.LOGFILE)
+        self.ifup_file = self.run_dir.new_file(AmarisoftEPC.IFUPFILE)
+        os.chmod(self.ifup_file, 0o744) # add execution permission
+        self.dbg(config_file=self.config_file)
+        with open(self.ifup_file, 'w') as f:
+            r = '''#!/bin/sh
+            set -x -e
+            # script + sudoers file available in osmo-gsm-tester.git/utils/{bin,sudoers.d}
+            sudo /usr/local/bin/osmo-gsm-tester_amarisoft_ltemme_ifup.sh "$@"
+            '''
+            f.write(r)
+
+        if not self._run_node.is_local():
+            self.rem_host = remote.RemoteHost(self.run_dir, self._run_node.ssh_user(), self._run_node.ssh_addr())
+            remote_prefix_dir = util.Dir(AmarisoftEPC.REMOTE_DIR)
+            self.remote_inst = util.Dir(remote_prefix_dir.child(os.path.basename(str(self.inst))))
+            remote_run_dir = util.Dir(remote_prefix_dir.child(AmarisoftEPC.BINFILE))
+
+            self.remote_config_file = remote_run_dir.child(AmarisoftEPC.CFGFILE)
+            self.remote_log_file = remote_run_dir.child(AmarisoftEPC.LOGFILE)
+            self.remote_ifup_file = remote_run_dir.child(AmarisoftEPC.IFUPFILE)
+
+        values = super().configure('amarisoftepc')
+
+        logfile = self.log_file if self._run_node.is_local() else self.remote_log_file
+        ifupfile = self.ifup_file if self._run_node.is_local() else self.remote_ifup_file
+        config.overlay(values, dict(epc=dict(log_filename=logfile,
+                                             ifup_filename=ifupfile)))
+
+        # Set qci for each subscriber:
+        #rlc_drb_mode = values['epc'].get('rlc_drb_mode', None)
+        #assert rlc_drb_mode is not None
+        #for i in range(len(self.subscriber_list)):
+        #    self.subscriber_list[i]['qci'] = rlc_drb_mode2qci(rlc_drb_mode)
+        config.overlay(values, dict(epc=dict(hss=dict(subscribers=self.subscriber_list))))
+
+        self.dbg('SRSEPC CONFIG:\n' + pprint.pformat(values))
+
+        with open(self.config_file, 'w') as f:
+            r = template.render(AmarisoftEPC.CFGFILE, values)
+            self.dbg(r)
+            f.write(r)
+
+        if not self._run_node.is_local():
+            self.rem_host.recreate_remote_dir(self.remote_inst)
+            self.rem_host.scp('scp-inst-to-remote', str(self.inst), remote_prefix_dir)
+            self.rem_host.recreate_remote_dir(remote_run_dir)
+            self.rem_host.scp('scp-cfg-to-remote', self.config_file, self.remote_config_file)
+            self.rem_host.scp('scp-ifup-to-remote', self.ifup_file, self.remote_ifup_file)
+
+    def subscriber_add(self, modem, msisdn=None, algo_str=None):
+        if msisdn is None:
+            msisdn = self.suite_run.resources_pool.next_msisdn(modem)
+        modem.set_msisdn(msisdn)
+
+        if algo_str is None:
+            algo_str = modem.auth_algo() or util.OSMO_AUTH_ALGO_NONE
+
+        if algo_str != util.OSMO_AUTH_ALGO_NONE and not modem.ki():
+            raise log.Error("Auth algo %r selected but no KI specified" % algo_str)
+
+        subscriber_id = len(self.subscriber_list) # list index
+        self.subscriber_list.append({'id': subscriber_id, 'imsi': modem.imsi(), 'msisdn': msisdn, 'auth_algo': algo_str, 'ki': modem.ki(), 'opc': None, 'apn_ipaddr': modem.apn_ipaddr()})
+
+        self.log('Add subscriber', msisdn=msisdn, imsi=modem.imsi(), subscriber_id=subscriber_id,
+                 algo_str=algo_str)
+        return subscriber_id
+
+    def enb_is_connected(self, enb):
+        # TODO: improve this a bit, like matching IP addr of enb. CTRL iface?
+        # The string is only available in log file, not in stdout:
+        #return 'S1 setup response' in (self.process.get_stdout() or '')
+        return True
+
+    def running(self):
+        return not self.process.terminated()
+
+    def tun_addr(self):
+        # TODO: set proper addr
+        return '192.168.4.1'
+
+# vim: expandtab tabstop=4 shiftwidth=4

src/osmo_gsm_tester/epc.py

@@ -0,0 +1,80 @@
+# osmo_gsm_tester: base classes to share code among EPC subclasses.
+#
+# Copyright (C) 2020 by sysmocom - s.f.m.c. GmbH
+#
+# Author: Pau Espin Pedrol <pespin@sysmocom.de>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# 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/>.
+
+from abc import ABCMeta, abstractmethod
+from . import log, config
+
+
+class EPC(log.Origin, metaclass=ABCMeta):
+
+##############
+# PROTECTED
+##############
+    def __init__(self, suite_run, run_node, name):
+        super().__init__(log.C_RUN, '%s' % name)
+        self._addr = run_node.run_addr()
+        self.set_name('%s_%s' % (name, self._addr))
+        self.suite_run = suite_run
+        self._run_node = run_node
+
+    def configure(self, default_specifics):
+        values = dict(epc=config.get_defaults('epc'))
+        config.overlay(values, dict(epc=config.get_defaults(default_specifics)))
+        config.overlay(values, dict(epc=self.suite_run.config().get('epc', {})))
+        config.overlay(values, dict(epc={'run_addr': self.addr()}))
+        return values
+
+########################
+# PUBLIC - INTERNAL API
+########################
+    def cleanup(self):
+        'Nothing to do by default. Subclass can override if required.'
+        pass
+
+###################
+# PUBLIC (test API included)
+###################
+    @abstractmethod
+    def start(self, epc):
+        'Starts ENB, it will connect to "epc"'
+        pass
+
+    @abstractmethod
+    def subscriber_add(self, modem, msisdn=None, algo_str=None):
+        pass
+
+    @abstractmethod
+    def enb_is_connected(self, enb):
+        pass
+
+    @abstractmethod
+    def running(self):
+        pass
+
+    @abstractmethod
+    def tun_addr(self):
+        pass
+
+    def addr(self):
+        return self._addr
+
+    def run_node(self):
+        return self._run_node
+
+# vim: expandtab tabstop=4 shiftwidth=4

src/osmo_gsm_tester/resource.py

@@ -29,7 +29,7 @@ from . import schema
 from . import bts_sysmo, bts_osmotrx, bts_osmovirtual, bts_octphy, bts_nanobts, bts_oc2g
 from . import modem
 from . import ms_osmo_mobile
-from . import srs_ue, srs_enb, amarisoft_enb
+from . import srs_ue, srs_enb, amarisoft_enb, srs_epc, amarisoft_epc
 
 from .util import is_dict, is_list
 
@@ -122,6 +122,7 @@ CONF_SCHEMA = util.dict_add(
     { 'defaults.timeout': schema.STR,
       'config.bsc.net.codec_list[]': schema.CODEC,
       'config.enb.enable_pcap': schema.BOOL_STR,
+      'config.epc.type': schema.STR,
       'config.epc.rlc_drb_mode': schema.LTE_RLC_DRB_MODE,
       'config.epc.enable_pcap': schema.BOOL_STR,
       'config.modem.enable_pcap': schema.BOOL_STR,
@@ -143,6 +144,11 @@ KNOWN_ENB_TYPES = {
         'amarisoftenb': amarisoft_enb.AmarisoftENB,
 }
 
+KNOWN_EPC_TYPES = {
+        'srsepc': srs_epc.srsEPC,
+        'amarisoftepc': amarisoft_epc.AmarisoftEPC,
+}
+
 KNOWN_MS_TYPES = {
         # Map None to ofono for forward compability
         None: modem.Modem,

src/osmo_gsm_tester/srs_epc.py

@@ -21,6 +21,7 @@ import os
 import pprint
 
 from . import log, util, config, template, process, remote
+from . import epc
 
 def rlc_drb_mode2qci(rlc_drb_mode):
     if rlc_drb_mode.upper() == "UM":
@@ -29,7 +30,7 @@ def rlc_drb_mode2qci(rlc_drb_mode):
         return 9;
     raise log.Error('Unexpected rlc_drb_mode', rlc_drb_mode=rlc_drb_mode)
 
-class srsEPC(log.Origin):
+class srsEPC(epc.EPC):
 
     REMOTE_DIR = '/osmo-gsm-tester-srsepc'
     BINFILE = 'srsepc'
@@ -39,9 +40,7 @@ class srsEPC(log.Origin):
     LOGFILE = 'srsepc.log'
 
     def __init__(self, suite_run, run_node):
-        super().__init__(log.C_RUN, 'srsepc')
-        self._addr = run_node.run_addr()
-        self.set_name('srsepc_%s' % self._addr)
+        super().__init__(suite_run, run_node, 'srsepc')
         self.run_dir = None
         self.config_file = None
         self.db_file = None
@@ -55,8 +54,6 @@ class srsEPC(log.Origin):
         self.remote_pcap_file = None
         self.enable_pcap = False
         self.subscriber_list = []
-        self.suite_run = suite_run
-        self._run_node = run_node
 
     def cleanup(self):
         if self.process is None:
@@ -161,9 +158,7 @@ class srsEPC(log.Origin):
         self.pcap_file = self.run_dir.child(srsEPC.PCAPFILE)
         self.dbg(config_file=self.config_file, db_file=self.db_file)
 
-        values = dict(epc=config.get_defaults('srsepc'))
-        config.overlay(values, dict(epc=self.suite_run.config().get('epc', {})))
-        config.overlay(values, dict(epc={'run_addr': self.addr()}))
+        values = super().configure('srsepc')
 
         # Convert parsed boolean string to Python boolean:
         self.enable_pcap = util.str2bool(values['epc'].get('enable_pcap', 'false'))
@@ -212,13 +207,7 @@ class srsEPC(log.Origin):
     def running(self):
         return not self.process.terminated()
 
-    def addr(self):
-        return self._addr
-
     def tun_addr(self):
         return '172.16.0.1'
 
-    def run_node(self):
-        return self._run_node
-
 # vim: expandtab tabstop=4 shiftwidth=4

src/osmo_gsm_tester/suite.py

@@ -25,7 +25,6 @@ from . import config, log, util, resource, test
 from .event_loop import MainLoop
 from . import osmo_nitb, osmo_hlr, osmo_mgcpgw, osmo_mgw, osmo_msc, osmo_bsc, osmo_stp, osmo_ggsn, osmo_sgsn, esme, osmocon, ms_driver, iperf3, process
 from . import run_node
-from . import srs_epc
 
 class Timeout(Exception):
     pass
@@ -374,9 +373,9 @@ class SuiteRun(log.Origin):
     def epc(self, run_node=None):
         if run_node is None:
             run_node = self.run_node()
-        epc_obj = srs_epc.srsEPC(self, run_node)
-        self.register_for_cleanup(epc_obj)
-        return epc_obj
+        epc = epc_obj(self, run_node)
+        self.register_for_cleanup(epc)
+        return epc
 
     def osmocon(self, specifics=None):
         conf = self.reserved_resources.get(resource.R_OSMOCON, specifics=specifics)
@@ -505,4 +504,16 @@ def enb_obj(suite_run, conf):
         raise RuntimeError('No such ENB type is defined: %r' % enb_type)
     return enb_class(suite_run, conf)
 
+def epc_obj(suite_run, run_node):
+    values = dict(epc=config.get_defaults('epc'))
+    config.overlay(values, dict(epc=suite_run.config().get('epc', {})))
+    epc_type = values['epc'].get('type', None)
+    if epc_type is None:
+        raise RuntimeError('EPC type is not defined!')
+    log.dbg('create EPC object', type=epc_type)
+    epc_class = resource.KNOWN_EPC_TYPES.get(epc_type)
+    if epc_class is None:
+        raise RuntimeError('No such EPC type is defined: %r' % epc_type)
+    return epc_class(suite_run, run_node)
+
 # vim: expandtab tabstop=4 shiftwidth=4

src/osmo_gsm_tester/templates/amarisoft_ltemme.cfg.tmpl

@@ -0,0 +1,116 @@
+/* ltemme configuration file
+ * version 2018-10-18
+ * Copyright (C) 2015-2018 Amarisoft
+ */
+{
+
+  license_server: {
+    server_addr: "${epc.license_server_addr}",
+    name: "amarisoft",
+  },
+
+  /* Log filter: syntax: layer.field=value[,...]
+
+     Possible layers are nas, ip, s1ap, gtpu and all. The 'all' layer
+     is used to address all the layers at the same time.
+
+     field values:
+
+     - 'level': the log level of each layer can be set to 'none',
+     'error', 'info' or 'debug'. Use 'debug' to log all the messages.
+
+     - 'max_size': set the maximum size of the hex dump. 0 means no
+       hex dump. -1 means no limit.
+  */
+  //log_options: "all.level=debug,all.max_size=32",
+  log_options: "all.level=error,all.max_size=0,nas.level=debug,nas.max_size=1,s1ap.level=debug,s1ap.max_size=1",
+  log_filename: "${epc.log_filename}",
+
+  /* Enable remote API and Web interface */
+  com_addr: "${epc.run_addr}:9000",
+
+  /* bind address for GTP-U. Normally = address of the PC, here bound
+    on local interface to be able to run ltemme on the same PC as
+    lteenb. By default, the S1AP SCTP connection is bound on the same
+    address. */
+  gtp_addr: "${epc.run_addr}",
+
+  s1ap_bind_addr: "${epc.run_addr}",
+
+  plmn: "${epc.mcc}${epc.mnc}",
+  mme_group_id: 32769,
+  mme_code: 1,
+
+  /* network name and network short name sent in the EMM information
+     message to the UE */
+  network_name: "Amarisoft Network",
+  network_short_name: "Amarisoft",
+
+  /* Control Plane Cellular IoT EPS optimization support */
+  cp_ciot_opt: true,
+
+  /* Public Data Networks. The first one is the default. */
+  pdn_list: [
+    {
+      /* Some UE requires a specific PDN for data access */
+      pdn_type: "ipv4",
+      access_point_name: "internet",
+      first_ip_addr: "192.168.4.2",
+      last_ip_addr: "192.168.4.254",
+      ip_addr_shift: 2,
+      dns_addr: "8.8.8.8", /* Google DNS address */
+      erabs: [
+        {
+          qci: 9,
+          priority_level: 15,
+          pre_emption_capability: "shall_not_trigger_pre_emption",
+          pre_emption_vulnerability: "not_pre_emptable",
+        },
+      ],
+    },
+  ],
+  /* Setup script for the network interface.
+     If no script is given, no network interface is created.
+     Script is called for each PDN with following parameters:
+        1) Interface name
+        2) PDN index
+        3) Access Point Name
+        4) IP version: 'ipv4' or 'ipv6'
+        5) IP address: first IP address for ipv4 and link local address for IPv6
+        6) First IP address
+        7) Last IP address
+  */
+  tun_setup_script: "${epc.ifup_filename}",
+
+  /* If true, inter-UE routing is done inside the MME (hence no IP
+     packet is output to the virtual network interface in case of
+     inter-UE communication). Otherwise, it is done by the Linux IP
+     layer. */
+  ue_to_ue_forwarding: false,
+
+  /* NAS ciphering algorithm preference. EEA0 is always the last. */
+  nas_cipher_algo_pref: [ ],
+  /* NAS integrity algorithm preference. EIA0 is always the last. */
+  nas_integ_algo_pref: [ 2, 1 ],
+
+  /* user data base */
+  ue_db: [
+%for sub in epc.hss.subscribers:
+    {
+      sim_algo: "${sub.auth_algo}", /* USIM authentication algorithm: xor, milenage or tuak */
+      imsi: "${sub.imsi}", /* Anritsu Test USIM */
+      amf: 0x9001, /* Authentication Management Field */
+      sqn: "000000000000", /* Sequence Number */
+      K: "${sub.ki}", /* Anritsu Test USIM */
+      /* if true, allow several UEs to have the same IMSI (useful
+         with test SIM cards). They are distinguished with their
+         IMEI. default = false. */
+      multi_sim: true,
+    },
+%endfor
+    /* Add new entries for each IMSI/K */
+  ],
+
+  /* persistent user database */
+  //ue_db_filename: "lte_ue.db",
+}

utils/bin/osmo-gsm-tester_amarisoft_ltemme_ifup.sh

@@ -0,0 +1,16 @@
+#!/bin/bash -e
+ifname="$1"     # Interface name
+index="$2"      # Network index (PDN index)
+apn="$3"        # Access point name
+type="$4"       # ipv4 or ipv6
+ifaddr="$5" # Interface address
+addr1="$6"  # First IP address
+addr2="$7"  # Last IP address
+mask="$8"   # Mask
+echo "*** Configuring $type APN[$index] '$apn' on ${ifname}, $ifaddr/$mask, ${addr1}..${addr2}"
+if [ "$type" = "ipv4" ] ; then
+        ifconfig ${ifname} ${ifaddr}/${mask} up
+else
+        ifconfig ${ifname} inet6 add ${addr1}/${mask} up
+fi
+echo "*** done configuring interface ${ifname}"

utils/sudoers.d/osmo-gsm-tester_amarisoft_ltemme_ifup

@@ -0,0 +1 @@
+%osmo-gsm-tester ALL=(root) NOPASSWD: /usr/local/bin/osmo-gsm-tester_amarisoft_ltemme_ifup.sh