def Connect(self,
username,
password=None,
ssh_keys=None,
enable_password=None,
ssl_cert_set=None):
"""Sets up a connection to the device.
Concrete classes must implement _Connect() instead, with the same arguments.
Concrete classes are expected not to disconnect the connection until it
is cleaned-up by Disconnect(). A generic exception handler at the top-
level should ensure sessions have an opportunity to be cleaned-up upon
abnormal program termination.
Args:
username: A string, the username (role account) to use.
password: A string, the password to use (optional; may be None).
ssh_keys: A tuple of strings, SSH private keys (optional; may be None).
enable_password: A string, an optional enable password (may be None).
ssl_cert_set: An optional SSLCertificateSet protobuf (may be None).
Raises:
exceptions.ConnectError: the connection could not be established.
exceptions.AuthenticationError: A device authentication error occurred, or
neither a password nor an SSH private key was supplied.
"""
# Either an SSH key or password must be supplied for authentication.
if (password is None and not ssh_keys and not ssl_cert_set
and not FLAGS.use_ssh_agent):
raise exceptions.AuthenticationError(
'Cannot connect. No authentication information provided to device '
'Connect method.')
self._username = username
self._password = password
self._ssh_keys = ssh_keys or ()
self._enable_password = enable_password
self._ssl_cert_set = ssl_cert_set
if not self.loopback_ipv4 and not self.accessproxy_device_dict:
raise exceptions.ConnectError(
'Device %r, or any access proxies, need to have an IPv4 '
'management address.' % self.host)
logging.debug('In BaseDevice.Connect, host is %s, _connected is %s',
self.host, self._connected)
while not self.connected:
try:
if self._host_status:
logging.debug('CONNECTING %s(%s)', self.host,
self.loopback_ipv4)
self._Connect(username,
password=password,
ssh_keys=self._ssh_keys,
enable_password=enable_password,
ssl_cert_set=ssl_cert_set)
self.connected = True
logging.debug('CONNECTED %s(%s)', self.host,
self.loopback_ipv4)
self._last_failure_time = None
else:
self._HostDownPrepareConnect()
except (exceptions.ConnectError,
exceptions.AuthenticationError), e:
logging.error('CONNECT FAILURE %s(%s)', self.host,
self.loopback_ipv4)
self._host_status = False
self.__exc = e
raise
class BrocadeMlxDevice(BrocadeDevice):
"""A base device model suitable for Brocade MLX devices.
See the base_device.BaseDevice method docstrings.
"""
disable_pager_command = _BROCADE_MLX_DISABLE_PAGER
def __init__(self, **kwargs):
self.vendor_name = 'brocademlx'
super(BrocadeMlxDevice, self).__init__(**kwargs)
def _GetFileSize(self, file_name, data):
"""Gets the size of a file in Brocade 'dir' output.
Args:
file_name: A string, the file name.
data: A string, the Brocade's "dir" output.
Returns:
An int, the file size, or None if the value could not be determined.
"""
for line in data.splitlines():
match = RE_FILE_LISTING.match(line)
if match is not None:
(file_size, fname) = match.groups()
for char in string.punctuation:
file_size = file_size.replace(char, '')
if file_name.strip() == fname.strip():
try:
return int(file_size)
except ValueError:
continue
return None
def _SetConfig(self, destination_file, data, canary):
# Canarying is not supported on BROCADE.
if canary:
raise exceptions.SetConfigCanaryingError(
'%s devices do not support '
'configuration canarying.' % self.vendor_name)
# The result object.
result = base_device.SetConfigResult()
# Check for a connection to the Brocade.
if not self._GetConnected():
raise exceptions.SetConfigError('Cannot use unless already '
'connected to the device.')
if destination_file in self.NON_FILE_DESTINATIONS:
# Use a random remote file name
file_name = 'push.%s' % os.urandom(8).encode('hex')
else:
# Okay, the user is just copying a file, not a configuraiton into either
# startup-config or running-config, therefore we should use the entire
# path.
file_name = destination_file
# Copy the file to the router using SCP.
scp = pexpect_connection.ScpPutConnection(host=self.loopback_ipv4,
username=self._username,
password=self._password)
# This is a workaround. Brocade case: 537017.
# Brocade changed all the filename to lowercases after scp
file_name = file_name.lower()
try:
scp.Copy(data, destination_file='slot1:' + file_name)
except pexpect_connection.Error, e:
raise exceptions.SetConfigError(
'Failed to copy configuration to remote device. %s' % str(e))
# Now that everything is OK locally and the file has been copied,
# check the file and tell the device to set the new configuration.
try:
# Get the file size on the Brocade.
try:
cmd = 'dir /slot1/%s' % file_name
dir_output = self._Cmd(cmd)
except exceptions.CmdError, e:
if 'Invalid input at' in str(e):
raise exceptions.AuthenticationError(
'Username/password for %s(%s) has insufficient privileges '
'to set configuration.' %
(self.host, self.loopback_ipv4))
else:
raise exceptions.SetConfigError(
'Could not traverse directory '
'output. Command was: %r. '
'Error: %r' % (cmd, str(e)))
destination_file_size = self._GetFileSize(file_name, dir_output)
# We couldn't parse the output for some reason.
if destination_file_size is None:
raise exceptions.SetConfigError(
'Could not find or parse remote '
'file size after copy to device.')
# Verify file is the correct size on the Brocade.
# This should use a checksum (e.g. MD5 or SHA1); Brocade case: 609719.
if destination_file_size != len(data):
raise exceptions.SetConfigError(
'File transfer corrupted. Source file was: %d bytes, '
'Destination file was: %d bytes.' %
(len(data), destination_file_size))
# Copy the file from flash to the
# destination(running-config, startup-config)
if destination_file == self.CONFIG_STARTUP:
try:
self._connection.child.send(
'copy slot1 startup-config %s\r' % file_name)
time.sleep(MINOR_PAUSE)
pindex = self._connection.child.expect(
['Total bytes', self._connection.re_prompt, 'Error'],
timeout=self.timeout_act_user)
if pindex == 2:
raise exceptions.SetConfigError(
'Could not copy temporary '
'file to startup-config.')
except (pexpect.EOF, pexpect.TIMEOUT), e:
raise exceptions.SetConfigError(str(e))
def Connect(hostname,
username,
password=None,
port=22,
ssh_keys=(),
timeout=TIMEOUT_DEFAULT):
"""Makes a paramiko SSH connection to a device.
Args:
hostname: A string, the hostname or IP address to connect to.
username: A string, the username to use on the connection.
password: A string, the password to use on the connection.
port: An int, the port number to connect to.
ssh_keys: A tuple of strings, SSH private keys (optional; may be None).
timeout: A float, the number of seconds before a connection times out.
Returns:
A paramiko.SSHClient() instance
"""
options = SshOptions()
hostname, port, username = options.Lookup(hostname, port, username)
ssh_client = None
def RaiseError(e, msg):
"""Raises an exception, disconnecting the SSH client.
Args:
e: An Exception.
msg: An object, exception arguments.
"""
raise e(msg)
try:
ssh_client = paramiko.SSHClient()
# Always auto-add remote SSH host keys.
ssh_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh_client.load_system_host_keys()
# Connect using paramiko with a timeout parameter (requires paramiko 1.7)
if ssh_keys:
pkeys = []
for key in ssh_keys:
logging.debug(
'Using SSH private key for device authentication.')
# Use a virtual temporary file to store the key.
ssh_key_fileobj = cStringIO.StringIO()
ssh_key_fileobj.write(key)
ssh_key_fileobj.reset()
try:
pkeys.append(paramiko.DSSKey(file_obj=ssh_key_fileobj))
logging.debug('Using SSH DSA key for %r', hostname)
except (IndexError, paramiko.SSHException) as e:
if (isinstance(e, IndexError)
or 'not a valid DSA private key file' in str(e)):
ssh_key_fileobj.reset()
try:
logging.debug('Using SSH RSA key for %r', hostname)
pkeys.append(
paramiko.RSAKey(file_obj=ssh_key_fileobj))
except (IndexError, paramiko.SSHException) as e:
raise exceptions.AuthenticationError(str(e))
else:
raise exceptions.ConnectError('SSHException: %s' %
str(e))
else:
logging.debug('Using password for %r', hostname)
pkeys = [None]
for pkey in pkeys:
saved_exception = None
try:
ssh_client.connect(hostname=hostname,
port=port,
username=username,
password=password,
pkey=pkey,
timeout=timeout,
allow_agent=FLAGS.use_ssh_agent,
look_for_keys=False)
break
except (paramiko.AuthenticationException,
paramiko.SSHException) as e:
saved_exception = e
if saved_exception is not None:
raise saved_exception # pylint: disable=raising-bad-type
transport = ssh_client.get_transport()
# Sometimes we have to authenticate a second time, eg. on Force10
# we always fail the first authentication (if we try pkey + pass,
# the pass succeeds; but if we do pass only, we have to do it
# twice). connect() above will have authenticated once.
if not transport.is_authenticated():
if pkeys != [None]:
for pkey in pkeys:
try:
transport.auth_publickey(username, pkey)
break
except paramiko.SSHException:
pass
if not transport.is_authenticated():
if password is not None:
try:
transport.auth_password(username, password)
except paramiko.SSHException:
pass
if not transport.is_authenticated():
msg = 'Not authenticated after two attempts on %r' % hostname
RaiseError(exceptions.ConnectError, msg)
except EOFError:
msg = 'EOFError connecting to: %r' % hostname
RaiseError(exceptions.ConnectError, msg)
except paramiko.AuthenticationException as e:
msg = 'Authentication error connecting to %s: %s' % (hostname, str(e))
RaiseError(exceptions.AuthenticationError, msg)
except paramiko.SSHException as e:
msg = 'SSHException connecting to %s: %s' % (hostname, str(e))
RaiseError(exceptions.ConnectError, msg)
except socket.timeout as e:
msg = 'Timed-out while connecting to %s: %s' % (hostname, str(e))
RaiseError(exceptions.ConnectError, msg)
except socket.error as e:
msg = 'Socket error connecting to %r: %s %s' % (hostname, e.__class__,
e)
RaiseError(exceptions.ConnectError, msg)
return ssh_client
