You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
538 lines
24 KiB
538 lines
24 KiB
2 years ago
|
'''This class extends pexpect.spawn to specialize setting up SSH connections.
|
||
|
|
This adds methods for login, logout, and expecting the shell prompt.
|
||
|
|
|
||
|
|
PEXPECT LICENSE
|
||
|
|
|
||
|
|
This license is approved by the OSI and FSF as GPL-compatible.
|
||
|
|
http://opensource.org/licenses/isc-license.txt
|
||
|
|
|
||
|
|
Copyright (c) 2012, Noah Spurrier <noah@noah.org>
|
||
|
|
PERMISSION TO USE, COPY, MODIFY, AND/OR DISTRIBUTE THIS SOFTWARE FOR ANY
|
||
|
|
PURPOSE WITH OR WITHOUT FEE IS HEREBY GRANTED, PROVIDED THAT THE ABOVE
|
||
|
|
COPYRIGHT NOTICE AND THIS PERMISSION NOTICE APPEAR IN ALL COPIES.
|
||
|
|
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
||
|
|
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
||
|
|
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
||
|
|
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
||
|
|
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
||
|
|
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
||
|
|
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
||
|
|
|
||
|
|
'''
|
||
|
|
|
||
|
|
from pexpect import ExceptionPexpect, TIMEOUT, EOF, spawn
|
||
|
|
import time
|
||
|
|
import os
|
||
|
|
import sys
|
||
|
|
import re
|
||
|
|
|
||
|
|
__all__ = ['ExceptionPxssh', 'pxssh']
|
||
|
|
|
||
|
|
# Exception classes used by this module.
|
||
|
|
class ExceptionPxssh(ExceptionPexpect):
|
||
|
|
'''Raised for pxssh exceptions.
|
||
|
|
'''
|
||
|
|
|
||
|
|
if sys.version_info > (3, 0):
|
||
|
|
from shlex import quote
|
||
|
|
else:
|
||
|
|
_find_unsafe = re.compile(r'[^\w@%+=:,./-]').search
|
||
|
|
|
||
|
|
def quote(s):
|
||
|
|
"""Return a shell-escaped version of the string *s*."""
|
||
|
|
if not s:
|
||
|
|
return "''"
|
||
|
|
if _find_unsafe(s) is None:
|
||
|
|
return s
|
||
|
|
|
||
|
|
# use single quotes, and put single quotes into double quotes
|
||
|
|
# the string $'b is then quoted as '$'"'"'b'
|
||
|
|
return "'" + s.replace("'", "'\"'\"'") + "'"
|
||
|
|
|
||
|
|
class pxssh (spawn):
|
||
|
|
'''This class extends pexpect.spawn to specialize setting up SSH
|
||
|
|
connections. This adds methods for login, logout, and expecting the shell
|
||
|
|
prompt. It does various tricky things to handle many situations in the SSH
|
||
|
|
login process. For example, if the session is your first login, then pxssh
|
||
|
|
automatically accepts the remote certificate; or if you have public key
|
||
|
|
authentication setup then pxssh won't wait for the password prompt.
|
||
|
|
|
||
|
|
pxssh uses the shell prompt to synchronize output from the remote host. In
|
||
|
|
order to make this more robust it sets the shell prompt to something more
|
||
|
|
unique than just $ or #. This should work on most Borne/Bash or Csh style
|
||
|
|
shells.
|
||
|
|
|
||
|
|
Example that runs a few commands on a remote server and prints the result::
|
||
|
|
|
||
|
|
from pexpect import pxssh
|
||
|
|
import getpass
|
||
|
|
try:
|
||
|
|
s = pxssh.pxssh()
|
||
|
|
hostname = raw_input('hostname: ')
|
||
|
|
username = raw_input('username: ')
|
||
|
|
password = getpass.getpass('password: ')
|
||
|
|
s.login(hostname, username, password)
|
||
|
|
s.sendline('uptime') # run a command
|
||
|
|
s.prompt() # match the prompt
|
||
|
|
print(s.before) # print everything before the prompt.
|
||
|
|
s.sendline('ls -l')
|
||
|
|
s.prompt()
|
||
|
|
print(s.before)
|
||
|
|
s.sendline('df')
|
||
|
|
s.prompt()
|
||
|
|
print(s.before)
|
||
|
|
s.logout()
|
||
|
|
except pxssh.ExceptionPxssh as e:
|
||
|
|
print("pxssh failed on login.")
|
||
|
|
print(e)
|
||
|
|
|
||
|
|
Example showing how to specify SSH options::
|
||
|
|
|
||
|
|
from pexpect import pxssh
|
||
|
|
s = pxssh.pxssh(options={
|
||
|
|
"StrictHostKeyChecking": "no",
|
||
|
|
"UserKnownHostsFile": "/dev/null"})
|
||
|
|
...
|
||
|
|
|
||
|
|
Note that if you have ssh-agent running while doing development with pxssh
|
||
|
|
then this can lead to a lot of confusion. Many X display managers (xdm,
|
||
|
|
gdm, kdm, etc.) will automatically start a GUI agent. You may see a GUI
|
||
|
|
dialog box popup asking for a password during development. You should turn
|
||
|
|
off any key agents during testing. The 'force_password' attribute will turn
|
||
|
|
off public key authentication. This will only work if the remote SSH server
|
||
|
|
is configured to allow password logins. Example of using 'force_password'
|
||
|
|
attribute::
|
||
|
|
|
||
|
|
s = pxssh.pxssh()
|
||
|
|
s.force_password = True
|
||
|
|
hostname = raw_input('hostname: ')
|
||
|
|
username = raw_input('username: ')
|
||
|
|
password = getpass.getpass('password: ')
|
||
|
|
s.login (hostname, username, password)
|
||
|
|
|
||
|
|
`debug_command_string` is only for the test suite to confirm that the string
|
||
|
|
generated for SSH is correct, using this will not allow you to do
|
||
|
|
anything other than get a string back from `pxssh.pxssh.login()`.
|
||
|
|
'''
|
||
|
|
|
||
|
|
def __init__ (self, timeout=30, maxread=2000, searchwindowsize=None,
|
||
|
|
logfile=None, cwd=None, env=None, ignore_sighup=True, echo=True,
|
||
|
|
options={}, encoding=None, codec_errors='strict',
|
||
|
|
debug_command_string=False, use_poll=False):
|
||
|
|
|
||
|
|
spawn.__init__(self, None, timeout=timeout, maxread=maxread,
|
||
|
|
searchwindowsize=searchwindowsize, logfile=logfile,
|
||
|
|
cwd=cwd, env=env, ignore_sighup=ignore_sighup, echo=echo,
|
||
|
|
encoding=encoding, codec_errors=codec_errors, use_poll=use_poll)
|
||
|
|
|
||
|
|
self.name = '<pxssh>'
|
||
|
|
|
||
|
|
#SUBTLE HACK ALERT! Note that the command that SETS the prompt uses a
|
||
|
|
#slightly different string than the regular expression to match it. This
|
||
|
|
#is because when you set the prompt the command will echo back, but we
|
||
|
|
#don't want to match the echoed command. So if we make the set command
|
||
|
|
#slightly different than the regex we eliminate the problem. To make the
|
||
|
|
#set command different we add a backslash in front of $. The $ doesn't
|
||
|
|
#need to be escaped, but it doesn't hurt and serves to make the set
|
||
|
|
#prompt command different than the regex.
|
||
|
|
|
||
|
|
# used to match the command-line prompt
|
||
|
|
self.UNIQUE_PROMPT = r"\[PEXPECT\][\$\#] "
|
||
|
|
self.PROMPT = self.UNIQUE_PROMPT
|
||
|
|
|
||
|
|
# used to set shell command-line prompt to UNIQUE_PROMPT.
|
||
|
|
self.PROMPT_SET_SH = r"PS1='[PEXPECT]\$ '"
|
||
|
|
self.PROMPT_SET_CSH = r"set prompt='[PEXPECT]\$ '"
|
||
|
|
self.SSH_OPTS = ("-o'RSAAuthentication=no'"
|
||
|
|
+ " -o 'PubkeyAuthentication=no'")
|
||
|
|
# Disabling host key checking, makes you vulnerable to MITM attacks.
|
||
|
|
# + " -o 'StrictHostKeyChecking=no'"
|
||
|
|
# + " -o 'UserKnownHostsFile /dev/null' ")
|
||
|
|
# Disabling X11 forwarding gets rid of the annoying SSH_ASKPASS from
|
||
|
|
# displaying a GUI password dialog. I have not figured out how to
|
||
|
|
# disable only SSH_ASKPASS without also disabling X11 forwarding.
|
||
|
|
# Unsetting SSH_ASKPASS on the remote side doesn't disable it! Annoying!
|
||
|
|
#self.SSH_OPTS = "-x -o'RSAAuthentication=no' -o 'PubkeyAuthentication=no'"
|
||
|
|
self.force_password = False
|
||
|
|
|
||
|
|
self.debug_command_string = debug_command_string
|
||
|
|
|
||
|
|
# User defined SSH options, eg,
|
||
|
|
# ssh.otions = dict(StrictHostKeyChecking="no",UserKnownHostsFile="/dev/null")
|
||
|
|
self.options = options
|
||
|
|
|
||
|
|
def levenshtein_distance(self, a, b):
|
||
|
|
'''This calculates the Levenshtein distance between a and b.
|
||
|
|
'''
|
||
|
|
|
||
|
|
n, m = len(a), len(b)
|
||
|
|
if n > m:
|
||
|
|
a,b = b,a
|
||
|
|
n,m = m,n
|
||
|
|
current = range(n+1)
|
||
|
|
for i in range(1,m+1):
|
||
|
|
previous, current = current, [i]+[0]*n
|
||
|
|
for j in range(1,n+1):
|
||
|
|
add, delete = previous[j]+1, current[j-1]+1
|
||
|
|
change = previous[j-1]
|
||
|
|
if a[j-1] != b[i-1]:
|
||
|
|
change = change + 1
|
||
|
|
current[j] = min(add, delete, change)
|
||
|
|
return current[n]
|
||
|
|
|
||
|
|
def try_read_prompt(self, timeout_multiplier):
|
||
|
|
'''This facilitates using communication timeouts to perform
|
||
|
|
synchronization as quickly as possible, while supporting high latency
|
||
|
|
connections with a tunable worst case performance. Fast connections
|
||
|
|
should be read almost immediately. Worst case performance for this
|
||
|
|
method is timeout_multiplier * 3 seconds.
|
||
|
|
'''
|
||
|
|
|
||
|
|
# maximum time allowed to read the first response
|
||
|
|
first_char_timeout = timeout_multiplier * 0.5
|
||
|
|
|
||
|
|
# maximum time allowed between subsequent characters
|
||
|
|
inter_char_timeout = timeout_multiplier * 0.1
|
||
|
|
|
||
|
|
# maximum time for reading the entire prompt
|
||
|
|
total_timeout = timeout_multiplier * 3.0
|
||
|
|
|
||
|
|
prompt = self.string_type()
|
||
|
|
begin = time.time()
|
||
|
|
expired = 0.0
|
||
|
|
timeout = first_char_timeout
|
||
|
|
|
||
|
|
while expired < total_timeout:
|
||
|
|
try:
|
||
|
|
prompt += self.read_nonblocking(size=1, timeout=timeout)
|
||
|
|
expired = time.time() - begin # updated total time expired
|
||
|
|
timeout = inter_char_timeout
|
||
|
|
except TIMEOUT:
|
||
|
|
break
|
||
|
|
|
||
|
|
return prompt
|
||
|
|
|
||
|
|
def sync_original_prompt (self, sync_multiplier=1.0):
|
||
|
|
'''This attempts to find the prompt. Basically, press enter and record
|
||
|
|
the response; press enter again and record the response; if the two
|
||
|
|
responses are similar then assume we are at the original prompt.
|
||
|
|
This can be a slow function. Worst case with the default sync_multiplier
|
||
|
|
can take 12 seconds. Low latency connections are more likely to fail
|
||
|
|
with a low sync_multiplier. Best case sync time gets worse with a
|
||
|
|
high sync multiplier (500 ms with default). '''
|
||
|
|
|
||
|
|
# All of these timing pace values are magic.
|
||
|
|
# I came up with these based on what seemed reliable for
|
||
|
|
# connecting to a heavily loaded machine I have.
|
||
|
|
self.sendline()
|
||
|
|
time.sleep(0.1)
|
||
|
|
|
||
|
|
try:
|
||
|
|
# Clear the buffer before getting the prompt.
|
||
|
|
self.try_read_prompt(sync_multiplier)
|
||
|
|
except TIMEOUT:
|
||
|
|
pass
|
||
|
|
|
||
|
|
self.sendline()
|
||
|
|
x = self.try_read_prompt(sync_multiplier)
|
||
|
|
|
||
|
|
self.sendline()
|
||
|
|
a = self.try_read_prompt(sync_multiplier)
|
||
|
|
|
||
|
|
self.sendline()
|
||
|
|
b = self.try_read_prompt(sync_multiplier)
|
||
|
|
|
||
|
|
ld = self.levenshtein_distance(a,b)
|
||
|
|
len_a = len(a)
|
||
|
|
if len_a == 0:
|
||
|
|
return False
|
||
|
|
if float(ld)/len_a < 0.4:
|
||
|
|
return True
|
||
|
|
return False
|
||
|
|
|
||
|
|
### TODO: This is getting messy and I'm pretty sure this isn't perfect.
|
||
|
|
### TODO: I need to draw a flow chart for this.
|
||
|
|
### TODO: Unit tests for SSH tunnels, remote SSH command exec, disabling original prompt sync
|
||
|
|
def login (self, server, username=None, password='', terminal_type='ansi',
|
||
|
|
original_prompt=r"[#$]", login_timeout=10, port=None,
|
||
|
|
auto_prompt_reset=True, ssh_key=None, quiet=True,
|
||
|
|
sync_multiplier=1, check_local_ip=True,
|
||
|
|
password_regex=r'(?i)(?:password:)|(?:passphrase for key)',
|
||
|
|
ssh_tunnels={}, spawn_local_ssh=True,
|
||
|
|
sync_original_prompt=True, ssh_config=None, cmd='ssh'):
|
||
|
|
'''This logs the user into the given server.
|
||
|
|
|
||
|
|
It uses 'original_prompt' to try to find the prompt right after login.
|
||
|
|
When it finds the prompt it immediately tries to reset the prompt to
|
||
|
|
something more easily matched. The default 'original_prompt' is very
|
||
|
|
optimistic and is easily fooled. It's more reliable to try to match the original
|
||
|
|
prompt as exactly as possible to prevent false matches by server
|
||
|
|
strings such as the "Message Of The Day". On many systems you can
|
||
|
|
disable the MOTD on the remote server by creating a zero-length file
|
||
|
|
called :file:`~/.hushlogin` on the remote server. If a prompt cannot be found
|
||
|
|
then this will not necessarily cause the login to fail. In the case of
|
||
|
|
a timeout when looking for the prompt we assume that the original
|
||
|
|
prompt was so weird that we could not match it, so we use a few tricks
|
||
|
|
to guess when we have reached the prompt. Then we hope for the best and
|
||
|
|
blindly try to reset the prompt to something more unique. If that fails
|
||
|
|
then login() raises an :class:`ExceptionPxssh` exception.
|
||
|
|
|
||
|
|
In some situations it is not possible or desirable to reset the
|
||
|
|
original prompt. In this case, pass ``auto_prompt_reset=False`` to
|
||
|
|
inhibit setting the prompt to the UNIQUE_PROMPT. Remember that pxssh
|
||
|
|
uses a unique prompt in the :meth:`prompt` method. If the original prompt is
|
||
|
|
not reset then this will disable the :meth:`prompt` method unless you
|
||
|
|
manually set the :attr:`PROMPT` attribute.
|
||
|
|
|
||
|
|
Set ``password_regex`` if there is a MOTD message with `password` in it.
|
||
|
|
Changing this is like playing in traffic, don't (p)expect it to match straight
|
||
|
|
away.
|
||
|
|
|
||
|
|
If you require to connect to another SSH server from the your original SSH
|
||
|
|
connection set ``spawn_local_ssh`` to `False` and this will use your current
|
||
|
|
session to do so. Setting this option to `False` and not having an active session
|
||
|
|
will trigger an error.
|
||
|
|
|
||
|
|
Set ``ssh_key`` to a file path to an SSH private key to use that SSH key
|
||
|
|
for the session authentication.
|
||
|
|
Set ``ssh_key`` to `True` to force passing the current SSH authentication socket
|
||
|
|
to the desired ``hostname``.
|
||
|
|
|
||
|
|
Set ``ssh_config`` to a file path string of an SSH client config file to pass that
|
||
|
|
file to the client to handle itself. You may set any options you wish in here, however
|
||
|
|
doing so will require you to post extra information that you may not want to if you
|
||
|
|
run into issues.
|
||
|
|
|
||
|
|
Alter the ``cmd`` to change the ssh client used, or to prepend it with network
|
||
|
|
namespaces. For example ```cmd="ip netns exec vlan2 ssh"``` to execute the ssh in
|
||
|
|
network namespace named ```vlan```.
|
||
|
|
'''
|
||
|
|
|
||
|
|
session_regex_array = ["(?i)are you sure you want to continue connecting", original_prompt, password_regex, "(?i)permission denied", "(?i)terminal type", TIMEOUT]
|
||
|
|
session_init_regex_array = []
|
||
|
|
session_init_regex_array.extend(session_regex_array)
|
||
|
|
session_init_regex_array.extend(["(?i)connection closed by remote host", EOF])
|
||
|
|
|
||
|
|
ssh_options = ''.join([" -o '%s=%s'" % (o, v) for (o, v) in self.options.items()])
|
||
|
|
if quiet:
|
||
|
|
ssh_options = ssh_options + ' -q'
|
||
|
|
if not check_local_ip:
|
||
|
|
ssh_options = ssh_options + " -o'NoHostAuthenticationForLocalhost=yes'"
|
||
|
|
if self.force_password:
|
||
|
|
ssh_options = ssh_options + ' ' + self.SSH_OPTS
|
||
|
|
if ssh_config is not None:
|
||
|
|
if spawn_local_ssh and not os.path.isfile(ssh_config):
|
||
|
|
raise ExceptionPxssh('SSH config does not exist or is not a file.')
|
||
|
|
ssh_options = ssh_options + ' -F ' + ssh_config
|
||
|
|
if port is not None:
|
||
|
|
ssh_options = ssh_options + ' -p %s'%(str(port))
|
||
|
|
if ssh_key is not None:
|
||
|
|
# Allow forwarding our SSH key to the current session
|
||
|
|
if ssh_key==True:
|
||
|
|
ssh_options = ssh_options + ' -A'
|
||
|
|
else:
|
||
|
|
if spawn_local_ssh and not os.path.isfile(ssh_key):
|
||
|
|
raise ExceptionPxssh('private ssh key does not exist or is not a file.')
|
||
|
|
ssh_options = ssh_options + ' -i %s' % (ssh_key)
|
||
|
|
|
||
|
|
# SSH tunnels, make sure you know what you're putting into the lists
|
||
|
|
# under each heading. Do not expect these to open 100% of the time,
|
||
|
|
# The port you're requesting might be bound.
|
||
|
|
#
|
||
|
|
# The structure should be like this:
|
||
|
|
# { 'local': ['2424:localhost:22'], # Local SSH tunnels
|
||
|
|
# 'remote': ['2525:localhost:22'], # Remote SSH tunnels
|
||
|
|
# 'dynamic': [8888] } # Dynamic/SOCKS tunnels
|
||
|
|
if ssh_tunnels!={} and isinstance({},type(ssh_tunnels)):
|
||
|
|
tunnel_types = {
|
||
|
|
'local':'L',
|
||
|
|
'remote':'R',
|
||
|
|
'dynamic':'D'
|
||
|
|
}
|
||
|
|
for tunnel_type in tunnel_types:
|
||
|
|
cmd_type = tunnel_types[tunnel_type]
|
||
|
|
if tunnel_type in ssh_tunnels:
|
||
|
|
tunnels = ssh_tunnels[tunnel_type]
|
||
|
|
for tunnel in tunnels:
|
||
|
|
if spawn_local_ssh==False:
|
||
|
|
tunnel = quote(str(tunnel))
|
||
|
|
ssh_options = ssh_options + ' -' + cmd_type + ' ' + str(tunnel)
|
||
|
|
|
||
|
|
if username is not None:
|
||
|
|
ssh_options = ssh_options + ' -l ' + username
|
||
|
|
elif ssh_config is None:
|
||
|
|
raise TypeError('login() needs either a username or an ssh_config')
|
||
|
|
else: # make sure ssh_config has an entry for the server with a username
|
||
|
|
with open(ssh_config, 'rt') as f:
|
||
|
|
lines = [l.strip() for l in f.readlines()]
|
||
|
|
|
||
|
|
server_regex = r'^Host\s+%s\s*$' % server
|
||
|
|
user_regex = r'^User\s+\w+\s*$'
|
||
|
|
config_has_server = False
|
||
|
|
server_has_username = False
|
||
|
|
for line in lines:
|
||
|
|
if not config_has_server and re.match(server_regex, line, re.IGNORECASE):
|
||
|
|
config_has_server = True
|
||
|
|
elif config_has_server and 'hostname' in line.lower():
|
||
|
|
pass
|
||
|
|
elif config_has_server and 'host' in line.lower():
|
||
|
|
server_has_username = False # insurance
|
||
|
|
break # we have left the relevant section
|
||
|
|
elif config_has_server and re.match(user_regex, line, re.IGNORECASE):
|
||
|
|
server_has_username = True
|
||
|
|
break
|
||
|
|
|
||
|
|
if lines:
|
||
|
|
del line
|
||
|
|
|
||
|
|
del lines
|
||
|
|
|
||
|
|
if not config_has_server:
|
||
|
|
raise TypeError('login() ssh_config has no Host entry for %s' % server)
|
||
|
|
elif not server_has_username:
|
||
|
|
raise TypeError('login() ssh_config has no user entry for %s' % server)
|
||
|
|
|
||
|
|
cmd += " %s %s" % (ssh_options, server)
|
||
|
|
if self.debug_command_string:
|
||
|
|
return(cmd)
|
||
|
|
|
||
|
|
# Are we asking for a local ssh command or to spawn one in another session?
|
||
|
|
if spawn_local_ssh:
|
||
|
|
spawn._spawn(self, cmd)
|
||
|
|
else:
|
||
|
|
self.sendline(cmd)
|
||
|
|
|
||
|
|
# This does not distinguish between a remote server 'password' prompt
|
||
|
|
# and a local ssh 'passphrase' prompt (for unlocking a private key).
|
||
|
|
i = self.expect(session_init_regex_array, timeout=login_timeout)
|
||
|
|
|
||
|
|
# First phase
|
||
|
|
if i==0:
|
||
|
|
# New certificate -- always accept it.
|
||
|
|
# This is what you get if SSH does not have the remote host's
|
||
|
|
# public key stored in the 'known_hosts' cache.
|
||
|
|
self.sendline("yes")
|
||
|
|
i = self.expect(session_regex_array)
|
||
|
|
if i==2: # password or passphrase
|
||
|
|
self.sendline(password)
|
||
|
|
i = self.expect(session_regex_array)
|
||
|
|
if i==4:
|
||
|
|
self.sendline(terminal_type)
|
||
|
|
i = self.expect(session_regex_array)
|
||
|
|
if i==7:
|
||
|
|
self.close()
|
||
|
|
raise ExceptionPxssh('Could not establish connection to host')
|
||
|
|
|
||
|
|
# Second phase
|
||
|
|
if i==0:
|
||
|
|
# This is weird. This should not happen twice in a row.
|
||
|
|
self.close()
|
||
|
|
raise ExceptionPxssh('Weird error. Got "are you sure" prompt twice.')
|
||
|
|
elif i==1: # can occur if you have a public key pair set to authenticate.
|
||
|
|
### TODO: May NOT be OK if expect() got tricked and matched a false prompt.
|
||
|
|
pass
|
||
|
|
elif i==2: # password prompt again
|
||
|
|
# For incorrect passwords, some ssh servers will
|
||
|
|
# ask for the password again, others return 'denied' right away.
|
||
|
|
# If we get the password prompt again then this means
|
||
|
|
# we didn't get the password right the first time.
|
||
|
|
self.close()
|
||
|
|
raise ExceptionPxssh('password refused')
|
||
|
|
elif i==3: # permission denied -- password was bad.
|
||
|
|
self.close()
|
||
|
|
raise ExceptionPxssh('permission denied')
|
||
|
|
elif i==4: # terminal type again? WTF?
|
||
|
|
self.close()
|
||
|
|
raise ExceptionPxssh('Weird error. Got "terminal type" prompt twice.')
|
||
|
|
elif i==5: # Timeout
|
||
|
|
#This is tricky... I presume that we are at the command-line prompt.
|
||
|
|
#It may be that the shell prompt was so weird that we couldn't match
|
||
|
|
#it. Or it may be that we couldn't log in for some other reason. I
|
||
|
|
#can't be sure, but it's safe to guess that we did login because if
|
||
|
|
#I presume wrong and we are not logged in then this should be caught
|
||
|
|
#later when I try to set the shell prompt.
|
||
|
|
pass
|
||
|
|
elif i==6: # Connection closed by remote host
|
||
|
|
self.close()
|
||
|
|
raise ExceptionPxssh('connection closed')
|
||
|
|
else: # Unexpected
|
||
|
|
self.close()
|
||
|
|
raise ExceptionPxssh('unexpected login response')
|
||
|
|
if sync_original_prompt:
|
||
|
|
if not self.sync_original_prompt(sync_multiplier):
|
||
|
|
self.close()
|
||
|
|
raise ExceptionPxssh('could not synchronize with original prompt')
|
||
|
|
# We appear to be in.
|
||
|
|
# set shell prompt to something unique.
|
||
|
|
if auto_prompt_reset:
|
||
|
|
if not self.set_unique_prompt():
|
||
|
|
self.close()
|
||
|
|
raise ExceptionPxssh('could not set shell prompt '
|
||
|
|
'(received: %r, expected: %r).' % (
|
||
|
|
self.before, self.PROMPT,))
|
||
|
|
return True
|
||
|
|
|
||
|
|
def logout (self):
|
||
|
|
'''Sends exit to the remote shell.
|
||
|
|
|
||
|
|
If there are stopped jobs then this automatically sends exit twice.
|
||
|
|
'''
|
||
|
|
self.sendline("exit")
|
||
|
|
index = self.expect([EOF, "(?i)there are stopped jobs"])
|
||
|
|
if index==1:
|
||
|
|
self.sendline("exit")
|
||
|
|
self.expect(EOF)
|
||
|
|
self.close()
|
||
|
|
|
||
|
|
def prompt(self, timeout=-1):
|
||
|
|
'''Match the next shell prompt.
|
||
|
|
|
||
|
|
This is little more than a short-cut to the :meth:`~pexpect.spawn.expect`
|
||
|
|
method. Note that if you called :meth:`login` with
|
||
|
|
``auto_prompt_reset=False``, then before calling :meth:`prompt` you must
|
||
|
|
set the :attr:`PROMPT` attribute to a regex that it will use for
|
||
|
|
matching the prompt.
|
||
|
|
|
||
|
|
Calling :meth:`prompt` will erase the contents of the :attr:`before`
|
||
|
|
attribute even if no prompt is ever matched. If timeout is not given or
|
||
|
|
it is set to -1 then self.timeout is used.
|
||
|
|
|
||
|
|
:return: True if the shell prompt was matched, False if the timeout was
|
||
|
|
reached.
|
||
|
|
'''
|
||
|
|
|
||
|
|
if timeout == -1:
|
||
|
|
timeout = self.timeout
|
||
|
|
i = self.expect([self.PROMPT, TIMEOUT], timeout=timeout)
|
||
|
|
if i==1:
|
||
|
|
return False
|
||
|
|
return True
|
||
|
|
|
||
|
|
def set_unique_prompt(self):
|
||
|
|
'''This sets the remote prompt to something more unique than ``#`` or ``$``.
|
||
|
|
This makes it easier for the :meth:`prompt` method to match the shell prompt
|
||
|
|
unambiguously. This method is called automatically by the :meth:`login`
|
||
|
|
method, but you may want to call it manually if you somehow reset the
|
||
|
|
shell prompt. For example, if you 'su' to a different user then you
|
||
|
|
will need to manually reset the prompt. This sends shell commands to
|
||
|
|
the remote host to set the prompt, so this assumes the remote host is
|
||
|
|
ready to receive commands.
|
||
|
|
|
||
|
|
Alternatively, you may use your own prompt pattern. In this case you
|
||
|
|
should call :meth:`login` with ``auto_prompt_reset=False``; then set the
|
||
|
|
:attr:`PROMPT` attribute to a regular expression. After that, the
|
||
|
|
:meth:`prompt` method will try to match your prompt pattern.
|
||
|
|
'''
|
||
|
|
|
||
|
|
self.sendline("unset PROMPT_COMMAND")
|
||
|
|
self.sendline(self.PROMPT_SET_SH) # sh-style
|
||
|
|
i = self.expect ([TIMEOUT, self.PROMPT], timeout=10)
|
||
|
|
if i == 0: # csh-style
|
||
|
|
self.sendline(self.PROMPT_SET_CSH)
|
||
|
|
i = self.expect([TIMEOUT, self.PROMPT], timeout=10)
|
||
|
|
if i == 0:
|
||
|
|
return False
|
||
|
|
return True
|
||
|
|
|
||
|
|
# vi:ts=4:sw=4:expandtab:ft=python:
|