sshuttle/ssh.py
Avery Pennarun 81c89ce9be Don't bother with a backtrace when we produce certain fatal errors.
We'll introduce a new "Fatal" exception for this purpose, and throw it when
we just want to print a user message and abort immediately.
2010-05-02 02:29:23 -04:00

39 lines
1.5 KiB
Python

import sys, os, re, subprocess, socket
import helpers
def connect(rhost):
main_exe = sys.argv[0]
nicedir = os.path.split(os.path.abspath(main_exe))[0]
nicedir = re.sub(r':', "_", nicedir)
if rhost == '-':
rhost = None
if not rhost:
argv = ['sshuttle', '--server'] + ['-v']*(helpers.verbose or 0)
else:
# WARNING: shell quoting security holes are possible here, so we
# have to be super careful. We have to use 'sh -c' because
# csh-derived shells can't handle PATH= notation. We can't
# set PATH in advance, because ssh probably replaces it. We
# can't exec *safely* using argv, because *both* ssh and 'sh -c'
# allow shellquoting. So we end up having to double-shellquote
# stuff here.
escapedir = re.sub(r'([^\w/])', r'\\\\\\\1', nicedir)
cmd = r"""
sh -c PATH=%s:'$PATH exec sshuttle --server%s'
""" % (escapedir, ' -v' * (helpers.verbose or 0))
argv = ['ssh', rhost, '--', cmd.strip()]
(s1,s2) = socket.socketpair()
def setup():
# runs in the child process
s2.close()
if not rhost:
os.environ['PATH'] = ':'.join([nicedir,
os.environ.get('PATH', '')])
os.setsid()
s1a,s1b = os.dup(s1.fileno()), os.dup(s1.fileno())
s1.close()
p = subprocess.Popen(argv, stdin=s1a, stdout=s1b, preexec_fn=setup)
os.close(s1a)
os.close(s1b)
return p, s2