mirror of
https://github.com/sshuttle/sshuttle.git
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bc065e368d
Previously, it was possible to run sshuttle locally without using ssh and connecting to a remote server. In this configuration, traffic was redirected to the sshuttle server running on the localhost. However, the firewall needed to distinguish between traffic leaving the sshuttle server and traffic that originated from the machine that still needed to be routed through the sshuttle server. The TTL of the packets leaving the sshuttle server were manipulated to indicate to the firewall what should happen. The TTL was adjusted for all packets leaving the sshuttle server (even if it wasn't necessary because the server and client were running on different machines). Changing the TTL caused trouble and some machines, and the --ttl option was added as a workaround to change how the TTL was set for traffic leaving sshuttle. All of this added complexity to the code for a feature (running the server on localhost) that is likely only used for testing and rarely used by others. This commit updates the associated documentation, but doesn't fully fix the ipfw method since I am unable to test that. This change will also make sshuttle fail to work if -r is used to specify a localhost. Pull request #610 partially addresses that issue. For example, see: #240, #490, #660, #606.
52 lines
1.6 KiB
Python
52 lines
1.6 KiB
Python
import socket
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import subprocess as ssubprocess
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from sshuttle.helpers import log, debug1, Fatal, family_to_string, get_env
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def nonfatal(func, *args):
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try:
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func(*args)
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except Fatal as e:
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log('error: %s' % e)
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def ipt_chain_exists(family, table, name):
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if family == socket.AF_INET6:
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cmd = 'ip6tables'
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elif family == socket.AF_INET:
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cmd = 'iptables'
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else:
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raise Exception('Unsupported family "%s"' % family_to_string(family))
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argv = [cmd, '-w', '-t', table, '-nL']
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try:
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output = ssubprocess.check_output(argv, env=get_env())
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for line in output.decode('ASCII').split('\n'):
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if line.startswith('Chain %s ' % name):
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return True
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except ssubprocess.CalledProcessError as e:
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raise Fatal('%r returned %d' % (argv, e.returncode))
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def ipt(family, table, *args):
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if family == socket.AF_INET6:
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argv = ['ip6tables', '-w', '-t', table] + list(args)
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elif family == socket.AF_INET:
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argv = ['iptables', '-w', '-t', table] + list(args)
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else:
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raise Exception('Unsupported family "%s"' % family_to_string(family))
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debug1('%s' % ' '.join(argv))
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rv = ssubprocess.call(argv, env=get_env())
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if rv:
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raise Fatal('%r returned %d' % (argv, rv))
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def nft(family, table, action, *args):
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if family in (socket.AF_INET, socket.AF_INET6):
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argv = ['nft', action, 'inet', table] + list(args)
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else:
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raise Exception('Unsupported family "%s"' % family_to_string(family))
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debug1('%s' % ' '.join(argv))
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rv = ssubprocess.call(argv, env=get_env())
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if rv:
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raise Fatal('%r returned %d' % (argv, rv))
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