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https://github.com/sshuttle/sshuttle.git
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Now if you do ./sshuttle -Nr username@myservername It'll automatically route the "local" subnets (ie., stuff in the routing table) from myservername. This is (hopefully a reasonable default setting for most people.
123 lines
3.5 KiB
Python
123 lines
3.5 KiB
Python
import re, struct, socket, select, subprocess
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if not globals().get('skip_imports'):
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import ssnet, helpers
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from ssnet import SockWrapper, Handler, Proxy, Mux, MuxWrapper
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from helpers import *
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def _ipmatch(ipstr):
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if ipstr == 'default':
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ipstr = '0.0.0.0/0'
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m = re.match(r'^(\d+(\.\d+(\.\d+(\.\d+)?)?)?)(?:/(\d+))?$', ipstr)
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if m:
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g = m.groups()
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ips = g[0]
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width = int(g[4] or 32)
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if g[1] == None:
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ips += '.0.0.0'
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width = min(width, 8)
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elif g[2] == None:
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ips += '.0.0'
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width = min(width, 16)
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elif g[3] == None:
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ips += '.0'
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width = min(width, 24)
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return (struct.unpack('!I', socket.inet_aton(ips))[0], width)
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def _ipstr(ip, width):
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if width >= 32:
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return ip
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else:
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return "%s/%d" % (ip, width)
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def _maskbits(netmask):
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if not netmask:
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return 32
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for i in range(32):
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if netmask[0] & (1<<i):
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return 32-i
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return 0
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def _list_routes():
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argv = ['netstat', '-rn']
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p = subprocess.Popen(argv, stdout=subprocess.PIPE)
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routes = []
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for line in p.stdout:
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cols = re.split(r'\s+', line)
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ipw = _ipmatch(cols[0])
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if not ipw:
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continue # some lines won't be parseable; never mind
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maskw = _ipmatch(cols[2]) # linux only
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mask = _maskbits(maskw) # returns 32 if maskw is null
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width = min(ipw[1], mask)
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ip = ipw[0] & (((1<<width)-1) << (32-width))
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routes.append((socket.inet_ntoa(struct.pack('!I', ip)), width))
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rv = p.wait()
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if rv != 0:
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raise Fatal('%r returned %d' % (argv, rv))
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return routes
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def list_routes():
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for (ip,width) in _list_routes():
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if not ip.startswith('0.') and not ip.startswith('127.'):
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yield (ip,width)
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def main():
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if helpers.verbose >= 1:
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helpers.logprefix = ' s: '
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else:
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helpers.logprefix = 'server: '
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routes = list(list_routes())
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debug1('available routes:\n')
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for r in routes:
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debug1(' %s/%d\n' % r)
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# synchronization header
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sys.stdout.write('SSHUTTLE0001')
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sys.stdout.flush()
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handlers = []
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mux = Mux(socket.fromfd(sys.stdin.fileno(),
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socket.AF_INET, socket.SOCK_STREAM),
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socket.fromfd(sys.stdout.fileno(),
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socket.AF_INET, socket.SOCK_STREAM))
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handlers.append(mux)
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routepkt = ''.join('%s,%d\n' % r
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for r in routes)
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mux.send(0, ssnet.CMD_ROUTES, routepkt)
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def new_channel(channel, data):
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(dstip,dstport) = data.split(',', 1)
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dstport = int(dstport)
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outwrap = ssnet.connect_dst(dstip,dstport)
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handlers.append(Proxy(MuxWrapper(mux, channel), outwrap))
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mux.new_channel = new_channel
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while mux.ok:
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r = set()
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w = set()
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x = set()
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handlers = filter(lambda s: s.ok, handlers)
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for s in handlers:
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s.pre_select(r,w,x)
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debug2('Waiting: %d[%d,%d,%d] (fullness=%d/%d)...\n'
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% (len(handlers), len(r), len(w), len(x),
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mux.fullness, mux.too_full))
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(r,w,x) = select.select(r,w,x)
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#log('r=%r w=%r x=%r\n' % (r,w,x))
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ready = set(r) | set(w) | set(x)
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for s in handlers:
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#debug2('check: %r: %r\n' % (s, s.socks & ready))
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if s.socks & ready:
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s.callback()
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mux.check_fullness()
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mux.callback()
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