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import struct, socket, select, errno, re
import compat.ssubprocess as ssubprocess
import helpers, ssnet, ssh
from ssnet import SockWrapper, Handler, Proxy, Mux, MuxWrapper
from helpers import *
def original_dst(sock):
try:
SO_ORIGINAL_DST = 80
SOCKADDR_MIN = 16
sockaddr_in = sock.getsockopt(socket.SOL_IP,
SO_ORIGINAL_DST, SOCKADDR_MIN)
(proto, port, a,b,c,d) = struct.unpack('!HHBBBB', sockaddr_in[:8])
assert(socket.htons(proto) == socket.AF_INET)
ip = '%d.%d.%d.%d' % (a,b,c,d)
return (ip,port)
except socket.error, e:
if e.args[0] == errno.ENOPROTOOPT:
return sock.getsockname()
raise
class FirewallClient:
def __init__(self, port, subnets_include, subnets_exclude):
self.port = port
self.auto_nets = []
self.subnets_include = subnets_include
self.subnets_exclude = subnets_exclude
argvbase = ([sys.argv[0]] +
['-v'] * (helpers.verbose or 0) +
['--firewall', str(port)])
argv_tries = [
['sudo'] + argvbase,
['su', '-c', ' '.join(argvbase)],
argvbase
]
# we can't use stdin/stdout=subprocess.PIPE here, as we normally would,
# because stupid Linux 'su' requires that stdin be attached to a tty.
# Instead, attach a *bidirectional* socket to its stdout, and use
# that for talking in both directions.
(s1,s2) = socket.socketpair()
def setup():
# run in the child process
s2.close()
e = None
for argv in argv_tries:
try:
self.p = ssubprocess.Popen(argv, stdout=s1, preexec_fn=setup)
e = None
break
except OSError, e:
pass
self.argv = argv
s1.close()
self.pfile = s2.makefile('wb+')
if e:
log('Spawning firewall manager: %r\n' % self.argv)
raise Fatal(e)
line = self.pfile.readline()
self.check()
if line != 'READY\n':
raise Fatal('%r expected READY, got %r' % (self.argv, line))
def check(self):
rv = self.p.poll()
if rv:
raise Fatal('%r returned %d' % (self.argv, rv))
def start(self):
self.pfile.write('ROUTES\n')
for (ip,width) in self.subnets_include+self.auto_nets:
self.pfile.write('%d,0,%s\n' % (width, ip))
for (ip,width) in self.subnets_exclude:
self.pfile.write('%d,1,%s\n' % (width, ip))
self.pfile.write('GO\n')
self.pfile.flush()
line = self.pfile.readline()
self.check()
if line != 'STARTED\n':
raise Fatal('%r expected STARTED, got %r' % (self.argv, line))
def sethostip(self, hostname, ip):
assert(not re.search(r'[^-\w]', hostname))
assert(not re.search(r'[^0-9.]', ip))
self.pfile.write('HOST %s,%s\n' % (hostname, ip))
self.pfile.flush()
def done(self):
self.pfile.close()
rv = self.p.wait()
if rv:
raise Fatal('cleanup: %r returned %d' % (self.argv, rv))
def _main(listener, fw, use_server, remotename, python, seed_hosts, auto_nets):
handlers = []
if use_server:
if helpers.verbose >= 1:
helpers.logprefix = 'c : '
else:
helpers.logprefix = 'client: '
debug1('connecting to server...\n')
try:
(serverproc, serversock) = ssh.connect(remotename, python)
except socket.error, e:
if e.errno == errno.EPIPE:
raise Fatal("failed to establish ssh session")
else:
raise
mux = Mux(serversock, serversock)
handlers.append(mux)
expected = 'SSHUTTLE0001'
initstring = serversock.recv(len(expected))
rv = serverproc.poll()
if rv:
raise Fatal('server died with error code %d' % rv)
if initstring != expected:
raise Fatal('expected server init string %r; got %r'
% (expected, initstring))
debug1('connected.\n')
def onroutes(routestr):
if auto_nets:
for line in routestr.strip().split('\n'):
(ip,width) = line.split(',', 1)
fw.auto_nets.append((ip,int(width)))
# we definitely want to do this *after* starting ssh, or we might end
# up intercepting the ssh connection!
#
# Moreover, now that we have the --auto-nets option, we have to wait
# for the server to send us that message anyway. Even if we haven't
# set --auto-nets, we might as well wait for the message first, then
# ignore its contents.
mux.got_routes = None
fw.start()
mux.got_routes = onroutes
def onhostlist(hostlist):
debug2('got host list: %r\n' % hostlist)
for line in hostlist.strip().split():
if line:
name,ip = line.split(',', 1)
fw.sethostip(name, ip)
mux.got_host_list = onhostlist
def onaccept():
sock,srcip = listener.accept()
dstip = original_dst(sock)
debug1('Accept: %r:%r -> %r:%r.\n' % (srcip[0],srcip[1],
dstip[0],dstip[1]))
if dstip == listener.getsockname():
debug1("-- ignored: that's my address!\n")
sock.close()
return
if use_server:
chan = mux.next_channel()
mux.send(chan, ssnet.CMD_CONNECT, '%s,%s' % dstip)
outwrap = MuxWrapper(mux, chan)
else:
outwrap = ssnet.connect_dst(dstip[0], dstip[1])
handlers.append(Proxy(SockWrapper(sock, sock), outwrap))
handlers.append(Handler([listener], onaccept))
if seed_hosts != None:
debug1('seed_hosts: %r\n' % seed_hosts)
mux.send(0, ssnet.CMD_HOST_REQ, '\n'.join(seed_hosts))
while 1:
if use_server:
rv = serverproc.poll()
if rv:
raise Fatal('server died with error code %d' % rv)
ssnet.runonce(handlers, mux)
if use_server:
mux.callback()
mux.check_fullness()
def main(listenip, use_server, remotename, python, seed_hosts, auto_nets,
subnets_include, subnets_exclude):
debug1('Starting sshuttle proxy.\n')
listener = socket.socket()
listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
if listenip[1]:
ports = [listenip[1]]
else:
ports = xrange(12300,9000,-1)
last_e = None
bound = False
debug2('Binding:')
for port in ports:
debug2(' %d' % port)
try:
listener.bind((listenip[0], port))
bound = True
break
except socket.error, e:
last_e = e
debug2('\n')
if not bound:
assert(last_e)
raise last_e
listener.listen(10)
listenip = listener.getsockname()
debug1('Listening on %r.\n' % (listenip,))
fw = FirewallClient(listenip[1], subnets_include, subnets_exclude)
try:
return _main(listener, fw, use_server, remotename,
python, seed_hosts, auto_nets)
finally:
fw.done()
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