apenwarr
Alter codification for utf-8 in file server.py line 69 to solve issue #93
import re import struct import socket import traceback import time import sys import os import platform
import sshuttle.ssnet as ssnet
import sshuttle.helpers as helpers
import sshuttle.hostwatch as hostwatch
import subprocess as ssubprocess
from sshuttle.ssnet import Handler, Proxy, Mux, MuxWrapper
from sshuttle.helpers import b, log, debug1, debug2, debug3, Fatal,
resolvconf_random_nameserver
def _ipmatch(ipstr): # FIXME: IPv4 only if ipstr == 'default': ipstr = '0.0.0.0/0' m = re.match('^(\d+(.\d+(.\d+(.\d+)?)?)?)(?:/(\d+))?$', ipstr) if m: g = m.groups() ips = g[0] width = int(g[4] or 32) if g[1] is None: ips += '.0.0.0' width = min(width, 8) elif g[2] is None: ips += '.0.0' width = min(width, 16) elif g[3] is None: ips += '.0' width = min(width, 24) ips = ips return (struct.unpack('!I', socket.inet_aton(ips))[0], width)
def _ipstr(ip, width): # FIXME: IPv4 only if width >= 32: return ip else: return "%s/%d" % (ip, width)
def _maskbits(netmask): # FIXME: IPv4 only if not netmask: return 32 for i in range(32): if netmask[0] & _shl(1, i): return 32 - i return 0
def _shl(n, bits): return n * int(2 ** bits)
def _list_routes(): # FIXME: IPv4 only argv = ['netstat', '-rn'] p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE) routes = [] for line in p.stdout: cols = re.split(r'\s+', line.decode("utf-8")) ipw = _ipmatch(cols[0]) if not ipw: continue # some lines won't be parseable; never mind maskw = _ipmatch(cols[2]) # linux only mask = _maskbits(maskw) # returns 32 if maskw is null width = min(ipw[1], mask) ip = ipw[0] & _shl(_shl(1, width) - 1, 32 - width) routes.append( (socket.AF_INET, socket.inet_ntoa(struct.pack('!I', ip)), width)) rv = p.wait() if rv != 0: log('WARNING: %r returned %d\n' % (argv, rv)) log('WARNING: That prevents --auto-nets from working.\n') return routes
def list_routes(): for (family, ip, width) in _list_routes(): if not ip.startswith('0.') and not ip.startswith('127.'): yield (family, ip, width)
def _exc_dump(): exc_info = sys.exc_info() return ''.join(traceback.format_exception(*exc_info))
def start_hostwatch(seed_hosts): s1, s2 = socket.socketpair() pid = os.fork() if not pid: # child rv = 99 try: try: s2.close() os.dup2(s1.fileno(), 1) os.dup2(s1.fileno(), 0) s1.close() rv = hostwatch.hw_main(seed_hosts) or 0 except Exception: log('%s\n' % _exc_dump()) rv = 98 finally: os._exit(rv) s1.close() return pid, s2
class Hostwatch:
def __init__(self):
self.pid = 0
self.sock = None
class DnsProxy(Handler):
def __init__(self, mux, chan, request):
Handler.__init__(self, [])
self.timeout = time.time() + 30
self.mux = mux
self.chan = chan
self.tries = 0
self.request = request
self.peers = {}
self.try_send()
def try_send(self):
if self.tries >= 3:
return
self.tries += 1
family, peer = resolvconf_random_nameserver()
sock = socket.socket(family, socket.SOCK_DGRAM)
sock.setsockopt(socket.SOL_IP, socket.IP_TTL, 42)
sock.connect((peer, 53))
self.peers[sock] = peer
debug2('DNS: sending to %r (try %d)\n' % (peer, self.tries))
try:
sock.send(self.request)
self.socks.append(sock)
except socket.error:
_, e = sys.exc_info()[:2]
if e.args[0] in ssnet.NET_ERRS:
# might have been spurious; try again.
# Note: these errors sometimes are reported by recv(),
# and sometimes by send(). We have to catch both.
debug2('DNS send to %r: %s\n' % (peer, e))
self.try_send()
return
else:
log('DNS send to %r: %s\n' % (peer, e))
return
def callback(self, sock):
peer = self.peers[sock]
try:
data = sock.recv(4096)
except socket.error:
_, e = sys.exc_info()[:2]
self.socks.remove(sock)
del self.peers[sock]
if e.args[0] in ssnet.NET_ERRS:
# might have been spurious; try again.
# Note: these errors sometimes are reported by recv(),
# and sometimes by send(). We have to catch both.
debug2('DNS recv from %r: %s\n' % (peer, e))
self.try_send()
return
else:
log('DNS recv from %r: %s\n' % (peer, e))
return
debug2('DNS response: %d bytes\n' % len(data))
self.mux.send(self.chan, ssnet.CMD_DNS_RESPONSE, data)
self.ok = False
class UdpProxy(Handler):
def __init__(self, mux, chan, family):
sock = socket.socket(family, socket.SOCK_DGRAM)
Handler.__init__(self, [sock])
self.timeout = time.time() + 30
self.mux = mux
self.chan = chan
self.sock = sock
if family == socket.AF_INET:
self.sock.setsockopt(socket.SOL_IP, socket.IP_TTL, 42)
def send(self, dstip, data):
debug2('UDP: sending to %r port %d\n' % dstip)
try:
self.sock.sendto(data, dstip)
except socket.error:
_, e = sys.exc_info()[:2]
log('UDP send to %r port %d: %s\n' % (dstip[0], dstip[1], e))
return
def callback(self, sock):
try:
data, peer = sock.recvfrom(4096)
except socket.error:
_, e = sys.exc_info()[:2]
log('UDP recv from %r port %d: %s\n' % (peer[0], peer[1], e))
return
debug2('UDP response: %d bytes\n' % len(data))
hdr = "%s,%r," % (peer[0], peer[1])
self.mux.send(self.chan, ssnet.CMD_UDP_DATA, hdr + data)
def main(latency_control): debug1('Starting server with Python version %s\n' % platform.python_version())
if helpers.verbose >= 1:
helpers.logprefix = ' s: '
else:
helpers.logprefix = 'server: '
debug1('latency control setting = %r\n' % latency_control)
routes = list(list_routes())
debug1('available routes:\n')
for r in routes:
debug1(' %d/%s/%d\n' % r)
# synchronization header
sys.stdout.write('\0\0SSHUTTLE0001')
sys.stdout.flush()
handlers = []
mux = Mux(socket.fromfd(sys.stdin.fileno(),
socket.AF_INET, socket.SOCK_STREAM),
socket.fromfd(sys.stdout.fileno(),
socket.AF_INET, socket.SOCK_STREAM))
handlers.append(mux)
routepkt = ''
for r in routes:
routepkt += '%d,%s,%d\n' % r
mux.send(0, ssnet.CMD_ROUTES, b(routepkt))
hw = Hostwatch()
hw.leftover = b('')
def hostwatch_ready(sock):
assert(hw.pid)
content = hw.sock.recv(4096)
if content:
lines = (hw.leftover + content).split(b('\n'))
if lines[-1]:
# no terminating newline: entry isn't complete yet!
hw.leftover = lines.pop()
lines.append(b(''))
else:
hw.leftover = b('')
mux.send(0, ssnet.CMD_HOST_LIST, b('\n').join(lines))
else:
raise Fatal('hostwatch process died')
def got_host_req(data):
if not hw.pid:
(hw.pid, hw.sock) = start_hostwatch(data.strip().split())
handlers.append(Handler(socks=[hw.sock],
callback=hostwatch_ready))
mux.got_host_req = got_host_req
def new_channel(channel, data):
(family, dstip, dstport) = data.decode("ASCII").split(',', 2)
family = int(family)
dstport = int(dstport)
outwrap = ssnet.connect_dst(family, dstip, dstport)
handlers.append(Proxy(MuxWrapper(mux, channel), outwrap))
mux.new_channel = new_channel
dnshandlers = {}
def dns_req(channel, data):
debug2('Incoming DNS request channel=%d.\n' % channel)
h = DnsProxy(mux, channel, data)
handlers.append(h)
dnshandlers[channel] = h
mux.got_dns_req = dns_req
udphandlers = {}
def udp_req(channel, cmd, data):
debug2('Incoming UDP request channel=%d, cmd=%d\n' % (channel, cmd))
if cmd == ssnet.CMD_UDP_DATA:
(dstip, dstport, data) = data.split(",", 2)
dstport = int(dstport)
debug2('is incoming UDP data. %r %d.\n' % (dstip, dstport))
h = udphandlers[channel]
h.send((dstip, dstport), data)
elif cmd == ssnet.CMD_UDP_CLOSE:
debug2('is incoming UDP close\n')
h = udphandlers[channel]
h.ok = False
del mux.channels[channel]
def udp_open(channel, data):
debug2('Incoming UDP open.\n')
family = int(data)
mux.channels[channel] = lambda cmd, data: udp_req(channel, cmd, data)
if channel in udphandlers:
raise Fatal('UDP connection channel %d already open' % channel)
else:
h = UdpProxy(mux, channel, family)
handlers.append(h)
udphandlers[channel] = h
mux.got_udp_open = udp_open
while mux.ok:
if hw.pid:
assert(hw.pid > 0)
(rpid, rv) = os.waitpid(hw.pid, os.WNOHANG)
if rpid:
raise Fatal(
'hostwatch exited unexpectedly: code 0x%04x\n' % rv)
ssnet.runonce(handlers, mux)
if latency_control:
mux.check_fullness()
if dnshandlers:
now = time.time()
remove = []
for channel, h in dnshandlers.items():
if h.timeout < now or not h.ok:
debug3('expiring dnsreqs channel=%d\n' % channel)
remove.append(channel)
h.ok = False
for channel in remove:
del dnshandlers[channel]
if udphandlers:
remove = []
for channel, h in udphandlers.items():
if not h.ok:
debug3('expiring UDP channel=%d\n' % channel)
remove.append(channel)
h.ok = False
for channel in remove:
del udphandlers[channel]
