import re, struct, socket, select, traceback if not globals().get('skip_imports'): import ssnet, helpers, hostwatch import compat.ssubprocess as ssubprocess from ssnet import SockWrapper, Handler, Proxy, Mux, MuxWrapper from helpers import * def _ipmatch(ipstr): if ipstr == 'default': ipstr = '0.0.0.0/0' m = re.match(r'^(\d+(\.\d+(\.\d+(\.\d+)?)?)?)(?:/(\d+))?$', ipstr) if m: g = m.groups() ips = g[0] width = int(g[4] or 32) if g[1] == None: ips += '.0.0.0' width = min(width, 8) elif g[2] == None: ips += '.0.0' width = min(width, 16) elif g[3] == None: ips += '.0' width = min(width, 24) return (struct.unpack('!I', socket.inet_aton(ips))[0], width) def _ipstr(ip, width): if width >= 32: return ip else: return "%s/%d" % (ip, width) def _maskbits(netmask): 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(): argv = ['netstat', '-rn'] p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE) routes = [] for line in p.stdout: cols = re.split(r'\s+', line) 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.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 (ip,width) in _list_routes(): if not ip.startswith('0.') and not ip.startswith('127.'): yield (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, e: 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 def main(): if helpers.verbose >= 1: helpers.logprefix = ' s: ' else: helpers.logprefix = 'server: ' routes = list(list_routes()) debug1('available routes:\n') for r in routes: debug1(' %s/%d\n' % r) # synchronization header sys.stdout.write('SSHUTTLE0001') 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 += '%s,%d\n' % r mux.send(0, ssnet.CMD_ROUTES, routepkt) hw = Hostwatch() def hostwatch_ready(): assert(hw.pid) content = hw.sock.recv(4096) if content: mux.send(0, ssnet.CMD_HOST_LIST, content) 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): (dstip,dstport) = data.split(',', 1) dstport = int(dstport) outwrap = ssnet.connect_dst(dstip,dstport) handlers.append(Proxy(MuxWrapper(mux, channel), outwrap)) mux.new_channel = new_channel while mux.ok: if hw.pid: (rpid, rv) = os.waitpid(hw.pid, os.WNOHANG) if rpid: raise Fatal('hostwatch exited unexpectedly: code 0x%04x\n' % rv) ssnet.runonce(handlers, mux) mux.check_fullness() mux.callback()