sshuttle.md: fix whitespace issues.

(Slightly modified by apenwarr)

.gitignore

@@ -1,3 +1,6 @@
 *.pyc
 *~
 *.8
+/.do_built
+/.do_built.dir
+/.redo

Makefile

@@ -1,19 +0,0 @@
-PANDOC:=$(shell \
-	if pandoc </dev/null 2>/dev/null; then \
-		echo pandoc; \
-	else \
-		echo "Warning: pandoc not installed; can't generate manpages." >&2; \
-		echo '@echo Skipping: pandoc'; \
-	fi)
-
-default: all
-
-all: sshuttle.8
-
-sshuttle.8: sshuttle.md
-
-%.8: %.md
-	$(PANDOC) -s -r markdown -w man -o $@ $<
-
-clean:
-	rm -f *~ */*~ .*~ */.*~ *.8 *.tmp */*.tmp *.pyc */*.pyc

README.md

@@ -1,3 +1,22 @@
+
+WARNING:
+On MacOS 10.6 (at least up to 10.6.6), your network will
+stop responding about 10 minutes after the first time you
+start sshuttle, because of a MacOS kernel bug relating to
+arp and the net.inet.ip.scopedroute sysctl.  To fix it,
+just switch your wireless off and on. Sshuttle makes the
+kernel setting it changes permanent, so this won't happen
+again, even after a reboot.
+
+Required Software
+=================
+
+ - You need PyXAPI, available here:
+   http://www.pps.univ-paris-diderot.fr/~ylg/PyXAPI/
+ - You also need autossh, available in various package management systems
+ - Python 2.x, both locally and the remote system
+
+
 sshuttle: where transparent proxy meets VPN meets ssh
 =====================================================
 
@@ -40,19 +59,46 @@ Prerequisites
    Linux.)
    
  - If you use MacOS or BSD on your client machine:
-   Your kernel needs to be compiled with IPFIREWALL_FORWARD
+   Your kernel needs to be compiled with `IPFIREWALL_FORWARD`
    (MacOS has this by default) and you need to have ipfw
    available. (The server doesn't need to be MacOS or BSD.)
 
 
-This is how you use it:
+Obtaining sshuttle
+------------------
+
+ - First, go get PyXAPI from the link above
+
+ - Clone github.com/jwyllie83/sshuttle/tree/local
+
+
+Usage on (Ubuntu) Linux
 -----------------------
 
- - <tt>git clone git://github.com/apenwarr/sshuttle</tt>
+ - `cd packaging; ./make_deb`
-    on your client machine. You'll need root or sudo
-    access, and python needs to be installed.
 
- - <tt>./sshuttle -r username@sshserver 0.0.0.0/0 -vv</tt>
+ - `sudo dpkg -i ./sshuttle-VERSION.deb`
+
+ - Check out the files in `/etc/sshuttle`; configure them so your tunnel works
+
+ - `sudo service sshuttle start`
+
+
+Usage on other Linuxes and OSes
+-------------------------------
+
+  <tt>./sshuttle -r username@sshserver 0.0.0.0/0 -vv</tt>
+
+ - There is a shortcut for 0.0.0.0/0 for those that value
+   their wrists
+   <tt>./sshuttle -r username@sshserver 0/0 -vv</tt>
+
+ - If you would also like your DNS queries to be proxied
+   through the DNS server of the server you are connect to:
+   <tt>./sshuttle --dns -vvr username@sshserver 0/0</tt>
+
+   The above is probably what you want to use to prevent
+   local network attacks such as Firesheep and friends.
 
 (You may be prompted for one or more passwords; first, the
 local password to become root using either sudo or su, and
@@ -60,6 +106,9 @@ then the remote ssh password.  Or you might have sudo and ssh set
 up to not require passwords, in which case you won't be
 prompted at all.)
 
+Usage Notes
+-----------
+
 That's it!  Now your local machine can access the remote network as if you
 were right there.  And if your "client" machine is a router, everyone on
 your local network can make connections to your remote network.

client.py

@@ -1,354 +0,0 @@
-import struct, socket, select, errno, re, signal
-import compat.ssubprocess as ssubprocess
-import helpers, ssnet, ssh, ssyslog
-from ssnet import SockWrapper, Handler, Proxy, Mux, MuxWrapper
-from helpers import *
-
-_extra_fd = os.open('/dev/null', os.O_RDONLY)
-
-def _islocal(ip):
-    sock = socket.socket()
-    try:
-        try:
-            sock.bind((ip, 0))
-        except socket.error, e:
-            if e.args[0] == errno.EADDRNOTAVAIL:
-                return False  # not a local IP
-            else:
-                raise
-    finally:
-        sock.close()
-    return True  # it's a local IP, or there would have been an error
-
-
-def got_signal(signum, frame):
-    log('exiting on signal %d\n' % signum)
-    sys.exit(1)
-
-
-_pidname = None
-def check_daemon(pidfile):
-    global _pidname
-    _pidname = os.path.abspath(pidfile)
-    try:
-        oldpid = open(_pidname).read(1024)
-    except IOError, e:
-        if e.errno == errno.ENOENT:
-            return  # no pidfile, ok
-        else:
-            raise Fatal("can't read %s: %s" % (_pidname, e))
-    if not oldpid:
-        os.unlink(_pidname)
-        return  # invalid pidfile, ok
-    oldpid = int(oldpid.strip() or 0)
-    if oldpid <= 0:
-        os.unlink(_pidname)
-        return  # invalid pidfile, ok
-    try:
-        os.kill(oldpid, 0)
-    except OSError, e:
-        if e.errno == errno.ESRCH:
-            os.unlink(_pidname)
-            return  # outdated pidfile, ok
-        elif e.errno == errno.EPERM:
-            pass
-        else:
-            raise
-    raise Fatal("%s: sshuttle is already running (pid=%d)"
-                % (_pidname, oldpid))
-
-
-def daemonize():
-    if os.fork():
-        os._exit(0)
-    os.setsid()
-    if os.fork():
-        os._exit(0)
-
-    outfd = os.open(_pidname, os.O_WRONLY|os.O_CREAT|os.O_EXCL, 0666)
-    try:
-        os.write(outfd, '%d\n' % os.getpid())
-    finally:
-        os.close(outfd)
-    os.chdir("/")
-
-    # Normal exit when killed, or try/finally won't work and the pidfile won't
-    # be deleted.
-    signal.signal(signal.SIGTERM, got_signal)
-    
-    si = open('/dev/null', 'r+')
-    os.dup2(si.fileno(), 0)
-    os.dup2(si.fileno(), 1)
-    si.close()
-
-    ssyslog.stderr_to_syslog()
-
-
-def daemon_cleanup():
-    try:
-        os.unlink(_pidname)
-    except OSError, e:
-        if e.errno == errno.ENOENT:
-            pass
-        else:
-            raise
-
-
-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)])
-        if ssyslog._p:
-            argvbase += ['--syslog']
-        argv_tries = [
-            ['sudo', '-p', '[local sudo] Password: '] + 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
-        if os.getuid() == 0:
-            argv_tries = argv_tries[-1:]  # last entry only
-        for argv in argv_tries:
-            try:
-                if argv[0] == 'su':
-                    sys.stderr.write('[local su] ')
-                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, ssh_cmd, remotename, python, seed_hosts, auto_nets,
-          syslog, daemon):
-    handlers = []
-    if helpers.verbose >= 1:
-        helpers.logprefix = 'c : '
-    else:
-        helpers.logprefix = 'client: '
-    debug1('connecting to server...\n')
-
-    try:
-        (serverproc, serversock) = ssh.connect(ssh_cmd, remotename, python,
-                        stderr=ssyslog._p and ssyslog._p.stdin)
-    except socket.error, e:
-        if e.args[0] == errno.EPIPE:
-            raise Fatal("failed to establish ssh session (1)")
-        else:
-            raise
-    mux = Mux(serversock, serversock)
-    handlers.append(mux)
-
-    expected = 'SSHUTTLE0001'
-    try:
-        initstring = serversock.recv(len(expected))
-    except socket.error, e:
-        if e.args[0] == errno.ECONNRESET:
-            raise Fatal("failed to establish ssh session (2)")
-        else:
-            raise
-    
-    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')
-    if daemon:
-        daemonize()
-        log('daemonizing (%s).\n' % _pidname)
-    elif syslog:
-        debug1('switching to syslog.\n')
-        ssyslog.stderr_to_syslog()
-
-    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():
-        global _extra_fd
-        try:
-            sock,srcip = listener.accept()
-        except socket.error, e:
-            if e.args[0] in [errno.EMFILE, errno.ENFILE]:
-                debug1('Rejected incoming connection: too many open files!\n')
-                # free up an fd so we can eat the connection
-                os.close(_extra_fd)
-                try:
-                    sock,srcip = listener.accept()
-                    sock.close()
-                finally:
-                    _extra_fd = os.open('/dev/null', os.O_RDONLY)
-                return
-            else:
-                raise
-        dstip = original_dst(sock)
-        debug1('Accept: %s:%r -> %s:%r.\n' % (srcip[0],srcip[1],
-                                              dstip[0],dstip[1]))
-        if dstip[1] == listener.getsockname()[1] and _islocal(dstip[0]):
-            debug1("-- ignored: that's my address!\n")
-            sock.close()
-            return
-        chan = mux.next_channel()
-        mux.send(chan, ssnet.CMD_CONNECT, '%s,%s' % dstip)
-        outwrap = MuxWrapper(mux, chan)
-        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:
-        rv = serverproc.poll()
-        if rv:
-            raise Fatal('server died with error code %d' % rv)
-        
-        ssnet.runonce(handlers, mux)
-        mux.callback()
-        mux.check_fullness()
-
-
-def main(listenip, ssh_cmd, remotename, python, seed_hosts, auto_nets,
-         subnets_include, subnets_exclude, syslog, daemon, pidfile):
-    if syslog:
-        ssyslog.start_syslog()
-    if daemon:
-        try:
-            check_daemon(pidfile)
-        except Fatal, e:
-            log("%s\n" % e)
-            return 5
-    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, ssh_cmd, remotename,
-                     python, seed_hosts, auto_nets, syslog, daemon)
-    finally:
-        try:
-            if daemon:
-                # it's not our child anymore; can't waitpid
-                fw.p.returncode = 0
-            fw.done()
-        finally:
-            if daemon:
-                daemon_cleanup()

firewall.py

@@ -1,304 +0,0 @@
-import re, errno
-import compat.ssubprocess as ssubprocess
-import helpers, ssyslog
-from helpers import *
-
-
-def ipt_chain_exists(name):
-    argv = ['iptables', '-t', 'nat', '-nL']
-    p = ssubprocess.Popen(argv, stdout = ssubprocess.PIPE)
-    for line in p.stdout:
-        if line.startswith('Chain %s ' % name):
-            return True
-    rv = p.wait()
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-
-
-def ipt(*args):
-    argv = ['iptables', '-t', 'nat'] + list(args)
-    debug1('>> %s\n' % ' '.join(argv))
-    rv = ssubprocess.call(argv)
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-
-
-# We name the chain based on the transproxy port number so that it's possible
-# to run multiple copies of sshuttle at the same time.  Of course, the
-# multiple copies shouldn't have overlapping subnets, or only the most-
-# recently-started one will win (because we use "-I OUTPUT 1" instead of
-# "-A OUTPUT").
-def do_iptables(port, subnets):
-    chain = 'sshuttle-%s' % port
-
-    # basic cleanup/setup of chains
-    if ipt_chain_exists(chain):
-        ipt('-D', 'OUTPUT', '-j', chain)
-        ipt('-D', 'PREROUTING', '-j', chain)
-        ipt('-F', chain)
-        ipt('-X', chain)
-
-    if subnets:
-        ipt('-N', chain)
-        ipt('-F', chain)
-        ipt('-I', 'OUTPUT', '1', '-j', chain)
-        ipt('-I', 'PREROUTING', '1', '-j', chain)
-
-        # create new subnet entries.  Note that we're sorting in a very
-        # particular order: we need to go from most-specific (largest swidth)
-        # to least-specific, and at any given level of specificity, we want
-        # excludes to come first.  That's why the columns are in such a non-
-        # intuitive order.
-        for swidth,sexclude,snet in sorted(subnets, reverse=True):
-            if sexclude:
-                ipt('-A', chain, '-j', 'RETURN',
-                    '--dest', '%s/%s' % (snet,swidth),
-                    '-p', 'tcp')
-            else:
-                ipt('-A', chain, '-j', 'REDIRECT',
-                    '--dest', '%s/%s' % (snet,swidth),
-                    '-p', 'tcp',
-                    '--to-ports', str(port),
-                    '-m', 'ttl', '!', '--ttl', '42'  # to prevent infinite loops
-                    )
-
-
-def ipfw_rule_exists(n):
-    argv = ['ipfw', 'list']
-    p = ssubprocess.Popen(argv, stdout = ssubprocess.PIPE)
-    found = False
-    for line in p.stdout:
-        if line.startswith('%05d ' % n):
-            if not ('ipttl 42 setup keep-state' in line
-                    or ('skipto %d' % (n+1)) in line
-                    or 'check-state' in line):
-                log('non-sshuttle ipfw rule: %r\n' % line.strip())
-                raise Fatal('non-sshuttle ipfw rule #%d already exists!' % n)
-            found = True
-    rv = p.wait()
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-    return found
-
-
-_oldctls = {}
-def _fill_oldctls(prefix):
-    argv = ['sysctl', prefix]
-    p = ssubprocess.Popen(argv, stdout = ssubprocess.PIPE)
-    for line in p.stdout:
-        assert(line[-1] == '\n')
-        (k,v) = line[:-1].split(': ', 1)
-        _oldctls[k] = v
-    rv = p.wait()
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-    if not line:
-        raise Fatal('%r returned no data' % (argv,))
-
-
-def _sysctl_set(name, val):
-    argv = ['sysctl', '-w', '%s=%s' % (name, val)]
-    debug1('>> %s\n' % ' '.join(argv))
-    rv = ssubprocess.call(argv, stdout = open('/dev/null', 'w'))
-
-
-_changedctls = []
-def sysctl_set(name, val):
-    PREFIX = 'net.inet.ip'
-    assert(name.startswith(PREFIX + '.'))
-    val = str(val)
-    if not _oldctls:
-        _fill_oldctls(PREFIX)
-    if not (name in _oldctls):
-        debug1('>> No such sysctl: %r\n' % name)
-        return
-    oldval = _oldctls[name]
-    if val != oldval:
-        _changedctls.append(name)
-        return _sysctl_set(name, val)
-    
-
-def ipfw(*args):
-    argv = ['ipfw', '-q'] + list(args)
-    debug1('>> %s\n' % ' '.join(argv))
-    rv = ssubprocess.call(argv)
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-
-
-def do_ipfw(port, subnets):
-    sport = str(port)
-    xsport = str(port+1)
-
-    # cleanup any existing rules
-    if ipfw_rule_exists(port):
-        ipfw('delete', sport)
-
-    while _changedctls:
-        name = _changedctls.pop()
-        oldval = _oldctls[name]
-        _sysctl_set(name, oldval)
-
-    if subnets:
-        sysctl_set('net.inet.ip.fw.enable', 1)
-        sysctl_set('net.inet.ip.scopedroute', 0)
-
-        ipfw('add', sport, 'check-state', 'ip',
-             'from', 'any', 'to', 'any')
-        
-        # create new subnet entries
-        for swidth,sexclude,snet in sorted(subnets, reverse=True):
-            if sexclude:
-                ipfw('add', sport, 'skipto', xsport,
-                     'log', 'tcp',
-                     'from', 'any', 'to', '%s/%s' % (snet,swidth))
-            else:
-                ipfw('add', sport, 'fwd', '127.0.0.1,%d' % port,
-                     'log', 'tcp',
-                     'from', 'any', 'to', '%s/%s' % (snet,swidth),
-                     'not', 'ipttl', '42', 'keep-state', 'setup')
-
-
-def program_exists(name):
-    paths = (os.getenv('PATH') or os.defpath).split(os.pathsep)
-    for p in paths:
-        fn = '%s/%s' % (p, name)
-        if os.path.exists(fn):
-            return not os.path.isdir(fn) and os.access(fn, os.X_OK)
-
-hostmap = {}
-def rewrite_etc_hosts(port):
-    HOSTSFILE='/etc/hosts'
-    BAKFILE='%s.sbak' % HOSTSFILE
-    APPEND='# sshuttle-firewall-%d AUTOCREATED' % port
-    old_content = ''
-    st = None
-    try:
-        old_content = open(HOSTSFILE).read()
-        st = os.stat(HOSTSFILE)
-    except IOError, e:
-        if e.errno == errno.ENOENT:
-            pass
-        else:
-            raise
-    if old_content.strip() and not os.path.exists(BAKFILE):
-        os.link(HOSTSFILE, BAKFILE)
-    tmpname = "%s.%d.tmp" % (HOSTSFILE, port)
-    f = open(tmpname, 'w')
-    for line in old_content.rstrip().split('\n'):
-        if line.find(APPEND) >= 0:
-            continue
-        f.write('%s\n' % line)
-    for (name,ip) in sorted(hostmap.items()):
-        f.write('%-30s %s\n' % ('%s %s' % (ip,name), APPEND))
-    f.close()
-
-    if st:
-        os.chown(tmpname, st.st_uid, st.st_gid)
-        os.chmod(tmpname, st.st_mode)
-    else:
-        os.chown(tmpname, 0, 0)
-        os.chmod(tmpname, 0644)
-    os.rename(tmpname, HOSTSFILE)
-
-
-def restore_etc_hosts(port):
-    global hostmap
-    hostmap = {}
-    rewrite_etc_hosts(port)
-
-
-# This is some voodoo for setting up the kernel's transparent
-# proxying stuff.  If subnets is empty, we just delete our sshuttle rules;
-# otherwise we delete it, then make them from scratch.
-#
-# This code is supposed to clean up after itself by deleting its rules on
-# exit.  In case that fails, it's not the end of the world; future runs will
-# supercede it in the transproxy list, at least, so the leftover rules
-# are hopefully harmless.
-def main(port, syslog):
-    assert(port > 0)
-    assert(port <= 65535)
-
-    if os.getuid() != 0:
-        raise Fatal('you must be root (or enable su/sudo) to set the firewall')
-
-    if program_exists('ipfw'):
-        do_it = do_ipfw
-    elif program_exists('iptables'):
-        do_it = do_iptables
-    else:
-        raise Fatal("can't find either ipfw or iptables; check your PATH")
-
-    # because of limitations of the 'su' command, the *real* stdin/stdout
-    # are both attached to stdout initially.  Clone stdout into stdin so we
-    # can read from it.
-    os.dup2(1, 0)
-
-    if syslog:
-        ssyslog.start_syslog()
-        ssyslog.stderr_to_syslog()
-
-    debug1('firewall manager ready.\n')
-    sys.stdout.write('READY\n')
-    sys.stdout.flush()
-
-    # ctrl-c shouldn't be passed along to me.  When the main sshuttle dies,
-    # I'll die automatically.
-    os.setsid()
-
-    # we wait until we get some input before creating the rules.  That way,
-    # sshuttle can launch us as early as possible (and get sudo password
-    # authentication as early in the startup process as possible).
-    line = sys.stdin.readline(128)
-    if not line:
-        return  # parent died; nothing to do
-
-    subnets = []
-    if line != 'ROUTES\n':
-        raise Fatal('firewall: expected ROUTES but got %r' % line)
-    while 1:
-        line = sys.stdin.readline(128)
-        if not line:
-            raise Fatal('firewall: expected route but got %r' % line)
-        elif line == 'GO\n':
-            break
-        try:
-            (width,exclude,ip) = line.strip().split(',', 2)
-        except:
-            raise Fatal('firewall: expected route or GO but got %r' % line)
-        subnets.append((int(width), bool(int(exclude)), ip))
-        
-    try:
-        if line:
-            debug1('firewall manager: starting transproxy.\n')
-            do_it(port, subnets)
-            sys.stdout.write('STARTED\n')
-        
-        try:
-            sys.stdout.flush()
-        except IOError:
-            # the parent process died for some reason; he's surely been loud
-            # enough, so no reason to report another error
-            return
-
-        # Now we wait until EOF or any other kind of exception.  We need
-        # to stay running so that we don't need a *second* password
-        # authentication at shutdown time - that cleanup is important!
-        while 1:
-            line = sys.stdin.readline(128)
-            if line.startswith('HOST '):
-                (name,ip) = line[5:].strip().split(',', 1)
-                hostmap[name] = ip
-                rewrite_etc_hosts(port)
-            elif line:
-                raise Fatal('expected EOF, got %r' % line)
-            else:
-                break
-    finally:
-        try:
-            debug1('firewall manager: undoing changes.\n')
-        except:
-            pass
-        do_it(port, [])
-        restore_etc_hosts(port)

helpers.py

@@ -1,37 +0,0 @@
-import sys, os
-
-logprefix = ''
-verbose = 0
-
-def log(s):
-    try:
-        sys.stdout.flush()
-        sys.stderr.write(logprefix + s)
-        sys.stderr.flush()
-    except IOError:
-        # this could happen if stderr gets forcibly disconnected, eg. because
-        # our tty closes.  That sucks, but it's no reason to abort the program.
-        pass
-
-def debug1(s):
-    if verbose >= 1:
-        log(s)
-
-def debug2(s):
-    if verbose >= 2:
-        log(s)
-
-def debug3(s):
-    if verbose >= 3:
-        log(s)
-
-
-class Fatal(Exception):
-    pass
-
-
-def list_contains_any(l, sub):
-    for i in sub:
-        if i in l:
-            return True
-    return False

main.py

@@ -1,122 +0,0 @@
-#!/usr/bin/env python
-import sys, os, re
-import helpers, options, client, server, firewall, hostwatch
-import compat.ssubprocess as ssubprocess
-from helpers import *
-
-
-# list of:
-# 1.2.3.4/5 or just 1.2.3.4
-def parse_subnets(subnets_str):
-    subnets = []
-    for s in subnets_str:
-        m = re.match(r'(\d+)(?:\.(\d+)\.(\d+)\.(\d+))?(?:/(\d+))?$', s)
-        if not m:
-            raise Fatal('%r is not a valid IP subnet format' % s)
-        (a,b,c,d,width) = m.groups()
-        (a,b,c,d) = (int(a or 0), int(b or 0), int(c or 0), int(d or 0))
-        if width == None:
-            width = 32
-        else:
-            width = int(width)
-        if a > 255 or b > 255 or c > 255 or d > 255:
-            raise Fatal('%d.%d.%d.%d has numbers > 255' % (a,b,c,d))
-        if width > 32:
-            raise Fatal('*/%d is greater than the maximum of 32' % width)
-        subnets.append(('%d.%d.%d.%d' % (a,b,c,d), width))
-    return subnets
-
-
-# 1.2.3.4:567 or just 1.2.3.4 or just 567
-def parse_ipport(s):
-    s = str(s)
-    m = re.match(r'(?:(\d+)\.(\d+)\.(\d+)\.(\d+))?(?::)?(?:(\d+))?$', s)
-    if not m:
-        raise Fatal('%r is not a valid IP:port format' % s)
-    (a,b,c,d,port) = m.groups()
-    (a,b,c,d,port) = (int(a or 0), int(b or 0), int(c or 0), int(d or 0),
-                      int(port or 0))
-    if a > 255 or b > 255 or c > 255 or d > 255:
-        raise Fatal('%d.%d.%d.%d has numbers > 255' % (a,b,c,d))
-    if port > 65535:
-        raise Fatal('*:%d is greater than the maximum of 65535' % port)
-    if a == None:
-        a = b = c = d = 0
-    return ('%d.%d.%d.%d' % (a,b,c,d), port)
-
-
-optspec = """
-sshuttle [-l [ip:]port] [-r [username@]sshserver[:port]] <subnets...>
-sshuttle --server
-sshuttle --firewall <port> <subnets...>
-sshuttle --hostwatch
---
-l,listen=  transproxy to this ip address and port number [127.0.0.1:0]
-H,auto-hosts scan for remote hostnames and update local /etc/hosts
-N,auto-nets  automatically determine subnets to route
-python=    path to python interpreter on the remote server [python]
-r,remote=  ssh hostname (and optional username) of remote sshuttle server
-x,exclude= exclude this subnet (can be used more than once)
-v,verbose  increase debug message verbosity
-e,ssh-cmd= the command to use to connect to the remote [ssh]
-seed-hosts= with -H, use these hostnames for initial scan (comma-separated)
-D,daemon   run in the background as a daemon
-syslog     send log messages to syslog (default if you use --daemon)
-pidfile=   pidfile name (only if using --daemon) [./sshuttle.pid]
-server     (internal use only)
-firewall   (internal use only)
-hostwatch  (internal use only)
-"""
-o = options.Options('sshuttle', optspec)
-(opt, flags, extra) = o.parse(sys.argv[1:])
-
-if opt.daemon:
-    opt.syslog = 1
-helpers.verbose = opt.verbose
-
-try:
-    if opt.server:
-        if len(extra) != 0:
-            o.fatal('no arguments expected')
-        sys.exit(server.main())
-    elif opt.firewall:
-        if len(extra) != 1:
-            o.fatal('exactly one argument expected')
-        sys.exit(firewall.main(int(extra[0]), opt.syslog))
-    elif opt.hostwatch:
-        sys.exit(hostwatch.hw_main(extra))
-    else:
-        if len(extra) < 1 and not opt.auto_nets:
-            o.fatal('at least one subnet (or -N) expected')
-        includes = extra
-        excludes = ['127.0.0.0/8']
-        for k,v in flags:
-            if k in ('-x','--exclude'):
-                excludes.append(v)
-        remotename = opt.remote
-        if remotename == '' or remotename == '-':
-            remotename = None
-        if opt.seed_hosts and not opt.auto_hosts:
-            o.fatal('--seed-hosts only works if you also use -H')
-        if opt.seed_hosts:
-            sh = re.split(r'[\s,]+', (opt.seed_hosts or "").strip())
-        elif opt.auto_hosts:
-            sh = []
-        else:
-            sh = None
-        sys.exit(client.main(parse_ipport(opt.listen or '0.0.0.0:0'),
-                             opt.ssh_cmd,
-                             remotename,
-                             opt.python,
-                             sh,
-                             opt.auto_nets,
-                             parse_subnets(includes),
-                             parse_subnets(excludes),
-                             opt.syslog, opt.daemon, opt.pidfile))
-except Fatal, e:
-    log('fatal: %s\n' % e)
-    sys.exit(99)
-except KeyboardInterrupt:
-    log('\n')
-    log('Keyboard interrupt: exiting.\n')
-    sys.exit(1)

packaging/control

@@ -0,0 +1,26 @@
+Package: sshuttle
+Version: 0.2
+Architecture: i386
+Maintainer: Jim Wyllie <jwyllie83@gmail.com>
+Depends: autossh, upstart, python (>=2.6)
+Section: utils
+Priority: optional
+Homepage: http://github.com/jwyllie83/sshuttle.udp
+Description: "Full-featured" VPN over an SSH tunnel, allowing full remote
+ access somewhere where all you have is an SSH connection.  It works well if
+ you generally find yourself in the following situation:
+ .
+ - Your client machine (or router) is Linux, FreeBSD, or MacOS.
+ - You have access to a remote network via ssh.
+ - You don't necessarily have admin access on the remote network.
+ - You do not wish to, or can't, use other VPN software
+ - You don't want to create an ssh port forward for every
+    single host/port on the remote network.
+ - You hate openssh's port forwarding because it's randomly
+    slow and/or stupid.
+ - You can't use openssh's PermitTunnel feature because
+    it's disabled by default on openssh servers; plus it does
+    TCP-over-TCP, which has suboptimal performance
+ .
+ It also has hooks for more complicated setups (VPN-in-a-SSH-VPN, etc) to allow
+ you to set it up as you like.

packaging/make_deb

@@ -0,0 +1,41 @@
+#!/bin/bash
+#
+# This script puts together a .deb package suitable for installing on an Ubuntu
+# system
+
+B="/tmp/sshuttle/build"
+
+if [ ! -x /usr/bin/dpkg ]; then
+	echo 'Unable to build: dpkg not found on system'
+	exit 1
+fi
+
+# Create the new directory structure
+mkdir -p ${B}/etc/sshuttle/pre-start.d
+mkdir -p ${B}/etc/sshuttle/post-stop.d
+mkdir -p ${B}/usr/share/sshuttle
+mkdir -p ${B}/usr/bin
+mkdir -p ${B}/etc/init
+mkdir -p ${B}/DEBIAN
+
+# Copy over all of the files
+cp -r ../src/* ${B}/usr/share/sshuttle
+cp ../src/sshuttle ${B}/usr/bin
+cp -r sshuttle.conf ${B}/etc/init
+cp prefixes.conf ${B}/etc/sshuttle
+cp tunnel.conf ${B}/etc/sshuttle
+
+# Copy the control file over, as well
+cp control ${B}/DEBIAN
+
+# Create the md5sum manifest
+if [ -x /usr/bin/md5sum ]; then
+	cd ${B}
+	find . -type f | egrep -v DEBIAN | sed -re 's/^..//' | xargs md5sum > ${B}/DEBIAN/md5sums
+	cd ${OLDPWD}
+fi
+
+# Build the debian package
+VERSION=$(egrep -e '^Version' control | sed -re 's/^[^:]*: //')
+dpkg --build ${B} ./sshuttle-${VERSION}.deb
+rm -rf ${B}

packaging/prefixes.conf

@@ -0,0 +1,5 @@
+# Output prefixes here, one per line.  Prefix is in:
+# prefix/netmask format
+# Like this:
+# 192.168.0.0/16
+# 192.0.43.10/32

packaging/sshuttle.conf

@@ -0,0 +1,90 @@
+description "Create a transparent proxy over SSH"
+author      "Jim Wyllie <jwyllie83@gmail.com>"
+
+manual
+nice -5
+
+# Edit this file with network prefixes that should be loaded through the SSH
+# tunnel.
+env PREFIX_LOCATION=/etc/sshuttle/prefixes.conf
+
+# Routing table; defaults to 100
+env ROUTE_TABLE=100
+
+# fwmark; defaults to 1
+env FWMARK=1
+
+# SSH tunnel configuration file
+env SSHUTTLE_TUNNEL_FILE=/etc/sshuttle/tunnel.conf
+
+# File containing the tunnel proxy name / host / whatever
+env TUNNEL_PROXY="/etc/sshuttle/tunnel.conf"
+
+# Any other commands needed to run before or after loading the SSH tunnel.
+# This is where you can put any of your hacks to set up tunnels-in-tunnels,
+# etc.  Scripts in this directory are executed in order.
+env MISC_START_DIR=/etc/sshuttle/pre-start.d
+env MISC_STOP_DIR=/etc/sshuttle/post-stop.d
+
+start on (local-filesystems and net-device-up IFACE!=lo)
+stop on stopping network-services
+
+#respawn
+
+pre-start script
+	# Make sure we have created the routes
+	sudo ip rule add fwmark ${FWMARK} lookup ${ROUTE_TABLE}
+	logger "Starting sshuttle..."
+
+	if [ -f "${PREFIX_LOCATION}" ]; then
+		cat "${PREFIX_LOCATION}" | while read ROUTE; do
+
+			# Skip comments
+			if [ -n "$(echo ${ROUTE} | egrep "^[ 	]*#")" ]; then
+				continue
+			fi
+
+			# Skip empty lines
+			if [ -z "${ROUTE}" ]; then
+				continue
+			fi
+
+			logger "Adding route: ${ROUTE}"
+			ip route add local ${ROUTE} dev lo table ${ROUTE_TABLE}
+		done
+	fi
+
+	for RUNFILE in ${MISC_START_DIR}/*; do
+		logger "Executing ${RUNFILE}"
+		/bin/sh -c "${RUNFILE}"
+	done
+end script
+
+post-stop script
+	if [ -f "${PREFIX_LOCATION}" ]; then
+		cat "${PREFIX_LOCATION}" | while read ROUTE; do
+
+			# Skip comments
+			if [ -n "$(echo ${ROUTE} | egrep "^[ 	]*#")" ]; then
+				continue
+			fi
+
+			# Skip empty lines
+			if [ -z "${ROUTE}" ]; then
+				continue
+			fi
+
+			logger "Deleting route: ${ROUTE}"
+			ip route del local ${ROUTE} dev lo table ${ROUTE_TABLE}
+		done
+	fi
+
+	ip rule del fwmark ${FWMARK}
+
+	for RUNFILE in "${MISC_STOP_DIR}/*"; do
+		logger "Executing ${RUNFILE}"
+		/bin/sh -c "${RUNFILE}"
+	done
+end script
+
+exec /usr/bin/sshuttle --dns --method=tproxy --listen 0.0.0.0 --remote sshuttle_tunnel -s /etc/sshuttle/prefixes.conf -e "ssh -F ${TUNNEL_PROXY}"

packaging/tunnel.conf

@@ -0,0 +1,19 @@
+# Here is where you can specify any SSH tunnel options See ssh_config(5) for
+# details.  You need to leave the Host line intact, but everything else can
+# specify whatever you want
+Host sshuttle_tunnel
+
+# REQUIRED: Set this to be the host to which you would like to connect your
+# tunnel
+#Hostname localhost
+
+# REQUIRED: Set this to be the target SSH user on the remote system
+#User foo
+
+# ---------------------------------------------------------------------------
+# The rest are all optional; see ssh_config(5) for the full list of what can
+# be specified.  Some very commonly needed ones are below.
+# ---------------------------------------------------------------------------
+
+# SSH key used for connecting
+#IdentityFile /path/to/key

server.py

@@ -1,176 +0,0 @@
-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()
-    hw.leftover = ''
-        
-    def hostwatch_ready():
-        assert(hw.pid)
-        content = hw.sock.recv(4096)
-        if content:
-            lines = (hw.leftover + content).split('\n')
-            if lines[-1]:
-                # no terminating newline: entry isn't complete yet!
-                hw.leftover = lines.pop()
-                lines.append('')
-            else:
-                hw.leftover = ''
-            mux.send(0, ssnet.CMD_HOST_LIST, '\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):
-        (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:
-            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)
-        mux.check_fullness()
-        mux.callback()

src/Makefile

@@ -0,0 +1,10 @@
+all:
+
+Makefile:
+	@
+
+%: FORCE
+	+./do $@
+
+.PHONY: FORCE
+

src/all.do

@@ -0,0 +1,11 @@
+exec >&2
+UI=
+[ "$(uname)" = "Darwin" ] && UI=ui-macos/all
+redo-ifchange sshuttle.8 $UI
+
+echo
+echo "What now?"
+[ -z "$UI" ] || echo "- Try the MacOS GUI: open ui-macos/Sshuttle*.app"
+echo "- Run sshuttle: ./sshuttle --dns -r HOSTNAME 0/0"
+echo "- Read the README: less README.md"
+echo "- Read the man page: less sshuttle.md"

src/assembler.py

@@ -1,4 +1,5 @@
-import sys, zlib
+import sys
+import zlib
 
 z = zlib.decompressobj()
 mainmod = sys.modules[__name__]

src/clean.do

@@ -0,0 +1,2 @@
+redo ui-macos/clean
+rm -f *~ */*~ .*~ */.*~ *.8 *.tmp */*.tmp *.pyc */*.pyc

src/client.py

@@ -0,0 +1,754 @@
+import struct
+import errno
+import re
+import signal
+import time
+import compat.ssubprocess as ssubprocess
+import helpers
+import os
+import ssnet
+import ssh
+import ssyslog
+import sys
+from ssnet import SockWrapper, Handler, Proxy, Mux, MuxWrapper
+from helpers import log, debug1, debug2, debug3, Fatal, islocal
+
+recvmsg = None
+try:
+    # try getting recvmsg from python
+    import socket as pythonsocket
+    getattr(pythonsocket.socket, "recvmsg")
+    socket = pythonsocket
+    recvmsg = "python"
+except AttributeError:
+    # try getting recvmsg from socket_ext library
+    try:
+        import socket_ext
+        getattr(socket_ext.socket, "recvmsg")
+        socket = socket_ext
+        recvmsg = "socket_ext"
+    except ImportError:
+        import socket
+
+_extra_fd = os.open('/dev/null', os.O_RDONLY)
+
+
+def got_signal(signum, frame):
+    log('exiting on signal %d\n' % signum)
+    sys.exit(1)
+
+
+_pidname = None
+IP_TRANSPARENT = 19
+IP_ORIGDSTADDR = 20
+IP_RECVORIGDSTADDR = IP_ORIGDSTADDR
+SOL_IPV6 = 41
+IPV6_ORIGDSTADDR = 74
+IPV6_RECVORIGDSTADDR = IPV6_ORIGDSTADDR
+
+
+if recvmsg == "python":
+    def recv_udp(listener, bufsize):
+        debug3('Accept UDP python using recvmsg.\n')
+        data, ancdata, msg_flags, srcip = listener.recvmsg(
+            4096, socket.CMSG_SPACE(24))
+        dstip = None
+        family = None
+        for cmsg_level, cmsg_type, cmsg_data in ancdata:
+            if cmsg_level == socket.SOL_IP and cmsg_type == IP_ORIGDSTADDR:
+                family, port = struct.unpack('=HH', cmsg_data[0:4])
+                port = socket.htons(port)
+                if family == socket.AF_INET:
+                    start = 4
+                    length = 4
+                else:
+                    raise Fatal("Unsupported socket type '%s'" % family)
+                ip = socket.inet_ntop(family, cmsg_data[start:start + length])
+                dstip = (ip, port)
+                break
+            elif cmsg_level == SOL_IPV6 and cmsg_type == IPV6_ORIGDSTADDR:
+                family, port = struct.unpack('=HH', cmsg_data[0:4])
+                port = socket.htons(port)
+                if family == socket.AF_INET6:
+                    start = 8
+                    length = 16
+                else:
+                    raise Fatal("Unsupported socket type '%s'" % family)
+                ip = socket.inet_ntop(family, cmsg_data[start:start + length])
+                dstip = (ip, port)
+                break
+        return (srcip, dstip, data)
+elif recvmsg == "socket_ext":
+    def recv_udp(listener, bufsize):
+        debug3('Accept UDP using socket_ext recvmsg.\n')
+        srcip, data, adata, flags = listener.recvmsg(
+            (bufsize,), socket.CMSG_SPACE(24))
+        dstip = None
+        family = None
+        for a in adata:
+            if a.cmsg_level == socket.SOL_IP and a.cmsg_type == IP_ORIGDSTADDR:
+                family, port = struct.unpack('=HH', a.cmsg_data[0:4])
+                port = socket.htons(port)
+                if family == socket.AF_INET:
+                    start = 4
+                    length = 4
+                else:
+                    raise Fatal("Unsupported socket type '%s'" % family)
+                ip = socket.inet_ntop(
+                    family, a.cmsg_data[start:start + length])
+                dstip = (ip, port)
+                break
+            elif a.cmsg_level == SOL_IPV6 and a.cmsg_type == IPV6_ORIGDSTADDR:
+                family, port = struct.unpack('=HH', a.cmsg_data[0:4])
+                port = socket.htons(port)
+                if family == socket.AF_INET6:
+                    start = 8
+                    length = 16
+                else:
+                    raise Fatal("Unsupported socket type '%s'" % family)
+                ip = socket.inet_ntop(
+                    family, a.cmsg_data[start:start + length])
+                dstip = (ip, port)
+                break
+        return (srcip, dstip, data[0])
+else:
+    def recv_udp(listener, bufsize):
+        debug3('Accept UDP using recvfrom.\n')
+        data, srcip = listener.recvfrom(bufsize)
+        return (srcip, None, data)
+
+
+def check_daemon(pidfile):
+    global _pidname
+    _pidname = os.path.abspath(pidfile)
+    try:
+        oldpid = open(_pidname).read(1024)
+    except IOError, e:
+        if e.errno == errno.ENOENT:
+            return  # no pidfile, ok
+        else:
+            raise Fatal("can't read %s: %s" % (_pidname, e))
+    if not oldpid:
+        os.unlink(_pidname)
+        return  # invalid pidfile, ok
+    oldpid = int(oldpid.strip() or 0)
+    if oldpid <= 0:
+        os.unlink(_pidname)
+        return  # invalid pidfile, ok
+    try:
+        os.kill(oldpid, 0)
+    except OSError, e:
+        if e.errno == errno.ESRCH:
+            os.unlink(_pidname)
+            return  # outdated pidfile, ok
+        elif e.errno == errno.EPERM:
+            pass
+        else:
+            raise
+    raise Fatal("%s: sshuttle is already running (pid=%d)"
+                % (_pidname, oldpid))
+
+
+def daemonize():
+    if os.fork():
+        os._exit(0)
+    os.setsid()
+    if os.fork():
+        os._exit(0)
+
+    outfd = os.open(_pidname, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0666)
+    try:
+        os.write(outfd, '%d\n' % os.getpid())
+    finally:
+        os.close(outfd)
+    os.chdir("/")
+
+    # Normal exit when killed, or try/finally won't work and the pidfile won't
+    # be deleted.
+    signal.signal(signal.SIGTERM, got_signal)
+
+    si = open('/dev/null', 'r+')
+    os.dup2(si.fileno(), 0)
+    os.dup2(si.fileno(), 1)
+    si.close()
+
+    ssyslog.stderr_to_syslog()
+
+
+def daemon_cleanup():
+    try:
+        os.unlink(_pidname)
+    except OSError, e:
+        if e.errno == errno.ENOENT:
+            pass
+        else:
+            raise
+
+
+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 MultiListener:
+
+    def __init__(self, type=socket.SOCK_STREAM, proto=0):
+        self.v6 = socket.socket(socket.AF_INET6, type, proto)
+        self.v4 = socket.socket(socket.AF_INET, type, proto)
+
+    def setsockopt(self, level, optname, value):
+        if self.v6:
+            self.v6.setsockopt(level, optname, value)
+        if self.v4:
+            self.v4.setsockopt(level, optname, value)
+
+    def add_handler(self, handlers, callback, method, mux):
+        if self.v6:
+            handlers.append(
+                Handler(
+                    [self.v6],
+                    lambda: callback(self.v6, method, mux, handlers)))
+        if self.v4:
+            handlers.append(
+                Handler(
+                    [self.v4],
+                    lambda: callback(self.v4, method, mux, handlers)))
+
+    def listen(self, backlog):
+        if self.v6:
+            self.v6.listen(backlog)
+        if self.v4:
+            try:
+                self.v4.listen(backlog)
+            except socket.error, e:
+                # on some systems v4 bind will fail if the v6 suceeded,
+                # in this case the v6 socket will receive v4 too.
+                if e.errno == errno.EADDRINUSE and self.v6:
+                    self.v4 = None
+                else:
+                    raise e
+
+    def bind(self, address_v6, address_v4):
+        if address_v6 and self.v6:
+            self.v6.bind(address_v6)
+        else:
+            self.v6 = None
+        if address_v4 and self.v4:
+            self.v4.bind(address_v4)
+        else:
+            self.v4 = None
+
+    def print_listening(self, what):
+        if self.v6:
+            listenip = self.v6.getsockname()
+            debug1('%s listening on %r.\n' % (what, listenip))
+        if self.v4:
+            listenip = self.v4.getsockname()
+            debug1('%s listening on %r.\n' % (what, listenip))
+
+
+class FirewallClient:
+
+    def __init__(self, port_v6, port_v4, subnets_include, subnets_exclude,
+                 dnsport_v6, dnsport_v4, method, udp):
+        self.auto_nets = []
+        self.subnets_include = subnets_include
+        self.subnets_exclude = subnets_exclude
+        argvbase = ([sys.argv[1], sys.argv[0], sys.argv[1]] +
+                    ['-v'] * (helpers.verbose or 0) +
+                    ['--firewall', str(port_v6), str(port_v4),
+                     str(dnsport_v6), str(dnsport_v4),
+                     method, str(int(udp))])
+        if ssyslog._p:
+            argvbase += ['--syslog']
+        argv_tries = [
+            ['sudo', '-p', '[local sudo] Password: '] + 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
+        if os.getuid() == 0:
+            argv_tries = argv_tries[-1:]  # last entry only
+        for argv in argv_tries:
+            try:
+                if argv[0] == 'su':
+                    sys.stderr.write('[local su] ')
+                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[0:5] != 'READY':
+            raise Fatal('%r expected READY, got %r' % (self.argv, line))
+        self.method = line[6:-1]
+
+    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 (family, ip, width) in self.subnets_include + self.auto_nets:
+            self.pfile.write('%d,%d,0,%s\n' % (family, width, ip))
+        for (family, ip, width) in self.subnets_exclude:
+            self.pfile.write('%d,%d,1,%s\n' % (family, 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))
+
+
+dnsreqs = {}
+udp_by_src = {}
+
+
+def expire_connections(now, mux):
+    for chan, timeout in dnsreqs.items():
+        if timeout < now:
+            debug3('expiring dnsreqs channel=%d\n' % chan)
+            del mux.channels[chan]
+            del dnsreqs[chan]
+    debug3('Remaining DNS requests: %d\n' % len(dnsreqs))
+    for peer, (chan, timeout) in udp_by_src.items():
+        if timeout < now:
+            debug3('expiring UDP channel channel=%d peer=%r\n' % (chan, peer))
+            mux.send(chan, ssnet.CMD_UDP_CLOSE, '')
+            del mux.channels[chan]
+            del udp_by_src[peer]
+    debug3('Remaining UDP channels: %d\n' % len(udp_by_src))
+
+
+def onaccept_tcp(listener, method, mux, handlers):
+    global _extra_fd
+    try:
+        sock, srcip = listener.accept()
+    except socket.error, e:
+        if e.args[0] in [errno.EMFILE, errno.ENFILE]:
+            debug1('Rejected incoming connection: too many open files!\n')
+            # free up an fd so we can eat the connection
+            os.close(_extra_fd)
+            try:
+                sock, srcip = listener.accept()
+                sock.close()
+            finally:
+                _extra_fd = os.open('/dev/null', os.O_RDONLY)
+            return
+        else:
+            raise
+    if method == "tproxy":
+        dstip = sock.getsockname()
+    else:
+        dstip = original_dst(sock)
+    debug1('Accept TCP: %s:%r -> %s:%r.\n' % (srcip[0], srcip[1],
+                                              dstip[0], dstip[1]))
+    if dstip[1] == sock.getsockname()[1] and islocal(dstip[0], sock.family):
+        debug1("-- ignored: that's my address!\n")
+        sock.close()
+        return
+    chan = mux.next_channel()
+    if not chan:
+        log('warning: too many open channels.  Discarded connection.\n')
+        sock.close()
+        return
+    mux.send(chan, ssnet.CMD_TCP_CONNECT, '%d,%s,%s' %
+             (sock.family, dstip[0], dstip[1]))
+    outwrap = MuxWrapper(mux, chan)
+    handlers.append(Proxy(SockWrapper(sock, sock), outwrap))
+    expire_connections(time.time(), mux)
+
+
+def udp_done(chan, data, method, family, dstip):
+    (src, srcport, data) = data.split(",", 2)
+    srcip = (src, int(srcport))
+    debug3('doing send from %r to %r\n' % (srcip, dstip,))
+
+    try:
+        sender = socket.socket(family, socket.SOCK_DGRAM)
+        sender.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        sender.setsockopt(socket.SOL_IP, IP_TRANSPARENT, 1)
+        sender.bind(srcip)
+        sender.sendto(data, dstip)
+        sender.close()
+    except socket.error, e:
+        debug1('-- ignored socket error sending UDP data: %r\n' % e)
+
+
+def onaccept_udp(listener, method, mux, handlers):
+    now = time.time()
+    srcip, dstip, data = recv_udp(listener, 4096)
+    if not dstip:
+        debug1(
+            "-- ignored UDP from %r: "
+            "couldn't determine destination IP address\n" % (srcip,))
+        return
+    debug1('Accept UDP: %r -> %r.\n' % (srcip, dstip,))
+    if srcip in udp_by_src:
+        chan, timeout = udp_by_src[srcip]
+    else:
+        chan = mux.next_channel()
+        mux.channels[chan] = lambda cmd, data: udp_done(
+            chan, data, method, listener.family, dstip=srcip)
+        mux.send(chan, ssnet.CMD_UDP_OPEN, listener.family)
+    udp_by_src[srcip] = chan, now + 30
+
+    hdr = "%s,%r," % (dstip[0], dstip[1])
+    mux.send(chan, ssnet.CMD_UDP_DATA, hdr + data)
+
+    expire_connections(now, mux)
+
+
+def dns_done(chan, data, method, sock, srcip, dstip, mux):
+    debug3('dns_done: channel=%d src=%r dst=%r\n' % (chan, srcip, dstip))
+    del mux.channels[chan]
+    del dnsreqs[chan]
+    if method == "tproxy":
+        debug3('doing send from %r to %r\n' % (srcip, dstip,))
+        sender = socket.socket(sock.family, socket.SOCK_DGRAM)
+        sender.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        sender.setsockopt(socket.SOL_IP, IP_TRANSPARENT, 1)
+        sender.bind(srcip)
+        sender.sendto(data, dstip)
+        sender.close()
+    else:
+        debug3('doing sendto %r\n' % (dstip,))
+        sock.sendto(data, dstip)
+
+
+def ondns(listener, method, mux, handlers):
+    now = time.time()
+    srcip, dstip, data = recv_udp(listener, 4096)
+    if method == "tproxy" and not dstip:
+        debug1(
+            "-- ignored UDP from %r: "
+            "couldn't determine destination IP address\n" % (srcip,))
+        return
+    debug1('DNS request from %r to %r: %d bytes\n' % (srcip, dstip, len(data)))
+    chan = mux.next_channel()
+    dnsreqs[chan] = now + 30
+    mux.send(chan, ssnet.CMD_DNS_REQ, data)
+    mux.channels[chan] = lambda cmd, data: dns_done(
+        chan, data, method, listener, srcip=dstip, dstip=srcip, mux=mux)
+    expire_connections(now, mux)
+
+
+def _main(tcp_listener, udp_listener, fw, ssh_cmd, remotename,
+          python, latency_control,
+          dns_listener, method, seed_hosts, auto_nets,
+          syslog, daemon):
+    handlers = []
+    if helpers.verbose >= 1:
+        helpers.logprefix = 'c : '
+    else:
+        helpers.logprefix = 'client: '
+    debug1('connecting to server...\n')
+
+    try:
+        (serverproc, serversock) = ssh.connect(
+            ssh_cmd, remotename, python,
+            stderr=ssyslog._p and ssyslog._p.stdin,
+            options=dict(latency_control=latency_control, method=method))
+    except socket.error, e:
+        if e.args[0] == errno.EPIPE:
+            raise Fatal("failed to establish ssh session (1)")
+        else:
+            raise
+    mux = Mux(serversock, serversock)
+    handlers.append(mux)
+
+    expected = 'SSHUTTLE0001'
+
+    try:
+        v = 'x'
+        while v and v != '\0':
+            v = serversock.recv(1)
+        v = 'x'
+        while v and v != '\0':
+            v = serversock.recv(1)
+        initstring = serversock.recv(len(expected))
+    except socket.error, e:
+        if e.args[0] == errno.ECONNRESET:
+            raise Fatal("failed to establish ssh session (2)")
+        else:
+            raise
+
+    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')
+    print 'Connected.'
+    sys.stdout.flush()
+    if daemon:
+        daemonize()
+        log('daemonizing (%s).\n' % _pidname)
+    elif syslog:
+        debug1('switching to syslog.\n')
+        ssyslog.stderr_to_syslog()
+
+    def onroutes(routestr):
+        if auto_nets:
+            for line in routestr.strip().split('\n'):
+                (family, ip, width) = line.split(',', 2)
+                fw.auto_nets.append((family, 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
+
+    tcp_listener.add_handler(handlers, onaccept_tcp, method, mux)
+
+    if udp_listener:
+        udp_listener.add_handler(handlers, onaccept_udp, method, mux)
+
+    if dns_listener:
+        dns_listener.add_handler(handlers, ondns, method, mux)
+
+    if seed_hosts is not None:
+        debug1('seed_hosts: %r\n' % seed_hosts)
+        mux.send(0, ssnet.CMD_HOST_REQ, '\n'.join(seed_hosts))
+
+    while 1:
+        rv = serverproc.poll()
+        if rv:
+            raise Fatal('server died with error code %d' % rv)
+
+        ssnet.runonce(handlers, mux)
+        if latency_control:
+            mux.check_fullness()
+        mux.callback()
+
+
+def main(listenip_v6, listenip_v4,
+         ssh_cmd, remotename, python, latency_control, dns,
+         method, seed_hosts, auto_nets,
+         subnets_include, subnets_exclude, syslog, daemon, pidfile):
+
+    if syslog:
+        ssyslog.start_syslog()
+    if daemon:
+        try:
+            check_daemon(pidfile)
+        except Fatal, e:
+            log("%s\n" % e)
+            return 5
+    debug1('Starting sshuttle proxy.\n')
+
+    if recvmsg is not None:
+        debug1("recvmsg %s support enabled.\n" % recvmsg)
+
+    if method == "tproxy":
+        if recvmsg is not None:
+            debug1("tproxy UDP support enabled.\n")
+            udp = True
+        else:
+            debug1("tproxy UDP support requires recvmsg function.\n")
+            udp = False
+        if dns and recvmsg is None:
+            debug1("tproxy DNS support requires recvmsg function.\n")
+            dns = False
+    else:
+        debug1("UDP support requires tproxy; disabling UDP.\n")
+        udp = False
+
+    if listenip_v6 and listenip_v6[1] and listenip_v4 and listenip_v4[1]:
+        # if both ports given, no need to search for a spare port
+        ports = [0, ]
+    else:
+        # if at least one port missing, we have to search
+        ports = xrange(12300, 9000, -1)
+
+    # search for free ports and try to bind
+    last_e = None
+    redirectport_v6 = 0
+    redirectport_v4 = 0
+    bound = False
+    debug2('Binding redirector:')
+    for port in ports:
+        debug2(' %d' % port)
+        tcp_listener = MultiListener()
+        tcp_listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+
+        if udp:
+            udp_listener = MultiListener(socket.SOCK_DGRAM)
+            udp_listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        else:
+            udp_listener = None
+
+        if listenip_v6 and listenip_v6[1]:
+            lv6 = listenip_v6
+            redirectport_v6 = lv6[1]
+        elif listenip_v6:
+            lv6 = (listenip_v6[0], port)
+            redirectport_v6 = port
+        else:
+            lv6 = None
+            redirectport_v6 = 0
+
+        if listenip_v4 and listenip_v4[1]:
+            lv4 = listenip_v4
+            redirectport_v4 = lv4[1]
+        elif listenip_v4:
+            lv4 = (listenip_v4[0], port)
+            redirectport_v4 = port
+        else:
+            lv4 = None
+            redirectport_v4 = 0
+
+        try:
+            tcp_listener.bind(lv6, lv4)
+            if udp_listener:
+                udp_listener.bind(lv6, lv4)
+            bound = True
+            break
+        except socket.error, e:
+            if e.errno == errno.EADDRINUSE:
+                last_e = e
+            else:
+                raise e
+    debug2('\n')
+    if not bound:
+        assert(last_e)
+        raise last_e
+    tcp_listener.listen(10)
+    tcp_listener.print_listening("TCP redirector")
+    if udp_listener:
+        udp_listener.print_listening("UDP redirector")
+
+    bound = False
+    if dns:
+        # search for spare port for DNS
+        debug2('Binding DNS:')
+        ports = xrange(12300, 9000, -1)
+        for port in ports:
+            debug2(' %d' % port)
+            dns_listener = MultiListener(socket.SOCK_DGRAM)
+
+            if listenip_v6:
+                lv6 = (listenip_v6[0], port)
+                dnsport_v6 = port
+            else:
+                lv6 = None
+                dnsport_v6 = 0
+
+            if listenip_v4:
+                lv4 = (listenip_v4[0], port)
+                dnsport_v4 = port
+            else:
+                lv4 = None
+                dnsport_v4 = 0
+
+            try:
+                dns_listener.bind(lv6, lv4)
+                bound = True
+                break
+            except socket.error, e:
+                if e.errno == errno.EADDRINUSE:
+                    last_e = e
+                else:
+                    raise e
+        debug2('\n')
+        dns_listener.print_listening("DNS")
+        if not bound:
+            assert(last_e)
+            raise last_e
+    else:
+        dnsport_v6 = 0
+        dnsport_v4 = 0
+        dns_listener = None
+
+    fw = FirewallClient(redirectport_v6, redirectport_v4, subnets_include,
+                        subnets_exclude, dnsport_v6, dnsport_v4, method, udp)
+
+    if fw.method == "tproxy":
+        tcp_listener.setsockopt(socket.SOL_IP, IP_TRANSPARENT, 1)
+        if udp_listener:
+            udp_listener.setsockopt(socket.SOL_IP, IP_TRANSPARENT, 1)
+            if udp_listener.v4 is not None:
+                udp_listener.v4.setsockopt(
+                    socket.SOL_IP, IP_RECVORIGDSTADDR, 1)
+            if udp_listener.v6 is not None:
+                udp_listener.v6.setsockopt(SOL_IPV6, IPV6_RECVORIGDSTADDR, 1)
+        if dns_listener:
+            dns_listener.setsockopt(socket.SOL_IP, IP_TRANSPARENT, 1)
+            if dns_listener.v4 is not None:
+                dns_listener.v4.setsockopt(
+                    socket.SOL_IP, IP_RECVORIGDSTADDR, 1)
+            if dns_listener.v6 is not None:
+                dns_listener.v6.setsockopt(SOL_IPV6, IPV6_RECVORIGDSTADDR, 1)
+
+    try:
+        return _main(tcp_listener, udp_listener, fw, ssh_cmd, remotename,
+                     python, latency_control, dns_listener,
+                     fw.method, seed_hosts, auto_nets, syslog,
+                     daemon)
+    finally:
+        try:
+            if daemon:
+                # it's not our child anymore; can't waitpid
+                fw.p.returncode = 0
+            fw.done()
+        finally:
+            if daemon:
+                daemon_cleanup()

src/default.8.do

@@ -0,0 +1,7 @@
+exec >&2
+if pandoc </dev/null 2>/dev/null; then
+	pandoc -s -r markdown -w man -o $3 $2.md
+else
+	echo "Warning: pandoc not installed; can't generate manpages."
+	redo-always
+fi

src/do

@@ -0,0 +1,175 @@
+#!/bin/sh
+#
+# A minimal alternative to djb redo that doesn't support incremental builds.
+# For the full version, visit http://github.com/apenwarr/redo
+#
+# The author disclaims copyright to this source file and hereby places it in
+# the public domain. (2010 12 14)
+#
+
+# By default, no output coloring.
+green=""
+bold=""
+plain=""
+
+if [ -n "$TERM" -a "$TERM" != "dumb" ] && tty <&2 >/dev/null 2>&1; then
+	green="$(printf '\033[32m')"
+	bold="$(printf '\033[1m')"
+	plain="$(printf '\033[m')"
+fi
+
+_dirsplit()
+{
+	base=${1##*/}
+	dir=${1%$base}
+}
+
+dirname()
+(
+	_dirsplit "$1"
+	dir=${dir%/}
+	echo "${dir:-.}"
+)
+
+_dirsplit "$0"
+export REDO=$(cd "${dir:-.}" && echo "$PWD/$base")
+
+DO_TOP=
+if [ -z "$DO_BUILT" ]; then
+	DO_TOP=1
+	[ -n "$*" ] || set all  # only toplevel redo has a default target
+	export DO_BUILT=$PWD/.do_built
+	: >>"$DO_BUILT"
+	echo "Removing previously built files..." >&2
+	sort -u "$DO_BUILT" | tee "$DO_BUILT.new" |
+	while read f; do printf "%s\0%s.did\0" "$f" "$f"; done |
+	xargs -0 rm -f 2>/dev/null
+	mv "$DO_BUILT.new" "$DO_BUILT"
+	DO_PATH=$DO_BUILT.dir
+	export PATH=$DO_PATH:$PATH
+	rm -rf "$DO_PATH"
+	mkdir "$DO_PATH"
+	for d in redo redo-ifchange; do
+		ln -s "$REDO" "$DO_PATH/$d";
+	done
+	[ -e /bin/true ] && TRUE=/bin/true || TRUE=/usr/bin/true
+	for d in redo-ifcreate redo-stamp redo-always; do 
+		ln -s $TRUE "$DO_PATH/$d";
+	done
+fi
+
+
+_find_dofile_pwd()
+{
+	dofile=default.$1.do
+	while :; do
+		dofile=default.${dofile#default.*.}
+		[ -e "$dofile" -o "$dofile" = default.do ] && break
+	done
+	ext=${dofile#default}
+	ext=${ext%.do}
+	base=${1%$ext}
+}
+
+
+_find_dofile()
+{
+	local prefix=
+	while :; do
+		_find_dofile_pwd "$1"
+		[ -e "$dofile" ] && break
+		[ "$PWD" = "/" ] && break
+		target=${PWD##*/}/$target
+		tmp=${PWD##*/}/$tmp
+		prefix=${PWD##*/}/$prefix
+		cd ..
+	done
+	base=$prefix$base
+}
+
+
+_run_dofile()
+{
+	export DO_DEPTH="$DO_DEPTH  "
+	export REDO_TARGET=$PWD/$target
+	local line1
+	set -e
+	read line1 <"$PWD/$dofile"
+	cmd=${line1#"#!/"}
+	if [ "$cmd" != "$line1" ]; then
+		/$cmd "$PWD/$dofile" "$@" >"$tmp.tmp2"
+	else
+		:; . "$PWD/$dofile" >"$tmp.tmp2"
+	fi
+}
+
+
+_do()
+{
+	local dir=$1 target=$2 tmp=$3
+	if [ ! -e "$target" ] || [ -d "$target" -a ! -e "$target.did" ]; then
+		printf '%sdo  %s%s%s%s\n' \
+			"$green" "$DO_DEPTH" "$bold" "$dir$target" "$plain" >&2
+		echo "$PWD/$target" >>"$DO_BUILT"
+		dofile=$target.do
+		base=$target
+		ext=
+		[ -e "$target.do" ] || _find_dofile "$target"
+		if [ ! -e "$dofile" ]; then
+			echo "do: $target: no .do file" >&2
+			return 1
+		fi
+		[ ! -e "$DO_BUILT" ] || [ ! -d "$(dirname "$target")" ] ||
+		: >>"$target.did"
+		( _run_dofile "$target" "$base" "$tmp.tmp" )
+		rv=$?
+		if [ $rv != 0 ]; then
+			printf "do: %s%s\n" "$DO_DEPTH" \
+				"$dir$target: got exit code $rv" >&2
+			rm -f "$tmp.tmp" "$tmp.tmp2"
+			return $rv
+		fi
+		mv "$tmp.tmp" "$target" 2>/dev/null ||
+		! test -s "$tmp.tmp2" ||
+		mv "$tmp.tmp2" "$target" 2>/dev/null
+		rm -f "$tmp.tmp2"
+	else
+		echo "do  $DO_DEPTH$target exists." >&2
+	fi
+}
+
+
+# Make corrections for directories that don't actually exist yet.
+_dir_shovel()
+{
+	local dir base
+	xdir=$1 xbase=$2 xbasetmp=$2
+	while [ ! -d "$xdir" -a -n "$xdir" ]; do
+		_dirsplit "${xdir%/}"
+		xbasetmp=${base}__$xbase
+		xdir=$dir xbase=$base/$xbase
+		echo "xbasetmp='$xbasetmp'" >&2
+	done
+}
+
+
+redo()
+{
+	for i in "$@"; do
+		_dirsplit "$i"
+		_dir_shovel "$dir" "$base"
+		dir=$xdir base=$xbase basetmp=$xbasetmp
+		( cd "$dir" && _do "$dir" "$base" "$basetmp" ) || return 1
+	done
+}
+
+
+set -e
+redo "$@"
+
+if [ -n "$DO_TOP" ]; then
+	echo "Removing stamp files..." >&2
+	[ ! -e "$DO_BUILT" ] ||
+	while read f; do printf "%s.did\0" "$f"; done <"$DO_BUILT" |
+	xargs -0 rm -f 2>/dev/null
+fi

src/firewall.py

@@ -0,0 +1,653 @@
+import errno
+import socket
+import select
+import signal
+import struct
+import compat.ssubprocess as ssubprocess
+import ssyslog
+import sys
+import os
+from helpers import log, debug1, debug3, islocal, Fatal, family_to_string, \
+    resolvconf_nameservers
+
+# python doesn't have a definition for this
+IPPROTO_DIVERT = 254
+
+
+def nonfatal(func, *args):
+    try:
+        func(*args)
+    except Fatal, e:
+        log('error: %s\n' % e)
+
+
+def ipt_chain_exists(family, table, name):
+    if family == socket.AF_INET6:
+        cmd = 'ip6tables'
+    elif family == socket.AF_INET:
+        cmd = 'iptables'
+    else:
+        raise Exception('Unsupported family "%s"' % family_to_string(family))
+    argv = [cmd, '-t', table, '-nL']
+    p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE)
+    for line in p.stdout:
+        if line.startswith('Chain %s ' % name):
+            return True
+    rv = p.wait()
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))
+
+
+def _ipt(family, table, *args):
+    if family == socket.AF_INET6:
+        argv = ['ip6tables', '-t', table] + list(args)
+    elif family == socket.AF_INET:
+        argv = ['iptables', '-t', table] + list(args)
+    else:
+        raise Exception('Unsupported family "%s"' % family_to_string(family))
+    debug1('>> %s\n' % ' '.join(argv))
+    rv = ssubprocess.call(argv)
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))
+
+
+_no_ttl_module = False
+
+
+def _ipt_ttl(family, *args):
+    global _no_ttl_module
+    if not _no_ttl_module:
+        # we avoid infinite loops by generating server-side connections
+        # with ttl 42.  This makes the client side not recapture those
+        # connections, in case client == server.
+        try:
+            argsplus = list(args) + ['-m', 'ttl', '!', '--ttl', '42']
+            _ipt(family, *argsplus)
+        except Fatal:
+            _ipt(family, *args)
+            # we only get here if the non-ttl attempt succeeds
+            log('sshuttle: warning: your iptables is missing '
+                'the ttl module.\n')
+            _no_ttl_module = True
+    else:
+        _ipt(family, *args)
+
+
+# We name the chain based on the transproxy port number so that it's possible
+# to run multiple copies of sshuttle at the same time.  Of course, the
+# multiple copies shouldn't have overlapping subnets, or only the most-
+# recently-started one will win (because we use "-I OUTPUT 1" instead of
+# "-A OUTPUT").
+def do_iptables_nat(port, dnsport, family, subnets, udp):
+    # only ipv4 supported with NAT
+    if family != socket.AF_INET:
+        raise Exception(
+            'Address family "%s" unsupported by nat method'
+            % family_to_string(family))
+    if udp:
+        raise Exception("UDP not supported by nat method")
+
+    table = "nat"
+
+    def ipt(*args):
+        return _ipt(family, table, *args)
+
+    def ipt_ttl(*args):
+        return _ipt_ttl(family, table, *args)
+
+    chain = 'sshuttle-%s' % port
+
+    # basic cleanup/setup of chains
+    if ipt_chain_exists(family, table, chain):
+        nonfatal(ipt, '-D', 'OUTPUT', '-j', chain)
+        nonfatal(ipt, '-D', 'PREROUTING', '-j', chain)
+        nonfatal(ipt, '-F', chain)
+        ipt('-X', chain)
+
+    if subnets or dnsport:
+        ipt('-N', chain)
+        ipt('-F', chain)
+        ipt('-I', 'OUTPUT', '1', '-j', chain)
+        ipt('-I', 'PREROUTING', '1', '-j', chain)
+
+    if subnets:
+        # create new subnet entries.  Note that we're sorting in a very
+        # particular order: we need to go from most-specific (largest swidth)
+        # to least-specific, and at any given level of specificity, we want
+        # excludes to come first.  That's why the columns are in such a non-
+        # intuitive order.
+        for f, swidth, sexclude, snet \
+                in sorted(subnets, key=lambda s: s[1], reverse=True):
+            if sexclude:
+                ipt('-A', chain, '-j', 'RETURN',
+                    '--dest', '%s/%s' % (snet, swidth),
+                    '-p', 'tcp')
+            else:
+                ipt_ttl('-A', chain, '-j', 'REDIRECT',
+                        '--dest', '%s/%s' % (snet, swidth),
+                        '-p', 'tcp',
+                        '--to-ports', str(port))
+
+    if dnsport:
+        nslist = resolvconf_nameservers()
+        for f, ip in filter(lambda i: i[0] == family, nslist):
+            ipt_ttl('-A', chain, '-j', 'REDIRECT',
+                    '--dest', '%s/32' % ip,
+                    '-p', 'udp',
+                    '--dport', '53',
+                    '--to-ports', str(dnsport))
+
+
+def do_iptables_tproxy(port, dnsport, family, subnets, udp):
+    if family not in [socket.AF_INET, socket.AF_INET6]:
+        raise Exception(
+            'Address family "%s" unsupported by tproxy method'
+            % family_to_string(family))
+
+    table = "mangle"
+
+    def ipt(*args):
+        return _ipt(family, table, *args)
+
+    def ipt_ttl(*args):
+        return _ipt_ttl(family, table, *args)
+
+    mark_chain = 'sshuttle-m-%s' % port
+    tproxy_chain = 'sshuttle-t-%s' % port
+    divert_chain = 'sshuttle-d-%s' % port
+
+    # basic cleanup/setup of chains
+    if ipt_chain_exists(family, table, mark_chain):
+        ipt('-D', 'OUTPUT', '-j', mark_chain)
+        ipt('-F', mark_chain)
+        ipt('-X', mark_chain)
+
+    if ipt_chain_exists(family, table, tproxy_chain):
+        ipt('-D', 'PREROUTING', '-j', tproxy_chain)
+        ipt('-F', tproxy_chain)
+        ipt('-X', tproxy_chain)
+
+    if ipt_chain_exists(family, table, divert_chain):
+        ipt('-F', divert_chain)
+        ipt('-X', divert_chain)
+
+    if subnets or dnsport:
+        ipt('-N', mark_chain)
+        ipt('-F', mark_chain)
+        ipt('-N', divert_chain)
+        ipt('-F', divert_chain)
+        ipt('-N', tproxy_chain)
+        ipt('-F', tproxy_chain)
+        ipt('-I', 'OUTPUT', '1', '-j', mark_chain)
+        ipt('-I', 'PREROUTING', '1', '-j', tproxy_chain)
+        ipt('-A', divert_chain, '-j', 'MARK', '--set-mark', '1')
+        ipt('-A', divert_chain, '-j', 'ACCEPT')
+        ipt('-A', tproxy_chain, '-m', 'socket', '-j', divert_chain,
+            '-m', 'tcp', '-p', 'tcp')
+    if subnets and udp:
+        ipt('-A', tproxy_chain, '-m', 'socket', '-j', divert_chain,
+            '-m', 'udp', '-p', 'udp')
+
+    if dnsport:
+        nslist = resolvconf_nameservers()
+        for f, ip in filter(lambda i: i[0] == family, nslist):
+            ipt('-A', mark_chain, '-j', 'MARK', '--set-mark', '1',
+                '--dest', '%s/32' % ip,
+                '-m', 'udp', '-p', 'udp', '--dport', '53')
+            ipt('-A', tproxy_chain, '-j', 'TPROXY', '--tproxy-mark', '0x1/0x1',
+                '--dest', '%s/32' % ip,
+                '-m', 'udp', '-p', 'udp', '--dport', '53',
+                '--on-port', str(dnsport))
+
+    if subnets:
+        for f, swidth, sexclude, snet \
+                in sorted(subnets, key=lambda s: s[1], reverse=True):
+            if sexclude:
+                ipt('-A', mark_chain, '-j', 'RETURN',
+                    '--dest', '%s/%s' % (snet, swidth),
+                    '-m', 'tcp', '-p', 'tcp')
+                ipt('-A', tproxy_chain, '-j', 'RETURN',
+                    '--dest', '%s/%s' % (snet, swidth),
+                    '-m', 'tcp', '-p', 'tcp')
+            else:
+                ipt('-A', mark_chain, '-j', 'MARK',
+                    '--set-mark', '1',
+                    '--dest', '%s/%s' % (snet, swidth),
+                    '-m', 'tcp', '-p', 'tcp')
+                ipt('-A', tproxy_chain, '-j', 'TPROXY',
+                    '--tproxy-mark', '0x1/0x1',
+                    '--dest', '%s/%s' % (snet, swidth),
+                    '-m', 'tcp', '-p', 'tcp',
+                    '--on-port', str(port))
+
+            if sexclude and udp:
+                ipt('-A', mark_chain, '-j', 'RETURN',
+                    '--dest', '%s/%s' % (snet, swidth),
+                    '-m', 'udp', '-p', 'udp')
+                ipt('-A', tproxy_chain, '-j', 'RETURN',
+                    '--dest', '%s/%s' % (snet, swidth),
+                    '-m', 'udp', '-p', 'udp')
+            elif udp:
+                ipt('-A', mark_chain, '-j', 'MARK',
+                    '--set-mark', '1',
+                    '--dest', '%s/%s' % (snet, swidth),
+                    '-m', 'udp', '-p', 'udp')
+                ipt('-A', tproxy_chain, '-j', 'TPROXY',
+                    '--tproxy-mark', '0x1/0x1',
+                    '--dest', '%s/%s' % (snet, swidth),
+                    '-m', 'udp', '-p', 'udp',
+                    '--on-port', str(port))
+
+
+def ipfw_rule_exists(n):
+    argv = ['ipfw', 'list']
+    p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE)
+    found = False
+    for line in p.stdout:
+        if line.startswith('%05d ' % n):
+            if not ('ipttl 42' in line
+                    or ('skipto %d' % (n + 1)) in line
+                    or 'check-state' in line):
+                log('non-sshuttle ipfw rule: %r\n' % line.strip())
+                raise Fatal('non-sshuttle ipfw rule #%d already exists!' % n)
+            found = True
+    rv = p.wait()
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))
+    return found
+
+
+_oldctls = {}
+
+
+def _fill_oldctls(prefix):
+    argv = ['sysctl', prefix]
+    p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE)
+    for line in p.stdout:
+        assert(line[-1] == '\n')
+        (k, v) = line[:-1].split(': ', 1)
+        _oldctls[k] = v
+    rv = p.wait()
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))
+    if not line:
+        raise Fatal('%r returned no data' % (argv,))
+
+
+def _sysctl_set(name, val):
+    argv = ['sysctl', '-w', '%s=%s' % (name, val)]
+    debug1('>> %s\n' % ' '.join(argv))
+    return ssubprocess.call(argv, stdout=open('/dev/null', 'w'))
+
+
+_changedctls = []
+
+
+def sysctl_set(name, val, permanent=False):
+    PREFIX = 'net.inet.ip'
+    assert(name.startswith(PREFIX + '.'))
+    val = str(val)
+    if not _oldctls:
+        _fill_oldctls(PREFIX)
+    if not (name in _oldctls):
+        debug1('>> No such sysctl: %r\n' % name)
+        return False
+    oldval = _oldctls[name]
+    if val != oldval:
+        rv = _sysctl_set(name, val)
+        if rv == 0 and permanent:
+            debug1('>>   ...saving permanently in /etc/sysctl.conf\n')
+            f = open('/etc/sysctl.conf', 'a')
+            f.write('\n'
+                    '# Added by sshuttle\n'
+                    '%s=%s\n' % (name, val))
+            f.close()
+        else:
+            _changedctls.append(name)
+        return True
+
+
+def _udp_unpack(p):
+    src = (socket.inet_ntoa(p[12:16]), struct.unpack('!H', p[20:22])[0])
+    dst = (socket.inet_ntoa(p[16:20]), struct.unpack('!H', p[22:24])[0])
+    return src, dst
+
+
+def _udp_repack(p, src, dst):
+    addrs = socket.inet_aton(src[0]) + socket.inet_aton(dst[0])
+    ports = struct.pack('!HH', src[1], dst[1])
+    return p[:12] + addrs + ports + p[24:]
+
+
+_real_dns_server = [None]
+
+
+def _handle_diversion(divertsock, dnsport):
+    p, tag = divertsock.recvfrom(4096)
+    src, dst = _udp_unpack(p)
+    debug3('got diverted packet from %r to %r\n' % (src, dst))
+    if dst[1] == 53:
+        # outgoing DNS
+        debug3('...packet is a DNS request.\n')
+        _real_dns_server[0] = dst
+        dst = ('127.0.0.1', dnsport)
+    elif src[1] == dnsport:
+        if islocal(src[0]):
+            debug3('...packet is a DNS response.\n')
+            src = _real_dns_server[0]
+    else:
+        log('weird?! unexpected divert from %r to %r\n' % (src, dst))
+        assert(0)
+    newp = _udp_repack(p, src, dst)
+    divertsock.sendto(newp, tag)
+
+
+def ipfw(*args):
+    argv = ['ipfw', '-q'] + list(args)
+    debug1('>> %s\n' % ' '.join(argv))
+    rv = ssubprocess.call(argv)
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))
+
+
+def do_ipfw(port, dnsport, family, subnets, udp):
+    # IPv6 not supported
+    if family not in [socket.AF_INET, ]:
+        raise Exception(
+            'Address family "%s" unsupported by ipfw method'
+            % family_to_string(family))
+    if udp:
+        raise Exception("UDP not supported by ipfw method")
+
+    sport = str(port)
+    xsport = str(port + 1)
+
+    # cleanup any existing rules
+    if ipfw_rule_exists(port):
+        ipfw('delete', sport)
+
+    while _changedctls:
+        name = _changedctls.pop()
+        oldval = _oldctls[name]
+        _sysctl_set(name, oldval)
+
+    if subnets or dnsport:
+        sysctl_set('net.inet.ip.fw.enable', 1)
+        changed = sysctl_set('net.inet.ip.scopedroute', 0, permanent=True)
+        if changed:
+            log("\n"
+                "        WARNING: ONE-TIME NETWORK DISRUPTION:\n"
+                "        =====================================\n"
+                "sshuttle has changed a MacOS kernel setting to work around\n"
+                "a bug in MacOS 10.6.  This will cause your network to drop\n"
+                "within 5-10 minutes unless you restart your network\n"
+                "interface (change wireless networks or unplug/plug the\n"
+                "ethernet port) NOW, then restart sshuttle.  The fix is\n"
+                "permanent; you only have to do this once.\n\n")
+            sys.exit(1)
+
+        ipfw('add', sport, 'check-state', 'ip',
+             'from', 'any', 'to', 'any')
+
+    if subnets:
+        # create new subnet entries
+        for f, swidth, sexclude, snet \
+                in sorted(subnets, key=lambda s: s[1], reverse=True):
+            if sexclude:
+                ipfw('add', sport, 'skipto', xsport,
+                     'tcp',
+                     'from', 'any', 'to', '%s/%s' % (snet, swidth))
+            else:
+                ipfw('add', sport, 'fwd', '127.0.0.1,%d' % port,
+                     'tcp',
+                     'from', 'any', 'to', '%s/%s' % (snet, swidth),
+                     'not', 'ipttl', '42', 'keep-state', 'setup')
+
+    # This part is much crazier than it is on Linux, because MacOS (at least
+    # 10.6, and probably other versions, and maybe FreeBSD too) doesn't
+    # correctly fixup the dstip/dstport for UDP packets when it puts them
+    # through a 'fwd' rule.  It also doesn't fixup the srcip/srcport in the
+    # response packet.  In Linux iptables, all that happens magically for us,
+    # so we just redirect the packets and relax.
+    #
+    # On MacOS, we have to fix the ports ourselves.  For that, we use a
+    # 'divert' socket, which receives raw packets and lets us mangle them.
+    #
+    # Here's how it works.  Let's say the local DNS server is 1.1.1.1:53,
+    # and the remote DNS server is 2.2.2.2:53, and the local transproxy port
+    # is 10.0.0.1:12300, and a client machine is making a request from
+    # 10.0.0.5:9999. We see a packet like this:
+    #    10.0.0.5:9999 -> 1.1.1.1:53
+    # Since the destip:port matches one of our local nameservers, it will
+    # match a 'fwd' rule, thus grabbing it on the local machine.  However,
+    # the local kernel will then see a packet addressed to *:53 and
+    # not know what to do with it; there's nobody listening on port 53.  Thus,
+    # we divert it, rewriting it into this:
+    #    10.0.0.5:9999 -> 10.0.0.1:12300
+    # This gets proxied out to the server, which sends it to 2.2.2.2:53,
+    # and the answer comes back, and the proxy sends it back out like this:
+    #    10.0.0.1:12300 -> 10.0.0.5:9999
+    # But that's wrong!  The original machine expected an answer from
+    # 1.1.1.1:53, so we have to divert the *answer* and rewrite it:
+    #    1.1.1.1:53 -> 10.0.0.5:9999
+    #
+    # See?  Easy stuff.
+    if dnsport:
+        divertsock = socket.socket(socket.AF_INET, socket.SOCK_RAW,
+                                   IPPROTO_DIVERT)
+        divertsock.bind(('0.0.0.0', port))  # IP field is ignored
+
+        nslist = resolvconf_nameservers()
+        for f, ip in filter(lambda i: i[0] == family, nslist):
+            # relabel and then catch outgoing DNS requests
+            ipfw('add', sport, 'divert', sport,
+                 'udp',
+                 'from', 'any', 'to', '%s/32' % ip, '53',
+                 'not', 'ipttl', '42')
+        # relabel DNS responses
+        ipfw('add', sport, 'divert', sport,
+             'udp',
+             'from', 'any', str(dnsport), 'to', 'any',
+             'not', 'ipttl', '42')
+
+        def do_wait():
+            while 1:
+                r, w, x = select.select([sys.stdin, divertsock], [], [])
+                if divertsock in r:
+                    _handle_diversion(divertsock, dnsport)
+                if sys.stdin in r:
+                    return
+    else:
+        do_wait = None
+
+    return do_wait
+
+
+def program_exists(name):
+    paths = (os.getenv('PATH') or os.defpath).split(os.pathsep)
+    for p in paths:
+        fn = '%s/%s' % (p, name)
+        if os.path.exists(fn):
+            return not os.path.isdir(fn) and os.access(fn, os.X_OK)
+
+
+hostmap = {}
+
+
+def rewrite_etc_hosts(port):
+    HOSTSFILE = '/etc/hosts'
+    BAKFILE = '%s.sbak' % HOSTSFILE
+    APPEND = '# sshuttle-firewall-%d AUTOCREATED' % port
+    old_content = ''
+    st = None
+    try:
+        old_content = open(HOSTSFILE).read()
+        st = os.stat(HOSTSFILE)
+    except IOError, e:
+        if e.errno == errno.ENOENT:
+            pass
+        else:
+            raise
+    if old_content.strip() and not os.path.exists(BAKFILE):
+        os.link(HOSTSFILE, BAKFILE)
+    tmpname = "%s.%d.tmp" % (HOSTSFILE, port)
+    f = open(tmpname, 'w')
+    for line in old_content.rstrip().split('\n'):
+        if line.find(APPEND) >= 0:
+            continue
+        f.write('%s\n' % line)
+    for (name, ip) in sorted(hostmap.items()):
+        f.write('%-30s %s\n' % ('%s %s' % (ip, name), APPEND))
+    f.close()
+
+    if st:
+        os.chown(tmpname, st.st_uid, st.st_gid)
+        os.chmod(tmpname, st.st_mode)
+    else:
+        os.chown(tmpname, 0, 0)
+        os.chmod(tmpname, 0644)
+    os.rename(tmpname, HOSTSFILE)
+
+
+def restore_etc_hosts(port):
+    global hostmap
+    hostmap = {}
+    rewrite_etc_hosts(port)
+
+
+# This is some voodoo for setting up the kernel's transparent
+# proxying stuff.  If subnets is empty, we just delete our sshuttle rules;
+# otherwise we delete it, then make them from scratch.
+#
+# This code is supposed to clean up after itself by deleting its rules on
+# exit.  In case that fails, it's not the end of the world; future runs will
+# supercede it in the transproxy list, at least, so the leftover rules
+# are hopefully harmless.
+def main(port_v6, port_v4, dnsport_v6, dnsport_v4, method, udp, syslog):
+    assert(port_v6 >= 0)
+    assert(port_v6 <= 65535)
+    assert(port_v4 >= 0)
+    assert(port_v4 <= 65535)
+    assert(dnsport_v6 >= 0)
+    assert(dnsport_v6 <= 65535)
+    assert(dnsport_v4 >= 0)
+    assert(dnsport_v4 <= 65535)
+
+    if os.getuid() != 0:
+        raise Fatal('you must be root (or enable su/sudo) to set the firewall')
+
+    if method == "auto":
+        if program_exists('ipfw'):
+            method = "ipfw"
+        elif program_exists('iptables'):
+            method = "nat"
+        else:
+            raise Fatal("can't find either ipfw or iptables; check your PATH")
+
+    if method == "nat":
+        do_it = do_iptables_nat
+    elif method == "tproxy":
+        do_it = do_iptables_tproxy
+    elif method == "ipfw":
+        do_it = do_ipfw
+    else:
+        raise Exception('Unknown method "%s"' % method)
+
+    # because of limitations of the 'su' command, the *real* stdin/stdout
+    # are both attached to stdout initially.  Clone stdout into stdin so we
+    # can read from it.
+    os.dup2(1, 0)
+
+    if syslog:
+        ssyslog.start_syslog()
+        ssyslog.stderr_to_syslog()
+
+    debug1('firewall manager ready method %s.\n' % method)
+    sys.stdout.write('READY %s\n' % method)
+    sys.stdout.flush()
+
+    # don't disappear if our controlling terminal or stdout/stderr
+    # disappears; we still have to clean up.
+    signal.signal(signal.SIGHUP, signal.SIG_IGN)
+    signal.signal(signal.SIGPIPE, signal.SIG_IGN)
+    signal.signal(signal.SIGTERM, signal.SIG_IGN)
+    signal.signal(signal.SIGINT, signal.SIG_IGN)
+
+    # ctrl-c shouldn't be passed along to me.  When the main sshuttle dies,
+    # I'll die automatically.
+    os.setsid()
+
+    # we wait until we get some input before creating the rules.  That way,
+    # sshuttle can launch us as early as possible (and get sudo password
+    # authentication as early in the startup process as possible).
+    line = sys.stdin.readline(128)
+    if not line:
+        return  # parent died; nothing to do
+
+    subnets = []
+    if line != 'ROUTES\n':
+        raise Fatal('firewall: expected ROUTES but got %r' % line)
+    while 1:
+        line = sys.stdin.readline(128)
+        if not line:
+            raise Fatal('firewall: expected route but got %r' % line)
+        elif line == 'GO\n':
+            break
+        try:
+            (family, width, exclude, ip) = line.strip().split(',', 3)
+        except:
+            raise Fatal('firewall: expected route or GO but got %r' % line)
+        subnets.append((int(family), int(width), bool(int(exclude)), ip))
+
+    try:
+        if line:
+            debug1('firewall manager: starting transproxy.\n')
+
+            subnets_v6 = filter(lambda i: i[0] == socket.AF_INET6, subnets)
+            if port_v6:
+                do_wait = do_it(
+                    port_v6, dnsport_v6, socket.AF_INET6, subnets_v6, udp)
+            elif len(subnets_v6) > 0:
+                debug1("IPv6 subnets defined but IPv6 disabled\n")
+
+            subnets_v4 = filter(lambda i: i[0] == socket.AF_INET, subnets)
+            if port_v4:
+                do_wait = do_it(
+                    port_v4, dnsport_v4, socket.AF_INET, subnets_v4, udp)
+            elif len(subnets_v4) > 0:
+                debug1('IPv4 subnets defined but IPv4 disabled\n')
+
+            sys.stdout.write('STARTED\n')
+
+        try:
+            sys.stdout.flush()
+        except IOError:
+            # the parent process died for some reason; he's surely been loud
+            # enough, so no reason to report another error
+            return
+
+        # Now we wait until EOF or any other kind of exception.  We need
+        # to stay running so that we don't need a *second* password
+        # authentication at shutdown time - that cleanup is important!
+        while 1:
+            if do_wait:
+                do_wait()
+            line = sys.stdin.readline(128)
+            if line.startswith('HOST '):
+                (name, ip) = line[5:].strip().split(',', 1)
+                hostmap[name] = ip
+                rewrite_etc_hosts(port_v6 or port_v4)
+            elif line:
+                raise Fatal('expected EOF, got %r' % line)
+            else:
+                break
+    finally:
+        try:
+            debug1('firewall manager: undoing changes.\n')
+        except:
+            pass
+        if port_v6:
+            do_it(port_v6, 0, socket.AF_INET6, [], udp)
+        if port_v4:
+            do_it(port_v4, 0, socket.AF_INET, [], udp)
+        restore_etc_hosts(port_v6 or port_v4)

src/helpers.py

@@ -0,0 +1,91 @@
+import sys
+import socket
+import errno
+
+logprefix = ''
+verbose = 0
+
+
+def log(s):
+    try:
+        sys.stdout.flush()
+        sys.stderr.write(logprefix + s)
+        sys.stderr.flush()
+    except IOError:
+        # this could happen if stderr gets forcibly disconnected, eg. because
+        # our tty closes.  That sucks, but it's no reason to abort the program.
+        pass
+
+
+def debug1(s):
+    if verbose >= 1:
+        log(s)
+
+
+def debug2(s):
+    if verbose >= 2:
+        log(s)
+
+
+def debug3(s):
+    if verbose >= 3:
+        log(s)
+
+
+class Fatal(Exception):
+    pass
+
+
+def list_contains_any(l, sub):
+    for i in sub:
+        if i in l:
+            return True
+    return False
+
+
+def resolvconf_nameservers():
+    l = []
+    for line in open('/etc/resolv.conf'):
+        words = line.lower().split()
+        if len(words) >= 2 and words[0] == 'nameserver':
+            if ':' in words[1]:
+                l.append((socket.AF_INET6, words[1]))
+            else:
+                l.append((socket.AF_INET, words[1]))
+    return l
+
+
+def resolvconf_random_nameserver():
+    l = resolvconf_nameservers()
+    if l:
+        if len(l) > 1:
+            # don't import this unless we really need it
+            import random
+            random.shuffle(l)
+        return l[0]
+    else:
+        return (socket.AF_INET, '127.0.0.1')
+
+
+def islocal(ip, family):
+    sock = socket.socket(family)
+    try:
+        try:
+            sock.bind((ip, 0))
+        except socket.error, e:
+            if e.args[0] == errno.EADDRNOTAVAIL:
+                return False  # not a local IP
+            else:
+                raise
+    finally:
+        sock.close()
+    return True  # it's a local IP, or there would have been an error
+
+
+def family_to_string(family):
+    if family == socket.AF_INET6:
+        return "AF_INET6"
+    elif family == socket.AF_INET:
+        return "AF_INET"
+    else:
+        return str(family)

src/hostwatch.py

@@ -1,19 +1,29 @@
-import time, socket, re, select, errno
+import time
+import socket
+import re
+import select
+import errno
+import os
+import sys
 if not globals().get('skip_imports'):
     import compat.ssubprocess as ssubprocess
     import helpers
-    from helpers import *
+    from helpers import log, debug1, debug2, debug3
 
-POLL_TIME = 60*15
+POLL_TIME = 60 * 15
 NETSTAT_POLL_TIME = 30
-CACHEFILE=os.path.expanduser('~/.sshuttle.hosts')
+CACHEFILE = os.path.expanduser('~/.sshuttle.hosts')
 
 
 _nmb_ok = True
 _smb_ok = True
 hostnames = {}
 queue = {}
-null = open('/dev/null', 'rb+')
+try:
+    null = open('/dev/null', 'wb')
+except IOError, e:
+    log('warning: %s\n' % e)
+    null = os.popen("sh -c 'while read x; do :; done'", 'wb', 4096)
 
 
 def _is_ip(s):
@@ -24,7 +34,7 @@ def write_host_cache():
     tmpname = '%s.%d.tmp' % (CACHEFILE, os.getpid())
     try:
         f = open(tmpname, 'wb')
-        for name,ip in sorted(hostnames.items()):
+        for name, ip in sorted(hostnames.items()):
             f.write('%s,%s\n' % (name, ip))
         f.close()
         os.rename(tmpname, CACHEFILE)
@@ -46,18 +56,18 @@ def read_host_cache():
     for line in f:
         words = line.strip().split(',')
         if len(words) == 2:
-            (name,ip) = words
+            (name, ip) = words
             name = re.sub(r'[^-\w]', '-', name).strip()
             ip = re.sub(r'[^0-9.]', '', ip).strip()
             if name and ip:
                 found_host(name, ip)
-                
+
 
 def found_host(hostname, ip):
     hostname = re.sub(r'\..*', '', hostname)
     hostname = re.sub(r'[^-\w]', '_', hostname)
-    if (ip.startswith('127.') or ip.startswith('255.') 
+    if (ip.startswith('127.') or ip.startswith('255.')
-        or hostname == 'localhost'):
+            or hostname == 'localhost'):
         return
     oldip = hostnames.get(hostname)
     if oldip != ip:
@@ -90,7 +100,7 @@ def _check_revdns(ip):
         debug3('<    %s\n' % r[0])
         check_host(r[0])
         found_host(r[0], ip)
-    except socket.herror, e:
+    except socket.herror:
         pass
 
 
@@ -101,7 +111,7 @@ def _check_dns(hostname):
         debug3('<    %s\n' % ip)
         check_host(ip)
         found_host(hostname, ip)
-    except socket.gaierror, e:
+    except socket.gaierror:
         pass
 
 
@@ -119,7 +129,7 @@ def _check_netstat():
     for ip in re.findall(r'\d+\.\d+\.\d+\.\d+', content):
         debug3('<    %s\n' % ip)
         check_host(ip)
-        
+
 
 def _check_smb(hostname):
     return
@@ -183,7 +193,7 @@ def _check_nmb(hostname, is_workgroup, is_master):
     global _nmb_ok
     if not _nmb_ok:
         return
-    argv = ['nmblookup'] + ['-M']*is_master + ['--', hostname]
+    argv = ['nmblookup'] + ['-M'] * is_master + ['--', hostname]
     debug2(' > n%d%d: %s\n' % (is_workgroup, is_master, hostname))
     try:
         p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, stderr=null)
@@ -224,13 +234,13 @@ def check_workgroup(hostname):
 
 
 def _enqueue(op, *args):
-    t = (op,args)
+    t = (op, args)
-    if queue.get(t) == None:
+    if queue.get(t) is None:
         queue[t] = 0
 
 
 def _stdin_still_ok(timeout):
-    r,w,x = select.select([sys.stdin.fileno()], [], [], timeout)
+    r, w, x = select.select([sys.stdin.fileno()], [], [], timeout)
     if r:
         b = os.read(sys.stdin.fileno(), 4096)
         if not b:
@@ -245,7 +255,7 @@ def hw_main(seed_hosts):
         helpers.logprefix = 'hostwatch: '
 
     read_host_cache()
-        
+
     _enqueue(_check_etc_hosts)
     _enqueue(_check_netstat)
     check_host('localhost')
@@ -257,8 +267,8 @@ def hw_main(seed_hosts):
 
     while 1:
         now = time.time()
-        for t,last_polled in queue.items():
+        for t, last_polled in queue.items():
-            (op,args) = t
+            (op, args) = t
             if not _stdin_still_ok(0):
                 break
             maxtime = POLL_TIME
@@ -271,7 +281,7 @@ def hw_main(seed_hosts):
                 sys.stdout.flush()
             except IOError:
                 break
-                
+
         # FIXME: use a smarter timeout based on oldest last_polled
         if not _stdin_still_ok(1):
             break

src/main.py

@@ -0,0 +1,230 @@
+import sys
+import re
+import socket
+import helpers
+import options
+import client
+import server
+import firewall
+import hostwatch
+from helpers import log, Fatal
+
+
+# 1.2.3.4/5 or just 1.2.3.4
+def parse_subnet4(s):
+    m = re.match(r'(\d+)(?:\.(\d+)\.(\d+)\.(\d+))?(?:/(\d+))?$', s)
+    if not m:
+        raise Fatal('%r is not a valid IP subnet format' % s)
+    (a, b, c, d, width) = m.groups()
+    (a, b, c, d) = (int(a or 0), int(b or 0), int(c or 0), int(d or 0))
+    if width is None:
+        width = 32
+    else:
+        width = int(width)
+    if a > 255 or b > 255 or c > 255 or d > 255:
+        raise Fatal('%d.%d.%d.%d has numbers > 255' % (a, b, c, d))
+    if width > 32:
+        raise Fatal('*/%d is greater than the maximum of 32' % width)
+    return(socket.AF_INET, '%d.%d.%d.%d' % (a, b, c, d), width)
+
+
+# 1:2::3/64 or just 1:2::3
+def parse_subnet6(s):
+    m = re.match(r'(?:([a-fA-F\d:]+))?(?:/(\d+))?$', s)
+    if not m:
+        raise Fatal('%r is not a valid IP subnet format' % s)
+    (net, width) = m.groups()
+    if width is None:
+        width = 128
+    else:
+        width = int(width)
+    if width > 128:
+        raise Fatal('*/%d is greater than the maximum of 128' % width)
+    return(socket.AF_INET6, net, width)
+
+
+# Subnet file, supporting empty lines and hash-started comment lines
+def parse_subnet_file(s):
+    try:
+        handle = open(s, 'r')
+    except OSError:
+        raise Fatal('Unable to open subnet file: %s' % s)
+
+    raw_config_lines = handle.readlines()
+    config_lines = []
+    for line_no, line in enumerate(raw_config_lines):
+        line = line.strip()
+        if len(line) == 0:
+            continue
+        if line[0] == '#':
+            continue
+        config_lines.append(line)
+
+    return config_lines
+
+
+# list of:
+# 1.2.3.4/5 or just 1.2.3.4
+# 1:2::3/64 or just 1:2::3
+def parse_subnets(subnets_str):
+    subnets = []
+    for s in subnets_str:
+        if ':' in s:
+            subnet = parse_subnet6(s)
+        else:
+            subnet = parse_subnet4(s)
+        subnets.append(subnet)
+    return subnets
+
+
+# 1.2.3.4:567 or just 1.2.3.4 or just 567
+def parse_ipport4(s):
+    s = str(s)
+    m = re.match(r'(?:(\d+)\.(\d+)\.(\d+)\.(\d+))?(?::)?(?:(\d+))?$', s)
+    if not m:
+        raise Fatal('%r is not a valid IP:port format' % s)
+    (a, b, c, d, port) = m.groups()
+    (a, b, c, d, port) = (int(a or 0), int(b or 0), int(c or 0), int(d or 0),
+                          int(port or 0))
+    if a > 255 or b > 255 or c > 255 or d > 255:
+        raise Fatal('%d.%d.%d.%d has numbers > 255' % (a, b, c, d))
+    if port > 65535:
+        raise Fatal('*:%d is greater than the maximum of 65535' % port)
+    if a is None:
+        a = b = c = d = 0
+    return ('%d.%d.%d.%d' % (a, b, c, d), port)
+
+
+# [1:2::3]:456 or [1:2::3] or 456
+def parse_ipport6(s):
+    s = str(s)
+    m = re.match(r'(?:\[([^]]*)])?(?::)?(?:(\d+))?$', s)
+    if not m:
+        raise Fatal('%s is not a valid IP:port format' % s)
+    (ip, port) = m.groups()
+    (ip, port) = (ip or '::', int(port or 0))
+    return (ip, port)
+
+
+optspec = """
+sshuttle [-l [ip:]port] [-r [username@]sshserver[:port]] <subnets...>
+sshuttle --server
+sshuttle --firewall <port> <subnets...>
+sshuttle --hostwatch
+--
+l,listen=  transproxy to this ip address and port number
+H,auto-hosts scan for remote hostnames and update local /etc/hosts
+N,auto-nets  automatically determine subnets to route
+dns        capture local DNS requests and forward to the remote DNS server
+method=    auto, nat, tproxy, or ipfw
+python=    path to python interpreter on the remote server
+r,remote=  ssh hostname (and optional username) of remote sshuttle server
+x,exclude= exclude this subnet (can be used more than once)
+X,exclude-from=  exclude the subnets in a file (whitespace separated)
+v,verbose  increase debug message verbosity
+e,ssh-cmd= the command to use to connect to the remote [ssh]
+seed-hosts= with -H, use these hostnames for initial scan (comma-separated)
+no-latency-control  sacrifice latency to improve bandwidth benchmarks
+wrap=      restart counting channel numbers after this number (for testing)
+D,daemon   run in the background as a daemon
+s,subnets= file where the subnets are stored, instead of on the command line
+syslog     send log messages to syslog (default if you use --daemon)
+pidfile=   pidfile name (only if using --daemon) [./sshuttle.pid]
+server     (internal use only)
+firewall   (internal use only)
+hostwatch  (internal use only)
+"""
+o = options.Options(optspec)
+(opt, flags, extra) = o.parse(sys.argv[2:])
+
+if opt.daemon:
+    opt.syslog = 1
+if opt.wrap:
+    import ssnet
+    ssnet.MAX_CHANNEL = int(opt.wrap)
+helpers.verbose = opt.verbose
+
+try:
+    if opt.server:
+        if len(extra) != 0:
+            o.fatal('no arguments expected')
+        server.latency_control = opt.latency_control
+        sys.exit(server.main())
+    elif opt.firewall:
+        if len(extra) != 6:
+            o.fatal('exactly six arguments expected')
+        sys.exit(firewall.main(int(extra[0]), int(extra[1]),
+                               int(extra[2]), int(extra[3]),
+                               extra[4], int(extra[5]), opt.syslog))
+    elif opt.hostwatch:
+        sys.exit(hostwatch.hw_main(extra))
+    else:
+        if len(extra) < 1 and not opt.auto_nets and not opt.subnets:
+            o.fatal('at least one subnet, subnet file, or -N expected')
+        includes = extra
+        excludes = ['127.0.0.0/8']
+        for k, v in flags:
+            if k in ('-x', '--exclude'):
+                excludes.append(v)
+            if k in ('-X', '--exclude-from'):
+                excludes += open(v).read().split()
+        remotename = opt.remote
+        if remotename == '' or remotename == '-':
+            remotename = None
+        if opt.seed_hosts and not opt.auto_hosts:
+            o.fatal('--seed-hosts only works if you also use -H')
+        if opt.seed_hosts:
+            sh = re.split(r'[\s,]+', (opt.seed_hosts or "").strip())
+        elif opt.auto_hosts:
+            sh = []
+        else:
+            sh = None
+        if opt.subnets:
+            includes = parse_subnet_file(opt.subnets)
+        if not opt.method:
+            method = "auto"
+        elif opt.method in ["auto", "nat", "tproxy", "ipfw"]:
+            method = opt.method
+        else:
+            o.fatal("method %s not supported" % opt.method)
+        if not opt.listen:
+            if opt.method == "tproxy":
+                ipport_v6 = parse_ipport6('[::1]:0')
+            else:
+                ipport_v6 = None
+            ipport_v4 = parse_ipport4('127.0.0.1:0')
+        else:
+            ipport_v6 = None
+            ipport_v4 = None
+            list = opt.listen.split(",")
+            for ip in list:
+                if '[' in ip and ']' in ip and opt.method == "tproxy":
+                    ipport_v6 = parse_ipport6(ip)
+                else:
+                    ipport_v4 = parse_ipport4(ip)
+        return_code = client.main(ipport_v6, ipport_v4,
+                                  opt.ssh_cmd,
+                                  remotename,
+                                  opt.python,
+                                  opt.latency_control,
+                                  opt.dns,
+                                  method,
+                                  sh,
+                                  opt.auto_nets,
+                                  parse_subnets(includes),
+                                  parse_subnets(excludes),
+                                  opt.syslog, opt.daemon, opt.pidfile)
+
+        if return_code == 0:
+            log('Normal exit code, exiting...')
+        else:
+            log('Abnormal exit code detected, failing...' % return_code)
+        sys.exit(return_code)
+
+except Fatal, e:
+    log('fatal: %s\n' % e)
+    sys.exit(99)
+except KeyboardInterrupt:
+    log('\n')
+    log('Keyboard interrupt: exiting.\n')
+    sys.exit(1)

src/options.py

@@ -1,9 +1,16 @@
 """Command-line options parser.
 With the help of an options spec string, easily parse command-line options.
 """
-import sys, os, textwrap, getopt, re, struct
+import sys
+import os
+import textwrap
+import getopt
+import re
+import struct
+
 
 class OptDict:
+
     def __init__(self):
         self._opts = {}
 
@@ -46,7 +53,8 @@ def _atoi(v):
 def _remove_negative_kv(k, v):
     if k.startswith('no-') or k.startswith('no_'):
         return k[3:], not v
-    return k,v
+    return k, v
+
 
 def _remove_negative_k(k):
     return _remove_negative_kv(k, None)[0]
@@ -55,15 +63,17 @@ def _remove_negative_k(k):
 def _tty_width():
     s = struct.pack("HHHH", 0, 0, 0, 0)
     try:
-        import fcntl, termios
+        import fcntl
+        import termios
         s = fcntl.ioctl(sys.stderr.fileno(), termios.TIOCGWINSZ, s)
     except (IOError, ImportError):
         return _atoi(os.environ.get('WIDTH')) or 70
-    (ysize,xsize,ypix,xpix) = struct.unpack('HHHH', s)
+    (ysize, xsize, ypix, xpix) = struct.unpack('HHHH', s)
-    return xsize
+    return xsize or 70
 
 
 class Options:
+
     """Option parser.
     When constructed, two strings are mandatory. The first one is the command
     name showed before error messages. The second one is a string called an
@@ -76,9 +86,9 @@ class Options:
     By default, the parser function is getopt.gnu_getopt, and the abort
     behaviour is to exit the program.
     """
-    def __init__(self, exe, optspec, optfunc=getopt.gnu_getopt,
+
+    def __init__(self, optspec, optfunc=getopt.gnu_getopt,
                  onabort=_default_onabort):
-        self.exe = exe
         self.optspec = optspec
         self._onabort = onabort
         self.optfunc = optfunc
@@ -96,7 +106,8 @@ class Options:
         first_syn = True
         while lines:
             l = lines.pop()
-            if l == '--': break
+            if l == '--':
+                break
             out.append('%s: %s\n' % (first_syn and 'usage' or '   or', l))
             first_syn = False
         out.append('\n')
@@ -122,8 +133,8 @@ class Options:
                     defval = None
                 flagl = flags.split(',')
                 flagl_nice = []
-                for f in flagl:
+                for _f in flagl:
-                    f,dvi = _remove_negative_kv(f, _intify(defval))
+                    f, dvi = _remove_negative_kv(_f, _intify(defval))
                     self._aliases[f] = _remove_negative_k(flagl[0])
                     self._hasparms[f] = has_parm
                     self._defaults[f] = dvi
@@ -135,14 +146,14 @@ class Options:
                         self._aliases[f_nice] = _remove_negative_k(flagl[0])
                         self._longopts.append(f + (has_parm and '=' or ''))
                         self._longopts.append('no-' + f)
-                        flagl_nice.append('--' + f)
+                        flagl_nice.append('--' + _f)
                 flags_nice = ', '.join(flagl_nice)
                 if has_parm:
                     flags_nice += ' ...'
                 prefix = '    %-20s  ' % flags_nice
                 argtext = '\n'.join(textwrap.wrap(extra, width=_tty_width(),
-                                                initial_indent=prefix,
+                                                  initial_indent=prefix,
-                                                subsequent_indent=' '*28))
+                                                  subsequent_indent=' ' * 28))
                 out.append(argtext + '\n')
                 last_was_option = True
             else:
@@ -171,17 +182,18 @@ class Options:
         and "extra" is a list of positional arguments.
         """
         try:
-            (flags,extra) = self.optfunc(args, self._shortopts, self._longopts)
+            (flags, extra) = self.optfunc(
+                args, self._shortopts, self._longopts)
         except getopt.GetoptError, e:
             self.fatal(e)
 
         opt = OptDict()
 
-        for k,v in self._defaults.iteritems():
+        for k, v in self._defaults.iteritems():
             k = self._aliases[k]
             opt[k] = v
 
-        for (k,v) in flags:
+        for (k, v) in flags:
             k = k.lstrip('-')
             if k in ('h', '?', 'help'):
                 self.usage()
@@ -196,6 +208,6 @@ class Options:
                 else:
                     v = _intify(v)
             opt[k] = v
-        for (f1,f2) in self._aliases.iteritems():
+        for (f1, f2) in self._aliases.iteritems():
             opt[f1] = opt._opts.get(f2)
-        return (opt,flags,extra)
+        return (opt, flags, extra)

src/server.py

@@ -0,0 +1,335 @@
+import re
+import struct
+import socket
+import traceback
+import time
+import sys
+import os
+if not globals().get('skip_imports'):
+    import ssnet
+    import helpers
+    import hostwatch
+    import compat.ssubprocess as ssubprocess
+    from ssnet import Handler, Proxy, Mux, MuxWrapper
+    from helpers import log, debug1, debug2, debug3, Fatal, \
+        resolvconf_random_nameserver
+
+
+if not globals().get('latency_control'):
+    latency_control = None
+
+
+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] 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)
+        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.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):
+        # FIXME! IPv4 specific
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        Handler.__init__(self, [sock])
+        self.timeout = time.time() + 30
+        self.mux = mux
+        self.chan = chan
+        self.tries = 0
+        self.peer = None
+        self.request = request
+        self.sock = sock
+        # FIXME! IPv4 specific
+        self.sock.setsockopt(socket.SOL_IP, socket.IP_TTL, 42)
+        self.try_send()
+
+    def try_send(self):
+        if self.tries >= 3:
+            return
+        self.tries += 1
+        # FIXME! Support IPv6 nameservers
+        self.peer = resolvconf_random_nameserver()[1]
+        self.sock.connect((self.peer, 53))
+        debug2('DNS: sending to %r\n' % self.peer)
+        try:
+            self.sock.send(self.request)
+        except socket.error, e:
+            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' % (self.peer, e))
+                self.try_send()
+                return
+            else:
+                log('DNS send to %r: %s\n' % (self.peer, e))
+                return
+
+    def callback(self):
+        try:
+            data = self.sock.recv(4096)
+        except socket.error, e:
+            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' % (self.peer, e))
+                self.try_send()
+                return
+            else:
+                log('DNS recv from %r: %s\n' % (self.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:
+            log('UDP send to %r port %d: %s\n' % (dstip[0], dstip[1], e))
+            return
+
+    def callback(self):
+        try:
+            data, peer = self.sock.recvfrom(4096)
+        except socket.error, e:
+            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():
+    if helpers.verbose >= 1:
+        helpers.logprefix = ' s: '
+    else:
+        helpers.logprefix = 'server: '
+    assert latency_control is not None
+    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, routepkt)
+
+    hw = Hostwatch()
+    hw.leftover = ''
+
+    def hostwatch_ready():
+        assert(hw.pid)
+        content = hw.sock.recv(4096)
+        if content:
+            lines = (hw.leftover + content).split('\n')
+            if lines[-1]:
+                # no terminating newline: entry isn't complete yet!
+                hw.leftover = lines.pop()
+                lines.append('')
+            else:
+                hw.leftover = ''
+            mux.send(0, ssnet.CMD_HOST_LIST, '\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.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()
+        mux.callback()
+
+        if dnshandlers:
+            now = time.time()
+            for channel, h in dnshandlers.items():
+                if h.timeout < now or not h.ok:
+                    debug3('expiring dnsreqs channel=%d\n' % channel)
+                    del dnshandlers[channel]
+                    h.ok = False
+            for channel, h in udphandlers.items():
+                if not h.ok:
+                    debug3('expiring UDP channel=%d\n' % channel)
+                    del udphandlers[channel]
+                    h.ok = False

src/ssh.py

@@ -1,7 +1,11 @@
-import sys, os, re, socket, zlib
+import sys
+import os
+import re
+import socket
+import zlib
 import compat.ssubprocess as ssubprocess
 import helpers
-from helpers import *
+from helpers import debug2
 
 
 def readfile(name):
@@ -14,20 +18,19 @@ def readfile(name):
     raise Exception("can't find file %r in any of %r" % (name, path))
 
 
-def empackage(z, filename):
+def empackage(z, filename, data=None):
-    (path,basename) = os.path.split(filename)
+    (path, basename) = os.path.split(filename)
-    content = z.compress(readfile(filename))
+    if not data:
+        data = readfile(filename)
+    content = z.compress(data)
     content += z.flush(zlib.Z_SYNC_FLUSH)
-    return '%s\n%d\n%s' % (basename,len(content), content)
+    return '%s\n%d\n%s' % (basename, len(content), content)
 
 
-def connect(ssh_cmd, rhostport, python, stderr):
+def connect(ssh_cmd, rhostport, python, stderr, options):
-    main_exe = sys.argv[0]
     portl = []
 
-    rhostIsIPv6 = False
     if (rhostport or '').count(':') > 1:
-        rhostIsIPv6 = True
         if rhostport.count(']') or rhostport.count('['):
             result = rhostport.split(']')
             rhost = result[0].strip('[')
@@ -35,9 +38,11 @@ def connect(ssh_cmd, rhostport, python, stderr):
                 result[1] = result[1].strip(':')
                 if result[1] is not '':
                     portl = ['-p', str(int(result[1]))]
-        else: # can't disambiguate IPv6 colons and a port number. pass the hostname through.
+        # can't disambiguate IPv6 colons and a port number. pass the hostname
+        # through.
+        else:
             rhost = rhostport
-    else: # IPv4
+    else:  # IPv4
         l = (rhostport or '').split(':', 1)
         rhost = l[0]
         if len(l) > 1:
@@ -46,19 +51,17 @@ def connect(ssh_cmd, rhostport, python, stderr):
     if rhost == '-':
         rhost = None
 
-    ipv6flag = []
-    if rhostIsIPv6:
-        ipv6flag = ['-6']
-
     z = zlib.compressobj(1)
     content = readfile('assembler.py')
-    content2 = (empackage(z, 'helpers.py') +
+    optdata = ''.join("%s=%r\n" % (k, v) for (k, v) in options.items())
+    content2 = (empackage(z, 'cmdline_options.py', optdata) +
+                empackage(z, 'helpers.py') +
                 empackage(z, 'compat/ssubprocess.py') +
                 empackage(z, 'ssnet.py') +
                 empackage(z, 'hostwatch.py') +
                 empackage(z, 'server.py') +
                 "\n")
-    
+
     pyscript = r"""
                 import sys;
                 skip_imports=1;
@@ -67,23 +70,29 @@ def connect(ssh_cmd, rhostport, python, stderr):
                 """ % (helpers.verbose or 0, len(content))
     pyscript = re.sub(r'\s+', ' ', pyscript.strip())
 
-        
     if not rhost:
-        argv = [python, '-c', pyscript]
+        # ignore the --python argument when running locally; we already know
+        # which python version works.
+        argv = [sys.argv[1], '-c', pyscript]
     else:
         if ssh_cmd:
             sshl = ssh_cmd.split(' ')
         else:
             sshl = ['ssh']
-        argv = (sshl + 
+        if python:
-                portl + 
+            pycmd = "'%s' -c '%s'" % (python, pyscript)
-                ipv6flag + 
+        else:
-                [rhost, '--', "'%s' -c '%s'" % (python, pyscript)])
+            pycmd = ("P=python2; $P -V 2>/dev/null || P=python; "
-    (s1,s2) = socket.socketpair()
+                     "exec \"$P\" -c '%s'") % pyscript
+        argv = (sshl +
+                portl +
+                [rhost, '--', pycmd])
+    (s1, s2) = socket.socketpair()
+
     def setup():
         # runs in the child process
         s2.close()
-    s1a,s1b = os.dup(s1.fileno()), os.dup(s1.fileno())
+    s1a, s1b = os.dup(s1.fileno()), os.dup(s1.fileno())
     s1.close()
     debug2('executing: %r\n' % argv)
     p = ssubprocess.Popen(argv, stdin=s1a, stdout=s1b, preexec_fn=setup,

src/sshuttle

@@ -0,0 +1,12 @@
+#!/bin/sh
+EXE=$0
+for i in 1 2 3 4 5 6 7 8 9 10; do
+	[ -L "$EXE" ] || break
+	EXE=$(readlink "$EXE")
+done
+DIR=$(dirname "$EXE")
+if python2 -V 2>/dev/null; then
+	exec python2 "$DIR/main.py" python2 "$@"
+else
+	exec python "$DIR/main.py" python "$@"
+fi

src/sshuttle.md

@@ -1,6 +1,6 @@
-% sshuttle(8) Sshuttle 0.44
+% sshuttle(8) Sshuttle 0.46
 % Avery Pennarun <apenwarr@gmail.com>
-% 2010-12-31
+% 2011-01-25
 
 # NAME
 
@@ -47,7 +47,7 @@ entire subnet to the VPN.
     not from outside machines.  If you want to accept
     connections from other machines on your network (ie. to
     run sshuttle on a router) try enabling IP Forwarding in
-    your kernel, then using `--listen 0.0.0.0:0`. 
+    your kernel, then using `--listen 0.0.0.0:0`.
 
 -H, --auto-hosts
 :   scan for remote hostnames and update the local /etc/hosts
@@ -63,22 +63,26 @@ entire subnet to the VPN.
     all running copies.  Third, if you're only routing a
     few subnets over the VPN, you probably would prefer to
     keep using your local DNS server for everything else.
-    
+
 -N, --auto-nets
 :   in addition to the subnets provided on the command
     line, ask the server which subnets it thinks we should
     route, and route those automatically.  The suggestions
     are taken automatically from the server's routing
     table.
-    
+
+--dns
+:   capture local DNS requests and forward to the remote DNS
+    server.
+
 --python
-:   specify the name/path of the remote python interpreter. 
+:   specify the name/path of the remote python interpreter.
     The default is just `python`, which means to use the
     default python interpreter on the remote system's PATH.
 
 -r, --remote=*[username@]sshserver[:port]*
 :   the remote hostname and optional username and ssh
-    port number to use for connecting to the remote server. 
+    port number to use for connecting to the remote server.
     For example, example.com, testuser@example.com,
     testuser@example.com:2222, or example.com:2244.
 
@@ -90,11 +94,15 @@ entire subnet to the VPN.
     `0/0 -x 1.2.3.0/24` to forward everything except the
     local subnet over the VPN, for example.
 
+-X, --exclude-from=*file*
+:   exclude the subnets specified in a file, one subnet per
+    line. Useful when you have lots of subnets to exclude.
+
 -v, --verbose
 :   print more information about the session.  This option
     can be used more than once for increased verbosity.  By
     default, sshuttle prints only error messages.
-    
+
 -e, --ssh-cmd
 :   the command to use to connect to the remote server. The
     default is just `ssh`.  Use this if your ssh client is
@@ -103,21 +111,37 @@ entire subnet to the VPN.
 
 --seed-hosts
 :   a comma-separated list of hostnames to use to
-    initialize the `--auto-hosts` scan algorithm. 
+    initialize the `--auto-hosts` scan algorithm.
     `--auto-hosts` does things like poll local SMB servers
     for lists of local hostnames, but can speed things up
     if you use this option to give it a few names to start
     from.
-    
+
+--no-latency-control
+:   sacrifice latency to improve bandwidth benchmarks. ssh
+    uses really big socket buffers, which can overload the
+    connection if you start doing large file transfers,
+    thus making all your other sessions inside the same
+    tunnel go slowly. Normally, sshuttle tries to avoid
+    this problem using a "fullness check" that allows only
+    a certain amount of outstanding data to be buffered at
+    a time.  But on high-bandwidth links, this can leave a
+    lot of your bandwidth underutilized.  It also makes
+    sshuttle seem slow in bandwidth benchmarks (benchmarks
+    rarely test ping latency, which is what sshuttle is
+    trying to control).  This option disables the latency
+    control feature, maximizing bandwidth usage.  Use at
+    your own risk.
+
 -D, --daemon
 :   automatically fork into the background after connecting
     to the remote server.  Implies `--syslog`.
-    
+
 --syslog
 :   after connecting, send all log messages to the
     `syslog`(3) service instead of stderr.  This is
     implicit if you use `--daemon`.
-    
+
 --pidfile=*pidfilename*
 :   when using `--daemon`, save sshuttle's pid to
     *pidfilename*.  The default is `sshuttle.pid` in the
@@ -135,7 +159,7 @@ entire subnet to the VPN.
     automatically run `sudo` or `su` to start the firewall
     manager, but the core of sshuttle still runs as a
     normal user.
-    
+
 --hostwatch
 :   (internal use only) run the hostwatch daemon.  This
     process runs on the server side and collects hostnames for
@@ -152,7 +176,7 @@ Test locally by proxying all local connections, without using ssh:
 
     Starting sshuttle proxy.
     Listening on ('0.0.0.0', 12300).
-    [local sudo] Password: 
+    [local sudo] Password:
     firewall manager ready.
     c : connecting to server...
      s: available routes:
@@ -206,7 +230,7 @@ there.  Thus, you don't need to install sshuttle on the
 remote server, and there are never sshuttle version
 conflicts between client and server.
 
-Unlike most VPNs, sshuttle forwards sessions, not packets. 
+Unlike most VPNs, sshuttle forwards sessions, not packets.
 That is, it uses kernel transparent proxying (`iptables
 REDIRECT` rules on Linux, or `ipfw fwd` rules on BSD) to
 capture outgoing TCP sessions, then creates entirely
@@ -237,7 +261,24 @@ between the two separate streams, so a tcp-based tunnel is
 fine.
 
 
+# BUGS
+
+On MacOS 10.6 (at least up to 10.6.6), your network will
+stop responding about 10 minutes after the first time you
+start sshuttle, because of a MacOS kernel bug relating to
+arp and the net.inet.ip.scopedroute sysctl.  To fix it,
+just switch your wireless off and on. Sshuttle makes the
+kernel setting it changes permanent, so this won't happen
+again, even after a reboot.
+
+On MacOS, sshuttle will set the kernel boot flag
+net.inet.ip.scopedroute to 0, which interferes with OS X
+Internet Sharing and some VPN clients. To reset this flag,
+you can remove any reference to net.inet.ip.scopedroute from
+/Library/Preferences/SystemConfiguration/com.apple.Boot.plist
+and reboot.
+
+
 # SEE ALSO
 
 `ssh`(1), `python`(1)
-

src/ssnet.py

@@ -1,7 +1,13 @@
-import struct, socket, errno, select
+import struct
+import socket
+import errno
+import select
+import os
 if not globals().get('skip_imports'):
-    from helpers import *
+    from helpers import log, debug1, debug2, debug3, Fatal
-    
+
+MAX_CHANNEL = 65535
+
 # these don't exist in the socket module in python 2.3!
 SHUT_RD = 0
 SHUT_WR = 1
@@ -14,27 +20,41 @@ HDR_LEN = 8
 CMD_EXIT = 0x4200
 CMD_PING = 0x4201
 CMD_PONG = 0x4202
-CMD_CONNECT = 0x4203
+CMD_TCP_CONNECT = 0x4203
-CMD_STOP_SENDING = 0x4204
+CMD_TCP_STOP_SENDING = 0x4204
-CMD_EOF = 0x4205
+CMD_TCP_EOF = 0x4205
-CMD_DATA = 0x4206
+CMD_TCP_DATA = 0x4206
 CMD_ROUTES = 0x4207
 CMD_HOST_REQ = 0x4208
 CMD_HOST_LIST = 0x4209
+CMD_DNS_REQ = 0x420a
+CMD_DNS_RESPONSE = 0x420b
+CMD_UDP_OPEN = 0x420c
+CMD_UDP_DATA = 0x420d
+CMD_UDP_CLOSE = 0x420e
 
 cmd_to_name = {
     CMD_EXIT: 'EXIT',
     CMD_PING: 'PING',
     CMD_PONG: 'PONG',
-    CMD_CONNECT: 'CONNECT',
+    CMD_TCP_CONNECT: 'TCP_CONNECT',
-    CMD_STOP_SENDING: 'STOP_SENDING',
+    CMD_TCP_STOP_SENDING: 'TCP_STOP_SENDING',
-    CMD_EOF: 'EOF',
+    CMD_TCP_EOF: 'TCP_EOF',
-    CMD_DATA: 'DATA',
+    CMD_TCP_DATA: 'TCP_DATA',
     CMD_ROUTES: 'ROUTES',
     CMD_HOST_REQ: 'HOST_REQ',
     CMD_HOST_LIST: 'HOST_LIST',
+    CMD_DNS_REQ: 'DNS_REQ',
+    CMD_DNS_RESPONSE: 'DNS_RESPONSE',
+    CMD_UDP_OPEN: 'UDP_OPEN',
+    CMD_UDP_DATA: 'UDP_DATA',
+    CMD_UDP_CLOSE: 'UDP_CLOSE',
 }
-    
+
+
+NET_ERRS = [errno.ECONNREFUSED, errno.ETIMEDOUT,
+            errno.EHOSTUNREACH, errno.ENETUNREACH,
+            errno.EHOSTDOWN, errno.ENETDOWN]
 
 
 def _add(l, elem):
@@ -76,11 +96,14 @@ def _try_peername(sock):
 
 
 _swcount = 0
+
+
 class SockWrapper:
+
     def __init__(self, rsock, wsock, connect_to=None, peername=None):
         global _swcount
         _swcount += 1
-        debug3('creating new SockWrapper (%d now exist\n)' % _swcount)
+        debug3('creating new SockWrapper (%d now exist)\n' % _swcount)
         self.exc = None
         self.rsock = rsock
         self.wsock = wsock
@@ -95,7 +118,7 @@ class SockWrapper:
         _swcount -= 1
         debug1('%r: deleting (%d remain)\n' % (self, _swcount))
         if self.exc:
-            debug1('%r: error was: %r\n' % (self, self.exc))
+            debug1('%r: error was: %s\n' % (self, self.exc))
 
     def __repr__(self):
         if self.rsock == self.wsock:
@@ -123,15 +146,34 @@ class SockWrapper:
             # connected successfully (Linux)
             self.connect_to = None
         except socket.error, e:
-            debug3('%r: connect result: %r\n' % (self, e))
+            debug3('%r: connect result: %s\n' % (self, e))
+            if e.args[0] == errno.EINVAL:
+                # this is what happens when you call connect() on a socket
+                # that is now connected but returned EINPROGRESS last time,
+                # on BSD, on python pre-2.5.1.  We need to use getsockopt()
+                # to get the "real" error.  Later pythons do this
+                # automatically, so this code won't run.
+                realerr = self.rsock.getsockopt(socket.SOL_SOCKET,
+                                                socket.SO_ERROR)
+                e = socket.error(realerr, os.strerror(realerr))
+                debug3('%r: fixed connect result: %s\n' % (self, e))
             if e.args[0] in [errno.EINPROGRESS, errno.EALREADY]:
                 pass  # not connected yet
+            elif e.args[0] == 0:
+                # connected successfully (weird Linux bug?)
+                # Sometimes Linux seems to return EINVAL when it isn't
+                # invalid.  This *may* be caused by a race condition
+                # between connect() and getsockopt(SO_ERROR) (ie. it
+                # finishes connecting in between the two, so there is no
+                # longer an error).  However, I'm not sure of that.
+                #
+                # I did get at least one report that the problem went away
+                # when we added this, however.
+                self.connect_to = None
             elif e.args[0] == errno.EISCONN:
                 # connected successfully (BSD)
                 self.connect_to = None
-            elif e.args[0] in [errno.ECONNREFUSED, errno.ETIMEDOUT,
+            elif e.args[0] in NET_ERRS + [errno.EACCES, errno.EPERM]:
-                               errno.EHOSTUNREACH, errno.ENETUNREACH,
-                               errno.EACCES, errno.EPERM]:
                 # a "normal" kind of error
                 self.connect_to = None
                 self.seterr(e)
@@ -142,8 +184,8 @@ class SockWrapper:
         if not self.shut_read:
             debug2('%r: done reading\n' % self)
             self.shut_read = True
-            #self.rsock.shutdown(SHUT_RD)  # doesn't do anything anyway
+            # self.rsock.shutdown(SHUT_RD)  # doesn't do anything anyway
-        
+
     def nowrite(self):
         if not self.shut_write:
             debug2('%r: done writing\n' % self)
@@ -171,7 +213,7 @@ class SockWrapper:
                 # unexpected error... stream is dead
                 self.seterr('uwrite: %s' % e)
                 return 0
-        
+
     def write(self, buf):
         assert(buf)
         return self.uwrite(buf)
@@ -186,7 +228,7 @@ class SockWrapper:
             return _nb_clean(os.read, self.rsock.fileno(), 65536)
         except OSError, e:
             self.seterr('uread: %s' % e)
-            return '' # unexpected error... we'll call it EOF
+            return ''  # unexpected error... we'll call it EOF
 
     def fill(self):
         if self.buf:
@@ -208,7 +250,8 @@ class SockWrapper:
 
 
 class Handler:
-    def __init__(self, socks = None, callback = None):
+
+    def __init__(self, socks=None, callback=None):
         self.ok = True
         self.socks = socks or []
         if callback:
@@ -220,7 +263,7 @@ class Handler:
 
     def callback(self):
         log('--no callback defined-- %r\n' % self)
-        (r,w,x) = select.select(self.socks, [], [], 0)
+        (r, w, x) = select.select(self.socks, [], [], 0)
         for s in r:
             v = s.recv(4096)
             if not v:
@@ -230,6 +273,7 @@ class Handler:
 
 
 class Proxy(Handler):
+
     def __init__(self, wrap1, wrap2):
         Handler.__init__(self, [wrap1.rsock, wrap1.wsock,
                                 wrap2.rsock, wrap2.wsock])
@@ -237,9 +281,11 @@ class Proxy(Handler):
         self.wrap2 = wrap2
 
     def pre_select(self, r, w, x):
-        if self.wrap1.shut_write: self.wrap2.noread()
+        if self.wrap1.shut_write:
-        if self.wrap2.shut_write: self.wrap1.noread()
+            self.wrap2.noread()
-        
+        if self.wrap2.shut_write:
+            self.wrap1.noread()
+
         if self.wrap1.connect_to:
             _add(w, self.wrap1.rsock)
         elif self.wrap1.buf:
@@ -270,18 +316,20 @@ class Proxy(Handler):
             self.wrap2.buf = []
             self.wrap2.noread()
         if (self.wrap1.shut_read and self.wrap2.shut_read and
-            not self.wrap1.buf and not self.wrap2.buf):
+                not self.wrap1.buf and not self.wrap2.buf):
             self.ok = False
             self.wrap1.nowrite()
             self.wrap2.nowrite()
 
 
 class Mux(Handler):
+
     def __init__(self, rsock, wsock):
         Handler.__init__(self, [rsock, wsock])
         self.rsock = rsock
         self.wsock = wsock
-        self.new_channel = self.got_routes = None
+        self.new_channel = self.got_dns_req = self.got_routes = None
+        self.got_udp_open = self.got_udp_data = self.got_udp_close = None
         self.got_host_req = self.got_host_list = None
         self.channels = {}
         self.chani = 0
@@ -296,7 +344,7 @@ class Mux(Handler):
         # channel 0 is special, so we never allocate it
         for timeout in xrange(1024):
             self.chani += 1
-            if self.chani > 65535:
+            if self.chani > MAX_CHANNEL:
                 self.chani = 1
             if not self.channels.get(self.chani):
                 return self.chani
@@ -306,31 +354,31 @@ class Mux(Handler):
         for b in self.outbuf:
             total += len(b)
         return total
-            
+
     def check_fullness(self):
         if self.fullness > 32768:
             if not self.too_full:
                 self.send(0, CMD_PING, 'rttest')
             self.too_full = True
         #ob = []
-        #for b in self.outbuf:
+        # for b in self.outbuf:
         #    (s1,s2,c) = struct.unpack('!ccH', b[:4])
         #    ob.append(c)
         #log('outbuf: %d %r\n' % (self.amount_queued(), ob))
-        
+
     def send(self, channel, cmd, data):
         data = str(data)
         assert(len(data) <= 65535)
         p = struct.pack('!ccHHH', 'S', 'S', channel, cmd, len(data)) + data
         self.outbuf.append(p)
         debug2(' > channel=%d cmd=%s len=%d (fullness=%d)\n'
-               % (channel, cmd_to_name.get(cmd,hex(cmd)),
+               % (channel, cmd_to_name.get(cmd, hex(cmd)),
                   len(data), self.fullness))
         self.fullness += len(data)
 
     def got_packet(self, channel, cmd, data):
-        debug2('<  channel=%d cmd=%s len=%d\n' 
+        debug2('<  channel=%d cmd=%s len=%d\n'
-               % (channel, cmd_to_name.get(cmd,hex(cmd)), len(data)))
+               % (channel, cmd_to_name.get(cmd, hex(cmd)), len(data)))
         if cmd == CMD_PING:
             self.send(0, CMD_PONG, data)
         elif cmd == CMD_PONG:
@@ -339,10 +387,18 @@ class Mux(Handler):
             self.fullness = 0
         elif cmd == CMD_EXIT:
             self.ok = False
-        elif cmd == CMD_CONNECT:
+        elif cmd == CMD_TCP_CONNECT:
             assert(not self.channels.get(channel))
             if self.new_channel:
                 self.new_channel(channel, data)
+        elif cmd == CMD_DNS_REQ:
+            assert(not self.channels.get(channel))
+            if self.got_dns_req:
+                self.got_dns_req(channel, data)
+        elif cmd == CMD_UDP_OPEN:
+            assert(not self.channels.get(channel))
+            if self.got_udp_open:
+                self.got_udp_open(channel, data)
         elif cmd == CMD_ROUTES:
             if self.got_routes:
                 self.got_routes(data)
@@ -361,8 +417,8 @@ class Mux(Handler):
         else:
             callback = self.channels.get(channel)
             if not callback:
-                log('warning: closed channel %d got cmd=%s len=%d\n' 
+                log('warning: closed channel %d got cmd=%s len=%d\n'
-                       % (channel, cmd_to_name.get(cmd,hex(cmd)), len(data)))
+                    % (channel, cmd_to_name.get(cmd, hex(cmd)), len(data)))
             else:
                 callback(cmd, data)
 
@@ -383,18 +439,18 @@ class Mux(Handler):
         except OSError, e:
             raise Fatal('other end: %r' % e)
         #log('<<< %r\n' % b)
-        if b == '': # EOF
+        if b == '':  # EOF
             self.ok = False
         if b:
             self.inbuf += b
 
     def handle(self):
         self.fill()
-        #log('inbuf is: (%d,%d) %r\n'
+        # log('inbuf is: (%d,%d) %r\n'
         #     % (self.want, len(self.inbuf), self.inbuf))
         while 1:
             if len(self.inbuf) >= (self.want or HDR_LEN):
-                (s1,s2,channel,cmd,datalen) = \
+                (s1, s2, channel, cmd, datalen) = \
                     struct.unpack('!ccHHH', self.inbuf[:HDR_LEN])
                 assert(s1 == 'S')
                 assert(s2 == 'S')
@@ -413,7 +469,7 @@ class Mux(Handler):
             _add(w, self.wsock)
 
     def callback(self):
-        (r,w,x) = select.select([self.rsock], [self.wsock], [], 0)
+        (r, w, x) = select.select([self.rsock], [self.wsock], [], 0)
         if self.rsock in r:
             self.handle()
         if self.outbuf and self.wsock in w:
@@ -421,6 +477,7 @@ class Mux(Handler):
 
 
 class MuxWrapper(SockWrapper):
+
     def __init__(self, mux, channel):
         SockWrapper.__init__(self, mux.rsock, mux.wsock)
         self.mux = mux
@@ -434,18 +491,18 @@ class MuxWrapper(SockWrapper):
         SockWrapper.__del__(self)
 
     def __repr__(self):
-        return 'SW%r:Mux#%d' % (self.peername,self.channel)
+        return 'SW%r:Mux#%d' % (self.peername, self.channel)
 
     def noread(self):
         if not self.shut_read:
             self.shut_read = True
-            self.mux.send(self.channel, CMD_STOP_SENDING, '')
+            self.mux.send(self.channel, CMD_TCP_STOP_SENDING, '')
             self.maybe_close()
 
     def nowrite(self):
         if not self.shut_write:
             self.shut_write = True
-            self.mux.send(self.channel, CMD_EOF, '')
+            self.mux.send(self.channel, CMD_TCP_EOF, '')
             self.maybe_close()
 
     def maybe_close(self):
@@ -462,34 +519,34 @@ class MuxWrapper(SockWrapper):
             return 0  # too much already enqueued
         if len(buf) > 2048:
             buf = buf[:2048]
-        self.mux.send(self.channel, CMD_DATA, buf)
+        self.mux.send(self.channel, CMD_TCP_DATA, buf)
         return len(buf)
 
     def uread(self):
         if self.shut_read:
-            return '' # EOF
+            return ''  # EOF
         else:
             return None  # no data available right now
 
     def got_packet(self, cmd, data):
-        if cmd == CMD_EOF:
+        if cmd == CMD_TCP_EOF:
             self.noread()
-        elif cmd == CMD_STOP_SENDING:
+        elif cmd == CMD_TCP_STOP_SENDING:
             self.nowrite()
-        elif cmd == CMD_DATA:
+        elif cmd == CMD_TCP_DATA:
             self.buf.append(data)
         else:
-            raise Exception('unknown command %d (%d bytes)' 
+            raise Exception('unknown command %d (%d bytes)'
                             % (cmd, len(data)))
 
 
-def connect_dst(ip, port):
+def connect_dst(family, ip, port):
     debug2('Connecting to %s:%d\n' % (ip, port))
-    outsock = socket.socket()
+    outsock = socket.socket(family)
     outsock.setsockopt(socket.SOL_IP, socket.IP_TTL, 42)
     return SockWrapper(outsock, outsock,
-                       connect_to = (ip,port),
+                       connect_to=(ip, port),
-                       peername = '%s:%d' % (ip,port))
+                       peername = '%s:%d' % (ip, port))
 
 
 def runonce(handlers, mux):
@@ -501,14 +558,14 @@ def runonce(handlers, mux):
         handlers.remove(h)
 
     for s in handlers:
-        s.pre_select(r,w,x)
+        s.pre_select(r, w, x)
-    debug2('Waiting: %d r=%r w=%r x=%r (fullness=%d/%d)\n' 
+    debug2('Waiting: %d r=%r w=%r x=%r (fullness=%d/%d)\n'
-            % (len(handlers), _fds(r), _fds(w), _fds(x),
+           % (len(handlers), _fds(r), _fds(w), _fds(x),
                mux.fullness, mux.too_full))
-    (r,w,x) = select.select(r,w,x)
+    (r, w, x) = select.select(r, w, x)
-    debug2('  Ready: %d r=%r w=%r x=%r\n' 
+    debug2('  Ready: %d r=%r w=%r x=%r\n'
-        % (len(handlers), _fds(r), _fds(w), _fds(x)))
+           % (len(handlers), _fds(r), _fds(w), _fds(x)))
-    ready = r+w+x
+    ready = r + w + x
     did = {}
     for h in handlers:
         for s in h.socks:

src/ssyslog.py

@@ -1,8 +1,11 @@
-import sys, os
+import sys
+import os
 from compat import ssubprocess
 
 
 _p = None
+
+
 def start_syslog():
     global _p
     _p = ssubprocess.Popen(['logger',

src/stresstest.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env python
+import socket
+import select
+import struct
+import time
+
+listener = socket.socket()
+listener.bind(('127.0.0.1', 0))
+listener.listen(500)
+
+servers = []
+clients = []
+remain = {}
+
+NUMCLIENTS = 50
+count = 0
+
+
+while 1:
+    if len(clients) < NUMCLIENTS:
+        c = socket.socket()
+        c.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        c.bind(('0.0.0.0', 0))
+        c.connect(listener.getsockname())
+        count += 1
+        if count >= 16384:
+            count = 1
+        print 'cli CREATING %d' % count
+        b = struct.pack('I', count) + 'x' * count
+        remain[c] = count
+        print 'cli  >> %r' % len(b)
+        c.send(b)
+        c.shutdown(socket.SHUT_WR)
+        clients.append(c)
+        r = [listener]
+        time.sleep(0.1)
+    else:
+        r = [listener] + servers + clients
+    print 'select(%d)' % len(r)
+    r, w, x = select.select(r, [], [], 5)
+    assert(r)
+    for i in r:
+        if i == listener:
+            s, addr = listener.accept()
+            servers.append(s)
+        elif i in servers:
+            b = i.recv(4096)
+            print 'srv <<  %r' % len(b)
+            if not i in remain:
+                assert(len(b) >= 4)
+                want = struct.unpack('I', b[:4])[0]
+                b = b[4:]
+                # i.send('y'*want)
+            else:
+                want = remain[i]
+            if want < len(b):
+                print 'weird wanted %d bytes, got %d: %r' % (want, len(b), b)
+                assert(want >= len(b))
+            want -= len(b)
+            remain[i] = want
+            if not b:  # EOF
+                if want:
+                    print 'weird: eof but wanted %d more' % want
+                    assert(want == 0)
+                i.close()
+                servers.remove(i)
+                del remain[i]
+            else:
+                print 'srv  >> %r' % len(b)
+                i.send('y' * len(b))
+                if not want:
+                    i.shutdown(socket.SHUT_WR)
+        elif i in clients:
+            b = i.recv(4096)
+            print 'cli <<  %r' % len(b)
+            want = remain[i]
+            if want < len(b):
+                print 'weird wanted %d bytes, got %d: %r' % (want, len(b), b)
+                assert(want >= len(b))
+            want -= len(b)
+            remain[i] = want
+            if not b:  # EOF
+                if want:
+                    print 'weird: eof but wanted %d more' % want
+                    assert(want == 0)
+                i.close()
+                clients.remove(i)
+                del remain[i]
+listener.accept()

src/ui-macos/.gitignore

@@ -0,0 +1,8 @@
+*.pyc
+*~
+/*.nib
+/debug.app
+/sources.list
+/Sshuttle VPN.app
+/*.tar.gz
+/*.zip

src/ui-macos/Info.plist

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>English</string>
+	<key>CFBundleDisplayName</key>
+	<string>Sshuttle VPN</string>
+	<key>CFBundleExecutable</key>
+	<string>Sshuttle</string>
+	<key>CFBundleIconFile</key>
+	<string>app.icns</string>
+	<key>CFBundleIdentifier</key>
+	<string>ca.apenwarr.Sshuttle</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>Sshuttle VPN</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>0.0.0</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>0.0.0</string>
+	<key>LSUIElement</key>
+	<string>1</string>
+	<key>LSHasLocalizedDisplayName</key>
+	<false/>
+	<key>NSAppleScriptEnabled</key>
+	<false/>
+	<key>NSHumanReadableCopyright</key>
+	<string>GNU LGPL Version 2</string>
+	<key>NSMainNibFile</key>
+	<string>MainMenu</string>
+	<key>NSPrincipalClass</key>
+	<string>NSApplication</string>
+</dict>
+</plist>

src/ui-macos/UserDefaults.plist

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>startAtLogin</key>
+	<false/>
+	<key>autoReconnect</key>
+	<true/>
+</dict>
+</plist>

src/ui-macos/all.do

@@ -0,0 +1 @@
+redo-ifchange debug.app dist

src/ui-macos/askpass.py

@@ -0,0 +1,30 @@
+import re
+import subprocess
+
+
+def askpass(prompt):
+    prompt = prompt.replace('"', "'")
+
+    if 'yes/no' in prompt:
+        return "yes"
+
+    script = """
+        tell application "Finder"
+            activate
+            display dialog "%s" \
+              with title "Sshuttle SSH Connection" \
+              default answer "" \
+              with icon caution \
+              with hidden answer
+        end tell
+    """ % prompt
+
+    p = subprocess.Popen(['osascript', '-e', script], stdout=subprocess.PIPE)
+    out = p.stdout.read()
+    rv = p.wait()
+    if rv:
+        return None
+    g = re.match("text returned:(.*), button returned:.*", out)
+    if not g:
+        return None
+    return g.group(1)

src/ui-macos/bits/.gitignore

@@ -0,0 +1 @@
+/runpython

src/ui-macos/bits/PkgInfo

@@ -0,0 +1 @@
+APPL????

src/ui-macos/bits/runpython.c

@@ -0,0 +1,23 @@
+/*
+ * This rather pointless program acts like the python interpreter, except
+ * it's intended to sit inside a MacOS .app package, so that its argv[0]
+ * will point inside the package.
+ *
+ * NSApplicationMain() looks for Info.plist using the path in argv[0], which
+ * goes wrong if your interpreter is /usr/bin/python.
+ */
+#include <Python/Python.h>
+#include <string.h>
+#include <unistd.h>
+
+int main(int argc, char **argv)
+{
+    char *path = strdup(argv[0]), *cptr;
+    char *args[] = {argv[0], "../Resources/main.py", NULL};
+    cptr = strrchr(path, '/');
+    if (cptr)
+	*cptr = 0;
+    chdir(path);
+    free(path);
+    return Py_Main(2, args);
+}

src/ui-macos/bits/runpython.do

@@ -0,0 +1,20 @@
+exec >&2
+redo-ifchange runpython.c
+ARCHES=""
+printf "Platforms: "
+if [ -d /usr/libexec/gcc/darwin ]; then
+    for d in /usr/libexec/gcc/darwin/*; do
+        PLAT=$(basename "$d")
+        [ "$PLAT" != "ppc64" ] || continue  # fails for some reason on my Mac
+        ARCHES="$ARCHES -arch $PLAT"
+        printf "$PLAT "
+    done
+fi
+printf "\n"
+PYTHON_LDFLAGS=$(python-config --ldflags)
+PYTHON_INCLUDES=$(python-config --includes)
+gcc $ARCHES \
+    -Wall -o $3 runpython.c \
+    $PYTHON_INCLUDES \
+    $PYTHON_LDFLAGS \
+    -framework Python

src/ui-macos/clean.do

@@ -0,0 +1,4 @@
+exec >&2
+find . -name '*~' | xargs rm -f
+rm -rf *.app *.zip *.tar.gz
+rm -f bits/runpython *.nib sources.list

src/ui-macos/debug.app.do

@@ -0,0 +1,15 @@
+redo-ifchange bits/runpython MainMenu.nib
+rm -rf debug.app
+mkdir debug.app debug.app/Contents
+cd debug.app/Contents
+ln -s ../.. Resources
+ln -s ../.. English.lproj
+ln -s ../../Info.plist .
+ln -s ../../app.icns .
+
+mkdir MacOS
+cd MacOS
+ln -s ../../../bits/runpython Sshuttle
+
+cd ../../..
+redo-ifchange $(find debug.app -type f)

src/ui-macos/default.app.do

@@ -0,0 +1,28 @@
+TOP=$PWD
+redo-ifchange sources.list
+redo-ifchange Info.plist bits/runpython \
+	$(while read name newname; do echo "$name"; done <sources.list)
+
+rm -rf "$2.app"
+mkdir "$2.app" "$2.app/Contents"
+cd "$2.app/Contents"
+
+cp "$TOP/Info.plist" .
+
+mkdir MacOS
+cp "$TOP/bits/runpython" MacOS/Sshuttle
+
+mkdir Resources
+
+cd "$TOP"
+while read name newname; do
+	[ -z "$name" ] && continue
+	: "${newname:=$name}"
+	outname=$2.app/Contents/Resources/$newname
+	outdir=$(dirname "$outname")
+	[ -d "$outdir" ] || mkdir "$outdir"
+	cp "${name-$newname}" "$outname"
+done <sources.list
+
+cd "$2.app"
+redo-ifchange $(find . -type f)

src/ui-macos/default.app.tar.gz.do

@@ -0,0 +1,5 @@
+exec >&2
+IFS="
+"
+redo-ifchange $2.app
+tar -czf $3 $2.app/

src/ui-macos/default.app.zip.do

@@ -0,0 +1,5 @@
+exec >&2
+IFS="
+"
+redo-ifchange $2.app
+zip -q -r $3 $2.app/

src/ui-macos/default.nib.do

@@ -0,0 +1,2 @@
+redo-ifchange $2.xib
+ibtool --compile $3 $2.xib

src/ui-macos/dist.do

@@ -0,0 +1 @@
+redo-ifchange "Sshuttle VPN.app.zip" "Sshuttle VPN.app.tar.gz"

src/ui-macos/git-export.do

@@ -0,0 +1,19 @@
+# update a local branch with pregenerated output files, so people can download
+# the completed tarballs from github.  Since we don't have any real binaries,
+# our final distribution package contains mostly blobs from the source code,
+# so this doesn't cost us much extra space in the repo.
+BRANCH=dist/macos
+redo-ifchange 'Sshuttle VPN.app'
+git update-ref refs/heads/$BRANCH origin/$BRANCH '' 2>/dev/null || true
+
+export GIT_INDEX_FILE=$PWD/gitindex.tmp
+rm -f "$GIT_INDEX_FILE"
+git add -f 'Sshuttle VPN.app'
+
+MSG="MacOS precompiled app package for $(git describe)"
+TREE=$(git write-tree --prefix=ui-macos)
+git show-ref refs/heads/$BRANCH >/dev/null && PARENT="-p refs/heads/$BRANCH"
+COMMITID=$(echo "$MSG" | git commit-tree $TREE $PARENT)
+
+git update-ref refs/heads/$BRANCH $COMMITID
+rm -f "$GIT_INDEX_FILE"

src/ui-macos/main.py

@@ -0,0 +1,387 @@
+import sys
+import os
+import pty
+from AppKit import *
+import my
+import models
+import askpass
+
+
+def sshuttle_args(host, auto_nets, auto_hosts, dns, nets, debug,
+                  no_latency_control):
+    argv = [my.bundle_path('sshuttle/sshuttle', ''), '-r', host]
+    assert(argv[0])
+    if debug:
+        argv.append('-v')
+    if auto_nets:
+        argv.append('--auto-nets')
+    if auto_hosts:
+        argv.append('--auto-hosts')
+    if dns:
+        argv.append('--dns')
+    if no_latency_control:
+        argv.append('--no-latency-control')
+    argv += nets
+    return argv
+
+
+class _Callback(NSObject):
+
+    def initWithFunc_(self, func):
+        self = super(_Callback, self).init()
+        self.func = func
+        return self
+
+    def func_(self, obj):
+        return self.func(obj)
+
+
+class Callback:
+
+    def __init__(self, func):
+        self.obj = _Callback.alloc().initWithFunc_(func)
+        self.sel = self.obj.func_
+
+
+class Runner:
+
+    def __init__(self, argv, logfunc, promptfunc, serverobj):
+        print 'in __init__'
+        self.id = argv
+        self.rv = None
+        self.pid = None
+        self.fd = None
+        self.logfunc = logfunc
+        self.promptfunc = promptfunc
+        self.serverobj = serverobj
+        self.buf = ''
+        self.logfunc('\nConnecting to %s.\n' % self.serverobj.host())
+        print 'will run: %r' % argv
+        self.serverobj.setConnected_(False)
+        pid, fd = pty.fork()
+        if pid == 0:
+            # child
+            try:
+                os.execvp(argv[0], argv)
+            except Exception, e:
+                sys.stderr.write('failed to start: %r\n' % e)
+                raise
+            finally:
+                os._exit(42)
+        # parent
+        self.pid = pid
+        self.file = NSFileHandle.alloc()\
+            .initWithFileDescriptor_closeOnDealloc_(fd, True)
+        self.cb = Callback(self.gotdata)
+        NSNotificationCenter.defaultCenter()\
+            .addObserver_selector_name_object_(
+                self.cb.obj, self.cb.sel,
+                NSFileHandleDataAvailableNotification, self.file)
+        self.file.waitForDataInBackgroundAndNotify()
+
+    def __del__(self):
+        self.wait()
+
+    def _try_wait(self, options):
+        if self.rv is None and self.pid > 0:
+            pid, code = os.waitpid(self.pid, options)
+            if pid == self.pid:
+                if os.WIFEXITED(code):
+                    self.rv = os.WEXITSTATUS(code)
+                else:
+                    self.rv = -os.WSTOPSIG(code)
+                self.serverobj.setConnected_(False)
+                self.serverobj.setError_('VPN process died')
+                self.logfunc('Disconnected.\n')
+        print 'wait_result: %r' % self.rv
+        return self.rv
+
+    def wait(self):
+        rv = None
+        while rv is None:
+            self.gotdata(None)
+            rv = self._try_wait(os.WNOHANG)
+
+    def poll(self):
+        return self._try_wait(os.WNOHANG)
+
+    def kill(self):
+        assert(self.pid > 0)
+        print 'killing: pid=%r rv=%r' % (self.pid, self.rv)
+        if self.rv is None:
+            self.logfunc('Disconnecting from %s.\n' % self.serverobj.host())
+            os.kill(self.pid, 15)
+            self.wait()
+
+    def gotdata(self, notification):
+        print 'gotdata!'
+        d = str(self.file.availableData())
+        if d:
+            self.logfunc(d)
+            self.buf = self.buf + d
+            if 'Connected.\r\n' in self.buf:
+                self.serverobj.setConnected_(True)
+            self.buf = self.buf[-4096:]
+            if self.buf.strip().endswith(':'):
+                lastline = self.buf.rstrip().split('\n')[-1]
+                resp = self.promptfunc(lastline)
+                add = ' (response)\n'
+                self.buf += add
+                self.logfunc(add)
+                self.file.writeData_(my.Data(resp + '\n'))
+            self.file.waitForDataInBackgroundAndNotify()
+        self.poll()
+        # print 'gotdata done!'
+
+
+class SshuttleApp(NSObject):
+
+    def initialize(self):
+        d = my.PList('UserDefaults')
+        my.Defaults().registerDefaults_(d)
+
+
+class SshuttleController(NSObject):
+    # Interface builder outlets
+    startAtLoginField = objc.IBOutlet()
+    autoReconnectField = objc.IBOutlet()
+    debugField = objc.IBOutlet()
+    routingField = objc.IBOutlet()
+    prefsWindow = objc.IBOutlet()
+    serversController = objc.IBOutlet()
+    logField = objc.IBOutlet()
+    latencyControlField = objc.IBOutlet()
+
+    servers = []
+    conns = {}
+
+    def _connect(self, server):
+        host = server.host()
+        print 'connecting %r' % host
+        self.fill_menu()
+
+        def logfunc(msg):
+            print 'log! (%d bytes)' % len(msg)
+            self.logField.textStorage()\
+                .appendAttributedString_(NSAttributedString.alloc()
+                                         .initWithString_(msg))
+            self.logField.didChangeText()
+
+        def promptfunc(prompt):
+            print 'prompt! %r' % prompt
+            return askpass.askpass(prompt)
+        nets_mode = server.autoNets()
+        if nets_mode == models.NET_MANUAL:
+            manual_nets = ["%s/%d" % (i.subnet(), i.width())
+                           for i in server.nets()]
+        elif nets_mode == models.NET_ALL:
+            manual_nets = ['0/0']
+        else:
+            manual_nets = []
+        noLatencyControl = (server.latencyControl() != models.LAT_INTERACTIVE)
+        conn = Runner(sshuttle_args(host,
+                                    auto_nets=nets_mode == models.NET_AUTO,
+                                    auto_hosts=server.autoHosts(),
+                                    dns=server.useDns(),
+                                    nets=manual_nets,
+                                    debug=self.debugField.state(),
+                                    no_latency_control=noLatencyControl),
+                      logfunc=logfunc, promptfunc=promptfunc,
+                      serverobj=server)
+        self.conns[host] = conn
+
+    def _disconnect(self, server):
+        host = server.host()
+        print 'disconnecting %r' % host
+        conn = self.conns.get(host)
+        if conn:
+            conn.kill()
+        self.fill_menu()
+        self.logField.textStorage().setAttributedString_(
+            NSAttributedString.alloc().initWithString_(''))
+
+    @objc.IBAction
+    def cmd_connect(self, sender):
+        server = sender.representedObject()
+        server.setWantConnect_(True)
+
+    @objc.IBAction
+    def cmd_disconnect(self, sender):
+        server = sender.representedObject()
+        server.setWantConnect_(False)
+
+    @objc.IBAction
+    def cmd_show(self, sender):
+        self.prefsWindow.makeKeyAndOrderFront_(self)
+        NSApp.activateIgnoringOtherApps_(True)
+
+    @objc.IBAction
+    def cmd_quit(self, sender):
+        NSApp.performSelector_withObject_afterDelay_(NSApp.terminate_,
+                                                     None, 0.0)
+
+    def fill_menu(self):
+        menu = self.menu
+        menu.removeAllItems()
+
+        def additem(name, func, obj):
+            it = menu.addItemWithTitle_action_keyEquivalent_(name, None, "")
+            it.setRepresentedObject_(obj)
+            it.setTarget_(self)
+            it.setAction_(func)
+
+        def addnote(name):
+            additem(name, None, None)
+
+        any_inprogress = None
+        any_conn = None
+        any_err = None
+        if len(self.servers):
+            for i in self.servers:
+                host = i.host()
+                title = i.title()
+                want = i.wantConnect()
+                connected = i.connected()
+                numnets = len(list(i.nets()))
+                if not host:
+                    additem('Connect Untitled', None, i)
+                elif i.autoNets() == models.NET_MANUAL and not numnets:
+                    additem('Connect %s (no routes)' % host, None, i)
+                elif want:
+                    any_conn = i
+                    additem('Disconnect %s' % title, self.cmd_disconnect, i)
+                else:
+                    additem('Connect %s' % title, self.cmd_connect, i)
+                if not want:
+                    msg = 'Off'
+                elif i.error():
+                    msg = 'ERROR - try reconnecting'
+                    any_err = i
+                elif connected:
+                    msg = 'Connected'
+                else:
+                    msg = 'Connecting...'
+                    any_inprogress = i
+                addnote('   State: %s' % msg)
+        else:
+            addnote('No servers defined yet')
+
+        menu.addItem_(NSMenuItem.separatorItem())
+        additem('Preferences...', self.cmd_show, None)
+        additem('Quit Sshuttle VPN', self.cmd_quit, None)
+
+        if any_err:
+            self.statusitem.setImage_(self.img_err)
+            self.statusitem.setTitle_('Error!')
+        elif any_conn:
+            self.statusitem.setImage_(self.img_running)
+            if any_inprogress:
+                self.statusitem.setTitle_('Connecting...')
+            else:
+                self.statusitem.setTitle_('')
+        else:
+            self.statusitem.setImage_(self.img_idle)
+            self.statusitem.setTitle_('')
+
+    def load_servers(self):
+        l = my.Defaults().arrayForKey_('servers') or []
+        sl = []
+        for s in l:
+            host = s.get('host', None)
+            if not host:
+                continue
+
+            nets = s.get('nets', [])
+            nl = []
+            for n in nets:
+                subnet = n[0]
+                width = n[1]
+                net = models.SshuttleNet.alloc().init()
+                net.setSubnet_(subnet)
+                net.setWidth_(width)
+                nl.append(net)
+
+            autoNets = s.get('autoNets', models.NET_AUTO)
+            autoHosts = s.get('autoHosts', True)
+            useDns = s.get('useDns', autoNets == models.NET_ALL)
+            latencyControl = s.get('latencyControl', models.LAT_INTERACTIVE)
+            srv = models.SshuttleServer.alloc().init()
+            srv.setHost_(host)
+            srv.setAutoNets_(autoNets)
+            srv.setAutoHosts_(autoHosts)
+            srv.setNets_(nl)
+            srv.setUseDns_(useDns)
+            srv.setLatencyControl_(latencyControl)
+            sl.append(srv)
+        self.serversController.addObjects_(sl)
+        self.serversController.setSelectionIndex_(0)
+
+    def save_servers(self):
+        l = []
+        for s in self.servers:
+            host = s.host()
+            if not host:
+                continue
+            nets = []
+            for n in s.nets():
+                subnet = n.subnet()
+                if not subnet:
+                    continue
+                nets.append((subnet, n.width()))
+            d = dict(host=s.host(),
+                     nets=nets,
+                     autoNets=s.autoNets(),
+                     autoHosts=s.autoHosts(),
+                     useDns=s.useDns(),
+                     latencyControl=s.latencyControl())
+            l.append(d)
+        my.Defaults().setObject_forKey_(l, 'servers')
+        self.fill_menu()
+
+    def awakeFromNib(self):
+        self.routingField.removeAllItems()
+        tf = self.routingField.addItemWithTitle_
+        tf('Send all traffic through this server')
+        tf('Determine automatically')
+        tf('Custom...')
+
+        self.latencyControlField.removeAllItems()
+        tf = self.latencyControlField.addItemWithTitle_
+        tf('Fast transfer')
+        tf('Low latency')
+
+        # Hmm, even when I mark this as !enabled in the .nib, it still comes
+        # through as enabled.  So let's just disable it here (since we don't
+        # support this feature yet).
+        self.startAtLoginField.setEnabled_(False)
+        self.startAtLoginField.setState_(False)
+        self.autoReconnectField.setEnabled_(False)
+        self.autoReconnectField.setState_(False)
+
+        self.load_servers()
+
+        # Initialize our menu item
+        self.menu = NSMenu.alloc().initWithTitle_('Sshuttle')
+        bar = NSStatusBar.systemStatusBar()
+        statusitem = bar.statusItemWithLength_(NSVariableStatusItemLength)
+        self.statusitem = statusitem
+        self.img_idle = my.Image('chicken-tiny-bw', 'png')
+        self.img_running = my.Image('chicken-tiny', 'png')
+        self.img_err = my.Image('chicken-tiny-err', 'png')
+        statusitem.setImage_(self.img_idle)
+        statusitem.setHighlightMode_(True)
+        statusitem.setMenu_(self.menu)
+        self.fill_menu()
+
+        models.configchange_callback = my.DelayedCallback(self.save_servers)
+
+        def sc(server):
+            if server.wantConnect():
+                self._connect(server)
+            else:
+                self._disconnect(server)
+        models.setconnect_callback = sc
+
+
+# Note: NSApplicationMain calls sys.exit(), so this never returns.
+NSApplicationMain(sys.argv)

src/ui-macos/models.py

@@ -0,0 +1,189 @@
+from AppKit import *
+import my
+
+
+configchange_callback = setconnect_callback = None
+objc_validator = objc.signature('@@:N^@o^@')
+
+
+def config_changed():
+    if configchange_callback:
+        configchange_callback()
+
+
+def _validate_ip(v):
+    parts = v.split('.')[:4]
+    if len(parts) < 4:
+        parts += ['0'] * (4 - len(parts))
+    for i in range(4):
+        n = my.atoi(parts[i])
+        if n < 0:
+            n = 0
+        elif n > 255:
+            n = 255
+        parts[i] = str(n)
+    return '.'.join(parts)
+
+
+def _validate_width(v):
+    n = my.atoi(v)
+    if n < 0:
+        n = 0
+    elif n > 32:
+        n = 32
+    return n
+
+
+class SshuttleNet(NSObject):
+
+    def subnet(self):
+        return getattr(self, '_k_subnet', None)
+
+    def setSubnet_(self, v):
+        self._k_subnet = v
+        config_changed()
+
+    @objc_validator
+    def validateSubnet_error_(self, value, error):
+        # print 'validateSubnet!'
+        return True, _validate_ip(value), error
+
+    def width(self):
+        return getattr(self, '_k_width', 24)
+
+    def setWidth_(self, v):
+        self._k_width = v
+        config_changed()
+
+    @objc_validator
+    def validateWidth_error_(self, value, error):
+        # print 'validateWidth!'
+        return True, _validate_width(value), error
+
+NET_ALL = 0
+NET_AUTO = 1
+NET_MANUAL = 2
+
+LAT_BANDWIDTH = 0
+LAT_INTERACTIVE = 1
+
+
+class SshuttleServer(NSObject):
+
+    def init(self):
+        self = super(SshuttleServer, self).init()
+        config_changed()
+        return self
+
+    def wantConnect(self):
+        return getattr(self, '_k_wantconnect', False)
+
+    def setWantConnect_(self, v):
+        self._k_wantconnect = v
+        self.setError_(None)
+        config_changed()
+        if setconnect_callback:
+            setconnect_callback(self)
+
+    def connected(self):
+        return getattr(self, '_k_connected', False)
+
+    def setConnected_(self, v):
+        print 'setConnected of %r to %r' % (self, v)
+        self._k_connected = v
+        if v:
+            self.setError_(None)  # connected ok, so no error
+        config_changed()
+
+    def error(self):
+        return getattr(self, '_k_error', None)
+
+    def setError_(self, v):
+        self._k_error = v
+        config_changed()
+
+    def isValid(self):
+        if not self.host():
+            return False
+        if self.autoNets() == NET_MANUAL and not len(list(self.nets())):
+            return False
+        return True
+
+    def title(self):
+        host = self.host()
+        if not host:
+            return host
+        an = self.autoNets()
+        suffix = ""
+        if an == NET_ALL:
+            suffix = " (all traffic)"
+        elif an == NET_MANUAL:
+            n = self.nets()
+            suffix = ' (%d subnet%s)' % (len(n), len(n) != 1 and 's' or '')
+        return self.host() + suffix
+
+    def setTitle_(self, v):
+        # title is always auto-generated
+        config_changed()
+
+    def host(self):
+        return getattr(self, '_k_host', None)
+
+    def setHost_(self, v):
+        self._k_host = v
+        self.setTitle_(None)
+        config_changed()
+
+    @objc_validator
+    def validateHost_error_(self, value, error):
+        # print 'validatehost! %r %r %r' % (self, value, error)
+        while value.startswith('-'):
+            value = value[1:]
+        return True, value, error
+
+    def nets(self):
+        return getattr(self, '_k_nets', [])
+
+    def setNets_(self, v):
+        self._k_nets = v
+        self.setTitle_(None)
+        config_changed()
+
+    def netsHidden(self):
+        # print 'checking netsHidden'
+        return self.autoNets() != NET_MANUAL
+
+    def setNetsHidden_(self, v):
+        config_changed()
+        # print 'setting netsHidden to %r' % v
+
+    def autoNets(self):
+        return getattr(self, '_k_autoNets', NET_AUTO)
+
+    def setAutoNets_(self, v):
+        self._k_autoNets = v
+        self.setNetsHidden_(-1)
+        self.setUseDns_(v == NET_ALL)
+        self.setTitle_(None)
+        config_changed()
+
+    def autoHosts(self):
+        return getattr(self, '_k_autoHosts', True)
+
+    def setAutoHosts_(self, v):
+        self._k_autoHosts = v
+        config_changed()
+
+    def useDns(self):
+        return getattr(self, '_k_useDns', False)
+
+    def setUseDns_(self, v):
+        self._k_useDns = v
+        config_changed()
+
+    def latencyControl(self):
+        return getattr(self, '_k_latencyControl', LAT_INTERACTIVE)
+
+    def setLatencyControl_(self, v):
+        self._k_latencyControl = v
+        config_changed()

src/ui-macos/my.py

@@ -0,0 +1,64 @@
+import os
+from AppKit import *
+import PyObjCTools.AppHelper
+
+
+def bundle_path(name, typ):
+    if typ:
+        return NSBundle.mainBundle().pathForResource_ofType_(name, typ)
+    else:
+        return os.path.join(NSBundle.mainBundle().resourcePath(), name)
+
+
+# Load an NSData using a python string
+def Data(s):
+    return NSData.alloc().initWithBytes_length_(s, len(s))
+
+
+# Load a property list from a file in the application bundle.
+def PList(name):
+    path = bundle_path(name, 'plist')
+    return NSDictionary.dictionaryWithContentsOfFile_(path)
+
+
+# Load an NSImage from a file in the application bundle.
+def Image(name, ext):
+    bytes = open(bundle_path(name, ext)).read()
+    img = NSImage.alloc().initWithData_(Data(bytes))
+    return img
+
+
+# Return the NSUserDefaults shared object.
+def Defaults():
+    return NSUserDefaults.standardUserDefaults()
+
+
+# Usage:
+#   f = DelayedCallback(func, args...)
+# later:
+#   f()
+#
+# When you call f(), it will schedule a call to func() next time the
+# ObjC event loop iterates.  Multiple calls to f() in a single iteration
+# will only result in one call to func().
+#
+def DelayedCallback(func, *args, **kwargs):
+    flag = [0]
+
+    def _go():
+        if flag[0]:
+            print 'running %r (flag=%r)' % (func, flag)
+            flag[0] = 0
+            func(*args, **kwargs)
+
+    def call():
+        flag[0] += 1
+        PyObjCTools.AppHelper.callAfter(_go)
+    return call
+
+
+def atoi(s):
+    try:
+        return int(s)
+    except ValueError:
+        return 0

src/ui-macos/run.do

@@ -0,0 +1,4 @@
+redo-ifchange debug.app
+exec >&2
+./debug.app/Contents/MacOS/Sshuttle
+

src/ui-macos/sources.list.do

@@ -0,0 +1,14 @@
+redo-always
+exec >$3
+cat <<-EOF
+	app.icns
+	MainMenu.nib English.lproj/MainMenu.nib
+	UserDefaults.plist
+	chicken-tiny.png
+	chicken-tiny-bw.png
+	chicken-tiny-err.png
+EOF
+for d in *.py sshuttle/*.py sshuttle/sshuttle sshuttle/compat/*.py; do
+	echo $d
+done
+redo-stamp <$3

src/ui-macos/sshuttle

@@ -0,0 +1 @@
+..

sshuttle

@@ -1 +0,0 @@
-main.py