Add a way to define network parameters in the registry and propagate them efficiently

re6st-registry

@@ -3,7 +3,7 @@ import httplib, logging, socket
 from BaseHTTPServer import BaseHTTPRequestHandler
 from SocketServer import ThreadingTCPServer
 from urlparse import parse_qsl
-from re6st import ctl, registry, utils
+from re6st import ctl, registry, utils, version
 
 # To generate server ca and key with serial for 2001:db8:42::/48
 #  openssl req -nodes -new -x509 -key ca.key -set_serial 0x120010db80042 -days 3650 -out ca.crt
@@ -89,8 +89,15 @@ def main():
     _('-v', '--verbose', default=1, type=int,
             help="Log level. 0 disables logging."
                  " Use SIGUSR1 to reopen log.")
+    _('--min-protocol', default=version.min_protocol, type=int,
+        help="Reject nodes that are too old. Current is %s." % version.protocol)
+
     config = parser.parse_args()
 
+    if not version.min_protocol <= config.min_protocol <= version.protocol:
+        parser.error("--min-protocol: value must between %s and %s (included)"
+                     % (version.min_protocol, version.protocol))
+
     utils.setupLog(config.verbose, config.logfile)
 
     server = registry.RegistryServer(config)

re6st/cache.py

-import logging, os, sqlite3, socket, subprocess, time
+import json, logging, os, sqlite3, socket, subprocess, time, zlib
 from re6st.registry import RegistryClient
-from . import utils
+from . import utils, version, x509
 
 class Cache(object):
 
-    # internal ip = temp arg/attribute
     def __init__(self, db_path, registry, cert, db_size=200):
         self._prefix = cert.prefix
         self._db_size = db_size
@@ -25,26 +24,28 @@ class Cache(object):
             try INTEGER NOT NULL DEFAULT 0)""")
         q("CREATE INDEX volatile.stat_try ON stat(try)")
         q("INSERT INTO volatile.stat (peer) SELECT prefix FROM peer")
+        self._db.commit()
+        self._loadConfig(q("SELECT * FROM config"))
         try:
-            a = q("SELECT value FROM config WHERE name='registry'").next()[0]
-            int(a, 2)
-        except (StopIteration, ValueError):
-            logging.info("Asking registry its private IP...")
+            cert.verifyVersion(self.version)
+        except (AttributeError, x509.VerifyError):
             retry = 1
-            while True:
-                try:
-                    a = self._registry.getPrefix(self._prefix)
-                    int(a, 2)
-                    break
-                except socket.error, e:
-                    logging.warning(e)
-                    time.sleep(retry)
-                    retry = min(60, retry * 2)
-            q("INSERT OR REPLACE INTO config VALUES ('registry',?)", (a,))
-            self._db.commit()
-        self.registry_prefix = a
-        logging.info("Cache initialized. Prefix of registry node is %s/%u",
-                     int(a, 2), len(a))
+            while not self.updateConfig():
+                time.sleep(retry)
+                retry = min(60, retry * 2)
+        else:
+            if (# re6stnet upgraded after being unused  for a long time.
+                self.protocol < version.protocol
+                # Always query the registry at startup in case we were down
+                # when it tried to send us new parameters.
+                or self._prefix == self.registry_prefix):
+                self.updateConfig()
+        if version.protocol < self.min_protocol:
+            logging.critical("Your version of re6stnet is too old."
+                             " Please update.")
+            sys.exit(1)
+        self.warnProtocol()
+        logging.info("Cache initialized.")
 
     def _open(self, path):
         db = sqlite3.connect(path, isolation_level=None)
@@ -59,6 +60,58 @@ class Cache(object):
             "value")
         return db
 
+    def _loadConfig(self, config):
+        cls = self.__class__
+        logging.debug("Loading network parameters:")
+        for k, v in config:
+            hasattr(cls, k) or setattr(self, k, v)
+            logging.debug("- %s: %r", k, v)
+
+    def updateConfig(self):
+        logging.info("Getting new network parameters from registry...")
+        try:
+            # TODO: When possible, the registry should be queried via the re6st.
+            config = json.loads(zlib.decompress(
+                self._registry.getNetworkConfig(self._prefix)))
+            base64 = config.pop('', ())
+            config = dict((str(k), v.decode('base64') if k in base64 else
+                                   str(v) if type(v) is unicode else v)
+                          for k, v in config.iteritems())
+        except socket.error, e:
+            logging.warning(e)
+            return
+        except Exception:
+            # Even if the response is authenticated, a mistake on the registry
+            # should not kill the whole network in a few seconds.
+            logging.exception("buggy registry ?")
+            return
+        # XXX: check version ?
+        self.delay_restart = config.pop("delay_restart", 0)
+        old = {}
+        with self._db as db:
+            remove = []
+            for k, v in db.execute("SELECT * FROM config"):
+                if k in config:
+                    old[k] = v
+                    continue
+                try:
+                    delattr(self, k)
+                except AttributeError:
+                    pass
+                remove.append(k)
+            db.execute("DELETE FROM config WHERE name in ('%s')"
+                       % "','".join(remove))
+            db.executemany("INSERT OR REPLACE INTO config VALUES(?,?)",
+                           config.iteritems())
+        self._loadConfig(config.iteritems())
+        return [k for k, v in config.iteritems()
+                  if k not in old or old[k] != v]
+
+    def warnProtocol(self):
+        if version.protocol < self.protocol:
+            logging.warning("There's a new version of re6stnet:"
+                            " you should update.")
+
     def log(self):
         if logging.getLogger().isEnabledFor(5):
             logging.trace("Cache:")

re6st/registry.py

@@ -20,7 +20,7 @@ Authenticated communication:
 """
 import base64, hmac, hashlib, httplib, inspect, json, logging
 import mailbox, os, random, select, smtplib, socket, sqlite3
-import string, sys, threading, time, weakref
+import string, struct, sys, threading, time, weakref, zlib
 from collections import defaultdict, deque
 from datetime import datetime
 from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
@@ -55,10 +55,12 @@ class RegistryServer(object):
         utils.makedirs(os.path.dirname(self.config.db))
         self.db = sqlite3.connect(self.config.db, isolation_level=None,
                                                   check_same_thread=False)
+        self.db.text_factory = str
         utils.sqliteCreateTable(self.db, "config",
                 "name TEXT PRIMARY KEY NOT NULL",
                 "value")
         self.prefix = self.getConfig("prefix", None)
+        self.version = self.getConfig("version", "\0")
         utils.sqliteCreateTable(self.db, "token",
                 "token TEXT PRIMARY KEY NOT NULL",
                 "email TEXT NOT NULL",
@@ -82,6 +84,9 @@ class RegistryServer(object):
             weakref.proxy(self), self.network)
 
         self.onTimeout()
+        if self.prefix:
+            with self.db:
+                self.updateNetworkConfig()
 
     def getConfig(self, name, *default):
         r, = next(self.db.execute(
@@ -92,6 +97,41 @@ class RegistryServer(object):
         self.db.execute("INSERT OR REPLACE INTO config VALUES (?, ?)",
                         name_value)
 
+    def updateNetworkConfig(self):
+        kw = {
+            'protocol': version.protocol,
+            'registry_prefix': self.prefix,
+        }
+        for x in 'min_protocol',:
+            kw[x] = getattr(self.config, x)
+        config = json.dumps(kw, sort_keys=True)
+        if config != self.getConfig('last_config', None):
+            self.version = self.encodeVersion(
+                1 + self.decodeVersion(self.version))
+            self.setConfig('version', self.version)
+            self.setConfig('last_config', config)
+            self.sendto(self.prefix, 0)
+        kw[''] = 'version',
+        # Example to avoid all nodes to restart at the same time:
+        # kw['delay_restart'] = 600 * random.random()
+        kw['version'] = self.version.encode('base64')
+        self.network_config = zlib.compress(json.dumps(kw))
+
+    # The 3 first bits code the number of bytes.
+    def encodeVersion(self, version):
+        for n in xrange(8):
+            x = 32 << 8 * n
+            if version < x:
+                x = struct.pack("!Q", version + n * x)[7-n:]
+                return x + self.cert.sign(x)
+            version -= x
+
+    def decodeVersion(self, version):
+        n = ord(version[0]) >> 5
+        version, = struct.unpack("!Q", '\0' * (7 - n) + version[:n+1])
+        return sum((32 << 8 * n for n in xrange(n)),
+                   version - (n * 32 << 8 * n))
+
     def sendto(self, prefix, code):
         self.sock.sendto("%s\0%c" % (prefix, code), ('::1', tunnel.PORT))
 
@@ -307,6 +347,7 @@ class RegistryServer(object):
                 if self.prefix is None:
                     self.prefix = prefix
                     self.setConfig('prefix', prefix)
+                    self.updateNetworkConfig()
                 subject = req.get_subject()
                 subject.serialNumber = str(self.getSubjectSerial())
                 return self.createCertificate(prefix, subject, req.get_pubkey())
@@ -337,8 +378,8 @@ class RegistryServer(object):
         cert.set_pubkey(pubkey)
         # Certificate serial, for revocation support. Contrary to
         # subject serial, it does not need to be as small as possible.
-        serial = 1 + self.getConfig('_serial', 0)
-        self.setConfig('_serial', serial)
+        serial = 1 + self.getConfig('serial', 0)
+        self.setConfig('serial', serial)
         cert.set_serial_number(serial)
         cert.sign(self.cert.key, 'sha1')
         cert = crypto.dump_certificate(crypto.FILETYPE_PEM, cert)
@@ -367,8 +408,8 @@ class RegistryServer(object):
         return crypto.dump_certificate(crypto.FILETYPE_PEM, self.cert.ca)
 
     @rpc
-    def getPrefix(self, cn):
-        return self.prefix
+    def getNetworkConfig(self, cn):
+        return self.network_config
 
     @rpc
     def getBootstrapPeer(self, cn):

re6st/tunnel.py

@@ -162,6 +162,11 @@ class TunnelKiller(object):
 
 class BaseTunnelManager(object):
 
+    # TODO: To minimize downtime when network parameters change, we should do
+    #       our best to not restart any process. Ideally, this list should be
+    #       empty and the affected subprocesses reloaded.
+    NEED_RESTART = frozenset()
+
     _forward = None
 
     def __init__(self, cache, cert, cert_renew, address=()):
@@ -172,6 +177,7 @@ class BaseTunnelManager(object):
         self._connecting = set()
         self._connection_dict = {}
         self._served = set()
+        self._version = cache.version
 
         address_dict = defaultdict(list)
         for family, address in address:
@@ -186,12 +192,27 @@ class BaseTunnelManager(object):
         self.sock.bind(('::', PORT))
 
         p = x509.Peer(self._prefix)
-        self._next_invalidated = p.stop_date = cert_renew
+        p.stop_date = cert_renew
         self._peers = [p]
+        self._timeouts = [(cert_renew, self.invalidatePeers)]
 
     def select(self, r, w, t):
         r[self.sock] = self.handlePeerEvent
-        t.append((self._next_invalidated, self.invalidatePeers))
+        t += self._timeouts
+
+    def selectTimeout(self, next, callback, force=True):
+        t = self._timeouts
+        for i, x in enumerate(t):
+            if x[1] == callback:
+                if not next:
+                    logging.debug("timeout: removing %r (%s)", callback.__name__, next)
+                    del t[i]
+                elif force or next < x[0]:
+                    logging.debug("timeout: updating %r (%s)", callback.__name__, next)
+                    t[i] = next, callback
+                return
+        logging.debug("timeout: adding %r (%s)", callback.__name__, next)
+        t.append((next, callback))
 
     def invalidatePeers(self):
         next = float('inf')
@@ -206,11 +227,14 @@ class BaseTunnelManager(object):
                 next = peer.stop_date
         for i in reversed(remove):
             del self._peers[i]
-        self._next_invalidated = next
+        self.selectTimeout(next, self.invalidatePeers)
+
+    def _getPeer(self, prefix):
+        return self._peers[bisect(self._peers, prefix) - 1]
 
     def sendto(self, prefix, msg):
         to = utils.ipFromBin(self._network + prefix), PORT
-        peer = self._peers[bisect(self._peers, prefix) - 1]
+        peer = self._getPeer(prefix)
         if peer.prefix != prefix:
             peer = x509.Peer(prefix)
             insort(self._peers, peer)
@@ -259,7 +283,7 @@ class BaseTunnelManager(object):
         if len(msg) <= 4 or not sender.startswith(self._network):
             return
         prefix = sender[len(self._network):]
-        peer = self._peers[bisect(self._peers, prefix) - 1]
+        peer = self._getPeer(prefix)
         msg = peer.decode(msg)
         if type(msg) is tuple:
             seqno, msg = msg
@@ -274,7 +298,8 @@ class BaseTunnelManager(object):
                     logging.debug('ignored new session key from %r',
                                   address, exc_info=1)
                     return
-                self._sendto(to, "", peer) # ack
+                peer.version = self._version \
+                    if self._sendto(to, '\0' + self._version, peer) else ''
                 return
             if seqno:
                 h = x509.fingerprint(self.cert.cert).digest()
@@ -298,8 +323,7 @@ class BaseTunnelManager(object):
                 insort(self._peers, peer)
             peer.cert = cert
             peer.stop_date = stop_date
-            if stop_date < self._next_invalidated:
-                self._next_invalidated = stop_date
+            self.selectTimeout(stop_date, self.invalidatePeers, False)
             if seqno:
                 self._sendto(to, peer.hello(self.cert))
             else:
@@ -330,7 +354,25 @@ class BaseTunnelManager(object):
                     self._makeTunnel(peer, msg)
             else:
                 return ';'.join(self._address.itervalues())
-        elif 2 <= code <= 3: # kill
+        elif not code: # ver
+            if peer:
+                try:
+                    if msg == self._version:
+                        return
+                    self.cert.verifyVersion(msg)
+                except x509.VerifyError:
+                    pass
+                else:
+                    if msg < self._version:
+                        return self._version
+                    self._version = msg
+                    self.selectTimeout(time.time() + 1, self.newVersion)
+                finally:
+                    if peer:
+                        self._getPeer(peer).version = self._version
+            else:
+                self.selectTimeout(time.time() + 1, self.newVersion)
+        elif code <= 3: # kill
             if peer:
                 try:
                     tunnel_killer = self._killing[peer]
@@ -353,6 +395,33 @@ class BaseTunnelManager(object):
                     for x in (self._connection_dict, self._served)
                     for x in x)
 
+    @staticmethod
+    def _restart():
+        raise utils.ReexecException(
+            "Restart with new network parameters")
+
+    def broadcastVersion(self):
+        pass
+
+    def newVersion(self):
+        changed = self.cache.updateConfig()
+        if changed is None:
+            logging.info("will retry to update network parameters in 5 minutes")
+            self.selectTimeout(time.time() + 300, self.newVersion)
+            return
+        logging.info("changed: %r", changed)
+        self.selectTimeout(None, self.newVersion)
+        self._version = self.cache.version
+        self.broadcastVersion()
+        self.cache.warnProtocol()
+        if not self.NEED_RESTART.isdisjoint(changed) or \
+           version.protocol < self.cache.min_protocol:
+            # Wait at least 1 second to broadcast new version to neighbours.
+            # If re6stnet is too old, don't abort now, because a new version
+            # may have been installed without restart.
+            self.selectTimeout(time.time() + 1 + self.cache.delay_restart,
+                               self._restart)
+
 
 class TunnelManager(BaseTunnelManager):
 
@@ -693,3 +762,13 @@ class TunnelManager(BaseTunnelManager):
             family, address = self._ip_changed(ip)
             if address:
                 self._address[family] = utils.dump_address(address)
+
+    def broadcastVersion(self):
+        for prefix in self.ctl.neighbours:
+            if prefix:
+                peer = self._getPeer(prefix)
+                if peer.prefix != prefix:
+                    self.sendto(prefix, None)
+                elif (peer.version < self._version and
+                      self.sendto(prefix, '\0' + self._version)):
+                    peer.version = self._version

re6st/version.py

@@ -27,5 +27,13 @@ version = "0-%s.g%s" % (revision, short)
 if dirty:
     version += ".dirty"
 
+# Because the software could be forked or have local changes/commits, above
+# properties can't be used to decide whether a peer runs an appropriate version:
+# they are intended to the network admin.
+# Only 'protocol' is important and it must be increased whenever they would be
+# a wish to force an update of nodes.
+protocol = 1
+min_protocol = 1
+
 if __name__ == "__main__":
     print version

re6st/x509.py

@@ -149,6 +149,13 @@ class Cert(object):
             raise subprocess.CalledProcessError(p.returncode, 'openssl', err)
         return out
 
+    def verifyVersion(self, version):
+        try:
+            n = 1 + (ord(version[0]) >> 5)
+            self.verify(version[n:], version[:n])
+        except (IndexError, crypto.Error):
+            raise VerifyError(None, None, 'invalid network version')
+
 
 class Peer(object):
     """
@@ -175,6 +182,7 @@ class Peer(object):
     _hello = _last = 0
     _key = newHmacSecret()
     stop_date = float('inf')
+    version = ''
 
     def __init__(self, prefix):
         assert len(prefix) == 16 or prefix == ('0' * 14 + '1' + '0' * 65), prefix