Check for unknown config options

The list of valid sections + config-items came from
grep'ing the source for `.get_config`

src/allmydata/client.py

@@ -17,7 +17,7 @@ from allmydata.immutable.offloaded import Helper
 from allmydata.control import ControlServer
 from allmydata.introducer.client import IntroducerClient
 from allmydata.util import (hashutil, base32, pollmixin, log, keyutil, idlib,
-                            yamlutil)
+                            yamlutil, configutil)
 from allmydata.util.encodingutil import (get_filesystem_encoding,
                                          from_utf8_or_none)
 from allmydata.util.fileutil import abspath_expanduser_unicode
@@ -28,7 +28,7 @@ from allmydata.history import History
 from allmydata.interfaces import IStatsProducer, SDMF_VERSION, MDMF_VERSION
 from allmydata.nodemaker import NodeMaker
 from allmydata.blacklist import Blacklist
-from allmydata.node import OldConfigOptionError
+from allmydata.node import OldConfigOptionError, _common_config_sections
 
 
 KiB=1024
@@ -37,6 +37,62 @@ GiB=1024*MiB
 TiB=1024*GiB
 PiB=1024*TiB
 
+def _valid_config_sections():
+    cfg = _common_config_sections()
+    cfg.update({
+        "client": (
+            "helper.furl",
+            "introducer.furl",
+            "key_generator.furl",
+            "mutable.format",
+            "peers.preferred",
+            "shares.happy",
+            "shares.needed",
+            "shares.total",
+            "stats_gatherer.furl",
+        ),
+        "drop_upload": (  # deprecated already?
+            "enabled",
+        ),
+        "ftpd": (
+            "accounts.file",
+            "accounts.url",
+            "enabled",
+            "port",
+        ),
+        "storage": (
+            "debug_discard",
+            "enabled",
+            "expire.cutoff_date",
+            "expire.enabled",
+            "expire.immutable",
+            "expire.mode",
+            "expire.mode",
+            "expire.mutable",
+            "expire.override_lease_duration",
+            "readonly",
+            "reserved_space",
+        ),
+        "sftpd": (
+            "accounts.file",
+            "accounts.url",
+            "enabled",
+            "host_privkey_file",
+            "host_pubkey_file",
+            "port",
+        ),
+        "helper": (
+            "enabled",
+        ),
+        "magic_folder": (
+            "download.umask",
+            "enabled",
+            "local.directory",
+        ),
+    })
+    return cfg
+
+
 def _make_secret():
     return base32.b2a(os.urandom(hashutil.CRYPTO_VAL_SIZE)) + "\n"
 
@@ -123,6 +179,7 @@ class Client(node.Node, pollmixin.PollMixin):
         node.Node.__init__(self, basedir)
         # All tub.registerReference must happen *after* we upcall, since
         # that's what does tub.setLocation()
+        configutil.validate_config(self.config_fname, self.config, _valid_config_sections())
         self._magic_folder = None
         self.started_timestamp = time.time()
         self.logSource="Client"

src/allmydata/introducer/server.py

@@ -5,13 +5,17 @@ from twisted.application import service
 from foolscap.api import Referenceable
 import allmydata
 from allmydata import node
-from allmydata.util import log, rrefutil
+from allmydata.util import log, rrefutil, configutil
 from allmydata.util.fileutil import abspath_expanduser_unicode
 from allmydata.introducer.interfaces import \
      RIIntroducerPublisherAndSubscriberService_v2
 from allmydata.introducer.common import unsign_from_foolscap, \
      SubscriberDescriptor, AnnouncementDescriptor
 
+def _valid_config_sections():
+    return node._common_config_sections()
+
+
 class FurlFileConflictError(Exception):
     pass
 
@@ -22,7 +26,7 @@ class IntroducerNode(node.Node):
 
     def __init__(self, basedir=u"."):
         node.Node.__init__(self, basedir)
-        self.read_config()
+        configutil.validate_config(self.config_fname, self.config, _valid_config_sections())
         self.init_introducer()
         webport = self.get_config("node", "web.port", None)
         if webport:

src/allmydata/node.py

@@ -29,6 +29,39 @@ def _import_i2p():
     except ImportError: # pragma: no cover
         return None
 
+def _common_config_sections():
+    return {
+        "connections": (
+            "tcp",
+        ),
+        "node": (
+            "log_gatherer.furl",
+            "nickname",
+            "reveal-ip-address",
+            "tempdir",
+            "timeout.disconnect",
+            "timeout.keepalive",
+            "tub.location",
+            "tub.port",
+            "web.port",
+            "web.static",
+        ),
+        "i2p": (
+            "enabled",
+            "i2p.configdir",
+            "i2p.executable",
+            "launch",
+            "sam.port",
+        ),
+        "tor": (
+            "control.port",
+            "enabled",
+            "launch",
+            "socks.port",
+            "tor.executable",
+        ),
+    }
+
 # Add our application versions to the data that Foolscap's LogPublisher
 # reports.
 for thing, things_version in get_package_versions().iteritems():
@@ -91,6 +124,7 @@ class Node(service.MultiService):
     def __init__(self, basedir=u"."):
         service.MultiService.__init__(self)
         self.basedir = abspath_expanduser_unicode(unicode(basedir))
+        self.config_fname = os.path.join(self.basedir, "tahoe.cfg")
         self._portnumfile = os.path.join(self.basedir, self.PORTNUMFILE)
         fileutil.make_dirs(os.path.join(self.basedir, "private"), 0700)
         open(os.path.join(self.basedir, "private", "README"), "w").write(PRIV_README)
@@ -159,11 +193,10 @@ class Node(service.MultiService):
         self.error_about_old_config_files()
         self.config = ConfigParser.SafeConfigParser()
 
-        tahoe_cfg = os.path.join(self.basedir, "tahoe.cfg")
         try:
-            self.config = configutil.get_config(tahoe_cfg)
+            self.config = configutil.get_config(self.config_fname)
         except EnvironmentError:
-            if os.path.exists(tahoe_cfg):
+            if os.path.exists(self.config_fname):
                 raise
 
     def error_about_old_config_files(self):

src/allmydata/test/test_configutil.py

@@ -32,3 +32,45 @@ class ConfigUtilTests(CLITestMixin, GridTestMixin, unittest.TestCase):
 
         config = configutil.get_config(tahoe_cfg)
         self.failUnlessEqual(config.get("node", "descriptor"), descriptor)
+
+    def test_config_validation_success(self):
+        d = self.mktemp()
+        os.mkdir(d)
+        fname = os.path.join(d, 'tahoe.cfg')
+
+        with open(fname, 'w') as f:
+            f.write('[node]\nvalid = foo\n')
+
+        config = configutil.get_config(fname)
+        # should succeed, no exceptions
+        configutil.validate_config(fname, config, dict(node=['valid']))
+
+    def test_config_validation_invalid_item(self):
+        d = self.mktemp()
+        os.mkdir(d)
+        fname = os.path.join(d, 'tahoe.cfg')
+
+        with open(fname, 'w') as f:
+            f.write('[node]\nvalid = foo\ninvalid = foo\n')
+
+        config = configutil.get_config(fname)
+        self.assertRaises(
+            configutil.UnknownConfigError,
+            configutil.validate_config,
+            fname, config, dict(node=['valid']),
+        )
+
+    def test_config_validation_invalid_section(self):
+        d = self.mktemp()
+        os.mkdir(d)
+        fname = os.path.join(d, 'tahoe.cfg')
+
+        with open(fname, 'w') as f:
+            f.write('[node]\nvalid = foo\n[invalid]\n')
+
+        config = configutil.get_config(fname)
+        self.assertRaises(
+            configutil.UnknownConfigError,
+            configutil.validate_config,
+            fname, config, dict(node=['valid']),
+        )

src/allmydata/util/configutil.py

@@ -2,6 +2,14 @@
 from ConfigParser import SafeConfigParser
 
 
+class UnknownConfigError(Exception):
+    """
+    An unknown config item was found.
+
+    This is possibly raised by validate_config()
+    """
+
+
 def get_config(tahoe_cfg):
     config = SafeConfigParser()
     f = open(tahoe_cfg, "rb")
@@ -27,3 +35,28 @@ def write_config(tahoe_cfg, config):
         config.write(f)
     finally:
         f.close()
+
+def validate_config(fname, cfg, valid_sections):
+    """
+    raises UnknownConfigError if there are any unknown sections or config
+    values.
+    """
+    for section in cfg.sections():
+        try:
+            valid_in_section = valid_sections[section]
+        except KeyError:
+            raise UnknownConfigError(
+                "'{fname}' contains unknown section [{section}]".format(
+                    fname=fname,
+                    section=section,
+                )
+            )
+        for option in cfg.options(section):
+            if option not in valid_in_section:
+                raise UnknownConfigError(
+                    "'{fname}' section [{section}] contains unknown option '{option}'".format(
+                        fname=fname,
+                        section=section,
+                        option=option,
+                    )
+                )