Add --allow_hosts option

Closes #3295

mitmproxy/options.py

@@ -67,6 +67,10 @@ class Options(optmanager.OptManager):
             regular expression and matched on the ip or the hostname.
             """
         )
+        self.add_option(
+            "allow_hosts", Sequence[str], [],
+            "Opposite of --ignore_hosts."
+        )
         self.add_option(
             "listen_host", str, "",
             "Address to bind proxy to."

mitmproxy/proxy/config.py

@@ -14,7 +14,8 @@ CONF_BASENAME = "mitmproxy"
 
 class HostMatcher:
 
-    def __init__(self, patterns=tuple()):
+    def __init__(self, handle, patterns=tuple()):
+        self.handle = handle
         self.patterns = list(patterns)
         self.regexes = [re.compile(p, re.IGNORECASE) for p in self.patterns]
 
@@ -22,8 +23,10 @@ class HostMatcher:
         if not address:
             return False
         host = "%s:%s" % address
-        if any(rex.search(host) for rex in self.regexes):
-            return True
+        if self.handle in ["ignore", "tcp"]:
+            return any(rex.search(host) for rex in self.regexes)
+        elif self.handle == "allow":
+            return any(not rex.search(host) for rex in self.regexes)
         else:
             return False
 
@@ -36,7 +39,7 @@ class ProxyConfig:
     def __init__(self, options: moptions.Options) -> None:
         self.options = options
 
-        self.check_ignore: HostMatcher = None
+        self.check_filter: HostMatcher = None
         self.check_tcp: HostMatcher = None
         self.certstore: certs.CertStore = None
         self.upstream_server: typing.Optional[server_spec.ServerSpec] = None
@@ -44,10 +47,18 @@ class ProxyConfig:
         options.changed.connect(self.configure)
 
     def configure(self, options: moptions.Options, updated: typing.Any) -> None:
-        if "ignore_hosts" in updated:
-            self.check_ignore = HostMatcher(options.ignore_hosts)
+        if options.allow_hosts and options.ignore_hosts:
+            raise exceptions.OptionsError("--ignore-hosts and --allow-hosts are mutually "
+                                          "exclusive; please choose one.")
+
+        if options.ignore_hosts:
+            self.check_filter = HostMatcher("ignore", options.ignore_hosts)
+        elif options.allow_hosts:
+            self.check_filter = HostMatcher("allow", options.allow_hosts)
+        else:
+            self.check_filter = HostMatcher(False)
         if "tcp_hosts" in updated:
-            self.check_tcp = HostMatcher(options.tcp_hosts)
+            self.check_tcp = HostMatcher("tcp", options.tcp_hosts)
 
         certstore_path = os.path.expanduser(options.confdir)
         if not os.path.exists(os.path.dirname(certstore_path)):

mitmproxy/proxy/root_context.py

@@ -48,17 +48,17 @@ class RootContext:
             raise exceptions.ProtocolException(str(e))
         client_tls = tls.is_tls_record_magic(d)
 
-        # 1. check for --ignore
-        if self.config.check_ignore:
-            ignore = self.config.check_ignore(top_layer.server_conn.address)
-            if not ignore and client_tls:
+        # 1. check for filter
+        if self.config.check_filter:
+            is_filtered = self.config.check_filter(top_layer.server_conn.address)
+            if not is_filtered and client_tls:
                 try:
                     client_hello = tls.ClientHello.from_file(self.client_conn.rfile)
                 except exceptions.TlsProtocolException as e:
                     self.log("Cannot parse Client Hello: %s" % repr(e), "error")
                 else:
-                    ignore = self.config.check_ignore((client_hello.sni, 443))
-            if ignore:
+                    is_filtered = self.config.check_filter((client_hello.sni, 443))
+            if is_filtered:
                 return protocol.RawTCPLayer(top_layer, ignore=True)
 
         # 2. Always insert a TLS layer, even if there's neither client nor server tls.

mitmproxy/tools/cmdline.py

@@ -65,6 +65,7 @@ def common_options(parser, opts):
     opts.make_parser(group, "listen_port", metavar="PORT", short="p")
     opts.make_parser(group, "server", short="n")
     opts.make_parser(group, "ignore_hosts", metavar="HOST")
+    opts.make_parser(group, "allow_hosts", metavar="HOST")
     opts.make_parser(group, "tcp_hosts", metavar="HOST")
     opts.make_parser(group, "upstream_auth", metavar="USER:PASS")
     opts.make_parser(group, "proxyauth", metavar="SPEC")

mitmproxy/tools/console/statusbar.py

@@ -215,6 +215,10 @@ class StatusBar(urwid.WidgetWrap):
             r.append("[")
             r.append(("heading_key", "I"))
             r.append("gnore:%d]" % len(self.master.options.ignore_hosts))
+        elif self.master.options.allow_hosts:
+            r.append("[")
+            r.append(("heading_key", "A"))
+            r.append("llow:%d]" % len(self.master.options.allow_hosts))
         if self.master.options.tcp_hosts:
             r.append("[")
             r.append(("heading_key", "T"))

test/mitmproxy/proxy/test_server.py

@@ -78,6 +78,16 @@ class TcpMixin:
         self.options.ignore_hosts = self._ignore_backup
         del self._ignore_backup
 
+    def _allow_on(self):
+        assert not hasattr(self, "_allow_backup")
+        self._allow_backup = self.options.allow_hosts
+        self.options.allow_hosts = ["(127.0.0.1|None):\\d+"] + self.options.allow_hosts
+
+    def _allow_off(self):
+        assert hasattr(self, "_allow_backup")
+        self.options.allow_hosts = self._allow_backup
+        del self._allow_backup
+
     def test_ignore(self):
         n = self.pathod("304")
         self._ignore_on()
@@ -111,6 +121,40 @@ class TcpMixin:
 
         self._ignore_off()
 
+    def test_allow(self):
+        n = self.pathod("304")
+        self._allow_on()
+        i = self.pathod("305")
+        i2 = self.pathod("306")
+        self._allow_off()
+
+        assert n.status_code == 304
+        assert i.status_code == 305
+        assert i2.status_code == 306
+
+        assert any(f.response.status_code == 304 for f in self.master.state.flows)
+        assert any(f.response.status_code == 305 for f in self.master.state.flows)
+        assert any(f.response.status_code == 306 for f in self.master.state.flows)
+
+        # Test that we get the original SSL cert
+        if self.ssl:
+            i_cert = certs.Cert(i.sslinfo.certchain[0])
+            i2_cert = certs.Cert(i2.sslinfo.certchain[0])
+            n_cert = certs.Cert(n.sslinfo.certchain[0])
+
+            assert i_cert == i2_cert
+            assert i_cert != n_cert
+
+        # Test Non-HTTP traffic
+        spec = "200:i0,@100:d0"  # this results in just 100 random bytes
+        # mitmproxy responds with bad gateway
+        assert self.pathod(spec).status_code == 502
+        self._allow_on()
+
+        self.pathod(spec)  # pathoc parses answer as HTTP
+
+        self._allow_off()
+
     def _tcpproxy_on(self):
         assert not hasattr(self, "_tcpproxy_backup")
         self._tcpproxy_backup = self.options.tcp_hosts
@@ -852,10 +896,12 @@ class TestUpstreamProxySSL(
 
     def _host_pattern_on(self, attr):
         """
-        Updates config.check_tcp or check_ignore, depending on attr.
+        Updates config.check_tcp or check_filter, depending on attr.
         """
         assert not hasattr(self, "_ignore_%s_backup" % attr)
         backup = []
+        handle = attr
+        attr = "filter" if attr in ["allow", "ignore"] else attr
         for proxy in self.chain:
             old_matcher = getattr(
                 proxy.tmaster.server.config,
@@ -865,12 +911,13 @@ class TestUpstreamProxySSL(
             setattr(
                 proxy.tmaster.server.config,
                 "check_%s" % attr,
-                HostMatcher([".+:%s" % self.server.port] + old_matcher.patterns)
+                HostMatcher(handle, [".+:%s" % self.server.port] + old_matcher.patterns)
             )
 
         setattr(self, "_ignore_%s_backup" % attr, backup)
 
     def _host_pattern_off(self, attr):
+        attr = "filter" if attr in ["allow", "ignore"] else attr
         backup = getattr(self, "_ignore_%s_backup" % attr)
         for proxy in reversed(self.chain):
             setattr(