Merge remote-tracking branch 'tor-github/pr/1430'

31 files changed, 252 insertions, 46 deletions

diff --git a/.travis.yml b/.travis.yml
index c65923d2c4..1d4f4bee18 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -54,6 +54,8 @@ matrix:
     - env: RUST_OPTIONS="--enable-rust" TOR_RUST_DEPENDENCIES=true
     ## We check asciidoc with distcheck, to make sure we remove doc products
     - env: DISTCHECK="yes" ASCIIDOC_OPTIONS="" SKIP_MAKE_CHECK="yes"
+    ## We check disable module relay
+    - env: MODULES_OPTIONS="--disable-module-relay"
     ## We check disable module dirauth
     - env: MODULES_OPTIONS="--disable-module-dirauth"
     ## We run rust on macOS, because we have seen macOS rust failures before
diff --git a/changes/ticket32123 b/changes/ticket32123
new file mode 100644
index 0000000000..8200f5fca6
--- /dev/null
+++ b/changes/ticket32123
@@ -0,0 +1,5 @@
+  o Major features (build system):
+    - Create an optional relay module, which can be disabled using the
+      --disable-module-relay configure option. When it is set, also disable
+      the dirauth module. Add a minimal implemention, which disables the
+      relay and dircache modes in tor. Closes ticket 32123.
diff --git a/configure.ac b/configure.ac
index c0db30e60e..9a903fb11e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -255,13 +255,22 @@ dnl Tor modules options. These options are namespaced with --disable-module-XXX
 dnl ---
 
 dnl All our modules.
-m4_define(MODULES, dirauth)
+m4_define(MODULES, relay dirauth)
+
+dnl Relay module.
+AC_ARG_ENABLE([module-relay],
+              AS_HELP_STRING([--disable-module-relay],
+                             [Build tor without the Relay modules: tor can not run as a relay, bridge, or authority. Implies --disable-module-dirauth]))
+AM_CONDITIONAL(BUILD_MODULE_RELAY, [test "x$enable_module_relay" != "xno"])
+AM_COND_IF(BUILD_MODULE_RELAY,
+           AC_DEFINE([HAVE_MODULE_RELAY], [1],
+                     [Compile with Relay feature support]))
 
 dnl Directory Authority module.
 AC_ARG_ENABLE([module-dirauth],
               AS_HELP_STRING([--disable-module-dirauth],
                              [Build tor without the Directory Authority module: tor can not run as a directory authority or bridge authority]))
-AM_CONDITIONAL(BUILD_MODULE_DIRAUTH,[test "x$enable_module_dirauth" != "xno"])
+AM_CONDITIONAL(BUILD_MODULE_DIRAUTH,[test "x$enable_module_dirauth" != "xno" && test "x$enable_module_relay" != "xno"])
 AM_COND_IF(BUILD_MODULE_DIRAUTH,
            AC_DEFINE([HAVE_MODULE_DIRAUTH], [1],
                      [Compile with Directory Authority feature support]))
diff --git a/doc/HACKING/Module.md b/doc/HACKING/Module.md
index 9cf36090b4..3a07d0c639 100644
--- a/doc/HACKING/Module.md
+++ b/doc/HACKING/Module.md
@@ -8,13 +8,18 @@ module in Tor.
 In the context of the tor code base, a module is a subsystem that we can
 selectively enable or disable, at `configure` time.
 
-Currently, there is only one module:
+Currently, tor has these modules:
 
+  - Relay subsystem (relay)
   - Directory Authority subsystem (dirauth)
 
-It is located in its own directory in `src/feature/dirauth/`. To disable it,
-one need to pass `--disable-module-dirauth` at configure time. All modules
-are currently enabled by default.
+dirauth is located in its own directory in `src/feature/dirauth/`.
+
+Relay is located in directories named `src/*/*relay` and `src/*/*dircache`,
+which are being progressively refactored and disabled.
+
+To disable a module, pass `--disable-module-{dirauth,relay}` at configure
+time. All modules are currently enabled by default.
 
 ## Build System ##
 
@@ -24,7 +29,7 @@ The changes to the build system are pretty straightforward.
    contains a list (white-space separated) of the module in tor. Add yours to
    the list.
 
-2. Use the `AC_ARG_ENABLE([module-dirauth]` template for your new module. We
+2. Use the `AC_ARG_ENABLE([module-relay]` template for your new module. We
    use the "disable module" approach instead of enabling them one by one. So,
    by default, tor will build all the modules.
 
@@ -32,7 +37,7 @@ The changes to the build system are pretty straightforward.
    the C code to conditionally compile things for your module. And the
    `BUILD_MODULE_<name>` is also defined for automake files (e.g: include.am).
 
-3. In the `src/core/include.am` file, locate the `MODULE_DIRAUTH_SOURCES`
+3. In the `src/core/include.am` file, locate the `MODULE_RELAY_SOURCES`
    value.  You need to create your own `_SOURCES` variable for your module
    and then conditionally add the it to `LIBTOR_A_SOURCES` if you should
    build the module.
@@ -40,18 +45,14 @@ The changes to the build system are pretty straightforward.
    It is then **very** important to add your SOURCES variable to
    `src_or_libtor_testing_a_SOURCES` so the tests can build it.
 
-4. Do the same for header files, locate `ORHEADERS +=` which always add all
-   headers of all modules so the symbol can be found for the module entry
-   points.
-
 Finally, your module will automatically be included in the
-`TOR_MODULES_ALL_ENABLED` variable which is used to build the unit tests. They
-always build everything in order to tests everything.
+`TOR_MODULES_ALL_ENABLED` variable which is used to build the unit tests.
+They always build everything in order to test everything.
 
 ## Coding ##
 
-As mentioned above, a module must be isolated in its own directory (name of
-the module) in `src/feature/`.
+As mentioned above, a module should be isolated in its own directories,
+suffixed with the name of the module, in `src/*/`.
 
 There are couples of "rules" you want to follow:
 
diff --git a/src/app/config/config.c b/src/app/config/config.c
index 37eab22912..c7ae453d5c 100644
--- a/src/app/config/config.c
+++ b/src/app/config/config.c
@@ -2757,6 +2757,7 @@ list_deprecated_options(void)
 static void
 list_enabled_modules(void)
 {
+  printf("%s: %s\n", "relay", have_module_relay() ? "yes" : "no");
   printf("%s: %s\n", "dirauth", have_module_dirauth() ? "yes" : "no");
 }
 
diff --git a/src/core/include.am b/src/core/include.am
index a5d11c24f6..17bfb2799f 100644
--- a/src/core/include.am
+++ b/src/core/include.am
@@ -71,6 +71,7 @@ LIBTOR_APP_A_SOURCES = 				\
 	src/feature/client/circpathbias.c	\
 	src/feature/client/dnsserv.c		\
 	src/feature/client/entrynodes.c		\
+	src/feature/client/proxymode.c		\
 	src/feature/client/transports.c		\
 	src/feature/control/btrack.c		\
 	src/feature/control/btrack_circuit.c	\
@@ -145,7 +146,6 @@ LIBTOR_APP_A_SOURCES = 				\
 	src/feature/relay/relay_sys.c		\
 	src/feature/relay/router.c		\
 	src/feature/relay/routerkeys.c		\
-	src/feature/relay/routermode.c		\
 	src/feature/relay/selftest.c		\
 	src/feature/rend/rendcache.c		\
 	src/feature/rend/rendclient.c		\
@@ -169,6 +169,10 @@ endif
 #
 LIBTOR_APP_TESTING_A_SOURCES = $(LIBTOR_APP_A_SOURCES)
 
+# The Relay module.
+MODULE_RELAY_SOURCES = 					    \
+	src/feature/relay/routermode.c
+
 # The Directory Authority module.
 MODULE_DIRAUTH_SOURCES = 					\
 	src/feature/dirauth/authmode.c				\
@@ -188,6 +192,10 @@ MODULE_DIRAUTH_SOURCES = 					\
 	src/feature/dirauth/shared_random_state.c		\
 	src/feature/dirauth/voteflags.c
 
+if BUILD_MODULE_RELAY
+LIBTOR_APP_A_SOURCES += $(MODULE_RELAY_SOURCES)
+endif
+
 if BUILD_MODULE_DIRAUTH
 LIBTOR_APP_A_SOURCES += $(MODULE_DIRAUTH_SOURCES)
 endif
@@ -196,6 +204,7 @@ src_core_libtor_app_a_SOURCES = $(LIBTOR_APP_A_SOURCES)
 if UNITTESTS_ENABLED
 
 # Add the sources of the modules that are needed for tests to work here.
+LIBTOR_APP_TESTING_A_SOURCES += $(MODULE_RELAY_SOURCES)
 LIBTOR_APP_TESTING_A_SOURCES += $(MODULE_DIRAUTH_SOURCES)
 
 src_core_libtor_app_testing_a_SOURCES = $(LIBTOR_APP_TESTING_A_SOURCES)
@@ -305,6 +314,7 @@ noinst_HEADERS +=					\
 	src/feature/client/circpathbias.h		\
 	src/feature/client/dnsserv.h			\
 	src/feature/client/entrynodes.h			\
+	src/feature/client/proxymode.h			\
 	src/feature/client/transports.h			\
 	src/feature/control/btrack_circuit.h		\
 	src/feature/control/btrack_orconn.h		\
diff --git a/src/core/mainloop/mainloop.c b/src/core/mainloop/mainloop.c
index 2f8be9961d..d58f263bdc 100644
--- a/src/core/mainloop/mainloop.c
+++ b/src/core/mainloop/mainloop.c
@@ -71,6 +71,7 @@
 #include "feature/client/bridges.h"
 #include "feature/client/dnsserv.h"
 #include "feature/client/entrynodes.h"
+#include "feature/client/proxymode.h"
 #include "feature/client/transports.h"
 #include "feature/control/control.h"
 #include "feature/control/control_events.h"
diff --git a/src/core/or/circuituse.c b/src/core/or/circuituse.c
index 606c5e2dd2..a74ecbfd54 100644
--- a/src/core/or/circuituse.c
+++ b/src/core/or/circuituse.c
@@ -42,6 +42,7 @@
 #include "feature/client/bridges.h"
 #include "feature/client/circpathbias.h"
 #include "feature/client/entrynodes.h"
+#include "feature/client/proxymode.h"
 #include "feature/control/control_events.h"
 #include "feature/dircommon/directory.h"
 #include "feature/hs/hs_circuit.h"
diff --git a/src/feature/client/proxymode.c b/src/feature/client/proxymode.c
new file mode 100644
index 0000000000..3b5fba5cda
--- /dev/null
+++ b/src/feature/client/proxymode.c
@@ -0,0 +1,27 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#include "core/or/or.h"
+
+#include "app/config/config.h"
+#include "core/mainloop/connection.h"
+#include "core/or/port_cfg_st.h"
+#include "feature/client/proxymode.h"
+
+/** Return true iff we are trying to proxy client connections. */
+int
+proxy_mode(const or_options_t *options)
+{
+  (void)options;
+  SMARTLIST_FOREACH_BEGIN(get_configured_ports(), const port_cfg_t *, p) {
+    if (p->type == CONN_TYPE_AP_LISTENER ||
+        p->type == CONN_TYPE_AP_TRANS_LISTENER ||
+        p->type == CONN_TYPE_AP_DNS_LISTENER ||
+        p->type == CONN_TYPE_AP_NATD_LISTENER)
+      return 1;
+  } SMARTLIST_FOREACH_END(p);
+  return 0;
+}
diff --git a/src/feature/client/proxymode.h b/src/feature/client/proxymode.h
new file mode 100644
index 0000000000..f8352922c7
--- /dev/null
+++ b/src/feature/client/proxymode.h
@@ -0,0 +1,17 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file proxymode.h
+ * \brief Header file for proxymode.c.
+ **/
+
+#ifndef TOR_PROXYMODE_H
+#define TOR_PROXYMODE_H
+
+int proxy_mode(const or_options_t *options);
+
+#endif
diff --git a/src/feature/dirauth/authmode.h b/src/feature/dirauth/authmode.h
index bfd5f4dc04..11bc40d8d1 100644
--- a/src/feature/dirauth/authmode.h
+++ b/src/feature/dirauth/authmode.h
@@ -27,6 +27,7 @@ authdir_mode_v3(const or_options_t *options)
   return authdir_mode(options) && options->V3AuthoritativeDir != 0;
 }
 
+/* Is the dirauth module enabled? */
 #define have_module_dirauth() (1)
 
 #else /* !defined(HAVE_MODULE_DIRAUTH) */
diff --git a/src/feature/relay/router.c b/src/feature/relay/router.c
index ab0762e17e..92803f88a9 100644
--- a/src/feature/relay/router.c
+++ b/src/feature/relay/router.c
@@ -372,6 +372,8 @@ assert_identity_keys_ok(void)
   }
 }
 
+#ifdef HAVE_MODULE_RELAY
+
 /** Returns the current server identity key; requires that the key has
  * been set, and that we are running as a Tor server.
  */
@@ -384,6 +386,8 @@ get_server_identity_key,(void))
   return server_identitykey;
 }
 
+#endif
+
 /** Return true iff we are a server and the server identity key
  * has been set. */
 int
diff --git a/src/feature/relay/router.h b/src/feature/relay/router.h
index 55b9ef9e68..a708b24889 100644
--- a/src/feature/relay/router.h
+++ b/src/feature/relay/router.h
@@ -28,7 +28,13 @@ struct ed25519_keypair_t;
 MOCK_DECL(crypto_pk_t *,get_onion_key,(void));
 time_t get_onion_key_set_at(void);
 void set_server_identity_key(crypto_pk_t *k);
+/* Some compilers are clever enough to know that when relay mode is disabled,
+ * this function never returns. */
+#ifdef HAVE_MODULE_RELAY
 MOCK_DECL(crypto_pk_t *,get_server_identity_key,(void));
+#else
+#define get_server_identity_key() (tor_abort_(),NULL)
+#endif
 int server_identity_key_is_set(void);
 void set_client_identity_key(crypto_pk_t *k);
 crypto_pk_t *get_tlsclient_identity_key(void);
diff --git a/src/feature/relay/routermode.c b/src/feature/relay/routermode.c
index 2a9ddeac4d..3613841b1e 100644
--- a/src/feature/relay/routermode.c
+++ b/src/feature/relay/routermode.c
@@ -7,8 +7,6 @@
 #include "core/or/or.h"
 
 #include "app/config/config.h"
-#include "core/mainloop/connection.h"
-#include "core/or/port_cfg_st.h"
 #include "feature/relay/router.h"
 #include "feature/relay/routermode.h"
 
@@ -25,21 +23,6 @@ dir_server_mode(const or_options_t *options)
     (server_mode(options) && router_has_bandwidth_to_be_dirserver(options));
 }
 
-/** Return true iff we are trying to proxy client connections. */
-int
-proxy_mode(const or_options_t *options)
-{
-  (void)options;
-  SMARTLIST_FOREACH_BEGIN(get_configured_ports(), const port_cfg_t *, p) {
-    if (p->type == CONN_TYPE_AP_LISTENER ||
-        p->type == CONN_TYPE_AP_TRANS_LISTENER ||
-        p->type == CONN_TYPE_AP_DNS_LISTENER ||
-        p->type == CONN_TYPE_AP_NATD_LISTENER)
-      return 1;
-  } SMARTLIST_FOREACH_END(p);
-  return 0;
-}
-
 /** Return true iff we are trying to be a server.
  */
 MOCK_IMPL(int,
diff --git a/src/feature/relay/routermode.h b/src/feature/relay/routermode.h
index be535af478..ddf621e5c7 100644
--- a/src/feature/relay/routermode.h
+++ b/src/feature/relay/routermode.h
@@ -12,13 +12,31 @@
 #ifndef TOR_ROUTERMODE_H
 #define TOR_ROUTERMODE_H
 
+#ifdef HAVE_MODULE_RELAY
+
 int dir_server_mode(const or_options_t *options);
 
 MOCK_DECL(int, server_mode, (const or_options_t *options));
 MOCK_DECL(int, public_server_mode, (const or_options_t *options));
 MOCK_DECL(int, advertised_server_mode, (void));
-int proxy_mode(const or_options_t *options);
 
 void set_server_advertised(int s);
 
+/* Is the relay module enabled? */
+#define have_module_relay() (1)
+
+#else
+
+#define dir_server_mode(options) (((void)(options)),0)
+#define server_mode(options) (((void)(options)),0)
+#define public_server_mode(options) (((void)(options)),0)
+#define advertised_server_mode() (0)
+
+/* We shouldn't be publishing descriptors when relay mode is disabled. */
+#define set_server_advertised(s) tor_assert_nonfatal(!(s))
+
+#define have_module_relay() (0)
+
+#endif
+
 #endif /* !defined(TOR_ROUTERMODE_H) */
diff --git a/src/test/conf_examples/bridgeauth_1/expected b/src/test/conf_examples/bridgeauth_1/expected
new file mode 100644
index 0000000000..d43aaf2c8b
--- /dev/null
+++ b/src/test/conf_examples/bridgeauth_1/expected
@@ -0,0 +1,7 @@
+Address 198.51.100.123
+AuthoritativeDirectory 1
+BridgeAuthoritativeDir 1
+ContactInfo tor_parse_test@example.com
+DirPort 80
+Nickname Unnamed
+ORPort 443
diff --git a/src/test/conf_examples/bridgeauth_1/expected_no_dirauth b/src/test/conf_examples/bridgeauth_1/expected_no_dirauth
new file mode 100644
index 0000000000..d43aaf2c8b
--- /dev/null
+++ b/src/test/conf_examples/bridgeauth_1/expected_no_dirauth
@@ -0,0 +1,7 @@
+Address 198.51.100.123
+AuthoritativeDirectory 1
+BridgeAuthoritativeDir 1
+ContactInfo tor_parse_test@example.com
+DirPort 80
+Nickname Unnamed
+ORPort 443
diff --git a/src/test/conf_examples/bridgeauth_1/expected_no_dirauth_relay b/src/test/conf_examples/bridgeauth_1/expected_no_dirauth_relay
new file mode 100644
index 0000000000..e059d79971
--- /dev/null
+++ b/src/test/conf_examples/bridgeauth_1/expected_no_dirauth_relay
@@ -0,0 +1,6 @@
+Address 198.51.100.123
+AuthoritativeDirectory 1
+BridgeAuthoritativeDir 1
+ContactInfo tor_parse_test@example.com
+DirPort 80
+ORPort 443
diff --git a/src/test/conf_examples/bridgeauth_1/torrc b/src/test/conf_examples/bridgeauth_1/torrc
new file mode 100644
index 0000000000..740bc6c2eb
--- /dev/null
+++ b/src/test/conf_examples/bridgeauth_1/torrc
@@ -0,0 +1,8 @@
+AuthoritativeDirectory 1
+BridgeAuthoritativeDir 1
+
+ContactInfo tor_parse_test@example.com
+
+Address 198.51.100.123
+ORPort 443
+DirPort 80
diff --git a/src/test/conf_examples/dirauth_1/expected b/src/test/conf_examples/dirauth_1/expected
new file mode 100644
index 0000000000..901f7d947f
--- /dev/null
+++ b/src/test/conf_examples/dirauth_1/expected
@@ -0,0 +1,8 @@
+Address 192.0.2.1
+AuthoritativeDirectory 1
+ContactInfo tor_parse_test@example.net
+DirPort 9030
+DownloadExtraInfo 1
+Nickname Unnamed
+ORPort 9001
+V3AuthoritativeDirectory 1
diff --git a/src/test/conf_examples/dirauth_1/expected_no_dirauth b/src/test/conf_examples/dirauth_1/expected_no_dirauth
new file mode 100644
index 0000000000..f006c6f8f2
--- /dev/null
+++ b/src/test/conf_examples/dirauth_1/expected_no_dirauth
@@ -0,0 +1,7 @@
+Address 192.0.2.1
+AuthoritativeDirectory 1
+ContactInfo tor_parse_test@example.net
+DirPort 9030
+Nickname Unnamed
+ORPort 9001
+V3AuthoritativeDirectory 1
diff --git a/src/test/conf_examples/dirauth_1/expected_no_dirauth_relay b/src/test/conf_examples/dirauth_1/expected_no_dirauth_relay
new file mode 100644
index 0000000000..4b9ad49bb2
--- /dev/null
+++ b/src/test/conf_examples/dirauth_1/expected_no_dirauth_relay
@@ -0,0 +1,6 @@
+Address 192.0.2.1
+AuthoritativeDirectory 1
+ContactInfo tor_parse_test@example.net
+DirPort 9030
+ORPort 9001
+V3AuthoritativeDirectory 1
diff --git a/src/test/conf_examples/dirauth_1/torrc b/src/test/conf_examples/dirauth_1/torrc
new file mode 100644
index 0000000000..b870e6e8e0
--- /dev/null
+++ b/src/test/conf_examples/dirauth_1/torrc
@@ -0,0 +1,8 @@
+AuthoritativeDirectory 1
+V3AuthoritativeDirectory 1
+
+ContactInfo tor_parse_test@example.net
+
+Address 192.0.2.1
+ORPort 9001
+DirPort 9030
diff --git a/src/test/conf_examples/ops_1/expected_no_dirauth_relay b/src/test/conf_examples/ops_1/expected_no_dirauth_relay
new file mode 100644
index 0000000000..2bb9bfa132
--- /dev/null
+++ b/src/test/conf_examples/ops_1/expected_no_dirauth_relay
@@ -0,0 +1 @@
+ORPort 1000
diff --git a/src/test/conf_examples/ops_3/expected_no_dirauth_relay b/src/test/conf_examples/ops_3/expected_no_dirauth_relay
new file mode 100644
index 0000000000..93dea50eeb
--- /dev/null
+++ b/src/test/conf_examples/ops_3/expected_no_dirauth_relay
@@ -0,0 +1,2 @@
+ORPort 9999
+ORPort 1000
diff --git a/src/test/conf_examples/ops_4/expected_no_dirauth_relay b/src/test/conf_examples/ops_4/expected_no_dirauth_relay
new file mode 100644
index 0000000000..56b3a5b71f
--- /dev/null
+++ b/src/test/conf_examples/ops_4/expected_no_dirauth_relay
@@ -0,0 +1 @@
+ORPort 9099
diff --git a/src/test/conf_examples/ops_5/expected_no_dirauth_relay b/src/test/conf_examples/ops_5/expected_no_dirauth_relay
new file mode 100644
index 0000000000..834a785090
--- /dev/null
+++ b/src/test/conf_examples/ops_5/expected_no_dirauth_relay
@@ -0,0 +1,2 @@
+ORPort 9000
+ORPort 9099
diff --git a/src/test/test_key_expiration.sh b/src/test/test_key_expiration.sh
index 54abb4a2fa..9d42c1cc4c 100755
--- a/src/test/test_key_expiration.sh
+++ b/src/test/test_key_expiration.sh
@@ -28,6 +28,11 @@ else
   TOR_BINARY="${TESTING_TOR_BINARY}"
 fi
 
+if "$TOR_BINARY" --list-modules | grep -q "relay: no"; then
+  echo "This test requires the relay module. Skipping." >&2
+  exit 77
+fi
+
 if [ $# -ge 1 ]; then
   dflt=0
 else
diff --git a/src/test/test_keygen.sh b/src/test/test_keygen.sh
index cbdfd1909c..57df888274 100755
--- a/src/test/test_keygen.sh
+++ b/src/test/test_keygen.sh
@@ -28,7 +28,10 @@ else
   TOR_BINARY="${TESTING_TOR_BINARY}"
 fi
 
-
+if "$TOR_BINARY" --list-modules | grep -q "relay: no"; then
+  echo "This test requires the relay module. Skipping." >&2
+  exit 77
+fi
 
   if [ $# -ge 1 ]; then
       dflt=0
diff --git a/src/test/test_parseconf.sh b/src/test/test_parseconf.sh
index eeb80cdfa7..d46be5e5cd 100755
--- a/src/test/test_parseconf.sh
+++ b/src/test/test_parseconf.sh
@@ -36,6 +36,27 @@
 #      matched by some line in the output of "--verify-config", which must
 #      fail. Exactly one of "expected" or "error" must be present, or the
 #      test will fail.
+#
+# {expected,error}_no_${TOR_MODULES_DISABLED} -- If this file is present,
+#      then the outcome is different when some modules are disabled. If there
+#      is no result file matching the exact list of disabled modules, the
+#      standard result file is used.
+#
+#      For example:
+#      A test that succeeds, regardless of any disabled modules:
+#       - expected
+#      A test that has a different result if the relay module is disabled
+#      (but the same result if just the dirauth module is disabled):
+#       - expected
+#       - expected_no_relay_dirauth
+#      A test that fails if the dirauth module is disabled:
+#       - expected
+#       - error_no_dirauth
+#       - error_no_relay_dirauth
+#      (Disabling the relay module also disables dirauth module. But we don't
+#      want to encode that knowledge in this test script, so we supply a
+#      separate result file for every combination of disabled modules that
+#      has a different result.)
 
 umask 077
 set -e
@@ -64,6 +85,11 @@ fi
 
 TOR_BINARY="$(abspath "$TOR_BINARY")"
 
+TOR_MODULES_DISABLED="$("$TOR_BINARY" --list-modules | grep ": no" \
+                        | cut -d ":" -f1 | sort | tr "\n" "_")"
+# Remove the last underscore, if there is one
+TOR_MODULES_DISABLED=${TOR_MODULES_DISABLED%_}
+
 # make a safe space for temporary files
 DATA_DIR=$(mktemp -d -t tor_parseconf_tests.XXXXXX)
 trap 'rm -rf "$DATA_DIR"' 0
@@ -125,12 +151,30 @@ for dir in "${EXAMPLEDIR}"/*; do
         CMDLINE=""
     fi
 
-    if test -f "./expected"; then
-        if test -f "./error"; then
-            echo "FAIL: Found both ${dir}/expected and ${dir}/error."
-            echo "(Only one of these files should exist.)"
-            exit $EXITCODE
+    # If tor has some modules disabled, search for a custom result file for
+    # the disabled modules
+    for suffix in "_no_$TOR_MODULES_DISABLED" ""; do
+
+        if test -f "./expected${suffix}"; then
+
+            # Check for broken configs
+            if test -f "./error${suffix}"; then
+                echo "FAIL: Found both ${dir}/expected${suffix}"
+                echo "and ${dir}/error${suffix}."
+                echo "(Only one of these files should exist.)"
+                exit $EXITCODE
+            fi
+
+            EXPECTED="./expected${suffix}"
+            break
+
+        elif test -f "./error${suffix}"; then
+            ERROR="./error${suffix}"
+            break
         fi
+    done
+
+    if test -f "$EXPECTED"; then
 
         # This case should succeed: run dump-config and see if it does.
 
@@ -141,7 +185,7 @@ for dir in "${EXAMPLEDIR}"/*; do
                         | "${FILTER}" > "${DATA_DIR}/output.${testname}" \
                         || die "Failure: Tor exited."
 
-        if cmp "./expected" "${DATA_DIR}/output.${testname}">/dev/null ; then
+        if cmp "$EXPECTED" "${DATA_DIR}/output.${testname}">/dev/null ; then
             # Check round-trip.
             "${TOR_BINARY}" -f "${DATA_DIR}/output.${testname}" \
                             --defaults-torrc "${DATA_DIR}/empty" \
@@ -166,11 +210,11 @@ for dir in "${EXAMPLEDIR}"/*; do
                                 --verify-config \
                                 ${CMDLINE} || true
             fi
-            diff -u "./expected" "${DATA_DIR}/output.${testname}" || /bin/true
+            diff -u "$EXPECTED" "${DATA_DIR}/output.${testname}" || /bin/true
             exit $EXITCODE
         fi
 
-   elif test -f "./error"; then
+   elif test -f "$ERROR"; then
         # This case should fail: run verify-config and see if it does.
 
         "${TOR_BINARY}" --verify-config \
@@ -180,7 +224,7 @@ for dir in "${EXAMPLEDIR}"/*; do
                         > "${DATA_DIR}/output.${testname}" \
                         && die "Failure: Tor did not report an error."
 
-        expect_err="$(cat ./error)"
+        expect_err="$(cat $ERROR)"
         if grep "${expect_err}" "${DATA_DIR}/output.${testname}" >/dev/null; then
             echo "OK"
         else
@@ -195,7 +239,7 @@ for dir in "${EXAMPLEDIR}"/*; do
         # This case is not actually configured with a success or a failure.
         # call that an error.
 
-        echo "FAIL: Did not find ${dir}/expected or ${dir}/error."
+        echo "FAIL: Did not find ${dir}/*expected or ${dir}/*error."
         exit $EXITCODE
     fi
 
diff --git a/src/test/test_zero_length_keys.sh b/src/test/test_zero_length_keys.sh
index 84ca513b0a..eeabab352d 100755
--- a/src/test/test_zero_length_keys.sh
+++ b/src/test/test_zero_length_keys.sh
@@ -1,6 +1,11 @@
 #!/bin/sh
 # Check that tor regenerates keys when key files are zero-length
 
+if "${builddir:-.}/src/app/tor" --list-modules | grep -q "relay: no"; then
+  echo "This test requires the relay module. Skipping." >&2
+  exit 77
+fi
+
 exitcode=0
 
 "${SHELL:-sh}" "${abs_top_srcdir:-.}/src/test/zero_length_keys.sh" "${builddir:-.}/src/app/tor" -z || exitcode=1