dirauth: Move authdir_mode_v3() to module

This function must return false if the module is not compiled in. In order to
do that, we move the authdir_mode_v3() function out of router.c and into the
dirauth module new header file named mode.h.

It is always returning false if we don't have the module.

Closes #25990

Signed-off-by: David Goulet <dgoulet@torproject.org>

3 files changed, 43 insertions, 2 deletions

diff --git a/src/or/dirauth/dirvote.c b/src/or/dirauth/dirvote.c
index 66a530b6db..cbc3ff7829 100644
--- a/src/or/dirauth/dirvote.c
+++ b/src/or/dirauth/dirvote.c
@@ -9,7 +9,6 @@
 #include "dircollate.h"
 #include "directory.h"
 #include "dirserv.h"
-#include "dirvote.h"
 #include "microdesc.h"
 #include "networkstatus.h"
 #include "nodelist.h"
@@ -23,9 +22,12 @@
 #include "routerparse.h"
 #include "entrynodes.h" /* needed for guardfraction methods */
 #include "torcert.h"
-#include "shared_random_state.h"
 #include "voting_schedule.h"
 
+#include "dirauth/dirvote.h"
+#include "dirauth/mode.h"
+#include "dirauth/shared_random_state.h"
+
 /**
  * \file dirvote.c
  * \brief Functions to compute directory consensus, and schedule voting.
diff --git a/src/or/dirauth/mode.h b/src/or/dirauth/mode.h
new file mode 100644
index 0000000000..8a0d3142f1
--- /dev/null
+++ b/src/or/dirauth/mode.h
@@ -0,0 +1,38 @@
+/* Copyright (c) 2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file mode.h
+ * \brief Standalone header file for directory authority mode.
+ **/
+
+#ifndef TOR_DIRAUTH_MODE_H
+#define TOR_DIRAUTH_MODE_H
+
+#ifdef HAVE_MODULE_DIRAUTH
+
+#include "router.h"
+
+/* Return true iff we believe ourselves to be a v3 authoritative directory
+ * server. */
+static inline int
+authdir_mode_v3(const or_options_t *options)
+{
+  return authdir_mode(options) && options->V3AuthoritativeDir != 0;
+}
+
+#else /* HAVE_MODULE_DIRAUTH */
+
+/* Without the dirauth module, we can't be a v3 directory authority, ever. */
+
+static inline int
+authdir_mode_v3(const or_options_t *options)
+{
+  (void) options;
+  return 0;
+}
+
+#endif /* HAVE_MODULE_DIRAUTH */
+
+#endif /* TOR_MODE_H */
+
diff --git a/src/or/dirauth/shared_random.c b/src/or/dirauth/shared_random.c
index f7ff5c58bb..0a89fa8d2d 100644
--- a/src/or/dirauth/shared_random.c
+++ b/src/or/dirauth/shared_random.c
@@ -101,6 +101,7 @@
 #include "voting_schedule.h"
 
 #include "dirauth/dirvote.h"
+#include "dirauth/mode.h"
 
 /* String prefix of shared random values in votes/consensuses. */
 static const char previous_srv_str[] = "shared-rand-previous-value";