Move dirclient-related functions out of dirserv, and reenable them

I had incorrectly identified these functions as dircache-only, when
in fact they apply to everyone who acts a directory client.

3 files changed, 109 insertions, 0 deletions

diff --git a/src/feature/dirclient/dirclient.c b/src/feature/dirclient/dirclient.c
index 721b0f8d1a..200e4e6a15 100644
--- a/src/feature/dirclient/dirclient.c
+++ b/src/feature/dirclient/dirclient.c
@@ -25,6 +25,7 @@
 #include "feature/dirauth/shared_random.h"
 #include "feature/dircache/dirserv.h"
 #include "feature/dirclient/dirclient.h"
+#include "feature/dirclient/dirclient_modes.h"
 #include "feature/dirclient/dlstatus.h"
 #include "feature/dircommon/consdiff.h"
 #include "feature/dircommon/directory.h"
diff --git a/src/feature/dirclient/dirclient_modes.c b/src/feature/dirclient/dirclient_modes.c
new file mode 100644
index 0000000000..37d2d7e044
--- /dev/null
+++ b/src/feature/dirclient/dirclient_modes.c
@@ -0,0 +1,85 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2020, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * @file dirclient_modes.c
+ * @brief Functions to answer questions about how we'd like to behave
+ *     as a directory client
+ **/
+
+#include "orconfig.h"
+
+#include "core/or/or.h"
+
+#include "feature/dirclient/dirclient_modes.h"
+#include "feature/dircache/dirserv.h"
+#include "feature/relay/router.h"
+#include "feature/relay/routermode.h"
+#include "feature/stats/predict_ports.h"
+
+#include "app/config/or_options_st.h"
+#include "feature/nodelist/routerinfo_st.h"
+
+/** Return 1 if we fetch our directory material directly from the
+ * authorities, rather than from a mirror. */
+int
+directory_fetches_from_authorities(const or_options_t *options)
+{
+  const routerinfo_t *me;
+  uint32_t addr;
+  int refuseunknown;
+  if (options->FetchDirInfoEarly)
+    return 1;
+  if (options->BridgeRelay == 1)
+    return 0;
+  if (server_mode(options) &&
+      router_pick_published_address(options, &addr, 1) < 0)
+    return 1; /* we don't know our IP address; ask an authority. */
+  refuseunknown = ! router_my_exit_policy_is_reject_star() &&
+    should_refuse_unknown_exits(options);
+  if (!dir_server_mode(options) && !refuseunknown)
+    return 0;
+  if (!server_mode(options) || !advertised_server_mode())
+    return 0;
+  me = router_get_my_routerinfo();
+  if (!me || (!me->supports_tunnelled_dir_requests && !refuseunknown))
+    return 0; /* if we don't service directory requests, return 0 too */
+  return 1;
+}
+
+/** Return 1 if we should fetch new networkstatuses, descriptors, etc
+ * on the "mirror" schedule rather than the "client" schedule.
+ */
+int
+directory_fetches_dir_info_early(const or_options_t *options)
+{
+  return directory_fetches_from_authorities(options);
+}
+
+/** Return 1 if we should fetch new networkstatuses, descriptors, etc
+ * on a very passive schedule -- waiting long enough for ordinary clients
+ * to probably have the info we want. These would include bridge users,
+ * and maybe others in the future e.g. if a Tor client uses another Tor
+ * client as a directory guard.
+ */
+int
+directory_fetches_dir_info_later(const or_options_t *options)
+{
+  return options->UseBridges != 0;
+}
+
+/** Return 1 if we have no need to fetch new descriptors. This generally
+ * happens when we're not a dir cache and we haven't built any circuits
+ * lately.
+ */
+int
+directory_too_idle_to_fetch_descriptors(const or_options_t *options,
+                                        time_t now)
+{
+  return !directory_caches_dir_info(options) &&
+         !options->FetchUselessDescriptors &&
+         rep_hist_circbuilding_dormant(now);
+}
diff --git a/src/feature/dirclient/dirclient_modes.h b/src/feature/dirclient/dirclient_modes.h
new file mode 100644
index 0000000000..ceb883038c
--- /dev/null
+++ b/src/feature/dirclient/dirclient_modes.h
@@ -0,0 +1,23 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2020, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * @file dirclient_modes.h
+ * @brief Header for feature/dirclient/dirclient_modes.c
+ **/
+
+#ifndef TOR_FEATURE_DIRCLIENT_DIRCLIENT_MODES_H
+#define TOR_FEATURE_DIRCLIENT_DIRCLIENT_MODES_H
+
+struct or_options_t;
+
+int directory_fetches_from_authorities(const struct or_options_t *options);
+int directory_fetches_dir_info_early(const struct or_options_t *options);
+int directory_fetches_dir_info_later(const struct or_options_t *options);
+int directory_too_idle_to_fetch_descriptors(const struct or_options_t *options,
+                                            time_t now);
+
+#endif /* !defined(TOR_FEATURE_DIRCLIENT_DIRCLIENT_MODES_H) */