Stop using all dirauth-only options in shared_random_client.c

This is not as clean a patch as I would like: see the comment on
ASSUME_AUTHORITY_SCHEDULING. This issue here is that the unit tests
sometimes assume that we are going to be looking at the dirauth
options and behaving like a dirauth, but without setting the options
to turn is into one.

This isn't an issue for actually running Tor, as far as I can tell
with chutney.

src/feature/dirauth/shared_random_state.c

@@ -139,7 +139,7 @@ get_state_valid_until_time(time_t now)
 
   voting_interval = get_voting_interval();
   /* Find the time the current round started. */
-  beginning_of_current_round = get_start_time_of_current_round();
+  beginning_of_current_round = dirauth_sched_get_cur_valid_after_time();
 
   /* Find how many rounds are left till the end of the protocol run */
   current_round = (now / voting_interval) % total_rounds;

src/feature/dirauth/voting_schedule.c

@@ -51,6 +51,7 @@ create_voting_schedule(const or_options_t *options, time_t now, int severity)
   }
 
   tor_assert(interval > 0);
+  new_voting_schedule->interval = interval;
 
   if (vote_delay + dist_delay > interval/2)
     vote_delay = dist_delay = interval / 4;
@@ -143,6 +144,24 @@ dirauth_sched_get_next_valid_after_time(void)
   return dirauth_get_voting_schedule()->interval_starts;
 }
 
+/**
+ * Return our best idea of what the valid-after time for the _current_
+ * consensus, whether we have one or not.
+ *
+ * Dirauth only.
+ **/
+time_t
+dirauth_sched_get_cur_valid_after_time(void)
+{
+  const voting_schedule_t *sched = dirauth_get_voting_schedule();
+  time_t next_start = sched->interval_starts;
+  int interval = sched->interval;
+  int offset = get_options()->TestingV3AuthVotingStartOffset;
+  return voting_sched_get_start_of_interval_after(next_start - interval - 1,
+                                                  interval,
+                                                  offset);
+}
+
 /** Return the voting interval that we are configured to use.
  *
  * Dirauth only. */

src/feature/dirauth/voting_schedule.h

@@ -26,6 +26,9 @@ typedef struct {
   /** When do we publish the consensus? */
   time_t interval_starts;
 
+  /** Our computed dirauth interval */
+  int interval;
+
   /** True iff we have generated and distributed our vote. */
   int have_voted;
   /** True iff we've requested missing votes. */
@@ -57,6 +60,7 @@ void dirauth_sched_recalculate_timing(const or_options_t *options,
                                         time_t now);
 
 time_t dirauth_sched_get_next_valid_after_time(void);
+time_t dirauth_sched_get_cur_valid_after_time(void);
 int dirauth_sched_get_configured_interval(void);
 
 #endif /* !defined(TOR_VOTING_SCHEDULE_H) */

src/feature/hs_common/shared_random_client.c

@@ -11,6 +11,7 @@
 #include "feature/hs_common/shared_random_client.h"
 
 #include "app/config/config.h"
+#include "feature/dirauth/authmode.h"
 #include "feature/dirauth/voting_schedule.h"
 #include "feature/nodelist/networkstatus.h"
 #include "lib/encoding/binascii.h"
@@ -31,6 +32,24 @@ srv_to_control_string(const sr_srv_t *srv)
   return srv_str;
 }
 
+/**
+ * If we have no consensus and we are not an authority, assume that this is
+ * the voting interval.  We should never actually use this: only authorities
+ * should be trying to figure out the schedule when they don't have a
+ * consensus.
+ **/
+#define DEFAULT_NETWORK_VOTING_INTERVAL (3600)
+
+/* This is an unpleasing workaround for tests.  Our unit tests assume that we
+ * are scheduling all of our shared random stuff as if we were a directory
+ * authority, but they do not always set V3AuthoritativeDir.
+ */
+#ifdef TOR_UNIT_TESTS
+#define ASSUME_AUTHORITY_SCHEDULING 1
+#else
+#define ASSUME_AUTHORITY_SCHEDULING 0
+#endif
+
 /** Return the voting interval of the tor vote subsystem. */
 int
 get_voting_interval(void)
@@ -40,39 +59,16 @@ get_voting_interval(void)
 
   if (consensus) {
     interval = (int)(consensus->fresh_until - consensus->valid_after);
+  } else if (authdir_mode(get_options()) || ASSUME_AUTHORITY_SCHEDULING) {
+    interval = dirauth_sched_get_configured_interval();
   } else {
-    /* Same for both a testing and real network. We voluntarily ignore the
-     * InitialVotingInterval since it complexifies things and it doesn't
-     * affect the SR protocol. */
-    interval = get_options()->V3AuthVotingInterval;
+    tor_assert_nonfatal_unreached_once();
+    interval = DEFAULT_NETWORK_VOTING_INTERVAL;
   }
   tor_assert(interval > 0);
   return interval;
 }
 
-/** Given the current consensus, return the start time of the current round of
- * the SR protocol. For example, if it's 23:47:08, the current round thus
- * started at 23:47:00 for a voting interval of 10 seconds.
- *
- * This function uses the consensus voting schedule to derive its results,
- * instead of the actual consensus we are currently using, so it should be used
- * for voting purposes. */
-time_t
-get_start_time_of_current_round(void)
-{
-  const or_options_t *options = get_options();
-  int voting_interval = get_voting_interval();
-  /* First, get the start time of the next round */
-  time_t next_start = dirauth_sched_get_next_valid_after_time();
-  /* Now roll back next_start by a voting interval to find the start time of
-     the current round. */
-  time_t curr_start = voting_sched_get_start_of_interval_after(
-                                     next_start - voting_interval - 1,
-                                     voting_interval,
-                                     options->TestingV3AuthVotingStartOffset);
-  return curr_start;
-}
-
 /*
  * Public API
  */
@@ -242,8 +238,14 @@ sr_state_get_start_time_of_current_protocol_run(void)
   networkstatus_t *ns = networkstatus_get_live_consensus(approx_time());
   if (ns) {
     beginning_of_curr_round = ns->valid_after;
+  } else if (authdir_mode(get_options()) || ASSUME_AUTHORITY_SCHEDULING) {
+    beginning_of_curr_round = dirauth_sched_get_cur_valid_after_time();
   } else {
-    beginning_of_curr_round = get_start_time_of_current_round();
+    tor_assert_nonfatal_unreached_once();
+    beginning_of_curr_round = voting_sched_get_start_of_interval_after(
+                                             approx_time() - voting_interval,
+                                             voting_interval,
+                                             0);
   }
 
   /* Get current SR protocol round */

src/feature/hs_common/shared_random_client.h

@@ -38,11 +38,9 @@ time_t sr_state_get_start_time_of_current_protocol_run(void);
 time_t sr_state_get_start_time_of_previous_protocol_run(void);
 unsigned int sr_state_get_phase_duration(void);
 unsigned int sr_state_get_protocol_run_duration(void);
-time_t get_start_time_of_current_round(void);
 
 #ifdef TOR_UNIT_TESTS
 
 #endif /* TOR_UNIT_TESTS */
 
 #endif /* !defined(TOR_SHARED_RANDOM_CLIENT_H) */
-

src/test/test_shared_random.c

@@ -384,7 +384,7 @@ test_get_start_time_functions(void *arg)
   tt_assert(start_time_of_protocol_run);
 
   /* Check that the round start time of the beginning of the run, is itself */
-  tt_int_op(get_start_time_of_current_round(), OP_EQ,
+  tt_int_op(dirauth_sched_get_cur_valid_after_time(), OP_EQ,
             start_time_of_protocol_run);
 
  done: