[tor-commits] [tor/master] Remove the (no longer compiled) code for legacy guard selection.

nickm at torproject.org nickm at torproject.org
Tue Jan 24 14:01:34 UTC 2017


commit 472b277207219d791a399d4d449af6ffdf00a081
Author: Nick Mathewson <nickm at torproject.org>
Date:   Wed Jan 18 15:27:10 2017 -0500

    Remove the (no longer compiled) code for legacy guard selection.
    
    Part of 20830.
---
 src/or/bridges.c           |    9 -
 src/or/channel.c           |   13 -
 src/or/circpathbias.c      |    8 -
 src/or/circuitbuild.c      |   20 -
 src/or/circuituse.c        |    4 -
 src/or/config.c            |   16 -
 src/or/connection_or.c     |   10 -
 src/or/entrynodes.c        | 1896 ++------------------------------------------
 src/or/entrynodes.h        |  122 ---
 src/or/routerlist.c        |   11 +-
 src/test/test_entrynodes.c |  764 ------------------
 src/test/test_routerlist.c |   84 --
 12 files changed, 54 insertions(+), 2903 deletions(-)

diff --git a/src/or/bridges.c b/src/or/bridges.c
index 7d1acdf..d9a8873 100644
--- a/src/or/bridges.c
+++ b/src/or/bridges.c
@@ -762,11 +762,7 @@ learned_bridge_descriptor(routerinfo_t *ri, int from_cache)
                    (int) bridge->port);
       }
       if (get_options()->UseDeprecatedGuardAlgorithm) {
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-        add_bridge_as_entry_guard(get_guard_selection_info(), node);
-#else
         tor_assert_nonfatal_unreached();
-#endif
       } else {
         entry_guard_learned_bridge_identity(&bridge->addrport_configured,
                                (const uint8_t*)ri->cache_info.identity_digest);
@@ -777,12 +773,7 @@ learned_bridge_descriptor(routerinfo_t *ri, int from_cache)
       /* set entry->made_contact so if it goes down we don't drop it from
        * our entry node list */
       if (get_options()->UseDeprecatedGuardAlgorithm) {
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-        entry_guard_register_connect_status(ri->cache_info.identity_digest,
-                                            1, 0, now);
-#else
         tor_assert_nonfatal_unreached();
-#endif
       }
       if (first) {
         routerlist_retry_directory_downloads(now);
diff --git a/src/or/channel.c b/src/or/channel.c
index dbf442e..45f1602 100644
--- a/src/or/channel.c
+++ b/src/or/channel.c
@@ -2577,19 +2577,6 @@ channel_do_open_actions(channel_t *chan)
   if (started_here) {
     circuit_build_times_network_is_live(get_circuit_build_times_mutable());
     rep_hist_note_connect_succeeded(chan->identity_digest, now);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-    // XXXX prop271 this call is no longer useful with the new algorithm.
-    if (entry_guard_register_connect_status(
-          chan->identity_digest, 1, 0, now) < 0) {
-      /* Close any circuits pending on this channel. We leave it in state
-       * 'open' though, because it didn't actually *fail* -- we just
-       * chose not to use it. */
-      log_debug(LD_OR,
-                "New entry guard was reachable, but closing this "
-                "connection so we can retry the earlier entry guards.");
-      close_origin_circuits = 1;
-    }
-#endif
     router_set_status(chan->identity_digest, 1);
   } else {
     /* only report it to the geoip module if it's not a known router */
diff --git a/src/or/circpathbias.c b/src/or/circpathbias.c
index d86d70f..cdcb6de 100644
--- a/src/or/circpathbias.c
+++ b/src/or/circpathbias.c
@@ -1279,10 +1279,6 @@ pathbias_measure_use_rate(entry_guard_t *guard)
                  tor_lround(pb->timeouts),
                  tor_lround(get_circuit_build_close_time_ms()/1000));
           pb->path_bias_disabled = 1;
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-          // XXXX
-          entry_guard_mark_bad(guard);
-#endif
           return;
         }
       } else if (!pb->path_bias_use_extreme) {
@@ -1388,10 +1384,6 @@ pathbias_measure_close_rate(entry_guard_t *guard)
                  tor_lround(pb->timeouts),
                  tor_lround(get_circuit_build_close_time_ms()/1000));
           pb->path_bias_disabled = 1;
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-          // XXXX
-          entry_guard_mark_bad(guard);
-#endif
           return;
         }
       } else if (!pb->path_bias_extreme) {
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index d4e3019..91bd823 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -2308,26 +2308,6 @@ choose_good_entry_server(uint8_t purpose, cpath_build_state_t *state,
      * family. */
     nodelist_add_node_and_family(excluded, node);
   }
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  /* and exclude current entry guards and their families,
-   * unless we're in a test network, and excluding guards
-   * would exclude all nodes (i.e. we're in an incredibly small tor network,
-   * or we're using TestingAuthVoteGuard *).
-   * This is an incomplete fix, but is no worse than the previous behaviour,
-   * and only applies to minimal, testing tor networks
-   * (so it's no less secure) */
-  if (options->UseEntryGuards
-      && (!options->TestingTorNetwork ||
-         smartlist_len(nodelist_get_list()) > smartlist_len(get_entry_guards())
-     )) {
-    SMARTLIST_FOREACH(get_entry_guards(), const entry_guard_t *, entry,
-      {
-        if ((node = entry_guard_find_node(entry))) {
-          nodelist_add_node_and_family(excluded, node);
-        }
-      });
-  }
-#endif
 
   if (state) {
     if (state->need_uptime)
diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index 72293f5..c2b4506 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -1732,10 +1732,6 @@ circuit_build_failed(origin_circuit_t *circ)
       /* New guard API: we failed. */
       if (circ->guard_state)
         entry_guard_failed(&circ->guard_state);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-      /* Old guard API: we failed. */
-      entry_guard_register_connect_status(n_chan_id, 0, 1, time(NULL));
-#endif
       /* if there are any one-hop streams waiting on this circuit, fail
        * them now so they can retry elsewhere. */
       connection_ap_fail_onehop(n_chan_id, circ->build_state);
diff --git a/src/or/config.c b/src/or/config.c
index f885cbc..7240308 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -2097,15 +2097,6 @@ options_act(const or_options_t *old_options)
       !options->BridgeAuthoritativeDir)
     rep_hist_desc_stats_term();
 
-  /* Check if we need to parse and add the EntryNodes config option. */
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  if (options->EntryNodes &&
-      (!old_options ||
-       !routerset_equal(old_options->EntryNodes,options->EntryNodes) ||
-       !routerset_equal(old_options->ExcludeNodes,options->ExcludeNodes)))
-    entry_nodes_should_be_added();
-#endif
-
   /* Since our options changed, we might need to regenerate and upload our
    * server descriptor.
    */
@@ -3009,13 +3000,6 @@ options_validate(or_options_t *old_options, or_options_t *options,
 
   warn_about_relative_paths(options);
 
-#ifndef ENABLE_LEGACY_GUARD_ALGORITHM
-  if (options->UseDeprecatedGuardAlgorithm) {
-    log_warn(LD_CONFIG, "DeprecatedGuardAlgorithm not supported.");
-    return -1;
-  }
-#endif
-
   if (server_mode(options) &&
       (!strcmpstart(uname, "Windows 95") ||
        !strcmpstart(uname, "Windows 98") ||
diff --git a/src/or/connection_or.c b/src/or/connection_or.c
index b3ae291..cefe42c 100644
--- a/src/or/connection_or.c
+++ b/src/or/connection_or.c
@@ -718,11 +718,6 @@ connection_or_about_to_close(or_connection_t *or_conn)
       rep_hist_note_connect_failed(or_conn->identity_digest, now);
       /* Tell the new guard API about the channel failure */
       entry_guard_chan_failed(TLS_CHAN_TO_BASE(or_conn->chan));
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-      /* Tell the old guard API about the channel failure */
-      entry_guard_register_connect_status(or_conn->identity_digest,0,
-                                          !options->HTTPSProxy, now);
-#endif
       if (conn->state >= OR_CONN_STATE_TLS_HANDSHAKING) {
         int reason = tls_error_to_orconn_end_reason(or_conn->tls_error);
         control_event_or_conn_status(or_conn, OR_CONN_EVENT_FAILED,
@@ -1728,11 +1723,6 @@ connection_or_client_learned_peer_id(or_connection_t *conn,
 
     /* Tell the new guard API about the channel failure */
     entry_guard_chan_failed(TLS_CHAN_TO_BASE(conn->chan));
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-    /* Tell the old guard API about the channel failure */
-    entry_guard_register_connect_status(conn->identity_digest, 0, 1,
-                                        time(NULL));
-#endif
     control_event_or_conn_status(conn, OR_CONN_EVENT_FAILED,
                                  END_OR_CONN_REASON_OR_IDENTITY);
     if (!authdir_mode_tests_reachability(options))
diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c
index ca3e57b..195c6b9 100644
--- a/src/or/entrynodes.c
+++ b/src/or/entrynodes.c
@@ -151,13 +151,6 @@ static guard_selection_t *curr_guard_context = NULL;
  * and those changes need to be flushed to disk. */
 static int entry_guards_dirty = 0;
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-static const node_t *choose_random_entry_impl(guard_selection_t *gs,
-                                              cpath_build_state_t *state,
-                                              int for_directory,
-                                              dirinfo_type_t dirtype,
-                                              int *n_options_out);
-#endif
 static void entry_guard_set_filtered_flags(const or_options_t *options,
                                            guard_selection_t *gs,
                                            entry_guard_t *guard);
@@ -232,9 +225,6 @@ guard_selection_new(const char *name,
   gs = tor_malloc_zero(sizeof(*gs));
   gs->name = tor_strdup(name);
   gs->type = type;
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  gs->chosen_entry_guards = smartlist_new();
-#endif
   gs->sampled_entry_guards = smartlist_new();
   gs->confirmed_entry_guards = smartlist_new();
   gs->primary_entry_guards = smartlist_new();
@@ -304,35 +294,6 @@ get_guard_selection_info(void)
   return curr_guard_context;
 }
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/** Return the list of entry guards for a guard_selection_t, creating it
- * if necessary. */
-const smartlist_t *
-get_entry_guards_for_guard_selection(guard_selection_t *gs)
-{
-  tor_assert(gs != NULL);
-  tor_assert(gs->chosen_entry_guards != NULL);
-
-  return gs->chosen_entry_guards;
-}
-
-/** Return the list of entry guards for the default guard_selection_t,
- * creating it if necessary. */
-const smartlist_t *
-get_entry_guards(void)
-{
-  return get_entry_guards_for_guard_selection(get_guard_selection_info());
-}
-
-/** Helper: mark an entry guard as not usable. */
-void
-entry_guard_mark_bad(entry_guard_t *guard)
-{
-  guard->bad_since = approx_time();
-  entry_guards_changed();
-}
-#endif
-
 /** Return a statically allocated human-readable description of <b>guard</b>
  */
 const char *
@@ -2927,291 +2888,6 @@ entry_guards_load_guards_from_state(or_state_t *state, int set)
   return n_errors ? -1 : 0;
 }
 
-/* XXXXX ----------------------------------------------- */
-/* XXXXX prop271 ----- end of new-for-prop271 code ----- */
-/* XXXXX ----------------------------------------------- */
-
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/**
- * @name Constants for old (pre-prop271) guard selection algorithm.
- */
-
-/**@{*/
-
-/* Default number of entry guards in the case where the NumEntryGuards
- * consensus parameter is not set */
-#define DEFAULT_N_GUARDS 1
-/* Minimum and maximum number of entry guards (in case the NumEntryGuards
- * consensus parameter is set). */
-#define MIN_N_GUARDS 1
-#define MAX_N_GUARDS 10
-/** Largest amount that we'll backdate chosen_on_date */
-#define CHOSEN_ON_DATE_SLOP (30*86400)
-/** How long (in seconds) do we allow an entry guard to be nonfunctional,
- * unlisted, excluded, or otherwise nonusable before we give up on it? */
-#define ENTRY_GUARD_REMOVE_AFTER (30*24*60*60)
-/**}@*/
-
-/**
- * @name Networkstatus parameters for old (pre-prop271) guard selection
- */
-/**@}*/
-/** Choose how many entry guards or directory guards we'll use. If
- * <b>for_directory</b> is true, we return how many directory guards to
- * use; else we return how many entry guards to use. */
-STATIC int
-decide_num_guards(const or_options_t *options, int for_directory)
-{
-  if (for_directory) {
-    int answer;
-    if (options->NumDirectoryGuards != 0)
-      return options->NumDirectoryGuards;
-    answer = networkstatus_get_param(NULL, "NumDirectoryGuards", 0, 0, 10);
-    if (answer) /* non-zero means use the consensus value */
-      return answer;
-  }
-
-  if (options->NumEntryGuards)
-    return options->NumEntryGuards;
-
-  /* Use the value from the consensus, or 3 if no guidance. */
-  return networkstatus_get_param(NULL, "NumEntryGuards", DEFAULT_N_GUARDS,
-                                 MIN_N_GUARDS, MAX_N_GUARDS);
-}
-
-/** Check whether the entry guard <b>e</b> is usable, given the directory
- * authorities' opinion about the router (stored in <b>ri</b>) and the user's
- * configuration (in <b>options</b>). Set <b>e</b>->bad_since
- * accordingly. Return true iff the entry guard's status changes.
- *
- * If it's not usable, set *<b>reason</b> to a static string explaining why.
- */
-static int
-entry_guard_set_status(entry_guard_t *e, const node_t *node,
-                       time_t now, const or_options_t *options,
-                       const char **reason)
-{
-  char buf[HEX_DIGEST_LEN+1];
-  int changed = 0;
-
-  *reason = NULL;
-
-  /* Do we want to mark this guard as bad? */
-  if (!node)
-    *reason = "unlisted";
-  else if (!node->is_running)
-    *reason = "down";
-  else if (options->UseBridges && (!node->ri ||
-                                   node->ri->purpose != ROUTER_PURPOSE_BRIDGE))
-    *reason = "not a bridge";
-  else if (options->UseBridges && !node_is_a_configured_bridge(node))
-    *reason = "not a configured bridge";
-  else if (!options->UseBridges && !node->is_possible_guard &&
-           !routerset_contains_node(options->EntryNodes,node))
-    *reason = "not recommended as a guard";
-  else if (routerset_contains_node(options->ExcludeNodes, node))
-    *reason = "excluded";
-  /* We only care about OR connection connectivity for entry guards. */
-  else if (!fascist_firewall_allows_node(node, FIREWALL_OR_CONNECTION, 0))
-    *reason = "unreachable by config";
-  else if (e->pb.path_bias_disabled)
-    *reason = "path-biased";
-
-  if (*reason && ! e->bad_since) {
-    /* Router is newly bad. */
-    base16_encode(buf, sizeof(buf), e->identity, DIGEST_LEN);
-    log_info(LD_CIRC, "Entry guard %s (%s) is %s: marking as unusable.",
-             e->nickname, buf, *reason);
-
-    e->bad_since = now;
-    control_event_guard(e->nickname, e->identity, "BAD");
-    changed = 1;
-  } else if (!*reason && e->bad_since) {
-    /* There's nothing wrong with the router any more. */
-    base16_encode(buf, sizeof(buf), e->identity, DIGEST_LEN);
-    log_info(LD_CIRC, "Entry guard %s (%s) is no longer unusable: "
-             "marking as ok.", e->nickname, buf);
-
-    e->bad_since = 0;
-    control_event_guard(e->nickname, e->identity, "GOOD");
-    changed = 1;
-  }
-
-  if (node) {
-    int is_dir = node_is_dir(node);
-    if (options->UseBridges && node_is_a_configured_bridge(node))
-      is_dir = 1;
-    if (e->is_dir_cache != is_dir) {
-      e->is_dir_cache = is_dir;
-      changed = 1;
-    }
-  }
-
-  return changed;
-}
-
-/** Return true iff enough time has passed since we last tried to connect
- * to the unreachable guard <b>e</b> that we're willing to try again. */
-STATIC int
-entry_is_time_to_retry(const entry_guard_t *e, time_t now)
-{
-  struct guard_retry_period_s {
-    time_t period_duration;
-    time_t interval_during_period;
-  };
-
-  struct guard_retry_period_s periods[] = {
-     {    6*60*60,    60*60 }, /* For first 6 hrs., retry hourly; */
-     { 3*24*60*60,  4*60*60 }, /* Then retry every 4 hrs. until the
-                                  3-day mark; */
-     { 7*24*60*60, 18*60*60 }, /* After 3 days, retry every 18 hours until
-                                  1 week mark. */
-     {   TIME_MAX, 36*60*60 }  /* After 1 week, retry every 36 hours. */
-  };
-
-  time_t ith_deadline_for_retry;
-  time_t unreachable_for;
-  unsigned i;
-
-  if (e->last_attempted < e->unreachable_since)
-    return 1;
-
-  unreachable_for = now - e->unreachable_since;
-
-  for (i = 0; i < ARRAY_LENGTH(periods); i++) {
-    if (unreachable_for <= periods[i].period_duration) {
-      ith_deadline_for_retry = e->last_attempted +
-                               periods[i].interval_during_period;
-
-      return (now > ith_deadline_for_retry);
-    }
-  }
-  return 0;
-}
-
-/** Return the node corresponding to <b>e</b>, if <b>e</b> is
- * working well enough that we are willing to use it as an entry
- * right now. (Else return NULL.) In particular, it must be
- * - Listed as either up or never yet contacted;
- * - Present in the routerlist;
- * - Listed as 'stable' or 'fast' by the current dirserver consensus,
- *   if demanded by <b>need_uptime</b> or <b>need_capacity</b>
- *   (unless it's a configured EntryNode);
- * - Allowed by our current ReachableORAddresses config option; and
- * - Currently thought to be reachable by us (unless <b>assume_reachable</b>
- *   is true).
- *
- * If the answer is no, set *<b>msg</b> to an explanation of why.
- *
- * If need_descriptor is true, only return the node if we currently have
- * a descriptor (routerinfo or microdesc) for it.
- */
-STATIC const node_t *
-entry_is_live(const entry_guard_t *e, entry_is_live_flags_t flags,
-              const char **msg)
-{
-  const node_t *node;
-  const or_options_t *options = get_options();
-  int need_uptime = (flags & ENTRY_NEED_UPTIME) != 0;
-  int need_capacity = (flags & ENTRY_NEED_CAPACITY) != 0;
-  const int assume_reachable = (flags & ENTRY_ASSUME_REACHABLE) != 0;
-  const int need_descriptor = (flags & ENTRY_NEED_DESCRIPTOR) != 0;
-
-  tor_assert(msg);
-
-  if (e->pb.path_bias_disabled) {
-    *msg = "path-biased";
-    return NULL;
-  }
-  if (e->bad_since) {
-    *msg = "bad";
-    return NULL;
-  }
-  /* no good if it's unreachable, unless assume_unreachable or can_retry. */
-  if (!assume_reachable && !e->can_retry &&
-      e->unreachable_since && !entry_is_time_to_retry(e, time(NULL))) {
-    *msg = "unreachable";
-    return NULL;
-  }
-  node = node_get_by_id(e->identity);
-  if (!node) {
-    *msg = "no node info";
-    return NULL;
-  }
-  if (need_descriptor && !node_has_descriptor(node)) {
-    *msg = "no descriptor";
-    return NULL;
-  }
-  if (get_options()->UseBridges) {
-    if (node_get_purpose(node) != ROUTER_PURPOSE_BRIDGE) {
-      *msg = "not a bridge";
-      return NULL;
-    }
-    if (!node_is_a_configured_bridge(node)) {
-      *msg = "not a configured bridge";
-      return NULL;
-    }
-  } else { /* !get_options()->UseBridges */
-    if (node_get_purpose(node) != ROUTER_PURPOSE_GENERAL) {
-      *msg = "not general-purpose";
-      return NULL;
-    }
-  }
-  if (routerset_contains_node(options->EntryNodes, node)) {
-    /* they asked for it, they get it */
-    need_uptime = need_capacity = 0;
-  }
-  if (node_is_unreliable(node, need_uptime, need_capacity, 0)) {
-    *msg = "not fast/stable";
-    return NULL;
-  }
-  if (!fascist_firewall_allows_node(node, FIREWALL_OR_CONNECTION, 0)) {
-    *msg = "unreachable by config";
-    return NULL;
-  }
-  return node;
-}
-
-/** Return the number of entry guards that we think are usable, in the
- * context of the given guard_selection_t */
-int
-num_live_entry_guards_for_guard_selection(guard_selection_t *gs,
-                                          int for_directory)
-{
-  int n = 0;
-  const char *msg;
-
-  tor_assert(gs != NULL);
-
-  /* Set the entry node attributes we are interested in. */
-  entry_is_live_flags_t entry_flags = ENTRY_NEED_CAPACITY;
-  if (!for_directory) {
-    entry_flags |= ENTRY_NEED_DESCRIPTOR;
-  }
-
-  if (!(gs->chosen_entry_guards)) {
-    return 0;
-  }
-
-  SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *, entry) {
-      if (for_directory && !entry->is_dir_cache)
-        continue;
-      if (entry_is_live(entry, entry_flags, &msg))
-        ++n;
-  } SMARTLIST_FOREACH_END(entry);
-  return n;
-}
-
-/** Return the number of entry guards that we think are usable, for the
- * default guard selection */
-int
-num_live_entry_guards(int for_directory)
-{
-  return num_live_entry_guards_for_guard_selection(
-      get_guard_selection_info(), for_directory);
-}
-#endif
-
 /** If <b>digest</b> matches the identity of any node in the
  * entry_guards list for the provided guard selection state,
  return that node. Else return NULL. */
@@ -3225,12 +2901,6 @@ entry_guard_get_by_id_digest_for_guard_selection(guard_selection_t *gs,
                     if (tor_memeq(digest, entry->identity, DIGEST_LEN))
                       return entry;
                    );
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  SMARTLIST_FOREACH(gs->chosen_entry_guards, entry_guard_t *, entry,
-                    if (tor_memeq(digest, entry->identity, DIGEST_LEN))
-                      return entry;
-                   );
-#endif
   return NULL;
 }
 
@@ -3253,234 +2923,6 @@ entry_guard_get_by_id_digest(const char *digest)
       get_guard_selection_info(), digest);
 }
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/** Dump a description of our list of entry guards in the given guard
- * selection context to the log at level <b>severity</b>. */
-static void
-log_entry_guards_for_guard_selection(guard_selection_t *gs, int severity)
-{
-  smartlist_t *elements = smartlist_new();
-  char *s;
-
-  /*
-   * TODO this should probably log more info about prop-271 state too
-   * when it's implemented.
-   */
-
-  tor_assert(gs != NULL);
-
-  SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *, e)
-    {
-      const char *msg = NULL;
-      if (entry_is_live(e, ENTRY_NEED_CAPACITY, &msg))
-        smartlist_add_asprintf(elements, "%s [%s] (up %s)",
-                     e->nickname,
-                     hex_str(e->identity, DIGEST_LEN),
-                     e->made_contact ? "made-contact" : "never-contacted");
-      else
-        smartlist_add_asprintf(elements, "%s [%s] (%s, %s)",
-                     e->nickname,
-                     hex_str(e->identity, DIGEST_LEN),
-                     msg,
-                     e->made_contact ? "made-contact" : "never-contacted");
-    }
-  SMARTLIST_FOREACH_END(e);
-
-  s = smartlist_join_strings(elements, ",", 0, NULL);
-  SMARTLIST_FOREACH(elements, char*, cp, tor_free(cp));
-  smartlist_free(elements);
-  log_fn(severity,LD_CIRC,"%s",s);
-  tor_free(s);
-}
-
-/** Called when one or more guards that we would previously have used for some
- * purpose are no longer in use because a higher-priority guard has become
- * usable again. */
-static void
-control_event_guard_deferred(void)
-{
-  /* XXXX We don't actually have a good way to figure out _how many_ entries
-   * are live for some purpose.  We need an entry_is_even_slightly_live()
-   * function for this to work right.  NumEntryGuards isn't reliable: if we
-   * need guards with weird properties, we can have more than that number
-   * live.
-   **/
-#if 0
-  int n = 0;
-  const char *msg;
-  const or_options_t *options = get_options();
-  if (!entry_guards)
-    return;
-  SMARTLIST_FOREACH(entry_guards, entry_guard_t *, entry,
-    {
-      if (entry_is_live(entry, 0, 1, 0, &msg)) {
-        if (n++ == options->NumEntryGuards) {
-          control_event_guard(entry->nickname, entry->identity, "DEFERRED");
-          return;
-        }
-      }
-    });
-#endif
-}
-
-/** Add a new (preferably stable and fast) router to our chosen_entry_guards
- * list for the supplied guard selection. Return a pointer to the router if
- * we succeed, or NULL if we can't find any more suitable entries.
- *
- * If <b>chosen</b> is defined, use that one, and if it's not
- * already in our entry_guards list, put it at the *beginning*.
- * Else, put the one we pick at the end of the list. */
-STATIC const node_t *
-add_an_entry_guard(guard_selection_t *gs,
-                   const node_t *chosen, int reset_status, int prepend,
-                   int for_discovery, int for_directory)
-{
-  const node_t *node;
-  entry_guard_t *entry;
-
-  tor_assert(gs != NULL);
-  tor_assert(gs->chosen_entry_guards != NULL);
-
-  if (chosen) {
-    node = chosen;
-    entry = entry_guard_get_by_id_digest_for_guard_selection(gs,
-        node->identity);
-    if (entry) {
-      if (reset_status) {
-        entry->bad_since = 0;
-        entry->can_retry = 1;
-      }
-      entry->is_dir_cache = node_is_dir(node);
-      if (get_options()->UseBridges && node_is_a_configured_bridge(node))
-        entry->is_dir_cache = 1;
-
-      return NULL;
-    }
-  } else if (!for_directory) {
-    node = choose_good_entry_server(CIRCUIT_PURPOSE_C_GENERAL, NULL, NULL);
-    if (!node)
-      return NULL;
-  } else {
-    const routerstatus_t *rs;
-    rs = router_pick_directory_server(MICRODESC_DIRINFO|V3_DIRINFO,
-                                      PDS_FOR_GUARD);
-    if (!rs)
-      return NULL;
-    node = node_get_by_id(rs->identity_digest);
-    if (!node)
-      return NULL;
-  }
-  if (entry_guard_get_by_id_digest_for_guard_selection(gs, node->identity)
-      != NULL) {
-    log_info(LD_CIRC, "I was about to add a duplicate entry guard.");
-    /* This can happen if we choose a guard, then the node goes away, then
-     * comes back. */
-    return NULL;
-  }
-  entry = tor_malloc_zero(sizeof(entry_guard_t));
-  entry->is_persistent = 1;
-  log_info(LD_CIRC, "Chose %s as new entry guard.",
-           node_describe(node));
-  strlcpy(entry->nickname, node_get_nickname(node), sizeof(entry->nickname));
-  memcpy(entry->identity, node->identity, DIGEST_LEN);
-  entry->is_dir_cache = node_is_dir(node);
-  if (get_options()->UseBridges && node_is_a_configured_bridge(node))
-    entry->is_dir_cache = 1;
-
-  /* Choose expiry time smudged over the past month. The goal here
-   * is to a) spread out when Tor clients rotate their guards, so they
-   * don't all select them on the same day, and b) avoid leaving a
-   * precise timestamp in the state file about when we first picked
-   * this guard. For details, see the Jan 2010 or-dev thread. */
-  time_t now = time(NULL);
-  entry->chosen_on_date = crypto_rand_time_range(now - 3600*24*30, now);
-  entry->chosen_by_version = tor_strdup(VERSION);
-
-  /* Are we picking this guard because all of our current guards are
-   * down so we need another one (for_discovery is 1), or because we
-   * decided we need more variety in our guard list (for_discovery is 0)?
-   *
-   * Currently we hack this behavior into place by setting "made_contact"
-   * for guards of the latter variety, so we'll be willing to use any of
-   * them right off the bat.
-   */
-  if (!for_discovery)
-    entry->made_contact = 1;
-
-  if (prepend)
-    smartlist_insert(gs->chosen_entry_guards, 0, entry);
-  else
-    smartlist_add(gs->chosen_entry_guards, entry);
-  entry->in_selection = gs;
-
-  control_event_guard(entry->nickname, entry->identity, "NEW");
-  control_event_guard_deferred();
-  log_entry_guards_for_guard_selection(gs, LOG_INFO);
-
-  return node;
-}
-
-/** Entry point for bridges.c to add a bridge as guard.
- *
- * XXXX prop271 refactor, bridge.*/
-void
-add_bridge_as_entry_guard(guard_selection_t *gs,
-                          const node_t *chosen)
-{
-  add_an_entry_guard(gs, chosen, 1, 1, 0, 0);
-}
-
-/**
- * Return the minimum lifetime of working entry guard, in seconds,
- * as given in the consensus networkstatus.  (Plus CHOSEN_ON_DATE_SLOP,
- * so that we can do the chosen_on_date randomization while achieving the
- * desired minimum lifetime.)
- */
-static int32_t
-guards_get_lifetime(void)
-{
-  const or_options_t *options = get_options();
-#define DFLT_GUARD_LIFETIME (86400 * 60)   /* Two months. */
-#define MIN_GUARD_LIFETIME  (86400 * 30)   /* One months. */
-#define MAX_GUARD_LIFETIME  (86400 * 1826) /* Five years. */
-
-  if (options->GuardLifetime >= 1) {
-    return CLAMP(MIN_GUARD_LIFETIME,
-                 options->GuardLifetime,
-                 MAX_GUARD_LIFETIME) + CHOSEN_ON_DATE_SLOP;
-  }
-
-  return networkstatus_get_param(NULL, "GuardLifetime",
-                                 DFLT_GUARD_LIFETIME,
-                                 MIN_GUARD_LIFETIME,
-                                 MAX_GUARD_LIFETIME) + CHOSEN_ON_DATE_SLOP;
-}
-
-/** If the use of entry guards is configured, choose more entry guards
- * until we have enough in the list. */
-static void
-pick_entry_guards(guard_selection_t *gs,
-                  const or_options_t *options,
-                  int for_directory)
-{
-  int changed = 0;
-  const int num_needed = decide_num_guards(options, for_directory);
-
-  tor_assert(gs != NULL);
-  tor_assert(gs->chosen_entry_guards != NULL);
-
-  while (num_live_entry_guards_for_guard_selection(gs, for_directory)
-         < num_needed) {
-    if (!add_an_entry_guard(gs, NULL, 0, 0, 0, for_directory))
-      break;
-    changed = 1;
-  }
-
-  if (changed)
-    entry_guards_changed_for_guard_selection(gs);
-}
-#endif
-
 /** Release all storage held by <b>e</b>. */
 STATIC void
 entry_guard_free(entry_guard_t *e)
@@ -3488,9 +2930,6 @@ entry_guard_free(entry_guard_t *e)
   if (!e)
     return;
   entry_guard_handles_clear(e);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  tor_free(e->chosen_by_version);
-#endif
   tor_free(e->sampled_by_version);
   tor_free(e->extra_state_fields);
   tor_free(e->selection_name);
@@ -3498,802 +2937,69 @@ entry_guard_free(entry_guard_t *e)
   tor_free(e);
 }
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/** Remove from a guard selection context any entry guard which was selected
- * by an unknown version of Tor, or which was selected by a version of Tor
- * that's known to select entry guards badly, or which was selected more 2
- * months ago. */
-/* XXXX The "obsolete guards" and "chosen long ago guards" things should
- * probably be different functions. */
-static int
-remove_obsolete_entry_guards(guard_selection_t *gs, time_t now)
+/** Return 0 if we're fine adding arbitrary routers out of the
+ * directory to our entry guard list, or return 1 if we have a
+ * list already and we must stick to it.
+ */
+int
+entry_list_is_constrained(const or_options_t *options)
 {
-  int changed = 0, i;
-  int32_t guard_lifetime = guards_get_lifetime();
-
-  tor_assert(gs != NULL);
-  if (!(gs->chosen_entry_guards)) goto done;
-
-  for (i = 0; i < smartlist_len(gs->chosen_entry_guards); ++i) {
-    entry_guard_t *entry = smartlist_get(gs->chosen_entry_guards, i);
-    const char *ver = entry->chosen_by_version;
-    const char *msg = NULL;
-    tor_version_t v;
-    int version_is_bad = 0, date_is_bad = 0;
-    if (!ver) {
-      msg = "does not say what version of Tor it was selected by";
-      version_is_bad = 1;
-    } else if (tor_version_parse(ver, &v)) {
-      msg = "does not seem to be from any recognized version of Tor";
-      version_is_bad = 1;
-    }
-    if (!version_is_bad && entry->chosen_on_date + guard_lifetime < now) {
-      /* It's been too long since the date listed in our state file. */
-      msg = "was selected several months ago";
-      date_is_bad = 1;
-    }
-
-    if (version_is_bad || date_is_bad) { /* we need to drop it */
-      char dbuf[HEX_DIGEST_LEN+1];
-      tor_assert(msg);
-      base16_encode(dbuf, sizeof(dbuf), entry->identity, DIGEST_LEN);
-      log_fn(version_is_bad ? LOG_NOTICE : LOG_INFO, LD_CIRC,
-             "Entry guard '%s' (%s) %s. (Version=%s.) Replacing it.",
-             entry->nickname, dbuf, msg, ver?escaped(ver):"none");
-      control_event_guard(entry->nickname, entry->identity, "DROPPED");
-      entry_guard_free(entry);
-      smartlist_del_keeporder(gs->chosen_entry_guards, i--);
-      log_entry_guards_for_guard_selection(gs, LOG_INFO);
-      changed = 1;
-    }
-  }
-
- done:
-  return changed ? 1 : 0;
+  // XXXX prop271 look at the current selection.
+  if (options->EntryNodes)
+    return 1;
+  if (options->UseBridges)
+    return 1;
+  return 0;
 }
 
-/** Remove all entry guards from this guard selection context that have
- * been down or unlisted for so long that we don't think they'll come up
- * again. Return 1 if we removed any, or 0 if we did nothing. */
-static int
-remove_dead_entry_guards(guard_selection_t *gs, time_t now)
+/** Return the number of bridges that have descriptors that are marked with
+ * purpose 'bridge' and are running.
+ */
+int
+num_bridges_usable(void)
 {
-  char dbuf[HEX_DIGEST_LEN+1];
-  char tbuf[ISO_TIME_LEN+1];
-  int i;
-  int changed = 0;
+  int n_options = 0;
 
-  tor_assert(gs != NULL);
-  if (!(gs->chosen_entry_guards)) goto done;
-
-  for (i = 0; i < smartlist_len(gs->chosen_entry_guards); ) {
-    entry_guard_t *entry = smartlist_get(gs->chosen_entry_guards, i);
-    if (entry->bad_since &&
-        ! entry->pb.path_bias_disabled &&
-        entry->bad_since + ENTRY_GUARD_REMOVE_AFTER < now) {
-
-      base16_encode(dbuf, sizeof(dbuf), entry->identity, DIGEST_LEN);
-      format_local_iso_time(tbuf, entry->bad_since);
-      log_info(LD_CIRC, "Entry guard '%s' (%s) has been down or unlisted "
-               "since %s local time; removing.",
-               entry->nickname, dbuf, tbuf);
-      control_event_guard(entry->nickname, entry->identity, "DROPPED");
-      entry_guard_free(entry);
-      smartlist_del_keeporder(gs->chosen_entry_guards, i);
-      log_entry_guards_for_guard_selection(gs, LOG_INFO);
-      changed = 1;
-    } else
-      ++i;
+  if (1) {
+    /* XXXX prop271 Is this quite right? */
+    tor_assert(get_options()->UseBridges);
+    guard_selection_t *gs  = get_guard_selection_info();
+    tor_assert(gs->type == GS_TYPE_BRIDGE);
+
+    SMARTLIST_FOREACH_BEGIN(gs->sampled_entry_guards, entry_guard_t *, guard) {
+      if (guard->is_reachable == GUARD_REACHABLE_NO)
+        continue;
+      if (tor_digest_is_zero(guard->identity))
+        continue;
+      const node_t *node = node_get_by_id(guard->identity);
+      if (node && node->ri)
+        ++n_options;
+    } SMARTLIST_FOREACH_END(guard);
   }
 
- done:
-  return changed ? 1 : 0;
+  return n_options;
 }
 
-/** Remove all currently listed entry guards for a given guard selection
- * context */
-void
-remove_all_entry_guards_for_guard_selection(guard_selection_t *gs)
+/** Check the pathbias use success count of <b>node</b> and disable it if it
+ *  goes over our thresholds. */
+static void
+pathbias_check_use_success_count(entry_guard_t *node)
 {
-  char dbuf[HEX_DIGEST_LEN+1];
-
-  tor_assert(gs != NULL);
+  const or_options_t *options = get_options();
+  const double EPSILON = 1.0e-9;
 
-  if (gs->chosen_entry_guards) {
-    while (smartlist_len(gs->chosen_entry_guards)) {
-      entry_guard_t *entry = smartlist_get(gs->chosen_entry_guards, 0);
-      base16_encode(dbuf, sizeof(dbuf), entry->identity, DIGEST_LEN);
-      log_info(LD_CIRC, "Entry guard '%s' (%s) has been dropped.",
-               entry->nickname, dbuf);
-      control_event_guard(entry->nickname, entry->identity, "DROPPED");
-      entry_guard_free(entry);
-      smartlist_del(gs->chosen_entry_guards, 0);
-    }
-  }
-
-  log_entry_guards_for_guard_selection(gs, LOG_INFO);
-  entry_guards_changed_for_guard_selection(gs);
-}
-
-/** Remove all currently listed entry guards. So new ones will be chosen. */
-void
-remove_all_entry_guards(void)
-{
-  // XXXX prop271 this function shouldn't exist, in the new order.
-  remove_all_entry_guards_for_guard_selection(get_guard_selection_info());
-}
-
-/** A new directory or router-status has arrived; update the down/listed
- * status of the entry guards.
- *
- * An entry is 'down' if the directory lists it as nonrunning.
- * An entry is 'unlisted' if the directory doesn't include it.
- *
- * Don't call this on startup; only on a fresh download. Otherwise we'll
- * think that things are unlisted.
- */
-void
-entry_guards_compute_status_for_guard_selection(guard_selection_t *gs,
-                                                const or_options_t *options,
-                                                time_t now)
-{
-  int changed = 0;
-  digestmap_t *reasons;
-
-  if ((!gs) || !(gs->chosen_entry_guards))
-    return;
-
-  if (!get_options()->UseDeprecatedGuardAlgorithm)
-    return;
-
-  if (options->EntryNodes) /* reshuffle the entry guard list if needed */
-    entry_nodes_should_be_added();
-
-  reasons = digestmap_new();
-  SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *, entry)
-    {
-      const node_t *r = node_get_by_id(entry->identity);
-      const char *reason = NULL;
-      if (entry_guard_set_status(entry, r, now, options, &reason))
-        changed = 1;
-
-      if (entry->bad_since)
-        tor_assert(reason);
-      if (reason)
-        digestmap_set(reasons, entry->identity, (char*)reason);
-    }
-  SMARTLIST_FOREACH_END(entry);
-
-  if (remove_dead_entry_guards(gs, now))
-    changed = 1;
-  if (remove_obsolete_entry_guards(gs, now))
-    changed = 1;
-
-  if (changed) {
-    SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *,
-                            entry) {
-      const char *reason = digestmap_get(reasons, entry->identity);
-      const char *live_msg = "";
-      const node_t *r = entry_is_live(entry, ENTRY_NEED_CAPACITY, &live_msg);
-      log_info(LD_CIRC, "Summary: Entry %s [%s] is %s, %s%s%s, and %s%s.",
-               entry->nickname,
-               hex_str(entry->identity, DIGEST_LEN),
-               entry->unreachable_since ? "unreachable" : "reachable",
-               entry->bad_since ? "unusable" : "usable",
-               reason ? ", ": "",
-               reason ? reason : "",
-               r ? "live" : "not live / ",
-               r ? "" : live_msg);
-    } SMARTLIST_FOREACH_END(entry);
-    log_info(LD_CIRC, "    (%d/%d entry guards are usable/new)",
-             num_live_entry_guards_for_guard_selection(gs, 0),
-             smartlist_len(gs->chosen_entry_guards));
-    log_entry_guards_for_guard_selection(gs, LOG_INFO);
-    entry_guards_changed_for_guard_selection(gs);
-  }
-
-  digestmap_free(reasons, NULL);
-}
-
-/** A new directory or router-status has arrived; update the down/listed
- * status of the entry guards.
- *
- * An entry is 'down' if the directory lists it as nonrunning.
- * An entry is 'unlisted' if the directory doesn't include it.
- *
- * Don't call this on startup; only on a fresh download. Otherwise we'll
- * think that things are unlisted.
- */
-void
-entry_guards_compute_status(const or_options_t *options, time_t now)
-{
-  entry_guards_compute_status_for_guard_selection(get_guard_selection_info(),
-                                                  options, now);
-}
-
-/** Called when a connection to an OR with the identity digest <b>digest</b>
- * is established (<b>succeeded</b>==1) or has failed (<b>succeeded</b>==0).
- * If the OR is an entry, change that entry's up/down status.
- * Return 0 normally, or -1 if we want to tear down the new connection.
- *
- * If <b>mark_relay_status</b>, also call router_set_status() on this
- * relay.
- */
-/* XXX We could change succeeded and mark_relay_status into 'int flags'.
- * Too many boolean arguments is a recipe for confusion.
- */
-int
-entry_guard_register_connect_status_for_guard_selection(
-    guard_selection_t *gs, const char *digest, int succeeded,
-    int mark_relay_status, time_t now)
-{
-  int changed = 0;
-  int refuse_conn = 0;
-  int first_contact = 0;
-  entry_guard_t *entry = NULL;
-  int idx = -1;
-  char buf[HEX_DIGEST_LEN+1];
-
-  if (!(gs) || !(gs->chosen_entry_guards)) {
-    return 0;
-  }
-
-  if (! get_options()->UseDeprecatedGuardAlgorithm) {
-    return 0;
-  }
-
-  SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *, e) {
-    tor_assert(e);
-    if (tor_memeq(e->identity, digest, DIGEST_LEN)) {
-      entry = e;
-      idx = e_sl_idx;
-      break;
-    }
-  } SMARTLIST_FOREACH_END(e);
-
-  if (!entry)
-    return 0;
-
-  base16_encode(buf, sizeof(buf), entry->identity, DIGEST_LEN);
-
-  if (succeeded) {
-    if (entry->unreachable_since) {
-      log_info(LD_CIRC, "Entry guard '%s' (%s) is now reachable again. Good.",
-               entry->nickname, buf);
-      entry->can_retry = 0;
-      entry->unreachable_since = 0;
-      entry->last_attempted = now;
-      control_event_guard(entry->nickname, entry->identity, "UP");
-      changed = 1;
-    }
-    if (!entry->made_contact) {
-      entry->made_contact = 1;
-      first_contact = changed = 1;
-    }
-  } else { /* ! succeeded */
-    if (!entry->made_contact) {
-      /* We've never connected to this one. */
-      log_info(LD_CIRC,
-               "Connection to never-contacted entry guard '%s' (%s) failed. "
-               "Removing from the list. %d/%d entry guards usable/new.",
-               entry->nickname, buf,
-               num_live_entry_guards_for_guard_selection(gs, 0) - 1,
-               smartlist_len(gs->chosen_entry_guards)-1);
-      control_event_guard(entry->nickname, entry->identity, "DROPPED");
-      entry_guard_free(entry);
-      smartlist_del_keeporder(gs->chosen_entry_guards, idx);
-      log_entry_guards_for_guard_selection(gs, LOG_INFO);
-      changed = 1;
-    } else if (!entry->unreachable_since) {
-      log_info(LD_CIRC, "Unable to connect to entry guard '%s' (%s). "
-               "Marking as unreachable.", entry->nickname, buf);
-      entry->unreachable_since = entry->last_attempted = now;
-      control_event_guard(entry->nickname, entry->identity, "DOWN");
-      changed = 1;
-      entry->can_retry = 0; /* We gave it an early chance; no good. */
-    } else {
-      char tbuf[ISO_TIME_LEN+1];
-      format_iso_time(tbuf, entry->unreachable_since);
-      log_debug(LD_CIRC, "Failed to connect to unreachable entry guard "
-                "'%s' (%s).  It has been unreachable since %s.",
-                entry->nickname, buf, tbuf);
-      entry->last_attempted = now;
-      entry->can_retry = 0; /* We gave it an early chance; no good. */
-    }
-  }
-
-  /* if the caller asked us to, also update the is_running flags for this
-   * relay */
-  if (mark_relay_status)
-    router_set_status(digest, succeeded);
-
-  if (first_contact) {
-    /* We've just added a new long-term entry guard. Perhaps the network just
-     * came back? We should give our earlier entries another try too,
-     * and close this connection so we don't use it before we've given
-     * the others a shot. */
-    SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *, e) {
-        if (e == entry)
-          break;
-        if (e->made_contact) {
-          const char *msg;
-          const node_t *r = entry_is_live(e,
-                     ENTRY_NEED_CAPACITY | ENTRY_ASSUME_REACHABLE,
-                     &msg);
-          if (r && e->unreachable_since) {
-            refuse_conn = 1;
-            e->can_retry = 1;
-          }
-        }
-    } SMARTLIST_FOREACH_END(e);
-    if (refuse_conn) {
-      log_info(LD_CIRC,
-               "Connected to new entry guard '%s' (%s). Marking earlier "
-               "entry guards up. %d/%d entry guards usable/new.",
-               entry->nickname, buf,
-               num_live_entry_guards_for_guard_selection(gs, 0),
-               smartlist_len(gs->chosen_entry_guards));
-      log_entry_guards_for_guard_selection(gs, LOG_INFO);
-      changed = 1;
-    }
-  }
-
-  if (changed)
-    entry_guards_changed_for_guard_selection(gs);
-  return refuse_conn ? -1 : 0;
-}
-
-/** Called when a connection to an OR with the identity digest <b>digest</b>
- * is established (<b>succeeded</b>==1) or has failed (<b>succeeded</b>==0).
- * If the OR is an entry, change that entry's up/down status in the default
- * guard selection context.
- * Return 0 normally, or -1 if we want to tear down the new connection.
- *
- * If <b>mark_relay_status</b>, also call router_set_status() on this
- * relay.
- */
-int
-entry_guard_register_connect_status(const char *digest, int succeeded,
-                                    int mark_relay_status, time_t now)
-{
-  return entry_guard_register_connect_status_for_guard_selection(
-      get_guard_selection_info(), digest, succeeded, mark_relay_status, now);
-}
-
-/** Called when the value of EntryNodes changes in our configuration. */
-void
-entry_nodes_should_be_added_for_guard_selection(guard_selection_t *gs)
-{
-  tor_assert(gs != NULL);
-
-  log_info(LD_CIRC, "EntryNodes config option set. Putting configured "
-           "relays at the front of the entry guard list.");
-  gs->should_add_entry_nodes = 1;
-}
-
-/** Called when the value of EntryNodes changes in our configuration. */
-void
-entry_nodes_should_be_added(void)
-{
-  entry_nodes_should_be_added_for_guard_selection(
-      get_guard_selection_info());
-}
-
-/** Adjust the entry guards list so that it only contains entries from
- * EntryNodes, adding new entries from EntryNodes to the list as needed. */
-STATIC void
-entry_guards_set_from_config(guard_selection_t *gs,
-                             const or_options_t *options)
-{
-  smartlist_t *entry_nodes, *worse_entry_nodes, *entry_fps;
-  smartlist_t *old_entry_guards_on_list, *old_entry_guards_not_on_list;
-  const int numentryguards = decide_num_guards(options, 0);
-
-  tor_assert(gs != NULL);
-  tor_assert(gs->chosen_entry_guards != NULL);
-
-  gs->should_add_entry_nodes = 0;
-
-  if (!options->EntryNodes) {
-    /* It's possible that a controller set EntryNodes, thus making
-     * should_add_entry_nodes set, then cleared it again, all before the
-     * call to choose_random_entry() that triggered us. If so, just return.
-     */
-    return;
-  }
-
-  {
-    char *string = routerset_to_string(options->EntryNodes);
-    log_info(LD_CIRC,"Adding configured EntryNodes '%s'.", string);
-    tor_free(string);
-  }
-
-  entry_nodes = smartlist_new();
-  worse_entry_nodes = smartlist_new();
-  entry_fps = smartlist_new();
-  old_entry_guards_on_list = smartlist_new();
-  old_entry_guards_not_on_list = smartlist_new();
-
-  /* Split entry guards into those on the list and those not. */
-
-  routerset_get_all_nodes(entry_nodes, options->EntryNodes,
-                          options->ExcludeNodes, 0);
-  SMARTLIST_FOREACH(entry_nodes, const node_t *,node,
-                    smartlist_add(entry_fps, (void*)node->identity));
-
-  SMARTLIST_FOREACH(gs->chosen_entry_guards, entry_guard_t *, e, {
-    if (smartlist_contains_digest(entry_fps, e->identity))
-      smartlist_add(old_entry_guards_on_list, e);
-    else
-      smartlist_add(old_entry_guards_not_on_list, e);
-  });
-
-  /* Remove all currently configured guard nodes, excluded nodes, unreachable
-   * nodes, or non-Guard nodes from entry_nodes. */
-  SMARTLIST_FOREACH_BEGIN(entry_nodes, const node_t *, node) {
-    if (entry_guard_get_by_id_digest_for_guard_selection(gs,
-          node->identity)) {
-      SMARTLIST_DEL_CURRENT(entry_nodes, node);
-      continue;
-    } else if (routerset_contains_node(options->ExcludeNodes, node)) {
-      SMARTLIST_DEL_CURRENT(entry_nodes, node);
-      continue;
-    } else if (!fascist_firewall_allows_node(node, FIREWALL_OR_CONNECTION,
-                                             0)) {
-      SMARTLIST_DEL_CURRENT(entry_nodes, node);
-      continue;
-    } else if (! node->is_possible_guard) {
-      smartlist_add(worse_entry_nodes, (node_t*)node);
-      SMARTLIST_DEL_CURRENT(entry_nodes, node);
-    }
-  } SMARTLIST_FOREACH_END(node);
-
-  /* Now build the new entry_guards list. */
-  smartlist_clear(gs->chosen_entry_guards);
-  /* First, the previously configured guards that are in EntryNodes. */
-  smartlist_add_all(gs->chosen_entry_guards, old_entry_guards_on_list);
-  /* Next, scramble the rest of EntryNodes, putting the guards first. */
-  smartlist_shuffle(entry_nodes);
-  smartlist_shuffle(worse_entry_nodes);
-  smartlist_add_all(entry_nodes, worse_entry_nodes);
-
-  /* Next, the rest of EntryNodes */
-  SMARTLIST_FOREACH_BEGIN(entry_nodes, const node_t *, node) {
-    add_an_entry_guard(gs, node, 0, 0, 1, 0);
-    if (smartlist_len(gs->chosen_entry_guards) > numentryguards * 10)
-      break;
-  } SMARTLIST_FOREACH_END(node);
-  log_notice(LD_GENERAL, "%d entries in guards",
-             smartlist_len(gs->chosen_entry_guards));
-  /* Finally, free the remaining previously configured guards that are not in
-   * EntryNodes. */
-  SMARTLIST_FOREACH(old_entry_guards_not_on_list, entry_guard_t *, e,
-                    entry_guard_free(e));
-
-  smartlist_free(entry_nodes);
-  smartlist_free(worse_entry_nodes);
-  smartlist_free(entry_fps);
-  smartlist_free(old_entry_guards_on_list);
-  smartlist_free(old_entry_guards_not_on_list);
-  entry_guards_changed_for_guard_selection(gs);
-}
-#endif
-
-/** Return 0 if we're fine adding arbitrary routers out of the
- * directory to our entry guard list, or return 1 if we have a
- * list already and we must stick to it.
- */
-int
-entry_list_is_constrained(const or_options_t *options)
-{
-  // XXXX prop271 look at the current selection.
-  if (options->EntryNodes)
-    return 1;
-  if (options->UseBridges)
-    return 1;
-  return 0;
-}
-
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/** Pick a live (up and listed) entry guard from entry_guards. If
- * <b>state</b> is non-NULL, this is for a specific circuit --
- * make sure not to pick this circuit's exit or any node in the
- * exit's family. If <b>state</b> is NULL, we're looking for a random
- * guard (likely a bridge).  If <b>dirinfo</b> is not NO_DIRINFO (zero),
- * then only select from nodes that know how to answer directory questions
- * of that type. */
-const node_t *
-choose_random_entry(cpath_build_state_t *state)
-{
-  tor_assert(get_options()->UseDeprecatedGuardAlgorithm);
-
-  return choose_random_entry_impl(get_guard_selection_info(),
-                                  state, 0, NO_DIRINFO, NULL);
-}
-
-/** Pick a live (up and listed) directory guard from entry_guards for
- * downloading information of type <b>type</b>. */
-const node_t *
-choose_random_dirguard(dirinfo_type_t type)
-{
-  tor_assert(get_options()->UseDeprecatedGuardAlgorithm);
-
-  return choose_random_entry_impl(get_guard_selection_info(),
-                                  NULL, 1, type, NULL);
-}
-#endif
-
-/** Return the number of bridges that have descriptors that are marked with
- * purpose 'bridge' and are running.
- */
-int
-num_bridges_usable(void)
-{
-  int n_options = 0;
-
-  if (get_options()->UseDeprecatedGuardAlgorithm) {
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-    tor_assert(get_options()->UseBridges);
-    (void) choose_random_entry_impl(get_guard_selection_info(),
-                                    NULL, 0, 0, &n_options);
-#else
-    tor_assert_nonfatal_unreached();
-#endif
-  } else {
-    /* XXXX prop271 Is this quite right? */
-    tor_assert(get_options()->UseBridges);
-    guard_selection_t *gs  = get_guard_selection_info();
-    tor_assert(gs->type == GS_TYPE_BRIDGE);
-
-    SMARTLIST_FOREACH_BEGIN(gs->sampled_entry_guards, entry_guard_t *, guard) {
-      if (guard->is_reachable == GUARD_REACHABLE_NO)
-        continue;
-      if (tor_digest_is_zero(guard->identity))
-        continue;
-      const node_t *node = node_get_by_id(guard->identity);
-      if (node && node->ri)
-        ++n_options;
-    } SMARTLIST_FOREACH_END(guard);
-  }
-
-  return n_options;
-}
-
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/** Filter <b>all_entry_guards</b> for usable entry guards and put them
- * in <b>live_entry_guards</b>. We filter based on whether the node is
- * currently alive, and on whether it satisfies the restrictions
- * imposed by the other arguments of this function.
- *
- * We don't place more guards than NumEntryGuards in <b>live_entry_guards</b>.
- *
- * If <b>chosen_exit</b> is set, it contains the exit node of this
- * circuit. Make sure to not use it or its family as an entry guard.
- *
- * If <b>need_uptime</b> is set, we are looking for a stable entry guard.
- * if <b>need_capacity</b> is set, we are looking for a fast entry guard.
- *
- * The rest of the arguments are the same as in choose_random_entry_impl().
- *
- * Return 1 if we should choose a guard right away. Return 0 if we
- * should try to add more nodes to our list before deciding on a
- * guard.
- */
-STATIC int
-populate_live_entry_guards(smartlist_t *live_entry_guards,
-                           const smartlist_t *all_entry_guards,
-                           const node_t *chosen_exit,
-                           dirinfo_type_t dirinfo_type,
-                           int for_directory,
-                           int need_uptime, int need_capacity)
-{
-  const or_options_t *options = get_options();
-  const node_t *node = NULL;
-  const int num_needed = decide_num_guards(options, for_directory);
-  smartlist_t *exit_family = smartlist_new();
-  int retval = 0;
-  entry_is_live_flags_t entry_flags = 0;
-
-  (void) dirinfo_type;
-
-  { /* Set the flags we want our entry node to have */
-    if (need_uptime) {
-      entry_flags |= ENTRY_NEED_UPTIME;
-    }
-    if (need_capacity) {
-      entry_flags |= ENTRY_NEED_CAPACITY;
-    }
-    if (!for_directory) {
-      entry_flags |= ENTRY_NEED_DESCRIPTOR;
-    }
-  }
-
-  tor_assert(all_entry_guards);
-
-  if (chosen_exit) {
-    nodelist_add_node_and_family(exit_family, chosen_exit);
-  }
-
-  SMARTLIST_FOREACH_BEGIN(all_entry_guards, const entry_guard_t *, entry) {
-      const char *msg;
-      node = entry_is_live(entry, entry_flags, &msg);
-      if (!node)
-        continue; /* down, no point */
-      if (for_directory) {
-        if (!entry->is_dir_cache)
-          continue; /* We need a directory and didn't get one. */
-      }
-      if (node == chosen_exit)
-        continue; /* don't pick the same node for entry and exit */
-      if (smartlist_contains(exit_family, node))
-        continue; /* avoid relays that are family members of our exit */
-      smartlist_add(live_entry_guards, (void*)node);
-      if (!entry->made_contact) {
-        /* Always start with the first not-yet-contacted entry
-         * guard. Otherwise we might add several new ones, pick
-         * the second new one, and now we've expanded our entry
-         * guard list without needing to. */
-        retval = 1;
-        goto done;
-      }
-      if (smartlist_len(live_entry_guards) >= num_needed) {
-        retval = 1;
-        goto done; /* We picked enough entry guards. Done! */
-      }
-  } SMARTLIST_FOREACH_END(entry);
-
- done:
-  smartlist_free(exit_family);
-
-  return retval;
-}
-
-/** Pick a node to be used as the entry guard of a circuit, relative to
- * a supplied guard selection context.
- *
- * If <b>state</b> is set, it contains the information we know about
- * the upcoming circuit.
- *
- * If <b>for_directory</b> is set, we are looking for a directory guard.
- *
- * <b>dirinfo_type</b> contains the kind of directory information we
- * are looking for in our node, or NO_DIRINFO (zero) if we are not
- * looking for any particular directory information (when set to
- * NO_DIRINFO, the <b>dirinfo_type</b> filter is ignored).
- *
- * If <b>n_options_out</b> is set, we set it to the number of
- * candidate guard nodes we had before picking a specific guard node.
- *
- * On success, return the node that should be used as the entry guard
- * of the circuit.  Return NULL if no such node could be found.
- *
- * Helper for choose_random{entry,dirguard}.
-*/
-static const node_t *
-choose_random_entry_impl(guard_selection_t *gs,
-                         cpath_build_state_t *state, int for_directory,
-                         dirinfo_type_t dirinfo_type, int *n_options_out)
-{
-  const or_options_t *options = get_options();
-  smartlist_t *live_entry_guards = smartlist_new();
-  const node_t *chosen_exit =
-    state?build_state_get_exit_node(state) : NULL;
-  const node_t *node = NULL;
-  int need_uptime = state ? state->need_uptime : 0;
-  int need_capacity = state ? state->need_capacity : 0;
-  int preferred_min = 0;
-  const int num_needed = decide_num_guards(options, for_directory);
-  int retval = 0;
-
-  tor_assert(gs != NULL);
-  tor_assert(gs->chosen_entry_guards != NULL);
-
-  if (n_options_out)
-    *n_options_out = 0;
-
-  if (gs->should_add_entry_nodes)
-    entry_guards_set_from_config(gs, options);
-
-  if (!entry_list_is_constrained(options) &&
-      smartlist_len(gs->chosen_entry_guards) < num_needed)
-    pick_entry_guards(gs, options, for_directory);
-
- retry:
-  smartlist_clear(live_entry_guards);
-
-  /* Populate the list of live entry guards so that we pick one of
-     them. */
-  retval = populate_live_entry_guards(live_entry_guards,
-                                      gs->chosen_entry_guards,
-                                      chosen_exit,
-                                      dirinfo_type,
-                                      for_directory,
-                                      need_uptime, need_capacity);
-
-  if (retval == 1) { /* We should choose a guard right now. */
-    goto choose_and_finish;
-  }
-
-  if (entry_list_is_constrained(options)) {
-    /* If we prefer the entry nodes we've got, and we have at least
-     * one choice, that's great. Use it. */
-    preferred_min = 1;
-  } else {
-    /* Try to have at least 2 choices available. This way we don't
-     * get stuck with a single live-but-crummy entry and just keep
-     * using it.
-     * (We might get 2 live-but-crummy entry guards, but so be it.) */
-    preferred_min = 2;
-  }
-
-  if (smartlist_len(live_entry_guards) < preferred_min) {
-    if (!entry_list_is_constrained(options)) {
-      /* still no? try adding a new entry then */
-      /* XXX if guard doesn't imply fast and stable, then we need
-       * to tell add_an_entry_guard below what we want, or it might
-       * be a long time til we get it. -RD */
-      node = add_an_entry_guard(gs, NULL, 0, 0, 1, for_directory);
-      if (node) {
-        entry_guards_changed_for_guard_selection(gs);
-        /* XXX we start over here in case the new node we added shares
-         * a family with our exit node. There's a chance that we'll just
-         * load up on entry guards here, if the network we're using is
-         * one big family. Perhaps we should teach add_an_entry_guard()
-         * to understand nodes-to-avoid-if-possible? -RD */
-        goto retry;
-      }
-    }
-    if (!node && need_uptime) {
-      need_uptime = 0; /* try without that requirement */
-      goto retry;
-    }
-    if (!node && need_capacity) {
-      /* still no? last attempt, try without requiring capacity */
-      need_capacity = 0;
-      goto retry;
-    }
-
-    /* live_entry_guards may be empty below. Oh well, we tried. */
-  }
-
- choose_and_finish:
-  if (entry_list_is_constrained(options)) {
-    /* We need to weight by bandwidth, because our bridges or entryguards
-     * were not already selected proportional to their bandwidth. */
-    node = node_sl_choose_by_bandwidth(live_entry_guards, WEIGHT_FOR_GUARD);
-  } else {
-    /* We choose uniformly at random here, because choose_good_entry_server()
-     * already weights its choices by bandwidth, so we don't want to
-     * *double*-weight our guard selection. */
-    node = smartlist_choose(live_entry_guards);
-  }
-  if (n_options_out)
-    *n_options_out = smartlist_len(live_entry_guards);
-  smartlist_free(live_entry_guards);
-  return node;
-}
-#endif
-
-/** Check the pathbias use success count of <b>node</b> and disable it if it
- *  goes over our thresholds. */
-static void
-pathbias_check_use_success_count(entry_guard_t *node)
-{
-  const or_options_t *options = get_options();
-  const double EPSILON = 1.0e-9;
-
-  /* Note: We rely on the < comparison here to allow us to set a 0
-   * rate and disable the feature entirely. If refactoring, don't
-   * change to <= */
-  if (node->pb.use_attempts > EPSILON &&
-      pathbias_get_use_success_count(node)/node->pb.use_attempts
-      < pathbias_get_extreme_use_rate(options) &&
-      pathbias_get_dropguards(options)) {
-    node->pb.path_bias_disabled = 1;
-    log_info(LD_GENERAL,
-             "Path use bias is too high (%f/%f); disabling node %s",
-             node->pb.circ_successes, node->pb.circ_attempts,
-             node->nickname);
+  /* Note: We rely on the < comparison here to allow us to set a 0
+   * rate and disable the feature entirely. If refactoring, don't
+   * change to <= */
+  if (node->pb.use_attempts > EPSILON &&
+      pathbias_get_use_success_count(node)/node->pb.use_attempts
+      < pathbias_get_extreme_use_rate(options) &&
+      pathbias_get_dropguards(options)) {
+    node->pb.path_bias_disabled = 1;
+    log_info(LD_GENERAL,
+             "Path use bias is too high (%f/%f); disabling node %s",
+             node->pb.circ_successes, node->pb.circ_attempts,
+             node->nickname);
   }
 }
 
@@ -4320,262 +3026,6 @@ pathbias_check_close_success_count(entry_guard_t *node)
   }
 }
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/** Parse <b>state</b> and learn about the entry guards it describes.
- * If <b>set</b> is true, and there are no errors, replace the guard
- * list in the provided guard selection context with what we find.
- * On success, return 0. On failure, alloc into *<b>msg</b> a string
- * describing the error, and return -1.
- */
-int
-entry_guards_parse_state_for_guard_selection(
-    guard_selection_t *gs,
-    or_state_t *state, int set, char **msg)
-{
-  entry_guard_t *node = NULL;
-  smartlist_t *new_entry_guards = smartlist_new();
-  config_line_t *line;
-  time_t now = time(NULL);
-  const char *state_version = state->TorVersion;
-  digestmap_t *added_by = digestmap_new();
-
-  tor_assert(gs != NULL);
-
-  *msg = NULL;
-  for (line = state->EntryGuards; line; line = line->next) {
-    if (!strcasecmp(line->key, "EntryGuard")) {
-      smartlist_t *args = smartlist_new();
-      node = tor_malloc_zero(sizeof(entry_guard_t));
-      /* all entry guards on disk have been contacted */
-      node->made_contact = 1;
-      node->is_persistent = 1;
-      smartlist_add(new_entry_guards, node);
-      smartlist_split_string(args, line->value, " ",
-                             SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
-      if (smartlist_len(args)<2) {
-        *msg = tor_strdup("Unable to parse entry nodes: "
-                          "Too few arguments to EntryGuard");
-      } else if (!is_legal_nickname(smartlist_get(args,0))) {
-        *msg = tor_strdup("Unable to parse entry nodes: "
-                          "Bad nickname for EntryGuard");
-      } else {
-        strlcpy(node->nickname, smartlist_get(args,0), MAX_NICKNAME_LEN+1);
-        if (base16_decode(node->identity, DIGEST_LEN, smartlist_get(args,1),
-                          strlen(smartlist_get(args,1))) != DIGEST_LEN) {
-          *msg = tor_strdup("Unable to parse entry nodes: "
-                            "Bad hex digest for EntryGuard");
-        }
-      }
-      if (smartlist_len(args) >= 3) {
-        const char *is_cache = smartlist_get(args, 2);
-        if (!strcasecmp(is_cache, "DirCache")) {
-          node->is_dir_cache = 1;
-        } else if (!strcasecmp(is_cache, "NoDirCache")) {
-          node->is_dir_cache = 0;
-        } else {
-          log_warn(LD_CONFIG, "Bogus third argument to EntryGuard line: %s",
-                   escaped(is_cache));
-        }
-      }
-      SMARTLIST_FOREACH(args, char*, cp, tor_free(cp));
-      smartlist_free(args);
-      if (*msg)
-        break;
-    } else if (!strcasecmp(line->key, "EntryGuardDownSince") ||
-               !strcasecmp(line->key, "EntryGuardUnlistedSince")) {
-      time_t when;
-      time_t last_try = 0;
-      if (!node) {
-        *msg = tor_strdup("Unable to parse entry nodes: "
-               "EntryGuardDownSince/UnlistedSince without EntryGuard");
-        break;
-      }
-      if (parse_iso_time_(line->value, &when, 0, 0)<0) {
-        *msg = tor_strdup("Unable to parse entry nodes: "
-                          "Bad time in EntryGuardDownSince/UnlistedSince");
-        break;
-      }
-      if (when > now) {
-        /* It's a bad idea to believe info in the future: you can wind
-         * up with timeouts that aren't allowed to happen for years. */
-        continue;
-      }
-      if (strlen(line->value) >= ISO_TIME_LEN+ISO_TIME_LEN+1) {
-        /* ignore failure */
-        (void) parse_iso_time(line->value+ISO_TIME_LEN+1, &last_try);
-      }
-      if (!strcasecmp(line->key, "EntryGuardDownSince")) {
-        node->unreachable_since = when;
-        node->last_attempted = last_try;
-      } else {
-        node->bad_since = when;
-      }
-    } else if (!strcasecmp(line->key, "EntryGuardAddedBy")) {
-      char d[DIGEST_LEN];
-      /* format is digest version date */
-      if (strlen(line->value) < HEX_DIGEST_LEN+1+1+1+ISO_TIME_LEN) {
-        log_warn(LD_BUG, "EntryGuardAddedBy line is not long enough.");
-        continue;
-      }
-      if (base16_decode(d, sizeof(d),
-                        line->value, HEX_DIGEST_LEN) != sizeof(d) ||
-                        line->value[HEX_DIGEST_LEN] != ' ') {
-        log_warn(LD_BUG, "EntryGuardAddedBy line %s does not begin with "
-                 "hex digest", escaped(line->value));
-        continue;
-      }
-      digestmap_set(added_by, d, tor_strdup(line->value+HEX_DIGEST_LEN+1));
-    } else if (!strcasecmp(line->key, "EntryGuardPathUseBias")) {
-      double use_cnt, success_cnt;
-
-      if (!node) {
-        *msg = tor_strdup("Unable to parse entry nodes: "
-               "EntryGuardPathUseBias without EntryGuard");
-        break;
-      }
-
-      if (tor_sscanf(line->value, "%lf %lf",
-                     &use_cnt, &success_cnt) != 2) {
-        log_info(LD_GENERAL, "Malformed path use bias line for node %s",
-                 node->nickname);
-        continue;
-      }
-
-      if (use_cnt < success_cnt) {
-        int severity = LOG_INFO;
-        /* If this state file was written by a Tor that would have
-         * already fixed it, then the overcounting bug is still there.. */
-        if (tor_version_as_new_as(state_version, "0.2.4.13-alpha")) {
-          severity = LOG_NOTICE;
-        }
-        log_fn(severity, LD_BUG,
-                   "State file contains unexpectedly high usage success "
-                   "counts %lf/%lf for Guard %s ($%s)",
-                   success_cnt, use_cnt,
-                   node->nickname, hex_str(node->identity, DIGEST_LEN));
-        success_cnt = use_cnt;
-      }
-
-      node->pb.use_attempts = use_cnt;
-      node->pb.use_successes = success_cnt;
-
-      log_info(LD_GENERAL, "Read %f/%f path use bias for node %s",
-               node->pb.use_successes, node->pb.use_attempts, node->nickname);
-
-      pathbias_check_use_success_count(node);
-
-    } else if (!strcasecmp(line->key, "EntryGuardPathBias")) {
-      double hop_cnt, success_cnt, timeouts, collapsed, successful_closed,
-               unusable;
-
-      if (!node) {
-        *msg = tor_strdup("Unable to parse entry nodes: "
-               "EntryGuardPathBias without EntryGuard");
-        break;
-      }
-
-      /* First try 3 params, then 2. */
-      /* In the long run: circuit_success ~= successful_circuit_close +
-       *                                     collapsed_circuits +
-       *                                     unusable_circuits */
-      if (tor_sscanf(line->value, "%lf %lf %lf %lf %lf %lf",
-                  &hop_cnt, &success_cnt, &successful_closed,
-                  &collapsed, &unusable, &timeouts) != 6) {
-        int old_success, old_hops;
-        if (tor_sscanf(line->value, "%u %u", &old_success, &old_hops) != 2) {
-          continue;
-        }
-        log_info(LD_GENERAL, "Reading old-style EntryGuardPathBias %s",
-                 escaped(line->value));
-
-        success_cnt = old_success;
-        successful_closed = old_success;
-        hop_cnt = old_hops;
-        timeouts = 0;
-        collapsed = 0;
-        unusable = 0;
-      }
-
-      if (hop_cnt < success_cnt) {
-        int severity = LOG_INFO;
-        /* If this state file was written by a Tor that would have
-         * already fixed it, then the overcounting bug is still there.. */
-        if (tor_version_as_new_as(state_version, "0.2.4.13-alpha")) {
-          severity = LOG_NOTICE;
-        }
-        log_fn(severity, LD_BUG,
-                "State file contains unexpectedly high success counts "
-                "%lf/%lf for Guard %s ($%s)",
-                success_cnt, hop_cnt,
-                node->nickname, hex_str(node->identity, DIGEST_LEN));
-        success_cnt = hop_cnt;
-      }
-
-      node->pb.circ_attempts = hop_cnt;
-      node->pb.circ_successes = success_cnt;
-
-      node->pb.successful_circuits_closed = successful_closed;
-      node->pb.timeouts = timeouts;
-      node->pb.collapsed_circuits = collapsed;
-      node->pb.unusable_circuits = unusable;
-
-      log_info(LD_GENERAL, "Read %f/%f path bias for node %s",
-               node->pb.circ_successes, node->pb.circ_attempts,
-               node->nickname);
-
-      pathbias_check_close_success_count(node);
-    } else {
-      log_warn(LD_BUG, "Unexpected key %s", line->key);
-    }
-  }
-
-  SMARTLIST_FOREACH_BEGIN(new_entry_guards, entry_guard_t *, e) {
-     char *sp;
-     char *val = digestmap_get(added_by, e->identity);
-     if (val && (sp = strchr(val, ' '))) {
-       time_t when;
-       *sp++ = '\0';
-       if (parse_iso_time(sp, &when)<0) {
-         log_warn(LD_BUG, "Can't read time %s in EntryGuardAddedBy", sp);
-       } else {
-         e->chosen_by_version = tor_strdup(val);
-         e->chosen_on_date = when;
-       }
-     } else {
-       if (state_version) {
-         e->chosen_on_date = crypto_rand_time_range(now - 3600*24*30, now);
-         e->chosen_by_version = tor_strdup(state_version);
-       }
-     }
-     if (e->pb.path_bias_disabled && !e->bad_since)
-       e->bad_since = time(NULL);
-    }
-  SMARTLIST_FOREACH_END(e);
-
-  if (*msg || !set) {
-    SMARTLIST_FOREACH(new_entry_guards, entry_guard_t *, e,
-                      entry_guard_free(e));
-    smartlist_free(new_entry_guards);
-  } else { /* !err && set */
-    if (gs->chosen_entry_guards) {
-      SMARTLIST_FOREACH(gs->chosen_entry_guards, entry_guard_t *, e,
-                        entry_guard_free(e));
-      smartlist_free(gs->chosen_entry_guards);
-    }
-    gs->chosen_entry_guards = new_entry_guards;
-    SMARTLIST_FOREACH(new_entry_guards, entry_guard_t *, e,
-                      e->in_selection = gs);
-
-    /* XXX hand new_entry_guards to this func, and move it up a
-     * few lines, so we don't have to re-dirty it */
-    if (remove_obsolete_entry_guards(gs, now))
-      entry_guards_dirty = 1;
-  }
-  digestmap_free(added_by, tor_free_);
-  return *msg ? -1 : 0;
-}
-#endif
-
 /** Parse <b>state</b> and learn about the entry guards it describes.
  * If <b>set</b> is true, and there are no errors, replace the guard
  * list in the default guard selection context with what we find.
@@ -4586,20 +3036,10 @@ int
 entry_guards_parse_state(or_state_t *state, int set, char **msg)
 {
   entry_guards_dirty = 0;
-
   int r1 = entry_guards_load_guards_from_state(state, set);
-
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  int r2 = entry_guards_parse_state_for_guard_selection(
-      get_guard_selection_by_name("legacy", GS_TYPE_LEGACY, 1),
-      state, set, msg);
-#else
-   int r2 = 0;
-#endif
-
   entry_guards_dirty = 0;
 
-  if (r1 < 0 || r2 < 0) {
+  if (r1 < 0) {
     if (msg && *msg == NULL) {
       *msg = tor_strdup("parsing error"); //xxxx prop271 should we try harder?
     }
@@ -4664,83 +3104,6 @@ entry_guards_update_state(or_state_t *state)
 
   entry_guards_dirty = 0;
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  config_line_t **next, *line;
-
-  guard_selection_t *gs;
-  gs = get_guard_selection_by_name("legacy", GS_TYPE_LEGACY, 0);
-  if (!gs)
-    return; // nothign to save.
-  tor_assert(gs->chosen_entry_guards != NULL);
-
-  config_free_lines(state->EntryGuards);
-  next = &state->EntryGuards;
-  *next = NULL;
-  SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *, e) {
-      char dbuf[HEX_DIGEST_LEN+1];
-      if (!e->made_contact)
-        continue; /* don't write this one to disk */
-      *next = line = tor_malloc_zero(sizeof(config_line_t));
-      line->key = tor_strdup("EntryGuard");
-      base16_encode(dbuf, sizeof(dbuf), e->identity, DIGEST_LEN);
-      tor_asprintf(&line->value, "%s %s %sDirCache", e->nickname, dbuf,
-                   e->is_dir_cache ? "" : "No");
-      next = &(line->next);
-      if (e->unreachable_since) {
-        *next = line = tor_malloc_zero(sizeof(config_line_t));
-        line->key = tor_strdup("EntryGuardDownSince");
-        line->value = tor_malloc(ISO_TIME_LEN+1+ISO_TIME_LEN+1);
-        format_iso_time(line->value, e->unreachable_since);
-        if (e->last_attempted) {
-          line->value[ISO_TIME_LEN] = ' ';
-          format_iso_time(line->value+ISO_TIME_LEN+1, e->last_attempted);
-        }
-        next = &(line->next);
-      }
-      if (e->bad_since) {
-        *next = line = tor_malloc_zero(sizeof(config_line_t));
-        line->key = tor_strdup("EntryGuardUnlistedSince");
-        line->value = tor_malloc(ISO_TIME_LEN+1);
-        format_iso_time(line->value, e->bad_since);
-        next = &(line->next);
-      }
-      if (e->chosen_on_date && e->chosen_by_version &&
-          !strchr(e->chosen_by_version, ' ')) {
-        char d[HEX_DIGEST_LEN+1];
-        char t[ISO_TIME_LEN+1];
-        *next = line = tor_malloc_zero(sizeof(config_line_t));
-        line->key = tor_strdup("EntryGuardAddedBy");
-        base16_encode(d, sizeof(d), e->identity, DIGEST_LEN);
-        format_iso_time(t, e->chosen_on_date);
-        tor_asprintf(&line->value, "%s %s %s",
-                     d, e->chosen_by_version, t);
-        next = &(line->next);
-      }
-      if (e->pb.circ_attempts > 0) {
-        *next = line = tor_malloc_zero(sizeof(config_line_t));
-        line->key = tor_strdup("EntryGuardPathBias");
-        /* In the long run: circuit_success ~= successful_circuit_close +
-         *                                     collapsed_circuits +
-         *                                     unusable_circuits */
-        tor_asprintf(&line->value, "%f %f %f %f %f %f",
-                     e->pb.circ_attempts, e->pb.circ_successes,
-                     pathbias_get_close_success_count(e),
-                     e->pb.collapsed_circuits,
-                     e->pb.unusable_circuits, e->pb.timeouts);
-        next = &(line->next);
-      }
-      if (e->pb.use_attempts > 0) {
-        *next = line = tor_malloc_zero(sizeof(config_line_t));
-        line->key = tor_strdup("EntryGuardPathUseBias");
-
-        tor_asprintf(&line->value, "%f %f",
-                     e->pb.use_attempts,
-                     pathbias_get_use_success_count(e));
-        next = &(line->next);
-      }
-
-  } SMARTLIST_FOREACH_END(e);
-#endif
   if (!get_options()->AvoidDiskWrites)
     or_state_mark_dirty(get_or_state(), 0);
   entry_guards_dirty = 0;
@@ -4761,22 +3124,8 @@ getinfo_helper_format_single_entry_guard(const entry_guard_t *e,
   char nbuf[MAX_VERBOSE_NICKNAME_LEN+1];
 
   if (legacy_guard) {
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-    if (!e->made_contact) {
-      status = "never-connected";
-    } else if (e->bad_since) {
-      when = e->bad_since;
-      status = "unusable";
-    } else if (e->unreachable_since) {
-      when = e->unreachable_since;
-      status = "down";
-    } else {
-      status = "up";
-    }
-#else
     tor_assert_nonfatal_unreached();
     status = "BUG";
-#endif
   } else {
     /* modern case.  This is going to be a bit tricky, since the status
      * codes above weren't really intended for prop271 guards.
@@ -4835,9 +3184,6 @@ getinfo_helper_entry_guards(control_connection_t *conn,
   guard_selection_t *gs = get_guard_selection_info();
 
   tor_assert(gs != NULL);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  tor_assert(gs->chosen_entry_guards != NULL);
-#endif
 
   (void) conn;
   (void) errmsg;
@@ -4847,13 +3193,8 @@ getinfo_helper_entry_guards(control_connection_t *conn,
     const smartlist_t *guards;
     int legacy_mode;
     if (gs->type == GS_TYPE_LEGACY) {
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-      guards = gs->chosen_entry_guards;
-      legacy_mode = 1;
-#else
       tor_assert_nonfatal_unreached();
       return 0;
-#endif
     } else {
       guards = gs->sampled_entry_guards;
       legacy_mode = 0;
@@ -4907,107 +3248,6 @@ guard_get_guardfraction_bandwidth(guardfraction_bandwidth_t *guardfraction_bw,
   guardfraction_bw->non_guard_bw = orig_bandwidth - (int) guard_bw;
 }
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/** Returns true iff the node is used as a guard in the specified guard
- * context */
-int
-is_node_used_as_guard_for_guard_selection(guard_selection_t *gs,
-                                          const node_t *node)
-{
-  int res = 0;
-
-  /*
-   * We used to have a using_as_guard flag in node_t, but it had to go away
-   * to allow for multiple guard selection contexts.  Instead, search the
-   * guard list for a matching digest.
-   */
-
-  tor_assert(gs != NULL);
-  tor_assert(node != NULL);
-
-  SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *, e) {
-    if (tor_memeq(e->identity, node->identity, DIGEST_LEN)) {
-      res = 1;
-      break;
-    }
-  } SMARTLIST_FOREACH_END(e);
-
-  return res;
-}
-
-/** Returns true iff the node is used as a guard in the default guard
- * context */
-MOCK_IMPL(int,
-is_node_used_as_guard, (const node_t *node))
-{
-  return is_node_used_as_guard_for_guard_selection(
-      get_guard_selection_info(), node);
-}
-
-/** Return 1 if we have at least one descriptor for an entry guard
- * (bridge or member of EntryNodes) and all descriptors we know are
- * down. Else return 0. If <b>act</b> is 1, then mark the down guards
- * up; else just observe and report. */
-static int
-entries_retry_helper(const or_options_t *options, int act)
-{
-  const node_t *node;
-  int any_known = 0;
-  int any_running = 0;
-  int need_bridges = options->UseBridges != 0;
-  guard_selection_t *gs = get_guard_selection_info();
-
-  tor_assert(gs != NULL);
-  tor_assert(gs->chosen_entry_guards != NULL);
-
-  SMARTLIST_FOREACH_BEGIN(gs->chosen_entry_guards, entry_guard_t *, e) {
-      node = node_get_by_id(e->identity);
-      if (node && node_has_descriptor(node) &&
-          node_is_bridge(node) == need_bridges &&
-          (!need_bridges || (!e->bad_since &&
-                             node_is_a_configured_bridge(node)))) {
-        any_known = 1;
-        if (node->is_running)
-          any_running = 1; /* some entry is both known and running */
-        else if (act) {
-          /* Mark all current connections to this OR as unhealthy, since
-           * otherwise there could be one that started 30 seconds
-           * ago, and in 30 seconds it will time out, causing us to mark
-           * the node down and undermine the retry attempt. We mark even
-           * the established conns, since if the network just came back
-           * we'll want to attach circuits to fresh conns. */
-          channel_update_bad_for_new_circs(node->identity, 1);
-
-          /* mark this entry node for retry */
-          router_set_status(node->identity, 1);
-          e->can_retry = 1;
-          e->bad_since = 0;
-        }
-      }
-  } SMARTLIST_FOREACH_END(e);
-  log_debug(LD_DIR, "%d: any_known %d, any_running %d",
-            act, any_known, any_running);
-  return any_known && !any_running;
-}
-
-/** Do we know any descriptors for our bridges / entrynodes, and are
- * all the ones we have descriptors for down? */
-int
-entries_known_but_down(const or_options_t *options)
-{
-  tor_assert(entry_list_is_constrained(options));
-  return entries_retry_helper(options, 0);
-}
-
-/** Mark all down known bridges / entrynodes up. */
-void
-entries_retry_all(const or_options_t *options)
-{
-  tor_assert(entry_list_is_constrained(options));
-  entries_retry_helper(options, 1);
-}
-#endif
-
 /** Helper: Update the status of all entry guards, in whatever algorithm
  * is used. Return true if we should stop using all previously generated
  * circuits, by calling circuit_mark_all_unused_circs() and
@@ -5023,11 +3263,7 @@ guards_update_all(void)
   tor_assert(curr_guard_context);
 
   if (curr_guard_context->type == GS_TYPE_LEGACY) {
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-    entry_guards_compute_status(get_options(), approx_time());
-#else
     tor_assert_nonfatal_unreached();
-#endif
   } else {
     if (entry_guards_update_all(curr_guard_context))
       mark_circuits = 1;
@@ -5043,12 +3279,8 @@ guards_choose_guard(cpath_build_state_t *state,
                    circuit_guard_state_t **guard_state_out)
 {
   if (get_options()->UseDeprecatedGuardAlgorithm) {
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-    return choose_random_entry(state);
-#else
     tor_assert_nonfatal_unreached();
     return NULL;
-#endif
   } else {
     const node_t *r = NULL;
     const uint8_t *exit_id = NULL;
@@ -5077,13 +3309,9 @@ guards_choose_dirguard(dirinfo_type_t info,
                       circuit_guard_state_t **guard_state_out)
 {
   if (get_options()->UseDeprecatedGuardAlgorithm) {
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-    return choose_random_dirguard(info);
-#else
     (void)info;
     tor_assert_nonfatal_unreached();
     return NULL;
-#endif
   } else {
     /* XXXX prop271 We don't need to look at the dirinfo_type_t here,
      * apparently. If you look at the old implementation, and you follow info
@@ -5114,15 +3342,6 @@ guards_retry_optimistic(const or_options_t *options)
   if (! entry_list_is_constrained(options))
     return 0;
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  if (options->UseDeprecatedGuardAlgorithm) {
-    if (entries_known_but_down(options)) {
-      entries_retry_all(options);
-      return 1;
-    }
-  }
-#endif
-
   // XXXX prop271 -- is this correct?
   mark_primary_guards_maybe_reachable(get_guard_selection_info());
 
@@ -5137,15 +3356,6 @@ guard_selection_free(guard_selection_t *gs)
 
   tor_free(gs->name);
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  if (gs->chosen_entry_guards) {
-    SMARTLIST_FOREACH(gs->chosen_entry_guards, entry_guard_t *, e,
-                      entry_guard_free(e));
-    smartlist_free(gs->chosen_entry_guards);
-    gs->chosen_entry_guards = NULL;
-  }
-#endif
-
   if (gs->sampled_entry_guards) {
     SMARTLIST_FOREACH(gs->sampled_entry_guards, entry_guard_t *, e,
                       entry_guard_free(e));
diff --git a/src/or/entrynodes.h b/src/or/entrynodes.h
index 5fa0fec..a1ede71 100644
--- a/src/or/entrynodes.h
+++ b/src/or/entrynodes.h
@@ -28,11 +28,6 @@ typedef struct circuit_guard_state_t circuit_guard_state_t;
    private. */
 typedef struct entry_guard_restriction_t entry_guard_restriction_t;
 
-/*
-  XXXX Prop271 undefine this in order to disable all legacy guard functions.
-*/
-// #define ENABLE_LEGACY_GUARD_ALGORITHM
-
 /* Information about a guard's pathbias status.
  * These fields are used in circpathbias.c to try to detect entry
  * nodes that are failing circuits at a suspicious frequency.
@@ -179,37 +174,6 @@ struct entry_guard_t {
   guard_selection_t *in_selection;
   /**@}*/
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  /**
-   * @name legacy guard selection algorithm fields
-   *
-   * These are used and maintained by the legacy (pre-prop271) entry guard
-   * algorithm.  Most of them we will remove as prop271 gets implemented.
-   * The rest we'll migrate over, if they are 100% semantically identical to
-   * their prop271 equivalents. XXXXprop271
-   */
-  /**@{*/
-  time_t chosen_on_date; /**< Approximately when was this guard added?
-                          * "0" if we don't know. */
-  char *chosen_by_version; /**< What tor version added this guard? NULL
-                            * if we don't know. */
-  unsigned int made_contact : 1; /**< 0 if we have never connected to this
-                                  * router, 1 if we have. */
-  unsigned int can_retry : 1; /**< Should we retry connecting to this entry,
-                               * in spite of having it marked as unreachable?*/
-  unsigned int is_dir_cache : 1; /**< Is this node a directory cache? */
-  time_t bad_since; /**< 0 if this guard is currently usable, or the time at
-                      * which it was observed to become (according to the
-                      * directory or the user configuration) unusable. */
-  time_t unreachable_since; /**< 0 if we can connect to this guard, or the
-                             * time at which we first noticed we couldn't
-                             * connect to it. */
-  time_t last_attempted; /**< 0 if we can connect to this guard, or the time
-                          * at which we last failed to connect to it. */
-
-  /**}@*/
-#endif
-
   /** Path bias information for this guard. */
   guard_pathbias_t pb;
 };
@@ -305,20 +269,6 @@ struct guard_selection_s {
    * confirmed_entry_guards receive? */
   int next_confirmed_idx;
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  /**
-   * A list of our chosen entry guards, as entry_guard_t structures; this
-   * preserves the pre-Prop271 behavior.
-   */
-  smartlist_t *chosen_entry_guards;
-
-  /**
-   * When we try to choose an entry guard, should we parse and add
-   * config's EntryNodes first?  This was formerly a global.  This
-   * preserves the pre-Prop271 behavior.
-   */
-  int should_add_entry_nodes;
-#endif
 };
 
 struct entry_guard_handle_t;
@@ -378,11 +328,6 @@ entry_guard_t *entry_guard_get_by_id_digest(const char *digest);
 void entry_guards_changed_for_guard_selection(guard_selection_t *gs);
 void entry_guards_changed(void);
 guard_selection_t * get_guard_selection_info(void);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-const smartlist_t *get_entry_guards_for_guard_selection(
-    guard_selection_t *gs);
-const smartlist_t *get_entry_guards(void);
-#endif
 int num_live_entry_guards_for_guard_selection(
     guard_selection_t *gs,
     int for_directory);
@@ -390,9 +335,6 @@ int num_live_entry_guards(int for_directory);
 #endif
 
 const node_t *entry_guard_find_node(const entry_guard_t *guard);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-void entry_guard_mark_bad(entry_guard_t *guard);
-#endif
 const char *entry_guard_get_rsa_id_digest(const entry_guard_t *guard);
 const char *entry_guard_describe(const entry_guard_t *guard);
 guard_pathbias_t *entry_guard_get_pathbias_state(entry_guard_t *guard);
@@ -432,10 +374,6 @@ void entry_guards_note_internet_connectivity(guard_selection_t *gs);
 int update_guard_selection_choice(const or_options_t *options);
 
 /* Used by bridges.c only. */
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-void add_bridge_as_entry_guard(guard_selection_t *gs,
-                               const node_t *chosen);
-#endif
 int num_bridges_usable(void);
 
 #ifdef ENTRYNODES_PRIVATE
@@ -612,68 +550,13 @@ STATIC unsigned entry_guards_note_guard_success(guard_selection_t *gs,
 STATIC int entry_guard_has_higher_priority(entry_guard_t *a, entry_guard_t *b);
 STATIC char *getinfo_helper_format_single_entry_guard(const entry_guard_t *e,
                                                       int is_legacy);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-// ---------- XXXX this stuff is pre-prop271.
-
-STATIC const node_t *add_an_entry_guard(guard_selection_t *gs,
-                                        const node_t *chosen,
-                                        int reset_status, int prepend,
-                                        int for_discovery, int for_directory);
-STATIC int populate_live_entry_guards(smartlist_t *live_entry_guards,
-                                      const smartlist_t *all_entry_guards,
-                                      const node_t *chosen_exit,
-                                      dirinfo_type_t dirinfo_type,
-                                      int for_directory,
-                                      int need_uptime, int need_capacity);
-STATIC int decide_num_guards(const or_options_t *options, int for_directory);
-
-STATIC void entry_guards_set_from_config(guard_selection_t *gs,
-                                         const or_options_t *options);
-
-/** Flags to be passed to entry_is_live() to indicate what kind of
- * entry nodes we are looking for. */
-typedef enum {
-  ENTRY_NEED_UPTIME = 1<<0,
-  ENTRY_NEED_CAPACITY = 1<<1,
-  ENTRY_ASSUME_REACHABLE = 1<<2,
-  ENTRY_NEED_DESCRIPTOR = 1<<3,
-} entry_is_live_flags_t;
-
-STATIC const node_t *entry_is_live(const entry_guard_t *e,
-                                   entry_is_live_flags_t flags,
-                                   const char **msg);
-
-STATIC int entry_is_time_to_retry(const entry_guard_t *e, time_t now);
-#endif
-
-#endif
-
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-void remove_all_entry_guards_for_guard_selection(guard_selection_t *gs);
-void remove_all_entry_guards(void);
 #endif
 
 struct bridge_info_t;
 void entry_guard_learned_bridge_identity(const tor_addr_port_t *addrport,
                                          const uint8_t *rsa_id_digest);
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-void entry_guards_compute_status_for_guard_selection(
-    guard_selection_t *gs, const or_options_t *options, time_t now);
-void entry_guards_compute_status(const or_options_t *options, time_t now);
-int entry_guard_register_connect_status_for_guard_selection(
-    guard_selection_t *gs, const char *digest, int succeeded,
-    int mark_relay_status, time_t now);
-int entry_guard_register_connect_status(const char *digest, int succeeded,
-                                        int mark_relay_status, time_t now);
-void entry_nodes_should_be_added_for_guard_selection(guard_selection_t *gs);
-void entry_nodes_should_be_added(void);
-#endif
 int entry_list_is_constrained(const or_options_t *options);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-const node_t *choose_random_entry(cpath_build_state_t *state);
-const node_t *choose_random_dirguard(dirinfo_type_t t);
-#endif
 int guards_retry_optimistic(const or_options_t *options);
 int entry_guards_parse_state_for_guard_selection(
     guard_selection_t *gs, or_state_t *state, int set, char **msg);
@@ -682,11 +565,6 @@ void entry_guards_update_state(or_state_t *state);
 int getinfo_helper_entry_guards(control_connection_t *conn,
                                 const char *question, char **answer,
                                 const char **errmsg);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-int is_node_used_as_guard_for_guard_selection(guard_selection_t *gs,
-                                              const node_t *node);
-MOCK_DECL(int, is_node_used_as_guard, (const node_t *node));
-#endif
 
 int entries_known_but_down(const or_options_t *options);
 void entries_retry_all(const or_options_t *options);
diff --git a/src/or/routerlist.c b/src/or/routerlist.c
index 72474b1..03f8bc7 100644
--- a/src/or/routerlist.c
+++ b/src/or/routerlist.c
@@ -1999,10 +1999,7 @@ router_pick_directory_server_impl(dirinfo_type_t type, int flags,
   const int for_guard = (flags & PDS_FOR_GUARD);
   int try_excluding = 1, n_excluded = 0, n_busy = 0;
   int try_ip_pref = 1;
-
-#ifndef ENABLE_LEGACY_GUARD_ALGORITHM
-  tor_assert_nonfatal(! for_guard);
-#endif
+  tor_assert_nonfatal(! for_guard); // XXXX prop271
 
   if (!consensus)
     return NULL;
@@ -2036,12 +2033,6 @@ router_pick_directory_server_impl(dirinfo_type_t type, int flags,
 
     SKIP_MISSING_TRUSTED_EXTRAINFO(type, node->identity);
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-    /* Don't make the same node a guard twice */
-     if (for_guard && is_node_used_as_guard(node)) {
-       continue;
-     }
-#endif
     /* Ensure that a directory guard is actually a guard node. */
     if (for_guard && !node->is_possible_guard) {
       continue;
diff --git a/src/test/test_entrynodes.c b/src/test/test_entrynodes.c
index 32f8b6e..2e7abd1 100644
--- a/src/test/test_entrynodes.c
+++ b/src/test/test_entrynodes.c
@@ -45,41 +45,6 @@ get_or_state_replacement(void)
   return dummy_state;
 }
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/* Unittest cleanup function: Cleanup the fake network. */
-static int
-fake_network_cleanup(const struct testcase_t *testcase, void *ptr)
-{
-  (void) testcase;
-  (void) ptr;
-
-  routerlist_free_all();
-  nodelist_free_all();
-  entry_guards_free_all();
-  or_state_free(dummy_state);
-
-  return 1; /* NOP */
-}
-
-/* Unittest setup function: Setup a fake network. */
-static void *
-fake_network_setup(const struct testcase_t *testcase)
-{
-  (void) testcase;
-
-  /* Setup fake state */
-  dummy_state = tor_malloc_zero(sizeof(or_state_t));
-  MOCK(get_or_state,
-       get_or_state_replacement);
-
-  /* Setup fake routerlist. */
-  helper_setup_fake_routerlist();
-
-  /* Return anything but NULL (it's interpreted as test fail) */
-  return dummy_state;
-}
-#endif
-
 static networkstatus_t *dummy_consensus = NULL;
 
 static smartlist_t *big_fake_net_nodes = NULL;
@@ -202,697 +167,6 @@ mock_get_options(void)
   return &mocked_options;
 }
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-/** Test choose_random_entry() with none of our routers being guard nodes. */
-static void
-test_choose_random_entry_no_guards(void *arg)
-{
-  const node_t *chosen_entry = NULL;
-
-  (void) arg;
-
-  MOCK(get_options, mock_get_options);
-
-  /* Check that we get a guard if it passes preferred
-   * address settings */
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  mocked_options.ClientUseIPv4 = 1;
-  mocked_options.ClientPreferIPv6ORPort = 0;
-  mocked_options.UseDeprecatedGuardAlgorithm = 1;
-
-  /* Try to pick an entry even though none of our routers are guards. */
-  chosen_entry = choose_random_entry(NULL);
-
-  /* Unintuitively, we actually pick a random node as our entry,
-     because router_choose_random_node() relaxes its constraints if it
-     can't find a proper entry guard. */
-  tt_assert(chosen_entry);
-
-  /* And with the other IP version active */
-  mocked_options.ClientUseIPv6 = 1;
-  chosen_entry = choose_random_entry(NULL);
-  tt_assert(chosen_entry);
-
-  /* And with the preference on auto */
-  mocked_options.ClientPreferIPv6ORPort = -1;
-  chosen_entry = choose_random_entry(NULL);
-  tt_assert(chosen_entry);
-
-  /* Check that we don't get a guard if it doesn't pass mandatory address
-   * settings */
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  mocked_options.ClientUseIPv4 = 0;
-  mocked_options.ClientPreferIPv6ORPort = 0;
-  mocked_options.UseDeprecatedGuardAlgorithm = 1;
-
-  chosen_entry = choose_random_entry(NULL);
-
-  /* If we don't allow IPv4 at all, we don't get a guard*/
-  tt_assert(!chosen_entry);
-
-  /* Check that we get a guard if it passes allowed but not preferred address
-   * settings */
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  mocked_options.ClientUseIPv4 = 1;
-  mocked_options.ClientUseIPv6 = 1;
-  mocked_options.ClientPreferIPv6ORPort = 1;
-  mocked_options.UseDeprecatedGuardAlgorithm = 1;
-
-  chosen_entry = choose_random_entry(NULL);
-  tt_assert(chosen_entry);
-
-  /* Check that we get a guard if it passes preferred address settings when
-   * they're auto */
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  mocked_options.ClientUseIPv4 = 1;
-  mocked_options.ClientPreferIPv6ORPort = -1;
-  mocked_options.UseDeprecatedGuardAlgorithm = 1;
-
-  chosen_entry = choose_random_entry(NULL);
-  tt_assert(chosen_entry);
-
-  /* And with IPv6 active */
-  mocked_options.ClientUseIPv6 = 1;
-
-  chosen_entry = choose_random_entry(NULL);
-  tt_assert(chosen_entry);
-
- done:
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  UNMOCK(get_options);
-}
-
-/** Test choose_random_entry() with only one of our routers being a
-    guard node. */
-static void
-test_choose_random_entry_one_possible_guard(void *arg)
-{
-  const node_t *chosen_entry = NULL;
-  node_t *the_guard = NULL;
-  smartlist_t *our_nodelist = NULL;
-
-  (void) arg;
-
-  MOCK(get_options, mock_get_options);
-
-  /* Set one of the nodes to be a guard. */
-  our_nodelist = nodelist_get_list();
-  the_guard = smartlist_get(our_nodelist, 4); /* chosen by fair dice roll */
-  the_guard->is_possible_guard = 1;
-
-  /* Check that we get the guard if it passes preferred
-   * address settings */
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  mocked_options.ClientUseIPv4 = 1;
-  mocked_options.ClientPreferIPv6ORPort = 0;
-  mocked_options.UseDeprecatedGuardAlgorithm = 1;
-
-  /* Pick an entry. Make sure we pick the node we marked as guard. */
-  chosen_entry = choose_random_entry(NULL);
-  tt_ptr_op(chosen_entry, OP_EQ, the_guard);
-
-  /* And with the other IP version active */
-  mocked_options.ClientUseIPv6 = 1;
-  chosen_entry = choose_random_entry(NULL);
-  tt_ptr_op(chosen_entry, OP_EQ, the_guard);
-
-  /* And with the preference on auto */
-  mocked_options.ClientPreferIPv6ORPort = -1;
-  chosen_entry = choose_random_entry(NULL);
-  tt_ptr_op(chosen_entry, OP_EQ, the_guard);
-
-  /* Check that we don't get a guard if it doesn't pass mandatory address
-   * settings */
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  mocked_options.ClientUseIPv4 = 0;
-  mocked_options.ClientPreferIPv6ORPort = 0;
-  mocked_options.UseDeprecatedGuardAlgorithm = 1;
-
-  chosen_entry = choose_random_entry(NULL);
-
-  /* If we don't allow IPv4 at all, we don't get a guard*/
-  tt_assert(!chosen_entry);
-
-  /* Check that we get a node if it passes allowed but not preferred
-   * address settings */
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  mocked_options.ClientUseIPv4 = 1;
-  mocked_options.ClientUseIPv6 = 1;
-  mocked_options.ClientPreferIPv6ORPort = 1;
-  mocked_options.UseDeprecatedGuardAlgorithm = 1;
-
-  chosen_entry = choose_random_entry(NULL);
-
-  /* We disable the guard check and the preferred address check at the same
-   * time, so we can't be sure we get the guard */
-  tt_assert(chosen_entry);
-
-  /* Check that we get a node if it is allowed but not preferred when settings
-   * are auto */
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  mocked_options.ClientUseIPv4 = 1;
-  mocked_options.ClientPreferIPv6ORPort = -1;
-  mocked_options.UseDeprecatedGuardAlgorithm = 1;
-
-  chosen_entry = choose_random_entry(NULL);
-
-  /* We disable the guard check and the preferred address check at the same
-   * time, so we can't be sure we get the guard */
-  tt_assert(chosen_entry);
-
-  /* and with IPv6 active */
-  mocked_options.ClientUseIPv6 = 1;
-
-  chosen_entry = choose_random_entry(NULL);
-  tt_assert(chosen_entry);
-
- done:
-  memset(&mocked_options, 0, sizeof(mocked_options));
-  UNMOCK(get_options);
-}
-
-/** Helper to conduct tests for populate_live_entry_guards().
-
-   This test adds some entry guards to our list, and then tests
-   populate_live_entry_guards() to mke sure it filters them correctly.
-
-   <b>num_needed</b> is the number of guard nodes we support. It's
-   configurable to make sure we function properly with 1 or 3 guard
-   nodes configured.
-*/
-static void
-populate_live_entry_guards_test_helper(int num_needed)
-{
-  smartlist_t *our_nodelist = NULL;
-  smartlist_t *live_entry_guards = smartlist_new();
-  guard_selection_t *gs = get_guard_selection_info();
-  const smartlist_t *all_entry_guards =
-    get_entry_guards_for_guard_selection(gs);
-  or_options_t *options = get_options_mutable();
-  int retval;
-
-  /* Set NumEntryGuards to the provided number. */
-  options->NumEntryGuards = num_needed;
-  tt_int_op(num_needed, OP_EQ, decide_num_guards(options, 0));
-
-  /* The global entry guards smartlist should be empty now. */
-  tt_int_op(smartlist_len(all_entry_guards), OP_EQ, 0);
-
-  /* Walk the nodelist and add all nodes as entry guards. */
-  our_nodelist = nodelist_get_list();
-  tt_int_op(smartlist_len(our_nodelist), OP_EQ, HELPER_NUMBER_OF_DESCRIPTORS);
-
-  SMARTLIST_FOREACH_BEGIN(our_nodelist, const node_t *, node) {
-    const node_t *node_tmp;
-    node_tmp = add_an_entry_guard(gs, node, 0, 1, 0, 0);
-    tt_assert(node_tmp);
-  } SMARTLIST_FOREACH_END(node);
-
-  /* Make sure the nodes were added as entry guards. */
-  tt_int_op(smartlist_len(all_entry_guards), OP_EQ,
-            HELPER_NUMBER_OF_DESCRIPTORS);
-
-  /* Ensure that all the possible entry guards are enough to satisfy us. */
-  tt_int_op(smartlist_len(all_entry_guards), OP_GE, num_needed);
-
-  /* Walk the entry guard list for some sanity checking */
-  SMARTLIST_FOREACH_BEGIN(all_entry_guards, const entry_guard_t *, entry) {
-    /* Since we called add_an_entry_guard() with 'for_discovery' being
-       False, all guards should have made_contact enabled. */
-    tt_int_op(entry->made_contact, OP_EQ, 1);
-
-  } SMARTLIST_FOREACH_END(entry);
-
-  /* First, try to get some fast guards. This should fail. */
-  retval = populate_live_entry_guards(live_entry_guards,
-                                      all_entry_guards,
-                                      NULL,
-                                      NO_DIRINFO, /* Don't care about DIRINFO*/
-                                      0, 0,
-                                      1); /* We want fast guard! */
-  tt_int_op(retval, OP_EQ, 0);
-  tt_int_op(smartlist_len(live_entry_guards), OP_EQ, 0);
-
-  /* Now try to get some stable guards. This should fail too. */
-  retval = populate_live_entry_guards(live_entry_guards,
-                                      all_entry_guards,
-                                      NULL,
-                                      NO_DIRINFO,
-                                      0,
-                                      1, /* We want stable guard! */
-                                      0);
-  tt_int_op(retval, OP_EQ, 0);
-  tt_int_op(smartlist_len(live_entry_guards), OP_EQ, 0);
-
-  /* Now try to get any guard we can find. This should succeed. */
-  retval = populate_live_entry_guards(live_entry_guards,
-                                      all_entry_guards,
-                                      NULL,
-                                      NO_DIRINFO,
-                                      0, 0, 0); /* No restrictions! */
-
-  /* Since we had more than enough guards in 'all_entry_guards', we
-     should have added 'num_needed' of them to live_entry_guards.
-     'retval' should be 1 since we now have enough live entry guards
-     to pick one.  */
-  tt_int_op(retval, OP_EQ, 1);
-  tt_int_op(smartlist_len(live_entry_guards), OP_EQ, num_needed);
-
- done:
-  smartlist_free(live_entry_guards);
-}
-
-/* Test populate_live_entry_guards() for 1 guard node. */
-static void
-test_populate_live_entry_guards_1guard(void *arg)
-{
-  (void) arg;
-
-  populate_live_entry_guards_test_helper(1);
-}
-
-/* Test populate_live_entry_guards() for 3 guard nodes. */
-static void
-test_populate_live_entry_guards_3guards(void *arg)
-{
-  (void) arg;
-
-  populate_live_entry_guards_test_helper(3);
-}
-
-/** Append some EntryGuard lines to the Tor state at <b>state</b>.
-
-   <b>entry_guard_lines</b> is a smartlist containing 2-tuple
-   smartlists that carry the key and values of the statefile.
-   As an example:
-   entry_guard_lines =
-     (("EntryGuard", "name 67E72FF33D7D41BF11C569646A0A7B4B188340DF DirCache"),
-      ("EntryGuardDownSince", "2014-06-07 16:02:46 2014-06-07 16:02:46"))
-*/
-static void
-state_insert_entry_guard_helper(or_state_t *state,
-                                smartlist_t *entry_guard_lines)
-{
-  config_line_t **next, *line;
-
-  next = &state->EntryGuards;
-  *next = NULL;
-
-  /* Loop over all the state lines in the smartlist */
-  SMARTLIST_FOREACH_BEGIN(entry_guard_lines, const smartlist_t *,state_lines) {
-    /* Get key and value for each line */
-    const char *state_key = smartlist_get(state_lines, 0);
-    const char *state_value = smartlist_get(state_lines, 1);
-
-    *next = line = tor_malloc_zero(sizeof(config_line_t));
-    line->key = tor_strdup(state_key);
-    tor_asprintf(&line->value, "%s", state_value);
-    next = &(line->next);
-  } SMARTLIST_FOREACH_END(state_lines);
-}
-
-/** Free memory occupied by <b>entry_guard_lines</b>. */
-static void
-state_lines_free(smartlist_t *entry_guard_lines)
-{
-  SMARTLIST_FOREACH_BEGIN(entry_guard_lines, smartlist_t *, state_lines) {
-    char *state_key = smartlist_get(state_lines, 0);
-    char *state_value = smartlist_get(state_lines, 1);
-
-    tor_free(state_key);
-    tor_free(state_value);
-    smartlist_free(state_lines);
-  } SMARTLIST_FOREACH_END(state_lines);
-
-  smartlist_free(entry_guard_lines);
-}
-
-/* Tests entry_guards_parse_state(). It creates a fake Tor state with
-   a saved entry guard and makes sure that Tor can parse it and
-   creates the right entry node out of it.
-*/
-static void
-test_entry_guards_parse_state_simple(void *arg)
-{
-  or_options_t *options = get_options_mutable();
-  options->UseDeprecatedGuardAlgorithm = 1;
-  or_state_t *state = or_state_new();
-  const smartlist_t *all_entry_guards = get_entry_guards();
-  smartlist_t *entry_state_lines = smartlist_new();
-  char *msg = NULL;
-  int retval;
-
-  /* Details of our fake guard node */
-  const char *nickname = "hagbard";
-  const char *fpr = "B29D536DD1752D542E1FBB3C9CE4449D51298212";
-  const char *tor_version = "0.2.5.3-alpha-dev";
-  const char *added_at = get_yesterday_date_str();
-  const char *unlisted_since = "2014-06-08 16:16:50";
-
-  (void) arg;
-
-  /* The global entry guards smartlist should be empty now. */
-  tt_int_op(smartlist_len(all_entry_guards), OP_EQ, 0);
-
-  { /* Prepare the state entry */
-
-    /* Prepare the smartlist to hold the key/value of each line */
-    smartlist_t *state_line = smartlist_new();
-    smartlist_add_asprintf(state_line, "EntryGuard");
-    smartlist_add_asprintf(state_line, "%s %s %s", nickname, fpr, "DirCache");
-    smartlist_add(entry_state_lines, state_line);
-
-    state_line = smartlist_new();
-    smartlist_add_asprintf(state_line, "EntryGuardAddedBy");
-    smartlist_add_asprintf(state_line, "%s %s %s", fpr, tor_version, added_at);
-    smartlist_add(entry_state_lines, state_line);
-
-    state_line = smartlist_new();
-    smartlist_add_asprintf(state_line, "EntryGuardUnlistedSince");
-    smartlist_add_asprintf(state_line, "%s", unlisted_since);
-    smartlist_add(entry_state_lines, state_line);
-  }
-
-  /* Inject our lines in the state */
-  state_insert_entry_guard_helper(state, entry_state_lines);
-
-  /* Parse state */
-  retval = entry_guards_parse_state(state, 1, &msg);
-  tt_int_op(retval, OP_GE, 0);
-
-  /* Test that the guard was registered.
-     We need to re-get the entry guard list since its pointer was
-     overwritten in entry_guards_parse_state(). */
-  all_entry_guards = get_entry_guards();
-  tt_int_op(smartlist_len(all_entry_guards), OP_EQ, 1);
-
-  { /* Test the entry guard structure */
-    char hex_digest[1024];
-    char str_time[1024];
-
-    const entry_guard_t *e = smartlist_get(all_entry_guards, 0);
-    tt_str_op(e->nickname, OP_EQ, nickname); /* Verify nickname */
-
-    base16_encode(hex_digest, sizeof(hex_digest),
-                  e->identity, DIGEST_LEN);
-    tt_str_op(hex_digest, OP_EQ, fpr); /* Verify fingerprint */
-
-    tt_assert(e->is_dir_cache); /* Verify dirness */
-
-    tt_str_op(e->chosen_by_version, OP_EQ, tor_version); /* Verify version */
-
-    tt_assert(e->made_contact); /* All saved guards have been contacted */
-
-    tt_assert(e->bad_since); /* Verify bad_since timestamp */
-    format_iso_time(str_time, e->bad_since);
-    tt_str_op(str_time, OP_EQ, unlisted_since);
-
-    /* The rest should be unset */
-    tt_assert(!e->unreachable_since);
-    tt_assert(!e->can_retry);
-    tt_assert(!e->pb.path_bias_noticed);
-    tt_assert(!e->pb.path_bias_warned);
-    tt_assert(!e->pb.path_bias_extreme);
-    tt_assert(!e->pb.path_bias_disabled);
-    tt_assert(!e->pb.path_bias_use_noticed);
-    tt_assert(!e->pb.path_bias_use_extreme);
-    tt_assert(!e->last_attempted);
-  }
-
- done:
-  state_lines_free(entry_state_lines);
-  or_state_free(state);
-  tor_free(msg);
-}
-
-/** Similar to test_entry_guards_parse_state_simple() but aims to test
-    the PathBias-related details of the entry guard. */
-static void
-test_entry_guards_parse_state_pathbias(void *arg)
-{
-  or_options_t *options = get_options_mutable();
-  options->UseDeprecatedGuardAlgorithm = 1;
-  or_state_t *state = or_state_new();
-  const smartlist_t *all_entry_guards = get_entry_guards();
-  char *msg = NULL;
-  int retval;
-  smartlist_t *entry_state_lines = smartlist_new();
-
-  /* Path bias details of the fake guard */
-  const double circ_attempts = 9;
-  const double circ_successes = 8;
-  const double successful_closed = 4;
-  const double collapsed = 2;
-  const double unusable = 0;
-  const double timeouts = 1;
-
-  (void) arg;
-
-  /* The global entry guards smartlist should be empty now. */
-  tt_int_op(smartlist_len(all_entry_guards), OP_EQ, 0);
-
-  { /* Prepare the state entry */
-
-    /* Prepare the smartlist to hold the key/value of each line */
-    smartlist_t *state_line = smartlist_new();
-    smartlist_add_asprintf(state_line, "EntryGuard");
-    smartlist_add_asprintf(state_line,
-             "givethanks B29D536DD1752D542E1FBB3C9CE4449D51298212 NoDirCache");
-    smartlist_add(entry_state_lines, state_line);
-
-    state_line = smartlist_new();
-    smartlist_add_asprintf(state_line, "EntryGuardAddedBy");
-    smartlist_add_asprintf(state_line,
-      "B29D536DD1752D542E1FBB3C9CE4449D51298212 0.2.5.3-alpha-dev "
-                           "%s", get_yesterday_date_str());
-    smartlist_add(entry_state_lines, state_line);
-
-    state_line = smartlist_new();
-    smartlist_add_asprintf(state_line, "EntryGuardUnlistedSince");
-    smartlist_add_asprintf(state_line, "2014-06-08 16:16:50");
-    smartlist_add(entry_state_lines, state_line);
-
-    state_line = smartlist_new();
-    smartlist_add_asprintf(state_line, "EntryGuardPathBias");
-    smartlist_add_asprintf(state_line, "%f %f %f %f %f %f",
-                           circ_attempts, circ_successes, successful_closed,
-                           collapsed, unusable, timeouts);
-    smartlist_add(entry_state_lines, state_line);
-  }
-
-  /* Inject our lines in the state */
-  state_insert_entry_guard_helper(state, entry_state_lines);
-
-  /* Parse state */
-  retval = entry_guards_parse_state(state, 1, &msg);
-  tt_int_op(retval, OP_GE, 0);
-
-  /* Test that the guard was registered */
-  all_entry_guards = get_entry_guards();
-  tt_int_op(smartlist_len(all_entry_guards), OP_EQ, 1);
-
-  { /* Test the path bias of this guard */
-    const entry_guard_t *e = smartlist_get(all_entry_guards, 0);
-
-    tt_assert(!e->is_dir_cache);
-    tt_assert(!e->can_retry);
-
-    /* XXX tt_double_op doesn't support equality. Cast to int for now. */
-    tt_int_op((int)e->pb.circ_attempts, OP_EQ, (int)circ_attempts);
-    tt_int_op((int)e->pb.circ_successes, OP_EQ, (int)circ_successes);
-    tt_int_op((int)e->pb.successful_circuits_closed, OP_EQ,
-              (int)successful_closed);
-    tt_int_op((int)e->pb.timeouts, OP_EQ, (int)timeouts);
-    tt_int_op((int)e->pb.collapsed_circuits, OP_EQ, (int)collapsed);
-    tt_int_op((int)e->pb.unusable_circuits, OP_EQ, (int)unusable);
-  }
-
- done:
-  or_state_free(state);
-  state_lines_free(entry_state_lines);
-  tor_free(msg);
-}
-
-/* Simple test of entry_guards_set_from_config() by specifying a
-   particular EntryNode and making sure it gets picked. */
-static void
-test_entry_guards_set_from_config(void *arg)
-{
-  or_options_t *options = get_options_mutable();
-  options->UseDeprecatedGuardAlgorithm = 1;
-  guard_selection_t *gs = get_guard_selection_info();
-  const smartlist_t *all_entry_guards =
-    get_entry_guards_for_guard_selection(gs);
-  const char *entrynodes_str = "test003r";
-  const node_t *chosen_entry = NULL;
-  int retval;
-
-  (void) arg;
-
-  /* Prase EntryNodes as a routerset. */
-  options->EntryNodes = routerset_new();
-  retval = routerset_parse(options->EntryNodes,
-                           entrynodes_str,
-                           "test_entrynodes");
-  tt_int_op(retval, OP_GE, 0);
-
-  /* Read nodes from EntryNodes */
-  entry_guards_set_from_config(gs, options);
-
-  /* Test that only one guard was added. */
-  tt_int_op(smartlist_len(all_entry_guards), OP_EQ, 1);
-
-  /* Make sure it was the guard we specified. */
-  chosen_entry = choose_random_entry(NULL);
-  tt_str_op(chosen_entry->ri->nickname, OP_EQ, entrynodes_str);
-
- done:
-  routerset_free(options->EntryNodes);
-}
-
-static void
-test_entry_is_time_to_retry(void *arg)
-{
-  entry_guard_t *test_guard;
-  time_t now;
-  int retval;
-  (void)arg;
-
-  now = time(NULL);
-
-  test_guard = tor_malloc_zero(sizeof(entry_guard_t));
-
-  test_guard->last_attempted = now - 10;
-  test_guard->unreachable_since = now - 1;
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,1);
-
-  test_guard->unreachable_since = now - (6*60*60 - 1);
-  test_guard->last_attempted = now - (60*60 + 1);
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,1);
-
-  test_guard->last_attempted = now - (60*60 - 1);
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,0);
-
-  test_guard->unreachable_since = now - (6*60*60 + 1);
-  test_guard->last_attempted = now - (4*60*60 + 1);
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,1);
-
-  test_guard->unreachable_since = now - (3*24*60*60 - 1);
-  test_guard->last_attempted = now - (4*60*60 + 1);
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,1);
-
-  test_guard->unreachable_since = now - (3*24*60*60 + 1);
-  test_guard->last_attempted = now - (18*60*60 + 1);
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,1);
-
-  test_guard->unreachable_since = now - (7*24*60*60 - 1);
-  test_guard->last_attempted = now - (18*60*60 + 1);
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,1);
-
-  test_guard->last_attempted = now - (18*60*60 - 1);
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,0);
-
-  test_guard->unreachable_since = now - (7*24*60*60 + 1);
-  test_guard->last_attempted = now - (36*60*60 + 1);
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,1);
-
-  test_guard->unreachable_since = now - (7*24*60*60 + 1);
-  test_guard->last_attempted = now - (36*60*60 + 1);
-
-  retval = entry_is_time_to_retry(test_guard,now);
-  tt_int_op(retval,OP_EQ,1);
-
- done:
-  tor_free(test_guard);
-}
-
-/** XXX Do some tests that entry_is_live() */
-static void
-test_entry_is_live(void *arg)
-{
-  smartlist_t *our_nodelist = NULL;
-  guard_selection_t *gs = get_guard_selection_info();
-  const smartlist_t *all_entry_guards =
-    get_entry_guards_for_guard_selection(gs);
-  const node_t *test_node = NULL;
-  const entry_guard_t *test_entry = NULL;
-  const char *msg;
-  int which_node;
-
-  (void) arg;
-
-  /* The global entry guards smartlist should be empty now. */
-  tt_int_op(smartlist_len(all_entry_guards), OP_EQ, 0);
-
-  /* Walk the nodelist and add all nodes as entry guards. */
-  our_nodelist = nodelist_get_list();
-  tt_int_op(smartlist_len(our_nodelist), OP_EQ, HELPER_NUMBER_OF_DESCRIPTORS);
-
-  SMARTLIST_FOREACH_BEGIN(our_nodelist, const node_t *, node) {
-    const node_t *node_tmp;
-    node_tmp = add_an_entry_guard(gs, node, 0, 1, 0, 0);
-    tt_assert(node_tmp);
-
-    tt_int_op(node->is_stable, OP_EQ, 0);
-    tt_int_op(node->is_fast, OP_EQ, 0);
-  } SMARTLIST_FOREACH_END(node);
-
-  /* Make sure the nodes were added as entry guards. */
-  tt_int_op(smartlist_len(all_entry_guards), OP_EQ,
-            HELPER_NUMBER_OF_DESCRIPTORS);
-
-  /* Now get a random test entry that we will use for this unit test. */
-  which_node = 3;  /* (chosen by fair dice roll) */
-  test_entry = smartlist_get(all_entry_guards, which_node);
-
-  /* Let's do some entry_is_live() tests! */
-
-  /* Require the node to be stable, but it's not. Should fail.
-     Also enable 'assume_reachable' because why not. */
-  test_node = entry_is_live(test_entry,
-                            ENTRY_NEED_UPTIME | ENTRY_ASSUME_REACHABLE,
-                            &msg);
-  tt_assert(!test_node);
-
-  /* Require the node to be fast, but it's not. Should fail. */
-  test_node = entry_is_live(test_entry,
-                            ENTRY_NEED_CAPACITY | ENTRY_ASSUME_REACHABLE,
-                            &msg);
-  tt_assert(!test_node);
-
-  /* Don't impose any restrictions on the node. Should succeed. */
-  test_node = entry_is_live(test_entry, 0, &msg);
-  tt_assert(test_node);
-  tt_ptr_op(test_node, OP_EQ, node_get_by_id(test_entry->identity));
-
-  /* Require descriptor for this node. It has one so it should succeed. */
-  test_node = entry_is_live(test_entry, ENTRY_NEED_DESCRIPTOR, &msg);
-  tt_assert(test_node);
-  tt_ptr_op(test_node, OP_EQ, node_get_by_id(test_entry->identity));
-
- done:
-  ; /* XXX */
-}
-#endif
-
 #define TEST_IPV4_ADDR "123.45.67.89"
 #define TEST_IPV6_ADDR "[1234:5678:90ab:cdef::]"
 
@@ -1475,12 +749,7 @@ test_entry_guard_parse_from_state_broken(void *arg)
   tt_int_op(smartlist_len(gs_df->sampled_entry_guards), OP_EQ, 1);
   guard_selection_t *gs_legacy =
     get_guard_selection_by_name("legacy", GS_TYPE_LEGACY, 0);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  tt_assert(gs_legacy != NULL);
-  tt_int_op(smartlist_len(gs_legacy->chosen_entry_guards), OP_EQ, 0);
-#else
   tt_assert(gs_legacy == NULL);
-#endif
 
  done:
   config_free_lines(lines);
@@ -3361,12 +2630,6 @@ test_enty_guard_should_expire_waiting(void *arg)
   tor_free(fake_state);
 }
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-static const struct testcase_setup_t fake_network = {
-  fake_network_setup, fake_network_cleanup
-};
-#endif
-
 static const struct testcase_setup_t big_fake_network = {
   big_fake_network_setup, big_fake_network_cleanup
 };
@@ -3383,33 +2646,6 @@ static const struct testcase_setup_t upgrade_circuits = {
       (void*)(arg) }
 
 struct testcase_t entrynodes_tests[] = {
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  { "entry_is_time_to_retry", test_entry_is_time_to_retry,
-    TT_FORK, NULL, NULL },
-  { "choose_random_entry_no_guards", test_choose_random_entry_no_guards,
-    TT_FORK, &fake_network, NULL },
-  { "choose_random_entry_one_possible_guard",
-    test_choose_random_entry_one_possible_guard,
-    TT_FORK, &fake_network, NULL },
-  { "populate_live_entry_guards_1guard",
-    test_populate_live_entry_guards_1guard,
-    TT_FORK, &fake_network, NULL },
-  { "populate_live_entry_guards_3guards",
-    test_populate_live_entry_guards_3guards,
-    TT_FORK, &fake_network, NULL },
-  { "entry_guards_parse_state_simple",
-    test_entry_guards_parse_state_simple,
-    TT_FORK, &fake_network, NULL },
-  { "entry_guards_parse_state_pathbias",
-    test_entry_guards_parse_state_pathbias,
-    TT_FORK, &fake_network, NULL },
-  { "entry_guards_set_from_config",
-    test_entry_guards_set_from_config,
-    TT_FORK, &fake_network, NULL },
-  { "entry_is_live",
-    test_entry_is_live,
-    TT_FORK, &fake_network, NULL },
-#endif
   { "node_preferred_orport",
     test_node_preferred_orport,
     0, NULL, NULL },
diff --git a/src/test/test_routerlist.c b/src/test/test_routerlist.c
index 73e8d10..78f1cf1 100644
--- a/src/test/test_routerlist.c
+++ b/src/test/test_routerlist.c
@@ -204,55 +204,6 @@ mock_usable_consensus_flavor(void)
   return mock_usable_consensus_flavor_value;
 }
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-static smartlist_t *mock_is_guard_list = NULL;
-
-static int
-mock_is_node_used_as_guard(const node_t *n)
-{
-  if (mock_is_guard_list) {
-    SMARTLIST_FOREACH_BEGIN(mock_is_guard_list, node_t *, e) {
-      if (e == n) return 1;
-    } SMARTLIST_FOREACH_END(e);
-  }
-
-  return 0;
-}
-
-static void
-mark_node_used_as_guard(node_t *n)
-{
-  if (!n) return;
-
-  if (!mock_is_guard_list) {
-    mock_is_guard_list = smartlist_new();
-  }
-
-  if (!mock_is_node_used_as_guard(n)) {
-    smartlist_add(mock_is_guard_list, n);
-  }
-}
-
-static void
-mark_node_unused_as_guard(node_t *n)
-{
-  if (!n) return;
-
-  if (!mock_is_guard_list) return;
-
-  smartlist_remove(mock_is_guard_list, n);
-}
-
-static void
-clear_mock_guard_list(void)
-{
-  if (mock_is_guard_list) {
-    smartlist_free(mock_is_guard_list);
-    mock_is_guard_list = NULL;
-  }
-}
-#endif
-
 static void
 test_router_pick_directory_server_impl(void *arg)
 {
@@ -273,9 +224,6 @@ test_router_pick_directory_server_impl(void *arg)
   (void)arg;
 
   MOCK(usable_consensus_flavor, mock_usable_consensus_flavor);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  MOCK(is_node_used_as_guard, mock_is_node_used_as_guard);
-#endif
 
   /* With no consensus, we must be bootstrapping, regardless of time or flavor
    */
@@ -388,34 +336,6 @@ test_router_pick_directory_server_impl(void *arg)
   node_router1->is_valid = 1;
   node_router3->is_valid = 1;
 
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  flags |= PDS_FOR_GUARD;
-  mark_node_used_as_guard(node_router1);
-  mark_node_used_as_guard(node_router2);
-  mark_node_used_as_guard(node_router3);
-  rs = router_pick_directory_server_impl(V3_DIRINFO, flags, NULL);
-  tt_assert(rs == NULL);
-  mark_node_unused_as_guard(node_router1);
-  rs = router_pick_directory_server_impl(V3_DIRINFO, flags, NULL);
-  tt_assert(rs != NULL);
-  tt_assert(tor_memeq(rs->identity_digest, router1_id, DIGEST_LEN));
-  rs = NULL;
-  mark_node_unused_as_guard(node_router2);
-  mark_node_unused_as_guard(node_router3);
-#endif
-
-  /* One not valid, one guard. This should leave one remaining */
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  node_router1->is_valid = 0;
-  mark_node_used_as_guard(node_router2);
-  rs = router_pick_directory_server_impl(V3_DIRINFO, flags, NULL);
-  tt_assert(rs != NULL);
-  tt_assert(tor_memeq(rs->identity_digest, router3_id, DIGEST_LEN));
-  rs = NULL;
-  node_router1->is_valid = 1;
-  mark_node_unused_as_guard(node_router2);
-#endif
-
   /* Manipulate overloaded */
 
   node_router2->rs->last_dir_503_at = now;
@@ -477,10 +397,6 @@ test_router_pick_directory_server_impl(void *arg)
 
  done:
   UNMOCK(usable_consensus_flavor);
-#ifdef ENABLE_LEGACY_GUARD_ALGORITHM
-  UNMOCK(is_node_used_as_guard);
-  clear_mock_guard_list();
-#endif
 
   if (router1_id)
     tor_free(router1_id);





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