Clients now use bandwidth values in the consensus

rather than the bandwidth values in each relay descriptor. This approach
opens the door to more accurate bandwidth estimates once the directory
authorities start doing active measurements. Implements more of proposal
141.

src/or/routerlist.c

@@ -1591,28 +1591,42 @@ smartlist_choose_by_bandwidth(smartlist_t *sl, bandwidth_weight_rule_t rule,
     int32_t flags = 0;
     uint32_t this_bw = 0;
     if (statuses) {
-      /* need to extract router info */
       status = smartlist_get(sl, i);
       if (router_digest_is_me(status->identity_digest))
         me_idx = i;
       router = router_get_by_digest(status->identity_digest);
       is_exit = status->is_exit;
       is_guard = status->is_possible_guard;
-      if (router) {
-        this_bw = router_get_advertised_bandwidth(router);
+      if (status->has_bandwidth) {
+        this_bw = status->bandwidth*1000;
       } else { /* guess */
+        /* XXX022 once consensuses always list bandwidths, we can take
+         * this guessing business out. -RD */
         is_known = 0;
         flags = status->is_fast ? 1 : 0;
         flags |= is_exit ? 2 : 0;
         flags |= is_guard ? 4 : 0;
       }
     } else {
+      routerstatus_t *rs;
       router = smartlist_get(sl, i);
+      rs = router_get_consensus_status_by_id(
+             router->cache_info.identity_digest);
       if (router_digest_is_me(router->cache_info.identity_digest))
         me_idx = i;
       is_exit = router->is_exit;
       is_guard = router->is_possible_guard;
-      this_bw = router_get_advertised_bandwidth(router);
+      if (rs && rs->has_bandwidth) {
+        this_bw = rs->bandwidth*1000;
+      } else if (rs) { /* guess; don't trust the descriptor */
+        /* XXX022 once consensuses always list bandwidths, we can take
+         * this guessing business out. -RD */
+        is_known = 0;
+        flags = router->is_fast ? 1 : 0;
+        flags |= is_exit ? 2 : 0;
+        flags |= is_guard ? 4 : 0;
+      } else /* bridge or other descriptor not in our consensus */
+        this_bw = router_get_advertised_bandwidth(router);
     }
     if (is_exit)
       bitarray_set(exit_bits, i);