Advertise dirport if accountingmax is large enough

When we have an effective bandwidthrate configured so that we cannot
exceed our bandwidth limit in one accounting interval, don't disable
advertising the dirport. Implements ticket 2434.

1 files changed, 20 insertions, 3 deletions

diff --git a/src/or/router.c b/src/or/router.c
index a08a2009a7..b2df3834fe 100644
--- a/src/or/router.c
+++ b/src/or/router.c
@@ -823,9 +823,26 @@ decide_to_advertise_dirport(const or_options_t *options, uint16_t dir_port)
    * make us choose not to publish. */
 
   if (accounting_is_enabled(options)) {
-    /* if we might potentially hibernate */
-    new_choice = 0;
-    reason = "AccountingMax enabled";
+    /* Don't spend bytes for directory traffic if we could end up hibernating,
+     * but allow DirPort otherwise. Some people set AccountingMax because
+     * they're confused or to get statistics. */
+    int interval_length = accounting_get_interval_length();
+    uint32_t effective_bw = get_effective_bwrate(options);
+    if (!interval_length) {
+      log_warn(LD_BUG, "An accounting interval is not allowed to be zero "
+                       "seconds long. Raising to 1.");
+      interval_length = 1;
+    }
+    log_info(LD_GENERAL, "Calculating whether to disable dirport: effective "
+                         "bwrate: %u, AccountingMax: "U64_FORMAT", "
+                         "accounting interval length %d", effective_bw,
+                         U64_PRINTF_ARG(options->AccountingMax),
+                         interval_length);
+    if (effective_bw >=
+        options->AccountingMax / interval_length) {
+      new_choice = 0;
+      reason = "AccountingMax enabled";
+    }
 #define MIN_BW_TO_ADVERTISE_DIRPORT 51200
   } else if (options->BandwidthRate < MIN_BW_TO_ADVERTISE_DIRPORT ||
              (options->RelayBandwidthRate > 0 &&