Add two hidden-service related statistics.

The two statistics are:
 1. number of RELAY cells observed on successfully established
    rendezvous circuits; and
 2. number of .onion addresses observed as hidden-service
    directory.

Both statistics are accumulated over 24 hours, obfuscated by rounding
up to the next multiple of a given number and adding random noise,
and written to local file stats/hidserv-stats.

Notably, no statistics will be gathered on clients or services, but
only on relays.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/or/command.c b/src/or/command.c
index 268c495371..8e214bf0a4 100644
--- a/src/or/command.c
+++ b/src/or/command.c
@@ -438,6 +438,7 @@ command_process_created_cell(cell_t *cell, channel_t *chan)
 static void
 command_process_relay_cell(cell_t *cell, channel_t *chan)
 {
+  const or_options_t *options = get_options();
   circuit_t *circ;
   int reason, direction;
 
@@ -511,6 +512,14 @@ command_process_relay_cell(cell_t *cell, channel_t *chan)
            direction==CELL_DIRECTION_OUT?"forward":"backward");
     circuit_mark_for_close(circ, -reason);
   }
+
+  /* If this is a cell in an RP circuit, count it as part of the
+     hidden service stats */
+  if (options->HiddenServiceStatistics &&
+      !CIRCUIT_IS_ORIGIN(circ) &&
+      TO_OR_CIRCUIT(circ)->circuit_carries_hs_traffic_stats) {
+    rep_hist_seen_new_rp_cell();
+  }
 }
 
 /** Process a 'destroy' <b>cell</b> that just arrived from