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, 8 insertions, 0 deletions

diff --git a/src/or/or.h b/src/or/or.h
index 0de37452bd..ee86697fd8 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -3204,6 +3204,10 @@ typedef struct or_circuit_t {
   /** True iff this circuit was made with a CREATE_FAST cell. */
   unsigned int is_first_hop : 1;
 
+  /** If set, this circuit carries HS traffic. Consider it in any HS
+   *  statistics. */
+  unsigned int circuit_carries_hs_traffic_stats : 1;
+
   /** Number of cells that were removed from circuit queue; reset every
    * time when writing buffer stats to disk. */
   uint32_t processed_cells;
@@ -3961,6 +3965,10 @@ typedef struct {
   /** If true, the user wants us to collect statistics as entry node. */
   int EntryStatistics;
 
+  /** If true, the user wants us to collect statistics as hidden service
+   * directory, introduction point, or rendezvous point. */
+  int HiddenServiceStatistics;
+
   /** If true, include statistics file contents in extra-info documents. */
   int ExtraInfoStatistics;