Vote on 'proto' lines and include them after 'v' lines.

(Despite the increased size of the consensus, this should have
approximately zero effect on the compressed consensus size, since
the "proto" line should be completely implied by the "v" line.)

3 files changed, 27 insertions, 2 deletions

diff --git a/src/or/dirvote.c b/src/or/dirvote.c
index 67f0ba8cc7..f606b07f7a 100644
--- a/src/or/dirvote.c
+++ b/src/or/dirvote.c
@@ -1563,6 +1563,7 @@ networkstatus_compute_consensus(smartlist_t *votes,
     smartlist_t *matching_descs = smartlist_new();
     smartlist_t *chosen_flags = smartlist_new();
     smartlist_t *versions = smartlist_new();
+    smartlist_t *protocols = smartlist_new();
     smartlist_t *exitsummaries = smartlist_new();
     uint32_t *bandwidths_kb = tor_calloc(smartlist_len(votes),
                                          sizeof(uint32_t));
@@ -1705,6 +1706,7 @@ networkstatus_compute_consensus(smartlist_t *votes,
       routerstatus_t rs_out;
       const char *current_rsa_id = NULL;
       const char *chosen_version;
+      const char *chosen_protocol_list;
       const char *chosen_name = NULL;
       int exitsummary_disagreement = 0;
       int is_named = 0, is_unnamed = 0, is_running = 0;
@@ -1718,6 +1720,7 @@ networkstatus_compute_consensus(smartlist_t *votes,
       smartlist_clear(matching_descs);
       smartlist_clear(chosen_flags);
       smartlist_clear(versions);
+      smartlist_clear(protocols);
       num_bandwidths = 0;
       num_mbws = 0;
       num_guardfraction_inputs = 0;
@@ -1737,6 +1740,12 @@ networkstatus_compute_consensus(smartlist_t *votes,
         if (rs->version && rs->version[0])
           smartlist_add(versions, rs->version);
 
+        if (rs->protocols) {
+          /* We include this one even if it's empty: voting for an
+           * empty protocol list actually is meaningful. */
+          smartlist_add(protocols, rs->protocols);
+        }
+
         /* Tally up all the flags. */
         for (int flag = 0; flag < n_voter_flags[voter_idx]; ++flag) {
           if (rs->flags & (U64_LITERAL(1) << flag))
@@ -1875,6 +1884,14 @@ networkstatus_compute_consensus(smartlist_t *votes,
         chosen_version = NULL;
       }
 
+      /* Pick the protocol list */
+      if (smartlist_len(protocols)) {
+        smartlist_sort_strings(protocols);
+        chosen_protocol_list = get_most_frequent_member(protocols);
+      } else {
+        chosen_protocol_list = NULL;
+      }
+
       /* If it's a guard and we have enough guardfraction votes,
          calculate its consensus guardfraction value. */
       if (is_guard && num_guardfraction_inputs > 2 &&
@@ -2028,6 +2045,10 @@ networkstatus_compute_consensus(smartlist_t *votes,
         smartlist_add(chunks, tor_strdup(chosen_version));
       }
       smartlist_add(chunks, tor_strdup("\n"));
+      if (chosen_protocol_list &&
+          consensus_method >= MIN_METHOD_FOR_RS_PROTOCOLS) {
+        smartlist_add_asprintf(chunks, "proto %s\n", chosen_protocol_list);
+      }
       /*     Now the weight line. */
       if (rs_out.has_bandwidth) {
         char *guardfraction_str = NULL;
@@ -2068,6 +2089,7 @@ networkstatus_compute_consensus(smartlist_t *votes,
     smartlist_free(matching_descs);
     smartlist_free(chosen_flags);
     smartlist_free(versions);
+    smartlist_free(protocols);
     smartlist_free(exitsummaries);
     tor_free(bandwidths_kb);
     tor_free(measured_bws_kb);
diff --git a/src/or/dirvote.h b/src/or/dirvote.h
index f29fe97f26..a6c847ec25 100644
--- a/src/or/dirvote.h
+++ b/src/or/dirvote.h
@@ -103,11 +103,9 @@
  * protocols. */
 #define MIN_METHOD_FOR_RECOMMENDED_PROTOCOLS 24
 
-#if 0
 /** Lowest consensus method where authorities add protocols to routerstatus
  * entries. */
 #define MIN_METHOD_FOR_RS_PROTOCOLS 24
-#endif
 
 /** Default bandwidth to clip unmeasured bandwidths to using method >=
  * MIN_METHOD_TO_CLIP_UNMEASURED_BW.  (This is not a consensus method; do not
diff --git a/src/or/routerparse.c b/src/or/routerparse.c
index 46209abcd5..9428e4560a 100644
--- a/src/or/routerparse.c
+++ b/src/or/routerparse.c
@@ -388,6 +388,7 @@ static token_rule_t rtrstatus_token_table[] = {
   T01("w",                   K_W,                   ARGS,    NO_OBJ ),
   T0N("m",                   K_M,               CONCAT_ARGS, NO_OBJ ),
   T0N("id",                  K_ID,                  GE(2),   NO_OBJ ),
+  T01("proto",               K_PROTO,           CONCAT_ARGS, NO_OBJ ),
   T0N("opt",                 K_OPT,             CONCAT_ARGS, OBJ_OK ),
   END_OF_TABLE
 };
@@ -2992,6 +2993,10 @@ routerstatus_parse_entry_from_string(memarea_t *area,
           }
         }
       }
+      if (t->tp == K_PROTO) {
+        tor_assert(t->n_args == 1);
+        vote_rs->protocols = tor_strdup(t->args[0]);
+      }
     } SMARTLIST_FOREACH_END(t);
   } else if (flav == FLAV_MICRODESC) {
     tok = find_opt_by_keyword(tokens, K_M);