Bug 6475: Demote pathbias log messages for 0.2.3.x

Also make a couple of them less scary.

We'll do a separate, additional commit on 0.2.4.x to bump them back
up again.

src/or/circuitbuild.c

@@ -2657,7 +2657,7 @@ pathbias_count_first_hop(origin_circuit_t *circ)
     if (circ->has_opened && circ->path_state != PATH_STATE_DID_FIRST_HOP) {
       if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
                                      approx_time()))) {
-        log_notice(LD_BUG,
+        log_info(LD_BUG,
                 "Opened circuit is in strange path state %s. "
                 "Circuit is a %s currently %s. %s",
                 pathbias_state_to_string(circ->path_state),
@@ -2684,7 +2684,7 @@ pathbias_count_first_hop(origin_circuit_t *circ)
         } else {
           if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
                   approx_time()))) {
-            log_notice(LD_BUG,
+            log_info(LD_BUG,
                    "Unopened circuit has strange path state %s. "
                    "Circuit is a %s currently %s. %s",
                    pathbias_state_to_string(circ->path_state),
@@ -2696,7 +2696,7 @@ pathbias_count_first_hop(origin_circuit_t *circ)
       } else {
         if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
                 approx_time()))) {
-          log_notice(LD_BUG,
+          log_info(LD_BUG,
               "Unopened circuit has no known guard. "
               "Circuit is a %s currently %s. %s",
               circuit_purpose_to_string(circ->_base.purpose),
@@ -2710,7 +2710,7 @@ pathbias_count_first_hop(origin_circuit_t *circ)
     if (circ->path_state == PATH_STATE_NEW_CIRC) {
       if ((rate_msg = rate_limit_log(&first_hop_notice_limit,
                 approx_time()))) {
-        log_notice(LD_BUG,
+        log_info(LD_BUG,
             "A %s circuit is in cpath state %d (opened: %d). "
             "Circuit is a %s currently %s. %s",
             pathbias_state_to_string(circ->path_state),
@@ -2770,7 +2770,7 @@ pathbias_count_success(origin_circuit_t *circ)
       } else {
         if ((rate_msg = rate_limit_log(&success_notice_limit,
                 approx_time()))) {
-          log_notice(LD_BUG,
+          log_info(LD_BUG,
               "Succeeded circuit is in strange path state %s. "
               "Circuit is a %s currently %s. %s",
               pathbias_state_to_string(circ->path_state),
@@ -2781,7 +2781,7 @@ pathbias_count_success(origin_circuit_t *circ)
       }
 
       if (guard->first_hops < guard->circuit_successes) {
-        log_warn(LD_BUG, "Unexpectedly high circuit_successes (%u/%u) "
+        log_notice(LD_BUG, "Unexpectedly high circuit_successes (%u/%u) "
                  "for guard %s=%s",
                  guard->circuit_successes, guard->first_hops,
                  guard->nickname, hex_str(guard->identity, DIGEST_LEN));
@@ -2792,7 +2792,7 @@ pathbias_count_success(origin_circuit_t *circ)
     } else if (circ->_base.purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
       if ((rate_msg = rate_limit_log(&success_notice_limit,
               approx_time()))) {
-        log_notice(LD_BUG,
+        log_info(LD_BUG,
             "Completed circuit has no known guard. "
             "Circuit is a %s currently %s. %s",
             circuit_purpose_to_string(circ->_base.purpose),
@@ -2804,7 +2804,7 @@ pathbias_count_success(origin_circuit_t *circ)
     if (circ->path_state != PATH_STATE_SUCCEEDED) {
       if ((rate_msg = rate_limit_log(&success_notice_limit,
               approx_time()))) {
-        log_notice(LD_BUG,
+        log_info(LD_BUG,
             "Opened circuit is in strange path state %s. "
             "Circuit is a %s currently %s. %s",
             pathbias_state_to_string(circ->path_state),
@@ -2834,9 +2834,11 @@ entry_guard_inc_first_hop_count(entry_guard_t *guard)
     if (guard->circuit_successes/((double)guard->first_hops)
         < pathbias_get_disable_rate(options)) {
 
+      /* This message is currently disabled by default. */
       log_warn(LD_PROTOCOL,
                "Extremely low circuit success rate %u/%u for guard %s=%s. "
-               "This might indicate an attack, or a bug.",
+               "This indicates either an overloaded guard, an attack, or "
+               "a bug.",
                guard->circuit_successes, guard->first_hops, guard->nickname,
                hex_str(guard->identity, DIGEST_LEN));
 
@@ -2857,6 +2859,11 @@ entry_guard_inc_first_hop_count(entry_guard_t *guard)
   /* If we get a ton of circuits, just scale everything down */
   if (guard->first_hops > (unsigned)pathbias_get_scale_threshold(options)) {
     const int scale_factor = pathbias_get_scale_factor(options);
+    log_info(LD_PROTOCOL,
+             "Scaling pathbias counts to (%u/%u)/%d for guard %s=%s",
+             guard->circuit_successes, guard->first_hops,
+             scale_factor, guard->nickname, hex_str(guard->identity,
+             DIGEST_LEN));
     guard->first_hops /= scale_factor;
     guard->circuit_successes /= scale_factor;
   }