Ticket 40872: Output conflux nonce and circ rtt to control port

src/core/or/conflux_util.c

@@ -462,8 +462,11 @@ conflux_get_circ_rtt(const circuit_t *circ)
 {
   if (circ->conflux) {
     conflux_leg_t *leg = conflux_get_leg(circ->conflux, circ);
-    tor_assert(leg);
-    return leg->circ_rtts_usec;
+    if (BUG(!leg)) {
+      return 0;
+    } else {
+      return leg->circ_rtts_usec;
+    }
   } else {
     return 0;
   }

src/feature/control/control_fmt.c

@@ -21,6 +21,7 @@
 #include "core/or/entry_connection_st.h"
 #include "core/or/or_connection_st.h"
 #include "core/or/origin_circuit_st.h"
+#include "core/or/conflux_util.h"
 #include "core/or/socks_request_st.h"
 #include "feature/control/control_connection_st.h"
 
@@ -160,6 +161,26 @@ circuit_describe_status_for_controller(origin_circuit_t *circ)
     smartlist_add_asprintf(descparts, "HS_POW=v1,%u", circ->hs_pow_effort);
   }
 
+  /* Add conflux id and RTT info, for accurate circuit display. The RTT is
+   * provided to indicate the primary (preferred) circuit of a set
+   * (which will have the lowest current RTT). */
+  if (CIRCUIT_IS_CONFLUX(TO_CIRCUIT(circ))) {
+    const uint8_t *nonce = conflux_get_nonce(TO_CIRCUIT(circ));
+    tor_assert(nonce);
+
+    /* The conflux nonce is sensitive data. Only output half of it. */
+    smartlist_add_asprintf(descparts, "CONFLUX_ID=%s",
+                           hex_str((const char *)nonce, DIGEST256_LEN/2));
+
+    /* If we have a conflux object, the circ is linked and has an RTT */
+    if (TO_CIRCUIT(circ)->conflux) {
+      uint64_t circ_rtt = conflux_get_circ_rtt(TO_CIRCUIT(circ));
+      if (circ_rtt) {
+        smartlist_add_asprintf(descparts, "CONFLUX_RTT=%" PRIu64, circ_rtt);
+      }
+    }
+  }
+
   rv = smartlist_join_strings(descparts, " ", 0, NULL);
 
   SMARTLIST_FOREACH(descparts, char *, cp, tor_free(cp));