Better support for mutiple introduction points, and more logging

3 files changed, 53 insertions, 36 deletions

diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c
index 947489636..68c9cd53c 100644
--- a/src/or/circuitlist.c
+++ b/src/or/circuitlist.c
@@ -1230,21 +1230,23 @@ circuit_get_next_by_pk_and_purpose(origin_circuit_t *start,
   return NULL;
 }
 
-/** Return the first OR circuit in the global list whose purpose is
- * <b>purpose</b>, and whose rend_token is the <b>len</b>-byte
- * <b>token</b>. */
-static or_circuit_t *
-circuit_get_by_rend_token_and_purpose(uint8_t purpose, const char *token,
-                                      size_t len)
+/** Return the circuits waiting for intro cells of the given digest.
+ *
+ */
+smartlist_t *
+circuits_get_intro_point(const char *digest)
 {
+  smartlist_t *circuits = smartlist_new();
+
   circuit_t *circ;
   TOR_LIST_FOREACH(circ, &global_circuitlist, head) {
     if (! circ->marked_for_close &&
-        circ->purpose == purpose &&
-        tor_memeq(TO_OR_CIRCUIT(circ)->rend_token, token, len))
-      return TO_OR_CIRCUIT(circ);
+        circ->purpose == CIRCUIT_PURPOSE_INTRO_POINT &&
+        tor_memeq(TO_OR_CIRCUIT(circ)->rend_token, digest, DIGEST_LEN))
+      smartlist_add(circuits, TO_OR_CIRCUIT(circ));
   }
-  return NULL;
+
+  return circuits;
 }
 
 /** Return the circuit waiting for a rendezvous with the provided cookie.
@@ -1253,20 +1255,14 @@ circuit_get_by_rend_token_and_purpose(uint8_t purpose, const char *token,
 or_circuit_t *
 circuit_get_rendezvous(const char *cookie)
 {
-  return circuit_get_by_rend_token_and_purpose(
-                                     CIRCUIT_PURPOSE_REND_POINT_WAITING,
-                                     cookie, REND_COOKIE_LEN);
-}
-
-/** Return the circuit waiting for intro cells of the given digest.
- * Return NULL if no such circuit is found.
- */
-or_circuit_t *
-circuit_get_intro_point(const char *digest)
-{
-  return circuit_get_by_rend_token_and_purpose(
-                                     CIRCUIT_PURPOSE_INTRO_POINT, digest,
-                                     DIGEST_LEN);
+  circuit_t *circ;
+  TOR_LIST_FOREACH(circ, &global_circuitlist, head) {
+    if (! circ->marked_for_close &&
+        circ->purpose == CIRCUIT_PURPOSE_REND_POINT_WAITING &&
+        tor_memeq(TO_OR_CIRCUIT(circ)->rend_token, cookie, REND_COOKIE_LEN))
+      return TO_OR_CIRCUIT(circ);
+  }
+  return NULL;
 }
 
 /** Return a circuit that is open, is CIRCUIT_PURPOSE_C_GENERAL,
diff --git a/src/or/circuitlist.h b/src/or/circuitlist.h
index 1c8cf7de2..bc7dc1e84 100644
--- a/src/or/circuitlist.h
+++ b/src/or/circuitlist.h
@@ -48,7 +48,7 @@ origin_circuit_t *circuit_get_ready_rend_circ_by_rend_data(
 origin_circuit_t *circuit_get_next_by_pk_and_purpose(origin_circuit_t *start,
                                          const char *digest, uint8_t purpose);
 or_circuit_t *circuit_get_rendezvous(const char *cookie);
-or_circuit_t *circuit_get_intro_point(const char *digest);
+smartlist_t *circuits_get_intro_point(const char *digest);
 origin_circuit_t *circuit_find_to_cannibalize(uint8_t purpose,
                                               extend_info_t *info, int flags);
 void circuit_mark_all_unused_circs(void);
diff --git a/src/or/rendmid.c b/src/or/rendmid.c
index 8741397fc..e7a7849db 100644
--- a/src/or/rendmid.c
+++ b/src/or/rendmid.c
@@ -27,7 +27,6 @@ rend_mid_establish_intro(or_circuit_t *circ, const uint8_t *request,
   char expected_digest[DIGEST_LEN];
   char pk_digest[DIGEST_LEN];
   size_t asn1len;
-  or_circuit_t *c;
   char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
   int reason = END_CIRC_REASON_INTERNAL;
 
@@ -93,14 +92,22 @@ rend_mid_establish_intro(or_circuit_t *circ, const uint8_t *request,
                 pk_digest, REND_SERVICE_ID_LEN);
 
   if (!get_options()->IntroPointAcceptMutipleConnections) {
-      /* Close any other intro circuits with the same pk. */
-      c = NULL;
-      while ((c = circuit_get_intro_point(pk_digest))) {
-        log_info(LD_REND, "Replacing old circuit for service %s",
-                 safe_str(serviceid));
-        circuit_mark_for_close(TO_CIRCUIT(c), END_CIRC_REASON_FINISHED);
-        /* Now it's marked, and it won't be returned next time. */
-      }
+    log_info(LD_REND, "Checking for existing circuits to remove %s as "
+             "IntroPointAcceptMutipleConnections is not set",
+             safe_str(serviceid));
+
+    smartlist_t *circuits = circuits_get_intro_point(pk_digest);
+
+    /* Close any other intro circuits with the same pk. */
+    SMARTLIST_FOREACH_BEGIN(circuits, or_circuit_t *, circ) {
+      log_info(LD_REND, "Replacing old circuit for service %s",
+               safe_str(serviceid));
+      circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
+    } SMARTLIST_FOREACH_END(circ);
+  } else {
+    log_info(LD_REND, "Not removing existing circuits for %s as "
+             "IntroPointAcceptMutipleConnections is set",
+             safe_str(serviceid));
   }
 
   /* Acknowledge the request. */
@@ -167,8 +174,13 @@ rend_mid_introduce(or_circuit_t *circ, const uint8_t *request,
                 (char*)request, REND_SERVICE_ID_LEN);
 
   /* The first 20 bytes are all we look at: they have a hash of Bob's PK. */
-  intro_circ = circuit_get_intro_point((char*)request);
-  if (!intro_circ) {
+  smartlist_t *intro_circuits = circuits_get_intro_point((char*)request);
+
+  log_info(LD_REND,
+           "found %i possible introduction circuits for service %s",
+           smartlist_len(intro_circuits), safe_str(serviceid));
+
+  if (smartlist_len(intro_circuits) == 0) {
     log_info(LD_REND,
              "No intro circ found for INTRODUCE1 cell (%s) from circuit %u; "
              "responding with nack.",
@@ -176,6 +188,15 @@ rend_mid_introduce(or_circuit_t *circ, const uint8_t *request,
     goto err;
   }
 
+  // Need to select which circuit to use
+  int circ_selection = crypto_rand_int(smartlist_len(intro_circuits));
+
+  log_info(LD_REND,
+           "selected circuit %i for service %s",
+           circ_selection, safe_str(serviceid));
+
+  intro_circ = smartlist_get(intro_circuits, circ_selection);
+
   log_info(LD_REND,
            "Sending introduction request for service %s "
            "from circ %u to circ %u",