Look up the rend circ whose INTRODUCE1 is being ACKed correctly

This change cannibalizes circuit_get_by_rend_query_and_purpose because it
had exactly one caller.

changes/bug4759

@@ -0,0 +1,14 @@
+  o Minor bugfixes:
+
+    - Make sure we never mark the wrong rendezvous circuit as having
+      had its introduction cell acknowleged by the introduction-point
+      relay.  Previously, when we received an INTRODUCE_ACK cell on a
+      client-side hidden-service introduction circuit, we might have
+      marked a rendezvous circuit other than the one we specified in
+      the INTRODUCE1 cell as INTRO_ACKED, which would have produced a
+      warning message and interfered with the hidden service
+      connection-establishment process.  Bugfix on 0.2.3.3-alpha, when
+      the stream-isolation feature which might cause Tor to open
+      multiple rendezvous circuits for the same hidden service was
+      added.  Fixes bug 4759.
+

src/or/circuitlist.c

@@ -873,26 +873,30 @@ circuit_unlink_all_from_or_conn(or_connection_t *conn, int reason)
   }
 }
 
-/** Return a circ such that:
+/** Return a circ such that
- *  - circ-\>rend_data-\>onion_address is equal to <b>rend_query</b>, and
+ *  - circ-\>rend_data-\>onion_address is equal to
- *  - circ-\>purpose is equal to <b>purpose</b>.
+ *    <b>rend_data</b>-\>onion_address,
+ *  - circ-\>rend_data-\>rend_cookie is equal to
+ *    <b>rend_data</b>-\>rend_cookie, and
+ *  - circ-\>purpose is equal to CIRCUIT_PURPOSE_C_REND_READY.
  *
  * Return NULL if no such circuit exists.
  */
 origin_circuit_t *
-circuit_get_by_rend_query_and_purpose(const char *rend_query, uint8_t purpose)
+circuit_get_ready_rend_circ_by_rend_data(const rend_data_t *rend_data)
 {
   circuit_t *circ;
 
-  tor_assert(CIRCUIT_PURPOSE_IS_ORIGIN(purpose));
-
   for (circ = global_circuitlist; circ; circ = circ->next) {
     if (!circ->marked_for_close &&
-        circ->purpose == purpose) {
+        circ->purpose == CIRCUIT_PURPOSE_C_REND_READY) {
       origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
       if (ocirc->rend_data &&
-          !rend_cmp_service_ids(rend_query,
+          !rend_cmp_service_ids(rend_data->onion_address,
-                                ocirc->rend_data->onion_address))
+                                ocirc->rend_data->onion_address) &&
+          tor_memeq(ocirc->rend_data->rend_cookie,
+                    rend_data->rend_cookie,
+                    REND_COOKIE_LEN))
         return ocirc;
     }
   }

src/or/circuitlist.h

@@ -32,8 +32,8 @@ int circuit_id_in_use_on_orconn(circid_t circ_id, or_connection_t *conn);
 circuit_t *circuit_get_by_edge_conn(edge_connection_t *conn);
 void circuit_unlink_all_from_or_conn(or_connection_t *conn, int reason);
 origin_circuit_t *circuit_get_by_global_id(uint32_t id);
-origin_circuit_t *circuit_get_by_rend_query_and_purpose(const char *rend_query,
+origin_circuit_t *circuit_get_ready_rend_circ_by_rend_data(
-                                                        uint8_t purpose);
+  const rend_data_t *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);

src/or/rendclient.c

@@ -350,8 +350,7 @@ rend_client_introduction_acked(origin_circuit_t *circ,
      * and tell it.
      */
     log_info(LD_REND,"Received ack. Telling rend circ...");
-    rendcirc = circuit_get_by_rend_query_and_purpose(
+    rendcirc = circuit_get_ready_rend_circ_by_rend_data(circ->rend_data);
-               circ->rend_data->onion_address, CIRCUIT_PURPOSE_C_REND_READY);
     if (rendcirc) { /* remember the ack */
 #ifndef NON_ANONYMOUS_MODE_ENABLED
       tor_assert(!(rendcirc->build_state->onehop_tunnel));