Backport bugfix for #814 (r16915 and r16916).

svn:r17258

ChangeLog

@@ -12,6 +12,14 @@ Changes in version 0.2.0.32 - 2008-??-??
     - Fix a DOS opportunity during the voting signature collection process
       at directory authorities. Spotted by rovv. Bugfix on 0.2.0.x.
 
+  o Major bugfixes (hidden services):
+    - When fetching v0 and v2 rendezvous service descriptors in parallel,
+      we were failing the whole hidden service request when the v0
+      descriptor fetch fails, even if the v2 fetch is still pending and
+      might succeed. Similarly, if the last v2 fetch fails, we were
+      failing the whole hidden service request even if a v0 fetch is
+      still pending. Fixes bug 814. Bugfix on 0.2.0.10-alpha.
+
   o Minor bugfixes:
     - Fix several infrequent memory leaks spotted by Coverity.
     - When testing for libevent functions, set the LDFLAGS variable

src/or/connection.c

@@ -479,8 +479,13 @@ connection_about_to_close_connection(connection_t *conn)
          * failed: forget about this router, and maybe try again. */
         connection_dir_request_failed(dir_conn);
       }
-      if (conn->purpose == DIR_PURPOSE_FETCH_RENDDESC)
-        rend_client_desc_here(dir_conn->rend_query); /* give it a try */
+      if (conn->purpose == DIR_PURPOSE_FETCH_RENDDESC) {
+        /* Give it a try. However, there is no re-fetching for v0 rend
+         * descriptors; if the response is empty or the descriptor is
+         * unusable, close pending connections (unless a v2 request is
+         * still in progress). */
+        rend_client_desc_trynow(dir_conn->rend_query, 0);
+      }
       /* If we were trying to fetch a v2 rend desc and did not succeed,
        * retry as needed. (If a fetch is successful, the connection state
        * is changed to DIR_PURPOSE_HAS_FETCHED_RENDDESC to mark that

src/or/directory.c

@@ -1805,7 +1805,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
         } else {
           /* success. notify pending connections about this. */
           conn->_base.purpose = DIR_PURPOSE_HAS_FETCHED_RENDDESC;
-          rend_client_desc_here(conn->rend_query);
+          rend_client_desc_trynow(conn->rend_query, -1);
         }
         break;
       case 404:
@@ -1851,7 +1851,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
             log_info(LD_REND, "Successfully fetched v2 rendezvous "
                      "descriptor.");
             conn->_base.purpose = DIR_PURPOSE_HAS_FETCHED_RENDDESC;
-            rend_client_desc_here(conn->rend_query);
+            rend_client_desc_trynow(conn->rend_query, -1);
             break;
         }
         break;

src/or/or.h

@@ -3645,7 +3645,7 @@ int rend_client_rendezvous_acked(origin_circuit_t *circ, const char *request,
                                  size_t request_len);
 int rend_client_receive_rendezvous(origin_circuit_t *circ, const char *request,
                                    size_t request_len);
-void rend_client_desc_here(const char *query);
+void rend_client_desc_trynow(const char *query, int rend_version);
 
 extend_info_t *rend_client_get_random_intro(const char *query);
 

src/or/rendclient.c

@@ -461,6 +461,8 @@ rend_client_refetch_v2_renddesc(const char *query)
   log_info(LD_REND, "Could not pick one of the responsible hidden "
                     "service directories to fetch descriptors, because "
                     "we already tried them all unsuccessfully.");
+  /* Close pending connections (unless a v0 request is still going on). */
+  rend_client_desc_trynow(query, 2);
   return;
 }
 
@@ -617,11 +619,14 @@ rend_client_receive_rendezvous(origin_circuit_t *circ, const char *request,
 
 /** Find all the apconns in state AP_CONN_STATE_RENDDESC_WAIT that
  * are waiting on query. If there's a working cache entry here
- * with at least one intro point, move them to the next state;
- * else fail them.
+ * with at least one intro point, move them to the next state. If
+ * <b>rend_version</b> is non-negative, fail connections that have
+ * requested <b>query</b> unless there are still descriptor fetch
+ * requests in progress for other descriptor versions than
+ * <b>rend_version</b>.
  */
 void
-rend_client_desc_here(const char *query)
+rend_client_desc_trynow(const char *query, int rend_version)
 {
   edge_connection_t *conn;
   rend_cache_entry_t *entry;
@@ -657,9 +662,15 @@ rend_client_desc_here(const char *query)
         connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
       }
     } else { /* 404, or fetch didn't get that far */
-      log_notice(LD_REND,"Closing stream for '%s.onion': hidden service is "
-                 "unavailable (try again later).", safe_str(query));
-      connection_mark_unattached_ap(conn, END_STREAM_REASON_RESOLVEFAILED);
+      /* Unless there are requests for another descriptor version pending,
+       * close the connection. */
+      if (rend_version >= 0 &&
+          !connection_get_by_type_state_rendquery(CONN_TYPE_DIR, 0, query,
+                                                  rend_version == 0 ? 2 : 0)) {
+        log_notice(LD_REND,"Closing stream for '%s.onion': hidden service is "
+                   "unavailable (try again later).", safe_str(query));
+        connection_mark_unattached_ap(conn, END_STREAM_REASON_RESOLVEFAILED);
+      }
     }
   });
 }