Merge branch 'tor-github/pr/1255' into maint-0.4.1

changes/bug23818_v2

@@ -0,0 +1,6 @@
+  o Minor bugfixes (v2 single onion services):
+    - Always retry v2 single onion service intro and rend circuits with a
+      3-hop path. Previously, v2 single onion services used a 3-hop path
+      when rend circuits were retried after a remote or delayed failure,
+      but a 1-hop path for immediate retries. Fixes bug 23818;
+      bugfix on 0.2.9.3-alpha.

src/feature/rend/rendservice.c

@@ -2123,8 +2123,12 @@ rend_service_receive_introduction(origin_circuit_t *circuit,
     int flags = CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_IS_INTERNAL;
     if (circ_needs_uptime) flags |= CIRCLAUNCH_NEED_UPTIME;
     /* A Single Onion Service only uses a direct connection if its
-     * firewall rules permit direct connections to the address. */
-    if (rend_service_use_direct_connection(options, rp)) {
+     * firewall rules permit direct connections to the address.
+     *
+     * We only use a one-hop path on the first attempt. If the first attempt
+     * fails, we use a 3-hop path for reachability / reliability.
+     * See the comment in rend_service_relauch_rendezvous() for details. */
+    if (rend_service_use_direct_connection(options, rp) && i == 0) {
       flags = flags | CIRCLAUNCH_ONEHOP_TUNNEL;
     }
     launched = circuit_launch_by_extend_info(
@@ -3086,8 +3090,15 @@ rend_service_launch_establish_intro(rend_service_t *service,
   extend_info_t *launch_ei = intro->extend_info;
   extend_info_t *direct_ei = NULL;
 
-  /* Are we in single onion mode? */
-  if (rend_service_allow_non_anonymous_connection(options)) {
+  /* Are we in single onion mode?
+   *
+   * We only use a one-hop path on the first attempt. If the first attempt
+   * fails, we use a 3-hop path for reachability / reliability.
+   * (Unlike v3, retries is incremented by the caller after it calls this
+   * function.)
+   */
+  if (rend_service_allow_non_anonymous_connection(options) &&
+      intro->circuit_retries == 0) {
     /* Do we have a descriptor for the node?
      * We've either just chosen it from the consensus, or we've just reviewed
      * our intro points to see which ones are still valid, and deleted the ones