From: Roger Dingledine <arma@torproject.org>
Date: Mon, 15 Jan 2018 21:30:55 +0000 (-0500)
Subject: MAX_REND_FAILURES is 1, but we would try three times
X-Git-Tag: tor-0.2.9.15~17^2^2~2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a15eb9ff439623f800de813c1a78eeb5d61f7f5a;p=thirdparty%2Ftor.git

MAX_REND_FAILURES is 1, but we would try three times

Fix an "off by 2" error in counting rendezvous failures on the onion
service side.

While we thought we would stop the rendezvous attempt after one failed
circuit, we were actually making three circuit attempts before giving up.

Fixes bug 24895; bugfix on 0.0.6.
---

diff --git a/changes/bug24895 b/changes/bug24895
new file mode 100644
index 0000000000..7b90f6d260
--- /dev/null
+++ b/changes/bug24895
@@ -0,0 +1,6 @@
+  o Major bugfixes (onion services):
+    - Fix an "off by 2" error in counting rendezvous failures on the
+      onion service side. While we thought we would stop the rendezvous
+      attempt after one failed circuit, we were actually making three
+      circuit attempts before giving up. Fixes bug 24895; bugfix on 0.0.6.
+
diff --git a/src/or/rendservice.c b/src/or/rendservice.c
index a8c383444d..acc431a577 100644
--- a/src/or/rendservice.c
+++ b/src/or/rendservice.c
@@ -2930,8 +2930,11 @@ rend_service_relaunch_rendezvous(origin_circuit_t *oldcirc)
   }
   oldcirc->hs_service_side_rend_circ_has_been_relaunched = 1;
 
+  /* We check failure_count >= MAX_REND_FAILURES-1 below rather than
+   * failure_count >= MAX_REND_FAILURES, because we increment the failure
+   * count for our current failure *after* this clause. */
   if (!oldcirc->build_state ||
-      oldcirc->build_state->failure_count > MAX_REND_FAILURES ||
+      oldcirc->build_state->failure_count >= MAX_REND_FAILURES-1 ||
       oldcirc->build_state->expiry_time < time(NULL)) {
     log_info(LD_REND,
              "Attempt to build circuit to %s for rendezvous has failed "