[tor-commits] [tor/master] Choose the correct address for one-hop connections

[nickm at torproject.org]

commit 0cf90bac2a7136e0abb9fed160f70c543ad8b88a
Author: teor (Tim Wilson-Brown) <teor2345 at gmail.com>
Date:   Thu Apr 28 16:03:23 2016 +1000

    Choose the correct address for one-hop connections
    
    After #17840 in 0.2.8.1-alpha, we incorrectly chose an IPv4
    address for all DIRIND_ONEHOP directory connections,
    even if the routerstatus didn't have an IPv4 address.
    
    This likely affected bridge clients with IPv6 bridges.
    
    Resolves #18921.
---
 changes/bug18921   |  4 ++++
 src/or/directory.c | 30 +++++++++++++++++++-----------
 2 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/changes/bug18921 b/changes/bug18921
new file mode 100644
index 0000000..934a604
--- /dev/null
+++ b/changes/bug18921
@@ -0,0 +1,4 @@
+  o Major bugfixes (IPv6 bridges):
+    - Fix directory address selection for IPv6 bridges.
+      Resolves #18921, bugfix on #17840 in 0.2.8.1-alpha.
+      Patch by "teor".
diff --git a/src/or/directory.c b/src/or/directory.c
index ab9f738..ca3b3e3 100644
--- a/src/or/directory.c
+++ b/src/or/directory.c
@@ -630,7 +630,6 @@ directory_choose_address_routerstatus(const routerstatus_t *status,
   tor_assert(use_or_ap != NULL);
   tor_assert(use_dir_ap != NULL);
 
-  const int anonymized_connection = dirind_is_anon(indirection);
   int have_or = 0, have_dir = 0;
 
   /* We expect status to have at least one reachable address if we're
@@ -652,13 +651,16 @@ directory_choose_address_routerstatus(const routerstatus_t *status,
   tor_addr_make_null(&use_dir_ap->addr, AF_UNSPEC);
   use_dir_ap->port = 0;
 
-  if (anonymized_connection) {
-    /* Use the primary (IPv4) OR address if we're making an indirect
-     * connection. */
-    tor_addr_from_ipv4h(&use_or_ap->addr, status->addr);
-    use_or_ap->port = status->or_port;
-    have_or = 1;
-  } else {
+  /* ORPort connections */
+  if (indirection == DIRIND_ANONYMOUS) {
+    if (status->addr) {
+      /* Since we're going to build a 3-hop circuit and ask the 2nd relay
+       * to extend to this address, always use the primary (IPv4) OR address */
+      tor_addr_from_ipv4h(&use_or_ap->addr, status->addr);
+      use_or_ap->port = status->or_port;
+      have_or = 1;
+    }
+  } else if (indirection == DIRIND_ONEHOP) {
     /* We use an IPv6 address if we have one and we prefer it.
      * Use the preferred address and port if they are reachable, otherwise,
      * use the alternate address and port (if any).
@@ -668,9 +670,15 @@ directory_choose_address_routerstatus(const routerstatus_t *status,
                                                  use_or_ap);
   }
 
-  have_dir = fascist_firewall_choose_address_rs(status,
-                                                FIREWALL_DIR_CONNECTION, 0,
-                                                use_dir_ap);
+  /* DirPort connections
+   * DIRIND_ONEHOP uses ORPort, but may fall back to the DirPort */
+  if (indirection == DIRIND_DIRECT_CONN ||
+      indirection == DIRIND_ANON_DIRPORT ||
+      indirection == DIRIND_ONEHOP) {
+    have_dir = fascist_firewall_choose_address_rs(status,
+                                                  FIREWALL_DIR_CONNECTION, 0,
+                                                  use_dir_ap);
+  }
 
   /* We rejected all addresses in the relay's status. This means we can't
    * connect to it. */