- refactorize path checking code, look both ways

3 files changed, 50 insertions, 5 deletions

diff --git a/src/cadet/cadet_path.c b/src/cadet/cadet_path.c
index 1b2d377f5..d1aa9dcf2 100644
--- a/src/cadet/cadet_path.c
+++ b/src/cadet/cadet_path.c
@@ -223,6 +223,40 @@ path_build_from_peer_ids (struct GNUNET_PeerIdentity *peers,
 
 
 /**
+ * Test if two paths are equivalent (equal or revese of each other).
+ *
+ * @param p1 First path
+ * @param p2 Second path
+ *
+ * @return GNUNET_YES if both paths are equivalent
+ *         GNUNET_NO otherwise
+ */
+int
+path_equivalent (const struct CadetPeerPath *p1,
+                 const struct CadetPeerPath *p2)
+{
+  unsigned int i;
+  unsigned int l;
+  unsigned int half;
+
+  if (p1->length != p2->length)
+    return GNUNET_NO;
+
+  l = p1->length;
+  if (0 == memcmp (p1->peers, p2->peers, sizeof (p1->peers[0]) * l))
+    return GNUNET_YES;
+
+  half = l / 2;
+  l = l - 1;
+  for (i = 0; i <= half; i++)
+    if (p1->peers[i] != p2->peers[l - i])
+      return GNUNET_NO;
+
+  return GNUNET_YES;
+}
+
+
+/**
  * Test if a path is valid (or at least not known to be invalid).
  *
  * @param path Path to test.
diff --git a/src/cadet/cadet_path.h b/src/cadet/cadet_path.h
index 6281ddc05..761e51156 100644
--- a/src/cadet/cadet_path.h
+++ b/src/cadet/cadet_path.h
@@ -138,6 +138,19 @@ void
 path_invalidate (struct CadetPeerPath *p);
 
 /**
+ * Test if two paths are equivalent (equal or revese of each other).
+ *
+ * @param p1 First path
+ * @param p2 Second path
+ *
+ * @return GNUNET_YES if both paths are equivalent
+ *         GNUNET_NO otherwise
+ */
+int
+path_equivalent (const struct CadetPeerPath *p1,
+                 const struct CadetPeerPath *p2);
+
+/**
  * Test if a path is valid (or at least not known to be invalid).
  *
  * @param path Path to test.
diff --git a/src/cadet/gnunet-service-cadet_connection.c b/src/cadet/gnunet-service-cadet_connection.c
index e1883ce00..24f63054a 100644
--- a/src/cadet/gnunet-service-cadet_connection.c
+++ b/src/cadet/gnunet-service-cadet_connection.c
@@ -1536,16 +1536,14 @@ check_path (void *cls, struct CadetConnection *c)
   struct CadetConnection *new_conn = cls;
   struct CadetPeerPath *path = new_conn->path;
 
-  LOG (GNUNET_ERROR_TYPE_DEBUG, "  checking %s, length %u\n",
-       GCC_2s (c), c->path->length);
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "  checking %s (%p), length %u\n",
+       GCC_2s (c), c, c->path->length);
 
   if (c != new_conn
       && c->destroy == GNUNET_NO
       && c->state != CADET_CONNECTION_BROKEN
       && c->state != CADET_CONNECTION_DESTROYED
-      && c->path->length == path->length
-      && 0 == memcmp (c->path->peers, path->peers,
-                      sizeof (path->peers[0]) * path->length))
+      && path_equivalent (path, c->path))
   {
     new_conn->destroy = GNUNET_YES;
     new_conn->path->c = c;