+
+struct FindClosestContext
+{
+ /**
+ * The currently known closest peer.
+ */
+ struct GNUNET_TESTING_Daemon *closest;
+
+ /**
+ * The info for the peer we are adding connections for.
+ */
+ struct PeerData *curr_peer;
+
+ /**
+ * The distance (bits) between the current
+ * peer and the currently known closest.
+ */
+ unsigned int closest_dist;
+
+ /**
+ * The offset of the closest known peer in
+ * the peer group.
+ */
+ unsigned int closest_num;
+};
+
+/**
+ * Iterator over hash map entries of the allowed
+ * peer connections. Find the closest, not already
+ * connected peer and return it.
+ *
+ * @param cls closure (struct FindClosestContext)
+ * @param key current key code (hash of offset in pg)
+ * @param value value in the hash map - a GNUNET_TESTING_Daemon
+ * @return GNUNET_YES if we should continue to
+ * iterate,
+ * GNUNET_NO if not.
+ */
+static int
+find_closest_peers (void *cls, const GNUNET_HashCode * key, void *value)
+{
+ struct FindClosestContext *closest_ctx = cls;
+ struct GNUNET_TESTING_Daemon *daemon = value;
+
+ if (((closest_ctx->closest == NULL) ||
+ (GNUNET_CRYPTO_hash_matching_bits
+ (&daemon->id.hashPubKey,
+ &closest_ctx->curr_peer->daemon->id.hashPubKey) >
+ closest_ctx->closest_dist))
+ && (GNUNET_YES !=
+ GNUNET_CONTAINER_multihashmap_contains (closest_ctx->
+ curr_peer->connect_peers,
+ key)))
+ {
+ closest_ctx->closest_dist =
+ GNUNET_CRYPTO_hash_matching_bits (&daemon->id.hashPubKey,
+ &closest_ctx->curr_peer->daemon->
+ id.hashPubKey);
+ closest_ctx->closest = daemon;
+ uid_from_hash (key, &closest_ctx->closest_num);
+ }
+ return GNUNET_YES;
+}
+
+/**
+ * From the set of connections possible, choose at num connections per
+ * peer based on depth which are closest out of those allowed. Guaranteed
+ * to add num peers to connect to, provided there are that many peers
+ * in the underlay topology to connect to.
+ *
+ * @param pg the peergroup we are dealing with
+ * @param num how many connections at least should each peer have (if possible)?
+ * @param proc processor to actually add the connections
+ */
+void
+add_closest (struct GNUNET_TESTING_PeerGroup *pg, unsigned int num,
+ GNUNET_TESTING_ConnectionProcessor proc)
+{
+ struct FindClosestContext closest_ctx;
+ uint32_t pg_iter;
+ uint32_t i;
+
+ for (i = 0; i < num; i++) /* Each time find a closest peer (from those available) */
+ {
+ for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
+ {
+ closest_ctx.curr_peer = &pg->peers[pg_iter];
+ closest_ctx.closest = NULL;
+ closest_ctx.closest_dist = 0;
+ closest_ctx.closest_num = 0;
+ GNUNET_CONTAINER_multihashmap_iterate (pg->
+ peers[pg_iter].allowed_peers,
+ &find_closest_peers,
+ &closest_ctx);
+ if (closest_ctx.closest != NULL)
+ {
+ GNUNET_assert (closest_ctx.closest_num < pg->total);
+ proc (pg, pg_iter, closest_ctx.closest_num);
+ }
+ }
+ }
+}
+
+/**
+ * From the set of connections possible, choose at least num connections per
+ * peer based on depth first traversal of peer connections. If DFS leaves
+ * peers unconnected, ensure those peers get connections.
+ *
+ * @param pg the peergroup we are dealing with
+ * @param num how many connections at least should each peer have (if possible)?
+ */
+void
+perform_dfs (struct GNUNET_TESTING_PeerGroup *pg, unsigned int num)