doxygen documentation
[oweals/gnunet.git] / src / testing / testing_group.c
index 269df5c210978ec659d02749284abd3bb2d38cd8..61e8675b1f2a307ca6664d5fb8706ee60ab09c8e 100644 (file)
@@ -4,7 +4,7 @@
 
       GNUnet is free software; you can redistribute it and/or modify
       it under the terms of the GNU General Public License as published
-      by the Free Software Foundation; either version 2, or (at your
+      by the Free Software Foundation; either version 3, or (at your
       option) any later version.
 
       GNUnet is distributed in the hope that it will be useful, but
 /**
  * @file testing/testing_group.c
  * @brief convenience API for writing testcases for GNUnet
+ * @author Nathan Evans
  * @author Christian Grothoff
+ *
  */
 #include "platform.h"
 #include "gnunet_arm_service.h"
 #include "gnunet_testing_lib.h"
+#include "gnunet_core_service.h"
 
 #define VERBOSE_TESTING GNUNET_NO
 
+#define DEBUG_CHURN GNUNET_NO
+
 /**
  * Lowest port used for GNUnet testing.  Should be high enough to not
  * conflict with other applications running on the hosts but be low
  * conflict with the port range for "local" ports (client apps; see
  * /proc/sys/net/ipv4/ip_local_port_range on Linux for example).
  */
-#define HIGH_PORT 32000
+#define HIGH_PORT 56000
+
+#define MAX_OUTSTANDING_CONNECTIONS 10
+
+#define MAX_CONCURRENT_HOSTKEYS 10
 
-#define MAX_OUTSTANDING_CONNECTIONS 50
+#define MAX_CONCURRENT_STARTING 10
 
-#define CONNECT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 160)
+#define MAX_CONCURRENT_SHUTDOWN 10
+
+#define CONNECT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 300)
 
 #define CONNECT_ATTEMPTS 8
 
  * Prototype of a function called whenever two peers would be connected
  * in a certain topology.
  */
-typedef int (*GNUNET_TESTING_ConnectionProcessor)
-(struct GNUNET_TESTING_PeerGroup *pg, unsigned int first, unsigned int second);
+typedef int (*GNUNET_TESTING_ConnectionProcessor)(struct GNUNET_TESTING_PeerGroup *pg, 
+                                                 unsigned int first,
+                                                 unsigned int second);
+
+
+/**
+ * Context for handling churning a peer group
+ */
+struct ChurnContext
+{
+  /**
+   * Callback used to notify of churning finished
+   */
+  GNUNET_TESTING_NotifyCompletion cb;
+
+  /**
+   * Closure for callback
+   */
+  void *cb_cls;
+
+  /**
+   * Number of peers that still need to be started
+   */
+  unsigned int num_to_start;
+
+  /**
+   * Number of peers that still need to be stopped
+   */
+  unsigned int num_to_stop;
+  /**
+   * Number of peers that failed to start
+   */
+  unsigned int num_failed_start;
+
+  /**
+   * Number of peers that failed to stop
+   */
+  unsigned int num_failed_stop;
+};
 
 struct RestartContext
 {
@@ -86,6 +135,47 @@ struct RestartContext
 
 };
 
+
+struct ShutdownContext
+{
+  /**
+   * Total peers to wait for
+   */
+  unsigned int total_peers;
+
+  /**
+   * Number of peers successfully shut down
+   */
+  unsigned int peers_down;
+
+  /**
+   * Number of peers failed to shut down
+   */
+  unsigned int peers_failed;
+
+  /**
+   * Number of peers we have started shutting
+   * down.  If too many, wait on them.
+   */
+  unsigned int outstanding;
+
+  /**
+   * Timeout for shutdown.
+   */
+  struct GNUNET_TIME_Relative timeout;
+
+  /**
+   * Callback to call when all peers either
+   * shutdown or failed to shutdown
+   */
+  GNUNET_TESTING_NotifyCompletion cb;
+
+  /**
+   * Closure for cb
+   */
+  void *cb_cls;
+};
+
 struct CreateTopologyContext
 {
 
@@ -116,6 +206,44 @@ struct PeerConnection
 };
 #endif
 
+struct InternalStartContext
+{
+  /**
+   * Pointer to peerdata
+   */
+  struct PeerData *peer;
+
+  /**
+   * Timeout for peer startup
+   */
+  struct GNUNET_TIME_Relative timeout;
+
+  /**
+   * Client callback for hostkey notification
+   */
+  GNUNET_TESTING_NotifyHostkeyCreated hostkey_callback;
+
+  /**
+   * Closure for hostkey_callback
+   */
+  void *hostkey_cls;
+
+  /**
+   * Client callback for peer start notification
+   */
+  GNUNET_TESTING_NotifyDaemonRunning start_cb;
+
+  /**
+   * Closure for cb
+   */
+  void *start_cb_cls;
+
+  /**
+   * Hostname, where to start the peer
+   */
+  const char *hostname;
+};
+
 /**
  * Data we keep per peer.
  */
@@ -139,10 +267,6 @@ struct PeerData
    */
   struct GNUNET_TESTING_PeerGroup *pg;
 
-  /**
-   * Linked list of peer connections (pointers)
-   */
-  //struct PeerConnection *connected_peers;
   /**
    * Hash map of allowed peer connections (F2F created topology)
    */
@@ -168,6 +292,12 @@ struct PeerData
    * creating any topology so the count is valid once finished.
    */
   int num_connections;
+
+  /**
+   * Context to keep track of peers being started, to
+   * stagger hostkey generation and peer startup.
+   */
+  struct InternalStartContext internal_context;
 };
 
 
@@ -188,6 +318,87 @@ struct HostData
   uint16_t minport;
 };
 
+struct TopologyIterateContext
+{
+  /**
+   * Callback for notifying of two connected peers.
+   */
+  GNUNET_TESTING_NotifyTopology topology_cb;
+
+  /**
+   * Closure for topology_cb
+   */
+  void *cls;
+
+  /**
+   * Number of peers currently connected to.
+   */
+  unsigned int connected;
+
+  /**
+   * Number of peers we have finished iterating.
+   */
+  unsigned int completed;
+
+  /**
+   * Number of peers total.
+   */
+  unsigned int total;
+};
+
+struct StatsIterateContext
+{
+  /**
+   * Continuation to call once all stats information has been retrieved.
+   */
+  GNUNET_STATISTICS_Callback cont;
+
+  /**
+   * Proc function to call on each value received.
+   */
+  GNUNET_TESTING_STATISTICS_Iterator proc;
+
+  /**
+   * Closure for topology_cb
+   */
+  void *cls;
+
+  /**
+   * Number of peers currently connected to.
+   */
+  unsigned int connected;
+
+  /**
+   * Number of peers we have finished iterating.
+   */
+  unsigned int completed;
+
+  /**
+   * Number of peers total.
+   */
+  unsigned int total;
+};
+
+struct CoreContext
+{
+  void *iter_context;
+  struct GNUNET_TESTING_Daemon *daemon;
+};
+
+struct StatsCoreContext
+{
+  void *iter_context;
+  struct GNUNET_TESTING_Daemon *daemon;
+  /**
+   * Handle to the statistics service.
+   */
+  struct GNUNET_STATISTICS_Handle *stats_handle;
+
+  /**
+   * Handle for getting statistics.
+   */
+  struct GNUNET_STATISTICS_GetHandle *stats_get_handle;
+};
 
 /**
  * Handle to a group of GNUnet peers.
@@ -207,12 +418,12 @@ struct GNUNET_TESTING_PeerGroup
   /**
    * Function to call on each started daemon.
    */
-  GNUNET_TESTING_NotifyDaemonRunning cb;
+  //GNUNET_TESTING_NotifyDaemonRunning cb;
 
   /**
    * Closure for cb.
    */
-  void *cb_cls;
+  //void *cb_cls;
 
   /*
    * Function to call on each topology connection created
@@ -244,6 +455,35 @@ struct GNUNET_TESTING_PeerGroup
    * At what time should we fail the peer startup process?
    */
   struct GNUNET_TIME_Absolute max_timeout;
+
+  /**
+   * How many peers are being started right now?
+   */
+  unsigned int starting;
+
+  /**
+   * How many peers have already been started?
+   */
+  unsigned int started;
+};
+
+struct UpdateContext
+{
+  struct GNUNET_CONFIGURATION_Handle *ret;
+  const struct GNUNET_CONFIGURATION_Handle *orig;
+  const char *hostname;
+  unsigned int nport;
+  unsigned int upnum;
+};
+
+
+struct ConnectContext
+{
+  struct GNUNET_TESTING_Daemon *first;
+
+  struct GNUNET_TESTING_Daemon *second;
+
+  struct GNUNET_TESTING_PeerGroup *pg;
 };
 
 /**
@@ -272,29 +512,164 @@ uid_from_hash (const GNUNET_HashCode *hash, uint32_t *uid)
   memcpy (uid, hash, sizeof(uint32_t));
 }
 
-struct UpdateContext
-{
-  struct GNUNET_CONFIGURATION_Handle *ret;
-  unsigned int nport;
-  const char *hostname;
-};
-
-
-struct ConnectContext
-{
-  struct GNUNET_TESTING_Daemon *first;
-
-  struct GNUNET_TESTING_Daemon *second;
-
-  struct GNUNET_TESTING_PeerGroup *pg;
-};
-
 /**
  * Number of connects we are waiting on, allows us to rate limit
  * connect attempts.
  */
 static int outstanding_connects;
 
+/**
+ * Get a topology from a string input.
+ *
+ * @param topology where to write the retrieved topology
+ * @param topology_string The string to attempt to
+ *        get a configuration value from
+ * @return GNUNET_YES if topology string matched a
+ *         known topology, GNUNET_NO if not
+ */
+int
+GNUNET_TESTING_topology_get(enum GNUNET_TESTING_Topology *topology, char * topology_string)
+{
+  /**
+   * Strings representing topologies in enum
+   */
+  static const char * topology_strings[] =
+    {
+      /**
+       * A clique (everyone connected to everyone else).
+       */
+      "CLIQUE",
+      
+      /**
+       * Small-world network (2d torus plus random links).
+       */
+      "SMALL_WORLD",
+      
+      /**
+       * Small-world network (ring plus random links).
+       */
+      "SMALL_WORLD_RING",
+      
+      /**
+       * Ring topology.
+       */
+      "RING",
+      
+      /**
+       * 2-d torus.
+       */
+      "2D_TORUS",
+      
+      /**
+       * Random graph.
+       */
+      "ERDOS_RENYI",
+      
+      /**
+       * Certain percentage of peers are unable to communicate directly
+       * replicating NAT conditions
+       */
+      "INTERNAT",
+      
+      /**
+       * Scale free topology.
+       */
+      "SCALE_FREE",
+      
+      /**
+       * Straight line topology.
+       */
+      "LINE",
+      
+      /**
+       * All peers are disconnected.
+       */
+      "NONE",
+
+      NULL
+    };
+
+  int curr = 0;
+  if (topology_string == NULL)
+    return GNUNET_NO;
+  while (topology_strings[curr] != NULL)
+    {
+      if (strcasecmp(topology_strings[curr], topology_string) == 0)
+       {
+         *topology = curr;
+         return GNUNET_YES;
+       }
+      curr++;
+    }
+  *topology = GNUNET_TESTING_TOPOLOGY_NONE;
+  return GNUNET_NO;
+}
+
+
+/**
+ * Get connect topology option from string input.
+ *
+ * @param topology_option where to write the retrieved topology
+ * @param topology_string The string to attempt to
+ *        get a configuration value from
+ * @return GNUNET_YES if string matched a known
+ *         topology option, GNUNET_NO if not
+ */
+int
+GNUNET_TESTING_topology_option_get (enum GNUNET_TESTING_TopologyOption *topology_option,
+                                   char * topology_string)
+{
+  /**
+   * Options for connecting a topology as strings.
+   */
+  static const char * topology_option_strings[] =
+    {
+      /**
+       * Try to connect all peers specified in the topology.
+       */
+      "CONNECT_ALL",
+      
+      /**
+       * Choose a random subset of connections to create.
+       */
+      "CONNECT_RANDOM_SUBSET",
+      
+      /**
+       * Create at least X connections for each peer.
+       */
+      "CONNECT_MINIMUM",
+      
+      /**
+       * Using a depth first search, create one connection
+       * per peer.  If any are missed (graph disconnected)
+       * start over at those peers until all have at least one
+       * connection.
+       */
+      "CONNECT_DFS",
+      
+      /**
+       * No options specified.
+       */
+      "CONNECT_NONE",
+
+      NULL
+    };
+  int curr = 0;
+
+  if (topology_string == NULL)
+    return GNUNET_NO;
+  while (NULL != topology_option_strings[curr])
+    {
+      if (strcasecmp(topology_option_strings[curr], topology_string) == 0)
+       {
+         *topology_option = curr;
+         return GNUNET_YES;
+       }
+      curr++;
+    } 
+  *topology_option = GNUNET_TESTING_TOPOLOGY_OPTION_NONE;
+  return GNUNET_NO;
+}
 
 /**
  * Function to iterate over options.  Copies
@@ -313,11 +688,35 @@ update_config (void *cls,
   struct UpdateContext *ctx = cls;
   unsigned int ival;
   char cval[12];
+  char uval[128];
+  char *single_variable;
 
   if ((0 == strcmp (option, "PORT")) && (1 == sscanf (value, "%u", &ival)))
     {
-      GNUNET_snprintf (cval, sizeof (cval), "%u", ctx->nport++);
-      value = cval;
+      GNUNET_asprintf(&single_variable, "single_%s_per_host", section);
+      if ((ival != 0) && (GNUNET_YES != GNUNET_CONFIGURATION_get_value_yesno(ctx->orig, "testing", single_variable)))
+       {
+         GNUNET_snprintf (cval, sizeof (cval), "%u", ctx->nport++);
+         value = cval;
+       }
+
+      GNUNET_free(single_variable);
+    }
+
+  if (0 == strcmp (option, "UNIXPATH"))
+    {
+      GNUNET_asprintf(&single_variable, "single_%s_per_host", section);
+      if (GNUNET_YES != GNUNET_CONFIGURATION_get_value_yesno(ctx->orig, "testing", single_variable))
+        {
+          GNUNET_snprintf (uval,
+                           sizeof (uval),
+                           "/tmp/test-service-%s-%u",
+                           section,
+                           ctx->upnum++);
+          value = uval;
+        }
+      GNUNET_free(single_variable);
+
     }
 
   if ((0 == strcmp (option, "HOSTNAME")) && (ctx->hostname != NULL))
@@ -338,12 +737,16 @@ update_config (void *cls,
  * @param cfg template configuration
  * @param port port numbers to use, update to reflect
  *             port numbers that were used
+ * @param upnum number to make unix domain socket names unique
  * @param hostname hostname of the controlling host, to allow control connections from
  *
  * @return new configuration, NULL on error
  */
 static struct GNUNET_CONFIGURATION_Handle *
-make_config (const struct GNUNET_CONFIGURATION_Handle *cfg, uint16_t * port, const char *hostname)
+make_config (const struct GNUNET_CONFIGURATION_Handle *cfg, 
+            uint16_t * port,
+            uint32_t * upnum,
+            const char *hostname)
 {
   struct UpdateContext uc;
   uint16_t orig;
@@ -352,8 +755,10 @@ make_config (const struct GNUNET_CONFIGURATION_Handle *cfg, uint16_t * port, con
 
   orig = *port;
   uc.nport = *port;
+  uc.upnum = *upnum;
   uc.ret = GNUNET_CONFIGURATION_create ();
   uc.hostname = hostname;
+  uc.orig = cfg;
 
   GNUNET_CONFIGURATION_iterate (cfg, &update_config, &uc);
   if (uc.nport >= HIGH_PORT)
@@ -365,8 +770,15 @@ make_config (const struct GNUNET_CONFIGURATION_Handle *cfg, uint16_t * port, con
 
   if (GNUNET_CONFIGURATION_get_value_string(cfg, "testing", "control_host", &control_host) == GNUNET_OK)
     {
-      GNUNET_asprintf(&allowed_hosts, "%s; 127.0.0.1;", control_host);
+      if (hostname != NULL)
+        GNUNET_asprintf(&allowed_hosts, "%s; 127.0.0.1; %s;", control_host, hostname);
+      else
+        GNUNET_asprintf(&allowed_hosts, "%s; 127.0.0.1;", control_host);
+
       GNUNET_CONFIGURATION_set_value_string(uc.ret, "core", "ACCEPT_FROM", allowed_hosts);
+      GNUNET_CONFIGURATION_set_value_string(uc.ret, "transport", "ACCEPT_FROM", allowed_hosts);
+      GNUNET_CONFIGURATION_set_value_string(uc.ret, "dht", "ACCEPT_FROM", allowed_hosts);
+      GNUNET_CONFIGURATION_set_value_string(uc.ret, "statistics", "ACCEPT_FROM", allowed_hosts);
       GNUNET_free_non_null(control_host);
       GNUNET_free(allowed_hosts);
     }
@@ -377,11 +789,19 @@ make_config (const struct GNUNET_CONFIGURATION_Handle *cfg, uint16_t * port, con
   if (hostname != NULL)
     {
       GNUNET_asprintf(&allowed_hosts, "%s; 127.0.0.1;", hostname);
+      GNUNET_CONFIGURATION_set_value_string(uc.ret, "transport-udp", "BINDTO", hostname);
+      GNUNET_CONFIGURATION_set_value_string(uc.ret, "transport-tcp", "BINDTO", hostname);
       GNUNET_CONFIGURATION_set_value_string(uc.ret, "arm", "ACCEPT_FROM", allowed_hosts);
       GNUNET_free(allowed_hosts);
     }
+  else
+    {
+      GNUNET_CONFIGURATION_set_value_string(uc.ret, "transport-tcp", "BINDTO", "127.0.0.1");
+      GNUNET_CONFIGURATION_set_value_string(uc.ret, "transport-udp", "BINDTO", "127.0.0.1");
+    }
 
   *port = (uint16_t) uc.nport;
+  *upnum = uc.upnum;
   return uc.ret;
 }
 
@@ -393,10 +813,8 @@ make_config (const struct GNUNET_CONFIGURATION_Handle *cfg, uint16_t * port, con
  * @param first index of the first peer
  * @param second index of the second peer
  *
- * @return the number of connections added (can be 0, 1 or 2)
- *         technically should only be 0 or 2, but the small price
- *         of iterating over the lists (hashmaps in the future)
- *         for being sure doesn't bother me!
+ * @return the number of connections added
+ *         technically should only be 0 or 2
  *
  */
 static int
@@ -667,7 +1085,7 @@ create_scale_free (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Connectio
         {
           probability = pg->peers[i].num_connections / (double)previous_total_connections;
           random = ((double) GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_WEAK,
-                                                      (uint64_t)-1LL)) / ( (double) (uint64_t) -1LL);
+                                                      UINT64_MAX)) / ( (double) UINT64_MAX);
 #if VERBOSE_TESTING
           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                       "Considering connecting peer %d to peer %d\n",
@@ -688,6 +1106,17 @@ create_scale_free (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Connectio
   return total_connections;
 }
 
+/**
+ * Create a topology given a peer group (set of running peers)
+ * and a connection processor.
+ *
+ * @param pg the peergroup to create the topology on
+ * @param proc the connection processor to call to actually set
+ *        up connections between two peers
+ *
+ * @return the number of connections that were set up
+ *
+ */
 int
 create_small_world_ring(struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionProcessor proc)
 {
@@ -761,7 +1190,7 @@ create_small_world_ring(struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Conn
       for (j = 0; j < connsPerPeer / 2; j++)
         {
           random = ((double) GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_WEAK,
-                                                     (uint64_t)-1LL)) / ( (double) (uint64_t) -1LL);
+                                                     UINT64_MAX) / ( (double) UINT64_MAX));
           if (random < percentage)
             {
               /* Connect to uniformly selected random peer */
@@ -799,7 +1228,17 @@ create_small_world_ring(struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Conn
   return connect_attempts;
 }
 
-
+/**
+ * Create a topology given a peer group (set of running peers)
+ * and a connection processor.
+ *
+ * @param pg the peergroup to create the topology on
+ * @param proc the connection processor to call to actually set
+ *        up connections between two peers
+ *
+ * @return the number of connections that were set up
+ *
+ */
 static int
 create_nated_internet (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionProcessor proc)
 {
@@ -851,8 +1290,17 @@ create_nated_internet (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Conne
 
 }
 
-
-
+/**
+ * Create a topology given a peer group (set of running peers)
+ * and a connection processor.
+ *
+ * @param pg the peergroup to create the topology on
+ * @param proc the connection processor to call to actually set
+ *        up connections between two peers
+ *
+ * @return the number of connections that were set up
+ *
+ */
 static int
 create_small_world (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionProcessor proc)
 {
@@ -870,6 +1318,7 @@ create_small_world (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Connecti
   unsigned int distance;
   double probability, random, percentage;
   unsigned int smallWorldConnections;
+  unsigned int small_world_it;
   char *p_string;
   int connect_attempts;
   square = floor (sqrt (pg->total));
@@ -890,6 +1339,13 @@ create_small_world (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Connecti
                    "TESTING");
       GNUNET_free (p_string);
     }
+  if (percentage < 0.0)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  _("Invalid value `%s' for option `%s' in section `%s': got %f, needed value greater than 0\n"),
+                  "PERCENTAGE", "TESTING", percentage);
+      percentage = 0.5;
+    }
   probability = 0.5; /* FIXME: default percentage? */
   if (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(pg->cfg,
                                                         "TESTING",
@@ -956,7 +1412,9 @@ create_small_world (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Connecti
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Total connections added thus far: %u!\n"), connect_attempts);
 #endif
   smallWorldConnections = 0;
-  for (i = 0; i < (int) (natLog * percentage); i++)
+  small_world_it = (unsigned int)(natLog * percentage);
+  GNUNET_assert(small_world_it > 0 && small_world_it < (unsigned int)-1);
+  for (i = 0; i < small_world_it; i++)
     {
       for (j = 0; j < pg->total; j++)
         {
@@ -976,7 +1434,7 @@ create_small_world (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Connecti
                   probability = 1.0 / (distance * distance);
                   /* Choose a random value between 0 and 1 */
                  random = ((double) GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_WEAK,
-                                                             (uint64_t)-1LL)) / ( (double) (uint64_t) -1LL);
+                                                             UINT64_MAX)) / ( (double) UINT64_MAX);
                   /* If random < probability, then connect the two nodes */
                   if (random < probability)
                     smallWorldConnections += proc (pg, j, k);
@@ -994,8 +1452,17 @@ create_small_world (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Connecti
   return connect_attempts;
 }
 
-
-
+/**
+ * Create a topology given a peer group (set of running peers)
+ * and a connection processor.
+ *
+ * @param pg the peergroup to create the topology on
+ * @param proc the connection processor to call to actually set
+ *        up connections between two peers
+ *
+ * @return the number of connections that were set up
+ *
+ */
 static int
 create_erdos_renyi (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionProcessor proc)
 {
@@ -1027,7 +1494,7 @@ create_erdos_renyi (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Connecti
            inner_count++)
         {
           temp_rand = ((double) GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_WEAK,
-                                                        (uint64_t)-1LL)) / ( (double) (uint64_t) -1LL);
+                                                        UINT64_MAX)) / ( (double) UINT64_MAX);
 #if VERBOSE_TESTING
           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                       _("rand is %f probability is %f\n"), temp_rand,
@@ -1043,6 +1510,17 @@ create_erdos_renyi (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_Connecti
   return connect_attempts;
 }
 
+/**
+ * Create a topology given a peer group (set of running peers)
+ * and a connection processor.
+ *
+ * @param pg the peergroup to create the topology on
+ * @param proc the connection processor to call to actually set
+ *        up connections between two peers
+ *
+ * @return the number of connections that were set up
+ *
+ */
 static int
 create_2d_torus (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionProcessor proc)
 {
@@ -1120,7 +1598,17 @@ create_2d_torus (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionP
 }
 
 
-
+/**
+ * Create a topology given a peer group (set of running peers)
+ * and a connection processor.
+ *
+ * @param pg the peergroup to create the topology on
+ * @param proc the connection processor to call to actually set
+ *        up connections between two peers
+ *
+ * @return the number of connections that were set up
+ *
+ */
 static int
 create_clique (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionProcessor proc)
 {
@@ -1147,10 +1635,53 @@ create_clique (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionPro
   return connect_attempts;
 }
 
-
-static int
-create_ring (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionProcessor proc)
-{
+/**
+ * Create a topology given a peer group (set of running peers)
+ * and a connection processor.
+ *
+ * @param pg the peergroup to create the topology on
+ * @param proc the connection processor to call to actually set
+ *        up connections between two peers
+ *
+ * @return the number of connections that were set up
+ *
+ */
+static int
+create_line (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionProcessor proc)
+{
+  unsigned int count;
+  int connect_attempts;
+
+  connect_attempts = 0;
+
+  /* Connect each peer to the next highest numbered peer */
+  for (count = 0; count < pg->total - 1; count++)
+    {
+#if VERBOSE_TESTING
+          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                      "Connecting peer %d to peer %d\n",
+                      count, count + 1);
+#endif
+      connect_attempts += proc(pg, count, count + 1);
+    }
+
+  return connect_attempts;
+}
+
+/**
+ * Create a topology given a peer group (set of running peers)
+ * and a connection processor.
+ *
+ * @param pg the peergroup to create the topology on
+ * @param proc the connection processor to call to actually set
+ *        up connections between two peers
+ *
+ * @return the number of connections that were set up
+ *
+ */
+static int
+create_ring (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_ConnectionProcessor proc)
+{
   unsigned int count;
   int connect_attempts;
 
@@ -1208,6 +1739,18 @@ friend_file_iterator (void *cls,
   return GNUNET_YES;
 }
 
+struct BlacklistContext
+{
+  /*
+   * The (open) file handle to write to
+   */
+  FILE *temp_file_handle;
+
+  /*
+   * The transport that this peer will be blacklisted on.
+   */
+  char *transport;
+};
 
 /**
  * Iterator for writing blacklist data to appropriate files.
@@ -1223,14 +1766,15 @@ blacklist_file_iterator (void *cls,
                          const GNUNET_HashCode * key,
                          void *value)
 {
-  FILE *temp_blacklist_handle = cls;
+  struct BlacklistContext *blacklist_ctx = cls;
+  //FILE *temp_blacklist_handle = cls;
   struct GNUNET_TESTING_Daemon *peer = value;
   struct GNUNET_PeerIdentity *temppeer;
   struct GNUNET_CRYPTO_HashAsciiEncoded peer_enc;
 
   temppeer = &peer->id;
   GNUNET_CRYPTO_hash_to_enc(&temppeer->hashPubKey, &peer_enc);
-  fprintf(temp_blacklist_handle, "tcp:%s\n", (char *)&peer_enc);
+  fprintf(blacklist_ctx->temp_file_handle, "%s:%s\n", blacklist_ctx->transport, (char *)&peer_enc);
 
   return GNUNET_YES;
 }
@@ -1345,6 +1889,7 @@ create_and_copy_friend_files (struct GNUNET_TESTING_PeerGroup *pg)
       count++;
       if (ret == GNUNET_SYSERR)
         {
+         /* FIXME: why sleep here? -CG */
           sleep(1);
         }
     }
@@ -1364,11 +1909,13 @@ create_and_copy_friend_files (struct GNUNET_TESTING_PeerGroup *pg)
  * to the appropriate place.
  *
  * @param pg the peer group we are dealing with
+ * @param transports space delimited list of transports to blacklist
  */
 static int
-create_and_copy_blacklist_files (struct GNUNET_TESTING_PeerGroup *pg)
+create_and_copy_blacklist_files (struct GNUNET_TESTING_PeerGroup *pg, char *transports)
 {
-  FILE *temp_friend_handle;
+  FILE *temp_file_handle;
+  static struct BlacklistContext blacklist_ctx;
   unsigned int pg_iter;
   char *temp_service_path;
   pid_t *pidarr;
@@ -1379,16 +1926,42 @@ create_and_copy_blacklist_files (struct GNUNET_TESTING_PeerGroup *pg)
   int count;
   int ret;
   int max_wait = 10;
+  int transport_len;
+  unsigned int i;
+  char *pos;
+  char *temp_transports;
 
   pidarr = GNUNET_malloc(sizeof(pid_t) * pg->total);
   for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
     {
       mytemp = GNUNET_DISK_mktemp("blacklist");
       GNUNET_assert(mytemp != NULL);
-      temp_friend_handle = fopen (mytemp, "wt");
-      GNUNET_assert(temp_friend_handle != NULL);
-      GNUNET_CONTAINER_multihashmap_iterate(pg->peers[pg_iter].blacklisted_peers, &blacklist_file_iterator, temp_friend_handle);
-      fclose(temp_friend_handle);
+      temp_file_handle = fopen (mytemp, "wt");
+      GNUNET_assert(temp_file_handle != NULL);
+      temp_transports = GNUNET_strdup(transports);
+      blacklist_ctx.temp_file_handle = temp_file_handle;
+      transport_len = strlen(temp_transports) + 1;
+      pos = NULL;
+
+      for (i = 0; i < transport_len; i++)
+      {
+        if ((temp_transports[i] == ' ') && (pos == NULL))
+          continue; /* At start of string (whitespace) */
+        else if ((temp_transports[i] == ' ') || (temp_transports[i] == '\0')) /* At end of string */
+        {
+          temp_transports[i] = '\0';
+          blacklist_ctx.transport = pos;
+          GNUNET_CONTAINER_multihashmap_iterate(pg->peers[pg_iter].blacklisted_peers, &blacklist_file_iterator, &blacklist_ctx);
+          pos = NULL;
+        } /* At beginning of actual string */
+        else if (pos == NULL)
+        {
+          pos = &temp_transports[i];
+        }
+      }
+
+      GNUNET_free (temp_transports);
+      fclose(temp_file_handle);
 
       if (GNUNET_OK !=
           GNUNET_CONFIGURATION_get_value_string(pg->peers[pg_iter].daemon->cfg, "PATHS", "SERVICEHOME", &temp_service_path))
@@ -1468,6 +2041,7 @@ create_and_copy_blacklist_files (struct GNUNET_TESTING_PeerGroup *pg)
       count++;
       if (ret == GNUNET_SYSERR)
         {
+         /* FIXME: why sleep here? -CG */
           sleep(1);
         }
     }
@@ -1488,6 +2062,7 @@ create_and_copy_blacklist_files (struct GNUNET_TESTING_PeerGroup *pg)
 static void internal_connect_notify (void *cls,
                                      const struct GNUNET_PeerIdentity *first,
                                      const struct GNUNET_PeerIdentity *second,
+                                     uint32_t distance,
                                      const struct GNUNET_CONFIGURATION_Handle *first_cfg,
                                      const struct GNUNET_CONFIGURATION_Handle *second_cfg,
                                      struct GNUNET_TESTING_Daemon *first_daemon,
@@ -1497,10 +2072,17 @@ static void internal_connect_notify (void *cls,
   struct GNUNET_TESTING_PeerGroup *pg = cls;
   outstanding_connects--;
 
-  pg->notify_connection(pg->notify_connection_cls, first, second, first_cfg, second_cfg, first_daemon, second_daemon, emsg);
-
+  pg->notify_connection(pg->notify_connection_cls, first, second, distance, first_cfg, second_cfg, first_daemon, second_daemon, emsg);
 }
 
+
+/**
+ * Either delay a connection (because there are too many outstanding)
+ * or schedule it for right now.
+ *
+ * @param cls a connection context
+ * @param tc the task runtime context
+ */
 static void schedule_connect(void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
   struct ConnectContext *connect_context = cls;
@@ -1514,7 +2096,7 @@ static void schedule_connect(void *cls, const struct GNUNET_SCHEDULER_TaskContex
           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                       _("Delaying connect, we have too many outstanding connections!\n"));
 #endif
-      GNUNET_SCHEDULER_add_delayed(connect_context->pg->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 3), &schedule_connect, connect_context);
+      GNUNET_SCHEDULER_add_delayed(connect_context->pg->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 100), &schedule_connect, connect_context);
     }
   else
     {
@@ -1533,6 +2115,7 @@ static void schedule_connect(void *cls, const struct GNUNET_SCHEDULER_TaskContex
     }
 }
 
+
 /**
  * Iterator for actually scheduling connections to be created
  * between two peers.
@@ -1561,6 +2144,7 @@ connect_iterator (void *cls,
   return GNUNET_YES;
 }
 
+
 /**
  * Iterator for copying all entries in the allowed hashmap to the
  * connect hashmap.
@@ -1610,12 +2194,11 @@ copy_allowed_topology (struct GNUNET_TESTING_PeerGroup *pg)
 }
 
 
-/*
+/**
  * Connect the topology as specified by the PeerConnection's
  * of each peer in the peer group
  *
  * @param pg the peer group we are dealing with
- *
  * @return the number of connections that will be attempted
  */
 static int
@@ -1655,20 +2238,22 @@ connect_topology (struct GNUNET_TESTING_PeerGroup *pg)
 }
 
 
-/*
+/**
  * Takes a peer group and creates a topology based on the
  * one specified.  Creates a topology means generates friend
  * files for the peers so they can only connect to those allowed
  * by the topology.  This will only have an effect once peers
  * are started if the FRIENDS_ONLY option is set in the base
  * config.  Also takes an optional restrict topology which
- * disallows direct TCP connections UNLESS they are specified in
- * the restricted topology.
+ * disallows connections based on a particular transport
+ * UNLESS they are specified in the restricted topology.
  *
  * @param pg the peer group struct representing the running peers
  * @param topology which topology to connect the peers in
  * @param restrict_topology allow only direct TCP connections in this topology
  *                          use GNUNET_TESTING_TOPOLOGY_NONE for no restrictions
+ * @param restrict_transports space delimited list of transports to blacklist
+ *                            to create restricted topology
  *
  * @return the maximum number of connections were all allowed peers
  *         connected to each other
@@ -1676,14 +2261,14 @@ connect_topology (struct GNUNET_TESTING_PeerGroup *pg)
 int
 GNUNET_TESTING_create_topology (struct GNUNET_TESTING_PeerGroup *pg,
                                 enum GNUNET_TESTING_Topology topology,
-                                enum GNUNET_TESTING_Topology restrict_topology)
+                                enum GNUNET_TESTING_Topology restrict_topology,
+                                char *restrict_transports)
 {
   int ret;
   int num_connections;
   int unblacklisted_connections;
 
   GNUNET_assert (pg->notify_connection != NULL);
-  ret = GNUNET_OK;
 
   switch (topology)
     {
@@ -1743,46 +2328,53 @@ GNUNET_TESTING_create_topology (struct GNUNET_TESTING_PeerGroup *pg,
 #endif
       num_connections = create_scale_free (pg, &add_allowed_connections);
       break;
+    case GNUNET_TESTING_TOPOLOGY_LINE:
+#if VERBOSE_TESTING
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating straight line topology\n"));
+#endif
+      num_connections = create_line (pg, &add_allowed_connections);
+      break;
     case GNUNET_TESTING_TOPOLOGY_NONE:
+#if VERBOSE_TESTING
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating no allowed topology (all peers can connect at core level)\n"));
+#endif
       num_connections = 0;
       break;
     default:
       num_connections = 0;
       break;
     }
-  if (num_connections < 1)
+
+  if (num_connections < 0)
     return GNUNET_SYSERR;
 
   if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno (pg->cfg, "TESTING", "F2F"))
     {
       ret = create_and_copy_friend_files(pg);
-    }
-
-  if (ret != GNUNET_OK)
-    {
+      if (ret != GNUNET_OK)
+        {
 #if VERBOSE_TESTING
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  _("Failed during friend file copying!\n"));
+          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                      _("Failed during friend file copying!\n"));
 #endif
-      return GNUNET_SYSERR;
-    }
-  else
-    {
+          return GNUNET_SYSERR;
+        }
+      else
+        {
 #if VERBOSE_TESTING
-          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                      _("Friend files created/copied successfully!\n"));
+              GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                          _("Friend files created/copied successfully!\n"));
 #endif
+        }
     }
 
-  /**
-   * Use the create clique method to initially set all connections
-   * as blacklisted.
-   */
-  create_clique (pg, &blacklist_connections);
+  /* Use the create clique method to initially set all connections as blacklisted. */
+  if (restrict_topology != GNUNET_TESTING_TOPOLOGY_NONE)
+    create_clique (pg, &blacklist_connections);
   unblacklisted_connections = 0;
-  /**
-   * Un-blacklist connections as per the topology specified
-   */
+  /* Un-blacklist connections as per the topology specified */
   switch (restrict_topology)
     {
     case GNUNET_TESTING_TOPOLOGY_CLIQUE:
@@ -1841,15 +2433,25 @@ GNUNET_TESTING_create_topology (struct GNUNET_TESTING_PeerGroup *pg,
 #endif
       unblacklisted_connections = create_scale_free (pg, &unblacklist_connections);
       break;
+    case GNUNET_TESTING_TOPOLOGY_LINE:
+#if VERBOSE_TESTING
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Blacklisting all but straight line topology\n"));
+#endif
+      unblacklisted_connections = create_line (pg, &unblacklist_connections);
+      break;
     case GNUNET_TESTING_TOPOLOGY_NONE:
-      /* Fall through */
+#if VERBOSE_TESTING
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating no blacklist topology (all peers can connect at transport level)\n"));
+#endif
     default:
       break;
     }
 
-  if (unblacklisted_connections > 0)
+  if ((unblacklisted_connections > 0) && (restrict_transports != NULL))
   {
-    ret = create_and_copy_blacklist_files(pg);
+    ret = create_and_copy_blacklist_files(pg, restrict_transports);
     if (ret != GNUNET_OK)
       {
 #if VERBOSE_TESTING
@@ -1866,8 +2468,6 @@ GNUNET_TESTING_create_topology (struct GNUNET_TESTING_PeerGroup *pg,
 #endif
       }
   }
-
-
   return num_connections;
 }
 
@@ -1980,7 +2580,7 @@ random_connect_iterator (void *cls,
   uint32_t second_pos;
   GNUNET_HashCode first_hash;
   random_number = ((double) GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_WEAK,
-                   (uint64_t)-1LL)) / ( (double) (uint64_t) -1LL);
+                                                    UINT64_MAX)) / ( (double) UINT64_MAX);
   if (random_number < random_ctx->percentage)
   {
     GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(random_ctx->first->connect_peers_working_set, key, value, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
@@ -2105,27 +2705,29 @@ choose_random_connections(struct GNUNET_TESTING_PeerGroup *pg, double percentage
  * @param pg the peergroup we are dealing with
  * @param num how many connections at least should each peer have (if possible)?
  */
-void
+static void
 choose_minimum(struct GNUNET_TESTING_PeerGroup *pg, unsigned int num)
 {
   struct MinimumContext minimum_ctx;
   uint32_t pg_iter;
 
   for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
-    {
-      pg->peers[pg_iter].connect_peers_working_set = GNUNET_CONTAINER_multihashmap_create(num);
-    }
+   {
+     pg->peers[pg_iter].connect_peers_working_set = GNUNET_CONTAINER_multihashmap_create(num);
+   }
 
   for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
     {
       minimum_ctx.first_uid = pg_iter;
-      minimum_ctx.pg_array = GNUNET_CRYPTO_random_permute(GNUNET_CRYPTO_QUALITY_WEAK, GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers));
+      minimum_ctx.pg_array = GNUNET_CRYPTO_random_permute(GNUNET_CRYPTO_QUALITY_WEAK, 
+                                                         GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers));
       minimum_ctx.first = &pg->peers[pg_iter];
       minimum_ctx.pg = pg;
       minimum_ctx.num_to_add = num;
       minimum_ctx.current = 0;
-      pg->peers[pg_iter].connect_peers_working_set = GNUNET_CONTAINER_multihashmap_create(pg->total);
-      GNUNET_CONTAINER_multihashmap_iterate(pg->peers[pg_iter].connect_peers, &minimum_connect_iterator, &minimum_ctx);
+      GNUNET_CONTAINER_multihashmap_iterate(pg->peers[pg_iter].connect_peers,
+                                           &minimum_connect_iterator, 
+                                           &minimum_ctx);
     }
 
   for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
@@ -2134,13 +2736,13 @@ choose_minimum(struct GNUNET_TESTING_PeerGroup *pg, unsigned int num)
       GNUNET_CONTAINER_multihashmap_destroy(pg->peers[pg_iter].connect_peers);
       /* And replace with the working set */
       pg->peers[pg_iter].connect_peers = pg->peers[pg_iter].connect_peers_working_set;
-      fprintf(stderr, "Finished! Hashmap size %u\n", GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers));
     }
 
 }
 
 
-static unsigned int count_workingset_connections(struct GNUNET_TESTING_PeerGroup *pg)
+static unsigned int
+count_workingset_connections(struct GNUNET_TESTING_PeerGroup *pg)
 {
   unsigned int count;
   unsigned int pg_iter;
@@ -2231,28 +2833,248 @@ perform_dfs (struct GNUNET_TESTING_PeerGroup *pg, unsigned int num)
       starting_peer = dfs_ctx.second_uid;
     }
 
-  for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
-    {
-
-    }
-
   for (pg_iter = 0; pg_iter < pg->total; pg_iter++)
     {
       /* Remove the "old" connections */
       GNUNET_CONTAINER_multihashmap_destroy(pg->peers[pg_iter].connect_peers);
       /* And replace with the working set */
       pg->peers[pg_iter].connect_peers = pg->peers[pg_iter].connect_peers_working_set;
-      fprintf(stderr, "Finished! Hashmap size %u\n", GNUNET_CONTAINER_multihashmap_size(pg->peers[pg_iter].connect_peers));
+    }
+}
+
+/**
+ * Internal callback for topology information for a particular peer.
+ */
+static void
+internal_topology_callback(void *cls,
+                           const struct GNUNET_PeerIdentity *peer,
+                           struct GNUNET_TIME_Relative latency, uint32_t distance)
+{
+  struct CoreContext *core_ctx = cls;
+  struct TopologyIterateContext *iter_ctx = core_ctx->iter_context;
+
+  if (peer == NULL) /* Either finished, or something went wrong */
+    {
+      iter_ctx->completed++;
+      iter_ctx->connected--;
+      /* One core context allocated per iteration, must free! */
+      GNUNET_free(core_ctx);
+    }
+  else
+    {
+      iter_ctx->topology_cb(iter_ctx->cls, &core_ctx->daemon->id, peer, latency, distance, NULL);
     }
 
+  if (iter_ctx->completed == iter_ctx->total)
+    {
+      iter_ctx->topology_cb(iter_ctx->cls, NULL, NULL, GNUNET_TIME_relative_get_zero(), 0, NULL);
+      /* Once all are done, free the iteration context */
+      GNUNET_free(iter_ctx);
+    }
 }
 
-/*
- * @param pg the peer group struct representing the running peers
- * @param topology which topology to connect the peers in
- * @param options options for connecting the topology
- * @param option_modifier modifier for options that take a parameter
+
+/**
+ * Check running topology iteration tasks, if below max start a new one, otherwise
+ * schedule for some time in the future.
+ */
+static void
+schedule_get_topology(void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct CoreContext *core_context = cls;
+  struct TopologyIterateContext *topology_context = (struct TopologyIterateContext *)core_context->iter_context;
+  if (tc->reason == GNUNET_SCHEDULER_REASON_SHUTDOWN)
+    return;
+
+  if (topology_context->connected > MAX_OUTSTANDING_CONNECTIONS)
+    {
+#if VERBOSE_TESTING > 2
+          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                      _("Delaying connect, we have too many outstanding connections!\n"));
+#endif
+      GNUNET_SCHEDULER_add_delayed(core_context->daemon->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 100), &schedule_get_topology, core_context);
+    }
+  else
+    {
+#if VERBOSE_TESTING > 2
+          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                      _("Creating connection, outstanding_connections is %d\n"), outstanding_connects);
+#endif
+      topology_context->connected++;
+      if (GNUNET_OK != GNUNET_CORE_iterate_peers (core_context->daemon->sched, core_context->daemon->cfg, &internal_topology_callback, core_context))
+        internal_topology_callback(core_context, NULL, GNUNET_TIME_relative_get_zero(), 0);
+
+    }
+}
+
+/**
+ * Iterate over all (running) peers in the peer group, retrieve
+ * all connections that each currently has.
+ */
+void
+GNUNET_TESTING_get_topology (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_NotifyTopology cb, void *cls)
+{
+  struct TopologyIterateContext *topology_context;
+  struct CoreContext *core_ctx;
+  unsigned int i;
+  unsigned int total_count;
+
+  /* Allocate a single topology iteration context */
+  topology_context = GNUNET_malloc(sizeof(struct TopologyIterateContext));
+  topology_context->topology_cb = cb;
+  topology_context->cls = cls;
+  total_count = 0;
+  for (i = 0; i < pg->total; i++)
+    {
+      if (pg->peers[i].daemon->running == GNUNET_YES)
+        {
+          /* Allocate one core context per core we need to connect to */
+          core_ctx = GNUNET_malloc(sizeof(struct CoreContext));
+          core_ctx->daemon = pg->peers[i].daemon;
+          /* Set back pointer to topology iteration context */
+          core_ctx->iter_context = topology_context;
+          GNUNET_SCHEDULER_add_now(pg->sched, &schedule_get_topology, core_ctx);
+          total_count++;
+        }
+    }
+  topology_context->total = total_count;
+  return;
+}
+
+/**
+ * Callback function to process statistic values.
+ * This handler is here only really to insert a peer
+ * identity (or daemon) so the statistics can be uniquely
+ * tied to a single running peer.
+ *
+ * @param cls closure
+ * @param subsystem name of subsystem that created the statistic
+ * @param name the name of the datum
+ * @param value the current value
+ * @param is_persistent GNUNET_YES if the value is persistent, GNUNET_NO if not
+ * @return GNUNET_OK to continue, GNUNET_SYSERR to abort iteration
+ */
+static int internal_stats_callback (void *cls,
+                                    const char *subsystem,
+                                    const char *name,
+                                    uint64_t value,
+                                    int is_persistent)
+{
+  struct StatsCoreContext *core_context = cls;
+  struct StatsIterateContext *stats_context = (struct StatsIterateContext *)core_context->iter_context;
+
+  return stats_context->proc(stats_context->cls, &core_context->daemon->id, subsystem, name, value, is_persistent);
+}
+
+/**
+ * Internal continuation call for statistics iteration.
  *
+ * @param cls closure, the CoreContext for this iteration
+ * @param success whether or not the statistics iterations
+ *        was canceled or not (we don't care)
+ */
+static void internal_stats_cont (void *cls, int success)
+{
+  struct StatsCoreContext *core_context = cls;
+  struct StatsIterateContext *stats_context = (struct StatsIterateContext *)core_context->iter_context;
+
+  stats_context->connected--;
+  stats_context->completed++;
+
+  if (stats_context->completed == stats_context->total)
+    {
+      stats_context->cont(stats_context->cls, GNUNET_YES);
+      GNUNET_free(stats_context);
+    }
+
+  if (core_context->stats_handle != NULL)
+    GNUNET_STATISTICS_destroy(core_context->stats_handle, GNUNET_NO);
+
+  GNUNET_free(core_context);
+}
+
+/**
+ * Check running topology iteration tasks, if below max start a new one, otherwise
+ * schedule for some time in the future.
+ */
+static void
+schedule_get_statistics(void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct StatsCoreContext *core_context = cls;
+  struct StatsIterateContext *stats_context = (struct StatsIterateContext *)core_context->iter_context;
+
+  if (tc->reason == GNUNET_SCHEDULER_REASON_SHUTDOWN)
+    return;
+
+  if (stats_context->connected > MAX_OUTSTANDING_CONNECTIONS)
+    {
+#if VERBOSE_TESTING > 2
+          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                      _("Delaying connect, we have too many outstanding connections!\n"));
+#endif
+      GNUNET_SCHEDULER_add_delayed(core_context->daemon->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 100), &schedule_get_statistics, core_context);
+    }
+  else
+    {
+#if VERBOSE_TESTING > 2
+          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                      _("Creating connection, outstanding_connections is %d\n"), outstanding_connects);
+#endif
+
+      stats_context->connected++;
+      core_context->stats_handle = GNUNET_STATISTICS_create(core_context->daemon->sched, "testing", core_context->daemon->cfg);
+      if (core_context->stats_handle == NULL)
+        {
+          internal_stats_cont (core_context, GNUNET_NO);
+          return;
+        }
+
+      core_context->stats_get_handle = GNUNET_STATISTICS_get(core_context->stats_handle, NULL, NULL, GNUNET_TIME_relative_get_forever(), &internal_stats_cont, &internal_stats_callback, core_context);
+      if (core_context->stats_get_handle == NULL)
+        internal_stats_cont (core_context, GNUNET_NO);
+
+    }
+}
+
+
+/**
+ * Iterate over all (running) peers in the peer group, retrieve
+ * all statistics from each.
+ */
+void
+GNUNET_TESTING_get_statistics (struct GNUNET_TESTING_PeerGroup *pg,
+                               GNUNET_STATISTICS_Callback cont,
+                               GNUNET_TESTING_STATISTICS_Iterator proc, void *cls)
+{
+  struct StatsIterateContext *stats_context;
+  struct StatsCoreContext *core_ctx;
+  unsigned int i;
+  unsigned int total_count;
+
+  /* Allocate a single stats iteration context */
+  stats_context = GNUNET_malloc(sizeof(struct StatsIterateContext));
+  stats_context->cont = cont;
+  stats_context->proc = proc;
+  stats_context->cls = cls;
+  total_count = 0;
+  for (i = 0; i < pg->total; i++)
+    {
+      if (pg->peers[i].daemon->running == GNUNET_YES)
+        {
+          /* Allocate one core context per core we need to connect to */
+          core_ctx = GNUNET_malloc(sizeof(struct StatsCoreContext));
+          core_ctx->daemon = pg->peers[i].daemon;
+          /* Set back pointer to topology iteration context */
+          core_ctx->iter_context = stats_context;
+          GNUNET_SCHEDULER_add_now(pg->sched, &schedule_get_statistics, core_ctx);
+          total_count++;
+        }
+    }
+  stats_context->total = total_count;
+  return;
+}
+
+/**
  * There are many ways to connect peers that are supported by this function.
  * To connect peers in the same topology that was created via the
  * GNUNET_TESTING_create_topology, the topology variable must be set to
@@ -2261,6 +3083,11 @@ perform_dfs (struct GNUNET_TESTING_PeerGroup *pg, unsigned int num)
  * connected.  This could result in some connections being impossible,
  * because some topologies are non-deterministic.
  *
+ * @param pg the peer group struct representing the running peers
+ * @param topology which topology to connect the peers in
+ * @param options options for connecting the topology
+ * @param option_modifier modifier for options that take a parameter
+ * @return the number of connections that will be attempted, GNUNET_SYSERR on error
  */
 int
 GNUNET_TESTING_connect_topology (struct GNUNET_TESTING_PeerGroup *pg,
@@ -2268,89 +3095,111 @@ GNUNET_TESTING_connect_topology (struct GNUNET_TESTING_PeerGroup *pg,
                                  enum GNUNET_TESTING_TopologyOption options,
                                  double option_modifier)
 {
-  int num_connections;
-
   switch (topology)
       {
       case GNUNET_TESTING_TOPOLOGY_CLIQUE:
-  #if VERBOSE_TESTING
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    _("Creating clique topology\n"));
-  #endif
-        num_connections = create_clique (pg, &add_actual_connections);
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating clique CONNECT topology\n"));
+#endif
+        create_clique (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_SMALL_WORLD_RING:
-  #if VERBOSE_TESTING
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    _("Creating small world (ring) topology\n"));
-  #endif
-        num_connections = create_small_world_ring (pg, &add_actual_connections);
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating small world (ring) CONNECT topology\n"));
+#endif
+        create_small_world_ring (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_SMALL_WORLD:
-  #if VERBOSE_TESTING
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    _("Creating small world (2d-torus) topology\n"));
-  #endif
-        num_connections = create_small_world (pg, &add_actual_connections);
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating small world (2d-torus) CONNECT topology\n"));
+#endif
+        create_small_world (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_RING:
-  #if VERBOSE_TESTING
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    _("Creating ring topology\n"));
-  #endif
-        num_connections = create_ring (pg, &add_actual_connections);
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating ring CONNECT topology\n"));
+#endif
+        create_ring (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_2D_TORUS:
-  #if VERBOSE_TESTING
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    _("Creating 2d torus topology\n"));
-  #endif
-        num_connections = create_2d_torus (pg, &add_actual_connections);
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating 2d torus CONNECT topology\n"));
+#endif
+        create_2d_torus (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_ERDOS_RENYI:
-  #if VERBOSE_TESTING
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    _("Creating Erdos-Renyi topology\n"));
-  #endif
-        num_connections = create_erdos_renyi (pg, &add_actual_connections);
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating Erdos-Renyi CONNECT topology\n"));
+#endif
+        create_erdos_renyi (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_INTERNAT:
-  #if VERBOSE_TESTING
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    _("Creating InterNAT topology\n"));
-  #endif
-        num_connections = create_nated_internet (pg, &add_actual_connections);
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating InterNAT CONNECT topology\n"));
+#endif
+        create_nated_internet (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_SCALE_FREE:
-  #if VERBOSE_TESTING
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    _("Creating Scale Free topology\n"));
-  #endif
-        num_connections = create_scale_free (pg, &add_actual_connections);
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating Scale Free CONNECT topology\n"));
+#endif
+        create_scale_free (pg, &add_actual_connections);
+        break;
+      case GNUNET_TESTING_TOPOLOGY_LINE:
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating straight line CONNECT topology\n"));
+#endif
+        create_line (pg, &add_actual_connections);
         break;
       case GNUNET_TESTING_TOPOLOGY_NONE:
-        num_connections = copy_allowed_topology(pg);
+#if VERBOSE_TOPOLOGY
+        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Creating no CONNECT topology\n"));
+#endif
+        copy_allowed_topology(pg);
         break;
       default:
-        GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Unknown topology specification, can't connect peers!\n");
+        GNUNET_log(GNUNET_ERROR_TYPE_WARNING, 
+                  _("Unknown topology specification, can't connect peers!\n"));
         return GNUNET_SYSERR;
       }
 
   switch (options)
     {
-    case GNUNET_TESTING_TOPOLOGY_OPTION_RANDOM: /* Create a random subset of total connections based on parameter */
+    case GNUNET_TESTING_TOPOLOGY_OPTION_RANDOM:
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Connecting random subset (%'.2f percent) of possible peers\n"), 100 * option_modifier);
+#endif
       choose_random_connections(pg, option_modifier);
       break;
-    case GNUNET_TESTING_TOPOLOGY_OPTION_MINIMUM: /* Create at least X connections per peer (if possible!) */
+    case GNUNET_TESTING_TOPOLOGY_OPTION_MINIMUM:
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Connecting a minimum of %u peers each (if possible)\n"), (unsigned int)option_modifier);
+#endif
       choose_minimum(pg, (unsigned int)option_modifier);
       break;
-    case GNUNET_TESTING_TOPOLOGY_OPTION_DFS: /* Choose a random starting point, randomly walk graph, try to get each peer X connections */
+    case GNUNET_TESTING_TOPOLOGY_OPTION_DFS:
+#if VERBOSE_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  _("Using DFS to connect a minimum of %u peers each (if possible)\n"), (unsigned int)option_modifier);
+#endif
       perform_dfs(pg, (int)option_modifier);
       break;
     case GNUNET_TESTING_TOPOLOGY_OPTION_NONE:
-      /* Fall through */
+      break;
     case GNUNET_TESTING_TOPOLOGY_OPTION_ALL:
-      /* Fall through */
+      break;
     default:
       break;
     }
@@ -2358,6 +3207,104 @@ GNUNET_TESTING_connect_topology (struct GNUNET_TESTING_PeerGroup *pg,
   return connect_topology(pg);
 }
 
+/**
+ * Callback that is called whenever a hostkey is generated
+ * for a peer.  Call the real callback and decrement the
+ * starting counter for the peergroup.
+ *
+ * @param cls closure
+ * @param id identifier for the daemon, NULL on error
+ * @param d handle for the daemon
+ * @param emsg error message (NULL on success)
+ */
+static void internal_hostkey_callback (void *cls,
+                                       const struct GNUNET_PeerIdentity *id,
+                                       struct GNUNET_TESTING_Daemon *d,
+                                       const char *emsg)
+{
+  struct InternalStartContext *internal_context = cls;
+  internal_context->peer->pg->starting--;
+  internal_context->peer->pg->started++;
+  if (internal_context->hostkey_callback != NULL)
+    internal_context->hostkey_callback(internal_context->hostkey_cls, id, d, emsg);
+  else if (internal_context->peer->pg->started == internal_context->peer->pg->total)
+    {
+      internal_context->peer->pg->started = 0; /* Internal startup may use this counter! */
+      GNUNET_TESTING_daemons_continue_startup(internal_context->peer->pg);
+    }
+}
+
+/**
+ * Callback that is called whenever a peer has finished starting.
+ * Call the real callback and decrement the starting counter
+ * for the peergroup.
+ *
+ * @param cls closure
+ * @param id identifier for the daemon, NULL on error
+ * @param d handle for the daemon
+ * @param emsg error message (NULL on success)
+ */
+static void internal_startup_callback (void *cls,
+                                       const struct GNUNET_PeerIdentity *id,
+                                       const struct GNUNET_CONFIGURATION_Handle *cfg,
+                                       struct GNUNET_TESTING_Daemon *d,
+                                       const char *emsg)
+{
+  struct InternalStartContext *internal_context = cls;
+  internal_context->peer->pg->starting--;
+  if (internal_context->start_cb != NULL)
+    internal_context->start_cb(internal_context->start_cb_cls, id, cfg, d, emsg);
+}
+
+static void
+internal_continue_startup (void *cls, const struct GNUNET_SCHEDULER_TaskContext * tc)
+{
+  struct InternalStartContext *internal_context = cls;
+
+  if (tc->reason == GNUNET_SCHEDULER_REASON_SHUTDOWN)
+    {
+      return;
+    }
+
+  if (internal_context->peer->pg->starting < MAX_CONCURRENT_STARTING)
+    {
+      internal_context->peer->pg->starting++;
+      GNUNET_TESTING_daemon_continue_startup (internal_context->peer->daemon);
+    }
+  else
+    {
+      GNUNET_SCHEDULER_add_delayed(internal_context->peer->pg->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 100), &internal_continue_startup, internal_context);
+    }
+}
+
+static void
+internal_start (void *cls, const struct GNUNET_SCHEDULER_TaskContext * tc)
+{
+  struct InternalStartContext *internal_context = cls;
+
+  if (tc->reason == GNUNET_SCHEDULER_REASON_SHUTDOWN)
+    {
+      return;
+    }
+
+  if (internal_context->peer->pg->starting < MAX_CONCURRENT_HOSTKEYS)
+    {
+      internal_context->peer->pg->starting++;
+      internal_context->peer->daemon = GNUNET_TESTING_daemon_start (internal_context->peer->pg->sched,
+                                                                    internal_context->peer->cfg,
+                                                                    internal_context->timeout,
+                                                                    internal_context->hostname,
+                                                                    &internal_hostkey_callback,
+                                                                    internal_context,
+                                                                    &internal_startup_callback,
+                                                                    internal_context);
+    }
+  else
+    {
+      GNUNET_SCHEDULER_add_delayed(internal_context->peer->pg->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 100), &internal_start, internal_context);
+    }
+}
+
 /**
  * Function which continues a peer group starting up
  * after successfully generating hostkeys for each peer.
@@ -2370,14 +3317,16 @@ GNUNET_TESTING_daemons_continue_startup(struct GNUNET_TESTING_PeerGroup *pg)
 {
   unsigned int i;
 
+  pg->starting = 0;
   for (i = 0; i < pg->total; i++)
     {
-      GNUNET_TESTING_daemon_continue_startup(pg->peers[i].daemon);
+      GNUNET_SCHEDULER_add_now (pg->sched, &internal_continue_startup, &pg->peers[i].internal_context);
+      //GNUNET_TESTING_daemon_continue_startup(pg->peers[i].daemon);
     }
 }
 
 /**
- * Start count gnunetd processes with the same set of transports and
+ * Start count gnunet instances with the same set of transports and
  * applications.  The port numbers (any option called "PORT") will be
  * adjusted to ensure that no two peers running on the same system
  * have the same port(s) in their respective configurations.
@@ -2395,8 +3344,8 @@ GNUNET_TESTING_daemons_continue_startup(struct GNUNET_TESTING_PeerGroup *pg)
  * @param cb_cls closure for cb
  * @param connect_callback function to call each time two hosts are connected
  * @param connect_callback_cls closure for connect_callback
- * @param hostnames space-separated list of hostnames to use; can be NULL (to run
- *        everything on localhost).
+ * @param hostnames linked list of hosts to use to start peers on (NULL to run on localhost only)
+ *
  * @return NULL on error, otherwise handle to control peer group
  */
 struct GNUNET_TESTING_PeerGroup *
@@ -2410,12 +3359,15 @@ GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
                               void *cb_cls,
                               GNUNET_TESTING_NotifyConnection
                               connect_callback, void *connect_callback_cls,
-                              const char *hostnames)
+                              const struct GNUNET_TESTING_Host *hostnames)
 {
   struct GNUNET_TESTING_PeerGroup *pg;
-  const char *rpos;
+  const struct GNUNET_TESTING_Host *hostpos;
+#if 0
   char *pos;
+  const char *rpos;
   char *start;
+#endif
   const char *hostname;
   char *baseservicehome;
   char *newservicehome;
@@ -2424,18 +3376,17 @@ GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
   unsigned int off;
   unsigned int hostcnt;
   uint16_t minport;
+  uint32_t upnum;
 
   if (0 == total)
     {
       GNUNET_break (0);
       return NULL;
     }
-
+  upnum = 0;
   pg = GNUNET_malloc (sizeof (struct GNUNET_TESTING_PeerGroup));
   pg->sched = sched;
   pg->cfg = cfg;
-  pg->cb = cb;
-  pg->cb_cls = cb_cls;
   pg->notify_connection = connect_callback;
   pg->notify_connection_cls = connect_callback_cls;
   pg->total = total;
@@ -2443,14 +3394,41 @@ GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
   pg->peers = GNUNET_malloc (total * sizeof (struct PeerData));
   if (NULL != hostnames)
     {
+      off = 2;
+      hostpos = hostnames;
+      while (hostpos != NULL)
+        {
+          hostpos = hostpos->next;
+          off++;
+        }
+      pg->hosts = GNUNET_malloc (off * sizeof (struct HostData));
+      off = 0;
+
+      hostpos = hostnames;
+      while (hostpos != NULL)
+        {
+          pg->hosts[off].minport = LOW_PORT;
+          pg->hosts[off++].hostname = GNUNET_strdup(hostpos->hostname);
+          hostpos = hostpos->next;
+        }
+
+      if (off == 0)
+        {
+          GNUNET_free (pg->hosts);
+          pg->hosts = NULL;
+        }
+      hostcnt = off;
+      minport = 0;
+
+#if NO_LL
       off = 2;
       /* skip leading spaces */
-      while ((0 != *hostnames) && (isspace (*hostnames)))
+      while ((0 != *hostnames) && (isspace ( (unsigned char) *hostnames)))
         hostnames++;
       rpos = hostnames;
       while ('\0' != *rpos)
         {
-          if (isspace (*rpos))
+          if (isspace ( (unsigned char) *rpos))
             off++;
           rpos++;
         }
@@ -2460,7 +3438,7 @@ GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
       pos = start;
       while ('\0' != *pos)
         {
-          if (isspace (*pos))
+          if (isspace ( (unsigned char) *pos))
             {
               *pos = '\0';
               if (strlen (start) > 0)
@@ -2485,6 +3463,7 @@ GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
         }
       hostcnt = off;
       minport = 0;              /* make gcc happy */
+#endif
     }
   else
     {
@@ -2496,12 +3475,18 @@ GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
       if (hostcnt > 0)
         {
           hostname = pg->hosts[off % hostcnt].hostname;
-          pcfg = make_config (cfg, &pg->hosts[off % hostcnt].minport, hostname);
+          pcfg = make_config (cfg, 
+                             &pg->hosts[off % hostcnt].minport,
+                             &upnum,
+                             hostname);
         }
       else
         {
           hostname = NULL;
-          pcfg = make_config (cfg, &minport, hostname);
+          pcfg = make_config (cfg,
+                             &minport,
+                             &upnum,
+                             hostname);
         }
 
       if (NULL == pcfg)
@@ -2539,16 +3524,16 @@ GNUNET_TESTING_daemons_start (struct GNUNET_SCHEDULER_Handle *sched,
       pg->peers[off].connect_peers = GNUNET_CONTAINER_multihashmap_create(total);
       pg->peers[off].blacklisted_peers = GNUNET_CONTAINER_multihashmap_create(total);
       pg->peers[off].pg = pg;
-      pg->peers[off].daemon = GNUNET_TESTING_daemon_start (sched,
-                                                           pcfg,
-                                                           timeout,
-                                                           hostname,
-                                                           hostkey_callback,
-                                                           hostkey_cls,
-                                                           cb, cb_cls);
-      if (NULL == pg->peers[off].daemon)
-        GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                    _("Could not start peer number %u!\n"), off);
+
+      pg->peers[off].internal_context.peer = &pg->peers[off];
+      pg->peers[off].internal_context.timeout = timeout;
+      pg->peers[off].internal_context.hostname = hostname;
+      pg->peers[off].internal_context.hostkey_callback = hostkey_callback;
+      pg->peers[off].internal_context.hostkey_cls = hostkey_cls;
+      pg->peers[off].internal_context.start_cb = cb;
+      pg->peers[off].internal_context.start_cb_cls = cb_cls;
+
+      GNUNET_SCHEDULER_add_now (sched, &internal_start, &pg->peers[off].internal_context);
 
     }
   return pg;
@@ -2567,10 +3552,34 @@ GNUNET_TESTING_daemon_get (struct GNUNET_TESTING_PeerGroup *pg, unsigned int pos
     return NULL;
 }
 
+/*
+ * Get a daemon by peer identity, so callers can
+ * retrieve the daemon without knowing it's offset.
+ *
+ * @param pg the peer group to retrieve the daemon from
+ * @param peer_id the peer identity of the daemon to retrieve
+ *
+ * @return the daemon on success, or NULL if no such peer identity is found
+ */
+struct GNUNET_TESTING_Daemon *
+GNUNET_TESTING_daemon_get_by_id (struct GNUNET_TESTING_PeerGroup *pg, struct GNUNET_PeerIdentity *peer_id)
+{
+  unsigned int i;
+
+  for (i = 0; i < pg->total; i ++)
+    {
+      if (0 == memcmp(&pg->peers[i].daemon->id, peer_id, sizeof(struct GNUNET_PeerIdentity)))
+        return pg->peers[i].daemon;
+    }
+
+  return NULL;
+}
+
 /**
  * Prototype of a function that will be called when a
  * particular operation was completed the testing library.
  *
+ * @param cls closure (a struct RestartContext)
  * @param id id of the peer that was restarted
  * @param cfg handle to the configuration of the peer
  * @param d handle to the daemon that was restarted
@@ -2606,16 +3615,274 @@ void restart_callback (void *cls,
 
 }
 
+/**
+ * Callback for informing us about a successful
+ * or unsuccessful churn stop call.
+ *
+ * @param cls a ChurnContext
+ * @param emsg NULL on success, non-NULL on failure
+ *
+ */
+void
+churn_stop_callback (void *cls, const char *emsg)
+{
+  struct ChurnContext *churn_ctx = cls;
+  unsigned int total_left;
+  char *error_message;
+
+  error_message = NULL;
+  if (emsg != NULL)
+    {
+      GNUNET_log(GNUNET_ERROR_TYPE_WARNING, 
+                "Churn stop callback failed with error `%s'\n", emsg);
+      churn_ctx->num_failed_stop++;
+    }
+  else
+    {
+      churn_ctx->num_to_stop--;
+    }
+
+#if DEBUG_CHURN
+  GNUNET_log(GNUNET_ERROR_TYPE_WARNING, 
+            "Stopped peer, %d left.\n", 
+            churn_ctx->num_to_stop);
+#endif
+  total_left = (churn_ctx->num_to_stop - churn_ctx->num_failed_stop) + (churn_ctx->num_to_start - churn_ctx->num_failed_start);
+
+  if (total_left == 0)
+  {
+    if ((churn_ctx->num_failed_stop > 0) || (churn_ctx->num_failed_start > 0))
+      {
+        GNUNET_asprintf(&error_message, 
+                       "Churn didn't complete successfully, %u peers failed to start %u peers failed to be stopped!", 
+                       churn_ctx->num_failed_start, 
+                       churn_ctx->num_failed_stop);
+      }
+    churn_ctx->cb(churn_ctx->cb_cls, error_message);
+    GNUNET_free_non_null(error_message);
+    GNUNET_free(churn_ctx);
+  }
+}
+
+/**
+ * Callback for informing us about a successful
+ * or unsuccessful churn start call.
+ *
+ * @param cls a ChurnContext
+ * @param id the peer identity of the started peer
+ * @param cfg the handle to the configuration of the peer
+ * @param d handle to the daemon for the peer
+ * @param emsg NULL on success, non-NULL on failure
+ *
+ */
+void
+churn_start_callback (void *cls,
+                      const struct GNUNET_PeerIdentity *id,
+                      const struct GNUNET_CONFIGURATION_Handle *cfg,
+                      struct GNUNET_TESTING_Daemon *d,
+                      const char *emsg)
+{
+  struct ChurnContext *churn_ctx = cls;
+  unsigned int total_left;
+  char *error_message;
+
+  error_message = NULL;
+  if (emsg != NULL)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING, 
+                 "Churn stop callback failed with error `%s'\n",
+                 emsg);
+      churn_ctx->num_failed_start++;
+    }
+  else
+    {
+      churn_ctx->num_to_start--;
+    }
+  
+#if DEBUG_CHURN
+  GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
+            "Started peer, %d left.\n", 
+            churn_ctx->num_to_start);
+#endif
+
+  total_left = (churn_ctx->num_to_stop - churn_ctx->num_failed_stop) + (churn_ctx->num_to_start - churn_ctx->num_failed_start);
+
+  if (total_left == 0)
+  {
+    if ((churn_ctx->num_failed_stop > 0) || (churn_ctx->num_failed_start > 0))
+      GNUNET_asprintf(&error_message, 
+                     "Churn didn't complete successfully, %u peers failed to start %u peers failed to be stopped!", 
+                     churn_ctx->num_failed_start,
+                     churn_ctx->num_failed_stop);
+    churn_ctx->cb(churn_ctx->cb_cls, error_message);
+    GNUNET_free_non_null(error_message);
+    GNUNET_free(churn_ctx);
+  }
+}
+
+
+/**
+ * Simulate churn by stopping some peers (and possibly
+ * re-starting others if churn is called multiple times).  This
+ * function can only be used to create leave-join churn (peers "never"
+ * leave for good).  First "voff" random peers that are currently
+ * online will be taken offline; then "von" random peers that are then
+ * offline will be put back online.  No notifications will be
+ * generated for any of these operations except for the callback upon
+ * completion.
+ *
+ * @param pg handle for the peer group
+ * @param voff number of peers that should go offline
+ * @param von number of peers that should come back online;
+ *            must be zero on first call (since "testbed_start"
+ *            always starts all of the peers)
+ * @param timeout how long to wait for operations to finish before
+ *        giving up
+ * @param cb function to call at the end
+ * @param cb_cls closure for cb
+ */
+void
+GNUNET_TESTING_daemons_churn (struct GNUNET_TESTING_PeerGroup *pg,
+                              unsigned int voff,
+                              unsigned int von,
+                              struct GNUNET_TIME_Relative timeout,
+                              GNUNET_TESTING_NotifyCompletion cb,
+                              void *cb_cls)
+{
+  struct ChurnContext *churn_ctx;
+  unsigned int running;
+  unsigned int stopped;
+  unsigned int total_running;
+  unsigned int total_stopped;
+  unsigned int i;
+  unsigned int *running_arr;
+  unsigned int *stopped_arr;
+  unsigned int *running_permute;
+  unsigned int *stopped_permute;
+
+  running = 0;
+  stopped = 0;
+
+  if ((von == 0) && (voff == 0)) /* No peers at all? */
+    {
+      cb(cb_cls, NULL);
+      return;
+    }
+
+  for (i = 0; i < pg->total; i++)
+  {
+    if (pg->peers[i].daemon->running == GNUNET_YES)
+    {
+      GNUNET_assert(running != -1);
+      running++;
+    }
+    else
+    {
+      GNUNET_assert(stopped != -1);
+      stopped++;
+    }
+  }
+
+  if (voff > running)
+  {
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Trying to stop more peers than are currently running!\n");
+    cb(cb_cls, "Trying to stop more peers than are currently running!");
+    return;
+  }
+
+  if (von > stopped)
+  {
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Trying to start more peers than are currently stopped!\n");
+    cb(cb_cls, "Trying to start more peers than are currently stopped!");
+    return;
+  }
+
+  churn_ctx = GNUNET_malloc(sizeof(struct ChurnContext));
+
+  running_arr = NULL;
+  if (running > 0)
+    running_arr = GNUNET_malloc(running * sizeof(unsigned int));
+
+  stopped_arr = NULL;
+  if (stopped > 0)
+    stopped_arr = GNUNET_malloc(stopped * sizeof(unsigned int));
+
+  running_permute = NULL;
+  stopped_permute = NULL;
+
+  if (running > 0)
+    running_permute = GNUNET_CRYPTO_random_permute(GNUNET_CRYPTO_QUALITY_WEAK, running);
+  if (stopped > 0)
+    stopped_permute = GNUNET_CRYPTO_random_permute(GNUNET_CRYPTO_QUALITY_WEAK, stopped);
+
+  total_running = running;
+  total_stopped = stopped;
+  running = 0;
+  stopped = 0;
+
+  churn_ctx->num_to_start = von;
+  churn_ctx->num_to_stop = voff;
+  churn_ctx->cb = cb;
+  churn_ctx->cb_cls = cb_cls;  
+
+  for (i = 0; i < pg->total; i++)
+  {
+    if (pg->peers[i].daemon->running == GNUNET_YES)
+    {
+      GNUNET_assert((running_arr != NULL) && (total_running > running));
+      running_arr[running] = i;
+      running++;
+    }
+    else
+    {
+      GNUNET_assert((stopped_arr != NULL) && (total_stopped > stopped));
+      stopped_arr[stopped] = i;
+      stopped++;
+    }
+  }
+
+  GNUNET_assert(running >= voff);
+  for (i = 0; i < voff; i++)
+  {
+#if DEBUG_CHURN
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Stopping peer %d!\n", running_permute[i]);
+#endif
+    GNUNET_assert(running_arr != NULL);
+    GNUNET_TESTING_daemon_stop (pg->peers[running_arr[running_permute[i]]].daemon,
+                               timeout, 
+                               &churn_stop_callback, churn_ctx, 
+                               GNUNET_NO, GNUNET_YES);
+  }
+
+  GNUNET_assert(stopped >= von);
+  for (i = 0; i < von; i++)
+    {
+#if DEBUG_CHURN
+      GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Starting up peer %d!\n", stopped_permute[i]);
+#endif
+      GNUNET_assert(stopped_arr != NULL);
+      GNUNET_TESTING_daemon_start_stopped(pg->peers[stopped_arr[stopped_permute[i]]].daemon, 
+                                         timeout, &churn_start_callback, churn_ctx);
+  }
+
+  GNUNET_free_non_null(running_arr);
+  GNUNET_free_non_null(stopped_arr);
+  GNUNET_free_non_null(running_permute);
+  GNUNET_free_non_null(stopped_permute);
+}
+
+
 /**
  * Restart all peers in the given group.
  *
  * @param pg the handle to the peer group
- * @param timeout how long to wait on failure
  * @param callback function to call on completion (or failure)
  * @param callback_cls closure for the callback function
  */
 void
-GNUNET_TESTING_daemons_restart (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TESTING_NotifyCompletion callback, void *callback_cls)
+GNUNET_TESTING_daemons_restart (struct GNUNET_TESTING_PeerGroup *pg,
+                                GNUNET_TESTING_NotifyCompletion callback,
+                                void *callback_cls)
 {
   struct RestartContext *restart_context;
   unsigned int off;
@@ -2636,36 +3903,173 @@ GNUNET_TESTING_daemons_restart (struct GNUNET_TESTING_PeerGroup *pg, GNUNET_TEST
 }
 
 /**
- * Shutdown all peers started in the given group.
+ * Start or stop an individual peer from the given group.
  *
  * @param pg handle to the peer group
+ * @param offset which peer to start or stop
+ * @param desired_status GNUNET_YES to have it running, GNUNET_NO to stop it
  * @param timeout how long to wait for shutdown
+ * @param cb function to call at the end
+ * @param cb_cls closure for cb
+ */
+void
+GNUNET_TESTING_daemons_vary (struct GNUNET_TESTING_PeerGroup *pg, 
+                            unsigned int offset,
+                            int desired_status,
+                            struct GNUNET_TIME_Relative timeout,
+                            GNUNET_TESTING_NotifyCompletion cb,
+                            void *cb_cls)
+{
+  struct ChurnContext *churn_ctx;
+
+  if (GNUNET_NO == desired_status)
+    {
+      if (NULL != pg->peers[offset].daemon)
+       {
+         churn_ctx = GNUNET_malloc(sizeof(struct ChurnContext));
+         churn_ctx->num_to_start = 0;
+         churn_ctx->num_to_stop = 1;
+         churn_ctx->cb = cb;
+         churn_ctx->cb_cls = cb_cls;  
+         GNUNET_TESTING_daemon_stop(pg->peers[offset].daemon, 
+                                    timeout, &churn_stop_callback, churn_ctx, 
+                                    GNUNET_NO, GNUNET_YES);     
+       }
+    }
+  else if (GNUNET_YES == desired_status)
+    {
+      if (NULL == pg->peers[offset].daemon)
+       {
+         churn_ctx = GNUNET_malloc(sizeof(struct ChurnContext));
+         churn_ctx->num_to_start = 1;
+         churn_ctx->num_to_stop = 0;
+         churn_ctx->cb = cb;
+         churn_ctx->cb_cls = cb_cls;  
+         GNUNET_TESTING_daemon_start_stopped(pg->peers[offset].daemon, 
+                                             timeout, &churn_start_callback, churn_ctx);
+       }
+    }
+  else
+    GNUNET_break (0);
+}
+
+
+/**
+ * Callback for shutting down peers in a peer group.
+ *
+ * @param cls closure (struct ShutdownContext)
+ * @param emsg NULL on success
+ */
+void internal_shutdown_callback (void *cls,
+                                 const char *emsg)
+{
+  struct ShutdownContext *shutdown_ctx = cls;
+
+  shutdown_ctx->outstanding--;
+  if (emsg == NULL)
+    {
+      shutdown_ctx->peers_down++;
+    }
+  else
+    {
+      shutdown_ctx->peers_failed++;
+    }
+
+  if ((shutdown_ctx->cb != NULL) && (shutdown_ctx->peers_down + shutdown_ctx->peers_failed == shutdown_ctx->total_peers))
+    {
+      if (shutdown_ctx->peers_failed > 0)
+        shutdown_ctx->cb(shutdown_ctx->cb_cls, "Not all peers successfully shut down!");
+      else
+        shutdown_ctx->cb(shutdown_ctx->cb_cls, NULL);
+      GNUNET_free(shutdown_ctx);
+    }
+}
+
+/**
+ * Individual shutdown context for a particular peer.
+ */
+struct PeerShutdownContext
+{
+  /**
+   * Pointer to the high level shutdown context.
+   */
+  struct ShutdownContext *shutdown_ctx;
+
+  /**
+   * The daemon handle for the peer to shut down.
+   */
+  struct GNUNET_TESTING_Daemon *daemon;
+};
+
+/**
+ * Task to rate limit the number of outstanding peer shutdown
+ * requests.  This is necessary for making sure we don't do
+ * too many ssh connections at once, but is generally nicer
+ * to any system as well (graduated task starts, as opposed
+ * to calling gnunet-arm N times all at once).
+ */
+static void
+schedule_shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext * tc)
+{
+  struct PeerShutdownContext *peer_shutdown_ctx = cls;
+  struct ShutdownContext *shutdown_ctx;
+
+  GNUNET_assert(peer_shutdown_ctx != NULL);
+  shutdown_ctx = peer_shutdown_ctx->shutdown_ctx;
+  GNUNET_assert(shutdown_ctx != NULL);
+
+  if (shutdown_ctx->outstanding > MAX_CONCURRENT_SHUTDOWN)
+    GNUNET_SCHEDULER_add_delayed(peer_shutdown_ctx->daemon->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 100), &schedule_shutdown_task, peer_shutdown_ctx);
+  else
+    {
+      shutdown_ctx->outstanding++;
+      GNUNET_TESTING_daemon_stop (peer_shutdown_ctx->daemon, shutdown_ctx->timeout, &internal_shutdown_callback, shutdown_ctx, GNUNET_YES, GNUNET_NO);
+      GNUNET_free(peer_shutdown_ctx);
+    }
+}
+/**
+ * Shutdown all peers started in the given group.
  *
+ * @param pg handle to the peer group
+ * @param timeout how long to wait for shutdown
+ * @param cb callback to notify upon success or failure
+ * @param cb_cls closure for cb
  */
 void
-GNUNET_TESTING_daemons_stop (struct GNUNET_TESTING_PeerGroup *pg, struct GNUNET_TIME_Relative timeout)
+GNUNET_TESTING_daemons_stop (struct GNUNET_TESTING_PeerGroup *pg, 
+                            struct GNUNET_TIME_Relative timeout,
+                            GNUNET_TESTING_NotifyCompletion cb,
+                             void *cb_cls)
 {
   unsigned int off;
+  struct ShutdownContext *shutdown_ctx;
+  struct PeerShutdownContext *peer_shutdown_ctx;
+
+  GNUNET_assert(pg->total > 0);
+
+  shutdown_ctx = GNUNET_malloc(sizeof(struct ShutdownContext));
+  shutdown_ctx->cb = cb;
+  shutdown_ctx->cb_cls = cb_cls;
+  shutdown_ctx->total_peers = pg->total;
+  shutdown_ctx->timeout = timeout;
+  /* shtudown_ctx->outstanding = 0; */
 
   for (off = 0; off < pg->total; off++)
     {
-      /* FIXME: should we wait for our
-         continuations to be called here? This
-         would require us to take a continuation
-         as well... */
-
-      if (NULL != pg->peers[off].daemon)
-        GNUNET_TESTING_daemon_stop (pg->peers[off].daemon, timeout, NULL, NULL, GNUNET_YES);
+      GNUNET_assert(NULL != pg->peers[off].daemon);
+      peer_shutdown_ctx = GNUNET_malloc(sizeof(struct PeerShutdownContext));
+      peer_shutdown_ctx->daemon = pg->peers[off].daemon;
+      peer_shutdown_ctx->shutdown_ctx = shutdown_ctx;
+      GNUNET_SCHEDULER_add_now(pg->peers[off].daemon->sched, &schedule_shutdown_task, peer_shutdown_ctx);
+      //GNUNET_TESTING_daemon_stop (pg->peers[off].daemon, timeout, shutdown_cb, shutdown_ctx, GNUNET_YES, GNUNET_NO);
       if (NULL != pg->peers[off].cfg)
         GNUNET_CONFIGURATION_destroy (pg->peers[off].cfg);
-
       if (pg->peers[off].allowed_peers != NULL)
         GNUNET_CONTAINER_multihashmap_destroy(pg->peers[off].allowed_peers);
       if (pg->peers[off].connect_peers != NULL)
         GNUNET_CONTAINER_multihashmap_destroy(pg->peers[off].connect_peers);
       if (pg->peers[off].blacklisted_peers != NULL)
         GNUNET_CONTAINER_multihashmap_destroy(pg->peers[off].blacklisted_peers);
-
     }
   GNUNET_free (pg->peers);
   if (NULL != pg->hosts)