LRN: Use GNUNET_EXTRA_LOGGING to manage compile-time logging calls

[oweals/gnunet.git] / src / peerinfo / peerinfo_api.c

diff --git a/src/peerinfo/peerinfo_api.c b/src/peerinfo/peerinfo_api.c
index 2a7c990e4a604c67c174d5b2e22a16dc0be230e5..28828f3a3f1be3680f59dfcbfc86538c6895eca9 100644 (file)
--- a/src/peerinfo/peerinfo_api.c
+++ b/src/peerinfo/peerinfo_api.c
@@ -1,10 +1,10 @@
 /*
      This file is part of GNUnet.
 /*
      This file is part of GNUnet.

-     (C) 2001, 2002, 2004, 2005, 2007, 2009 Christian Grothoff (and other contributing authors)
+     (C) 2001, 2002, 2004, 2005, 2007, 2009, 2010 Christian Grothoff (and other contributing authors)

 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
 
      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
      option) any later version.
 
      GNUnet is distributed in the hope that it will be useful, but


@@ -25,547 +25,634 @@
  */
 #include "platform.h"
 #include "gnunet_client_lib.h"
  */
 #include "platform.h"
 #include "gnunet_client_lib.h"

+#include "gnunet_container_lib.h"

 #include "gnunet_peerinfo_service.h"
 #include "gnunet_protocols.h"
 #include "gnunet_time_lib.h"
 #include "peerinfo.h"
 
 #include "gnunet_peerinfo_service.h"
 #include "gnunet_protocols.h"
 #include "gnunet_time_lib.h"
 #include "peerinfo.h"
 

-#define ADD_PEER_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
+/**
+ * Function to call after transmission has succeeded.
+ *
+ * @param cls closure
+ * @param success GNUNET_OK if transmission worked, GNUNET_SYSERR on error
+ */
+typedef void (*TransmissionContinuation) (void *cls, int success);

 
 
 
 

-struct CAFContext
+/**
+ * Entry in the transmission queue to PEERINFO service.
+ */
+struct TransmissionQueueEntry

 {
 {

-  struct GNUNET_CLIENT_Connection *client;
-  struct GNUNET_MessageHeader *msg;
-};
-
+  /**
+   * This is a linked list.
+   */
+  struct TransmissionQueueEntry *next;

 
 

-static size_t
-copy_and_free (void *cls, size_t size, void *buf)
-{
-  struct CAFContext *cc = cls;
-  struct GNUNET_MessageHeader *msg = cc->msg;
-  uint16_t msize;
+  /**
+   * This is a linked list.
+   */
+  struct TransmissionQueueEntry *prev;

 
 

-  if (buf == NULL)
-    {
-#if DEBUG_PEERINFO
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  _
-                  ("Failed to transmit message of type %u to `%s' service.\n"),
-                  ntohs (msg->type), "peerinfo");
-#endif
-      GNUNET_free (msg);
-      GNUNET_CLIENT_disconnect (cc->client, GNUNET_NO);
-      GNUNET_free (cc);
-      return 0;
-    }
-  msize = ntohs (msg->size);
-  GNUNET_assert (size >= msize);
-  memcpy (buf, msg, msize);
-  GNUNET_free (msg);
-  GNUNET_CLIENT_disconnect (cc->client, GNUNET_YES);
-  GNUNET_free (cc);
-  return msize;
-}
+  /**
+   * Function to call after request has been transmitted, or NULL (in which
+   * case we must consider sending the next entry immediately).
+   */
+  TransmissionContinuation cont;

 
 

+  /**
+   * Closure for 'cont'.
+   */
+  void *cont_cls;

 
 

+  /**
+   * Timeout for the operation.
+   */
+  struct GNUNET_TIME_Absolute timeout;

 
 

-/**
- * Add a host to the persistent list.
- *
- * @param cfg configuration to use
- * @param sched scheduler to use
- * @param peer identity of the peer
- * @param hello the verified (!) HELLO message
- */
-void
-GNUNET_PEERINFO_add_peer (const struct GNUNET_CONFIGURATION_Handle *cfg,
-                          struct GNUNET_SCHEDULER_Handle *sched,
-                          const struct GNUNET_PeerIdentity *peer,
-                          const struct GNUNET_HELLO_Message *hello)
-{
-  struct GNUNET_CLIENT_Connection *client;
-  struct PeerAddMessage *pam;
-  uint16_t hs;
-  struct CAFContext *cc;
+  /**
+   * Number of bytes of the request message (follows after this struct).
+   */
+  size_t size;

 
 

-#if DEBUG_PEERINFO
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Adding peer `%s' to peerinfo database\n",
-             GNUNET_i2s(peer));
-#endif
-  client = GNUNET_CLIENT_connect (sched, "peerinfo", cfg);
-  if (client == NULL)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _("Could not connect to `%s' service.\n"), "peerinfo");
-      return;
-    }
-  hs = GNUNET_HELLO_size (hello);
-#if DEBUG_PEERINFO
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Size of `%s' is %u bytes\n",
-             "HELLO",
-             (unsigned int) GNUNET_HELLO_size (hello));
-#endif  
-  pam = GNUNET_malloc (sizeof (struct PeerAddMessage) + hs);
-  pam->header.size = htons (hs + sizeof (struct PeerAddMessage));
-  pam->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_ADD);
-  memcpy (&pam->peer, peer, sizeof (struct GNUNET_PeerIdentity));
-  memcpy (&pam[1], hello, hs);
-  cc = GNUNET_malloc (sizeof (struct CAFContext));
-  cc->client = client;
-  cc->msg = &pam->header;
-  GNUNET_CLIENT_notify_transmit_ready (client,
-                                       ntohs (pam->header.size),
-                                       ADD_PEER_TIMEOUT, 
-                                      GNUNET_NO,
-                                      &copy_and_free, cc);
-}
+};

 
 
 /**
 
 
 /**

- * Context for the info handler.
+ * Handle to the peerinfo service.

  */
  */

-struct GNUNET_PEERINFO_IteratorContext
+struct GNUNET_PEERINFO_Handle

 {
 {

+  /**
+   * Our configuration.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;

 
   /**
 
   /**

-   * Our connection to the PEERINFO service.
+   * Connection to the service.

    */
   struct GNUNET_CLIENT_Connection *client;
 
   /**
    */
   struct GNUNET_CLIENT_Connection *client;
 
   /**

-   * Function to call with information.
+   * Head of transmission queue.

    */
    */

-  GNUNET_PEERINFO_Processor callback;
+  struct TransmissionQueueEntry *tq_head;

 
   /**
 
   /**

-   * Closure for callback.
+   * Tail of transmission queue.

    */
    */

-  void *callback_cls;
+  struct TransmissionQueueEntry *tq_tail;

 
   /**
 
   /**

-   * When should we time out?
+   * Handle for the current transmission request, or NULL if none is pending.

    */
    */

-  struct GNUNET_TIME_Absolute timeout;
+  struct GNUNET_CLIENT_TransmitHandle *th;
+
+  /**
+   * ID for a reconnect task.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier r_task;
+
+  /**
+   * Set to GNUNET_YES if we are currently receiving replies from the
+   * service.
+   */
+  int in_receive;

 
 };
 
 
 /**
 
 };
 
 
 /**

- * Type of a function to call when we receive a message
- * from the service.
+ * Connect to the peerinfo service.

  *
  *

- * @param cls closure
- * @param msg message received, NULL on timeout or fatal error
+ * @param cfg configuration to use
+ * @return NULL on error (configuration related, actual connection
+ *         establishment may happen asynchronously).
+ */
+struct GNUNET_PEERINFO_Handle *
+GNUNET_PEERINFO_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_PEERINFO_Handle *ret;
+
+  ret = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_Handle));
+  ret->client = GNUNET_CLIENT_connect ("peerinfo", cfg);
+  ret->cfg = cfg;
+  return ret;
+}
+
+
+/**
+ * Disconnect from the peerinfo service.  Note that all iterators must
+ * have completed or have been cancelled by the time this function is
+ * called (otherwise, calling this function is a serious error).
+ * Furthermore, if 'GNUNET_PEERINFO_add_peer' operations are still
+ * pending, they will be cancelled silently on disconnect.
+ *
+ * @param h handle to disconnect
+ */
+void
+GNUNET_PEERINFO_disconnect (struct GNUNET_PEERINFO_Handle *h)
+{
+  struct TransmissionQueueEntry *tqe;
+
+  while (NULL != (tqe = h->tq_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (h->tq_head, h->tq_tail, tqe);
+    if (tqe->cont != NULL)
+      tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
+    GNUNET_free (tqe);
+  }
+  if (h->th != NULL)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
+    h->th = NULL;
+  }
+  if (NULL != h->client)
+  {
+    GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
+    h->client = NULL;
+  }
+  if (GNUNET_SCHEDULER_NO_TASK != h->r_task)
+  {
+    GNUNET_SCHEDULER_cancel (h->r_task);
+    h->r_task = GNUNET_SCHEDULER_NO_TASK;
+  }
+  GNUNET_free (h);
+}
+
+
+/**
+ * Check if we have a request pending in the transmission queue and are
+ * able to transmit it right now.  If so, schedule transmission.
+ *
+ * @param h handle to the service
+ */
+static void
+trigger_transmit (struct GNUNET_PEERINFO_Handle *h);
+
+
+/**
+ * Close the existing connection to PEERINFO and reconnect.
+ *
+ * @param h handle to the service
+ */
+static void
+reconnect (struct GNUNET_PEERINFO_Handle *h);
+
+/**
+ * Task scheduled to re-try connecting to the peerinfo service.
+ *
+ * @param cls the 'struct GNUNET_PEERINFO_Handle'
+ * @param tc scheduler context

  */
 static void
  */
 static void

-info_handler (void *cls, const struct GNUNET_MessageHeader *msg)
+reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)

 {
 {

-  struct GNUNET_PEERINFO_IteratorContext *ic = cls;
-  const struct InfoMessage *im;
-  const struct GNUNET_HELLO_Message *hello;
-  uint16_t ms;
+  struct GNUNET_PEERINFO_Handle *h = cls;

 
 

-  if (msg == NULL)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _("Failed to receive response from `%s' service.\n"),
-                  "peerinfo");
-      ic->callback (ic->callback_cls, NULL, NULL, 1);
-      GNUNET_CLIENT_disconnect (ic->client, GNUNET_NO);
-      GNUNET_free (ic);
-      return;
-    }
-  if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END)
-    {
-#if DEBUG_PEERINFO
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                 "Received end of list of peers from peerinfo database\n");
-#endif
-      ic->callback (ic->callback_cls, NULL, NULL, 0);
-      GNUNET_CLIENT_disconnect (ic->client, GNUNET_NO);
-      GNUNET_free (ic);
-      return;
-    }
-  ms = ntohs (msg->size);
-  if ((ms < sizeof (struct InfoMessage)) ||
-      (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
-    {
-      GNUNET_break (0);
-      ic->callback (ic->callback_cls, NULL, NULL, 2);
-      GNUNET_CLIENT_disconnect (ic->client, GNUNET_NO);
-      GNUNET_free (ic);
-      return;
-    }
-  im = (const struct InfoMessage *) msg;
-  hello = NULL;
-  if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
-    {
-      hello = (const struct GNUNET_HELLO_Message *) &im[1];
-      if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
-        {
-          GNUNET_break (0);
-          ic->callback (ic->callback_cls, NULL, NULL, 2);
-          GNUNET_CLIENT_disconnect (ic->client, GNUNET_NO);
-          GNUNET_free (ic);
-          return;
-        }
-    }
-#if DEBUG_PEERINFO
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Received information about peer `%s' from peerinfo database\n",
-             GNUNET_i2s (&im->peer));
-#endif
-#if DEBUG_PEERINFO
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Size of `%s' is %u bytes\n",
-             "HELLO",
-             (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello));
-#endif  
-  ic->callback (ic->callback_cls, &im->peer, hello, ntohl (im->trust));
-  GNUNET_CLIENT_receive (ic->client,
-                         &info_handler,
-                         ic,
-                         GNUNET_TIME_absolute_get_remaining (ic->timeout));
+  h->r_task = GNUNET_SCHEDULER_NO_TASK;
+  reconnect (h);

 }
 
 
 /**
 }
 
 
 /**

- * Call a method for each known matching host and change
- * its trust value.  The method will be invoked once for
- * each host and then finally once with a NULL pointer.
- * Note that the last call can be triggered by timeout or
- * by simply being done; however, the trust argument will
- * be set to zero if we are done and to 1 if we timed out.
+ * Close the existing connection to PEERINFO and reconnect.

  *
  *

- * @param cfg configuration to use
- * @param sched scheduler to use
- * @param peer restrict iteration to this peer only (can be NULL)
- * @param trust_delta how much to change the trust in all matching peers
- * @param timeout how long to wait until timing out
- * @param callback the method to call for each peer
- * @param callback_cls closure for callback
- * @return NULL on error, otherwise an iterator context
+ * @param h handle to the service

  */
  */

-struct GNUNET_PEERINFO_IteratorContext *
-GNUNET_PEERINFO_iterate (const struct GNUNET_CONFIGURATION_Handle *cfg,
-                         struct GNUNET_SCHEDULER_Handle *sched,
-                         const struct GNUNET_PeerIdentity *peer,
-                         int trust_delta,
-                         struct GNUNET_TIME_Relative timeout,
-                         GNUNET_PEERINFO_Processor callback,
-                         void *callback_cls)
+static void
+reconnect (struct GNUNET_PEERINFO_Handle *h)

 {
 {

-  struct GNUNET_CLIENT_Connection *client;
-  struct ListAllPeersMessage *lapm;
-  struct ListPeerMessage *lpm;
-  struct GNUNET_PEERINFO_IteratorContext *ihc;
+  if (h->r_task != GNUNET_SCHEDULER_NO_TASK)
+  {
+    GNUNET_SCHEDULER_cancel (h->r_task);
+    h->r_task = GNUNET_SCHEDULER_NO_TASK;
+  }
+  if (NULL != h->th)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
+    h->th = NULL;
+  }
+  if (NULL != h->client)
+  {
+    GNUNET_CLIENT_disconnect (h->client, GNUNET_SYSERR);
+    h->client = NULL;
+  }
+  h->client = GNUNET_CLIENT_connect ("peerinfo", h->cfg);
+  if (NULL == h->client)
+  {
+    h->r_task =
+        GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect_task,
+                                      h);
+    return;
+  }
+  trigger_transmit (h);
+}

 
 

-  client = GNUNET_CLIENT_connect (sched, "peerinfo", cfg);
-  if (client == NULL)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _("Could not connect to `%s' service.\n"), "peerinfo");
-      return NULL;
-    }
+
+/**
+ * Transmit the request at the head of the transmission queue
+ * and trigger continuation (if any).
+ *
+ * @param cls the 'struct GNUNET_PEERINFO_Handle' (with the queue)
+ * @param size size of the buffer (0 on error)
+ * @param buf where to copy the message
+ * @return number of bytes copied to buf
+ */
+static size_t
+do_transmit (void *cls, size_t size, void *buf)
+{
+  struct GNUNET_PEERINFO_Handle *h = cls;
+  struct TransmissionQueueEntry *tqe = h->tq_head;
+  size_t ret;
+
+  h->th = NULL;
+  if (tqe == NULL)
+    return 0;
+  if (buf == NULL)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                _("Failed to transmit message to `%s' service.\n"), "PEERINFO");
+    GNUNET_CONTAINER_DLL_remove (h->tq_head, h->tq_tail, tqe);
+    reconnect (h);
+    if (tqe->cont != NULL)
+      tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
+    GNUNET_free (tqe);
+    return 0;
+  }
+  ret = tqe->size;
+  GNUNET_assert (size >= ret);
+  memcpy (buf, &tqe[1], ret);

 #if DEBUG_PEERINFO
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 #if DEBUG_PEERINFO
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,

-             "Requesting list of peers from peerinfo database\n");
+              "Transmitting request of size %u to `%s' service.\n", ret,
+              "PEERINFO");

 #endif
 #endif

-  if (peer == NULL)
-    {
-      ihc = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_IteratorContext) +
-                          sizeof (struct ListAllPeersMessage));
-      lapm = (struct ListAllPeersMessage *) &ihc[1];
-      lapm->header.size = htons (sizeof (struct ListAllPeersMessage));
-      lapm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL);
-      lapm->trust_change = htonl (trust_delta);
-    }
+  GNUNET_CONTAINER_DLL_remove (h->tq_head, h->tq_tail, tqe);
+  if (tqe->cont != NULL)
+    tqe->cont (tqe->cont_cls, GNUNET_OK);

   else
   else

-    {
-      ihc = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_IteratorContext) +
-                          sizeof (struct ListPeerMessage));
-      lpm = (struct ListPeerMessage *) &ihc[1];
-      lpm->header.size = htons (sizeof (struct ListPeerMessage));
-      lpm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET);
-      lpm->trust_change = htonl (trust_delta);
-      memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity));
-    }
-  ihc->client = client;
-  ihc->callback = callback;
-  ihc->callback_cls = callback_cls;
-  ihc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
-  if (GNUNET_OK != 
-      GNUNET_CLIENT_transmit_and_get_response (client,
-                                              (const struct GNUNET_MessageHeader*) &ihc[1],
-                                              timeout,
-                                              GNUNET_YES,
-                                              &info_handler,
-                                              ihc))
-    {
-      GNUNET_break (0);
-      GNUNET_CLIENT_disconnect (ihc->client, GNUNET_NO);
-      GNUNET_free (ihc);
-      return NULL;
-    }
-  return ihc;
+    trigger_transmit (h);
+  GNUNET_free (tqe);
+  return ret;

 }
 
 
 /**
 }
 
 
 /**

- * Cancel an iteration over peer information.
+ * Check if we have a request pending in the transmission queue and are
+ * able to transmit it right now.  If so, schedule transmission.

  *
  *

- * @param ic context of the iterator to cancel
+ * @param h handle to the service

  */
  */

-void
-GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic)
+static void
+trigger_transmit (struct GNUNET_PEERINFO_Handle *h)

 {
 {

-  GNUNET_CLIENT_disconnect (ic->client, GNUNET_NO);
-  GNUNET_free (ic);
+  struct TransmissionQueueEntry *tqe;
+
+  if (NULL == (tqe = h->tq_head))
+    return;
+  if (h->th != NULL)
+    return;
+  if (h->in_receive == GNUNET_YES)
+    return;
+  if (NULL == h->client)
+  {
+    reconnect (h);
+    return;
+  }
+  h->th =
+      GNUNET_CLIENT_notify_transmit_ready (h->client, tqe->size,
+                                           GNUNET_TIME_absolute_get_remaining
+                                           (tqe->timeout), GNUNET_YES,
+                                           &do_transmit, h);

 }
 
 
 /**
 }
 
 
 /**

- * Context for the info handler.
+ * Add a host to the persistent list.  This method operates in
+ * semi-reliable mode: if the transmission is not completed by
+ * the time 'GNUNET_PEERINFO_disconnect' is called, it will be
+ * aborted.  Furthermore, if a second HELLO is added for the
+ * same peer before the first one was transmitted, PEERINFO may
+ * merge the two HELLOs prior to transmission to the service.
+ *
+ * @param h handle to the peerinfo service
+ * @param hello the verified (!) HELLO message

  */
  */

-struct GNUNET_PEERINFO_NotifyContext
+void
+GNUNET_PEERINFO_add_peer (struct GNUNET_PEERINFO_Handle *h,
+                          const struct GNUNET_HELLO_Message *hello)

 {
 {

+  uint16_t hs = GNUNET_HELLO_size (hello);
+  struct TransmissionQueueEntry *tqe;
+
+#if DEBUG_PEERINFO
+  struct GNUNET_PeerIdentity peer;
+
+  GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_id (hello, &peer));
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Adding peer `%s' to PEERINFO database (%u bytes of `%s')\n",
+              GNUNET_i2s (&peer), hs, "HELLO");
+#endif
+  tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) + hs);
+  tqe->size = hs;
+  tqe->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
+  memcpy (&tqe[1], hello, hs);
+  GNUNET_CONTAINER_DLL_insert_after (h->tq_head, h->tq_tail, h->tq_tail, tqe);
+  trigger_transmit (h);
+}

 
 

+
+/**
+ * Context for an iteration request.
+ */
+struct GNUNET_PEERINFO_IteratorContext
+{

   /**
   /**

-   * Our connection to the PEERINFO service.
+   * Handle to the PEERINFO service.

    */
    */

-  struct GNUNET_CLIENT_Connection *client;
+  struct GNUNET_PEERINFO_Handle *h;

 
   /**
 
   /**

-   * Function to call with information.
+   * Function to call with the results.

    */
   GNUNET_PEERINFO_Processor callback;
 
   /**
    */
   GNUNET_PEERINFO_Processor callback;
 
   /**

-   * Closure for callback.
+   * Closure for 'callback'.

    */
   void *callback_cls;
 
   /**
    */
   void *callback_cls;
 
   /**

-   * Handle to our initial request for message transmission to
-   * the peerinfo service.
+   * Our entry in the transmission queue.

    */
    */

-  struct GNUNET_CLIENT_TransmitHandle *init;
+  struct TransmissionQueueEntry *tqe;

 
   /**
 
   /**

-   * Configuration.
+   * Task responsible for timeout.

    */
    */

-  const struct GNUNET_CONFIGURATION_Handle *cfg;
+  GNUNET_SCHEDULER_TaskIdentifier timeout_task;

 
   /**
 
   /**

-   * Scheduler.
+   * Timeout for the operation.

    */
    */

-  struct GNUNET_SCHEDULER_Handle *sched;
-};
-
-
-/**
- * Send a request to the peerinfo service to start being
- * notified about all changes to peer information.
- *
- * @param nc our context
- */
-static void
-request_notifications (struct GNUNET_PEERINFO_NotifyContext *nc);
-
+  struct GNUNET_TIME_Absolute timeout;

 
 

-/**
- * Read notifications from the client handle and pass them
- * to the callback.
- *
- * @param nc our context
- */
-static void
-receive_notifications (struct GNUNET_PEERINFO_NotifyContext *nc);
+  /**
+   * Are we now receiving?
+   */
+  int in_receive;
+};

 
 
 /**
 
 
 /**

- * Receive a peerinfo information message, process it and
- * go for more.
+ * Type of a function to call when we receive a message
+ * from the service.

  *
  * @param cls closure
  * @param msg message received, NULL on timeout or fatal error
  */
 static void
  *
  * @param cls closure
  * @param msg message received, NULL on timeout or fatal error
  */
 static void

-process_notification (void *cls,
-                     const struct
-                     GNUNET_MessageHeader * msg)
+peerinfo_handler (void *cls, const struct GNUNET_MessageHeader *msg)

 {
 {

-  struct GNUNET_PEERINFO_NotifyContext *nc = cls;
+  struct GNUNET_PEERINFO_IteratorContext *ic = cls;

   const struct InfoMessage *im;
   const struct GNUNET_HELLO_Message *hello;
   uint16_t ms;
 
   const struct InfoMessage *im;
   const struct GNUNET_HELLO_Message *hello;
   uint16_t ms;
 

+  ic->h->in_receive = GNUNET_NO;

   if (msg == NULL)
   if (msg == NULL)

-    {
-      GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
-      nc->client = GNUNET_CLIENT_connect (nc->sched, "peerinfo", nc->cfg);
-      request_notifications (nc);
-      return;
-    }
+  {
+    reconnect (ic->h);
+    if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+      GNUNET_SCHEDULER_cancel (ic->timeout_task);
+    if (ic->callback != NULL)
+      ic->callback (ic->callback_cls, NULL, NULL,
+                    _("Failed to receive response from `PEERINFO' service."));
+    GNUNET_free (ic);
+    return;
+  }
+  if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END)
+  {
+#if DEBUG_PEERINFO
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Received end of list of peers from `%s' service\n",
+                "PEERINFO");
+#endif
+    trigger_transmit (ic->h);
+    if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+      GNUNET_SCHEDULER_cancel (ic->timeout_task);
+    if (ic->callback != NULL)
+      ic->callback (ic->callback_cls, NULL, NULL, NULL);
+    GNUNET_free (ic);
+    return;
+  }

   ms = ntohs (msg->size);
   if ((ms < sizeof (struct InfoMessage)) ||
       (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
   ms = ntohs (msg->size);
   if ((ms < sizeof (struct InfoMessage)) ||
       (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))

-    {
-      GNUNET_break (0);
-      GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
-      nc->client = GNUNET_CLIENT_connect (nc->sched, "peerinfo", nc->cfg);
-      request_notifications (nc);
-      return;
-    }
+  {
+    GNUNET_break (0);
+    reconnect (ic->h);
+    if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+      GNUNET_SCHEDULER_cancel (ic->timeout_task);
+    if (ic->callback != NULL)
+      ic->callback (ic->callback_cls, NULL, NULL,
+                    _("Received invalid message from `PEERINFO' service.\n"));
+    GNUNET_free (ic);
+    return;
+  }

   im = (const struct InfoMessage *) msg;
   im = (const struct InfoMessage *) msg;

+  GNUNET_break (0 == ntohl (im->reserved));

   hello = NULL;
   if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
   hello = NULL;
   if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))

+  {
+    hello = (const struct GNUNET_HELLO_Message *) &im[1];
+    if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))

     {
     {

-      hello = (const struct GNUNET_HELLO_Message *) &im[1];
-      if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
-        {
-          GNUNET_break (0);
-         GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
-         nc->client = GNUNET_CLIENT_connect (nc->sched, "peerinfo", nc->cfg);
-         request_notifications (nc);
-          return;
-        }
+      GNUNET_break (0);
+      reconnect (ic->h);
+      if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+        GNUNET_SCHEDULER_cancel (ic->timeout_task);
+      if (ic->callback != NULL)
+        ic->callback (ic->callback_cls, NULL, NULL,
+                      _("Received invalid message from `PEERINFO' service.\n"));
+      GNUNET_free (ic);
+      return;

     }
     }

+  }

 #if DEBUG_PEERINFO
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 #if DEBUG_PEERINFO
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,

-             "Received information about peer `%s' from peerinfo database\n",
-             GNUNET_i2s (&im->peer));
+              "Received %u bytes of `%s' information about peer `%s' from `%s' service\n",
+              (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello),
+              "HELLO", GNUNET_i2s (&im->peer), "PEERINFO");

 #endif
 #endif

-  nc->callback (nc->callback_cls, &im->peer, hello, ntohl (im->trust));
-  receive_notifications (nc);
+  ic->h->in_receive = GNUNET_YES;
+  if (ic->callback != NULL)
+    ic->callback (ic->callback_cls, &im->peer, hello, NULL);
+  GNUNET_CLIENT_receive (ic->h->client, &peerinfo_handler, ic,
+                         GNUNET_TIME_absolute_get_remaining (ic->timeout));

 }
 
 
 /**
 }
 
 
 /**

- * Read notifications from the client handle and pass them
- * to the callback.
+ * We've transmitted the iteration request.  Now get ready to process
+ * the results (or handle transmission error).

  *
  *

- * @param nc our context
+ * @param cls the 'struct GNUNET_PEERINFO_IteratorContext'
+ * @param transmit_success GNUNET_OK if transmission worked

  */
 static void
  */
 static void

-receive_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
+iterator_start_receive (void *cls, int transmit_success)

 {
 {

-  GNUNET_CLIENT_receive (nc->client,
-                        &process_notification,
-                        nc,
-                        GNUNET_TIME_UNIT_FOREVER_REL);
-}
-
-
-/**
- * Transmit our init-notify request, start receiving.
- *
- * @param cls closure (our 'struct GNUNET_PEERINFO_NotifyContext')
- * @param size number of bytes available in buf
- * @param buf where the callee should write the message
- * @return number of bytes written to buf
- */
-static size_t 
-transmit_notify_request (void *cls,
-                        size_t size, 
-                        void *buf)
-{
-  struct GNUNET_PEERINFO_NotifyContext *nc = cls;
-  struct GNUNET_MessageHeader hdr;
+  struct GNUNET_PEERINFO_IteratorContext *ic = cls;

 
 

-  nc->init = NULL;
-  if (buf == NULL)
+  if (GNUNET_OK != transmit_success)
+  {
+    if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)

     {
     {

-      GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
-      nc->client = GNUNET_CLIENT_connect (nc->sched, "peerinfo", nc->cfg);
-      request_notifications (nc);
-      return 0;
+      GNUNET_SCHEDULER_cancel (ic->timeout_task);
+      ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;

     }
     }

-  GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
-  hdr.size = htons (sizeof (struct GNUNET_MessageHeader));
-  hdr.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_NOTIFY);
-  memcpy (buf, &hdr, sizeof (struct GNUNET_MessageHeader));
-  receive_notifications (nc);
-  return sizeof (struct GNUNET_MessageHeader);
+    reconnect (ic->h);
+    if (ic->callback != NULL)
+      ic->callback (ic->callback_cls, NULL, NULL,
+                    _
+                    ("Failed to transmit iteration request to `PEERINFO' service\n"));
+    GNUNET_free (ic);
+    return;
+  }
+#if DEBUG_PEERINFO
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Waiting for response from `%s' service.\n", "PEERINFO");
+#endif
+  ic->h->in_receive = GNUNET_YES;
+  ic->in_receive = GNUNET_YES;
+  ic->tqe = NULL;
+  GNUNET_CLIENT_receive (ic->h->client, &peerinfo_handler, ic,
+                         GNUNET_TIME_absolute_get_remaining (ic->timeout));

 }
 
 
 /**
 }
 
 
 /**

- * Send a request to the peerinfo service to start being
- * notified about all changes to peer information.
+ * Peerinfo iteration request has timed out.

  *
  *

- * @param nc our context
+ * @param cls the 'struct GNUNET_PEERINFO_IteratorContext*'
+ * @param tc scheduler context

  */
 static void
  */
 static void

-request_notifications (struct GNUNET_PEERINFO_NotifyContext *nc)
+signal_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)

 {
 {

-  GNUNET_assert (NULL == nc->init);
-  nc->init =GNUNET_CLIENT_notify_transmit_ready (nc->client,
-                                                sizeof (struct GNUNET_MessageHeader),
-                                                GNUNET_TIME_UNIT_FOREVER_REL,
-                                                GNUNET_YES,
-                                                &transmit_notify_request,
-                                                nc);
+  struct GNUNET_PEERINFO_IteratorContext *ic = cls;
+
+  ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+  if (!ic->in_receive)
+    GNUNET_CONTAINER_DLL_remove (ic->h->tq_head, ic->h->tq_tail, ic->tqe);
+  else
+    reconnect (ic->h);
+  ic->callback (ic->callback_cls, NULL, NULL,
+                _
+                ("Timeout transmitting iteration request to `PEERINFO' service.\n"));
+  ic->callback = NULL;
+  GNUNET_free_non_null (ic->tqe);
+  GNUNET_free (ic);

 }
 
 
 /**
 }
 
 
 /**

- * Call a method whenever our known information about peers
- * changes.  Initially calls the given function for all known
- * peers and then only signals changes.
+ * Call a method for each known matching host and change its trust
+ * value.  The callback method will be invoked once for each matching
+ * host and then finally once with a NULL pointer.  After that final
+ * invocation, the iterator context must no longer be used.

  *
  *

- * @param cfg configuration to use
- * @param sched scheduler to use
+ * Instead of calling this function with 'peer == NULL' it is often
+ * better to use 'GNUNET_PEERINFO_notify'.
+ *
+ * @param h handle to the peerinfo service
+ * @param peer restrict iteration to this peer only (can be NULL)
+ * @param timeout how long to wait until timing out

  * @param callback the method to call for each peer
  * @param callback_cls closure for callback
  * @param callback the method to call for each peer
  * @param callback_cls closure for callback

- * @return NULL on error
+ * @return iterator context

  */
  */

-struct GNUNET_PEERINFO_NotifyContext *
-GNUNET_PEERINFO_notify (const struct GNUNET_CONFIGURATION_Handle *cfg,
-                       struct GNUNET_SCHEDULER_Handle *sched,
-                       GNUNET_PEERINFO_Processor callback,
-                       void *callback_cls)
+struct GNUNET_PEERINFO_IteratorContext *
+GNUNET_PEERINFO_iterate (struct GNUNET_PEERINFO_Handle *h,
+                         const struct GNUNET_PeerIdentity *peer,
+                         struct GNUNET_TIME_Relative timeout,
+                         GNUNET_PEERINFO_Processor callback, void *callback_cls)

 {
 {

-  struct GNUNET_PEERINFO_NotifyContext *nc;
-  struct GNUNET_CLIENT_Connection *client;
+  struct GNUNET_MessageHeader *lapm;
+  struct ListPeerMessage *lpm;
+  struct GNUNET_PEERINFO_IteratorContext *ic;
+  struct TransmissionQueueEntry *tqe;

 
 

-  client = GNUNET_CLIENT_connect (sched, "peerinfo", cfg);
-  if (client == NULL)
-    {      
-      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _("Could not connect to `%s' service.\n"), "peerinfo");
-      return NULL;
-    }
-  nc = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_NotifyContext));
-  nc->sched = sched;
-  nc->cfg = cfg;
-  nc->client = client;
-  nc->callback = callback;
-  nc->callback_cls = callback_cls; 
-  request_notifications (nc);
-  return nc;
+  if (peer == NULL)
+  {
+#if DEBUG_PEERINFO
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Requesting list of peers from PEERINFO service\n");
+#endif
+    tqe =
+        GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
+                       sizeof (struct GNUNET_MessageHeader));
+    tqe->size = sizeof (struct GNUNET_MessageHeader);
+    lapm = (struct GNUNET_MessageHeader *) &tqe[1];
+    lapm->size = htons (sizeof (struct GNUNET_MessageHeader));
+    lapm->type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL);
+  }
+  else
+  {
+#if DEBUG_PEERINFO
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Requesting information on peer `%4s' from PEERINFO service\n",
+                GNUNET_i2s (peer));
+#endif
+    tqe =
+        GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
+                       sizeof (struct ListPeerMessage));
+    tqe->size = sizeof (struct ListPeerMessage);
+    lpm = (struct ListPeerMessage *) &tqe[1];
+    lpm->header.size = htons (sizeof (struct ListPeerMessage));
+    lpm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET);
+    memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity));
+  }
+  ic = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_IteratorContext));
+  ic->h = h;
+  ic->tqe = tqe;
+  ic->callback = callback;
+  ic->callback_cls = callback_cls;
+  ic->timeout = GNUNET_TIME_relative_to_absolute (timeout);
+  ic->timeout_task =
+      GNUNET_SCHEDULER_add_delayed (timeout, &signal_timeout, ic);
+  tqe->timeout = ic->timeout;
+  tqe->cont = &iterator_start_receive;
+  tqe->cont_cls = ic;
+  tqe->timeout = ic->timeout;
+  GNUNET_CONTAINER_DLL_insert_after (h->tq_head, h->tq_tail, h->tq_tail, tqe);
+  trigger_transmit (h);
+  return ic;

 }
 
 
 /**
 }
 
 
 /**

- * Stop notifying about changes.
+ * Cancel an iteration over peer information.

  *
  *

- * @param nc context to stop notifying
+ * @param ic context of the iterator to cancel

  */
 void
  */
 void

-GNUNET_PEERINFO_notify_cancel (struct GNUNET_PEERINFO_NotifyContext *nc)
+GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic)

 {
 {

-  if (NULL != nc->init)
-    {
-      GNUNET_CLIENT_notify_transmit_ready_cancel (nc->init);
-      nc->init = NULL;
-    }
-  GNUNET_CLIENT_disconnect (nc->client, GNUNET_NO);
-  GNUNET_free (nc);
+  if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+  {
+    GNUNET_SCHEDULER_cancel (ic->timeout_task);
+    ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+  }
+  ic->callback = NULL;
+  if (GNUNET_YES == ic->in_receive)
+    return;                     /* need to finish processing */
+  GNUNET_CONTAINER_DLL_remove (ic->h->tq_head, ic->h->tq_tail, ic->tqe);
+  GNUNET_free (ic->tqe);
+  GNUNET_free (ic);

 }
 
 
 }