X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Fpeerinfo%2Fpeerinfo_api.c;h=e0806978b4c81b57841876c3f0dc8b3787a6b916;hb=1ffbab2de23c37b8df3d8c22d6704979f156a9b0;hp=ba5ade199b58d89756068024db18ff112933a430;hpb=0a217a8df1657b4334b55b0e4a6c7837a8dbcfd9;p=oweals%2Fgnunet.git

diff --git a/src/peerinfo/peerinfo_api.c b/src/peerinfo/peerinfo_api.c
index ba5ade199..e0806978b 100644
--- a/src/peerinfo/peerinfo_api.c
+++ b/src/peerinfo/peerinfo_api.c
@@ -25,118 +25,343 @@
  */
 #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"
 
-#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);
+
+
+/**
+ * Entry in the transmission queue to PEERINFO service.
+ */
+struct TransmissionQueueEntry
+{
+  /**
+   * This is a linked list.
+   */
+  struct TransmissionQueueEntry *next;
+  
+  /**
+   * This is a linked list.
+   */
+  struct TransmissionQueueEntry *prev;
+
+  /**
+   * 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;
+
+  /**
+   * Number of bytes of the request message (follows after this struct).
+   */
+  size_t size;
+
+};
 
 
-struct CAFContext
+/**
+ * Handle to the peerinfo service.
+ */
+struct GNUNET_PEERINFO_Handle
 {
+  /**
+   * Our configuration.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Our scheduler.
+   */
+  struct GNUNET_SCHEDULER_Handle *sched;
+
+  /**
+   * Connection to the service.
+   */
   struct GNUNET_CLIENT_Connection *client;
-  struct GNUNET_MessageHeader *msg;
+
+  /**
+   * Head of transmission queue.
+   */
+  struct TransmissionQueueEntry *tq_head;
+
+  /**
+   * Tail of transmission queue.
+   */
+  struct TransmissionQueueEntry *tq_tail;
+
+  /**
+   * Handle for the current transmission request, or NULL if none is pending.
+   */
+  struct GNUNET_CLIENT_TransmitHandle *th;
+
+  /**
+   * Set to GNUNET_YES if we are currently receiving replies from the
+   * service.
+   */
+  int in_receive;
+
 };
 
 
+/**
+ * Connect to the peerinfo service.
+ *
+ * @param sched scheduler to use
+ * @param cfg configuration to use
+ * @return NULL on error (configuration related, actual connection
+ *         etablishment may happen asynchronously).
+ */
+struct GNUNET_PEERINFO_Handle *
+GNUNET_PEERINFO_connect (struct GNUNET_SCHEDULER_Handle *sched,
+			 const struct GNUNET_CONFIGURATION_Handle *cfg)			 
+{
+  struct GNUNET_CLIENT_Connection *client;
+  struct GNUNET_PEERINFO_Handle *ret;
+
+  client = GNUNET_CLIENT_connect (sched, "peerinfo", cfg);
+  if (client == NULL)
+    return NULL;
+  ret = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_Handle));
+  ret->client = client;
+  ret->cfg = cfg;
+  ret->sched = sched;
+  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;
+    }
+  GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
+  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)
+{
+  GNUNET_CLIENT_disconnect (h->client, GNUNET_SYSERR);
+  h->client = GNUNET_CLIENT_connect (h->sched, "peerinfo", h->cfg);
+  GNUNET_assert (h->client != 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
-copy_and_free (void *cls, size_t size, void *buf)
+do_transmit (void *cls, size_t size, void *buf)
 {
-  struct CAFContext *cc = cls;
-  struct GNUNET_MessageHeader *msg = cc->msg;
-  uint16_t msize;
+  struct GNUNET_PEERINFO_Handle *h = cls;
+  struct TransmissionQueueEntry *tqe = h->tq_head;
+  size_t ret;
 
+  h->th = NULL;
   if (buf == NULL)
     {
-      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+#if DEBUG_PEERINFO
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                   _
                   ("Failed to transmit message of type %u to `%s' service.\n"),
                   ntohs (msg->type), "peerinfo");
-      GNUNET_free (msg);
-      GNUNET_CLIENT_disconnect (cc->client);
-      GNUNET_free (cc);
+#endif
+      GNUNET_CONTAINER_DLL_remove (h->tq_head,
+				   h->tq_tail,
+				   tqe);
+      reconnect (h);
+      trigger_transmit (h);
+      if (tqe->cont != NULL)
+	tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
+      GNUNET_free (tqe);
       return 0;
     }
-  msize = ntohs (msg->size);
-  GNUNET_assert (size >= msize);
-  memcpy (buf, msg, msize);
-  GNUNET_free (msg);
-  GNUNET_CLIENT_disconnect (cc->client);
-  GNUNET_free (cc);
-  return msize;
+  ret = tqe->size;
+  GNUNET_assert (size >= ret);
+  memcpy (buf, &tqe[1], ret);
+  GNUNET_CONTAINER_DLL_remove (h->tq_head,
+			       h->tq_tail,
+			       tqe);
+  if (tqe->cont != NULL)
+    tqe->cont (tqe->cont_cls, GNUNET_OK);
+  else
+    trigger_transmit (h);
+  GNUNET_free (tqe);
+  return ret;
 }
 
 
+/**
+ * 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)
+{
+  struct TransmissionQueueEntry *tqe;
+
+  /* FIXME: need to handle case where we are still *receiving* (and then
+     do nothing here as well!) */
+  if (NULL == (tqe = h->tq_head))
+    return;
+  if (h->th != NULL)
+    return;
+  if (h->in_receive == GNUNET_YES)
+    return;
+  h->th = GNUNET_CLIENT_notify_transmit_ready (h->client,
+					       tqe->size,
+					       GNUNET_TIME_absolute_get_remaining (tqe->timeout),
+					       GNUNET_YES,
+					       &do_transmit, h);  
+}
+
 
 /**
- * Add a host to the persistent list.
+ * 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 cfg configuration to use
- * @param sched scheduler to use
- * @param peer identity of the peer
+ * @param h handle to the peerinfo service
  * @param hello the verified (!) HELLO message
- * @param expiration when the HELLO will expire
  */
 void
-GNUNET_PEERINFO_add_peer (struct GNUNET_CONFIGURATION_Handle *cfg,
-                          struct GNUNET_SCHEDULER_Handle *sched,
-                          const struct GNUNET_PeerIdentity *peer,
-                          const struct GNUNET_HELLO_Message *hello)
+GNUNET_PEERINFO_add_peer (struct GNUNET_PEERINFO_Handle *h,
+			  const struct GNUNET_HELLO_Message *hello)
 {
-  struct GNUNET_CLIENT_Connection *client;
-  struct PeerAddMessage *pam;
-  uint16_t hs;
-  struct CAFContext *cc;
-
-  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);
-  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, &copy_and_free, cc);
+  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 the info handler.
+ * Context for an iteration request.
  */
-struct InfoContext
+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;
 
   /**
-   * Closure for callback.
+   * Closure for 'callback'.
    */
   void *callback_cls;
 
   /**
-   * When should we time out?
+   * Our entry in the transmission queue.
+   */
+  struct TransmissionQueueEntry *tqe;
+
+  /**
+   * Task responsible for timeout.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier timeout_task;
+
+  /**
+   * Timeout for the operation.
    */
   struct GNUNET_TIME_Absolute timeout;
 
+  /**
+   * Are we now receiving?
+   */
+  int in_receive;
 };
 
 
@@ -148,27 +373,41 @@ struct InfoContext
  * @param msg message received, NULL on timeout or fatal error
  */
 static void
-info_handler (void *cls, const struct GNUNET_MessageHeader *msg)
+peerinfo_handler (void *cls, const struct GNUNET_MessageHeader *msg)
 {
-  struct InfoContext *ic = cls;
+  struct GNUNET_PEERINFO_IteratorContext *ic = cls;
   const struct InfoMessage *im;
   const struct GNUNET_HELLO_Message *hello;
   uint16_t ms;
 
+  ic->h->in_receive = GNUNET_NO;
   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);
+      reconnect (ic->h);
+      trigger_transmit (ic->h);
+      if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+	GNUNET_SCHEDULER_cancel (ic->h->sched, 
+				 ic->timeout_task);
+      if (ic->callback != NULL)
+	ic->callback (ic->callback_cls, NULL, NULL, 1);
       GNUNET_free (ic);
       return;
     }
   if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END)
     {
-      ic->callback (ic->callback_cls, NULL, NULL, 0);
-      GNUNET_CLIENT_disconnect (ic->client);
+#if DEBUG_PEERINFO
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+		  "Received end of list of peers from peerinfo database\n");
+#endif
+      trigger_transmit (ic->h);
+      if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+	GNUNET_SCHEDULER_cancel (ic->h->sched, 
+				 ic->timeout_task);
+      if (ic->callback != NULL)
+	ic->callback (ic->callback_cls, NULL, NULL, 0);
       GNUNET_free (ic);
       return;
     }
@@ -177,8 +416,13 @@ info_handler (void *cls, const struct GNUNET_MessageHeader *msg)
       (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
     {
       GNUNET_break (0);
-      ic->callback (ic->callback_cls, NULL, NULL, 2);
-      GNUNET_CLIENT_disconnect (ic->client);
+      reconnect (ic->h);
+      trigger_transmit (ic->h);
+      if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+	GNUNET_SCHEDULER_cancel (ic->h->sched, 
+				 ic->timeout_task);
+      if (ic->callback != NULL)
+	ic->callback (ic->callback_cls, NULL, NULL, 2);
       GNUNET_free (ic);
       return;
     }
@@ -189,114 +433,205 @@ info_handler (void *cls, const struct GNUNET_MessageHeader *msg)
       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_free (ic);
+	  GNUNET_break (0);
+	  reconnect (ic->h);
+	  trigger_transmit (ic->h);
+	  if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+	    GNUNET_SCHEDULER_cancel (ic->h->sched, 
+				     ic->timeout_task);
+	  if (ic->callback != NULL)
+	    ic->callback (ic->callback_cls, NULL, NULL, 2);
+	  GNUNET_free (ic);
           return;
         }
     }
-  ic->callback (ic->callback_cls, &im->peer, hello, ntohl (im->trust));
-  GNUNET_CLIENT_receive (ic->client,
-                         &info_handler,
+#if DEBUG_PEERINFO
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+	      "Received %u bytes of `%s' information about peer `%s' from PEERINFO database\n",
+	      (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello),
+	      "HELLO",
+	      GNUNET_i2s (&im->peer));
+#endif
+  ic->h->in_receive = GNUNET_YES;
+  if (ic->callback != NULL)
+    ic->callback (ic->callback_cls, &im->peer, hello, ntohl (im->trust));
+  GNUNET_CLIENT_receive (ic->h->client,
+                         &peerinfo_handler,
                          ic,
                          GNUNET_TIME_absolute_get_remaining (ic->timeout));
 }
 
 
-static size_t
-copy_then_receive (void *cls, size_t size, void *buf)
+/**
+ * We've transmitted the iteration request.  Now get ready to process
+ * the results (or handle transmission error).
+ *
+ * @param cls the 'struct GNUNET_PEERINFO_IteratorContext'
+ * @param transmit_success GNUNET_OK if transmission worked
+ */
+static void
+iterator_start_receive (void *cls,
+			int transmit_success)
 {
-  struct InfoContext *ic = cls;
-  const struct GNUNET_MessageHeader *msg =
-    (const struct GNUNET_MessageHeader *) &ic[1];
-  uint16_t msize;
+  struct GNUNET_PEERINFO_IteratorContext *ic = cls;
 
-  if (buf == NULL)
+  if (GNUNET_OK != transmit_success)
     {
-      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  _
-                  ("Failed to transmit message of type %u to `%s' service.\n"),
-                  ntohs (msg->type), "peerinfo");
+      if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+	{
+	  GNUNET_SCHEDULER_cancel (ic->h->sched,
+				   ic->timeout_task);
+	  ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+	}
+      reconnect (ic->h);
+      trigger_transmit (ic->h);
       ic->callback (ic->callback_cls, NULL, NULL, 1);
-      GNUNET_CLIENT_disconnect (ic->client);
       GNUNET_free (ic);
-      return 0;
-    }
-  msize = ntohs (msg->size);
-  GNUNET_assert (size >= msize);
-  memcpy (buf, msg, msize);
-  GNUNET_CLIENT_receive (ic->client,
-                         &info_handler,
+      return;
+    }  
+  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));
-  return msize;
 }
 
 
 /**
- * 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.
+ * Peerinfo iteration request has timed out.  
  *
- * @param cfg configuration to use
- * @param sched scheduler to use
+ * @param cls the 'struct GNUNET_PEERINFO_IteratorContext*'
+ * @param tc scheduler context
+ */
+static void
+signal_timeout (void *cls,
+		const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  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);
+  ic->callback (ic->callback_cls, NULL, NULL, 1);
+  ic->callback = NULL;
+  if (ic->in_receive)
+    return;
+  GNUNET_free (ic->tqe);
+  GNUNET_free (ic);
+}
+
+
+/**
+ * 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.
+ *
+ * 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, 1 if we timed out and 2 for fatal error.
+ *
+ * Instead of calling this function with 'peer == NULL' and 'trust ==
+ * 0', 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 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 (in this case, 'callback' is never called!), 
+ *         otherwise an iterator context
  */
-void
-GNUNET_PEERINFO_for_all (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)
+struct GNUNET_PEERINFO_IteratorContext *
+GNUNET_PEERINFO_iterate (struct GNUNET_PEERINFO_Handle *h,
+			 const struct GNUNET_PeerIdentity *peer,
+			 int trust_delta,
+			 struct GNUNET_TIME_Relative timeout,
+			 GNUNET_PEERINFO_Processor callback,
+			 void *callback_cls)
 {
-  struct GNUNET_CLIENT_Connection *client;
   struct ListAllPeersMessage *lapm;
   struct ListPeerMessage *lpm;
-  size_t hs;
-  struct InfoContext *ihc;
+  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");
-      callback (callback_cls, NULL, NULL, 2);
-      return;
-    }
-  ihc = GNUNET_malloc (sizeof (struct InfoContext) +
-                       sizeof (struct ListPeerMessage));
-  ihc->client = client;
-  ihc->callback = callback;
-  ihc->callback_cls = callback_cls;
-  ihc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
-  hs = 0;
+#if DEBUG_PEERINFO
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+	      "Requesting list of peers from peerinfo database\n");
+#endif
   if (peer == NULL)
     {
-      lapm = (struct ListAllPeersMessage *) &ihc[1];
-      lapm->header.size = htons (hs = sizeof (struct ListAllPeersMessage));
+      tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
+			   sizeof (struct ListAllPeersMessage));
+      tqe->size = sizeof (struct ListAllPeersMessage);
+      lapm = (struct ListAllPeersMessage *) &tqe[1];
+      lapm->header.size = htons (sizeof (struct ListAllPeersMessage));
       lapm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL);
       lapm->trust_change = htonl (trust_delta);
     }
   else
     {
-      lpm = (struct ListPeerMessage *) &ihc[1];
-      lpm->header.size = htons (hs = sizeof (struct ListPeerMessage));
+      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);
       lpm->trust_change = htonl (trust_delta);
       memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity));
     }
-  GNUNET_CLIENT_notify_transmit_ready (client,
-                                       hs, timeout, &copy_then_receive, ihc);
+  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 (h->sched, 
+						   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;
+}
+
+
+
+/**
+ * Cancel an iteration over peer information.
+ *
+ * @param ic context of the iterator to cancel
+ */
+void
+GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic)
+{
+  if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+    {
+      GNUNET_SCHEDULER_cancel (ic->h->sched,
+			       ic->timeout_task);
+      ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+    }
+  ic->callback = NULL;
+  if (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);
 }
 
+
 /* end of peerinfo_api.c */