1 files changed, 203 insertions, 0 deletions
diff --git a/src/include/gnunet_fragmentation_lib.h b/src/include/gnunet_fragmentation_lib.h
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+++ b/src/include/gnunet_fragmentation_lib.h
@@ -0,0 +1,203 @@
+/*
+     This file is part of GNUnet
+     (C) 2009, 2011 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
+     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
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+/**
+ * @file include/gnunet_fragmentation_lib.h
+ * @brief library to help fragment messages
+ * @author Christian Grothoff
+ *
+ * TODO: consider additional flow-control for sending from
+ *       fragmentation based on continuations.
+ */
+
+#ifndef GNUNET_FRAGMENTATION_LIB_H
+#define GNUNET_FRAGMENTATION_LIB_H
+
+#include "gnunet_util_lib.h"
+#include "gnunet_bandwidth_lib.h"
+#include "gnunet_statistics_service.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#if 0                           /* keep Emacsens' auto-indent happy */
+}
+#endif
+#endif
+
+
+/**
+ * Fragmentation context.
+ */
+struct GNUNET_FRAGMENT_Context;
+
+
+/**
+ * Function that is called with messages created by the fragmentation
+ * module.  In the case of the 'proc' callback of the
+ * GNUNET_FRAGMENT_context_create function, this function must
+ * eventually call 'GNUNET_FRAGMENT_context_transmission_done'.
+ *
+ * @param cls closure
+ * @param msg the message that was created
+ */
+typedef void (*GNUNET_FRAGMENT_MessageProcessor) (void *cls,
+                                                  const struct
+                                                  GNUNET_MessageHeader * msg);
+
+
+/**
+ * Create a fragmentation context for the given message.
+ * Fragments the message into fragments of size "mtu" or
+ * less.  Calls 'proc' on each un-acknowledged fragment,
+ * using both the expected 'delay' between messages and
+ * acknowledgements and the given 'tracker' to guide the
+ * frequency of calls to 'proc'.
+ *
+ * @param stats statistics context
+ * @param mtu the maximum message size for each fragment
+ * @param tracker bandwidth tracker to use for flow control (can be NULL)
+ * @param delay expected delay between fragment transmission
+ *              and ACK based on previous messages
+ * @param msg the message to fragment
+ * @param proc function to call for each fragment to transmit
+ * @param proc_cls closure for proc
+ * @return the fragmentation context
+ */
+struct GNUNET_FRAGMENT_Context *
+GNUNET_FRAGMENT_context_create (struct GNUNET_STATISTICS_Handle *stats,
+                                uint16_t mtu,
+                                struct GNUNET_BANDWIDTH_Tracker *tracker,
+                                struct GNUNET_TIME_Relative delay,
+                                const struct GNUNET_MessageHeader *msg,
+                                GNUNET_FRAGMENT_MessageProcessor proc,
+                                void *proc_cls);
+
+
+/**
+ * Continuation to call from the 'proc' function after the fragment
+ * has been transmitted (and hence the next fragment can now be
+ * given to proc).
+ *
+ * @param fc fragmentation context
+ */
+void
+GNUNET_FRAGMENT_context_transmission_done (struct GNUNET_FRAGMENT_Context *fc);
+
+
+/**
+ * Process an acknowledgement message we got from the other
+ * side (to control re-transmits).
+ *
+ * @param fc fragmentation context
+ * @param msg acknowledgement message we received
+ * @return GNUNET_OK if this ack completes the work of the 'fc'
+ *                   (all fragments have been received);
+ *         GNUNET_NO if more messages are pending
+ *         GNUNET_SYSERR if this ack is not valid for this fc
+ */
+int
+GNUNET_FRAGMENT_process_ack (struct GNUNET_FRAGMENT_Context *fc,
+                             const struct GNUNET_MessageHeader *msg);
+
+
+/**
+ * Destroy the given fragmentation context (stop calling 'proc', free
+ * resources).
+ *
+ * @param fc fragmentation context
+ * @return average delay between transmission and ACK for the
+ *         last message, FOREVER if the message was not fully transmitted
+ */
+struct GNUNET_TIME_Relative
+GNUNET_FRAGMENT_context_destroy (struct GNUNET_FRAGMENT_Context *fc);
+
+
+/**
+ * Defragmentation context (one per connection).
+ */
+struct GNUNET_DEFRAGMENT_Context;
+
+
+/**
+ * Function that is called with acknowledgement messages created by
+ * the fragmentation module.  Acknowledgements are cummulative,
+ * so it is OK to only transmit the 'latest' ack message for the same
+ * message ID.
+ *
+ * @param cls closure
+ * @param id unique message ID (modulo collisions)
+ * @param msg the message that was created
+ */
+typedef void (*GNUNET_DEFRAGMENT_AckProcessor) (void *cls, uint32_t id,
+                                                const struct
+                                                GNUNET_MessageHeader * msg);
+
+
+/**
+ * Create a defragmentation context.
+ *
+ * @param stats statistics context
+ * @param mtu the maximum message size for each fragment
+ * @param num_msgs how many fragmented messages
+ *                 to we defragment at most at the same time?
+ * @param cls closure for proc and ackp
+ * @param proc function to call with defragmented messages
+ * @param ackp function to call with acknowledgements (to send
+ *             back to the other side)
+ * @return the defragmentation context
+ */
+struct GNUNET_DEFRAGMENT_Context *
+GNUNET_DEFRAGMENT_context_create (struct GNUNET_STATISTICS_Handle *stats,
+                                  uint16_t mtu, unsigned int num_msgs,
+                                  void *cls,
+                                  GNUNET_FRAGMENT_MessageProcessor proc,
+                                  GNUNET_DEFRAGMENT_AckProcessor ackp);
+
+
+/**
+ * Destroy the given defragmentation context.
+ *
+ * @param dc defragmentation context
+ */
+void
+GNUNET_DEFRAGMENT_context_destroy (struct GNUNET_DEFRAGMENT_Context *dc);
+
+
+/**
+ * We have received a fragment.  Process it.
+ *
+ * @param dc the context
+ * @param msg the message that was received
+ * @return GNUNET_OK on success, GNUNET_NO if this was a duplicate, GNUNET_SYSERR on error
+ */
+int
+GNUNET_DEFRAGMENT_process_fragment (struct GNUNET_DEFRAGMENT_Context *dc,
+                                    const struct GNUNET_MessageHeader *msg);
+
+
+#if 0                           /* keep Emacsens' auto-indent happy */
+{
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+/* end of gnunet_fragmentation_lib.h */
+#endif