Merge pull request #2781 from authmillenon/ng_sixlowpan_frag/feat/ini…

…tial

ng_sixlowpan: Initial import of datagram fragmentation

Makefile.dep

@@ -48,6 +48,11 @@ ifneq (,$(filter sixlowpan,$(USEMODULE)))
   USEMODULE += vtimer
 endif
 
+ifneq (,$(filter ng_sixlowpan_frag,$(USEMODULE)))
+  USEMODULE += ng_sixlowpan
+  USEMODULE += vtimer
+endif
+
 ifneq (,$(filter ng_sixlowpan,$(USEMODULE)))
   USEMODULE += ng_ipv6
   USEMODULE += ng_sixlowpan_netif

sys/Makefile

@@ -101,6 +101,9 @@ endif
 ifneq (,$(filter ng_sixlowpan_ctx,$(USEMODULE)))
     DIRS += net/network_layer/ng_sixlowpan/ctx
 endif
+ifneq (,$(filter ng_sixlowpan_frag,$(USEMODULE)))
+    DIRS += net/network_layer/ng_sixlowpan/frag
+endif
 ifneq (,$(filter ng_sixlowpan_netif,$(USEMODULE)))
     DIRS += net/network_layer/ng_sixlowpan/netif
 endif

sys/include/net/ng_sixlowpan.h

@@ -24,6 +24,8 @@
 
 #include "kernel_types.h"
 
+#include "net/ng_sixlowpan/frag.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif

sys/include/net/ng_sixlowpan/frag.h

@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup    net_ng_sixlowpan_frag   6LoWPAN Fragmentation
+ * @ingroup     net_ng_sixlowpan
+ * @brief       6LoWPAN Fragmentation headers and functionality
+ * @see <a href="https://tools.ietf.org/html/rfc4944#section-5.3">
+ *          RFC 4944, section 5.3
+ *      </a>
+ * @{
+ *
+ * @file
+ * @brief   6LoWPAN Fragmentation definitions
+ *
+ * @author  Martine Lenders <mlenders@inf.fu-berlin.de>
+ */
+#ifndef NG_SIXLOWPAN_FRAG_H_
+#define NG_SIXLOWPAN_FRAG_H_
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include "byteorder.h"
+#include "kernel_types.h"
+#include "net/ng_pkt.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define NG_SIXLOWPAN_FRAG_DISP_MASK     (0xf8)      /**< mask for fragmentation
+                                                     *   dispatch */
+#define NG_SIXLOWPAN_FRAG_1_DISP        (0xc0)      /**< dispatch for 1st fragment */
+#define NG_SIXLOWPAN_FRAG_N_DISP        (0xe0)      /**< dispatch for subsequent
+                                                     *   fragments */
+#define NG_SIXLOWPAN_FRAG_SIZE_MASK     (0x07ff)    /**< mask for datagram size */
+
+/**
+ * @brief   General and 1st 6LoWPAN fragmentation header
+ *
+ * @see <a href="https://tools.ietf.org/html/rfc4944#section-5.1">
+ *          RFC 4944, section 5.1
+ *      </a>
+ */
+typedef struct __attribute__((packed)) {
+    /**
+     * @brief   Dispatch and datagram size.
+     *
+     * @details The 5 most significant bits are the dispatch, the remaining
+     *          bits are the size.
+     */
+    network_uint16_t disp_size;
+    network_uint16_t tag;       /**< datagram tag */
+} ng_sixlowpan_frag_t;
+
+/**
+ * @brief   Subsequent 6LoWPAN fragmentation header
+ *
+ * @see <a href="https://tools.ietf.org/html/rfc4944#section-5.3">
+ *          RFC 4944, section 5.3
+ *      </a>
+ *
+ * @extends ng_sixlowpan_frag_t
+ */
+typedef struct __attribute__((packed)) {
+    /**
+     * @brief   Dispatch and datagram size.
+     *
+     * @details The 5 most significant bits are the dispatch, the remaining
+     *          bits are the size.
+     */
+    network_uint16_t disp_size;
+    network_uint16_t tag;       /**< datagram tag */
+    uint8_t offset;             /**< offset */
+} ng_sixlowpan_frag_n_t;
+
+/**
+ * @brief   Checks if a given fragment is a 6LoWPAN fragment.
+ *
+ * @param[in] hdr   A 6LoWPAN fragmentation header.
+ *
+ * @return  true, if given fragment is a 6LoWPAN fragment.
+ * @return  false, if given fragment is not a 6LoWPAN fragment.
+ */
+static inline bool ng_sixlowpan_frag_is(ng_sixlowpan_frag_t *hdr)
+{
+    return ((hdr->disp_size.u8[0] & NG_SIXLOWPAN_FRAG_DISP_MASK) ==
+            NG_SIXLOWPAN_FRAG_1_DISP) ||
+           ((hdr->disp_size.u8[0] & NG_SIXLOWPAN_FRAG_DISP_MASK) ==
+            NG_SIXLOWPAN_FRAG_N_DISP);
+}
+
+/**
+ * @brief   Sends a packet fragmented.
+ *
+ * @param[in] pid           The interface to send the packet over.
+ * @param[in] pkt           The packet to send.
+ * @param[in] payload_len   The length of the payload to send (IPv6 packet size
+ *                          + inner 6LoWPAN dispatches).
+ *                          This value is purely given to not calculate the
+ *                          payload length using @ref ng_pkt_len() repeatedly.
+ * @param[in] datagram_size The length of just the IPv6 packet. It is the value
+ *                          set that the ng_sixlowpan_frag_t::disp_size will be
+ *                          set to.
+ */
+void ng_sixlowpan_frag_send(kernel_pid_t pid, ng_pktsnip_t *pkt,
+                            size_t payload_len, size_t datagram_size);
+
+/**
+ * @brief   Handles a packet containing a fragment header.
+ *
+ * @param[in] pkt   The packet to handle.
+ */
+void ng_sixlowpan_frag_handle_pkt(ng_pktsnip_t *pkt);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NG_SIXLOWPAN_FRAG_H_ */
+/** @} */

sys/net/network_layer/ng_sixlowpan/frag/Makefile

@@ -0,0 +1,3 @@
+MODULE = ng_sixlowpan_frag
+
+include $(RIOTBASE)/Makefile.base