From a2eb3c7f15f128bdc6d11ca063b4fe57d938608c Mon Sep 17 00:00:00 2001
From: Martine Lenders <m.lenders@fu-berlin.de>
Date: Tue, 19 Jun 2018 14:59:49 +0200
Subject: [PATCH] gnrc_sixlowpan_frag: adapt for #8511
This refactors the `gnrc_sixlowpan_frag` module for the API proposed
in #8511.
The `ctx` for `gnrc_sixlowpan_frag_send()` is required to be a
`gnrc_sixlowpan_msg_frag_t` object, so IPHC can later on use it to
provide the *original* datagram size (otherwise, we would need to adapt
the API just for that, which seems to me as convoluted as this
proposal).
I also provide an expose function with a future possibility to provide
more than just one `gnrc_sixlowpan_msg_frag_t` object later on (plus
having cleaner module separation in general).
---
sys/include/net/gnrc/sixlowpan/frag.h | 35 ++++++++++++++-----
.../sixlowpan/frag/gnrc_sixlowpan_frag.c | 20 +++++++++--
.../network_layer/sixlowpan/gnrc_sixlowpan.c | 35 ++++++++-----------
3 files changed, 59 insertions(+), 31 deletions(-)
diff --git a/sys/include/net/gnrc/sixlowpan/frag.h b/sys/include/net/gnrc/sixlowpan/frag.h
index 96841b882e..f557470ebc 100644
--- a/sys/include/net/gnrc/sixlowpan/frag.h
+++ b/sys/include/net/gnrc/sixlowpan/frag.h
@@ -74,26 +74,45 @@ typedef struct {
*/
typedef struct {
gnrc_pktsnip_t *pkt; /**< Pointer to the IPv6 packet to be fragmented */
- size_t datagram_size; /**< Length of just the IPv6 packet to be fragmented */
+ size_t datagram_size; /**< Length of just the (uncompressed) IPv6 packet to be fragmented */
uint16_t offset; /**< Offset of the Nth fragment from the beginning of the
* payload datagram */
kernel_pid_t pid; /**< PID of the interface */
} gnrc_sixlowpan_msg_frag_t;
/**
- * @brief Sends a packet fragmented.
+ * @brief Allocates a @ref gnrc_sixlowpan_msg_frag_t object
*
- * @param[in] fragment_msg Message containing status of the 6LoWPAN
- * fragmentation progress
+ * @return A @ref gnrc_sixlowpan_msg_frag_t if available
+ * @return NULL, otherwise
*/
-void gnrc_sixlowpan_frag_send(gnrc_sixlowpan_msg_frag_t *fragment_msg);
+gnrc_sixlowpan_msg_frag_t *gnrc_sixlowpan_msg_frag_get(void);
/**
- * @brief Handles a packet containing a fragment header.
+ * @brief Sends a packet fragmented
*
- * @param[in] pkt The packet to handle.
+ * @pre `ctx != NULL`
+ * @pre gnrc_sixlowpan_msg_frag_t::pkt of @p ctx is equal to @p pkt or
+ * `pkt == NULL`.
+ *
+ * @param[in] pkt A packet. May be NULL.
+ * @param[in] ctx Message containing status of the 6LoWPAN fragmentation
+ * progress. Expected to be of type
+ * @ref gnrc_sixlowpan_msg_frag_t, with
+ * gnrc_sixlowpan_msg_frag_t set to @p pkt. Must not be
+ * NULL.
+ * @param[in] page Current 6Lo dispatch parsing page.
+ */
+void gnrc_sixlowpan_frag_send(gnrc_pktsnip_t *pkt, void *ctx, unsigned page);
+
+/**
+ * @brief Handles a packet containing a fragment header
+ *
+ * @param[in] pkt The packet to handle
+ * @param[in] ctx Context for the packet. May be NULL.
+ * @param[in] page Current 6Lo dispatch parsing page.
*/
-void gnrc_sixlowpan_frag_handle_pkt(gnrc_pktsnip_t *pkt);
+void gnrc_sixlowpan_frag_recv(gnrc_pktsnip_t *pkt, void *ctx, unsigned page);
#ifdef __cplusplus
}
diff --git a/sys/net/gnrc/network_layer/sixlowpan/frag/gnrc_sixlowpan_frag.c b/sys/net/gnrc/network_layer/sixlowpan/frag/gnrc_sixlowpan_frag.c
index ce137cdd73..6724dc929a 100644
--- a/sys/net/gnrc/network_layer/sixlowpan/frag/gnrc_sixlowpan_frag.c
+++ b/sys/net/gnrc/network_layer/sixlowpan/frag/gnrc_sixlowpan_frag.c
@@ -31,6 +31,10 @@
#define ENABLE_DEBUG (0)
#include "debug.h"
+static gnrc_sixlowpan_msg_frag_t _fragment_msg = {
+ NULL, 0, 0, KERNEL_PID_UNDEF
+ };
+
#if ENABLE_DEBUG
/* For PRIu16 etc. */
#include <inttypes.h>
@@ -209,8 +213,15 @@ static uint16_t _send_nth_fragment(gnrc_netif_t *iface, gnrc_pktsnip_t *pkt,
return local_offset;
}
-void gnrc_sixlowpan_frag_send(gnrc_sixlowpan_msg_frag_t *fragment_msg)
+gnrc_sixlowpan_msg_frag_t *gnrc_sixlowpan_msg_frag_get(void)
+{
+ return (_fragment_msg.pkt == NULL) ? &_fragment_msg : NULL;
+}
+
+void gnrc_sixlowpan_frag_send(gnrc_pktsnip_t *pkt, void *ctx, unsigned page)
{
+ assert(ctx != NULL);
+ gnrc_sixlowpan_msg_frag_t *fragment_msg = ctx;
gnrc_netif_t *iface = gnrc_netif_get_by_pid(fragment_msg->pid);
uint16_t res;
/* payload_len: actual size of the packet vs
@@ -218,6 +229,9 @@ void gnrc_sixlowpan_frag_send(gnrc_sixlowpan_msg_frag_t *fragment_msg)
size_t payload_len = gnrc_pkt_len(fragment_msg->pkt->next);
msg_t msg;
+ assert((fragment_msg->pkt == pkt) || (pkt == NULL));
+ (void)page;
+ (void)pkt;
#if defined(DEVELHELP) && ENABLE_DEBUG
if (iface == NULL) {
DEBUG("6lo frag: iface == NULL, expect segmentation fault.\n");
@@ -275,13 +289,15 @@ void gnrc_sixlowpan_frag_send(gnrc_sixlowpan_msg_frag_t *fragment_msg)
}
}
-void gnrc_sixlowpan_frag_handle_pkt(gnrc_pktsnip_t *pkt)
+void gnrc_sixlowpan_frag_recv(gnrc_pktsnip_t *pkt, void *ctx, unsigned page)
{
gnrc_netif_hdr_t *hdr = pkt->next->data;
sixlowpan_frag_t *frag = pkt->data;
uint16_t offset = 0;
size_t frag_size;
+ (void)ctx;
+ (void)page;
switch (frag->disp_size.u8[0] & SIXLOWPAN_FRAG_DISP_MASK) {
case SIXLOWPAN_FRAG_1_DISP:
frag_size = (pkt->size - sizeof(sixlowpan_frag_t));
diff --git a/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c b/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
index cd744dd051..18c615851c 100644
--- a/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
+++ b/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
@@ -34,10 +34,6 @@
static kernel_pid_t _pid = KERNEL_PID_UNDEF;
-#ifdef MODULE_GNRC_SIXLOWPAN_FRAG
-static gnrc_sixlowpan_msg_frag_t fragment_msg = {NULL, 0, 0, KERNEL_PID_UNDEF};
-#endif
-
#if ENABLE_DEBUG
static char _stack[GNRC_SIXLOWPAN_STACK_SIZE + THREAD_EXTRA_STACKSIZE_PRINTF];
#else
@@ -164,7 +160,7 @@ static void _receive(gnrc_pktsnip_t *pkt)
#ifdef MODULE_GNRC_SIXLOWPAN_FRAG
else if (sixlowpan_frag_is((sixlowpan_frag_t *)dispatch)) {
DEBUG("6lo: received 6LoWPAN fragment\n");
- gnrc_sixlowpan_frag_handle_pkt(pkt);
+ gnrc_sixlowpan_frag_recv(pkt, NULL, 0);
return;
}
#endif
@@ -305,27 +301,24 @@ static void _send(gnrc_pktsnip_t *pkt)
return;
}
#ifdef MODULE_GNRC_SIXLOWPAN_FRAG
- else if (fragment_msg.pkt != NULL) {
- DEBUG("6lo: Fragmentation already ongoing. Dropping packet\n");
- gnrc_pktbuf_release(pkt2);
- return;
- }
else if (datagram_size <= SIXLOWPAN_FRAG_MAX_LEN) {
DEBUG("6lo: Send fragmented (%u > %" PRIu8 ")\n",
(unsigned int)datagram_size, iface->sixlo.max_frag_size);
- msg_t msg;
+ gnrc_sixlowpan_msg_frag_t *fragment_msg;
- fragment_msg.pid = hdr->if_pid;
- fragment_msg.pkt = pkt2;
- fragment_msg.datagram_size = datagram_size;
+ fragment_msg = gnrc_sixlowpan_msg_frag_get();
+ if (fragment_msg == NULL) {
+ DEBUG("6lo: Not enough resources to fragment packet. Dropping packet\n");
+ gnrc_pktbuf_release(pkt2);
+ return;
+ }
+ fragment_msg->pid = hdr->if_pid;
+ fragment_msg->pkt = pkt2;
+ fragment_msg->datagram_size = datagram_size;
/* Sending the first fragment has an offset==0 */
- fragment_msg.offset = 0;
+ fragment_msg->offset = 0;
- /* set the outgoing message's fields */
- msg.type = GNRC_SIXLOWPAN_MSG_FRAG_SND;
- msg.content.ptr = &fragment_msg;
- /* send message to self */
- msg_send_to_self(&msg);
+ gnrc_sixlowpan_frag_send(pkt2, fragment_msg, 0);
}
else {
DEBUG("6lo: packet too big (%u > %" PRIu16 ")\n",
@@ -380,7 +373,7 @@ static void *_event_loop(void *args)
#ifdef MODULE_GNRC_SIXLOWPAN_FRAG
case GNRC_SIXLOWPAN_MSG_FRAG_SND:
DEBUG("6lo: send fragmented event received\n");
- gnrc_sixlowpan_frag_send(msg.content.ptr);
+ gnrc_sixlowpan_frag_send(NULL, msg.content.ptr, 0);
break;
#endif
--
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