From 931b179d14d3749e9fbcc722eefced5bf23bdfed Mon Sep 17 00:00:00 2001
From: Martine Lenders <m.lenders@fu-berlin.de>
Date: Mon, 25 Feb 2019 17:08:30 +0100
Subject: [PATCH] gnrc_sixlowpan_frag: encapsulate msg_send_to_self()

This makes it easier to access this functionality for test cases e.g.
from the `main` thread.
---
 sys/include/net/gnrc/sixlowpan/frag.h         | 26 ++++++++++++++++++-
 sys/include/net/gnrc/sixlowpan/internal.h     |  8 ++++++
 .../sixlowpan/frag/gnrc_sixlowpan_frag.c      |  5 +---
 .../network_layer/sixlowpan/gnrc_sixlowpan.c  |  5 ++++
 4 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/sys/include/net/gnrc/sixlowpan/frag.h b/sys/include/net/gnrc/sixlowpan/frag.h
index ff6a7c4987a3..cf5ab60a5cad 100644
--- a/sys/include/net/gnrc/sixlowpan/frag.h
+++ b/sys/include/net/gnrc/sixlowpan/frag.h
@@ -29,9 +29,10 @@
 #include <stdbool.h>
 
 #include "byteorder.h"
-#include "kernel_types.h"
+#include "msg.h"
 #include "net/gnrc/pkt.h"
 #include "net/gnrc/netif/hdr.h"
+#include "net/gnrc/sixlowpan/internal.h"
 #include "net/ieee802154.h"
 #include "net/sixlowpan.h"
 
@@ -133,6 +134,29 @@ void gnrc_sixlowpan_frag_recv(gnrc_pktsnip_t *pkt, void *ctx, unsigned page);
  */
 void gnrc_sixlowpan_frag_rbuf_gc(void);
 
+/**
+ * @brief   Sends a message to pass a further fragment down the network stack
+ *
+ * @see GNRC_SIXLOWPAN_MSG_FRAG_SND
+ *
+ * @param[in] fragment_msg  A @ref gnrc_sixlowpan_msg_frag_t object
+ *
+ * @return  true, when the message was sent
+ * @return  false when sending the message failed.
+ */
+static inline bool gnrc_sixlowpan_frag_send_msg(gnrc_sixlowpan_msg_frag_t *fragment_msg)
+{
+    msg_t msg;
+
+    msg.content.ptr = fragment_msg;
+    msg.type = GNRC_SIXLOWPAN_MSG_FRAG_SND;
+#ifdef TEST_SUITES
+    return (msg_try_send(&msg, gnrc_sixlowpan_get_pid()) > 0);
+#else
+    return (msg_send_to_self(&msg) != 0);
+#endif
+}
+
 #if defined(MODULE_GNRC_SIXLOWPAN_FRAG) || defined(DOXYGEN)
 /**
  * @brief   Removes an entry from the reassembly buffer
diff --git a/sys/include/net/gnrc/sixlowpan/internal.h b/sys/include/net/gnrc/sixlowpan/internal.h
index 19f3f1f0591a..bf95d81caf60 100644
--- a/sys/include/net/gnrc/sixlowpan/internal.h
+++ b/sys/include/net/gnrc/sixlowpan/internal.h
@@ -27,6 +27,14 @@
 extern "C" {
 #endif
 
+/**
+ * @brief   Returns the PID of the 6Lo thread
+ *
+ * @return  The PID of the 6Lo thread on success
+ * @return  KERNEL_PID_UNDEF, when 6Lo thread was not started.
+ */
+kernel_pid_t gnrc_sixlowpan_get_pid(void);
+
 /**
  * @brief   Delegates a packet to the network layer
  *
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 4a7de40c6cc7..79cb69a5563d 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
@@ -241,7 +241,6 @@ void gnrc_sixlowpan_frag_send(gnrc_pktsnip_t *pkt, void *ctx, unsigned page)
     /* payload_len: actual size of the packet vs
      * datagram_size: size of the uncompressed IPv6 packet */
     size_t payload_len = gnrc_pkt_len(fragment_msg->pkt->next);
-    msg_t msg;
 
     assert((fragment_msg->pkt == pkt) || (pkt == NULL));
     (void)page;
@@ -284,9 +283,7 @@ void gnrc_sixlowpan_frag_send(gnrc_pktsnip_t *pkt, void *ctx, unsigned page)
         goto error;
     }
     fragment_msg->offset += res;
-    msg.type = GNRC_SIXLOWPAN_MSG_FRAG_SND,
-    msg.content.ptr = fragment_msg;
-    if (msg_send_to_self(&msg) == 0) {
+    if (!gnrc_sixlowpan_frag_send_msg(fragment_msg)) {
         DEBUG("6lo frag: message queue full, can't issue next fragment "
               "sending\n");
         goto error;
diff --git a/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c b/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
index d7be77b5aa04..b192ad1f13b1 100644
--- a/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
+++ b/sys/net/gnrc/network_layer/sixlowpan/gnrc_sixlowpan.c
@@ -55,6 +55,11 @@ kernel_pid_t gnrc_sixlowpan_init(void)
     return _pid;
 }
 
+kernel_pid_t gnrc_sixlowpan_get_pid(void)
+{
+    return _pid;
+}
+
 void gnrc_sixlowpan_dispatch_recv(gnrc_pktsnip_t *pkt, void *context,
                                   unsigned page)
 {