diff --git a/sys/include/net/gnrc/pktbuf.h b/sys/include/net/gnrc/pktbuf.h
index f9f29850b7b213851ff8a3d549e2537c53db9f9a..ad109bb3ef055990c22349672c676926af04cb8a 100644
--- a/sys/include/net/gnrc/pktbuf.h
+++ b/sys/include/net/gnrc/pktbuf.h
@@ -298,6 +298,60 @@ gnrc_pktsnip_t *gnrc_pktbuf_reverse_snips(gnrc_pktsnip_t *pkt);
*/
gnrc_pktsnip_t *gnrc_pktbuf_duplicate_upto(gnrc_pktsnip_t *pkt, gnrc_nettype_t type);
+/**
+ * @brief Merge pktsnip chain to single pktsnip.
+ *
+ * Specifically it calls @ref gnrc_pktbuf_realloc_data() on @p pkt, then copies
+ * the data of all following packet snips into that reallocated space, and
+ * removes the packet snip the data was copied from afterwards.
+ *
+ * ### Example
+ * #### Input
+ *
+ * buffer
+ * +---------------------------+ +------+
+ * | size = 8 | data +-------->| |
+ * | type = NETTYPE_IPV6 |------------+ +------+
+ * +---------------------------+ . .
+ * | next . .
+ * v . .
+ * +---------------------------+ +------+
+ * | size = 40 | data +----------->| |
+ * | type = NETTYPE_UDP |---------+ +------+
+ * +---------------------------+ . .
+ * | next . .
+ * v
+ * +---------------------------+ +------+
+ * | size = 14 | data +-------------->| |
+ * | type = NETTYPE_UNDEF |------+ +------+
+ * +---------------------------+ . .
+ *
+ *
+ * #### Output
+ *
+ * buffer
+ * +---------------------------+ +------+
+ * | size = 62 | data +-------->| |
+ * | type = NETTYPE_IPV6 |------------+ | |
+ * +---------------------------+ | |
+ * | |
+ * | |
+ * | |
+ * +------+
+ * . .
+ *
+ * @warning @p pkt needs to write protected before calling this function.
+ * @note Packets in receive order need to call
+ * @ref gnrc_pktbuf_reverse_snips() first to get the data in the
+ * correct order.
+ *
+ * @param[in,out] pkt The snip to merge.
+ *
+ * @return 0, on success
+ * @return ENOMEM, if no space is left in the packet buffer.
+ */
+int gnrc_pktbuf_merge(gnrc_pktsnip_t *pkt);
+
#ifdef DEVELHELP
/**
* @brief Prints some statistics about the packet buffer to stdout.
diff --git a/sys/net/gnrc/pktbuf/gnrc_pktbuf.c b/sys/net/gnrc/pktbuf/gnrc_pktbuf.c
index 83e0a89e3121d9f6990b1136bd35d3ae63a37c5a..503e66c7b3806047fbc1fdecc152660ff64b58e6 100644
--- a/sys/net/gnrc/pktbuf/gnrc_pktbuf.c
+++ b/sys/net/gnrc/pktbuf/gnrc_pktbuf.c
@@ -109,5 +109,32 @@ gnrc_pktsnip_t *gnrc_pktbuf_reverse_snips(gnrc_pktsnip_t *pkt)
return reversed;
}
+int gnrc_pktbuf_merge(gnrc_pktsnip_t *pkt)
+{
+ size_t offset = pkt->size;
+ size_t size = gnrc_pkt_len(pkt);
+ int res = 0;
+
+ if (pkt->size == size) {
+ return res;
+ }
+
+ /* Re-allocate data */
+ res = gnrc_pktbuf_realloc_data(pkt, size);
+ if (res != 0) {
+ return res;
+ }
+
+ /* Copy data to new buffer */
+ for (gnrc_pktsnip_t *ptr = pkt->next; ptr != NULL; ptr = ptr->next) {
+ memcpy(((uint8_t *)pkt->data) + offset, ptr->data, ptr->size);
+ offset += ptr->size;
+ }
+
+ /* Release old pktsnips and data*/
+ gnrc_pktbuf_release(pkt->next);
+ pkt->next = NULL;
+ return res;
+}
/** @} */
diff --git a/tests/unittests/tests-pktbuf/tests-pktbuf.c b/tests/unittests/tests-pktbuf/tests-pktbuf.c
index 64d000b26ab127c9964b7de03b4c625fba7cc3c7..8f204afa85a9d79ab20bc88d4d68ea380e1c223a 100644
--- a/tests/unittests/tests-pktbuf/tests-pktbuf.c
+++ b/tests/unittests/tests-pktbuf/tests-pktbuf.c
@@ -653,6 +653,52 @@ static void test_pktbuf_realloc_data__success3(void)
TEST_ASSERT(gnrc_pktbuf_is_empty());
}
+static void test_pktbuf_merge_data__memfull(void)
+{
+ gnrc_pktsnip_t *pkt = gnrc_pktbuf_add(NULL, NULL, (GNRC_PKTBUF_SIZE / 4),
+ GNRC_NETTYPE_TEST);
+
+ pkt = gnrc_pktbuf_add(pkt, NULL, (GNRC_PKTBUF_SIZE / 4) + 1,
+ GNRC_NETTYPE_TEST);
+ TEST_ASSERT_EQUAL_INT(ENOMEM, gnrc_pktbuf_merge(pkt));
+ gnrc_pktbuf_release(pkt);
+ TEST_ASSERT(gnrc_pktbuf_is_empty());
+}
+
+static void test_pktbuf_merge_data__success1(void)
+{
+ gnrc_pktsnip_t *pkt = gnrc_pktbuf_add(NULL, NULL, 0, GNRC_NETTYPE_TEST);
+
+ TEST_ASSERT_NOT_NULL(pkt);
+ TEST_ASSERT_NULL(pkt->data);
+
+ TEST_ASSERT_EQUAL_INT(0, gnrc_pktbuf_merge(pkt));
+ gnrc_pktbuf_release(pkt);
+ TEST_ASSERT(gnrc_pktbuf_is_empty());
+}
+
+static void test_pktbuf_merge_data__success2(void)
+{
+ gnrc_pktsnip_t *pkt = gnrc_pktbuf_add(NULL, TEST_STRING4,
+ sizeof(TEST_STRING4),
+ GNRC_NETTYPE_TEST);
+
+ pkt = gnrc_pktbuf_add(pkt, TEST_STRING8, sizeof(TEST_STRING8), GNRC_NETTYPE_TEST);
+ pkt = gnrc_pktbuf_add(pkt, TEST_STRING16, sizeof(TEST_STRING16), GNRC_NETTYPE_TEST);
+
+ TEST_ASSERT_EQUAL_INT(0, gnrc_pktbuf_merge(pkt));
+ TEST_ASSERT_NULL(pkt->next);
+ TEST_ASSERT_EQUAL_STRING(TEST_STRING16, pkt->data);
+ TEST_ASSERT_EQUAL_STRING(TEST_STRING8,
+ (char *) pkt->data + sizeof(TEST_STRING16));
+ TEST_ASSERT_EQUAL_STRING(TEST_STRING4,
+ (char *) pkt->data + sizeof(TEST_STRING16) +
+ sizeof(TEST_STRING8));
+ gnrc_pktbuf_release(pkt);
+ TEST_ASSERT(gnrc_pktbuf_is_empty());
+ TEST_ASSERT(gnrc_pktbuf_is_sane());
+}
+
static void test_pktbuf_hold__pkt_null(void)
{
gnrc_pktbuf_hold(NULL, 1);
@@ -895,6 +941,9 @@ Test *tests_pktbuf_tests(void)
new_TestFixture(test_pktbuf_realloc_data__success),
new_TestFixture(test_pktbuf_realloc_data__success2),
new_TestFixture(test_pktbuf_realloc_data__success3),
+ new_TestFixture(test_pktbuf_merge_data__memfull),
+ new_TestFixture(test_pktbuf_merge_data__success1),
+ new_TestFixture(test_pktbuf_merge_data__success2),
new_TestFixture(test_pktbuf_hold__pkt_null),
new_TestFixture(test_pktbuf_hold__pkt_external),
new_TestFixture(test_pktbuf_hold__success),