gnrc_netif_hdr: provide wrappers for gnrc_netif_ipv6_iid_from_addr()

For convenience ;-).

sys/include/net/gnrc/netif/hdr.h

@@ -24,6 +24,7 @@
 #include <string.h>
 #include <stdint.h>
 
+#include "net/gnrc/netif.h"
 #include "net/gnrc/pkt.h"
 #include "net/gnrc/pktbuf.h"
 
@@ -196,6 +197,58 @@ static inline void gnrc_netif_hdr_set_dst_addr(gnrc_netif_hdr_t *hdr, uint8_t *a
     memcpy(((uint8_t *)(hdr + 1)) + hdr->src_l2addr_len, addr, addr_len);
 }
 
+/**
+ * @brief   Converts the source address of a given @ref net_gnrc_netif_hdr to
+ *          an IPv6 IID
+ *
+ * @note    @p netif is intentionally required to be provided so that the caller
+ *          needs to retrieve it from gnrc_netif_hdr_t::if_pid of @p hdr only
+ *          once instead of this function retrieving it at every call.
+ *
+ * @pre `netif->pid == hdr->if_pid`
+ *
+ * @param[in] netif A network interface. gnrc_netif_t::pid must be equal to
+ *                  gnrc_netif_hdr_t::if_pid of @p hdr.
+ * @param[in] hdr   Header to convert source address from.
+ * @param[out] iid  The IID based on gnrc_netif_t::device_type.
+ *
+ * @return  same as @ref gnrc_netif_ipv6_iid_from_addr().
+ */
+static inline int gnrc_netif_hdr_ipv6_iid_from_src(const gnrc_netif_t *netif,
+                                                   const gnrc_netif_hdr_t *hdr,
+                                                   eui64_t *iid)
+{
+    return gnrc_netif_ipv6_iid_from_addr(
+            netif,gnrc_netif_hdr_get_src_addr(hdr), hdr->src_l2addr_len, iid
+        );
+}
+
+/**
+ * @brief   Converts the destination address of a given @ref net_gnrc_netif_hdr
+ *          to an IPv6 IID
+ *
+ * @note    @p netif is intentionally required to be provided so that the caller
+ *          needs to retrieve it from gnrc_netif_hdr_t::if_pid of @p hdr only
+ *          once instead of this function retrieving it at every call.
+ *
+ * @pre `netif->pid == hdr->if_pid`
+ *
+ * @param[in] netif A network interface. gnrc_netif_t::pid must be equal to
+ *                  gnrc_netif_hdr_t::if_pid of @p hdr.
+ * @param[in] hdr   Header to convert destination address from.
+ * @param[out] iid  The IID based on gnrc_netif_t::device_type.
+ *
+ * @return  same as @ref gnrc_netif_ipv6_iid_from_addr().
+ */
+static inline int gnrc_netif_hdr_ipv6_iid_from_dst(const gnrc_netif_t *netif,
+                                                   const gnrc_netif_hdr_t *hdr,
+                                                   eui64_t *iid)
+{
+    return gnrc_netif_ipv6_iid_from_addr(
+            netif,gnrc_netif_hdr_get_dst_addr(hdr), hdr->dst_l2addr_len, iid
+        );
+}
+
 /**
  * @brief   Builds a generic network interface header for sending and
  *          adds it to the packet buffer.