From d99972791a3573cdcfe58ea0058023b2bca6cb05 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benpicco@beuth-hochschule.de>
Date: Wed, 28 Jul 2021 00:25:03 +0200
Subject: [PATCH] gnrc/rpl: add gnrc_rpl_configure_root() convenience function

---
 sys/include/net/gnrc/rpl.h          | 12 ++++++++++++
 sys/net/gnrc/routing/rpl/gnrc_rpl.c | 12 ++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/sys/include/net/gnrc/rpl.h b/sys/include/net/gnrc/rpl.h
index f792b5ace1..e5fb179075 100644
--- a/sys/include/net/gnrc/rpl.h
+++ b/sys/include/net/gnrc/rpl.h
@@ -736,6 +736,18 @@ static inline void gnrc_rpl_config_pio(gnrc_rpl_dodag_t *dodag, bool status)
     }
 }
 
+#if IS_USED(MODULE_GNRC_RPL) || DOXYGEN
+/**
+ * @brief Convenience function to start a RPL root using the default configuration.
+ *
+ * @param[in] netif             Network interface to use as RPL root
+ * @param[in] dodag_id          Id of the DODAG
+ */
+void gnrc_rpl_configure_root(gnrc_netif_t *netif, const ipv6_addr_t *dodag_id);
+#else
+#define gnrc_rpl_configure_root(netif, dodag_id)  ((void)netif)
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/sys/net/gnrc/routing/rpl/gnrc_rpl.c b/sys/net/gnrc/routing/rpl/gnrc_rpl.c
index 35879e2bca..1b4c7c80e2 100644
--- a/sys/net/gnrc/routing/rpl/gnrc_rpl.c
+++ b/sys/net/gnrc/routing/rpl/gnrc_rpl.c
@@ -419,6 +419,18 @@ uint8_t gnrc_rpl_gen_instance_id(bool local)
     return instance_id;
 }
 
+void gnrc_rpl_configure_root(gnrc_netif_t *netif, const ipv6_addr_t *dodag_id)
+{
+    gnrc_rpl_init(netif->pid);
+    gnrc_rpl_instance_t *inst = gnrc_rpl_instance_get(
+            CONFIG_GNRC_RPL_DEFAULT_INSTANCE
+        );
+    if (inst) {
+        gnrc_rpl_instance_remove(inst);
+    }
+    gnrc_rpl_root_init(CONFIG_GNRC_RPL_DEFAULT_INSTANCE, dodag_id, false, false);
+}
+
 /**
  * @}
  */