From 3d819ce70728c721d34e63868dfe67248cd4f971 Mon Sep 17 00:00:00 2001
From: Martine Lenders <m.lenders@fu-berlin.de>
Date: Fri, 18 Feb 2022 16:42:08 +0100
Subject: [PATCH] gnrc_netif: make auto-config of compression context optional

---
 sys/include/net/gnrc/netif/conf.h | 10 ++++++++++
 sys/net/gnrc/netif/Kconfig        |  7 +++++++
 sys/net/gnrc/netif/gnrc_netif.c   | 10 ++++++----
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/sys/include/net/gnrc/netif/conf.h b/sys/include/net/gnrc/netif/conf.h
index 6156028010c0..4d679c23d4bf 100644
--- a/sys/include/net/gnrc/netif/conf.h
+++ b/sys/include/net/gnrc/netif/conf.h
@@ -194,6 +194,16 @@ extern "C" {
 #define CONFIG_GNRC_NETIF_NONSTANDARD_6LO_MTU 0
 #endif
 
+/**
+ * @brief   Automatically add 6LoWPAN compression at border router
+ *
+ * When set, 6LoWPAN compression context 0 will be automatically set for the prefix configured by
+ * prefix deligation at the border router.
+ */
+#ifndef CONFIG_GNRC_NETIF_IPV6_BR_AUTO_6CTX
+#define CONFIG_GNRC_NETIF_IPV6_BR_AUTO_6CTX   1
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/sys/net/gnrc/netif/Kconfig b/sys/net/gnrc/netif/Kconfig
index 213d64c57bb8..481e425e94cc 100644
--- a/sys/net/gnrc/netif/Kconfig
+++ b/sys/net/gnrc/netif/Kconfig
@@ -74,5 +74,12 @@ config GNRC_NETIF_LORAWAN_NETIF_HDR
         GNRC LoRaWAN packets will include the GNRC Netif
         header. Therefore this parameter will be removed
 
+config GNRC_NETIF_IPV6_BR_AUTO_6CTX
+    bool "Automatically add 6LoWPAN compression at border router"
+    default y
+    depends on USEMODULE_GNRC_IPV6_NIB_6LBR && USEMODULE_GNRC_SIXLOWPAN_IPHC && USEMODULE_GNRC_SIXLOWPAN_CTX
+    help
+        When set, 6LoWPAN compression context 0 will be automatically set for the prefix configured
+        by prefix deligation at the border router.
 
 endif # KCONFIG_USEMODULE_GNRC_NETIF
diff --git a/sys/net/gnrc/netif/gnrc_netif.c b/sys/net/gnrc/netif/gnrc_netif.c
index 4c197e999e23..94e3fe5ead4d 100644
--- a/sys/net/gnrc/netif/gnrc_netif.c
+++ b/sys/net/gnrc/netif/gnrc_netif.c
@@ -1287,10 +1287,12 @@ int gnrc_netif_ipv6_add_prefix(gnrc_netif_t *netif,
         IS_ACTIVE(CONFIG_GNRC_IPV6_NIB_MULTIHOP_P6C) &&
         gnrc_netif_is_6ln(netif)) {
 
-        /* configure compression context */
-        if (gnrc_sixlowpan_ctx_update_6ctx(pfx, pfx_len, valid)) {
-            DEBUG("gnrc_netif: add compression context for prefix %s/%u\n",
-                   ipv6_addr_to_str(addr_str, pfx, sizeof(addr_str)), pfx_len);
+        if (IS_ACTIVE(CONFIG_GNRC_NETIF_IPV6_BR_AUTO_6CTX)) {
+            /* configure compression context */
+            if (gnrc_sixlowpan_ctx_update_6ctx(pfx, pfx_len, valid)) {
+                DEBUG("gnrc_netif: add compression context for prefix %s/%u\n",
+                       ipv6_addr_to_str(addr_str, pfx, sizeof(addr_str)), pfx_len);
+            }
         }
 
         (void)gnrc_ipv6_nib_abr_add(&addr);