gnrc/ipv6_auto_subnets: allow to configure minimal prefix length

RIOT-OS · May 23, 2023 · 2a76911 · 2a76911
1 parent 9358a44
commit 2a76911
Showing 1 changed file with 13 additions and 0 deletions.
diff --git a/sys/net/gnrc/routing/ipv6_auto_subnets/gnrc_ipv6_auto_subnets.c b/sys/net/gnrc/routing/ipv6_auto_subnets/gnrc_ipv6_auto_subnets.c
@@ -89,6 +89,7 @@
  * @author Benjamin Valentin <benjamin.valentin@ml-pa.com>
  */
 
+#include "compiler_hints.h"
 #include "net/gnrc/ipv6.h"
 #include "net/gnrc/netif.h"
 #include "net/gnrc/netif/hdr.h"
@@ -141,6 +142,14 @@
 #define CONFIG_GNRC_IPV6_AUTO_SUBNETS_PREFIX_FIX_LEN (0)
 #endif
 
+/**
+ * @brief Minimal length of a new prefix.
+ * e.g. Linux will only accept /64 prefixes for SLAAC
+ */
+#ifndef CONFIG_GNRC_IPV6_AUTO_SUBNETS_PREFIX_MIN_LEN
+#define CONFIG_GNRC_IPV6_AUTO_SUBNETS_PREFIX_MIN_LEN (0)
+#endif
+
 /**
  * @brief Number of subnets that can be configured.
  *
@@ -369,6 +378,10 @@ static void _configure_subnets(uint8_t subnets, uint8_t start_idx, gnrc_netif_t
  return;
  }
 
+ if (new_prefix_len < may_be_zero(CONFIG_GNRC_IPV6_AUTO_SUBNETS_PREFIX_MIN_LEN)) {
+ new_prefix_len = CONFIG_GNRC_IPV6_AUTO_SUBNETS_PREFIX_MIN_LEN;
+ }
+
  while ((downstream = gnrc_netif_iter(downstream))) {
  gnrc_pktsnip_t *tmp;
  ipv6_addr_t new_prefix;