net: ipv6: select DST_CACHE from IPV6_RPL_LWTUNNEL

The rpl sr tunnel code contains calls to dst_cache_*() which are
only present when the dst cache is built.
Select DST_CACHE to build the dst cache, similar to other kconfig
options in the same file.
Compiling the rpl sr tunnel without DST_CACHE will lead to linker
errors.

Fixes: a7a29f9c361f ("net: ipv6: add rpl sr tunnel")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Simon Horman <horms@kernel.org> # build-tested
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 08d4b7132d4c45b56486140c4daaf51866b56f2d..1c9c686d9522f7864130f9ba8f2197fff252f5f7 100644 (file)
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -323,6 +323,7 @@ config IPV6_RPL_LWTUNNEL
        bool "IPv6: RPL Source Routing Header support"
        depends on IPV6
        select LWTUNNEL
+       select DST_CACHE
        help
          Support for RFC6554 RPL Source Routing Header using the lightweight
          tunnels mechanism.