ip_gre: Fix dependencies wrt. ipv6.

The GRE tunnel driver needs to invoke icmpv6 helpers in the
ipv6 stack when ipv6 support is enabled.

Therefore if IPV6 is enabled, we have to enforce that GRE's
enabling (modular or static) matches that of ipv6.

Reported-by: Patrick McHardy <kaber@trash.net>
Reported-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 571f895..72380a3 100644 (file)
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -217,6 +217,7 @@ config NET_IPIP
 
 config NET_IPGRE
        tristate "IP: GRE tunnels over IP"
+       depends on IPV6 || IPV6=n
        help
          Tunneling means encapsulating data of one protocol type within
          another protocol and sending it over a channel that understands the