[PATCH] kernel: enable SRv6 support

[vincent at systemli.org]

From: Nick Hainke <vincent at systemli.org>

Enable the ability to use segment routing based on IPv6. It allows the
packet to specify a path that the packet should take through the network.

Further, enable LWL-Tunnel. It allows an easy encapsulation of a package.
You can just install ip-full package and use it:

  ip -6 route add  2003::/64 dev eth0 encap seg6 mode encap \
    segs 2001::1,2002::2

An IPv6 package looks like this:
  [IPv6 HDR][IPv6 RH][IPv6 HDR][Data...]

Further I added netifd support:
  http://lists.openwrt.org/pipermail/openwrt-devel/
  2020-December/032467.html

Signed-off-by: Nick Hainke <vincent at systemli.org>
---
 target/linux/generic/config-5.4 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/linux/generic/config-5.4 b/target/linux/generic/config-5.4
index 10d14f6be5..942777b41e 100644
--- a/target/linux/generic/config-5.4
+++ b/target/linux/generic/config-5.4
@@ -2387,7 +2387,7 @@ CONFIG_IO_STRICT_DEVMEM=y
 # CONFIG_IPC_NS is not set
 # CONFIG_IPMB_DEVICE_INTERFACE is not set
 # CONFIG_IPMI_HANDLER is not set
-# CONFIG_IPV6 is not set
+CONFIG_IPV6=y
 # CONFIG_IPV6_FOU is not set
 # CONFIG_IPV6_FOU_TUNNEL is not set
 # CONFIG_IPV6_ILA is not set
@@ -2400,7 +2400,7 @@ CONFIG_IPV6_NDISC_NODETYPE=y
 # CONFIG_IPV6_ROUTER_PREF is not set
 # CONFIG_IPV6_ROUTE_INFO is not set
 # CONFIG_IPV6_SEG6_HMAC is not set
-# CONFIG_IPV6_SEG6_LWTUNNEL is not set
+CONFIG_IPV6_SEG6_LWTUNNEL=y
 # CONFIG_IPV6_SIT is not set
 # CONFIG_IPV6_SIT_6RD is not set
 # CONFIG_IPV6_TUNNEL is not set
-- 
2.29.2