xfrm: interface: support IPIP and IPIP6 tunnels processing with .cb_handler

Similar to ip_vti, IPIP and IPIP6 tunnels processing can easily
be done with .cb_handler for xfrm interface.

v1->v2:
  - no change.
v2-v3:
  - enable it only when CONFIG_INET_XFRM_TUNNEL is defined, to fix the
    build error, reported by kbuild test robot.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
index b9ef496d3d7cd650f80eaa4e11fd0386b502dbc1..a79eb49a4e0df0b44ac846e9e40fd5319b5686e5 100644 (file)
--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -842,6 +842,20 @@ static struct xfrm4_protocol xfrmi_ipcomp4_protocol __read_mostly = {
        .priority       =       10,
 };
 
+#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
+static int xfrmi4_rcv_tunnel(struct sk_buff *skb)
+{
+       return xfrm4_rcv_spi(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr);
+}
+
+static struct xfrm_tunnel xfrmi_ipip_handler __read_mostly = {
+       .handler        =       xfrmi4_rcv_tunnel,
+       .cb_handler     =       xfrmi_rcv_cb,
+       .err_handler    =       xfrmi4_err,
+       .priority       =       -1,
+};
+#endif
+
 static int __init xfrmi4_init(void)
 {
        int err;
@@ -855,9 +869,23 @@ static int __init xfrmi4_init(void)
        err = xfrm4_protocol_register(&xfrmi_ipcomp4_protocol, IPPROTO_COMP);
        if (err < 0)
                goto xfrm_proto_comp_failed;
+#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
+       err = xfrm4_tunnel_register(&xfrmi_ipip_handler, AF_INET);
+       if (err < 0)
+               goto xfrm_tunnel_ipip_failed;
+       err = xfrm4_tunnel_register(&xfrmi_ipip_handler, AF_INET6);
+       if (err < 0)
+               goto xfrm_tunnel_ipip6_failed;
+#endif
 
        return 0;
 
+#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
+xfrm_tunnel_ipip6_failed:
+       xfrm4_tunnel_deregister(&xfrmi_ipip_handler, AF_INET);
+xfrm_tunnel_ipip_failed:
+       xfrm4_protocol_deregister(&xfrmi_ipcomp4_protocol, IPPROTO_COMP);
+#endif
 xfrm_proto_comp_failed:
        xfrm4_protocol_deregister(&xfrmi_ah4_protocol, IPPROTO_AH);
 xfrm_proto_ah_failed:
@@ -868,6 +896,10 @@ xfrm_proto_esp_failed:
 
 static void xfrmi4_fini(void)
 {
+#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
+       xfrm4_tunnel_deregister(&xfrmi_ipip_handler, AF_INET6);
+       xfrm4_tunnel_deregister(&xfrmi_ipip_handler, AF_INET);
+#endif
        xfrm4_protocol_deregister(&xfrmi_ipcomp4_protocol, IPPROTO_COMP);
        xfrm4_protocol_deregister(&xfrmi_ah4_protocol, IPPROTO_AH);
        xfrm4_protocol_deregister(&xfrmi_esp4_protocol, IPPROTO_ESP);