[PATCH ipsec-next 02/10] tunnel4: add cb_handler to struct xfrm_tunnel

[Xin Long]

This patch is to register a callback function tunnel4_rcv_cb with
is_ipip set in a xfrm_input_afinfo object for tunnel4 and tunnel64.

It will be called by xfrm_rcv_cb() from xfrm_input() when family
is AF_INET and proto is IPPROTO_IPIP or IPPROTO_IPV6.

Signed-off-by: Xin Long <lucien....@gmail.com>
---
 include/net/xfrm.h |  1 +
 net/ipv4/tunnel4.c | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 4aa118d..c69410d 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1415,6 +1415,7 @@ struct xfrm6_protocol {
 /* XFRM tunnel handlers.  */
 struct xfrm_tunnel {
        int (*handler)(struct sk_buff *skb);
+       int (*cb_handler)(struct sk_buff *skb, int err);
        int (*err_handler)(struct sk_buff *skb, u32 info);
 
        struct xfrm_tunnel __rcu *next;
diff --git a/net/ipv4/tunnel4.c b/net/ipv4/tunnel4.c
index c4b2ccb..5968d78 100644
--- a/net/ipv4/tunnel4.c
+++ b/net/ipv4/tunnel4.c
@@ -110,6 +110,30 @@ static int tunnel4_rcv(struct sk_buff *skb)
        return 0;
 }
 
+static int tunnel4_rcv_cb(struct sk_buff *skb, u8 proto, int err)
+{
+       struct xfrm_tunnel *head, *handler;
+       int ret;
+
+       head = (proto == IPPROTO_IPIP) ? tunnel4_handlers : tunnel64_handlers;
+
+       for_each_tunnel_rcu(head, handler) {
+               if (handler->cb_handler) {
+                       ret = handler->cb_handler(skb, err);
+                       if (ret <= 0)
+                               return ret;
+               }
+       }
+
+       return 0;
+}
+
+static const struct xfrm_input_afinfo tunnel4_input_afinfo = {
+       .family         =       AF_INET,
+       .is_ipip        =       true,
+       .callback       =       tunnel4_rcv_cb,
+};
+
 #if IS_ENABLED(CONFIG_IPV6)
 static int tunnel64_rcv(struct sk_buff *skb)
 {
@@ -231,6 +255,7 @@ static int __init tunnel4_init(void)
                goto err;
        }
 #endif
+       xfrm_input_register_afinfo(&tunnel4_input_afinfo);
        return 0;
 
 err:
@@ -240,6 +265,7 @@ static int __init tunnel4_init(void)
 
 static void __exit tunnel4_fini(void)
 {
+       xfrm_input_unregister_afinfo(&tunnel4_input_afinfo);
 #if IS_ENABLED(CONFIG_MPLS)
        if (inet_del_protocol(&tunnelmpls4_protocol, IPPROTO_MPLS))
                pr_err("tunnelmpls4 close: can't remove protocol\n");
-- 
2.1.0