sock_diag: allow to dump bpf filters

This patch allows to dump BPF filters attached to a socket with
SO_ATTACH_FILTER.
Note that we check CAP_SYS_ADMIN before allowing to dump this info.

For now, only AF_PACKET sockets use this feature.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h
index e8d702e..54f91d3 100644
--- a/include/linux/sock_diag.h
+++ b/include/linux/sock_diag.h
@@ -1,6 +1,7 @@
 #ifndef __SOCK_DIAG_H__
 #define __SOCK_DIAG_H__
 
+#include <linux/user_namespace.h>
 #include <uapi/linux/sock_diag.h>
 
 struct sk_buff;
@@ -22,5 +23,7 @@
 void sock_diag_save_cookie(void *sk, __u32 *cookie);
 
 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attr);
+int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk,
+			     struct sk_buff *skb, int attrtype);
 
 #endif