Merge branch 'sock_diag_destruction_events'

Craig Gallek says:

====================
Socket destruction events via netlink sock_diag

This series extends the netlink sock_diag interface to broadcast
socket information as they are being destroyed.  The current
interface is poll based and can not be used to retreive information
about sockets that are destroyed between poll intervals.

Only inet sockets are broadcast in this implementation, but other
families could easily be added as needed in the future.

If this patch set is accepted, a follow-up patch to the ss utility
in the iproute2 suite will also be submitted.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 43 insertions, 0 deletions

diff --git a/include/linux/inet_diag.h b/include/linux/inet_diag.h
index ac48b10c9395..0e707f0c1a3e 100644
--- a/include/linux/inet_diag.h
+++ b/include/linux/inet_diag.h
@@ -24,6 +24,7 @@ struct inet_diag_handler {
 					  struct inet_diag_msg *r,
 					  void *info);
 	__u16		idiag_type;
+	__u16		idiag_info_size;
 };
 
 struct inet_connection_sock;
diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h
index 083ac388098e..fddebc617469 100644
--- a/include/linux/sock_diag.h
+++ b/include/linux/sock_diag.h
@@ -1,7 +1,10 @@
 #ifndef __SOCK_DIAG_H__
 #define __SOCK_DIAG_H__
 
+#include <linux/netlink.h>
 #include <linux/user_namespace.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
 #include <uapi/linux/sock_diag.h>
 
 struct sk_buff;
@@ -11,6 +14,7 @@ struct sock;
 struct sock_diag_handler {
 	__u8 family;
 	int (*dump)(struct sk_buff *skb, struct nlmsghdr *nlh);
+	int (*get_info)(struct sk_buff *skb, struct sock *sk);
 };
 
 int sock_diag_register(const struct sock_diag_handler *h);
@@ -26,4 +30,42 @@ int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attr);
 int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk,
 			     struct sk_buff *skb, int attrtype);
 
+static inline
+enum sknetlink_groups sock_diag_destroy_group(const struct sock *sk)
+{
+	switch (sk->sk_family) {
+	case AF_INET:
+		switch (sk->sk_protocol) {
+		case IPPROTO_TCP:
+			return SKNLGRP_INET_TCP_DESTROY;
+		case IPPROTO_UDP:
+			return SKNLGRP_INET_UDP_DESTROY;
+		default:
+			return SKNLGRP_NONE;
+		}
+	case AF_INET6:
+		switch (sk->sk_protocol) {
+		case IPPROTO_TCP:
+			return SKNLGRP_INET6_TCP_DESTROY;
+		case IPPROTO_UDP:
+			return SKNLGRP_INET6_UDP_DESTROY;
+		default:
+			return SKNLGRP_NONE;
+		}
+	default:
+		return SKNLGRP_NONE;
+	}
+}
+
+static inline
+bool sock_diag_has_destroy_listeners(const struct sock *sk)
+{
+	const struct net *n = sock_net(sk);
+	const enum sknetlink_groups group = sock_diag_destroy_group(sk);
+
+	return group != SKNLGRP_NONE && n->diag_nlsk &&
+		netlink_has_listeners(n->diag_nlsk, group);
+}
+void sock_diag_broadcast_destroy(struct sock *sk);
+
 #endif