packet: Report fanout status via diag engine

Reported value is the same reported by the FANOUT getsockoption, but
unlike it, the absent fanout setup results in absent nlattr, rather
than in nlattr with zero value. This is done so, since zero fanout
report may mean both -- no fanout, and fanout with both id and type zero.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 20 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 8a1605ae4029..226b2cdfc339 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -207,24 +207,6 @@ static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 		struct tpacket3_hdr *);
 static void packet_flush_mclist(struct sock *sk);
 
-#define PACKET_FANOUT_MAX	256
-
-struct packet_fanout {
-#ifdef CONFIG_NET_NS
-	struct net		*net;
-#endif
-	unsigned int		num_members;
-	u16			id;
-	u8			type;
-	u8			defrag;
-	atomic_t		rr_cur;
-	struct list_head	list;
-	struct sock		*arr[PACKET_FANOUT_MAX];
-	spinlock_t		lock;
-	atomic_t		sk_ref;
-	struct packet_type	prot_hook ____cacheline_aligned_in_smp;
-};
-
 struct packet_skb_cb {
 	unsigned int origlen;
 	union {
@@ -1148,7 +1130,8 @@ static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
 	return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
 }
 
-static DEFINE_MUTEX(fanout_mutex);
+DEFINE_MUTEX(fanout_mutex);
+EXPORT_SYMBOL_GPL(fanout_mutex);
 static LIST_HEAD(fanout_list);
 
 static void __fanout_link(struct sock *sk, struct packet_sock *po)
@@ -1260,9 +1243,9 @@ static void fanout_release(struct sock *sk)
 	if (!f)
 		return;
 
+	mutex_lock(&fanout_mutex);
 	po->fanout = NULL;
 
-	mutex_lock(&fanout_mutex);
 	if (atomic_dec_and_test(&f->sk_ref)) {
 		list_del(&f->list);
 		dev_remove_pack(&f->prot_hook);