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>

diff --git a/include/linux/packet_diag.h b/include/linux/packet_diag.h
index 34ade828979b38fa015e403bb74067e4251739f4..93f5fa94a431c167d70902ce6ded5a2275215b53 100644 (file)
--- a/include/linux/packet_diag.h
+++ b/include/linux/packet_diag.h
@@ -15,6 +15,7 @@ struct packet_diag_req {
 #define PACKET_SHOW_INFO       0x00000001 /* Basic packet_sk information */
 #define PACKET_SHOW_MCLIST     0x00000002 /* A set of packet_diag_mclist-s */
 #define PACKET_SHOW_RING_CFG   0x00000004 /* Rings configuration parameters */
+#define PACKET_SHOW_FANOUT     0x00000008
 
 struct packet_diag_msg {
        __u8    pdiag_family;
@@ -30,6 +31,7 @@ enum {
        PACKET_DIAG_MCLIST,
        PACKET_DIAG_RX_RING,
        PACKET_DIAG_TX_RING,
+       PACKET_DIAG_FANOUT,
 
        PACKET_DIAG_MAX,
 };

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 8a1605ae40299df7a52ffdca96b9d429d9a3f9bd..226b2cdfc33940fa221486146162cf176aa58873 100644 (file)
--- 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);

diff --git a/net/packet/diag.c b/net/packet/diag.c
index e3975e4d458ce8266ea7c6914a8a5f49dbe23ac0..bc33fbe8a5ef36227e8c5ba9b0cc6e20484b4de0 100644 (file)
--- a/net/packet/diag.c
+++ b/net/packet/diag.c
@@ -109,6 +109,22 @@ static int pdiag_put_rings_cfg(struct packet_sock *po, struct sk_buff *skb)
        return ret;
 }
 
+static int pdiag_put_fanout(struct packet_sock *po, struct sk_buff *nlskb)
+{
+       int ret = 0;
+
+       mutex_lock(&fanout_mutex);
+       if (po->fanout) {
+               u32 val;
+
+               val = (u32)po->fanout->id | ((u32)po->fanout->type << 16);
+               ret = nla_put_u32(nlskb, PACKET_DIAG_FANOUT, val);
+       }
+       mutex_unlock(&fanout_mutex);
+
+       return ret;
+}
+
 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct packet_diag_req *req,
                u32 pid, u32 seq, u32 flags, int sk_ino)
 {
@@ -139,6 +155,10 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct packet_diag
                        pdiag_put_rings_cfg(po, skb))
                goto out_nlmsg_trim;
 
+       if ((req->pdiag_show & PACKET_SHOW_FANOUT) &&
+                       pdiag_put_fanout(po, skb))
+               goto out_nlmsg_trim;
+
        return nlmsg_end(skb, nlh);
 
 out_nlmsg_trim:

diff --git a/net/packet/internal.h b/net/packet/internal.h
index 2c5fca28b242e58aa14c304f58e18cdf04ee8190..44945f6b7252c5c42e3fddf265a610824b6a646c 100644 (file)
--- a/net/packet/internal.h
+++ b/net/packet/internal.h
@@ -67,7 +67,25 @@ struct packet_ring_buffer {
        atomic_t                pending;
 };
 
-struct packet_fanout;
+extern struct mutex fanout_mutex;
+#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_sock {
        /* struct sock has to be the first member of packet_sock */
        struct sock             sk;