packet: Report rings cfg via diag engine

One extension bit may result in two nlattrs -- one per ring type.
If some ring type is not configured, then the respective nlatts
will be empty.

The structure reported contains the data, that is given to the
corresponding ring setup socket option.

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

2 files changed, 60 insertions, 1 deletions

diff --git a/include/linux/packet_diag.h b/include/linux/packet_diag.h
index ea2e8923bd7e..34ade828979b 100644
--- a/include/linux/packet_diag.h
+++ b/include/linux/packet_diag.h
@@ -14,6 +14,7 @@ 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 */
 
 struct packet_diag_msg {
         __u8    pdiag_family;
@@ -27,6 +28,8 @@ struct packet_diag_msg {
 enum {
         PACKET_DIAG_INFO,
         PACKET_DIAG_MCLIST,
+        PACKET_DIAG_RX_RING,
+        PACKET_DIAG_TX_RING,
 
         PACKET_DIAG_MAX,
 };
@@ -54,4 +57,14 @@ struct packet_diag_mclist {
         __u8    pdmc_addr[MAX_ADDR_LEN];
 };
 
+struct packet_diag_ring {
+        __u32   pdr_block_size;
+        __u32   pdr_block_nr;
+        __u32   pdr_frame_size;
+        __u32   pdr_frame_nr;
+        __u32   pdr_retire_tmo;
+        __u32   pdr_sizeof_priv;
+        __u32   pdr_features;
+};
+
 #endif
diff --git a/net/packet/diag.c b/net/packet/diag.c
index 3dda4ecb9a46..e3975e4d458c 100644
--- a/net/packet/diag.c
+++ b/net/packet/diag.c
@@ -67,12 +67,54 @@ static int pdiag_put_mclist(const struct packet_sock *po, struct sk_buff *nlskb)
         return 0;
 }
 
+static int pdiag_put_ring(struct packet_ring_buffer *ring, int ver, int nl_type,
+                struct sk_buff *nlskb)
+{
+        struct packet_diag_ring pdr;
+
+        if (!ring->pg_vec || ((ver > TPACKET_V2) &&
+                                (nl_type == PACKET_DIAG_TX_RING)))
+                return 0;
+
+        pdr.pdr_block_size = ring->pg_vec_pages << PAGE_SHIFT;
+        pdr.pdr_block_nr = ring->pg_vec_len;
+        pdr.pdr_frame_size = ring->frame_size;
+        pdr.pdr_frame_nr = ring->frame_max + 1;
+
+        if (ver > TPACKET_V2) {
+                pdr.pdr_retire_tmo = ring->prb_bdqc.retire_blk_tov;
+                pdr.pdr_sizeof_priv = ring->prb_bdqc.blk_sizeof_priv;
+                pdr.pdr_features = ring->prb_bdqc.feature_req_word;
+        } else {
+                pdr.pdr_retire_tmo = 0;
+                pdr.pdr_sizeof_priv = 0;
+                pdr.pdr_features = 0;
+        }
+
+        return nla_put(nlskb, nl_type, sizeof(pdr), &pdr);
+}
+
+static int pdiag_put_rings_cfg(struct packet_sock *po, struct sk_buff *skb)
+{
+        int ret;
+
+        mutex_lock(&po->pg_vec_lock);
+        ret = pdiag_put_ring(&po->rx_ring, po->tp_version,
+                        PACKET_DIAG_RX_RING, skb);
+        if (!ret)
+                ret = pdiag_put_ring(&po->tx_ring, po->tp_version,
+                                PACKET_DIAG_TX_RING, skb);
+        mutex_unlock(&po->pg_vec_lock);
+
+        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)
 {
         struct nlmsghdr *nlh;
         struct packet_diag_msg *rp;
-        const struct packet_sock *po = pkt_sk(sk);
+        struct packet_sock *po = pkt_sk(sk);
 
         nlh = nlmsg_put(skb, pid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rp), flags);
         if (!nlh)
@@ -93,6 +135,10 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct packet_diag
                         pdiag_put_mclist(po, skb))
                 goto out_nlmsg_trim;
 
+        if ((req->pdiag_show & PACKET_SHOW_RING_CFG) &&
+                        pdiag_put_rings_cfg(po, skb))
+                goto out_nlmsg_trim;
+
         return nlmsg_end(skb, nlh);
 
 out_nlmsg_trim: