xsk: statistics support

In this commit, a new getsockopt is added: XDP_STATISTICS. This is
used to obtain stats from the sockets.

v2: getsockopt now returns size of stats structure.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

2 files changed, 49 insertions, 1 deletions

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index b33c535c7996..009c5af5bba5 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -468,6 +468,49 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname,
         return -ENOPROTOOPT;
 }
 
+static int xsk_getsockopt(struct socket *sock, int level, int optname,
+                          char __user *optval, int __user *optlen)
+{
+        struct sock *sk = sock->sk;
+        struct xdp_sock *xs = xdp_sk(sk);
+        int len;
+
+        if (level != SOL_XDP)
+                return -ENOPROTOOPT;
+
+        if (get_user(len, optlen))
+                return -EFAULT;
+        if (len < 0)
+                return -EINVAL;
+
+        switch (optname) {
+        case XDP_STATISTICS:
+        {
+                struct xdp_statistics stats;
+
+                if (len < sizeof(stats))
+                        return -EINVAL;
+
+                mutex_lock(&xs->mutex);
+                stats.rx_dropped = xs->rx_dropped;
+                stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
+                stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
+                mutex_unlock(&xs->mutex);
+
+                if (copy_to_user(optval, &stats, sizeof(stats)))
+                        return -EFAULT;
+                if (put_user(sizeof(stats), optlen))
+                        return -EFAULT;
+
+                return 0;
+        }
+        default:
+                break;
+        }
+
+        return -EOPNOTSUPP;
+}
+
 static int xsk_mmap(struct file *file, struct socket *sock,
                     struct vm_area_struct *vma)
 {
@@ -524,7 +567,7 @@ static const struct proto_ops xsk_proto_ops = {
         .listen =       sock_no_listen,
         .shutdown =     sock_no_shutdown,
         .setsockopt =   xsk_setsockopt,
-        .getsockopt =   sock_no_getsockopt,
+        .getsockopt =   xsk_getsockopt,
         .sendmsg =      xsk_sendmsg,
         .recvmsg =      sock_no_recvmsg,
         .mmap =         xsk_mmap,
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index 3497e8808608..7aa9a535db0e 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -36,6 +36,11 @@ struct xsk_queue {
 
 /* Common functions operating for both RXTX and umem queues */
 
+static inline u64 xskq_nb_invalid_descs(struct xsk_queue *q)
+{
+        return q ? q->invalid_descs : 0;
+}
+
 static inline u32 xskq_nb_avail(struct xsk_queue *q, u32 dcnt)
 {
         u32 entries = q->prod_tail - q->cons_tail;