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authorMatias Ezequiel Vara Larsen <matiasevara@gmail.com>2019-09-30 18:25:23 +0000
committerDavid S. Miller <davem@davemloft.net>2019-10-01 21:26:51 -0400
commita786ab36ae6f486d59e05cd5570319508d23477e (patch)
tree3da833fc93443879248e1503c4a44cdeeebb6971 /net/vmw_vsock
parent678799194a5311765263b6aa940910ab232767eb (diff)
downloadlinux-a786ab36ae6f486d59e05cd5570319508d23477e.tar.bz2
vsock/virtio: add support for MSG_PEEK
This patch adds support for MSG_PEEK. In such a case, packets are not removed from the rx_queue and credit updates are not sent. Signed-off-by: Matias Ezequiel Vara Larsen <matiasevara@gmail.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Tested-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/vmw_vsock')
-rw-r--r--net/vmw_vsock/virtio_transport_common.c55
1 files changed, 52 insertions, 3 deletions
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 5bb70c692b1e..d31f1478c3da 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -264,6 +264,55 @@ static int virtio_transport_send_credit_update(struct vsock_sock *vsk,
}
static ssize_t
+virtio_transport_stream_do_peek(struct vsock_sock *vsk,
+ struct msghdr *msg,
+ size_t len)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+ struct virtio_vsock_pkt *pkt;
+ size_t bytes, total = 0, off;
+ int err = -EFAULT;
+
+ spin_lock_bh(&vvs->rx_lock);
+
+ list_for_each_entry(pkt, &vvs->rx_queue, list) {
+ off = pkt->off;
+
+ if (total == len)
+ break;
+
+ while (total < len && off < pkt->len) {
+ bytes = len - total;
+ if (bytes > pkt->len - off)
+ bytes = pkt->len - off;
+
+ /* sk_lock is held by caller so no one else can dequeue.
+ * Unlock rx_lock since memcpy_to_msg() may sleep.
+ */
+ spin_unlock_bh(&vvs->rx_lock);
+
+ err = memcpy_to_msg(msg, pkt->buf + off, bytes);
+ if (err)
+ goto out;
+
+ spin_lock_bh(&vvs->rx_lock);
+
+ total += bytes;
+ off += bytes;
+ }
+ }
+
+ spin_unlock_bh(&vvs->rx_lock);
+
+ return total;
+
+out:
+ if (total)
+ err = total;
+ return err;
+}
+
+static ssize_t
virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
struct msghdr *msg,
size_t len)
@@ -335,9 +384,9 @@ virtio_transport_stream_dequeue(struct vsock_sock *vsk,
size_t len, int flags)
{
if (flags & MSG_PEEK)
- return -EOPNOTSUPP;
-
- return virtio_transport_stream_do_dequeue(vsk, msg, len);
+ return virtio_transport_stream_do_peek(vsk, msg, len);
+ else
+ return virtio_transport_stream_do_dequeue(vsk, msg, len);
}
EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);