Stefano Garzarella
2021-Feb-11 13:58 UTC
[RFC PATCH v4 10/17] virtio/vsock: fetch length for SEQPACKET record
On Sun, Feb 07, 2021 at 06:17:08PM +0300, Arseny Krasnov wrote:>This adds transport callback which tries to fetch record begin marker >from socket's rx queue. It is called from af_vsock.c before reading data >packets of record. > >Signed-off-by: Arseny Krasnov <arseny.krasnov at kaspersky.com> >--- > include/linux/virtio_vsock.h | 1 + > net/vmw_vsock/virtio_transport_common.c | 40 +++++++++++++++++++++++++ > 2 files changed, 41 insertions(+) > >diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h >index 4d0de3dee9a4..a5e8681bfc6a 100644 >--- a/include/linux/virtio_vsock.h >+++ b/include/linux/virtio_vsock.h >@@ -85,6 +85,7 @@ virtio_transport_dgram_dequeue(struct vsock_sock *vsk, > struct msghdr *msg, > size_t len, int flags); > >+size_t virtio_transport_seqpacket_seq_get_len(struct vsock_sock *vsk); > s64 virtio_transport_stream_has_data(struct vsock_sock *vsk); > s64 virtio_transport_stream_has_space(struct vsock_sock *vsk); > >diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c >index 4572d01c8ea5..7ac552bfd90b 100644 >--- a/net/vmw_vsock/virtio_transport_common.c >+++ b/net/vmw_vsock/virtio_transport_common.c >@@ -420,6 +420,46 @@ static size_t virtio_transport_drop_until_seq_begin(struct virtio_vsock_sock *vv > return bytes_dropped; > } > >+size_t virtio_transport_seqpacket_seq_get_len(struct vsock_sock *vsk) >+{ >+ struct virtio_vsock_seq_hdr *seq_hdr; >+ struct virtio_vsock_sock *vvs; >+ struct virtio_vsock_pkt *pkt; >+ size_t bytes_dropped; >+ >+ vvs = vsk->trans; >+ >+ spin_lock_bh(&vvs->rx_lock); >+ >+ /* Fetch all orphaned 'RW', packets, and >+ * send credit update.Single line?>+ */ >+ bytes_dropped = virtio_transport_drop_until_seq_begin(vvs); >+ >+ if (list_empty(&vvs->rx_queue)) >+ goto out; >+ >+ pkt = list_first_entry(&vvs->rx_queue, struct virtio_vsock_pkt, list); >+ >+ vvs->user_read_copied = 0; >+ >+ seq_hdr = (struct virtio_vsock_seq_hdr *)pkt->buf; >+ vvs->user_read_seq_len = le32_to_cpu(seq_hdr->msg_len); >+ vvs->curr_rx_msg_cnt = le32_to_cpu(seq_hdr->msg_cnt); >+ virtio_transport_dec_rx_pkt(vvs, pkt); >+ virtio_transport_remove_pkt(pkt); >+out: >+ spin_unlock_bh(&vvs->rx_lock); >+ >+ if (bytes_dropped) >+ virtio_transport_send_credit_update(vsk, >+ VIRTIO_VSOCK_TYPE_SEQPACKET, >+ NULL); >+ >+ return vvs->user_read_seq_len; >+} >+EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_seq_get_len); >+ > static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, > struct msghdr *msg, > bool *msg_ready) >-- >2.25.1 >