[RFC PATCH v5 12/19] virtio/vsock: fetch length for SEQPACKET record
From: Arseny Krasnov <hidden>
Date: 2021-02-18 05:56:16
Also in:
kvm, lkml
Subsystem:
networking [general], the rest, virtio and vhost vsock driver, virtio core, vm sockets (af_vsock) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Stefan Hajnoczi, Stefano Garzarella, "Michael S. Tsirkin", Jason Wang
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 <redacted> --- include/linux/virtio_vsock.h | 1 + net/vmw_vsock/virtio_transport_common.c | 53 +++++++++++++++++++++++++ 2 files changed, 54 insertions(+)
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 003d06ae4a85..022667d57884 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); int virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index d8ec2dfa2315..e9a2de72ebbf 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c@@ -399,6 +399,59 @@ static inline void virtio_transport_remove_pkt(struct virtio_vsock_pkt *pkt) virtio_transport_free_pkt(pkt); } +static size_t virtio_transport_drop_until_seq_begin(struct virtio_vsock_sock *vvs) +{ + struct virtio_vsock_pkt *pkt, *n; + size_t bytes_dropped = 0; + + list_for_each_entry_safe(pkt, n, &vvs->rx_queue, list) { + if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_SEQ_BEGIN) + break; + + bytes_dropped += le32_to_cpu(pkt->hdr.len); + virtio_transport_dec_rx_pkt(vvs, pkt); + virtio_transport_remove_pkt(pkt); + } + + 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. */ + 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); + + 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