--- v5
+++ v3
@@ -1,221 +1,25 @@
-This adds transport callback and it's logic for SEQPACKET dequeue.
-Callback fetches RW packets from rx queue of socket until whole record
-is copied(if user's buffer is full, user is not woken up). This is done
-to not stall sender, because if we wake up user and it leaves syscall,
-nobody will send credit update for rest of record, and sender will wait
-for next enter of read syscall at receiver's side. So if user buffer is
-full, we just send credit update and drop data. If during copy SEQ_BEGIN
-was found(and not all data was copied), copying is restarted by reset
-user's iov iterator(previous unfinished data is dropped).
+This adds SEQPACKET ops for virtio transport
Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
---
- include/linux/virtio_vsock.h | 10 +++
- include/uapi/linux/virtio_vsock.h | 16 ++++
- net/vmw_vsock/virtio_transport_common.c | 114 ++++++++++++++++++++++++
- 3 files changed, 140 insertions(+)
+ net/vmw_vsock/virtio_transport.c | 4 ++++
+ 1 file changed, 4 insertions(+)
-diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
-index dc636b727179..003d06ae4a85 100644
---- a/include/linux/virtio_vsock.h
-+++ b/include/linux/virtio_vsock.h
-@@ -36,6 +36,11 @@ struct virtio_vsock_sock {
- u32 rx_bytes;
- u32 buf_alloc;
- struct list_head rx_queue;
+diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
+index 2700a63ab095..5a7ab1befee8 100644
+--- a/net/vmw_vsock/virtio_transport.c
++++ b/net/vmw_vsock/virtio_transport.c
+@@ -469,6 +469,10 @@ static struct virtio_transport virtio_transport = {
+ .stream_is_active = virtio_transport_stream_is_active,
+ .stream_allow = virtio_transport_stream_allow,
+
++ .seqpacket_seq_send_len = virtio_transport_seqpacket_seq_send_len,
++ .seqpacket_seq_get_len = virtio_transport_seqpacket_seq_get_len,
++ .seqpacket_dequeue = virtio_transport_seqpacket_dequeue,
+
-+ /* For SOCK_SEQPACKET */
-+ u32 user_read_seq_len;
-+ u32 user_read_copied;
-+ u32 curr_rx_msg_cnt;
- };
-
- struct virtio_vsock_pkt {
-@@ -80,6 +85,11 @@ virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
- struct msghdr *msg,
- size_t len, int flags);
-
-+int
-+virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
-+ struct msghdr *msg,
-+ int flags,
-+ bool *msg_ready);
- s64 virtio_transport_stream_has_data(struct vsock_sock *vsk);
- s64 virtio_transport_stream_has_space(struct vsock_sock *vsk);
-
-diff --git a/include/uapi/linux/virtio_vsock.h b/include/uapi/linux/virtio_vsock.h
-index 1d57ed3d84d2..cf9c165e5cca 100644
---- a/include/uapi/linux/virtio_vsock.h
-+++ b/include/uapi/linux/virtio_vsock.h
-@@ -63,8 +63,14 @@ struct virtio_vsock_hdr {
- __le32 fwd_cnt;
- } __attribute__((packed));
-
-+struct virtio_vsock_seq_hdr {
-+ __le32 msg_cnt;
-+ __le32 msg_len;
-+} __attribute__((packed));
-+
- enum virtio_vsock_type {
- VIRTIO_VSOCK_TYPE_STREAM = 1,
-+ VIRTIO_VSOCK_TYPE_SEQPACKET = 2,
- };
-
- enum virtio_vsock_op {
-@@ -83,6 +89,11 @@ enum virtio_vsock_op {
- VIRTIO_VSOCK_OP_CREDIT_UPDATE = 6,
- /* Request the peer to send the credit info to us */
- VIRTIO_VSOCK_OP_CREDIT_REQUEST = 7,
-+
-+ /* Record begin for SOCK_SEQPACKET */
-+ VIRTIO_VSOCK_OP_SEQ_BEGIN = 8,
-+ /* Record end for SOCK_SEQPACKET */
-+ VIRTIO_VSOCK_OP_SEQ_END = 9,
- };
-
- /* VIRTIO_VSOCK_OP_SHUTDOWN flags values */
-@@ -91,4 +102,9 @@ enum virtio_vsock_shutdown {
- VIRTIO_VSOCK_SHUTDOWN_SEND = 2,
- };
-
-+/* VIRTIO_VSOCK_OP_RW flags values */
-+enum virtio_vsock_rw {
-+ VIRTIO_VSOCK_RW_EOR = 1,
-+};
-+
- #endif /* _UAPI_LINUX_VIRTIO_VSOCK_H */
-diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
-index 833104b71a1c..d8ec2dfa2315 100644
---- a/net/vmw_vsock/virtio_transport_common.c
-+++ b/net/vmw_vsock/virtio_transport_common.c
-@@ -393,6 +393,108 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
- return err;
- }
-
-+static inline void virtio_transport_remove_pkt(struct virtio_vsock_pkt *pkt)
-+{
-+ list_del(&pkt->list);
-+ virtio_transport_free_pkt(pkt);
-+}
-+
-+static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
-+ struct msghdr *msg,
-+ bool *msg_ready)
-+{
-+ struct virtio_vsock_sock *vvs = vsk->trans;
-+ struct virtio_vsock_pkt *pkt;
-+ int err = 0;
-+ size_t user_buf_len = msg->msg_iter.count;
-+
-+ *msg_ready = false;
-+ spin_lock_bh(&vvs->rx_lock);
-+
-+ while (!*msg_ready && !list_empty(&vvs->rx_queue) && !err) {
-+ pkt = list_first_entry(&vvs->rx_queue, struct virtio_vsock_pkt, list);
-+
-+ switch (le16_to_cpu(pkt->hdr.op)) {
-+ case VIRTIO_VSOCK_OP_SEQ_BEGIN: {
-+ /* Unexpected 'SEQ_BEGIN' during record copy:
-+ * Leave receive loop, 'EAGAIN' will restart it from
-+ * outer receive loop, packet is still in queue and
-+ * counters are cleared. So in next loop enter,
-+ * 'SEQ_BEGIN' will be dequeued first. User's iov
-+ * iterator will be reset in outer loop. Also
-+ * send credit update, because some bytes could be
-+ * copied. User will never see unfinished record.
-+ */
-+ err = -EAGAIN;
-+ break;
-+ }
-+ case VIRTIO_VSOCK_OP_SEQ_END: {
-+ struct virtio_vsock_seq_hdr *seq_hdr;
-+
-+ seq_hdr = (struct virtio_vsock_seq_hdr *)pkt->buf;
-+ /* First check that whole record is received. */
-+
-+ if (vvs->user_read_copied != vvs->user_read_seq_len ||
-+ (le32_to_cpu(seq_hdr->msg_cnt) - vvs->curr_rx_msg_cnt) != 1) {
-+ /* Tail of current record and head of next missed,
-+ * so this EOR is from next record. Restart receive.
-+ * Current record will be dropped, next headless will
-+ * be dropped on next attempt to get record length.
-+ */
-+ err = -EAGAIN;
-+ } else {
-+ /* Success. */
-+ *msg_ready = true;
-+ }
-+
-+ break;
-+ }
-+ case VIRTIO_VSOCK_OP_RW: {
-+ size_t bytes_to_copy;
-+ size_t pkt_len;
-+
-+ pkt_len = (size_t)le32_to_cpu(pkt->hdr.len);
-+ bytes_to_copy = min(user_buf_len, pkt_len);
-+
-+ /* 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);
-+
-+ if (memcpy_to_msg(msg, pkt->buf, bytes_to_copy)) {
-+ spin_lock_bh(&vvs->rx_lock);
-+ err = -EINVAL;
-+ break;
-+ }
-+
-+ spin_lock_bh(&vvs->rx_lock);
-+ user_buf_len -= bytes_to_copy;
-+ vvs->user_read_copied += pkt_len;
-+
-+ if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_RW_EOR)
-+ msg->msg_flags |= MSG_EOR;
-+ break;
-+ }
-+ default:
-+ ;
-+ }
-+
-+ /* For unexpected 'SEQ_BEGIN', keep such packet in queue,
-+ * but drop any other type of packet.
-+ */
-+ if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_SEQ_BEGIN) {
-+ virtio_transport_dec_rx_pkt(vvs, pkt);
-+ virtio_transport_remove_pkt(pkt);
-+ }
-+ }
-+
-+ spin_unlock_bh(&vvs->rx_lock);
-+
-+ virtio_transport_send_credit_update(vsk);
-+
-+ return err;
-+}
-+
- ssize_t
- virtio_transport_stream_dequeue(struct vsock_sock *vsk,
- struct msghdr *msg,
-@@ -405,6 +507,18 @@ virtio_transport_stream_dequeue(struct vsock_sock *vsk,
- }
- EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
-
-+int
-+virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
-+ struct msghdr *msg,
-+ int flags, bool *msg_ready)
-+{
-+ if (flags & MSG_PEEK)
-+ return -EOPNOTSUPP;
-+
-+ return virtio_transport_seqpacket_do_dequeue(vsk, msg, msg_ready);
-+}
-+EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
-+
- int
- virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
- struct msghdr *msg,
+ .notify_poll_in = virtio_transport_notify_poll_in,
+ .notify_poll_out = virtio_transport_notify_poll_out,
+ .notify_recv_init = virtio_transport_notify_recv_init,
--
2.25.1