On 12.03.2021 18:17, Stefano Garzarella wrote:
> On Sun, Mar 07, 2021 at 08:59:45PM +0300, Arseny Krasnov wrote:
>> This adds receive loop for SEQPACKET. It looks like receive loop for
>> STREAM, but there is a little bit difference:
>> 1) It doesn't call notify callbacks.
>> 2) It doesn't care about 'SO_SNDLOWAT' and 'SO_RCVLOWAT' values, because
>> there is no sense for these values in SEQPACKET case.
>> 3) It waits until whole record is received or error is found during
>> receiving.
>> 4) It processes and sets 'MSG_TRUNC' flag.
>>
>> So to avoid extra conditions for two types of socket inside one loop, two
>> independent functions were created.
>>
>> Signed-off-by: Arseny Krasnov <arseny.krasnov@xxxxxxxxxxxxx>
>> ---
>> include/net/af_vsock.h | 5 +++
>> net/vmw_vsock/af_vsock.c | 95 +++++++++++++++++++++++++++++++++++++++-
>> 2 files changed, 99 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
>> index b1c717286993..5ad7ee7f78fd 100644
>> --- a/include/net/af_vsock.h
>> +++ b/include/net/af_vsock.h
>> @@ -135,6 +135,11 @@ struct vsock_transport {
>> bool (*stream_is_active)(struct vsock_sock *);
>> bool (*stream_allow)(u32 cid, u32 port);
>>
>> + /* SEQ_PACKET. */
>> + size_t (*seqpacket_seq_get_len)(struct vsock_sock *vsk);
>> + int (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
>> + int flags, bool *msg_ready);
>> +
>> /* Notification. */
>> int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);
>> int (*notify_poll_out)(struct vsock_sock *, size_t, bool *);
>> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>> index 0bc661e54262..ac2f69362f2e 100644
>> --- a/net/vmw_vsock/af_vsock.c
>> +++ b/net/vmw_vsock/af_vsock.c
>> @@ -1973,6 +1973,96 @@ static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg,
>> return err;
>> }
>>
>> +static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
>> + size_t len, int flags)
>> +{
>> + const struct vsock_transport *transport;
>> + const struct iovec *orig_iov;
>> + unsigned long orig_nr_segs;
>> + bool msg_ready;
>> + struct vsock_sock *vsk;
>> + size_t record_len;
>> + long timeout;
>> + int err = 0;
>> + DEFINE_WAIT(wait);
>> +
>> + vsk = vsock_sk(sk);
>> + transport = vsk->transport;
>> +
>> + timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
>> + orig_nr_segs = msg->msg_iter.nr_segs;
>> + orig_iov = msg->msg_iter.iov;
>> + msg_ready = false;
>> + record_len = 0;
>> +
>> + while (1) {
>> + err = vsock_wait_data(sk, &wait, timeout, NULL, 0);
>> +
>> + if (err <= 0) {
>> + /* In case of any loop break(timeout, signal
>> + * interrupt or shutdown), we report user that
>> + * nothing was copied.
>> + */
>> + err = 0;
>> + break;
>> + }
>> +
>> + if (record_len == 0) {
>> + record_len =
>> + transport->seqpacket_seq_get_len(vsk);
>> +
>> + if (record_len == 0)
>> + continue;
>> + }
>> +
>> + err = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready);
> In order to simplify the transport interface, can we do the work of
> seqpacket_seq_get_len() at the beginning of seqpacket_dequeue()?
>
> So in this way seqpacket_dequeue() can return the 'record_len' or an
> error.
Ack
>
>
