Re: [RFC PATCH v9 12/19] virtio/vsock: add SEQPACKET receive logic

From: Arseny Krasnov <arseny.krasnov@kaspersky.com>
To: Stefano Garzarella <sgarzare@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Jason Wang <jasowang@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Jorgen Hansen <jhansen@vmware.com>,
	Andra Paraschiv <andraprs@amazon.com>,
	Norbert Slusarek <nslusarek@gmx.net>,
	Colin Ian King <colin.king@canonical.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"virtualization@lists.linux-foundation.org" 
	<virtualization@lists.linux-foundation.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"stsp2@yandex.ru" <stsp2@yandex.ru>,
	"oxffffaa@gmail.com" <oxffffaa@gmail.com>
Subject: Re: [RFC PATCH v9 12/19] virtio/vsock: add SEQPACKET receive logic
Date: Thu, 13 May 2021 17:43:21 +0300	[thread overview]
Message-ID: <e1fbcc54-9c5a-d23a-b5c8-02f1ec5b5065@kaspersky.com> (raw)
In-Reply-To: <20210513121400.7u7kectkxwame76b@steredhat>


On 13.05.2021 15:14, Stefano Garzarella wrote:
> On Sat, May 08, 2021 at 07:35:40PM +0300, Arseny Krasnov wrote:
>> This modifies current receive logic for SEQPACKET support:
>> 1) Inserts 'RW' packet to socket's rx queue, but without merging with
>>   buffer of last packet in queue.
> This is not true anymore, right?
>
>> 2) Performs check for packet and socket types on receive(if mismatch,
>>   then reset connection).
>>
>> Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
>> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
> Also this patch is changed :-)
>
>> ---
>> net/vmw_vsock/virtio_transport_common.c | 28 +++++++++++++++++++++++--
>> 1 file changed, 26 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>> index f649a21dd23b..7fea0a2192f7 100644
>> --- a/net/vmw_vsock/virtio_transport_common.c
>> +++ b/net/vmw_vsock/virtio_transport_common.c
>> @@ -165,6 +165,14 @@ void virtio_transport_deliver_tap_pkt(struct virtio_vsock_pkt *pkt)
>> }
>> EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
>>
>> +static u16 virtio_transport_get_type(struct sock *sk)
>> +{
>> +	if (sk->sk_type == SOCK_STREAM)
>> +		return VIRTIO_VSOCK_TYPE_STREAM;
>> +	else
>> +		return VIRTIO_VSOCK_TYPE_SEQPACKET;
>> +}
>> +
>> /* This function can only be used on connecting/connected sockets,
>>  * since a socket assigned to a transport is required.
>>  *
>> @@ -980,11 +988,15 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
>> 		/* If there is space in the last packet queued, we copy the
>> 		 * new packet in its buffer.
>> 		 */
>> -		if (pkt->len <= last_pkt->buf_len - last_pkt->len) {
>> +		if ((pkt->len <= last_pkt->buf_len - last_pkt->len) &&
>> +		    !(le32_to_cpu(last_pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR)) {
> Maybe we should update the comment above.
>
>> 			memcpy(last_pkt->buf + last_pkt->len, pkt->buf,
>> 			       pkt->len);
>> 			last_pkt->len += pkt->len;
>> 			free_pkt = true;
>> +
>> +			if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR)
>> +				last_pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
> What about doing the following in any case?
>
> 			last_pkt->hdr.flags |= pkt->hdr.flags;
Ack
>
>> 			goto out;
>> 		}
>> 	}
>