This adds support of MSG_PEEK flag for SOCK_SEQPACKET type of socket.
Difference with SOCK_STREAM is that this callback returns either length
of the message or error.
Signed-off-by: Arseniy Krasnov <[email protected]>
---
net/vmw_vsock/virtio_transport_common.c | 63 +++++++++++++++++++++++--
1 file changed, 60 insertions(+), 3 deletions(-)
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 2ee40574c339..352d042b130b 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -460,6 +460,63 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
return err;
}
+static ssize_t
+virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk,
+ struct msghdr *msg)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+ struct sk_buff *skb;
+ size_t total, len;
+
+ spin_lock_bh(&vvs->rx_lock);
+
+ if (!vvs->msg_count) {
+ spin_unlock_bh(&vvs->rx_lock);
+ return 0;
+ }
+
+ total = 0;
+ len = msg_data_left(msg);
+
+ skb_queue_walk(&vvs->rx_queue, skb) {
+ struct virtio_vsock_hdr *hdr;
+
+ if (total < len) {
+ size_t bytes;
+ int err;
+
+ bytes = len - total;
+ if (bytes > skb->len)
+ bytes = skb->len;
+
+ spin_unlock_bh(&vvs->rx_lock);
+
+ /* sk_lock is held by caller so no one else can dequeue.
+ * Unlock rx_lock since memcpy_to_msg() may sleep.
+ */
+ err = memcpy_to_msg(msg, skb->data, bytes);
+ if (err)
+ return err;
+
+ spin_lock_bh(&vvs->rx_lock);
+ }
+
+ total += skb->len;
+ hdr = virtio_vsock_hdr(skb);
+
+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
+ msg->msg_flags |= MSG_EOR;
+
+ break;
+ }
+ }
+
+ spin_unlock_bh(&vvs->rx_lock);
+
+ return total;
+}
+
static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
struct msghdr *msg,
int flags)
@@ -554,9 +611,9 @@ virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
int flags)
{
if (flags & MSG_PEEK)
- return -EOPNOTSUPP;
-
- return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
+ return virtio_transport_seqpacket_do_peek(vsk, msg);
+ else
+ return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
}
EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
--
2.25.1
On Sun, Jun 18, 2023 at 09:24:49AM +0300, Arseniy Krasnov wrote:
>This adds support of MSG_PEEK flag for SOCK_SEQPACKET type of socket.
>Difference with SOCK_STREAM is that this callback returns either length
>of the message or error.
>
>Signed-off-by: Arseniy Krasnov <[email protected]>
>---
> net/vmw_vsock/virtio_transport_common.c | 63 +++++++++++++++++++++++--
> 1 file changed, 60 insertions(+), 3 deletions(-)
>
>diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>index 2ee40574c339..352d042b130b 100644
>--- a/net/vmw_vsock/virtio_transport_common.c
>+++ b/net/vmw_vsock/virtio_transport_common.c
>@@ -460,6 +460,63 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
> return err;
> }
>
>+static ssize_t
>+virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk,
>+ struct msghdr *msg)
>+{
>+ struct virtio_vsock_sock *vvs = vsk->trans;
>+ struct sk_buff *skb;
>+ size_t total, len;
>+
>+ spin_lock_bh(&vvs->rx_lock);
>+
>+ if (!vvs->msg_count) {
>+ spin_unlock_bh(&vvs->rx_lock);
>+ return 0;
>+ }
>+
>+ total = 0;
>+ len = msg_data_left(msg);
>+
>+ skb_queue_walk(&vvs->rx_queue, skb) {
>+ struct virtio_vsock_hdr *hdr;
>+
>+ if (total < len) {
>+ size_t bytes;
>+ int err;
>+
>+ bytes = len - total;
>+ if (bytes > skb->len)
>+ bytes = skb->len;
>+
>+ spin_unlock_bh(&vvs->rx_lock);
>+
>+ /* sk_lock is held by caller so no one else can dequeue.
>+ * Unlock rx_lock since memcpy_to_msg() may sleep.
>+ */
>+ err = memcpy_to_msg(msg, skb->data, bytes);
>+ if (err)
>+ return err;
>+
>+ spin_lock_bh(&vvs->rx_lock);
>+ }
>+
>+ total += skb->len;
>+ hdr = virtio_vsock_hdr(skb);
>+
>+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
>+ if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
>+ msg->msg_flags |= MSG_EOR;
>+
>+ break;
>+ }
>+ }
>+
>+ spin_unlock_bh(&vvs->rx_lock);
>+
>+ return total;
Should we return the minimum between total and len?
Thanks,
Stefano
>+}
>+
> static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
> struct msghdr *msg,
> int flags)
>@@ -554,9 +611,9 @@ virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
> int flags)
> {
> if (flags & MSG_PEEK)
>- return -EOPNOTSUPP;
>-
>- return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
>+ return virtio_transport_seqpacket_do_peek(vsk, msg);
>+ else
>+ return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
> }
> EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
>
>--
>2.25.1
>
On 26.06.2023 19:28, Stefano Garzarella wrote:
> On Sun, Jun 18, 2023 at 09:24:49AM +0300, Arseniy Krasnov wrote:
>> This adds support of MSG_PEEK flag for SOCK_SEQPACKET type of socket.
>> Difference with SOCK_STREAM is that this callback returns either length
>> of the message or error.
>>
>> Signed-off-by: Arseniy Krasnov <[email protected]>
>> ---
>> net/vmw_vsock/virtio_transport_common.c | 63 +++++++++++++++++++++++--
>> 1 file changed, 60 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>> index 2ee40574c339..352d042b130b 100644
>> --- a/net/vmw_vsock/virtio_transport_common.c
>> +++ b/net/vmw_vsock/virtio_transport_common.c
>> @@ -460,6 +460,63 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
>> return err;
>> }
>>
>> +static ssize_t
>> +virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk,
>> + struct msghdr *msg)
>> +{
>> + struct virtio_vsock_sock *vvs = vsk->trans;
>> + struct sk_buff *skb;
>> + size_t total, len;
>> +
>> + spin_lock_bh(&vvs->rx_lock);
>> +
>> + if (!vvs->msg_count) {
>> + spin_unlock_bh(&vvs->rx_lock);
>> + return 0;
>> + }
>> +
>> + total = 0;
>> + len = msg_data_left(msg);
>> +
>> + skb_queue_walk(&vvs->rx_queue, skb) {
>> + struct virtio_vsock_hdr *hdr;
>> +
>> + if (total < len) {
>> + size_t bytes;
>> + int err;
>> +
>> + bytes = len - total;
>> + if (bytes > skb->len)
>> + bytes = skb->len;
>> +
>> + spin_unlock_bh(&vvs->rx_lock);
>> +
>> + /* sk_lock is held by caller so no one else can dequeue.
>> + * Unlock rx_lock since memcpy_to_msg() may sleep.
>> + */
>> + err = memcpy_to_msg(msg, skb->data, bytes);
>> + if (err)
>> + return err;
>> +
>> + spin_lock_bh(&vvs->rx_lock);
>> + }
>> +
>> + total += skb->len;
>> + hdr = virtio_vsock_hdr(skb);
>> +
>> + if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
>> + if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
>> + msg->msg_flags |= MSG_EOR;
>> +
>> + break;
>> + }
>> + }
>> +
>> + spin_unlock_bh(&vvs->rx_lock);
>> +
>> + return total;
>
> Should we return the minimum between total and len?
I guess no, because seqpacket dequeue callback always returns length of message,
then, in af_vsock.c we return either number of bytes read or length of message
depending on MSG_TRUNC flags.
Thanks, Arseniy
>
> Thanks,
> Stefano
>
>> +}
>> +
>> static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
>> struct msghdr *msg,
>> int flags)
>> @@ -554,9 +611,9 @@ virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
>> int flags)
>> {
>> if (flags & MSG_PEEK)
>> - return -EOPNOTSUPP;
>> -
>> - return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
>> + return virtio_transport_seqpacket_do_peek(vsk, msg);
>> + else
>> + return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
>> }
>> EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
>>
>> --
>> 2.25.1
>>
>
On Tue, Jun 27, 2023 at 07:34:29AM +0300, Arseniy Krasnov wrote:
>
>
>On 26.06.2023 19:28, Stefano Garzarella wrote:
>> On Sun, Jun 18, 2023 at 09:24:49AM +0300, Arseniy Krasnov wrote:
>>> This adds support of MSG_PEEK flag for SOCK_SEQPACKET type of socket.
>>> Difference with SOCK_STREAM is that this callback returns either length
>>> of the message or error.
>>>
>>> Signed-off-by: Arseniy Krasnov <[email protected]>
>>> ---
>>> net/vmw_vsock/virtio_transport_common.c | 63 +++++++++++++++++++++++--
>>> 1 file changed, 60 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>>> index 2ee40574c339..352d042b130b 100644
>>> --- a/net/vmw_vsock/virtio_transport_common.c
>>> +++ b/net/vmw_vsock/virtio_transport_common.c
>>> @@ -460,6 +460,63 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
>>> ????return err;
>>> }
>>>
>>> +static ssize_t
>>> +virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk,
>>> +?????????????????? struct msghdr *msg)
>>> +{
>>> +??? struct virtio_vsock_sock *vvs = vsk->trans;
>>> +??? struct sk_buff *skb;
>>> +??? size_t total, len;
>>> +
>>> +??? spin_lock_bh(&vvs->rx_lock);
>>> +
>>> +??? if (!vvs->msg_count) {
>>> +??????? spin_unlock_bh(&vvs->rx_lock);
>>> +??????? return 0;
>>> +??? }
>>> +
>>> +??? total = 0;
>>> +??? len = msg_data_left(msg);
>>> +
>>> +??? skb_queue_walk(&vvs->rx_queue, skb) {
>>> +??????? struct virtio_vsock_hdr *hdr;
>>> +
>>> +??????? if (total < len) {
>>> +??????????? size_t bytes;
>>> +??????????? int err;
>>> +
>>> +??????????? bytes = len - total;
>>> +??????????? if (bytes > skb->len)
>>> +??????????????? bytes = skb->len;
>>> +
>>> +??????????? spin_unlock_bh(&vvs->rx_lock);
>>> +
>>> +??????????? /* sk_lock is held by caller so no one else can dequeue.
>>> +???????????? * Unlock rx_lock since memcpy_to_msg() may sleep.
>>> +???????????? */
>>> +??????????? err = memcpy_to_msg(msg, skb->data, bytes);
>>> +??????????? if (err)
>>> +??????????????? return err;
>>> +
>>> +??????????? spin_lock_bh(&vvs->rx_lock);
>>> +??????? }
>>> +
>>> +??????? total += skb->len;
>>> +??????? hdr = virtio_vsock_hdr(skb);
>>> +
>>> +??????? if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
>>> +??????????? if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
>>> +??????????????? msg->msg_flags |= MSG_EOR;
>>> +
>>> +??????????? break;
>>> +??????? }
>>> +??? }
>>> +
>>> +??? spin_unlock_bh(&vvs->rx_lock);
>>> +
>>> +??? return total;
>>
>> Should we return the minimum between total and len?
>
>I guess no, because seqpacket dequeue callback always returns length of message,
>then, in af_vsock.c we return either number of bytes read or length of message
>depending on MSG_TRUNC flags.
Right! We should always return the total lenght of the packet.
Thanks,
Stefano
>
>Thanks, Arseniy
>
>>
>> Thanks,
>> Stefano
>>
>>> +}
>>> +
>>> static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
>>> ???????????????????????? struct msghdr *msg,
>>> ???????????????????????? int flags)
>>> @@ -554,9 +611,9 @@ virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
>>> ?????????????????? int flags)
>>> {
>>> ????if (flags & MSG_PEEK)
>>> -??????? return -EOPNOTSUPP;
>>> -
>>> -??? return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
>>> +??????? return virtio_transport_seqpacket_do_peek(vsk, msg);
>>> +??? else
>>> +??????? return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
>>> }
>>> EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
>>>
>>> --?
>>> 2.25.1
>>>
>>
>