Commit e381d2b4 authored by David S. Miller's avatar David S. Miller

Merge branch 'vsock-virtio-make-the-credit-mechanism-more-robust'

Stefano Garzarella says:

====================
vsock/virtio: make the credit mechanism more robust

This series makes the credit mechanism implemented in the
virtio-vsock devices more robust.
Patch 1 sends an update to the remote peer when the buf_alloc
change.
Patch 2 prevents a malicious peer (especially the guest) can
consume all the memory of the other peer, discarding packets
when the credit available is not respected.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 2e978795 ae6fcfbf
...@@ -204,10 +204,14 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, ...@@ -204,10 +204,14 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
return virtio_transport_get_ops()->send_pkt(pkt); return virtio_transport_get_ops()->send_pkt(pkt);
} }
static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
struct virtio_vsock_pkt *pkt) struct virtio_vsock_pkt *pkt)
{ {
if (vvs->rx_bytes + pkt->len > vvs->buf_alloc)
return false;
vvs->rx_bytes += pkt->len; vvs->rx_bytes += pkt->len;
return true;
} }
static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
...@@ -458,6 +462,9 @@ void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val) ...@@ -458,6 +462,9 @@ void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
vvs->buf_size_max = val; vvs->buf_size_max = val;
vvs->buf_size = val; vvs->buf_size = val;
vvs->buf_alloc = val; vvs->buf_alloc = val;
virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
NULL);
} }
EXPORT_SYMBOL_GPL(virtio_transport_set_buffer_size); EXPORT_SYMBOL_GPL(virtio_transport_set_buffer_size);
...@@ -876,14 +883,18 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk, ...@@ -876,14 +883,18 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
struct virtio_vsock_pkt *pkt) struct virtio_vsock_pkt *pkt)
{ {
struct virtio_vsock_sock *vvs = vsk->trans; struct virtio_vsock_sock *vvs = vsk->trans;
bool free_pkt = false; bool can_enqueue, free_pkt = false;
pkt->len = le32_to_cpu(pkt->hdr.len); pkt->len = le32_to_cpu(pkt->hdr.len);
pkt->off = 0; pkt->off = 0;
spin_lock_bh(&vvs->rx_lock); spin_lock_bh(&vvs->rx_lock);
virtio_transport_inc_rx_pkt(vvs, pkt); can_enqueue = virtio_transport_inc_rx_pkt(vvs, pkt);
if (!can_enqueue) {
free_pkt = true;
goto out;
}
/* Try to copy small packets into the buffer of last packet queued, /* Try to copy small packets into the buffer of last packet queued,
* to avoid wasting memory queueing the entire buffer with a small * to avoid wasting memory queueing the entire buffer with a small
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment