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virtio-9p: break device if buffers are misconfigured

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The 9P protocol is transport agnostic: if the guest misconfigured the
buffers, the best we can do is to set the broken flag on the device.

Signed-off-by: Greg Kurz <groug@kaod.org>
This commit is contained in:
Greg Kurz 2017-06-29 15:11:51 +02:00
parent a4d9985450
commit 8d37de41ca
4 changed files with 40 additions and 7 deletions
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2
hw/9pfs/9p.c
View File

@ -1664,7 +1664,7 @@ static void v9fs_init_qiov_from_pdu(QEMUIOVector *qiov, V9fsPDU *pdu,
unsigned int niov;
if (is_write) {
pdu->s->transport->init_out_iov_from_pdu(pdu, &iov, &niov);
pdu->s->transport->init_out_iov_from_pdu(pdu, &iov, &niov, size + skip);
} else {
pdu->s->transport->init_in_iov_from_pdu(pdu, &iov, &niov, size + skip);
}

2
hw/9pfs/9p.h
View File

@ -363,7 +363,7 @@ struct V9fsTransport {
void (*init_in_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
unsigned int *pniov, size_t size);
void (*init_out_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
unsigned int *pniov);
unsigned int *pniov, size_t size);
void (*push_and_notify)(V9fsPDU *pdu);
};

40
hw/9pfs/virtio-9p-device.c
View File

@ -146,8 +146,16 @@ static ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
V9fsState *s = pdu->s;
V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
VirtQueueElement *elem = v->elems[pdu->idx];
ssize_t ret;
return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
ret = v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
if (ret < 0) {
VirtIODevice *vdev = VIRTIO_DEVICE(v);
virtio_error(vdev, "Failed to encode VirtFS reply type %d",
pdu->id + 1);
}
return ret;
}
static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
@ -156,28 +164,52 @@ static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
V9fsState *s = pdu->s;
V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
VirtQueueElement *elem = v->elems[pdu->idx];
ssize_t ret;
return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
ret = v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
if (ret < 0) {
VirtIODevice *vdev = VIRTIO_DEVICE(v);
virtio_error(vdev, "Failed to decode VirtFS request type %d", pdu->id);
}
return ret;
}
/* The size parameter is used by other transports. Do not drop it. */
static void virtio_init_in_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
unsigned int *pniov, size_t size)
{
V9fsState *s = pdu->s;
V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
VirtQueueElement *elem = v->elems[pdu->idx];
size_t buf_size = iov_size(elem->in_sg, elem->in_num);
if (buf_size < size) {
VirtIODevice *vdev = VIRTIO_DEVICE(v);
virtio_error(vdev,
"VirtFS reply type %d needs %zu bytes, buffer has %zu",
pdu->id + 1, size, buf_size);
}
*piov = elem->in_sg;
*pniov = elem->in_num;
}
static void virtio_init_out_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
unsigned int *pniov)
unsigned int *pniov, size_t size)
{
V9fsState *s = pdu->s;
V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
VirtQueueElement *elem = v->elems[pdu->idx];
size_t buf_size = iov_size(elem->out_sg, elem->out_num);
if (buf_size < size) {
VirtIODevice *vdev = VIRTIO_DEVICE(v);
virtio_error(vdev,
"VirtFS request type %d needs %zu bytes, buffer has %zu",
pdu->id, size, buf_size);
}
*piov = elem->out_sg;
*pniov = elem->out_num;

3
hw/9pfs/xen-9p-backend.c
View File

@ -147,7 +147,8 @@ static ssize_t xen_9pfs_pdu_vunmarshal(V9fsPDU *pdu,
static void xen_9pfs_init_out_iov_from_pdu(V9fsPDU *pdu,
struct iovec **piov,
unsigned int *pniov)
unsigned int *pniov,
size_t size)
{
Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];