net: introduce qemu_receive_packet()

Some NIC supports loopback mode and this is done by calling
nc->info->receive() directly which in fact suppresses the effort of
reentrancy check that is done in qemu_net_queue_send().

Unfortunately we can't use qemu_net_queue_send() here since for
loopback there's no sender as peer, so this patch introduce a
qemu_receive_packet() which is used for implementing loopback mode
for a NIC with this check.

NIC that supports loopback mode will be converted to this helper.

This is intended to address CVE-2021-3416.

Cc: Prasad J Pandit <ppandit@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Jason Wang 2021-02-24 11:44:36 +08:00
parent 3de46e6fc4
commit 705df5466c
4 changed files with 66 additions and 7 deletions

View file

@ -144,12 +144,17 @@ void *qemu_get_nic_opaque(NetClientState *nc);
void qemu_del_net_client(NetClientState *nc);
typedef void (*qemu_nic_foreach)(NICState *nic, void *opaque);
void qemu_foreach_nic(qemu_nic_foreach func, void *opaque);
int qemu_can_receive_packet(NetClientState *nc);
int qemu_can_send_packet(NetClientState *nc);
ssize_t qemu_sendv_packet(NetClientState *nc, const struct iovec *iov,
int iovcnt);
ssize_t qemu_sendv_packet_async(NetClientState *nc, const struct iovec *iov,
int iovcnt, NetPacketSent *sent_cb);
ssize_t qemu_send_packet(NetClientState *nc, const uint8_t *buf, int size);
ssize_t qemu_receive_packet(NetClientState *nc, const uint8_t *buf, int size);
ssize_t qemu_receive_packet_iov(NetClientState *nc,
const struct iovec *iov,
int iovcnt);
ssize_t qemu_send_packet_raw(NetClientState *nc, const uint8_t *buf, int size);
ssize_t qemu_send_packet_async(NetClientState *nc, const uint8_t *buf,
int size, NetPacketSent *sent_cb);