linux/net/vmw_vsock/vsock_loopback.c

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// SPDX-License-Identifier: GPL-2.0-only
/* loopback transport for vsock using virtio_transport_common APIs
*
* Copyright (C) 2013-2019 Red Hat, Inc.
* Authors: Asias He <asias@redhat.com>
* Stefan Hajnoczi <stefanha@redhat.com>
* Stefano Garzarella <sgarzare@redhat.com>
*
*/
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/virtio_vsock.h>
struct vsock_loopback {
struct workqueue_struct *workqueue;
spinlock_t pkt_list_lock; /* protects pkt_list */
struct list_head pkt_list;
struct work_struct pkt_work;
};
static struct vsock_loopback the_vsock_loopback;
static u32 vsock_loopback_get_local_cid(void)
{
return VMADDR_CID_LOCAL;
}
static int vsock_loopback_send_pkt(struct virtio_vsock_pkt *pkt)
{
struct vsock_loopback *vsock = &the_vsock_loopback;
int len = pkt->len;
spin_lock_bh(&vsock->pkt_list_lock);
list_add_tail(&pkt->list, &vsock->pkt_list);
spin_unlock_bh(&vsock->pkt_list_lock);
queue_work(vsock->workqueue, &vsock->pkt_work);
return len;
}
static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
{
struct vsock_loopback *vsock = &the_vsock_loopback;
struct virtio_vsock_pkt *pkt, *n;
LIST_HEAD(freeme);
spin_lock_bh(&vsock->pkt_list_lock);
list_for_each_entry_safe(pkt, n, &vsock->pkt_list, list) {
if (pkt->vsk != vsk)
continue;
list_move(&pkt->list, &freeme);
}
spin_unlock_bh(&vsock->pkt_list_lock);
list_for_each_entry_safe(pkt, n, &freeme, list) {
list_del(&pkt->list);
virtio_transport_free_pkt(pkt);
}
return 0;
}
static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
static struct virtio_transport loopback_transport = {
.transport = {
.module = THIS_MODULE,
.get_local_cid = vsock_loopback_get_local_cid,
.init = virtio_transport_do_socket_init,
.destruct = virtio_transport_destruct,
.release = virtio_transport_release,
.connect = virtio_transport_connect,
.shutdown = virtio_transport_shutdown,
.cancel_pkt = vsock_loopback_cancel_pkt,
.dgram_bind = virtio_transport_dgram_bind,
.dgram_dequeue = virtio_transport_dgram_dequeue,
.dgram_enqueue = virtio_transport_dgram_enqueue,
.dgram_allow = virtio_transport_dgram_allow,
.stream_dequeue = virtio_transport_stream_dequeue,
.stream_enqueue = virtio_transport_stream_enqueue,
.stream_has_data = virtio_transport_stream_has_data,
.stream_has_space = virtio_transport_stream_has_space,
.stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
.stream_is_active = virtio_transport_stream_is_active,
.stream_allow = virtio_transport_stream_allow,
.seqpacket_dequeue = virtio_transport_seqpacket_dequeue,
.seqpacket_enqueue = virtio_transport_seqpacket_enqueue,
.seqpacket_allow = vsock_loopback_seqpacket_allow,
.seqpacket_has_data = virtio_transport_seqpacket_has_data,
.notify_poll_in = virtio_transport_notify_poll_in,
.notify_poll_out = virtio_transport_notify_poll_out,
.notify_recv_init = virtio_transport_notify_recv_init,
.notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
.notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
.notify_send_init = virtio_transport_notify_send_init,
.notify_send_pre_block = virtio_transport_notify_send_pre_block,
.notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
.notify_buffer_size = virtio_transport_notify_buffer_size,
},
.send_pkt = vsock_loopback_send_pkt,
};
static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
{
return true;
}
static void vsock_loopback_work(struct work_struct *work)
{
struct vsock_loopback *vsock =
container_of(work, struct vsock_loopback, pkt_work);
LIST_HEAD(pkts);
spin_lock_bh(&vsock->pkt_list_lock);
list_splice_init(&vsock->pkt_list, &pkts);
spin_unlock_bh(&vsock->pkt_list_lock);
while (!list_empty(&pkts)) {
struct virtio_vsock_pkt *pkt;
pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list);
list_del_init(&pkt->list);
virtio_transport_deliver_tap_pkt(pkt);
virtio_transport_recv_pkt(&loopback_transport, pkt);
}
}
static int __init vsock_loopback_init(void)
{
struct vsock_loopback *vsock = &the_vsock_loopback;
int ret;
vsock->workqueue = alloc_workqueue("vsock-loopback", 0, 0);
if (!vsock->workqueue)
return -ENOMEM;
spin_lock_init(&vsock->pkt_list_lock);
INIT_LIST_HEAD(&vsock->pkt_list);
INIT_WORK(&vsock->pkt_work, vsock_loopback_work);
ret = vsock_core_register(&loopback_transport.transport,
VSOCK_TRANSPORT_F_LOCAL);
if (ret)
goto out_wq;
return 0;
out_wq:
destroy_workqueue(vsock->workqueue);
return ret;
}
static void __exit vsock_loopback_exit(void)
{
struct vsock_loopback *vsock = &the_vsock_loopback;
struct virtio_vsock_pkt *pkt;
vsock_core_unregister(&loopback_transport.transport);
flush_work(&vsock->pkt_work);
spin_lock_bh(&vsock->pkt_list_lock);
while (!list_empty(&vsock->pkt_list)) {
pkt = list_first_entry(&vsock->pkt_list,
struct virtio_vsock_pkt, list);
list_del(&pkt->list);
virtio_transport_free_pkt(pkt);
}
spin_unlock_bh(&vsock->pkt_list_lock);
destroy_workqueue(vsock->workqueue);
}
module_init(vsock_loopback_init);
module_exit(vsock_loopback_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Stefano Garzarella <sgarzare@redhat.com>");
MODULE_DESCRIPTION("loopback transport for vsock");
MODULE_ALIAS_NETPROTO(PF_VSOCK);