1 // SPDX-License-Identifier: GPL-2.0-only
2 /* loopback transport for vsock using virtio_transport_common APIs
4 * Copyright (C) 2013-2019 Red Hat, Inc.
5 * Authors: Asias He <asias@redhat.com>
6 * Stefan Hajnoczi <stefanha@redhat.com>
7 * Stefano Garzarella <sgarzare@redhat.com>
10 #include <linux/spinlock.h>
11 #include <linux/module.h>
12 #include <linux/list.h>
13 #include <linux/virtio_vsock.h>
15 struct vsock_loopback {
16 struct workqueue_struct *workqueue;
18 struct sk_buff_head pkt_queue;
19 struct work_struct pkt_work;
22 static struct vsock_loopback the_vsock_loopback;
24 static u32 vsock_loopback_get_local_cid(void)
26 return VMADDR_CID_LOCAL;
29 static int vsock_loopback_send_pkt(struct sk_buff *skb)
31 struct vsock_loopback *vsock = &the_vsock_loopback;
34 skb_queue_tail(&vsock->pkt_queue, skb);
36 queue_work(vsock->workqueue, &vsock->pkt_work);
41 static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
43 struct vsock_loopback *vsock = &the_vsock_loopback;
45 virtio_transport_purge_skbs(vsk, &vsock->pkt_queue);
50 static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
52 static struct virtio_transport loopback_transport = {
54 .module = THIS_MODULE,
56 .get_local_cid = vsock_loopback_get_local_cid,
58 .init = virtio_transport_do_socket_init,
59 .destruct = virtio_transport_destruct,
60 .release = virtio_transport_release,
61 .connect = virtio_transport_connect,
62 .shutdown = virtio_transport_shutdown,
63 .cancel_pkt = vsock_loopback_cancel_pkt,
65 .dgram_bind = virtio_transport_dgram_bind,
66 .dgram_dequeue = virtio_transport_dgram_dequeue,
67 .dgram_enqueue = virtio_transport_dgram_enqueue,
68 .dgram_allow = virtio_transport_dgram_allow,
70 .stream_dequeue = virtio_transport_stream_dequeue,
71 .stream_enqueue = virtio_transport_stream_enqueue,
72 .stream_has_data = virtio_transport_stream_has_data,
73 .stream_has_space = virtio_transport_stream_has_space,
74 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
75 .stream_is_active = virtio_transport_stream_is_active,
76 .stream_allow = virtio_transport_stream_allow,
78 .seqpacket_dequeue = virtio_transport_seqpacket_dequeue,
79 .seqpacket_enqueue = virtio_transport_seqpacket_enqueue,
80 .seqpacket_allow = vsock_loopback_seqpacket_allow,
81 .seqpacket_has_data = virtio_transport_seqpacket_has_data,
83 .notify_poll_in = virtio_transport_notify_poll_in,
84 .notify_poll_out = virtio_transport_notify_poll_out,
85 .notify_recv_init = virtio_transport_notify_recv_init,
86 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
87 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
88 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
89 .notify_send_init = virtio_transport_notify_send_init,
90 .notify_send_pre_block = virtio_transport_notify_send_pre_block,
91 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
92 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
93 .notify_buffer_size = virtio_transport_notify_buffer_size,
96 .send_pkt = vsock_loopback_send_pkt,
99 static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
104 static void vsock_loopback_work(struct work_struct *work)
106 struct vsock_loopback *vsock =
107 container_of(work, struct vsock_loopback, pkt_work);
108 struct sk_buff_head pkts;
111 skb_queue_head_init(&pkts);
113 spin_lock_bh(&vsock->pkt_queue.lock);
114 skb_queue_splice_init(&vsock->pkt_queue, &pkts);
115 spin_unlock_bh(&vsock->pkt_queue.lock);
117 while ((skb = __skb_dequeue(&pkts))) {
118 virtio_transport_deliver_tap_pkt(skb);
119 virtio_transport_recv_pkt(&loopback_transport, skb);
123 static int __init vsock_loopback_init(void)
125 struct vsock_loopback *vsock = &the_vsock_loopback;
128 vsock->workqueue = alloc_workqueue("vsock-loopback", 0, 0);
129 if (!vsock->workqueue)
132 skb_queue_head_init(&vsock->pkt_queue);
133 INIT_WORK(&vsock->pkt_work, vsock_loopback_work);
135 ret = vsock_core_register(&loopback_transport.transport,
136 VSOCK_TRANSPORT_F_LOCAL);
143 destroy_workqueue(vsock->workqueue);
147 static void __exit vsock_loopback_exit(void)
149 struct vsock_loopback *vsock = &the_vsock_loopback;
151 vsock_core_unregister(&loopback_transport.transport);
153 flush_work(&vsock->pkt_work);
155 virtio_vsock_skb_queue_purge(&vsock->pkt_queue);
157 destroy_workqueue(vsock->workqueue);
160 module_init(vsock_loopback_init);
161 module_exit(vsock_loopback_exit);
162 MODULE_LICENSE("GPL v2");
163 MODULE_AUTHOR("Stefano Garzarella <sgarzare@redhat.com>");
164 MODULE_DESCRIPTION("loopback transport for vsock");
165 MODULE_ALIAS_NETPROTO(PF_VSOCK);