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Linux kernel mirror (for testing)
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1// SPDX-License-Identifier: GPL-2.0-only
2/* loopback transport for vsock using virtio_transport_common APIs
3 *
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>
8 *
9 */
10#include <linux/spinlock.h>
11#include <linux/module.h>
12#include <linux/list.h>
13#include <linux/virtio_vsock.h>
14
15struct vsock_loopback {
16 struct workqueue_struct *workqueue;
17
18 struct sk_buff_head pkt_queue;
19 struct work_struct pkt_work;
20};
21
22static struct vsock_loopback the_vsock_loopback;
23
24static u32 vsock_loopback_get_local_cid(void)
25{
26 return VMADDR_CID_LOCAL;
27}
28
29static int vsock_loopback_send_pkt(struct sk_buff *skb)
30{
31 struct vsock_loopback *vsock = &the_vsock_loopback;
32 int len = skb->len;
33
34 skb_queue_tail(&vsock->pkt_queue, skb);
35
36 queue_work(vsock->workqueue, &vsock->pkt_work);
37
38 return len;
39}
40
41static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
42{
43 struct vsock_loopback *vsock = &the_vsock_loopback;
44
45 virtio_transport_purge_skbs(vsk, &vsock->pkt_queue);
46
47 return 0;
48}
49
50static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
51
52static struct virtio_transport loopback_transport = {
53 .transport = {
54 .module = THIS_MODULE,
55
56 .get_local_cid = vsock_loopback_get_local_cid,
57
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,
64
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,
69
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,
77
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,
82
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,
94 },
95
96 .send_pkt = vsock_loopback_send_pkt,
97};
98
99static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
100{
101 return true;
102}
103
104static void vsock_loopback_work(struct work_struct *work)
105{
106 struct vsock_loopback *vsock =
107 container_of(work, struct vsock_loopback, pkt_work);
108 struct sk_buff_head pkts;
109 struct sk_buff *skb;
110
111 skb_queue_head_init(&pkts);
112
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);
116
117 while ((skb = __skb_dequeue(&pkts))) {
118 virtio_transport_deliver_tap_pkt(skb);
119 virtio_transport_recv_pkt(&loopback_transport, skb);
120 }
121}
122
123static int __init vsock_loopback_init(void)
124{
125 struct vsock_loopback *vsock = &the_vsock_loopback;
126 int ret;
127
128 vsock->workqueue = alloc_workqueue("vsock-loopback", 0, 0);
129 if (!vsock->workqueue)
130 return -ENOMEM;
131
132 skb_queue_head_init(&vsock->pkt_queue);
133 INIT_WORK(&vsock->pkt_work, vsock_loopback_work);
134
135 ret = vsock_core_register(&loopback_transport.transport,
136 VSOCK_TRANSPORT_F_LOCAL);
137 if (ret)
138 goto out_wq;
139
140 return 0;
141
142out_wq:
143 destroy_workqueue(vsock->workqueue);
144 return ret;
145}
146
147static void __exit vsock_loopback_exit(void)
148{
149 struct vsock_loopback *vsock = &the_vsock_loopback;
150
151 vsock_core_unregister(&loopback_transport.transport);
152
153 flush_work(&vsock->pkt_work);
154
155 virtio_vsock_skb_queue_purge(&vsock->pkt_queue);
156
157 destroy_workqueue(vsock->workqueue);
158}
159
160module_init(vsock_loopback_init);
161module_exit(vsock_loopback_exit);
162MODULE_LICENSE("GPL v2");
163MODULE_AUTHOR("Stefano Garzarella <sgarzare@redhat.com>");
164MODULE_DESCRIPTION("loopback transport for vsock");
165MODULE_ALIAS_NETPROTO(PF_VSOCK);