Linux kernel mirror (for testing)
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linux
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 virtio_vsock_skb_queue_tail(&vsock->pkt_queue, skb);
35 queue_work(vsock->workqueue, &vsock->pkt_work);
36
37 return len;
38}
39
40static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
41{
42 struct vsock_loopback *vsock = &the_vsock_loopback;
43
44 virtio_transport_purge_skbs(vsk, &vsock->pkt_queue);
45
46 return 0;
47}
48
49static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
50static bool vsock_loopback_msgzerocopy_allow(void)
51{
52 return true;
53}
54
55static struct virtio_transport loopback_transport = {
56 .transport = {
57 .module = THIS_MODULE,
58
59 .get_local_cid = vsock_loopback_get_local_cid,
60
61 .init = virtio_transport_do_socket_init,
62 .destruct = virtio_transport_destruct,
63 .release = virtio_transport_release,
64 .connect = virtio_transport_connect,
65 .shutdown = virtio_transport_shutdown,
66 .cancel_pkt = vsock_loopback_cancel_pkt,
67
68 .dgram_bind = virtio_transport_dgram_bind,
69 .dgram_dequeue = virtio_transport_dgram_dequeue,
70 .dgram_enqueue = virtio_transport_dgram_enqueue,
71 .dgram_allow = virtio_transport_dgram_allow,
72
73 .stream_dequeue = virtio_transport_stream_dequeue,
74 .stream_enqueue = virtio_transport_stream_enqueue,
75 .stream_has_data = virtio_transport_stream_has_data,
76 .stream_has_space = virtio_transport_stream_has_space,
77 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
78 .stream_is_active = virtio_transport_stream_is_active,
79 .stream_allow = virtio_transport_stream_allow,
80
81 .seqpacket_dequeue = virtio_transport_seqpacket_dequeue,
82 .seqpacket_enqueue = virtio_transport_seqpacket_enqueue,
83 .seqpacket_allow = vsock_loopback_seqpacket_allow,
84 .seqpacket_has_data = virtio_transport_seqpacket_has_data,
85
86 .msgzerocopy_allow = vsock_loopback_msgzerocopy_allow,
87
88 .notify_poll_in = virtio_transport_notify_poll_in,
89 .notify_poll_out = virtio_transport_notify_poll_out,
90 .notify_recv_init = virtio_transport_notify_recv_init,
91 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
92 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
93 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
94 .notify_send_init = virtio_transport_notify_send_init,
95 .notify_send_pre_block = virtio_transport_notify_send_pre_block,
96 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
97 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
98 .notify_buffer_size = virtio_transport_notify_buffer_size,
99
100 .read_skb = virtio_transport_read_skb,
101 },
102
103 .send_pkt = vsock_loopback_send_pkt,
104};
105
106static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
107{
108 return true;
109}
110
111static void vsock_loopback_work(struct work_struct *work)
112{
113 struct vsock_loopback *vsock =
114 container_of(work, struct vsock_loopback, pkt_work);
115 struct sk_buff_head pkts;
116 struct sk_buff *skb;
117
118 skb_queue_head_init(&pkts);
119
120 spin_lock_bh(&vsock->pkt_queue.lock);
121 skb_queue_splice_init(&vsock->pkt_queue, &pkts);
122 spin_unlock_bh(&vsock->pkt_queue.lock);
123
124 while ((skb = __skb_dequeue(&pkts))) {
125 virtio_transport_deliver_tap_pkt(skb);
126 virtio_transport_recv_pkt(&loopback_transport, skb);
127 }
128}
129
130static int __init vsock_loopback_init(void)
131{
132 struct vsock_loopback *vsock = &the_vsock_loopback;
133 int ret;
134
135 vsock->workqueue = alloc_workqueue("vsock-loopback", 0, 0);
136 if (!vsock->workqueue)
137 return -ENOMEM;
138
139 skb_queue_head_init(&vsock->pkt_queue);
140 INIT_WORK(&vsock->pkt_work, vsock_loopback_work);
141
142 ret = vsock_core_register(&loopback_transport.transport,
143 VSOCK_TRANSPORT_F_LOCAL);
144 if (ret)
145 goto out_wq;
146
147 return 0;
148
149out_wq:
150 destroy_workqueue(vsock->workqueue);
151 return ret;
152}
153
154static void __exit vsock_loopback_exit(void)
155{
156 struct vsock_loopback *vsock = &the_vsock_loopback;
157
158 vsock_core_unregister(&loopback_transport.transport);
159
160 flush_work(&vsock->pkt_work);
161
162 virtio_vsock_skb_queue_purge(&vsock->pkt_queue);
163
164 destroy_workqueue(vsock->workqueue);
165}
166
167module_init(vsock_loopback_init);
168module_exit(vsock_loopback_exit);
169MODULE_LICENSE("GPL v2");
170MODULE_AUTHOR("Stefano Garzarella <sgarzare@redhat.com>");
171MODULE_DESCRIPTION("loopback transport for vsock");
172MODULE_ALIAS_NETPROTO(PF_VSOCK);