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
15 struct vsock_loopback {
16 struct workqueue_struct *workqueue;
17
18 struct sk_buff_head pkt_queue;
19 struct work_struct pkt_work;
20 };
21
22 static struct vsock_loopback the_vsock_loopback;
23
vsock_loopback_get_local_cid(void)24 static u32 vsock_loopback_get_local_cid(void)
25 {
26 return VMADDR_CID_LOCAL;
27 }
28
vsock_loopback_send_pkt(struct sk_buff * skb)29 static 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
vsock_loopback_cancel_pkt(struct vsock_sock * vsk)40 static 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
49 static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
50
51 static struct virtio_transport loopback_transport = {
52 .transport = {
53 .module = THIS_MODULE,
54
55 .get_local_cid = vsock_loopback_get_local_cid,
56
57 .init = virtio_transport_do_socket_init,
58 .destruct = virtio_transport_destruct,
59 .release = virtio_transport_release,
60 .connect = virtio_transport_connect,
61 .shutdown = virtio_transport_shutdown,
62 .cancel_pkt = vsock_loopback_cancel_pkt,
63
64 .dgram_bind = virtio_transport_dgram_bind,
65 .dgram_dequeue = virtio_transport_dgram_dequeue,
66 .dgram_enqueue = virtio_transport_dgram_enqueue,
67 .dgram_allow = virtio_transport_dgram_allow,
68
69 .stream_dequeue = virtio_transport_stream_dequeue,
70 .stream_enqueue = virtio_transport_stream_enqueue,
71 .stream_has_data = virtio_transport_stream_has_data,
72 .stream_has_space = virtio_transport_stream_has_space,
73 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
74 .stream_is_active = virtio_transport_stream_is_active,
75 .stream_allow = virtio_transport_stream_allow,
76
77 .seqpacket_dequeue = virtio_transport_seqpacket_dequeue,
78 .seqpacket_enqueue = virtio_transport_seqpacket_enqueue,
79 .seqpacket_allow = vsock_loopback_seqpacket_allow,
80 .seqpacket_has_data = virtio_transport_seqpacket_has_data,
81
82 .notify_poll_in = virtio_transport_notify_poll_in,
83 .notify_poll_out = virtio_transport_notify_poll_out,
84 .notify_recv_init = virtio_transport_notify_recv_init,
85 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
86 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
87 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
88 .notify_send_init = virtio_transport_notify_send_init,
89 .notify_send_pre_block = virtio_transport_notify_send_pre_block,
90 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
91 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
92 .notify_buffer_size = virtio_transport_notify_buffer_size,
93 .notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat,
94
95 .read_skb = virtio_transport_read_skb,
96 },
97
98 .send_pkt = vsock_loopback_send_pkt,
99 };
100
vsock_loopback_seqpacket_allow(u32 remote_cid)101 static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
102 {
103 return true;
104 }
105
vsock_loopback_work(struct work_struct * work)106 static void vsock_loopback_work(struct work_struct *work)
107 {
108 struct vsock_loopback *vsock =
109 container_of(work, struct vsock_loopback, pkt_work);
110 struct sk_buff_head pkts;
111 struct sk_buff *skb;
112
113 skb_queue_head_init(&pkts);
114
115 spin_lock_bh(&vsock->pkt_queue.lock);
116 skb_queue_splice_init(&vsock->pkt_queue, &pkts);
117 spin_unlock_bh(&vsock->pkt_queue.lock);
118
119 while ((skb = __skb_dequeue(&pkts))) {
120 virtio_transport_deliver_tap_pkt(skb);
121 virtio_transport_recv_pkt(&loopback_transport, skb);
122 }
123 }
124
vsock_loopback_init(void)125 static int __init vsock_loopback_init(void)
126 {
127 struct vsock_loopback *vsock = &the_vsock_loopback;
128 int ret;
129
130 vsock->workqueue = alloc_workqueue("vsock-loopback", 0, 0);
131 if (!vsock->workqueue)
132 return -ENOMEM;
133
134 skb_queue_head_init(&vsock->pkt_queue);
135 INIT_WORK(&vsock->pkt_work, vsock_loopback_work);
136
137 ret = vsock_core_register(&loopback_transport.transport,
138 VSOCK_TRANSPORT_F_LOCAL);
139 if (ret)
140 goto out_wq;
141
142 return 0;
143
144 out_wq:
145 destroy_workqueue(vsock->workqueue);
146 return ret;
147 }
148
vsock_loopback_exit(void)149 static void __exit vsock_loopback_exit(void)
150 {
151 struct vsock_loopback *vsock = &the_vsock_loopback;
152
153 vsock_core_unregister(&loopback_transport.transport);
154
155 flush_work(&vsock->pkt_work);
156
157 virtio_vsock_skb_queue_purge(&vsock->pkt_queue);
158
159 destroy_workqueue(vsock->workqueue);
160 }
161
162 module_init(vsock_loopback_init);
163 module_exit(vsock_loopback_exit);
164 MODULE_LICENSE("GPL v2");
165 MODULE_AUTHOR("Stefano Garzarella <sgarzare@redhat.com>");
166 MODULE_DESCRIPTION("loopback transport for vsock");
167 MODULE_ALIAS_NETPROTO(PF_VSOCK);
168