summaryrefslogtreecommitdiffstats
path: root/net/vmw_vsock/vsock_loopback.c
blob: a45f7ffca8c56f0b41e68be862c2641a7f315fd4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
// 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 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,

		.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 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);