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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 spinlock_t pkt_list_lock;
19 struct list_head pkt_list;
20 struct work_struct pkt_work;
21};
22
23static struct vsock_loopback the_vsock_loopback;
24
25static u32 vsock_loopback_get_local_cid(void)
26{
27 return VMADDR_CID_LOCAL;
28}
29
30static int vsock_loopback_send_pkt(struct virtio_vsock_pkt *pkt)
31{
32 struct vsock_loopback *vsock = &the_vsock_loopback;
33 int len = pkt->len;
34
35 spin_lock_bh(&vsock->pkt_list_lock);
36 list_add_tail(&pkt->list, &vsock->pkt_list);
37 spin_unlock_bh(&vsock->pkt_list_lock);
38
39 queue_work(vsock->workqueue, &vsock->pkt_work);
40
41 return len;
42}
43
44static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
45{
46 struct vsock_loopback *vsock = &the_vsock_loopback;
47 struct virtio_vsock_pkt *pkt, *n;
48 LIST_HEAD(freeme);
49
50 spin_lock_bh(&vsock->pkt_list_lock);
51 list_for_each_entry_safe(pkt, n, &vsock->pkt_list, list) {
52 if (pkt->vsk != vsk)
53 continue;
54 list_move(&pkt->list, &freeme);
55 }
56 spin_unlock_bh(&vsock->pkt_list_lock);
57
58 list_for_each_entry_safe(pkt, n, &freeme, list) {
59 list_del(&pkt->list);
60 virtio_transport_free_pkt(pkt);
61 }
62
63 return 0;
64}
65
66static struct virtio_transport loopback_transport = {
67 .transport = {
68 .module = THIS_MODULE,
69
70 .get_local_cid = vsock_loopback_get_local_cid,
71
72 .init = virtio_transport_do_socket_init,
73 .destruct = virtio_transport_destruct,
74 .release = virtio_transport_release,
75 .connect = virtio_transport_connect,
76 .shutdown = virtio_transport_shutdown,
77 .cancel_pkt = vsock_loopback_cancel_pkt,
78
79 .dgram_bind = virtio_transport_dgram_bind,
80 .dgram_dequeue = virtio_transport_dgram_dequeue,
81 .dgram_enqueue = virtio_transport_dgram_enqueue,
82 .dgram_allow = virtio_transport_dgram_allow,
83
84 .stream_dequeue = virtio_transport_stream_dequeue,
85 .stream_enqueue = virtio_transport_stream_enqueue,
86 .stream_has_data = virtio_transport_stream_has_data,
87 .stream_has_space = virtio_transport_stream_has_space,
88 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
89 .stream_is_active = virtio_transport_stream_is_active,
90 .stream_allow = virtio_transport_stream_allow,
91
92 .notify_poll_in = virtio_transport_notify_poll_in,
93 .notify_poll_out = virtio_transport_notify_poll_out,
94 .notify_recv_init = virtio_transport_notify_recv_init,
95 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
96 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
97 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
98 .notify_send_init = virtio_transport_notify_send_init,
99 .notify_send_pre_block = virtio_transport_notify_send_pre_block,
100 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
101 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
102 .notify_buffer_size = virtio_transport_notify_buffer_size,
103 },
104
105 .send_pkt = vsock_loopback_send_pkt,
106};
107
108static void vsock_loopback_work(struct work_struct *work)
109{
110 struct vsock_loopback *vsock =
111 container_of(work, struct vsock_loopback, pkt_work);
112 LIST_HEAD(pkts);
113
114 spin_lock_bh(&vsock->pkt_list_lock);
115 list_splice_init(&vsock->pkt_list, &pkts);
116 spin_unlock_bh(&vsock->pkt_list_lock);
117
118 while (!list_empty(&pkts)) {
119 struct virtio_vsock_pkt *pkt;
120
121 pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list);
122 list_del_init(&pkt->list);
123
124 virtio_transport_deliver_tap_pkt(pkt);
125 virtio_transport_recv_pkt(&loopback_transport, pkt);
126 }
127}
128
129static int __init vsock_loopback_init(void)
130{
131 struct vsock_loopback *vsock = &the_vsock_loopback;
132 int ret;
133
134 vsock->workqueue = alloc_workqueue("vsock-loopback", 0, 0);
135 if (!vsock->workqueue)
136 return -ENOMEM;
137
138 spin_lock_init(&vsock->pkt_list_lock);
139 INIT_LIST_HEAD(&vsock->pkt_list);
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 struct virtio_vsock_pkt *pkt;
158
159 vsock_core_unregister(&loopback_transport.transport);
160
161 flush_work(&vsock->pkt_work);
162
163 spin_lock_bh(&vsock->pkt_list_lock);
164 while (!list_empty(&vsock->pkt_list)) {
165 pkt = list_first_entry(&vsock->pkt_list,
166 struct virtio_vsock_pkt, list);
167 list_del(&pkt->list);
168 virtio_transport_free_pkt(pkt);
169 }
170 spin_unlock_bh(&vsock->pkt_list_lock);
171
172 destroy_workqueue(vsock->workqueue);
173}
174
175module_init(vsock_loopback_init);
176module_exit(vsock_loopback_exit);
177MODULE_LICENSE("GPL v2");
178MODULE_AUTHOR("Stefano Garzarella <sgarzare@redhat.com>");
179MODULE_DESCRIPTION("loopback transport for vsock");
180MODULE_ALIAS_NETPROTO(PF_VSOCK);
181
