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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 bool vsock_loopback_seqpacket_allow(u32 remote_cid);
67
68static struct virtio_transport loopback_transport = {
69 .transport = {
70 .module = THIS_MODULE,
71
72 .get_local_cid = vsock_loopback_get_local_cid,
73
74 .init = virtio_transport_do_socket_init,
75 .destruct = virtio_transport_destruct,
76 .release = virtio_transport_release,
77 .connect = virtio_transport_connect,
78 .shutdown = virtio_transport_shutdown,
79 .cancel_pkt = vsock_loopback_cancel_pkt,
80
81 .dgram_bind = virtio_transport_dgram_bind,
82 .dgram_dequeue = virtio_transport_dgram_dequeue,
83 .dgram_enqueue = virtio_transport_dgram_enqueue,
84 .dgram_allow = virtio_transport_dgram_allow,
85
86 .stream_dequeue = virtio_transport_stream_dequeue,
87 .stream_enqueue = virtio_transport_stream_enqueue,
88 .stream_has_data = virtio_transport_stream_has_data,
89 .stream_has_space = virtio_transport_stream_has_space,
90 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
91 .stream_is_active = virtio_transport_stream_is_active,
92 .stream_allow = virtio_transport_stream_allow,
93
94 .seqpacket_dequeue = virtio_transport_seqpacket_dequeue,
95 .seqpacket_enqueue = virtio_transport_seqpacket_enqueue,
96 .seqpacket_allow = vsock_loopback_seqpacket_allow,
97 .seqpacket_has_data = virtio_transport_seqpacket_has_data,
98
99 .notify_poll_in = virtio_transport_notify_poll_in,
100 .notify_poll_out = virtio_transport_notify_poll_out,
101 .notify_recv_init = virtio_transport_notify_recv_init,
102 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
103 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
104 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
105 .notify_send_init = virtio_transport_notify_send_init,
106 .notify_send_pre_block = virtio_transport_notify_send_pre_block,
107 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
108 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
109 .notify_buffer_size = virtio_transport_notify_buffer_size,
110 },
111
112 .send_pkt = vsock_loopback_send_pkt,
113};
114
115static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
116{
117 return true;
118}
119
120static void vsock_loopback_work(struct work_struct *work)
121{
122 struct vsock_loopback *vsock =
123 container_of(work, struct vsock_loopback, pkt_work);
124 LIST_HEAD(pkts);
125
126 spin_lock_bh(&vsock->pkt_list_lock);
127 list_splice_init(&vsock->pkt_list, &pkts);
128 spin_unlock_bh(&vsock->pkt_list_lock);
129
130 while (!list_empty(&pkts)) {
131 struct virtio_vsock_pkt *pkt;
132
133 pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list);
134 list_del_init(&pkt->list);
135
136 virtio_transport_deliver_tap_pkt(pkt);
137 virtio_transport_recv_pkt(&loopback_transport, pkt);
138 }
139}
140
141static int __init vsock_loopback_init(void)
142{
143 struct vsock_loopback *vsock = &the_vsock_loopback;
144 int ret;
145
146 vsock->workqueue = alloc_workqueue("vsock-loopback", 0, 0);
147 if (!vsock->workqueue)
148 return -ENOMEM;
149
150 spin_lock_init(&vsock->pkt_list_lock);
151 INIT_LIST_HEAD(&vsock->pkt_list);
152 INIT_WORK(&vsock->pkt_work, vsock_loopback_work);
153
154 ret = vsock_core_register(&loopback_transport.transport,
155 VSOCK_TRANSPORT_F_LOCAL);
156 if (ret)
157 goto out_wq;
158
159 return 0;
160
161out_wq:
162 destroy_workqueue(vsock->workqueue);
163 return ret;
164}
165
166static void __exit vsock_loopback_exit(void)
167{
168 struct vsock_loopback *vsock = &the_vsock_loopback;
169 struct virtio_vsock_pkt *pkt;
170
171 vsock_core_unregister(&loopback_transport.transport);
172
173 flush_work(&vsock->pkt_work);
174
175 spin_lock_bh(&vsock->pkt_list_lock);
176 while (!list_empty(&vsock->pkt_list)) {
177 pkt = list_first_entry(&vsock->pkt_list,
178 struct virtio_vsock_pkt, list);
179 list_del(&pkt->list);
180 virtio_transport_free_pkt(pkt);
181 }
182 spin_unlock_bh(&vsock->pkt_list_lock);
183
184 destroy_workqueue(vsock->workqueue);
185}
186
187module_init(vsock_loopback_init);
188module_exit(vsock_loopback_exit);
189MODULE_LICENSE("GPL v2");
190MODULE_AUTHOR("Stefano Garzarella <sgarzare@redhat.com>");
191MODULE_DESCRIPTION("loopback transport for vsock");
192MODULE_ALIAS_NETPROTO(PF_VSOCK);
193
