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 | |
24 | static u32 vsock_loopback_get_local_cid(void) |
25 | { |
26 | return VMADDR_CID_LOCAL; |
27 | } |
28 | |
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(list: &vsock->pkt_queue, skb); |
35 | queue_work(wq: vsock->workqueue, work: &vsock->pkt_work); |
36 | |
37 | return len; |
38 | } |
39 | |
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, list: &vsock->pkt_queue); |
45 | |
46 | return 0; |
47 | } |
48 | |
49 | static bool vsock_loopback_seqpacket_allow(u32 remote_cid); |
50 | static bool vsock_loopback_msgzerocopy_allow(void) |
51 | { |
52 | return true; |
53 | } |
54 | |
55 | static 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 | .notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat, |
100 | |
101 | .read_skb = virtio_transport_read_skb, |
102 | }, |
103 | |
104 | .send_pkt = vsock_loopback_send_pkt, |
105 | }; |
106 | |
107 | static bool vsock_loopback_seqpacket_allow(u32 remote_cid) |
108 | { |
109 | return true; |
110 | } |
111 | |
112 | static void vsock_loopback_work(struct work_struct *work) |
113 | { |
114 | struct vsock_loopback *vsock = |
115 | container_of(work, struct vsock_loopback, pkt_work); |
116 | struct sk_buff_head pkts; |
117 | struct sk_buff *skb; |
118 | |
119 | skb_queue_head_init(list: &pkts); |
120 | |
121 | spin_lock_bh(lock: &vsock->pkt_queue.lock); |
122 | skb_queue_splice_init(list: &vsock->pkt_queue, head: &pkts); |
123 | spin_unlock_bh(lock: &vsock->pkt_queue.lock); |
124 | |
125 | while ((skb = __skb_dequeue(list: &pkts))) { |
126 | virtio_transport_deliver_tap_pkt(skb); |
127 | virtio_transport_recv_pkt(t: &loopback_transport, skb); |
128 | } |
129 | } |
130 | |
131 | static int __init vsock_loopback_init(void) |
132 | { |
133 | struct vsock_loopback *vsock = &the_vsock_loopback; |
134 | int ret; |
135 | |
136 | vsock->workqueue = alloc_workqueue(fmt: "vsock-loopback" , flags: 0, max_active: 0); |
137 | if (!vsock->workqueue) |
138 | return -ENOMEM; |
139 | |
140 | skb_queue_head_init(list: &vsock->pkt_queue); |
141 | INIT_WORK(&vsock->pkt_work, vsock_loopback_work); |
142 | |
143 | ret = vsock_core_register(t: &loopback_transport.transport, |
144 | VSOCK_TRANSPORT_F_LOCAL); |
145 | if (ret) |
146 | goto out_wq; |
147 | |
148 | return 0; |
149 | |
150 | out_wq: |
151 | destroy_workqueue(wq: vsock->workqueue); |
152 | return ret; |
153 | } |
154 | |
155 | static void __exit vsock_loopback_exit(void) |
156 | { |
157 | struct vsock_loopback *vsock = &the_vsock_loopback; |
158 | |
159 | vsock_core_unregister(t: &loopback_transport.transport); |
160 | |
161 | flush_work(work: &vsock->pkt_work); |
162 | |
163 | virtio_vsock_skb_queue_purge(list: &vsock->pkt_queue); |
164 | |
165 | destroy_workqueue(wq: vsock->workqueue); |
166 | } |
167 | |
168 | module_init(vsock_loopback_init); |
169 | module_exit(vsock_loopback_exit); |
170 | MODULE_LICENSE("GPL v2" ); |
171 | MODULE_AUTHOR("Stefano Garzarella <sgarzare@redhat.com>" ); |
172 | MODULE_DESCRIPTION("loopback transport for vsock" ); |
173 | MODULE_ALIAS_NETPROTO(PF_VSOCK); |
174 | |