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 spinlock_t pkt_list_lock; /* protects pkt_list */ 19 struct list_head pkt_list; 20 struct work_struct pkt_work; 21 }; 22 23 static struct vsock_loopback the_vsock_loopback; 24 25 static u32 vsock_loopback_get_local_cid(void) 26 { 27 return VMADDR_CID_LOCAL; 28 } 29 30 static 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 44 static 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 66 static bool vsock_loopback_seqpacket_allow(u32 remote_cid); 67 68 static 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 }; 114 115 static bool vsock_loopback_seqpacket_allow(u32 remote_cid) 116 { 117 return true; 118 } 119 120 static 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 } 140 141 static 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; 160 161 out_wq: 162 destroy_workqueue(vsock->workqueue); 163 return ret; 164 } 165 166 static 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 } 186 187 module_init(vsock_loopback_init); 188 module_exit(vsock_loopback_exit); 189 MODULE_LICENSE("GPL v2"); 190 MODULE_AUTHOR("Stefano Garzarella <sgarzare@redhat.com>"); 191 MODULE_DESCRIPTION("loopback transport for vsock"); 192 MODULE_ALIAS_NETPROTO(PF_VSOCK); 193