vsock_loopback.c 5.3 KB

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