1 /*
2 * Copyright (C) 2003-2008 Takahiro Hirofuchi
3 *
4 * This is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
17 * USA.
18 */
19
20 #include <linux/kthread.h>
21 #include <linux/slab.h>
22
23 #include "usbip_common.h"
24 #include "vhci.h"
25
26 /* get URB from transmitted urb queue. caller must hold vdev->priv_lock */
pickup_urb_and_free_priv(struct vhci_device * vdev,__u32 seqnum)27 struct urb *pickup_urb_and_free_priv(struct vhci_device *vdev, __u32 seqnum)
28 {
29 struct vhci_priv *priv, *tmp;
30 struct urb *urb = NULL;
31 int status;
32
33 list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
34 if (priv->seqnum != seqnum)
35 continue;
36
37 urb = priv->urb;
38 status = urb->status;
39
40 usbip_dbg_vhci_rx("find urb %p vurb %p seqnum %u\n",
41 urb, priv, seqnum);
42
43 switch (status) {
44 case -ENOENT:
45 /* fall through */
46 case -ECONNRESET:
47 dev_info(&urb->dev->dev,
48 "urb %p was unlinked %ssynchronuously.\n", urb,
49 status == -ENOENT ? "" : "a");
50 break;
51 case -EINPROGRESS:
52 /* no info output */
53 break;
54 default:
55 dev_info(&urb->dev->dev,
56 "urb %p may be in a error, status %d\n", urb,
57 status);
58 }
59
60 list_del(&priv->list);
61 kfree(priv);
62 urb->hcpriv = NULL;
63
64 break;
65 }
66
67 return urb;
68 }
69
vhci_recv_ret_submit(struct vhci_device * vdev,struct usbip_header * pdu)70 static void vhci_recv_ret_submit(struct vhci_device *vdev,
71 struct usbip_header *pdu)
72 {
73 struct usbip_device *ud = &vdev->ud;
74 struct urb *urb;
75
76 spin_lock(&vdev->priv_lock);
77 urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
78 spin_unlock(&vdev->priv_lock);
79
80 if (!urb) {
81 pr_err("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
82 pr_info("max seqnum %d\n",
83 atomic_read(&the_controller->seqnum));
84 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
85 return;
86 }
87
88 /* unpack the pdu to a urb */
89 usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
90
91 /* recv transfer buffer */
92 if (usbip_recv_xbuff(ud, urb) < 0)
93 return;
94
95 /* recv iso_packet_descriptor */
96 if (usbip_recv_iso(ud, urb) < 0)
97 return;
98
99 /* restore the padding in iso packets */
100 usbip_pad_iso(ud, urb);
101
102 if (usbip_dbg_flag_vhci_rx)
103 usbip_dump_urb(urb);
104
105 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
106
107 spin_lock(&the_controller->lock);
108 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
109 spin_unlock(&the_controller->lock);
110
111 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
112
113 usbip_dbg_vhci_rx("Leave\n");
114
115 return;
116 }
117
dequeue_pending_unlink(struct vhci_device * vdev,struct usbip_header * pdu)118 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
119 struct usbip_header *pdu)
120 {
121 struct vhci_unlink *unlink, *tmp;
122
123 spin_lock(&vdev->priv_lock);
124
125 list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
126 pr_info("unlink->seqnum %lu\n", unlink->seqnum);
127 if (unlink->seqnum == pdu->base.seqnum) {
128 usbip_dbg_vhci_rx("found pending unlink, %lu\n",
129 unlink->seqnum);
130 list_del(&unlink->list);
131
132 spin_unlock(&vdev->priv_lock);
133 return unlink;
134 }
135 }
136
137 spin_unlock(&vdev->priv_lock);
138
139 return NULL;
140 }
141
vhci_recv_ret_unlink(struct vhci_device * vdev,struct usbip_header * pdu)142 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
143 struct usbip_header *pdu)
144 {
145 struct vhci_unlink *unlink;
146 struct urb *urb;
147
148 usbip_dump_header(pdu);
149
150 unlink = dequeue_pending_unlink(vdev, pdu);
151 if (!unlink) {
152 pr_info("cannot find the pending unlink %u\n",
153 pdu->base.seqnum);
154 return;
155 }
156
157 spin_lock(&vdev->priv_lock);
158 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
159 spin_unlock(&vdev->priv_lock);
160
161 if (!urb) {
162 /*
163 * I get the result of a unlink request. But, it seems that I
164 * already received the result of its submit result and gave
165 * back the URB.
166 */
167 pr_info("the urb (seqnum %d) was already given back\n",
168 pdu->base.seqnum);
169 } else {
170 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
171
172 /* If unlink is successful, status is -ECONNRESET */
173 urb->status = pdu->u.ret_unlink.status;
174 pr_info("urb->status %d\n", urb->status);
175
176 spin_lock(&the_controller->lock);
177 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
178 spin_unlock(&the_controller->lock);
179
180 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
181 urb->status);
182 }
183
184 kfree(unlink);
185 }
186
vhci_priv_tx_empty(struct vhci_device * vdev)187 static int vhci_priv_tx_empty(struct vhci_device *vdev)
188 {
189 int empty = 0;
190
191 spin_lock(&vdev->priv_lock);
192 empty = list_empty(&vdev->priv_rx);
193 spin_unlock(&vdev->priv_lock);
194
195 return empty;
196 }
197
198 /* recv a pdu */
vhci_rx_pdu(struct usbip_device * ud)199 static void vhci_rx_pdu(struct usbip_device *ud)
200 {
201 int ret;
202 struct usbip_header pdu;
203 struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
204
205 usbip_dbg_vhci_rx("Enter\n");
206
207 memset(&pdu, 0, sizeof(pdu));
208
209 /* receive a pdu header */
210 ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
211 if (ret < 0) {
212 if (ret == -ECONNRESET)
213 pr_info("connection reset by peer\n");
214 else if (ret == -EAGAIN) {
215 /* ignore if connection was idle */
216 if (vhci_priv_tx_empty(vdev))
217 return;
218 pr_info("connection timed out with pending urbs\n");
219 } else if (ret != -ERESTARTSYS)
220 pr_info("xmit failed %d\n", ret);
221
222 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
223 return;
224 }
225 if (ret == 0) {
226 pr_info("connection closed");
227 usbip_event_add(ud, VDEV_EVENT_DOWN);
228 return;
229 }
230 if (ret != sizeof(pdu)) {
231 pr_err("received pdu size is %d, should be %d\n", ret,
232 (unsigned int)sizeof(pdu));
233 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
234 return;
235 }
236
237 usbip_header_correct_endian(&pdu, 0);
238
239 if (usbip_dbg_flag_vhci_rx)
240 usbip_dump_header(&pdu);
241
242 switch (pdu.base.command) {
243 case USBIP_RET_SUBMIT:
244 vhci_recv_ret_submit(vdev, &pdu);
245 break;
246 case USBIP_RET_UNLINK:
247 vhci_recv_ret_unlink(vdev, &pdu);
248 break;
249 default:
250 /* NOT REACHED */
251 pr_err("unknown pdu %u\n", pdu.base.command);
252 usbip_dump_header(&pdu);
253 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
254 break;
255 }
256 }
257
vhci_rx_loop(void * data)258 int vhci_rx_loop(void *data)
259 {
260 struct usbip_device *ud = data;
261
262 while (!kthread_should_stop()) {
263 if (usbip_event_happened(ud))
264 break;
265
266 vhci_rx_pdu(ud);
267 }
268
269 return 0;
270 }
271