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 seqnum %u\n", seqnum);
41
42 switch (status) {
43 case -ENOENT:
44 /* fall through */
45 case -ECONNRESET:
46 dev_dbg(&urb->dev->dev,
47 "urb seq# %u was unlinked %ssynchronuously\n",
48 seqnum, status == -ENOENT ? "" : "a");
49 break;
50 case -EINPROGRESS:
51 /* no info output */
52 break;
53 default:
54 dev_dbg(&urb->dev->dev,
55 "urb seq# %u may be in a error, status %d\n",
56 seqnum, status);
57 }
58
59 list_del(&priv->list);
60 kfree(priv);
61 urb->hcpriv = NULL;
62
63 break;
64 }
65
66 return urb;
67 }
68
vhci_recv_ret_submit(struct vhci_device * vdev,struct usbip_header * pdu)69 static void vhci_recv_ret_submit(struct vhci_device *vdev,
70 struct usbip_header *pdu)
71 {
72 struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
73 struct vhci *vhci = vhci_hcd->vhci;
74 struct usbip_device *ud = &vdev->ud;
75 struct urb *urb;
76 unsigned long flags;
77
78 spin_lock_irqsave(&vdev->priv_lock, flags);
79 urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
80 spin_unlock_irqrestore(&vdev->priv_lock, flags);
81
82 if (!urb) {
83 pr_err("cannot find a urb of seqnum %u max seqnum %d\n",
84 pdu->base.seqnum,
85 atomic_read(&vhci_hcd->seqnum));
86 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
87 return;
88 }
89
90 /* unpack the pdu to a urb */
91 usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
92
93 /* recv transfer buffer */
94 if (usbip_recv_xbuff(ud, urb) < 0) {
95 urb->status = -EPROTO;
96 goto error;
97 }
98
99 /* recv iso_packet_descriptor */
100 if (usbip_recv_iso(ud, urb) < 0) {
101 urb->status = -EPROTO;
102 goto error;
103 }
104
105 /* restore the padding in iso packets */
106 usbip_pad_iso(ud, urb);
107
108 error:
109 if (usbip_dbg_flag_vhci_rx)
110 usbip_dump_urb(urb);
111
112 if (urb->num_sgs)
113 urb->transfer_flags &= ~URB_DMA_MAP_SG;
114
115 usbip_dbg_vhci_rx("now giveback urb %u\n", pdu->base.seqnum);
116
117 spin_lock_irqsave(&vhci->lock, flags);
118 usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
119 spin_unlock_irqrestore(&vhci->lock, flags);
120
121 usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);
122
123 usbip_dbg_vhci_rx("Leave\n");
124 }
125
dequeue_pending_unlink(struct vhci_device * vdev,struct usbip_header * pdu)126 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
127 struct usbip_header *pdu)
128 {
129 struct vhci_unlink *unlink, *tmp;
130 unsigned long flags;
131
132 spin_lock_irqsave(&vdev->priv_lock, flags);
133
134 list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
135 pr_info("unlink->seqnum %lu\n", unlink->seqnum);
136 if (unlink->seqnum == pdu->base.seqnum) {
137 usbip_dbg_vhci_rx("found pending unlink, %lu\n",
138 unlink->seqnum);
139 list_del(&unlink->list);
140
141 spin_unlock_irqrestore(&vdev->priv_lock, flags);
142 return unlink;
143 }
144 }
145
146 spin_unlock_irqrestore(&vdev->priv_lock, flags);
147
148 return NULL;
149 }
150
vhci_recv_ret_unlink(struct vhci_device * vdev,struct usbip_header * pdu)151 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
152 struct usbip_header *pdu)
153 {
154 struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
155 struct vhci *vhci = vhci_hcd->vhci;
156 struct vhci_unlink *unlink;
157 struct urb *urb;
158 unsigned long flags;
159
160 usbip_dump_header(pdu);
161
162 unlink = dequeue_pending_unlink(vdev, pdu);
163 if (!unlink) {
164 pr_info("cannot find the pending unlink %u\n",
165 pdu->base.seqnum);
166 return;
167 }
168
169 spin_lock_irqsave(&vdev->priv_lock, flags);
170 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
171 spin_unlock_irqrestore(&vdev->priv_lock, flags);
172
173 if (!urb) {
174 /*
175 * I get the result of a unlink request. But, it seems that I
176 * already received the result of its submit result and gave
177 * back the URB.
178 */
179 pr_info("the urb (seqnum %d) was already given back\n",
180 pdu->base.seqnum);
181 } else {
182 usbip_dbg_vhci_rx("now giveback urb %d\n", pdu->base.seqnum);
183
184 /* If unlink is successful, status is -ECONNRESET */
185 urb->status = pdu->u.ret_unlink.status;
186 pr_info("urb->status %d\n", urb->status);
187
188 spin_lock_irqsave(&vhci->lock, flags);
189 usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
190 spin_unlock_irqrestore(&vhci->lock, flags);
191
192 usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);
193 }
194
195 kfree(unlink);
196 }
197
vhci_priv_tx_empty(struct vhci_device * vdev)198 static int vhci_priv_tx_empty(struct vhci_device *vdev)
199 {
200 int empty = 0;
201 unsigned long flags;
202
203 spin_lock_irqsave(&vdev->priv_lock, flags);
204 empty = list_empty(&vdev->priv_rx);
205 spin_unlock_irqrestore(&vdev->priv_lock, flags);
206
207 return empty;
208 }
209
210 /* recv a pdu */
vhci_rx_pdu(struct usbip_device * ud)211 static void vhci_rx_pdu(struct usbip_device *ud)
212 {
213 int ret;
214 struct usbip_header pdu;
215 struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
216
217 usbip_dbg_vhci_rx("Enter\n");
218
219 memset(&pdu, 0, sizeof(pdu));
220
221 /* receive a pdu header */
222 ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
223 if (ret < 0) {
224 if (ret == -ECONNRESET)
225 pr_info("connection reset by peer\n");
226 else if (ret == -EAGAIN) {
227 /* ignore if connection was idle */
228 if (vhci_priv_tx_empty(vdev))
229 return;
230 pr_info("connection timed out with pending urbs\n");
231 } else if (ret != -ERESTARTSYS)
232 pr_info("xmit failed %d\n", ret);
233
234 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
235 return;
236 }
237 if (ret == 0) {
238 pr_info("connection closed");
239 usbip_event_add(ud, VDEV_EVENT_DOWN);
240 return;
241 }
242 if (ret != sizeof(pdu)) {
243 pr_err("received pdu size is %d, should be %d\n", ret,
244 (unsigned int)sizeof(pdu));
245 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
246 return;
247 }
248
249 usbip_header_correct_endian(&pdu, 0);
250
251 if (usbip_dbg_flag_vhci_rx)
252 usbip_dump_header(&pdu);
253
254 switch (pdu.base.command) {
255 case USBIP_RET_SUBMIT:
256 vhci_recv_ret_submit(vdev, &pdu);
257 break;
258 case USBIP_RET_UNLINK:
259 vhci_recv_ret_unlink(vdev, &pdu);
260 break;
261 default:
262 /* NOT REACHED */
263 pr_err("unknown pdu %u\n", pdu.base.command);
264 usbip_dump_header(&pdu);
265 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
266 break;
267 }
268 }
269
vhci_rx_loop(void * data)270 int vhci_rx_loop(void *data)
271 {
272 struct usbip_device *ud = data;
273
274 while (!kthread_should_stop()) {
275 if (usbip_event_happened(ud))
276 break;
277
278 vhci_rx_pdu(ud);
279 }
280
281 return 0;
282 }
283