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/socket.h>
22
23 #include "usbip_common.h"
24 #include "stub.h"
25
stub_free_priv_and_urb(struct stub_priv * priv)26 static void stub_free_priv_and_urb(struct stub_priv *priv)
27 {
28 struct urb *urb = priv->urb;
29
30 kfree(urb->setup_packet);
31 kfree(urb->transfer_buffer);
32 list_del(&priv->list);
33 kmem_cache_free(stub_priv_cache, priv);
34 usb_free_urb(urb);
35 }
36
37 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
stub_enqueue_ret_unlink(struct stub_device * sdev,__u32 seqnum,__u32 status)38 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
39 __u32 status)
40 {
41 struct stub_unlink *unlink;
42
43 unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
44 if (!unlink) {
45 usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
46 return;
47 }
48
49 unlink->seqnum = seqnum;
50 unlink->status = status;
51
52 list_add_tail(&unlink->list, &sdev->unlink_tx);
53 }
54
55 /**
56 * stub_complete - completion handler of a usbip urb
57 * @urb: pointer to the urb completed
58 *
59 * When a urb has completed, the USB core driver calls this function mostly in
60 * the interrupt context. To return the result of a urb, the completed urb is
61 * linked to the pending list of returning.
62 *
63 */
stub_complete(struct urb * urb)64 void stub_complete(struct urb *urb)
65 {
66 struct stub_priv *priv = (struct stub_priv *) urb->context;
67 struct stub_device *sdev = priv->sdev;
68 unsigned long flags;
69
70 usbip_dbg_stub_tx("complete! status %d\n", urb->status);
71
72 switch (urb->status) {
73 case 0:
74 /* OK */
75 break;
76 case -ENOENT:
77 dev_info(&urb->dev->dev, "stopped by a call to usb_kill_urb() "
78 "because of cleaning up a virtual connection\n");
79 return;
80 case -ECONNRESET:
81 dev_info(&urb->dev->dev, "unlinked by a call to "
82 "usb_unlink_urb()\n");
83 break;
84 case -EPIPE:
85 dev_info(&urb->dev->dev, "endpoint %d is stalled\n",
86 usb_pipeendpoint(urb->pipe));
87 break;
88 case -ESHUTDOWN:
89 dev_info(&urb->dev->dev, "device removed?\n");
90 break;
91 default:
92 dev_info(&urb->dev->dev, "urb completion with non-zero status "
93 "%d\n", urb->status);
94 break;
95 }
96
97 /* link a urb to the queue of tx. */
98 spin_lock_irqsave(&sdev->priv_lock, flags);
99 if (priv->unlinking) {
100 stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
101 stub_free_priv_and_urb(priv);
102 } else {
103 list_move_tail(&priv->list, &sdev->priv_tx);
104 }
105 spin_unlock_irqrestore(&sdev->priv_lock, flags);
106
107 /* wake up tx_thread */
108 wake_up(&sdev->tx_waitq);
109 }
110
setup_base_pdu(struct usbip_header_basic * base,__u32 command,__u32 seqnum)111 static inline void setup_base_pdu(struct usbip_header_basic *base,
112 __u32 command, __u32 seqnum)
113 {
114 base->command = command;
115 base->seqnum = seqnum;
116 base->devid = 0;
117 base->ep = 0;
118 base->direction = 0;
119 }
120
setup_ret_submit_pdu(struct usbip_header * rpdu,struct urb * urb)121 static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
122 {
123 struct stub_priv *priv = (struct stub_priv *) urb->context;
124
125 setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
126 usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
127 }
128
setup_ret_unlink_pdu(struct usbip_header * rpdu,struct stub_unlink * unlink)129 static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
130 struct stub_unlink *unlink)
131 {
132 setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
133 rpdu->u.ret_unlink.status = unlink->status;
134 }
135
dequeue_from_priv_tx(struct stub_device * sdev)136 static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
137 {
138 unsigned long flags;
139 struct stub_priv *priv, *tmp;
140
141 spin_lock_irqsave(&sdev->priv_lock, flags);
142
143 list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
144 list_move_tail(&priv->list, &sdev->priv_free);
145 spin_unlock_irqrestore(&sdev->priv_lock, flags);
146 return priv;
147 }
148
149 spin_unlock_irqrestore(&sdev->priv_lock, flags);
150
151 return NULL;
152 }
153
stub_send_ret_submit(struct stub_device * sdev)154 static int stub_send_ret_submit(struct stub_device *sdev)
155 {
156 unsigned long flags;
157 struct stub_priv *priv, *tmp;
158
159 struct msghdr msg;
160 size_t txsize;
161
162 size_t total_size = 0;
163
164 while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
165 int ret;
166 struct urb *urb = priv->urb;
167 struct usbip_header pdu_header;
168 struct usbip_iso_packet_descriptor *iso_buffer = NULL;
169 struct kvec *iov = NULL;
170 int iovnum = 0;
171
172 txsize = 0;
173 memset(&pdu_header, 0, sizeof(pdu_header));
174 memset(&msg, 0, sizeof(msg));
175
176 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
177 iovnum = 2 + urb->number_of_packets;
178 else
179 iovnum = 2;
180
181 iov = kzalloc(iovnum * sizeof(struct kvec), GFP_KERNEL);
182
183 if (!iov) {
184 usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
185 return -1;
186 }
187
188 iovnum = 0;
189
190 /* 1. setup usbip_header */
191 setup_ret_submit_pdu(&pdu_header, urb);
192 usbip_dbg_stub_tx("setup txdata seqnum: %d urb: %p\n",
193 pdu_header.base.seqnum, urb);
194 usbip_header_correct_endian(&pdu_header, 1);
195
196 iov[iovnum].iov_base = &pdu_header;
197 iov[iovnum].iov_len = sizeof(pdu_header);
198 iovnum++;
199 txsize += sizeof(pdu_header);
200
201 /* 2. setup transfer buffer */
202 if (usb_pipein(urb->pipe) &&
203 usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
204 urb->actual_length > 0) {
205 iov[iovnum].iov_base = urb->transfer_buffer;
206 iov[iovnum].iov_len = urb->actual_length;
207 iovnum++;
208 txsize += urb->actual_length;
209 } else if (usb_pipein(urb->pipe) &&
210 usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
211 /*
212 * For isochronous packets: actual length is the sum of
213 * the actual length of the individual, packets, but as
214 * the packet offsets are not changed there will be
215 * padding between the packets. To optimally use the
216 * bandwidth the padding is not transmitted.
217 */
218
219 int i;
220 for (i = 0; i < urb->number_of_packets; i++) {
221 iov[iovnum].iov_base = urb->transfer_buffer +
222 urb->iso_frame_desc[i].offset;
223 iov[iovnum].iov_len =
224 urb->iso_frame_desc[i].actual_length;
225 iovnum++;
226 txsize += urb->iso_frame_desc[i].actual_length;
227 }
228
229 if (txsize != sizeof(pdu_header) + urb->actual_length) {
230 dev_err(&sdev->interface->dev,
231 "actual length of urb %d does not "
232 "match iso packet sizes %zu\n",
233 urb->actual_length,
234 txsize-sizeof(pdu_header));
235 kfree(iov);
236 usbip_event_add(&sdev->ud,
237 SDEV_EVENT_ERROR_TCP);
238 return -1;
239 }
240 }
241
242 /* 3. setup iso_packet_descriptor */
243 if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
244 ssize_t len = 0;
245
246 iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
247 if (!iso_buffer) {
248 usbip_event_add(&sdev->ud,
249 SDEV_EVENT_ERROR_MALLOC);
250 kfree(iov);
251 return -1;
252 }
253
254 iov[iovnum].iov_base = iso_buffer;
255 iov[iovnum].iov_len = len;
256 txsize += len;
257 iovnum++;
258 }
259
260 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg,
261 iov, iovnum, txsize);
262 if (ret != txsize) {
263 dev_err(&sdev->interface->dev,
264 "sendmsg failed!, retval %d for %zd\n",
265 ret, txsize);
266 kfree(iov);
267 kfree(iso_buffer);
268 usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
269 return -1;
270 }
271
272 kfree(iov);
273 kfree(iso_buffer);
274
275 total_size += txsize;
276 }
277
278 spin_lock_irqsave(&sdev->priv_lock, flags);
279 list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
280 stub_free_priv_and_urb(priv);
281 }
282 spin_unlock_irqrestore(&sdev->priv_lock, flags);
283
284 return total_size;
285 }
286
dequeue_from_unlink_tx(struct stub_device * sdev)287 static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
288 {
289 unsigned long flags;
290 struct stub_unlink *unlink, *tmp;
291
292 spin_lock_irqsave(&sdev->priv_lock, flags);
293
294 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
295 list_move_tail(&unlink->list, &sdev->unlink_free);
296 spin_unlock_irqrestore(&sdev->priv_lock, flags);
297 return unlink;
298 }
299
300 spin_unlock_irqrestore(&sdev->priv_lock, flags);
301
302 return NULL;
303 }
304
stub_send_ret_unlink(struct stub_device * sdev)305 static int stub_send_ret_unlink(struct stub_device *sdev)
306 {
307 unsigned long flags;
308 struct stub_unlink *unlink, *tmp;
309
310 struct msghdr msg;
311 struct kvec iov[1];
312 size_t txsize;
313
314 size_t total_size = 0;
315
316 while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
317 int ret;
318 struct usbip_header pdu_header;
319
320 txsize = 0;
321 memset(&pdu_header, 0, sizeof(pdu_header));
322 memset(&msg, 0, sizeof(msg));
323 memset(&iov, 0, sizeof(iov));
324
325 usbip_dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
326
327 /* 1. setup usbip_header */
328 setup_ret_unlink_pdu(&pdu_header, unlink);
329 usbip_header_correct_endian(&pdu_header, 1);
330
331 iov[0].iov_base = &pdu_header;
332 iov[0].iov_len = sizeof(pdu_header);
333 txsize += sizeof(pdu_header);
334
335 ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
336 1, txsize);
337 if (ret != txsize) {
338 dev_err(&sdev->interface->dev,
339 "sendmsg failed!, retval %d for %zd\n",
340 ret, txsize);
341 usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
342 return -1;
343 }
344
345 usbip_dbg_stub_tx("send txdata\n");
346 total_size += txsize;
347 }
348
349 spin_lock_irqsave(&sdev->priv_lock, flags);
350
351 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
352 list_del(&unlink->list);
353 kfree(unlink);
354 }
355
356 spin_unlock_irqrestore(&sdev->priv_lock, flags);
357
358 return total_size;
359 }
360
stub_tx_loop(void * data)361 int stub_tx_loop(void *data)
362 {
363 struct usbip_device *ud = data;
364 struct stub_device *sdev = container_of(ud, struct stub_device, ud);
365
366 while (!kthread_should_stop()) {
367 if (usbip_event_happened(ud))
368 break;
369
370 /*
371 * send_ret_submit comes earlier than send_ret_unlink. stub_rx
372 * looks at only priv_init queue. If the completion of a URB is
373 * earlier than the receive of CMD_UNLINK, priv is moved to
374 * priv_tx queue and stub_rx does not find the target priv. In
375 * this case, vhci_rx receives the result of the submit request
376 * and then receives the result of the unlink request. The
377 * result of the submit is given back to the usbcore as the
378 * completion of the unlink request. The request of the
379 * unlink is ignored. This is ok because a driver who calls
380 * usb_unlink_urb() understands the unlink was too late by
381 * getting the status of the given-backed URB which has the
382 * status of usb_submit_urb().
383 */
384 if (stub_send_ret_submit(sdev) < 0)
385 break;
386
387 if (stub_send_ret_unlink(sdev) < 0)
388 break;
389
390 wait_event_interruptible(sdev->tx_waitq,
391 (!list_empty(&sdev->priv_tx) ||
392 !list_empty(&sdev->unlink_tx) ||
393 kthread_should_stop()));
394 }
395
396 return 0;
397 }
398