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 urb = priv->urb;
36 status = urb->status;
37
38 usbip_dbg_vhci_rx("find urb %p vurb %p seqnum %u\n",
39 urb, priv, seqnum);
40
41 /* TODO: fix logic here to improve indent situtation */
42 if (status != -EINPROGRESS) {
43 if (status == -ENOENT ||
44 status == -ECONNRESET)
45 dev_info(&urb->dev->dev,
46 "urb %p was unlinked "
47 "%ssynchronuously.\n", urb,
48 status == -ENOENT ? "" : "a");
49 else
50 dev_info(&urb->dev->dev,
51 "urb %p may be in a error, "
52 "status %d\n", urb, status);
53 }
54
55 list_del(&priv->list);
56 kfree(priv);
57 urb->hcpriv = NULL;
58
59 break;
60 }
61 }
62
63 return urb;
64 }
65
vhci_recv_ret_submit(struct vhci_device * vdev,struct usbip_header * pdu)66 static void vhci_recv_ret_submit(struct vhci_device *vdev,
67 struct usbip_header *pdu)
68 {
69 struct usbip_device *ud = &vdev->ud;
70 struct urb *urb;
71 unsigned long flags;
72
73 spin_lock(&vdev->priv_lock);
74 urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
75 spin_unlock(&vdev->priv_lock);
76
77 if (!urb) {
78 pr_err("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
79 pr_info("max seqnum %d\n",
80 atomic_read(&the_controller->seqnum));
81 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
82 return;
83 }
84
85 /* unpack the pdu to a urb */
86 usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
87
88 /* recv transfer buffer */
89 if (usbip_recv_xbuff(ud, urb) < 0)
90 return;
91
92 /* recv iso_packet_descriptor */
93 if (usbip_recv_iso(ud, urb) < 0)
94 return;
95
96 /* restore the padding in iso packets */
97 usbip_pad_iso(ud, urb);
98
99 if (usbip_dbg_flag_vhci_rx)
100 usbip_dump_urb(urb);
101
102 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
103
104 spin_lock_irqsave(&the_controller->lock, flags);
105 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
106 spin_unlock_irqrestore(&the_controller->lock, flags);
107
108 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
109
110 usbip_dbg_vhci_rx("Leave\n");
111
112 return;
113 }
114
dequeue_pending_unlink(struct vhci_device * vdev,struct usbip_header * pdu)115 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
116 struct usbip_header *pdu)
117 {
118 struct vhci_unlink *unlink, *tmp;
119
120 spin_lock(&vdev->priv_lock);
121
122 list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
123 pr_info("unlink->seqnum %lu\n", unlink->seqnum);
124 if (unlink->seqnum == pdu->base.seqnum) {
125 usbip_dbg_vhci_rx("found pending unlink, %lu\n",
126 unlink->seqnum);
127 list_del(&unlink->list);
128
129 spin_unlock(&vdev->priv_lock);
130 return unlink;
131 }
132 }
133
134 spin_unlock(&vdev->priv_lock);
135
136 return NULL;
137 }
138
vhci_recv_ret_unlink(struct vhci_device * vdev,struct usbip_header * pdu)139 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
140 struct usbip_header *pdu)
141 {
142 struct vhci_unlink *unlink;
143 struct urb *urb;
144 unsigned long flags;
145
146 usbip_dump_header(pdu);
147
148 unlink = dequeue_pending_unlink(vdev, pdu);
149 if (!unlink) {
150 pr_info("cannot find the pending unlink %u\n",
151 pdu->base.seqnum);
152 return;
153 }
154
155 spin_lock(&vdev->priv_lock);
156 urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
157 spin_unlock(&vdev->priv_lock);
158
159 if (!urb) {
160 /*
161 * I get the result of a unlink request. But, it seems that I
162 * already received the result of its submit result and gave
163 * back the URB.
164 */
165 pr_info("the urb (seqnum %d) was already given backed\n",
166 pdu->base.seqnum);
167 } else {
168 usbip_dbg_vhci_rx("now giveback urb %p\n", urb);
169
170 /* If unlink is succeed, status is -ECONNRESET */
171 urb->status = pdu->u.ret_unlink.status;
172 pr_info("urb->status %d\n", urb->status);
173
174 spin_lock_irqsave(&the_controller->lock, flags);
175 usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb);
176 spin_unlock_irqrestore(&the_controller->lock, flags);
177
178 usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
179 urb->status);
180 }
181
182 kfree(unlink);
183 }
184
vhci_priv_tx_empty(struct vhci_device * vdev)185 static int vhci_priv_tx_empty(struct vhci_device *vdev)
186 {
187 int empty = 0;
188
189 spin_lock(&vdev->priv_lock);
190 empty = list_empty(&vdev->priv_rx);
191 spin_unlock(&vdev->priv_lock);
192
193 return empty;
194 }
195
196 /* recv a pdu */
vhci_rx_pdu(struct usbip_device * ud)197 static void vhci_rx_pdu(struct usbip_device *ud)
198 {
199 int ret;
200 struct usbip_header pdu;
201 struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
202
203 usbip_dbg_vhci_rx("Enter\n");
204
205 memset(&pdu, 0, sizeof(pdu));
206
207 /* 1. receive a pdu header */
208 ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
209 if (ret < 0) {
210 if (ret == -ECONNRESET)
211 pr_info("connection reset by peer\n");
212 else if (ret == -EAGAIN) {
213 /* ignore if connection was idle */
214 if (vhci_priv_tx_empty(vdev))
215 return;
216 pr_info("connection timed out with pending urbs\n");
217 } else if (ret != -ERESTARTSYS)
218 pr_info("xmit failed %d\n", ret);
219
220 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
221 return;
222 }
223 if (ret == 0) {
224 pr_info("connection closed");
225 usbip_event_add(ud, VDEV_EVENT_DOWN);
226 return;
227 }
228 if (ret != sizeof(pdu)) {
229 pr_err("received pdu size is %d, should be %d\n", ret,
230 (unsigned int)sizeof(pdu));
231 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
232 return;
233 }
234
235 usbip_header_correct_endian(&pdu, 0);
236
237 if (usbip_dbg_flag_vhci_rx)
238 usbip_dump_header(&pdu);
239
240 switch (pdu.base.command) {
241 case USBIP_RET_SUBMIT:
242 vhci_recv_ret_submit(vdev, &pdu);
243 break;
244 case USBIP_RET_UNLINK:
245 vhci_recv_ret_unlink(vdev, &pdu);
246 break;
247 default:
248 /* NOT REACHED */
249 pr_err("unknown pdu %u\n", pdu.base.command);
250 usbip_dump_header(&pdu);
251 usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
252 break;
253 }
254 }
255
vhci_rx_loop(void * data)256 int vhci_rx_loop(void *data)
257 {
258 struct usbip_device *ud = data;
259
260 while (!kthread_should_stop()) {
261 if (usbip_event_happened(ud))
262 break;
263
264 vhci_rx_pdu(ud);
265 }
266
267 return 0;
268 }
269